l/sub /spl infin// performance analysis of feedback systems with saturation nonlinearities: an approach based on polytopic representation

In this paper, we show a method of estimating l/sub /spl infin//-norm of an output signal of discrete-time feedback systems with saturation nonlinearities. The analysis condition for estimating l/sub /spl infin//-norm is derived based on the parameter dependent Lyapunov function (PDLF) and is reduced to a condition based on the linear matrix inequality (LMI) representation. Further, we show that the condition is guaranteed to be less conservative than the condition based on the standard sector condition. A numerical example is provided to illustrate effectiveness of the proposed method.