High precision size measurement system of industrial profiles section

This paper implements a non-contact measurement system based on machine vision for industrial profiles section, which uses double telecentric lens optical system as image acquisition device. The key procedures using double telecentric lens optical system to get cross section image of measured profile are described in details. Based on the profile characteristic of section itself, we applied smooth filtering and automatic threshold binarization algorithm in image preprocessing, and improve the detection accuracy through subpixel edge detection algorithm. Moreover, combined with high precision section edge images, we realized some practical functions such as geometric measurement, fitting, and contrasting with CAD drawings, etc. The proposed system with high speed, high accuracy and easy maintenance can satisfy the requirement of high precision for industrial profiles section size measurement.