Sensor-less monitoring of cutting force during ultraprecision machining

Future ultraprecision machining systems will require intelligent machine tools equipped with effective systems for in-process monitoring of machining status. To meet the requirement, much attention has been directed to the monitoring method of cutting force, temperature, acoustic emission, etc. Cutting force includes useful information on machining status, however, it is difficult to apply these methods for an ultraprecision machining environment. In this paper, a sensor-less monitoring method has been proposed based on a new concept. In the proposed method, a disturbance observer is installed in the position controller for a linear motor-driven aerostatic table system. The performance of the monitoring system has been evaluated through a series of ultraprecision machining experiments.