Patent Description:
A traditional an end-of-train (EOT) device is an electronic device mounted on the last railway car of a train that can monitor and provide information, such as brake system status, to a head-end-unit (HEU) at the front of the train. Conventional EOT devices are powered by batteries that must be sufficiently charged at train departure and during a route. As a result, both the EOT devices and the batteries are subject to incorrect installation and equipment failure, thereby increasing maintenance costs, disrupting the operation of the train, and causing schedule delays. As a result, there is a need in the art for a system that can provide EOT functionality without the need for a dedicated EOT device, thereby reducing maintenance costs and the risk of delays due to EOT device problems.

<CIT> discloses a multifunctional end-of-train device using an arming switch for indicating that a railway car is positioned at the end of train, without however identifying the orientation of the concerned railway car. <CIT> discloses another similar train car identification system.

The present invention suggests the end-of-train system defined in Claim <NUM> and the method of providing end-of-train functions defined in Claim <NUM>. Further advantageous features are set out in the dependent claims.

The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:.

Referring to the figures, wherein like numerals refer to like parts throughout, there in seen in <FIG> an end-of-train (EOT) system <NUM> that is implemented in connection with an electronically controlled pneumatic (ECP) railway car <NUM> that can be configured to act in an EOT device mode. ECP car <NUM> is associated with a selection device <NUM> that can be used to manually select EOT device mode for ECP car <NUM>. More specifically, the selection of EOT functions using selection device <NUM> is detected by an input/output (I/O) end-of-train module <NUM> that is in communication with the car control device (CCD) <NUM> of ECP car <NUM> and railcar specific identification module (IDM) <NUM>. I/O module is programmed to implement EOT device mode according to the present invention by establishing the transmission of EOT status messages (referred to as EOT beacons) from ECP car <NUM> to the Head End Unit (HEU) of the train as well as the isolation of whichever of "A" end intercar ECP trainline communication network (ECP T/L) connector <NUM> or "B" end intercar ECP trainline connector <NUM> is positioned at the end of the train.

When I/O module detects initiation of EOT functions via selection device <NUM>, I/O module places ECP car <NUM> into an EOT device mode whereby ECP car <NUM> acts as an EOT device. ECP car <NUM> provides the appropriate EOT status information to the HEU via connector <NUM> or <NUM> to indicate that ECP car <NUM> is at the end of the train. More specifically, CCD <NUM> obtains ECP car <NUM> identification using IDM <NUM> that provides a car specific network node, connects to the ECP network via the appropriate intercar connector <NUM> or <NUM>, and identifies itself to the Head End Unit (HEU) as being in EOT device mode. CCD <NUM> also begins transmission of EOT status messages and ECP car identification to the HEU. ECP car <NUM> will communicate with the HEU regardless of its "A" or "B" orientation in the train to ensure inclusion of ECP car <NUM> in the train makeup as the last car in the train and to ensure that ECP car <NUM> is properly identified and is recognized as the ECP car <NUM> providing EOT device functionality. Once EOT beacons and identifying information are received by HEU from ECP car <NUM>, ECP trainline power can be energized so that the conventional ECP RUN Mode may be selected by the train operator. For safety, the trainline may not be energized until an EOT signal is received, thereby demonstrating that the makeup of the train is complete.

Referring to <FIG>, an exemplary process <NUM> implemented by I/O module <NUM> begins with a check whether EOT mode has been selected <NUM>. If not, the conventional ECP mode is enabled <NUM> for ECP car <NUM>. If so, EOT device mode is enabled <NUM>. The ECP car ID is then obtained <NUM>, and the ECP car ID and EOT beacons are broadcast <NUM> to the head end unit. As the same time, a determination is made which intercar connector is at the rear of the train <NUM> and that intercar connector is electrically isolated <NUM>. The determination is made based on selection device <NUM>, where one position must be selected before CCD <NUM> will enter EOT mode and begin broadcasting. Thus, steps <NUM> and <NUM> may be performed using selection device <NUM> rather than software.

