Train Approach Detection System Based on Track Impedance Measurements

The paper presents the principle used in the development of a device for measuring the distance of a train from a level crossing, which is based on the measured impedance of the track circuit shorted by a train axle i.e. based on the measurements of the real parameters of a track circuit. A hardware simulation model of the track circuit was built and used during the development of the measurement device. This paper concludes by presenting the results of a pilot operation of the measuring device on a real track and shows the measured impedance and phase waveforms obtained when a train passes a level crossing.