New approaches to delay-dependent robust H_∞ control of uncertain discrete-time T-s fuzzy systems with time-varying delay

This paper investigates the problem of delay-dependent robust H_∞ state-feedback control for a class of uncertain discrete-time state-delayed T-S fuzzy systems. The state delay is assumed to be time-varying and of an interval-like type with the lower and upper bounds. The parameter uncertainties are assumed to have a structured linear-fractional form. Based on a novel fuzzy-basis-dependent Lyapunov-Krasovskii functional incorporating a free-weighting matrix approach, some new delay-dependent sufficient conditions for robust H_∞ performance analysis and controller synthesis are derived in terms of linear matrix inequalities (LMIs). Numerical examples are also provided to illustrate the effectiveness of the proposed approaches.