Device and method for measuring dynamic performance of fast steering mirror

Abstract

The invention relates to the field of optical measurement, in particular to a dynamic performance measuring device and method for a fast reflecting mirror, and the device comprises a swing table which is used for simulating the external dynamic disturbance of the fast reflecting mirror; the gyroscope is used for collecting motion data of an azimuth axis and a pitch axis of the swing table; the main control upper computer is used for controlling the swinging table to swing; the fast reflecting mirror controller is used for receiving motion data of the swing table monitored by the gyroscope in real time and generating a reverse control signal according to the received motion data to control the fast reflecting mirror to perform reverse compensation motion, and the camera is used for collecting image data of light spots on the fast reflecting mirror; and the image acquisition and analysis upper computer analyzes the motion trail of the light spot according to the received image data, calculates the drift rate of the gyroscope, and obtains the compensation effect of the fast reflecting mirror on the motion of the swing table in the single-axis direction, so that the single-axis compensation dynamic performance of the fast reflecting mirror is tested. According to the invention, the compensation performance of the fast steering mirror under different working conditions can be accurately and conveniently evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of optical measurement, and particularly to a fast steering mirror dynamic performance measurement device and method. Background Art

[0002] As a core optical element capable of rapidly and precisely adjusting the beam direction, the fast steering mirror has extensive and crucial applications in high-end fields such as laser communication, adaptive optical imaging, and high-precision laser aiming. The quality of its dynamic performance directly determines the performance upper limit of the entire optical system. Therefore, achieving accurate measurement of the fast steering mirror's dynamic performance has important engineering significance and application value.

[0003] Traditional measurement methods mainly rely on accelerometers or angular displacement sensors to directly obtain the motion parameters of the fast steering mirror. However, such methods have significant defects: on the one hand, the installation process of the sensors is complex and cumbersome, and it is easy to introduce additional mechanical errors; on the other hand, such contact measurement means cannot directly reflect the compensation effect of the fast steering mirror in the actual optical system. In addition, gyro drift errors will have a significant impact on the dynamic measurement results, leading to data distortion, and the existing technology has not proposed an effective solution strategy. Generally speaking, the existing measurement schemes have certain limitations in terms of accuracy, operation convenience, and comprehensiveness of the fast steering mirror performance evaluation, and it is difficult to meet the high-standard requirements of actual engineering applications. Summary of the Invention

[0004] In order to solve the technical problems that the contact measurement means used for measuring the dynamic performance of the fast steering mirror in the existing technology cannot directly reflect the compensation effect of the fast steering mirror in the actual optical system, and the gyro drift error will have a significant impact on the dynamic measurement results, resulting in data distortion, the embodiments of the present invention provide a fast steering mirror dynamic performance measurement device and method. The technical solutions are as follows: On the one hand, a fast steering mirror dynamic performance measurement device is provided. The measurement device includes: a swing table, a fast steering mirror, a fast steering mirror controller, a power supply, a camera, a point light source, an adjustment bracket, a gyroscope, a main control upper computer, and an image acquisition and analysis upper computer; The gyroscope and the fast steering mirror are respectively arranged on the swing table, and the swing table is communicatively connected to the main control upper computer, The fast steering mirror controller is communicatively connected to the gyroscope and the fast steering mirror respectively; The camera is communicatively connected to the image acquisition and analysis upper computer, and the image acquisition and analysis upper computer is communicatively connected to the fast steering mirror controller; The point light source is the target light source, and the fast steering mirror receives the light of the target light source to generate a light spot; The swing table is equipped with a two-axis drive system for the azimuth axis and the pitch axis, and is used to simulate the external dynamic disturbance of the fast steering mirror; The gyroscope is used to collect the motion data of the azimuth axis and the pitch axis of the swing table; The master host computer is used to input drive information to the swing table and control the swing table to perform single-axis or double-axis periodic swinging according to the fixed amplitude and frequency set by the master host computer. The fast steering mirror controller is used to receive the motion data collected by the gyroscope in real time, generate a reverse control signal according to the received motion data to control the fast steering mirror to perform reverse compensation motion; the fast steering mirror controller is also used to receive the gyroscope drift rate and calibrate the zero bias drift of the gyroscope according to the gyroscope drift rate. The camera is used to collect the image data of the light spot on the fast steering mirror and transmit the image data of the light spot to the image acquisition and analysis host computer. The image acquisition and analysis host computer is used to receive the image data collected by the camera, analyze the motion trajectory of the light spot according to the received image data, and calculate the gyroscope drift rate; the fast steering mirror controller is also used to receive the gyroscope drift rate input by the image acquisition and analysis host computer; transmit the gyroscope drift rate to the fast steering mirror controller, and the fast steering mirror controller calibrates the zero bias drift of the gyroscope according to the gyroscope drift rate. Through the analysis of the image data, the compensation effect of the fast steering mirror on the motion of the swing table in the single-axis direction is obtained, so as to test the compensation dynamic performance of the fast steering mirror in the single axis.

