A separation principle of time-varying dynamical systems: A practical stability approach

In this paper we treat the problem of practical feedback stabilization for a class of nonlinear time-varying systems by means of an observer. A separation principle is given under a restriction about the perturbed term that the perturbation is bounded by an integrable function where the nominal system is supposed to be globally asymptotically stabilizable by a linear feedback. A practical stability approach is obtained. Furthermore, we give an example to show the applicability of our result.