VEHICLE PRESENCE DETECTION SYSTEM

摘要

A passive magnetic detector (10) is provided at or below ground level in between rails of a railroad track at a distance from a level crossing (103) for detecting magnetic field disturbances caused by ferromagnetic objects passing overhead on the track. Magnetic field reversals are detected in the passive detector signal. The reversal signal is analyzed and a train presence output signal is generated for controlling the level crossing gate system. At the crossing, static magnetic field detectors (12) are used to ensure that no equipment remains on the island after detecting that the moving train has left the crossing (103).