[0005] Among them, the swing table is used to simulate external dynamic disturbances and has a two-axis servo drive structure. The two axes are the azimuth axis and the pitch axis. The swing table controls the structure on it to perform single-axis or double-axis periodic swinging along the azimuth axis and the pitch axis according to the fixed amplitude and frequency set by the master host computer, and can realize the independent control of the azimuth axis and the pitch axis; the fast steering mirror and the fast steering mirror controller are installed on the swing table. Among them, the fast steering mirror is fixed on the swing table through an adapter and integrates the dual-axis rotation functions of azimuth and pitch. The fast steering mirror controller can integrate the motion speed of the swing table measured by the gyroscope in real time, convert it into the position control quantity of the fast steering mirror, control the deflection of the fast steering mirror, and compensate the optical path between the point light source, the fast steering mirror and the camera. The fast steering mirror controller adopts a closed-loop control architecture based on FPGA, supports the PID control algorithm, and the control period ≤10μs to ensure fast response and precise control; the measuring device is also provided with a power supply, and the power supply supplies power to the fast steering mirror controller and the point light source; the camera is used to collect the image data after the fast steering mirror is stabilized; the point light source is used as the target light source, and its light spot is adjusted to the center of the camera's field of view through an adjusting frame; the gyroscope is directly installed on the swing table, and collects the motion data of the swing table in real time and transmits it to the fast steering mirror controller. The host computer system includes the master host computer and the image acquisition and analysis host computer. The master host computer is used to set the motion parameters of the swing table and coordinate the work of each module; the image acquisition and analysis host computer integrates functions such as parameter setting, real-time image data acquisition, image display and test report generation, realizing the automation of the measurement process and the high efficiency of data processing.

[0006] On the other hand, a method for measuring the dynamic performance of a fast steering mirror is provided. The method for measuring the dynamic performance of the fast steering mirror uses the above-mentioned device for measuring the dynamic performance of the fast steering mirror, and the method includes the following steps: Step 1: System initialization: Adjust the point light source, start the point light source, camera and fast steering mirror controller in sequence, and keep the swing table stationary; Step 2: Perform drift compensation calibration and drift compensation verification on the gyroscope. The parameters of the drift compensation calibration of the gyroscope are obtained by analyzing and calculating the drift trajectory of the center of the light spot recorded by the camera; Step 3: Drive the swing table to simulate the external environment of the fast steering mirror. The gyroscope collects the motion data of the swing table. Among them, the swing table is driven by the main control host computer to make the swing table swing uniaxially or swing in a biaxial compound manner; Step 4: Start the fast steering mirror controller. The fast steering mirror controller receives the motion data of the azimuth axis, pitch axis or both the azimuth axis and pitch axis of the swing table, and controls the fast steering mirror to enter the real-time compensation mode; The gyroscope collects the motion data of the azimuth axis or pitch axis of the swing table and inputs it into the fast steering mirror controller. The fast steering mirror controller can integrate according to the motion speed of the swing table measured by the gyroscope in real time, convert it into the position control quantity of the fast steering mirror, control the fast steering mirror to yaw, and compensate the optical path between the point light source, the fast steering mirror and the camera; The fast steering mirror controller generates a reverse control signal based on the motion data of the azimuth axis or pitch axis collected by the gyroscope, and drives the fast steering mirror to perform azimuth axis compensation motion or pitch axis compensation motion according to the reverse control signal; Step 5: The camera collects the image data of the light spot of the fast steering mirror and transmits it to the image acquisition and analysis host computer; Step 6: The image acquisition and analysis host computer calculates and processes the image data of the light spot, and measures and judges the dynamic performance of the fast steering mirror through the characteristics of the light spot trajectory; The image acquisition and analysis host computer calculates the centroid of each frame of image, obtains the offset Δx of the light spot on the X-axis corresponding to the azimuth axis, or obtains the offset Δy of the light spot on the Y-axis corresponding to the pitch axis, and statistically analyzes the Δx sequence or Δy sequence, calculates its peak-to-peak value P-P and standard deviation σ. (The peak-to-peak value refers to the difference between the highest value and the lowest value of a signal within one period, referring to the range between the maximum and the minimum) Calculate its peak-to-peak value P-P and standard deviation σ according to the Δx sequence as the evaluation index of the azimuth axis tracking error, calculate its peak-to-peak value P-P and standard deviation σ according to the Δy sequence as the evaluation index of the pitch axis tracking error. The peak value reflects the maximum fluctuation range of the light spot offset after compensation, and the standard deviation reflects the stability of the compensation process. Calculate the composite error of the light spot coordinates (Δx, Δy) of each frame of image as the evaluation index of the biaxial comprehensive tracking error; Define the maximum values Δx max and Δy max of the X-axis and Y-axis offsets, and calculate the cross-coupling degree to quantify the degree of mutual influence between the biaxial motions.

