Adaptive frequency division reverse compensation method for fast steering mirror of optoelectronic platform under static and dynamic base conditions

Abstract

The application discloses a fast mirror frequency division reverse compensation method of an optoelectronic platform, and belongs to the field of precise servo control technology of optoelectronic reconnaissance and fire control systems of complex platforms such as airborne, vehicle-mounted and ship-mounted platforms, and aims to solve the problems of the traditional optoelectronic platform, such as the inability to automatically distinguish between dynamic and static working conditions, the easy damage of the fast mirror due to overstroke when the platform is running and bumping, the imaging drift caused by gyro drift in the static state, and the insufficient compensation stroke caused by long-term deviation of the fast mirror; the application synchronously collects the base IMU motion data and the image miss distance, automatically distinguishes the working conditions through disturbance energy and hysteresis comparison, adopts a washout filter to divide the high and low frequency disturbances for the dynamic platform, superimposes the outputs of the two branches to drive the fast mirror, and only relies on the image PID to suppress slow drift for the static platform by cutting off the gyro feedforward, simultaneously collects the fast mirror deflection angle to form an unloading closed loop by backflowing the coarse shaft speed ring, and continuously maintains the fast mirror at the mechanical center; the method is suitable for precise servo control of various complex platform optoelectronic reconnaissance and fire control systems.

Description

Technical Field

[0001] This invention belongs to the field of precision servo control technology for optoelectronic reconnaissance and fire control systems of complex platforms such as airborne, vehicle-mounted, and shipborne systems, specifically involving a fast-reflecting mirror frequency division reverse compensation method for optoelectronic platforms under adaptive dynamic and static base conditions. Background Technology

[0002] The modern "coarse-fine composite axis" optoelectronic turntable consists of a large frame (coarse axis, driven by a torque motor) and a miniature fast reflector (fine axis, driven by a piezoelectric ceramic or voice coil motor, abbreviated as FSM). Its working principle is: the coarse axis is responsible for large-range low-frequency tracking, while the fine axis is responsible for "reverse compensation" of extremely small-range high-frequency line-of-sight jitter.

[0003] However, existing technologies have the following irreconcilable contradictions: (1) The physical travel of the fast-reflecting mirror is extremely small (easily saturates and fails): the mechanical deflection range of the fast-reflecting mirror is usually only to (i.e., tens of milliradians). When conducting reconnaissance on moving platforms (such as off-road vehicles traveling at high speeds or helicopters performing high-maneuver flights), the base will experience extremely large low-frequency swaying (up to several degrees or even tens of degrees). If a fast-reflecting mirror attempts to directly compensate for these large disturbances, it will hit the mechanical limit switch (i.e., stroke saturation) within tens of milliseconds, causing the precision axis to instantly fail, ultimately resulting in violent image jitter and loss of the target.

[0004] (2) Low-speed crawling caused by gyroscope drift: When conducting reconnaissance on a static platform (such as when a vehicle is parked or a fixed-point hovering sentry post), the system is mainly affected by the wind load and the small friction force inside the turntable. The traditional all-time feedforward back-compensation algorithm introduces the low-frequency constant drift and random walk noise of the base gyroscope, which will cause the fast-reflection mirror to integrate the wrong compensation amount for a long time, resulting in slow drift of the line of sight (crawling phenomenon) when the target is stationary. Summary of the Invention

