Due to the late response to process condition changes, forging processes are normally exposed to a large number of defective products. To achieve online process monitoring, multichannel tonnage signals are often collected from the forging press. The tonnage signals contain significant amount of real time information regarding the product and the process conditions. In this paper, a methodology is developed to detect profile changes of multichannel tonnage signals for forging process monitoring and to classify fault patterns. The changes include global or local profile deviations, which correspond to deviations of a whole process cycle or process segment(s) within a cycle, respectively. The principal curve method is used to conduct feature extraction and discrimination of tonnage signals. The developed methodology is demonstrated with industry data from a crankshaft forging processes.

1.
Seem
,
J. E.
, and
Knussmann
,
K. D.
, 1994, “
Statistical Methods for On-Line Fault Detection in Press-Working Applications
,” Signature Technology Technical Report.
2.
Robbins
,
T.
, 1995, “
Signature-Based Process Control & SPC Trending Evaluate Press Performance
,”
Metal Forming
,
50
, pp.
44
50
.
3.
Koh
,
C. K. H.
,
Shi
,
J.
, and
Williams
,
W.
, 1995, “
Tonnage Signature Analysis Using the Orthogonal (Harr) Transforms
,”
NAMRI/SME Transactions
,
23
, pp.
229
234
.
4.
Jin
,
J.
, and
Shi
,
J.
, 2000, “
Automatic Feature Extraction for In-Process Diagnostic Performance Improvement
,”
J. Intell. Manuf.
0956-5515,
12
, pp.
267
268
.
5.
Kim
,
J.
,
Zhou
,
S.
,
Shi
,
J.
, and
Chang
,
T.
, 2000, “
Forging Process Monitoring Through Multivariate Analysis of Tonnage Signals
,”
24th Forging Industry Technical Conference
, pp.
167
188
.
6.
Koh
,
C. K.-H.
,
Shi
,
J.
,
Black
,
J. M.
, and
Ni
,
J.
, 1996, “
Tonnage Signature Analysis for Stamping Process
,”
Trans. NAMRC/SME
1047-3025,
24
, pp.
193
198
.
7.
Jin
,
J.
, and
Shi
,
J.
, 2002, “
Diagnostic Feature Extraction From Stamping Tonnage Signals Based on Design of Experiment
,”
ASME J. Manuf. Sci. Eng.
1087-1357,
122
, pp.
360
369
.
8.
Jin
,
J.
, and
Shi
,
J.
, 1999, “
Feature-Preserving Data Compression of Stamping Tonnage Information Using Wavelets
,”
Technometrics
0040-1706,
41
, pp.
327
339
.
9.
Hastie
,
T.
, and
Stuetzle
,
W.
, 1989, “
Principal Curves
,”
J. Am. Stat. Assoc.
0162-1459,
84
, pp.
502
516
.
10.
Banfield
,
J. D.
, and
Raftery
,
A. E.
, 1992, “
Ice Floe Identification in Satellite Images Using Mathematical Morphology and Clustering About Principal Curves
,”
J. Am. Stat. Assoc.
0162-1459,
87
, pp.
7
16
.
11.
Kégl
,
B.
, and
Krzyzak
,
A.
, 2002, “
Piecewise Linear Skeletonization Using Principal Curves
,”
IEEE Trans. Pattern Anal. Mach. Intell.
0162-8828,
24
, pp.
59
74
.
12.
Kramer
,
M. A.
, 1991, “
Nonlinear Principal Component Analysis Using Autoassociative Neural Networks
,”
AIChE J.
0001-1541,
37
, pp.
233
243
.
13.
Dong
,
D.
, and
McAvoy
,
T. J.
, 1995, “
Nonlinear Principal Component Analysis—Based on Principal Curves and Neural Networks
,”
Comput. Chem. Eng.
0098-1354,
20
, pp.
65
78
.
14.
Wilson
,
D. J. H.
,
Irwin
,
G. W.
, and
Lightbody
,
G.
, 1999, “
RBF Principal Manifolds for Process Monitoring
,”
IEEE Trans. Neural Netw.
1045-9227,
10
, pp.
1424
1434
.
15.
Nomikos
,
P.
, and
MacGregor
,
J.
, 1995, “
Multivariate SPC Charts for Monitoring Batch Processes
,”
Technometrics
0040-1706,
37
, pp.
41
59
.
16.
do Carmo Manfredo
,
P.
, 1976,
Differential Geometry of Curves and Surfaces
,
Prentice-Hall
,
Englewood, Cliffs, NJ
.
You do not currently have access to this content.