A control method and apparatus for reducing oscillation of a large inertia rudder system

Abstract

The present application relates to a kind of control method and device for reducing the oscillation of large inertia rudder system, belong to flight control technical field, solve the problem that existing large inertia system due to nonlinearity and hysteresis can extend system adjustment time, increase oscillation frequency and reduce temperature margin and cannot meet the performance requirement of aircraft large maneuvering.The method includes when instruction signal is unchanged and tracking deviation signal is larger, determine that rudder system enters step motion state;When instruction signal is in change state or motion state, through high frequency motion excitation to rudder system, make rudder system in motion state;Predict whether rudder system is in the motion state of approaching target position or moving away from target position;And when rudder system is in the motion state of approaching target position, brake control in advance and when rudder system is in the motion state of moving away from target position, pull bias control in advance.Through the control steps of trajectory prediction, brake in advance, dynamic excitation, reduce large inertia load rudder system oscillation and overshoot.

Description

Technical Field

[0001] This invention relates to the field of flight control technology, and in particular to a control method and apparatus for reducing oscillations in a large inertia rudder system. Background Technology

[0002] The electric servo system (hereinafter referred to as the "servo system") is an important component of the aircraft control system. It is the actuator of the flight control system, and its performance determines the dynamic quality of the flight process. As aircraft develop towards higher speeds, greater maneuverability, longer flight times, and more complex flight environments, the performance requirements for the servo system are becoming increasingly demanding. In particular, with increasing flight altitudes and maneuverability, in the case of high altitudes and low dynamic pressure, in order to obtain greater servo effectiveness and meet the maneuverability requirements of the aircraft, the control surfaces are made larger. In order to achieve rapid maneuverability, the servo system is required to have the characteristics of low overshoot, fast response, and no oscillation under high inertia loads.

[0003] The transient and steady-state performance of a rudder system is affected by system damping, natural frequency, gain, and load inertia. In the early days, when rudder system performance requirements were not high, the large inertia load factor was often ignored to simplify the problem and facilitate controller design. However, with the continuous improvement of aircraft performance and the increasing response speed of rudder systems, the load inertia can no longer be ignored. Because of the flexible deformation of the transmission system, the impact on the fast, reciprocating motion of the rudder system is significant; the rudder system is no longer rigid but flexible. A large load inertia prevents abrupt changes in the rudder system's state during operation, leading to greater control difficulty, larger overshoot, and longer settling times during the start-up and braking phases, limiting its application in highly maneuverable aircraft. During the start-up phase, especially the long response time from static to dynamic, there is significant lag in dynamically tracking commands. During the braking phase, the system has high kinetic energy during rapid step maneuvers, and the stored kinetic energy is large when approaching commands and braking, resulting in larger overshoot, increased oscillations, and decreased performance. Therefore, the speed of the rudder system and the large inertial load become contradictory. If you want to speed up the system response, it will inevitably increase the overshoot, increase the oscillation, decrease the stability margin, or even cause the system to diverge, which is something that the aircraft does not want to see.

[0004] The traditional approach is to use a larger motor or reducer to match the moment of inertia of the motor with the moment of inertia of the control surface load. This increases the size and weight of the control system. This is feasible for general servo systems, but it cannot meet the requirements of missiles and other applications with high requirements for size, weight and performance. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a control method and apparatus for reducing oscillations in large inertia rudder systems, in order to solve the problem that existing large inertia systems, due to nonlinearity and hysteresis, prolong system adjustment time, increase the number of oscillations, and reduce temperature margin, cannot meet the performance requirements of high maneuverability of aircraft.

[0006] On one hand, embodiments of the present invention provide a control method for reducing oscillations in a large inertia rudder system, comprising: a motion determination step: when the command signal remains unchanged and the tracking deviation signal is large, determining that the rudder system has entered a step motion state; a motion excitation step: when the command signal is in a changing state or a motion state, causing the rudder system to be in a motion state by performing high-frequency motion excitation on the rudder system; a trajectory prediction step: predicting whether the rudder system is in a motion state approaching or far from the target position; and an advance control step: when the rudder system is in a motion state approaching the target position, performing advance braking control and when the rudder system is in a motion state far from the target position, performing advance yaw control.

