Development of Robust Motor Servo Control for Rear Steering Actuator Based on Two-Degree-of-Freedom Control System

Abstract

A rear steering system can improve vehicle stability by actively controlling the rear wheel angles. For designing the rear steering system, environmental conditions, performance deterioration due to ageing and component variation as a result of manufacturing tolerance under mass production must be taken into consideration. We have applied two-degree-of- freedom (2DOF) feedback control with feed-forward control for the motor servo control so that the rear steering actuator can track the target rear steering angle accurately and stably. The control system is designed based upon a nominal mathematical model and its variation range. As a result, the rear steering actuator can be controlled with excellent performance and high reliability. This paper describes the mathematical model construction in the frequency domain and a robust motor servo controller design based on 2DOF feedback control with feed-forward control.