Krein space approach to H∞ mixed sensitivity minimization for a class of infinite dimensional systems

Motivated by the computation of the H^∞ optimal performance and optimal mixed sensitivity for a class of infinite dimensional systems, the author considers the explicit computation of the norm and minimal symbols of a class of “Hankel plus Toeplitz” type operators with irrational symbols using the Krein space approach. The author shows how to explicitly compute the norm and parameterize all the minimal symbols. The results are used to obtain a complete solution to the H^∞ optimal mixed sensitivity synthesis problem for a class of infinite dimensional systems: an explicit formula for computing the H^∞ optimal performance and explicit parameterization of all optimal and suboptimal mixed sensitivities. An illustrative example is given