Method and apparatus for autonomous train control system

Abstract

A method and a structure for an Autonomous Train Control System (ATCS) are disclosed, and are based on a plurality of autonomous train control elements that operate independent of each other. An autonomous train control element operates within an allocated track space, and based on predefined rules. Further, autonomous train control elements are paired together to exchange operational data. Pursuant to the predefined rules, an autonomous train control element acquires needed track space from a paired element, and relinquishes track space that is not required for its autonomous operation to a paired element. Further, an autonomous train control element is assigned a priority level with respect to the acquisition/relinquishment of track space.

Claims

1. A train control system that includes a plurality of autonomous train control elements, wherein the train control system controls the movement of trains within a section of track, wherein an autonomous train control element operates independent of other elements, wherein said plurality of autonomous train control elements include a virtual train control element and at least one physical autonomous control element that includes at least one of a physical train control element, an interlocking control element, a grade crossing control element and an absolute block control element, wherein the virtual train control element is assigned free track space that extends beyond the entire length of the virtual train, wherein said at least one physical autonomous control element has designated track space, and wherein at least one autonomous train control element acquires track space from a first autonomous train control element and relinquishes track space to a second autonomous train control element.

2. A train control system as recited in claim 1, wherein at least one autonomous train control element is assigned a higher level of priority with respect to the acquisition of track space.

3. A train control system as recited in claim 1, further comprising a communication interface module that performs the function of pairing at least two autonomous train control elements together.

4. A train control system as recited in claim 1, wherein a virtual train control element operates in accordance with predefined rules that determine the amount of track space to be relinquished to a paired autonomous train control element.

5. A train control system as recited in claim 1, wherein a physical train control element controls the movement of a physical train operating within allocated track space based on predefined rules.

6. A train control system as recited in claim 1, wherein an interlocking train control element establishes and secures train routes at an interlocking, and wherein the interlocking control element performs interlocking functions within designated track space based on predefined rules.

7. A train control system as recited in claim 1, wherein a grade crossing control element controls the operation of a grade crossing that operates based on predefined rules within designated track space.

8. A train control system as recited in claim 1, wherein an absolute block signal element provides a backup mode of operation, wherein said absolute block signal element operates autonomously based on the absolute block principle, and predefined rules within allocated track space.

9. A train control system that includes a plurality of autonomous train control elements, wherein the train control system controls the movement of trains within a section of track, wherein an autonomous train control element operates independent of other elements, wherein said plurality of autonomous train control elements include a virtual train control element and at least one physical autonomous control element that includes at least one of a physical train control element, an interlocking control element, a grade crossing control element and an absolute block control element, wherein the virtual train control element is assigned free track space that extends beyond the entire length of the virtual train, wherein said at least one physical autonomous control element requires assigned track space to operate based on predefined rules, and wherein said predefined rules include rules that determine the amount of track space to be relinquished to a different autonomous train control element.

10. A train control system that controls the movement of trains within a section of track comprising: a plurality of autonomous train control elements, wherein an autonomous train control element operates independent of other elements based on predefined rules within allocated track space, and wherein one autonomous train control element is defined as a virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, a control module that manages the interfaces between said plurality of autonomous train control elements, and a communication interface module that performs the function of pairing at least two autonomous train control elements together.

11. A train control system as recited in claim 10, wherein at least one autonomous train control element is assigned a higher level of priority with respect to the acquisition of track space.

12. A train control system as recited in claim 10, wherein an autonomous train control elements operates within allocated track space, wherein at least one autonomous train control element acquires track space from a first train control element, and relinquishes track space to a second train control element.

13. A train control element as recited in claim 10, wherein said control module and communication interface module are implemented in a cloud computing environment.

14. A train control system that controls the movement of trains within a section of track comprising: at least one autonomous train control element that controls the operation of a physical train based on predefined rules within a designated track space, at least one autonomous train control element that controls the operation of a physical interlocking within an assigned track space based on predefined rules, an autonomous train control element defined as virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, wherein said virtual train operates based on predefined rules within the assigned free track space, a control module that manages the interfaces between autonomous train control elements, and a communication interface module that performs the function of pairing at least two autonomous train control elements together.

15. A train control system as recited in claim 14, wherein said control module provides computing resources to implement virtual trains.

16. A train control system that controls the movement of trains within a section of track comprising: an autonomous train control element that controls the operation of a physical train based on predefined rules within a designated track space, an autonomous train control element that controls the operation of a physical interlocking based on predefined rules within an assigned track space, an autonomous train control element defined as virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, wherein said virtual train operates based on predefined rules within the assigned free track space, means for managing the interfaces between autonomous train control elements, and means for pairing at least two autonomous train control elements together.

17. A train control system that controls the movement of trains within a section of track, wherein said train control system includes a plurality of autonomous train control elements, wherein an autonomous train control element operates independent of other elements based on predefined rules within allocated track spaces, wherein one of said plurality of autonomous train control elements is defined as a virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, and wherein said predefined rules include rules for the acquisition of track space and rules for relinquishing track space.

18. A train control system that controls the movement of trains within a section of track comprising: a plurality of modules implemented in a cloud computing environment to provide a plurality of autonomous virtual train control elements, wherein a virtual autonomous train control element operates based on predefined rules, wherein a virtual autonomous train control element corresponds to a physical train control element, and wherein one of said virtual train control elements is defined as a virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, and controls the allocation of free track space to other virtual train control elements, means for providing communication between virtual autonomous train control elements and physical train control element, and means for pairing at least two virtual autonomous train control elements together.

19. A train control system that includes a plurality of autonomous train control elements, wherein one of said autonomous train control elements is defined as a virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, wherein one of said train control elements controls the operation of grade crossing equipment at a rail/vehicle intersection, wherein the train control element that controls the operation of grade crossing equipment operates based on predefined rules within an allocated track space, and wherein the train control element that controls the operation of grade crossing equipment communicates directly with road vehicles approaching the intersection.

