Using the Ferromagnetic Fingerprint of Rails for Velocity Estimation and absolute Localization of Railway Vehicles

This paper describes the difference inductance sensor that provides position, velocity, and acceleration of railway vehicles based on an analysis of the ferromagnetic fingerprint of the rail. We describe the algorithms for velocity estimation based on a correlation principle, for acceleration estimation based on a warping principle, and for position estimation based on a comparison of ferromagnetic signatures with a digital map. The empirical results exhibit high accuracy and high availability of the estimates.