[0005] To address the technical problems mentioned in the background section, this invention proposes an adaptive frequency division and reverse compensation method for a fast-reflecting mirror on an optoelectronic platform under both dynamic and static platform conditions. The principle is to intelligently determine the state of the dynamic and static platform using inertial data. In dynamic conditions, a "high-pass washout filter" is introduced to protect the fast-reflecting mirror; in static conditions, low-frequency noise sources are cut off, and "clean full-band reverse compensation" is performed based on the image miss distance. This solves the dual technical challenges of fast-reflecting mirror stroke saturation failure under conditions of large platform disturbances and low-speed line-of-sight crawling caused by low-frequency gyroscope drift under static platform conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a method for frequency division and reverse compensation of a fast-reflection mirror on an adaptive dynamic and static base, the method comprising the following steps: Step 1: Collect the motion data of the photoelectric turntable base, construct the base disturbance energy function model based on the motion data, and use a hysteresis comparator to determine whether the current working condition is a moving platform or a static platform and output the working condition identifier. Step 2: Collect the target imaging focal plane miss distance, complete the line-of-sight residual disturbance calculation based on the miss distance, obtain the optical compensation angle used to cancel the disturbance, and then convert the optical compensation angle into a fast-reflection mirror mechanical compensation angle command through the optomechanical inverse mapping model. Step 3: If the working condition is identified as the moving platform working condition, use the wash-out filter to perform frequency division filtering on the mechanical compensation angle command of the fast-reflecting mirror, and output the total control voltage of the fast-reflecting mirror; Step 4: If the working condition is identified as static platform working condition, turn off the washing filter and cut off the feedforward integration path of the base gyroscope, and use PID control to output the total control voltage of the fast mirror only based on the image miss distance. Step 5: Real-time acquisition of the actual deflection angle of the fast-reflection mirror, scaling the fine axis position with a gain coefficient and feeding it back to the coarse axis speed control loop as a feedforward bias, forming a coarse axis unloading follow-up closed loop and generating a coarse axis speed command.

[0007] Furthermore, in step 1 of this invention, the base motion data is collected by a reference inertial measurement unit installed on the base of the photoelectric turntable; the variance features of the base's three-axis angular velocity and linear acceleration are extracted using a time sliding window, and the base disturbance energy function model is constructed through the two types of variance features; the hysteresis comparator is configured with two sets of thresholds, high and low, and the working condition is determined by combining the values ​​output by the base disturbance energy function model.

[0008] Furthermore, the hysteresis comparator described in this invention is used to prevent frequent switching oscillations of the controller in critical states.

[0009] Furthermore, the optomechanical inverse mapping model described in step 2 of this invention introduces the resting angle between the incident ray and the secondary mirror normal, and the total optical magnification of the system to complete the conversion of the optical compensation angle to the mechanical compensation angle command of the fast-reflecting mirror. The conversion process includes a reverse compensation mechanism to achieve reverse compensation of the line-of-sight disturbance.

[0010] Furthermore, in step 3 of the present invention, the washing filter is a second-order washing filter. This second-order washing filter has high impedance characteristics for low-frequency signals and full-pass characteristics for high-frequency signals, filtering out the low-frequency disturbance components of the gyroscope contained in the mechanical compensation angle command.

[0011] Furthermore, in step 3 of the present invention, the second-order wash-out filter is set with a frequency division cutoff frequency. Low-frequency disturbance components below the frequency division cutoff frequency are filtered out and compensated by the coarse axis, while high-frequency disturbance components above the frequency division cutoff frequency are retained and compensated by the fast-reflection mirror.

[0012] Furthermore, in step 4 of this invention, PID control based solely on the image miss distance is used to compensate for bearing friction and low-frequency, slow line-of-sight disturbances caused by external breezes.

[0013] Furthermore, the PID control described in this invention is an anti-integral saturation PID control law.

[0014] Furthermore, in step 5 of this invention, the actual deflection angle of the fast-reflecting mirror is collected by the built-in eddy current displacement sensor of the fast-reflecting mirror; the coarse axis speed command is obtained by superimposing the scaled actual offset of the fast-reflecting mirror with the coarse axis basic tracking speed command.

[0015] Based on the same inventive concept, this invention also provides a vehicle-mounted optoelectronic reconnaissance stabilization platform. The platform is embedded with the aforementioned adaptive dynamic and static base working condition optoelectronic platform fast reflector frequency division reverse compensation method. The method is used to divide and isolate the fast reflector from high-frequency vibration disturbances under vehicle moving and bumpy conditions, and at the same time, it eliminates the slow crawling of the line of sight caused by gyroscope drift under vehicle stationary conditions. It also continuously maintains the fast reflector in the middle position of the mechanical stroke through coarse shaft unloading and following closed loop, so as to achieve pixel-level stable locking of imaging under all working conditions.

