Robust servomechanism problem for robotic systems described by delay-differential-algebraic equations

Many robotic systems can be described by delay-differential-algebraic equations. An important problem in the control of robotic systems is to design a controller such that the overall system is asymptotically stable and its output tracks a given reference signal in the presence of certain disturbances and modeling uncertainties. In this paper we consider this problem, which is usually referred to as the robust servomechanism problem, for linear time-invariant systems described by delay-differential-algebraic equations. Specifically, we present the necessary and sufficient conditions for the solvability of the robust servomechanism problem for such systems and also present the structure of the controller, when it exists, which solves this problem.