Geometric error calibration of multi-axis machines using an auto-alignmentlaser interferometer

This work will report the development and application of an auto-alignment laser interferometer system for the geometric error calibration of CNC mult i-axis machines. The system is capable of a diagonal displacement measureme nt, where multiple machine axes are moved simultaneously, with automatic op tic alignment. This capability provides a solution for quick evaluation of the overall volumetric error of a multi-axis machine tool. One application of the system is that the 21 geometric errors of a 3-axis machine can be qu ickly estimated from the displacement measurements of some determined diago nal lines in the working volume. Compared with a time of several days using a conventional laser interferometer system, it takes only 1 hour for the p roposed system to complete the geometry calibration of a 3-axis machine. A method for the roll calibration of a vertical axis is also proposed and dem onstrated in this work. (C) 1999 Elsevier Science Inc. All rights reserved.