Identification of Track Irregularity using Wavelet Transfer Function

웨이브렛 전달함수를 이용한 궤도틀림 식별

  • 신수봉 (인하대학교 대학원) ;
  • 이형진 (창원대학교 대학원) ;
  • 김만철 (한국철도기술연구원 차륜궤도연구실) ;
  • 윤석준 (인하대학교 대학원 토목공학과)
  • Received : 2010.02.10
  • Accepted : 2010.05.31
  • Published : 2010.06.26

Abstract

This paper presents a methodology for identifying track irregularity using a wavelet transfer function. An equivalent wavelet SISO (single-input single-output) transfer function is defined by the measured track geometry and the acceleration data measured at a bogie of a train. All the measured data with various sampling frequencies were rearranged according to the constant 25cm reference recording distance of the track recording vehicle used in the field. Before applying the wavelet transform, measured data were regressed by eliminating those out of the range. The inverse wavelet transfer function is also formulated to estimate track geometry. The closeness of the estimated track geometry to the actual one is evaluated by the coherence function and also by FRF (frequency response function). A track irregularity index is defined by comparing the variance of the estimation error from the intact condition and that from the current condition. A simulation study has been carried out to examine the proposed algorithm.

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