Integrated Control Strategy for Each wheel of AutonomousElectrical Vehicles with In-wheel Motors

Electric vehicles equipped with in-wheel motors provide the ability to apply the torque of each wheel, separately. This paper addresses the problem of integrated lateral and longitudinal trajectory tracking for autonomous electrical vehicles. The lateral controller provides the steering angles of the front wheels using a combination of road profile information as feedforward and the lateral distance and heading errors as feedback. A longitudinal controller is proposed to determine the torque of each wheel separately, based on the sliding mode control. The desired values of position, velocity and acceleration of each wheel incorporated in the sliding surface of SMC are determined by kinematic relations with respect to the center of gravity of the vehicle. A ۷-DOF vehicle model in MATLAB/Simulink software is hired to evaluate the performance of the proposed control system. The results of lane-change path tacking show that the maximum absolute errors of longitudinal and lateral positions, and the velocity error are lower than ۱.۵ and ۲.۴ cm, and ۰.۰۳ km/h, respectively, and the heading angle and yaw rate errors did not exceed ۰.۱ o and ۰.۳ o/s, respectively.

Keywords:

Active front steering , Autonomous electrical vehicle , In-wheel motor , Kinematic relations , Sliding mode control.