“…As can be seen in Assumption 2.2, the parameter uncertainties are assumed to be of the polytopic type, entering into all the matrices of the system model. The polytopic uncertainty has been widely used in studies on the problems of robust control and filtering for uncertain systems (see, e.g., [5,7,9]), and many practical systems possess parameter uncertainties which can be either exactly modeled or overbounded by the polytope ℜ. In addition, the nonlinear disturbance in Assumption 2.1 has also been widely used in the literature (see, e.g., [4,10,11]).…”