Monitoring of tool collision in drilling by disturbance observer

Disturbance observation is a sensorless process monitoring technique that has not yet been applied to the monitoring of tool collision in the use of machine tools. This paper presents a monitoring algorithm that detects collisions that involve the breakage of drills through observation of the disturbance force change rate. A comprehensive experimental study of diverse operator-induced collisions was conducted to analyze the collision detection potential of the disturbance observer. It was found that collision monitoring by the disturbance observer is more sensitive and responsive than that using a sensorless jerk observer.