JP5891893B2 - Laser radar equipment - Google Patents

Description

  The present invention relates to a laser radar device.

  In the field of laser radar devices, a configuration of a horizontal scanning method as in Patent Document 1 is widely provided. For example, in the apparatus of Patent Document 1, an optical isolator that transmits laser light and reflects reflected light from a detection object toward the detection means is provided on the optical axis of the laser light from the laser light generation means. . Furthermore, a concave mirror that rotates about the central axis in the optical axis direction is provided on the optical axis of the laser light that passes through the optical isolator. The concave mirror reflects the laser light toward the space and reflects it from the detection object. Reflecting light toward the optical isolator enables 360 ° horizontal scanning. However, in such a general horizontal scanning method, there is a problem that the detection area is limited to a plane, and an area outside the scanning plane cannot be detected. Therefore, an object outside the scanning plane cannot be detected, and even if an object exists in the scanning plane, the object cannot be grasped in three dimensions.

Japanese Patent No. 2789741 JP 2006-209318 A

  On the other hand, as a technique for solving such a problem, Patent Document 2 is provided. The laser radar head disclosed in Patent Document 2 rotates around a polygon mirror (1c) that rotates about a predetermined rotation axis and a rotation axis that is orthogonal to the rotation axis of the polygon mirror (1c). The oscillating mirror (1d) is provided, the laser beam from the laser light source (1a) is reflected by the polygon mirror (1c), and the oscillating mirror (1d) is positioned on the path of the reflected laser beam. It is like that. In this configuration, the rotation of the polygon mirror (1c) changes the direction of the laser beam in the external space in the main scanning direction (lateral direction), and the rotation of the oscillating mirror (1d) causes the laser beam in the external space. The direction of the laser beam is changed in the sub-scanning direction (vertical direction), and the scanning direction of the laser light irradiated to the space is not limited to a single plane direction, and three-dimensional detection is possible. Yes.

  However, in the method of Patent Document 2, since the tilt of the laser beam is changed in the height direction with the position of the oscillating mirror as the irradiation base point, the height of the laser beam is changed at a certain distance from the oscillating mirror. Although the detection range becomes wide, the detection range in the height direction becomes very narrow at a position close to the oscillating mirror (that is, near the apparatus), and object detection can be performed only in a very limited height range. For this reason, there is a problem in that a blind spot is easily formed in the vicinity of the apparatus, and an omission in detection of an object entering the blind spot is likely to occur.

  For example, taking FIG. 3 of Patent Document 2 as an example, in this configuration, the above-described laser radar head (1) is arranged on a predetermined wall, and gradually increases from the wall with the laser radar head (1) as a base point. However, the detection area is extremely narrow at a position close to the laser radar head (1), and the laser beam is directly below the laser radar head (1). Is a blind spot that cannot be reached at all. With such a configuration, for example, when a detection target (a person in Patent Document 2) approaches along the wall to which the laser radar head (1) is attached, the detection target cannot be detected and detected. Leakage will occur.

  The present invention has been made to solve the above-described problems, and can detect three-dimensionally so that the scanning range extends not only in the horizontal direction but also in the vertical direction (height direction). An object of the present invention is to provide a laser radar device that can easily secure a wide height range of a detection area even in the vicinity.

The present invention has been made to solve the above-described problems,
A light projecting unit that includes a laser light source that generates laser light and guides the laser light emitted from the laser light source through the light projecting path in the height direction when the predetermined direction is the height direction;
A rotating structure in which a plurality of deflecting portions are integrally rotatable around a rotation axis parallel to the light projecting path in the height direction through which the laser light is guided, and a drive for rotating the rotating structure Each of the plurality of deflecting portions is arranged around the rotation axis so as to be shifted from each other in the circumferential direction around the rotation axis, and each deflection surface is orthogonal to the height direction. Are arranged so as to be shifted from each other in the height direction so that they do not overlap with each other, and each deflecting portion sequentially passes through the light projecting path of the laser light as the rotating structure rotates, by the driving means Rotation deflecting means for deflecting the laser light in turn by each deflecting unit while rotating the rotating structure;
When the laser light is generated by the laser light source and the laser light is guided to the external space by the deflecting unit, the reflected light generated by the reflection of the laser light by the object in the external space is converted into the deflecting unit or the Guiding means (conscious of coaxial and other axes) guided to the light receiving path by the second deflecting unit rotating around the rotation axis so as to be synchronized with the deflecting unit;
A light receiving means for receiving the reflected light guided by the guiding means;
An azimuth detecting means for detecting at least the azimuth of the object based on a rotation angle of the rotating structure when the light receiving means receives the reflected light;
It is provided with.

