JP2017190985A - Tubular body inner surface inspection apparatus, tubular body inner surface inspection method, drift gage, and drift inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically detect irregular defects and patterned defects existing on an inner surface of a tubular body even when an imaging device for imaging inner surfaces of a tubular body is displaced in its posture.SOLUTION: A tubular body inner surface inspection apparatus comprises: a tubular body imaging device which, while moving along a tubular direction of a tubular body for measuring the direction and magnitude of rotations occurring circumferentially of the tubular body, irradiates the inner surfaces of the tubular body with an annular laser beam to generate a plurality of annular-beam images; and an arithmetic processing device for judging whether or not a defect exists on inner surfaces of the tubular body. The arithmetic processing device: calculates the barycentric position of a portion irradiated with the annular laser beam in each annular-beam image; generates a plurality of optical cut images from the annular-beam image; and based on the fringe image frames generated from each optical cut image, calculates depth images and luminance images; corrects the effects of rotations superimposed on the calculated depth images and luminance images, and detects a defect existing on the inner surface based on the corrected depth images and luminance images.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tubular body surface inspection apparatus, a tubular body surface inspection method, a drift gauge, and a drift inspection method.

  The inner surface inspection of a tubular body for inspecting the inner surface of a tubular body represented by a metal pipe such as a steel pipe or a resin pipe is one of the important inspection items particularly in a metal pipe such as a steel pipe, Usually, a visual inspection is performed by providing a separate process from the manufacturing process of the tubular body.

  The visual inspection of the tubular body largely depends on the skill of the inspector. In particular, the internal inspection for inspecting the inner surface of the tubular body makes it difficult to sufficiently perform the visual inspection. Therefore, in particular, in the axial direction deep part of the tubular body, there is a possibility that a shameful spilling out of the spear or a serious claim may occur. In addition, depending on the inspection method, there are irregularities on the surface of the tubular body that are difficult to detect, so it is important to directly monitor the inner surface of the tubular body.

  As an inspection method of the inner surface of such a tubular body, an imaging mechanism comprising optical means such as an imaging device or an illuminating device that images the entire inner surface of the tubular body is arranged in the tube axis direction inside the tubular body. Optical inspections are often performed that are moved along.

  For example, the following Patent Document 1 discloses a technique in which a photographing camera is arranged on the inner surface of an end portion of a steel pipe and the photographing camera is rotated when photographing an entire circumference image. In Patent Document 1, the amount of rotation of the photographing camera is measured by an encoder, the photographing pitch (length interval) in the tube circumferential direction is derived from the obtained rotational movement amount, and the entire circumferential direction is photographed at a constant pitch. A method has been proposed.

  The following Patent Document 2 discloses a technique for imaging an entire length of an inner surface of a steel pipe while feeding an imaging unit in which a lighting and a camera are arranged into the inside of the steel pipe and remotely operating a projection angle of the lighting. Has been. In Patent Document 2, the imaging field of view is not for the entire inner surface of the steel pipe, the inner surface of the steel pipe is not secured for 360 °, and an image for the entire circumferential direction is acquired by inverting the imaging unit. It is said.

  Patent Document 3 below discloses a technique for detecting a laser beam from a light cut image obtained by inserting a measuring instrument into a tubular body and irradiating a slit laser. Patent Document 3 proposes a method of changing the color of a laser beam in accordance with the laser light reception intensity, overwriting it on a light cut image, and displaying a weld bead portion that is an unevenness on the inner surface of the steel pipe.

  Patent Document 4 below irradiates the inner surface of the tubular body with a disk-shaped laser, forms a light section image, and sequentially images the light section plane while moving in the tube axis direction of the inner surface of the tubular body, A technique for constructing an inner surface shape of a tubular body is disclosed.

  Patent Document 5 below discloses a technique of irradiating the inner surface of a tubular body with two types of light sources, and irradiates an annular laser from one light source in the circumferential direction to obtain a light section image, Uniform surface illumination is emitted from the other light source. Patent Document 5 proposes a method of receiving light emitted from these different illuminations and measuring the unevenness and pattern on the inner surface of the tubular body.

  In Patent Document 6 below, a light cut image is obtained from an annular beam image obtained by irradiating an inner surface of a tubular body with an annular laser beam while moving along the tube axis direction of the tubular body. An apparatus for simultaneously detecting irregularities on the inner surface and pattern-type defects is disclosed.

Japanese Patent Laid-Open No. 10-176994 JP-A-61-202109 JP 2004-93195 A JP 2007-285891 A Japanese Patent Laid-Open No. 5-149885 JP 2012-159491 A

  Here, in the technique disclosed in Patent Document 1, a measuring machine is fed into the inner surface of the end of the tubular body, and imaging is performed by a camera from the axial direction of the steel pipe, and the end of the steel pipe reflected by the mirror The inner surface is imaged by the camera. At this time, for imaging of the entire inner surface, the camera and mirror are rotated, the camera rotation amount is measured by the encoder, and the rotation amount is calculated from the encoder measurement value in order to make the capture resolution in the steel pipe circumferential direction constant. Is derived. However, the technique disclosed in Patent Document 1 has a problem that it is difficult to suppress a change in visual field due to an inclination or a change in imaging equipment.

  Further, in the technique disclosed in Patent Document 2, an image for the entire circumference is acquired by rotating the imaging unit in order to eliminate the influence of the imaging unit shielding the inner surface of the steel pipe. However, the rotation amount of the image pickup unit is not mentioned, and it depends on a manual operation such as paying attention to the multiple count of wrinkles. For this reason, there is a problem in that an image obtained according to a change in posture of the imaging unit cannot be quantitatively corrected.

  In addition, the technique disclosed in Patent Document 3 only changes the color of the laser thin line portion according to the laser light receiving intensity and displays it on the inner surface light cut image of the steel pipe. There is a problem that it is difficult to automatically detect or determine the bead portion existing on the inner surface.

  In the technique disclosed in Patent Document 4, the shape of the inner surface of the tubular body is continuously acquired by scanning the camera and the light source in the tube axis direction. However, in this technique, a three-dimensional shape is displayed. However, there is a problem that it is difficult to automatically determine harmful / innocence such as uneven wrinkles.

  Further, in the technique disclosed in Patent Document 5, the unevenness and the pattern of the inner surface of the tubular body are mainly determined visually by using the shape monitor and the state monitor, and it is difficult to automatically determine the harmful part. There is a problem.

  In addition, the technique disclosed in Patent Document 6 has a problem in that it is necessary to scan the tubular body imaging device in the tube axis direction, and it is impossible to follow the change in posture of the tubular body imaging device during scanning.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a tubular body even when a posture change occurs in an imaging equipment that images the inner surface of the tubular body. It is an object of the present invention to provide a tubular body surface inspection apparatus, a tubular body surface inspection method, a drift gauge, and a drift inspection method capable of automatically detecting uneven ridges and pattern creases present on the inner surface of the body.

  In order to solve the above-described problem, according to an aspect of the present invention, while moving along the tube axis direction of a tubular body, an annular laser beam is irradiated to the entire circumferential direction of the inner surface of the tubular body. Tubular that generates a plurality of annular beam images that are captured images of the annular laser light on the inner surface along the tube axis direction of the tubular body by imaging the inner surface irradiated with the annular laser light A body imaging device, and an arithmetic processing device that performs image processing on the annular beam image generated by the tubular body imaging device and determines whether a defect exists on the inner surface of the tubular body, The tubular body imaging device includes an illumination mechanism having at least a laser light irradiation device that irradiates the annular laser light to the entire circumferential direction of the inner surface of the tubular body, and an inner surface irradiated with the annular laser light. An imaging device for imaging; A rotation amount measuring device for measuring the direction and size of rotation in the tube circumferential direction of the tubular body that occurs when the tubular body of the tubular body imaging device moves along the tube axis direction; The arithmetic processing unit includes an annular beam center calculating unit that calculates a center of gravity position and a radius of an irradiation portion of the annular laser beam in each of the annular beam images, the calculated center of gravity position, and the center of gravity position. The coordinate system of the annular beam image is converted on the basis of the distance between the annular laser beam irradiation portion and the annular laser beam irradiation portion is expanded in the tube circumferential direction of the tubular body. A coordinate conversion unit that generates a plurality of light-cutting images, which are band-like regions including a light-cutting line, and a striped image frame in which each of the light-cutting images is sequentially arranged along the tube axis direction. body An image calculation unit that calculates a depth image representing an uneven state of the inner surface and a luminance image representing a luminance distribution of the annular laser beam on the inner surface of the tubular body, the calculated depth image, and the For each of the luminance images, a rotation correction unit that corrects a positional deviation in the tube circumferential direction due to the rotation in the tube circumferential direction using the rotation direction and magnitude measured by the rotation amount measuring device is corrected. A detection processing unit that detects a defect present on the inner surface of the tubular body based on the depth image and the luminance image, and the image calculation unit includes the light along the tube circumferential direction. The center of gravity position in the line width direction of the cutting line is calculated, and the radius is set as a reference position that is a position in the tube axis direction designated in advance with respect to the light section image, and the displacement amount between the reference position and the center of gravity position is calculated. Calculate the depth image based on A tubular body surface inspection device is provided.

  The depth image is an image representing a two-dimensional uneven state distribution in which the one-dimensional distribution of the uneven state at each position in the tube axis direction is sequentially arranged along the tube axis direction, and the luminance The image is an image representing a two-dimensional luminance distribution in which the one-dimensional distribution of the luminance of the annular laser beam at each position in the tube axis direction is sequentially arranged along the tube axis direction, and the rotation correction The unit reverses the one-dimensional distribution at each position in the tube axis direction with respect to each of the depth image and the luminance image from the rotation direction measured at the corresponding position in the tube axis direction. It is preferable to correct the positional deviation by translating in the direction by the measured magnitude of the rotation.

  The rotation amount measuring device may be an accelerometer, a gyro sensor, or a rotary encoder.

  The tubular body imaging device includes a drive mechanism that performs at least movement of the illumination mechanism and the imaging device along the tube axis direction and rotation of the tube circumferential direction, and the drive mechanism includes the rotation amount. Using the direction and magnitude of the rotation measured by the measuring device, the illumination mechanism and the imaging device are controlled while controlling the rotation in the tube circumferential direction so that the magnitude of the rotation is a predetermined threshold value or less. It may be moved along the tube axis direction.

  When the magnitude of the rotation measured by the rotation amount measuring device is equal to or greater than a predetermined threshold value, warning information for warning that the tubular body imaging device is rotating too much may be output.

  The detection processing unit identifies a defective part based on whether the pixel values of the depth image and the luminance image are equal to or greater than a second threshold value for specifying a defective part, and the identified defective part It is preferable that feature amount information relating to the form and pixel value of the defective part is extracted, and a defect present on the inner surface of the tubular body is determined based on the extracted feature amount information.

  The tubular body imaging device further includes one or a plurality of connecting members that connect and fix the illumination mechanism and the imaging device, and when the tubular body imaging device is fed into the tubular body; and And generating the annular beam image including a shielding region generated by shielding the annular laser light by the connecting member each time the tubular body imaging device is sent out from the inside of the tubular body. The tubular body imaging device is arranged so that the shielding area of the annular beam image at the time of sending and the shielding area of the annular beam image at the time of sending do not overlap between the sending and sending of the tubular body imaging device. The coordinate conversion unit converts the coordinate system of the annular beam image at the time of sending and at the time of sending with a predetermined position on the inner surface of the tubular body as a reference point, and a plurality of the light at the time of sending Cutting image and sending Generating a plurality of the light-cut images, and the image calculation unit uses the light-cut image at the time of sending or the light-cut image at the time of sending to identify the position of the shielding area in the light-cut image Then, in the depth image and the luminance image calculated based on the annular beam image at the time of sending or sending and corrected by the rotation correction unit, the shielding area is changed to the one at the time of sending or sending. It is preferable to complement using the depth image and the luminance image calculated based on the annular beam image and corrected by the rotation correction unit.

  The illumination mechanism further includes a conical illumination light source that irradiates a conical illumination light with respect to the entire circumferential direction of the inner surface of the tubular body, and the imaging device includes the annular laser light and the cone. The inner surface irradiated with the illumination light is imaged so that the irradiation portion of the annular laser light and the irradiation region of the conical illumination light are within the same field of view, the coordinate conversion unit, Further, a plurality of illumination light luminance images, which are band-like regions obtained by expanding the irradiation region of the conical illumination light in the tube circumferential direction of the tubular body, are generated along the tube axis direction of the tubular body, and the rotation correction unit For the calculated illumination light luminance image, using the direction and magnitude of the rotation measured by the rotation amount measuring device, correct the displacement in the tube circumferential direction accompanying the rotation in the tube circumferential direction, The detection processing unit updates the corrected illumination light luminance image. Using may detect a defect existing on the inner surface of the tubular body.

  At least the illumination mechanism and the imaging device of the tubular body imaging device may be provided at a distal end portion on a feeding side of a drift gauge that moves along the tube axis direction in the steel tube during a drift inspection of the steel tube.

  In order to solve the above-mentioned problem, according to another aspect of the present invention, movement is performed along the tube axis direction of a tubular body while measuring the direction and magnitude of rotation occurring in the tube circumferential direction of the tubular body. However, the annular laser beam on the inner surface is obtained by irradiating an annular laser beam to the entire circumferential direction of the inner surface of the tubular body and imaging the inner surface irradiated with the annular laser beam. Generating a plurality of annular beam images that are captured images of the annular body along the tube axis direction of the tubular body, and calculating the center-of-gravity position and radius of the irradiated portion of the annular laser light in each annular beam image The coordinate system of the annular beam image is converted based on the step, the calculated center of gravity position, and the distance between the center of gravity position and the irradiation portion of the annular laser light, and the annular laser light of each annular laser light is converted. Irradiation Generating a plurality of light cutting images that are band-like regions including light cutting lines that are line segments developed in the circumferential direction of the tubular body, and arranging each of the light cutting images in order along the tube axis direction. A step of calculating a depth image representing an uneven state of the inner surface of the tubular body and a luminance image representing a luminance distribution of the annular laser light on the inner surface of the tubular body based on the stripe image frame that has been made And, for each of the calculated depth image and luminance image, correcting the positional deviation in the pipe circumferential direction accompanying the rotation in the pipe circumferential direction using the measured rotation direction and magnitude. Detecting a defect present on the inner surface of the tubular body based on the corrected depth image and the luminance image, and calculating the depth image and the luminance image, Previous A barycentric position in the line width direction of the light cutting line along the circumferential direction is calculated, and the radius is set as a reference position that is a position in the tube axis direction designated in advance with respect to the light cutting image. A tubular body surface inspection method is provided in which the depth image is calculated based on the amount of displacement from the position of the center of gravity.

  In order to solve the above-mentioned problem, according to still another aspect of the present invention, a drift gauge that moves along the pipe axis direction in the steel pipe during a drift inspection of a steel pipe, the surface inspection in the tubular body Among the tubular body imaging devices included in the apparatus, at least the illumination mechanism and the imaging device are provided at the distal end portion on the feeding side, and the arithmetic processing device included in the tubular body surface inspection device has a defect on the inner surface of the steel pipe A drift gauge is provided to determine if exists.

  The arithmetic processing device performs imaging control including movement control of the tubular body imaging device along the tube axis direction, irradiation control of the illumination mechanism in the tubular body imaging device, and imaging control in the imaging device. The imaging control unit further includes an imaging control unit that starts imaging processing at predetermined time intervals as the drift gauge starts moving, and images the steel pipe and the periphery of the steel pipe around the drift gauge. A plurality of surrounding captured images may be generated along the tube axis direction of the tubular body.

  The arithmetic processing unit determines whether the imaging device has reached a position where the annular laser beam irradiation should start based on a result of detecting an outer diameter of the steel pipe based on a luminance distribution in the surrounding captured image. A laser irradiation position determination unit that performs the annular laser beam when the laser irradiation position determination unit determines that the laser beam irradiation position determination unit has reached a position where irradiation of the annular laser beam should start. You may start irradiation to the said inner surface of light.

  The laser irradiation position determination unit identifies a luminance distribution with respect to a predetermined monitoring direction in the surrounding captured image, and a position corresponding to an outer diameter of the installed steel pipe based on a predetermined threshold regarding luminance with respect to the monitoring direction. When the detected outer diameter of the steel pipe has a value equal to or greater than a predetermined threshold value, it may be determined that the position where irradiation of the annular laser beam should be started has been reached. .

  The arithmetic processing unit determines whether the steel pipe is installed at a position where the drift gauge can be inserted based on the result of detecting the installation position of the steel pipe based on the luminance distribution in the surrounding captured image. A determination unit, wherein the imaging control unit determines that the steel pipe is not installed at a position where the drift gauge can be inserted by the gauge input determination unit; May be stopped.

  The gauge feeding determination unit identifies luminance distributions in two monitoring directions orthogonal to each other for the surrounding captured image when the separation distance between the steel pipe and the light receiving surface of the imaging device becomes a predetermined value. Then, for each of the two monitoring directions, a position corresponding to the outer diameter of the installed steel pipe is detected based on a predetermined threshold relating to luminance, and the detected position of the outer diameter of the steel pipe is a surrounding captured image. When the center is located within a predetermined range, the steel pipe may be determined to be installed at a position where the drift gauge can be inserted.

  At least a part of the arithmetic processing unit may be provided inside the drift gauge.

  In order to solve the above problems, according to still another aspect of the present invention, a drift inspection method for performing a drift inspection of a steel pipe using a drift gauge that moves inside the steel pipe along the pipe axis direction. In the tubular body imaging device included in the tubular body surface inspection device, a drift gauge provided with at least an illumination mechanism and an imaging device is provided along the tube axis direction of the steel pipe at the distal end portion on the sending side. A plurality of annular beam images are generated along the tube axis direction of the tubular body by moving, and it is determined whether or not there is a defect on the inner surface of the steel pipe by the arithmetic processing device included in the tubular body surface inspection device. Drift inspection method

  As described above, according to the present invention, even when the posture of the imaging equipment for imaging the inner surface of the tubular body is changed, the uneven wrinkles and the pattern-based wrinkles present on the inner surface of the tubular body are removed. It can be automatically detected.

It is the block diagram which showed typically the structure of the tubular body surface inspection apparatus which concerns on the 1st Embodiment of this invention. It is explanatory drawing which showed typically an example of the structure of the tubular body imaging device which concerns on the embodiment. It is explanatory drawing which showed typically an example of the structure of the tubular body imaging device which concerns on the embodiment. It is explanatory drawing which showed typically an example of the structure of the tubular body imaging device which concerns on the embodiment. It is explanatory drawing which showed typically an example of the rotation amount measuring apparatus which concerns on the same embodiment. It is explanatory drawing which showed typically an example of the rotation amount measuring apparatus which concerns on the same embodiment. It is the block diagram which showed an example of the structure of the image process part with which the arithmetic processing apparatus which concerns on the same embodiment is provided. It is explanatory drawing which showed an example of the annular beam image which concerns on the same embodiment. It is explanatory drawing for demonstrating the coordinate transformation process which concerns on the same embodiment. It is explanatory drawing which showed an example of the fringe image frame which concerns on the same embodiment. It is explanatory drawing for demonstrating the optical cutting line process which concerns on the same embodiment. It is explanatory drawing for demonstrating the optical cutting line process which concerns on the same embodiment. It is explanatory drawing which showed the two-dimensional arrangement | sequence of the optical cutting line displacement which concerns on the same embodiment. It is explanatory drawing which showed the two-dimensional arrangement | sequence of the sum total of the luminance which concerns on the same embodiment. It is explanatory drawing which showed the two-dimensional arrangement | sequence of the number of pixels of the bright line based on the embodiment. It is explanatory drawing which showed the relationship between the displacement of an optical cutting line, and the height of a defect. It is explanatory drawing for demonstrating the approximate correction process of the optical section line which concerns on the same embodiment. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing which showed an example of the rotation amount specific process which concerns on the same embodiment. It is explanatory drawing which showed an example of the rotation amount specific process which concerns on the same embodiment. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing which showed typically an example of the logic table used by the defect detection process which concerns on the same embodiment. It is the flowchart which showed an example of the flow of the tubular body surface inspection method which concerns on the embodiment. It is the flowchart which showed an example of the flow of the tubular body surface inspection method which concerns on the embodiment. It is the block diagram which showed an example of the structure of the image process part in the arithmetic processing apparatus with which the tubular body surface inspection apparatus which concerns on the 2nd Embodiment of this invention is provided. It is explanatory drawing which showed an example of the irradiation area | region of the annular beam which concerns on the embodiment. It is explanatory drawing which showed typically an example of the annular beam image which concerns on the same embodiment. It is explanatory drawing which showed an example of the fringe image frame at the time of sending which concerns on the embodiment. It is explanatory drawing which showed an example of the fringe image frame at the time of transmission concerning the embodiment. It is explanatory drawing which showed an example of distribution of the brightness | luminance of the shielding area | region which concerns on the same embodiment. It is explanatory drawing which showed an example of distribution of the number of pixels of the bright line which concerns on the embodiment. It is explanatory drawing for demonstrating the complementation process of the depth image which concerns on the embodiment. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the influence by rotation of a tubular body imaging device. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing for demonstrating the rotation correction process which concerns on the same embodiment. It is explanatory drawing which showed typically the complementary image of the depth image and luminance image which concern on the embodiment. It is the flowchart which showed an example of the flow of the tubular body surface inspection method which concerns on the embodiment. It is explanatory drawing which showed typically an example of the structure of the tubular body imaging device with which the tubular body surface inspection apparatus which concerns on the 3rd Embodiment of this invention is provided. It is explanatory drawing which showed typically an example of the structure of the tubular body imaging device which concerns on the embodiment. It is explanatory drawing which showed typically an example of the structure of the tubular body imaging device which concerns on the embodiment. It is explanatory drawing which showed typically an example of the annular beam image which concerns on the same embodiment. It is explanatory drawing which showed typically an example of the annular beam image which concerns on the same embodiment. It is the block diagram which showed typically an example of the structure of the image process part which the arithmetic processing apparatus with which the tubular body surface inspection apparatus which concerns on the same embodiment is provided. It is explanatory drawing for demonstrating the coordinate transformation process which concerns on the same embodiment. It is explanatory drawing for demonstrating the coordinate transformation process which concerns on the same embodiment. It is explanatory drawing for demonstrating a drift test | inspection. It is explanatory drawing which showed typically the structure of the drift gauge which concerns on embodiment of this invention. It is explanatory drawing which showed typically the structure of the tubular body imaging device with which the drift gauge concerning the embodiment is provided. It is explanatory drawing for demonstrating the surrounding captured image produced | generated by the tubular body imaging device which concerns on the embodiment. It is explanatory drawing which showed typically the structure of the tubular body imaging device with which the drift gauge concerning the embodiment is provided. It is the block diagram which showed typically an example of the structure of the image processing part which the arithmetic processing apparatus with which the drift gauge concerning the embodiment is provided has. It is explanatory drawing for demonstrating the laser irradiation position determination process which the image process part which concerns on the embodiment implements. It is explanatory drawing for demonstrating the laser irradiation position determination process which the image process part which concerns on the same embodiment implements. It is explanatory drawing for demonstrating the gauge feeding determination process which the image process part which concerns on the embodiment implements. It is explanatory drawing for demonstrating the gauge feeding determination process which the image process part which concerns on the embodiment implements. It is explanatory drawing for demonstrating the gauge feeding determination process which the image process part which concerns on the embodiment implements. It is the block diagram which showed an example of the hardware constitutions of the arithmetic processing unit which concerns on each embodiment of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(First embodiment)
<Overall structure of tubular body surface inspection device>
First, the overall configuration of the tubular body surface inspection apparatus 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory view showing an example of the configuration of a tubular body surface inspection apparatus 10 according to the present embodiment.

  The tubular body surface inspection apparatus 10 according to the present embodiment is an apparatus that inspects the inner surface of the tubular body 1 by imaging the inner surface of the tubular body 1 and performing image processing on an image obtained as a result of the imaging. More specifically, it is an apparatus for inspecting whether or not surface defects (concave and flaws and pattern-type wrinkles) are present on the inner surface of the tubular body 1.

  The tubular body 1 according to the present embodiment is not particularly limited as long as the tubular body 1 has a hollow portion, but examples of the tubular body 1 include spiral steel pipes, ERW steel pipes, UO steel pipes, seams. Not only metal pipes and pipes typified by various steel pipes such as non-steel pipes (seamless steel pipes), forged steel pipes, TIG welded steel pipes, but also tubular items such as cylinders used in hot extrusion methods. .

  As shown in FIG. 1, the tubular body surface inspection apparatus 10 according to the present embodiment captures an inner surface of the tubular body 1 and moves along the tube axis direction of the tubular body imaging apparatus 100. A drive control device 150 that controls the image and an arithmetic processing device 200 that performs image processing on an image obtained as a result of imaging.

  The tubular body imaging device 100 is installed in a hollow portion of the tubular body 1. The tubular body imaging device 100 sequentially captures the inner surface of the tubular body 1 along the tube axis direction while changing the position along the tube axis direction of the tubular body 1 as needed, and a captured image obtained as a result of the imaging. Is output to the arithmetic processing unit 200. The position of the tubular body imaging device 100 along the tube axis direction is controlled by the drive control device 150, and a PLG signal from a PLG (Pulse Logic Generator: pulse type velocity detector) or the like as the tubular body imaging device 100 moves. Is output to the arithmetic processing unit 200. In the tubular body imaging device 100, the imaging timing of the tubular body 1 is controlled by the arithmetic processing device 200.

  The drive control device 150 is a device such as an actuator that controls the movement of the tubular body imaging device 100 in the tube axis direction and the rotation in the tubular body circumferential direction with the tube center axis direction as a rotation axis. The drive control device 150 controls operations such as movement of the tubular body imaging device 100 in the tube axis direction and rotation of the tubular body circumferential direction under the control of the arithmetic processing device 200.

  More specifically, the drive control device 150 sends / receives the tubular body imaging device 100 to / from the tubular body. Moreover, it is preferable that the drive control device 150 controls the rotation in the tubular body circumferential direction so that the rotation in the tubular body circumferential direction of the tubular body imaging device 100 is suppressed to a predetermined threshold angle or less.

