It deals with the design of the reduced-order \(H_{\infty }\) filter for switched systems with uncertain subsystems via an output-dependent switching method in this paper. The norm-bounded uncertainties, which can affect the system’s behavior, are considered in the uncertain switched systems. When there are also uncertainties in the system outputs, an output-dependent switching strategy is specified to achieve the quadratical stability given by a sufficient condition in the form of LMIs for the given switched uncertain system. The proposed method offers a new choose to solve the switching control problem with finite and measurable outputs that contain uncertainties. Then, for the given switched uncertain system, consider the joint design of a reduced-order \(H_{\infty }\) filter and an output-dependent switching strategy to assure the asymptotical stability of the filtering error system and an \(H_{\infty }\) performance for the estimation error. Meanwhile, the design methodology of the reduced-order \(H_{\infty }\) filter and output-dependent switching strategy are also given. Finally, the validity and feasibility of this study is illustrated by simulation examples.
