This paper focuses on the lane keeping assistance system (LKAS) for a four in-wheel motor drive electric vehicle. A new method for lane keeping assistance is presented, which applies additional yaw moment to the electric vehicle to achieve lane maintenance with active distribution of four wheels driving/braking torque. The lane keeping assistance system is divided into three layers. In the upper layer, assistance control decision is made, and the desired yaw rate is calculated by considering vehicle-lane deviation, vehicle dynamic and limitation of road adhesion. In the middle layer, a sliding mode controller (SMC) is designed to control the additional yaw moment. In the lower layer, yaw moment is produced by distributing of drive/brake torques between the four wheels. Lane keeping assistance is carried out by tracking desired yaw response. The LKAS is evaluated via Carsim/Simulink. The simulation result for a single lane change test shows that the proposed method can make the vehicle have good dynamic stability, and can restrict the vehicle within the lane and avoid lane departure accidents.

electric vehicle  /  independent drive/brake  /  lane active torque  /  distribution keeping assistance control