The statistical gauge in geometrical verification. Part II. The virtual gauge and verification process

Abstract

Currently, most measurement and geometrical verification processes are based on the characterization of distances or angles between geometrical elements. Methods have already been developed for the verification of ISO specifications using the statistical information included in a set of points. These methods are however based on the development of measurement sequences and hence a set of geometrical constructions. The main problem in this verification process is the propagation of uncertainties. With a correct expression of a virtual gauge, it is possible to avoid this propagation; indeed by using a virtual gauge manipulation, initial best-fitted surfaces are never altered. The aim of this paper is to present a new approach using this statistical information to describe the measured part and develop a virtual gauge system for verification. This has been done in two parts. The first one focused on the statistical modeling of the measured surface; this second part will now describe a verification method based on a virtual, i.e. numerical, gauge.