According to the first aspect of the present invention, there is provided a rotating structure in which a plurality of deflecting portions are integrally rotatable around a rotation axis parallel to the light projection path in the height direction of the laser beam. Each of the plurality of deflecting portions is arranged to be shifted in the circumferential direction around the rotation axis, and each of the deflecting surfaces is arranged to be shifted in the height direction so as not to overlap in the direction orthogonal to the height direction. Yes. Then, as the rotating structure is rotated by the driving unit, each deflecting unit sequentially passes the laser light projecting path and deflects the laser light at each position shifted in the height direction. In this configuration, a plurality of starting positions (deflection positions) when irradiating laser light to the space are shifted in the height direction, and laser light can be emitted from each position in the height direction of the apparatus. The detection area can be set so as to cover a wide range of heights to a certain extent even at a position very close to.
In particular, according to the conventional technique represented by Patent Document 2, the detection area can be secured only within a very narrow height range in the vicinity of the apparatus due to the characteristic that the laser beam is swung up and down with the vicinity of the deflection unit as the base point (starting position). There is a problem, and there is a concern that the area below the narrow detection area becomes a blind spot, and an object approaching the apparatus cannot be detected from this blind spot, resulting in a detection failure. The blind spot can be reduced as much as possible, and the detection omission due to the blind spot can be suppressed.

  In the invention of claim 2, all of the plurality of deflecting portions deflect the laser light in a direction (horizontal direction) orthogonal to the height direction. As described above, since each deflection unit (reflecting member) deflects the laser beam in the horizontal direction, the detectable range (the height range in which the laser beam can be irradiated) near the apparatus continues to a farther position. Become. That is, the detection area can be maintained within a certain height range from a position very close to the apparatus to a far position.

In the invention of claim 3, the projection areas when the respective deflection surfaces of the plurality of deflection units are projected onto a virtual plane orthogonal to the rotation axis are arranged side by side in the circumferential direction around the rotation axis on the virtual plane. In addition, each projection region is continuous with other projection regions adjacent to both sides in the circumferential direction on the virtual plane.
In this configuration, when the rotating structure is viewed in plan, the deflecting surface of each deflecting unit is continuous with the other deflecting surfaces on both sides in the circumferential direction. Therefore, the rotating structure is rotated to emit laser light to each deflecting unit. A blank time (a time during which no deflector is irradiated with laser light) does not occur when the light is incident in order. For this reason, laser light is irradiated without waste by each deflecting unit, and the angular range that can be scanned by each deflecting unit can be made as wide as possible.

FIG. 1 is a cross-sectional view schematically illustrating a laser radar device according to a first embodiment of the invention. FIG. 2 is a perspective view schematically showing a rotating structure used in the laser radar apparatus of FIG. 1, and FIG. 2A shows a state in which the first deflection unit is located on the laser light projecting system path. 2B is a perspective view showing a state in which the second deflecting unit is positioned on the laser light projecting system path, and FIG. 2C is a third deflecting unit. It is a perspective view which shows the state which is located on the light projection system path of a laser beam. FIG. 3 is a plan view schematically showing a rotating structure used in the laser radar apparatus of FIG. 1. FIG. 3 (A) shows a state immediately after the first deflection unit enters the laser light projecting path. 3 (B) is a plan view showing a state rotated to some extent from the state of FIG. 3 (A), and FIG. 3 (C) is from the state of FIG. 3 (B). It is a top view which shows the state which rotated further. FIG. 4 is an explanatory view for conceptually explaining a laser scanning region in the laser radar apparatus of FIG. FIG. 5 is a plan view schematically showing a rotating structure used in the laser radar apparatus of the second embodiment. FIG. 5A shows the position of the first deflection unit on the laser light projecting system path. 5 (B) is a plan view showing a state rotated to some extent from the state of FIG. 5 (A), and FIG. 5 (C) is a state of FIG. 5 (B). It is a top view which shows the state which rotated further from. FIG. 6 is an explanatory diagram schematically illustrating a laser radar device according to another embodiment. FIG. 7 is an explanatory diagram for explaining a conventional problem.

[First embodiment]
Hereinafter, a first embodiment embodying the present invention will be described with reference to the drawings.
(Whole structure of laser radar device)
First, the overall configuration of the laser radar apparatus according to the first embodiment will be outlined with reference to FIG. FIG. 1 is a schematic cross-sectional view of the laser radar device according to the first embodiment of the present invention. As shown in FIG. 1, the laser radar device 1 includes a laser diode 10 and a photodiode 20 that receives reflected light L2 from a detection object, and is configured as a device that detects the distance and direction to the detection object. Yes.

  The laser diode 10 corresponds to an example of a laser light source that generates laser light, and is configured by, for example, a known laser diode. The laser diode 10 is supplied with a pulse current from a drive circuit (not shown) and intermittently projects a pulse laser beam (laser beam L1) at predetermined intervals according to the pulse current.

