Angle Tracking Control Strategy for Steering-by- Wire System with Dual Steering Actuator Motors

Steering-by-wire (SBW) is a key technology to realize angle tracking for autonomous vehicles, and it directly affects the performance of active steering. The reliability performance of SBW system can be greatly improved by adopting dual motor steering structure. However, the dual-motor SBW vehicle often loses its stability due to the external interference, and the asynchronous response between the dual steering actuator motors will further deteriorate the stability of the vehicle. The purpose of this paper is to establish a method of angle tracking for the dual-motor steering by wire system. Firstly, the model of SBW was established and its validity was proofed by comparing the steering performance between the SBW and the traditional mechanical steering system. Secondly, by considering parameters uncertainties and difference of wheel load torque of the dual steering actuator motors, the steering angle tracking control strategy of dual motor SBW was proposed. This paper established methods for the synchronization control of dual motor and closed-loop control of angle tracking. And the angle synchronization error was decreased by current compensation feedback. The validation results show that the proposed control strategy can decrease the synchronization error of dual motor and ensure the reliability of angle tracking.