Yaw stability of 4WS with variable steering ratio strategy using inertial delay control based sliding mode control

In this paper Inertial delay control(IDC) based sliding mode control(SMC) for 4 wheel steering(4WS) vehicle which focuses on the maneuvering flexibility and steering stability of the vehicle. To achieve above a new method for variable steering ratio(VSR) is introduced. A nonlinear vehicle model is considered along with the uncertainties in cornering stiffness, mass and vehicle speed. To compensate the effect of nonlinearities and uncertainties and also controlling lateral dynamics an IDC based SMC is proposed to achieve required side-slip angle and yaw rate of vehicle based on VSR. Further a simulation is executed to analyze the performance of proposed controller for 4WS by tracking the system dynamics to follow the desired model regardless of the nonlinearities and uncertainties. The proposed controller is also validated with Carsim software.