Self-tuning sliding mode control for vehicle lane keeping under uncertain and time delay disturbances

Aiming at the problem of uncertainty and state time delay disturbances in vehicle lane keeping control, a self-tuning sliding mode control method is proposed. With the method firstly the sufficient condition for the existence of integral sliding surface is given by applying linear matrix inequality theory, so that the system has complete invariance to uncertainty and state time delay disturbances under sliding mode. Then bipolar Sigmoid function is introduced to replace signum function and a sliding mode controller with self-tuning capability is designed based on Lyapunov stability theory so that the switching gain and the boundary layer thickness of Sigmoid function can be adaptively adjusted to mitigate the phenomena of the excessive quantity and chattering of sliding mode controller output. Finally, the simulation results of vehicle lane keeping control on curved road verify the feasibility and effectiveness of the control method.