[0016] The beneficial effects of this invention are as follows: (1) A reverse compensation model for a variable topology architecture was constructed: This invention breaks the traditional mode of “coarse and fine dual-axis fixed cutoff frequency allocation”. This invention proposes for the first time a controller switching based on the platform energy method threshold discrimination, so that the system’s anti-disturbance capability and anti-drift capability can be optimally configured within the physical limits.

[0017] (2) Innovative introduction of servo-level “wash-out filter” anti-saturation mechanism: The second-order high-pass filter space is embedded in the photoelectric image inverse algorithm. The algorithm cuts off the pressure of low-frequency overshoot on the micron-level mechanical mirror, fundamentally solving the technical problem that the FSM mechanism often fails due to collision with the limit under high cooling and high vibration conditions.

[0018] (3) This invention is an optomechanical composite control method that uses a microelectromechanical / piezoelectric fast steering mirror (FSM) to eliminate line-of-sight broadband disturbances for two different working conditions: platform motion and stationary conditions, and adopts adaptive filtering and frequency division compensation strategies. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the principle of the fast-reflection mirror frequency division reverse compensation method for the photoelectric platform under adaptive dynamic and static base conditions proposed in this invention. Figure 2 This is the topology of the adaptive dynamic-static inverse complementation algorithm of this invention; Figure 3 This is a schematic diagram of the frequency response characteristic curve of the photoelectric stabilization system of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0022] Implementation Method 1: Combination Figures 1 to 3 This embodiment describes an adaptive control strategy for various operating conditions, namely, an adaptive frequency division and reverse compensation method for the fast-reflecting mirror of an optoelectronic platform under both dynamic and static base conditions. The principle is to intelligently determine the state of the dynamic and static platform using inertial data. In dynamic conditions, a "high-pass washout filter" is introduced to protect the fast-reflecting mirror; in static conditions, low-frequency noise sources are cut off, and "pure full-band reverse compensation" is performed based on the image miss distance. This solves the dual technical challenges of fast-reflecting mirror stroke saturation failure under conditions of large platform disturbances and low-speed line-of-sight crawling caused by low-frequency gyroscope drift under static platform conditions.

[0023] The adaptive dynamic and static base working condition photoelectric platform fast-reflection mirror frequency division reverse compensation method includes the following steps: Step 1: Multi-dimensional feature extraction and adaptive discrimination of dynamic and static base conditions Collect the motion data of the photoelectric turntable base, construct the base disturbance energy function model based on the motion data, and use a hysteresis comparator to determine whether the current working condition is a moving platform or a static platform and output the working condition identifier. Step 2: Solving for residual line-of-sight perturbations and inverse optomechanical mapping (extraction of inverse source) The target imaging focal plane miss distance is collected, and the residual disturbance of the line of sight is calculated based on the miss distance to obtain the optical compensation angle used to cancel the disturbance. Then, the optical compensation angle is converted into a fast-reflection mirror mechanical compensation angle command through the optomechanical inverse mapping model. Step 3: "Wash out anti-saturation" frequency division inverse compensation law under dynamic platform mode ( ) If the operating condition is identified as the moving platform operating condition, the washing filter is used to perform frequency division filtering on the mechanical compensation angle command of the fast-reflecting mirror, and the total control voltage of the fast-reflecting mirror is output. Step 4: "Staring Anti-Drift" Full-Band Inverse Compensation Law in Static Platform Mode ( ) If the working condition is identified as static platform working condition, turn off the washing filter and cut off the feedforward integration path of the base gyroscope, and use PID control to output the total control voltage of the fast mirror only based on the image miss distance. Step 5: Fine shaft position backflow and coarse shaft unloading follow-up closed loop The actual deflection angle of the fast-reflection mirror is acquired in real time. The position of the fine axis is scaled by the gain coefficient and fed back to the coarse axis speed control loop as a feedforward bias, forming a coarse axis unloading follow-up closed loop and generating a coarse axis speed command.

