Integrated AFS and DYC Sliding Mode Controller Design for Hybrid Electric Vehicle

An integrated controller of active front steering and direct yaw moment is developed in this paper. In upper layer, the corrective steering angle and yaw moment are obtained using sliding mode control. A combined sliding surface is defined in order that the yaw rate and side slip angle of vehicle track the desired values. The corrective yaw moments are applied by electrical motors embedded in rear wheels. The desired value for yaw rate and sideslip angle are obtained from a 4-DOF nonlinear vehicle model. In the lower layer, the active steering, wheel slip and electrical motor torque controllers are designed. Wheel slip and motors torque controllers generate the longitudinal forces in the rear wheels to produce the desired yaw moment. A nonlinear nine degrees of freedom vehicle model is used for simulation purposes. The simulation results illustrate considerable improvements in vehicle handling.