Frequency criteria in the absolute output stabilization problem for infinite dimensional systems

The paper deals with the output stabilization problem for nonlinear feedback systems with unmodelled functional block. The processes of the unmodelled block are assumed to be unmeasurable in general case. The infinite dimensional system case is considered. The problem solution is related to the generalized H
^∞
-control problem, for which the solution existence criteria are established. These criteria are obtained via the solution existence conditions of the generalized minimax optimization problem, related to above H
^∞
-problem. The class of controllers solving above problems is presented. The stabilization theorems are established. The application to MIMO-systems, described by the integral equations has been considered.