Variable frequency train detection

摘要

A method and device capable of reliable and accurate train prediction determinations that account for, and overcome the problems associated with, changing ballast conditions. The method and device will detect the presence of a train in an approach area based on a rail characteristic measured in relation to a first measurement frequency transmitted along the rails. If there is a condition such as a ballast condition that may affect the rail characteristic, the method and device will detect the distance and speed of the train based on a rail characteristic measured in relation to a second measurement frequency transmitted along the rails. Otherwise, the distance and speed of the train will be determined based on the rail characteristic measured in relation to the first measurement frequency.

主权项

1. A method of detecting the presence of a train on a railroad track, said method comprising:
transmitting a first signal having a first frequency along rails of the railroad track; determining if the train is in an approach area based on a characteristic of the rails measured in relation to the first frequency; in response to determining that a train is in the approach area, determining if there is a condition that could alter the characteristic of the rails, and if it is determined that there is a condition that could alter the characteristic of the rails, transmitting a second signal having a second frequency along rails of the railroad track, and detecting the presence of the train based on the characteristic of the rails measured in relation to the second frequency.