Real Time Monitoring Of Tool Breakage In A Milling Operation Using A Digital Signal Processor.pdf

Journal of Materials Processing Technology 100 (2000) 266±272
Real time monitoring of tool breakage in a milling
operation using a digital signal processor
Dae Kyun Baeka, Tae Jo Kob,*, Hee Sool Kimb
aAndong Institute of Information Technology, 1217 Imha, Andong, Kyoungbuk 760-830, South Korea
bSchool of Mechanical Engineering, Yeungnam University, 214-1 Daedong, Gyoungsan, Kyoungbuk 712-749, South Korea
Accepted 17 December 1999
Abstract
A monitoring system that can detect tool breakage and chipping in real time was developed using a digital signal processor (DSP) board
in a face milling operation. An autoregressive (AR) model and a band energy method were used to extract the features of tool states from
cutting force signals. Then, two arti®cial works, which have a parallel processing capability, were embedded on the DSP board to
discriminate different malfunction states from features obtained by each of the two methods of signal processing. In experiments, we found
that feature parameters extracted by AR modeling were more accurate indicators of malfunctions in the process than those from the band
energy method, although puting speed is slower. By using the selected features, we were able to monitor malfunctions in real time.
# 2000 Elsevier Science . All rights reserved.
Keywords: Milling operation; Tool breakage; Real time; AR modeling; DSP (digita