[0007] The beneficial effects brought by the technical solution provided in the embodiment of the present invention at least include: The present invention provides a device and method for measuring the dynamic performance of a fast steering mirror, which can accurately and conveniently evaluate the compensation performance of the fast steering mirror under different working conditions, provide reliable data support for its performance optimization, and realize the drift compensation and calibration of the gyroscope through the provided gyro drift error compensation algorithm, reduce the influence of the gyro drift error on the measurement result of the dynamic performance of the fast steering mirror, and thus realize the high-precision evaluation of the single-axis and double-axis dynamic compensation performance of the fast steering mirror. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0009] Figure 1 It is a structural block diagram of the fast steering mirror dynamic performance measurement device provided by the embodiment of the present invention; Figure 2 : It is a flow chart of the gyroscope drift compensation and calibration provided by the embodiment of the present invention; Figure 3 It is a flow chart of the method for measuring the dynamic performance of the azimuth axis of the fast steering mirror provided by the embodiment of the present invention; Figure 4 It is a flow chart of the method for measuring the dynamic performance of the pitch axis of the fast steering mirror provided by the embodiment of the present invention; Figure 5 It is a flow chart of the method for measuring the dynamic performance of the azimuth axis and pitch axis of the fast steering mirror provided by the embodiment of the present invention.

[0010] In the figure: swing table 1, fast steering mirror 2, fast steering mirror controller 3, power supply 4, camera 5, point light source 6, adjustment bracket 7, gyroscope 8, main control upper computer 9, image acquisition and analysis upper computer 10, adapter 11. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] The following will describe the technical solutions in the present invention in conjunction with the drawings.

[0012] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "example" in the present invention should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. Exactly, the use of the word "example" is intended to present concepts in a specific manner. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one of the two.

[0013] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference is not emphasized, their intended meanings are the same. "Of", "corresponding", and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference is not emphasized, their intended meanings are the same.

[0014] In the embodiments of the present invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, their intended meanings are the same.

[0015] To make the technical problems, technical solutions, and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0016] As Figure 1 shown, an embodiment of the present invention provides a fast steering mirror dynamic performance measurement device, which includes: a swing table 1, a fast steering mirror 2, a fast steering mirror controller 3, a power supply 4, a camera 5, a point light source 6, an adjustment bracket 7, a gyroscope 8, a main control host computer 9, and an image acquisition and analysis host computer 10; The gyroscope 8 and the fast steering mirror 2 are respectively arranged on the swing table 1, and the swing table 1 is communicatively connected to the main control host computer 9. The fast steering mirror controller 3 is communicatively connected to the gyroscope 8 and the fast steering mirror 2 respectively; The camera 5 is communicatively connected to the image acquisition and analysis host computer 10, and the image acquisition and analysis host computer 10 is communicatively connected to the fast steering mirror controller 3; The point light source 6 is a target light source, and the fast steering mirror 2 receives the light of the target light source to generate a light spot; The swing table 1 is equipped with a two-axis drive system for azimuth axis and pitch axis, and is used to simulate the external dynamic disturbance of the fast steering mirror 2; The gyroscope 8 is used to collect the motion data of the azimuth axis and pitch axis of the swing table 1; The main control host computer 9 is used to input drive information to the swing table 1 and control the swing table 1 to perform single-axis or two-axis periodic swinging according to the fixed amplitude and frequency set by the main control host computer 9; The fast steering mirror controller 3 is used to receive the motion data collected by the gyroscope 8 in real time, generate a reverse control signal according to the received motion data to control the fast steering mirror 2 to perform reverse compensation motion; the fast steering mirror controller 3 is also used to receive the drift rate of the gyroscope 8 and calibrate the zero bias drift of the gyroscope 8 according to the drift rate of the gyroscope 8; The camera 5 is used to collect the image data of the light spot on the fast steering mirror 2 and transmit the image data of the light spot to the image acquisition and analysis host computer 10; The upper computer 10 for image acquisition and analysis is used to receive the image data collected by the camera 5, analyze the motion trajectory of the light spot based on the received image data, and calculate the drift rate of the gyroscope 8; the fast steering mirror controller 3 is also used to receive the drift rate of the gyroscope 8 input by the upper computer 10 for image acquisition and analysis; transmit the drift rate of the gyroscope 8 to the fast steering mirror controller 3, and the fast steering mirror controller 3 calibrates the zero-offset drift of the gyroscope 8 according to the drift rate of the gyroscope 8. Through the analysis of the image data, the compensation effect of the fast steering mirror 2 on the motion of the swing table 1 in the single-axis direction is obtained, so as to test the compensation dynamic performance of the single axis of the fast steering mirror 2.

