Abstract: 3D data from blade surfaces can be measured using contact or non-contact methods. A new fast measurement method was proposed based on the non-contact method of equidistance measurement. On the basis of the theoretical model data， feature points were extracted from the blade feature section curve with the improved method of straight angle and were compared with original data， thus the Hausdroff distance was calculated. On the premise of the fitting accuracy， the number of measurement points was reduced. A hardware system and software were developed to realize the non-contact equidistance measurement and feature point fast measurement. Finally， two sets of experiments for measuring complex blade were carried out. The results of data processing and error analyzing confirm the feasibility of fast measurement method.

Key words: blade surface, quick measurement, feature point extraction, non-contact measurement, Hausdroff distance