Robust Sample-and-Hold Stabilization for Nonlinear Retarded Systems*

In this paper we deal with the stabilization in the sample and hold sense of retarded systems affected by actuation disturbances and observation errors. We make use of input-to-state stability redesign methods in order to arbitrarily attenuate the effects of the above disturbances and measures errors. We show that stabilization in the sample-and-hold sense can be achieved, as long as actuation disturbances and observation errors are bounded and the bounds are known a priori, and as long as the observation errors do not affect or affect marginally the new added control term.