[0017] Among them, the swing table 1 is used to simulate external dynamic disturbances and has a two-axis servo drive structure. The two axes are the azimuth axis and the pitch axis. The swing table 1 controls the structure thereon to perform single-axis or two-axis periodic swinging along the azimuth axis and the pitch axis according to the fixed amplitude and frequency set by the main control host computer 9, and can realize the independent control of the azimuth axis and the pitch axis; the fast steering mirror 2 and the fast steering mirror controller 3 are installed on the swing table 1. Among them, the fast steering mirror 2 is fixed on the swing table 1 through the adapter 11 and integrates the dual-axis rotation functions of azimuth and pitch. The fast steering mirror controller 3 can integrate the movement speed of the swing table 1 measured by the gyroscope 8 in real time, convert it into the position control quantity of the fast steering mirror 2, and control the deflection of the fast steering mirror 2 to compensate the optical path between the point light source 6, the fast steering mirror 2 and the camera 5. A gyroscope 8 compensation system is set in the fast steering mirror controller 3. The gyroscope 8 compensation system adopts a closed-loop control architecture based on FPGA, supports the PID control algorithm, and the control period ≤ 10 μs to ensure fast response and precise control; the measuring device is also provided with a power supply 4, and the power supply 4 supplies power to the fast steering mirror controller 3 and the point light source 6; the camera 5 is used to collect the image data after the fast steering mirror 2 is stabilized; the point light source 6 is used as the target light source, and its light spot is adjusted to the center of the field of view of the camera 5 through the adjustment frame 7; the gyroscope 8 is directly installed on the swing table 1, and the movement data of the swing table 1 is collected in real time and transmitted to the fast steering mirror controller 3. The host computer system includes a main control host computer 9 and an image acquisition and analysis host computer 10. The main control host computer 9 is used to set the movement parameters of the swing table 1 and coordinate the work of each module; an image acquisition and analysis software is set in the image acquisition and analysis host computer 10. The image acquisition and analysis host computer 10 integrates functions such as parameter setting, real-time image data acquisition, image display, and test report generation. The image acquisition and analysis host computer 10 receives the image data collected by the camera 5, analyzes the movement trajectory of the light spot according to the received image data, and calculates the drift rate of the gyroscope 8; the fast steering mirror controller 3 receives the drift rate of the gyroscope 8 input by the image acquisition and analysis host computer 10, and calibrates the zero bias drift of the gyroscope 8 according to the drift rate of the gyroscope 8; the image acquisition and analysis host computer 10 obtains the compensation effect of the fast steering mirror 2 on the movement of the swing table 1 in the single-axis direction through the analysis of the image data, so as to measure the single-axis compensation dynamic performance of the fast steering mirror 2. By measuring the azimuth axis and the pitch axis of the fast steering mirror 2 respectively and simultaneously, the two-axis compensation dynamic performance of the fast steering mirror 2 can be measured. The image acquisition and analysis host computer 10 realizes the automation of the measurement process and the high efficiency of data processing.

[0018] In one embodiment, as Figure 3 shown, the technical solution provided by the present application proposes a method for measuring the dynamic performance of a fast steering mirror. This measurement method uses the above-mentioned device for measuring the dynamic performance of a fast steering mirror. Applying this measurement method, the performance test of the pitch axis of the fast steering mirror is as follows: This measurement method includes the following steps: Step 1: System initialization: Adjust the point light source, start the point light source, camera, and fast steering mirror controller in sequence, and keep the swing table stationary; Specific operation process of Step 1: Turn on the power, turn off the swing table drive system of the main control host computer, start the point light source, camera, and fast steering mirror controller in sequence, initialize each system, adjust the point light source. The point light source is used as the target light source, and its light spot is adjusted to the center of the camera's field of view through the adjustment frame; precisely align the light spot center with the camera's field of view center, and control the error within 1 pixel.

[0019] Step 2: Perform drift compensation calibration and drift compensation verification on the gyroscope. The parameters for drift compensation calibration of the gyroscope are obtained through the analysis and calculation of the drift trajectory of the light spot center recorded by the camera; Performing drift compensation calibration on the gyroscope includes: Recording the drift trajectory of the light spot center through the camera, calculating the gyro drift rate by the image acquisition and analysis host computer, writing the gyro drift rate into the compensation parameter table of the fast steering mirror controller to obtain the drift calibration parameters, and compensating the gyro drift according to the drift calibration parameters to complete the calibration of the gyro zero bias drift.

[0020] Specific gyro drift compensation calibration process: As Figure 2 shown, the camera continuously acquires light spot images at a frame rate of 200fps for 5 minutes, a total of 60000 frames. Receive the centroid calculation of each frame image by the image acquisition and analysis host computer to obtain the offset sequence of the light spot in the pixel coordinate system. Perform linear fitting on this sequence by the least squares method, and the slope of the fitting line is the gyro drift rate ω (unit: ° / h), which is written into the compensation parameter table of the fast steering mirror controller to complete the calibration of the gyro zero bias drift; Drift compensation verification includes: Starting the fast steering mirror controller, enabling the gyro compensation system in the fast steering mirror controller to continuously operate for a period of time under the input of external disturbance signals; Recording the drift trajectory of the light spot center through the camera, calculating the root mean square value RMS of the light spot center drift amount before gyro drift compensation and after introducing the drift calibration parameters to perform drift compensation on the gyroscope respectively, and comparing the differences between the two; If the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