[0007] The beneficial effects of the above technical solution are as follows: Without increasing the volume and weight of the rudder system or reducing its speed, this application reduces the oscillation and overshoot of the large inertia load rudder system by adopting control steps such as trajectory prediction, early braking, and dynamic excitation, thereby improving the dynamic quality of the flight control system and meeting the performance requirements of large maneuverability of aircraft in high-altitude and low-dynamic-pressure environments.

[0008] Based on a further improvement of the above method, when the command signal remains unchanged and the tracking error is large, determining that the rudder system enters a step motion state further includes: acquiring the current command signal and the previous command signal and comparing the current command signal with the previous command signal to determine whether the current command signal has changed; when the current command signal changes, determining whether the rudder system is in a tracking state or a stationary state based on the tracking deviation signal; and when the rudder system is in a tracking state, controlling the rudder system to enter a step motion state to eliminate oscillations during the tracking process.

[0009] Further improvements to the above method include, when the command signal is in a changing or moving state, using high-frequency motion excitation to put the rudder system into a moving state further comprising: acquiring command change flags and tracking status flags to determine whether the command signal is in a changing or moving state; when the command signal is stationary, clearing the motion excitation variable to zero and outputting the original control quantity; and when the command signal is in a moving state, incrementing the motion excitation variable by 1 and applying a changing control quantity different from the original control quantity based on the incremented motion excitation variable.

[0010] A further improvement to the above method, applying a different control quantity than the original control quantity based on the motion excitation variable plus 1, further includes: applying the change control quantity when the motion excitation variable plus 1 is less than a motion excitation variable threshold, wherein the change control quantity is the difference between the original control quantity and the control quantity threshold; and applying the change control quantity when the motion excitation variable plus 1 is less than twice the motion excitation variable threshold, wherein the change control quantity is the sum of the original control quantity and the control quantity threshold.

[0011] Based on a further improvement of the above method, predicting whether the rudder system is in a motion state close to or far from the target position further includes: acquiring the current deviation and the previous deviation, and calculating the difference between the current deviation and the previous deviation; when the difference between the current deviation and the previous deviation is less than a first threshold, the rudder system is in a motion state close to the target position; and when the difference between the current deviation and the previous deviation is greater than a second threshold, the rudder system is in a motion state far from the target position, wherein the first threshold is negative and the second threshold is positive.

[0012] Based on further improvements to the above method, the motion state of the rudder system when it is close to the target position further includes: incrementing the approach flag by 1, resetting the distance flag to zero, and decrementing the stop flag, while simultaneously limiting the change in magnitude; and the motion state of the rudder system when it is far from the target position further includes: resetting the approach flag to zero, incrementing the distance flag by 1, and decrementing the stop flag, while simultaneously limiting the change in magnitude.

[0013] Based on further improvements to the above method, the early braking control when the rudder system is in a motion state approaching the target position further includes: when the rudder system is in a motion state approaching the target position, the rudder system is braked quickly by means of early braking control to avoid large overshoot; and the early pull-back control when the rudder system is in a motion state away from the target position further includes: when the rudder system is in a motion state away from the target position, a high-gain proportional control is used to make the rudder system quickly pull back, while reasonable zeroing measures are used to avoid secondary overshoot and eliminate oscillation.

[0014] Based on further improvements to the above method, when the rudder system is in a motion state close to the target position and the tracking deviation is large, the proportional parameter, integral parameter, and derivative parameter are reduced; and when the rudder system is in a motion state far from the target position and the tracking deviation is large, the proportional parameter is increased, the integral parameter is cleared to zero, and the derivative parameter is cleared to zero.

[0015] On the other hand, embodiments of the present invention provide a control device for reducing oscillations in a large inertia rudder system, comprising: a motion determination module, used to determine that the rudder system has entered a step motion state when the command signal remains unchanged and the tracking deviation signal is large; a motion excitation module, used to excite the rudder system to a motion state by performing high-frequency motion excitation on the rudder system when the command signal is in a changing state or a motion state; a trajectory prediction module, used to predict whether the rudder system is in a motion state approaching or far from the target position; and an advance control module, used to perform advance braking control when the rudder system is in a motion state approaching the target position and advance yaw control when the rudder system is in a motion state far from the target position.

