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.