Sensors (Mar 2023)

Squat Detection of Railway Switches and Crossings Using Point Machine Vibration Measurements

  • Yang Zuo,
  • Jan Lundberg,
  • Taoufik Najeh,
  • Matti Rantatalo,
  • Johan Odelius

DOI
https://doi.org/10.3390/s23073666
Journal volume & issue
Vol. 23, no. 7
p. 3666

Abstract

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Railway switches and crossings (S&C) are among the most important high-value components in a railway network and a failure of such an asset could result in severe network disturbance. Therefore, potential defects need to be detected at an early stage to prevent traffic-disturbing downtime or even severe accidents. A squat is a common defect of S&Cs that has to be monitored and repaired to reduce such risks. In this study, a testbed including a full-scale S&C and a bogie wagon was developed. Vibrations were measured for different squat sizes by an accelerometer mounted at the point machine. A method of processing the vibration data and the speed data is proposed to investigate the possibility of detecting and quantifying the severity of a squat. One key technology used is wavelet denoising. The study shows that it is possible to monitor the development of the squat size on the rail up to around 13 m from the point machine. The relationships between the normalised peak-to-peak amplitude of the vibration signal and the squat depth were also estimated.

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