CN101368819A - Photoelectric Measuring Method of Large Platform Deformation - Google Patents

Abstract

The invention discloses a photoelectric measurement method for the deformation of a large platform. The position information received by several CCD line array image sensors vertically arranged at the position to be measured on the platform is output to the computer as the relative elevation information of the point; The elevation information position points received by two or three CCD line array image sensors are used as the baseline or datum, and all elevation information is converted into elevation output values; the elevation output value data at different load conditions and at different times are compared, thereby Obtain the relative deformation data of the platform under various load conditions and at different times. The invention can greatly improve the measurement accuracy of the deformation of the large-scale platform, and has high measurement speed and high degree of automation.

Description

Photoelectric Measuring Method of Large Platform Deformation

technical field

The invention relates to a measurement method, in particular to a measurement method for real-time monitoring of the deformation of a large platform.

Background technique

The platform mentioned in the present invention refers to a platform that pays special attention to the amount of deformation, especially refers to a relatively complicated optical test platform where the amount of deformation has a great influence on its performance.

At present, there are many kinds of automatic monitoring methods for the deformation of various platforms, including mechanical, magnetoelectric, optical, photoelectric and so on. The mechanical measurement method uses the calipers of various types of calipers as a typical method, and the magnetoelectric measurement method converts the displacement into an electrical signal through a magnetoelectric method for recording and measurement. There are two main types of optical methods used in linear measurements: (1) full imaging magnification methods that use light wave interference or imaging magnification for very precise measurements of small dimensions or small displacements; (2) use collimating telescopes with accessories and projection A partial zoom-in method for the system to measure large dimensions. However, the current photoelectric measurement method mainly collects the image of the object to be measured and interprets the image to obtain the parameters to be measured.

The mechanical measurement method will become very difficult to measure large-scale (above several meters) and some inconvenient or difficult-to-reach objects; the magnetoelectric measurement method is difficult to find the measurement reference for large-scale measurement objects, resulting in deformation of the platform Quantitative measurement is not possible. The photoelectric measurement method has many advantages, but the previous photoelectric measurement method mainly used the CCD sensor as an image sensor (so far the industry is still accustomed to calling the CCD sensor a CCD line array image sensor), such as the application number 200510017064.3 The patent application "real-time deformation measurement device based on video image" is analyzed and processed after the platform image is collected by the CCD sensor. Due to the low accuracy of the image sensor for large-scale measurement objects and the difficulty in measuring the deformation of the platform surface due to the viewing angle, the photoelectric measurement method cannot be popularized and applied in the automatic measurement and monitoring of large-scale plane deformation.

Contents of the invention

In order to overcome the shortcomings of existing technologies that cannot be popularized and applied in the automatic measurement and monitoring of large-scale plane deformation, the present invention provides a measurement method suitable for real-time detection of large-scale platform deformation, which can use the CCD line array image sensor as a height scale for Large-scale platform deformation measurement solves the shortcomings of the previous large-scale platform deformation measurement, such as low efficiency and inability to perform overall real-time monitoring.

The technical solution adopted by the present invention to solve its technical problems comprises the following steps:

(1) Several CCD line array image sensors are arranged vertically on the platform to be measured facing the light source as measuring scales, and the horizontal line laser beam of the line laser is irradiated to the pixel array area of each CCD line array image sensor at the same time Inside, the position information received by each CCD line image sensor is output to the computer as the relative elevation information of the point for processing.

The inline laser is a laser that modulates the point-shaped laser beam of an ordinary laser into an inline-shaped laser beam through a prism.

(2) Take the line connecting the elevation information position points received by two CCD line array image sensors on the platform as the baseline, and all the elevation information received by the CCD line array image sensors are transformed into the baseline with the linear coordinate substitution method. Elevation output value for coincident coordinates.

In this step, the plane determined by the elevation information position points received by the CCD line array image sensors at three points on the platform can also be used as the reference plane, and the elevation information received by all the CCD line array image sensors adopts the linear coordinate substitution method. Outputs the value for the elevation at coordinates coincident with the datum.

(3) Comparing the elevation output data under various load conditions and at different times, so as to obtain the relative deformation data of the platform under various load conditions and at different times.

In order to more conveniently obtain the deformation data of the platform under different ground conditions during the movement process, the present invention can integrate the height and position information measured by each CCD line array image sensor and output it wirelessly, and set a wireless receiving device above the movement range of the platform , After the signal is received, it is sent to the computer for processing.

