Global Output-Feedback Tracking Control for Uncertain Planar Nonlinear Systems with Polynomial Growth

This paper investigates the adaptive tracking control problem for a class of nonlinear systems with unknown output polynomial growth. By combining ideas of universal control and deadzone with the backstepping technique, this paper proposes a new adaptive output-feedback tracking control scheme which incorporates an observer consisting of two dynamic high-gain update laws. The results show that the designed controller ensures that the tracking error converges to a prescribed arbitrarily small interval range after a finite time, while ensuring that the closed-loop system is globally bounded. Finally, the simulation example illustrates that the proposed tracking control scheme is effective.