A Fully Instrumented Drilling Unit For Robotic Drilling

This paper introduces the techniques for drill wear and breakage sensing as well as machine failure diagnosis. The techniques have been implemented on a compact drilling machine which serves as an end-effector for the robotic drilling of aircraft holes. The drilling unit is instrumented with five sensors: thrust force, spindle speed, vibration, displacement, and air pressure. With eight outputs from the five sensors and computer algorithms, the system is able to monitor all dynamic events of the drilling process, detect drill wear and breakage, diagnose machine failure comprehensively, and predict the quality of drilled holes.