  A lens (not shown) is provided on the optical axis of the laser beam L1 emitted from the laser diode 10. This lens is configured as a collimating lens and has a function of converting the laser light L1 from the laser diode 10 into substantially parallel light. In the laser radar device 1 of FIG. 1, the laser diode 10 and this lens correspond to an example of a light projecting unit, and when the predetermined direction (the direction parallel to the rotation shaft 49a) is the height direction, the laser diode 10 The laser beam L1 emitted from the laser beam is guided so as to pass through the light projection path in the height direction. In the example of FIG. 1, the laser light L1 is irradiated downward from the laser diode 10, but the laser light L1 is irradiated from the laser diode 10 sideways, for example, and converted into parallel light by a lens. You may make it change downward by reflecting this with a mirror. In this case, the path after the laser light is reflected by the mirror corresponds to the light projecting path in the height direction, and the laser diode 10, the lens, and the mirror correspond to an example of the light projecting means.

  In the present specification, the direction parallel to the direction of the rotation shaft 49a is the height direction (vertical direction), and is indicated as the Y-axis direction. The direction perpendicular to the height direction is the horizontal direction. A predetermined direction orthogonal to the height direction is defined as the front-rear direction, and this direction is indicated as the X-axis direction. In addition, the direction orthogonal to the height direction and the front-rear direction is the left-right direction (lateral direction), and this direction is the Z-axis direction.

  On the lower side of the laser diode 10, a mirror 30 having a vertical through hole 30a is disposed. The mirror 30 is arranged so that the laser light L1 from the laser diode 10 passes through the through hole 30a, and a reflecting surface is provided on the lower side so that the angle formed with the rotary shaft 49a is 45 °. It has been. Then, the laser beam L1 irradiated to the space (any one of the laser beam L11 from the deflection unit 41, the laser beam L12 from the deflection unit 42, and the laser beam L13 from the deflection unit 43) is reflected by an object in the external space. When the generated reflected light is incident on any of the deflecting units 41 to 43, the reflected light guided upward by any of the deflecting units 41 to 43 functions to reflect to the photodiode 20 side.

  A rotary reflection device 7 is provided below the mirror 30. The rotary reflection device 7 is mainly composed of a rotary structure 40, a motor 50, a rotation angle sensor 52, and the like.

  As shown in FIG. 2, the rotating structure 40 includes a plurality of deflecting units around a rotating shaft 49 a in the height direction parallel to the projecting path in the height direction of the laser beam L <b> 1 (path guided by the above-described projecting means). 41, 42, and 43 are integrally rotatable. The rotary structure 40 includes a longitudinal rotation center portion 45 that is long in the vertical direction, and the deflection portions 41, 42, and 43 protrude from the rotation center portion 45 in the radial direction centering on the rotation shaft 49 a. The shaft portion 49 is provided in a form protruding downward from the lower end portion of the rotation center portion 45.

  As shown in FIGS. 2 and 3, the plurality of deflecting portions 41, 42, and 43 constituting the rotating structure 40 are shifted from each other in the circumferential direction (circumferential direction around the rotating shaft 49 a) around the rotating shaft 49 a. Has been placed. That is, as shown in FIG. 3, when the rotary structure 40 is viewed in plan, each deflection unit does not overlap with other deflection units, and the deflection unit 41, which is the first deflection unit, is centered on the rotation shaft 49a. The deflection unit 42 as the second deflection unit is arranged at the second position in the circumferential direction, and the deflection unit 43 as the third deflection unit is arranged at the third position in the circumferential direction. ing.

  Each of the plurality of deflecting portions 41, 42, 43 is arranged so as to be shifted in the height direction. That is, the deflection unit 41 that is the first deflection unit is disposed at the first position (lowest position) in the height direction, and the deflection unit 42 that is the second deflection unit is a height that is higher than the deflection unit 41. The deflecting unit 43 that is the third deflecting unit is disposed at the third position in the height direction that is higher than the deflecting unit 42. Each of these deflecting portions 41, 42, 43 is configured as a mirror having a flat reflecting surface, and any of the deflecting portions faces the laser beam L1 on which the reflecting surface faces obliquely upward and the reflecting surface is incident. It is arranged to incline.

  More specifically, the deflecting unit 41, which is the first deflecting unit, is a reflection orthogonal to a predetermined first plane passing through the rotation shaft 49a (in FIG. 3A, the position of the predetermined first plane is indicated by F1). The reflecting surface 41a and a horizontal plane (a plane orthogonal to the rotation axis 49a) are arranged such that an angle θ1 is a constant angle (for example, 45 °), and receives the driving force of the motor 50. When the rotating structure 40 rotates, the rotating structure 40 rotates while maintaining this angle θ1 at a constant angle (for example, 45 °). As shown in FIG. 2A or FIG. 3, when the laser beam L1 in the vertical direction is incident on the deflecting portion 41, the direction parallel to the horizontal plane and parallel to the predetermined first plane with the incident position as a base point. It is reflected so as to irradiate the laser beam L1 in any direction. In FIG. 2 and the like, the laser beam L1 guided in the height direction is separately indicated by a symbol L10, and the laser beam L1 irradiated to the space by reflection at the deflecting unit 41 is separately indicated by a symbol L11. ing.

