A new method of diagnosis is introduced for helicopter gearboxes that relies on the knowledge of the gearbox “structure” and characteristics of the “features” of vibration for component fault isolation. Both the structural knowledge and featural knowledge in this method are defined as the fuzzy weights of a connectionist network that maps each sampled set of vibration features, obtained from a signal analyzer, into fault possibility values associated with individual gearbox components. The structural weights in this network are defined to represent the influence of gearbox component faults on the overall vibration sensed by each accelerometer, and the featural weights are defined to denote the influence of components faults on individual vibration features. Given the extremely complex structure of helicopter gearboxes which prohibits accurate modeling of the effect of faults on their vibration, the structural weights in this method are defined based on the root mean square value of the frequency response of a simplified lumped-mass model of the gearbox. The experimental evaluation of the method based on vibration data from two different gearboxes is included in a separate paper.

1.
Agogino
A. M.
,
Srinivas
S.
, and
Schneider
K. M.
,
1988
, “
Multiple Sensor Expert System for Diagnostic Reasoning, Monitoring and Control of Mechanical Systems
,”
Mechanical Systems and Signal Processing
, Vol.
2
, No.
2
, pp.
165
185
.
2.
Astridge
D. G.
,
1989
, “
Helicopter Transmission—Design for Safety and Reliability
,”
Proc. of Inst. of Mech. Engrs.
, Vol.
203
, pp.
123
138
.
3.
Badgley, R. H., and Hartman, R. M., 1974, “Gearbox Noise Reduction: Prediction and Measurement of Mesh-Frequency Vibrations Within an Operating Helicopter Rotor-Drive gearbox,” ASME Journal of Engineering for Industry, May, pp. 567–577.
4.
Boyd
L. S.
, and
Pike
J.
,
1989
, “
Epicyclic Gear Dynamics
,”
AIAA Journal
, Vol.
27
, No.
5
, pp.
603
609
.
5.
Cantone, R. R., Pipitone, F. J., Lander, W. B., and Marrone, M. P., 1983, “Model-Based Probabilistic Reasoning for Electronics Troubleshooting,” Proc. of 8th International Joint Conference of Artificial Intelligence Applications, AAAI-1, pp. 207–211.
6.
Carpenter, G. A., and Grossberg, S., 1987, “ART2: Self-Organization of Stable Category Recognition Codes for Analog Input Patterns, Applied Optics.
7.
Chin
H.
,
Danai
K.
, and
Lewicki
D. G.
,
1993
, “
Pattern Classifier for Fault Diagnosis of Helicopter Gearboxes
,”
IFAC J. of Control Eng. Practice
, Vol.
1
, No.
5
, pp.
771
778
.
8.
Choy, F. K., and Qian, W., 1993, Global Dynamic Modeling of a Transmission System, NASA Contractor Report 191117, ARL-CR-11, Lewis Research Center, Cleveland, Ohio.
9.
Cornell
R. W.
, and
Westervelt
W. W.
,
1978
, “
Dynamic Tooth Loads and Stressing for High Contact Ratio Spur Gears
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
100
, pp.
69
76
.
10.
Davis
R.
,
1984
, “
Diagnostic Reasoning Based on Structure and Behavior
,”
Artificial Intelligence
, Vol.
24
, pp.
347
410
.
11.
Gilmore, J. F., and Gingher, Kurt, 1987, “A Survey of Diagnostic Expert Systems,” Applications of Artificial Intelligence 5, SPIE, pp. 2–11.
12.
Harris, T. A., 1966, Rolling Bearing Analysis, John Wiley and Sons, Inc., New York, New York.
13.
Hertz, J., Krogh, A., Palmer, R. G., and Palmer, R. G., 1991, Introduction to the Theory of Neural Computation, Addison-Wesley, Redwood City, CA.
14.
Huang, W. Y., and Solorzano, M. R., 1991, “Wavelet Preprocessing of Acoustic Signals,” 25th Asilomar Conference on Signals, Systems & Computers, CA.
15.
James, M. L., Smith, G. M., Wolford, J. C., and Whaley, P. W., 1994, Vibration of Mechanical and Structural Systems, Harper Collins College Publishers, New York, NY.
16.
Jammu
V. B.
, and
Danai
K.
,
1996
, “
Unsupervised Pattern Classifier for Fault Detection of Helicopter Power Train
,”
Machine Vibration
, Vol.
5
, No.
3
, pp.
154
162
.
17.
Jammu
V. B.
,
Danai
K.
, and
Lewicki
D. G.
,
1998
, “
Experimental Evaluation of A Structure-Based Connectionist Network for Fault Diagnosis of Helicopter Gearboxes
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
120
, No.
1
, pp.
106
112
.
18.
Karel, G., and Kenner, M., 1988, “KLUE: A Diagnostic Expert System Tool for Manufacturing,” Computing in Engineering, San Francisco, CA, pp. 331–336.
19.
Kasuba
R.
, and
Evans
J. W.
,
1981
, “
An Extended Model for Determining Dynamic Loads in Spur Gearing
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
103
, April, pp.
398
409
.
20.
Kazlas, P. T., Monsen, P. T., and LeBlanc, M. J., “Neural Network-Based Helicopter Gearbox Health Monitoring System,” IEEE-SP Workshop on Neural Networks for Signal Processing, Linthicum, Maryland, Sep. 1993.
