| With the development of the global economy and technology, thedemand for resources is growing. However, resources on land are limitedand they will be far from enough for daily use someday in the future. Theworld ocean cover70%of the earth surface and contain large amount ofresources, the exploitation of ocean resources will be an effective energysolution for the future. On the other hand, ocean also plays an irreplaceablerole in shipping goods. In both cases, cranes or lifting equipments areindispensable. Cranes or lifting equipments have been widely used inoffshore platforms and vessels for loading or unloading goods.Differently from those used on land, lifting equipments for ocean-usedwill heave rolling which is affected by the sea wave. It may result incrashing between cargo and deck, or even worse to make damage to thecargo and the crew and leads to large amount of economy lost. Thus it’smeaningful to compensate the heave rolling caused by the sea wave for thesake of ensuring the safety during loading and unloading. And it’s promisingfor the exploitation of ocean resources.Focusing on the ocean-used lifting equipments, a simulation system hasbeen developed to study the heave compensation issue. This system includesa6-DOF parallel platform for simulating the wave motion and anelectro-hydraulic lifting device based on valve-control hydraulic motor system for simulating the ocean-used lifting equipment. This paper hasfinished tasks including structure design for the simulation system, modelingand computer simulation for the simulation system, control strategy design,computer simulation and software/hardware design for the simulationsystem and at last experiment.The main research work is presented as below.Firstly, according to the requirements of the6-DOF wave simulationplatform and the electro-hydraulic lifting system, structure design andrelevant components have been design and selected.3D model has beendeveloped in UG software.Secondly, modeling and simulation for the6-DOF wave simulationplatform has been done. Position reverse solution has been achieved and asimulation model has been setup based on this solution in Matlab/Simulink.Displacement curve for each axis has been calculated according to the givenplatform motion. After that motion simulation has been done in UG software,and the position reverse solution has been proved correct. On the other hand,modeling and simulation for the electro-hydraulic lifting system has beendone. Equations for the valve-control hydraulic motor have been derived anda simulation model in AMESim software has been setup. The controlstrategy of fuzzy adaptive PID has been proposed. The effectiveness of thecontrol strategy has been proved by co-simulation between AMESim andSimulink.Thirdly, software and hardware design for both the6-DOF wavesimulation platform and the electro-hydraulic lifting system have been done,including selection for motor driver, motion control card, data acquisitioncard and angular encoder. Control software for both the6-DOF wave simulation platform and the electro-hydraulic lifting system are both basedon MFC.At last, experiment has been done. A method of integrating twice aboutthe acceleration to get the displacement is proposed to improve theeffectiveness of the system. What’s more, analysis and improvementsuggestion for further study are proposed.Experiment shows that the6-DOF wave simulation platform canreproduce the pre-define motion given in the simulation so that wave motioncan be simulated. The electro-hydraulic lifting system can trace given valueunder the wave disturbance simulated by the6-DOF wave simulationplatform. Heave compensation can be accomplished by the electro-hydrauliclifting system and the experiment results are coincident with the simulation. |
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