Fuzzy robust control for discrete-time nonlinear systems using input-output linearization and H∞ optimization.

This paper deals with H. control for discrete-time nonlinear systems using input-output linearization concept. Based on the ability of fuzzy systems to approximate any nonlinear mapping, the unknown nonlinear system is represented by a Takagi-Sugeno fuzzy model. The control problem is then tackled using a feedback linearization of the fuzzy nonlinear system. However, this feedback linearization can not guarantee robustness in the presence of uncertainties and disturbances. In order to solve this problem, an additive H. control component is added to the linearizing controller to attenuate uncertainty and disturbance influence on the control performances. In this work, the H. control component is designed in terms of modified Riccati inequality. Finally, an illustrative example is included to demonstrate the feasibility of-the proposed method.