  The deflecting unit 42 as the second deflecting unit has a reflecting surface 42a orthogonal to a predetermined second plane passing through the rotation shaft 49a (in FIG. 3A, the position of the predetermined second plane is indicated by F2). The angle θ2 formed by the reflecting surface 42a and a horizontal plane (a plane orthogonal to the rotation axis 49a) is arranged to be a constant angle (for example, 45 °). The angle formed between the predetermined first plane F1 and the predetermined second plane F2 is 120 °, for example. When the rotary structure 40 is rotated by receiving the driving force of the motor 50, the rotation structure 40 is rotated while being maintained at a constant angle (for example, 45 °). As shown in FIG. 2B, when the laser beam L1 in the vertical direction is incident on the deflecting portion 42, the incident position is set as a base point in a direction parallel to the horizontal plane and in a direction parallel to the predetermined second plane. It is reflected so as to irradiate the laser beam L1. Note that the laser beam L1 irradiated to the space by reflection at the deflecting unit 42 is separately indicated by a symbol L12.

  Further, the deflection unit 43 as the third deflection unit has a reflection surface 43a orthogonal to a predetermined third plane passing through the rotation shaft 49a (in FIG. 3A, the position of the predetermined third plane is indicated by F3). The angle θ2 formed by the reflecting surface 43a and a horizontal plane (a plane orthogonal to the rotation axis 49a) is arranged to be a constant angle (for example, 45 °). The angle formed between the predetermined first plane F1 and the predetermined third plane F3 and the angle formed between the predetermined second plane F2 and the predetermined third plane F3 are both 120 °. When the rotary structure 40 is rotated by receiving the driving force of the motor 50, the angle θ3 rotates while maintaining a constant angle (for example, 45 °). As shown in FIG. 2C, when the vertical laser beam L1 is incident on the deflecting portion 43, the incident position is a base point in a direction parallel to the horizontal plane and in a direction parallel to the predetermined third plane. It is reflected so as to irradiate the laser beam L1. In addition, the laser beam L1 irradiated to the space by the reflection at the deflection unit 43 is separately indicated by a symbol L13. As described above, each of the plurality of deflecting units 41, 42, and 43 has a direction parallel to the horizontal plane (a direction orthogonal to the height direction) of the laser beam L1 (see reference L10) guided to the light projecting path in the height direction. It comes to be biased to.

  The rotating structure 40 configured as described above is configured integrally with an output shaft (rotating shaft) of the motor 50 while a vertically extending shaft portion 49 protruding downward is rotatably supported by a bearing (not shown). When the shaft portion 49 receives the driving force of the motor 50 and rotates, the entire rotating structure 40 rotates.

  The motor 50 corresponds to an example of “driving means” that rotationally drives the rotary structure 40, and is configured by, for example, a known DC motor or a known AC motor. When a driving instruction is issued from the control unit 70, the driving state (for example, rotation timing and rotation speed) is controlled by a motor driver (not shown). At this time, the rotating structure 40 is moved. Steady rotation is performed at a predetermined constant rotational speed.

  Further, as shown in FIG. 1, a rotation angle sensor 52 that detects the rotation angle position of the drive shaft of the motor 50 or the shaft portion 49 (that is, the rotation angle position of the rotating structure 40) is provided. As the rotation angle sensor 52, various types of sensors can be used as long as they can detect the rotation angle position of the drive shaft and the shaft portion 49, such as a rotary encoder.

  In the rotary reflection device 7 configured as described above, as the rotary structure 40 is driven to rotate by the motor 50, each deflection unit 41, as shown in FIGS. 2 (A), 2 (B), and 2 (C). 42 and 43 are configured to sequentially pass through a laser light projecting path (path indicated by L10), and the laser light L1 is sequentially rotated by the deflecting units 41, 42, and 43 while rotating the rotating structure 40. It is designed to deflect. Therefore, for example, in the angle range in which the deflection unit 41 reflects the laser beam L1, horizontal scanning is performed at a low position as indicated by reference numeral L11 ′ shown in FIG. 4, and in the angle range in which the deflection unit 42 reflects the laser beam L1. Horizontal scanning at the middle position is performed as indicated by reference numeral L12 ′ shown in FIG. 4, and horizontal scanning at a high position is executed as indicated by reference numeral L13 ′ shown in FIG. 4 in the angle range in which the deflection unit 43 reflects the laser light L1. Will be done.

  A condensing lens 62 that condenses the reflected light toward the photodiode 20 is provided on the optical path of the reflected light from the rotary reflection device 7 to the photodiode 20. When the deflecting units 41, 42, and 43 are positioned on the path of the laser beam L1, the condenser lens 62 reflects the reflected light from the deflecting units 41, 42, and 43 (that is, the laser beam L1 is applied to the object). The generated reflected light is taken into each deflecting portion, and the light guided upward is condensed and guided to the photodiode 20. Note that light having a specific wavelength corresponding to the reflected light L2 (for example, light having a wavelength in a certain region) is transmitted on the path of the reflected light (for example, between the condensing lens 62 and the photodiode 20) and deviated from the specific wavelength. You may provide the wavelength selection filter etc. which interrupt | block.

