An algorithm for registration of points measured on coordinate measuring machine

Résumé

In the measuring process of a part on coordinate measuring machines (CMM), one of the frequent problems is the necessity to modify the part position during measuring operation, so the measuring system has access to the various compounding surfaces. This thing assumes the modification of the piece reference system initially established and requires the reestablishment of the reference system or the establishing of a new reference system. Sometimes, due to the new position of the part, it is impossible to achieve the features used for the creation of the initial reference system. Moreover, the simultaneous measuring of the two necessary reference systems may be impossible. In this paper, are proposed an algorithm and a software which allow for the correlation of the points measured in two distinct stages, respectively in the two different positions of the same part. The algorithm is based on the determination of three control points in the two distinct measuring positions and then the establishing of the coordinate transformation which determines the modified position of the measured part.