Performance Testing Device and Method for Fine Tracking System Driven by Coarse Tracking Error

Abstract

The present invention discloses a performance testing device and method for a fine tracking system driven by coarse tracking error, which relates to the field of compound axis tracking control and includes: a light source, an off-axis reflective collimator, a target simulation fast steering mirror, a fine detector, a fine tracking fast steering mirror, a fine tracking controller, a coarse tracking platform dynamics simulation computer, a coarse tracking platform management unit, a collimator pan-tilt mechanism, a primary mirror, and a secondary mirror. The method is to drive the movement of the target simulation fast steering mirror by the error of the coarse tracking system, couple the target to the fine tracking system through the off-axis reflective collimator, extract the miss distance by the fine detector, complete the image closed-loop control with the miss distance by the fine tracking fast steering mirror, and at the same time, the fine tracking system outputs the unloading amount to the coarse tracking simulation system to complete the unloading of the coarse and fine two-stage systems. The present invention can complete the verification of the key functions and performance of the fine tracking system in an environment without a real coarse tracking platform, effectively saving the test cost and being beneficial to practical engineering applications.

Description

Technical Field

[0001] The present invention relates to the field of compound axis tracking control, and particularly to a performance test device and method for a fine tracking system driven by coarse tracking error. Background Art

[0002] A compound axis tracking system is a high-precision tracking system composed of coarse and fine two-stage subsystems, with a wide dynamic range and fast response speed. The tracking accuracy can reach the micro-radian level, and it is widely used in fields such as optical communication, laser ranging, and beam stabilization. Coarse tracking is usually completed by a two-dimensional turntable with low accuracy but large motion stroke to achieve coarse capture of the tracking target, and fine tracking is completed by a tilt mirror with small stroke but high bandwidth to achieve high-precision tracking of the target.

[0003] Currently, for the test and verification of key functions such as the unloading function and tracking accuracy of the compound axis tracking system, it is necessary to assemble the two-stage tracking systems, and it is impossible to complete the performance test of the compound axis tracking system without a real coarse tracking platform. However, in many cases, due to limitations in site, time, and cost, it is difficult to realize the combination of the two-stage tracking systems. Summary of the Invention

[0004] In order to overcome the deficiencies of the existing performance test methods for compound axis tracking systems, the present invention provides a test device and test method that can complete the performance verification of the compound axis without a real coarse tracking platform, and can complete the verification of the tracking accuracy performance and unloading function of the fine tracking system in an environment without a real coarse tracking platform. The test process is simple and convenient, without the need for a large amount of manpower and material resources for the assembly and debugging of the coarse and fine stages, shortening the test time for key functions such as the unloading function and tracking accuracy performance of the coarse and fine compound axis tracking systems, effectively saving the test cost, and being very beneficial to practical engineering applications.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A performance test device for a fine tracking system driven by coarse tracking error, comprising a coarse tracking simulation system, a fine tracking system, a light source, an off-axis reflective collimator, and a collimator pan-tilt mechanism; the coarse tracking simulation system includes a coarse tracking platform dynamics simulation computer, a coarse tracking platform management unit, and a target simulation fast steering mirror; the fine tracking system includes a fine detector, a fine tracking fast steering mirror, a fine tracking controller, a primary mirror, and a secondary mirror.

[0007] The target generated by the light source passes through the target simulation fast steering mirror and then reaches the off-axis reflective collimator to form a parallel light beam. The parallel light beam passes through the primary mirror and secondary mirror in the fine tracking system and then reaches the fine tracking fast steering mirror. After being reflected by the fine tracking fast steering mirror, it enters the fine detector, and the fine detector extracts the image miss distance information. The fine tracking controller is connected to the fine detector through a serial port to receive the image miss distance information for the closed-loop control of the fine tracking fast steering mirror. The calculated control quantity is sent by the fine tracking controller to the driver of the fine tracking fast steering mirror to drive the fine tracking fast steering mirror to deflect, realizing the image closed-loop control. The fine tracking controller sends the unloading quantity to the coarse tracking platform management unit through the serial port. The coarse tracking platform dynamics simulation computer communicates with the coarse tracking platform management unit, and the coarse tracking platform dynamics simulation computer is used to simulate the on-orbit working conditions. The collimator pan-tilt mechanism controls the movement of the off-axis reflective collimator to test the polarity of the unloading quantity output by the fine tracking system.