20. A train control system that includes a plurality of autonomous train control elements that are linked by a data communication system, wherein an autonomous train control element operates independent of other elements, wherein one class of said train control elements is defined as virtual train that is assigned free track space, which extends beyond the entire length of the virtual train, and wherein the train control elements are used to propagate at least one of operational data and failure data in a daisy chain configuration within the train control system territory.

21. A train control system that controls the movement of trains within a section of track, wherein said train control system includes a plurality of autonomous train control elements that operate within defined track space based on predefined rules, wherein an autonomous train control element operates independent of other elements, wherein an autonomous train control element is paired with at least one other autonomous train control element, wherein free track space that is not occupied by physical trains is assigned to autonomous train control elements defined as virtual trains and wherein an autonomous train control element includes a processor module with a computer-readable medium encoded with a computer program to control the operation of the autonomous train control element, comprising the following steps: performing autonomous train control functions within allocated track space, determining if additional track space is needed to perform said autonomous functions, acquiring track space from paired autonomous train control element, and relinquishing track space to at least one paired autonomous train control element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other more detailed and specific objectives will be disclosed in the course of the following description taken in conjunction with the accompanying drawings wherein:

(2) FIG. 1 is a general conceptual diagram of an Autonomous Train Control System showing the various autonomous train control elements, and the interaction between paired elements related to the acquisition and relinquishment of track space in accordance with the preferred embodiment of the invention.

(3) FIG. 2 shows a general block diagram of the Autonomous Train Control System in accordance with the preferred embodiment of the invention.

(4) FIG. 3 shows a diagram that demonstrates the autonomous operation of a physical train with respect to the acquisition and relinquishment of track space in accordance with the invention.

(5) FIG. 4 shows an operational scenario that demonstrates a rule for the autonomous operation of a physical train in accordance with the invention.

(6) FIG. 5 shows an operational scenario that demonstrates a rule for the autonomous operation of a physical train in accordance with the invention.

(7) FIG. 6 shows an operational scenario that demonstrates a rule for the autonomous operation of a physical train in accordance with the invention.

(8) FIG. 7 shows various configurations of physical train signature in accordance with the invention.

(9) FIG. 8 shows a diagram that demonstrates the concept of propagation of train failure information in accordance with the invention.

(10) FIG. 9 shows a diagram that demonstrates the autonomous operation of a virtual train with respect to the acquisition and relinquishment of track space in accordance with the invention.

(11) FIG. 10 shows an operational scenario that demonstrates a rule for the autonomous operation of a virtual train in accordance with the invention.

(12) FIG. 11 shows the various operational scenarios during which a virtual train relinquishes track space.

(13) FIG. 12 shows a diagram that demonstrates the autonomous operation of an interlocking element with respect to the acquisition and relinquishment of track space in accordance with the invention.

(14) FIG. 13 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(15) FIG. 14 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(16) FIG. 15 shows a proposed route section designation for the autonomous operation of an interlocking element in accordance with the invention.

(17) FIG. 16 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(18) FIG. 17 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(19) FIG. 18 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(20) FIG. 19 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(21) FIG. 20 shows an operational scenario that demonstrates a rule for the autonomous operation of an interlocking element in accordance with the invention.

(22) FIG. 21 shows a diagram that demonstrates the autonomous operation of grade crossing element with respect to the acquisition and relinquishment of track space in accordance with the invention.

(23) FIG. 22 shows an operational scenario that demonstrates a rule for the autonomous operation of a grade crossing element in accordance with the invention.

(24) FIG. 23 shows an operational scenario that demonstrates a rule for the autonomous operation of a grade crossing element in accordance with the invention.

(25) FIG. 24 shows a generic configuration of an Absolute Signal Block Unit in accordance with the invention.

(26) FIG. 25 shows a diagram that demonstrates the autonomous operation of an Absolute Signal Block Unit with respect to the acquisition and relinquishment of track space in accordance with the invention.

(27) FIG. 26 shows an operational scenario that demonstrates a rule for the autonomous operation of an Absolute Signal Block Unit in accordance with the invention.

(28) FIG. 27 shows an operational scenario that demonstrates a rule for the autonomous operation of an Absolute Signal Block Unit in accordance with the invention.

(29) FIG. 28 shows an example of the operation of an Absolute Signal Block Unit during the initialization of a physical train.

(30) FIG. 29 shows a general block diagram of the Autonomous Train Control System, identifying the main interconnections between the Track Space Controller, the Communication Interface Controller, the Data Communication Network, and the physical autonomous train control elements in accordance with the invention.

(31) FIG. 30 shows a detailed block diagram of the Track Space Controller in accordance with the preferred embodiment of the invention.

(32) FIG. 31 shows a detailed block diagram of the Communication Interface Controller in accordance with the preferred embodiment of the invention.

(33) FIG. 32 shows a general block diagram of the Autonomous Train Control System in accordance with the alternate embodiment of the invention.

(34) FIG. 33 is a general conceptual diagram of an Autonomous Train Control System showing the various autonomous train control elements, and the interaction between elements related to the acquisition and relinquishment of track space in accordance with the alternate embodiment of the invention.

(35) FIG. 34 shows a diagram that demonstrates the autonomous operation of an avatar train with respect to the acquisition and relinquishment of track space in accordance with the invention.

(36) FIG. 35 shows an operational scenario that demonstrates a rule for the autonomous operation of an avatar train in accordance with the invention.

(37) FIG. 36 shows an operational scenario that demonstrates a rule for the autonomous operation of an avatar train in accordance with the invention.

(38) FIG. 37 shows a detailed block diagram of the Track Space Controller in accordance with the alternate embodiment of the invention.