21.
Kohonen, T., 1989, Self-Organization and Associative Memory, Springer-Verlag, Berlin, Germany.
22.
Lin
H-H.
,
Huston
R. L.
, and
Coy
J. J.
,
1988
, “
On Dynamic Loads in Parallel Shaft Transmission: Part I—Modelling and Analysis
,”
ASME JOURNAL OF MECHANISMS, TRANSMISSIONS, AND AUTOMATION IN DESIGN
, Vol.
110
, June, pp.
221
229
.
23.
Lyon, R. H., 1995, “Structural Diagnostics Using Vibration Transfer Functions,” Sound and Vibration, Jan., pp. 28–31.
24.
Mark
W. D.
,
1987
, “
Use of the Generalized Transmission Error in Equations of Motion of Gear Systems
,”
ASME JOURNAL OF MECHANISMS, TRANSMISSIONS, AND AUTOMATION IN DESIGN
, Vol.
109
, June, pp.
283
291
.
25.
Mcfadden
P. D.
, and
Smith
J. D.
,
1985
, “
A Signal Processing Technique for Detecting Local Defects in a Gear from Signal Average of the Vibration
,”
Proc. of the Institute of Mechanical Engineers
, Vol.
199
, No.
c4
, pp.
287
292
.
26.
McKeever, B., and Blundell, J. K., 1986, “FAULTS—An Expert Systems Environment for Fault Detection and Diagnosis,” Knowledge-Based Expert Systems for Manufacturing, ASME, Dec., pp. 85–96.
27.
Mertaugh, L. J., 1986, “Evaluation of Vibration Analysis Techniques for Detection of Gear and Bearing Faults in Helicopter Gearboxes,” Proc. of Mechanical Failure Prevention Group 41th Meeting, Oct., pp. 28–30.
28.
Milne
R.
,
1987
, “
Strategies for Diagnosis
,”
IEEE Transactions On Systems, Man, and Cybernetics
, Vol.
17
, No.
2
, May/June, pp.
333
339
.
29.
Mitchell
L. D.
, and
Davis
J. W.
,
1985
, “
Proposed Solution Methodology for the Dynamically Coupled, Nonlinear Geared Rotor Mechanics Equations
,”
ASME Journal of Vibration, Acoustics, Stress, and Reliability in Design
, Vol.
107
, Jan., pp.
112
116
.
30.
Pau
L. F.
,
1986
, “
Survey of Expert Systems for Fault Detection, Test Generation and Maintenance
,”
Expert Systems
, Vol.
3
, No.
2
, pp.
100
111
.
31.
Pratt, J. L., 1986, “Engine and Transmission Monitoring—A Summary of Promising Approaches,” Proc. of Mechanical Failure Prevention Group 41th Meeting, Oct., pp. 229–236.
32.
Rebbechi, B., Oswald, F. B., and Townsend, D. P., 1991, Dynamic Measurements of Gear Tooth Friction and Load, NASA Tech. Memorandum 103281, TR-90-C-0023, Lewis Research Center, Cleveland, Ohio.
33.
Reiter
R.
,
1987
, “
A Theory of Diagnosis from First Principles
,”
Artificial Intelligence
, Vol.
32
, pp.
57
95
.
34.
Scarl
E. A.
,
Jamieson
J. R.
, and
Delaune
C. I.
,
1987
, “
Diagnosis and Sensor Validation through Knowledge of Structure and Function
,”
IEEE Transactions On Systems, Man, and Cybernetics
, Vol.
SMC-17
, No.
3
, May/June, pp.
360
368
.
35.
Smith, J. D., 1983, Gears and their Vibrations, Marcel Dekker, The Macmillan Press Ltd., Newyork, NY.
36.
Stewart Hughes Ltd., 1986, MSDA User’s Guide, Technical Report, Southampton, UK.
37.
Walford
T. L. H.
, and
Stone
B. J.
,
1983
, “
The Sources of Damping in Rolling Element Bearings Under Oscillating Conditions
,”
Proc. of the Institute of Mechanical Engineers
, Vol.
197c
, Dec, pp.
225
232
.
38.
Yamada, N., and Motoda, H., 1983, “A Diagnosis Method of Dynamic System Using the Knowledge on System Description,” Proc. of 8th International Joint Conference of Artificial Intelligence Applications, AAAI-1, pp. 225–229.
39.
Yaram, T., and Rosenberg, R. C., 1990, “Catastrophic Fault Diagnosis in Dynamic Systems Using Bond Graph Methods,” ASME Winter Annual Meeting, Dallas, Texas, 25th-30th, Nov.
40.
Zadeh
L. A.
,
1975
, “
The Concept of a Linguistic Variable and Its Application to Approximate Reasoning-1
,”
Information Sciences
, Vol.
8
, pp.
199
249
.
41.
Zakrajsek, J. J., Handschuh, R. F., Lewicki, D. G., and Decker, H. J., 1995, “Detecting Gear Tooth Fracture in a High Contact Ratio Face Gear Mesh,” Proc. of 49th Meeting of the Society of Machinery Failure Prevention Technology, VA, April, pp. 91–102.
This content is only available via PDF.
You do not currently have access to this content.