[0024] Furthermore, in one specific embodiment, in step 1, the base motion data is collected by a reference inertial measurement unit installed on the base of the photoelectric turntable; the variance features of the base's three-axis angular velocity and linear acceleration are extracted using a time sliding window, and the base disturbance energy function model is constructed using the two types of variance features; a hysteresis comparator is configured with two sets of thresholds, high and low, and the operating condition is determined by combining the values ​​output by the base disturbance energy function model. The hysteresis comparator is also used to prevent frequent switching oscillations of the controller under critical conditions.

[0025] Furthermore, in one specific embodiment, the optomechanical inverse mapping model described in step 2 incorporates the resting angle between the incident ray and the secondary mirror normal, and the total optical magnification of the system to complete the conversion from the optical compensation angle to the mechanical compensation angle command of the fast-reflecting mirror. The conversion process includes a reverse compensation mechanism to achieve reverse compensation for line-of-sight disturbances. Additionally, the second-order wash-out filter is set with a frequency cutoff frequency. Low-frequency disturbance components below the cutoff frequency are filtered out and compensated by the coarse axis, while high-frequency disturbance components above the cutoff frequency are retained and compensated by the fast-reflecting mirror.

[0026] Furthermore, in one specific embodiment, in step 4, PID control based solely on the image miss distance is used to compensate for bearing friction and low-frequency, slow line-of-sight disturbances caused by external breezes. Moreover, the PID control is an anti-integral saturation PID control law.

[0027] Furthermore, in one specific embodiment, in step 5, the actual deflection angle of the fast-reflecting mirror is acquired by the built-in eddy current displacement sensor of the fast-reflecting mirror; the coarse axis speed command is obtained by superimposing the scaled actual offset of the fast-reflecting mirror onto the coarse axis basic tracking speed command.

[0028] Furthermore, in one specific implementation, combined with Figure 1 The fast-reflection mirror frequency division reverse compensation method described in this invention will be specifically explained; like Figure 1As shown, this invention simultaneously acquires motion data of the base IMU and the miss distance of the imaging image. A dynamic / static base condition discrimination module calculates the base disturbance energy and automatically distinguishes between dynamic and static platform conditions based on hysteresis comparison. Under the dynamic platform condition of vehicle vibration, the base disturbance signal is sent to a second-order high-pass filter for frequency division and filtering to obtain the IMU feedforward compensation amount, which drives the fast-reflecting mirror. The frequency division characteristic is used to compensate for low-frequency large swings by the coarse axis, avoiding fast-reflecting mirror stroke saturation impact. Under the static platform condition, the filter is turned off and the gyroscope feedforward integration path is cut off. Only PID control of the image miss distance is used to eliminate the line-of-sight caused by gyroscope drift. The system crawls slowly while simultaneously acquiring the actual deflection angle of the fine axis in real time via the built-in displacement sensor of the fast-reflecting mirror. After being scaled by the unloading gain, the data is fed back to the coarse axis speed control loop to form a coarse axis unloading follow-up closed loop. This allows the coarse axis to move synchronously with the deflection of the fast-reflecting mirror, continuously maintaining the fast-reflecting mirror in the mechanical neutral position and releasing all compensation strokes. After the attitude of the coarse axis changes, the image is re-acquired to update the miss error and complete the global closed-loop iteration. This solves several technical problems of traditional optoelectronic stabilization platforms, such as the inability to automatically distinguish between dynamic and static conditions, the easy overtravel damage of the fast-reflecting mirror under dynamic load and bumps, the imaging drift caused by gyroscope drift in the static staring state, and the insufficient available compensation stroke due to long-term offset of the fast-reflecting mirror.

[0029] pass Figure 2 The adaptive dynamic and static inverse compensation algorithm topology shown in this invention can automatically adjust the compensation path according to the motion state of the base. Under dynamic base conditions, it uses washing-out filtering to achieve high-frequency compensation of FSM and suppress low-frequency saturation. Under static base conditions, it uses high-gain full-frequency compensation to improve the line-of-sight stabilization accuracy.

