A self-calibration scheme to monitor long-term changes in linear and rotary axis geometric errors

Abstract

A calibration scheme of position and orientation errors of rotary axis average lines based on touch-trigger probing is widely available on many commercial five-axis machine tools. Such a measurement is influenced by error motions of both linear and rotary axes. This paper proposes a novel scheme to separately identify linear and rotary axis geometric errors by using a touch-trigger probe and an uncalibrated test piece. Whereas the proposed scheme is based on well-developed self-calibration schemes for the circularity measurement, an original contribution is that it is applied to separate linear and rotary axis geometric errors. Two case studies are presented. First, the proposed tests are performed on the same five-axis machine tool for half a year to observe a long-term change in linear and rotary axis geometric errors. The second case study investigates the influence of room temperature change on linear axis and rotary axis error motions.