A method for determining spatial light rays based on the calibration CQP of a hexapod platform

Abstract

A method for determining spatial light based on the calibration CQP of a hexapod platform relates to the technical field of gravitational wave measurement, solves the problems of cumbersome existing calibration methods and low accuracy, and the process is as follows: adjust the pitch angle and yaw angle of the first hexapod platform, adjust the second hexapod platform to make the parallel light beam emitted by the collimating laser parallel to the z-axis of the Cartesian coordinate system of the first hexapod platform; confirm that the parallel light beam points to the centers of the first quadrant photodetector and the second quadrant photodetector at the same time, and then move the collimating laser along the y-axis stroke and x-axis stroke of the first hexapod platform, record the moving distance of the collimating laser, record the spot position on the first quadrant photodetector and the spot position on the second quadrant photodetector; calculate and fit the corresponding functional relationship between the spot position and the parallel light beam position. The present invention uses a hexapod platform to perform high-precision dimensional calibration on CQP, which can ensure the simplicity and accuracy of the calibration process.

Description

Technical Field

[0001] The present invention relates to the technical field of gravitational wave measurement, and particularly relates to a method for determining a spatial light beam based on the calibration of a six-legged platform CQP. Background Art

[0002] When detecting gravitational waves using the method of laser interferometry, a fully glass laser interferometer platform is required. When manufacturing a fully glass laser interferometer platform, CQP (calibrated quadrant photodiode pair) is used to determine the exact position of the spatial light beam on the laser interferometer platform. CQP consists of two quadrant photodetectors. As Figure 1 , any parallel light beam 1 in space is split into two light beams after passing through a beam splitter 2 placed at 45°, namely the first spatial light beam 6 and the second spatial light beam 3. The first spatial light beam 6 is incident on the first quadrant photodetector 7, and the first display interface 8 shows the screen display of the first quadrant photodetector 7. The closer to the center of the quadrant detector 8, the more accurate the value feedback by the photodetector. Similarly, the second spatial light beam 3 is incident on the second quadrant photodetector 4, and the second display interface 5 is the effective screen display area of the second quadrant photodetector 4. The center of the first photodetector 8 and the center of the second photodetector 5 can uniquely determine a straight line in space, which is also the spatial position point to be aligned when manufacturing a fully glass laser interferometer platform.

[0003] Before CQP is calibrated, it cannot truly display the central position coordinates of the light beam incident on the quadrant detector. The displayed result is only a value between 0 and 1. 0 represents that the parallel laser signal light beam is incident on the center of the quadrant detector, and 1 represents that the center of the parallel light beam is incident on the edge of the quadrant detector. However, the relative display value far from the center of the quadrant detector is not accurate, and it cannot display the true value of the actual deviation of the light beam center from the center of the quadrant detector. In order to make the displayed value accurate, and also to accurately view the magnitude of the deviation of the parallel light beam from the center of the quadrant detector, and to enable CQP to obtain ultra-precise measurement accuracy, CQP needs to be dimensionally calibrated before use.

[0004] When calibrating the precise dimensions of the CQP, the accuracy of conventional calibration methods is insufficient or the operation is not easily achievable. If the conventional calibration method is used to directly measure the distance that an arbitrary parallel light beam 1 moves along the horizontal or vertical direction, the following results may occur: First, there will be a large error in the measurement accuracy, and the movement accuracy of the hexapod platform cannot be achieved. Second, when the spatial light moves along the horizontal or vertical direction, its moving direction may not be perpendicular to the propagation direction of the light, so there is an error in the dimensions calibrated on the CQP. At the same time, during the calibration process, the corresponding distance needs to be moved multiple times. Each time a distance is moved, a measurement needs to be carried out, so the operation process is very cumbersome.

[0005] Conventional methods include the direct measurement method, that is, directly moving the parallel light beam used as a mark by the corresponding distance, and then using the quadrant detector on the CQP to record the position coordinates of the spot center at this time. Move the parallel light source multiple times, and use the quadrant detector in the CQP to record the point coordinates of the spot center respectively. Linear interpolation is performed on multiple sets of point coordinates to finally obtain the functional relationship between the spot position on the quadrant detector and the spot movement distance. When other unknown parallel light sources are incident on the quadrant detector on the CQP, use the acquisition data stored on the CQP and the position of the unknown light beam on the quadrant detector to inversely calculate the distance of this unknown light beam from the origin of the quadrant detector on the CQP, and then determine the positions and directions that each glass device on the all-glass laser interferometer platform needs to be adjusted when manufacturing the all-glass laser interferometer platform. However, this direct measurement method requires manually adjusting the moving distance of the laser light source, and the actual displacement accuracy and repeat accuracy are not high, and the spot data marked on the CQP is also inaccurate.