[0021] Specific gyroscope drift compensation verification process: After gyroscope drift compensation calibration, continue to ensure that the swing table is in a stationary state to avoid external disturbances affecting the test results. Start the fast steering mirror controller, and make the gyroscope compensation system in the fast steering mirror controller continuously operate for 5 minutes to perform drift compensation on the gyroscope under the input of external disturbance signals. During this period, the camera collects spot images in real time at a frame rate of 200fps and records the drift trajectory of the spot center. Calculate the root mean square value RMS of the spot center drift amount before gyroscope drift compensation and after introducing drift calibration parameters to perform drift compensation on the gyroscope respectively, and compare the differences between the two; if the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

[0022] Step 3: Drive the swing table through the main control host computer to make the azimuth axis of the swing table swing; specifically, set the azimuth axis of the swing table to perform sinusoidal swing through the main control host computer, and the parameters are: frequency 10Hz, amplitude 0.05°, and at the same time lock the pitch axis to avoid unnecessary movement.

[0023] Step 4: Start the fast steering mirror controller to make its fast steering mirror compensation system enter the real-time compensation mode. The gyroscope collects the motion data of the azimuth axis and inputs it into the fast steering mirror controller. The fast steering mirror controller generates a reverse control signal based on the motion data of the azimuth axis collected by the gyroscope, and the fast steering mirror controller drives the fast steering mirror to perform azimuth axis compensation movement according to the reverse control signal.

[0024] Step 5: The camera continuously collects spot motion trajectory images at a frame rate of 200fps for 30 seconds and transmits them to the image acquisition and analysis host computer, a total of 6000 frames.

[0025] Step 6: The image acquisition and analysis host computer calculates the centroid of each frame of image to obtain the offset Δx of the spot on the X-axis (corresponding to the azimuth axis), performs statistical analysis on the Δx sequence, and calculates its peak-to-peak value P-P and standard deviation σ as evaluation indicators of the azimuth axis tracking error. The peak-to-peak value reflects the maximum fluctuation range of the spot offset after compensation, and the standard deviation reflects the stability of the compensation process. By judging the evaluation indicators of the azimuth axis tracking error, the peak value reflects the maximum fluctuation range of the spot offset after compensation, and the standard deviation reflects the stability of the compensation process, measure the dynamic performance of the fast steering mirror.

[0026] In another embodiment, as Figure 4 shown, apply the fast steering mirror dynamic performance measurement method provided by the present invention to test the performance of the fast steering mirror pitch axis: This measurement method includes the following steps: Step 1: System initialization: Adjust the point light source, start the point light source, camera and fast steering mirror controller in sequence, and keep the swing table stationary; Specific operation process of Step 1: Turn on the power supply, turn off the swing table drive system of the main control host computer, start the point light source, camera, and fast steering mirror controller in sequence, initialize each system, and adjust the point light source. As the target light source, the light spot of the point light source is adjusted to the center of the camera's field of view through the adjustment frame; precisely align the center of the light spot with the center of the camera's field of view, and control the error within 1 pixel.

[0027] Step 2: Perform drift compensation calibration and drift compensation verification on the gyroscope. The parameters for drift compensation calibration of the gyroscope are obtained through the analysis and calculation of the drift trajectory of the center of the light spot recorded by the camera. Performing drift compensation calibration on the gyroscope includes: recording the drift trajectory of the center of the light spot through the camera, calculating the gyroscope drift rate by the image acquisition and analysis host computer, writing the gyroscope drift rate into the compensation parameter table of the fast steering mirror controller to obtain drift calibration parameters, and compensating for the gyroscope drift according to the drift calibration parameters to complete the calibration of the gyroscope zero bias drift.

[0028] Specific process of gyroscope drift compensation calibration: As Figure 2 shown, the camera continuously acquires light spot images at a frame rate of 200 fps for 5 minutes, a total of 60,000 frames. The image acquisition and analysis host computer receives and calculates the centroid of each frame of image to obtain the offset sequence of the light spot in the pixel coordinate system. Perform linear fitting on this sequence by the least squares method. The slope of the fitting line is the gyro drift rate ω (unit: ° / h), which is written into the compensation parameter table of the fast steering mirror controller to complete the calibration of the gyroscope zero bias drift. Drift compensation verification includes: Start the fast steering mirror controller, and make the gyroscope compensation system in the fast steering mirror controller continuously run for a period of time under the input of external disturbance signals; record the drift trajectory of the center of the light spot through the camera, calculate the root mean square value RMS of the drift amount of the center of the light spot before gyroscope drift compensation and after introducing drift calibration parameters to perform drift compensation on the gyroscope respectively, and compare the differences between the two; if the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

[0029] Specific process of gyroscope drift compensation verification: After gyroscope drift compensation calibration, continue to ensure that the swing table is in a stationary state to avoid the influence of external disturbances on the test results. Start the fast steering mirror controller, and make the gyroscope compensation system in the fast steering mirror controller continuously run for 5 minutes to perform drift compensation on the gyroscope under the input of external disturbance signals. During this period, the camera continuously acquires light spot images at a frame rate of 200 fps in real time and records the drift trajectory of the center of the light spot. Calculate the root mean square value RMS of the drift amount of the center of the light spot before gyroscope drift compensation and after introducing drift calibration parameters to perform drift compensation on the gyroscope respectively, and compare the differences between the two; if the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

[0030] Step 3: Drive the swing table by the master host computer to make the swing table's pitch axis swing; specifically, set the pitch axis of the swing table to perform sinusoidal swing through the master host computer, with parameters: frequency 10 Hz, amplitude 0.05°, and at the same time lock the azimuth axis to avoid unnecessary movement.