[0030] pass Figure 3 To further explain, compared with the traditional coarse axis control and FSM direct compensation method, the present invention achieves a wider frequency band anti-interference performance by using coarse and fine composite frequency domain coordination to make low-frequency disturbances bear the burden of the coarse axis and high-frequency disturbances bear the burden of the FSM.

[0031] Implementation Method Two: This implementation method provides a detailed explanation of each step in Implementation Method One; Step 1: Multi-dimensional feature extraction and adaptive discrimination of dynamic and static base conditions A reference inertial measurement unit is installed on the base of the photoelectric turntable. (And slide the window at a certain time interval). Extracting the triaxial angular velocity of the base With linear acceleration The variance characteristics.

[0032] Constructing the base perturbation energy function : in, , These are the normalized weighting coefficients. This is the mean.

[0033] Furthermore, a hysteresis comparator threshold is set. .when At that time, the system status flag position is (Dynamic platform high sea state / high off-road mode); When hour, (Static platform dwell mode). The hysteresis comparator has hysteresis characteristics to prevent frequent switching oscillations of the controller in critical states.

[0034] Step 2: Solving for residual line-of-sight perturbations and inverse optomechanical mapping (extraction of inverse source) Let the target miss distance (pixel deviation converted to angle) in the image focal plane be... In an optical path, the optical reflection effect of a fast-reflecting mirror has a magnifying property.

[0035] The absolute optical compensation angle required by the fast-reflecting mirror is :

[0036] in, The representative represents the image error angle conversion coefficient. , The size of the detector pixel; This refers to the focal length of the optical system. It is used to convert pixel deviation to view axis angular deviation. The symbol represents the residual angular velocity disturbance along the line of sight. ,in: The base angular velocity is obtained from the Base-IMU measurement; This term represents the theoretical angular velocity predicted and compensated by the coarse-axis control system. It is used to estimate the cumulative line-of-sight deviation caused by low-frequency drift. Due to the double-angle effect of the FSM mirror: .

[0037] Based on the absolute optical compensation angle, a mechanical motion angle command is applied to the fast-reflecting mirror actuator. (Inverse mapping model): Among them, the symbol " "This represents a reverse compensation mechanism; The resting angle between the incident ray and the normal of the secondary mirror; This represents the total optical magnification of the system.

[0038] Step 3: "Wash out anti-saturation" frequency division inverse compensation law under dynamic platform mode ( ) When the platform is in motion, a second-order washout filter is introduced. It processes gyroscope feedforward and position commands. The washout filter's function is to present extremely high impedance to low-frequency signals and full pass for high-frequency characteristics, thereby forcing the fast-reflecting mirror's low-frequency movements to "wash out / return" to the zero mechanical center point.

[0039] The transfer function of the second-order washout filter is: in, The cutoff frequency for the frequency division is typically set to 0.8 times the coarse-axis closed-loop bandwidth, such as... ; The damping ratio is typically taken as 0.707.

[0040] At this time, the total control voltage of the fast-reflecting mirror for: The physical meaning of step 3 is: to reduce the size of the component to a smaller size. The large swing is intercepted, and this part of the error will naturally flow to the coarse axis in (step five) for compensation; the fast-reflection mirror only receives and performs micro-adjustment compensation. The high-frequency vibration successfully prevented it from being damaged by impact during severe turbulence.

[0041] Step 4: "Staring Anti-Drift" Full-Band Inverse Compensation Law in Static Platform Mode ( ) When the reconnaissance vehicle remains stationary and concealed, the feedforward integration path of the base gyroscope is cut off, so that... It directly relies on the high-precision miss distance of the image extractor for overdrive control. Turning off the wash-out filter (equivalent to...) ).

[0042] At this point, the control law switches to PID regulation to resist integral saturation.

[0043] The physical significance of step 4 is that, in a static state, there is no large-amplitude shaking, and the fast-reflecting mirror does not need to prevent saturation. It can use its extraordinary resolution (at the level of a few microradians) to fully absorb the slow drift caused by bearing friction and wind blowing inside the photoelectric turntable, thereby achieving "pixel-level" fixed locking of the target image.

