Design of a Robust Rack Position Controller Based on 1-Dimensional AMESim Model of a Steer-by-Wire System

This paper presents a robust rack position control method based on a disturbance observer to enhance maneuverability and steering robustness during steering situation. It is shown that the rack and pinion system of Steer-by-Wire system with irregular parameters and external disturbance from the tires and mechanical elements can be modelled as a simple second-order system. In control design, robust control method, e.g., two-degree-of-freedom control (2-DOF) with a disturbance observer, is used for improving the steering robustness. Moreover, A friction compensator is designed to eliminate the friction generated by mechanical gear contact that hinders precise position control. The simulation model of the Steer-by-Wire system is designed with a permanent magnet synchronous motor (PMSM) and mechanical parts using AMESim program. The proposed controller was verified through simulation using AMESim and Matlab/Simulink cosimulation with different references.