1990 年 56 巻 10 号 p. 1841-1846
An automated measurement method of drill wear and chipping is developed for applications to machining centers. Two ITV cameras are used. A global image via the first ITV camera is used to rotate the drill for a major cutting edge to be a central vertical line in each of three detailed images via the second camera. The second camera, in turn, focuses automatically towards a potentially affected small region of the drill, the three detailed images are inputted into a computer, and failed portions are extracted by image processing techniques. One or two dimensional quantities such as wear width, chipping width, and failed portion area are determined successfully together with three dimensional shapes as drill surface contours. Lighting directions are determined in such a way as a diffuse component dominates a specular reflection and the failed portions are more illuminated than normal portions.