Three dimensional coordinate metrology is a firmly established technique in industry.Scanning technology is now widely used in coordinate metrology and is increasingly usedfor the measurement of small features. This paper presents a new real shape approach toclosest point inspection involutes curve of gear tooth by coordinate measuring machinery(CMM). This method aims to select the most likely contact point for each successive arc byapplying geometrical criteria and a fuzzy logic estimator. This method is particularly,but not exclusively, suitable for the metrology of features with small radii as well asmetrological discontinuities. It does not require obtaining the normal vectortraditionally used for probe tip correction. Elapsed time is 144.09 s. Tests have beendone on limps of machine tool speed (pinion type cutter), which is highly applied in ourcountry.