[0008] The present invention also provides a performance testing method for a performance testing device of a fine tracking system driven by coarse tracking error, including the following steps:

[0009] Step 1: Form a performance testing device of a fine tracking system driven by coarse tracking error;

[0010] Step 2: Conduct a polarity test on the unloading quantity sent by the fine tracking system to the coarse tracking simulation system;

[0011] Step 3: Conduct a polarity and dimension test on the voltage value of the target simulation fast steering mirror in the coarse tracking simulation system;

[0012] Step 4: Complete the dimension test of the unloading quantity output from the fine tracking system to the coarse tracking simulation system;

[0013] Step 5: Conduct an experiment using the performance testing device of the fine tracking system driven by coarse tracking error; the coarse tracking platform dynamics simulation computer sends the coarse tracking error to guide the target into the field of view of the fine tracking system. The fine tracking fast steering mirror uses the miss distance to complete the image closed-loop and outputs the unloading quantity to the coarse tracking simulation system in real time. The coarse tracking platform dynamics simulation computer performs bias control according to the unloading quantity to cooperate in reducing the error. Considering the on-orbit usage situation, verify the image processing, closed-loop, unloading function, tracking accuracy performance, etc. of the fine tracking system.

[0014] Beneficial effects:

[0015] The present invention provides a test and verification method for the key unloading function and tracking accuracy performance of a compound axis tracking system without a coarse tracking platform. This method uses a large-stroke target simulation fast steering mirror to replace the coarse tracking platform and combines the dynamics simulation computer of the coarse tracking platform to simulate complex on-orbit working conditions. It can verify the image closed-loop, unloading function, and tracking accuracy performance indicators of the coarse-fine compound axis system in an environment without a coarse tracking platform. The test process is simple and convenient, without the need for a large amount of manpower and material resources for the assembly and debugging of the coarse-fine two-stage system, shortening the test time for the key unloading function and tracking accuracy performance of the coarse-fine compound axis tracking system, effectively saving the test cost, and being very beneficial for practical engineering applications. Brief Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the performance test device of the fine tracking system based on the coarse tracking error drive of the present invention.

[0017] Figure 2 It is a comparison diagram of the control amount of the fine tracking fast steering mirror before and after the unloading control of the coarse tracking simulation system.

[0018] Among them, the reference numerals are: A is the coarse tracking simulation system; B is the fine tracking system; 1 is the dynamics simulation computer of the coarse tracking platform; 2 is the management unit of the coarse tracking platform; 3 is the light source; 4 is the target simulation fast steering mirror; 5 is the off-axis reflective collimator; 6 is the collimator pan-tilt mechanism; 7 is the primary mirror; 8 is the secondary mirror; 9 is the fine tracking fast steering mirror; 10 is the fine detector; 11 is the fine tracking controller. Detailed Embodiments

[0019] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. The present invention is described below with reference to the drawings and specific embodiments, and those skilled in the art can understand the effects and advantages of the present invention according to the content disclosed in this specification.

[0020] As Figure 1As shown in the figure, the present invention provides a performance testing device for a fine tracking system driven by coarse tracking error, mainly including a coarse tracking simulation system A and a fine tracking system B. Among them, the coarse tracking simulation system A includes a coarse tracking platform dynamics simulation computer 1, a coarse tracking platform management unit 2, and a target simulation fast steering mirror 4. The fine tracking system B includes a fine detector 10, a fine tracking fast steering mirror 9, a fine tracking controller 11, a primary mirror 7, and a secondary mirror 8. In addition, the performance testing device for the fine tracking system driven by coarse tracking error further includes a light source 3, an off-axis reflective collimator 5, and a collimator pan-tilt mechanism 6.

