Reduced-order observer-based saturated finite-time stabilization of high-order feedforward nonlinear systems by output feedback.

This paper is concerned with the problem of global finite-time stabilization by output feedback for a class of feedforward (upper-triangular) nonlinear systems in p-normal form. Remarkably, both the high order powers and the saturated input are involved in the system under consideration, that renders the existing output feedback control methods are inapplicable. Based on the finite-time stability theorem, and by skillfully using the homogeneous domination approach and the nested saturation technique, a reduced order observer-based saturated finite-time output feedback control scheme is successfully developed. With choosing appropriate design parameters, the proposed controller ensures that the states of the closed-loop system are regulated to zero in a finite time without violation of the input constraint. Finally, two simulation examples are provided to demonstrate the effectiveness of the proposed method.