[0006] Since the dimensional accuracy of the standard gauge block is very high, the moving distance of the spatial light can be made very precise, so it is considered to use the standard gauge block to determine the moving distance of the parallel laser beam. Although the displacement accuracy of this method for moving the laser light source is high enough, when multiple sets of data need to be sampled and the sampling interval for each set of data is very small, the number and size specifications of the standard gauge blocks required are very large, which is also a difficult condition to meet for ordinary conventional laboratories, increasing the difficulty of CQP calibration. And because the spatial light needs to be moved multiple times, when using standard gauge blocks of various specifications to move the laser light source, the operation will be very cumbersome and time-consuming. In addition, its moving direction may still not be perpendicular to the propagation direction of the spatial light, resulting in inaccurate final measurement accuracy, thereby affecting the accuracy of calibration; second, standard gauge blocks of various specifications and sizes are required.

[0007] Therefore, there is a need to provide a method for calibrating the CQP size with high precision and easy operation and determining the spatial light. Summary of the Invention

[0008] To solve the above problems, the present invention provides a method for determining spatial light based on the calibration CQP of a hexapod platform.

[0009] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0010] A method for determining spatial light based on the calibration CQP of a hexapod platform, comprising the following steps:

[0011] S1. Adjust the pitch angle of the first hexapod platform and adjust the second hexapod platform so that the parallel light beam emitted by the collimating laser is parallel to the xoz plane of the Cartesian coordinate system of the first hexapod platform. The xoz plane is parallel to the horizontal plane. The collimating laser is located on the first hexapod platform, and a first quadrant photodetector and a second quadrant photodetector are provided on the second hexapod platform;

[0012] S2. Adjust the yaw angle of the first hexapod platform and adjust the second hexapod platform so that the parallel light beam emitted by the collimating laser is parallel to the yoz plane of the first hexapod platform;

[0013] S3. By adjusting the second hexapod platform and adjusting the first hexapod platform along the z-axis stroke of the first hexapod platform, confirm that the light-emitting direction of the collimating laser is parallel to the z-axis of the first hexapod platform;

[0014] S4. Confirm that the parallel light beam simultaneously points to the centers of the first quadrant photodetector and the second quadrant photodetector. Then, move the collimating laser along the y-axis stroke and x-axis stroke of the first hexapod platform, record the moving distance of the collimating laser, record the spot positions on the first quadrant photodetector and the second quadrant photodetector;

[0015] S5. Calculate the corresponding functional relationship between the fitted spot position and the parallel light beam position.

[0016] Further, the method for determining that the parallel light beam is parallel to the xoz plane in S1, the method for determining that the parallel light beam is parallel to the yoz plane in S2, and the method for determining that the parallel light beam is parallel to the z-axis in S3 are all:

[0017] Adjust the first hexapod platform and adjust the second hexapod platform so that the parallel light beam is incident on the centers of the first quadrant photodetector and the second quadrant photodetector. Then, adjust the first hexapod platform along the z-axis stroke of the first hexapod platform, and observe whether the spots on the first quadrant photodetector and the second quadrant photodetector deviate from the center. If they do not deviate from the center, the adjustment of the first hexapod platform is completed; otherwise, readjust the first hexapod platform.

[0018] Further, both S1 and S2 include the following steps:

[0019] Adjust the second six-legged platform to make the parallel light beam incident on the centers of the first quadrant photodetector and the second quadrant photodetector. Then adjust the first six-legged platform. After adjusting the pitch angle or yaw angle of the first six-legged platform by one step, readjust the second six-legged platform to make the parallel light beam incident on the centers of the first quadrant photodetector and the second quadrant photodetector.

[0020] Further, S3 is as follows: Adjust the first six-legged platform to z = 0, and adjust the second six-legged platform to make the parallel light beam incident on the centers of the first quadrant photodetector and the second quadrant photodetector simultaneously; Move the first six-legged platform along the +z axis direction to the maximum stroke in the +z axis direction. At this time, observe the spot positions of the parallel light beam on the first quadrant photodetector and the second quadrant photodetector. If the spots still remain at the centers of the corresponding quadrant photodetectors, the direction of the parallel light beam is parallel to the z axis of the first six-legged platform; otherwise, return to S1 or S2.

