System, Method, and Apparatus for Determining an End-of-Train Position

Abstract

A system, method, and apparatus for determining a location of a train as it travels on a track network is provided. The system includes an end-of-train device located on an end of the train, the end-of-train device comprising at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout at least a portion of the track network. The system also includes at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to determine a location of the train based at least partially on at least a portion of the transponder data.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to determining the position of a train and, in particular, a system, method, and apparatus for determining the position of an end of a train by using passive transponders in a rail network.

Description of Related Art

Safety concerns in managing a track network require vital separation between trains that could potentially occupy the same physical space. Aside from potential collisions, another concern is the presence of trains on a track segment where some action is occurring, such as the movement of a switch from one alignment to another.

Traditionally, detecting the presence of a train has been performed by using track circuits or axle counters. Track circuits detect the presence of a train and use that detection to provide vital interlocking for switch position changes or signal indications for other trains in a given track network. For example, if a train is present on a particular track circuit that is associated with a switch, it would be known that the switch alignment cannot be changed because it would occur underneath a moving train and cause a derailment. Further, track circuits are used to detect the presence of a train in a given block (e.g., in a fixed block signal system) to indicate to other trains and/or individuals that it would be unsafe to approach a particular block, thereby avoiding collisions.

Track circuits and other active wayside equipment require routine and frequent maintenance throughout the track network. For track circuits in particular, electrical insulation is required between track blocks to allow for the circuits to detect a train from one block to another. This implementation requires cuts in the rail which tend to cause poor ride quality and require frequent maintenance and high installation costs. Moreover, active wayside equipment requires a power supply and frequent maintenance.

Axle counters are also traditionally used to detect the presence of a train in a particular track segment. For example, by counting the number of axles that pass a particular axle counter and the number of axles that pass another axle counter farther down the track, it can be determined that a train is present in the track segment between the counters if the number of axles counted on the latter portion of the track is less than the number of axles counted initially when the train was moving into that particular track segment.

SUMMARY OF THE INVENTION

Generally, provided are an improved system, method, and apparatus for determining a position of a train.

According to one preferred and non-limiting embodiment or aspect, provided is a system for determining a location of a train as it travels on a track network, comprising: an end-of-train device located on an end of the train, the end-of-train device comprising at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout at least a portion of the track network; and at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to determine a location of the train based at least partially on at least a portion of the transponder data.

In one preferred and non-limiting embodiment or aspect, the at least one processor is an on-board computer in a locomotive of the train and/or a processor in the end-of-train device.

In one preferred and non-limiting embodiment or aspect, the transponder data stored on each passive transponder of the plurality of passive transponders comprises an identifier that uniquely identifies at least one track segment of the track network. In another preferred and non-limiting embodiment or aspect, the at least one processor is further programmed or configured to correlate the location of the train with a track database based at least partially on the identifier.

In one preferred and non-limiting embodiment or aspect, the location of the train determined by the at least one processor comprises a location of a front of the train and a location of a back of the train.

In one preferred and non-limiting embodiment or aspect, the location of the train determined by the at least one processor comprises a location of an end of the train.

In one preferred and non-limiting embodiment or aspect, the at least one processor is further programmed or configured to: determine that a position of the train is past a track segment corresponding to at least one passive transponder; and transmit, to a back office system, an indication that the position of the train is past the track segment.

In one preferred and non-limiting embodiment or aspect, the system further comprises a GPS receiver in communication with the at least one processor, wherein the at least one processor is further programmed or configured to: determine a location of the train based on GPS data received from the GPS receiver; and determine when a passive transponder of the plurality of passive transponders is expected to be encountered based at least partially on the location of the train determined based on the GPS data.

