Self-tuning sliding mode control with smooth control input

In this paper, a self-tuning sliding mode control for nonlinear systems is proposed. The control scheme not only retains the advantages of conventional sliding mode control, but also eliminates the chattering by introducing a self-tuning saturation function. Base on Lyapunov stability theorem, the stability of the control system is proven. The proposed approach guarantees system robustness against system uncertainties. The varying control gain and the varying boundary layer width are altered until the tracking error approaches zero. The simulation results are given to demonstrate the validity of this algorithm.