[0044] Step 5: Fine shaft position backflow and coarse shaft unloading follow-up closed loop Regardless of the operating conditions, the fast-reflecting mirror contains a high-precision eddy current displacement sensor to measure its actual deflection angle in real time. .

[0045] Will Multiply by a small gain factor It is added as a feedforward bias to the speed control loop input of the coarse shaft (large frame turntable).

[0046]

[0047] in, The basic velocity tracking command generated by the coarse axis based on target tracking error, inertial navigation information, and its own controller output: ;in, The desired angular velocity generated by the target motion, For coarse shaft angle error, For coarse shaft controller; The FSM position unloading gain is used to adjust the conversion ratio of the fast-reflecting mirror deflection angle to the coarse-axis motion (generally). ).

[0048] This gives the large turntable a tendency to "catch up with and cover up" the deflection of the fast reflector. Once the fast reflector counteracts an external force, the coarse shaft will rotate accordingly, thereby "unloading" the force that caused the fast reflector to deviate from the center due to the counteracting force, and always ensuring that the core component of the fast reflector is in the center of the mechanical stroke in preparation for the next impact.

[0049] Implementation Method 3: This implementation method, based on a real-world scenario, discusses the technical advantages of the adaptive dynamic and static base working condition photoelectric platform fast-reflection mirror frequency division reverse compensation method proposed in this invention. Implementation background and parameters: A certain type of vehicle-mounted laser communication and reconnaissance turntable, main axis field of view The fast-reflective mirror uses a voice coil drive mechanism with a maximum physical travel. System optical magnification The control cycle is set to... .

[0050] Scenario 1 (High-speed off-road advance): off-road vehicles Driving on unpaved roads produces significant rolling and bumping (frequency) Amplitude ) and engine high-frequency knock (frequency) Amplitude ).

[0051] The system calculates the disturbance energy. leap to Trigger action mode ( ).

[0052] At this point, if the present invention (traditional direct back-compensation) is not used, the fast-reflecting mirror will need to catch up. The extreme turbulence instantly pushed it beyond its mechanical limits. When the device hits the edge of the frame, the servo locks up.

[0053] After adopting this invention, the washing filter Will The following The jitter command was forcibly blocked to 0 (handed over to the coarse shaft for slow digestion), and the fast-reflection command segment was only stripped out. The high-frequency vibration command enables precise counter-attack (reverse compensation). The actual deflection of the fast-reaction mirror is... Operating at high speeds, it remains safe without saturation. The detector's images enable smooth, motionless, high-speed reconnaissance.

[0054] Scenario 2 (Shoulder Parking Gaze): The command to remain dormant was issued, and the off-road vehicle shut down. The base sensor determined that the energy had dropped to [a certain level]. (Parking mode). At this time, environmental interference is mainly... Low-speed nonlinear frictional crawling. The algorithm automatically removes the gyroscope drift path and uses a parallel bypass filter to switch to a pure image anti-interference mode. The fast-reflecting mirror achieves extremely high spatial resolution ( The target feature is firmly fixed in the center of the crosshair on the visible light CCD target surface, and the residual is suppressed within... (Equivalent to less than 0.1 pixels). After 2 hours of continuous reconnaissance, no cumulative drift or off-target failure as seen in traditional modes was observed.

[0055] In summary, the adaptive dynamic and static base working condition photoelectric platform fast-reflection mirror frequency division reverse compensation method proposed in this invention has the following technical innovations: (1) A reverse compensation model with variable topology architecture was constructed: breaking the traditional mode of "coarse and fine dual-axis fixed cutoff frequency allocation", this invention proposes for the first time a controller switching based on platform energy method threshold discrimination, so that the system's anti-disturbance capability and anti-drift capability can be optimally configured within the physical limits.

[0056] (2) Innovative introduction of servo-level “wash-out filter” anti-saturation mechanism: The second-order high-pass filter space is embedded in the photoelectric image inverse algorithm. The algorithm cuts off the pressure of low-frequency overshoot on the micron-level mechanical mirror, fundamentally solving the technical problem that the FSM mechanism often fails due to collision with the limit under high cooling and high vibration conditions.

