Research on tool condition monitoring method based on current signal

Abstract：In order to reduce the probability of scrap and equipment failure due to tool failure and to improve the efficiency of failure-free operation of CNC machine tool, the current sensor was used to collect the current from the input side of the converter, while the three phase distortion line current was used to calculate the average effective current.The average effective current signal and the traditional RMS effective current signal were respectively analyzed in time domain, frequency domain and time-frequency domain.Through comparison and verification, the tool wear state could be zoned well by using the proposed method, and its applicability was proved.The board of IPC, DAQ card and Hall current sensor were used for building hardware platform, while the software was designed by using Qt framework.The tool condition monitoring system was tested on CNC machining center.The results showed that the proposed monitoring system could reflect the tool wear status to some extent and give early warning, and that the monitoring method was effective.

Keyword：tool wearing;fault diagnosis;current signal;condition monitoring;