The Robust Control of a Servomechanism Problem with Time Delay

Abstract In this paper, the servomechanism problem for a linear, time- invariant multivariable system is extended to systems with time delay. Necessary and sufficient conditions for the existence of a solution to the time delay servomechanism problem and the structure of compensators required for this problem are obtained. The robust time delay servomechanism problem is then studied in which plant perturbations are allowed to occur in the system. Necessary and sufficient conditions for the existence of a solution to this robust servomechanism problem, and a characterization of all compensators which solve the robust servomechanism problem are obtained.