[0057] Implementation Method 4: The adaptive dynamic and static base working condition optoelectronic platform fast reflector frequency division reverse compensation method proposed in this invention is applicable to the precision servo control scenarios of optoelectronic reconnaissance and fire control systems on complex platforms such as airborne, vehicle-mounted, and shipborne systems.

[0058] This embodiment provides a vehicle-mounted optoelectronic reconnaissance stabilization platform. The platform is embedded with the optoelectronic platform fast-reflection mirror frequency division reverse compensation method described above for adaptive dynamic and static base conditions, thus fully realizing line-of-sight stabilization control under all working conditions.

[0059] During operation, the base IMU collects the base angular velocity and linear acceleration data caused by vehicle bumps in real time, and the imaging detector synchronously outputs the image pixel miss amount representing the residual deviation of the line of sight. The two data are synchronously transmitted to the working condition discrimination module of the embedded controller. The controller calculates the base disturbance energy based on the motion data collected by the IMU, and automatically determines whether the current working condition is a moving platform (vehicle moving and bumping) or a static platform (vehicle parked and concealed) by combining the hysteresis comparator and the preset disturbance energy threshold.

[0060] When the condition is determined to be a moving platform, the controller inputs the base disturbance signal into a second-order high-pass filter to perform frequency division filtering, filtering out low-frequency large sway components below 15Hz and retaining only high-frequency vibration signals. After filtering, the signal is fused with the image miss quantity to generate IMU feedforward compensation quantity, which is sent to the FSM dual-axis driver to drive the fast-reflecting mirror deflection. The low-frequency large sway disturbance is diverted to the thick shaft frame turntable to bear the load, avoiding fast-reflecting mirror deflection stroke saturation and lens impact with the limiting structure, thus achieving frequency division isolation protection against high-frequency vibration disturbance.

[0061] When the system is determined to be in a static platform condition, the controller automatically bypasses the filter and cuts off the feedforward integration path of the base gyroscope to isolate the low-frequency noise introduced by the gyroscope drift. It only relies on the high-precision image miss distance output by the imaging detector to perform anti-integral saturation PID full-band compensation, which is specifically designed to offset the slow drift of the line of sight caused by the friction of the turntable bearing and the blowing of the outdoor breeze, so as to achieve pixel-level fixed locking of the target image.

[0062] Regardless of whether it is in motion or stationary conditions, the built-in eddy current displacement sensor of the fast-reflecting mirror collects the actual mechanical deflection angle of the fast-reflecting mirror in real time. The controller scales this deflection angle with a preset unloading gain coefficient and uses it as a feedforward offset to feed back to the speed control loop of the coarse axis frame turntable. This is superimposed with the coarse axis basic target tracking angular velocity to generate a coarse axis speed command, thus constructing a coarse axis unloading follow-up closed loop. The coarse axis frame turntable rotates synchronously with the deflection of the fast-reflecting mirror according to this speed command, continuously offsetting the static offset of the fast-reflecting mirror and always keeping the fast-reflecting mirror lens in the middle of its mechanical stroke. The maximum compensation stroke is reserved throughout the entire process to cope with sudden disturbances. After the coarse axis attitude is adjusted, the imaging detector re-acquires the target image and updates the miss error to complete the closed loop iteration. The entire process takes into account both vehicle movement and stationary reconnaissance scenarios, continuously ensuring stable and clear electro-optical observation and aiming imaging, and extending the service life of the core components of the fast-reflecting mirror.

