Variable gain photoelectric pod stability control algorithm based on frequency decomposition

Abstract

The invention provides a variable gain photoelectric pod stability control algorithm based on frequency decomposition, and belongs to the technical field of automatic control, the variable gain photoelectric pod stability control algorithm comprises the following steps: S1, collecting azimuth and pitch axis gyro angular velocity signals and aiming line angular velocity given values in a photoelectric pod; s2, decomposing the set value of the angular velocity of the aiming line into a high frequency band, a medium frequency band and a low frequency band; s3, aiming line angular velocity given values and gyro sub-signals of the three frequency bands are used as given values and feedback values of three different controllers respectively; and S4, adding the control output quantities of the three different controllers to obtain final output, and outputting the final output to an execution mechanism. According to the algorithm, the stabilization precision of the photoelectric pod stabilization platform is remarkably improved under the condition that the cost and complexity of the system are not increased. The algorithm can be integrated in servo control software of the photoelectric pod, real-time output of a stable precision estimated value is achieved, the algorithm is applied to multiple photoelectric pod models, a good effect is achieved in test flight, and the algorithm has high engineering practicability and practical value.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology, specifically relating to a variable gain optoelectronic pod stabilization control algorithm based on frequency decomposition. Background Technology

[0002] Stabilization accuracy is one of the most important indicators of an optoelectronic pod, directly affecting its imaging performance. Currently, the requirements for stabilization accuracy are becoming increasingly stringent. Many factors influence the stabilization accuracy of an optoelectronic pod's stabilization platform. Increasing the gain of the control system is one of the most direct and effective ways to improve system stability accuracy. However, due to system stability limitations, the gain of traditional PID controllers or lead-lag compensators is constrained by system stability. Increasing the gain will eventually cause the system to transition from a stable state to a critically stable or unstable state. In traditional control algorithms, increasing the controller gain can improve the system's anti-interference and response performance, but it also reduces the gain margin and phase margin, preventing further improvement in open-loop gain and system stability accuracy.

[0003] Therefore, we hope to find a control algorithm that can improve the controller gain while maintaining stability margin. Summary of the Invention

[0004] The purpose of this invention is to provide a variable gain optoelectronic pod stabilization control algorithm that significantly improves the stabilization accuracy of an optoelectronic pod stabilization platform without increasing system cost or complexity, by using frequency band decomposition, independent gain control, and signal synthesis, without requiring additional circuitry or hardware.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a variable gain optoelectronic pod stabilization control algorithm based on frequency decomposition. S1: Collect the gyro angular velocity signals of the azimuth and pitch axes and the target line angular velocity setpoint inside the optoelectronic pod. The gyro angular velocity signals are divided into low-frequency gyro sub-signals, medium-frequency gyro sub-signals and high-frequency gyro sub-signals. S2: Decompose the target line angular velocity setpoint into three frequency bands: high, medium, and low. S3: Use the aiming line angular velocity setpoint and gyroscope signal of the three frequency bands as the setpoint and feedback value of three different controllers respectively; S4: The control outputs of the three different controllers are added together to obtain the final output, which is then output to the actuator of the stable platform.

[0006] The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm provided by this invention also has the following technical features: S1 includes sequentially passing the acquired gyroscope angular velocity signal through different filters to obtain low-frequency gyroscope sub-signals, mid-frequency gyroscope sub-signals, and high-frequency gyroscope sub-signals.

[0007] The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm provided by this invention also has the following technical features: the gyroscope angular velocity signal is passed through a 30Hz low-pass filter to obtain a low-frequency gyroscope sub-signal, and then passed through a 30-60Hz band-pass filter to obtain a mid-frequency gyroscope sub-signal, with the remaining signal being a high-frequency gyroscope sub-signal.

[0008] The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm provided by this invention also has the following technical features: in S2, the decomposition of the aiming line angular velocity setpoint is achieved using a filter, and the filter is the same as the filter used in S1 when obtaining different gyro angular velocity signals.

[0009] The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm provided by this invention also has the following technical feature: the three different controllers in S3 have different gains.

[0010] The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm provided by this invention also has the following technical features: in step S3, based on the gain of the high-frequency controller, the gain of the mid-frequency controller is not less than 1.4 times the gain of the high-frequency controller, and the gain of the low-frequency controller is not less than 2 times the gain of the high-frequency controller.

[0011] Beneficial effects: The frequency decomposition-based variable-gain optoelectronic pod stabilization control algorithm provided in this invention significantly improves the stability accuracy of the optoelectronic pod stabilization platform without increasing system cost or complexity. This algorithm can be integrated into the servo control software of the optoelectronic pod, enabling real-time output of stability accuracy estimates. It has been applied in multiple optoelectronic pod models and achieved excellent results in flight tests, demonstrating high engineering practicality and application value. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a block diagram of a variable gain optoelectronic pod stabilization platform based on frequency decomposition provided in an embodiment of the present invention; Figure 2 This is a block diagram of the gyroscope signal frequency decomposition module provided in an embodiment of the present invention; Figure 3 This is a comparison chart of the angular velocities of the algorithm-stabilized platform provided in this embodiment of the invention. Figure 4 This is a comparison chart of the angular velocity spectrum of the algorithm switching stabilization platform provided in the embodiments of the present invention. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent transformations or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0015] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0016] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0017] The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0018] Different frequency bands of gyroscope signals have varying impacts on the stabilization platform. Test results indicate that the main reason for the inability to increase control gain is the high-frequency signal above 60Hz. While maintaining the gain margin, there is room for increasing the gain in the mid-to-low frequency bands. Furthermore, most of the main disturbance signals to the stabilization platform are concentrated in the low-frequency band. Using traditional control methods is equivalent to using the same gain across all frequency bands. Separating the mid-to-low frequency bands from the high-frequency bands could improve the gain in the mid-to-low frequency bands, thereby improving the stabilization accuracy of the electro-optical pod stabilization platform.