  In addition, the arithmetic processing device 200 generates a striped image frame using the captured image generated by the tubular body imaging device 100 and performs image processing on the striped image frame, whereby the inner surface of the tubular body 1 is obtained. This is a device for detecting a defect that may be present.

<About the structure of the tubular body imaging device 100>
Next, the configuration of the tubular body imaging apparatus 100 according to the present embodiment will be described in detail with reference to FIGS. 2A to 3B. 2A to 2C are explanatory diagrams schematically illustrating an example of the configuration of the tubular body imaging apparatus 100 according to the present embodiment. 3A and 3B are explanatory diagrams schematically showing an example of the rotation amount measuring apparatus according to the present embodiment.

  As schematically illustrated in FIG. 2A, the tubular body imaging device 100 according to the present embodiment includes an illumination mechanism 110, a camera 120 that is an example of an imaging device, a rotation amount measurement device 130, an illumination mechanism 110, and a camera. The holding substrate 141 to which each of 120 is fixed, and the connection member 143 which is a support | pillar which connects the two holding substrates 141 are provided.

  The illumination mechanism 110 is a mechanism that illuminates the inner surface of the tubular body 1 by irradiating the inner surface of the tubular body 1 with predetermined light. The illumination mechanism 110 has at least a laser beam irradiation device that irradiates an annular laser beam with respect to the entire circumferential direction of the inner surface of the tubular body 1.

  Such a laser beam irradiation device is a device that irradiates an annular laser beam (hereinafter also referred to as “annular beam”) along the tube circumferential direction of the inner surface of the tubular body 1, and as shown in FIG. It has a laser light source 111 and a conical optical element 113.

  The laser light source 111 is a light source that oscillates laser light having a predetermined wavelength. As such a laser light source 111, it is possible to use, for example, a CW laser light source that continuously performs laser oscillation. The wavelength of light oscillated by the laser light source 111 is not particularly limited, but is preferably a wavelength belonging to the visible light band of about 400 nm to 800 nm, for example. The laser light source 111 oscillates laser light based on an irradiation timing control signal sent from the arithmetic processing unit 200 described later.

  The conical optical element 113 is an optical element including a conical mirror or prism, and is installed so that the apex of the conical portion faces the laser light source 111. The spot-shaped laser light emitted from the laser light source 111 is reflected by the apex of the conical portion of the optical element 113, and a line beam is generated in a ring shape. Here, when the cone angle of the cone portion is 90 °, as shown in FIG. 2A, the annular beam is irradiated in a direction perpendicular to the laser incident direction from the laser light source 111.

  As shown in FIG. 2A, the camera 120, which is an example of the imaging apparatus, may be provided behind the illumination mechanism 110 in the tube axis direction (on the opposite side to the feeding direction to the material to be inspected). It may be provided in the forward direction in the inspection material. An image pickup device such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) is mounted on the camera 120 as an example of an image pickup apparatus. The camera 120 may be a monochrome camera or a color camera. The camera 120 images the annular beam irradiated perpendicularly to the inner surface of the tubular body 1 from the direction of the angle φ as shown in FIG. 2A.

  The focal length and angle of view of the lens mounted on the camera 120 and the distance between the illumination mechanism 110 and the image sensor of the camera 120 are not particularly limited, but the ring irradiated on the inner surface of the tubular body 1 is not limited. It is preferable to select so that an entire image of the beam can be captured. Further, the size and pixel size of the image sensor mounted on the camera 120 are not particularly limited, but it is preferable to use a large image sensor in consideration of the image quality, image resolution, and the like of the generated image. Further, from the viewpoint of image processing described below, the line width (line width) of the annular beam is preferably adjusted to be about 1 to 3 pixels on the image sensor.

  Such an illumination mechanism 110 and the camera 120 are arranged so that the central axis of the laser light emitted from the illumination mechanism 110 and the central axis (optical axis) of the camera 120 are coaxial, and constitute an imaging probe. doing. Such an imaging probe is supported by a support bar of the imaging probe as schematically shown in FIG. 2A. When the support bar is driven in the tube axis direction by the drive control device 150, the illumination mechanism 110 and the camera 120 are moved in the tube axis direction so as to substantially coincide with the central axis of the tubular body 1 by the drive control device 150. The inner surface of the tubular body 1 is scanned.

  Here, the arithmetic processing unit 200 described later outputs a trigger signal for imaging to the camera 120 every time the tubular body imaging device 100 moves a predetermined distance in the tube axis direction. Although the movement interval in the tube axis direction of the illumination mechanism 110 and the camera 120 can be set as appropriate, for example, it is preferable to set the same as the pixel size of the image sensor provided in the camera 120. By matching the movement distance in the tube axis direction with the pixel size of the image sensor, the vertical resolution and the horizontal resolution can be matched in the captured image.

  The angle φ shown in FIG. 2A can be set to an arbitrary value, but is preferably about 30 to 60 degrees, for example. If the angle is too large, the scattered light (reflected light) of the annular beam from the inner surface of the tubular body 1 becomes weak. This is because the amount of movement of the stripes in the image is reduced, and information on the depth of the concave portion (or the height of the convex portion) existing on the inner surface of the tubular body 1 is deteriorated.

  The rotation amount measuring device 130 measures the direction and magnitude of rotation of the illumination mechanism 110 and the camera 120 in the circumferential direction of the tubular body 1 that occur when the illumination mechanism 110 and the camera 120 move along the tube axis direction of the tubular body 1. It is a device to do. The direction and magnitude of the rotation represent the direction changed from the predetermined reference position and the amount of change from the predetermined reference position, respectively. As will be described in detail below, in the present embodiment, the measurement result of the rotation amount measurement device 130 at the timing when imaging by the camera 120 is started is handled as the reference position. As shown schematically in FIG. 2A, the rotation amount measuring device 130 is disposed, for example, with respect to the holding substrate 141 to which the camera 120 is fixed. In FIG. 2A, the rotation amount measuring device 130 is arranged with respect to the holding substrate 141 to which the camera 120 is fixed, but may be arranged to the holding substrate 141 to which the illumination mechanism 110 is fixed. Needless to say.

  Here, every time the tubular body imaging device 100 moves a predetermined distance in the tube axis direction, the arithmetic processing device 200 described later outputs a trigger signal for measurement to the rotation amount measuring device 130, and the rotation amount measuring device. 130 determines the direction and magnitude of the rotation. Such a rotation amount measuring device 130 is not particularly limited, but various known measuring devices used as posture detecting sensors such as an accelerometer, a gyro sensor, and a rotary encoder can be appropriately used. It is.

  When a device capable of measuring a rotation angle, such as an accelerometer or a gyro sensor, is used as the rotation amount measurement device 130, the rotation amount measurement device 130 is connected to the illumination mechanism 110 and the rotation amount measurement device 130 as shown in FIG. It is preferable to arrange so as to be coaxial with the camera 120. A measuring device such as an accelerometer or a gyro sensor often has three coordinate axes that are orthogonal to each other, but the rotation amount measuring device 130 according to the present embodiment is schematically shown in FIG. 3A. Thus, it is preferable to use two coordinate axes orthogonal to each other in the same plane.

Now, two coordinate axes that are orthogonal to each other are the A axis and the B axis, respectively, and in a state where the rotation angle is 0 degree, the positive direction of the A axis is downward in the vertical direction, and the positive direction of the B axis is in the horizontal direction to the right. (FIG. 3A, center diagram). In this state, a value of 9.80665 m / s ² that is the magnitude of the gravitational acceleration G is detected downward in the vertical direction on the A axis, and no acceleration is detected on the B axis. On the other hand, if the rotation amount measuring device 130 is rotated 45 degrees clockwise (+45 degrees to rotate. FIG. 3A left view), A-axis and B-axis, downward in the vertical direction, 9.80665m / ^{s 2} × ^{2 0 .5} , when the rotation measuring device 130 rotates 45 degrees counterclockwise (-45 degrees rotation, right figure in FIG. 3A), the A axis is 9 detects the magnitude acceleration of ^{.80665m / s 2 × 2 0.5,} B axis in the upward vertical direction, for detecting the acceleration of the magnitude of 9.80665m / ^{s 2} × ^{2 0.5.} Thus, a device capable of measuring a rotation angle such as an accelerometer or a gyro sensor measures a rotation angle (direction and size) based on the magnitude and direction of gravity acceleration detected on each axis. It becomes possible. In FIG. 3A, the rotation amount measuring device 130 is illustrated with respect to a case where two coordinate axes orthogonal to each other are defined, but in principle, the two coordinate axes are in a positional relationship in which they are parallel to each other. If not, they need not be orthogonal.

  In addition, when the apparatus for measuring the length of the object to be moved with rotation such as a rotary encoder having a touch roll schematically shown in FIG. 3B is used as the rotation amount measuring apparatus 130, These rotation amount measuring devices 130 are preferably mounted on a portion where the same rotation as that of the measurement object (that is, the illumination mechanism 110 and the camera 120 in the present embodiment) occurs. For example, as schematically shown in FIG. 2B, the rotation amount measuring device 130 such as a rotary encoder is mounted on the support bar itself or the support bar holding portion in which the same rotation as the illumination mechanism 110 and the camera 120 is generated. It is possible.

  The illumination mechanism 110 and the camera 120 are each fixed to a holding substrate 141, and these two holding substrates 141 are connected by one or a plurality of connecting members 143. The illumination mechanism 110 and the camera 120 are fixed by the holding substrate 141 and the connecting member 143, whereby an imaging probe for imaging the inner surface of the tubular body 1 is formed.

  The material of the holding substrate 141 is preferably selected as appropriate according to the strength required for the tubular body imaging device 100. For the connecting member 143, it is preferable to use a material that can be regarded as transparent to the wavelength of the annular beam, such as glass. Further, the number of the connecting members 143 may be set as appropriate according to the strength required of the tubular body imaging device 100, and may be one or plural. If the illumination mechanism 110 and the camera 120 are weighted and the connection member 143 is required to have sufficient strength, the connection member 143 may be regarded as transparent to the wavelength of the annular beam, such as metal. It will be formed using materials that cannot. However, in such a case, it is possible to perform imaging by performing the processing according to the second embodiment described below.

  Here, when a plurality of connecting members 143 are provided, the connecting members 143 are arranged at equal intervals along the tube circumferential direction of the holding substrate 141, for example, as shown in FIG. 2C. Preferably they are arranged.

  Hereinafter, specific configurations, set values, and the like of the devices included in the tubular body imaging device 100 according to the present embodiment are listed. Such a configuration and set values are merely examples, and the tubular body imaging device 100 according to the present invention is not limited to the following specific examples.

○ Tubular body inner diameter 50mm ~ 500mm, length 10m ~ 20m
○ Illumination mechanism The laser light source 111 emits red laser light with an output of 100 mW. The conical optical element 113 (conical angle 90 degrees) is irradiated as an annular beam of 50 mW onto the inner surface of the tubular body. The line beam width irradiated on the inner surface of the tubular body is 0.25 mm. However, the line beam width in this case is defined as 13.5% from the peak intensity value.
○ Camera A CCD (pixel size: 5.5 μm × 5.5 μm) of 1024 pixels × 1024 pixels is mounted as an image sensor, and the frame rate is 90 fps. The focal length of the lens is 1.81 mm, and the angle of view is 180 °. The captured image has a pixel size of 0.5 mm × 0.5 mm and a line beam width of 1 to 3 pixels on the captured image.
○ Rotation amount measuring device 16bit 3-axis accelerometer (± 6G), Sampling cycle: Max 1000Hz
It has an excellent angular resolution of about 20 times the imaging resolution of 0.5 mm / pixel realized by the camera.
The camera 120 takes an image of the inner surface of the tubular body every 0.5 mm in the direction of the tube axis, and the rotation amount measuring device 130 rotates each time it advances the inner surface of the tubular body by 0.5 mm in the direction of the tube axis. Outputs the measured angle value.

<About Overall Configuration of Arithmetic Processing Device 200>
The configuration of the tubular body imaging apparatus 100 according to the present embodiment has been described above. Next, returning to FIG. 1 again, the overall configuration of the arithmetic processing apparatus 200 according to the present embodiment will be described.

  For example, as illustrated in FIG. 1, the arithmetic processing device 200 according to the present embodiment mainly includes an imaging control unit 201, an image processing unit 203, a display control unit 205, and a storage unit 207.

  The imaging control unit 201 is realized by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a communication device, and the like. The imaging control unit 201 performs imaging control of the inspection object by the tubular body imaging apparatus 100 according to the present embodiment. More specifically, the imaging control unit 201 sends a control signal for starting oscillation of laser light to the illumination mechanism 110 when imaging of the tubular body 1 is started.

  Further, when the tubular body imaging apparatus 100 starts imaging the tubular body 1, a PLG signal is periodically transmitted from the tubular body imaging apparatus 100 (for example, every time the tubular body imaging apparatus 100 moves 0.5 mm, one pulse of the PLG signal). However, every time the PLG signal is acquired, the imaging control unit 201 sends a trigger signal for starting imaging to the camera 120 and measures the rotation amount with respect to the rotation amount measuring device 130. Send a trigger signal to start.

  The image processing unit 203 is realized by, for example, a CPU, a ROM, a RAM, a communication device, and the like. The image processing unit 203 uses the imaging data acquired from the tubular body imaging device 100 (more specifically, the camera 120 of the tubular body imaging device 100) to generate a fringe image frame to be described later. Thereafter, image processing as described below is performed on the generated fringe image frame to detect defects that may exist on the inner surface of the tubular body that is the measurement object. When the image processing unit 203 finishes the defect detection process on the inner surface of the tubular body 1, the image processing unit 203 transmits information about the obtained detection result to the display control unit 205.

  The image processing unit 203 will be described in detail later again.

  The display control unit 205 is realized by, for example, a CPU, a ROM, a RAM, an output device, and the like. The display control unit 205 is provided outside the arithmetic processing device 200 and the output device such as a display provided in the arithmetic processing device 200, and the defect detection result of the tubular body 1 that is the inspection object transmitted from the image processing unit 203. Display control when displaying on the output device. Thereby, the user of the defect detection apparatus 10 can grasp the detection results regarding various defects existing on the inner surface of the inspection object (tubular body 1) on the spot.

  The storage unit 207 is realized by, for example, a RAM or a storage device included in the arithmetic processing device 200 according to the present embodiment. The storage unit 207 stores various parameters, intermediate progress of processing, and various databases and programs that need to be saved when the arithmetic processing apparatus 200 according to the present embodiment performs some processing, as appropriate. To be recorded. The storage unit 207 allows the imaging control unit 201, the image processing unit 203, the display control unit 205, and the like to execute read / write processing.

<Regarding Image Processing Unit 203>
Next, the image processing unit 203 included in the arithmetic processing apparatus 200 according to the present embodiment will be described in detail with reference to FIG. FIG. 4 is a block diagram illustrating a configuration of an image processing unit included in the arithmetic processing apparatus according to the present embodiment.

  As shown in FIG. 4, the image processing unit 203 according to the present embodiment includes an A / D conversion unit 211, an annular beam center calculation unit 213, a coordinate conversion unit 215, a fringe image frame generation unit 217, and an image. A calculation unit 219 and a detection processing unit 229 are mainly provided.

  The A / D conversion unit 211 is realized by, for example, a CPU, a ROM, a RAM, and the like. The A / D conversion unit 211 performs A / D conversion on the captured image output from the camera 120, and outputs it as digital multi-valued image data (that is, an annular beam image) as shown in FIG. Such digital multivalued image data is stored in an image memory provided in the storage unit 207 or the like. By using these digital multi-valued image data sequentially along the tube axis direction of the tubular body, a stripe image frame as described later is formed.

  As shown in FIG. 5, the annular beam image is an image of the annular beam irradiated on the inner surface of the tubular body at a certain position along the tube axis direction of the inner surface of the tubular body 1. In the annular beam image, by appropriately setting the camera gain and the lens aperture in advance, as shown in FIG. 5, for example, the portion irradiated with the annular beam is displayed in white, and the other portions are displayed in black. It is a gray image. Further, the unevenness superimposed on the circumference of the annular beam includes information on the cross-sectional shape of the inner surface of the tubular body and the defects existing on the inner surface.

  When the A / D conversion unit 211 generates an annular beam image as shown in FIG. 5 based on the captured image output from the camera 120, data corresponding to the generated annular beam image is converted into an annular beam center calculation unit 213 described later. Output to.

  The annular beam center calculation unit 213 is realized by, for example, a CPU, a ROM, a RAM, and the like. The annular beam center calculation unit 213 calculates the center of gravity position of the ring and the radius of the ring for each annular beam image output from the A / D conversion unit 211.

  The method for calculating the center of gravity position and the radius of the ring is not particularly limited, and any known method can be used. As specific examples of the method for calculating the center of gravity position and the radius of the ring, for example, when the annular beam image is close to a perfect circle, the following two methods can be cited.

Extract any three points on the binarized annular beam image and calculate the center of gravity of the position coordinates of these three points. The distance between the obtained barycentric position and any one of the three points is the radius of the ring.
-Circle extraction by Hough transformation is performed, and the center of gravity and radius of the circle (that is, the annular beam) are calculated.

  When the annular beam center calculation unit 213 calculates the center of gravity position and radius of the ring for each annular beam image, the annular beam center calculation unit 213 generates information about the center of gravity position and radius of the ring, and outputs the information to the coordinate conversion unit 215 described later.

  In addition, in this embodiment, although the case where the cross-sectional shape of the inner surface of the tubular body 1 is close to a perfect circle is described, it can be applied to any cross-sectional shape. For example, the cross-sectional shape is an ellipse or a rounded corner. It may be a rectangle or the like. The center of gravity in such a case can be obtained from the shape of the annular beam, and by using the average value of the maximum value and the minimum value of the distance to the obtained center of gravity as the radius, coordinate conversion described later is performed in the same procedure. Can be implemented.

  The coordinate conversion unit 215 is realized by, for example, a CPU, a ROM, a RAM, and the like. The coordinate conversion unit 215 converts the coordinate system of the annular beam image based on the calculated gravity center position and the separation distance between the gravity center position and the irradiated portion of the annular beam. Thereafter, the coordinate conversion unit 215 generates a light section image that represents the irradiated portion of the annular beam as a line segment developed in the tube circumferential direction of the tubular body.

By calculating the position of the center of gravity of the annular beam, the pixel position corresponding to the irradiation position of the annular beam can be represented by polar coordinates (r, θ) with the center of gravity position as the origin. As shown in FIG. 6, the coordinate conversion unit 215 provides a margin of ± Δr in the radial direction with respect to the radius r calculated by the annular beam center calculation unit 213 (that is, a range of r−Δr to r + Δr). ), Coordinate transformation is performed with 0 ° ≦ θ ≦ 360 °. Here, the position of θ = 0 ° is the position of the value of the rotation angle measured by the rotation amount measuring device 130 at the start of imaging. In the present embodiment, the case where coordinate transformation is performed in the range of r−Δr to r + Δr in the radial direction has been described. However, the value of the margin Δr is a range including the irradiated portion of the annular beam and is in the plus direction. The value may be different in the minus direction. In such a case, for example, the range in which the coordinate conversion is performed can be expressed as r−Δr _{1 to} r + Δr ₂ . However, in the present embodiment, the following description will be given for the case where the same value Δr is used in the plus direction and the minus direction.

  By performing such coordinate conversion, as shown on the right side of FIG. 6, the radial direction has a height of 2Δr around the radius r, and the angular direction has a length of 360 °. A band-like image is extracted. As is clear from the above description, the extracted belt-like image includes a line segment (hereinafter, also referred to as “light cutting line”) in which the irradiated portion of the annular beam is developed in the tube circumferential direction. It becomes. Further, by extracting a range of 2Δr with the radius r as the center in the radial direction, it is possible to extract the entire circumference of the annular beam including the irregularities even if irregularities exist around the circumference of the annular beam. It becomes. The band-like image obtained in this way is hereinafter referred to as a light section image.

  The magnitude of Δr can be determined by roughly calculating in advance the range of the height of the unevenness that can exist in the tubular body 1 based on past operation data and the like.

  The annular beam image captured by the tubular body imaging device 100 as described above includes a ring having a radius corresponding to about 300 pixels. Therefore, when r = 300 pixels and Δr = 25 pixels and a light section image is extracted in a range of 0 ° ≦ θ ≦ 360 °, a light section image having a width of 1,855 pixels × height of 50 pixels is generated. Become.

  In addition, the coordinate conversion unit 215 converts the coordinates of the pixels included in the light cut image into orthogonal coordinates (r cos θ, rsin θ) by using the coordinates (r, θ) of each pixel in the extracted light cut image. . Here, since the coordinate value conversion performed by the coordinate conversion unit 215 is conversion from the polar coordinate system to the orthogonal coordinate system, the lattice point (that is, the center position of the pixel) in the polar coordinate system is always a lattice in the orthogonal coordinate system. It does not necessarily correspond to a point, and there also exists a thing corresponding to a non-grid point. Therefore, in order to interpolate the density (pixel value) of the non-grid points in the orthogonal coordinate system, the coordinate conversion unit 215 performs interpolation based on the density of other grid points located in the vicinity of the point of interest. It is preferable to implement the image interpolation method together.

  Such an image interpolation method is not particularly limited, and for example, a well-known image interpolation method described in “Shokudo Image Processing Handbook” or the like can be used. Examples of such an image interpolation method include a nearest neighbor method, a bi-linear interpolation method, and a cubic interpolation method. Of these methods, the former has a higher processing speed, and the latter has a higher quality result. Therefore, the coordinate conversion unit 215 may determine the type of image interpolation method to be used as appropriate according to the amount of resources that can be used for processing, the processing time, and the like. In the specific example of the light section image shown in the present embodiment, the cubic interpolation method is applied as the image interpolation method.

  When the coordinate conversion unit 215 completes the coordinate conversion process and the image interpolation process as described above, the image data corresponding to the obtained light-cut image is stored in the image memory provided in the storage unit 207 or the like in the tubular body. Store sequentially along the axial direction.

  The stripe image frame generation unit 217 is realized by, for example, a CPU, a ROM, a RAM, and the like. The fringe image frame generation unit 217 sequentially acquires the light section images stored along the tube axis direction of the tubular body from the image memory provided in the storage unit 207 or the like. Thereafter, the fringe image frame generation unit 217 sequentially arranges the acquired light section images along the tube axis direction of the tubular body to generate a fringe image frame.

  The number of light section images constituting one striped image frame may be set as appropriate. For example, one striped image frame may be composed of 256 light section images. Each light section image exists at every imaging interval (for example, 0.5 mm interval) of the annular beam image as described above. Therefore, one striped image frame composed of 256 light section images based on an annular beam image captured at intervals of 0.5 mm is 128 mm (=) along the tube axis direction along the entire inner surface of the tubular body. This corresponds to the result of imaging in a range of 256 × 0.5 mm.

  FIG. 7 shows an example of a stripe image frame generated by the stripe image frame generation unit 217. The fringe image frame shown in FIG. 7 shows 16 light cut images out of 256 light cut images. In the striped image frame shown in FIG. 7, one line segment extending in the horizontal direction of the drawing corresponds to a developed annular beam image, and the horizontal direction of the drawing is the tube circumference of the annular beam. It corresponds to the direction. In the striped image frame shown in FIG. 7, the vertical direction of the drawing corresponds to the tube axis direction of the tubular body 1.

  When the stripe image frame generation unit 217 generates the stripe image frame as illustrated in FIG. 7, the stripe image frame generation unit 217 outputs the generated stripe image frame to the image calculation unit 219 described later. Further, the fringe image frame generation unit 217 may associate the time information related to the date and time when the fringe image frame is generated with the data corresponding to the generated fringe image frame, and store the data as history information in the storage unit 207 or the like. .

  The image calculation unit 219 is realized by, for example, a CPU, a ROM, a RAM, and the like. Based on the fringe image frame generated by the fringe image frame generation unit 217, the image calculation unit 219 calculates the depth image representing the uneven state of the inner surface of the tubular body and the luminance distribution of the annular beam on the inner surface of the tubular body. And a luminance image to be expressed. As shown in FIG. 4, the image calculation unit 219 includes a light section line processing unit 221, a depth image calculation unit 223, a luminance image calculation unit 225, and a rotation correction unit 227.

  The light section line processing unit 221 is realized by, for example, a CPU, a ROM, a RAM, and the like. The light section line processing unit 221 calculates, for each light section line included in the fringe image frame, a light section line feature amount including a displacement amount of the light section line (bending degree of the bright line). Hereinafter, the processing performed by the light section line processing unit 221 and the calculated light section line feature amount will be described in detail with reference to FIGS. 8A and 8B. FIG. 8A is an explanatory diagram schematically showing a fringe image frame. FIG. 8B is an explanatory diagram for explaining the optical section line processing performed by the optical section line processing unit.

  In FIG. 8A, it is assumed that there are N light cutting lines in one striped image frame, and the horizontal length of the striped image frame is M pixels. In addition, one light section image including one light section line is composed of vertical 2Δr pixels × horizontal M pixels.

Here, for convenience of explanation, the X-axis is taken in the tube circumferential direction (horizontal direction in FIG. 8A) of the stripe image frame, and the Y-axis is taken in the tube axis direction (vertical direction in FIG. 8A) of the stripe image frame. Assume that the position of a pixel in a frame is expressed by XY coordinates. In the following description, the position of the m-th pixel (1 ≦ m ≦ M) from the left side of the j (1 ≦ j ≦ N) th light section line existing in the fringe image frame (ie, represented by X _{j, m} ). The position).

The light section line processing unit 221 first determines an X coordinate position (a position represented by X _{j, m} in the present description) of a light section line to be focused (hereinafter also simply referred to as “line”). When the selection is made, as shown in FIG. 8B, the distribution of the pixel values (that is, the luminance value of the annular beam) associated with the pixel at the focused X coordinate position of the focused line is referred to. At this time, the light section line processing unit 221 does not perform the process described below for all the pixels at the X coordinate position in the light section image, but the Y coordinate reference position Y _s in the light section image. The processing described below is performed on pixels belonging to the range of W before and after (that is, pixels belonging to the range of Y _s −W to Y _s + W).

