Robust H∞ and guaranteed-cost filter designs of uncertain time-varying delay systems

In this paper, we consider the problems of robust H-infinity. filter design and guaranteed- cost. filter design for uncertain time- varying delay systems. Moreover, norm bounded parameter uncertainties and convex bounded uncertainties are investigated to. find an admissible robust H-infinity. filter which guarantees the asymptotic stability and optimal H-infinity norm bound of. filtering- error dynamics. The appropriate condition for the existence of. filter, the robust H-infinity. filter- design method, and the optimal upper bound are proposed by the linear matrix inequality approach. Furthermore, the robust guaranteed- cost. filter- design problem can be solved using the proposed method and proper manipulations. In this case, we present an optimization problem to obtain the optimal upper bound of the guaranteed cost and the guaranteed- cost. filter- design method.