A novel 3-DOF rope-driven wave motion compensation device for marine crane: System modeling and analysis.

The influence of wave motion can cause undesired motion in the spreader during the use of cranes for marine replenishment operations, potentially leading to significant impacts on the efficiency and safety of such operations. A novel rope-driven wave motion compensation device (R-WMCD) has been developed to achieve wave motion compensation for marine cranes in roll, pitch, and heave directions. Firstly, the attitude forward/inverse solution models of R-WMCD are established using Newton-Raphson iteration method, and the kinematic model is derived based on the vector closure method. Secondly, the dynamic model of R-WMCD is established using Newton-Euler method, considering the uneven loading condition. Furthermore, to enhance the precision of wave motion compensation, a robust proportional-derivative (R-PD) controller based on the nominal model is formulated, and the stability of the controller is demonstrated. The feasibility and validity of the scheme are ultimately confirmed through simulation and experimentation, demonstrating R-WMCD's capability to achieve wave motion compensation. The research presented in this paper offers a novel approach to the design of the structure and theoretical analysis of 3-degree-of-freedom (3-DOF) wave motion compensation device. • A novel 3-DOF wave motion compensation device is proposed for marine cranes. • The mathematical model of the R-WMCD is established in a non-inertial frame. • The danger area of the barycenter position of the spreader is analyzed. • A robust PD controller based on the nominal model is designed. [ABSTRACT FROM AUTHOR]