Delayed Dynamic Output Feedback Control
This chapter investigates the effect of a time-delay on dynamic output feedback control of an offshore steel jacket platform subject to a nonlinear wave-induced force. First, a conventional dynamic output feedback controller is designed to reduce the internal oscillations of the offshore platform. It is found that the designed controller is of a larger gain in the sense of Euclidean norm, which demands a larger control force. Second, a time-delay is introduced intentionally to design a new dynamic output feedback controller such that (i) the controller is of a small gain in the sense of Euclidean norm and (ii) the internal oscillations of the offshore platform can be dramatically reduced. It is shown through simulation results that purposefully introducing time-delays can be used to improve control performance.