Application Design And Research Of Parallel Manipulator Based On Metamorphosis Principl

There are more than 3,000 ancient shipwrecks in China’s coastal waters,and their excavation and protection are mostly carried out after accidental discoveries.Marine development projects in the southeastern coastal region may lead to the discovery or damage of marine cultural relics.Ancient shipwrecks are important objects of marine archaeology,among which ceramics are the most common and most vulnerable cultural relics.There are many types and shapes of ceramics in ancient shipwrecks,and effective salvage protection methods need to be found.In view of the difficulty in salvaging ceramics of different shapes in ancient shipwrecks,this paper designs a metamorphic parallel manipulator that uses different grasping configurations for three types of ceramic shapes in ancient shipwrecks,focusing on the design of metamorphic palm configurations,drive mechanism design,kinematic analysis and simulation of metamorphic parallel manipulators.Firstly,through the analysis of human palm grasping posture,the configuration of the grasping mechanism is determined.The metamorphic mechanical palm can achieve changes in mobility and workspace through joint motion;after comparing various types of six-degree-of-freedom parallel platforms,it is determined that the driving mechanism of the metamorphic palm is a 3-UPS parallel platform,and the platform is improved.Secondly,a quaternion system for metamorphic palms under different configurations is established.The mobility of O,L and Q configurations was 3,3 and 2,respectively.By solving the constraint quaternion system,the mobility of the mechanism under different configurations is determined;according to the palm configuration,the installation position of the fingers is determined.The spatial position coordinates of the fingers are solved by analytical methods.The stability of grabbing cultural relics on the working plane of fingers is analyzed.The grabbing motion of shipwreck ceramics is simulated.Thirdly,inverse kinematics analysis was performed on the metamorphic parallel manipulator.The changes in configuration and spatial posture of the metamorphic manipulator are mainly affected by the length of electric push rods and the rotation angle of Hooke’s hinge cross axis on the base.The three-dimensional graph of fixed posture workspace under different parameters was drawn using analytical methods.And specific parameters for the length of the connecting rod of the metamorphic parallel manipulator and the parameters for the metamorphic palm and fixed base were determined.Fourthly,according to the size of grabbing target to determine size of mechanical hand,using Solid Works software to carry out 3D model design for variable cell parallel manipulator and detailed design for flexible finger and drive joint Hooke hinge.The flexible robotic arm adopts a combination of silicone and elastic thin plates,and the Hooke hinge uses a Five Bar mechanism.Finally,kinematic simulation analysis was carried out on three grasping configurations of metamorphic parallel manipulators using ADAMS software.The acceleration and velocity trends of related driving joints under short-distance grabbing,long-distance synchronous grabbing and long-distance step-by-step grabbing were analyzed.The acceleration numerical curve diagrams for step-by-step motion and synchronous motion were compared.It was found that motion impact will occur when hand configuration changes and spatial posture changes.