Robust Exponential H_∞ Filtering for Discrete-Time Switched Fuzzy Systems with Time-Varying Delay

This paper considers H_∞ filtering of discrete-time uncertain switched nonlinear systems with time-varying delay via Takagi–Sugeno fuzzy model which is used to approximate each nonlinear subsystem. Fuzzy piecewise Lyapunov–Krasovskii functionals and average dwell time approaches are utilized for the exponential stability analysis and H_∞ filter design. A new sufficient condition is obtained to guarantee the exponential stability with a prescribed H_∞ performance index for the filtering error system. Filter parameter matrices can be obtained by solving sets of linear matrix inequalities. An example of an uncertain single-link robot arm is given to demonstrate the effectiveness of the proposed method.