Journal of the Japan Cociety for Precision Engineerig, Vol.66, No. 9 (2000) 1378-1382.

Coordinate Measuring Machine using Parallel Mechanism (3rd Report)
-Abbe's Principle-

Takaaki OIWA and Kouki YAMAGUCHI

Abstract

This study has proposed a new coordinate measuring machine (CMM) based on a spatial parallel mechanism consisting of closed loop link mechanism. In conventional CMM employing of XYZ mechanism, the motion error of the mechanism strongly influences the measurement accuracy because of violation of the Abbe's principle which is the basis of the precision measurement. In this paper, the relationship between the link layout of proposed mechanism and the influence of joint runouts on the measurement error has been investigated analytically and experimentally. The obtained main results are as follows. (1) The joint runout in the scale direction strongly affects the measurement error. (2) Effects of the runouts except the scale direction are negligible when the measuring point is in the extensional direction of the scale. (3) The dispersion of measured value has decreased in above link layout. In conclusion, the Abbe's principle can be applied in proposed parallel mechanism.

Key words

coordinate measuring machine, Abbe's principle, parallel mechanism, link layout, error analysis, joint runout