Interval type-2 fuzzy model based indirect adaptive tracking control design for nonlinear systems with dead-zones

In this paper, an H_∞ control performance via interval type-2 fuzzy adaptive tracking control scheme for a class of nonlinear systems with dead-zones is proposed. The Takagi-Sugeno (T-S) fuzzy model is used for representing a nonlinear system, where the parameters of the fuzzy model are obtained from both the fuzzy rules and online updates. An inverse function is cascaded with the plant to cancel the effects of dead-zone. Based on the fuzzy model, a state feedback controller is developed to override the nonlinearities and external disturbances such that the uniform ultimate boundedness of all signals in the closed loop and the H_∞ tracking performance are achieved. From Lyapunov stability and linear matrix inequalities (LMIs), the effect of the external disturbance on the tracking error can be attenuated to any prescribed level. An inverted pendulum system is used to illustrate the effectiveness of the proposed method.