Sampled data observer for a class of nonlinear delayed systems

This paper proposes a state observer with a cas- cade structure for a class of continuous time dynamical systems with non-uniformly sampled delayed output measurements. The first subsystem in the cascade is an impulsive observer which provides an estimation of the delayed state. Each remaining subsystem in the cascade is a predictor, which estimates the state over a small horizon equal to a fraction of the time delay using the previous estimation, allowing thereby the last predictor state to be an estimate of the system actual state. The design of the cascade observer is achieved by assuming a set of conditions under which the exponential convergence of the observation error to the origin is established.