Visual Inspection And Control System Of Rotary Tool Wear In Nc Machine Tool

In the process of NC machine tool processing,tool wear can directly affect the workpiece processing effect.Timely detection of machining tool wear and adjustment of tool repair or tool replacement according to the degree of wear can effectively improve machining efficiency and reduce machining cost.At present,the indirect detection of tool wear is mainly based on the indirect monitoring of cutting force,current power and other signals.This paper,based on the difficulty of automatic detection of tool wear in machine,design and build a set of machine vision based endmill wear detection system,and complete the development of detection software integrating visual detection,hardware control and NC system communication function.Analyze the main wear types of end mills.After comparing experiments with different illumination environments,a dual camera detection scheme combining circular illumination with forward illumination and rectangular illumination with backlight illumination is proposed.The detection process of blade deflection angle extraction,motor-driven camera rotation,side camera acquisition and processing are designed.Design and build a testing organization.Based on the internal space of NC machine tool,the double-arm rotary motion mechanism is designed and constructed without affecting the normal machining process.As the main body of the detection system,the mechanism is built at the position of the detachable side window of the machine without changing the original structure.At the same time,the electrical control module of the system is designed,and the control of the system detection process is realized by the upper computer.The processing algorithm of end mill face and side image is studied,and an improved collinear edge contour fitting algorithm is proposed for the Angle of blade deflection.Based on Canny operator,the preprocessed high-contrast image edge is extracted and segmented,and the collinear contour is combined to fit the straight line to extract the Angle.Aiming at the profile image of the cutter,the ideal cutting-edge contour is obtained by using the helical plane projection equation and the contour coordinate,the wear area is generated and the wear amount is calculated.Based on C#development environment and Halcon function and Modbus communication protocol,the user software of tool wear visual detection and control system is written.Compared with the test data of the high-precision image measuring instrument,the test system in this paper has a detection error of less than 5%on the wear of the tool back face,which basically meets the needs of actual production and processing.