A control method and device for improving frequency characteristics of a large-inertia rudder system

Abstract

The application relates to a control method and device for improving the frequency characteristics of a large-inertia rudder system, and belongs to the technical field of aircraft control. The method solves the problem that the existing method matches the rotational inertia of a motor with the rotational inertia of a rudder surface load by using a large motor or increasing the speed reduction ratio, resulting in the increase of the volume and weight of the rudder system and failing to meet the requirements of high-speed aircraft. The method comprises the following steps: determining whether the rudder system is in rapid motion; when the rudder system is in rapid motion, determining whether the rudder system is in a normal tracking state or a lag tracking state through trajectory prediction; when the rudder system is in the lag tracking state, predicting the lag error amount; and dynamically enhancing the control parameters according to the trajectory prediction and the lag error amount to improve the bandwidth of the rudder system. Under the premise of not changing the system hardware, the frequency characteristics of the large-inertia rudder system are improved by adopting the trajectory prediction and dynamically enhanced control algorithm, so that the requirements of high-altitude high-speed aircraft on the fast response and high bandwidth of the rudder system are met.

Description

Technical Field

[0001] This invention relates to the field of aircraft control technology, and in particular to a control method and apparatus for improving the frequency characteristics of a large inertia rudder system. Background Technology

[0002] The rudder system (hereinafter referred to as "rudder 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 rudder system are becoming increasingly demanding. In particular, with increasing flight altitudes and distances, under conditions of high maneuverability and low dynamic pressure, in order to obtain greater rudder effectiveness and meet the aircraft's maneuverability requirements, the control surfaces need to be larger. To achieve rapid maneuverability, the rudder system needs to be miniaturized and have high-frequency band characteristics under high inertia loads.

[0003] A high-performance rudder system should possess characteristics of fast response and low overshoot. The transient and steady-state performance of the system is affected by system damping, natural frequency, gain, and load rotational 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, load rotational 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 rotational inertia prevents abrupt changes in the rudder system's state during operation, leading to greater control difficulty and a lower frequency band 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's kinetic energy is large during rapid step maneuvers, and the stored kinetic energy is large when approaching commands and braking, resulting in large overshoot, increased oscillations, and performance degradation. Therefore, the high frequency band and large inertial load of the rudder system become contradictory. If we want to speed up the system response and increase the system frequency band, it will inevitably lead to larger overshoot, increased oscillation, reduced stability margin, or even system divergence, which is something that the aircraft does not want to see.

[0004] The traditional approach is to use a larger motor or increase the reduction ratio of the rudder system to match the rotational inertia of the motor with that of the rudder surface load. This increases the size and weight of the rudder system. This is feasible for general servo systems, but it cannot meet the requirements of missiles and other applications with high requirements for size and weight.

[0005] To achieve higher control efficiency, high-altitude, high-speed aircraft often use control surfaces with large inertia. During high-maneuvering maneuvers, due to the flexible deformation of the transmission system, the control system is no longer rigid but flexible, which increases the control system response time and reduces the system bandwidth, thus failing to meet the requirements of high-maneuvering aircraft.

[0006] Generally, the most important indicator for evaluating the performance of a rudder system is its steady-state tracking error. A smaller steady-state tracking error indicates higher tracking accuracy. In the actual control process of a rudder system, traditional PID and fuzzy PID algorithms are based on real-time error control. The values ​​of control parameters Kp, Ki, and Kd depend on the current error. To ensure system stability, especially to ensure minimal overshoot and short settling time during rudder system actions, control parameters are small when the error is small. However, when the command signal changes rapidly, a small error results in a small output control quantity, leading to significant lag in the rudder system during dynamic command tracking. Simply increasing the control quantity to improve system bandwidth will inevitably increase rudder system overshoot, exacerbate oscillations, and decrease stability. Summary of the Invention

[0007] Based on the above analysis, the present invention aims to provide a control method for improving the frequency characteristics of a large inertia rudder system, in order to solve the problem that existing methods, by using a large motor or increasing the reduction ratio to match the rotational inertia of the motor with the rotational inertia of the rudder surface load, result in an increase in the size and weight of the rudder system, which cannot meet the requirements of high-speed aircraft.