[0021] Further, S4 includes:

[0022] Confirm that the parallel light beam points to the centers of the first quadrant photodetector and the second quadrant photodetector simultaneously, and confirm the position of the first six-legged platform at z = 0;

[0023] Move the first six-legged platform along the y-axis stroke of the first six-legged platform on the +y axis side, and record the spot positions on the first quadrant photodetector and the second quadrant photodetector;

[0024] Move the first six-legged platform along the y-axis stroke of the first six-legged platform on the -y axis side, and record the spot positions on the first quadrant photodetector and the second quadrant photodetector;

[0025] Move the first six-legged platform along the x-axis stroke of the first six-legged platform on the +x axis side, and record the spot positions on the first quadrant photodetector and the second quadrant photodetector;

[0026] Move the first six-legged platform along the x-axis stroke of the first six-legged platform on the -x axis side, and record the spot positions on the first quadrant photodetector and the second quadrant photodetector.

[0027] Further, S5 is as follows: According to the corresponding relationship between the moving distances and the spot positions recorded in S4, use the linear interpolation method to convert the coordinates of the spot center positions in the coordinate system of the quadrant photodetector when any light beam in space irradiates on the first quadrant photodetector and the second quadrant photodetector.

[0028] Further, the method further includes: S6, determining the adjustment method of the parallel light beam.

[0029] Further, S6 is specifically as follows: The parallel light beam to be adjusted irradiates on the CQP. According to the functional relationship obtained in S5 and the spot position information displayed on the first quadrant photodetector and the second quadrant photodetector, the direction and distance that the parallel light beam to be adjusted needs to be adjusted can be determined.

[0030] The beneficial effects of the present invention are as follows:

[0031] The present invention uses a six-legged platform to perform high-precision dimensional calibration on the CQP. The six-legged platform has ultra-high-precision position movement ability and ultra-high-precision reset ability, and at the same time, the position movement is controllable. When using the six-legged platform to calibrate the spatial light determined by the CQP, not only the accuracy is high, but also the calibration speed is very fast. When using the six-legged platform and adopting the above calibration method to calibrate the CQP, it can not only meet the accuracy of calibrating the CQP, but also ensure the simplicity of the calibration process. The experimental operation has good feasibility, and at the same time, the calibration time period will also be greatly shortened. Description of the Drawings

[0032] Figure 1 It is a schematic diagram of the working principle of the CQP.

[0033] Figure 2 It is a front view of the six-legged platform calibrating the CQP.

[0034] Figure 3 It is a top view of the six-legged platform calibrating the CQP.

[0035] Figure 4 It is a screen display diagram of two quadrant detectors without light illumination.

[0036] Figure 5 It is a screen display diagram of the light spot incident on the center of two quadrant detectors.

[0037] Figure 6 It is a screen display diagram of the quadrant detector when the parallel light beam moves a distance d1.

[0038] Figure 7 It is a screen display diagram of the quadrant detector when the parallel light beam moves a distance d2.

[0039] Figure 8 It is a screen display diagram of the quadrant detector when the parallel light beam moves a distance d3.

[0040] Figure 9 It is a schematic flow diagram of the present invention for calibrating the CQP.

[0041] In the figure: 1. Parallel beam, 2. Beam splitter, 3. Second spatial beam, 4. Second quadrant photodetector, 5. Second display interface, 6. First spatial beam, 7. First quadrant photodetector, 8. First display interface, 9. Collimation laser, 10. First hexapod platform, 11. Second hexapod platform. Detailed implementation mode

[0042] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation modes.

[0043] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0044] The present invention proposes to use the first hexapod platform 10 and the second hexapod platform 11 to calibrate the position of the spatial light determined by the CQP. The hexapod platform has the advantages of high displacement accuracy, high rotation angle resolution, and very high reset accuracy, and the control operation is simple. The calibration device for calibrating the position of the spatial light determined by the CQP based on the hexapod platform includes the first hexapod platform 10, the collimation laser 9 located on the first hexapod platform 10, the beam splitter 2, the first quadrant photodetector 7, the second quadrant photodetector 4, and the second hexapod platform 11. The first quadrant photodetector 7 and the second quadrant photodetector 4 are located on the second hexapod platform 11, and the beam splitter 2 is also located on the second hexapod platform 11. The beam emitted by the collimation laser 9 is a parallel beam 1. The first hexapod platform 10 is used to adjust the position of the collimation laser 9, and the second hexapod platform 11 is used to adjust the positions of the first quadrant photodetector 7 and the second quadrant photodetector 4. The parallel beam 1 emitted by the collimation laser 9 is split into two beams by the beam splitter 2. One beam (first spatial beam 6) is incident on the first quadrant photodetector 7, and its first display interface 8 displays a light spot. The other beam (second spatial beam 3) is incident on the second quadrant photodetector 4, and its second display interface 5 displays a light spot. The hexapod platform is a hexapod displacement stage. In this embodiment, a German PI hexapod displacement stage is used. The coordinate system of the first hexapod platform 10 is the default Cartesian coordinate system oxyz of the first hexapod platform 10. The following describes the present invention in detail based on the coordinate system oxyz.

