Design Of Lifting Beam Lifting System And Wave Compensation System Of Catamaran

With the development of offshore resources,marine engineering equipment is receiving more and more attention,and the disassembly and assembly equipment of large marine facilities is gradually entering people’s vision.Especially in the disassembly and assembly operation of offshore platforms,the overall disassembly and assembly of offshore oil platforms can achieve better economic efficiency.So this article takes a catamaran as the working mother ship and designs the overall disassembly and assembly equipment for offshore oil platforms.During the disassembly and assembly process,the mother ship undergoes heave motion due to the influence of sea waves.This motion can reduce the stability of the lifting mechanism of the catamaran,may cause damage to the equipment,and may also endanger personal safety.Therefore,a heave compensation system can be used to complete the disassembly during the work process,It can increase security and achieve better economy.This article compensates for the heave motion of the mother ship by controlling the lifting mechanism on the lifting beam of the catamaran and the heave compensation system,so as to maintain the load mechanism in the ideal position for dismantling and assembling the offshore platform.A design scheme for a split type active passive series heave compensation system is proposed,which is divided into two working conditions.Firstly,a small hydraulic cylinder is used to connect with the offshore platform,and after the docking is completed,a large hydraulic cylinder is used for lifting and active passive compensation.The fitting and compensation structure is an improvement on the crank slider mechanism,with the power part relying on the hydraulic system.A schematic diagram of the active and passive compensation system was designed,and the main structural parameters and hydraulic system parameters of the lifting system were determined.A three-dimensional model of the lifting system was established using SolidWorks.Using Workbench,static and modal analysis was conducted on the assembly of the lifting system under different working conditions,and it was found that the designed mechanism meets the requirements of strength and stiffness,further verifying the rationality and safety of the design.Analyze the mechanical characteristics of the lifting system,and design the passive compensation system based on passive hydraulic cylinders and accumulators.The working process of the passive compensation system does not require external energy input,which can greatly compensate for the load displacement changes caused by the lifting motion of the crane carrier ship and reduce impact.After establishing the model,it was simulated under 5 levels of sea conditions,and the impact of different accumulator volumes on the compensation effect was analyzed,as well as the compensation effect of the passive compensation system on different periods of sea conditions.Due to many unfavorable factors,such as low compensation rate and relative motion lag,active compensation is introduced to improve its compensation accuracy.According to the design requirements of this paper,the dynamic model of the active and passive series hydraulic compensation system is established.For this model,PID and fuzzy PID controllers are used to control the active parton subsystems respectively.Through the simulation analysis of tracking the given sine wave and random wave,the effectiveness of the control measures is verified.The active compensation system ensures that the system can achieve high-precision and strong robustness compensation through control algorithms,while the passive system can reduce the input of external energy and save energy.This article demonstrates the effectiveness of the design through principles analysis,system modeling,simulation calculations,and other methods.