Simulation Research On Friction Compensation For Brushless DC Motor Servo System

The widespread application of high and new technology in modern warfare has caused great changes in combat methods,and has higher requirements for accuracy and efficiency.Precision guidance technology has become a hot spot in current research in various countries.The core of the guidance control is the steering gear.The performance of the steering gear directly affects the guidance accuracy.However,due to the internal friction of the steering gear,the system increases the error in the process of following a given signal,the driving delay and other phenomena.In view of the improvement of the dynamic performance of the servo system,in view of this issue,a series of studies have been carried out on the steering gear system containing friction,and corresponding compensation methods have been designed to reduce the influence of friction.This paper studies the friction compensation of the widely used brushless DC servo system.Using the brushless DC motor as the actuator,a three-closed-loop control system of position speed and current is established.When a position signal is given,the rudder surface can be quickly deflected to achieve adjustment.The purpose of the flight trajectory is to improve strike accuracy.At the same time,in order to verify the rationality of the control strategy,the overall model was built with Matlab / Simulink for simulation analysis based on the analysis of the working principle and mathematical model of the steering gear.In the process of studying friction,this paper analyzes the characteristics of the more comprehensive Stribeck and Lu Gre friction models to select a model that can accurately describe the friction,and identifies relevant parameters,and then analyzes the influences.At the same time,the friction model is divided into two cases: fixed parameters and variable parameters.The corresponding compensation methods are designed according to the internal structure of the system.The feasibility of the compensation method is verified by Lyapunov method and overall model simulation.Considering the influence of interference torque in reality,this paper optimizes the original compensation method,adopts multiple methods combined with composite control,integrates the advantages of each method,and analyzes that the optimization method can effectively reduce the influence of interference torque.It can further improve system tracking performance.