All position-dependent geometric error identification for rotary axes of five-axis machine tool using double ball bar

Abstract

The position-dependent geometric errors (PDGEs) of the rotary axes have a critical influence on the accuracy of the five-axis machine tool. It is necessary to measure, identify, and further compensate the PDGEs to improve the accuracy of the five-axis machine tool. The present study presents a method to identify the PDGEs of the rotary axes using the double ball bar (DBB). The presented method requires eight measurement patterns based on four different installation positions of the DBB. All 12 PDGEs of the rotary axes can be identified, especially the angular positioning error that cannot be identified in most of the other presented methods. Experimental verification is carried out, and the measurement uncertainty and the limitations of the presented method are analyzed. Compared with some other reported studies, the advantage of the presented method is that it can identify all PDGEs of the rotary axis and requires less measurement patterns.