Structural reliability based energy-efficient arctic position mooring control of moored offshore structures under ice loads

This work develops an energy-efficient robust control for arctic position mooring systems subject to discontinuous ice loads and system uncertainties. To provide a safe reference moored offshore structures, improved structural reliability-based setpoint chasing algorithm is proposed. An ice-load disturbance observer constructed handle the environmental disturbances, relax continuity, differentiability, boundedness requirements of disturbances. The uncertainties are addressed by adaptive fuzzy estimator. With estimation, dynamic surface law derived introducing novel filter improve convergence rate error, it enhances also performance with fast response. Theoretical analysis proves stability resulting closed-loop all its signals invariant set mechanism Lyapunov theory. Comparative numerical simulations carried out on turret-moored floating production storage offloading (FPSO) vessel demonstrate effectiveness proposed scheme.