Motor torque based vehicle stability control for four-wheel-drive electric vehicle

Motor torque based active yaw moment control law is investigated in this paper, based on which vehicle stability control algorithm for four-wheel-drive electric vehicle is proposed using fuzzy logic control method. As four motors are mounted in the four wheels individually to drive the vehicle, it has great advantage to use the advanced motion control technique to enhance vehicle stability. The four driving and braking forces can be controlled independently to generate active yaw moment. However it is more complex to allocate the desired yaw moment to over-actuators. So the control law for fuzzy logic control algorithm is designed based on the dynamic analysis of vehicle instability. The electric vehicle models including motor model, dynamic battery model, tire model and vehicle dynamics model are built in MATLAB/Simulink^reg. Simulation performance is evaluated in the Simulink^reg, and the results have shown that the design control law and fuzzy logic controller can enhance the yaw stability and improve the maneuverability of the vehicle significantly.