[0008] On one hand, embodiments of the present invention provide a control method for improving the frequency characteristics of a large inertia rudder system, comprising: determining whether the rudder system is moving rapidly; when the rudder system is moving rapidly, determining whether the rudder system is in a normal tracking state or a lagging tracking state through trajectory prediction; when the rudder system is in the lagging tracking state, predicting the lag error; and dynamically enhancing control parameters to improve the bandwidth of the rudder system based on the trajectory prediction and the lag error.

[0009] The beneficial effects of the above technical solution are as follows: Without changing the system hardware, the embodiments of the present invention improve the frequency characteristics of a large inertia rudder system by adopting trajectory prediction and dynamic enhancement control algorithms, thus meeting the requirements of high-altitude, high-speed aircraft for fast response and high bandwidth of the rudder system. Therefore, this application 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 methods, it can greatly improve the system frequency characteristics, making it suitable for high-reliability, high-performance missile rudder systems.

[0010] Further improvements to the above method include determining whether the rudder system is moving rapidly by: acquiring the rudder system feedback signal in real time and calculating the current speed based on the rudder system feedback signal; when the current speed of the rudder system is lower than the speed threshold, determining that the rudder system is in a low-speed movement state, and incrementing the low-speed movement flag variable by 1; and when the current speed of the rudder system is greater than or equal to the speed threshold, determining that the rudder system has started high-speed movement, and clearing the low-speed movement flag variable to zero.

[0011] Based on a further improvement of the above method, when the rudder system is in a low-speed motion state and is in a low-speed motion state for a continuous threshold number of times, the frequency characteristic compensation flag is cleared, and the low-speed motion flag variable is assigned the value of the threshold number plus 1, until the current motion speed is greater than or equal to the speed threshold.

[0012] Further improvements to the above method, determining whether the rudder system is in normal tracking or lagging tracking state through trajectory prediction, further include: calculating the absolute value of the current deviation; when the current deviation is greater than a first deviation threshold, the rudder system enters lagging tracking state, and the lagging tracking flag variable is incremented by 1, while the normal tracking flag variable is cleared to zero; when the current deviation is less than a second deviation threshold, the rudder system enters normal tracking state, and the lagging tracking flag variable is cleared to zero, while the normal tracking flag variable is incremented by 1, wherein the first deviation threshold is greater than the second deviation threshold.

[0013] Based on a further improvement of the above method, when the hysteresis tracking flag variable is greater than the first threshold, the rudder system continuously enters the hysteresis tracking state, providing a larger control quantity while dynamically enhancing the flag position 1, and the hysteresis tracking flag variable is the first threshold plus 1.

[0014] Based on a further improvement of the above method, when the normal tracking flag variable is greater than the second threshold, the rudder system continuously enters the normal tracking state, providing normal control quantity while dynamically enhancing the flag position 0, and the hysteresis tracking flag variable is the second threshold plus 1.

[0015] A further improvement to the above method, based on the trajectory prediction and the hysteresis error, dynamically enhancing the control parameters to improve the rudder system bandwidth further includes: acquiring the dynamic enhancement flag and determining whether the dynamic enhancement flag is 1; when the dynamic enhancement flag is 1, dynamically enhancing the control parameters, wherein the control parameters include proportional parameters, integral parameters, and derivative parameters.

[0016] Further improvements to the above method include a control method for improving the frequency characteristics of a large inertia rudder system, which further includes limiting the proportional parameter, the integral parameter, and the derivative parameter to avoid excessive gain that could cause instability in the rudder system.

[0017] On the other hand, embodiments of the present invention provide a control device for improving the frequency characteristics of a large inertia rudder system, comprising: a determination module for determining whether the rudder system is moving rapidly; a trajectory prediction module for determining whether the rudder system is in a normal tracking state or a lagging tracking state when the rudder system is moving rapidly; a hysteresis error prediction module for predicting the hysteresis error when the rudder system is in the lagging tracking state; and a dynamic enhancement module for dynamically enhancing control parameters to improve the bandwidth of the rudder system based on the trajectory prediction and the hysteresis error.

[0018] Based on further improvements to the above-mentioned device, the determination module further includes: a data acquisition submodule for real-time acquisition of feedback signals from the rudder system; a speed calculation submodule for calculating the current motion speed based on the feedback signals from the rudder system; and a comparison submodule for comparing the current motion speed with a speed threshold, wherein when the current motion speed of the rudder system is lower than the speed threshold, it is determined that the rudder system is in a low-speed motion state, and the low-speed motion flag variable is incremented by 1; and when the current motion speed of the rudder system is greater than or equal to the speed threshold, it is determined that the rudder system has started high-speed motion, and the low-speed motion flag variable is cleared to zero.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] 1. Methods to improve the frequency characteristics of a large inertia load rudder system

[0021] This invention improves the frequency characteristics of a large inertia rudder system by adopting trajectory prediction and dynamic enhancement control algorithms without changing the system hardware, thus meeting the requirements of high-altitude, high-speed aircraft for fast response and high bandwidth of the rudder system.