Here, the reference position Y _s Y-coordinate is the tube axis direction of the position designated in advance for j-th line of the light section image of the fringe image frame, for example, specify the tube axis direction of the center of the optical section image If the same margin value Δr is used in the plus direction and the minus direction as described above, it becomes equal to the radius r (that is, the position of the light cutting line) calculated by the annular beam center calculation unit. The parameter W defining a processing range based on the height range of the irregularities which may be present in the tubular body 1 in the past operation data, the Y coordinate in the light section images before and after W reference position Y _s A rough calculation may be performed in advance so that the range fits in the light-cut image, and the range may be determined as appropriate. If the value of the parameter W can be reduced, the processing load of the optical section line processing unit 221 to be described later can be reduced.

Light section line unit 221, first, from among the pixels included in the range of Y _s -W~Y _s + _W, the first threshold value for specifying the pixels corresponding to the light section line given as an example A pixel having a pixel value equal to or greater than the threshold Th is specified. In the example shown in FIG. 8B, three pixels represented by Y _{j, k} , Y _{j, k + 1} , Y _{j, k + 2} have pixel values I _{j, k} , I _{j, k + 1} , I _j that are equal to or greater than the threshold Th, respectively. _{, K + 2} . Accordingly, the light section line processing unit 221 sets the number p _{j, m} = 3 obtained by adding pixels having pixel values equal to or greater than the predetermined threshold Th in the line width direction. The number p _{j, m} obtained by adding pixels having pixel values equal to or greater than the predetermined threshold Th in the line width direction is a value corresponding to the number of pixels of the bright line at the position (j, m). one of. In addition, the light section line processing unit 221 performs information (Y _{j, k} , I _{j, k} ), (Y _{j, k + 1} , I _{j, k + 1} ), (Y _{j, k + 2} ) regarding the extracted pixels in the following processing. , I _{j, k + 2} ) (hereinafter, sometimes simply abbreviated as (Y, I)), further light section line feature quantities are calculated.

Further, the light section line processing unit 221 calculates the total sum K _{j, m} of the luminances of the extracted pixels using the parameters p _{j, m} and the information (Y, I) regarding the extracted pixels. In the case of the example shown in FIG. 8B, the sum of the luminances calculated by the light section line processing unit 221 is K _{j, m} = I _{j, k} + I _{j, k + 1} + I _{j, k + 2} . This total luminance K _{j, m} is also one of the features of the light section line.

Further, the light section line processing unit 221 uses the information (Y, I) regarding the extracted pixel and the reference position Y _{s of the} Y coordinate, and the barycentric position Y _C (j, m) and a displacement amount Δd _{j, m} = Y _s −Y _C (j, m) of the center of gravity Y _C (j, m) from the reference position Y _s are calculated.

Here, the center-of-gravity position Y _C (j, m) is a value represented by the following expression 101, where A is a set of extracted pixels. Therefore, in the case of the example shown in FIG. 8B, the center-of-gravity position Y _C (j, m) is a value represented by the following expression 101a.

Here, the position in the tube axis direction corresponding to the pixel is a value quantized by the movement width (for example, 0.5 mm) of the tubular body imaging device 100. On the other hand, the center-of-gravity position Y _C (j, m) calculated by the calculation shown in the above equation 101 is a value calculated by using a numerical calculation called division. The value can be smaller than the width (so-called quantization unit). Therefore, the displacement amount Δd _{j, m} calculated using the center-of-gravity position Y _C (j, m) is also a value that can have a value smaller than the movement width. The displacement amount Δd _{j, m} calculated in this way is also one of the light section line feature amounts.

  The light section line processing unit 221 calculates the above three types of feature amounts with respect to M elements included in each section line. As a result, as shown in FIGS. 9A to 9C, a two-dimensional array of M columns × N rows is generated with respect to the displacement Δd of the light section line, the luminance sum K, and the number of pixels p of the bright line. In the specific example of the striped image frame according to the present embodiment as shown in FIG. 7, since M = 1888 and N = 256, the number of data constituting each light section line feature amount is 1885 × 256. It becomes.

  The light section line processing unit 221 outputs the feature amount related to the displacement amount Δd of the light section line among the calculated light section line feature amounts to the depth image calculation unit 223 described later. In addition, the light section line processing unit 221 outputs, to the brightness image calculation unit 225, which will be described later, among the calculated light section line feature quantities, the brightness sum K and the feature quantity related to the number p of bright line pixels.

  The depth image calculation unit 223 is realized by, for example, a CPU, a ROM, a RAM, and the like. The depth image calculation unit 223 generates a depth image representing the uneven state of the inner surface of the tubular body based on the optical section line feature amount (particularly, the feature amount related to the displacement amount Δd) generated by the optical section line processing unit 221. calculate.

  Specifically, the depth image calculation unit 223 obtains the feature amount (two-dimensional array) related to the displacement amount Δd as shown in FIG. 9A and the vertical component incident angle (angle φ in FIG. 2A) of the annular beam. Using this, a depth image is calculated. The depth image is an image representing a two-dimensional uneven state distribution in which the one-dimensional distribution of the uneven state at each position in the tube axis direction is sequentially arranged along the tube axis direction.

  First, the relationship between the height of the unevenness present on the inner surface of the tubular body and the amount of displacement Δd of the light cutting line will be described with reference to FIG. FIG. 10 is an explanatory diagram showing the relationship between the displacement of the optical cutting line and the height of the defect.

  In FIG. 10, the case where the dent exists in the inner surface of the tubular body 1 is shown typically. Here, the difference between the height of the surface position and the height of the bottom of the dent when there is no dent on the inner surface is represented by Δh. Paying attention to the case where the vertically incident annular beam reflects the surface, if there is no dent on the inner surface, the reflected light propagates as shown by the light ray A in FIG. 10, but there is a dent on the inner surface. In this case, the reflected light propagates like the light beam B in FIG. The deviation between the light beam A and the light beam B is observed as the displacement Δd of the light cutting line in this embodiment. Here, as is apparent from the geometrical positional relationship, the relationship Δd = Δh · sinφ is established between the displacement Δd of the light cutting line and the depth Δh of the recess.

  In addition, in FIG. 10, although the case where a dent exists in the inner surface of a tubular body was demonstrated, even if it is a case where a convex part exists in the inner surface of a tubular body, the same relationship is materialized.

  The depth image calculation unit 223 uses the relationship as described above, and based on the feature amount related to the displacement Δd of the optical cutting line calculated by the optical cutting line processing unit 221, the amount related to the unevenness of the inner surface of the tubular body Δh is calculated.

  Here, the displacement amount Δd of the optical cutting line used for the calculation of the depth image is calculated based on the barycentric position of the optical cutting line as described above, and has a value smaller than the moving width. It is a possible value. Therefore, the depth image calculated by the depth image calculation unit 223 is an image in which unevenness is reproduced with a resolution finer than the pixel size of the image sensor.

The specific example of the striped image frame shown in the present embodiment is obtained by accumulating the displacements of the optical cutting lines imaged at an imaging pitch of 0.5 mm. Therefore, when each displacement amount Δd is converted to Δh, the width is 0. A depth image of 5 mm × 0.5 mm height is calculated. In this specific example, since the angle φ = 45 °, the relationship Δd = (1/2 ^0.5 ) · Δh is established.

  In addition, as shown in FIG. 11, distortion such as curvature occurs in the optical cutting line due to a change in the shape of the inner surface of the tubular body that is the object to be inspected and the camera scanning direction axis deviating from the center of the tubular body. There is a case. On the other hand, in the defect detection method according to the present embodiment, the unevenness superimposed on the light cutting line is information on the cross-sectional shape of the inner surface of the tubular body and the surface defect existing on the inner surface. Therefore, when the depth image calculation unit 223 calculates the depth image based on the displacement amount Δd of the light cutting line, the depth image calculation unit 223 performs distortion correction processing for each light cutting line, and the unevenness superimposed on the light cutting line. Only the information regarding may be extracted. By performing such a distortion correction process, even if the camera scanning direction axis does not exactly coincide with the central axis of the tubular body or the shape of the inner surface is not a circle, it exists on the inner surface. It is possible to obtain only the information on the uneven surface.

  As specific examples of such distortion correction processing, (i) a fitting process using a multidimensional function or various nonlinear functions, and a difference calculation between the obtained fitting curve and the observed light cutting line, ii) A process of applying a low-pass filter such as a floating filter or a median filter by using the fact that the information on the unevenness is a high-frequency component can be mentioned. By performing such a distortion correction process, it is possible to flatten the light section line while maintaining the information on the uneven surface existing on the inner surface.

  The depth image calculation unit 223 outputs information on the depth image calculated as described above to the rotation correction unit 227 described later.

  The luminance image calculation unit 225 is realized by a CPU, a ROM, a RAM, and the like, for example. The luminance image calculation unit 225 generates an annular beam on the inner surface of the tubular body based on the optical cutting line feature amount generated by the optical cutting line processing unit 221 (particularly, the feature amount relating to the luminance sum K and the number of pixels p of the bright line). A luminance image representing the luminance distribution is calculated.

Specifically, the luminance image calculation unit 225 performs the feature amount (two-dimensional array) regarding the luminance sum K as illustrated in FIG. 9B and the feature amount regarding the pixel number p of the bright line as illustrated in FIG. 9C ( The average luminance K _AVE (j, m) = K _{j, m} / p _{j, m} (1 ≦ j ≦ N, 1 ≦ m ≦), which is the average value of the total luminance in the line width direction. M) is calculated. Thereafter, the luminance image calculation unit 225 sets the data array including the calculated average luminance K _AVE (j, m) as the luminance image of the focused tubular body. Such a luminance image is an image representing a two-dimensional luminance distribution in which a one-dimensional distribution of the luminance of the annular laser beam at each position in the tube axis direction is sequentially arranged along the tube axis direction.

  The luminance image calculation unit 225 outputs information on the luminance image calculated as described above to the rotation correction unit 227 described later.

  Next, prior to describing the rotation correction unit 227 according to the present embodiment, the significance of the rotation correction process performed by the rotation correction unit 227 will be specifically described with reference to FIGS. 12 and 13. 12 and 13 are explanatory diagrams for explaining the influence of the rotation of the tubular body imaging device.

  When the camera and the annular laser are sent into the tubular body 1 and the irregularity inspection of the inner surface of the tubular body is performed by the so-called optical cutting method, the posture of the camera sent into the tubular body 1 changes (to the tubular body) In contrast, when the camera rotates in the tube circumferential direction), images that are continuously captured (that is, captured at different timings) are not captured at the same location in the tube circumferential direction. The continuity of the pattern and the oversight of the pattern may occur. Even when the tubular body imaging device 100 as shown in FIG. 2A is sent into the tubular body 1 to obtain a continuous image in the tube axis direction, the attitude of the tubular body imaging device 100 changes in the tube circumferential direction ( In the case of rotation), the continuity of wrinkles and patterns may be lost. In addition, when the tubular body imaging device 100 is manually or automatically sent, the above-described rotation may occur unintentionally. In particular, when the tubular body imaging device 100 is manually fed. May cause a significant uninspected area due to manual operation. Therefore, when performing a quantitative wrinkle inspection necessary for quality assurance and management over the entire circumference and the entire length of the inner surface of the tubular body 1, the attitude of the tubular body imaging device 100 is detected and the attitude is controlled. It becomes important.

  Now, as schematically shown in FIG. 12, a rectangular convex portion is linearly formed on a part of the inner surface of the tubular body 1 in the tube circumferential direction from the front end to the rear end in a straight line. It is assumed that it is distributed. First, the tubular body imaging device 100 (particularly, an imaging probe including the illumination mechanism 110 and the camera 120) can scan the inner surface of the tubular body 1 along the tube axis direction without rotating in the tube circumferential direction of the tubular body 1. Think about the case. In this case, since there is no rotation in the tube circumferential direction of the tubular body imaging device 100, the rectangular convex portion exists at the same position in each light cutting line, and a striped image as shown in the upper part of FIG. A frame will be obtained. As is apparent from the diagram shown in the upper part of FIG. 13, in such a case, the continuity of the tube-shaped position of the rectangular convex portion in the tube axis direction is maintained, and such a convex portion is predetermined. If it exists continuously for more than the detection judgment length, it will be detected as a defect.

  On the other hand, when the tubular body imaging device 100 (particularly, an imaging probe including the illumination mechanism 110 and the camera 120) rotates in the tube circumferential direction of the tubular body 1 (whether intentional or not), a rectangular protrusion The part exists at various positions in the tube circumferential direction of each light cutting line by rotation, and a fringe image frame as shown in the lower part of FIG. 13 is obtained. As is apparent from the diagram shown in the lower part of FIG. 13, in such a case, the positional deviation of the rectangular convex portion causes the continuity of the rectangular convex portion in the pipe circumferential direction to the tube axis direction. There is a case where a rectangular convex portion is not held as a defect and is not held.

  Therefore, the rotation correction unit 227 according to the present embodiment performs rotation correction processing as will be described in detail below, and ensures continuity of the tube circumferential direction position in the depth image and the luminance image with respect to the tube axis direction.

  The rotation correction unit 227 is realized by a CPU, a ROM, a RAM, and the like, for example. The rotation correction unit 227 performs the rotation direction measured by the rotation amount measuring device 130 and the depth image calculated by the depth image calculation unit 223 and the luminance image calculated by the luminance image calculation unit 225, and Using the size, the positional deviation accompanying the rotation in the pipe circumferential direction is corrected.

  More specifically, for each of the depth image and the luminance image, the rotation correcting unit 227 calculates the one-dimensional distribution of the uneven state and the one-dimensional distribution of the luminance at the respective positions in the tube axis direction in the corresponding tube axis direction. The positional deviation is corrected by translating the measured rotation amount in the opposite direction to the rotation direction measured at the position.

  Hereinafter, the rotation correction process will be described in detail with reference to FIGS. 14A to 16. 14A and 14B are explanatory diagrams showing an example of the rotation amount specifying process according to the present embodiment, and FIGS. 15 and 16 are explanatory diagrams for explaining the rotation correction process according to the present embodiment. .

  First, the rotation correction unit 227 specifies the direction and magnitude of rotation generated in the tubular body imaging device 100 using the measurement result from the rotation amount measurement device 130. At this time, the rotation correction unit 227 uses the angle of the tubular body imaging device 100 at the start of the inspection as a reference (that is, the rotation angle = 0 °), and specifies the relative rotation direction and magnitude from the reference.

With reference to FIG. 14A, a description will be given of a process for specifying the rotation amount when a device for measuring a rotation angle such as an accelerometer or a gyro sensor is provided as the rotation amount measurement device 130. Now, as shown in FIG. 14A, the A-axis positive direction is set to the vertical downward direction, the B-axis positive direction is set to the right in the horizontal direction, and after a certain time has elapsed from the start of the inspection, the tubular body imaging device 100 is rotated counterclockwise. It is assumed that the angle is rotated by θ degrees (rotated by −θ degrees). When the positive direction of the A-axis is directed downward in the vertical direction, the rotation amount measuring device 130 outputs a value of −G if the gravitational acceleration is expressed as G [m / s ² ]. Similarly, when the B-axis positive direction is directed downward in the vertical direction, the rotation amount measuring device 130 outputs a value of −G.

Now, if the output value of the A axis is expressed as g _A , the output value of the B axis is expressed as g _B , the inner diameter of the tubular body is φ [mm], and the imaging pixel resolution is α [mm / pixel], The rotation correction unit 227 can calculate the rotation angle θ from θ = Arcos (g _A / G) from cos θ = g _A / G. Further, the rotation correction unit 227 rotates the rotation direction clockwise when the output value of g _B is 0 or less, and reverses the rotation direction when the output value of g _B exceeds 0. It can be determined to be clockwise.

Here, if the movement amount on the inner surface of the tubular body (surface to be inspected) due to rotation is expressed as L _r [mm], L _r = 2πφ / {2 × (θ / 360)}. Therefore, the rotation correction unit 227 can calculate the correction amount in units of pixels by dividing the movement amount L _r due to rotation by the pixel resolution α. That is, the correction amount in pixel units = L _r / α.

Next, the rotation amount specifying process in the case where a device for measuring the amount of movement by rotation such as a rotary encoder is provided as the rotation amount measuring device 130 will be described with reference to FIG. 14B. In this case, the rotation correction unit 227 normalizes the movement amount of the tubular body imaging device 100 at the start of the inspection as 0 mm. Now, it is assumed that the position where the rotary encoder is installed (for example, the support bar itself or the support bar holding portion in which the same rotation as the illumination mechanism 110 and the camera 120 is generated) corresponds to the pipe outer diameter Φ [mm]. Assuming that the rotation amount L ₀ [mm] is output from the rotation amount measuring device 130 such as a rotary encoder, the rotation angle θ is calculated by θ = L ₀ / (πΦ). Accordingly, the inner diameter equivalent movement amount L _r due to the rotation is L _r = 2πφ / {2 × (θ / 360)}, where the inner diameter is φ [mm]. Therefore, the rotation correction unit 227 can calculate the correction amount in pixel units by dividing the inner diameter equivalent movement amount L _r due to rotation by the pixel resolution α. That is, the correction amount in pixel units = L _r / α.

  The rotation correction unit 227 calculates the magnitude of the correction amount in pixel units and the correction direction for each position in the tube axis direction in the depth image and the luminance image.

  When the inner surface of the tubular body 1 is scanned in the tube axis direction using the tubular body imaging device 100, even if the rotation in the tube circumferential direction is controlled by the drive control device 150, There is a possibility that slight rotation in the direction has occurred, and when scanning is performed without controlling the rotation in the tube circumferential direction, it is considered that rotation in the tube circumferential direction is always occurring. As a result, for example, the positions of the pixels corresponding to the rectangular protrusions as shown in FIG. 12 (the pixels indicated by hatching in FIG. 15) are arranged in the tube axis direction as schematically shown in FIG. Each may be different. Therefore, as schematically shown in FIG. 16, the rotation correction unit 227 uses the calculated correction amount in pixel units and the specified rotation direction to perform pixel tube at each position in the tube axis direction. The positional displacement is corrected by translating the circumferential array in the tube circumferential direction in units of pixels. For example, assuming that one pixel is rotated counterclockwise at a certain tube axis direction position, the rotation correction unit 227 corresponds to the corresponding tube axis direction position in the depth image and the luminance image. A group of pixels constituting a row to be translated is translated by one pixel in the tube circumferential direction corresponding to the clockwise direction. As a result, the positional deviation caused by the rotation in the pipe circumferential direction at the position in the pipe axis direction is corrected.

  Such rotation correction processing by the rotation correction unit 227 is preferably performed even when rotation in the tube circumferential direction is controlled by the drive control device 150. When the rotation in the pipe circumferential direction is controlled by the drive control device 150, it is considered that the generated positional deviation is a small value, but it is not always possible to completely eliminate the positional deviation. By further performing the correction process, the error due to the positional deviation is further corrected, and a more accurate inspection can be performed.

  The rotation correction unit 227 outputs the corrected depth image and luminance image to the detection processing unit 229 when the rotation correction processing as described above is performed on each of the depth image and the luminance image. The rotation correction unit 227 may store information regarding the corrected depth image and luminance image as history information in the storage unit 207 or the like in association with time information regarding the date and time when the information is corrected. Further, the rotation correction unit 227 may output information regarding the corrected depth image and luminance image to the display control unit 205 and output the information to the display unit (not shown).

Further, the rotation correction unit 227 outputs information on the rotation direction and magnitude calculated as described above to the imaging control unit 201, and the tubular body imaging device of the drive control device 150 by the imaging control unit 201. You may make it use for rotation control with respect to 100. FIG. The imaging control unit 201 uses the information regarding the rotation direction and magnitude output from the rotation correction unit 227 to support and drive the tubular body imaging device 100 and the diameter of the support bar in the drive control device 150 that is driven. The direction of rotation and the magnitude of the rotation are calculated. Assuming that the diameter of the support bar that controls the rotation is φ ″, with respect to the measured rotation angle θ, the magnitude of the rotation at the support bar that controls the rotation is L _s. L _s = 2πφ ″ / {2 × (θ / 360)}. The drive control device 150 is feedback-controlled in the opposite direction with respect to the calculated amount corresponding to the rotation size L _s at the support bar, so that the rotation size of the tubular body imaging device 100 is a predetermined value. The tubular body imaging device 100 can be moved while being controlled to be equal to or less than the threshold value.

  Further, the imaging control unit 201 warns that the tubular body imaging device 100 is rotating too much when the magnitude of the rotation output from the rotation correction unit 227 is equal to or greater than a predetermined reference threshold. (For example, warning information appealing to sight, hearing, touch, etc., such as warning sound, warning display, vibration, etc.) may be output. Thereby, the administrator of the tubular body surface inspection apparatus 10 or the user who manually uses the tubular body imaging apparatus 100 can grasp on the spot that the tubular body imaging apparatus 100 is rotating too much. It becomes possible.

Returning to FIG. 4 again, the detection processing unit 229 will be described.
The detection processing unit 229 is realized by, for example, a CPU, a ROM, a RAM, and the like. The detection processing unit 229 detects a defect present on the inner surface of the tubular body based on the depth image and the luminance image corrected by the rotation correction unit 227.

  The detection processing unit 229 extracts a defective part specifying function that specifies a defective part based on the depth image and the luminance image, a feature quantity extracting function that extracts a feature quantity relating to the form and pixel value of the specified defective part, and A defect discrimination function for discriminating the type of defect, the degree of harmfulness, and the like based on the feature amount. Hereinafter, these functions will be briefly described.

Defect site identification function The detection processing unit 229 obtains a linear sum of pixel values (values representing depths or luminance values) with peripheral pixels for each pixel of the acquired depth image and luminance image. Regions such as vertical line wrinkles, horizontal line wrinkles, and fine wrinkles are emphasized by the processing, and it is determined whether or not the obtained value is equal to or greater than a second threshold value for specifying a defect site. By performing such a filtering process and a determination process based on the filtering process result, the detection processing unit 229 can generate a binarized image for specifying a defective part. In such a binarized image, a pixel whose calculated value is less than the second threshold corresponds to a normal location (that is, pixel value of the binarized image = 0), and the calculated value is equal to or greater than the second threshold. The pixel in question corresponds to a defective portion (that is, the pixel value of the binarized image = 1). Furthermore, the detection processing unit 229 identifies each defective portion by combining consecutively generated defect portions.

Feature amount extraction function When the defect processing part 229 specifies a defect part in the depth image and the luminance image by the defect part specifying function, the feature processing unit 229 extracts a feature value regarding the form and pixel value of the defect part for each specified defect part. Examples of the feature quantity related to the form of the defective part include the width of the defective part, the length of the defective part, the peripheral length of the defective part, the area of the defective part, and the area of the circumscribed rectangle of the defective part. In addition, as the feature amount related to the pixel value of the defective part, for the depth image, the maximum value, the minimum value, the average value, etc. of the depth of the defective part can be mentioned. Value, minimum value, average value, and the like.

Defect determination function When the detection processing unit 229 extracts the feature amount of each defective portion by the feature amount extraction function, the detection processing unit 229 determines the type of defect, the degree of harm, and the like for each defective portion based on the extracted feature amount. The determination processing such as the type of defect and the degree of harmfulness based on the feature amount is performed using a logic table as shown in FIG. That is, the detection processing unit 229 determines the type of defect and the degree of harmfulness based on the determination condition represented by the logic table illustrated in FIG.

  As illustrated in FIG. 17, defect types (defects A1 to An) are described as vertical items in the logic table, and feature types (feature amounts B1) are displayed as horizontal items in the logic table. To feature quantity Bm). Also, in each cell of the table defined by the defect type and the feature amount, a discrimination conditional expression (conditional expression C11 to conditional expression Cnm) based on the size of the corresponding feature amount is described. Each row of such a logic table is a set, and becomes a determination condition for each type of defect. The determination process is performed in order from the type described in the top line, and ends when all the determination conditions described in any one line are satisfied.

  Such a logic table is obtained by a known method using a database constructed by a learning process in which past operation data and a result of specifying a defect type and a hazard level by an examiner based on the operation data are used as teacher data. It is possible to generate.

  The detection processing unit 229 specifies the type of defect and the degree of harm for each defective part detected in this way, and outputs the obtained detection result to the display control unit 205. Thereby, the information regarding the defect which exists in the inner surface of the tubular body which is a detection target will be output to a display part (not shown). In addition, the detection processing unit 229 may output the obtained detection result to an external device such as a manufacturing control process control computer or create a product defect form using the obtained detection result. Good. Further, the detection processing unit 229 may store the information related to the detection result of the defective part as history information in the storage unit 207 or the like in association with time information related to the date and time when the information is calculated.

  In the above description, the case where the type of the defect and the harmfulness are determined using the logic table has been described. However, the method for determining the type of the defect and the harmfulness is not limited to the above example. For example, a discriminator such as a neural network or a support vector machine (SVM) is generated by learning processing using past operation data and a result of specifying a defect type and a hazard level by a tester based on the operation data as teacher data, Such a discriminator may be used for discriminating the type of defect and the degree of harm.

  The configuration of the image processing unit 203 included in the arithmetic processing device 200 according to the present embodiment has been described above in detail.

  In the above description, when the depth image calculation unit 223 calculates the depth image, the case where the approximate correction process such as the difference calculation process or the low-pass filter process is performed has been described. However, the optical cutting line processing unit 221 may perform the approximate correction process before the optical cutting line processing unit 221 calculates the optical cutting line feature amount.

  Heretofore, an example of the function of the arithmetic processing apparatus 200 according to the present embodiment has been shown. Each component described above may be configured using a general-purpose member or circuit, or may be configured by hardware specialized for the function of each component. In addition, the CPU or the like may perform all functions of each component. Therefore, it is possible to appropriately change the configuration to be used according to the technical level at the time of carrying out the present embodiment.

