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Instantaneous Angular Speed: Encoder-Counter Estimation Compared with Vibration Data

Conference paper
Part of the Lecture Notes in Mechanical Engineering book series (LNME)

Abstract

In rotating machinery, actions of the moving parts take place at specific angular positions rather than at specific times. For this reason, having a geometrical reference, such as the one provided by an encoder, and studying the Instantaneous Angular Speed (IAS) variations can provide a large amount of information about the health status of the machine. In fact, from the variation of the IAS during the machine loads’ cycle it is possible to identify defects and faults. The current work focuses on the estimation of the IAS through the Elapsed Time (ET) method, using a counter in order to measure the time elapsed between the pulses of an encoder. Both IAS and vibration measurement are conducted on an asynchronous four poles electrical motor driven by 50 Hz line current, without load. The study compares the order analysis of both signals. The bearing’s Fundamental Train Frequency is detected using IAS estimation.

Keywords

Instantaneous angular speed Encoder Elapsed time method AC DC electrical machine Slip effect 

Notes

Acknowledgments

This research is supported by Università degli Studi di Trieste, Nidec ASI S.p.A. and "Programma Operativo del Fondo Sociale Europeo 2007/2013 della Regione Autonoma Friuli Venezia Giulia".

References

  1. 1.
    Li Y, Gu F, Harris G, Ball AD, Bennett N, Travis K (2005) The measurement of instantaneous angular speed. Mech Syst Signal Process 19(4):786–805CrossRefGoogle Scholar
  2. 2.
    André H, Bourdon A, Antoni J, Remond D (2012) Precision of the IAS monitoring system based on the elapsed time method in the spectral domain. In: Proceedings of the international conference on noise and vibration engineering ISMA 2012, Belgium, pp 1126–1142Google Scholar
  3. 3.
    Renaudin L, Bonnardot F, Musy O, Doray JB, Remond D (2010) Natural roller bearing fault detection by angular measurement of true instantaneous angular speed. Mech Syst Signal Process 24(7):1998–2011CrossRefGoogle Scholar
  4. 4.
    Youssef W, Guillet F, Elbadaoui M (2011) Characterization of counter technique for instantaneous angular speed measurement: Application on gear box signal. In: Proceedings of the ICS6, Université Technologique de Compiègne, FranceGoogle Scholar
  5. 5.
    National Instruments (2013) Frequency measurements: how-to guide. Tutorial, 7111Google Scholar
  6. 6.
    Spagnol M, Bregant L, Boscarol A (2013) Instantaneous angular speed: comparisons between torsional laser vibrometer and encoder-counter estimations. In: Proceedings of COMADEM 2013Google Scholar
  7. 7.
    Resor BR, Trethewey MMW, Maynard. KPK (2005) Compensation for encoder geometry and shaft speed variation in time interval torsional vibration measurement. J Sound Vib 286(4–5):897–920CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Università degli Studi di TriesteTriesteItaly

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