[0016] Based on further improvements to the above-mentioned device, the motion determination module further includes: an acquisition module for acquiring a current command signal and a previous command signal; a comparison module for comparing the current command signal with the previous command signal to determine whether the current command signal has changed; when the current command signal changes, determining whether the rudder system is in a tracking state or a stationary state based on the tracking deviation signal; and when the rudder system is in a tracking state, controlling the rudder system to enter a step motion state to eliminate oscillations during the tracking process.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0018] 1. Without increasing the size and weight of the rudder system (i.e., hardware) or reducing its speed, this invention reduces oscillation and overshoot of the rudder system under large inertia load by employing control steps such as trajectory prediction, early braking, and dynamic excitation. This improves the dynamic quality of the flight control system, meets the performance requirements of high maneuverability of aircraft under high-altitude and low dynamic pressure environments, and satisfies the aircraft's requirements for a fast-response, small-volume, and low-overshoot rudder system.

[0019] 2. Method for determining the trajectory motion of a large inertia load rudder system

[0020] This invention uses trajectory prediction to identify step and continuous movements of the rudder system, predict the starting and braking processes, and classify the motion state of the rudder system into three types: approaching the target, moving away from the target, and stopping, thereby enabling the rudder system to be braked in advance.

[0021] 3. Early braking method for large inertia load rudder systems

[0022] This invention uses trajectory prediction and early braking to enable the rudder system to begin braking before reaching the designated position, thereby reducing the oscillation of the fast-response, high-inertia load rudder system, reducing rudder system overshoot, improving system stability, and meeting the usage requirements of high-altitude, high-speed aircraft.

[0023] 4. Motion excitation method for large inertia load rudder system

[0024] This invention uses a high-frequency injection method to put a large-inertia rudder system into motion, thereby eliminating the action delay caused by the inertia characteristics of the rudder system, reducing system friction, increasing system damping, and improving system speed and stability.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1 This is a flowchart of a control method for reducing oscillations in a large inertia rudder system according to an embodiment of the present invention.

[0028] Figure 2 This is a graph showing the typical step response of a rudder system.

[0029] Figure 3 This is a flowchart of a control method for reducing oscillations according to an embodiment of the present invention.

[0030] Figure 4 This is a flowchart of the motion determination steps according to an embodiment of the present invention.

[0031] Figure 5 This is a flowchart of the motion excitation steps according to an embodiment of the present invention.

[0032] Figure 6 This is a flowchart of the trajectory prediction steps according to an embodiment of the present invention.

[0033] Figure 7 This is a flowchart of the pre-braking step according to an embodiment of the present invention.

[0034] Figure 8 This is a block diagram of a control device for reducing oscillations in a large inertia rudder system according to an embodiment of the present invention. Detailed Implementation

[0035] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0036] One specific embodiment of the present invention discloses a control method for reducing oscillations in a large inertia rudder system. For example... Figure 1 As shown, the control method for reducing oscillations in a large inertia rudder system includes: motion determination step S102: when the command signal remains unchanged and the tracking deviation signal is large, the rudder system is determined to enter a step motion state; motion excitation step S104: when the command signal is in a changing state or a motion state, the rudder system is put into motion state by performing high-frequency motion excitation; trajectory prediction step S106: predicting whether the rudder system is in motion state approaching or far from the target position; and advance control step S108: when the rudder system is in motion state approaching the target position, advance braking control is performed, and when the rudder system is in motion state far from the target position, advance yaw control is performed.

[0037] Compared with the prior art, the control method for reducing the oscillation of a large inertia rudder system provided in this embodiment reduces the oscillation and overshoot of the large inertia load rudder system without increasing the volume and weight of the rudder system (i.e., hardware) or reducing the speed of the rudder system. It improves the dynamic quality of the flight control system by adopting control steps such as trajectory prediction, early braking, and dynamic excitation, thereby meeting the performance requirements of the aircraft for high maneuverability in high-altitude and low dynamic pressure environments and satisfying the aircraft's requirements for a fast-response, small-volume, and low-overshoot rudder system.

