A New Approach for Simultaneous Vehicle Handling and Path Tracking Improvement Through SBW System

A nonlinear adaptive sliding mode control for simultaneous vehicle handling and path tracking improvement through the Steer-By-Wire system is presented in this paper. The proposed adaptive sliding mode controller, which is insensitive to system uncertainties, offers an adaptive sliding gain to eliminate the precise determination of the bound of uncertainties. The sliding gain value is calculated using a simple adaptation algorithm which does not require extensive computational load. A driver control model is also presented according to the preview or look-ahead strategy to generate the appropriate steering angles using the vehicle states feedback and the future information about the path to be followed. Moreover, because of the inertia and viscous damping in the steering mechanism and the effects of coulomb friction and self-aligning moment of the front tires, the steering system controller based on the proposed adaptive sliding mode scheme, is designed to control the front steering angle. A complete stability analysis based on the Lyapunov theory is presented in order to guarantee the closed loop stability. Eventually, the simulation results confirm that the proposed adaptive robust controller not only improves the vehicle handling and path tracking performance but also reduces the chattering problem in presence of uncertainties in the tire cornering stiffness and the external disturbance.