Method and system for locating end of train units

Abstract

An EOT unit periodically reports its position to an EOT unit tracking station using wireless communication. The location message preferably includes an EOT identifier and a time associated with the position. Optionally, the EOT units are configured to periodically reawaken from a low power state (which may be entered when the EOT units are tipped over while installed on a train or laid on their sides along a wayside or elsewhere) in order to transmit the location message. Optionally, the EOT unit includes a cellular modem and periodically transmits the location message using a cellular network. Optionally, the EOT units are equipped with transceivers and have the ability to receive a query message and transmit a location message in response, and further have the ability to receive a disable message and respond by entering a “no service” state until a special command is entered.

1 . An end of train unit suitable for use on a train, the end of train unit comprising: 
 a processor;    an end of train marker light connected to be turned on and off under the control of the processor;    a first wireless transceiver connected to the processor;    a second wireless transceiver connected to the processor, the second wireless transceiver being configured to communicate with a device located at a head of the train; and    a positioning system connected to the processor;    wherein the processor is configured to periodically perform the steps of 
 obtaining a location of the end of train unit from the positioning system; and  
 sending a message via the first wireless transceiver to a device located off of the train, the message comprising an identifier associated with the end of train unit and location information pertaining to the end of train unit.  
   
     
     
         2 . The end of train unit of  claim 1 , wherein the message further comprises a time corresponding to the location information.  
     
     
         3 . The end of train unit of  claim 1 , wherein the processor is further configured to enter a low power state upon detecting a condition indicating that it is not necessary for the end of train unit to continue normal operation, and wherein the processor is further configured to perform the obtaining and sending steps during the condition.  
     
     
         4 . The end of train unit of  claim 3 , further comprising a tilt sensor connected to the processor, wherein the condition is an indication from the tilt sensor that the end of train unit is not in a vertical orientation.  
     
     
         5 . The end of train unit of  claim 3 , further comprising a pressure transducer connected to the processor, the pressure transducer being configured to measure an air pressure in an air brake pipe of the train, wherein the condition is an indication from the pressure transducer that an air pressure in the air brake pipe is below a threshold.  
     
     
         6 . The end of train unit of  claim 1 , further comprising an air powered generator connected to supply at least some power to the processor, the air powered generator being configured to generate electrical power when in fluid communication with a pressurized air supply from an air brake pipe of the train.  
     
     
         7 . The end of train unit of  claim 1 , wherein the processor is further configured to receive a query message and transmit a message including the identifier and a location of the end of train unit in response.  
     
     
         8 . The end of train unit of  claim 1 , wherein the processor is further configured to receive a disable message and suspend normal operations until an enable command is received.  
     
     
         9 . The end of train unit of  claim 1 , wherein the first wireless transceiver comprises a cellular modem.  
     
     
         10 . A method for displaying a location of at least one end of train unit to the user comprising the steps of: 
 receiving a message from the end of train unit, the message comprising a location of the end of train unit and an identifier of the end of train unit;    storing the location and the identifier;    receiving a query from a user; and    displaying the location and the identifier to the user in response to the query.    
     
     
         11 . The method of  claim 10 , further comprising the steps of accepting a designation of an end of train unit identifier and a ping command from a user and transmitting a query message including the identifier in response to the ping command.  
     
     
         12 . The method of  claim 10 , further comprising the steps of accepting a designation of an end of train unit identifier and a disable command from a user and transmitting a disable message including the identifier in response to the disable command.  
     
     
         13 . A method for operating an end of train unit on a train comprising the steps of: 
 periodically obtaining a location of the end of train unit from a positioning system; and    periodically transmitting a message via a wireless transceiver to a device located off of the train, the message including the location and an identifier of the end of train unit.    
     
     
         14 . The method of  claim 13 , further comprising the steps of: 
 detecting a condition indicating that normal operation of the end of train unit is not necessary; and    entering a low power state upon detection of the condition;    wherein the periodically obtaining and periodically transmitting steps are performed both during normal operation and during periods in which the condition is detected.    
     
     
         15 . The method of  claim 13 , further comprising the steps of: 
 receiving a query message; and    transmitting a message including a position of the end of train unit and an identifier of the end of train unit in response to the query message.    
     
     
         16 . The method of  claim 13 , further comprising the steps of: 
 receiving a disable message; and    halting normal operations in response to the disable message.