Abstract:
An apparatus that enables a train or trailer vehicle to communicate with other vehicles in the same train without using vehicle identifiers other than the relative positions of the two vehicles within the train. It uses short-range communication methodologies to communicate signals between a vehicle and the adjacent vehicle. Vehicles in the same train that are not adjacent intercommunicate via relay.

Description:
BACKGROUND OF THE INVENTION 
     A train, or any string of vehicles with one or more coupled trailers, usually requires communication between the coupled vehicles. The communication may consist of commands and status report. 
     Examples of commands include instructions to turn on or turn off lights, brakes or refrigeration units, instructions to operate an automated uncoupling mechanism between two of the vehicles, and requests for the recipient to send a status report. 
     Examples of a status report include the current temperature, the identification of the next scheduled stop, and whether or not a light bulb is burnt out. 
     Existing methods of conveying communication include electrical signals sent over wires, changes in air pressure in air hoses, and radio signals between transmitter and receiver. 
     There are situations where it is infeasible or undesirable to physically connect communication wires or hoses, so radio is often used. However, it is difficult to target radio signals to a specific vehicle in the train, if it is farther away than the vehicle adjacent to the sender, without interception by other vehicles in the same or any other train, so such communication usually requires the use of an addressing or other identification technique. 
     There is a need to provide for communication between vehicles in a train that requires neither of the direct connection of wires or hoses between the vehicles nor the addressing of radio communication. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention comprises multiple instances of an Apparatus, one per vehicle of a train, that relay Messages to each other using short-range Transmitters and Receivers. Each interfaces with appliances and sensors in the various vehicles of a train and passes command and report messages between them. 
     Communication to a non-adjacent vehicle in the same train is effected by first transmitting the message to the adjacent vehicle, with an annotation that the communication must be relayed further down the train. The Apparatus in the adjacent vehicle forwards the communication to another instance of the Apparatus in the next-adjacent vehicle. The intended recipient is thereby identified by its position in the train relative to the originator. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1 . The Relay Method showing 3 vehicles in a train with instances of the Apparatus, Transmitters, Receivers and connected devices. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Vehicles are considered to form a train if they are coupled together or if they are adjacent to each other in positions similar to where they would be if they were coupled, about to be coupled, or recently uncoupled from each other. In  FIG. 1 , Vehicle  1 , Vehicle  2  and Vehicle  3  form a train. Vehicle  1  is adjacent to Vehicle  2 , Vehicle  2  is adjacent to Vehicle  3 , but Vehicle  1  is not adjacent to Vehicle  3 . 
     In  FIG. 1 , items  11 ,  21  and  31  are instances of the Apparatus. Apparatus  11  is connected to devices  15  and  16 , Apparatus  21  is connected to devices  25  and  26  and Apparatus  31  is connected to device  35 . Each vehicle may contain zero or more devices. 
     Instances of the Apparatus intercommunicate using Messages which may originate from a device that is connected to the originating Apparatus or the Apparatus itself. Similarly, the destination may be an Apparatus or a device that is connected to the destination Apparatus. In addition to the content that an Apparatus wishes to send to another Apparatus, a Message contains a Destination Relay Counter value. The Destination Relay Counter value specifies the number of relays to be performed before the receiving Apparatus concludes that the Message is intended for it or one of the devices connected to it. 
     Refer to  FIG. 1 . If Apparatus  11  in Vehicle  1  wishes to send a Message to Apparatus  21  in Vehicle  2 , i.e. the adjacent vehicle, Apparatus  11  initializes the Message&#39;s Destination Relay Counter value to a Terminal Value, e.g. 0 and passes the Message to Transmitter  12 , which is mounted on or near the end of Vehicle. Transmitter  12  then sends ( 10 ) the message toward Receiver  23 , which passes it to Apparatus  21 . Apparatus  21  notices that the Message&#39;s Destination Relay Counter value equals the Terminal Value, and deduces that the Message was targeted to it or one of the devices connected to it. 
     If the Message is instead meant to be sent to a vehicle that is not the adjacent vehicle, the Message&#39;s Destination Relay Counter value is initialized to values other than the Terminal Value. If Apparatus  11  in Vehicle  1  wishes to send a Message to Apparatus  31  in Vehicle  3 , Apparatus  11  initializes the Message&#39;s Destination Relay Counter value to the number of relays, in this case  1 , which must be performed before the Message reaches its intended target. When Apparatus  21  receives the Message it notices that the Message&#39;s Destination Relay Counter value does not equal the Terminal Value, and decrements it or otherwise adjusts it so that it becomes closer to the Terminal Value. Apparatus  21  then relays ( 20 ) the so-modified Message to Apparatus  31  via Transmitter  22  and Receiver  33 . Apparatus  31  notices that the Message&#39;s Destination Relay Counter value equals the Terminal Value and deduces that the Message was targeted to it or one of the devices connected to it. 
     Through the use of the appropriate Destination Relay Counter value, it is possible to convey Messages to any specific vehicle in the train. To determine the Destination Relay Counter value to use for any particular destination vehicle, the originating Apparatus counts the number of relays from the adjacent vehicle needed before the Message reaches the targeted vehicle. It is important to note that any methodology may be used as a counting scheme for the Relay Counters, as long as there is a knowable and predictable sequence to it. 
     In some embodiments, bi-directional communication is implemented by connecting two Transmitters and two Receivers to each Apparatus, one of each at each end of the vehicle. 
     This invention applies to both real-world vehicles and models. 
     In an embodiment of the present invention, a train communication system includes a train provided with at least three or more railcars connected to each other, wherein a first end one of said railcars includes a transmitter in communication with a plurality of controllers, an intermediate one of said railcars includes a receiver in communication with a plurality of controllers and with a transmitter, and a second end one of said railcars includes a receiver in communication with a plurality of controllers. Each of the controllers of said first end railcar is configured to present a message to the transmitter of the same car for transmitting to the receiver of an adjacent intermediate one of the railcars. The message contains a destination relay counter, and a controller information section, wherein the destination relay counter has a value that corresponds to the number of adjacent railcars predetermined to receive the message in a sequential order and is configured to be decreased by one when the message is transmitted and received by an adjacent one of the railcars. The receiver of one of the railcars receiving the message is configured to continue sending the message to an adjacent one of the railcars when the destination relay counter is not reduced to a terminal value, and to stop sending the message to another adjacent one of the railcars when the destination relay counter is reduced to a terminal value.