  A computer program for realizing each function of the arithmetic processing apparatus according to the present embodiment as described above can be produced and installed in a personal computer or the like. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

  The configuration of the tubular body surface inspection apparatus 10 according to the present embodiment has been described in detail above. By utilizing the tubular body surface inspection apparatus 10 according to the present embodiment, it becomes possible to inspect the inner surface of the tubular body over the entire circumference in the tube circumferential direction and over the entire length in the tube axis direction. These defects can be simultaneously detected with high accuracy regardless of whether or not the tubular body imaging apparatus 100 is rotated. In addition, since the tubular body surface inspection apparatus 10 according to the present embodiment can accurately identify the position where the defect occurs, it greatly contributes to improvement of productivity and yield of tubular bodies such as steel pipes and quality assurance. can do.

<About the tubular body surface inspection method>
Next, the flow of the tubular body surface inspection method according to the present embodiment will be briefly described with reference to FIG. FIG. 18 is a flowchart showing an example of the flow of the tubular body surface inspection method according to the present embodiment.

  First, the tubular body imaging device 100 of the tubular body surface inspection apparatus 10 captures an inner surface of a tubular body that is a processing target using an annular beam, and outputs the captured image to the arithmetic processing device 200. In addition to the imaging processing, the rotation amount measuring device 130 measures the rotation generated in the tubular body imaging device 100 as needed and outputs the measured rotation to the arithmetic processing device 200. The A / D conversion unit 211 of the image processing unit 203 included in the arithmetic processing device 200 performs A / D conversion processing on the acquired captured image to generate an annular beam image (step S101).

  Next, the annular beam center calculation unit 213 calculates the center of gravity position and radius of the annular beam image using the annular beam image generated by the A / D conversion unit 211 (Step S103), and the obtained calculation result is The data is output to the coordinate conversion unit 215.

  Subsequently, the coordinate conversion unit 215 performs coordinate conversion of the annular beam image using the calculated center of gravity position, radius, and the like, and generates a light section image (step S105). The generated light section images are sequentially stored in an image memory provided in the storage unit 207 and the like along the tube axis direction of the tubular body.

  Thereafter, the fringe image frame generation unit 217 sequentially arranges the generated light section images along the tube axis direction of the tubular body to generate a fringe image frame (step S107). The striped image frame generation unit 217 outputs the generated striped image frame to the light section line processing unit 221.

  The light section line processing unit 221 uses the generated striped image frame, and for each light section line, the number of pixels having a luminance equal to or higher than a predetermined threshold Th, the sum of the brightness of the pixels, and the displacement of the light section line. The amount is calculated (step S109). These calculation results are used as the feature value of the light section line. The calculated light section line feature amount is output to the depth image calculation unit 223 and the luminance image calculation unit 225, respectively.

  The depth image calculation unit 223 calculates a depth image using the calculated light section line feature amount (particularly, a feature amount related to the displacement amount of the light section line) (step S111). In addition, the luminance image calculation unit 225 uses the calculated light section line feature amount (particularly, the feature amount related to the number of pixels having a luminance equal to or higher than the threshold and the feature amount related to the sum of luminance) to obtain a luminance image. Is calculated (step S111). The depth image calculation unit 223 and the luminance image generation unit 225 output the calculated images to the rotation correction unit 227.

  The rotation correction unit 227 corrects the depth image and the luminance image by the method described above based on the information about the direction and magnitude of the rotation output from the rotation amount measuring device 130 (step S113). Thereby, it is possible to correct the positional deviation caused by the rotation of the tubular body imaging device 100 in the tube circumferential direction. The rotation correction unit 227 outputs the corrected depth image and luminance image to the detection processing unit 229.

  Thereafter, the detection processing unit 229 detects a defect site existing on the inner surface of the tubular body using the corrected depth image and the luminance image, and specifies the type of defect and the harmfulness of the detected defect site. (Step S115). By the flow as described above, defects existing on the inner surface of the tubular body are detected.

  Next, an example of the flow of the rotation determination process using the information regarding the direction and magnitude of rotation output from the rotation amount measuring device 130 will be briefly described with reference to FIG. FIG. 19 is a flowchart illustrating an example of the flow of the rotation determination process using information on the direction and size of rotation.

  When the rotation correction unit 227 of the arithmetic processing device 200 acquires the measurement value output from the rotation amount measurement device 130 (step S121), the rotation direction and magnitude from the inspection start point are determined by the method described above. Specify (step S123). Thereafter, the rotation correction unit 227 outputs information regarding the specified rotation direction and magnitude to the imaging control unit 201 as needed.

  The imaging control unit 201 determines whether the specified magnitude of rotation is within a predetermined range (step S125). Here, when the specified magnitude of the rotation is within a predetermined range (for example, within a range that can be dealt with by the rotation correction processing by the rotation correction unit 227), the imaging control unit 201 is a tubular body. The angle of the imaging device 100 is determined to be appropriate (step S127), and the inner surface imaging process by the tubular body imaging device 100 is continued (step S129).

  On the other hand, when it is determined in step S125 that the specified rotation magnitude is outside the predetermined range, the imaging control unit 201 uses the specified rotation direction and magnitude to capture the tubular body. The angle of the apparatus 100 is controlled (step S131). Specifically, the imaging control unit 201 feedback-controls the drive control device 150 using the specified rotation direction and rotation magnitude, controls the angle of the tubular body imaging device 100, and rotates amount measurement device 130. Output the detection result. Thereafter, the imaging control unit 201 causes the rotation correction unit 227 to specify the direction and magnitude of the rotation again, and causes the imaging control unit 201 to output it.

  Subsequently, the imaging control unit 201 determines whether the re-specified rotation magnitude is within a predetermined range using the re-specified rotation magnitude (step S133). When the specified magnitude of the rotation is within a predetermined range (for example, within a range that can be dealt with by the rotation correction process by the rotation correction unit 227), the imaging control unit 201 may detect the tubular body imaging device 100. Is determined to be appropriate (step S127), and the imaging process of the inner surface by the tubular body imaging device 100 is continued (step S129). On the other hand, if it is determined in step S133 that the specified rotation magnitude is outside the predetermined range, the imaging control unit 201 outputs warning information and stops the imaging process (step S135). . Thereby, it becomes possible to carry out the inspection process while maintaining the detection accuracy of the inner surface of the tubular body 1.

  Heretofore, the tubular body surface inspection apparatus and the tubular body surface inspection method according to the first embodiment of the present invention have been described in detail.

(Second Embodiment)
The tubular body imaging device provided in the tubular body surface inspection device of interest in the embodiment of the present invention irradiates the inner surface of the tubular body with an annular laser beam while moving along the axial direction of the tubular body, A plurality of annular beam images are taken. For this purpose, in the tubular body imaging device, as described above, it is required to arrange the illumination mechanism and the imaging device such as a camera on the same axis. Here, when the inner diameter of the tubular body is relatively small, the laser light output does not have to be so high, and the resolution required for the imaging device does not have to be so high. By connecting each other using a transparent connecting member made of glass or the like, it is possible to perform imaging and inspection by the method described in the first embodiment.

  However, when the inner diameter of the tubular body is large, it is possible to increase the size of the laser light source and the imaging device in order to increase the output of the laser light and improve the resolution (that is, increase the number of pixels of the captured image). Desired. Further, in order to secure the imaging field of view, the separation distance between the imaging device and the laser light source is also increased, so that a more robust connecting member that connects the illumination mechanism and the imaging device is required. As a result, the connecting member such as a support becomes a material that is not transparent to the wavelength of the laser beam, such as various metals, and in some cases, the signal / power cable or the like blocks the annular laser beam irradiation, and the imaging field of view. Therefore, a dead zone is generated in the annular beam image. Therefore, even when a dead zone is generated in the annular beam image, a technique capable of detecting defects by inspecting the inner surface of the tubular body over the entire periphery is required.

  In the second embodiment of the present invention described below, a defect detection device capable of detecting a defect by inspecting the entire inner surface of the tubular body even when a dead zone is generated in the annular beam image, and The defect detection method will be described in detail.

<Overall structure of tubular body surface inspection device>
The overall configuration of the tubular body surface inspection apparatus 10 according to the present embodiment has the same configuration as the overall structure of the tubular body surface inspection apparatus 10 according to the first embodiment shown in FIG. The difference from the embodiment will be mainly described.

  The tubular body surface inspection device 10 according to the present embodiment is used when the tubular body imaging device 100 is fed into the tubular body and when the tubular body imaging device 100 is fed out of the tubular body. Whether the surface defect (uneven surface wrinkles and pattern type wrinkles) exists on the inner surface of the tubular body 1 by imaging the inner surface of the tubular body on both sides and processing the image obtained as a result of the imaging. It is a device to inspect.

  As described above, the tubular body imaging device 100 according to the present embodiment images the inner surface of the tubular body 1 when being fed into the tubular body, and also when being sent from the inside of the tubular body. The inner surface of 1 is imaged.

  Further, the drive control device 150 sends the tubular body imaging device 100 into the tubular body, and when the tubular body imaging device 100 finishes imaging the inner surface to be inspected, the feeding operation of the tubular body imaging device 100 is performed. To stop. Thereafter, the drive control device 150 rotates the tubular body imaging device 100 in the tube circumferential direction of the tubular body with the central axis of the tubular body imaging device 100 as a rotation axis. Thereafter, the drive control device 150 causes the tubular body imaging device 100 to be sent out from the inside of the tubular body. In the series of controls as described above, the drive control device 150 is configured so that the rotation in the tube circumferential direction generated in the moving tubular body imaging device 100 is equal to or less than a predetermined threshold angle, as in the first embodiment. Control to suppress rotation in the pipe circumferential direction is performed.

  In addition, the arithmetic processing device 200 generates a striped image frame using the captured image generated by the tubular body imaging device 100 and performs image processing on the striped image frame, whereby the inner surface of the tubular body 1 is obtained. This is a device for detecting a defect that may be present.

  At this time, the arithmetic processing device 200 according to the present embodiment is generated from the captured image captured at the time of transmission so as to eliminate the dead zone due to the connecting member that connects the illumination mechanism and the imaging device in the tubular body imaging device 100. Using the image, an image generated from the captured image captured at the time of sending is complemented. Thereby, even when there is a dead zone in the captured image captured at the time of sending or sending, the inner surface of the tubular body can be inspected over the entire periphery.

<About the structure of the tubular body imaging device 100>
The configuration of the tubular body imaging apparatus 100 according to the present embodiment is the same as that of the tubular body imaging apparatus 100 according to the first embodiment, except that the connecting member 143 is a material that is not transparent to laser light. Therefore, the following description will focus on the differences from the first embodiment.

  In the tubular body imaging device 100 according to the present embodiment, there is a high possibility that a dead zone exists in the captured image due to the connecting member 143 and the like. Therefore, the thickness of the connecting member 143 (for example, the tube diameter in the case of the cylindrical connecting member 143) is determined by the annular beam irradiation region (hereinafter also referred to as “beam irradiation region”). The field of view is set so as to be wider than the area shielded by the connecting member 143 (hereinafter also referred to as “shielding area”). Further, when a plurality of connecting members 143 are installed, it is preferable to determine the number so that the shielding area is as narrow as possible.

  The tubular body imaging device 100 according to the present embodiment moves the inner surface of the tubular body 1 at the time of feeding and sending while moving in the tube axis direction so as to substantially coincide with the central axis of the tubular body 1 by the drive control device 150. Scan both.

  Here, when the imaging of the surface of the tubular body at the time of feeding is completed, the drive control device 150 rotates the tubular body imaging device 100 in the tube circumferential direction according to the number of the connecting members 143. The magnitude of this rotation angle is such that the shielding area produced by the arrangement of the connecting member 143 is different at the time of feeding and at the time of sending when the reference line virtually set on the surface of the tubular body is taken as a reference. (In other words, the shielding area at the time of sending and the shielding area at the time of sending do not overlap). Specifically, when the number of connecting members 143 is one, the drive control device 150 rotates the tubular body imaging device 100 by, for example, 180 ° along the tube circumferential direction. Further, when two connecting members 143 are installed at equal intervals, the drive control device 150 rotates the tubular body imaging device 100 by 90 ° in the pipe circumferential direction, for example, and is installed at three equal intervals. In that case, it is rotated by 60 ° in the pipe circumferential direction, for example. As shown in FIG. 2C, when four connecting members 143 are installed at equal intervals, the drive control device 150 rotates the tubular body imaging device 100 by, for example, 45 ° in the tube circumferential direction.

<Configuration of Arithmetic Processing Device 200>
Similar to the arithmetic processing apparatus 200 according to the first embodiment illustrated in FIG. 1, the arithmetic processing apparatus 200 according to the present embodiment includes an imaging control unit 201, an image processing unit 203, a display control unit 205, and a storage. And 207 mainly.

  Here, the display control unit 205 and the storage unit 207 according to the present embodiment have the same configurations as the display control unit 205 and the storage unit 207 included in the arithmetic processing device 200 according to the first embodiment, and the same Since this produces an effect, a detailed description is omitted below.

  In addition, the imaging control unit 201 according to the present embodiment is the same as the first embodiment except that the drive control device 150 further transmits a control signal for causing the tubular body imaging device 100 to move and rotate. It has the same configuration as the imaging control unit 201 and has the same effect. Therefore, detailed description is omitted below.

  The image processing unit 203 is realized by, for example, a CPU, a ROM, a RAM, a communication device, and the like. The image processing unit 203 uses the imaging data acquired from the tubular body imaging apparatus 100 (more specifically, the camera 120 of the tubular body imaging apparatus 100) to generate a fringe image frame. Thereafter, image processing as described below is performed on the generated fringe image frame to detect defects that may exist on the inner surface of the tubular body that is the measurement object. When the image processing unit 203 finishes the defect detection process on the inner surface of the tubular body 1, the image processing unit 203 transmits information about the obtained detection result to the display control unit 205.

  Further, in the image captured by the tubular body imaging apparatus 100 according to the present embodiment, as described above, the shielding region caused by the connecting member 143 exists. Therefore, the image processing unit 203 according to the present embodiment complements the image generated from the striped image frame captured at the time of sending using the image generated from the striped image frame captured at the time of sending, and there is no shielding area. After generating an image, a defect present on the inner surface is detected.

  The image processing performed by the image processing unit 203 will be described in detail later.

<Regarding Image Processing Unit 203>
Next, the image processing unit 203 included in the arithmetic processing apparatus 200 according to the present embodiment will be described in detail with reference to FIG. FIG. 20 is a block diagram illustrating a configuration of an image processing unit included in the arithmetic processing apparatus according to the present embodiment.

  As shown in FIG. 20, the image processing unit 203 according to the present embodiment includes an A / D conversion unit 251, an annular beam center calculation unit 253, a coordinate conversion unit 255, a fringe image frame generation unit 257, and an image. A calculation unit 259 and a detection processing unit 273 are mainly provided.

  The A / D conversion unit 251 is realized by a CPU, a ROM, a RAM, and the like, for example. The A / D conversion unit 251 performs A / D conversion on the captured images output from the camera 120 at the time of sending and sending, and outputs them as digital multivalued image data (that is, an annular beam image). Such digital multivalued image data is stored in an image memory provided in the storage unit 207 or the like. By using these digital multi-valued image data sequentially along the tube axis direction of the tubular body, a stripe image frame as described later is formed.

  As described above, the annular beam image is obtained by imaging the annular beam irradiated on the inner surface of the tubular body at a certain position along the tube axis direction of the inner surface of the tubular body 1. The annular beam image is a grayscale image in which the portion irradiated with the annular beam is displayed in white and the other portions are displayed in black by appropriately setting the camera gain and the lens aperture in advance. Further, the unevenness superimposed on the circumference of the annular beam includes information on defects existing on the inner surface of the tubular body.

  Here, as schematically illustrated in FIG. 21, the annular beam image according to the present embodiment includes a beam irradiation region where the annular beam is irradiated on the inner surface, and a dead zone where the annular beam is shielded by the connecting member 143. There is a shielding area. Further, when switching from the sending state to the sending state, the tubular body imaging device 100 rotates by a predetermined angle in the tube circumferential direction of the tubular body (in FIG. 21, it rotates 45 degrees clockwise), so When attention is paid to a virtual reference point K having a surface, the position of the shielding region is different between the sending time and the sending time.

  When the A / D conversion unit 251 generates the annular beam images at the time of sending and sending as schematically shown in FIG. 21 based on the two types of captured images output from the camera 120, Data corresponding to the annular beam image is output to an annular beam center calculation unit 253 described later.

  The annular beam center calculation unit 253 is realized by, for example, a CPU, a ROM, a RAM, and the like. The annular beam center calculation unit 253 calculates the center of gravity of the ring and the radius of the ring for each of the annular beam images output from the A / D conversion unit 251 at the time of sending and at the time of sending.

  Here, the method of calculating the center of gravity position and the radius of the ring is not particularly limited, and any known method can be used. As specific examples of the method for calculating the center of gravity position and radius of the ring, for example, the two methods shown in the first embodiment can be cited, which can be used regardless of the presence or absence of a shielding region. is there.

  When the annular beam center calculation unit 253 calculates the center of gravity position and radius of the ring for each annular beam image at the time of sending and sending, the annular beam center calculation unit 253 generates information on the center of gravity position and radius of the ring, respectively, and a coordinate conversion unit 255 described later. Output to.

  The coordinate conversion unit 255 is realized by a CPU, a ROM, a RAM, and the like, for example. The coordinate conversion unit 255 converts the coordinate system of the annular beam image based on the calculated gravity center position and the separation distance between the gravity center position and the irradiated portion of the annular beam. Thereafter, the coordinate conversion unit 255 generates a light section image that represents the irradiated portion of the annular beam as a line segment developed in the tube circumferential direction of the tubular body.

  Here, the coordinate conversion unit 255 according to the present embodiment performs the conversion process with reference to the reference point K virtually set on the surface of the tubular body when performing the conversion of the coordinate system. The reference point K is conveniently set to a position corresponding to the angle of the tubular body imaging device 100 at the start of feeding, measured by the rotation amount measuring device 130. The reference point K is selected so as to be the same position between the annular beam images captured at each position in the tube axis direction.

  When the coordinates of the reference point K on the annular beam image at the start of feeding are specified, the position of the reference point K in the annular beam image at the time of sending is set to the coordinates of the reference point K at the time of feeding. It can be specified by rotating the angle. That is, when the angle difference between the rotation angle value obtained from the rotation amount measuring device 130 at the start of delivery and the rotation angle at the start of delivery is + X degrees when the clockwise direction is the positive direction. By rotating the position of the reference point K at the time of sending by −X degrees, the position of the reference point K at the time of sending can be specified.

  FIG. 22 schematically illustrates an annular beam image captured by the tubular body imaging apparatus 100 at the time of sending and sending. In the case of the example shown in FIG. 21, the tubular body imaging device 100 generates an annular beam image at the time of transmission after being rotated 45 degrees clockwise. Here, since the illumination mechanism 110 and the camera 120 of the tubular body imaging apparatus 100 are integrally formed, the camera 120 also rotates in accordance with the rotation of the tubular body imaging apparatus 100. Therefore, in the annular beam image shown in FIG. 22, the reference point K rotates 45 degrees counterclockwise.

  The coordinate conversion unit 255 performs a coordinate conversion process based on the reference point K (that is, a position corresponding to the rotation angle at the start of feeding = 0 °) or an image interpolation process as described in the first embodiment. When the processing is completed, the image data corresponding to the obtained light section image is sequentially stored in the image memory provided in the storage unit 207 and the like along the tube axis direction of the tubular body.

  The stripe image frame generation unit 257 is realized by, for example, a CPU, a ROM, a RAM, and the like. The fringe image frame generation unit 257 sequentially acquires the light section images stored along the tube axis direction of the tubular body from the image memory provided in the storage unit 207 or the like. Thereafter, the fringe image frame generation unit 257 sequentially arranges the obtained light section images along the tube axis direction of the tubular body, and generates a fringe image frame at the time of sending and a fringe image frame at the time of sending, respectively.

  The number of light section images constituting one striped image frame may be set as appropriate. For example, one striped image frame may be composed of 256 light section images. Each light section image exists at every imaging interval (for example, 0.5 mm interval) of the annular beam image as described above. Therefore, one striped image frame composed of 256 light section images based on an annular beam image captured at intervals of 0.5 mm is 128 mm (=) along the tube axis direction along the entire inner surface of the tubular body. This corresponds to the result of imaging in a range of 256 × 0.5 mm.

  FIG. 23 is an explanatory diagram schematically showing the in-strip stripe image frame generated in this way, and FIG. 24 schematically shows the in-strip stripe image frame generated in this way. It is explanatory drawing shown.

  The striped image frames generated by the striped image frame generation unit 257 at the time of sending and at the time of sending depend on the number of connecting members 143 provided in the tubular body imaging device 100 as shown in FIGS. Thus, there is a shielding area. Also, the origin of the fringe image frame in the tube circumferential direction is coordinate-converted by using the common reference point K (that is, the position corresponding to the rotation angle at the start of feeding = 0 degree) by the coordinate conversion unit 255 as a starting point. Therefore, the reference points are equal to each other.

  When the fringe image frame generation unit 257 generates a fringe image frame at the time of sending and a fringe image frame at the time of sending, the fringe image frame is output to the image calculation unit 259 described later. Further, the fringe image frame generation unit 257 associates time information related to the date and time when the fringe image frame is generated with the data corresponding to each of the generated fringe image frames, and stores the data in the storage unit 207 or the like as history information. Good.

  The image calculation unit 259 is realized by, for example, a CPU, a ROM, a RAM, and the like. The image calculation unit 259 includes a depth image representing the uneven state of the inner surface of the tubular body, the tubular body based on the two types of striped image frames generated by the striped image frame generation unit 257 at the time of sending and sending. And a luminance image representing the distribution of the luminance of the annular beam on the inner surface. As shown in FIG. 20, the image calculation unit 259 includes a light section line processing unit 261, a depth image calculation unit 263, a luminance image calculation unit 265, a rotation correction unit 267, and a depth image complementing unit 269. And a luminance image complementing unit 271.

  The light section line processing unit 261 is realized by, for example, a CPU, a ROM, a RAM, and the like. The light cutting line processing unit 261 has three types of light cutting line feature values regarding the amount of displacement of the light cutting line (bending degree of the bright line), the number of pixels of the bright line, and the sum of the luminance for each light cutting line included in the stripe image frame. Is calculated.

  Since the calculation method of these three types of light section line feature values is the same as the calculation method performed by the light section line processing unit 221 according to the first embodiment, detailed description thereof is omitted.

  The light section line processing unit 261 according to the present embodiment performs a process of specifying the position of the shielding region in addition to the above three types of light section line feature values. Hereinafter, the process of specifying the position of the shielding area will be described in detail.

Since the annular laser beam is not imaged by the camera 120 in the shielding region by the connecting member 143, there is no bright line having a luminance higher than the predetermined threshold Th as schematically shown in FIG. Accordingly, in the process of calculating the light section line feature amount, the light section line feature amount p _{j, m} for the number of pixels of the bright line is zero in the shielding region.

Therefore, the light section line processing unit 261 according to the present embodiment pays attention to the number of pixels of the bright line in each tube circumferential direction (X direction) position, and calculates the tube circumferential direction coordinate (X coordinate) indicating the range of the shielding region. Identify. In the following, description will be given by taking as an example the case of calculating the start position X _s1s and the end position X _s1e of the shielding area present first from the left in the striped image frame image.

The optical cutting line processing unit 261, for each of the N optical cutting lines constituting the annular beam image at the time of transmission, the X coordinate position X _{s1js at} which the shielding area starts and the X coordinate position at which the shielding area ends. X _s1je (j = 1 to N) is specified. In addition, in consideration of the case where the start position and the end position of the shielding area are shifted due to the influence of the vibration generated in the tubular body imaging device 100, among the identified N shielding area start positions X _{s1js Is} set to X _s1s, and the maximum value of the shielding region end position X _s1je is set to X _s1e .

Further, the start position X _s1js and the end position X _s1je of the first shielding area from the left in the j-th line can be specified as follows. Hereinafter, a method for specifying the start position X _s1js and the end position X _s1je of the shielding area will be specifically described with reference to FIG.

The light cutting line processing unit 261 pays attention to the pixel number p _{j, m} (m = 1 to M) of the bright line in each X coordinate of the jth light cutting line. Then, the light section line processing unit 261 determines whether or not an X position where p _{j, m} = 0 appears for the number of bright line pixels p _{j, m at} each X position. When there is an X position where p _{j, m} = 0, the optical cutting line processing unit 261 stores the coordinate X _m and continues the state in which p _{j, m} = 0 for the subsequent X coordinates. Count the number. Here, as schematically shown in FIG. 26, when the number of consecutive states in which p _{j, m} = 0 is equal to or greater than a predetermined threshold TH _s (for example, TH _s = 10), light cutting is performed. line processing unit 261, the X coordinate _{X m} which had been stored is specified as the start position _{X S1js} of the first shielding area from the left in the j-th line.

Also, in the state where the start position X _s1js of the shielding area is specified, it is assumed that an X coordinate X _n where p _{j, m} ≠ 0 appears while searching for the number of bright line pixels in the X direction. . In this case, the light section line processing unit 261 stores the coordinates _Xn and counts the number of consecutive states where p _{j, m} ≠ 0 for the subsequent X coordinates. Here, as schematically shown in FIG. 26, when the number of consecutive states in which p _{j, m} ≠ 0 is equal to or greater than a predetermined threshold value TH _s (for example, TH _s = 10), the optical cutting is performed. The line processing unit 261 specifies the X position _immediately before the stored X coordinate X _n as the end position X _s1je of the first shielding region from the left in the j-th line. Here, the threshold value TH _s is an example of the third threshold value for determining the continuous number and the fourth threshold value for determining the continuous number, and the third threshold value and the fourth threshold value are the same value. This is the case. In the above description has shown the case with the threshold value TH _s used to identify the start position of the shielding region, and the threshold value TH _s used to identify an end position of the shielding region is the same value The two threshold values may be different from each other.

Further, another method for determining the start position X _s1s and the end position X _s1e of the shielding area may be as follows.
For each X coordinate of the light cutting line of the j-th line, while moving the coordinate position, predetermined left and right k pixels (for example, k = 3 etc.) of the number of bright line pixels p _{j, m} (m = 1 to M). Average values q _{j, m} (m = 1 to M) are sequentially obtained (moving average processing). Next, an X coordinate position at which the obtained average value q _{j, m} is less than a preset threshold A (for example, A = 0.5) is set as a start position X _s1s of the shielding area. In addition, an X _coordinate position where the start position X _s1s of the shielding area is specified and the obtained average value q _{j, m} is equal to or greater than a preset threshold A is defined as an end position X _s1e of the shielding area. The threshold A is an example of a fifth threshold for moving average determination.

