Method and system for testing stability precision in real time based on photoelectric pod sensor

Abstract

The invention discloses a stability precision real-time testing method and system based on a photoelectric pod sensor. Belongs to the technical field of photoelectric equipment detection. The technical problem that real-time and high-precision stable precision index measurement cannot be realized in the prior art is solved. The method comprises the following steps: S1, gyroscope zero drift calibration: obtaining a gyroscope zero drift mean value based on time drift; s2, gyro signal preprocessing: preprocessing the gyro original signal through the gyro zero drift mean value to obtain corrected gyro angular velocity data; s3, stability precision dynamic calculation based on time window integration: in a preset sliding time window, calculating the corrected gyro angular velocity data to obtain an angle root-mean-square value of stability precision, and taking the angle root-mean-square value of the stability precision as a stability precision index of a sensor of the photoelectric pod; and S4, stable precision value transmission: reporting a stable precision index to an upper computer through an interface.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic equipment testing technology, specifically relating to the field of real-time stability and accuracy testing technology based on the sensors of the optoelectronic pod itself. Background Technology

[0002] An electro-optical pod is an airborne or vehicle-mounted device used for electro-optical detection and target tracking. It typically carries payloads such as visible light and infrared cameras and lasers, and is commonly used in military fields for intelligence gathering and target tracking and positioning, and in civilian fields for search and rescue and environmental monitoring. When using an electro-optical pod, stability accuracy is one of the most important performance indicators. Due to disturbances in the aircraft's attitude and airflow during operation, the line of sight can become jittery, reducing the resolution of the output image and leading to unreadable or lost targets. Stability accuracy can also be used as a means of detecting faults and resonance. Therefore, a rapid, accurate, and simple method for verifying stability accuracy is crucial.

[0003] Conventional methods for stabilization accuracy testing utilize optical equipment such as collimators or interferometers, employing image processing algorithms to calculate image offsets and infer line-of-sight angle jitter. However, these methods are limited by factors such as image frame rate and detector pixel size. Furthermore, the acquisition of image data followed by post-processing software cannot achieve real-time, high-precision measurement of stabilization accuracy. There is an urgent need for a testing method that can evaluate the line-of-sight stability accuracy of optoelectronic pods in real time without relying on external testing platforms or equipment. This would reduce testing costs, improve adaptability and timeliness, and meet the diverse testing needs of modern optoelectronic pods across various scenarios. Summary of the Invention

[0004] To address the technical problem that existing technologies cannot achieve real-time, high-precision, and stable accuracy measurement, and rely on external testing platforms or equipment, resulting in insufficient testing costs, adaptability, and timeliness to meet the multi-scenario testing needs of modern optoelectronic pods, this invention provides a stable accuracy real-time testing method and system based on the optoelectronic pod's own sensors.

[0005] The method includes the following steps: S1. Gyroscope Zero-Drift Calibration: Obtain the average zero-point drift value of the gyroscope based on time drift. ; S2. Gyroscope signal preprocessing: The original gyroscope signal is preprocessed using the gyroscope zero-point drift average to obtain corrected gyroscope angular velocity data; S3. Dynamic calculation of stable accuracy based on time window integration: Within a preset sliding time window, the corrected gyroscope angular velocity data is calculated to obtain the root mean square value of the stable accuracy angle. The root mean square value of the stable accuracy angle is used as the stable accuracy index of the photoelectric pod's own sensor. S4. Stable accuracy value transmission: The stable accuracy index is reported to the host computer through the interface.

[0006] Further, step S1 specifically involves: placing the photoelectric pod on the swing platform to be tested, with the platform stationary, and the pod entering position control mode. The azimuth and pitch axes of the pod are rotated to a stable accuracy test angle via a joystick or command. After the pod stabilizes to a stationary state, it is switched to gyro speed stabilization mode, simultaneously recording the azimuth and pitch axis encoder angle changes over a certain period. The gyro zero-point drift value based on time drift is obtained by combining the angle differential, and the average of several sets of gyro zero-point drift values ​​is calculated. .

[0007] further, ;in, Indicates the number of groups being calculated. Indicates the Secondary gyroscope zero-point drift value , express and The time interval of time, and They are and The encoder angle value at any given time.

[0008] Further, step S2 specifically involves subtracting the mean zero-point drift of the gyroscope obtained in step S1 from the original gyroscope signal, and then performing low-pass filtering to suppress high-frequency noise components, resulting in the corrected gyroscope angular velocity data. ; in: : No. The raw angular velocity data of the gyroscope sampled in the second sampling; : No. The raw angular velocity data of the gyroscope sampled in the second sampling; : No. The corrected gyro angular velocity data after filtering and removal of zero-point drift; : Filtering factor.