In one preferred and non-limiting embodiment or aspect, the track network comprises a plurality of switches, each switch corresponding to a clearance point on a track segment, and wherein at least one passive transponder of the plurality of passive transponders is located proximate to the clearance point of each switch. In another preferred and non-limiting embodiment or aspect, at least one other passive transponder of the plurality of passive transponders is located adjacent a track segment approaching the clearance point of each switch. In another preferred and non-limiting embodiment or aspect, the at least one processor is further programmed or configured to: determine a distance traveled by the train based at least partially on measurements received from a wheel tachometer; and determine if the train has passed a clearance point based at least partially on the distance traveled and the transponder data.

According to one preferred and non-limiting embodiment or aspect, provided is a method for determining a location of a train in a track network, wherein a plurality of transponders are located throughout the track network, each transponder of the plurality of transponders comprising transponder data, comprising: activating at least one transponder with a signal receiving device located in an end-of-train device attached to the train as the train is traveling on a track segment; receiving transponder data from the at least one transponder; and determining a location of the train based at least partially on the transponder data received from the at least one transponder.

In one preferred and non-limiting embodiment or aspect, the signal receiving device is disposed on or in the end-of-train device.

In one preferred and non-limiting embodiment or aspect, the transponder data stored on each transponder of the plurality of passive transponders comprises an identifier that uniquely identifies at least one track segment of the track network. In another preferred and non-limiting embodiment or aspect, the method further comprises correlating the location of the train with a track database based at least partially on the identifier.

In one preferred and non-limiting embodiment or aspect, the location of the train comprises a location of a front of the train and a location of an end of the train.

In one preferred and non-limiting embodiment or aspect, the method further comprises: determining that a position of the train is past a track segment corresponding to at least one passive transponder; and transmitting, to a back office system, an indication that the position of the train is past the track segment.

In one preferred and non-limiting embodiment or aspect, the method further comprises: determining a location of the train based on GPS data received from a GPS receiver; and determining when a transponder of the plurality of transponders is expected to be encountered based at least partially on the location of the train determined based on the GPS data.

In one preferred and non-limiting embodiment or aspect, the track network comprises a plurality of switches, each switch corresponding to a clearance point on a track segment, and wherein at least one transponder of the plurality of transponders is located proximate to the clearance point of each switch. In another preferred and non-limiting embodiment or aspect, at least one other transponder of the plurality of transponders is located adjacent a track segment approaching the clearance point of each switch.

In one preferred and non-limiting embodiment or aspect, the at least one processor is further programmed or configured to: determine a distance traveled by the train based at least partially on measurements received from a wheel tachometer; and determine if the train has passed a clearance point based at least partially on the distance traveled and the transponder data.

According to one preferred and non-limiting embodiment or aspect, provided is an end-of-train device adapted to be attached to an end of a train, comprising: a housing; at least one processor disposed in the housing; and at least one signal receiving device disposed in or attached to the housing, the at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout a track network, such that the at least one processor and/or an on-board computer is enabled to determine a location of the train based at least partially on the transponder data.

According to one preferred and non-limiting embodiment or aspect, provided is a system for determining a location of a train as it travels in a track network, comprising: a plurality of passive transponders located throughout the track network, each passive transponder comprising transponder data uniquely identifying a track segment; at least one signal receiving device disposed in or attached to an end-of-train device, the at least one signal receiving device configured to activate and receive transponder data from the plurality of passive transponders; and at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to: (i) determine that the train has passed a location based on the transponder data, and (ii) in response to determining that the train has passed the location, communicating an indication to a back office system.

Further preferred and non-limiting embodiments or aspects are set forth in the following numbered clauses.

Clause 1: A system for determining a location of a train as it travels on a track network, comprising: an end-of-train device located on an end of the train, the end-of-train device comprising at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout at least a portion of the track network; and at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to determine a location of the train based at least partially on at least a portion of the transponder data.

Clause 2: The system of clause 1, wherein the at least one processor is an on-board computer in a locomotive of the train and/or a processor in the end-of-train device.

Clause 3: The system of clause 1 or 2, wherein the transponder data stored on each passive transponder of the plurality of passive transponders comprises an identifier that uniquely identifies at least one track segment of the track network.

