Crossing predictor with authorized track speed input
AssigneeSafetran Systems Corporation
InventorsRandy M. O'Dell, Patrick J. Venneman
Life of this patent
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Abstract
A method and apparatus for controlling a grade crossing warning system employs a track occupancy circuit or other device to detect the presence of a train in the approach to a grade crossing and an indirect indication of a maximum authorized speed of the train in order to determine an amount of time to delay activation of the grade crossing warning system after the train has been detected. The indirect indication is preferably encoded onto a signal associated with the track occupancy circuit, preferably using a frequency shift technique. The indirect indication may be supplied by a wayside signal device.
Claims18
A method for controlling a grade crossing warning system comprising:
- inputting by a control unit an indication of a time-varying maximum allowable speed of a train in an approach to a grade crossing;
- determining by the control unit a delay period using the indication;
- detecting the presence of a train in the approach by the control unit using a first track occupancy circuit;
- activating by the control unit a grade crossing warning system in response to the train being detected and the delay period expiring.
A system for controlling a grade crossing warning device, the system comprising:
- a control unit having an input for inputting an indication of a time-varying maximum allowable speed of a train in the approach;
- a first track occupancy circuit connected to the control unit, the first track occupancy circuit being configured to detect a presence of a train in an approach to a grade crossing;
- wherein the control unit
- inputs an indication of a time-varying maximum authorized speed of a train in the approach;
- determines a delay period using the indication;
- receives a first track occupancy signal from the first track occupancy circuit indicating the presence of a train in the approach:
- and
- activates a grade crossing warning system in response to the first track occupancy signal and an expiration of the delay period.
Dependencies are inferred from the claim text.