Global finite-time output-feedback stabilization for uncertain nonlinear systems with unknown growth rate

This paper considers the global finite-time output-feedback stabilization for a class of uncertain nonlinear systems. Essentially different from the existing related literature, the systems in question allow serious parametric unknowns and serious time-variations coupling to the unmeasurable states, and possess remarkably inherent nonlinearities allowing to be low-order and high-order with respect to the unmeasurable states. By combining time-varying technique, homogeneous domination approach and certainty equivalence principle, a delicate time-varying output-feedback strategy is established to achieve the finite-time stabilization for the systems under investigation. It is shown that, as long as the involved time-varying gain is chosen fast enough to overtake the serious parametric unknowns and the serious time-variations, the output-feedback controller designed renders the closed-loop system states converge to zero in finite time.