Clause 4: The system of any of clauses 1-3, wherein the at least one processor is further programmed or configured to correlate the location of the train with a track database based at least partially on the identifier.

Clause 5: The system of any of clauses 1-4, wherein the location of the train determined by the at least one processor comprises a location of a front of the train and a location of a back of the train.

Clause 6: The system of any of clauses 1-5, wherein the location of the train determined by the at least one processor comprises a location of an end of the train.

Clause 7: The system of any of clauses 1-6, wherein the at least one processor is further programmed or configured to: determine that a position of the train is past a track segment corresponding to at least one passive transponder; and transmit, to a back office system, an indication that the position of the train is past the track segment.

Clause 8: The system of any of clauses 1-7, further comprising a GPS receiver in communication with the at least one processor, wherein the at least one processor is further programmed or configured to: determine a location of the train based on GPS data received from the GPS receiver; and determine when a passive transponder of the plurality of passive transponders is expected to be encountered based at least partially on the location of the train determined based on the GPS data.

Clause 9: The system of any of clauses 1-8, wherein the track network comprises a plurality of switches, each switch corresponding to a clearance point on a track segment, and wherein at least one passive transponder of the plurality of passive transponders is located proximate to the clearance point of each switch.

Clause 10: The system of any of clauses 1-9, wherein at least one other passive transponder of the plurality of passive transponders is located adjacent a track segment approaching the clearance point of each switch.

Clause 11: The system of any of clauses 1-10, wherein the at least one processor is further programmed or configured to: determine a distance traveled by the train based at least partially on measurements received from a wheel tachometer; and determine if the train has passed a clearance point based at least partially on the distance traveled and the transponder data.

Clause 12: A method for determining a location of a train in a track network, wherein a plurality of transponders are located throughout the track network, each transponder of the plurality of transponders comprising transponder data, comprising: activating at least one transponder with a signal receiving device located in an end-of-train device attached to the train as the train is traveling on a track segment; receiving transponder data from the at least one transponder; and determining a location of the train based at least partially on the transponder data received from the at least one transponder.

Clause 13: The method of clause 12, wherein the signal receiving device is disposed on or in the end-of-train device.

Clause 14: The method of clause 12 or 13, wherein the transponder data stored on each transponder of the plurality of passive transponders comprises an identifier that uniquely identifies at least one track segment of the track network.

Clause 15: The method of any of clauses 12-14, further comprising correlating the location of the train with a track database based at least partially on the identifier.

Clause 16: The method of any of clauses 12-15, wherein the location of the train comprises a location of a front of the train and a location of an end of the train.

Clause 17: The method of any of clauses 12-16, further comprising: determining that a position of the train is past a track segment corresponding to at least one passive transponder; and transmitting, to a back office system, an indication that the position of the train is past the track segment.

Clause 18: The method of any of clauses 12-17, further comprising: determining a location of the train based on GPS data received from a GPS receiver; and determining when a transponder of the plurality of transponders is expected to be encountered based at least partially on the location of the train determined based on the GPS data.

Clause 19: The method of any of clauses 12-18, wherein the track network comprises a plurality of switches, each switch corresponding to a clearance point on a track segment, and wherein at least one transponder of the plurality of transponders is located proximate to the clearance point of each switch.

Clause 20: The method of any of clauses 12-19, wherein at least one other transponder of the plurality of transponders is located adjacent a track segment approaching the clearance point of each switch.

Clause 21: The method of any of clauses 12-20, wherein the at least one processor is further programmed or configured to: determine a distance traveled by the train based at least partially on measurements received from a wheel tachometer; and determine if the train has passed a clearance point based at least partially on the distance traveled and the transponder data.

Clause 22: An end-of-train device adapted to be attached to an end of a train, comprising: a housing; at least one processor disposed in the housing; and at least one signal receiving device disposed in or attached to the housing, the at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout a track network, such that the at least one processor and/or an on-board computer is enabled to determine a location of the train based at least partially on the transponder data.