[0021] Among them, the target generated by the light source 3 reaches the off-axis reflective collimator 5 through the target simulation fast steering mirror 4 to obtain a parallel light beam. The parallel light beam passes through the primary mirror 7 and the secondary mirror 8 of the opto-mechanical combination in the fine tracking system B and then reaches the fine tracking fast steering mirror 9. After being reflected by the fine tracking fast steering mirror 9, it enters the fine detector 10, and the fine detector 10 extracts the image miss distance information. The fine tracking controller 11 is connected to the fine detector 10 through a serial port, receives the image miss distance, and is used for the closed-loop control of the fine tracking fast steering mirror 9. The calculated control quantity is sent by the fine tracking controller 11 to the fine tracking fast steering mirror 9 driver to drive the fine tracking fast steering mirror 9 to deflect, realizing the image closed-loop control. The fine tracking controller 11 sends the unloading quantity to the coarse tracking platform management unit 2 through a serial port. The coarse tracking platform dynamics simulation computer 1 communicates with the coarse tracking platform management unit 2, and the coarse tracking platform dynamics simulation computer 1 is used to simulate the on-orbit working conditions. The collimator pan-tilt mechanism 6 is rigidly connected to the off-axis reflective collimator 5, and it can control the movement of the off-axis reflective collimator 5 to test the polarity of the unloading quantity output by the fine tracking system B.

[0022] Preferably, the target simulation fast steering mirror 4 is driven by a voice coil motor to simulate the movement of a real coarse tracking platform, so as to complete the verification of the image processing, closed-loop, unloading function, and tracking accuracy performance of the fine tracking system without a real coarse tracking platform.

[0023] Preferably, the coarse tracking platform dynamics simulation computer 1 is used to simulate different complex on-orbit working conditions.

[0024] Preferably, the used target simulation fast steering mirror 4 is a fast steering mirror driven by a voice coil motor, which has the characteristic of a large deflection angle, so it can be used to simulate a coarse tracking platform with a wide dynamic range.

[0025] Preferably, the off-axis reflective collimator is moved in the horizontal and vertical directions by using the collimator pan-tilt mechanism 6, which can test the polarity of the unloading quantity output by the fine tracking system B and verify whether there is image rotation between the imaging plane and the measurement coordinate system.

[0026] Preferably, when there is image rotation between the imaging plane and the measurement coordinate system, the unloaded amount needs to be unwound before being sent to the coarse tracking simulation system A, and the correct polarity can be output only after unwinding. The rotation relationship is as follows:

[0027] ;

[0028] Among them, is the fixed rotation angle between the imaging plane and the measurement coordinate system, and are the azimuth unloaded amount and pitch unloaded amount before unwinding, respectively; and are the azimuth unloaded amount and pitch unloaded amount output to the coarse tracking simulation system after unwinding, respectively.

[0029] The present invention also provides a performance testing method for a performance testing device of a fine tracking system driven by coarse tracking error, including the following steps:

[0030] Step 1: Layout and connect the performance testing device according to Figure 1 ;

[0031] Step 2: Perform a polarity test on the unloaded amount sent from the fine tracking system B to the coarse tracking simulation system A. Control the off-axis reflecting collimator 5 to move through the collimator pan-tilt mechanism 6, and sequentially deflect the optical axis of the off-axis reflecting collimator in the horizontal and vertical directions in a single direction to test the polarity in a single direction and verify whether there is rotation in the imaging. If there is rotation, after calculating the rotation angle, unwind according to the rotation formula described above. Rotate the off-axis reflecting collimator in a predetermined direction to test whether the polarities of the azimuth unloaded amount and pitch unloaded amount output from the fine tracking system to the coarse tracking simulation system are consistent with the proposed protocol. Perform polarity calibration to make the polarity of the unloaded amount consistent with the protocol.

[0032] Step 3: Perform polarity and dimension calibration on the voltage value of the target simulation fast steering mirror 4 in the coarse tracking simulation system A.

[0033] First, complete the communication test between the coarse tracking platform dynamics simulation computer 1 and the coarse tracking platform management unit 2, and between the coarse tracking platform management unit 2 and the target simulation fast steering mirror 4. Complete the calibration of the voltage value polarity and dimension of the target simulation fast steering mirror 4, so that the target simulation fast steering mirror 4 can control the target to deflect to the pixel point position expected by the imaging plane of the fine tracking system B according to the azimuth angle and pitch angle output by the coarse tracking platform dynamics simulation computer 1. In addition, finely adjust the optical path to make the deflection angle range meet the requirements.

[0034] Step 4: Complete the dimension test of the unloaded amount output from the fine tracking system B to the coarse tracking simulation system A.