In the present invention, a word-line laser can be placed at one end of the platform, and a plurality of CCD linear array image sensors can be used as measuring scales to be vertically arranged on the platform to be measured along a certain axis, approximately in a straight line, slightly staggered, and staggered to avoid the back The CCD line array image sensor measures the field of view light beam accepted by the ruler. Taking the line connecting the elevation information position points of any two CCD line array image sensors as the baseline, comparing the elevation difference of other points relative to the baseline, the deformation parameter on a certain axis of the platform is obtained.

In the present invention, a word-line laser can also be placed at one end of the platform, and a plurality of CCD line array image sensors can be vertically arranged on the platform to be measured as measuring scales, and distributed in an unequal fan shape as required. Take the plane determined by the elevation information position points of any three CCD line array image sensors as the reference plane, and compare the elevation differences of the other points relative to the reference plane to obtain the deformation parameters of the platform.

The beneficial effects of the present invention are: since the CCD line array image sensor is used as the height scale for the measurement of the deformation of the large platform, the measured height information is directly output by utilizing the strong position information of the pixel of the CCD line array image sensor; The word line laser allows multiple CCD line array image sensors to receive the same straight beam signal at the same time, using the straight line propagation principle of light, especially the precise straight line propagation principle of laser, to form a stable and high-precision straight line beam; thus the present invention can Greatly improve the measurement accuracy of the deformation of large platforms, and the measurement speed is fast and the degree of automation is high. Good implementation results have been achieved in the real-time monitoring of deformation of a large-scale optical test platform. The test platform is 20m long and 6m wide. The relative deformation of 36 measuring points in four axes has been measured. The mechanical method is used to compare and calibrate the measurement accuracy. Error ≤ ± 0.1mm, sampling period ≤ 1s.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Figure 1 is a schematic diagram of the present invention.

In the figure, 1-CCD line array image sensor; 2-platform; 3-inline laser; 4-wireless receiving device; 5-computer.

Detailed ways

Method embodiment 1:

A large movable optical test platform is about 20m long and 6m wide. Any slight deformation of the test platform may affect the measurement accuracy of the optical equipment arranged on the platform. The deformation of the platform mainly comes from: ① the deformation of the platform caused by the change of the flatness of the ground under different ground conditions during the movement of the platform; ②The deformation of the platform caused by the change of the platform load due to the replacement of measuring equipment and other reasons.

In order to monitor the impact of platform deformation on the measurement accuracy of optical equipment in real time, the monitoring device in the method of the present invention is arranged on the flanks of four main optical measurement axes as close to the optical measurement axes as possible.

Each monitoring line is arranged with 8 CCD line array image sensor measuring points and 1 inline laser measuring point. All measuring points are fixed on the optical test platform body with a magnetic base. Place the measuring point of a word line laser at one end of the monitoring axis, and place the measuring points of the other CCD line array image sensors at other positions on the monitoring axis. The specific layout position is determined according to the position concerned by the actual optical test system itself. The measuring points are distributed approximately in a straight line, and attention should be slightly staggered to avoid the situation that the CCD line array image sensor itself may block the subsequent measurement scale to receive the field of view light beam.

Accurately measure the distance between each monitoring point on each monitoring axis along the monitoring optical axis, and substitute it into the linear coordinate transformation system for future use. The position information received by each CCD line array image sensor is output to the computer as the relative elevation information of the point for processing, so as to obtain the relative elevation data of 9 measuring points for each monitoring optical axis. The relative elevation data of a word-line laser measuring point can be obtained through this linear coordinate transformation.

In order to more conveniently obtain the deformation data of the platform under different ground conditions during the movement process, the height signals measured by each CCD line array image sensor are transmitted to the wireless transmitting terminal through the signal cable, and then wirelessly output after integration. Set up a wireless receiving device at an appropriate position above the platform's motion range, and transmit the signal to the computer for processing after receiving it.

Taking the line connecting the elevation information position points of two CCD line array image sensors as the baseline, comparing the elevation difference of other points with respect to the baseline, the deformation parameters on a certain axis of the platform are obtained. According to actual needs, compare the elevation difference between the elevation data of other points under different load conditions and at different times relative to the baseline, so as to obtain the relative deformation of each point on a certain axis of the platform under various load conditions and at different times Quantitative data.

The pixel pitch of the CCD line array image sensor selected in this embodiment is 14 μm, and the line width of a word line laser in the detection area is 2-4 mm. Among the measured relative deformations of 36 measuring points on the four axes, the measurement accuracy error is ≤±0.1mm and the sampling period is ≤1s through comparison with the mechanical method. Good implementation effect has been obtained in the real-time monitoring of the deformation of the movable large-scale optical test platform.

