Vehicle Gearbox Fault Diagnosis Based On Cepstrum Analysis

Research on damage of gears and gear pairs using
vibration signals remains very attractive, because vibration signals
from a gear pair are complex in nature and not easy to interpret.
Predicting gear pair defects by analyzing changes in vibration signal
of gears pairs in operation is a very reliable method. Therefore, a
suitable vibration signal processing technique is necessary to extract
defect information generally obscured by the noise from dynamic
factors of other gear pairs.This article presents the value of cepstrum
analysis in vehicle gearbox fault diagnosis. Cepstrum represents the
overall power content of a whole family of harmonics and sidebands
when more than one family of sidebands is present at the same time.
The concept for the measurement and analysis involved in using the
technique are briefly outlined. Cepstrum analysis is used for detection
of an artificial pitting defect in a vehicle gearbox loaded with
different speeds and torques. The test stand is equipped with three
dynamometers; the input dynamometer serves asthe internal
combustion engine, the output dynamometers introduce the load on
the flanges of the output joint shafts. The pitting defect is
manufactured on the tooth side of a gear of the fifth speed on the
secondary shaft. Also, a method for fault diagnosis of gear faults is
presented based on order Cepstrum. The procedure is illustrated with
the experimental vibration data of the vehicle gearbox. The results
show the effectiveness of Cepstrum analysis in detection and
diagnosis of the gear condition.

• Mohamed El Morsy
• Gabriela Achtenová

• Cepstrum analysis
• fault diagnosis
• gearbox.

[1] Norton, M.P., "Fundamentals of vibration and noise analysis for
engineers" Chap.8, 2005.
[2] Hans Konstantin-Hansen and HenrikHerlufsen, "Envelope and Cepstrum
Analyses for Machinery Fault Identification", SOUND & VIBRATION,
Brüel and Kjaer, N وrum, Denmark, pp. 10-12 MAY 2010.
[3] Xinyan Zhang et al. "Summarization and Study of Fault Diagnosis
Technology of the Main Components of Wind Turbine Generator
System", ICSET, IEEE, pp. 1223-1226, 2008.
[4] Childers, D.G., Skinner, D.P. &Kemerait, R.C., "The Cepstrum: A
Guide to Processing". IEEE Proc. Vol. 65, No. 10, pp. 1428-1443,
October 1977.
[5] R. B. Randall and J. Hee1981 Brüel el &Kjaer technical Review No. 3,
3}40. Cepstrum analysis.
[6] B.D. Forrester, "Advanced Vibration Analysis Techniques for Fault
Detection and Diagnosis in Geared Transmission Systems", Ph.D.
Thesis, Swinburne University of Technology, Australia, 1996.