  In the present embodiment, the rotary reflection device 7, the mirror 30, and the condenser lens 62 correspond to an example of “guidance means”, and the laser diode 10 (laser light source) generates laser light L 1, and the laser When the light L1 is guided to the external space by any one of the deflection units 41, 42, and 43, the reflected light L2 that is generated by the reflection of the laser light L1 by the object in the external space is transmitted through any of the deflection units. And function to guide the light receiving path to the photodiode 20.

  The photodiode 20 corresponds to an example of a light receiving unit that receives the reflected light guided by the guiding unit, and is formed of a known photodiode such as an avalanche photodiode. The photodiode 20 is configured to receive the reflected light L2 reflected by an object existing in the external space and convert it into an electrical signal when the laser light L1 is generated from the laser diode 10. . The reflected light L2 from the detection object is configured to be captured in a predetermined visual field range. For example, when the laser light L1 is irradiated to the space by the deflecting unit 41, the reflected light L2 is indicated by reference numerals L21a and L21b. The reflected light passing through the region between the two lines is taken in by the deflecting unit 41 and received by the photodiode 20. Further, when the laser beam L1 is irradiated to the space by the deflecting unit 42 (that is, when the deflecting unit 42 is disposed at the position of the two-dot chain line shown in FIG. 1), the distance between the two lines indicated by the symbols L22a and L22b The reflected light passing through the region is taken in by the deflection unit 42 and received by the photodiode 20. Further, when the laser beam L1 is irradiated to the space by the deflecting unit 43 (that is, when the deflecting unit 43 is disposed at the two-dot chain line position shown in FIG. 1), the distance between the two lines indicated by reference numerals L23a and L23b The reflected light passing through the region is taken in by the deflection unit 43 and received by the photodiode 20.

  The control unit 70 includes one or a plurality of control circuits such as a microcomputer provided with a CPU, and is configured to control the light projecting operation of the laser diode 10 and the rotation operation of the motor 50 described above. . Moreover, it is connected to the photodiode 20 and the rotation angle sensor 52, and is configured to be able to acquire signals from these. In addition, a memory (not shown) such as a ROM, a RAM, and a nonvolatile memory is connected to the control unit 70, and the control unit 70 can read and write information in the memory.

  In the present embodiment, the laser diode 10, the photodiode 20, the mirror 30, the rotary reflection device 7 and the like are accommodated in the case 3, and dust protection and impact protection are achieved. Around the rotating structure 40 in the case 3, a light guide portion 4 that allows the laser light L <b> 1 and the reflected light L <b> 2 to pass is formed so as to surround the deflection portion 41. The light guide 4 is provided in an opening form over a predetermined area so that at least the laser light from each of the deflectors 41, 42, 43 always passes through the light guide 4. A laser light transmission plate 5 made of a glass plate or the like is arranged in a form that closes the wall, and dust prevention is achieved.

(Object detection operation)
Next, the basic operation of the object detection process (monitoring process) performed by the laser radar device 1 will be described.
In the laser radar device 1 shown in FIG. 1, when a pulse current is supplied to the laser diode 10, a pulse laser beam (laser beam L1) at a short time interval corresponding to the timing and pulse width of the pulse current is converted into a laser diode. 10 is output intermittently. The laser light L1 is projected as diffused light having a certain spread angle, is converted into parallel light by passing through a lens (not shown), and passes through a light projecting path in the height direction through the through hole 30a. It will be. Thus, when the laser beam L1 (see symbol L10) passing in the height direction hits any one of the deflection units, the laser beam L1 is reflected by the deflection unit and irradiated toward the space. Then, when the laser light L1 irradiated from any of the deflecting units hits an object (detection object) existing in the external space, the reflected light that is reflected by the detection object and returns to the apparatus side. A part (reflected light L2) enters the case through the laser light transmitting plate 5 and enters the irradiation deflection unit. Upon receiving such reflected light, the irradiation source deflection unit guides (reflects) the reflected light toward the mirror 30, and the guided reflected light is reflected by the mirror 30 and condensed by the condenser lens 62. And enters the photodiode 20. When the photodiode 20 receives such reflected light, the photodiode 20 outputs an electrical signal corresponding to the intensity of the received reflected light (for example, a voltage value corresponding to the received reflected light L2).

