Delay-dependent robust H _∞ filtering for interval systems with state delays

This paper deals with the problem of robust H _∞ filtering for a class of linear continuous-time interval systems with delay dependence and structured uncertainties, which are not restricted to the matched uncertainty or the norm-bounded uncertainty. The problem aims at designing a stable linear filtering assuring asymptotic stability and a prescribed H _∞ performance level for the filtering error system. A sufficient condition for the existence of such a filter is developed in terms of linear matrix inequalities. A numerical example demonstrates the validity of the newly developed theoretical results.