Clause 23: A system for determining a location of a train as it travels in a track network, comprising: a plurality of passive transponders located throughout the track network, each passive transponder comprising transponder data uniquely identifying a track segment; at least one signal receiving device disposed in or attached to an end-of-train device, the at least one signal receiving device configured to activate and receive transponder data from the plurality of passive transponders; and at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to: (i) determine that the train has passed a location based on the transponder data, and (ii) in response to determining that the train has passed the location, communicating an indication to a back office system.

These and other features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic diagram of one embodiment of a system for determining a position of an end-of-train device according to the principles of the present invention;

FIG. 2 illustrates a step diagram for a method of determining a position of an end-of-train device according to the principles of the present invention;

FIG. 3 illustrates a train traveling in a track network according to the principles of the present invention; and

FIG. 4 illustrates a step diagram for a method of determining a position of an end-of-train device according to the principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal,” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

As used herein, the terms “communication” and “communicate” refer to the receipt, transmission, or transfer of one or more signals, messages, commands, or other type of data. For one unit or device to be in communication with another unit or device means that the one unit or device is able to receive data from and/or transmit data to the other unit or device. A communication may use a direct or indirect connection, and may be wired and/or wireless in nature. Additionally, two units or devices may be in communication with each other even though the data transmitted may be modified, processed, routed, etc., between the first and second unit or device. It will be appreciated that numerous arrangements are possible. Any known electronic communication protocols and/or algorithms may be used such as, for example, TCP/IP (including HTTP and other protocols), WLAN (including 802.11 and other radio frequency-based protocols and methods), analog transmissions, cellular networks (e.g., Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Long-Term Evolution (LTE), Worldwide Interoperability for Microwave Access (WiMAX), etc.), and/or the like.

In a preferred and non-limiting embodiment of the present invention, provided is a system, method, and apparatus for determining a location of a train, and particularly, a location of an end of a train. The system includes a plurality of passive transponders located throughout a track network that each include transponder data uniquely identifying a track segment or location where the transponder is positioned, such as, but not limited to, a portion of a track, a switch, a region, coordinates, and/or the like. The transponder data may be any type of data that uniquely identifies a track segment or location and, in a preferred and non-limiting embodiment, includes a unique identifier that can be correlated with a track location from a track database. Moreover, the transponders may be located anywhere throughout a track network and, in a preferred and non-limiting embodiment, may be located adjacent a clearance point of a switch or adjacent a track segment approaching a clearance point of a switch. However, it will be appreciated that transponders may be positioned at other locations throughout the track network to control movement of multiple trains by establishing boundaries that may be used to hold trains in a particular location for traffic control or the like.

A train includes an end-of-train (EOT) device arranged on an end of the train (e.g., on an end of a rear railcar) that includes a signal receiving device. The passive transponders and signal receiving device are configured such that when a train is traveling on a track, the signal receiving device activates and receives data from the stationary transponders. Thus, the transponders may be located on the track, adjacent the track, or in sufficient proximity to the track such that the signal receiving device is able to communicate with them. Using the transponder data stored on the transponders, an on-board computer on the train and/or the EOT device determines a location of the train and, particularly, a location of an end of the train relative to the track. By using passive transponders rather than active wayside equipment, less maintenance is required.

Referring to FIG. 1, a system 1000 for determining a location of a train 116 is shown according to a preferred and non-limiting embodiment or aspect. The train 116 is traveling on a track 112 and includes a locomotive 114 and an EOT device 101. An on-board computer 109 located in the locomotive 114 is in communication with a track database 106 in the locomotive 114 or elsewhere on the train 116, and a remote back office system 104. The EOT device 101 includes a signal receiving device 110 which communicates with a transponder 102 when in sufficient proximity to the transponder 102. In preferred and non-limiting embodiments or aspects, an additional signal receiving device 113 may be located in the locomotive 114 or another railcar and may be configured to communicate with the transponder 102.

