Research On Vision Measurement Technology Of Three-face Milling Cutter

Three-face milling cutter is a commonly used tool for milling of mechanical parts.As companies have the increasing quality requirements for the production of milled workpieces,the milling accuracy of milling cutter has become a key factor that cannot be ignored.The milling parameters of milling cutters directly affect production cost and production efficiency of companies.Traditional milling cutter size measurement methods mainly rely on manual completion,which is not only inefficient,but also has low detection accuracy,and therefore,is difficult to meet the quality control requirements of a large number of parts.In recent years,with the rapid development of visual measurement technology,visual measurement has been widely used in tool size measurement.It has many advantages that manual measurement does not have,such as high precision,high efficiency,high automation,etc.Therefore,a non-contact dimension measurement method based on machine vision for three-sided milling cutter was presented,whilst its dimension measurement principle was focused,and the key technology of image processing was improve.In order to improve the accuracy of image size measurement,the following research work has been completed in this study:1)According to the size of the three-face milling cutter,the appropriate rotation and translation platform was selected,the hardware system was built,MATLAB was selected as the image processing software,the camera was corrected for distortion,the error analysis of the factors affecting the pixel equivalent was carried out,and the size of the pixel equivalent was finally determined.2)The different contour extraction methods were introduced respectively,and the existing pixel-level and sub-pixel-level edge detection MATLAB source codes were improved and optimized.The overall contour of the original image was obtained by processing the milling cutter image,which laid a foundation for the measurement of the main size parameters.3)The problem of residual noise points was eliminated by the method of expansion and removal of isolated points.By filtering the abnormal points,the automatic extraction of the tool contour point set was realized,and the least square method was used to fit the inner hole and outer circle of the milling cutter.The radial runout value of the milling cutter was finally obtained according to the distance between the tool tip point and the circle center point.4)The composition forms of tool angles at different tool tip positions were analyzed,and the contour of tool tip within the specified range was extracted.Meanwhile,by improving the boundary tracking criteria,the set of straight line points on the front and rear face of the milling cutter was obtained,which was fitted by RANSAC straight line,and the front and rear angles of the cutter were acquired by using the position relationship between the straight lines.