(39) FIG. 38 shows a detailed block diagram of the Communication Interface Controller in accordance with the alternate embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(40) The present invention describes a new structure, and/or a new method to implement an Autonomous Train Control System (ATCS). This new structure is based on the concept of a plurality of autonomous train control elements that operate independent of each other, and interface with each other for the purpose of relinquishing and/or acquiring “track space.” The ATCS normally controls train movements within a section of a railroad or within a transit line. Similar to other train control systems, an ATCS installation covers a plurality of tracks, as well as track switches that provide means for trains to move from one track to another. The “track space” is defined as the longitudinal stretch along the entire physical track installed within the ATCS territory, and including the track within interlockings. For the preferred embodiment, the track space within the ATCS territory is allocated to the various autonomous train control elements, which include physical trains, interlocking elements, absolute block signal units (optional), grade crossings, and any other train control element that requires an allocation of track space. An additional class of autonomous train control elements is used in the preferred embodiment to represent free, un-occupied, or un-allocated track space. This additional class is defined as “virtual trains.” Each of the autonomous train control elements operate pursuant to a set of rules. Further, each class of autonomous train control elements is assigned a priority level with respect to the acquisition or relinquishment of track space. An element with a higher priority level, can acquire allocated track space from another element with lower priority level.

(41) The use of virtual trains to represent free track space requires the introduction of a secondary concept related to the acquisition and relinquishing of track space. Since a virtual train does not represent, or correspond to a physical train entity, certain physical train functions are not suitable to be performed by a virtual train. For example, a virtual train should not activate grade crossing protection as it moves in the approach to and through a grade crossing territory. However, there is still a need for a virtual train to operate and move through grade crossing territory. Similarly, some interlocking functions require the acquisition of track space held by a grade crossing element. For example, when performing traffic reversal between interlockings the track space allocated to a grade crossing element must be assigned to interlocking element. Such assignment must be performed without activating the grade crossing element. As such, the preferred embodiment employs the concept of “leasing” and “vacating” track space. By leasing track space assigned to a grade crossing control element, a virtual train can proceed through the grade crossing track section without activating the crossing. Similarly, by leasing track space from a grade crossing element, an interlocking element can reverse traffic without activating the grade crossing. It should be noted that although a grade crossing element leases track space to a virtual train or an interlocking element, the track space remains assigned to the grade crossing element. As such leased rack space must be returned to the grade crossing element when it is vacated and cannot be transferred directly to another element. For example, a virtual train that vacates a track space leased from a grade crossing element returns the vacated track space back to the grade crossing element for releasing to a following virtual train, or to be relinquished to a following physical train.

(42) The interfaces between autonomous train control elements are identified based on relative geographic locations, and include the communication pairing of adjacent elements for the purpose of acquiring/relinquishing track space, as well as exchanging operational data. The preferred embodiment includes two additional elements: The first element is defined as Track Space Controller (TSC), and its main functions include the implementation and management of virtual trains, as well as to facilitate the interfaces between various autonomous train control elements. The second element is defined as a Communication Interface Controller (CIC), and its main function is to manage the communication pairing of autonomous train control elements.

(43) Referring now to the drawings where the illustrations are for the purpose of describing the preferred embodiment of the invention and are not intended to limit the invention hereto, FIG. 1 is a conceptual abstract diagram of the proposed ATCS, showing the track space 10, and the various autonomous train control elements, including physical trains 20, interlocking elements 30, grade crossing elements 40, virtual trains 50, Absolute Block Signal Units (ABSU) 60 & any other train control element 62. The initial allocation of track space to the train control elements is made during system and/or train initialization, and is based on predefined rules. With respect to fixed location train control elements, track space initial allocation is based on fixed geographical limits. For example, the initial track space allocated to an interlocking element 30 includes the switch detector area as well as the approaches to the interlocking. Similarly, the initial track space allocated to a grade crossing element 40 includes the track space along the grade crossing island as well as the approaches. ABSUs 60 receive an initial track space allocation that includes the associated absolute signal block. A virtual train 50 receives an initial track space allocation, or a leased track space allocation, upon the creation of the train based on predefined rules. Similarly, a physical train 20 receives an initial track space allocation upon the initialization of the train based on predefined rules. It should be noted that the initial allocation to ABSUs 60 is an interim allocation until the track space is reallocated to other train control elements during normal system operation.

(44) The system initialization process, during which track space is initially allocated to train control elements, is based on an initial sweep of the track space sections to ensure that they are vacant. As a design choice, fixed block detection could also be used in certain track sections to ensure that no trains are present in these track sections. For example, fixed block detection could be used within switch detector areas and the island sections of grade crossings. Upon system and train initializations, and the establishment of normal operation, the train control elements relinquish and acquire 70 track space to paired element based on operating conditions and predefined set of rules. Virtual trains operating in the vicinity of grade crossing elements lease and vacate track space 71 based on operating conditions and predefined set of rules.

(45) FIG. 2 shows a block diagram of a typical configuration for the proposed ATCS in accordance with the teachings of the preferred embodiment. This configuration includes physical trains T-1 108 and T-2 112, virtual trains V-3 136, V-6 122 & V-8 128, interlocking element 126, absolute block signal units ABSU2 116 & ABSU3 117. The ATCS also includes centralized computing resources 100, which includes two main elements: the Track Space Controller (TCS) 120, and the Communication Interface Controller (CIC) 110. The main functions performed by the TCS 120 include the implementation and management of virtual trains 130 & 134, and the management of interfaces with physical elements 124 as well as interfaces with external systems 134. The main function of the CIC 110 is to pair the autonomous train control elements together based on location and operational data received from the TCS 120. As such, for the ATCS configuration shown in FIG. 2, and for the relative positions of trains shown, virtual train V6 122 is paired 140 with physical train T-1 108, virtual train V-8 128 is also paired 142 with T-1 108. In turn, V-8 128 is also paired 144 with physical train T-2 112 and absolute block signal unit ABU2 116. Further, physical train T-2 112 is paired 146 with interlocking element IXL-1 126. In addition, virtual train V-3 136 is paired 148 with IXL-1 126 and ABSU3 117. It should be noted that as the relative positions of trains change, the pairing of train control elements changes. This is a dynamic process based train locations and operational data.

