Abstract
The heave movement caused by the movement of the mother ship during the operation of the marine crane has great harm to the safety of equipment and personnel. In this paper, the structural model of the marine crane is established. According to the rigid-flexible coupling system existing in the marine crane, the Newton-Euler method and the Lagrange method are used to model the rigid part and the flexible part respectively, and the rigid part and the flexible part are modeled. The kinematics and dynamics are analyzed in this model, and the influence of the in-plane angle and out-of-plane angle generated by the swing of the hanging object cable on the heave direction of the hanging object is studied. Considering the influence of the in-plane angle and the out-of-plane angle, a heave compensation system based on the secondary adjustment technology is established, and the heave compensation is realized through the hydraulic secondary adjustment technology. The numerical simulation of the kinematic model of the marine crane is carried out, the inner loop and the outer loop of the secondary element double closed-loop speed control system model are simulated respectively, and finally the overall heave compensation system is simulated. The simulation results show that the marine crane model obtained by using the Newton-Euler method and the Lagrange method to model the rigid part and the flexible part respectively is effective, and the double closed-loop speed regulation of the secondary element is effective and the system model is also feasible. In addition, the heave compensation system can well suppress the displacement deviation of the hanging object in the heave direction.