[0045] A method for calibrating the spatial light determined by the CQP based on a hexapod platform includes the following steps:

[0046] S1. Adjust the pitch angle of the first hexapod platform 10 and the second hexapod platform 11 to make the parallel light beam 1 emitted by the collimating laser 9 parallel to the xoz plane of the Cartesian coordinate system of the first hexapod platform 10, that is, the angle with the vertical direction of the z-axis is 0°. The xoz plane is parallel to the horizontal plane. The collimating laser 9 is located on the first hexapod platform 10, and a first quadrant photodetector 7 and a second quadrant photodetector 4 are provided on the second hexapod platform 11;

[0047] Generally, the initial spatial direction of the parallel light beam 1 emitted by the collimating laser 9 is roughly in the z-axis direction.

[0048] S2. Adjust the yaw angle of the first hexapod platform 10 and the second hexapod platform 11 to make the parallel light beam 1 emitted by the collimating laser 9 parallel to the yoz plane of the first hexapod platform 10, that is, the angle with the horizontal direction of the z-axis is 0°.

[0049] S3. By adjusting the second hexapod platform 11 and adjusting the first hexapod platform 10 along the z-axis stroke of the first hexapod platform 10, confirm that the light-emitting direction of the collimating laser 9 is parallel to the z-axis of the first hexapod platform 10.

[0050] S4. Confirm that the parallel light beam 1 simultaneously points to the centers of the first quadrant photodetector 7 and the second quadrant photodetector 4 (specifically, the spatial position of the second hexapod platform 11 can be adjusted to make the parallel light beam 1 simultaneously point to the centers of the first quadrant photodetector 7 and the second quadrant photodetector 4), and then move the collimating laser 9 along the y-axis stroke and x-axis stroke of the first hexapod platform 10, record the moving distance of the collimating laser 9, record the spot position on the first quadrant photodetector 7 and the spot position on the second quadrant photodetector 4.

[0051] S5. Calculate the corresponding functional relationship between the fitted spot position and the position of the parallel light beam 1.

[0052] According to the functional relationship obtained in S5 and the spot position information on the first display interface 8 and the second display interface 5, determine the distance information of the space light beam determined by the centers of the two quadrant detectors of any space light beam from CQP, that is, through the display numbers of the two quadrant detectors on CQP, the direction and distance to be adjusted for the parallel light beam 1 incident on CQP can be inversely deduced. When the parallel light beam 1 to be adjusted irradiates on CQP, the direction and distance that the parallel light beam 1 needs to be adjusted can be determined.

[0053] The above S1, S2 and S3 all include the step of judging whether the angle with the z-axis is zero, that is, all include the following steps:

[0054] Adjust the second six-legged platform 11 so that the parallel beam 1 is incident on the centers of the first quadrant photodetector 7 and the second quadrant photodetector 4 after being split by the beam splitter 2. Adjust the first six-legged platform 10 along the z-axis travel of the first six-legged platform 10, and observe whether the light spots on the first quadrant photodetector 7 and the second quadrant photodetector 4 deviate from the center. In S1, if it does not deviate from the center, the parallel beam emitted by the collimation laser 9 is parallel to the xoz plane of the first six-legged platform 10, and the adjustment of the first six-legged platform 10 is completed; otherwise, continue to adjust the pitch angle of the first six-legged platform 10. In S2, if it does not deviate from the center, the parallel beam emitted by the collimation laser 9 is parallel to the yoz plane of the first six-legged platform 10, and the adjustment of the first six-legged platform 10 is completed; otherwise, continue to adjust the yaw angle of the first six-legged platform 10. In S3, if it does not deviate from the center, the parallel beam emitted by the collimation laser 9 is parallel to the z-axis of the first six-legged platform 10, and the adjustment of the first six-legged platform 10 is completed; otherwise, readjust the pitch angle and / or yaw angle of the first six-legged platform 10.

[0055] A method for determining a spatial light ray based on the calibration CQP of a six-legged platform according to the present invention is as Figure 9 shown, specifically:

[0056] The first step: Fix the collimation laser 9 on the first six-legged platform 10, and the front view of the entire device is as Figure 2 shown. The parallel beam 1 emitted by the collimation laser 9 has an angle with the z-axis of the default Cartesian coordinate system of the first six-legged platform 10, that is, the parallel beam 1 emitted by the laser is in the yz plane of the first six-legged platform 10 and has an angle α with the z-axis. The z-axis of the default Cartesian coordinate system of the first six-legged platform 10 points to the beam splitter 2; the y-axis is in the vertical direction, pointing upward; the x-axis is perpendicular to the paper surface direction, pointing inside the paper surface.

