Output regulation for a class of uncertain systems via fuzzy adaptive control

For a class of nonlinear uncertain systems driven by a linear, neutrally stable exosystem, output regulation problem is considered with the existence of unkown nonlinear function and external disturbances. Using fuzzy logic systems (FLS) to approximate the unknown functions, a fuzzy adaptive observer is designed to estimate the state. An internal model equation with error is designed via exosystem information, fuzzy adaptive output feedback control is constructed recursively that combined the backstepping technique with adaptive FLS. It is shown that the proposed fuzzy adaptive control approach ensures all signals to be bounded and the error signal to be within a desired range. Simulation results via exosystem information illustrate the effectiveness of the control scheme.