TESTING OF COORDINATE MEASURING MACHINE SOFTWARE

The measuring accuracy of coordinate measuring machines (CMMs) depends to a large extent on the software system implemented. For this reason , the Physikalisch-Technische Bundesanstalt (PTB) supported by the Com mission of the European Communities (Community Bureau of Reference; BC R) has started a project to test this software. Simulated data sets re presenting parts of geometric elements with known distortions were dis tributed to manufacturers of CMM software. The results of various soft ware packages were compared with those of PTB's reference software. Al l evaluations were based on the Gaussian least-squares method. The mai n result of the test showed that only 37% of the solutions were accept able. An investigation was also conducted into the ability of current CMM software to measure gears and to check geometric tolerances accord ing to ISO 1101 and ISO 5459.