H∞ filtering design for continuous-time nonlinear systems with interval time-varying delay via T-S fuzzy models

This paper investigates the problem of delay dependent robust stability analysis and H_infin filtering design for a class of uncertain continuous-time nonlinear systems with time-varying state delay represented by T-S fuzzy models. Based on a newly developed Lyapunov-Krasovskii functional combined with an improved free-weighting matrix technique, a new sufficient condition for robust stability analysis is firstly derived and then the filter synthesis is developed based on some matrix relaxation techniques. It is shown that the desired filters can be constructed by solving a set of linear matrix inequalities. Finally, simulation examples are given to show the effectiveness and less conservatism of the proposed method in comparison with the existing results.