6. Assessment of Geometrical Accuracy

A modern 3D metrology employs measurements on coordinate measuring machines (CMM) for obserThe minimum zone problem in Mathematicaation of actual features (AF) [1–3]. The measurements present initial data for estimation of the geometrical accuracy, and a key step of the estimation process is an optimization procedure. Over a long period of time, only the least mean square (LMS)-based assessments were applied. Nowadays international and national standards for geometrical product specification use the minimax optimization criteria formulated through the tolerance zone limiting the possible location of results of measurement. The zone is formed by one or several geometrically perfect boundaries (lines or surfaces) and featured by minimum value of a single tolerance geometrical element. The results of measurement must lie between or at the boundaries of the minimal zone (MinZ), called tolerance zone.