CCD <NUM> will continue to transmit EOT beacons, normally once per second, to HEU, thereby acting as the last physical network node on the train. As a result, ECP car <NUM> can provide traditional EOT device train break-in-two detection by delivering continuous brake pipe pressure status to HEU. CCD <NUM> may thus include a brake pipe (BP) pressure transducer for determining EOT BP pressure status. This pressure status reporting can be used to verify trainline brake pipe continuity and to provide closed cut-out cock detection. ECP car <NUM>, when switched into EOT device mode, can additionally transmit conventional ECP Car brake status information to HEU as it would normally do when acting as a conventional ECP car. Thus, in the event of a brake fault at ECP car <NUM>, CCD <NUM> will transmit normal ECP car brake fault messages to HEU, just as any other ECP car in the train would do. In the event of a failure of CCD <NUM>, EOT beacon transmissions to HEU will cease, thereby resulting in stoppage of the train as would be the case in the event of a failure of a conventional EOT device.

ECP car <NUM> is additionally configured to de-energize the rear-most intercar connector of ECP car <NUM> to mitigate any potential electrical shock hazard. Thus, when EOT mode is initiated via EOT selection device <NUM>, ECP car <NUM> is configured to electrically isolate the rearmost "A" or "B" intercar connector <NUM> or <NUM>. For example, in an exemplary embodiment of the invention, selection device <NUM> may comprise a switch having three positions, i.e., normal ECP, EOT mode with "A" intercar connector <NUM> at the rear, or EOT mode with "B" intercar connector <NUM> at the rear. ECP trainline voltage is then isolated to whichever intercar connector <NUM> or <NUM> is indicated by device <NUM> to be rearmost and thus to be isolated. In addition, the end of traine intercar connector isolation circuit include a <NUM> ohm resistor/capacitor to provide network termination. The last connector is isolated from trainline power so there is no 240V direct current (DC) on the end of the train connector. In addition, there is a <NUM> ohm trainline impedance connecting the A and B trainlines to terminate the network (capacitor block the DC). This electrical isolation independent of ECP trainline and control voltage status is provided to ensure failsafe elimination of any potential electrical shock hazard at the end of the train connector. It should be recognized that the physically unterminated intercar connector <NUM> or <NUM> that is at the end of the train may still be manually fitted with an environmental plug to prevent water and contamination ingress. Selection device <NUM> may be a manually operated or controlled remotely via electronic signaling. Selection device <NUM> may alternatively comprise a separate smart module coupled to the rearmost intercar connector <NUM> or <NUM> that physically isolates that intercar connector <NUM> or <NUM> and communicates back to I/O to signal to initiate EOT device mode.

When ECP car <NUM> is not selected to operate in EOT device mode, selection device <NUM> is used to configure ECP car <NUM> for normal operation as part of an ECP Train. ECP Trainline voltage may then be connected to intercar connectors <NUM> and <NUM> at both ends of ECP car <NUM> to allow power and communication continuity through ECP car <NUM> for conventional ECP mode. Functionality of the car an EOT device is thus disabled, and ECP car <NUM> operates normally.

System <NUM> will comply with standard regulations regarding the use of EOT devices. For example, selection device <NUM> allows ECP car <NUM> to be selected either for normal operation when the car is positioned anywhere except as last car in an ECP train, or as the ECP EOT device to operate with integral ECP EOT functionality in addition to nominal ECP car functionality whenever the ECP car is positioned as the last car in the ECP train. As a result, a conventional ECP EOT device is no longer required for ECP Mode operations. System <NUM> also provides for an ECP car <NUM> that can sequence and operate in any mode selected regardless of physical orientation in the train. The ECP trainline remains physically connected to the IDM / CCD, and local area network (LAN) (or similar/equivalent) communications between IDM <NUM> and CCD <NUM> remain connected regardless of operational mode. System <NUM> will also ensure that the ECP trainline remains connected regardless of operational mode to allow CCD wake-up / battery charging whenever ECP trainline is energized by ECP mode. System <NUM> also ensures that ECP trainline voltage is isolated from the intercar connector at the end of the train regardless of car orientation whenever the ECP car is placed into EOT device mode. In the event of a power loss, the intercar connector at the end of the train will thus not have any ECP trainline voltage applied to it to prevent any potential electrical shock hazard.