[0038] The following text will refer to Figure 1 The steps of the control method for reducing oscillations in a large inertia rudder system according to embodiments of the present invention will be described in detail.

[0039] Motion determination step S102: When the command signal remains unchanged and the tracking deviation signal is large, determine that the rudder system has entered a step motion state. Specifically, determining that the rudder system has entered a step motion state when the command signal remains unchanged and the tracking error is large further includes: acquiring the current command signal and the previous command signal and comparing the current command signal with the previous command signal to determine whether the current command signal has changed; when the current command signal has changed, determining whether the rudder system is in a tracking state or a stationary state based on the tracking deviation signal; and when the rudder system is in a tracking state, controlling the rudder system to enter a step motion state to eliminate oscillations during the tracking process.

[0040] Motion excitation step S104: When the command signal is in a changing or moving state, the rudder system is put into motion state by performing high-frequency motion excitation on the rudder system. Specifically, when the command signal is in a changing or moving state, performing high-frequency motion excitation on the rudder system to put the rudder system into motion state further includes: acquiring the command change flag bit and the tracking status flag bit to determine whether the command signal is in a changing or moving state; when the command signal is in a stationary state, the motion excitation variable is cleared to zero, and the original control quantity is output; and when the command signal is in motion state, the motion excitation variable is incremented by 1, and a change control quantity different from the original control quantity is applied based on the incremented motion excitation variable. Specifically, applying a change control quantity different from the original control quantity based on the incremented motion excitation variable further includes: when the incremented motion excitation variable is less than the motion excitation variable threshold, a change control quantity is applied, wherein the change control quantity is the difference between the original control quantity and the control quantity threshold; and when the incremented motion excitation variable is less than twice the motion excitation variable threshold, a change control quantity is applied, wherein the change control quantity is the sum of the original control quantity and the control quantity threshold.

[0041] Trajectory prediction step S106: Predict whether the rudder system is approaching or moving away from the target position. Specifically, predicting whether the rudder system is approaching or moving away from the target position further includes: collecting the current deviation and the previous deviation, and calculating the difference between the current deviation and the previous deviation; when the difference between the current deviation and the previous deviation is less than a first threshold, the rudder system is in a motion state approaching the target position; and when the difference between the current deviation and the previous deviation is greater than a second threshold, the rudder system is in a motion state moving away from the target position, wherein the first threshold is negative and the second threshold is positive. Specifically, the motion state of the rudder system approaching the target position further includes: incrementing the approach flag by 1, resetting the away flag to zero, and decrementing the stop flag, while simultaneously limiting the change, wherein the change is the change in tracking deviation; and the motion state of the rudder system moving away from the target position further includes: resetting the approach flag to zero, incrementing the away flag by 1, and decrementing the stop flag, while simultaneously limiting the change.

[0042] Advance control step S108: Advance braking control when the rudder system is approaching the target position and advance yaw control when the rudder system is moving away from the target position. Specifically, advance braking control when the rudder system is approaching the target position further includes: when the rudder system is approaching the target position, using advance braking control to make the rudder system brake quickly to avoid large overshoot; and advance yaw control when the rudder system is moving away from the target position further includes: when the rudder system is moving away from the target position, using high-gain proportional control to make the rudder system quickly return, while using reasonable zeroing measures to avoid secondary overshoot and eliminate oscillation. Specifically, when the rudder system is approaching the target position and the tracking deviation is large, the proportional parameter, integral parameter, and derivative parameter are reduced; and when the rudder system is moving away from the target position and the tracking deviation is large, the proportional parameter is increased, the integral parameter is zeroed, and the derivative parameter is zeroed.

[0043] Another specific embodiment of the present invention discloses a control device for reducing oscillations in a large inertia rudder system. (See reference...) Figure 8 According to an embodiment of the present invention, a control device for reducing oscillations in a large inertia rudder system includes: a motion determination module 802 for determining that the rudder system has entered a step motion state when the command signal remains unchanged and the tracking deviation signal is large; a motion excitation module 804 for causing the rudder system to be in motion state by performing high-frequency motion excitation on the rudder system when the command signal is in a changing state or a motion state; a trajectory prediction module 806 for predicting whether the rudder system is in a motion state approaching or far from the target position; and an advance control module 808 for early braking control when the rudder system is in a motion state approaching the target position and early yaw control when the rudder system is in a motion state far from the target position.

