Error mapping of CMMs and machine tools by a single tracking interferometer

This paper presents a novel approach for the mapping of geometric errors of machine tools and coordinate measuring machines by a single tracking interferometer. The concept is based on interferometric displacement measurements between reference points that are fixed to the base and offset points fixed to the machine head. The experimental comparison with an independent technique on a high accuracy CMM demonstrated the agreement of parameters in the sub-micron range. Thus, the method proved to be suitable for the highest accuracy demands. Furthermore, it has almost no limitation for the maximum size of the working volume. It does not require any alignment of equipment and yields a very simple data structure, which can be evaluated by the developed software with very little additional information from the operator. The method has also been tested on a large horizontal arm machine and on a smaller high precision machine tool.