It is important to take countermeasures against tool collision to avoid serious damage to the machine tool. Though rapid collision detection is needed, the introduction of additional sensors to a machine tool is not desirable owing to cost, machine-tool stiffness, and failure rate considerations. In this study, a sensor-less tool collision detection method is proposed on the basis of the disturbance observer theory. It only uses the servo information of a ball-screw-driven stage and does not require external sensors. The proposed method successfully detects the collision between a tool and a workpiece in less than 3 ms with a feed rate of 50 m/min.
ASJC Scopus subject areas