Adaptive asymptotic tracking of uncertain nonlinear systems with unknown hysteresis nonlinearity

This paper deals with the problem of dynamic surface asymptotic tracking for a class of uncertain nonlinear systems preceded by a hysteresis input nonlinearity, where the hysteresis is described by the Bouc-Wen model. By utilizing the modified nonlinear filters and a positive time-varying integral function, a smooth adaptive controller is designed via dynamic surface approach, where the compensating terms with the estimate of unknown bounds are employed to eliminate the effects of given continuous functions on a certain compact, unknown hysteresis and external disturbance. It is shown that all the resulting closed loop signals are semiglobally bounded, and the output tracking error converges to zero asymptotically. Finally, simulation results are presented to validate the effectiveness of the proposed methodology.