[0057] The second step: Adjust the pitch angle of the first six-legged platform 10 so that the angle α between the parallel beam emitted by the collimation laser 9 and the xoz plane of the first six-legged platform 10 is 0°.

[0058] The judgment method is as follows: After adjusting the pitch angle of the first hexapod platform 10 by one step, readjust the position change of the second hexapod platform 11 to make the parallel beam 1 pass through the centers of the two quadrant detectors in the CQP simultaneously. After determining that the parallel beam 1 passes through the centers of the first quadrant photodetector 7 and the second quadrant photodetector 4 in the CQP simultaneously, move the first hexapod platform 10 along the +z axis direction by a distance equal to its maximum stroke in the +z axis direction. When the first hexapod platform 10 moves the maximum stroke along the +z axis direction, observe the spot positions of the parallel beam 1 on the first quadrant photodetector 7 and the second quadrant photodetector 4 on the CQP again at this time. If the spots are not at the centers of the two quadrant detectors in the CQP, it means that the direction of the parallel beam 1 is not parallel to the xoz plane of the default Cartesian coordinate system of the first hexapod platform 10, and the pitch angle of the first hexapod platform 10 needs to be readjusted to make the angle α 0°. The adjustment direction judgment method is as follows: After moving the first hexapod platform 10 from the origin along the +z axis direction to the maximum stroke, observe the spot positions of the spots on the first quadrant detector 7 and the second quadrant detector 4 in the CQP. If both spots are on the -y' axis (the vertical direction is the y' axis direction of the first quadrant detector 7, the horizontal direction is the x' axis direction of the first quadrant detector 7, and the center of the first quadrant detector 7 is the coordinate origin) part of the two quadrant photodetectors, it is proved that the included angle between the parallel beam 1 and the xoz plane of the default Cartesian coordinate system of the first hexapod platform 10 is positive, and the pitch angle of the first hexapod platform 10 needs to be readjusted to make the angle α closer to 0°. If after moving the first hexapod platform 10 from the origin o along the +z axis direction to the maximum stroke, observe the positions of the spots on the first quadrant detector 7 and the second quadrant detector 4 in the CQP. If both spots are on the +y' axis part of the two quadrant photodetectors, it is proved that the included angle between the parallel beam 1 and the xoz plane of the default Cartesian coordinate system of the first hexapod platform 10 is negative, and the pitch angle of the first hexapod platform 10 needs to be readjusted to make the angle α closer to 0°.

[0059] Step 3: Adjust the yaw angle of the parallel beam 1 to make the included angle β between the parallel beam 1 and the yoz plane of the first hexapod platform 0°. The adjustment method is: Adjust the yaw angle of the first hexapod platform 10. Figure 3 It is the top view of the entire calibration device.

[0060] The judgment method is as follows: After adjusting the yaw angle of the first hexapod platform 10 by one step, readjust the position of the second hexapod platform 11 so that the parallel light beam 1 passes through the centers of the two quadrant detectors in the CQP simultaneously. After determining that the parallel light beam 1 passes through the centers of the first quadrant photodetector 7 and the second quadrant photodetector 4 in the CQP simultaneously, move the first hexapod platform 10 along the +z axis direction by a distance equal to its maximum stroke in the +z axis direction. When the first hexapod platform 10 has moved the maximum stroke along the +z axis direction, observe the spot positions of the parallel light beam 1 on the first quadrant photodetector 7 and the second quadrant photodetector 4 in the CQP again at this time. If the spot on the first quadrant photodetector 7 is not at its center and / or the spot on the second quadrant photodetector 4 is not at its center, it indicates that the direction of the parallel light beam 1 is not parallel to the yoz plane of the default Cartesian coordinate system of the first hexapod platform 10, and the yaw angle of the first hexapod platform 10 needs to be readjusted so that the included angle β with the yoz plane of the first hexapod platform is 0°. The adjustment direction judgment method is as follows: After moving the first hexapod platform 10 from the origin along the +z axis direction to the maximum stroke position, observe the spot positions of the spots on the CQP first quadrant detector 7 and the second quadrant detector 4. If both spots are on the -x' axis part of the two quadrant photodetectors, it proves that the included angle between the parallel light beam 1 and the yoz plane of the default Cartesian coordinate system of the first hexapod platform 10 is positive, and the angle β needs to be readjusted so that the angle β is further close to 0°. If, after moving the first hexapod platform 10 from the origin along the +z axis direction to the maximum stroke position, observe the spot positions of the spots on the CQP quadrant detector 7 and the quadrant detector 4. If both spots are on the +x' axis part of the two quadrant photodetectors, it proves that the included angle between the parallel light beam 1 and the yoz plane of the default Cartesian coordinate system of the first hexapod platform 10 is negative, and the angle β of the first hexapod platform 10 needs to be readjusted so that the angle β is further close to 0°.

