Drill wear monitoring based on current signals

This paper presents a simple method for on-line wear state monitoring and tool replacement decision-making using spindle motor and feed motor current signals in drilling. In the paper, the effects of tool wear as well as cutting parameters on the cutting current signals are analyzed. The models on the relationship between the current signals and the cutting parameters are established under different tool wear states with a partial experimental design and regression analysis. Finally, a fuzzy classification method is used to classify the tool wear states so as to facilitate defective tool replacement at the proper time. The validity and reliability of the method are verified by experimental results. q 1999 Elsevier Science S.A. All rights reserved.