[0022] 2. Methods for predicting the motion trajectory of a large inertia load rudder system

[0023] This invention predicts the motion trajectory of the rudder system, distinguishes between rudder system lag and tracking, predicts the motion process, and then adopts appropriate methods to dynamically enhance the control parameters.

[0024] 3. Methods for Enhancing Dynamic Parameters of Large Inertia Load Rudder Systems

[0025] This invention improves the frequency characteristics of a large inertia load rudder system by dynamically enhancing control parameters.

[0026] 4. The control method and system for improving the frequency characteristics of a large inertia rudder system of the present invention are simple and reliable. They do not require changes to the rudder system hardware, do not consume processor memory, and do not affect the system stability margin. Through adaptive and self-learning control methods, the frequency characteristics of the system can be greatly improved, making it suitable for high-reliability and high-performance missile rudder systems.

[0027] 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

[0028] 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.

[0029] Figure 1 This is a flowchart of a control method for improving the frequency characteristics of a large inertia rudder system according to an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of a method for controlling the bandwidth of a booster system according to an embodiment of the present invention.

[0031] Figure 3 This is a flowchart of the tracking and determination steps according to an embodiment of the present invention.

[0032] Figure 4 This is a flowchart of the trajectory prediction steps according to an embodiment of the present invention.

[0033] Figure 5 This is a flowchart of the dynamic enhancement steps according to an embodiment of the present invention.

[0034] Figure 6 This is a block diagram of a control device for improving the frequency characteristics of 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] This invention provides a control method and system for improving the frequency characteristics of a large inertia rudder system. 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, without changing the physical rudder system.

[0037] One specific embodiment of the present invention discloses a control method for improving the frequency characteristics of a large inertia rudder system. For example... Figure 1 As shown, the control method for improving the frequency characteristics of a large inertia rudder system includes: in step S102, determining whether the rudder system is moving rapidly; in step S104, when the rudder system is moving rapidly, determining whether the rudder system is in a normal tracking state or a lagging tracking state through trajectory prediction; in step S106, when the rudder system is in a lagging tracking state, predicting the lag error; and in step S108, dynamically enhancing the control parameters to improve the rudder system bandwidth based on the trajectory prediction and the lag error.

[0038] Compared with existing technologies, the control method for improving the frequency characteristics of a large inertia rudder system provided in this embodiment, without changing the system hardware, achieves improved frequency characteristics of the large inertia rudder system by adopting trajectory prediction and dynamic enhancement control algorithms, thus meeting the requirements of high-altitude, high-speed aircraft for fast response and high bandwidth of the rudder system. Therefore, this application 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 methods, it can greatly improve the system frequency characteristics, making it suitable for high-reliability, high-performance missile rudder systems.

[0039] The following text will refer to Figure 1 The steps of the control method for improving the frequency characteristics of a large inertia rudder system according to embodiments of the present invention will be described in detail.

[0040] In step S102, it is determined whether the rudder system is moving rapidly. Specifically, determining whether the rudder system is moving rapidly further includes: acquiring the rudder system feedback signal in real time and calculating the current movement speed based on the rudder system feedback signal; when the current movement speed of the rudder system is lower than a speed threshold, it is determined that the rudder system is in a low-speed movement state, and the low-speed movement flag variable is incremented by 1; and when the current movement speed of the rudder system is greater than or equal to the speed threshold, it is determined that the rudder system has started high-speed movement, and the low-speed movement flag variable is cleared to zero. For example, the speed threshold is 100° / s. When the rudder system is in a low-speed movement state and is moving at low speed for a continuous number of threshold values, the frequency characteristic compensation flag is cleared, and the low-speed movement flag variable is assigned the value of the threshold value plus 1 (i.e., 2001), until the current movement speed is greater than or equal to the speed threshold. For example, the threshold value is 2000.