(46) As indicated above, physical trains acquire and relinquish track space from/to other train control elements. More specifically, and as shown in FIG. 3, a physical train 150 can acquire track space from another physical train 152, a virtual train 154, an interlocking control element 156, a grade crossing control element 157, or an absolute block signal unit (ABSU) 158. The acquisition of track space takes place as a train ahead (physical 152 or virtual 154) vacates track space, in response to a route request to an interlocking control element 156, in response to a request for track space to a grade crossing control element 157, or during a failure condition, wherein an ABSU 158 relinquishes the track space associated with its absolute signal block (ASB) after ensuring that the ASB is vacant. It should be noted that to proceed through a grade crossing section, it is necessary for the physical train to acquire track space directly from the grade crossing. A train (physical or virtual) moving ahead of the physical train must relinquish/release vacated track space to the grade crossing element for reassignment to the following physical train.

(47) Similarly, a physical train 150 can relinquish track space to another physical train 160, a virtual train 162, an interlocking control element 164, a grade crossing control element 166, or an absolute block signal unit (ABSU) 168. The relinquishing of track space takes place after the physical train 150 vacates track space upon its movement in the indicated direction 151.

(48) FIGS. 4 & 5 show certain characteristics of the autonomous operation for physical trains. Each physical train control element establishes a movement authority limit (MAL) based on the available track space it has acquired from paired elements. Also, a physical train control element establishes a stopping profile that is based on the MAL. As disclosed above, to the extent possible, it is desirable to provide an “optimum” track space to a physical train in order for the physical train to operate at the maximum allowable operating speed within the territory. As such, FIG. 4 reflects an operating scenario, wherein the current track space and associated MAL 170 for a physical train is less than the required optimum track space 172. Based on the premise that physical trains have an assigned level of track space acquisition priority that is higher than that of virtual trains, the autonomous operation of physical trains includes a feature wherein a physical train acquires more track space from a paired virtual train to satisfy its optimum track space requirements. As such, in FIG. 4, physical train 153 requests track space from paired front virtual train 176 to satisfy the requirement for an optimized track space 172. In the event the needed track space 174 is more that the track space 175 allocated to the virtual train 176, the process is repeated until the optimized track space 172 is satisfied. Alternatively, if the needed track space 174 is less than the track space 175 allocated to the virtual train 176, then the virtual train 176 will relinquish the needed track space 174 to the physical train 153. However, if the remaining track space for the virtual train 176 is less than a certain threshold, the entire track space 175 assigned to the virtual train 176 is relinquished to the physical train 153. In such a case, the virtual train 176 is retired.

(49) A second characteristic of the physical train autonomous operation is associated with the operating scenario depicted in FIG. 5, wherein the track space 180 allocated to a physical train 155 exceeds a maximum track space threshold 182. In the preferred embodiment, it is not desirable for a physical train to acquire track space way in excess of its optimum track space. As such, one autonomous operation characteristics of physical train is to relinquish track space when its allocated space exceeds a maximum threshold. An example of an operational scenario that results in excess track space 186 occurs when a physical train is delayed and keeps accumulating track space from a train ahead that is moving away from its location. In FIG. 5, when the track space allocated to a physical train 155 exceeds the maximum track space threshold 182, the physical train relinquishes the excess track space 186 for the creation or activation of a new virtual train 181.

(50) FIG. 6 shows another operating scenario, wherein a physical train relinquishes track space to a paired autonomous train control element. In the preferred embodiment, a physical train is requested to relinquish track space to a paired autonomous train control element that has a higher assigned level of track space acquisition priority. Upon receiving such request, the physical train relinquishes part or all of the requested track space provided that it does not violate safety rules. In FIG. 6, interlocking element IXL-1 188 requests physical train T-5 157 to relinquish part of its track space 190 in order to process a higher priority move for physical train T-7 159 through the interlocking. As part of the physical train autonomous operation, physical train T-5 157 relinquishes the requested track space to IXL-1 188 only if it can stop using service brake prior to reaching the interlocking, within its truncated track space 192. It should be noted that, under rare operating conditions, a physical train will truncate its movement authority without relinquishing any track space, and resulting in an emergency brake application in order to mitigate safety hazards. An example of such operating condition is an open switch point within the track space assigned to the physical train. An alternate design requires the allocated track space to be relinquished to the interlocking element in the event of an open switch point.

(51) Another characteristic of physical train autonomous operation is related to failure conditions. One unique characteristic of the ATCS is the mechanism used to detect failures of physical trains and communicate failure information to other train control elements. A failure is detected by self-diagnostics of the failed physical train element or by loss of communication with a paired train control element. Failure information, including the identity and characteristics of the failed physical train are propagated within the ATCS using daisy chain communication by paired train control elements. The preferred embodiment identifies a physical train by a “train signature.” FIG. 7 shows various design options to provide physical train signature for a train consist 161. A first design option is to define the train signature as the number of axles 193 in the train consist 161. A second design option is to define the train signature as the combination of a fixed ID 195 embedded in a first passive transponder (tag) 196, and the number of train axles 193. The third design option is similar to the second option, wherein the train signature is a combination of a train ID and the number of axles. However, the train ID includes a fixed field based on information embedded in a transponder, and a variable field that reflects the route ID for the train 197. The route ID changes for each train trip, but remains fixed during a train trip. In the preferred embodiment, a train trip is defined as the trip from an initiating terminal station to a destination terminal station. The fourth design option is to define the train signature as a combination of a first fixed train ID 195, the number of axles 193 in the train consist, and a second fixed train ID 199 embedded in a second passive transponder 194. It should be noted that additional train status information could be included in the train signature. For example, the train signature could reflect the train operating status, including if the train is operating with a restricted speed or based on a movement authority limit.