[0044] The motion determination module 802 further includes: an acquisition module for acquiring the current command signal and the previous command signal; a comparison module for comparing the current command signal with the previous command signal to determine whether the current command signal has changed; when the current command signal changes, determining whether the rudder system is in a tracking state or a stationary state based on the tracking deviation signal; and when the rudder system is in a tracking state, controlling the rudder system to enter a step motion state to eliminate oscillations during the tracking process.

[0045] The following text will refer to Figures 2 to 7 The control method for reducing oscillations in a large inertia rudder system according to embodiments of the present invention will be described in detail with specific examples.

[0046] In order to achieve higher control efficiency and improve aircraft performance, high-altitude and high-speed aircraft often use control surfaces with large inertia. During high-maneuver operations, due to the flexible deformation of the transmission system, the control system is no longer rigid but flexible, resulting in a large overshoot. In addition, the system nonlinearity leads to a longer adjustment time, more oscillations, and a decrease in stability margin, which cannot meet the requirements of high-maneuver operations of aircraft.

[0047] The most important indicators for evaluating the performance of a rudder system are settling time and steady-state error. The shorter the settling time and the smaller the steady-state tracking error, the higher the tracking accuracy and the faster the response of the system. In the actual control process of the rudder system, traditional PID, fuzzy PID and other algorithms are based on real-time error control. The values ​​of control parameters Kp, Ki and Kd depend on the current error. In order to ensure system stability, the control parameters are small when the error is small. However, when the rudder system performs a step action, the large inertia causes the rudder system to have a large lag. Coupled with the fast speed, the rudder system produces a large overshoot and a large number of oscillations, which may even affect the stability of the flight control system.

[0048] Conventional rudder systems are servo position control systems. Generally, the most important indicator of a system's steady-state performance is its steady-state tracking error; the smaller the steady-state tracking error, the higher the system's tracking accuracy. In a practical system, the step response curve of the rudder system is as follows: Figure 2 As shown, its dynamic characteristics and corresponding control strategies can be divided into four stages:

[0049] In segment OA, e>0 and ec<0, the system needs to eliminate the deviation as soon as possible and prevent overshoot when approaching point A;

[0050] In segment AB, e<0 and ec<0, overshoot needs to be suppressed;

[0051] In segment BC, e < 0 and ec > 0, the system tends towards a steady state, and a callback should be avoided.

[0052] In segment CD, e>0 and ec<0, there is an overshoot in the system, requiring appropriate callback.

[0053] e represents the tracking error, and ec represents the rate of change of the error.

[0054] The functions of each component in a conventional PID controller are as follows:

[0055] Proportional element: It reflects the deviation signal e(t) of the control system in real time and proportionally. Once the deviation occurs, the controller immediately takes control action to reduce the deviation.

[0056] Integral element: Represents the steady-state error signal e(t) of the control system, in order to eliminate steady-state error. A large integral will produce hysteresis and overshoot, while a small integral will lead to steady-state deviation.

[0057] Differential element: It can reflect the changing trend (rate of change) of the deviation signal and introduce an effective early correction signal into the system before the deviation signal becomes larger, thereby speeding up the system's response, reducing the settling time, and improving the system's dynamic performance.

[0058] Due to nonlinearity and hysteresis, large inertia rudder systems are unlikely to achieve their intended goals by relying solely on the above control strategies and conventional PID parameters. Therefore, more appropriate control strategies and methods are needed. Figure 3 As shown, the process is divided into four steps: (1) Determine the motion characteristics of the system. Only when the command remains unchanged and the tracking error is large is the rudder system considered to have entered a step motion state, requiring oscillation elimination and control. (2) Use a motion excitation method. When the rudder system command is changing or in motion, inject a high-frequency oscillation signal to reduce the hysteresis effect caused by the large inertia of the rudder system, and at the same time avoid the rudder system from moving continuously when stationary, thus reducing system losses. (3) Use a trajectory prediction program to determine whether the system is approaching or far from the target position, so as to take appropriate control measures. (4) Use an advance braking program to eliminate and control the oscillation. When the system approaches the target position, use an advance braking strategy to make the system brake quickly and avoid large overshoot. When the system is far from the target position, use a high-gain proportional control to make the system quickly return to the target position, and at the same time use reasonable zeroing measures to avoid secondary overshoot and eliminate oscillation.

