Robust H∞ filtering for uncertain discrete-time systerms with time-varying delay

This paper focuses on robust Ho filter design for discrete-time systems with time-varying delay. Base on Lyapunov method, and a new technique to deal with the upper bound of some terms in the Lyapunov functions, a new less conservative Ho, performance analysis result is obtained. Moreover, the result deduces a new sufficient condition for systems with polytopic-type uncertainties. Based on the result above, the Ho filter is designed in terms of linear matrix inequalities (LMIS). Finally, numerical examples are presented to show less conservativeness of the proposed method.