(52) FIG. 8 demonstrates the concept of propagating physical train failure information by relaying the failure data from one train control element to the next. In FIG. 8, physical train T-1 200 has experienced a failure and is unable to communicate with paired 205 virtual train 204 and paired 203 physical train 202. Upon losing communication with T-1 200, physical train T-2 202 transmits a “Trailing Train Failure” (“TTF”) message 207 to paired train control elements ABSU-3 210 and virtual train V-12 208. The TTF message 207 identifies the failed physical train as T-1 200, using its train signature. Upon the movement of physical train T-2 202 past ABSU-3 210, ABSU-3 is preconditioned to detect the crossing of T-1 200. Further, as physical train T-2 202 continues to move, it will propagate the T-1 200 failure data to paired fixed location train control elements.

(53) Similarly, upon losing communication with T-1 200, virtual train V-8 204 transmits a “Leading Train Failure” (“LTF”) message 209 to paired train control elements ABSU-2 212 and virtual train V-6 206. The LTF message 209 identifies the failed physical train as T-1 200, using its train signature. Upon receiving the LTF message 209, ABSU-2 212 requests V-8 204 to relinquish its entire track space. In addition, ABSU-2 212 requests V-6 206 to relinquish part of its track space that falls within the absolute signal block 211. The track space controller will then retire virtual train V-8, and ABSU-2 212 switches to the active mode to control the movement of trains into its associated absolute signal block. Upon receiving confirmation from ABSU-3 210 that failed train T-1 200 has passed its location, ABSU2 212 will switch to a permissive state and will relinquish its entire track space (equal to the absolute signal block) to an approaching train. It should be noted that with respect to virtual train V-6 206, it will relay the LTF message to an approaching train, and will most likely relinquish its remaining track space to the approaching train.

(54) Although physical trains have a high level of priority with respect to the acquisition of track space, this high priority level is reduced in the event of a failure or a loss of communication. The movement of a failed physical train and the recovery of the ATCS from such failure are described as part of the ABSU autonomous operation.

(55) Virtual trains are logical elements that represent free/unassigned track space, but have a similar operational behavior to physical trains. These logical elements are implemented as part of the TSC and operate autonomously based on predefined rules. FIG. 9 shows the interactions between a virtual train 220 and other train control elements. A virtual train 220 can acquire track space from a physical train 222, another virtual train 224, an interlocking control element 228, or an absolute block signal unit (ABSU) 226. In addition, virtual train 220 can lease space from a grade crossing element 230. The acquisition of track space takes place as a train ahead (physical 222 or virtual 224) vacates track space, in response to a route request to an interlocking control element 228, or during a failure condition, wherein an ABSU 226 relinquishes the track space associated with its absolute signal block (ASB) after ensuring that the ASB is vacant. Further, the virtual train 220 receives leased space in response to a request for track space to a grade crossing control element 230.

(56) In addition, a virtual train 220 can relinquish track space to a physical train 232, another virtual train 234, an interlocking control element 238, or an absolute block signal unit (ABSU) 236. Also, the virtual train 220 returns vacated space back to a grade crossing control element 240. The relinquishing of track space takes place after the virtual train 220 vacates track space upon its movement in the indicated direction 221.

(57) FIG. 10 shows certain characteristics of the autonomous operation for virtual trains. Similar to physical trains, each virtual train establishes a movement authority limit (MAL) based on the available track space it has acquired from paired elements. Also, a virtual train establishes a stopping profile that is based on the MAL, as well as simulation engine parameters that provide operation of virtual trains based on line operating conditions. It should be noted that although a virtual train has a stopping profile associated with a MAL, such a stopping profile does not constrain certain autonomous functions for virtual trains. For example, if a virtual train needs to be retired, this function could be executed without a delay associated with stopping the virtual train. Referring to FIG. 10, upon the creation of a virtual train 245, it receives an initial track space allocation 250, and the virtual train is then paired with adjacent train control elements to acquire/relinquish track space. As the virtual train 245 continues to operate on the line, its allocated track space varies. If the allocated track space falls below a minimum threshold 252, the virtual train 245 is retired and its allocated track space is relinquished to a paired train control element. Conversely, if the allocated track space exceeds a maximum track space threshold 254, the allocated track space is truncated to the initial track space 250, and the excess track space 256 is used to create a new virtual train. These autonomous rules for the operation of a virtual train ensures that during service interruption affecting the movement of a physical train, there is a manageable track space assigned to the virtual train.

(58) FIG. 11 shows examples of operating scenarios during which a virtual train 258 relinquishes a part or its entire allocated track space to another autonomous train control element. In the first example, virtual train 258 relinquishes track space 259 to physical train 260 during the initialization process of the physical train. In the second example, virtual train 258 relinquishes track space 261 to physical train 260 for the purpose of enabling physical train 260 to meet its optimum space requirements. In the third example, virtual train 258 relinquishes track space 263 to interlocking element 262 to enable interlocking operation (for example, the movement of a switch, or the establishment of a route). In the fourth example, virtual train 258 relinquishes track space 265 to an ABSU element 264 upon the detection of a physical train failure. It should be noted that additional rules for the autonomous operation of virtual trains may be required under unique operating conditions. Such rules will supplement the rules disclosed herein, and will be based on the premise that virtual trains have the lowest priority with respect to track space acquisition. It should also be noted that the concept of virtual trains provides a number of benefits to the ATCS, including flexibility of operation for autonomous train control architecture.

(59) FIG. 12 shows characteristics of the autonomous operation of an interlocking element 270 for an operating traffic direction 271. In general, an interlocking element acquires track space from a paired element when it is necessary to modify an existing route, establish a new route or modify traffic directions. There are a number of alternate design choices when routes are fleeted (same route is established for consecutive trains). In the first alternative, and pursuant to one design choice, a train moving away from the interlocking relinquishes vacated track space to a following train that is operating on the same route. In such a case, the interlocking element simply monitors the track space transaction between the two trains, and ensures that the route remains secured and locked. In the second alternative, a train moving away from the interlocking relinquishes vacated track space to the interlocking element for reassignment to a following train. As such, FIG. 12 shows various operating conditions during which the interlocking element 270 acquires track space from paired elements. The interlocking element 270 acquires vacated track space from physical train 272 and virtual train 277 as they move away from its location. Also, the interlocking element 270 acquires track space from a second interlocking element 274, and leases track space from grade crossing element 278 for the purpose of changing a traffic direction. Further, the interlocking element 270 acquires track space from an ABSU 276 for the purpose of performing an interlocking function.