[0059] Step 1: Motion Determination

[0060] refer to Figure 4The system collects the current command `Target_angle` and the previous command signal `Pre_Target_angle`, and compares their changes to determine if the rudder system command signal has changed. If the command signal has not changed, the command change flag `Cmd_Change` is set to zero; otherwise, it is set to 1. If the command signal has not changed, the system further examines the tracking deviation signal `Now_Error` to see if it is in the tracking process or in a tracked, stationary state. If the deviation `Now_Error` is less than `e1` (typically 0.05°), the small deviation flag `Error_S_Num` is incremented by 1; otherwise, it is cleared. If the small deviation flag `Error_S_Num` is greater than `K1` (typically 20000), the system is considered to be in a tracked, stationary state, and the small deviation flag `Error_S_Num` is set to `K1+1` (typically 20001), while the tracking status flag `Run_State` is set to 0, indicating that the system should be in a stationary state. When the small deviation flag Error_S_Num is less than or equal to K1 (usually 20000), the system is considered to be in tracking state. The tracking state flag Run_State is set to 1, indicating that the system should be in tracking state and control measures should be taken to eliminate oscillations during the tracking process.

[0061] Step 2: Exercise Motivation

[0062] refer to Figure 5 The system acquires the command change flag Cmd_Change and the tracking status flag Run_State to determine whether the command is in a changing or moving state. If it is in a moving state, the motion excitation variable Run_Num is incremented by 1; otherwise, Run_Num is cleared and the original control quantity Motor is output. An injection signal is applied based on the motion excitation variable Run_Num. When Run_Num is less than K2 (typically 5000), the control quantity is subtracted by a certain value Motor = Motor – Motor_K (typically 500). When Run_Num is less than twice K2 (typically 10000), the control quantity is added by a certain value Motor = Motor + Motor_K (typically 500). Otherwise, the motion excitation variable Run_Num is cleared and the control quantity outputs its original value.

[0063] Step 3: Trajectory Prediction

[0064] refer to Figure 6When the command change flag Cmd_Change is 0, the trajectory prediction program is entered. If the tracking deviation is greater than e2 (typically 1000), the current motion state can be determined based on the deviation change trend. This step categorizes the rudder system's motion state into three types: approaching the target, moving away from the target, and stopping. If the difference between the current deviation and the deviation at the previous moment is less than a certain value Now_Error - Now_Error_Pre < -K3 (typically 2000), the rudder system is in a motion state approaching the target position. The approach flag Run_N++, the moving away flag Run_F is cleared, the stop flag Run_S is decremented, and the change is subject to a safety limit, typically 1000. If the difference between the current deviation and the deviation at the previous moment is greater than a certain value Now_Error - Now_Error_Pre...

[0065] When _Pre>K4 (typically 50), the rudder system is in a state of motion away from the target position. The approach flag Run_N is cleared to zero, the distance flag Run_F is incremented, and the stop flag Run_S is decremented, with the change being subject to a safety limit, typically 10000. Otherwise, the rudder system is considered to be in a state of tracking, with the approach flag Run_N cleared to zero, the distance flag Run_F cleared to zero, and the stop flag Run_S incremented, with the change being subject to a safety limit, typically 10000.

[0066] Step 4: Braking in advance

[0067] refer to Figure 7 When the approach flag Run_N is greater than K5 (usually 5000), the early braking program is entered. The PID control parameters are dynamically adjusted according to the error magnitude. The enhanced variables are represented by BC_P, BC_I, and BC_D.

