Measurement and evaluation for profile tolerance based on images

Abstract

A profile measurement and evaluation method for the micro-parts based on the images is presented.This method includes the method of profile data modeling in theory,bound searching method of expansion polar angle corresponding theoretical points and evaluation method of least-deviation profile error.The evaluation method of least deviation profile error and classical least-square profile error are analyzed and compared based on several examples.The experiments on actual image show that the iterative times of the least deviation method are 0~3 fewer and the accuracy are 4%~12% higher than that of least-square method,which can meet the requirements of high accuracy and fast profile tolerance measurement of micro-parts.