Development Of Anti-Swing System For Hook Mounted On The Large-Size Crane Vessel

The hook's swing is the key issue to affect the efficiency of a crane."LANJIANG"is the maximal crane vessel in our country, on which the transverse vibration of the hook is intense and the longitudinal vibration is infirm. As a result, the crane's hook mounted on the vessel swings hugely in longitudinal direction when the ship is working, thus the efficiency of hook decreases dramatically. These affect the speed of exploitation to the ocean oil. Mechatronic-based and Mechanism-based anti-swing system reported demonstrated characteristic such as complex structure, unreliable performance and the huge crane-based modification, which cannot satisfy the needs of"LANJIANG"and other large-size crane vessels. It is essential to develop a more suitable vibration absorption system.Tuned Mass Damper (TMD), Active Mass Damper (AMD) and Semi-active Mass Damper (SAMD) based on the structure vibration absorption theory in civil engineering were used to develop a novel anti-swing system for hook mounted on the crane vessel. Based on the theory discussed above, the system developed in this thesis makes the swing of the hook immune when the crane structure is not changed.By the way of analysis and the practical test, the hook's swing contains 2 kinds of motions: translational component and rotational component. And the schemes of anti-swing for the hook proposed are finalized accordingly. The gear-type pendulum TMD was used to decrease the hook's translational component. Through Adams-based simulation, the optimized parameters of structure were obtained. It should take into account that the swing period of the gear-type pendulum changes a lot with the maximum angle, in additions to which the swing is only of the direction, and these affect the performance of the gear-type pendulum. To do so a series of improvement have been made. The period constant and acclimatize anti-swing orientation to hook's swing orientation were realized. The fly-wheel TID were utilized to anti-swing the hook's rotational component. Through Adams-based simulation, the optimized parameters of the structure were obtained. The fly-wheel miniaturization was studied because of the large size and heavy quantity of the TID. The system based on fly-wheel AID and fly-wheel SAID was designed to miniaturize the structure. The optimized active torsion and the impulse torsion were obtained through the simulation.2 sets of the gear-type pendulum TMD models and 2 sets of the fly-wheel TID models were developed for tests. These were mounted on the nacelle and on the crane hook for the anti-swing experiments about the translational component and the rotational component. The hook's swing angle was measured under different conditions of which were compartmentalized in lights of the frequency modulation ratio and power mode. The experiments show that the hook's translational component was decreased by gear-type pendulum TMD and the hook's rotational component was decreased by fly-wheel TID remarkably.The swing absorption system for the hook developed in this thesis demonstrated effectiveness in decreasing the swing. It has been approved by China National Offshore Oil Corporation, which has set foundation for the further application in practice.