Definition and applications of the spatially discrete metrological descriptor framework for triangle mesh geometry data in 3D coordinate metrology

Description

In 3D coordinate metrology, the surface of a measurement object is probed and a decision is made regarding the conformity of the object with respect to the specification on the basis of the measuring points determined. In principle, each measuring point can only be captured with finite accuracy. Thus, the measurement uncertainty derived from the measurement deviations has a direct effect on the conformity assessment. Due to the technical limitations of the measurement system, the uncertainty of different data points is usually not identical. This work describes the development and application of a framework with which the measurement uncertainty can be determined at arbitrary points on the geometry of the component. It is based exclusively on the statistical processing of reference measurement data, measurement data of the target system and the nominal geometry of the object. The determination of substitute geometry elements is avoided and in return only the local relationship of the different geometry data is evaluated. Various metrological descriptors (e.g. the measurement uncertainty) offer the possibility of a detailed analysis of the target measurement system with regard to its metrological properties. Thus, due to the availability of point-by-point information, comprehensive measurement system analyses with a high sensitivity can be carried out, with which the local effects of various influences on the measurement chain can be reliably identified and quantified.