Dimensional Synthesis of a 2-UPR-SPR Parallel Manipulator

doi:10.3901/JME.2015.21.024

Abstract

Abstract:

The Exechon manipulator consists of a 2-UPR-SPR PM (parallel manipulator) which can perform two coupled rotational DOFs and one translational DOF and a RR serial manipulator (where U is a universal pair, P is a prismatic pair, R is a revolute pair, and S is a spherical pair). It has been extensively applied to advanced manufacturing industry. Few literatures focus on the dimensional synthesis of the 2-UPR-SPR PM until now. Based on the concept of screw theory, the dimensional synthesis of the 2-UPR-SPR PM is addressed by taking motion/force transmission into account. The inverse kinematics module and screws of the manipulator are analyzed. The local transmission index and global transmission index are defined as the performance evaluation criterion of the manipulator. With the approach of optimal design space, the atlases of performance indices are presented. The optimum region is obtained according to the demands of practical application requirements, where all the possibilities of the dimensionless parameter of the manipulator are included, and a set of numerical resultants are randomly chosen from the optimum region in order to determine the best parameters that satisfy practical requirements.

Key words: dimensional synthesis, performance indices, screw theory, parallel manipulators

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