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

• Published in: Ocean engineering Vol. 268; p. 113435
• Main Authors: Zhang, Xiaoyue, Wang, Yuanhui, Chemori, Ahmed
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2023; Elsevier
• Subjects: Adaptive fuzzy dynamic surface control; Arctic position mooring control; Automatic; Automatic Control Engineering; Computer Science; Engineering Sciences; Ice-load disturbance observer; Setpoint chasing; Structural reliability; Structural reliability; Arctic position mooring control; Adaptive fuzzy dynamic surface control; Ice-load disturbance observer; Setpoint chasing; Arctic Position Mooring Control; Ice-load Disturbance Observer; Adaptive Fuzzy Dynamic Surface Control; Structural Reliability; Setpoint Chasing
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2022.113435

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