ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The railway contact wire, which supplies electric railways with electric power, plays animportant role in determining the maximum railway velocity. In general, the maximum allowablevelocity of an electric railway is less than seventy percent of the wave propagation velocity of thecontact wire. Because the contact wire is more a beam model with dispersive wave characteristicsthan a string model, the wave propagation velocity depends on the frequency. For this reason, therehave been only few studies on the wave propagation of the contact wire. In this paper, we proposedtwo useful methods for estimating the wave propagation velocity of the railway contact wire by usingthe Gabor wavelet transform on the experimental signals. In the first method, the ridges of wavelettransform, which contain the essential information about dispersive characteristics, are used.Specifically, the wave propagation velocity of the contact wire can be extracted from the timedifference of the wavelet ridges of the measured signals. In the second method, the cross-correlationanalysis of each wavelet transform is used to extract the wave propagation. The selection of theoptimal Gabor shaping factor for the best time-frequency localization by using the Shannon entropycost function is also discussed.[removed info]
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.321-323.1609.pdf
Permalink