Condition Monitoring of Micro-drilling Processes on Glass by Using Machine Vision

Optical and medical devices require microdrilling of holes on glass. Brittle fracture occurs during the drilling. Cone and radial cracks are generated due to impact load and walking when a drill hit a glass to make a hole. To produce good holes without cracks and fracture, a condition monitoring of glass drilling processes is required. In this paper, to develop a costeffective direct monitoring system in microdrilling processes on glass, a machine vision unit with the edge detection and 3D measurement functions is studied. It consists of a CCD camera with a zoom lens attached to the precision servo stage and a novel illumination unit. Performance of the developed machine vision system is verified in micro-drilling processes on glass using diamond and carbide drills.