Track geometry estimation of a conventional railway from car-body acceleration measurement

Abstract

This study proposes a track condition monitoring technique using car-body acceleration that can be easily measured by an in-service vehicle for the sake of an increase in safety of railway transportation. This paper demonstrates the possibility of estimating track irregularities of conventional railway tracks using car-body acceleration only. The methodology proposed uses inverse dynamics to estimate track irregularity from car-body acceleration, applying a Kalman filter to solve this problem. This technique estimates the track irregularity in the longitudinal plane (track geometry and 10m-chord versine). The Kalman filter is able to apply to inverse analysis by expressing track geometry as a random walk model, and incorporating the model in an equation of state. The estimation technique can support a change of the vehicle velocity by selecting an appropriate impulse response in the measurement equation for the vehicle velocity. Estimation results in simulation and full scale tests revealed that the proposed estimation technique is effective for track condition monitoring with acceptable accuracy for conventional railways.