  For example, as shown in FIGS. 1 and 2A, when the deflection unit 41 is positioned on the path of the laser beam L1, the laser beam L1 reflected and irradiated by the deflection unit 41 exists in the external space. When it hits an object to be detected (detected object), a part of the reflected light (reflected light L2) reflected by the detected object and returning to the apparatus side enters the deflection unit 41 that is the irradiation source. The illuminating source deflection unit 41 that has received such reflected light guides (reflects) the reflected light toward the mirror 30, and the guided reflected light is reflected by the mirror 30 and collected by the condenser lens 62. Light is incident on the photodiode 20. When the photodiode 20 receives such reflected light, the photodiode 20 outputs an electrical signal corresponding to the intensity of the received reflected light (for example, a voltage value corresponding to the received reflected light L2). The same applies when the deflection unit 42 is positioned on the path of the laser beam L1 as shown in FIG. 2B, and the laser beam L1 reflected and irradiated by the deflection unit 42 exists in the external space. When an object (detected object) is hit, a part of the reflected light (reflected light L2) reflected by the detected object and returning to the apparatus side enters the deflection unit 42 that is the irradiation source. Upon receiving such reflected light, the illuminating deflection unit 42 guides (reflects) the reflected light toward the mirror 30, and the guided reflected light is reflected by the mirror 30 and collected by the condenser lens 62. The light is incident on the photodiode 20.

  Based on the transmission timing of the pulse signal to the laser diode 10 and the timing at which the light reception signal from the photodiode 20 is output, the controller 70 projects the time T from the light emission of the laser light L1 to the light reception (ie, the laser diode 10). Measuring the time from when the pulse laser beam L1 is output until the photodiode 20 receives the reflected light L2 corresponding to the pulse laser beam. Further, the control unit 70 outputs the output value from the rotation angle sensor 52 when the pulse laser beam L1 is irradiated (that is, the rotation angle θ from the reference angle of the rotating structure 40 at the timing when the pulse laser beam L1 is irradiated). ) Can also be grasped. When the rotation angle θ of the rotating structure 40 is determined, it is possible to specify which deflection unit the laser beam L1 is incident on (that is, it is possible to specify the height of the scanning plane) and also specify the direction of the deflection unit. Therefore, the irradiation direction from the deflection unit can also be specified. Accordingly, the direction in which the laser beam L1 is directed can be specified as one direction. When the azimuth of the laser beam L1 is determined in this way, the length T of the path from the irradiation of the laser beam L1 from the laser diode 10 onto the object to the return to the photodiode 20 is set as the time T and the known light velocity C. Therefore, it is possible to specify the position of the detected object.

  In the present embodiment, a table for specifying the height, azimuth, and distance (position) of the object in association with the combination of the rotation angle θ of the rotating structure 40 and the time T is stored in a memory (not shown) in advance. Then, when the rotation angle θ and the time T are detected, the height, azimuth, and distance (position) of the detected object can be immediately specified. Further, an arithmetic expression for calculating the height, azimuth, and distance (position) of the object using the rotation angle θ of the rotating structure 40 and the time T as parameters is provided, and the rotation angle θ and the time T are When detected, the height, direction, and distance (position) of the detected object may be calculated based on this arithmetic expression.

  In the present embodiment, the control unit 70 corresponds to an example of “azimuth detection unit”, and when the photodiode 20 (light receiving unit) receives reflected light from an object, at least based on the rotation angle of the rotating structure 40. It functions to detect the orientation of an object.

(Main effects of the first embodiment)
In the configuration of the first embodiment, the plurality of deflecting units 41, 42, and 43 can rotate integrally around a rotation shaft 49a parallel to the light projection path (path L10) in the height direction of the laser light L1. The rotating structure 40 is provided, and in this rotating structure 40, each of the plurality of deflecting portions 41, 42, 43 is arranged in the circumferential direction around the rotation shaft 49a and each is in the height direction. They are offset. As the rotary structure 40 is rotated by the motor 50 (driving means), each deflecting portion 41, 42, 43 sequentially passes the laser light L1 projection path (path L10) and shifts in the height direction. The laser beam L1 is deflected at each position. In this configuration, a plurality of starting positions (deflection positions) for irradiating laser light to the space are shifted in the height direction, and laser light is emitted from each position in the height direction of the apparatus as shown in FIG. Therefore, even in a position very close to the apparatus, the detection area can be set so as to cover a certain wide height range.
In the prior art that enables three-dimensional detection, a method of oscillating the laser beam up and down with the vicinity of the deflection unit as the base point (starting position) is adopted, so that the height near the apparatus is very narrow as shown in FIG. There is a problem that the detection area can be secured only in the range, and the area below the narrow detection area becomes a blind spot, and there is a concern that an object approaching the device cannot be detected from this blind spot and a detection omission occurs. It was. On the other hand, in the configuration of the first embodiment, such a blind spot can be reduced as much as possible, and detection omission due to the blind spot can be suppressed.

