关键词: 线控转向, 电机故障, 固定时间滑模控制, 容错控制, 非奇异滑模面

Abstract: Aiming at the angle control problem of the steer-by-wire system with motor torque fault,this paper firstly establishes an equivalent dynamic model and a torque fault model of the steer-by-wire system.Then,in order to improve the response speed and fault-tolerance performance of the system,a non-singular fixed-time sliding mode controller with fault-tolerance performance is designed with the ideal front wheel angle as the tracking target.Besides,aiming at the problem that it is difficult to determine the upper bound of the disturbance and fault in the controller,an adaptive scheme is given by combining the nonsingular sliding mode surface.Finally,based on Lyapunov stability condition,the fixed-time stability of the closed-loop control system is proved.The co-simulation results of Simulink and Carsim show that the proposed control method can make the closed-loop steering system have a faster response speed,and it can still effectively maintain the stability of the system and ensure the tracking accuracy of the steering angle in the case of torque failure and saturation.