Relaxed H∞ filtering designs for discrete-time Takagi-Sugeno fuzzy systems

This paper deals with the problem of H_∞ filtering for a class of discrete-time nonlinear systems that are represented by a Takagi-Sugeno (T-S) fuzzy model. The main result given here concerns its H_∞ filter design based on a relaxed approach in which both Finsler´s Lemma and delayed nonquadratic Lyapunov function are used. New relaxed conditions and linear matrix inequality-based design methods are proposed that allow outperforming previous results found in the literature. Finally, an example is given to demonstrate the efficiency of the proposed approaches.