Output feedback guaranteed cost control for T-S fuzzy systems with time-varying delays

This paper considers the problem of output feed back guaranteed cost control for nonlinear systems with time-varying delays which is represented by Takagi-Sugeno (T-S) fuzzy models with time-varying delays. Based on the free weighting matrix method, sufficient conditions for the existence of output feedback fuzzy guaranteed cost controller are given in terms of linear matrix inequalities (LMIs). A minimizing method is also presented to achieve a suboptimal guaranteed cost. The results are delay-dependent but contain delay-independent criteria as a special case. Our results cover the delay independent ones as a special case. Two numerical examples are given to illustrate the effectiveness and less conservativeness of the proposed method.