H∞ optimal compensators for a class of infinite dimensional systems

We study the computation of the H^∞ optimal weighted pure sensitivity for a class of infinite dimensional systems by characterizing certain wandering sub-spaces of a related Kre¿n space. The new characterization can be used to obtain explicit bases for the wandering sub-space. Explicit formulas for the optimal sensitivity can be obtained from these bases. The new characterization can also be used to obtain fast algorithms for computing the H^∞ optimal performance. Some results for delay systems are generalized in an example.