Multi-wavelength vertical track irregularity evaluation based on vehicle response

The safety of high-speed train operations is a critical issue in railway transportation. The wheel–rail relationship is the connection between vehicles and tracks, and its condition determines the safety of high-speed railways. This article conducts an analysis of the characteristics of vehicle response data and the response characteristics caused by short, medium and long wavelength irregularities in the track. Utilising the comprehensive inspection train’s detection of the entire section’s dynamic response, a multi-wavelength irregularity evaluation method is proposed. This involves the use of axle box acceleration (ABA), bogie frame acceleration (BFA) and car body acceleration (CBA). The response characteristics of ABA, BFA and CBA at different running speeds, along with the sensitive frequency components at different speeds, are analysed. It is proposed to use the integrated ABA to obtain the vertical track displacement and combine this with the root mean square of acceleration after bandpass filtering to diagnose track irregularities. Envelope analysis is performed on the vertical displacement after bandpass filtering. Subsequently, peak extraction is conducted to identify the positions of track slabs, base plates and simply supported girder bridges. For changes occurring in a short period, the proposed method can serve as an auxiliary tool in evaluating the track status.