Small gain method for adaptive robust fuzzy control of a class of nonlinear systems

A new adaptive robust fuzzy control (ARFC) algorithm is presented for a class of nonlinear systems with unstructured uncertainties which are coming from modelling errors and external disturbances. In the algorithm, without any prior knowledge of the bounding functions of the uncertainties, Takagi-Sugeno type fuzzy logic systems are employed to approximate uncertain functions. A systematic procedure is developed for the synthesis of adaptive robust fuzzy control whose adaptive mechanism has minimal learning parameterizations by use of dissipative theoretical approach and small gain approach. Application example illustrating the method described is included for ship roll system, which is shown that the designed system guarantees the performance of the global asymptotic stability.