[0009] Further, in step S3, the control pod is in encoder position control mode. The azimuth and pitch frame angle positions of the pod are adjusted so that they are parallel to the azimuth and pitch direction of the test swing table, respectively. Then, the pod is switched to gyro stabilization mode, and the swing table is started to swing sinusoidally according to a preset frequency and amplitude, collecting the corrected gyro angular velocity data in real time. Within a preset sliding time window, the corrected gyro angular velocity data is calculated to obtain the root mean square value of the stabilization accuracy. .

[0010] further, ; ; in, This represents the angular increment value of the integral of the angular velocity; Indicates the Corrected gyro angular velocity data at specific times; Indicates the time interval for gyroscope data sampling; ; in, This represents the average value of the angle change sequence within the sliding time window; This indicates the number of sampling points within the sliding time window; This indicates the conversion factor for converting angular units from degrees to microradians.

[0011] Furthermore, in step S4, the communication interface connects the photoelectric pod servo system to the host computer main control system or test terminal.

[0012] The system includes: Gyroscope zero-drift calibration module: Obtains the average zero-point drift value of the gyroscope based on time drift. ; Gyroscope signal preprocessing module: preprocesses the original gyroscope signal using the gyroscope zero-point drift average to obtain corrected gyroscope angular velocity data; The dynamic calculation module for stable accuracy based on time window integration calculates the corrected gyroscope angular velocity data within a preset sliding time window to obtain the root mean square value of the stable accuracy. The root mean square value of the stable accuracy is used as the stability accuracy index of the optoelectronic pod's own sensor. Stable accuracy value transmission module: Reports stable accuracy indicators to the host computer through the interface.

[0013] The beneficial effects of the method described in this invention are as follows: The method described in this invention is based on a servo system that collects motion information from inertial sensors inside the pod. Without relying on external high-precision testing platforms or devices, it can evaluate the line-of-sight stability performance in various working environments in real time. By collecting inertial angular velocity data from the optoelectronic pod control system, the raw data undergoes preprocessing such as filtering and zero drift elimination. Within a preset time window, the root mean square value of the angle jitter after integrating the short-time angular velocity is calculated as an indicator of the pod's stability accuracy in the azimuth and pitch directions. The stability accuracy is then uploaded to a host computer, which can graphically visualize the stability accuracy values ​​and trend curves according to specific needs, supporting real-time monitoring, recording, and subsequent analysis.

[0014] The method described in this invention has the characteristics of high computational efficiency, simple implementation, strong real-time performance, and no need for additional equipment. It can be widely used in the acceptance of ground indicators of optoelectronic pods, flight tests, and other occasions. It can also be used for the optimization of optoelectronic image stabilization control algorithms, and for the judgment of resonance and fault detection. Attached Figure Description

[0015] Figure 1 This is a flowchart of a real-time stability accuracy testing method based on the sensor of the photoelectric pod itself in an embodiment of the present invention. Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0017] Example 1 This embodiment provides a real-time stability accuracy testing method based on the sensors of the photoelectric pod itself, such as... Figure 1 As shown, the method includes the following steps: S1. Gyroscope Zero-Drift Calibration: Obtain the average zero-point drift value of the gyroscope based on time drift. ; S2. Gyroscope signal preprocessing: The original gyroscope signal is preprocessed using the gyroscope zero-point drift average to obtain corrected gyroscope angular velocity data; S3. Dynamic calculation of stability accuracy based on time window integration: Within a preset sliding time window, the corrected gyroscope angular velocity data is calculated to obtain the root mean square value of the line of sight stability. The root mean square value of the stability accuracy is used as the stability accuracy index of the optoelectronic pod's own sensor. S4. Stable accuracy value transmission: The stable accuracy index is reported to the host computer through the interface.

[0018] Example 2 This embodiment further defines embodiment 1 and provides further explanation of step S1.

