Abstract
Keywords - electric vehicle (EV); direct yaw-moment control (DYC); fuzzy logic control; active front steering; four-wheel drive
A Direct Yaw-moment Control (DYC) control method is proposed to improve the handling and stability of a four-independent-wheel drive electric vehicle. The control system comprises a fuzzy logic direct yaw-moment controller together with an active front steering controller based on sliding mode control. By measurements of vehicle states, the control algorithm determines the level of vehicle stability and intervenes as necessary through individual wheel traction control to provide added stability and handing predictability. Therefore, the DYC system distributes torque and power to each motor to meet the requirements of each wheel. The effectiveness and validation of the proposed control method are evaluated in the Matlab/Simulink environment. In addition, experimental validation is conducted to verify the accuracy and effectiveness of the proposed yaw-rate control algorithm. Simulation and experiment results manifest that the DYC system can assist drivers with controlling the stability of the vehicle during adverse driving maneuvers over a variety of road conditions. The new DYC system maintains the vehicle stability and enhances the performances of the EV significantly.