Optical Wear Inspection of Countersink Drill Bit for Drilling Operation in Aircraft Manufacturing and Assembly Industry: A Method

Abstract

Assembling aircraft skin requires thousands of rivets in order to fasten the skin together with rib. Therefore, there will be a lot of drilling operations daily. This could lead to wastage of drill bit usage if the operation is not fully utilized or reduce the hole quality if it is overused. An inspection system is developed to monitor the condition of the countersink drill bit and put these issues under control. Currently, the existing optical wear inspection system is capable to detect and measure the percentage of wear of the drill bit. The theory and application of image processing used in the detection and measurement were already discussed in previous work. In this paper, a method is proposed to inspect the wear of countersink drill bit by using the current existing system. Several key factors that may affect the accuracy of the optical inspection such as relation between illumination and image quality, and subject positioning and alignment are discussed in this paper. An external illumination system is developed to improve the quality of image captured. The drill bit positioning and alignment are corrected using image registration method in image processing. Another relevant precaution is also added into account before finally implement the complete step of performing the inspection.