Method embodiment 2:

A large working platform is about 30m long and 25m wide, on which a precision control system is arranged. During the work of the platform, the movement of the working system may cause deformation of the platform plane, which will affect the control accuracy of the control system.

In order to monitor the influence of the deformation of the platform on the control system in real time, several measuring points are selected on the platform to arrange the monitoring device in the method of the present invention for monitoring the deformation of the platform. In this embodiment, 23 measuring points are distributed, including 1 line laser measuring point and 22 CCD line array image sensor measuring points. One line laser measuring point is placed at one end of the platform, and 22 CCD line array image sensor measuring points are arranged in a fan-shaped unequal distance distribution on the platform where the deformation needs to be detected. All measuring points are fixed on the optical test platform body with a magnetic base. When arranging each measuring point, care should be taken to avoid the situation that the CCD line array image sensor itself may block the subsequent measurement scale to receive the field of view light beam.

Accurately measure the plane position coordinates of each monitoring point on the platform to be substituted into the linear coordinate transformation system for backup. The elevation position information received by each CCD line array image sensor is output to the computer as the relative elevation information of the point for processing, so as to obtain the relative elevation data of each measuring point.

Take the plane determined by the elevation information position points of any three CCD line array image sensors as the datum plane, and compare the elevation difference between the elevation data of other points at different load conditions and at different times relative to the datum plane, so as to obtain the platform at each level. The relative deformation data between different loading conditions and different moments. The relative elevation data of a word-line laser measuring point can be obtained through this linear coordinate transformation.

The pixel pitch of the CCD line array image sensor selected in this embodiment is 14 μm, and the line width of a word line laser in the detection area is 2-4 mm. Among the measured relative deformations of 23 measuring points, the measurement accuracy error is ≤±0.1mm and the sampling period is ≤1s through comparison and calibration with the mechanical method. Good implementation effect has been achieved in real-time monitoring of deformation of large precision control work platform.

Claims (6)

1. the photoelectric measurement method of macrotype platform deflection is characterized in that comprising the steps:

(a) several CCD line scan image sensors vertically are arranged in platform position to be measured as surveyors' staff towards light source, the level one word laser beam of one word line laser instrument is shone in the pixel array region of each CCD line scan image sensor simultaneously, and the positional information that each CCD line scan image sensor is received outputs in the computing machine as the relative altitude information of this point and handles;

(b) line of the elevation information location point that certain two CCD line scan image sensor on the platform are received is as baseline, the elevation information that all CCD line scan image sensors receive all adopts the linear coordinate substitution method, changes the absolute altitude output valve that overlaps coordinate with baseline into;

(c) various different loads conditions, different absolute altitude output valve data are constantly compared, thereby obtain platform in various different loads conditions, relative deformation's data of difference between the moment.

2. the photoelectric measurement method of macrotype platform deflection according to claim 1, it is characterized in that: a described word line laser instrument is a kind of laser instrument that the point-like laser wire harness of common lasers is modulated to a word slice shape laser wire harness by prism.

3. the photoelectric measurement method of macrotype platform deflection according to claim 1, it is characterized in that: the plane that the elevation information location point that described step (b) receives certain CCD line scan image sensor of 3 on the platform is determined is as reference field, the elevation information that all CCD line scan image sensors receive all adopts the linear coordinate substitution method, changes the absolute altitude output valve that overlaps coordinate with reference field into.

4. the photoelectric measurement method of macrotype platform deflection according to claim 1, it is characterized in that: wireless output after the height and position information integration that described each CCD line scan image sensor records, above the platform motion scope, radio receiver is set, reaches computing machine after signal receives and handle.

5. the photoelectric measurement method of macrotype platform deflection according to claim 1, it is characterized in that: described step (a) places platform one end with a word line laser instrument, a plurality of CCD line scan image sensors vertically are arranged in platform position to be measured as surveyors' staff along a certain axis, near linear distributes, slightly stagger, the visual-field beam that the distance that staggers is accepted with the CCD line scan image sensor surveyors' staff of dodging the back is as the criterion.

6. the photoelectric measurement method of macrotype platform deflection according to claim 1, it is characterized in that: described step (a) places platform one end with a word line laser instrument, a plurality of CCD line scan image sensors vertically are arranged in platform position to be measured as surveyors' staff, are not equidistant fan-shaped distribution as required.

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