[0019] The optoelectronic pod is placed on the swing platform under test. With the platform stationary, the optoelectronic pod enters position control mode. The azimuth and pitch axes of the optoelectronic pod are rotated to the angle for stable accuracy testing via a joystick or command. After the optoelectronic pod stabilizes to a stationary state, it is switched to gyro speed stabilization mode. At the same time, the azimuth and pitch axis encoder angle changes are recorded over a certain period of time. The gyro zero-point drift value based on time drift is constructed by combining the angle differential, providing correction data for subsequent stable accuracy calculation. Since the gyro zero-point drift value changes continuously with time, temperature, and pod angle position, the current gyro zero-point drift value needs to be reacquired before each swing or flight test to obtain accurate stable accuracy. In addition, to reduce encoder quantization error or sampling noise interference, multiple sets of values ​​are averaged.

[0020] When the pod is in gyro-speed stabilization mode, the encoder on one axis is... The change in angle over time is from Change to The zero-point drift of the gyroscope The calculation is as follows: ; ; : No. Secondary gyroscope zero-point drift value, unit: ; Mean zero-point drift of the gyroscope, unit: ; : and Time interval, unit: ; and They are respectively and Encoder angle value at time, unit: ; : The number of groups to be calculated; Step S1 aims to obtain the zero-point deviation value of the current gyroscope in a stationary state, as a basis for subsequent signal correction.

[0021] Example 3 This embodiment further defines embodiment 1 and provides further explanation of step S2.

[0022] The original gyroscope signal is subtracted from the gyroscope zero-point drift value obtained in step 1, and then subjected to low-pass filtering to suppress high-frequency noise components, including mechanical vibration, electromagnetic interference, and noise from the sensor itself. The corrected gyroscope data is as follows: ; The formula is for a first-order low-pass filter, where: : No. The original angular velocity data of the gyroscope sampled from the previous sample, in units of: ; : No. The raw angular velocity data of the gyroscope sampled from the previous sample, in units of: ; : No. The gyro angular velocity data after filtering and removal of zero-point drift is in units of: ; : is the filter factor, which has no unit; Mean zero-point drift of the gyroscope, unit: ; Filtering factor Control the cutoff frequency of the gyroscope filter. The larger the filter, the smaller the cutoff frequency, the stronger the ability to suppress high-frequency noise, but the slower the response.

[0023] Example 4 This embodiment further defines embodiment 1 and provides further explanation of step S3.

[0024] The control pod is in encoder position control mode. The pod's azimuth and pitch frame angles are adjusted to be parallel to the azimuth and pitch directions of the test swing platform, respectively. Then, the pod switches to gyro-stabilized mode, and the swing platform is started to oscillate sinusoidally according to a preset frequency and amplitude. Corrected gyro angular velocity data for the azimuth and pitch axes are collected in real time. Within a preset sliding time window, the angular velocity signal is calculated to obtain the root mean square (RMS) value of the change in the line-of-sight angle, which serves as the gyroscope stability accuracy index for that period. The calculation process is as follows: First, the corrected gyroscope angular velocity data is integrated using a recursive method to obtain the change in the line-of-sight angle at each moment: ; Secondly, calculate the mean of the angle sequence within the sliding time window: ; Then, after converting the angular change sequence to microradians, its root mean square (RMS) value is calculated: ; : The angular increment of the integral of angular velocity, in units of: ; : No. Corrected gyro angular velocity data for each moment, in units of: ; : Gyroscope data sampling time interval, unit: ; : The average value of the angle change sequence within the window, in units of: ; : Root mean square (RMS) value of stable accuracy angle, unit: ; Number of sampling points within the sliding window; : The conversion factor for converting angular units from degrees to microradians, i.e. The calculation yielded the result.

[0025] The result obtained by the above method The degree of line-of-sight angle jitter of the pod within the current time window can objectively reflect the stable control performance of the pod under dynamic disturbance conditions, which is a stability accuracy index.

[0026] Example 5 This embodiment further defines embodiment 1 and provides further explanation of step S4.

[0027] The electro-optical pod servo system typically communicates with the host computer control system or test terminal via a conductive slip ring. The communication interface can be a standard form such as RS422 or Ethernet. Using this interface, the servo control system reports the real-time calculated azimuth and pitch axis stabilization accuracy data to the host computer. The host computer is equipped with a dynamic graphics component that can generate real-time curves, multi-dimensional views, or time-series graphs of stabilization accuracy, supporting functions such as time trend analysis of stabilization accuracy, abnormal threshold alarms, and historical data backtracking. This display method facilitates operators in intuitively evaluating the stabilization performance of the electro-optical pod and debugging the servo system in application scenarios such as flight tests and ground factory tests.

[0028] All four steps of the method described in this invention are implemented and completed by a servo control system. In order not to affect the normal operation and control of the servo system, the MCU in the servo system runs the FreeRTOS real-time operating system. According to the importance of the task program, the priority of the method task in this invention is set to a low level to prevent it from affecting the real-time performance of the normal control program task.