By performing the above processing for each optical cutting line with j = 1 to N, the optical cutting line processing unit 261 determines the start position X _s1s and the end position X _s1e of the first shielding region from the left. Can be determined. Further, the same processing is performed on the second and subsequent shielding areas from the left, whereby the start position and end position of the shielding area can be determined.

The light section line processing unit 261 uses the light section line feature amount Δd _{j, m} for the amount of displacement of the light section line in the shielding region and the light section line feature amount K _{j, m} for the sum of luminance in the shielding region. Are each treated as zero.

Therefore, for example, for the first shielding region from the left _, a two-dimensional array of bright line pixels p _{j, m,} a two-dimensional array of bright line luminance sums K _{j, m} , and a bright line displacement amount Δd _{j, m} The two-dimensional arrays are as follows.

p _{j, m} = 0 (j = 1 to N, m = X _s1s ,..., X _s1e )
K _{j, m} = 0 (j = 1 to N, m = X _s1s ,..., X _s1e )
Δd _{j, m} = 0 (j = 1 to N, m = X _s1s ,..., X _s1e )

  For example, the optical section line processing unit 261 performs the above-described processing on the fringe image frame corresponding to the annular beam image at the time of feeding in which the four connecting members 143 are reflected as shown in FIG. By implementing, as shown in FIG. 23, the start position and the end position of each of the four shielding areas can be specified.

In addition, the light section line processing unit 261 calculates the light section line feature amount for the striped image frame at the time of transmission illustrated in FIG. 24 as in the first embodiment. However, for the striped image frame at the time of transmission, the start position and end position of the shielding area need not be specified. Here, when an X position where the number of bright line pixels p _{j, m} = 0 appears in the striped image frame at the time of transmission, the light cutting line processing unit 261 causes the luminance sum K K _{, m} , and The displacement amount Δd _{j, m} of the bright line is treated as zero.

  The light section line processing unit 261 outputs the feature amount related to the displacement amount Δd of the light section line among the calculated light section line feature amounts to the depth image calculation unit 263 described later. In addition, the light section line processing unit 261 outputs, to the brightness image calculation unit 265, which will be described later, among the calculated light section line feature quantities, the brightness sum K and the feature quantity regarding the number of pixels p of the bright line.

Furthermore, the light section line processing unit 261 includes information indicating the start position and end position of each shielding region present in the striped image frame at the time of sending (for example, information indicating X _{s1s to} X _s4e in FIG. 23). It outputs to the rotation correction part 267 mentioned later.

  The depth image calculation unit 263 is realized by, for example, a CPU, a ROM, a RAM, and the like. The depth image calculation unit 263 determines whether the inside of the tubular body at the time of feeding and at the time of sending based on the optical cutting line feature amount (particularly, the feature amount related to the displacement amount Δd) generated by the optical cutting line processing unit 261. A depth image representing the uneven state of the surface is calculated. Hereinafter, the depth image at the time of sending is also referred to as a depth image at the time of sending, and the depth image at the time of sending is also referred to as a depth image at the time of sending.

  Here, the depth image calculation unit 263 calculates the in-feed depth image and the send-out depth image in the depth image calculation method performed by the depth image calculation unit 223 according to the first embodiment. Therefore, detailed description will be omitted below.

  When the depth image calculation unit 263 calculates the sending depth image and the sending depth image, the depth image calculation unit 263 outputs information about the calculated images to the rotation correction unit 267 described later.

  The luminance image calculation unit 265 is realized by a CPU, a ROM, a RAM, and the like, for example. The luminance image calculation unit 265 is based on the light cutting line feature amount generated by the light cutting line processing unit 261 (particularly, the feature amount relating to the luminance sum K and the number of pixels p of the bright line). A luminance image representing the luminance distribution of the annular beam on the inner surface of the tubular body is calculated. Hereinafter, the luminance image at the time of sending is also referred to as a luminance image at the time of sending, and the luminance image at the sending time is also referred to as a luminance image at the time of sending.

  Here, the method by which the luminance image calculation unit 265 calculates the in-transmission luminance image and the transmission luminance image is the same as the luminance image calculation method performed by the luminance image calculation unit 225 according to the first embodiment. Detailed description will be omitted below.

  When the luminance image calculation unit 265 calculates the transmission luminance image and the transmission luminance image, the luminance image calculation unit 265 outputs information about the calculated images to the rotation correction unit 267 described later.

  Here, in the tubular body imaging device 100 according to the present embodiment, when the imaging process is being performed and the rotation along the tube circumferential direction of the tubular body 1 has not occurred, FIG. It is possible to complement a portion corresponding to the shielding region generated by the connecting member 143 and the like by performing a complementing process as described with reference to FIG. In the following, first, the outline of the complementing process will be briefly described with reference to FIG.

  In the depth image at the time of sending and the depth image at the time of sending calculated by the depth image calculating unit 263, the portion corresponding to the shielding region by the connecting member 143 is a portion where there is no change in the pixel value. Therefore, it is impossible to obtain accurate knowledge about the uneven state of the inner surface of the tubular body. Therefore, processing for complementing the depth information of the shielding area is performed using these two types of depth images.

  Hereinafter, with reference to FIG. 23, FIG. 24, and FIG. 27, the supplement processing for the portion corresponding to the shielding region that exists first from the left in the depth image will be specifically described.

  In the tubular body imaging apparatus 100 according to the present embodiment, the entire tubular body imaging apparatus 100 is predetermined when switching from the state of capturing an annular beam image at the time of sending to the state of capturing the annular beam image at the time of sending. Rotate by an angle. Further, in the tubular body imaging device 100, as described above, the thickness and the arrangement position of the connecting member 143 are determined so that the beam irradiation region is wider than the shielding region.

  Because of the above settings, in the tubular body surface inspection apparatus 10 according to the present embodiment, as shown in the striped image frames of FIGS. The position of will change. As apparent from FIGS. 23 and 24, since the beam irradiation region is wider than the shielding region, the shielding region in one striped image frame (for example, the striped image frame at the time of sending) is the other striped image frame ( For example, it is included in a non-shielding area in a striped image frame at the time of transmission.

  Therefore, for example, as shown in FIG. 27, the depth image at the time of sending is used to complement the shielding area of the depth image at the time of sending to generate a depth image that does not have a portion corresponding to the shielding area. It becomes possible to do.

In FIG. 27, the process for complementing the shielding area present first from the left is schematically illustrated.
The start position X _s1s and the end position X _s1e of the shielding area in the image at the time of sending are specified by the light section line processing unit 261. Therefore, the depth information of the part (X _{s1s to} X _s1e ) corresponding to the shielding area of the in-feed depth image is acquired with reference to the sending-out depth image, and the depth information in the sending-in depth image is obtained. The acquired depth information is substituted into the corresponding part.

  Here, as is apparent from the operation of the tubular body imaging apparatus 100, the Nth light cutting line in the striped image frame at the time of sending is the same as the first light cutting line in the striped image frame at the time of sending. It corresponds to the position of the tube axis direction. Therefore, when the depth information corresponding to the first line of the depth image at the time of sending is complemented, a complementing process is performed using the depth image corresponding to the Nth line of the depth image at the time of sending. The Similarly, when the depth information corresponding to the j-th line of the sending depth image is complemented, the depth information corresponding to the (N + 1−j) -th line of the sending depth image is complemented. Processing is performed.

  By performing such a complementing process on the part corresponding to the 1st to Nth lines, the depth information of the shielding area existing first from the left in the in-feed depth image is complemented. Can do. In addition, by applying the same complement processing to the portion corresponding to the second and subsequent occluded regions from the left, the depth information of the portions corresponding to all the occluded regions existing in the in-feed depth image Can be complemented.

  Further, the same complement processing is performed for the in-transmission luminance image and the in-transmission luminance image, so that the depth information of the portions corresponding to all the shielding areas existing in the in-transmission luminance image can be supplemented. it can.

  However, when the tubular body imaging device 100 as noted in the present invention is rotated along the tube axis direction, rotation in the tube circumferential direction of the tubular body is performed in the complementing process. However, it is important to correct the rotation.

  Therefore, prior to describing the rotation correction unit 267 according to the present embodiment, the significance of the rotation correction processing performed by the rotation correction unit 267 will be specifically described with reference to FIGS. 28 to 33.

  When the tubular body imaging device 100 as shown in FIG. 2A is sent into the tubular body 1 to acquire continuous images in the tube axis direction, the attitude of the tubular body imaging device 100 changes (rotates) in the tube circumferential direction. ), There is a possibility that the continuity of the wrinkles and the pattern may be lost, and the continuity of the wrinkles may be lost due to the sequential change of the shielding areas by the connecting member 143, or imaging of the wrinkles itself may be impossible. Sometimes it becomes possible.

  In addition, since there is a shielding area, even if the position of the shielding area is changed by rotating the tubular body imaging device 100 between the above-described sending and sending, the sending time is the same as the sending time. Are likely to have different rotational behaviors, it is highly possible that the shielded area at the time of delivery cannot be matched with the unshielded area at the time of delivery. Excluding only the shielding area from the image obtained by changing the direction of the tubular body imaging device 100 by rotation at the time of sending and sending is not preferable because it also eliminates a necessary inspection part.

  In the case where the tubular body imaging apparatus 100 is manually or automatically sent / sent out, the above-described rotation during scanning may occur unintentionally. In particular, the tubular body imaging apparatus 100 is manually sent. When entering / sending out, there is a possibility that a significant uninspected area may be generated due to manual operation. Therefore, when performing a quantitative wrinkle inspection necessary for quality assurance and management over the entire circumference and the entire length of the inner surface of the tubular body 1, the attitude of the tubular body imaging device 100 is detected and the attitude is controlled. It becomes important.

  Now, as schematically shown in FIG. 28, a rectangular convex portion and a triangular convex portion are separated from each other at an interval of 45 degrees on a portion of the inner surface of the tubular body 1 in the tube circumferential direction. Thus, it is assumed that the pipe is uniformly distributed from the front end to the rear end in the tube axis direction.

  First, the tubular body imaging device 100 (particularly, an imaging probe including the illumination mechanism 110 and the camera 120) can scan the inner surface of the tubular body 1 along the tube axis direction without rotating in the tube circumferential direction of the tubular body 1. Think about the case.

  In this case, as shown in the upper part of FIG. 29, at the time of feeding, the rectangular convex portion is hidden by the connecting member 143b, and only the triangular convex portion is imaged. Moreover, since the tubular body imaging device 100 is rotated 45 degrees in the tube circumferential direction of the tubular body when the imaging at the time of feeding is completed, the triangular convex portion is hidden by the connecting member 143b at the time of delivery. On the other hand, only a rectangular convex part is imaged. As a result, a fringe image frame as schematically shown in FIG. 30 is generated.

  In this case, since there is no rotation in the tube circumferential direction of the tubular body imaging device 100, the triangular convex portion imaged at the time of feeding is present at the same position in each light cutting line as shown in the upper part of FIG. As a result, a fringe image frame as shown in the upper part of FIG. 30 is obtained. Similarly, since there is no rotation in the tube circumferential direction of the tubular body imaging device 100, the rectangular convex portion imaged at the time of delivery also exists at the same position in each light cutting line as shown in the lower part of FIG. As a result, a fringe image frame as shown in the lower part of FIG. 30 is obtained.

  As is clear from the diagram shown in FIG. 30, in such a case, the continuity of the triangular circumferential portion and the rectangular convex portion with respect to the tube axis direction of the tube circumferential direction position is maintained. If a convex portion is continuously present longer than a predetermined detection determination length, it is detected as a defect.

  Next, with reference to FIGS. 31 to 33, consider a case where the posture of the tubular body imaging device 100 changes sequentially both at the time of sending and at the time of sending. In the following, a case will be described in which the tubular body imaging apparatus 100 changes its posture into three types at the time of feeding / sending into the tubular body 1.

  It is assumed that the tubular body imaging device 100 rotates in the tube circumferential direction because natural rotation occurs when moving inside the tubular body 1. For this reason, while the tubular body imaging device 100 moves inside the tubular body 1, the positions of the two types of convex portions in the captured image change.

  FIG. 31 schematically shows changes in captured images at the time of sending. At the start of feeding as shown in the upper diagram of FIG. 31, the triangular convex portion exists below the captured image in the vertical direction, and the rectangular convex portion is shielded by the connecting member 143. Yes. Thereafter, as the tubular body imaging apparatus 100 moves inside the tubular body 1, it is assumed that rotation of 45 degrees in the clockwise direction occurs. As a result, as shown in the middle diagram of FIG. 31, the triangular convex portion is shielded by the connecting member 143, and the rectangular convex portion that is shielded by the connecting member 143 at the start of feeding is not Appears in the occluded area. Thereafter, if the tubular body imaging device 100 is further rotated 45 degrees in the clockwise direction, the shielded triangular convex portion appears again in the non-shielding region as shown in the lower part of FIG. The convex portion having the shape is again shielded by the connecting member 143.

  When the scanning at the time of sending is completed, the tubular body imaging device 100 is rotated clockwise by 45 degrees, and the scanning at the time of sending is started. FIG. 32 schematically shows changes in captured images at the time of transmission. At the start of sending as shown in the upper diagram of FIG. 32, the rectangular convex portion is present vertically above the captured image, and the triangular convex portion is shielded by the connecting member 143. . Thereafter, as the tubular body imaging apparatus 100 moves inside the tubular body 1, it is assumed that rotation of 45 degrees in the clockwise direction occurs. As a result, as shown in the middle diagram of FIG. 32, the rectangular convex portion is shielded by the connecting member 143, and the triangular convex portion that was shielded by the connecting member 143 at the start of delivery is not shielded. Appears in the area. Thereafter, if the tubular body imaging device 100 is further rotated 45 degrees clockwise, as shown in the lower diagram of FIG. 32, the shielded rectangular convex portion appears again in the non-shielding region, and the triangle The convex portion is again shielded by the connecting member 143.

  An example of a fringe image frame generated in the state schematically shown in FIGS. 31 and 32 is shown in FIG. In FIG. 33, the position in the pipe circumferential direction where the triangular convex portion is present in FIG. As is apparent from FIG. 33, if there is a shielding area in the image to be captured and an unintended natural rotation occurs in the tubular body imaging apparatus 100, the convex tube existing on the inner surface of the tubular body 1. Not only does the continuity of the circumferential position with respect to the tube axis direction disappear, but part of the convex portions are buried in the shielding region, or the buried convex portions appear again.

  Even if the depth image and the luminance image are generated from the striped image frame in such a state, and the complementary processing as described above is performed, the rotation of the tubular body imaging device 100 when switching from the sending time to the sending time is performed. In addition, due to unintended discontinuous rotation at the time of sending and sending, not only the continuity of the original pipe circumferential direction position to the pipe axis direction is lost, but also the lack of length information at the approach to the shielding area or The non-photographing of the convex portion also occurs. In addition, since the continuity of the tube circumferential direction position with respect to the tube axis direction has disappeared, the length of the convex portion existing in the image may be less than the detection determination length. There may be cases where parts are missed.

  Accordingly, the rotation correction unit 267 according to the present embodiment performs the rotation correction process as described in the first embodiment, and the position in the tube circumferential direction in the depth image and the luminance image at the time of sending and sending. Ensures continuity in the tube axis direction.

  The rotation correction unit 267 is realized by a CPU, a ROM, a RAM, and the like, for example. The rotation correction unit 267 performs the depth image at the time of sending and sending calculated by the depth image calculating unit 263 and the luminance image at the time of sending and sending calculated by the luminance image calculating unit 265. Using the rotation direction and magnitude measured by the rotation amount measuring device 130, the positional deviation accompanying the rotation in the pipe circumferential direction is corrected.

  In addition, by performing the rotation correction process as described in the first embodiment, the position of the shielding area also changes from that before the correction. Therefore, the rotation correction unit 267 not only includes each depth image and each luminance image, but also information indicating the start position and the end position of each shielding region in each image specified by the light section line processing unit 261. Correct in the same way.

  Note that, in a situation where there is a shielding area in the captured image as noted in the present embodiment, the position of the shielding area changes within the field of view due to rotation during scanning. Therefore, in order to perform the complementary processing as described above, it is important that the shielding regions do not interfere with each other with the rotation.

  FIG. 34 shows a connecting member 143 at the start of feeding (the connecting member 143 at the position shown in black in FIG. 34) and a connecting member 143 at the start of sending (when the position of the tubular body is fixed). FIG. 34 schematically shows the positional relationship with the connecting member 143) in the position shown in white. In FIG. 34, when the angle difference between the position of the connecting member 143 at the start of feeding and the position of the connecting member 143 at the start of sending is ω, the shielding regions do not interfere with each other with rotation. It is important to satisfy β ≦ ω / 2, where β is the magnitude of rotation that occurs during scanning.

  If the amount of rotation β that occurs during scanning exceeds ω / 2, there will be a region of the inner surface that is not imaged both at the time of sending and at the time of sending, and the complementary processing as described above Even if it implements, it cannot test | inspect all the inner surfaces of a tubular body.

  FIG. 35 schematically shows a depth image and a luminance image generated at the time of sending, and FIG. 36 schematically shows a depth image and a luminance image generated at the time of sending. When the magnitude β of rotation that occurs during scanning satisfies the relationship β ≦ ω / 2, the shielding region in one depth image / luminance image (for example, the depth image / luminance image at the time of sending) is The other depth image / luminance image (for example, the depth image / luminance image at the time of transmission) is included in the non-shielding region.

  The rotation correction unit 267 performs a rotation correction process as described in the first embodiment on these images, thereby correcting the in-feed depth image and the transmission image as shown in FIG. The incoming luminance image and the corrected incoming depth image and outgoing luminance image as shown in FIG. 38 are generated.

  Here, a rotation correction method for depth images and luminance images at the time of sending and sending, and a rotation correction method for information indicating the start position and end position of each shielding area will be described in the first embodiment. Since this is the same as the rotation correction method described above, detailed description is omitted.

  When the rotation correction process as described above is completed, the rotation correction unit 267 performs the corrected in-feed depth image, the corrected in-feed depth image, and the corrected start position and end position of each shielding region. Is output to the depth image complementing unit 269. In addition, the rotation correction unit 267 performs luminance image complementation on the corrected in-transmission luminance image, the corrected in-transmission luminance image, and information indicating the corrected start position and end position of each shielding area. Output to the unit 271.

  Note that the rotation correction unit 267 outputs information on the rotation direction and magnitude calculated by the same method as in the first embodiment to the imaging control unit 201, and the drive control device 150 by the imaging control unit 201. It is important to provide rotation control for the tubular body imaging device 100. The imaging control unit 201 uses the information regarding the rotation direction and magnitude output from the rotation correction unit 267 to feedback-control the drive control device 150 in the same manner as in the first embodiment, so that the tubular body imaging device The tubular body imaging apparatus 100 can be moved while controlling the rotation magnitude θ of 100 to satisfy the relationship θ ≦ ω / 2.

  Further, the imaging control unit 201 warns that the tubular body imaging device 100 is rotating too much (for example, when the magnitude of the rotation output from the rotation correction unit 267 exceeds ω / 2) (for example, Warning information appealing to sight, hearing, touch, etc., such as warning sound, warning display, vibration, etc. may be output. Thereby, the administrator of the tubular body surface inspection apparatus 10 can grasp on the spot that the tubular body imaging apparatus 100 is rotating too much.

  The depth image complementing unit 269 is realized by, for example, a CPU, a ROM, a RAM, and the like. The depth image complementing unit 269 performs the complementing process of the portion corresponding to the shielding area in the depth image using the depth image at the time of sending and the depth image at the time of sending corrected by the rotation correcting unit 267. Here, the complementing process performed by the depth image complementing unit 269 is described with reference to FIG. 27 except that the in-feed depth image and the sending-out depth image corrected by the rotation correcting unit 267 are used. The detailed description is omitted because it is the same as the above complement processing.

  Note that the depth image and the luminance image generated in the present embodiment are standardized with the attitude of the tubular body imaging device 100 at the start of feeding as the rotation angle of 0 degrees, and thus the start of each corrected shielding area By using the information indicating the position and the end position, it is possible to easily associate the positional relationship between the shielding area in the image at the time of sending and the non-shielding area in the image at the time of sending. Therefore, the complementing process described with reference to FIG. 27 can be similarly performed.

  When the depth image complementing unit 269 complements the depth information of the portion corresponding to the shielding region by the complementing process described above, the depth image complementing unit 269 outputs information regarding the complemented depth image to the detection processing unit 273 described later. . In addition, the depth image complementing unit 269 may store information regarding the supplemented depth image as history information in the storage unit 207 or the like in association with time information regarding the date and time when the information is calculated. Further, the depth image complementing unit 269 may output information regarding the complemented depth image to the display control unit 205 and may cause the display unit (not shown) to output the information.

  The luminance image complementing unit 271 is realized by, for example, a CPU, a ROM, a RAM, and the like. The luminance image complementing unit 271 uses the in-transmission luminance image and the in-transmission luminance image corrected by the rotation correction unit 267 to perform a complementing process of a portion corresponding to the shielding area in the luminance image. Here, the complementing process performed by the brightness image complementing unit 271 is the same as the complementing process by the depth image complementing unit 265 except that the sending-in brightness image and the sending-out brightness image corrected by the rotation correcting unit 267 are used. Since it is the same, detailed description is abbreviate | omitted.

  When the luminance image complementing unit 271 completes the luminance information of the portion corresponding to the shielding region by the above complementing process, the luminance image complementing unit 271 outputs information on the complemented luminance image to the detection processing unit 273 described later. Further, the luminance image complementing unit 271 may store information regarding the complemented luminance image as history information in the storage unit 207 or the like in association with time information regarding the date and time when the information is calculated. Further, the luminance image complementing unit 271 may output information regarding the complemented luminance image to the display control unit 205 and output the information to the display unit (not shown).

  The depth image complementing unit 269 and the brightness image complementing unit 271 perform the above-described complementing process, thereby generating the complemented depth image and the brightness image as schematically illustrated in FIG. The Rukoto.

Returning to FIG. 20 again, the detection processing unit 273 according to the present embodiment will be described.
The detection processing unit 273 according to the present embodiment is realized by, for example, a CPU, a ROM, a RAM, and the like. The detection processing unit 273 detects a defect present on the inner surface of the tubular body based on the depth image complemented by the depth image complementing unit 269 and the luminance image supplemented by the luminance image complementing unit 271.

  Here, the defect detection process performed by the detection processing unit 273 according to the present embodiment is the same as the defect detection process performed by the detection processing unit 229 according to the first embodiment, and thus will be described in detail below. Is omitted.

  The configuration of the image processing unit 203 included in the arithmetic processing device 200 according to the present embodiment has been described above in detail.

In the above description, the portion corresponding to the shielding area of the depth image at the time of sending and the luminance image at the time of sending is complemented by using the portion corresponding to the beam irradiation area of the depth image at sending time and the luminance image at sending time. However, the reverse process can also be performed.
That is, the light section line processing unit 261 pays attention to the stripe image frame at the time of transmission, and specifies the start position and the end position of the shielding area in the stripe image frame at the time of transmission. In addition, the depth image complementing unit 269 and the luminance image complementing unit 271 use the portion corresponding to the beam irradiation area of the in-feed depth image and the in-feed luminance image, and send out the depth image and send out. A portion corresponding to the occluded area of the temporal luminance image may be complemented.

  Heretofore, an example of the function of the arithmetic processing apparatus 200 according to the present embodiment has been shown. Each component described above may be configured using a general-purpose member or circuit, or may be configured by hardware specialized for the function of each component. In addition, the CPU or the like may perform all functions of each component. Therefore, it is possible to appropriately change the configuration to be used according to the technical level at the time of carrying out the present embodiment.

  A computer program for realizing each function of the arithmetic processing apparatus according to the present embodiment as described above can be produced and installed in a personal computer or the like. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

  The configuration of the tubular body surface inspection apparatus 10 according to the present embodiment has been described in detail above. By utilizing the tubular body surface inspection apparatus 10 according to the present embodiment, it becomes possible to inspect the inner surface of the tubular body over the entire circumference in the tube circumferential direction and over the entire length in the tube axis direction. Can be detected simultaneously with high accuracy. In addition, since the tubular body surface inspection apparatus 10 according to the present embodiment can accurately identify the position where the defect occurs, it greatly contributes to improvement of productivity and yield of tubular bodies such as steel pipes and quality assurance. can do.

<About defect detection method>
Subsequently, the flow of the tubular body surface inspection method according to the present embodiment will be briefly described with reference to FIG. FIG. 40 is a flowchart showing an example of the flow of the tubular body surface inspection method according to the present embodiment.

  First, the tubular body imaging device 100 of the tubular body surface inspection apparatus 10 uses the annular beam irradiated from the probe to image the inner surface of the tubular body at the time of feeding the probe and sending the probe, and at the time of feeding the probe. And two types of captured images when the probe is sent out are output to the arithmetic processing unit 200. In addition to the imaging processing, the rotation amount measuring device 130 measures the rotation generated in the tubular body imaging device 100 as needed and outputs the measured rotation to the arithmetic processing device 200. The A / D conversion unit 251 of the image processing unit 203 included in the arithmetic processing device 200 performs A / D conversion processing on the two types of acquired captured images, and generates an annular beam image at the time of transmission and a beam image at the time of transmission. (Step S201).

  Next, the annular beam center calculation unit 253 calculates the position of the center of gravity and the radius of each annular beam image using the annular beam images at the time of transmission and transmission generated by the A / D conversion unit 251 (step S203). ), And outputs the obtained calculation result to the coordinate conversion unit 255.

