Suboptimal robustness in the gap metric for MIMO delay systems

Considers the problem of robustness optimization in the gap metric for MIMO systems with a scalar time delay. The authors present an algorithm for the parameterization of all suboptimal controllers. In the authors´ algorithm the AAK theory plays the central role. Using this approach, suboptimal controllers can be found by computing solutions to certain infinite rank operator equations. The authors show that these equations can be solved numerically by modifying the two point boundary value problem approach reported earlier for the computation of optimal robustness radius.