Monitoring of tool fracture in milling

For untended manufacturing operations, in-process monitoring of tool fracture plays a critically important role. A tool fracture feature in the spectrum of the displacement signal of the spindle in milling has been discovered. Therefore, a new signal processing algorithm called the band-limited average energy method using the tool fracture feature to monitor tool fracture is proposed. The energy content of the tool fracture feature is extracted and normalised to detect tool fracture. It is shown, by theoretical studies and experimental results, that tool fracture can be detected under varying cutting conditions in milling.