Claims

1. A real-time stability and accuracy testing method based on the self-sensors of the photoelectric pod, characterized in that, The method includes the following steps: S1. Gyroscope Zero-Drift Calibration: Obtain the average zero-point drift value of the gyroscope based on time drift. ; S2. Gyroscope signal preprocessing: The original gyroscope signal is preprocessed using the gyroscope zero-point drift average to obtain corrected gyroscope angular velocity data; S3. Dynamic calculation of stable accuracy based on time window integration: Within a preset sliding time window, the corrected gyroscope angular velocity data is calculated to obtain the root mean square value of the stable accuracy angle. The root mean square value of the stable accuracy angle is used as the stable accuracy index of the photoelectric pod's own sensor. S4. Stable accuracy value transmission: The stable accuracy index is reported to the host computer through the interface.

2. The real-time stability and accuracy testing method based on the photoelectric pod's own sensors according to claim 1, characterized in that, Step S1 is as follows: Place the photoelectric pod on the swing platform to be tested. With the swing platform stationary, the pod enters position control mode. Control the pod's azimuth and pitch axes to rotate to the angle for stable accuracy testing via a joystick or command. After the pod stabilizes to a stationary state, switch the pod to gyro speed stabilization mode. Simultaneously, start recording the azimuth and pitch axis encoder angle changes over a certain period of time. Combine the angle differential to obtain the gyro zero-point drift value based on time drift, and calculate the average of several sets of gyro zero-point drift values. .

3. The real-time stability and accuracy testing method based on the self-sensor of the photoelectric pod according to claim 2, characterized in that, ;in, Indicates the number of groups being calculated. Indicates the first Secondary gyroscope zero-point drift value , express and The time interval of time, and They are and The encoder angle value at any given time.

4. The real-time stability accuracy testing method based on the photoelectric pod's own sensors according to claim 3, characterized in that, Step S2 specifically involves subtracting the mean zero-point drift of the gyroscope obtained in step S1 from the original gyroscope signal, and then performing low-pass filtering to suppress high-frequency noise components, resulting in the corrected gyroscope angular velocity data. ； in: : No. The raw angular velocity data of the gyroscope sampled in the second sampling; : No. The raw angular velocity data of the gyroscope sampled in the second sampling; : No. The corrected gyro angular velocity data after filtering and removal of zero-point drift; : Filtering factor.

5. The real-time stability accuracy testing method based on the photoelectric pod's own sensors according to claim 4, characterized in that, In step S3, the control pod is in encoder position control mode. The azimuth and pitch frame angle positions of the pod are adjusted so that they are parallel to the azimuth and pitch direction of the test swing table, respectively. Then, the pod is switched to gyro stabilization mode, and the swing table is started to swing sinusoidally according to a preset frequency and amplitude. The corrected gyro angular velocity data is collected in real time. Within a preset sliding time window, the corrected gyro angular velocity data is calculated to obtain the root mean square value of the stabilization accuracy. .

6. The real-time stability accuracy testing method based on the self-sensor of the photoelectric pod according to claim 5, characterized in that, ； ； in, This represents the angular increment value of the integral of the angular velocity; Indicates the first Corrected gyro angular velocity data at specific times; Indicates the time interval for sampling gyroscope data; ； in, This represents the average value of the angle change sequence within the sliding time window; This indicates the number of sampling points within the sliding time window; This indicates the conversion factor for converting angular units from degrees to microradians.

7. The real-time stability accuracy testing method based on the photoelectric pod's own sensors according to claim 6, characterized in that, In step S4, the communication interface connects the photoelectric pod servo system to the host computer main control system or test terminal.

8. A real-time stability and accuracy testing system based on the sensor of the photoelectric pod itself, characterized in that, The system includes: Gyroscope zero-drift calibration module: Obtains the average zero-point drift value of the gyroscope based on time drift. ; Gyroscope signal preprocessing module: preprocesses the original gyroscope signal using the gyroscope zero-point drift average to obtain corrected gyroscope angular velocity data; The dynamic calculation module for stable accuracy based on time window integration calculates the corrected gyroscope angular velocity data within a preset sliding time window to obtain the root mean square value of the stable accuracy. The root mean square value of the stable accuracy is used as the stability accuracy index of the optoelectronic pod's own sensor. Stable accuracy value transmission module: Reports stable accuracy indicators to the host computer through the interface.

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