A matrix transformation approach to H∞ control via static output feedback for input delay systems

This paper addresses the static output feedback (SOF) H
_infin
control for continuous-time linear systems with an unknown input delay from a novel perspective. New equivalent characterizations on the stability and H
_infin
performance of the closed-loop system are established in terms of nonlinear matrix inequalities with free parametrization matrices. These delay-dependent characterizations possess a special monotonic structure, which leads to linearized iterative computation. The effectiveness and merits of the proposed approach are shown through numerical examples.