Robust Adaptive Fuzzy Control for Uncertain Nonlinear Systems

摘要

Two different fuzzy control approaches are proposed for a class of nonlinear systems with mismatched uncertainties, transformable to the strict-feedback form. A fuzzy logic system (FLS) is used as a universal approximator to approximate unstructured uncertain functions and the bounds of the reconstruction errors are estimated online. By employing special design techniques, the controller singularity problem is completely avoided for the two approaches. Furthermore, all the signals in the closed-loop systems are guaranteed to be semi-globally uniformly ultimately bounded and the outputs of the system are proved to converge to a small neighborhood of the desired trajectory. The control performance can be guaranteed by an appropriate choice of the design parameters. In addition, the proposed fuzzy controllers are highly structural and particularly suitable for parallel processing in the practical applications.