Research On Control Method And C Ompensation Strategy Of Recirculating Ball Electric Power Steering System

Due to its high transmission efficiency,the recirculating ball steering gear has a simple mechanical structure and good steering portability;the electric power steering system is currently the most commonly used form of power assistance in passenger cars,which can be well adjustment of steering assist characteristics.The thesis studied the control method and compensation strategy of the recirculating ball elactric power steering system,and completed the physical control experiment by building a single-chip control circuit.Based on the mechanical structure of the recirculating ball steering gear,the paper designs the dynamic model of the steering system,uses Matlab/Simulink to build a recirculating ball electric power steering simulation system:models the entire vehicle in CarSim software,builds CarSim and Simulink Co-simulation platform.The current assist curve and steering system’s wheel return control strategy that meets the road sense input conditions is designed,and the real-time control of the motor is realized through the fuzzy adaptive control strategy.In order to make the dynamic response of the steering system more excellent friction compensation and shock compensation control strategies are designed to compensate the dynamic characteristics of the system.The LuGre model is selected to describe the internal friction loss of the entire steering system,and then the purpose of offsetting the friction loss torque is achieved through the control strategy;the torque diffrential compensation is used to reduce the steering system swing caused by the road impact.The controller circuit hardware and the software program of the control circuit of the power steering system are designed,and the steering control experiment is realized through the designed hardware circuit.The research results of the paper show that the designed control strategy can achieve the effect of tracking control in the recirculating ball structure steering system,and the compensation control strategy also achieves the purpose of characteristics of the system.