Effects of Filtering Factors of Scan Data on GD&T Analysis with Metrology Software

Abstract

Scanned point clouds must pass through diverse filters to eliminate the noise arising from environmental and material reflectivity factors. The use of these filters can have significant effects on GD&T (Geometric Dimensioning and Tolerancing) analysis results. The aim of this paper is to analyze the measurement procedures for part inspection with metrology software using scanners in a non-controlled environment and demonstrate the impact of different filtering factors on GD&T analysis. The effects of GD&T fit methods (Least Squares vs. Mating Zone) are also investigated, since their behavior vary greatly with noise levels. An experimental plan based on Design of Experiments (DOE) methodology is applied to determine factors affecting the variability in GD&T Analysis. Experimental test cases combining these factors are discussed and, accordingly, best practices are proposed.