Observer-based direct adaptive fuzzy controller with no additional dynamic order

In this paper, a direct adaptive fuzzy output feedback controller is developed for a class of nonlinear SISO systems with system uncertainties and external disturbance. The state observer is introduced to resolve the problem of the unavailability of the state variables. Assisted by the observer, a fuzzy system is designed to approximate the modified ideal control law. A robust control term is designed to suppress the influence of the lump uncertainty including the filtering of fuzzy basis function (FBF). Based on the SPR- Lyapunov design approach, the adaptive laws and the control laws are derived, and all the signals in the closed-loop system are guaranteed to be uniformly ultimately bounded. Simulation results demonstrate the feasibility of the proposed control scheme. © 2013 ISSN 1881-803X.