In an embodiment, system <NUM> may implement logic with respect to the position of selection device <NUM> have three positions as seen in <FIG>, where a first sensor <NUM> is used to detect the switch position entitled EOT DEVICE MODE - A END AT REAR OF TRAIN and a second sensor <NUM> is used to detect the switch position entitled EOT DEVICE MODE - B END AT REAR OF TRAIN. In this manner, only two sensors <NUM> and <NUM> need to be hardwired from selection device <NUM> to I/O end-of-train module <NUM> that is in communication with CCD <NUM>. As explained below, software implementing logic can compare both inputs to confirm detection of valid switch positions prior to establishing the ECP car configuration with CCD <NUM>. When ECP car <NUM> is first powered up, operation of the EOT device mode may automatically transition to the current position of selection device <NUM> as detected by I/O end-of-train module <NUM>.

As seen in truth table set forth in Table <NUM> below, the outputs of the first and second sensors can be used to determine the desired functionality as well as fault conditions.

As seen in Table <NUM>, when no input is detected from either switch sensor, selection device <NUM> is in the central position indicating NORMAL ECP MODE or has been isolated from system <NUM>. In either case, ECP car <NUM> is configured for normal ECP operation. This approach allows ECP car <NUM> to remain in service as an ECP car if the remote switch cable is disconnected as ECP T/L power is connected through the car interface box. If ECP car is positioned at the end of the train and selection device <NUM> is in either EOT DEVICE MODE position with the cable disconnected, the train will not enter ECP run mode without an EOT device. If an invalid position is detected, e.g., both switch sensors are active, ECP T/L power may be isolated at both ends of the car, thereby causing an ECP emergency brake application.

As seen in <FIG>, a visual indicator, such as LED <NUM>, that is responsive to the switch position feedback analysis may be provided in a readily visible location to the train operator to provide a local visual indication of selection device <NUM> status. The LED may also provide a troubleshooting aid to help identify any ECP car <NUM> that has had selection device <NUM> inadvertently positioned incorrectly without an operator having to check the physical status of each selection device <NUM>, particular if selection device <NUM> is positioned in a harder to access location. As ECP T/L continuity through CCD <NUM> is hardwired to transition to the current setting of selection device <NUM>, control software and LED <NUM> must also automatically transition to the current position of selection device <NUM> to synchronize with switching of ECP T/L within CCD <NUM>. While powered in ECP mode, LED <NUM> should be activated whenever selection device <NUM> is positioned in either EOT position,.

Claim 1:
An end-of-train system (<NUM>), comprising:
an electronically controlled pneumatic railway car (<NUM>) having a car control device (<NUM>), a railcar specific identification module (<NUM>), and first and second intercar trainline network connectors (<NUM>, <NUM>) positioned at either end of the electronically controlled pneumatic railway car;
a selection device (<NUM>) associated with the railway car and configured to be moveable to selectively indicate whether the electronically controlled pneumatic railway car is located at the end of a train and to indicate which of the first and second intercar trainline network connectors is positioned at the rear of the train; and
an input/output end-of-train module (<NUM>) in communication with the car control device and with the railcar specific identification module and programmed to determine whether the selection device has indicated that the electronically controlled pneumatic railway car is at the end of the train and to initiate a broadcast of an end-of-train beacon from the car control device over one of the first and second intercar trainline network connectors.