Sampled-data control for offshore steel jacket platform with TMD mechanisms

This paper deals with the sampled-data active control problem for an offshore steel jacket platform with an active tuned mass damper mechanism. The offshore platform under consideration is subject to the nonlinear hydrodynamic self-excited wave force. By introducing an artificial time-delay, the corresponding closed-loop system is cast into a continuous-time system, and then based on a Lyapunov functional, a sufficient condition of the existence of a sampleddata controller is derived. The sampled-data controller can be obtained by solving linear matrix inequalities. Based on a simulation example, the effectiveness of the proposed control scheme is demonstrated. Simulation results show that compared the designed sampled-data controller with the nonlinear controller and the integral sliding mode controller, both the oscillation amplitudes of the offshore platform and the required control force under the former are smaller than the ones under the latter.