Dynamic measurement accuracy evaluation of coordinate measuring machines

Abstract

The coordinate measuring machine (CMM) is one of the most flexible and versatile inspection machines in the manufacturing industry. Used around the world, the CMM has become a symbol of industrialization. However, there is still no reliable method for evaluating the accuracy of a CMM. The current commonly used method—the static evaluation method—may result in an incorrect assessment owing to the very dynamic nature of the CMM. In order to evaluate CMM dynamic accuracy, in this paper an error separation method for dynamic measuring data is presented to obtain their accuracy evaluation indices. Referring to international evaluating principles of measurement uncertainty, this method was derived through the analysis of dynamic measuring data and dynamic measuring error. To verify the validity of the proposed method, the dynamic accuracy of a CMM was evaluated and was found to be much better than that of the current static evaluation method.