Multi-mode backstepping sliding mode control for nonlinear systems with unmatched uncertainties (Q2766050)

This paper considers nonlinear systems with unmatched uncertainties. It is well known that the variable structure control method is very effective for nonlinear systems with uncertainties. Based on a combination of the backstepping design method and the variable structure control, the authors propose a new method for designing stable controllers with arbitrarily small tracking error for systems with unmatched uncertainties. The proposed approach designs a backstepping variable structure controller and provides robust output tracking even in the presence of an unknown disturbance. The closed-loop system reaches the sliding surface in a finite time. Simulations are provided to illustrate the performance of the controller.