A sampled-data observer with time-varying gain for a class of nonlinear systems with sampled-measurements

In this paper a new exponential observer for a class of nonlinear systems with sampled measurements is presented. This observer uses a time-varying gain, which is solution of an ordinary differential equation between two sampling instants. The proposed algorithm can be viewed as a generalization of the observer developed in [1]. The exponential convergence of the proposed observer is proved by using small gain arguments and a bound of the maximum allowable sampling period is provided. Performances of our observer and comparisons with existing observers are also presented.