A Method of Cutting Power Monitoring for Feed Axes in Milling by Power Measurement Device

Abstract

This study shows a method to monitor the cutting power by a power measurement device installed on the feed-drive motors of a machining center. The load information, which is one of the critical process variables, is highly demanded in monitoring/analyzing machining process. Although force/torque sensors can directly measure the load information of the cutting process, their investments costs are high and they reduce the stiffness of the machine-workpiece systems. Therefore, this study utilizes a power measurement device, which is composed of voltage and current sensors. The cutting power is the multiplication of cutting force (the load information) and the speed information. However, in this study, the cutting power is monitored by estimating the induced voltage of the drive motor and correcting the motor current. The method is experimentally validated in a two-dimensional milling test and compared to a dynamometer-based signal.