[0068] In the approaching state: when the tracking error is large, decrease the proportional parameter Kp, integral parameter Ki, and derivative parameter Kd. The smaller the tracking error, the closer to the target. Increase the derivative control action, increase the system damping, and decelerate in advance, as shown in the following formula:

[0069] BC_P=f1(Now_Error)=0.5+Now_Error / Angle*Z1

[0070] BC_I=f2(Now_Error)=1-BC_Error / Angle*Z2

[0071] BC_D=f3(Now_Error)=1-BC_Error / Angle*Z3

[0072] In the formula, Angle represents the unidirectional travel of the rudder system, typically 360°; Now_Error represents the current deviation; Z1 is the proportional dynamic coefficient, typically 2000; Z2 is the integral dynamic coefficient, typically 1000; and Z3 is the differential dynamic coefficient, typically 300. The gain parameter can be adjusted appropriately depending on the system's inertia load.

[0073] In a distanced state: When the tracking error is large, increase the proportional parameter Kp and reset the integral parameter Ki and derivative parameter Kd to allow the system to quickly eliminate the error while avoiding lag. When the tracking error is small, indicating that the system is closer to the target, resume normal control mode. The formula is as follows:

[0074] BC_P=f4(Now_Error)=1+Now_Error / Angle*Z4

[0075] BC_I = f5(Now_Error) = 0

[0076] BC_D = f6(Now_Error) = 0

[0077] Z4 is the proportional dynamic coefficient, which is usually 20.

[0078] When the system is stationary, it returns to normal control mode, with BC_P, BC_I, and BC_D all set to 0.

[0079] Next, the dynamic coefficients are limited to prevent excessive gain from causing system instability; BC_P, BC_I, and BC_D are generally limited to within 20. After dynamically adjusting the control parameters, the PID control program is entered. Referring to the typical PID calculation formula, the output Q = Kp * Now_Error

[0080] +Kd*Speed+Ki*Sum, where Now_Error is the current error, Speed ​​is the current speed, and Sum is the integral of the error.

[0081] This invention provides a control method for a large inertia load rudder system. This method can achieve rapid start-up and braking of the rudder system by means of trajectory prediction, advance braking and dynamic excitation, while keeping the physical rudder system unchanged. This improves the stability margin of the rudder system and reduces overshoot and settling time.

[0082] This invention provides a control method for reducing oscillations in a rudder system under large inertia load. This method can improve the frequency characteristics of the rudder system by tracking the rudder system's motion trajectory and dynamically enhancing control parameters, while ensuring the stability margin of the rudder system, while keeping the physical rudder system unchanged.

[0083] The control algorithm for reducing oscillations in large inertia rudder systems of the present invention is simple and reliable. It does not require changes to the rudder system hardware, does not consume processor memory, and does not affect the system stability margin. Through adaptive and self-learning control algorithms, it can greatly reduce system oscillations, reduce overshoot, and improve stability, making it suitable for high-reliability and high-performance missile rudder systems.

[0084] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer or microprocessor program instructing related hardware, and the program can be stored in a computer-readable storage medium or a microprocessor. The computer-readable storage medium may be a disk, optical disk, microprocessor, read-only memory, or random access memory, etc.

[0085] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for reducing oscillations in a large inertia rudder system, characterized in that, include: When the command signal remains unchanged and the tracking deviation signal is large, it is determined that the rudder system has entered a step motion state; When the command signal is in a changing state or the rudder system is in motion, the rudder system is put into motion by applying high-frequency motion excitation. This process further includes: acquiring a command change flag and a tracking status flag to determine whether the command signal is in a changing state or the rudder system is in motion; when the command signal is stationary, the motion excitation variable is cleared to zero, and the original control quantity is output; and when the rudder system is in motion, the motion excitation variable is incremented by 1, and a different control quantity than the original control quantity is applied based on the incremented motion excitation variable. Predict whether the rudder system is approaching or moving away from the target position; and When the rudder system is in motion approaching the target position, it performs early braking control; when the rudder system is in motion away from the target position, it performs early yaw control.

2. The control method for reducing oscillations in a large inertia rudder system according to claim 1, characterized in that, When the command signal remains unchanged and the tracking error is large, determining that the rudder system has entered a step motion state further includes: Collect the current command signal and the previous command signal, and compare the current command signal with the previous command signal to determine whether the current command signal has changed; When the current command signal remains unchanged, the system is determined to be in a tracking state or a stationary state based on the tracking deviation signal; and When the rudder system is in tracking mode, it is controlled to enter a step motion state to eliminate oscillations during the tracking process.