[0063] The above description of the technical solution provided by the present invention through several specific embodiments is intended to highlight the advantages and benefits of the technical solution provided by the present invention. However, the above-described specific embodiments are not intended to limit the present invention. Any reasonable modifications and improvements to the present invention, reasonable combinations of implementation methods and equivalent substitutions based on the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for frequency division and reverse compensation of a fast-reflecting mirror on an adaptive dynamic and static base, characterized in that, Includes the following steps: Step 1: Collect the motion data of the photoelectric turntable base, construct the base disturbance energy function model based on the motion data, and use a hysteresis comparator to determine whether the current working condition is a moving platform or a static platform and output the working condition identifier. Step 2: Collect the target imaging focal plane miss distance, complete the line-of-sight residual disturbance calculation based on the miss distance, obtain the optical compensation angle used to cancel the disturbance, and then convert the optical compensation angle into a fast-reflection mirror mechanical compensation angle command through the optomechanical inverse mapping model. Step 3: If the working condition is identified as the moving platform working condition, use the wash-out filter to perform frequency division filtering on the mechanical compensation angle command of the fast-reflecting mirror, and output the total control voltage of the fast-reflecting mirror; Step 4: If the working condition is identified as static platform working condition, turn off the washing filter and cut off the feedforward integration path of the base gyroscope, and use PID control to output the total control voltage of the fast mirror only based on the image miss distance. Step 5: Real-time acquisition of the actual deflection angle of the fast-reflection mirror, scaling the fine axis position with a gain coefficient and feeding it back to the coarse axis speed control loop as a feedforward bias, forming a coarse axis unloading follow-up closed loop and generating a coarse axis speed command.

2. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 1, characterized in that, In step 1, the base motion data is collected by a reference inertial measurement unit installed on the base of the photoelectric turntable; the variance features of the base's three-axis angular velocity and linear acceleration are extracted using a time sliding window, and the base disturbance energy function model is constructed using the two types of variance features; the hysteresis comparator is configured with two sets of thresholds, high and low, and the working condition is determined by combining the values ​​output by the base disturbance energy function model.

3. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 2, characterized in that, The hysteresis comparator is used to prevent frequent switching oscillations of the controller in critical states.

4. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 1, characterized in that, In step 2, the optomechanical inverse mapping model introduces the resting angle between the incident ray and the secondary mirror normal, and the total optical magnification of the system to complete the conversion of the optical compensation angle to the mechanical compensation angle command of the fast-reflecting mirror. The conversion process includes a reverse compensation mechanism to achieve reverse compensation of the line-of-sight disturbance.

5. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 1, characterized in that, In step 3, the washing filter is a second-order washing filter. This second-order washing filter has high impedance characteristics for low-frequency signals and full-pass characteristics for high-frequency signals, filtering out the low-frequency disturbance components of the gyroscope contained in the mechanical compensation angle command.

6. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 1, characterized in that, In step 3, the second-order wash-out filter is set with a frequency cutoff frequency. Low-frequency disturbance components below the frequency cutoff frequency are filtered out and compensated by the coarse axis, while high-frequency disturbance components above the frequency cutoff frequency are retained and compensated by the fast-reflection mirror.

7. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 1, characterized in that, In step 4, PID control based solely on the image miss distance is used to compensate for bearing friction and low-frequency, slow line-of-sight disturbances caused by external breezes.

8. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 7, characterized in that, The PID control described is an anti-integral saturation PID control law.

9. The photoelectric platform fast-reflection mirror frequency division and reverse compensation method for adaptive dynamic and static base conditions according to claim 1, characterized in that, In step 5, the actual deflection angle of the fast-reflecting mirror is collected by the built-in eddy current displacement sensor; the coarse axis speed command is obtained by superimposing the scaled actual offset of the fast-reflecting mirror with the coarse axis basic tracking speed command.

10. A vehicle-mounted optoelectronic reconnaissance stabilization platform, characterized in that, The platform is embedded with the adaptive dynamic and static base working condition photoelectric platform fast reflector frequency division reverse compensation method as described in any one of claims 1-9. The method is used to divide and isolate the fast reflector from high-frequency vibration disturbances under vehicle moving and bumpy working conditions, and at the same time eliminates the slow crawl of the line of sight caused by gyroscope drift under vehicle stationary working conditions. It also continuously maintains the fast reflector in the middle position of the mechanical stroke through coarse shaft unloading and following closed loop, so as to achieve pixel-level stable locking of imaging under all working conditions.

Images