The Research On The Heave Compensation System Of Lift Equipment On Ship Deck

As we all know, the 21 century is the century of ocean. The exploring action in ocean constantly drives the development of resource acquisition, marine transportation and marine engineering equipment. The development of marine engineering equipment technology has a direct impact on economic development and national security. The importance of ocean equipment is more and more obvious. The marine operations capability is an important indicator of the ability of countries to the sea. During the operation, the heave motion of waves will have great influence on the ship, which will make much trouble to the operation. At this point the heave compensation equipment is needed to aid the operation. Though heave compensation, the security and reliability can be enhanced.This article designs an active-passive integrated heave compensation system which is based on a hydraulic cylinder group of parallel structure. This system has two compensation conditions which are passive compensation condition and semi-active compensation condition and it could be switched by different sea conditions. This system also has the structure of fourfold increase in distance which can solve the problem of the phase of the wave is too high. Then, the hydraulic system is calculated to supply the data base for farther analysis and simulation.These works which are analyzing the principle, analyzing the Dynamics, mathematical modeling and time domain analysis have been done for the passive compensation condition. The result indicates that properly increasing the damping ratio dose good to improving the compensation rate. On this basis, the correction scheme of throttling method is put forward. Several results of simulation indicate that this correction can improve the compensation rate. And the frequency of wave has the greatest influence on the compensation rate, so the analysis of frequency domain should be the most important. At the same time, the simulation result directs that the passive compensation system has limitations. The compensation rate is not enough and it’s necessary to bring in the active compensation system. In some special sea conditions the passive compensation system may compensate negatively. Then the reasons and measures for this condition are analyzed.These works which are analyzing the principle, analyzing the Dynamics, mathematical modeling and frequency domain analysis have been done for the semi-active compensation condition. And the influence of natural frequency and damping ratio to the stability and compensation ratio has been focused on. The result indicates that correctly adjusting the natural frequency and damping ratio contributes to correcting the parameters of control system and designing apposite control scheme. At this basis, the control algorithm of speed and acceleration closed loop is put forward which is adding speed closed loop and acceleration closed loop to control system. Using the bode plot, the frequency domain analysis of corrected system is carried out and the result explain that this correction control algorithm can make the system meeting the stability and compensate rate and has good frequency domain index.The AMESim-Adams co-simulation is carried out. The method is described and several simulations are carried out to make contrast. The simulation result indicates that the active-passive integrated compensation system can compensate the interference of the wave and the system design requirement can be achieved. The co-simulation system based on AMESim-Adams can provide a good virtual test platform for heave compensation system.On the base of the analysis and simulation above, the development of heave compensation experimental prototype is started. By the similarity theory, calculating for the main parameters of hydraulic cylinder is completed. The overall scheme design, control system scheme design, PLC software system development, PC software system development and the integration of control system and mechanical system have been done, which can lay a good foundation for farther theory verification, algorithm correction and system improvement.