[0031] Step 4: Start the fast steering mirror controller. The fast steering mirror controller controls the fast steering mirror to enter the real-time compensation mode. The gyroscope collects the motion data of the pitch axis and inputs it into the fast steering mirror controller. The fast steering mirror controller generates a reverse control signal based on the motion data of the azimuth axis or pitch axis collected by the gyroscope, and drives the fast steering mirror to perform pitch axis compensation motion according to the reverse control signal; Step 5: The camera continuously collects the spot motion trajectory images at a frame rate of 200 fps for 30 seconds and transmits them to the image acquisition and analysis host computer, a total of 6000 frames; Step 6: The image acquisition and analysis host computer calculates the centroid of each frame of image to obtain the offset Δy of the spot on the Y-axis corresponding to the pitch axis. Conduct statistical analysis on the Δy sequence, calculate its peak-to-peak value P-P and standard deviation σ, and calculate its peak-to-peak value P-P and standard deviation σ based on the Δy sequence as the evaluation index of the pitch axis tracking error. The peak value reflects the maximum fluctuation range of the spot offset after compensation, and the standard deviation reflects the stability of the compensation process; Measure the dynamic performance of the fast steering mirror through the evaluation index of the pitch axis tracking error, the peak value reflecting the maximum fluctuation range of the spot offset after compensation and the standard deviation reflecting the stability of the compensation process.

[0032] In another embodiment, as Figure 5 shown, apply the fast steering mirror dynamic performance measurement method provided by the present invention to test the two-axis coupling performance of the azimuth axis and pitch axis of the fast steering mirror: This measurement method includes the following steps: Step 1: System initialization: Adjust the point light source, start the point light source, camera, and fast steering mirror controller in sequence, and keep the swing table stationary; The specific operation process of Step 1: Turn on the power, turn off the swing table drive system of the master host computer, start the point light source, camera, and fast steering mirror controller in sequence, initialize each system, adjust the point light source. The point light source is used as the target light source, and its spot is adjusted to the center of the camera's field of view through the adjustment frame; Align the spot center with the camera's field of view center precisely, with the error controlled within 1 pixel.

[0033] Step 2: Perform drift compensation calibration and drift compensation verification on the gyroscope. The parameters of the gyroscope's drift compensation calibration are obtained through the analysis and calculation of the drift trajectory of the camera recording the spot center; The drift compensation and calibration of the gyroscope include: recording the drift trajectory of the spot center through the camera, calculating the gyroscope drift rate by the upper computer for image acquisition and analysis, writing the gyroscope drift rate into the compensation parameter table of the fast steering mirror controller to obtain the drift calibration parameter, and compensating the gyroscope drift according to the drift calibration parameter to complete the calibration of the gyroscope zero-offset drift.

[0034] The specific process of gyroscope drift compensation and calibration is as follows Figure 2 As shown, the camera continuously acquires spot images at a frame rate of 200 fps for 5 minutes, a total of 60,000 frames. The upper computer for image acquisition and analysis receives each frame of the image for centroid calculation to obtain the offset sequence of the spot in the pixel coordinate system. Linear fitting is performed on this sequence by the least squares method, and the slope of the fitted straight line is the gyro drift rate ω (unit: ° / h), which is written into the compensation parameter table of the fast steering mirror controller to complete the calibration of the gyroscope zero-offset drift; The drift compensation verification includes: starting the fast steering mirror controller to make the gyroscope compensation system in the fast steering mirror controller continuously run for a period of time under the input of an external disturbance signal; recording the drift trajectory of the spot center through the camera, respectively calculating the root mean square value RMS of the spot center drift amount before gyroscope drift compensation and after introducing the drift calibration parameter to perform drift compensation on the gyroscope, and comparing the differences between the two; if the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

[0035] The specific process of gyroscope drift compensation verification: After the gyroscope drift compensation and calibration, continue to ensure that the swing table is in a stationary state to avoid the influence of external disturbances on the test results. Start the fast steering mirror controller to make the gyroscope compensation system in the fast steering mirror controller continuously run for 5 minutes to perform drift compensation on the gyroscope under the input of an external disturbance signal. During this period, the camera acquires spot images in real time at a frame rate of 200 fps and records the drift trajectory of the spot center. Respectively calculate the root mean square value RMS of the spot center drift amount before gyroscope drift compensation and after introducing the drift calibration parameter to perform drift compensation on the gyroscope, and compare the differences between the two; if the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

[0036] Step 3: Perform a two-axis composite sine motion on the swing table through the main control upper computer, setting the frequency to 10 Hz, the amplitude to 0.05°, and the phase difference to 90° to generate a standard Lissajous figure.

