Research On An Open Moded Structure And Dynamics Optimization Of Deep Sea Underwater Manipulator

With the exploration of deep sea advancing on,more and more emphasis is put on the development of underwater manipulator,especially deep-sea manipulator as well . As known, the dynamic properties of the underwater manipulator is one of the most important factors relevant to its operational capability. Such factors as mechanical structure, manufacturing methods , operation control systems, marine environment will affect the dynamic properties of underwater manipulator.This paper is derived from national"863"item named"The study on key techniques of precision operation for deep-sea manipulator". Considering a 3500 meters deep-sea manipulator , based on the scheme principles analysis of the system , an open moded mechanical structure of underwater manipulator is presented in accordance with the function requirements and the corresponding performance parameters, most of whose components can work in the water environment directly. The structure reduced the complexity of the seal structure and the weight of the manipulator. The static analysis results shows that the mechanical structure can effectively meet the needs of static load strength and stiffness requirements;Kinematics is analyzed , including calculation of the working space, as well as the kinematics direct solutions and inverse solution are analyzed based on the presented mechanical structure. In order to lay the foundation for dynamic analysis, dynamic model is built depending on the Lagrange Equations;Matlab simulation combined with Adams are used to test and verify the dynamic properties of underwater manipulator. Especially on the assumption of the current and gravity environment , the movement control process of manipulator is simulated and the variety of parameters of joints such as angles, locations and torques are obtained consequently ; The simulation resuls shows that , in the move process to the designated location , the load capacity of joint motors can meet the control torque demands , and responds of joints are instant enough, static errors are small .Under the distrubance of the current , responds and torques varies much little, but overshoots exist in common, which could affect the operation effect.Optimization and detailed design of the underwater manipulator are fullfilled according to the simulation results. Thickness of the first arm is reduced , and flangs are added to the second arm to mount the sliding bears , which could reduce the weight of both arms that influence the property of manipulator to some extent. The whole weight of manipulator is reduced consequently, which is only the half of the demanding weight. The static analysis shows that the improved manipulator meet the static load strength and stiffness requirements . Dynamics simulation shows that the systems has better dynamic characteristics.According to the detailed eventual design, the manufacturing and mounting of a prototype underwater manipulator is finished.