Monitoring method for machine tool cutter state

The invention discloses a monitoring method for the machine tool cutter state. The monitoring method comprises the following steps of processing a current signal of a spindle motor of a machine tool;obtaining upper and lower boundary curves of the current signal during normal cutting by a cutter by a probability distribution theory in statistics; and with the upper and lower boundary curves as astandard of monitoring the current signal of the spindle motor, monitoring the wear degree of the machine tool cutter by recognizing fine change of the current signal of the spindle motor, wherein thecutter state can be monitored effectively, and the upper and lower boundary curves are obtained by self-learning in a machine tool machining process. Therefore, the monitoring method provided by theinvention has the advantage of being suitable for various machining conditions. In addition, the monitoring method provided by the invention monitors the cutter state by measuring the current signal rather than a force signal, a