[0037] Step 4: Start the fast steering mirror controller. The fast steering mirror controller controls the fast steering mirror to enter the real-time compensation mode. The gyroscope acquires the motion data of the azimuth axis and the pitch axis and inputs them into the fast steering mirror controller. The fast steering mirror controller simultaneously receives the gyroscope data of the azimuth axis and the pitch axis, and through the composite strategy of feedforward compensation and PID control, adjusts the two-axis angle of the fast steering mirror in real time to synchronously compensate the two-axis disturbance of the swing table; Step 5: The camera continuously captures the spot motion trajectory images at a frame rate of 200 fps for 30 seconds and transmits them to the upper computer for image acquisition and analysis, totaling 6000 frames. The Lissajous figure is generated using image analysis software.

[0038] Step 6: The upper computer for image acquisition and analysis calculates the synthesis error of the spot coordinates (Δx, Δy) of each frame of image to obtain , which is used as an evaluation index for the biaxial comprehensive tracking error.

[0039] Define the maximum values Δx max and Δy max of the X-axis and Y-axis offsets, calculate the cross-coupling degree and , , , which is used to quantify the mutual influence degree between the biaxial motions. The smaller the cross-coupling degree, the better the biaxial decoupling control performance of the fast steering mirror.

[0040] This application adopts a high-precision anti-drift measurement technology: aiming at the problem that the traditional gyro drift error affects the dynamic measurement accuracy, a drift calibration method based on optical image feedback is proposed. The gyro drift rate is accurately calculated through the spot offset in the static state, and the dynamic compensation of the gyro zero bias is realized, fundamentally solving the problem of data distortion caused by insufficient gyro stability in long-term tests, and significantly improving the long-term measurement accuracy of the compensation system.

[0041] Optical feedback and inertial measurement integration: Innovatively combine the camera image acquisition with the gyro inertial measurement. Through the sub-pixel level detection (accuracy up to 0.1 pixel) of the spot centroid, it directly reflects the actual optical compensation effect of the fast steering mirror. Compared with the traditional contact sensor, this method avoids the mechanical installation error and can more intuitively and accurately evaluate the performance of the fast steering mirror in the actual optical system.

[0042] Full-dimensional dynamic performance evaluation system: A test scheme covering key indicators such as single-axis compensation accuracy, biaxial coupling error, and response speed is designed, supporting single-axis / double-axis dynamic perturbation simulation and cross-coupling error detection. The whole process of parameter setting, data acquisition and analysis is realized automatically through the upper computer software. The operation interface is user-friendly, without complex manual intervention, greatly reducing the use threshold of the measurement system and improving the convenience in engineering applications. Through the automated test process, the full-item performance evaluation of the fast steering mirror can be completed within 15 minutes, significantly improving the test efficiency and meeting the ex-factory inspection requirements in mass production.

[0043] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware, or any combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that contains one or more collections of available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, or magnetic tape), an optical medium (such as a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0044] It should be understood that the term "and / or" in this document is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. Additionally, the character " / " in this document generally represents an "or" relationship between the associated objects before and after, but it may also represent an "and / or" relationship, which can be understood specifically with reference to the context.

[0045] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0046] It should be understood that in various embodiments of the present invention, the magnitudes of the serial numbers of the above processes do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0047] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0048] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described devices, apparatuses, and units can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0049] In several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0050] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0051] In addition, the functional units in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0052] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0053] As described above, the above are only specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A fast-steering mirror dynamic performance measurement device, characterized in that, The device includes: a swing table, a fast steering mirror, a fast steering mirror controller, a power supply, a camera, a point light source, a gyroscope, a main control host computer, and an image acquisition and analysis host computer; The gyroscope and the fast steering mirror are respectively arranged on the swing table. The swing table is communicatively connected to the main control host computer. The fast steering mirror controller is communicatively connected to the gyroscope and the fast steering mirror respectively; The camera is communicatively connected to the image acquisition and analysis host computer, and the image acquisition and analysis host computer is communicatively connected to the fast steering mirror controller; The point light source is the target light source. The fast steering mirror receives the light of the target light source to generate a light spot; The swing table is equipped with a two-axis drive system for azimuth axis and pitch axis, and is used to simulate the external dynamic disturbance of the fast steering mirror; The gyroscope is used to collect the motion data of the azimuth axis and pitch axis of the swing table; The main control host computer is used to input drive information to the swing table and control the swing table to perform single-axis or two-axis periodic swing according to the fixed amplitude and frequency set by the main control host computer; The fast steering mirror controller is used to receive the motion data of the swing table monitored by the gyroscope in real time, generate a reverse control signal according to the received motion data to control the fast steering mirror to perform reverse compensation motion, and maintain the continuous swing of the mirror surface of the fast steering mirror; Keep the light spot stable in the camera field of view. The fast steering mirror controller calibrates the zero bias drift of the gyroscope according to the built-in compensation parameter table; The camera is used to collect the image data of the light spot on the fast steering mirror and transmit the image data to the image acquisition and analysis host computer; The image acquisition and analysis host computer is used to receive the image data collected by the camera, analyze the motion trajectory of the light spot according to the received image data, and calculate the gyroscope drift rate; The fast steering mirror controller is also used to receive the gyroscope drift rate input by the image acquisition and analysis host computer; Transmit the gyroscope drift rate to the fast steering mirror controller; Through the analysis of the image data, the compensation effect of the fast steering mirror on the motion of the swing table in the single-axis direction is obtained, so as to test the single-axis compensation dynamic performance of the fast steering mirror.

