An advanced method to assess mechanical filtering effect of tactile coordinate-measuring system in dimensional measurement of additive manufacturing parts

Abstract

The primary challenge faced by tactile coordinate-measuring systems (CMS) in dimension metrology of additive manufacturing (AM) components is the CMS mechanical filtering effect – an offset error caused by finite tip size working on the rough surface texture of AM parts. We previously simulated the mechanical filtering effect of physical measurements by applying morphological opening/closing operations to the surface profile. However, because this method only focuses on the profile, the impact of surrounding surface topography was ignored. Consequently, the dimension offset can be underestimated up to a quarter of the deviation as observed in physical measurements. In this work, we propose an advanced method to optimise and preprocess the surface data such that the simulation of 3D surface morphological filtering is enabled even using the profile algorithm. The results showed that the proposed method can compensate up to 94% of the dimension offset of the CMS mechanical filtering effect.