(60) The interlocking element 270 also relinquishes track space 285 to paired elements under various operating conditions. For example, upon receiving a request for a route from an approaching physical train 280, or an approaching virtual train 286, the interlocking element 270 will establish and secure the requested route and will relinquish the associated track space to the train that has requested the route. Also the interlocking element 270 relinquishes track space to another interlocking element 284 to enable the modification of a traffic direction. Further, the interlocking element 270 relinquishes track space to an ABSU 284 to enable a failed train to operate in a section controlled by the ABSU 284. In addition, the interlocking element 270 vacates track space 287 that was leased from a grade crossing element 288 after completing a traffic reversal operation. It should be noted that a physical train is not required to be paired to an interlocking element to request an interlocking route. The preferred embodiment employs a concept wherein an interlocking route request could be relayed to an interlocking element through a daisy chain configuration of virtual trains ahead of its location.

(61) FIGS. 13 & 14 show the configuration of the various routes at a typical diamond crossover interlocking for the preferred embodiment. In general, there are three route sections for each interlocking route: an “approach” section “R1NA” 300, “R2NA” 302, “R1SA” 304 & “R2SA” 306, a “switch” section “R1NN” 301, “R1NR” 303, “R2NN” 305, “R2NR” 307, “R1SN” 309, “R1SR” 311, “R2SN” 313 & “R2SR” 315, and an “exit” section “R1NX” 310, “R2NX” 312, “R1SX” 314 & “R2SX” 316.

(62) FIG. 15 explains the designation of the route sections for the preferred embodiment. The left most letter “R” 320 is the designation for “Route.” The second letter 322 designates the track where the route initiated. In this case, the designation is “1” for TK1 or “2” for TK2. The third letter 324 designates direction of travel: “N” for North and “S” for South. The fourth (right most) letter 326 designates the function of route section, i.e. “A” for an approach section, “N” for a switch section in the Normal position, “R” for a switch section in the Reverse position, and “X” for an exit route section. It should be noted that this designation is provided for the purpose of demonstrating the preferred embodiment and is not intended to limit the invention hereto. As would be understood by a person skilled in the art, different route designations could be used. For example, a designation based on switch number could be used.

(63) With respect to the interaction between a train 290 approaching an interlocking element 291, the train 290 requests track space associated with a route to reach a destination track. For example, in FIG. 14 train 290 moving South on track TK2 requests the interlocking element 291 to relinquish track space to reach destination track TK1. In such case, the interlocking element 291 establishes and secures a route that includes the route sections “R2SA” 306, “R2SR” 315 and “R1SX” 314. The interlocking element 291 will then relinquish the track space associated with the route sections to train 290. In effect, the interlocking element 291 is paired with approaching train 290, and as such it has the origination point for the route. Upon receiving the destination point, it is able to establish and secure the requested route.

(64) FIG. 16 demonstrates the concept of advanced route setting, wherein physical train 330 relays its request for a route to TK2 336 to paired virtual train 332. In turn, virtual train 332 will request the interlocking element 334 to establish a route to track TK2 336. Upon receiving this request from virtual train 332, the interlocking element 334 establishes the requested route for both the virtual train 332 and the physical train 330.

(65) FIG. 17 demonstrates one of the autonomous functions performed by an interlocking element 344 related to the creation of a virtual train 346 under certain operating conditions. In this operational scenario, physical train 340 is moving over an interlocking route from track TK1 to track TK2. During the operation of physical train T-3 340, the interlocking element acquires vacated track space from virtual train V-9 342, which is moving away from the interlocking. Since no train is able to follow virtual train V-9 342 while the physical train 340 movement is in progress, the interlocking element will continue to acquire more track space 343. When the acquired track space exceeds a maximum threshold 343, the interlocking element creates a new virtual train V-5 346 that is assigned the excess track space 347. This process continues until a train is able to make a normal move over the interlocking.

(66) FIG. 18 demonstrates another autonomous function performed by the interlocking element related to the traffic reversal process. In the shown example, Traffic 362 is set to a Northern direction. The traffic reversal process starts by a request from physical train T5 358 to interlocking element IXL-2 356 to establish a route from track TK2 to track TK1. To implement the requested route, IXL-2 356 requires the reversal of traffic direction 362. Interlocking element IXL-2 356 initiates a request for traffic reversal to IXL-1 352. To implement the traffic reversal function, IXL-1 352 needs to acquire the entire track space 364 between IXL-1 352 and IXL-2 356 on TK1. As such, IXL-1 352 continues to acquire vacated track space 366 from physical train 354. Upon the acquisition of the entire track space 364 between the two interlockings, IXL-1 352 relinquishes the entire track space 364 to IXL-2 356. In turn, IXL-2 356 reverses traffic direction 362 and establishes the requested route for physical train T5 356.

(67) FIG. 19 demonstrates an alternative configuration of autonomous train control elements, and an associated process for traffic reversal. Similar to the operational scenario of FIG. 18, physical train T5 358 requests interlocking element IXL-2 356 to establish a route from track TK2 to track TK1. This requires that the direction of traffic 362 be reversed to a Southern direction. As explained above, interlocking element IXL-2 356 initiates a request for traffic reversal to IXL-1 352. To implement the traffic reversal function, IXL-1 352 needs to acquire the entire track space 364 between IXL-1 352 and IXL-2 356 on TK1. In this case, the track space 364 between IXL-1 and IXL-2 includes track space that is allocated to virtual train V-9 372, virtual train V-7 374 and grade crossing 370. In view of the premise that virtual trains have the lowest priority with respect to track acquisition, upon receiving a request from interlocking element IXL-1 352, virtual trains V-9 372 and V-7 374 relinquish their entire allocated track space to IXL-1 352. Virtual trains V-9 and V-7 are then retired. With respect to the track space 376 allocated to grade crossing 370, it cannot be relinquished to IXL-1 352, as such transfer of track space will result in the activation of the grade crossing 370, which is operationally undesirable. However, as explained above, the preferred embodiment includes the premise of leasing the track space allocated to the grade crossing to an interlocking element for the purpose of enabling traffic reversal. As such, upon receiving a request from IXL-1 352, grade crossing 370 leases its allocated track space 376 to IXL-1. The interlocking element IXL-1 352 then transfers the entire track space 364 to IXL-2 356. This will enable IXL-2 to reverse traffic direction and establishes the route requested by physical train T-5 358. Upon the completion of the traffic reversal, interlocking element IXL-2 356 releases track space 376 back to the grade crossing element 370.