[0035] In the open-loop and closed-loop states of the fine tracking fast steering mirror 9, the azimuth angle is sent by the dynamics simulation computer 1 of the coarse tracking platform and the pitch angle to control the movement of the simulated fast steering mirror 4, simulating the deflection of the coarse tracking platform by an angle; calibrating the azimuth unloading amount and the pitch unloading amount (that is, the azimuth unloading amount and the pitch unloading amount output to the coarse tracking simulation system after unwrapping), so that and .

[0036] Step Five: Conduct tests using the Figure 1 performance test device.

[0037] First, the dynamics simulation computer 1 of the coarse tracking platform sends the azimuth angle to the target simulated fast steering mirror 4, causing the target to deviate out of the field of view, and then sending a bias angle smaller than the azimuth angle to simulate the coarse tracking error and guide the target into the field of view of the fine tracking system. Once the miss distance is effective, the fine tracking fast steering mirror 9 autonomously completes the image closed-loop and outputs the unloading amount to the coarse tracking simulation system A in real time. The azimuth angle , the bias angle .

[0038] If the coarse tracking simulation system A turns on the unloading mode, the dynamics simulation computer 1 of the coarse tracking platform performs bias control according to the unloading amount to cooperate in reducing the tracking error. Figure 2 shows the change in the control amount of the fine tracking fast steering mirror before and after turning on the unloading. Since initially, the tracking error is large, the closed-loop control amount of the fine tracking fast steering mirror reaches the saturation threshold of 32000, which is a pure numerical value, and 16 numbers are equivalent to 0.9 micro-radians. After the coarse tracking simulation system turns on the unloading mode, the control amount decreases significantly and remains near 0, indicating that the coarse tracking simulation system successfully unloads the fine tracking system, increasing the target tracking range and tracking accuracy. At the same time, by using the dynamics simulation computer 1 of the coarse tracking platform to send a bias to simulate the target entering the field of view → the target leaving the field of view → the target re-entering the field of view, the key functions of image processing and closed-loop of the fine tracking system can be verified.

[0039] For multi-aperture (multi-dimensional system with multiple fine tracking fast steering mirrors) and three-stage or even multi-stage composite optoelectronic tracking systems, the method proposed by the present invention is still applicable and is also within the scope of protection.

[0040] The content not described in detail in the specification is the prior art well-known to those skilled in the art.

Claims

1. A performance testing device for a fine tracking system driven by coarse tracking error, characterized in that It includes a coarse tracking simulation system, a fine tracking system, a light source, an off-axis reflective collimator, and a collimator pan-tilt mechanism; the coarse tracking simulation system includes a coarse tracking platform dynamics simulation computer, a coarse tracking platform management unit, and a target simulation fast steering mirror; the fine tracking system includes a fine detector, a fine tracking fast steering mirror, a fine tracking controller, a primary mirror, and a secondary mirror. The target generated by the light source passes through the target simulation fast steering mirror and then reaches the off-axis reflective collimator to form a parallel light beam. The parallel light beam passes through the primary mirror and the secondary mirror in the fine tracking system and then reaches the fine tracking fast steering mirror. After being reflected by the fine tracking fast steering mirror, it enters the fine detector, and the fine detector extracts the image miss distance information. The fine tracking controller is connected to the fine detector through a serial port to receive the image miss distance information for the closed-loop control of the fine tracking fast steering mirror. The calculated control quantity is sent by the fine tracking controller to the driver of the fine tracking fast steering mirror to drive the fine tracking fast steering mirror to deflect, realizing the image closed-loop control; the fine tracking controller sends the unloading quantity to the coarse tracking platform management unit through the serial port. The coarse tracking platform dynamics simulation computer communicates with the coarse tracking platform management unit, and the coarse tracking platform dynamics simulation computer is used to simulate the on-orbit working conditions; the collimator pan-tilt mechanism controls the movement of the off-axis reflective collimator to test the polarity of the unloading quantity output by the fine tracking system.

2. The performance testing device for a fine tracking system driven by coarse tracking error as described in claim 1, characterized in that, Utilize the coarse tracking error to drive the target simulation fast steering mirror to simulate the movement of a real coarse tracking platform, and complete the image processing, closed-loop, unloading functions and verification of the tracking accuracy performance of the fine tracking system without a real coarse tracking platform.

3. The performance testing device of a fine tracking system based on coarse tracking error driving according to claim 1, characterized in that, Use the coarse tracking platform dynamics simulation computer to simulate different complex on-orbit working conditions.