2. The fast-steering mirror dynamic performance measurement device according to claim 1, wherein The point light source is arranged on the adjustment frame, and the light spot of the point light source is adjusted to the center of the camera field of view through the adjustment frame.

3. The fast-steering mirror dynamic performance measurement device according to claim 1, characterized in that, The fast steering mirror is fixed on the swing table through an adapter.

4. A method for measuring the dynamic performance of a fast steering mirror, which uses the fast steering mirror dynamic performance measurement device described in any one of claims 1-3 to implement the method for measuring the dynamic performance of the fast steering mirror, characterized in that, The measurement method includes the following steps: Step 1: System initialization: Adjust the point light source, start the point light source, the camera and the fast steering mirror controller in sequence, and keep the swing table stationary; Step 2: Perform drift compensation calibration and drift compensation verification on the gyroscope. The parameters of the drift compensation calibration of the gyroscope are obtained through the analysis and calculation of the drift trajectory of the light spot center recorded by the camera; Step 3: Drive the swing table to simulate the external environment of the fast steering mirror. The gyroscope collects the motion data of the swing table. Among them, the swing table is driven by the main control host computer to make the swing table swing uniaxially or swing in a two-axis compound manner; Step 4: Start the fast steering mirror controller. The fast steering mirror controller receives the motion data of the azimuth axis, pitch axis or both azimuth axis and pitch axis of the swing table, and controls the fast steering mirror to enter the real-time compensation mode; The gyroscope collects the motion data of the azimuth axis or pitch axis of the swing table and inputs it to the fast steering mirror controller. The fast steering mirror controller generates a reverse control signal based on the motion data of the azimuth axis or pitch axis collected by the gyroscope, and drives the fast steering mirror to perform azimuth axis compensation motion or pitch axis compensation motion according to the reverse control signal; Step 5: The image data of the light spot collected by the camera's fast steering mirror is transmitted to the upper computer for image acquisition and analysis. Step 6: The upper computer for image acquisition and analysis calculates and processes the image data of the light spot, and measures and judges the dynamic performance of the fast steering mirror through the characteristics of the light spot trajectory; the upper computer for image acquisition and analysis calculates the centroid of each frame of image, obtains the offset Δx of the light spot on the X-axis corresponding to the azimuth axis, or obtains the offset Δy of the light spot on the Y-axis corresponding to the pitch axis, statistically analyzes the Δx sequence or the Δy sequence, calculates its peak-to-peak value P-P and standard deviation σ, and calculates its peak-to-peak value P-P and standard deviation σ according to the Δx sequence as the evaluation index of the azimuth axis tracking error; calculates its peak-to-peak value P-P and standard deviation σ according to the Δy sequence as the evaluation index of the pitch axis tracking error; the peak value reflects the maximum fluctuation range of the light spot offset after compensation, and the standard deviation reflects the stability of the compensation process; calculates the composite error of the light spot coordinates of each frame of image as the evaluation index of the biaxial comprehensive tracking error; defines the maximum values Δx max and Δy max , calculates the cross coupling degree, and is used to quantify the mutual influence degree between the biaxial motions.

5. The dynamic performance measurement method of the fast-steering mirror according to claim 4, characterized in that In step 1, the point light source is adjusted. Specifically, the center of the light spot is precisely aligned with the center of the camera's field of view, and the error is controlled within 1 pixel.

6. The dynamic performance measurement method of the fast-steering mirror according to claim 4, characterized in that, The drift compensation and calibration of the gyroscope include: recording the drift trajectory of the light spot center by the camera, calculating the gyroscope drift rate by the upper computer for image acquisition and analysis, writing the gyroscope drift rate into the compensation parameter table of the fast steering mirror controller to obtain the drift calibration parameter, and compensating the gyroscope drift according to the drift calibration parameter to complete the calibration of the gyroscope zero-bias drift.

7. The dynamic performance measurement method of the fast-steering mirror according to claim 6, characterized in that The drift compensation verification includes: starting the fast steering mirror controller to make the gyroscope compensation system in the fast steering mirror controller continuously run for a period of time under the input of external disturbance signals; recording the drift trajectory of the light spot center by the camera, respectively calculating the root mean square value RMS of the drift amount of the light spot center before gyroscope drift compensation and after introducing the drift calibration parameter to compensate the gyroscope drift, and comparing the differences between the two; if the drift amount after compensation is significantly reduced, the effectiveness of the gyro drift compensation algorithm is verified.

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