Driver-vehicle closed-loop simulation of differential drive assist steering control system for motorized-wheel electric vehicle

A novel power assisted steering measure and torque distribution control system were proposed in this paper, due to the independent driving characteristics of motorized-wheel-drive electric vehicle. The basic theory of differential drive assist steering method is introduced briefly at first. After that, the system architecture of differential drive assist steering control system and its compensators were presented. Therein, the proportional-integral (PI) feedback control loop was employed to track the reference steering effort by controlling the drive torque distribution between the two sides wheels of the front-axle. The direct yaw moment compensator performed by differential drive torque of two rear in-wheel motors and the stability compensator for tyre/road adhesion limit, which were employed to make the differential drive assist steering work well as wished were introduced simultaneously. After the preview following driver model was built, the driver-vehicle closed-loop simulation was performed. The results verified that, the proposed differential drive torque assisted steering system cannot only reduce the steering efforts obviously, as well as ensure the most possible ldquoroad feelrdquo feedback at high vehicle speed, but also hardly change the vehicle motion direction and moving trajectory.