[0041] In step S104, when the rudder system moves rapidly, trajectory prediction determines whether the rudder system is in normal tracking or lagging tracking state. Specifically, determining whether the rudder system is in normal tracking or lagging tracking state through trajectory prediction further includes: calculating the absolute value of the current deviation; when the current deviation is greater than a first deviation threshold, the rudder system enters lagging tracking state, and the lagging tracking flag variable is incremented by 1, while the normal tracking flag variable is cleared to zero; when the current deviation is less than a second deviation threshold, the rudder system enters normal tracking state, and the lagging tracking flag variable is cleared to zero, while the normal tracking flag variable is incremented by 1, wherein the first deviation threshold is greater than the second deviation threshold. Specifically, when the lagging tracking flag variable is greater than the first threshold, the rudder system continuously enters lagging tracking state, providing increased control input while dynamically increasing the flag position to 1, and the lagging tracking flag variable is the first threshold plus 1. When the normal tracking flag variable is greater than the second threshold, the rudder system continuously enters normal tracking state, providing normal control input while dynamically increasing the flag position to 0, and the lagging tracking flag variable is the second threshold plus 1.

[0042] In step S106, when the rudder system is in a lag tracking state, the lag error is predicted. Specifically, the lag error is the difference between the feedback of the day and the error value of the day.

[0043] In step S108, the control parameters are dynamically enhanced to increase the rudder system bandwidth based on the trajectory prediction and hysteresis error. Specifically, the process of dynamically enhancing the control parameters to increase the rudder system bandwidth based on the trajectory prediction and hysteresis error further includes: acquiring a dynamic enhancement flag and determining whether the dynamic enhancement flag is 1; when the dynamic enhancement flag is 1, the control parameters are dynamically enhanced, wherein the control parameters include proportional parameters, integral parameters, and derivative parameters.

[0044] The control method for improving the frequency characteristics of a large inertia rudder system according to an embodiment of the present invention further includes limiting the proportional parameters, integral parameters, and derivative parameters to avoid excessive gain causing instability in the rudder system.

[0045] Another specific embodiment of the present invention discloses a control device for improving the frequency characteristics of a large inertia rudder system. (See reference) Figure 6The control device for improving the frequency characteristics of a large inertia rudder system includes: a determination module 602 for determining whether the rudder system is moving rapidly; a trajectory prediction module 604 for determining whether the rudder system is in a normal tracking state or a lagging tracking state when the rudder system is moving rapidly; a hysteresis error prediction module 606 for predicting the hysteresis error when the rudder system is in a lagging tracking state; and a dynamic enhancement module 608 for dynamically enhancing control parameters to improve the rudder system bandwidth based on the trajectory prediction and the hysteresis error. Specifically, the determination module 602 further includes: an acquisition submodule for acquiring the rudder system feedback signal in real time; a speed calculation submodule for calculating the current movement speed based on the rudder system feedback signal; and a comparison submodule for comparing the current movement speed with a speed threshold, wherein when the current movement speed of the rudder system is lower than the speed threshold, it is determined that the rudder system is in a low-speed movement state, and the low-speed movement flag variable is incremented by 1; and when the current movement speed of the rudder system is greater than or equal to the speed threshold, it is determined that the rudder system has started high-speed movement, and the low-speed movement flag variable is cleared to zero.

[0046] The following text will refer to Figures 2 to 5 The present invention provides a detailed description of a control method for improving the frequency characteristics of a large inertia rudder system according to an embodiment of the present invention.

[0047] The purpose of this invention is to improve the frequency characteristics of a large inertia load rudder system and enhance the dynamic quality of the flight control system by adopting a self-learning and adaptive control algorithm, without increasing the size and weight of the rudder system or reducing its stability margin, so as to meet the performance requirements of high maneuverability of aircraft in high-altitude and low-dynamic-pressure environments.

[0048] refer to Figure 2 To improve the bandwidth of a large-inertia rudder system, this invention employs the following three steps: First, a tracking determination program determines whether the rudder system is moving rapidly. The next step is only performed when the rudder system is moving rapidly, allowing it to exit the compensation program when moving slowly or not moving at all, thus improving system reliability and stability. Second, a trajectory prediction program determines whether the system is in a normal tracking command action or lagging state during rapid movement, calculating and predicting the lag error in real time to provide input for parameter enhancement. Finally, a dynamic enhancement program is entered, where, based on the trajectory determination and prediction, the control parameters Kp, Kd, ​​and Ki are dynamically enhanced using the following formula.

