Indirect adaptive fuzzy control for SISO nonaffine nonlinear system with unknown dead-zone input

Abstract:

To cope with the controller design problem that the control input of single-input single-output (SISO) nonaffine nonlinear system is with an unknown dead-zone character, a controller design strategy based on fuzzy adaptive technique is proposed. Within this scheme, the unknown dead-zone is treated as a combination of a linear and a bounded disturbance-like term. For the case that the system states are measurable, an indirect adaptive fuzzy controller is constructed by using fuzzy logic systems and adaptive laws are given out according to the information of tracking error. On basis of the above controller design method, another indirect adaptive fuzzy output-feedback controller for immeasurable system states is designed based on the estimated states which are generated by an error observer. The theoretic prove process indicates that the two controllers can guarantee that the tracking errors converge to a small neighbourhood of the origin and all signals in closed-loop system are bounded. Simulation results demonstrate that the constructed controllers can make the system achieve the tracking control objective.