[0061] Step 4: After the pitch angle α and yaw angle β of the parallel beam 1 and the +z axis of the first hexapod platform 10 have been corrected to 0° respectively, verify again whether the direction of the parallel beam 1 is parallel to the +z axis of the first hexapod platform 10. The verification method is as follows: Readjust the position of the first hexapod platform 10 on the z-axis back to the origin o, that is, at z = 0, and readjust the position change of the second hexapod platform 11 so that the parallel beam 1 passes through the centers of the two quadrant detectors in the CQP simultaneously. After determining that the parallel beam 1 passes through the centers of the first quadrant photodetector 7 and the second quadrant photodetector 4 of the CQP simultaneously, move the first hexapod platform 10 along the +z axis direction by a distance equal to its maximum stroke in the +z axis direction. After the first hexapod platform 10 has moved the maximum stroke along the +z axis direction, observe again the spot positions of the parallel beam 1 on the first quadrant photodetector 7 and the second quadrant photodetector 4 of the CQP at this time. If the spot of the parallel beam 1 is not at the centers of the two quadrant detectors of the CQP, it means that the direction of the parallel beam 1 is not parallel to the +z axis of the first hexapod platform 10, and the pitch angle α and yaw angle β of the first hexapod platform 10 need to be readjusted. If the spot of the parallel beam 1 is at the centers of the two quadrant detectors of the CQP, it means that the direction of the parallel beam 1 is parallel to the +z axis of the first hexapod platform 10.

[0062] Step 5: If it has been determined that the spatial orientation of the parallel beam 1 emitted by the laser light source 9 coincides with the +z axis of the default Cartesian coordinate system of the first hexapod platform 10, then its spatial propagation direction must be perpendicular to the +x axis and +y axis of the default Cartesian coordinate system of the first hexapod platform 10. At this time, keep the position of the first hexapod platform 10 in the +z direction at the origin, and ensure that the parallel beam 1 points to the centers of the two quadrant detectors of the CQP simultaneously, as Figure 5 shown. Figure 4 represents that no light is incident on the two quadrant photodetectors. The +y axis direction of the quadrant photodetector is upward in the vertical direction, and the +x axis direction is to the right in the horizontal direction. The center origin of the quadrant detector is represented by a solid circle.

[0063] When light is incident on the first quadrant photodetector 7 and the second quadrant photodetector 4, light spots will be formed on the first display interface 8 and the second display interface 5 of the photosensitive surface interfaces of the two quadrant photodetectors, as Figure 5 shown, and the two light spots are represented by squares. Figure 5 In the photosensitive surfaces of the two quadrant detectors in, there are two square light spots at the center origin of the photosensitive surface, representing that the parallel beam 1 passes through the exact centers of the two quadrant detectors simultaneously.

[0064] Then, calibrate CQP vertically. Start moving the first hexapod platform 10 in the +y-axis direction along the y-axis travel of the first hexapod platform 10 on the +y-axis side. Each time the first hexapod platform 10 is moved, the positions of the light spots need to be recorded on the first quadrant detector 7 and the second quadrant detector 4 of CQP (the entire CQP system has the function of recording the positions of the light spots, that is, the function of recording the positions of the light spots belongs to the prior art). At the same time, record the actual distance that the first hexapod platform 10 moves along its +y-axis direction. Similarly, move the first hexapod platform 10 in the -y-axis direction along the y-axis travel of the first hexapod platform 10 on the -y-axis side. Each time the first hexapod platform 10 is moved, the positions of the light spots need to be recorded on the first quadrant detector 7 and the second quadrant detector 4 of CQP, and at the same time, record the actual distance that the first hexapod platform 10 moves along its -y-axis direction. During this movement along the y-axis, keep the first hexapod platform 10 at the position of z = 0.

[0065] Figure 6 Shows the positions of the two square light spots on the first display interface 8 of the first quadrant detector 7 and the second display interface 5 of the second quadrant detector 4 when the first hexapod platform 10 moves a distance d1 along the +y-axis direction.

[0066] Similarly, when the first hexapod platform 10 moves a distance d2 along the +y-axis direction, the positions of the two square light spots on the first display interface 8 of the first quadrant detector 7 and the second display interface 5 of the second quadrant detector 4 are represented by Figure 7 Shown.

[0067] When the first hexapod platform 10 moves a distance d3 along the +y-axis direction, the positions of the two square light spots on the first display interface 8 of the first quadrant detector 7 and the second display interface 5 of the second quadrant detector 4 are represented by Figure 8 Shown.