[0049]

[0050] Among them, u k To control the quantity, e k e represents the current error. k-1 K represents the error from the previous time step. P K Iand K D These are control parameters.

[0051] Step 1: Tracking and Judgment Procedure

[0052] refer to Figure 3 The program acquires feedback signals from the steering system in real time and calculates and generates a speed signal. The steering system is equipped with a position sensor, which acquires the feedback signals. For example, the speed signal is generated by differentiating the acquired feedback signal using the following formula:

[0053] Speed ​​signal = (current day's position - previous moment's position) / time interval

[0054] When the rudder system's speed is below a certain value K1 (usually 100° / s), the low-speed movement flag variable SL_Num is incremented by 1. When the rudder system's speed is greater than or equal to K1, the low-speed movement flag variable SL_Num is cleared to zero, indicating that the rudder system has started high-speed movement. If the system moves at low speed for K2 consecutive times (usually 2000), the frequency characteristic compensation flag BC_FLAG is cleared, and SL_Num is assigned the value K2+1 (usually 2001) to ensure continuous exit until a speed greater than or equal to K1 occurs.

[0055] Step 2: Trajectory Prediction Program

[0056] refer to Figure 4 Calculate the absolute value of the current deviation, BC_Error. The current deviation is the difference between the current command and the current feedback. Take the absolute value of the current deviation, rounding negative numbers to positive for easier subsequent calculations. When the deviation is greater than e1 (typically 0.02°), increment the hysteresis flag variable BC_Num_A by 1 and clear the normal tracking flag variable BC_Num_D, indicating that the rudder system has entered a hysteresis state. When the deviation is less than e2 (typically 0.01°), increment the normal tracking flag variable BC_Num_D by 1 and clear the hysteresis tracking flag variable BC_Num_A, indicating that the rudder system has entered a normal tracking state. When the hysteresis flag variable BC_Num_A is greater than K3 (typically 2000), it indicates that the rudder system is continuously in a hysteresis tracking state, requiring increased control input. Set the dynamic enhancement flag BC_FLAG to 1 and the hysteresis tracking flag BC_Num_A to K3+1 (typically 2001), and the rudder system continues to enter a dynamic enhancement state. When the normal tracking flag variable BC_Num_D is greater than K4 (usually 2000), it indicates that the rudder system has continuously entered the normal tracking state and requires normal control. The dynamic enhancement flag BC_FLAG is set to 0, and the normal tracking flag BC_Num_D is set to K4+1 (usually 2001), and the rudder system enters the normal control state.

[0057] Step 3: Dynamic Enhancement Program

[0058] refer to Figure 5 The system checks if the dynamic enhancement flag BC_FLAG is 1. If it is not 1, it directly enters the normal control program. If it is 1, it indicates that dynamic enhancement is required. Generally, the control parameters P, I, and D are enhanced. The enhancement coefficient is related to the error BC_Error in real time. The enhanced variables are represented by BC_P, BC_I, and BC_D, as shown in the following formula:

[0059] BC_P=f1(BC_Error)=BC_Error / E*Z1+1

[0060] BC_I=f2(BC_Error)=BC_Error / E*Z2+1

[0061] BC_D=f3(BC_Error)=BC_Error / E*Z3+1

[0062] In the formula, E is typically 0.2, Z1 is typically 10, Z2 is typically 5, and Z3 is typically 5. The gain parameters can be adjusted appropriately depending on the system's inertial load.

[0063] The gain coefficient is limited to prevent excessive gain from causing system instability; it is generally limited to within 2 times. After amplifying the control parameters, the PID control program is entered. Referring to the typical PID calculation formula, the output Q = Kp * BC_Error + Kd * Speed ​​+ Ki * Sum, where BC_Error is the current error, Speed ​​is the current speed, and Sum is the integral of the error.

[0064] Under the condition of constant load rotational inertia, a motor or reducer with greater power, size, and weight is required. Compared with the proposed solution, the rudder system is larger, more expensive, and heavier, which cannot meet the requirements of missile use. The control method and system for improving the frequency characteristics of a large inertia rudder system of the present invention are simple and reliable. They do not require changes to the rudder system hardware, do not consume processor memory, and do not affect the system stability margin. Through adaptive and self-learning control algorithms, the system frequency characteristics can be greatly improved, making it suitable for high-reliability, high-performance missile rudder systems.

[0065] 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.

