A New Measuring Strategy for Sculptured Surfaces Using Offset Surfaces

Abstract

This paper presents a new measuring strategy that can be used to inspect the quality of sculptured surfaces. For dimensional inspection of sculptured surfaces, one important issue is how to compensate the alignment error because the alignment of sculptured surface leads to significant problems. The key aspect of the method is to use probe approach direction in the Z-direction (that is, an arbitrary or uniform direction) of CAD surfaces, in constructing the measured surface, in order not to be effected by alignment error. In the proposed method, the offset surface concept is introduced to eliminate normal directional error. The method uses the probe center points instead of its surface contact points as measured data for localization. Then the surface points are calculated from the localized measured data and surface normal vectors of the offset surface. For the new measuring strategy, a practical offset surface generation algorithm and localization algorithm are developed. A measuring experiment has been performed for a sculptured surface to show the effectiveness of the proposed method.