On-line tool-wear monitoring using a PC

Abstract

With the increasing use of computer numerical control, there is a growing need to ensure a reliable tool-wear monitoring system to optimise tool usage or tool wear. Findings have shown a good correlation between the dynamic tangential force and flank wear. This dynamic tangential force, when presented in a frequency spectrum, shows a characteristic peak which corresponds to the resonant frequency of the tool holder. Tracking of this peak during machining reveals a trend whereby the dynamic force increases as flank wear increases, and the dynamic tangential force declines preceding the onset of tool failure. A software program is being develop on a personal computer installed with a Fast Fourier Transform card. Signals collected during the cutting process are transformed of the FFT card to secure meaningful data. A pre-warning condition can be set in the software program to indicate the onset of tool failure when the dynamic force starts to decline. So far, the progress has been very satisfactory. © 1992.