  Further, in the configuration of the first embodiment, since the plurality of deflecting units 41, 42, 43 all deflect the laser light in a direction (horizontal direction) perpendicular to the height direction, a detectable range in the vicinity of the apparatus. (The height range in which the laser beam can be irradiated) continues to a farther position. That is, the detection area can be maintained within a certain height range from a position very close to the apparatus to a far position.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 5 is a plan view schematically showing a rotating structure used in the laser radar apparatus of the second embodiment. FIG. 5A shows the position of the first deflection unit on the laser light projecting system path. 5 (B) is a plan view showing a state rotated to some extent from the state of FIG. 5 (A), and FIG. 5 (C) is a state of FIG. 5 (B). It is a top view which shows the state which rotated further from. In the second embodiment, the configuration of the rotating structure (particularly only the configuration of each deflection unit is different from the first embodiment, and other than that is the same as the first embodiment. Therefore, the deflection units 41, 42, and 43 are the same. Other than the above, the same reference numerals as those in the first embodiment are given, and detailed description thereof is omitted.

  In the rotating structure 40 used in the second embodiment, each of the deflection surfaces (reflection surfaces 41a, 42a, 43a) of the plurality of deflection units 41, 42, 43 is projected onto a virtual plane orthogonal to the rotation axis 49a. Projection areas (that is, areas of the reflecting surfaces 41a, 42a, and 43a when viewed in plan as shown in FIG. 5) are arranged side by side in the circumferential direction around the rotation axis 49a on the virtual plane. In the virtual plane, each projection area is continuous with other projection areas adjacent to both sides in the circumferential direction. That is, when viewed in plan as shown in FIG. 5, the reflection surface 41a is continuous with the adjacent reflection surfaces 42a and 43a, respectively, and the reflection surface 42a is connected to the reflection surfaces 41a and 43a on both sides. Each of the reflection surfaces 43a is continuous with each other, and the reflection surface 43a is continuous with each of the adjacent reflection surfaces 41a and 42a. For example, when the rotating structure 40 is directed in a predetermined direction (specifically, when the laser beam L1 is incident on the boundary between the reflecting surface 41a and the reflecting surface 43a), the rotation angle (reference rotation angle) is 0 °. In this case, the laser beam L1 is incident on the reflection surface 41a as shown in FIGS. 5A to 5C until the rotating structure 40 rotates counterclockwise from 0 ° and reaches a rotation angle of 120 °. When the rotating structure 40 is at a rotation angle of 120 ° to 240 °, the laser beam L1 is incident on the reflecting surface 42a. When the rotating structure 40 is at a rotation angle of 240 ° to 360 °, the laser beam L1 is reflected at the reflecting surface 43a. It is made to enter. That is, horizontal scanning can be performed at an angle range of 120 ° at each height.

  In this configuration, when the rotating structure 40 is rotated and the laser beams are sequentially incident on the deflecting units 41, 42, and 43, a blank time (a time during which no deflecting unit is irradiated with the laser beam) does not occur. For this reason, laser light is irradiated without waste by each deflecting unit, and the angular range that can be scanned by each deflecting unit can be made as wide as possible.

[Other Embodiments]
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  In the above-described embodiment, each deflecting unit is configured by a plane mirror, but may be configured as a concave mirror.

  In the above-described embodiment, an example is shown in which three deflection units are provided in a form shifted in the height direction and the circumferential direction to configure a three-stage scanning region. However, even if the number of deflection units is four or more, It may be well (that is, four or more may be provided so as to be shifted in the circumferential direction), and may be two stages.

  In the above-described embodiment, an example in which three deflection units are provided so as to be shifted in the circumferential direction has been described. However, the number of deflection units may be four or more, or may be two.

  In the above-described embodiment, the configuration in which one laser light source and one light receiving unit are provided is illustrated, but a plurality of laser light sources and light receiving units may be provided. For example, in a configuration in which the deflection units 41, 42, and 43 having a horizontal scanning range of 120 degrees as shown in FIG. 5 are provided, a light projecting path in the height direction of the laser light L1 is provided by a separate laser diode different from the laser diode 10. 10 may be irradiated in parallel with the laser beam. Specifically, the second laser diode irradiates a laser beam so as to pass through a path at a position rotated by 120 ° about the central axis 49a with respect to the light projecting path L10 in the height direction. If the third laser diode irradiates the laser beam so as to pass through a path rotated by 240 ° about the central axis 49a with respect to the direction light projection path L10, for example, a scanning range by the laser diode 10 If the (angle range) is 0 ° to 120, the scan range (angle range) by the second laser diode is 120 ° to 240 °, and the scan range (angle range) by the third laser diode is 240 ° to 360. °. In this way, multistage detection can be performed within a range of 360 °. In the above case, the same members as the mirror 30, the condensing lens 62, and the photodiode 20 (the second mirror, the second condensing lens, the second condensing lens) correspond to the light projection by the second laser diode. And the reflected light corresponding to the light projection by the second laser diode can be received by the second photodiode. Similarly, the same members as the mirror 30, the condensing lens 62, and the photodiode 20 (the third mirror, the third condensing lens, and the third photodiode so as to correspond to the light projection by the third laser diode. ) So that the reflected light corresponding to the light projected by the third laser diode can be received by the third photodiode. Such a configuration is applicable not only to the configuration of FIG. 5 but also to the configurations of FIGS.

