Two Degrees Of Freedom Of A High Rigidity Of The Structure Of The Translational Motion Parallel Robot Parameter Optimization

Two freedom degree pure translational motion parallel manipulator has many advantages, such as, closed kinematics, low cost in manufacturing, and easy controlling. It will be developed and used in many fields in the future. This thesis studied a high stiffness two degree pure translational motion parallel manipulator, which can be used as the main motional structure of general parallel tool machine. The subject of this thesis includes: theory proving of its freedom degree; the designing of the optimum mechanism; kinematics stimulation; stiffness analysis by finite element software.Firstly , theory proving of its freedom degree is finished by taking advantage of a family of three freedom degree translational parallel manipulators. Kinematic are studied, inverse Jacobian matrix is derived by constraint equation.With the aid of geometry, the theoretical workspace and the usable workspace configuration of the manipulator is analyzed. The relationship between workspace configuration, area and lever dimension is studied and the distributing regulation in mechanism design space is discussedAccording to the definition of the global performance indices ,the area, dexterity ,output rate are calculated. The theory of design space are adopted to study the relationship between the full performances and the lever sizes of manipulator and to draw the performances diagram. And the optimum region of good performance indices is got.The simulation for a typical motion is carried out, the kinematics state and the number of the freedom degree are presented. Analyzing theoretically the static stiffness of the manipulator, an expression is given relevantly. The stiffness under different forcing conditions are analyzed simulatively using FEA software.