With continued reference to the preferred and non-limiting embodiment or aspect shown in FIG. 1, the transponder 102 may include any signal emitting device that communicates data in response to being activated. For example, the transponder 102 may be a passive radio frequency identification (RFID) transponder (e.g., tag) and the signal receiving device 110 may be an RFID reader that energizes the transponder 102 to retrieve data stored thereon. It will be appreciated, however, that the transponder 102 may include any number of signal-emitting devices such as, for example, near field communication (NFC) tags, low-power Bluetooth® devices, and/or the like, and that the signal receiving device 110 may include any device capable of communicating with the transponder 102. The plurality of transponders 102 located throughout the track network may be the same type of transponder or, in other examples, may differ such that more than one type of signal receiving device 110 is used in the EOT device, or the signal receiving device 110 may be programmed or configured to communicate with different types of transponders 102 using different communication protocols. It will be appreciated that other variations are possible.

In some non-limiting examples, a plurality of printed data sources (e.g., a two- or three-dimensional barcode, a visual code, printed text, etc.) may be used. In such examples, the EOT device is configured to illuminate the printed data source (e.g., with an infrared light or another light source) and capture the data printed thereon with an image capture device. The EOT device and/or on-board computer may then decode and/or process the captured image to obtain the data encoded or printed thereon.

Still referring to FIG. 1, the on-board computer 109 may be in communication with a positioning system, such as a Global Positioning System (GPS) satellite 103 (wherein the on-board computer 109 is in communication with a GPS receiver 120 on the train 116), to determine or receive positional coordinates of the train 116. Various other techniques may also be used to determine the position of the train 116 such as, for example, axle counters, signal triangulation, wheel tachometers, and/or the like. The on-board computer 109 may use data received from the transponders 102 to confirm and/or verify the location of the train as determined by GPS and/or other methods. In this manner, the transponders 102 may be used as a failsafe mechanism for verifying that the location of the train 116, as determined by the GPS, axle counters, signal triangulation, wheel tachometers, and/or the like, is correct.

The location of the train 116, as determined by GPS and/or other methods, may also be used to determine when a transponder 102 is expected to be encountered. This provides information for the EOT device 101 to anticipate a transponder 102 so that it can activate the transponder 102 at the appropriate time. Because activating a transponder 102 utilizes power, attempting to activate a transponder 102 only when it is anticipated, rather than continually or periodically, minimizes the amount of power that the EOT device 101 consumes. It will be appreciated, however, that the transponders 102 may also be used as a primary source for determining train location, and that GPS and/or other like devices and methods may be used to confirm such determinations or may not be used at all. In preferred and non-limiting embodiments or aspects, and as discussed above, a GPS receiver 120 may be located in the locomotive 114 and/or the EOT device 101. In preferred and non-limiting embodiments or aspects, in which a GPS receiver 120 is located in both the locomotive 114 and the EOT device 101, the location data received from both GPS receivers 120 may be used to determine or confirm the length of the train 116. Methods for determining the overall length of a train are described in U.S. Pat. No. 6,081,769 to Curtis, the disclosure of which is hereby incorporated by reference in its entirety.

In the preferred and non-limiting embodiment or aspect shown in FIG. 1, the back office system 104 includes a back office system server 105 and a remote track database 107. The on-board computer 109 generates report data 108 and communicates this data to the back office system server 105, which stores the report data 108 or a portion thereof in the remote track database 107. The report data 108 may include the transponder data and/or be generated by the on-board computer 109 based on various inputs including, for example, the transponder data obtained from the signal receiving device 110. It will be appreciated that the report data 108 may also include raw, unprocessed data received from the signal receiving device 110 (e.g., the transponder data itself), or may be processed and/or combined with other data by the EOT device 101 and/or on-board computer 109. Moreover, in preferred and non-limiting embodiments or aspects, the EOT device 101 may also be in communication with the back office system 104 and may transmit report data 108 received from the transponder 102 and/or derived from the transponder data directly to the back office system server 105 upon receiving it or at intervals.

