Observer-based tracking control for a class of switched fuzzy systems with fast switching controller

Observer-based robust tracking control for a class of switched fuzzy (SF) systems with time delay is investigated in this paper. An SF system, which differs from the existing systems, is first employed to describe a non-linear system. Next, a fast switching controller consisting of a number of simple sub-controllers is proposed. The designed controller based on measured output instead of the state information integrates the advantages of both the linear and switching state-feedback controllers but eliminates their disadvantages. Tracking hybrid control schemes, which are based upon a combination of the H_∞ tracking theory, fast switching control algorithm and switching law design, are developed such that the observer-based H_∞ model reference tracking performance is guaranteed. Sufficient conditions for the solvability of the tracking control problem are given for the case in which the state of system is not available. Since convex combination techniques are used to derive the delay independent criteria, some subsystems are allowed to be unstable. Finally, various comparisons of the elaborated examples are performed to demonstrate the effectiveness of the proposed control design approach.