Please cite this article in press as: Corne R, et al. Study of spindle power data with neural network for predicting real-time tool
wear/breakage during inconel drilling. J Manuf Syst (2017), http://dx.doi.org/10.1016/j.jmsy.2017.01.004
ARTICLE IN PRESS
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JMSY-524; No. of Pages 9
Journal of Manufacturing Systems xxx (2017) xxx–xxx
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Journal of Manufacturing Systems
j ourna l h omepage: www.elsevier.com/locate/jmansys
Study of spindle power data with neural network for predicting
real-time tool wear/breakage during inconel drilling
Raphael Corne
a,b
, Chandra Nath
a,∗
, Mohamed El Mansori
b
, Thomas Kurfess
a
a
School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
b
Arts et Métiers ParisTech, Aix-en-Provence, 13617, France
a r t i c l e i n f o
Article history:
Received 27 September 2016
Received in revised form
30 November 2016
Accepted 13 January 2017
Available online xxx
Keywords:
Spindle power data
Digital manufacturing
Neural network
Wear prediction
Drilling
Superalloys
a b s t r a c t
Digital manufacturing systems are determined to be a major key to enhance productivity and quality
mainly due to real-time process monitoring and control capability with instant data processing. During
machining, such systems are anticipated to excerpt reliable data within a short time-lapse, monitor tool
wear progress, anticipate its wear and breakage, alert the machinist in real time to avoid unexpected
failure of tool or machine, and help obtaining quality products. This is vital, especially, when drilling
Ni-/Ti-based superalloys because catastrophic failure and premature breakage of tools occur in random
manner due to aggressive welding and chipping of tool including the rake and/or flank faces and tool
corner.
Nowadays, spindle power data are easy to collect directly from modern machine tools and can be made
available in production floor for such real-time data processing. This work aims to evaluate spindle power
data for real-time tool wear/breakage prediction during drilling of a Ni-based superalloy, Inconel 625.
Experiments were performed by varying speed and feed. Spindle power data were collected from the
power meter (also called load meter) to feed into the neural network (NN) for functional processing. To
understand the reliability of the spindle power data, force data were also collected and compared. The
results show that the trends of these two different types of data over cutting time are similar for any
feed and speed combinations. The error in NN prediction from actual wear was found to be between
0.8–18.4% with power data as compared to that between 0.4–17.9% with force data. Findings suggest
that spindle power data integrated with the artificial intelligence (NN) system can be used for real-time
tool wear/breakage monitoring and process control, thus appreciate digital manufacturing systems.
© 2017 Published by Elsevier Ltd on behalf of The Society of Manufacturing Engineers.
1. Introduction
In recent years, the manufacturing world has made considerable
progress towards digital intelligent manufacturing technologies
and systems – from data processing to shop floor data mining to
final products [1]. Many different intelligent hardware and soft-
ware, including sensors and data acquisition (DAQ) systems are
being developed to improving both manufacturing productivity
and product quality [2,3]. Nonetheless, a syndrome called “DRIP
– Data Rich Information Poor” is still common to engineers and
machine operators at the manufacturing shop floor [4]. A major-
ity of data are analyzed offline by researchers or engineers rather
than machine operators, which slows down productivity. Analy-
∗
Corresponding author. Current address: Hitachi America Ltd. R&D Division,
Farmington Hills, MI 48335, USA.
E-mail addresses: raph.corne@gmail.com (R. Corne), nathc2@asme.org (C. Nath),
mohamed.elmansori@ensam.eu (M. El Mansori), kurfess@gatech.edu (T. Kurfess).
ses are performed mainly by developing analytical force and wear
models or statistical tool life models based on experimental data,
such as force, wear, and surface metrology. However, in a produc-
tion line, e.g., in machining, there is a serious need of intelligent
manufacturing systems that can automatically collect reliable data
during machining, monitor tool wear progress based on the col-
lected data, anticipate wear and breakage, alert the machinist in
real time to avoid unexpected tool failure, and help to obtaining
quality products.
Drilling is counted to be one-third of all machining operations
[5] and usually comes last in the entire process. It is therefore crit-
ical for this process to be as precise and optimized as possible.
Drill wear monitoring is very important since worn tools affect hole
quality (e.g., cylindricity, circularity, surface roughness), and prod-
uct life [6]. The problem becomes more critical when machining
superalloys, such as, Ni- and Ti-based alloys that possess unique
physical and metallurgical properties [7–9]. Due to mainly poor
machinability, significant chip welding at the cutting edge, and
http://dx.doi.org/10.1016/j.jmsy.2017.01.004
0278-6125/© 2017 Published by Elsevier Ltd on behalf of The Society of Manufacturing Engineers.