Robust H∞ control of uncertain nonlinear systems with state and input time-varying delays

In this paper, the problem of robust H_∞ controller design for uncertain nonlinear systems with state and input time delays is considered. Firstly, for a class of uncertain nonlinear systems with constant delays, a set of sufficient conditions are given, which guarantee the closed-loop system is robust stable and has H_∞ performance γ. Then, for a class of uncertain nonlinear systems with time delay, the controller is designed, and it is proved that the corresponding closed-loop system is robust stable and has H_∞ performance γ under certain appropriate conditions. Finally, a numerical example illustrates the effectiveness of the proposed method.