(68) FIG. 20 demonstrates the autonomous functions performed by an interlocking element IXL-2 355 upon completing a traffic reversal function. The first action performed by IXL-2 355 is to release track space 376 to grade crossing element 370. IXL-2 355 relinquishes track space to physical train 358 as part of the established route from track TK2 to track TK1. IXL-2 358 also relinquishes the remaining traffic track space 364 to a newly created virtual train V-5 379. It should be noted that the initial assignment of track space associated with traffic to the physical train 358 and the newly created virtual train 379 is performed without consideration of the track space rules associated with the autonomous operation of physical trains and virtual trains. These rules become effective after such initial assignment, and may result in the creation of additional virtual trains.

(69) FIG. 21 shows characteristics of the autonomous operation of a grade crossing control element 400 for an operating traffic direction 401. In general, a grade crossing control element maintains track space that enables vehicle traffic to proceed on the intersecting roadway. It communicates with traffic signal controller to provide advance notification of an approaching physical train, and receive status information related to traffic signal operating and health conditions. The grade crossing element 400 relinquishes its track space only after ensuring that the traffic signal controller is operating correctly, that all minimum functional timing requirements for traffic signals and any associated pedestrian signals have been complied with, and that its warning signals and gates have been activated. As such, grade crossing element 400 relinquishes track space 403 to an approaching physical train 402 or to an absolute block signal unit 404 in the event of a failure condition. The grade crossing element leases track space 407 (without affecting road traffic operation) to virtual trains 406 and interlocking elements 408.

(70) Upon the movement of a physical train 410 past its location or the completion of manual train operation under the supervision of an ABSU 412, the grade crossing element 400 acquires the associated track space 405 before notifying the traffic signal controller to resume road traffic. Similarly, a virtual train 414 or an interlocking element 416 will release track space 409 back to the grade crossing element 400 either after the completion of the virtual train movement, or the completion of the interlocking function requiring the leased track space.

(71) FIG. 22 demonstrates interactions between the grade crossing control element 430 and other autonomous train control elements. The grade crossing element 430 controls the warning lights and gates 440 at the intersecting roadway 438. In general, the grade crossing element holds track space associated with grade crossing islands 444 for TK1 and TK2. The grade crossing islands 444 correspond to the intersections between railroad tracks TK1 & TK2 and the roadway 438 protected by the grade crossing element. Further, the grade crossing element 430 controls track space in the approach to island sections 440 on both tracks from both the North and South directions 442. There are two main trigger mechanisms for the grade crossing element 430. The first trigger is based on normal operation, wherein a physical train 420 activates the crossing as it moves within a predetermined distance from the intersection. The second trigger occurs during a physical train failure condition, wherein the operation of the failed physical train 426 is under the control of ABSUs 432 & 434.

(72) Under normal train operation, the grade crossing element 430 must provide adequate warning time to pedestrian and vehicle traffic when a physical train approaches the intersection. With respect to operation on TK1 of FIG. 22, virtual trains V-7 422 and V-9 424 traverse through the grade crossing boundaries (track space associated with approaches and island) without activating the grade crossing equipment. This is based on the above described concept of leased track space. Virtual train V-9 422 is paired with following physical train T-1 420, and as such it informs the grade crossing controller 430 that physical train T-1 420 is approaching. Upon receiving such notification, the grade crossing controller 430 monitors the position of virtual train V-9 422, and when the virtual train V-9 422 is at the boundary of its southern approach, it acquires the entire track space leased to virtual train V-9 422 and effect the retirement of this virtual train. This will result in the pairing of grade crossing controller 430 with approaching physical train T-1 420. When physical train T-1 420 reaches a predefined location from the grade crossing island, the grade crossing controller 430 will execute a process to communicate with traffic light signal controller, and activate the grade crossing equipment 440. After receiving confirmation that the grade crossing equipment 440 has been activated, the grade crossing controller 430 relinquishes track space to the physical train T-1 420 to proceed through the grade crossing territory. It should be noted that the location of physical train T-1 420 at which the grade crossing controller 430 starts to execute the grade crossing activation process can vary based on the speed of the approaching physical train T-1 420. In order to ensure adequate warning time at the grade crossing, the grade crossing controller 430 transmits to approaching physical train T1 420 a minimum time duration before physical train T-1 can enter the island track space. When physical train T-1 420 vacates the island track space 444, the grade crossing controller 430 commences a process to deactivate the grade crossing equipment 440.

(73) With respect to the operation on track T-2 of FIG. 22, failed physical train T-5 426 is held at ABSU3 434, until the absolute block track space 436 associated with ABSU3 434 is free of physical trains. Upon acquiring the entire absolute block track space 436, including leased track space 442 & 444 from the grade crossing controller 430, ABSU3 434 requests the grade crossing controller 430 to acquire the leased track space associated with the grade crossing 442 & 444 in order to enable failed physical train T-5 426 to proceed through the absolute block territory 436. Upon receiving such request, the grade crossing controller 430 executes the grade crossing activation process and upon receiving confirmation that the grade crossing equipment 440 has been activated, it enables failed physical train T-5 426 to proceed through the absolute block track space 436. Then upon receiving confirmation from ABSU5 432 that failed physical train T-5 426 has crossed its location, the grade crossing controller starts the process to deactivate the grade crossing equipment 440. It should be noted that under this operation scenario, the activation time for grade crossing equipment could be long. One design choice is to use auxiliary detection at the crossing island 444 to shorten the activation time by deactivating the crossing equipment 440 after the failed physical train T-5 426 leaves the crossing island 444.

