REAL-TIME INSPECTION STRATEGY FOR DIMENSIONAL ACCURACY OF SCULPTURED SURFACES IN COORDINATE MEASURING MACHINE

摘要

This paper presents a new inspection strategy that effectively compensates the measuring error caused by the requirement of the probe's normal direction approach and workpiece alignment. In this study, the offset surface concept is introduced to eliminate normal directional error. This is based on the fact that when a surface is measured using a ball probe, the center of the probe is always located on another parallel surface (offset surface), offset from the original surface by an amount equal to the probe radius along the surface normal direction. If the probe center points are used instead of surface points for localization, the measuring method becomes more accurate and effective because an incorrect surface normal vector is not used. Therefore, in the new measuring strategy, the probe ball is not required to approach the surface along the normal direction. Also, this paper presents the real-time measuring point selection method that can be used to select the position of measuring points during the inspection procedure.