Transactions of the Korean Society for Noise and Vibration Engineering (한국소음진동공학회논문집)

The Korean Society for Noise and Vibration Engineering (한국소음진동공학회)
권호 표지
DOI QR코드

DOI QR Code

Comparison of Window Functions for the Estimation of Leak Location for Underground Plastic Pipes

지하매설 플라스틱 배관의 누수지점 추정을 위한 창함수 비교 연구

  • 이영섭 (인천대학교 임베디드시스템공학과)
  • Received : 2010.04.12
  • Accepted : 2010.05.04
  • Published : 2010.06.20
Download PDF
⟨ Previous Next ⟩

Abstract

It is widely known that the leak locating of underground plastic pipelines is much more difficult than that of cast iron pipelines. The precision of the leak locating depends upon the speed of leak signal and the time delay estimation between the two sensors on the pipeline. In this paper, six different windowing filters are considered to improve the time delay estimation especially for the plastic pipelines. The time delay is usually estimated from the peak time of cross-correlation functions. The filtering windows including rectangle, Roth, Wiener, SCOT, PHAT and maximum likelihood are applied to derive the generalized cross-correlation function and compared each other. Experimental results for the actual plastic underground water supply pipeline show that the introduction of the filtering windows improved the precision of time delay estimation. Some window functions provide excellent leak locating capability for the plastic pipe of 98 m long, which is less than 1 % of the pipe lengths. Also a new probabilistic approach that the combinations of all results from each filtering window is suggested for the better leak locating.

Keywords

References

  1. Fuchs, H. V. and Riehle, R., 1991, “Ten Years of Experience with Leak Detection by Acoustic Signal Analysis,” Applied Acoustics, Vol. 33, pp. 1-19. https://doi.org/10.1016/0003-682X(91)90062-J
  2. Lee, Y.-S. and Yoon, D.-J., 2004, “Pinpointing of Leakage Location Using Pipe-fluid Coupled Vibration,” Transactions of the Korean Society for Noise and Vibration Engineering, Vol. 14, No. 2, pp. 95-104. https://doi.org/10.5050/KSNVN.2004.14.2.095
  3. Hunaidi, O. and Chu, W. T., 1999, “Acoustical Characteristics of Leak Signals in Plastic Water Distribution Pipes,” Applied Acoustics, Vol. 58, No. 234-254.
  4. Palmer Environmental, MicroCorr, Palmer Environmental Services.
  5. Knapp, C. H. and Carter, G. C., 1976, “The Generalized Correlation Method for the Estimation of Time-delay,” IEEE ASSP, Vol. 24, No. 4, pp. 320-327.
  6. Roth, P. R., 1971, “Effective Measurements Using Digital Signal Analysis,” IEEE Spectrum, Vol. 8, pp. 62-72.
  7. Hero, A. O. and Schwartz, S. C., “A New Generalized Cross Correlator,” IEEE ASSP, Vol. 33, No. 1, pp. 38-45.
  8. Carter, G. C., Nuttall, A. H. and Cable, P. G., “The Smoothed Coherence Transform,” Proceedings of the IEEE, 61, pp. 1497-1498. https://doi.org/10.1109/PROC.1973.9300
  9. Brandstein, M. S., Silverman, H. F., 1997, “A Robust Method for Speech Signal Time-delay Estimation in Reverberant Rooms,” IEEE Conference ICASSP-97, pp. 375-378.
  10. Hannan, E. J., Thomson, P. J., 1973, “Eliminating Group Delay,” Biometrika, 60, pp. 241-253. https://doi.org/10.1093/biomet/60.2.241
  11. Bendat J. S. and Piersol A. G., 1991, Random Data, John Wiley & Sons.