In the above embodiment, when laser light is irradiated from each deflection unit, the reflected light from the object is guided to the photodiode 20 side by the deflection unit of the irradiation source. Good. For example, when the laser light L1 is generated by the laser diode 10 (laser light source) and the laser light L1 is guided to the external space by the deflecting unit, the laser light is generated in the external space. The reflected light that is reflected by the object may be guided to the light receiving path by the second deflection unit that rotates about the rotation shaft 49a so as to be synchronized with the deflection unit. In the configuration of FIG. 6, a second deflection unit 241 that is vertically symmetrical with the deflection unit 41 is provided below the deflection unit 41, and a second deflection unit 242 that is symmetrical with the deflection unit 42 is provided below the deflection unit 42. It has been. Further, below the deflection unit 43, a second deflection unit (not shown) that is vertically symmetrical with the deflection unit 43 is provided. Such a second deflection section is integrally provided at a position below the rotary structure 40 so as to protrude in the radial direction around the rotation shaft 49a, and each second deflection section corresponds to an upper deflection section. Are rotated in synchronization with each other in a form protruding in the same direction. In FIG. 6, a structure in which the second deflecting units 241, 242 and the like are integrally configured is referred to as a second structure 240.
In this configuration, as shown in FIG. 6, when the laser light L1 is guided to the external space by the deflecting unit 41, the reflected light generated by the reflection of the laser light by the object in the external space is synchronized with the deflecting unit 41. As described above, the light is reflected downward by the second deflecting unit 241 that rotates about the rotation shaft 49 a and guided toward the photodiode 20 via the mirror 30. Similarly, when the laser beam L1 is guided to the external space by the deflecting unit 42, the rotation shaft 49a is adjusted so that the reflected light generated by reflecting the laser beam by the object in the external space is synchronized with the deflecting unit 42. When the laser beam L1 is guided to the external space by the deflecting unit 43, the laser beam is reflected by an object in the external space. The reflected light is guided toward the photodiode 20 by a second deflection unit (not shown) that rotates about the rotation axis 49 a so as to be synchronized with the deflection unit 43. Note that various known methods can be used as a method of synchronizing the rotating structure 40 and the second structure 240. For example, the rotating structure 40 and the second structure 240 are connected to each other and a common motor is used. (E.g., the power from the motor is transmitted and rotated by a gear transmission mechanism, a belt / pulley mechanism, or the like). Alternatively, the rotating structure 40 and the second structure 240 may be rotated so as to be synchronized by different motors, or other various methods may be used as long as two objects can be rotated in synchronization. Also good.

DESCRIPTION OF SYMBOLS 1 ... Laser radar apparatus 7 ... Rotation reflection apparatus (rotation deflection means)
10 ... Laser diode (laser light source, light projecting means)
20 ... Photodiode (light receiving means)
30. Mirror (guidance means)
40 ... Rotating structure 41, 42, 43 ... Deflection part (guidance means)
49a ... Rotating shaft 70 ... Control unit (azimuth detecting means)

Claims (3)

A light projecting unit that includes a laser light source that generates laser light and guides the laser light emitted from the laser light source through the light projecting path in the height direction when the predetermined direction is the height direction;
A rotating structure in which a plurality of deflecting portions are integrally rotatable around a rotation axis parallel to the light projecting path in the height direction through which the laser light is guided, and a drive for rotating the rotating structure Each of the plurality of deflecting portions is arranged around the rotation axis so as to be shifted from each other in the circumferential direction around the rotation axis, and each deflection surface is orthogonal to the height direction. Are arranged so as to be shifted from each other in the height direction so that they do not overlap with each other, and each deflecting portion sequentially passes through the light projecting path of the laser light as the rotating structure rotates, by the driving means Rotation deflecting means for deflecting the laser light in turn by each deflecting unit while rotating the rotating structure;
When the laser light is generated by the laser light source and the laser light is guided to the external space by the deflecting unit, the reflected light generated by the reflection of the laser light by the object in the external space is converted into the deflecting unit or the Guidance means for guiding the light receiving path by a second deflecting unit that rotates about the rotation axis so as to be synchronized with the deflecting unit;
A light receiving means for receiving the reflected light guided by the guiding means;
An azimuth detecting means for detecting at least the azimuth of the object based on a rotation angle of the rotating structure when the light receiving means receives the reflected light;
A laser radar device comprising:   2. The laser radar according to claim 1, wherein each of the plurality of deflection units deflects the laser light guided to the light projecting path in the height direction in a direction orthogonal to the height direction. apparatus.   Projection areas when the respective deflection surfaces of the plurality of deflection units are projected onto a virtual plane orthogonal to the rotation axis are arranged side by side in the circumferential direction around the rotation axis on the virtual plane. The projection area according to claim 1, wherein each projection area is continuous with another projection area adjacent to both sides in the circumferential direction in the virtual plane. Laser radar device.

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