Stable H∞ controller design for time-delay systems

This paper investigates stable suboptimal [image omitted] controllers for a class of single-input single-output time-delay systems. For a given plant and weighting functions, the optimal controller minimizing the mixed sensitivity (and the central suboptimal controller) may be unstable with finitely or infinitely many poles in +. For each of these cases, search algorithms are proposed to find stable suboptimal [image omitted] controllers. These design methods are illustrated with examples