Globally stable robust tracking of uncertain systems via fuzzy integral sliding mode control

In this paper, a fuzzy integral sliding mode control (FISMC) is proposed to deal with three problems of the conventional sliding mode control: steady state error, robustness and unknown uncertainties during the reaching phase. The design procedure of FISMC controller consists of two steps: first choosing an integral sliding surface, instead of conventional sliding surface, then constructing a sliding mode controller with fuzzy logic control (FLC). It is shown that the global robustness and stability of closed-loop system can be guaranteed with the proposed control strategy. A step tracking control of a longitudinal motion for a helicopter near hover is investigated to show the effectiveness of the new method