  Subsequently, the coordinate conversion unit 255 performs coordinate conversion of the in-feed annular beam image and the in-transit annular beam image using the calculated center of gravity position, radius, and the like, and generates a light section image (step S505). At this time, the coordinate conversion unit 255 performs coordinate conversion processing based on the posture of the tubular body imaging apparatus 100 at the time of sending. This makes it possible to unify the origins of the position coordinates in the tube circumferential direction of the respective light cutting lines in the stripe image frames generated at the subsequent stage and at the time of transmission. The generated light section images are sequentially stored in an image memory provided in the storage unit 207 and the like along the tube axis direction of the tubular body.

  After that, the fringe image frame generation unit 257 sequentially arranges the generated light section images along the tube axis direction of the tubular body, and generates the fringe image frames at the time of sending and at the time of sending (step S207). The striped image frame generation unit 257 outputs the generated striped image frame to the light section line processing unit 261.

  The light section line processing unit 261 uses the generated stripe image frames at the time of sending and sending, and for each light section line, the number of pixels having a luminance equal to or higher than the threshold, the sum of the luminance of the pixels, and the light A displacement amount of the cutting line is calculated (step S209). These calculation results are used as the feature value of the light section line. The calculated light section line feature amount is output to the depth image calculation unit 263 and the luminance image calculation unit 265, respectively.

  The light section line processing unit 261 also specifies the position of the shielding area (that is, the start position and the end position of the shielding area) for the striped image frame at the time of sending, along with the calculation of the feature value of the light section line. (Step S211). Thereafter, the light section line processing unit 261 outputs information regarding the position of the identified shielding area to the rotation correction unit 267.

  The depth image calculation unit 263 calculates the depth image at the time of sending and the depth image at the time of sending using the calculated optical section line feature amount (particularly, the feature amount related to the displacement amount of the optical section line) ( Step S213). In addition, the luminance image calculation unit 265 uses the calculated light section line feature amount (particularly, the feature amount related to the number of pixels having luminance equal to or higher than the threshold and the feature amount related to the sum of luminance) to send in A time luminance image and a transmission time luminance image are calculated (step S213). The depth image calculation unit 263 outputs the calculated sending depth image and sending depth image to the rotation correction unit 267. In addition, the luminance image calculation unit 265 outputs the calculated transmission luminance image and transmission luminance image to the rotation correction unit 267.

  The rotation correction unit 267 uses the method described in the first embodiment based on the information about the rotation direction and magnitude output from the rotation amount measuring device 130, and the depth image and the luminance image at the time of sending and sending. Each of these is corrected (step S215). Thereby, it is possible to correct the positional deviation caused by the rotation of the tubular body imaging device 100 in the tube circumferential direction. In addition, the rotation correction unit 267 similarly corrects information indicating the start position and the end position of each shielding area in each image specified by the light section line processing unit 261. Thereafter, the rotation correction unit 227 performs depth image complementation on the corrected depth images at the time of sending and sending and the corrected information indicating the start position and end position of each shielding area in each image. The luminance image complementing unit 271 outputs the corrected luminance image at the time of sending and sending and the corrected information indicating the start position and the end position of each shielding area in each image. To output.

  Next, the depth image complementing unit 269 uses the corrected information regarding the position of the occluded region and the corrected depth image at the time of sending, and performs a process of complementing the depth image at the time of sending (step) S217). Further, the luminance image complementing unit 271 performs the supplementing process of the luminance image at the time of sending using the corrected information on the position of the shielding area and the corrected luminance image at the time of sending (Step S217). Thereafter, the depth image complementing unit 269 outputs the complemented depth image to the detection processing unit 273, and the luminance image complementing unit 271 outputs the complemented luminance image to the detection processing unit 273.

  The detection processing unit 273 detects the defect site existing on the inner surface of the tubular body using the complemented depth image and the luminance image, and specifies the type of defect and the harmfulness of the detected defect site (step) S219). By the flow as described above, defects existing on the inner surface of the tubular body are detected.

  The defect detection apparatus and the defect detection method according to the second embodiment of the present invention have been described above in detail.

(Third embodiment)
The tubular body imaging device 100 according to the first embodiment and the second embodiment as described above has only the laser beam irradiation device that irradiates the annular laser beam as the illumination mechanism 110. The tubular body imaging apparatus 100 according to the third embodiment described below radiates conical illumination light (hereinafter also referred to as “conical illumination light”) in addition to the annular laser light. It further has a light source. By having such a conical illumination light source, in addition to fine irregularities of wrinkles, wrinkles with different surface roughness and fine rubbing wrinkles with no irregularities can be distinguished from overexamination factors such as background patterns and dirt. However, it can be detected with high accuracy and at the same time, and the position where wrinkles are generated can be accurately grasped.

<Overall structure of tubular body surface inspection device>
The overall configuration of the tubular body surface inspection apparatus 10 according to the present embodiment is the entire structure of the tubular body surface inspection apparatus 10 according to the first embodiment shown in FIG. 1 and the tubular body surface according to the second embodiment. Since it has the same configuration as the entire configuration of the inspection apparatus, detailed description will be omitted below.

<About the structure of the tubular body imaging device 100>
The configuration of the tubular body imaging device 100 according to the present embodiment is also conical with respect to the tubular body imaging device 100 according to the first embodiment or the tubular body imaging device 100 according to the second embodiment. The tubular body imaging apparatus 100 according to the first embodiment or the second embodiment has substantially the same configuration except that it further includes a conical illumination light source that irradiates the illumination light. It plays. Therefore, the following description will be focused on differences from the first or second embodiment with reference to FIGS. 41A to 43B.

  As shown in FIGS. 41A and 41B, the tubular body imaging device 100 according to the present embodiment is further provided as a conical illumination light source as the illumination mechanism 110 in the tubular body imaging device 100 according to the first or second embodiment. 115.

  The conical illumination light source 115 irradiates, for example, conical illumination light having a wavelength belonging to a visible light band of about 400 nm to 800 nm while spreading over the entire circumference of the tubular body surface (expansion width on the inner surface: d). Light source. For example, as shown in FIG. 42, the conical illumination light source 115 includes a light emitting element 119 provided with a lens for controlling the irradiation direction of illumination light along the circumference of an annular base 117, and the like. A plurality are arranged at intervals. The conical illumination light is emitted from each light emitting element 119 radially to the center of the annular base 117 (that is, outward in the radial direction of the ring).

  The number and installation interval of the light emitting elements 119 provided on the annular base 117 are not particularly limited, and may be determined so that the visual field of the inner surface to be focused has a desired uniform brightness. Further, instead of the plurality of light emitting elements 119 as shown in FIG. 42, one ring-shaped light emitting element provided with a lens for controlling the irradiation direction of the illumination light may be used.

  The laser light source 111 and the conical illumination light source 115 as described above are fixed to the holding substrate 141 so as to be concentric with each other.

  Further, the focal length, the angle of view, and the like of the lens mounted on the camera 120 according to the present embodiment are not particularly limited, but the reflection of the annular laser beam irradiated on the inner surface of the tubular body 1 on the inner surface. Each of the light and the reflected light at the inner surface of the conical illumination light is selected to be located in the same field of view.

  The camera 120 according to the present embodiment images the reflected light on the inner surface of the annular laser beam focused in the same field of view and the reflected light on the inner surface of the conical illumination light, respectively. Thereby, the camera 120 can specify data indicating the intensity of the reflected light on the inner surface of the annular laser light or the conical illumination light. As a result of the imaging performed by the camera 120 every time the tubular body imaging device 100 travels the inside of the tubular body 1 by a certain distance, the camera 120 is able to detect the distribution of the reflected light on the inner surface of the annular laser light in the tube circumferential direction and the conical illumination. The distribution in the tube circumferential direction of the reflected light on the inner surface of the light can be specified.

  Here, as shown in FIGS. 41A and 41B, the irradiation area of the conical illumination light has a spread d. Therefore, if the annular laser light and the reflected light of the conical illumination light are simultaneously imaged at a certain timing, then the reflected light of the conical illumination light is imaged while the annular laser light travels in the tube axis direction by the distance d. However, it is not necessary to take an image. This is because the reflected light of the conical illumination light that is imaged simultaneously with the annular laser light can be used as the reflected light of the conical illumination light while the annular laser light travels in the tube axis direction by the distance d. Therefore, in the tubular body imaging device 100 according to the present embodiment, the reflected light of the conical illumination light may be captured every time the reflected light of the annular laser light is imaged, or the reflected light of the annular laser light. The reflected light of the conical illumination light may be imaged once while the image is captured for d lines (while the irradiation portion of the annular laser light advances by d in the tube axis direction). By adopting the latter configuration, it becomes possible to use resources more effectively, so that the processing speed can be further increased.

  Next, the positional relationship among the laser light source 111, the conical illumination light source 115, and the camera 120 will be described. In the tubular body imaging device 100 according to the present embodiment, as schematically shown in FIG. 41A, the irradiation position of the annular laser beam on the inner surface of the tubular body 1 and the conical illumination on the inner surface of the tubular body 1 The laser light source 111 and the conical illumination light source 115 may be arranged so that the light irradiation position is different from each other in the tube axis direction of the tubular body. As schematically shown in FIG. 41B, the laser light source 111 and the conical illumination are arranged so that the irradiation position of the annular laser light is included in the conical illumination light irradiation region on the inner surface of the tubular body 1. A light source 115 may be provided.

In any of the cases shown in FIGS. 41A and 41B, the conical illumination light source 115 is arranged so that the conical illumination light is incident on the inner surface at an incident angle φ ₂ (φ ₂ <90 °). The camera 120 is arranged so that regular reflection light of conical illumination light forms an image. That is, the camera 120, the angle between the optical axis in the normal direction and the camera 120 of the inner surface are disposed so as to be substantially equal to phi _2. At this time, the length in the tube axis direction of the inner surface irradiated with the conical illumination light is represented by d.

Here, when the tubular body imaging device 100 adopts the configuration as shown in FIG. 41A, the conical illumination light source 115 has an incident angle φ _{2 based on} the reflection angle φ _{1 of the} annular laser light in addition to the above conditions. (Ie, φ ₂ > φ ₁ is satisfied). In addition, it is preferable that the irradiation portion of the annular laser beam and the irradiation region of the conical illumination light are separated as much as possible within a range where these irradiation regions are located in the same field of view of the camera 120. By separating the irradiation portion of the annular laser light from the irradiation region of the conical illumination light, it is possible to suppress a decrease in S / N of the annular laser light that is caused by the conical illumination light becoming background light.

Further, when the tubular body imaging device 100 adopts the configuration shown in FIG. 41B, the conical illumination light source 115 and the camera 120 are arranged so that φ ₁ ≈φ ₂ is satisfied in addition to the above conditions. Is done.

  Further, the wavelength of each illumination light emitted from the laser light source 111 and the conical illumination light source 115. When the tubular body imaging device 100 adopts the configuration shown in FIG. 41A, the wavelength of the annular laser light, The wavelength of the conical illumination light is not particularly limited, and the wavelength of the annular laser light and the wavelength of the conical illumination light may be equal. This is because the irradiation position of the annular laser light and the irradiation position of the conical illumination light are set so as to be different within the field of view of the camera 120, so that the imaging results of the reflected light of both can be easily distinguished. Because it is possible. In this case, a color camera capable of color imaging may be used as the camera 120, but it is easier to use a monochrome camera.

  On the other hand, when the tubular body imaging device 100 adopts the configuration shown in FIG. 41B, the annular laser light and the conical illumination light are imaged while being distinguished from each other by the camera 120, and the reflected light intensities thereof are separately set. For example, the wavelength, the irradiation timing, or the polarization needs to be different from each other.

  When the wavelengths of the annular laser light and the conical illumination light are different, the intensity of the annular laser light and the intensity of the conical illumination light can be measured separately by color filters having different transmission bands. In addition, when the irradiation timings of the annular laser light and the conical illumination light are different, the timing at which each illumination light irradiates the surface of the tubular body is time-divided, and one illumination light is irradiated on the inner surface. In this case, the other illumination light is not irradiated on the inner surface. Therefore, the intensity of the annular laser light and the intensity of the conical illumination light are obtained by separately handling the image photographed at the irradiation timing of the annular laser light and the image photographed at the irradiation timing of the conical illumination light. Can be measured separately. Further, in order to make the polarizations of the annular laser beam and the conical illumination light different from each other, polarizers having polarization directions orthogonal to each other may be disposed on the optical axis of each light source. By arranging analyzers orthogonal to each other in the camera 120, the intensity of the annular laser light and the intensity of the conical illumination light can be measured separately.

  When visible light beams having different wavelengths are used as the annular laser light and the conical illumination light, the combination of the hues of the annular laser light and the conical illumination light is (red / blue), (blue / green). , (Red / green), it is preferable to combine visible light sources. In addition, when using the light source which has a continuous spectrum as a visible light source, it is preferable to select the light source which the overlap of light emission wavelength decreases. In this case, it is convenient and preferable to use a known color camera as the camera 120. As a result, it is possible to simultaneously measure the sizes of the red component, the green component, and the blue component contained in the reflected light of the annular laser beam and the reflected light of the conical illumination light independently of each other.

  Note that red indicates light having a wavelength of 600 to 700 nm, green indicates light having a wavelength of 500 to 560 nm, and blue indicates light having a wavelength of 430 nm to 500 nm.

  FIG. 43A and FIG. 43B schematically show examples of captured images. As shown schematically in FIGS. 43A and 43B, the image generated by the tubular body imaging apparatus 100 according to the present embodiment has an area where a part of the illumination mechanism is reflected at the center of the image. In addition, a region where the inner surface of the tubular body 1 including the irradiation portion of the annular laser beam and the irradiation region of the conical illumination light is imaged is present further outside this region. Hereinafter, a captured image using two types of illumination light captured by the tubular body imaging device 100 according to the present embodiment is also referred to as a tube inner surface image. Further, according to the positional relationship between the annular laser light and the conical illumination light, as shown in FIG. 43A, an image in which the irradiation portion of the annular laser light and the irradiation area of the conical illumination light are separated is obtained. Or, as shown in FIG. 43B, an image in which the irradiation portion of the annular laser light is included in the irradiation region of the conical illumination light may be obtained. The data of the area corresponding to the inner surface of the tubular body is used in the image processing apparatus 200 described later.

  The tubular body imaging device 100 according to the present embodiment has been described above with reference to FIGS. 41A to 43B.

<Configuration of Arithmetic Processing Device 200>
Similar to the arithmetic processing device 200 according to the first embodiment and the arithmetic processing device 200 according to the second embodiment shown in FIG. The image processing unit 203, the display control unit 205, and the storage unit 207 are mainly provided.

  Here, regarding the imaging control unit 201, the display control unit 205, and the storage unit 207 according to the present embodiment, the imaging control unit 201, the display control unit 205, and the like included in the arithmetic processing device 200 according to the first or second embodiment. Since it has the same configuration as the storage unit 207 and has the same effect, a detailed description is omitted below.

  The image processing unit 203 is realized by, for example, a CPU, a ROM, a RAM, a communication device, and the like. The image processing unit 203 uses the imaging data acquired from the tubular body imaging device 100 (more specifically, the camera 120 of the tubular body imaging device 100) to generate two types of image frames described later. Thereafter, image processing as described below is performed on the two types of generated image frames to detect defects that may exist on the inner surface of the tubular body that is the measurement target. When the image processing unit 203 finishes the defect detection process on the inner surface of the tubular body 1, the image processing unit 203 transmits information about the obtained detection result to the display control unit 205.

  Note that, as described in the second embodiment, there may be a shielding region due to the connecting member 143 in the image captured by the tubular body imaging apparatus 100 according to the present embodiment. For this reason, the image processing unit 203 according to the present embodiment uses the method described in the second embodiment to capture an image captured at the time of feeding when the image captured by the tubular body imaging device 100 includes a shielding area. The image generated from the above is complemented using an image generated from the image captured at the time of transmission, and an image having no shielding area is generated, and then a defect existing on the inner surface is detected.

<Regarding Image Processing Unit 203>
Hereinafter, the configuration of the image processing unit 203 included in the arithmetic processing device 200 according to the present embodiment will be described with reference to FIGS. 44 to 45B with a focus on differences from the image processing unit 203 according to the first embodiment. As will be described, it goes without saying that the configuration of the image processing unit 203 according to the present embodiment can be similarly realized for the image processing unit 203 according to the second embodiment.

  As shown in FIG. 44, the image processing unit 203 according to the present embodiment includes an A / D conversion unit 281, an annular beam center calculation unit 283, a coordinate conversion unit 285, a fringe image frame generation unit 287, an image A calculation unit 289 and a detection processing unit 301 are mainly provided.

  The A / D conversion unit 281 is realized by a CPU, a ROM, a RAM, and the like, for example. The A / D conversion unit 281 performs A / D conversion on the captured image output from the camera 120 in the same manner as the A / D conversion unit 211 according to the first embodiment, and performs digital multilevel image data (that is, in-tube). (Surface image). Such digital multivalued image data is stored in an image memory provided in the storage unit 207 or the like. By sequentially using these digital multivalued image data along the tube axis direction of the tubular body, a light-cutting image frame and a conical illumination light image frame as described later are formed.

  As schematically shown in FIG. 43A and FIG. 43B, the tube inner surface image shows the annular laser beam and the cone irradiated to the inner surface of the tubular body at a certain position along the tube axis direction of the inner surface of the tubular body 1. The reflected light of the illumination light is imaged. In the tube surface image, by appropriately setting the camera gain and the lens aperture in advance, the portion irradiated with the annular beam and the conical illumination light is displayed in white, for example, and the other portions are displayed in black. It becomes a grayscale image.

  When the A / D conversion unit 281 generates a tube surface image as schematically illustrated in FIG. 43A or 43B based on the captured image output from the camera 120, the A / D conversion unit 281 generates data corresponding to the generated tube surface image. And output to an annular beam center calculation unit 283 described later.

  The annular beam center calculation unit 283 is realized by, for example, a CPU, a ROM, a RAM, and the like. The annular beam center calculation unit 283 is similar to the annular beam center calculation unit 213 according to the first embodiment, and the center of gravity of the ring corresponding to the annular beam is obtained for each in-tube surface image output from the A / D conversion unit 281. Calculate the position and radius respectively.

  When the annular beam center calculation unit 283 calculates the center of gravity position and radius of the ring for each tube inner surface image, the annular beam center calculation unit 283 generates information on the center of gravity position and radius of the ring, and outputs the information to the coordinate conversion unit 285 described later.

  In addition, in this embodiment, although the case where the cross-sectional shape of the inner surface of the tubular body 1 is close to a perfect circle is described, it can be applied to any cross-sectional shape. For example, the cross-sectional shape is an ellipse or a rounded corner. It may be a rectangle or the like. The center of gravity in such a case can be obtained from the shape of the annular beam, and by using the average value of the maximum value and the minimum value of the distance to the obtained center of gravity as the radius, coordinate conversion described later is performed in the same procedure. Can be implemented.

  The coordinate conversion unit 285 is realized by a CPU, a ROM, a RAM, and the like, for example. The coordinate conversion unit 285 converts the coordinate system of the tube inner surface image based on the calculated barycentric position and the separation distance between the barycentric position and the irradiated portion of the annular beam. After that, the coordinate conversion unit 285 generates a light-cut image representing the irradiation portion of the annular beam as a line segment developed in the tube circumferential direction of the tubular body, and the irradiation region of the conical illumination light is changed to the tube circumferential direction of the tubular body. To generate a conical illumination light image.

  By calculating the position of the center of gravity of the annular beam, the pixel position corresponding to the irradiation position of the annular beam can be represented by polar coordinates (r, θ) with the center of gravity position as the origin. As shown in FIGS. 43A and 43B, the coordinate conversion unit 285 provides a predetermined margin in the radial direction with respect to the radius r calculated by the annular beam center calculation unit 283, and then 0 ° ≦ ψ Coordinate conversion to orthogonal coordinates (r cos Ψ, r sin Ψ) is performed with ≦ 360 °.

At this time, when the tubular body imaging device 100 has a structure as shown in FIG. 41A, the irradiation position of the annular laser light or the conical illumination light in the tube inner surface image is the center of gravity position of the annular beam (with a radius r). The corresponding position is as shown in FIG. 43A. Therefore, as shown in FIG. 44A, the coordinate conversion unit 285 provides a margin of ± Δr in the radial direction with respect to the radius r calculated by the annular beam center calculation unit 283, and then in the radial direction. In the range of r−Δr to r + Δr + d, coordinate transformation is performed with 0 ° ≦ ψ ≦ 360 °. At this time, the value of the margin Δr may be different in the plus direction and the minus direction within a range including the irradiated portion of the annular beam. In such a case, for example, the range in which the coordinate conversion is performed can be expressed as r−Δr _{1 to} r + Δr ₂ . However, in the present embodiment, the following description will be given for the case where the same value Δr is used in the plus direction and the minus direction.

  By performing such coordinate transformation, as shown on the right side of FIG. 44A, the annular laser light irradiated portion has a height of 2Δr centered on the radius r in the radial direction, and in the angular direction. A belt-like image having a length of 360 ° is extracted, and the cone-shaped illumination light irradiation region has a belt-like shape having a height of d in the radial direction and a length of 360 ° in the angular direction. Are extracted. As is clear from the above description, the band-shaped image extracted from the annular laser light irradiated portion is a line segment (hereinafter referred to as “light cutting line”) in which the annular laser light irradiated portion is developed in the tube circumferential direction. Also referred to as). Further, by extracting a range of 2Δr with the radius r as the center in the radial direction, it is possible to extract the entire circumference of the annular beam including the irregularities even if irregularities exist around the circumference of the annular beam. It becomes. The band-like image obtained in this way is hereinafter referred to as a light section image.

  Further, the band-shaped image extracted from the conical illumination light irradiation region is an image related to the reflected light of the conical illumination light imaged on the camera 120 so as to satisfy the regular reflection condition, and the regular reflection light of the conical illumination light. This is an image in which the luminance distribution is expanded in the tube circumferential direction of the tubular body. The band-like image obtained in this way is hereinafter referred to as a conical illumination light developed image.

  When the tubular body imaging device 100 has a structure as shown in FIG. 41A, the conical illumination light irradiation region and the annular laser light irradiation portion are separated from each other in advance by a separation amount b + Δr. The light-cutting image frame generation unit 287 and the illumination light luminance image generation unit 297 that can perform the separation of the light-cutting image and the conical illumination light development image can be easily performed.

  In addition, the magnitude | size of (DELTA) r is by calculating roughly the range of the height of the unevenness | corrugation which can exist in the tubular body 1 based on the past operation data etc. so that the separation amount b> 0 may be satisfied. It is possible to determine.

  On the other hand, when the tubular body imaging device 100 has a structure as shown in FIG. 41B, the irradiation position of the annular laser light or the conical illumination light in the tube inner surface image is a figure with respect to the center of gravity position of the annular beam. The positional relationship is as shown in 43B. Therefore, as shown in FIG. 44B, the coordinate conversion unit 285 provides a margin of ± d / 2 in the radial direction with respect to the radius r calculated by the annular beam center calculation unit 283, and then adjusts the radial radius. In the range of rd / 2 to r + d / 2 in the direction, coordinate transformation is performed with 0 ° ≦ ψ ≦ 360 °.

  By performing such coordinate transformation, as shown on the right side of FIG. 44B, a belt-like shape having a height d around the radius r in the radial direction and a length of 360 ° in the angular direction. Are extracted.

  When the tubular body imaging device 100 has a structure as shown in FIG. 41B, the conical illumination light irradiation region and the annular laser light irradiation portion overlap each other. However, when the tubular body imaging device 100 has a structure as shown in FIG. 41B, the conical illumination light and the annular laser light are selected so as to be distinguishable from each other, so that the light cutting described later is performed. The image frame generation unit 287 and the illumination light luminance image generation unit 297 can easily separate the light-cut image and the conical illumination light development image.

  The tube surface image captured by the tubular body imaging device 100 as described above includes a ring having a radius r corresponding to about 300 pixels. Therefore, when r = 300 pixels and Δr = 25 pixels and a light section image is extracted in a range of 0 ° ≦ Ψ ≦ 360 °, a light section image of horizontal 2041 pixels × height 50 pixels is generated. Become. When d = 25 pixels, a regular reflection developed image of horizontal 2041 pixels × height 50 pixels is generated. Note that the pixel size at this time is 0.5 mm wide × 0.5 mm long.

  As described above, the tubular body imaging apparatus 100 according to the present embodiment images the irradiation area of the conical illumination light every time the reflected light of the annular laser light is imaged (that is, the conical illumination light). May be configured so that the irradiation region of the conical illumination light is imaged only once while the annular laser light travels by d in the tube axis direction (that is, the conical illumination light is captured by the annular laser). It is also possible to irradiate the light only once while the light travels by d in the tube axis direction). For this reason, when the irradiation control of the conical illumination light source is performed as in the latter case, there is no irradiation area of the cone illumination light in the tube inner surface image when the cone illumination light is not irradiated. Become. In that case, the coordinate conversion part 285 should just perform the above coordinate conversion processes only with respect to the irradiation part of a cyclic | annular laser beam, and should just produce | generate a light cutting image.

  Even when the cone-shaped illumination light is irradiated every time, both the irradiation portion of the ring-shaped laser light and the irradiation region of the cone-shaped illumination light are only once while the ring-shaped laser light travels by d in the tube axis direction. On the other hand, while the coordinate conversion process as described above is performed, in other cases, the coordinate conversion process as described above may be performed only on the portion irradiated with the annular laser beam.

  In addition, the coordinate conversion unit 285 uses the coordinates (r, Ψ) of each pixel in the extracted light section image and the conical illumination light developed image to be included in the light section image and the conical illumination light developed image. Pixel coordinates are converted into orthogonal coordinates (r cos Ψ, r sin Ψ). Here, since the coordinate value conversion performed by the coordinate conversion unit 285 is conversion from the polar coordinate system to the orthogonal coordinate system, the lattice point (that is, the center position of the pixel) in the polar coordinate system is always a lattice in the orthogonal coordinate system. It does not necessarily correspond to a point, and there also exists a thing corresponding to a non-grid point. Therefore, in the same manner as in the first embodiment, the coordinate conversion unit 285 uses another grid positioned in the vicinity of the point of interest in order to interpolate the density (pixel value) of the non-grid points in the orthogonal coordinate system. It is preferable to implement a so-called image interpolation method that interpolates based on the density of points.

