Intermittent observer for nonlinear systems with state delays

A new type of observer is presented for a class of nonlinear time-delay systems in this paper. Different from the traditional observers, the design of new observers is based on the assumption that the output is measured intermittently. The methods of designing observers for systems with fast-varying state delay and slow-varying state delay are investigated, respectively, by constructing two novel time-varying switching Lyapunov function/functional combined with the convex combination technique. Some sufficient conditions are derived to guarantee the stability of the corresponding error systems, and the observers can be designed by solving a set of linear matrix inequalities. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed methods.