Analysis And Research On A Class Of Three-freedom Flexible Parallel Mechanism

With the development of computer technology and the integrated manufacturing technology, and the high precision machining in the field of growing demand, flexible parallel composition has become a hotspot of research of parallel mechanism, which based on flexure hinge rigid flexible coupling robot with micro space, high resolution,and the advantages of high precision gradually and attracted more and more scholars to research and more application. In this paper, designed a class of 3-DOF flexible parallel mechanism which has two-dimensional rotation and one translational, but the characteristic of the two kinds of parallel mechanism is the same joint placed in different positions, with the same degree of freedom movement, but has different kinematics and statics mechanics, and not with the static stiffness and precision feature index. In order to more further study and provide more comprehensive engineering application, this paper studied the longitudinal elementary, and made a comprehensive comparison of the transverse analysis of the two parallel structure.Designed the flexible parallel mechanism 3-SPR and 3-RPS with rigid-flexible coupling by making stiffness parts malleability. Based on the theory of pseudo rigid body model and screw theory, analyzed the degree of freedom and a rotating shaft of the two parallel mechanisms, and solved the mechanism of constraint relations and the position inverse solution, through the comparative analysis of two different motion characteristics.Designed the same size and pose of the two flexible parallel mechanism except the joint position. Choosed and designed the construction of flexure hinge and analyzed its restriction of angle to build the 3D model and topology model. Based the above size design, solved the workspace and got the 3D nephogram by using boundary search method in MATLAB. Seen that different workspace of same mechanism is caused by the different position of same joint. After comparison, supplied the base theory for industry application.Studied the effect of kinematic pairs with different distribution of parallel mechanism in Statics mechanics. Based on the screw analysis method, solved the two institutions equivalent binding to build the static equilibrium equation, and analyzed the different static characteristics in addition to solve the second mechanism the completeJacobian matrix.Analyzed the stiffness of The flexible hinge, built the overall stiffness model of the two mechanism, and verified the design meet the stiffness requirement through the finite element simulation; finally analyzed the static stiffness characteristics of two different institutions.Finally, analyzed the factors that affect the precision for precision studies, built the error mapping model and solved the mapping matrix. Analyzed the natural frequency of the two mechanism and built the dynamic constraint conditions and the kinetic equation.Analyzed the modal of the mechanism and solved the natural frequency and made the precision compare analysis of the two mechanism; In addition, innovatively analyzed the temperature affect to the precision and made simulation and optimization by thermos-mechanical coupling of drives.This paper studied the statics, kinematics, static stiffness, precision of the two mechanism, comparatively analyzed the different characteristics of similar two kinds of flexible mechanism by transverse through a number of indicators, and provided a theoretical basis for engineering application.