Research On Control Strategy Of Ship’s Steering Gear Loading System

The function of the steering gear loading system is to simulate the seawater dynamic torque load spectrum to the ship’s rudder during the ship navigating in laboratory conditions.The steering gear loading system is an important experimental device in the semi-physical simulation of the navigation control system.The accuracy of the simulation of the actual environmental load and the real-time loading of the steering gear loading system directly determine whether the performance test data of the marine steering gear servo mechanism is accurate and effective,which indirectly affects the reliability of the ship’s navigation.In this paper,the load dynamics modeling problem involved in the simulation load control and the inherent coupling characteristics of the load simulator are discussed in depth,and then the corresponding load control strategy is designed to achieve high-precision loading of the simulated load.First,based on the working principle and actual mechanical structure of the electro-hydraulic load simulator,a mathematical model of the servo load simulation system is established,and the generation mechanism of the excess force phenomenon is explained theoretically.And the comprehensive impact of various disturbance factors such as the position disturbance of the servo mechanism of the steering gear,the mechanical clearance of the transmission mechanism and the friction inside the loading hydraulic cylinder on the dynamic loading process of the load is analyzed,for the subsequent analysis of the impact of coupled disturbance on the loading performance and design loading The control strategy lays a theoretical foundation.Aiming at the problem of how to achieve high-precision loading of simulated loads under the influence of servo motion disturbances,it is decided to use the feed-forward compensation channel compensation method to compensate the excess force based on the principle of structural invariance.By comparing the compensation effects of different feedforward signals,it is finally determined to use the ideal displacement signal of the tested servo as the feedforward compensation input of the loaded servo.And based on this compensation method,the structure invariance compensation method using phase correction is decided,which can effectively compensate the excess force.Aiming at the shortcomings such as poor adaptive ability of the feedforward compensation controller and the sensitivity of the controller parameters to environmental changes,a redundant force compensation strategy based on fuzzy iterative learning is adopted.Through theoretical analysis and experimental verification,the surplus force compensation method was studied in depth.And use AMESIM and MATLAB co-simulation to verify the loading control strategy to improve the force loading accuracy and dynamic performance.In order to prove the feasibility of the designed loading control strategy in engineering application,Iocomp Active X instrument component control is used to compile the measurement and control software interface,so that the man-machine interface is more in line with ergonomic principles,and the foolproof settings are added to make the operation more convenient.Not easy to make mistakes.Use the built load simulation test software and hardware system to test and verify the load control strategy.On the basis of verifying the feasibility of the system,the performance differences between the proposed fuzzy iterative control strategy and the PID strategy based on structure invariant feedforward compensation commonly used in the industry are compared respectively,so as to give the engineering practicality of the involved algorithms.Give guidance.