Research On Tool Wear Detection Technology Based On Structured Light Projection 3D Imaging

In recent years,with the rapid development of industrial automation and intelligence in China,the scale and quality of the manufacturing industry has been developing rapidly.Although the total amount of CNC machine made in China and the consuming of CNC are very large,but the production efficiency and precision of the CNC made in China remains big gap to the world’s top level.As the basic industrial machine,the production stability,reliability and lifetime of the CNC are the key elements that affect its production quality and efficiency.The degree of wear of turning tools can affect the reliability of machine tools during the machining process,so turning tool wear detection is one of key technologies for the CNC.Traditional turning tool abrasion detection mainly used manual work.During the machine tool downtime,workers rely on their own experience to determine the degree of turning tool abrasion.The detection results of this method are too easily influenced by the subjective judgment of workers.With the emergence of automatic testing equipment and methods,workers use these tools to obtain relevant data on tool wear.Common methods include coordinate measuring instruments and ultrasonic testing,etc.These measuring tools may cause damage to the measured object.With the development of machine vision technology,non-destructive testing has been developed.However,most of the non-contact measuring method are based the two-dimensional image processing technology,which can not obtain the 3D information of the turning tool abrasion.This dissertation studied the turning toll abrasion 3D detection based on the fringe projection profilometry technology.The main works are listed as followed:(1)In order to obtain the 3D image of the turning tool wear,a method based on fringe projection profilometry technology to extract the 3D feature information of the tool wear area is proposed.After matching and segmentation of the obtained 3D point cloud information,the point cloud set of the wear area is extracted,Then use standard gauge blocks to calculate the proportional relationship between the point cloud and the actual physical distance,and finally calculate the depth information of the wear area.(2)Based on the aforementioned 3D image technology,a software program for tool wear detection has been developed according to the requirements.The software is based on the Pycharm platform and uses Python as the language and pyqt as the interface plugin.The 3D point cloud display module for tool wear,the maximum and minimum wear depth modules for tool wear,and the display module for whether it meets the national blunt wear standard have been designed.Finally,the tool wear error measured is less than 5% of the actual error,which can meet the actual production requirement.