Design And Research Of Platform System For 3-DOF Wave Compensation Device

With the developm ent of our comprehens ive national strength,China has gradually increased the intensity of the development on the ocean.Maritime operation is often caused by wave,which has become a problem that cannot be ignored.In order to reduce the impact of sea wave on the lifting work at sea,a nd make it work sm oothly under the harsh sea conditions,strengthening the research on the heave com pensation system appears very important.Firstly,this paper takes Dalian Maritim e University "Yukun" as the research object to explore the three degrees of freedom(3-DOF)of rolling,pitching and heave under six levels of sea state in Chinese coastal area,and draw the duration motion curves of the ship rolling and pitching angle and heave displacement using Matlab simulation software.Secondly,this paper takes the maximum simulation values of rolling,pitching angle and heave displacement as the technical param eters of the platform system of wave com pensation device motion to design the technical schem es of the wave com pensation device platform,and the structural design is accomplished.Then this paper verifies the freedom degree of the device by s pace freedom formula,and its in verse and f orward kinematics is analyzed.Thirdly,this paper draws the platform structure by the Solidworks software,simplifying the components that does not affect the analysis results,and imports the model into Ada ms software to carry out kinem atics and dynam ics simulation of wave compensation device platform.Then the dynam ics and kinem atics simulation results are analyzed and the platform size parameters are optimized,laying a theoretical foundation for m aking physical prototypes rapidly and accurately.In the end,this paper takes the valve controlled asymmetric cylinder as the actuator and establishes mathematical expressions of the transfer function for the control system to make a simple analysis on th e amplitude-frequency characteristic of open-loop control system.Due to the bigger im pact of the open loop gain on the servo valve in the system loop,the simulation is carried out under the different ga in parameters,and the control system is optimized with the gen etic algorithm according to the simulation results: adding a simple PID controller in the control l oop to obtain the reas onable control parameters of PID based on the Design Exploration m odule of Amesim software.The simulation results show that,the dynamic response of the servo hydraulic cylinder is improved obviously and quite stable,establishing a theoretical and practical foundation for developing the wave com pensation device platform.