Robust adaptive tracking control for uncertain nonlinear systems with external disturbances

This paper is concerned with the tracking control problem for nonlinear systems with unknown time-varying parameter uncertainties and unknown external disturbances. The problem addressed is to design robust adaptive controllers that guarantee the tracking of a given reference signal. A robust adaptive control scheme is firstly proposed for the case the external disturbance is square-integrable. Then the design scheme is extend to the asymptotically tracking control of the nonlinear system with bounded disturbances. Finally, the effectiveness of the proposed design method is demonstrated by an application example.