With continued reference to FIG. 1, the report data 108 may be communicated to the back office system server 105 as it is received and/or determined, or may be communicated at a predetermined interval or time period. For example, once a position of the EOT device 101 is confirmed to have passed a transponder 102 (or some other location on the track 112), the on-board computer 109 and/or EOT device 101 may transmit the report data 108 to the back office system server 105 where it is stored in the remote track database 107. The report data 108 can then be used by the back office system server 105, other remote systems, and/or railroad personnel to make decisions for safely moving switches or routing trains through the track network. It will be appreciated that the back office system server 105 and/or other remote systems may implement one or more algorithms for generating train and/or switch commands based on the report data 108.

In a preferred and non-limiting embodiment or aspect, the transponder data stored on each of the transponders 102 includes a unique identifier that uniquely identifies the transponder 102 and/or a location of the transponder 102. For example, a unique identifier from a transponder may correspond to a track location in the track database(s) 106, 107, such that the position of the train 116, and particularly the position of the front and/or end of the train 116, can be correlated with the track database(s) 106, 107. In a non-limiting example, the track database(s) 106, 107 include identifiers corresponding with track locations (e.g., geographic locations, landmark-based locations, specific track segments or switches, etc.), such that the unique identifier from the transponder data may be matched to an identifier in the track database(s) 106, 107 to determine a track location. Unique identifiers may be in any suitable format such as, for example, integers, alphanumeric strings, coordinates, and/or the like. In this manner, the on-board computer 109 may receive the transponder data from a transponder 102, extract or determine a unique identifier from the transponder data, and look-up the unique identifier on the on-board track database 106 to find a corresponding identifier associated with a track location. The on-board computer 109 may then generate the report data 108 based on the unique identifier and/or corresponding information retrieved from the track database. It will be appreciated that transponder data may alternatively or additionally be correlated with the remote track database 107.

In a preferred and non-limiting embodiment or aspect, a failsafe protocol may be implemented by the on-board computer 109 and/or EOT device 101 to confirm the detection of a transponder 102. In such embodiments or aspects, a signal receiving device 113 in the locomotive 114 and a signal receiving device 110 in the EOT device 101 may both detect and/or obtain transponder data from the transponders 102. The on-board computer 109 and/or EOT device 101 may then compare the transponder data and/or ensure that transponder data is received by both signal receiving devices 110, 113.

Referring to FIG. 3, a train 116 traveling in a track network is shown according to a preferred and non-limiting embodiment or aspect. A clearance transponder 304 may be located at a clearance point of a switch 306 in the track network to facilitate a determination of when the train 116 has passed the clearance point. A switch 306 may have two clearance points, one for each leg of the switch 306, and therefore two clearance transponders. Depending on which leg of the switch the train was traveling, one of the two clearance transponders may be activated. Once it is determined that the train 116 has passed the clearance transponder 304, and therefore the clearance point, the switch 306 can be moved or another train can be routed on the associated track segment. An approach transponder 302 is located at a distance (d) from the switch 306 on the track, and the clearance transponder 304 is located substantially proximate to the switch 306. It will be appreciated that the clearance transponder 304 may also be located at a distance past the switch 306 or elsewhere. The EOT device 101 at the end of the train 116 has a signal-receiving device (not shown) for receiving data from the transponders 302, 304.

