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Plenary Lecture
From Linear to Non-Linear Signal
Processing Applied to Mechanical Fault Detection
Professor Vincenzo Niola
Department of Mechanical Engineering for Energetics,
University of Naples Federico II,
Via Claudio 21, 80125 Naples,
ITALY
Email:
vincenzo.niola@unina.it
Web Page:
http://niola.dime.unina.it
Abstract: The early detection of failures in mechanical systems is an
important industrial problem which has still to be addressed from both an
experimental and theoretical viewpoint.
The detection of the modulating signal is traditionally realised through
identification of sidebands in the frequency domain. The short-time Fourier
transform is probably the most widely used time-frequency representation.
Recently, interest in the use of wavelet transforms for processing
non-stationary signals has grown.
The wavelet transforms possess fine time resolution in the high frequency
ranges and excellent frequency resolution in low frequency region. However,
it is not easy do identify impulsive vibration especially when the SNR of
the detected signal is low. In fact, in this condition, the extraction of
impulsive features in vibration signals is vital for diagnosing such
machines as engines, rolling bearings, gearboxes, etc.
In the last decade, distinguishing deterministic chaos from noise has became
an important problem.
For this reason, new methods have been developed for quantifying chaos. In
particular, methods exist for calculating dimension, Kolmogorov entropy and
Lyapunov exponents.
However, in certain cases it is important to distinguish deterministic data
from truly random signals. In many cases, the multiresolution analysis,
using specific decomposition levels, yields a good separation of sub-bands
which are subjected to subsequent chaos analysis.
Specific applications are also presented in order to further evaluate the
performance, the effectiveness and the robustness of the main algorithms.
Brief Biography of the Speaker:
Vincenzo Niola is professor of Applied Mechanics at Naples University
Federico II since 31 march 1987. After he got an Univerisity Degree in
Mechanical Engineering, he started in january 1978 didactics activity as
helper at course of Applied Mechanics and Machines et as member of their
committee of examination. Since september 1979 he carried on that
collaboration as owner of a scholarship from C.N.R. (National Research
Council). Since december 1981 to march 1987 he was a researcher carrying on
the practice course for Applied Mechanics, taking a part at examination
meeting and working as proposer in many degree thesis. Since 1981 to 1984 he
carried on his didactics activity as university teacher for Bioengineering
course of locomotive apparatus at Orthopaedy and Traumathology
specialization school of 2th Department of Medicine and Surgery of Naples
University. Since 31 March 1987 is professor of Applied Mechanics at Naples
University Federico II, and since A.A. 86/87 to A.A. 92/93 he carried on the
Applied Mechanics and Machines course for electronic engineers, and since
A.A. 93/94 to today carry on the Applied Mechanics course for computer
science engineers. Since A.A. 88/89 to 89/90 he carried on as supply teacher
the Applied Mechanics course for building engineers at Salerno Engineering
University. By A.A. 94/95 to A.A. 97/98 he carried on as supply professor
Tribology course at Naples University Federico II. By A.A. 2001/2002 he
holds the chair of Applied Mechanics for University Degree of “Orthopaedic
Technician” at 2th Department of Medicine and Surgery of Naples University.
Since A.A. 2005/2006 is professor of Tribology and of Complements of
Mechanics. During this years Prof. Vincenzo Niola has been the chairman of
his courses examination meetings, and was proposer of many degree thesis..
During his activity Prof. Vincenzo Niola was owner of financings from MURST
and (in past and present) cooperate scientifically with research corporation
and national industries (MERISINTER, MONTEFLUOS, INDESIT, ALENIA, C.I.R.A.).
He's scientific member of Naples research unit for PRIN 2003. He's fellow of
Italian Association of Theoretical and Applied Mechanics (AIMETA). He's
member of IFToMM Linkages on cams committee. He belongs to the International
Scientific Committee of the "World Scientific and Engineering Academy and
Society (WSEAS). He is President of the WSEAS Italy Chapter on the “Analysis
of the Mechanical Systems”. He was been Chairman and "invited author" in
some session of Internatinal Conferences. He's author of more than 130
national and international papers. Is author of two chapters in the
international books. In the past he focused his research activity on :
• Applied Mechanics
• Tribology
• Robot dynamics
• Funicular Railways
• Static and dynamic behaviour of rotors on lubricated journal bearings
• Industrial robot calibration
• Analysis of Mechanical systems by means Wavelet Transform.
The Prof. Niola is member of the “Editorial Board” of two International
Journals. He is also Editor-in-Chief of a International Journal.
During these years he has also been speaker of a lot of invited plenary
lectures in the International Conferences.
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