Observer-based optimal fault-tolerant control for offshore platforms

•A dynamic model of the offshore steel jacket platform with the actuator fault has been proposed.•An actuator fault observer has been designed to diagnose the actuator fault.•A feedforward and feedback optimal fault-tolerant control scheme has been developed.

This paper is concerned with an observer-based optimal fault-tolerant control for an offshore steel jacket platform. The dynamic characteristics of the actuator faults under consideration are formulated by an exogenous system. Based on a dynamic fault observer designed, a feedforward and feedback optimal fault-tolerant controller is developed to improve the reliability of the offshore platform. The controller can be obtained by solving an algebraic Riccati equation and Sylvester equations, respectively. It is shown through simulation results that the proposed control scheme is effective to guarantee the reliability of the offshore platform with the actuator faults. The vibration amplitudes of the displacement, the velocity of the offshore platform and the required control force under the proposed fault-tolerant controller can be reduced significantly.