An Application of Optimal Control with Specified Decay Rate to Offshore Steel Jacket Platforms

This paper is to investigate the effects of decay rate on optimal control of an offshore steel jacket structure subject to a nonlinear wave-induced force. An optimal controller with specified decay rate is designed for the nominal linear system. Then the active controller is applied to the offshore structure to control the dynamic responses of the offshore structure. It is found that properly introducing decay rate in the optimal control design can be used to further reduce the vibration amplitudes and control forces, and improve the control performance. The valid and effectiveness of the proposed control scheme are illustrated by a simulation example.