Research On The Effect Of Light Intensity Of End Mill Size Measurement Based On Machine Vision

Since CNC machining technology has been widely used in industrial manufacturing,the dimensional measurement of tools has been an important research content in modern manufacturing industry,and its geometric dimensions have a great impact on the accuracy and efficiency of cutting processing.To address the three problems of visual measurement: the lack of theoretical verification of the influence of light intensity on the measurement of workpiece edge position,the large influence of dimensional measurement accuracy of end mills under different light intensities,and the low measurement accuracy due to the uneven image grayscale caused by the installation error and the manufacturing error of the system itself,this paper takes the practical problem of the influence of light intensity in the process of high-precision measurement of end mills as the starting point,takes the collected images of end mills as the research object,takes theoretical simulation and experimental verification as the main line,and aims to improve the accuracy and efficiency of cutting.In this paper,we have studied the technique of high precision visual measurement of end mills with the objective of improving the measurement accuracy of radial dimensions of end mills under different light intensities and uneven light intensities,using the collected images of end mills as the object of study and theoretical simulation and experimental verification as the main lines.The main elements of the study and the innovation of the work are as follows.1)A radial dimension measurement system for end mills based on vision measurement technology was designed and built.According to the requirements of the end mill vision measurement system,the light source system,image sensor,lens and other important components were analyzed and selected.The measurement system was programmed with Halcon as the software development environment for system hardware control,image acquisition,and end mill dimension measurement.2)A theoretical simulation model based on point light source imaging is proposed.Through Trace Pro and Matlab joint simulation,a model of simulated cutter,light source,lens and other components is established,and simulation analysis research is conducted for edge imaging under different light intensities and uneven light intensities to investigate the influence of light intensity distribution on the imaging of the object edge position law.3)The image processing and data extraction scheme of the whole vision measurement system is designed.For image segmentation,a local variable threshold-based segmentation method is used for grayscale uneven images,which enables the system to correctly segment the end mill image under uneven light intensity;for edge extraction,Gaussian fitting is used for sub-pixel edge extraction,which improves the accuracy of end mill edge position measurement.4)A dual dynamic pixel-equivalent method is proposed to characterize the light intensity in terms of the image background gray level and to address the effect of uneven light intensity.The experimental results show that the dual dynamic pixel equivalent method can effectively improve the measurement accuracy of end mills.