Journal of the Japan Cociety for Precision Engineerig, Vol.64, No. 12 (1998) 1791-1795.

New Coordinate Measuring Machine using Parallel Mechanism
-Fundamentals and Kinematics-

Takaaki OIWA

Abstract

This study proposes a new coordinate measuring machine (CMM) based on a parallel mechanism consisting of closed loop link mechanism. The use of this mechanism instead of conventional orthogonal slide mechanism will potentially improve the stiffness, accuracy and efficiency of the CMM. This report describes the fundamentals, type synthesis, number synthesis and kinematics of the new CMM. Synthesized parallel mechanism with spatial three degree-of-freedom (DOF) comprises one base, one stage and three sets of three types of joints which are a revolutionary joint, a spherical joint and actuated prismatic joint. The direct kinematics calculated the coordinate of the probe from the link length, and estimated the measuring space. An experimental manipulator with 3 DOF was constructed to examine the validity of the new mechanism.

Key words

coordinate measuring machine, parallel mechanism, closed loop mechanism, 3 DOF mechanism, kinematic analysis, dimensional metrology, number synthesis