Fuzzy Disturbance Observer Approach to Robust Tracking Control of Nonlinear Sampled Systems With the Guaranteed H∞ Performance.

This paper presents a new approach to robust tracking control of the nonlinear sampled systems using a discrete-time fuzzy disturbance observer (DFDO). Novel update and control laws are proposed to guarantee that all the signals in the closed-loop control system are uniformly ultimately bounded (UUB) in a compact set. No persistence of excitation (PE) condition, nor the assumption on the slowness of the change of the fuzzy parameters, Is required. In addition, a robustifying controller is designed to improve the tracking performance. Finally, a computer simulation example Is presented to illustrate the effectiveness and the applicability of the suggested method. [ABSTRACT FROM AUTHOR]