  When the coordinate conversion unit 285 finishes the coordinate conversion process and the image interpolation process as described above, the image data corresponding to the obtained light-cut image and the conical illumination light developed image is provided in the storage unit 207 or the like. The memory is sequentially stored along the tube axis direction of the tubular body.

  The stripe image frame generation unit 287 is realized by, for example, a CPU, a ROM, a RAM, and the like. The fringe image frame generation unit 287 is stored along the tube axis direction of the tubular body from the image memory provided in the storage unit 207 and the like in the same manner as the fringe image frame generation unit 217 according to the first embodiment. Light cut images are acquired in order. After that, the fringe image frame generation unit 287 sequentially arranges the acquired light section images along the tube axis direction of the tubular body to generate a fringe image frame.

  When the fringe image frame generation unit 287 generates the fringe image frame in the same manner as the method described in the first embodiment, the fringe image frame generation unit 287 outputs the generated stripe image frame to the light section line processing unit 291 described later. Further, the fringe image frame generation unit 287 may associate the time information related to the date and time when the fringe image frame is generated with the data corresponding to the generated stripe image frame, and store the data in the storage unit 207 or the like as history information. .

  The image calculation unit 289 is realized by a CPU, a ROM, a RAM, and the like, for example. Based on the fringe image frame generated by the fringe image frame generation unit 287, the image calculation unit 289 calculates the depth image representing the uneven state of the inner surface of the tubular body and the luminance distribution of the annular beam on the inner surface of the tubular body. And a luminance image to be expressed. The image calculation unit 289 generates an illumination light luminance image using the conical illumination light developed image generated by the coordinate conversion unit 285. As shown in FIG. 44, the image calculation unit 289 includes a light section line processing unit 291, a depth image calculation unit 293, a luminance image calculation unit 295, an illumination light luminance image generation unit 297, and a rotation correction unit. 299.

  Here, the light section line processing unit 291, the depth image calculation unit 293, and the luminance image calculation unit 295 according to the present embodiment are the same as the light section line processing unit 221, the depth image calculation unit according to the first embodiment. 223 and the luminance image calculation unit 295, and have the same effects. Therefore, in the following, detailed description of these processing units is omitted.

  The illumination light luminance image generation unit 297 is realized by, for example, a CPU, a ROM, a RAM, and the like. The illumination light luminance image generation unit 297 sequentially acquires conical illumination light developed images stored along the tube axis direction of the tubular body from the image memory provided in the storage unit 207 or the like. At this time, the cone-shaped illumination light developed image corresponding to the d-line arrangement of the light-cut images by the fringe image frame generation unit 287 was captured simultaneously with the light-cut image of the first line as mentioned above. It is possible to cope with one conical illumination light developed image. Therefore, the illumination light luminance image generation unit 297 acquires a conical illumination light development image for each d line, arranges the acquired conical illumination light development images in order along the tube axis direction of the tubular body, and performs illumination. A light intensity image is generated.

  When the illumination light luminance image generation unit 297 generates the illumination light luminance image as described above, the illumination light luminance image generation unit 297 outputs the generated illumination light luminance image to the rotation correction unit 299 described later. In addition, the illumination light luminance image generation unit 297 associates time information related to the date and time when the illumination light luminance image is generated with the data corresponding to the generated illumination light luminance image, and stores it in the storage unit 207 or the like as history information. May be.

  The rotation correction unit 299 is realized by a CPU, a ROM, a RAM, and the like, for example. The rotation correction unit 299 is similar to the method described in the first embodiment in that the depth image calculated by the depth image calculation unit 293, the luminance image calculated by the luminance image calculation unit 295, and the illumination light For each of the illumination light luminance images generated by the luminance image generation unit 297, the positional deviation associated with the rotation in the tube circumferential direction is corrected using the rotation direction and size measured by the rotation amount measuring device 130.

  Here, the details of the rotation correction processing performed on each image are the same as the method described in the first embodiment, and thus detailed description thereof will be omitted below. By applying the rotation correction process to the illumination light luminance image in the same manner as in the first embodiment, it is possible to correct the positional deviation accompanying the rotation in the tube circumferential direction.

  When the rotation correction processing as described above is performed on each of the depth image, the luminance image, and the illumination light luminance image, the rotation correction unit 299 performs the corrected depth image, luminance image, and illumination light luminance image. And output to the detection processing unit 301. Further, the rotation correction unit 299 stores information on the corrected depth image, luminance image, and illumination light luminance image as history information in the storage unit 207 or the like in association with time information on the date and time when the information is corrected. May be. Furthermore, the rotation correction unit 299 may output information regarding the corrected depth image, luminance image, and illumination light luminance image to the display control unit 205 and output the information to a display unit (not shown).

  Further, as in the first embodiment, the rotation correction unit 299 outputs information related to the calculated rotation direction and magnitude to the imaging control unit 201, and the drive control device 150 of the imaging control unit 201 outputs the information. You may make it use for rotation control with respect to the tubular body imaging device 100. FIG. Further, as in the first embodiment, the rotation correction unit 299 rotates the tubular body imaging device 100 when the magnitude of the rotation output from the rotation correction unit 299 exceeds a predetermined reference threshold. Warning information (for example, warning information appealing to sight, hearing, touch, etc. such as warning sound, warning display, vibration, etc.) may be output.

  The detection processing unit 301 is realized by, for example, a CPU, a ROM, a RAM, and the like. The detection processing unit 301 detects a defect existing on the inner surface of the tubular body based on the depth image, the luminance image, and the illumination light luminance image corrected by the rotation correction unit 299.

  Here, the defect detection processing performed by the detection processing unit 301 according to the present embodiment is the defect detection performed by the detection processing unit 229 according to the first embodiment, except that the illumination light luminance image is further used. Since it is the same as the processing, detailed description is omitted below.

  The configuration of the image processing unit 203 included in the arithmetic processing device 200 according to the present embodiment has been described above in detail.

  Heretofore, an example of the function of the arithmetic processing apparatus 200 according to the present embodiment has been shown. Each component described above may be configured using a general-purpose member or circuit, or may be configured by hardware specialized for the function of each component. In addition, the CPU or the like may perform all functions of each component. Therefore, it is possible to appropriately change the configuration to be used according to the technical level at the time of carrying out the present embodiment.

  A computer program for realizing each function of the arithmetic processing apparatus according to the present embodiment as described above can be produced and installed in a personal computer or the like. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

  The configuration of the tubular body surface inspection apparatus 10 according to the present embodiment has been described in detail above. In the above description, the case where the tubular body imaging apparatus 100 performs the imaging process using both the annular laser light and the conical illumination light has been described. However, the tubular body imaging apparatus 100 uses only the conical illumination light. However, it goes without saying that the rotation correction process according to the present embodiment can be similarly applied to the case where the detection process is performed using only the illumination light luminance image.

(Fourth embodiment)
By mounting the tubular body surface inspection apparatus 10 according to the first to third embodiments as described above on other inspection devices, the first to third embodiments are provided for other inspection devices. It is also possible to add the function of the tubular body surface inspection apparatus 10 according to the above. Below, about the case where the function of the tubular body surface inspection apparatus 10 which concerns on the 1st-3rd embodiment is added with respect to the drift gauge utilized for the drift inspection implemented with respect to the steel pipe for oil country pipes according to API specification. A brief explanation.

  Steel pipes for oil well pipes (hereinafter also simply referred to as “steel pipes”) conforming to the API standard are equipped with drift gauges that have been finished to the standard outer diameter in order to inspect the inner diameter accuracy and bending accuracy over the entire length of the steel pipe. Inspection (so-called drift inspection) is performed. In particular, in a drift inspection for a mass-produced steel pipe, an automatic device for driving a drift gauge is used. The drift inspection is performed by passing the drift gauge through the inside of the steel pipe to be inspected using such an automatic device and then passing the drift gauge in the reverse direction to the original position.

  Hereinafter, first, a drift inspection performed on an oil well steel pipe according to the API standard will be briefly described with reference to FIG. FIG. 46 is an explanatory diagram for explaining the drift inspection.

  The drift inspection is an inspection for inspecting whether the oil well steel pipe has a prescribed inner diameter accuracy or bending accuracy, and allows a drift gauge finished to an outer diameter in accordance with the API standard to pass through the entire length of the steel pipe. When the drift gauge can pass through the entire length of the steel pipe, it means that the steel pipe to be inspected conforms to a predetermined API standard, and when the drift gauge cannot pass through the inside of the steel pipe, The steel pipe to be inspected means that the inner diameter accuracy and the bending accuracy do not satisfy the API standard.

  In the drift inspection for mass-produced steel pipes, an automatic device for driving a drift gauge is used. The drift inspection is performed by passing the drift gauge through the inside of the steel pipe to be inspected using such an automatic device and then passing the drift gauge in the reverse direction to the original position.

  Here, as shown in FIG. 46, for example, a typical automatic device used for drift inspection includes a drift bar having a full length longer than the steel pipe to be inspected, and a drift detachably provided at the tip of the drift bar. It consists of a gauge. The drift bar is supported by a plurality of V rollers so that it can move horizontally along the axial direction of the steel pipe. In such an automatic apparatus, the drift gauge attached to the tip of the drift bar is passed through the steel pipe by driving the driving roller connected to the motor and moving the drift bar in the horizontal direction.

  As a result of intensive studies on a method for inspecting a steel pipe inner surface simultaneously with a drift inspection using such a drift gauge, the present inventor has come up with a drift gauge as described below.

<Overall configuration of drift gauge>
Hereinafter, first, the overall configuration of the drift gauge according to the present embodiment will be briefly described with reference to FIG.
The drift gauge according to the present embodiment is used for a drift inspection for inspecting whether a steel pipe conforming to the API standard is manufactured in conformity with the standard, and at the same time as the drift inspection, an inner surface inspection of the steel pipe is performed. It is possible. In the following description, the drift gauge according to this embodiment is applied to the inspection of steel pipes for oil wells (steel pipes). However, the drift gauge can be applied to the inspection of various tubular bodies other than steel pipes. It goes without saying that.

  As schematically shown in FIG. 47, the drift gauge according to this embodiment includes the tubular body imaging device 100 according to the first, second, or third embodiment, and the first, second, or third implementation. A drive control device 150 (not shown) according to the embodiment, and an arithmetic processing device 200 according to the first, second, or third embodiment.

Here, drift gauge is provided detachably on the tip portion of the drift bars as shown in FIG. 47, the length L _d and the diameter D _d of the drift gauge API standard is inspected steel pipe S Is preset in accordance with

  The tip of the drift gauge on the side fed into the steel pipe S has a tapered shape so that the drift gauge is reliably fed into the steel pipe S. The tip of the drift gauge is provided with the tubular body imaging device 100 according to the first, second, or third embodiment so as to be coaxial with the center axis of the drift bar and the drift gauge. Here, the tubular body imaging device 100 according to the first, second, or third embodiment may be attached to the tip of the drift gauge, or as shown schematically in FIG. 47, the tubular body imaging. A part of the device 100 may be provided so as to be located inside the drift gauge.

  Here, as shown in FIG. 47, when a part of the tubular body imaging device 100 is located inside the drift gauge, the irradiation of the annular beam from the tubular body imaging device 100 should not be hindered. Is preferred. Therefore, in such a case, the end of the tubular body imaging device 100 on the side where the camera 120 is located is located inside the drift gauge, not the end of the tubular body imaging device 100 on the side where the illumination mechanism 110 is located. It is preferable. In such an arrangement, the camera 120 that captures the annular beam is positioned inside the drift gauge, but an opening portion having a reverse taper shape is provided at the tip of the drift gauge so as not to obstruct the line of sight of the camera 120. It is preferable that a part of the tubular body imaging device 100 is disposed in the drift gauge through the opening.

  The arithmetic processing unit 200 may be provided inside the drift gauge as schematically shown in FIG. The arithmetic processing device 200 according to the present embodiment can communicate with an external server such as a management server that manages a drift inspection line, provided outside the drift gauge, via wired communication or wireless communication. Is possible.

  In addition, a part of the arithmetic processing device 200 according to the present embodiment is mounted inside the drift gauge, and the rest is provided outside the drift gauge 10 in the form of an information processing device such as various computers or servers. Also good. Further, the arithmetic processing device 200 according to the present embodiment may be provided outside the drift gauge.

  Even when a part or all of the arithmetic processing device 200 is provided outside the drift gauge, mutual communication between two or more arithmetic processing devices or between the tubular body imaging device 100 and the arithmetic processing device 200 is possible. The mutual communication can be performed by wired communication or wireless communication.

  In the example shown in FIG. 47, when mutual communication between apparatuses is realized by wired communication, it is conceivable that the communication cable is led to the outside through the inside of the drift gauge or the drift bar. However, in the actual drift inspection process, it is considered that such a communication cable hinders operation. Therefore, it is preferable that mutual communication between apparatuses is realized by various types of wireless communication such as wireless LAN, Bluetooth, Wi-Fi, and the like. .

  When the functions of the arithmetic processing device 200 are distributed and implemented, it is possible to appropriately set up to which of the functions of the arithmetic processing device 200 are to be mounted inside the drift gauge. At this time, it is preferable that the function to be mounted inside the drift gauge is determined according to the communication speed of mutual communication with the outside, the frame rate of the tubular body imaging device 100, and the like.

<About the structure of the tubular body imaging device 100>
Next, the structure of the tubular body imaging device 100 provided detachably with respect to the drift gauge which concerns on this embodiment is demonstrated.

The tubular body imaging device 100 according to the present embodiment is provided at the tip of the drift gauge as mentioned above. Incidentally, in order not to interfere with the drift test due to drift gauge, the diameter of the tubular body imaging apparatus 100 is set to be smaller than the diameter D _d of the drift gauge.

  The configuration of the tubular body imaging device 100 is the same as that of the tubular body imaging device 100 according to the first, second, or third embodiment, and has the same effect. The explanation will focus on points.

  As schematically shown in FIG. 48, the tubular body imaging apparatus 100 according to the present embodiment includes a tube end of the steel pipe S, a light receiving surface of the camera 120 (also an end surface of a lens provided in the camera 120). When the separation distance L between is larger than a predetermined threshold value, it is determined that the tubular body imaging device 100 is separated from the steel pipe S. In such a case, the tubular body imaging device 100 performs only an imaging process by the camera 120 without irradiating the annular beam, and obtains a surrounding imaging image obtained by imaging the steel pipe and the periphery of the steel pipe around the drift gauge. Generate multiple times at the time interval.

  An example of the surrounding captured image generated in this way is schematically shown in FIG. As schematically shown in FIG. 49, the surrounding captured image is an image having a width of W pixels × a height of H pixels. In the configuration of the tubular body imaging device 100 as shown in FIG. 47, the illumination mechanism 110 is located at the center of the surrounding captured image. In addition, as shown in FIG. 49, the pipe end of the steel pipe S and the inner surface of the steel pipe S are imaged in the surrounding captured image.

  The arithmetic processing device 200 described below determines whether or not the steel pipe S and the drift gauge are in an appropriate positional relationship using the surrounding captured image obtained in this way, Judgment is turned off.

Further, the tubular body imaging apparatus 100 according to this embodiment, when the distance L mentioned above is equal to or less than a predetermined threshold value L _s is configured to initiate the illumination of the annular beam, the imaging processing by the camera 120 is continued . The threshold value L _s is set at a position where the annular beam is irradiated onto the pipe end of the steel pipe S as shown in FIG. When the annular beam forms an image on the inner surface of the steel pipe S, the camera 120 images the reflected light of the annular beam on the inner surface of the steel pipe S, and an annular beam image is generated.

<Configuration of Arithmetic Processing Device 200>
Next, the configuration of the arithmetic processing apparatus 200 according to the present embodiment will be described.
Since the overall configuration of the arithmetic processing apparatus 200 according to the present embodiment is the same as the overall configuration of the arithmetic processing apparatus 200 described in the first to third embodiments, detailed description thereof will be omitted below.

<Regarding Configuration of Image Processing Unit 203>
Next, the configuration of the image processing unit 203 according to the present embodiment will be described with reference to FIGS. 51 to 55B.
The image processing unit 203 according to the present embodiment is different from the configuration of the image processing unit 203 according to the first, second, or third embodiment as described below with a laser irradiation position determination unit and a gauge feed determination. The part is further added. Therefore, in the following, a brief description will be given with reference to FIGS. 51 to 55B with a focus on differences from the configuration of the image processing unit 203 according to the first embodiment. Needless to say, the configuration of the image processing unit 203 according to the present embodiment can be similarly realized for the image processing unit 203 according to the second or third embodiment.

  The image processing unit 203 according to the present embodiment includes an A / D conversion unit 211, an annular beam center calculation unit 213, a coordinate conversion unit 215, a fringe image frame generation unit 217, and the image processing unit 203 according to the first embodiment. In addition to the image calculation unit 219 and the detection processing unit 229, a laser irradiation position determination unit 311 and a gauge feed determination unit 313 are further included.

  Here, the A / D conversion unit 211, the annular beam center calculation unit 213, the coordinate conversion unit 215, the fringe image frame generation unit 217, the image calculation unit 219, and the detection processing unit 229 according to the present embodiment include the first Since it has the same configuration as each processing unit according to the embodiment and has the same effect, the rotation correction unit 227 included in the image calculation unit 219 will be briefly described below and other processing will be performed. Detailed description of the parts is omitted.

  Note that, as described in the first embodiment, the depth image calculation unit 223 and the luminance image calculation unit 225 in the image calculation unit 219 according to this embodiment perform rotation correction on the generated depth image and luminance image. Output to the unit 227. In addition, the depth image calculation unit 223 and the luminance image calculation unit 225 associate the time information regarding the date and time when the depth image and the luminance image are generated with the data corresponding to the generated depth image and the luminance image, and record the history. Information may be stored in the storage unit 207 or the like.

  Further, the rotation correction unit 227 according to the present embodiment is realized by a CPU, a ROM, a RAM, and the like, for example. The rotation correction unit 227 performs the depth image calculated by the depth image calculation unit 223 and the luminance image calculated by the luminance image calculation unit 225 in the same manner as the method described in the first embodiment. Using the rotation direction and magnitude measured by the rotation amount measuring device 130, the positional deviation accompanying the rotation in the pipe circumferential direction is corrected.

  Here, the details of the rotation correction processing performed on each image are the same as the method described in the first embodiment, and thus detailed description thereof will be omitted below. By performing the rotation correction process on the obtained depth image and luminance image in the same manner as in the first embodiment, it is possible to correct the positional deviation accompanying the rotation in the tube circumferential direction.

  The rotation correction unit 227 outputs the corrected depth image and luminance image to the detection processing unit 229 when the rotation correction processing as described above is performed on each of the depth image and the luminance image. In addition, the rotation correction unit 227 may store the information related to the corrected depth image and luminance image as history information in the storage unit 207 or the like in association with time information related to the date and time when the information is corrected. Further, the rotation correction unit 227 may output information regarding the corrected depth image and luminance image to the display control unit 205 and output the information to the display unit (not shown).

  Further, as in the first embodiment, the rotation correction unit 227 outputs information on the calculated rotation direction and magnitude to the imaging control unit 201, and the drive control device 150 of the imaging control unit 201 performs the operation. You may make it use for rotation control with respect to the tubular body imaging device 100. FIG. Similarly to the first embodiment, the rotation correction unit 227 indicates that the tubular body imaging device 100 has rotated too much when the rotation amount output from the rotation correction unit 227 is equal to or greater than a predetermined reference threshold. Warning information (for example, warning information appealing to sight, hearing, touch, etc., such as warning sound, warning display, vibration, etc.) may be output.

  The laser irradiation position determination unit 311 is realized by, for example, a CPU, a ROM, a RAM, a communication device, and the like. The laser irradiation position determination unit 311 refers to the surrounding captured image output from the A / D conversion unit 211, and based on the result of detecting the outer diameter of the steel pipe S based on the luminance distribution in the surrounding captured image, the tubular body imaging Whether the apparatus 100 has reached the position where irradiation of the annular beam should be started (in other words, the steel pipe in the irradiation direction (direction perpendicular to the central axis of the tubular body imaging apparatus 100) in which the annular beam will be irradiated) Whether the inner surface of S is located).

  Details of the laser irradiation position determination processing in the laser irradiation position determination unit 311 will be described with reference to FIGS. 52 and 53.

  When the inner surface of the steel pipe S is inspected in parallel with the drift inspection using the drift gauge according to the present embodiment, the irradiation of the annular beam may be started together with the start of the movement of the drift gauge. If irradiation of the annular beam is started in a state where it is away from the steel pipe S, it is often not preferable in terms of operational safety. On the other hand, as schematically shown in FIG. 52, in the surrounding captured image that starts to be imaged as the drift gauge starts moving, the smaller the distance L from the end of the steel pipe S, the smaller the correspondence to the steel pipe S in the ambient captured image. The area of the area to be increased will increase.

  Therefore, the laser irradiation position determination unit 311 according to the present embodiment estimates how close the drift gauge is to the pipe end of the steel pipe S by paying attention to the size of the region corresponding to the steel pipe S in the surrounding captured image, It is determined whether or not the drift gauge has reached a position where irradiation of the annular beam should be started.

  Here, when considering the environment where the drift inspection is performed, while the surroundings where the drift inspection is performed are maintained at a certain level of brightness by various types of lighting, the inner surface of the steel pipe S is the steel pipe S. Therefore, it is considered that the surrounding ambient light does not reach and the image is darker than the surroundings. Further, when the image output from the A / D conversion unit 211 is not an ambient captured image but an annular beam image, the luminance distribution in the captured image is significantly different from the ambient captured image. It is easy to distinguish the beam image.

  Therefore, the laser irradiation position determination unit 311 according to this embodiment focuses on the luminance distribution of the image output from the A / D conversion unit 211. Then, when the laser irradiation position determination unit 311 determines that the output image is a surrounding captured image, the drift gauge starts to irradiate the annular beam while paying attention to the luminance distribution of the surrounding captured image. It is determined whether or not the position to be reached has been reached.

  More specifically, the laser irradiation position determination unit 311 according to the present embodiment specifies a luminance distribution with respect to a predetermined monitoring direction in the surrounding captured image, and is installed based on a predetermined threshold regarding luminance with respect to the monitoring direction. A position corresponding to the outer diameter of the steel pipe S is detected. Thereafter, the laser irradiation position determination unit 311 is a position where the tubular body imaging device 100 should start irradiation of the annular beam when the detected outer diameter of the steel pipe S has a value equal to or greater than a predetermined threshold value. It is judged that it has reached.

  Here, the laser irradiation position determination unit 311 pays attention to the size corresponding to the outer diameter of the steel pipe S, and the steel pipe S is considered to be captured almost symmetrically with the center of the surrounding captured image as a reference. . Therefore, as shown in FIG. 52, the laser irradiation position determination unit 311 pays attention to one direction passing through the center of the surrounding captured image (in FIG. 52, the width direction of the surrounding captured image). Note that the monitoring direction is not limited to the monitoring direction as described above, and other monitoring directions may be employed, for example, the height direction of the surrounding captured image or the direction of the diagonal line is set as the monitoring direction.

  As described above, the environment where the drift inspection is performed is brighter than the portion corresponding to the steel pipe S, and the position of the steel pipe S is not appropriate, and the other pipe end is reflected in the surrounding captured image. It is considered that the other end of the tube is also brightened. Therefore, by verifying in advance the ambient light at the place where the drift inspection is to be performed (specifically, the ambient light is actually imaged using the tubular body imaging device 100 to be used), thereby obtaining a luminance threshold Th. Can be determined appropriately. In addition, the laser irradiation position determination unit 311 calculates the luminance value of the corresponding position and the threshold value Th from both ends in the monitoring direction of the surrounding captured image (for example, the left end portion and the right end portion of the horizontal axis coordinates in FIG. 53). We will carry out large and small comparisons. The laser irradiation position determination unit 311 can detect the position where the luminance value is equal to or less than the threshold Th for the first time as the position corresponding to the outer diameter of the steel pipe in the monitoring direction of interest.

As shown in FIG. 53, the number of pixels Xd in the region existing inside the position corresponding to the outer diameter of the steel pipe corresponds to the size of the outer diameter of the steel pipe S in the monitoring direction of interest. It can be judged. Here, as shown in the lower part of FIG. 52, the laser irradiation position determination unit 311 has the tube end of the steel pipe S positioned exactly in the irradiation direction of the annular beam (the direction perpendicular to the central axis of the tubular body imaging device 100). In this case, the number of pixels D _p of the outer diameter of the steel pipe S in the surrounding captured image is used as a threshold value. In other words, the laser irradiation position determination unit 311, the pixel number D _p of the outer diameter of the steel pipe S at the periphery captured image when distance L between the light receiving surface of the pipe end and the camera 120 of the steel pipe S is L _s Used as a threshold value. On top of that, the laser irradiation position determination unit 311, when the specified number of pixels Xd is the predetermined threshold value D _p or (Xd ≧ D _p is satisfied), has reached a position to start the irradiation of the annular beam Judge.

  When the laser irradiation position determination unit 311 determines that the tubular body imaging apparatus 100 has reached the position where the irradiation of the annular beam should start, the laser irradiation position determination unit 311 notifies the imaging control unit 201 and the processing unit after the annular beam center calculation unit 213 to that effect. Is output. Thereby, the imaging control unit 201 outputs a control signal for starting the irradiation of the laser light to the illumination mechanism 110 of the tubular body imaging device 100, and the processing units after the annular beam center calculation unit 213 are annular. Based on the annular beam image obtained by imaging the beam, the defect detection process for the inner surface of the steel pipe S is started.

  Thereby, in the drift gauge according to the present embodiment, it is possible to irradiate the annular beam only for the minimum necessary time to irradiate the annular beam, and it is possible to realize a safer inspection state.

  The laser irradiation position determination unit 311 also distributes the luminance of the image output as needed from the A / D conversion unit 211 even after the tubular body imaging apparatus 100 determines that the position where the annular beam irradiation should start is reached. It may be determined whether the output image is a surrounding captured image or an annular beam image. In addition, when the image output from the A / D conversion unit 211 is switched from the annular beam image to the surrounding captured image, the tubular body imaging device 100 determines that the inside of the steel pipe S has been passed, and accordingly. You may output to the imaging control part 201 and the process part after the annular beam center calculation part 213. FIG. Thereby, the imaging control unit 201 can output a control signal for stopping the irradiation of the laser light.

