A novel H∞ filter design for nonlinear systems with time delay via T-S fuzzy models

This paper is concerned with the filter design for nonlinear systems with time-varying delay via Takagi-Sugeno fuzzy model approach. A Novel H_∞ filter design method is proposed through the use of inequality transformation of the derivatives of Lyapunov functionals without ignoring some useful terms, which improves the existing ones. The main technique is the free-weighting matrix method combined with a matrix decoupling approach. In addition, a sufficient condition for the existence of such an H_∞ filter is established in terms of solutions to a set of linear matrix inequalities (LMIs). Finally, an illustrative example is given to show the effectiveness of the method.