On the Computation of Suboptimal H 1 Controllers for Unstable Innnite Dimensional Systems

In this paper we show how to compute suboptimal H 1 controllers, for a class of (possibly) unstable and (possibly) innnite dimensional plants, from a nite set of linear equations. A solution to the H 1 suboptimal control problem for innnite dimensional stable plants was obtained in 6]. Also, in 13] and 14] the H 1 optimal control problem was solved for unstable distributed plants. Our solution for the suboptimal control problem of unstable distributed plants is based on the techniques developed in 6] and 13]. We obtain a computable expression for the suboptimal H 1 controllers and identify their nite and innnite dimensional parts.