[0068] After all the distances in the +y direction are calibrated, mark the positions of the two quadrant detectors in the -y direction in the same way, and thus complete the marking of the y-axis direction of the two quadrant detectors of CQP.

[0069] Step 6: Similarly, after it has been determined that the spatial orientation of the collimation laser 9 coincides with the z-axis of the default Cartesian coordinate system and is perpendicular to the x-axis and y-axis of the default Cartesian coordinate system, perform the horizontal calibration of the CQP according to the operation method in Step 5. Move the collimation laser 9 along the x-axis direction of the first hexapod platform 10, and move the first hexapod platform 10 along the x-axis travel of the first hexapod platform 10 on the +x-axis side and the -x-axis side (i.e., move the collimation laser 9 and the parallel light beam 1 emitted therefrom). During this movement along the x-axis, keep the first hexapod platform 10 at the position of z = 0, so that the two quadrant detectors on the CQP collect and mark data, record the spot position information of the two photosensitive surfaces on the CQP at this time, and establish a corresponding relationship between it and the position movement distance information of the first hexapod platform 10 along the x-axis.

[0070] Step 7: According to the corresponding relationship between the movement distance and the spot position recorded in S4, use the linear interpolation method to calculate the horizontal and vertical distances from the center of the spot to the center of the first quadrant photodetector 7 and the second quadrant photodetector 4 when any light beam in space irradiates the first quadrant photodetector 7 and the second quadrant photodetector 4, that is, obtain the coordinates of the spot center on the first quadrant photodetector 7 and the second quadrant photodetector 4, that is, the coordinates in the quadrant detector coordinate system o'x'y'.

[0071] Using the data collected by the two quadrant detectors on the CQP and the corresponding position information of the parallel light beam 1, adopt the linear interpolation algorithm to calculate the distances in the x'-axis direction and y'-axis direction from the center of the spot to the center of the quadrant photodetector when any light beam in space irradiates the quadrant photodetector, so that the CQP has the function of accurately displaying the position. The center of the quadrant detector is point o’, the horizontal axis is the x'-axis, and the vertical axis is the y'-axis. Specifically, the coordinate system of the first quadrant photodetector 7 is o1'x1'y1', and the coordinate system of the second quadrant photodetector 4 is o'2x'2y'2.

[0072] Since the position information of multiple pairs of light spots on the y-axis of the four-quadrant detector has been collected and recorded, and the position of each pair of light spots corresponds to the movement distance information of a parallel beam 1, through interpolation algorithm processing, any pair of points on the first display interface 8 of the first four-quadrant detector 7 and the second display interface 5 of the second four-quadrant detector 4 can be obtained when the parallel beam 1 moves to any distance on the y-axis, and the corresponding relationship with the light rays at any position in space. That is, through the light spot position information on the first display interface 8 and the second display interface 5, the distance information of the light rays in space determined by the centers of the two four-quadrant detectors of any space light from CQP can be determined. That is, through the display numbers of the two four-quadrant detectors on CQP, the direction and distance to be adjusted for the parallel beam 1 incident on CQP can be deduced inversely.

[0073] The present invention uses a six-legged platform to perform high-precision dimensional calibration on CQP. The six-legged platform has ultra-high-precision position movement ability and ultra-high-precision reset ability, and the position movement is controllable. When using the six-legged platform to calibrate the space light rays determined by CQP, not only the accuracy is high, but the calibration speed is also very fast. When using the six-legged platform and adopting the above calibration method to calibrate CQP, it can not only meet the accuracy requirements for calibrating CQP, but also ensure the simplicity of the calibration process. The experimental operation has good feasibility, and at the same time, the calibration time period will also be greatly shortened.

