Abstract
This article describes a geometric calibration method for a coordinate measuring machine based on a three degree of freedom parallel mechanism. In generally, identifying whole, necessary and sufficient, kinematic parameters included in kinematic models of parallel mechanisms is hard because of the strong correlation between each parameter. In this study, we propose to use some different links on the calibration to improve the mathematical condition of the Jacobian matrix on the least squares method. To use the different links, all kinematic parameters are estimated and the positioning accuracy of the parallel coordinate measuring machine is improved from 100 μm to 5 μm in the experiments. Firstly, the pilot unit of the parallel coordinate measuring machine is introduced. Secondly, necessary and sufficient kinematic parameters of the parallel coordinate machine for calibration are formulated. Finally, kinematic parameters are estimated through the calibration experiment.
