Dynamic analysis and experimental testing of a multi-tagline anti-sway and positioning system for slender-beam payload lifting during offshore operations

Abstract

To address the issues of anti-slip and anti-sway during the lifting of slender-beam payloads (SBP) in offshore environment, this paper presents a novel Multi-Tagline Anti-Sway and Positioning System (MTAPS). The entire lifting process is divided into two stages: the single-point lifting stage and the multi-tagline damping constraint stage. Dynamic modeling is performed at these two stages, and both Damping Control (DC) and Hierarchical Control (HC) strategies are designed for the MTAPS. Matlab/Simulink is used to analyze the dynamic characteristics of the SBP from the horizontal position to the lift-off stage. The sway reduction effect of the two MTAPS control strategies are then compared. Comprehensive experiments are conducted to validate the accuracy of the dynamic models and the effectiveness of the control methods. These experiments demonstrate that the MTAPS effectively mitigates the swinging of the SBP caused by single-point lifting, achieving an average reduction of sway motion by 86.25% during the suspension stage. The simulations and experiments shed lights on multi-tagline control strategies, as well as on the optimization of the offshore lifting process of SBP.