An indirect method for rail corrugation measurement based on numerical models and wavelet packet decomposition

Abstract

Estimation of corrugation amplitude is an important but difficult point for indirect methods, to advance related research, an indirect method based on wavelet packet decomposition (WPD) and energy level of wheel-rail noise is developed. For this purpose, firstly, numerical models are proposed to calculate wheel-rail noise under various corrugation statuses. Next, the WPD is conducted on wheel-rail noise, the energy levels of relevant nodes are used as evaluation indicators for corrugation amplitude. With this treatment, the amplitude of corrugation with diverse wavelengths can be evaluated. Then, by using numerical fitting and the Kriging interpolation model, nonlinear mapping from corrugation amplitude to energy level is established. Finally, the proposed method is verified by direct measurement, the estimated amplitudes have an average error of 10.5 % compared with the directly measured results. Therefore, the proposed indirect method has great potential for practical engineering, since it has encouraging results in the first attempt.