4. The performance testing device of a fine tracking system based on coarse tracking error driving according to claim 1, characterized in that, The target simulation fast steering mirror is a fast steering mirror driven by a voice coil motor and is used to simulate a coarse tracking platform with a wide dynamic range.

5. The performance testing device of a fine tracking system driven by coarse tracking error as claimed in claim 1, characterized in that, Use the collimator pan-tilt mechanism to move the off-axis reflective collimator in the horizontal and vertical directions, test the polarity of the unloading quantity output by the fine tracking system, and verify whether there is image rotation between the imaging plane and the measurement coordinate system.

6. The performance testing device of a fine tracking system driven by coarse tracking error as claimed in claim 5, wherein, In the case where there is image rotation between the imaging plane and the measurement coordinate system, the unloading quantity is de-rotated and then sent to the coarse tracking simulation system, and the correct unloading quantity is output after de-rotation; the rotation relationship is as follows: ； Among them, is the fixed rotation angle between the imaging plane and the measurement coordinate system, and are the azimuth unloading amount and the pitch unloading amount before unwinding respectively; and are the azimuth unloading amount and the pitch unloading amount output to the coarse tracking simulation system after unwinding respectively.

7. The performance testing method of a performance testing device for a fine tracking system driven by coarse tracking error according to claim 1, characterized in that It includes the following steps: Step 1: Form a performance test device for the fine tracking system driven by the coarse tracking error. Step 2: Conduct a polarity test on the unloading quantity sent from the fine tracking system to the coarse tracking simulation system. Step 3: Conduct a polarity and dimension test on the voltage value of the target simulation fast steering mirror in the coarse tracking simulation system. Step 4: Complete the dimension test on the unloading quantity output from the fine tracking system to the coarse tracking simulation system. Step 5: Use the performance test device for the fine tracking system driven by the coarse tracking error to carry out experiments. The coarse tracking platform dynamics simulation computer sends the coarse tracking error to guide the target into the field of view of the fine tracking system. The fine tracking fast steering mirror uses the miss distance to complete the image closed-loop and outputs the unloading quantity to the coarse tracking simulation system in real time. The coarse tracking platform dynamics simulation computer performs bias control according to the unloading quantity to cooperate in reducing the error; considering the on-orbit use situation, complete the image processing, closed-loop, unloading functions and verification of the tracking accuracy performance of the fine tracking system.

8. The performance testing method according to claim 7, wherein The second step includes: controlling the movement of the off-axis reflective collimator through the collimator pan-tilt mechanism, deflecting the collimator unidirectionally in the horizontal and vertical directions in sequence for polarity testing to verify whether there is rotation in imaging; if rotation exists, calculate the rotation angle and then perform unwinding according to the following formula: ； Among them, is the fixed rotation angle between the imaging plane and the measurement coordinate system, and are the azimuth unloading amount and the pitch unloading amount before unwrapping respectively; and are the azimuth unloading amount and the pitch unloading amount output to the coarse tracking simulation system after unwrapping respectively; Rotate the off-axis reflective collimator in a predetermined direction, test whether the polarities and protocols of the azimuth unloading amount and pitch unloading amount output by the fine tracking system to the coarse tracking simulation system are consistent, and finally ensure that the polarities of the unloading amounts are consistent with the protocols.

9. The performance testing method according to claim 8, wherein The third step includes: First, complete the communication tests between the rough tracking platform dynamics simulation computer and the rough tracking platform management unit, and between the rough tracking platform management unit and the target simulation fast steering mirror; complete the calibration of the polarity and dimension of the voltage value of the target simulation fast steering mirror, so that the target simulation fast steering mirror deflects to the position of the pixel point expected by the image plane of the fine tracking system according to the azimuth angle and pitch angle output by the rough tracking platform dynamics simulation computer.

10. The performance testing method according to claim 9, characterized in that, Step 4 includes: when the fine tracking fast steering mirror is in open-loop and closed-loop states, the dynamic simulation computer of the coarse tracking platform sends azimuth angle and pitch angle to control the target to simulate the movement of the fast steering mirror and simulate the coarse tracking error; calibrate the azimuth unloading amount and pitch unloading amount output to the coarse tracking simulation system after unwinding, so that and .

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