  Whether or not the tubular body imaging device 100 has passed through the steel pipe S should be determined by the imaging control unit 201 and the PLG signal output from the tubular body imaging device 100, the drive control device 150, and the like. It can also be specified by determining whether or not the tubular body imaging device 100 has moved a length equal to or greater than the total length of the steel pipe based on management information such as the total length of the steel pipe regarding the steel pipe S.

In addition, the laser irradiation position determination unit 311 pays attention to the outer diameter of the steel pipe S in the surrounding captured image in the same manner as described above, so that the separation distance L between the pipe end of the steel pipe S and the light receiving surface of the camera 120 is increased. , it is possible to determine whether a distance L _G should perform gauge infeed determination process will be described later. If the magnitude of the distance L becomes L _G, the laser irradiation position determination unit 311 outputs and its effect to the input determination unit 313 transmission gauge. As a result, gauge feeding determination processing is performed in a gauge feeding determination unit 313 described later.

Referring back to FIG. 51 again, the gauge feeding determination unit 313 will be described in detail.
The gauge feeding determination unit 313 is realized by, for example, a CPU, a ROM, a RAM, a communication device, and the like. The gauge feed determination unit 313 refers to the surrounding captured image output from the A / D conversion unit 211, and based on the result of detecting the installation position of the steel pipe S based on the luminance distribution in the ambient captured image, the steel pipe S is Determine if the drift gauge is properly installed at a position where it can be inserted.

  Details of the gauge feeding determination process in the gauge feeding determining unit 313 will be described with reference to FIGS. 54 to 55B.

  When the steel pipe S is transported to the drift inspection line for performing the drift inspection on the steel pipe S, when the steel pipe S is not properly transported or the steel pipe S itself is bent, The steel pipe S may not be appropriately positioned at a position where the drift gauge can be inserted.

  In that case, in the surrounding captured image, for example, as schematically shown in FIG. 54, the illumination mechanism 110 itself is located at the center, but the region corresponding to the steel pipe S is decentered from the center of the surrounding captured image. Become. For example, when a bending or the like occurs in the steel pipe S, the region corresponding to the steel pipe S corresponds to the vertical direction (the direction of the height H in FIG. 54) or the horizontal direction (the width in FIG. 54). Eccentric in the direction of W). Further, when the steel pipe S is not properly transported and does not reach the original position or passes through the original position, the region corresponding to the steel pipe S is decentered in the left-right direction.

Therefore, the gauge infeed determining unit 313 according to this embodiment, the laser irradiation position determination unit 311, the information indicating that the distance L becomes L _G is outputted, output from the A / D converter 211 Further, attention is paid to the luminance distribution of the surrounding captured image at the corresponding position. In addition, the gauge feeding determination unit 313 determines whether or not the steel pipe S is appropriately positioned at a position where the drift gauge can be inserted, paying attention to the luminance distribution of the surrounding captured image.

  As described earlier, as the direction in which the region corresponding to the steel pipe S in the surrounding captured image is decentered, the horizontal direction and the vertical direction in the surrounding captured image, and the direction defined by the combination of these two directions are conceivable. Therefore, the gauge feeding determination unit 313 according to the present embodiment sets two directions orthogonal to each other as monitoring directions, as shown in FIG. 54, for example. For convenience, the direction parallel to the left-right direction of the surrounding captured image is defined as a monitoring direction A, and the direction parallel to the vertical direction of the surrounding captured image is defined as a monitoring direction B. Note that the monitoring direction is not limited to the two monitoring directions as described above, and other monitoring directions may be adopted, for example, the diagonal direction of the surrounding captured image is set as the monitoring direction.

Gauge infeed determination unit 313, the separation distance from the end portion of the steel pipe S to get around captured image when a predetermined value L _G, based on a predetermined luminance threshold value Th, a region corresponding to the steel pipe S A boundary with the surroundings (that is, a portion corresponding to the edge of the outer surface of the steel pipe S) is detected. Such boundary detection processing is performed for each of the two monitoring directions (monitoring direction A and monitoring direction B) as shown in FIGS. 55A and 55B. The above values L _G is set from the light receiving surface of the camera 120 as drift gauge is equal to or greater than a value obtained by adding the stopping distance to reach the stop from moving operation for the distance to the holding substrate 141 of the tip of the imaging probe Let

  Here, the gauge feed determining unit 313 determines the luminance value and threshold value Th of the corresponding position from both ends of the surrounding captured image in the monitoring direction (for example, the left end and the right end of the horizontal coordinate in FIGS. 55A and 55B). We will carry out a size comparison with. In addition, the gauge feeding determination unit 313 can detect the position where the luminance value is equal to or less than the threshold Th for the first time as the position corresponding to the outer diameter of the steel pipe in the monitoring direction of interest.

With respect to the two monitoring directions A and B, it can be determined that the region existing inside the position corresponding to the outer diameter of the steel pipe is a portion corresponding to the steel pipe S. Therefore, the gauge feeding determination unit 313 determines that the separation distance from the end of the steel pipe S to the light receiving surface of the camera 120 is L _G with reference to the center of the surrounding captured image (position corresponding to W / 2 and H / 2). When the outer diameter on the captured image when the steel pipe S is in the optimal position is D _s (the center of the circle is equal to the image center), the width of the region corresponding to the steel pipe S is D _{s to} D _s. It is determined whether it is within the range of + α. Here, considering that the drift gauge diameter of D _d is even deviated from the center of the steel pipe S, the portion of the tapered shape provided at a distal end (diameter D _T) need be fed to the interior of the steel pipe S Thus, the specific size of the allowable range α is appropriately determined. Actually, the value of α is determined according to how many pixels the size represented by (D _d −D _T ) / 2 corresponds to in the surrounding captured image.

  Specifically, as shown in FIG. 55A and FIG. 55B, the gauge feeding determination unit 313 is the left side X1 of the steel pipe background region (steel pipe outer diameter) determined by the threshold Th in the monitoring direction A passing through the center of the image. And the lower side Y1 and the upper side Y2 of the steel pipe background region (steel pipe outer diameter) determined by the threshold Th in the monitoring direction B passing through the center of the image. In addition, the gauge feed determination unit 313 is appropriately positioned at a position where the steel pipe S can be inserted with the drift gauge when all of the four conditions represented by the following formulas 201 to 207 are satisfied. to decide.

W / 2− (D _s + α) / 2 <X1 <W / 2−D _s / 2 (Formula 201)
W / 2− (D _s + α) / 2 <X2 <W / 2−D _s / 2 (Formula 203)
H / 2− (D _s + α) / 2 <Y1 <H / 2−D _s / 2 (Formula 205)
H / 2− (D _s + α) / 2 <Y2 <H / 2−D _s / 2 (Formula 207)

  When the gauge feeding determination unit 313 determines that the steel pipe S is appropriately positioned at a position where the drift gauge can be inserted, the gauge feeding determination unit 313 outputs that fact to the imaging control unit 201. Thereby, the imaging control unit 201 can continue the movement operation of the drift gauge. On the other hand, when the gauge feeding determination unit 313 determines that the steel pipe S is not properly positioned at a position where the drift gauge can be inserted, the gauge feeding determination unit 313 outputs that fact to the imaging control unit 201. As a result, the imaging control unit 201 stops the movement operation of the drift gauge and outputs a warning signal to the outside. As a result, it is possible to eliminate factors that hinder efficient inspection, such as the drift gauge not being fed into the steel pipe S or the drift gauge being broken by colliding with the steel pipe S. As a result, the drift inspection and the steel pipe inner surface inspection can be efficiently performed by using the drift gauge according to the present embodiment.

  As described above, the laser irradiation position determination unit 311 and the gauge feed determination unit 313 according to this embodiment perform the determination process as described above by paying attention to the luminance distribution (luminance profile) in the surrounding captured image. Is going. Here, in the ambient captured image, the ambient light is illuminated from the pipe end of the steel pipe S without illuminating the inside of the steel pipe in order to perform the above-described determination processing more accurately by setting the brightness of the ambient light to a more reliably high value A separate light source may be provided.

  The configuration of the image processing unit 203 included in the arithmetic processing device 200 according to the present embodiment has been described above in detail.

  Heretofore, an example of the function of the arithmetic processing apparatus 200 according to the present embodiment has been shown. Each component described above may be configured using a general-purpose member or circuit, or may be configured by hardware specialized for the function of each component. In addition, the CPU or the like may perform all functions of each component. Therefore, it is possible to appropriately change the configuration to be used according to the technical level at the time of carrying out the present embodiment.

  A computer program for realizing each function of the arithmetic processing apparatus according to the present embodiment as described above can be produced and installed in a personal computer or the like. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

  The configuration of the drift gauge according to the present embodiment has been described in detail above. By utilizing the drift gauge according to the present embodiment, it is possible to inspect the inner surface of the steel pipe S over the entire circumference in the circumferential direction and at the same time, while performing the drift inspection on the steel pipe S. Defects and pattern-like defects can be detected simultaneously with high accuracy. In addition, since the drift gauge according to the present embodiment can accurately identify the position where the defect occurs, it can greatly contribute to the improvement of the productivity and yield of the steel pipe S and the quality assurance.

(About hardware configuration)
Next, the hardware configuration of the arithmetic processing device 200 according to each embodiment of the present invention will be described in detail with reference to FIG.

  The arithmetic processing device 200 mainly includes a CPU 901, a ROM 903, and a RAM 905. The arithmetic processing device 200 further includes a bus 907, an input device 909, an output device 911, a storage device 913, a drive 915, a connection port 917, and a communication device 919.

  The CPU 901 functions as a central processing device and control device, and controls all or a part of the operation in the arithmetic processing device 200 according to various programs recorded in the ROM 903, the RAM 905, the storage device 913, or the removable recording medium 921. To do. The ROM 903 stores programs used by the CPU 901, calculation parameters, and the like. The RAM 905 primarily stores programs used by the CPU 901, parameters that change as appropriate during execution of the programs, and the like. These are connected to each other by a bus 907 constituted by an internal bus such as a CPU bus.

  The bus 907 is connected to an external bus such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge.

  The input device 909 is an operation unit operated by the user, such as a mouse, a keyboard, a touch panel, a button, a switch, and a lever. The input device 909 may be, for example, remote control means (so-called remote control) using infrared rays or other radio waves, or may be an external connection device 923 such as a PDA corresponding to the operation of the arithmetic processing device 200. May be. Furthermore, the input device 909 includes, for example, an input control circuit that generates an input signal based on information input by a user using the operation unit and outputs the input signal to the CPU 901. By operating the input device 909, the user can input various data or instruct processing operations to the arithmetic processing device 200.

  The output device 911 is configured by a device capable of visually or audibly notifying acquired information to the user. Such devices include display devices such as CRT display devices, liquid crystal display devices, plasma display devices, EL display devices and lamps, audio output devices such as speakers and headphones, printer devices, mobile phones, and facsimiles. The output device 911 outputs results obtained by various processes performed by the arithmetic processing device 200, for example. Specifically, the display device displays the results obtained by various processes performed by the arithmetic processing device 200 as text or images. On the other hand, the audio output device converts an audio signal composed of reproduced audio data, acoustic data, and the like into an analog signal and outputs the analog signal.

  The storage device 913 is a data storage device configured as an example of a storage unit of the arithmetic processing device 200. The storage device 913 includes, for example, a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device. The storage device 913 stores programs executed by the CPU 901, various data, various data acquired from the outside, and the like.

  The drive 915 is a recording medium reader / writer, and is built in or externally attached to the arithmetic processing unit 200. The drive 915 reads information recorded on a removable recording medium 921 such as a mounted magnetic disk, optical disk, magneto-optical disk, or semiconductor memory, and outputs the information to the RAM 905. The drive 915 can also write a record on a removable recording medium 921 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. The removable recording medium 921 is, for example, a CD medium, a DVD medium, a Blu-ray (registered trademark) medium, or the like. Further, the removable recording medium 921 may be a compact flash (registered trademark) (CompactFlash: CF), a flash memory, an SD memory card (Secure Digital memory card), or the like. Further, the removable recording medium 921 may be, for example, an IC card (Integrated Circuit card) on which a non-contact type IC chip is mounted, an electronic device, or the like.

  The connection port 917 is a port for directly connecting a device to the arithmetic processing device 200. Examples of the connection port 917 include a USB (Universal Serial Bus) port, an IEEE 1394 port, a SCSI (Small Computer System Interface) port, and an RS-232C port. By connecting the external connection device 923 to the connection port 917, the arithmetic processing apparatus 200 acquires various data directly from the external connection device 923 or provides various data to the external connection device 923.

  The communication device 919 is a communication interface configured with, for example, a communication device for connecting to the communication network 925. The communication device 919 is, for example, a communication card for wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), or WUSB (Wireless USB). The communication device 919 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various communication. The communication device 919 can transmit and receive signals and the like according to a predetermined protocol such as TCP / IP, for example, with the Internet and other communication devices. In addition, the communication network 925 connected to the communication device 919 is configured by a wired or wireless network, for example, the Internet, a home LAN, an in-house LAN, infrared communication, radio wave communication, satellite communication, or the like. May be.

  Heretofore, an example of the hardware configuration capable of realizing the function of the arithmetic processing device 200 according to each embodiment of the present invention has been shown. Each component described above may be configured using a general-purpose member, or may be configured by hardware specialized for the function of each component. Therefore, it is possible to change the hardware configuration to be used as appropriate according to the technical level at the time of carrying out this embodiment.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Tubular body surface inspection apparatus 100 Tubular body imaging device 110 Illumination mechanism 111 Laser light source 113 Conical optical element 115 Conical illumination light source 117 Toroidal base 119 Light emitting element 120 Camera 130 Rotation amount measuring device 141 Holding substrate 143 Connecting member DESCRIPTION OF SYMBOLS 150 Drive control apparatus 200 Arithmetic processing apparatus 201 Imaging control part 203 Image processing part 205 Display control part 207 Storage part 211,251,281 A / D conversion part 213,253,283 Annular beam center calculation part 215,255,285 Coordinate conversion Sections 217, 257, 287 Stripe image frame generation section 219, 259, 289 Image calculation section 221, 261, 291 Optical section line processing section 223, 263, 293 Depth image calculation section 225, 265, 295 Luminance image calculation section 227, 267, 299 Rotation correction unit 29,273,301 detection processing unit 269 depth image compensating unit 271 luminance image compensating unit 297 light luminance image generating unit

Claims (18)

While moving along the tube axis direction of the tubular body, irradiating an annular laser beam to the entire circumferential direction of the inner surface of the tubular body, and imaging the inner surface irradiated with the annular laser beam A tubular body imaging device that generates a plurality of annular beam images, which are captured images of the annular laser light on the inner surface, along the tube axis direction of the tubular body;
An arithmetic processing unit that performs image processing on the annular beam image generated by the tubular body imaging device and determines whether a defect exists on the inner surface of the tubular body;
With
The tubular body imaging device comprises:
An illumination mechanism having at least a laser beam irradiation device that irradiates the annular laser beam to the entire circumferential direction of the inner surface of the tubular body;
An imaging device for imaging the inner surface irradiated with the annular laser beam;
A rotation amount measuring device that measures the direction and magnitude of rotation of the tubular body in the tube circumferential direction that occurs when the tubular body imaging device moves along the tube axis direction of the tubular body;
Have
The arithmetic processing unit includes:
An annular beam center calculating unit for calculating the center of gravity position and radius of the irradiated portion of the annular laser beam in each of the annular beam images;
The coordinate system of the annular beam image is converted based on the calculated center-of-gravity position and the distance between the center-of-gravity position and the annular laser light irradiation portion, and each annular laser light irradiation portion is converted. A coordinate conversion unit that generates a plurality of light cutting images that are band-like regions including light cutting lines that are line segments developed in the tube circumferential direction of the tubular body;
Based on a striped image frame in which each of the light-cut images is sequentially arranged along the tube axis direction, a depth image representing an uneven state of the inner surface of the tubular body, and the annular shape on the inner surface of the tubular body A luminance image representing the luminance distribution of the laser light, and an image calculating unit for calculating
For each of the calculated depth image and luminance image, the displacement in the tube circumferential direction accompanying the rotation in the tube circumferential direction is determined using the direction and magnitude of the rotation measured by the rotation amount measuring device. A rotation correction unit to correct,
Based on the corrected depth image and the luminance image, a detection processing unit that detects a defect present on the inner surface of the tubular body;
Have
The image calculation unit calculates a barycentric position in the line width direction of the light cutting line along the tube circumferential direction, and the radius is a reference that is a position in the tube axis direction designated in advance for the light cutting image. A tubular body surface inspection apparatus that calculates the depth image as a position based on a displacement amount between the reference position and the gravity center position. The depth image is an image representing a two-dimensional uneven state distribution in which the one-dimensional distribution of the uneven state at each position in the tube axis direction is sequentially arranged along the tube axis direction,
The luminance image is an image representing a two-dimensional luminance distribution in which a one-dimensional distribution of the luminance of the annular laser beam at each position in the tube axis direction is sequentially arranged along the tube axis direction,
The rotation correction unit, for each of the depth image and the brightness image, the one-dimensional distribution at each position in the tube axis direction, and the rotation direction measured at the corresponding position in the tube axis direction. The tubular body surface inspection apparatus according to claim 1, wherein the positional deviation is corrected by translating the measured amount of rotation in the opposite direction.   The tubular body surface inspection device according to claim 1 or 2, wherein the rotation amount measuring device is one of an accelerometer, a gyro sensor, and a rotary encoder. The tubular body imaging device includes a drive mechanism that performs at least movement of the illumination mechanism and the imaging device along the tube axis direction and rotation of the tube circumferential direction,
The drive mechanism uses the direction and magnitude of the rotation measured by the rotation amount measuring device, while controlling the rotation in the pipe circumferential direction so that the magnitude of the rotation is a predetermined threshold value or less. The tubular body surface inspection device according to claim 1, wherein the illumination mechanism and the imaging device are moved along the tube axis direction.   The warning information that warns that the tubular body imaging device is rotating excessively is output when the magnitude of the rotation measured by the rotation amount measuring device exceeds a predetermined threshold value. The tubular body surface inspection apparatus according to any one of? The detection processing unit
Identifying a defect site based on whether the pixel values of the depth image and the luminance image are greater than or equal to a second threshold for defect site identification;
For the identified defective part, extract feature quantity information regarding the form and pixel value of the defective part,
The tubular body surface inspection apparatus according to any one of claims 1 to 5, wherein a defect existing on an inner surface of the tubular body is determined based on the extracted feature amount information. The tubular body imaging device comprises:
It further has one or a plurality of connecting members for connecting and fixing the illumination mechanism and the imaging device,
When the tubular body imaging device is sent into the tubular body and when the tubular body imaging device is sent out from the inside of the tubular body, the annular laser beam is emitted by the connecting member. The annular beam image including the shielding area generated by being shielded is generated, and between the sending and sending of the tubular body imaging device, the shielding area of the annular beam image at the time of feeding and Rotate the tubular body imaging device so as not to overlap the shielded area of the annular beam image,
The coordinate conversion unit converts a coordinate system of the annular beam image at the time of sending and at the time of sending, with a predetermined position on the inner surface of the tubular body as a reference point, and a plurality of the light-cut images at the time of sending and Generating a plurality of the light-cutting images at the time of transmission;
The image calculation unit
Using the light cut image at the time of sending or the light cut image at the time of sending, the position of the shielding area in the light cut image is specified,
In the depth image and the luminance image calculated based on the annular beam image at the time of sending or sending and corrected by the rotation correction unit, the shielded region is defined as the annular beam at the time of sending or sending. The tubular body surface inspection apparatus according to any one of claims 1 to 6, which is complemented using the depth image and the luminance image calculated based on an image and corrected by the rotation correction unit. The illumination mechanism further includes a conical illumination light source that emits conical illumination light with respect to the entire circumferential direction of the inner surface of the tubular body,
In the imaging apparatus, the irradiation surface of the annular laser light and the irradiation area of the conical illumination light are within the same field of view on the inner surface irradiated with the annular laser light and the conical illumination light. Image to fit in,
The coordinate conversion unit further generates a plurality of illumination light luminance images, which are band-like regions obtained by expanding the irradiation region of the conical illumination light in the tube circumferential direction of the tubular body along the tube axis direction of the tubular body. And
The rotation correction unit uses the rotation direction and size measured by the rotation amount measurement device for the calculated illumination light luminance image, and causes a displacement in the tube circumferential direction accompanying the rotation in the tube circumferential direction. To correct
The tubular body surface inspection according to any one of claims 1 to 7, wherein the detection processing unit further detects a defect existing on the inner surface of the tubular body using the corrected illumination light luminance image. apparatus.   2. At least the illumination mechanism and the imaging device of the tubular body imaging device are provided at a distal end portion on a feeding side of a drift gauge that moves in the steel tube along a tube axis direction during a drift inspection of the steel tube. The tubular body surface inspection apparatus according to any one of? 7. An annular laser beam with respect to the entire circumferential direction of the inner surface of the tubular body while moving along the tube axis direction of the tubular body while measuring the direction and magnitude of rotation occurring in the circumferential direction of the tubular body And an annular beam image, which is an image of the annular laser light on the inner surface, is taken along the tube axis direction of the tubular body by imaging the inner surface irradiated with the annular laser light. Generating step;
Calculating a center of gravity position and a radius of an irradiation portion of the annular laser beam in each of the annular beam images;
The coordinate system of the annular beam image is converted based on the calculated center-of-gravity position and the distance between the center-of-gravity position and the annular laser light irradiation portion, and each annular laser light irradiation portion is converted. Generating a plurality of light cutting images that are band-like regions including light cutting lines that are line segments developed in the circumferential direction of the tubular body;
Based on a striped image frame in which each of the light-cut images is sequentially arranged along the tube axis direction, a depth image representing an uneven state of the inner surface of the tubular body, and the annular shape on the inner surface of the tubular body Calculating a luminance image representing a luminance distribution of the laser light;
For each of the calculated depth image and the luminance image, using the measured rotation direction and magnitude, correcting the displacement in the tube circumferential direction accompanying the rotation in the tube circumferential direction;
Detecting a defect present on the inner surface of the tubular body based on the corrected depth image and the luminance image;
Including
In the step of calculating the depth image and the luminance image, a barycentric position in the line width direction of the light cutting line along the circumferential direction is calculated, and the radius is designated in advance for the light cutting image. A tubular body surface inspection method in which the depth image is calculated based on a displacement amount between the reference position and the gravity center position as a reference position that is a position in the tube axis direction. A drift gauge that moves inside the steel pipe along the pipe axis direction during drift inspection of the steel pipe,
Among the tubular body imaging devices included in the tubular body surface inspection device according to any one of claims 1 to 7 and claim 9, at least the illumination mechanism and the imaging device are provided at the distal end portion on the feeding side. ,
The arithmetic processing apparatus which the tubular body surface inspection apparatus of any one of Claims 1-7 and Claim 9 has is a drift gauge which judges whether a defect exists in the internal surface of the said steel pipe. The arithmetic processing device performs imaging control including movement control of the tubular body imaging device along the tube axis direction, irradiation control of the illumination mechanism in the tubular body imaging device, and imaging control in the imaging device. An imaging control unit;
The imaging control unit starts imaging processing at a predetermined time interval with the start of movement of the drift gauge, and captures a surrounding captured image obtained by imaging the steel pipe and the periphery of the steel pipe with the drift gauge as a center. The drift gauge according to claim 11, wherein a plurality of drift gauges are generated along the tube axis direction. The arithmetic processing unit determines whether the imaging device has reached a position where the annular laser beam irradiation should start based on a result of detecting an outer diameter of the steel pipe based on a luminance distribution in the surrounding captured image. A laser irradiation position determination unit that
The imaging control unit starts irradiation of the inner surface of the annular laser beam when the laser irradiation position determination unit determines that the position where irradiation of the annular laser beam is to start is reached. The drift gauge according to claim 12. The laser irradiation position determination unit
Specifying a luminance distribution for a predetermined monitoring direction in the surrounding captured image;
For the monitoring direction, based on a predetermined threshold value for brightness, detect a position corresponding to the outer diameter of the installed steel pipe,
It is judged that the position where irradiation of the annular laser beam should be started is determined when the detected outer diameter of the steel pipe has a value equal to or greater than a predetermined threshold value. Drift gauge. The arithmetic processing unit determines whether the steel pipe is installed at a position where the drift gauge can be inserted based on the result of detecting the installation position of the steel pipe based on the luminance distribution in the surrounding captured image. A determination unit;
The imaging control unit stops the operation of feeding the drift gauge when the gauge feeding determination unit determines that the steel pipe is not installed at a position where the drift gauge can be inserted. The drift gauge of any one of -14. The gauge feeding determination unit
For the surrounding captured image when the separation distance between the steel pipe and the light receiving surface of the imaging device becomes a predetermined value, specify the luminance distribution in two monitoring directions orthogonal to each other,
For each of the two monitoring directions, based on a predetermined threshold value for brightness, a position corresponding to the outer diameter of the steel pipe that is installed is detected,
When the detected position of the outer diameter of the steel pipe is located within a predetermined range with reference to the center of the surrounding captured image, it is determined that the steel pipe is installed at a position where the drift gauge can be inserted. The drift gauge according to claim 15.   The drift gauge according to any one of claims 12 to 16, wherein at least a part of the arithmetic processing unit is provided inside the drift gauge. A drift inspection method for performing a drift inspection of a steel pipe using a drift gauge that moves along the pipe axis direction inside the steel pipe,
A drift in which at least an illumination mechanism and an imaging device are provided among the tubular body imaging devices included in the tubular body surface inspection device according to any one of claims 1 to 7 and claim 9 at a distal end portion on a sending side. A plurality of annular beam images are generated along the tube axis direction of the tubular body by moving the gauge along the tube axis direction of the steel tube;
The drift inspection method which judges whether the defect exists in the internal surface of the said steel pipe with the arithmetic processing apparatus which the tubular body surface inspection apparatus of any one of Claims 1-7 and Claim 9 has.