H2 guaranteed cost output-feedback control for discrete-time fuzzy system

This study deals with H₂ guaranteed cost control problem for discrete time nonlinear systems with parameter uncertainties. The Takagi and Sugeno (T-S) fuzzy model with parameter uncertainties is employed to represent an uncertain discrete time nonlinear system. Based on the structural information in rule base, an output feedback controller design method is introduced. Sufficient conditions for the existence of H₂ guaranteed cost output feedback controllers are given. Further more, a convex optimization problem with linear matrix inequality (LMI) constraints is applied to design the suboptimal H₂ guaranteed cost output feedback controller which minimizes the guaranteed cost of the closed-loop uncertain system. Numerical example is given to demonstrate the effectiveness of the proposed method.