3. The control method for reducing oscillations in a large inertia rudder system according to claim 1, characterized in that, The application of a change control variable, different from the original control variable, based on the motion excitation variable plus 1, further includes: When the motion excitation variable that is incremented by 1 is less than the motion excitation variable threshold, the change control amount is applied, wherein the change control amount is the difference between the original control amount and the control amount threshold; and When the motion excitation variable that is increased by 1 is less than twice the motion excitation variable threshold, the change control amount is applied, wherein the change control amount is the sum of the original control amount and the control amount threshold.

4. The control method for reducing oscillations in a large inertia rudder system according to claim 1, characterized in that, Predicting whether the rudder system is approaching or moving away from the target position further includes: Collect the current deviation and the previous deviation, and calculate the difference between the current deviation and the previous deviation; When the difference between the current deviation and the previous deviation is less than a first threshold, the rudder system is in a motion state approaching the target position; and When the difference between the current deviation and the previous deviation is greater than a second threshold, the rudder system is in a motion state away from the target position, wherein the first threshold is negative and the second threshold is positive.

5. The control method for reducing oscillations in a large inertia rudder system according to claim 4, characterized in that, The motion state of the rudder system approaching the target position further includes: incrementing the approach marker by 1, resetting the departure marker to zero, and decrementing the stop marker, while simultaneously limiting the change in amplitude; and The motion state of the rudder system away from the target position further includes: clearing the approach flag to zero, incrementing the distance flag by 1, and decreasing the stop flag, while simultaneously limiting the change in amplitude for safety.

6. The control method for reducing oscillations in a large inertia rudder system according to claim 1, characterized in that, When the rudder system is in a motion state approaching the target position, the early braking control further includes: when the rudder system is in a motion state approaching the target position, using early braking control to make the rudder system brake quickly to avoid large overshoot; and When the rudder system is moving away from the target position, the pre-pulling control further includes: when the rudder system is moving away from the target position, using high-gain proportional control to allow the rudder system to quickly return to its original position, while using reasonable zeroing measures to avoid secondary overshoot and eliminate oscillation.

7. The control method for reducing oscillations in a large inertia rudder system according to claim 6, characterized in that, When the rudder system is in motion close to the target position and the tracking deviation is large, reduce the proportional parameter, integral parameter and derivative parameter; as well as When the rudder system is moving away from the target position and the tracking deviation is large, the proportional parameter is increased, the integral parameter is cleared to zero, and the derivative parameter is cleared to zero.

8. A control device for reducing oscillations in a large inertia rudder system, characterized in that, include: The motion determination module is used to determine that the rudder system has entered a step motion state when the command signal remains unchanged and the tracking deviation signal is large. The motion excitation module is used to induce a motion state in the rudder system by applying high-frequency motion excitation when the command signal is in a changing state or the rudder system is in motion. Specifically, it acquires a command change flag and a tracking status flag to determine whether the command signal is in a changing state or the rudder system is in motion. When the command signal is stationary, the motion excitation variable is cleared to zero, and the original control quantity is output. When the rudder system is in motion, the motion excitation variable is incremented by 1, and a change control quantity different from the original control quantity is applied based on the incremented motion excitation variable. The trajectory prediction module is used to predict whether the rudder system is approaching or moving away from the target position; and An advance control module is used for advance braking control when the rudder system is in a motion state approaching the target position and advance yaw control when the rudder system is in a motion state away from the target position.

9. The control device for reducing oscillations in a large inertia rudder system according to claim 8, characterized in that, The motion determination module further includes: The acquisition module is used to acquire the current command signal and the previous command signal; The comparison module is used to compare the current command signal with the previous command signal to determine whether the current command signal has changed; When the current command signal changes, the tracking deviation signal is used to determine whether the rudder system is in a tracking state or a stationary state; and When the rudder system is in tracking mode, it is controlled to enter a step motion state to eliminate oscillations during the tracking process.

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