On the stability of discrete -time nonlinear systems with uncertainties

Two distinguish theorem of robust stability for discreteem are put forward in this paper. The first-order discrete nonlinear systems with uncertainties and second-order discrete nonlinear systems with uncertainties are researched, respectively, the discrete robust controller is designed, and the constrained conditions for control gain and sample frequency are given, the sensitivity of sample frequency is defined. The simulation results prove that the performance is improved when the sample frequency increases.