Abstract: Road friction is closely related to the performance of vehicle stability control system. Thus it is necessary to design a vehicle side-slip angle based control threshold for different kinds of road conditions. First the vehicle 7 DOFs nonlinear dynamic model is created. According to the features between wheel lateral force and road friction, the side slip angle control strategy is studied. The upper limit border and the linear region border are defined to design the side slip angle dynamic border which is varying with the road friction. According to the wheel force model, the lateral force will decrease while braking and the side slip trend will strengthened. To avoid such trend, the control offset is adjusted basing on yaw rate gain to maintain vehicle stability in advance. The side slip angle controller is designed based on the nonlinear input sliding mode control strategy. The simulation and experiment results verified the effectiveness of the vehicle stability control strategy.

Key words: Side slip angle, Road friction, Vehicle stability control