Adaptive fuzzy output-feedback control of switched uncertain nonlinear systems

This paper investigates the problem of adaptive fuzzy output-feedback control for a class of switched uncertain nonlinear systems without the measurements of the system states. By utilizing fuzzy logic systems to approximate unknown nonlinear functions, a novel adaptive fuzzy control technique for the problem studied is set up by exploiting the average dwell time method and backstepping. A switched observer is designed to reduce the conservativeness caused by adoption of a common observer for all subsystems. The proposed controllers of subsystems guarantee that all closed-loop signals remain semiglobally uniformly ultimately bounded under a class of switching signals with average dwell time, while the output tracking error converges to a small neighborhood of the origin.