H-infinity model reduction for linear time-delay systems: continuous-time case

This paper deals with the problem of H-infinity model reduction for linear continuous time-delay systems. For a given delay system, the problem we add ress is the construction of a reduced-order model such that the associated model error satisfies a prescribed H-infinity norm bound constraint. Two al ternative methods for obtaining reduced-order models are presented. Suffici ent conditions for the existence of desired reduced-order models are propos ed in terms of linear matrix inequalities (LMIs) and a coupling non-convex rank constraint set. Conditions based on strict LMIs are obtained for the z eroth-order H-infinity approximation problem. When these conditions are sat isfied, an explicit parametrization of the desired reduced-order models is also presented. All these results are extended to time-delay systems with p arameter uncertainties. Finally, an illustrative example is provided to dem onstrate the effectiveness of the proposed approach.