With continued reference to FIG. 3, after passing over the approach transponder 302, the signal-receiving device obtains transponder data from the transponder 302. The transponder data received from the approach transponder 302 may be used to confirm that the signal receiving device is working properly as the train 116 approaches a clearance transponder 304 located at a clearance point of the switch 306, and to indicate to the EOT device 101 and/or on-board computer of the train 116 that detection of another transponder (e.g., the clearance transponder 304) can be expected. For example, approach transponder 302 may be located at a distance (d) from the switch 306 or another clearance point to account for GPS position errors. After detecting the approach transponder 302, the on-board computer and/or EOT device 101 of the train 116 may then utilize any suitable method or device for determining the distance traveled, such as but not limited to a wheel tachometer, to independently determine when the clearance point associated with the clearance transponder 304 can be expected. In some preferred and non-limiting embodiments or aspects, two or more transponders may be used in any given location or region for redundancy. Transponders may also be used in connection with other clearance points, such as train stations, authority blocks, and/or the like.

Referring now to FIG. 2, a method for determining the location of an EOT device is shown according to a preferred and non-limiting embodiment or aspect. At a first step 200, the position of the EOT device is determined using GPS or another suitable method. At a next step 202, the EOT device detects a stationary transponder in the track network. At step 204, the EOT device receives transponder data from the transponder by, for example, activating a passive transponder. Next, at step 205, the on-board computer, EOT device, and/or another computing device correlates a unique identifier from the transponder data to a track location in a track database. At step 206, the on-board computer, EOT device, and/or another computing device may confirm that the position of the EOT device is past a clearance point based on the transponder data received from the transponder and the corresponding track location retrieved from the track database. At step 208, the transponder data may be submitted to a back office system.

In a preferred and non-limiting embodiment, the on-board computer determines that the position of the train and/or EOT device is past a particular track segment. The on-board computer may also use the EOT device position to release authority for a following train to use the track segment. Thus, the data submitted to a back office system may include a location of the front of the train, a location of the end of the train (or EOT device), and/or a release of movement authority.

Referring now to FIG. 4, a method for determining the location of an EOT device using an approach transponder is shown according to a preferred and non-limiting embodiment or aspect. At a first step 400, a first transponder (e.g., an approach transponder) is detected by a signal receiving device. Then, at step 402, transponder data is received from the first transponder. Using this transponder data, the operability of the signal receiving device can be confirmed. At step 404, the distance traveled by the train is measured using, for example, any suitable method or device for determining the distance traveled, such as, but not limited to, a wheel tachometer. Then, at step 406, a second transponder is detected at a clearance point. Transponder data is then received from the second transponder at a next step 408. At step 410, at least a portion of the transponder data, such as but not limited to an indication that the train has passed the clearance point, is transmitted to a back office system.

In a preferred and non-limiting embodiment or aspect, the system 1000 for determining a location of a train 116 can be used for implementing moving block train control without the need for active wayside equipment. By determining the locations of trains throughout a track network with the system 1000, one or more movement authorities may facilitate movement of the trains at a closer proximity.

In non-limiting embodiments or aspects, a method to determine the location of a train may be performed by at least one non-transitory computer-readable medium including program instructions that, when executed by at least one processor, cause one or more devices to perform the steps. With the sole exception of transitory propagating signals, a non-transitory computer-readable medium may include any medium capable of storing data such as, but not limited to, random-access memory (RAM), read-only memory (ROM), hard drives, compact and floppy discs, and/or other like mediums.

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments or aspects, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments or aspects, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment or aspect.

Claims

1. A system for determining a location of a train as it travels on a track network, comprising:

an end-of-train device located on an end of the train, the end-of-train device comprising at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout at least a portion of the track network; and

at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to determine a location of the train based at least partially on at least a portion of the transponder data.

2. The system of claim 1, wherein the at least one processor is an on-board computer in a locomotive of the train and/or a processor in the end-of-train device.

3. The system of claim 1, wherein the transponder data stored on each passive transponder of the plurality of passive transponders comprises an identifier that uniquely identifies at least one track segment of the track network.

4. The system of claim 3, wherein the at least one processor is further programmed or configured to correlate the location of the train with a track database based at least partially on the identifier.

5. The system of claim 1, wherein the location of the train determined by the at least one processor comprises a location of a front of the train and a location of a back of the train.

6. The system of claim 1, wherein the location of the train determined by the at least one processor comprises a location of an end of the train.