[0066] 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 improving the frequency characteristics of a large inertia rudder system, characterized in that, include: Determining whether the rudder system is moving rapidly, wherein determining whether the rudder system is moving rapidly further includes: acquiring the rudder system feedback signal in real time, and calculating the current movement speed based on the rudder system feedback signal; when the current movement speed of the rudder system is lower than a speed threshold, determining that the rudder system is in a low-speed movement state, and incrementing the low-speed movement flag variable by 1; and when the current movement speed of the rudder system is greater than or equal to the speed threshold, determining that the rudder system has started high-speed movement, and resetting the low-speed movement flag variable to zero. When the rudder system moves rapidly, trajectory prediction determines whether the rudder system is in a normal tracking state or a lagging tracking state. When the steering system is in the hysteresis tracking state, predict the hysteresis error; and Based on the trajectory prediction and the hysteresis error, the control parameters are dynamically enhanced to increase the bandwidth of the rudder system.

2. The control method for improving the frequency characteristics of a large inertia rudder system according to claim 1, characterized in that, When the rudder system is in a low-speed motion state and remains in low-speed motion for a continuous threshold number of times, the frequency characteristic compensation flag is cleared, and the low-speed motion flag variable is assigned the value of the threshold number plus 1, until the current motion speed is greater than or equal to the speed threshold.

3. The control method for improving the frequency characteristics of a large inertia rudder system according to claim 1, characterized in that, Determining whether the rudder system is in normal tracking or lagging tracking state through trajectory prediction further includes: Calculate the absolute value of the current deviation; When the current deviation is greater than the first deviation threshold, the rudder system enters the lag tracking state, and the lag tracking flag variable is incremented by 1, while the normal tracking flag variable is cleared to zero. When the current deviation is less than the second deviation threshold, the rudder system enters the normal tracking state, and the lag tracking flag variable is cleared to zero, while the normal tracking flag variable is incremented by 1, wherein the first deviation threshold is greater than the second deviation threshold.

4. The control method for improving the frequency characteristics of a large inertia rudder system according to claim 3, characterized in that, When the hysteresis tracking flag variable is greater than the first threshold, the rudder system continuously enters the hysteresis tracking state, providing increased control quantity and dynamically enhancing the flag position 1. The hysteresis tracking flag variable is the first threshold plus 1.

5. The control method for improving the frequency characteristics of a large inertia rudder system according to claim 3, characterized in that, When the normal tracking flag variable is greater than the second threshold, the rudder system continuously enters the normal tracking state, providing normal control while dynamically enhancing the flag position 0, and the hysteresis tracking flag variable is the second threshold plus 1.

6. The control method for improving the frequency characteristics of a large inertia rudder system according to claim 1, characterized in that, Based on the trajectory prediction and the hysteresis error, dynamically enhancing the control parameters to improve the rudder system bandwidth further includes: Obtain the dynamic enhancement flag and determine whether the dynamic enhancement flag is 1; When the dynamic enhancement flag is 1, the dynamic enhancement control parameters are used, wherein the control parameters include proportional parameters, integral parameters, and derivative parameters.

7. The control method for improving the frequency characteristics of a large inertia rudder system according to claim 6, characterized in that, The method further includes limiting the gain of the proportional parameter, the integral parameter, and the derivative parameter to avoid excessive gain causing instability in the rudder system.

8. A control device for improving the frequency characteristics of a large inertia rudder system, characterized in that, include: The determination module is used to determine whether the rudder system is moving rapidly; The trajectory prediction module is used to determine whether the rudder system is in a normal tracking state or a lagging tracking state when the rudder system moves rapidly by trajectory prediction. The hysteresis error prediction module is used to predict the hysteresis error when the rudder system is in the hysteresis tracking state. as well as A dynamic enhancement module is used to dynamically enhance control parameters to improve the bandwidth of the rudder system based on the trajectory prediction and the hysteresis error, wherein the determination module further includes: The acquisition submodule is used to acquire feedback signals from the steering system in real time. The speed calculation submodule is used to calculate the current motion speed based on the feedback signal from the steering system. The comparison submodule is used to compare the current motion speed with a speed threshold. When the current motion speed of the rudder system is lower than the speed threshold, it is determined that the rudder system is in a low-speed motion state, and the low-speed motion flag variable is incremented by 1. When the current motion speed of the rudder system is greater than or equal to the speed threshold, it is determined that the rudder system has started high-speed motion, and the low-speed motion flag variable is cleared to zero.

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