Nonlinear adaptive observers with finite-time convergence for a class of Lipschitz nonlinear systems

In this paper, adaptive observers are designed for a class of Lipschitz nonlinear systems. These observers are featured with the property of finite-time convergence of state estimation and unknown parameter estimation under some normal persistence excitation condition. The convergence are obtained by assuming existence of a Lyapunnov function under certain condition, by the finite-time stability and by the high gain technique. A numerical example is given to show the validity of the new method.