7. The system of claim 1, wherein the at least one processor is further programmed or configured to:

determine that a position of the train is past a track segment corresponding to at least one passive transponder; and

transmit, to a back office system, an indication that the position of the train is past the track segment.

8. The system of claim 1, further comprising a GPS receiver in communication with the at least one processor, wherein the at least one processor is further programmed or configured to:

determine a location of the train based on GPS data received from the GPS receiver; and

determine when a passive transponder of the plurality of passive transponders is expected to be encountered based at least partially on the location of the train determined based on the GPS data.

9. The system of claim 1, wherein the track network comprises a plurality of switches, each switch corresponding to a clearance point on a track segment, and wherein at least one passive transponder of the plurality of passive transponders is located proximate to the clearance point of each switch.

10. The system of claim 9, wherein at least one other passive transponder of the plurality of passive transponders is located adjacent a track segment approaching the clearance point of each switch.

11. The system of claim 10, wherein the at least one processor is further programmed or configured to:

determine a distance traveled by the train based at least partially on measurements received from a wheel tachometer; and

determine if the train has passed a clearance point based at least partially on the distance traveled and the transponder data.

12. A method for determining a location of a train in a track network, wherein a plurality of transponders are located throughout the track network, each transponder of the plurality of transponders comprising transponder data, comprising:

activating at least one transponder with a signal receiving device located in an end-of-train device attached to the train as the train is traveling on a track segment;

receiving transponder data from the at least one transponder; and

determining a location of the train based at least partially on the transponder data received from the at least one transponder.

13. The method of claim 12, wherein the signal receiving device is disposed on or in the end-of-train device.

14. The method of claim 12, wherein the transponder data stored on each transponder of the plurality of passive transponders comprises an identifier that uniquely identifies at least one track segment of the track network.

15. The method of claim 14, further comprising correlating the location of the train with a track database based at least partially on the identifier.

16. The method of claim 12, wherein the location of the train comprises a location of a front of the train and a location of an end of the train.

17. The method of claim 12, further comprising:

determining that a position of the train is past a track segment corresponding to at least one passive transponder; and

transmitting, to a back office system, an indication that the position of the train is past the track segment.

18. The method of claim 12, further comprising:

determining a location of the train based on GPS data received from a GPS receiver; and

determining when a transponder of the plurality of transponders is expected to be encountered based at least partially on the location of the train determined based on the GPS data.

19. The method of claim 12, wherein the track network comprises a plurality of switches, each switch corresponding to a clearance point on a track segment, and wherein at least one transponder of the plurality of transponders is located proximate to the clearance point of each switch.

20. The method of claim 19, wherein at least one other transponder of the plurality of transponders is located adjacent a track segment approaching the clearance point of each switch.

21. The method of claim 12, wherein the at least one processor is further programmed or configured to:

determine a distance traveled by the train based at least partially on measurements received from a wheel tachometer; and

determine if the train has passed a clearance point based at least partially on the distance traveled and the transponder data.

22. An end-of-train device adapted to be attached to an end of a train, comprising:

a housing;

at least one processor disposed in the housing; and

at least one signal receiving device disposed in or attached to the housing, the at least one signal receiving device configured to activate and receive transponder data from a plurality of passive transponders located throughout a track network, such that the at least one processor and/or an on-board computer is enabled to determine a location of the train based at least partially on the transponder data.

23. A system for determining a location of a train as it travels in a track network, comprising:

a plurality of passive transponders located throughout the track network, each passive transponder comprising transponder data uniquely identifying a track segment;

at least one signal receiving device disposed in or attached to an end-of-train device, the at least one signal receiving device configured to activate and receive transponder data from the plurality of passive transponders; and

at least one processor in communication with the at least one signal receiving device, the at least one processor programmed or configured to: (i) determine that the train has passed a location based on the track data, and (ii) in response to determining that the train has passed the location, communicating an indication to a back office system.