[0019] Based on the above principles, such as Figure 1-4As shown, this embodiment of the invention provides a variable gain optoelectronic pod stabilization control algorithm based on frequency decomposition. S1: Collect the gyro angular velocity signals of the azimuth and pitch axes and the target line angular velocity setpoint inside the optoelectronic pod. The gyro angular velocity signals are divided into low-frequency gyro sub-signals, medium-frequency gyro sub-signals and high-frequency gyro sub-signals. S2: Decompose the target line angular velocity setpoint into three frequency bands: high, medium, and low. S3: Use the aiming line angular velocity setpoint and gyroscope signal of the three frequency bands as the setpoint and feedback value of three different controllers respectively; S4: The control outputs of the three different controllers are added together to obtain the final output, which is then output to the actuator of the stable platform.

[0020] Let the total gyroscope signal be The three components decomposed by the filter bank are low frequencies. , intermediate frequency and high frequency The components, decomposed into three parts, should satisfy: ; Then set the angular velocity of the aiming line. Decompose the frequency into high, medium, and low bands using the same filter:

[0021] Set the aiming line angular velocity to low, medium, and high frequencies. , , gyroscope signal splitting , , These are taken as the setpoint and feedback values ​​of three different controllers. All other parameters of the three controllers are the same, except for the gain.

[0022] In the above embodiments, after frequency decomposition of the signal, different gains can be used for each frequency band, significantly improving the gain in the low-frequency and mid-frequency bands. Since the main interference signals of the stabilization platform are also concentrated in the low-frequency and mid-frequency bands, the control system's isolation capability against disturbances in these bands is greatly improved, thereby enhancing the stability accuracy under swaying and vibration conditions. Compared with the original lead-lag compensation control method, the stability accuracy is improved. The algorithm does not require additional circuitry or hardware; through frequency band decomposition, independent gain control, and signal synthesis, it significantly improves the stability accuracy of the optoelectronic pod stabilization platform without increasing system cost or complexity.

[0023] In some embodiments, S1 includes sequentially passing the acquired gyroscope angular velocity signal through different filters to obtain a low-frequency gyroscope sub-signal, a medium-frequency gyroscope sub-signal, and a high-frequency gyroscope sub-signal.

[0024] In some embodiments, the gyroscope angular velocity signal is passed through a 30Hz low-pass filter to obtain a low-frequency gyroscope signal, and then passed through a 30-60Hz band-pass filter to obtain a mid-frequency gyroscope signal. The remaining signal is a high-frequency gyroscope signal.

[0025] In some embodiments, the decomposition of the aiming line angular velocity setpoint in S2 is achieved using a filter, which is the same filter used in S1 when obtaining different gyroscope angular velocity signals.

[0026] In some embodiments, the three different controllers in S3 have different gains.

[0027] In some embodiments, in step S3, based on the gain of the high-frequency controller, the gain of the mid-frequency controller is not less than 1.4 times the gain of the high-frequency controller, and the gain of the low-frequency controller is not less than 2 times the gain of the high-frequency controller.

[0028] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A variable-gain optoelectronic pod stabilization control algorithm based on frequency decomposition, characterized in that, S1: Collect the gyro angular velocity signals of the azimuth and pitch axes and the target line angular velocity setpoint inside the optoelectronic pod. The gyro angular velocity signals are divided into low-frequency gyro sub-signals, medium-frequency gyro sub-signals and high-frequency gyro sub-signals. S2: Decompose the target line angular velocity setpoint into three frequency bands: high, medium, and low. S3: Use the aiming line angular velocity setpoint and gyroscope signal of the three frequency bands as the setpoint and feedback value of three different controllers respectively; S4: The control outputs of the three different controllers are added together to obtain the final output, which is then output to the actuator of the stable platform.

2. The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm according to claim 1, characterized in that, S1 includes sequentially passing the acquired gyroscope angular velocity signal through different filters to obtain low-frequency gyroscope sub-signals, medium-frequency gyroscope sub-signals, and high-frequency gyroscope sub-signals.

3. The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm according to claim 2, characterized in that, The gyroscope angular velocity signal is passed through a 30Hz low-pass filter to obtain a low-frequency gyroscope signal, and then passed through a 30-60Hz band-pass filter to obtain a mid-frequency gyroscope signal. The remaining signal is the high-frequency gyroscope signal.

4. The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm according to claim 2, characterized in that, In S2, the decomposition of the aiming line angular velocity setpoint is achieved using a filter, which is the same filter used in S1 when obtaining different gyroscope angular velocity signals.

5. The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm according to claim 1, characterized in that, The three different controllers in S3 have different gains.

6. The frequency decomposition-based variable gain optoelectronic pod stabilization control algorithm according to claim 4, characterized in that, In S3, based on the gain of the high-frequency controller, the gain of the mid-frequency controller is not less than 1.4 times the gain of the high-frequency controller, and the gain of the low-frequency controller is not less than 2 times the gain of the high-frequency controller.

Images