A MACHINE VISION SYSTEM FOR MEASURING WEAR AND CHIPPING OF DRILLING TOOLS

An automated measurement system for detection of drilling tool malfunc tions such as wear and chipping has been developed for application to machining centres. A machine vision system with two industrial televis ion cameras has been developed. A global image provided by the first c amera is used to rotate the drill such that a major cutting edge is a central vertical line in each of the detailed images provided by the s econd camera. The second camera, with an autofocusing mechanism, focus es towards a potentially affected small region of the drill. Three det ailed images are used for detection of drilling tool malfunctions, and failed portions are extracted using image-processing techniques. Thre e-dimensional surface contours of the failed portions along with one- and two-dimensional quantities such as wear width, chipping width, and the failed portion area are measured. Lighting directions are determi ned so that the diffusion component dominates specular reflection, and the failed portions are illuminated more than the normal portions.