Lateral stability enhancement based on a novel sliding mode prediction control for a four-wheel-independently actuated electric vehicle

This study presents a novel direct yaw-moment control scheme to improve the lateral stability for a four-wheel-independently actuated electric vehicle. The proposed scheme adopts a cascaded structure that consists in an upper and a lower controller. A novel sliding mode prediction controller is proposed and used in the upper controller for deriving the desired additional yaw moment for lateral stability enhancement. By using the historic and current sliding mode information for the futuristic sliding mode dynamic prediction, the synthesised control law exhibits better robustness to matched/unmatched uncertainties and significantly mitigates the chattering phenomenon. An optimisation-based torque allocation algorithm is presented in the lower controller to optimally appropriate the driving torques to each in-wheel motor based on selected criteria. The effectiveness of the proposed method is verified through simulation and hardware-in-the-loop tests, which yields better performance compared to the rule-based method.