Cascade sliding-mode controller for large-scale underactuated systems

On the basis of sliding mode control, a new cascade sliding-mode controller (CSMC) for a class of large-scale underactuated systems is proposed. The large-scale underactuated systems include several subsystems. Firstly, two states are chosen to construct the first-layer sliding surface. Secondly, the first-layer sliding surface and one of the left states are used to construct the second-layer sliding surface. This process continues till the last-layer sliding surface is obtained. By theoretical analysis, the cascade sliding-mode controller is proved to be globally stable in the sense that all signals involved are bounded. The simulation results show the validity of this method.