Integrated Handling and Stability Control with AFS and DYC for 4WID–EVs via Dual Sliding Mode Control

To improve the handling and stability for four-wheel-independent-drive electric vehicles (4WID–EVs), an integrated controller of active front-wheel steering (AFS) and direct yaw-moment control (DYC) systems with hierarchical architecture is designed. In order to enhance the handling and stability of 4WID–EVs, the AFS and DYC systems is integrated in the upper controller which contains of sideslip angle and yaw rate controllers. The sideslip angle and yaw rate controllers are designed via dual sliding mode control to calculate the target additional front-wheel steering angle and yaw moment and ensure the actual sideslip angle and yaw rate could track the target values. In the lower controller, the additional front-wheel steering angle is achieved by the steering system, and the target yaw moment is achieved by the driving and braking system. With minimum the tire utilization as target, the Lagrange algorithm is used to optimize distribute tire forces. A simulation model which contains vehicle model and controller model is established in MATLAB/Simulink platform, and the simulation is performed under different simulation condition. The results show that the integrated controller could enhance the handling and stability of vehicle effectively, which is reflected by the actual sideslip angle and yaw rate, and desired values.