Claims

1. A method for determining spatial light rays based on the calibration CQP of a hexapod platform, characterized in that Including the following steps: S1. Adjust the pitch angle of the first hexapod platform (10) and adjust the second hexapod platform (11) to make the parallel light beam (1) emitted by the collimating laser (9) parallel to the xoz plane of the Cartesian coordinate system of the first hexapod platform (10). The xoz plane is parallel to the horizontal plane. The collimating laser (9) is located on the first hexapod platform (10), and a first quadrant photodetector (7) and a second quadrant photodetector (4) are provided on the second hexapod platform (11). S2. Adjust the yaw angle of the first hexapod platform (10) and adjust the second hexapod platform (11) to make the parallel light beam (1) emitted by the collimating laser (9) parallel to the yoz plane of the first hexapod platform (10). S3. By adjusting the second hexapod platform (11) and adjusting the first hexapod platform (10) along the z-axis stroke of the first hexapod platform (10), confirm that the light-emitting direction of the collimating laser (9) is parallel to the z-axis of the first hexapod platform (10). S4. Confirm that the parallel light beam (1) points to the centers of the first quadrant photodetector (7) and the second quadrant photodetector (4) simultaneously. Then, by moving the collimating laser (9) along the y-axis stroke and the x-axis stroke of the first hexapod platform (10), record the moving distance of the collimating laser (9), and record the spot positions on the first quadrant photodetector (7) and the second quadrant photodetector (4). S5. Calculate and fit the corresponding functional relationship between the spot positions on the first quadrant photodetector (7), the spot positions on the second quadrant photodetector (4), and the position of the parallel light beam (1). S6. Determine the adjustment method of the parallel light beam (1). Specifically: the parallel light beam (1) to be adjusted is irradiated on the CQP. According to the functional relationship obtained in S5 and the spot position information displayed on the first quadrant photodetector (7) and the second quadrant photodetector (4), the adjustment direction and distance that the parallel light beam (1) to be adjusted needs can be determined.

2. The method for determining a spatial light based on the calibration CQP of a hexapod platform according to claim 1, wherein The method for judging that the parallel light beam (1) is parallel to the xoz plane in S1, the method for judging that the parallel light beam (1) is parallel to the yoz plane in S2, and the method for the parallel light beam (1) to be parallel to the z-axis in S3 are all: Adjust the first hexapod platform (10) and adjust the second hexapod platform (11) to make the parallel light beam (1) incident on the centers of the first quadrant photodetector (7) and the second quadrant photodetector (4). Then, adjust the first hexapod platform (10) along the z-axis stroke of the first hexapod platform (10), and observe whether the spots on the first quadrant photodetector (7) and the second quadrant photodetector (4) deviate from the center. If they do not deviate from the center, the adjustment of the first hexapod platform (10) is completed; otherwise, readjust the first hexapod platform (10).

3. A method for determining spatial light based on calibration CQP of a hexapod platform according to claim 1, characterized in that, Both S1 and S2 include the following steps: Adjust the second six - foot platform (11) to make the parallel beam (1) incident on the centers of the first quadrant photodetector (7) and the second quadrant photodetector (4). Then adjust the first six - foot platform (10). After adjusting the pitch angle or yaw angle of the first six - foot platform (10) each time, readjust the second six - foot platform (11) to make the parallel beam (1) incident on the centers of the first quadrant photodetector (7) and the second quadrant photodetector (4).

4. The method for determining a spatial light ray based on the calibration CQP of a hexapod platform according to claim 1, wherein S3 is as follows: Adjust the first six - foot platform (10) to z = 0, and adjust the second six - foot platform (11) to make the parallel beam (1) incident on the centers of the first quadrant photodetector (7) and the second quadrant photodetector (4) simultaneously; Move the first six - foot platform (10) along the +z - axis direction to the maximum stroke in the +z - axis direction. At this time, observe the spot position of the parallel beam (1) on the first quadrant photodetector (7) and the second quadrant photodetector (4). If it is still located at the center of the quadrant photodetector, the direction of the parallel beam (1) is parallel to the z - axis of the first six - foot platform (10); otherwise, return to S1 or S2.

5. A method for determining spatial light based on the calibration CQP of a hexapod platform as claimed in claim 1, wherein, S4 includes: Confirm that the parallel beam (1) points to the centers of the first quadrant photodetector (7) and the second quadrant photodetector (4) simultaneously, and confirm the position of the first six - foot platform (10) at z = 0; Move the first six - foot platform (10) along the y - axis stroke of the first six - foot platform (10) on the +y - axis side, and record the spot positions on the first quadrant photodetector (7) and the second quadrant photodetector (4); Move the first six - foot platform (10) along the y - axis stroke of the first six - foot platform (10) on the -y - axis side, and record the spot positions on the first quadrant photodetector (7) and the second quadrant photodetector (4); Move the first six - foot platform (10) along the x - axis stroke of the first six - foot platform (10) on the +x - axis side, and record the spot positions on the first quadrant photodetector (7) and the second quadrant photodetector (4); Move the first six - foot platform (10) along the x - axis stroke of the first six - foot platform (10) on the -x - axis side, and record the spot positions on the first quadrant photodetector (7) and the second quadrant photodetector (4).

6. The method for determining a spatial light based on the calibration CQP of a hexapod platform according to claim 1, characterized in that, S5 is as follows: According to the corresponding relationship between the moving distance and the spot position recorded in S4, use the linear interpolation method to convert the coordinates of the spot center position in the coordinate system of the quadrant photodetector when any beam in space irradiates on the first quadrant photodetector (7) and the second quadrant photodetector (4).

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