(74) As explained above, the grade crossing element 430 normally holds the track space at the intersection islands 444, and controls the track space 442 in the approach to intersections. This enables the grade crossing element 430 to allow vehicle traffic on the roadway 438 when there are no physical trains approaching the intersection, or in the event of an operational scenario that requires a physical train to move close to the intersection without actually crossing the intersecting roadway. One such operating scenario is shown in FIG. 23, wherein physical train T-1 420 makes a station stop and then turns back over an interlocking switch 447 without reaching the intersection island track space 444. The grade crossing controller 430 relinquishes only the approach track space 442 to physical train T-1 420 upon receiving a stop assurance that the physical train will stop before reaching the grade crossing island 444. A stop assurance function is generated by the physical train 420, and indicates that the train is able to stop within its allocated track space that was relinquished to the train by the grade crossing controller 430.

(75) As explained above, the ATCS includes an optional autonomous train control element, which is defined as an Absolute Block Signal Unit (ABSU), to provide a backup mode of operation during system failures. Further, the ABSU facilitates system and train initializations. The ABSU operation is based on the absolute permissive block principle, wherein a train is given a movement authority to proceed through a block from the entering boundary of the block to its exit boundary when the entire block is vacant. The design of the ABSU is based on a generic configuration of traditional signal elements. As shown in FIG. 24, a typical ABSU 500 includes a processing module 512, a communication module 502, an axle counter 506, a transponder antenna 508, an optional active transponder 510 and an optional signal/stop element 514.

(76) FIG. 25 shows characteristics of the autonomous operation of an Absolute Block Signal Unit (ABSU) 515 for an operating traffic direction 520. In general, an ABSU element acquires track space from a paired element when it is necessary to provide a backup mode of operation during system failures. As such, FIG. 25 shows various operating conditions during which the ABSU element 515 acquires track space from paired elements. The ABSU element 515 acquires vacated track space from physical train 532 during a failure condition. This ABSU function is triggered upon the detection of a failed physical train approaching its location. Similarly, when operationally required, the ABSU element 515 acquires track space from a virtual train 534 during a failure condition. The acquisition of track space from a virtual train 534 is not based on vacated track space, but rather an ABSU element acquires the entire track space assigned to a virtual train, and which falls within the ABSU territory. Further, an ABSU element 515 acquires track space within its associated absolute block territory from an interlocking element 536. In such a case, the ABSU element 515 also ensures that an interlocking route is secured for the movement of a failed physical train through its absolute block territory. Similarly, an ABSU element leases/acquires track space from a grade crossing element 528 that is located within its absolute block territory.

(77) Normal ATCS operation does not require an ABSU element 515 to acquire track space from an ABSU ahead 540. However, under unique operating condition, wherein it is desirable to operate a manual train, an ABSU element acquires track space from an ABSU ahead to provide an overlap (sufficient breaking distance) for manual train operation.

(78) The ABSU element 515 does not directly relinquish track space to a failed physical train since the failed physical train may not be paired with the ABSU element. Rather, the ABSU 515 permits the failed physical train to proceed through its track space until it leaves its absolute block territory. Further, upon receiving confirmation from the ABSU ahead that the failed physical train has passed its location, the ABSU element 515 relinquishes its track space to an approaching physical train 522. Similarly, an ABSU element 515 relinquishes its track space to a new created virtual train 524 upon the completion of a failed physical train movement outside of its absolute block territory. In addition, an ABSU element 515 relinquishes track space to an interlocking element 526 to enable the execution of interlocking functions. Also, the ABSU element 515 relinquishes space to a grade crossing element 528 as demonstrated in FIG. 22. Furthermore, the ABSU 515 relinquishes track space to an approach ABSU 530 to support manual train operation as explained above.

(79) FIG. 26 demonstrates the basic autonomous operation of an ABSU element. As explained above, during normal ATCS operation, the ABSU elements operate in a passive mode to monitor the operation of autonomous trains (physical and virtual), without performing any control function that affects train movements. Upon the detection of failed physical train T-7 542 that is approaching its location, ABSU-5 543 switches to an active mode of operation wherein it controls the movement of trains into its associated absolute block track space 548. ABSU-5 543 acquires track space 550 that is vacated by a physical train T-5 544, which is moving away from its location. Then upon acquiring the entire absolute block track space 550, ABSU-5 543 permits failed train T-5 544 to move past its location and enter its associated absolute block territory 550. Depending on the type of failure, ABSU-5 543 can transmit a movement authority limit to failed train T-5 544 using an active transponder 510 (FIG. 24). Alternatively, ABSU-5 543 can activate a permissive wayside signal to authorize failed train T-5 543 to operate manually past its location.

(80) FIG. 27 illustrates certain ABSU autonomous functions associated with a physical train T-5 553 failure. In this figure, physical trains T-3 555, T-5 553 and T-7 551 are operating in the vicinity of ABSU-3 559 and ABSU-5 551. Prior to the failure, the physical trains had track space allocations 552, 554 & 556 as shown in FIG. 27. Upon the failure of physical train T-5 553, and especially if physical train T-5 is not able to communicate with paired train control elements T-3 555 and T-7 551, physical train T-5 553 cannot relinquish vacated track space to T-7 551, and cannot acquire additional track space from T-3 555. As such, failed physical train T-5 553 initially retains the track space it had 554 at the time of the failure. The movement of T-5 is then governed by operating rules and procedures. Typically in the preferred embodiment, T-5 receives authorization to proceed at restricted speed passed the limit of its allocated track space 554. Further, physical train T-7 551 is not able to acquire additional track space, and as such is not able to move past the movement authority limit associated with its track space 552. In addition, track space vacated by T-3 555 cannot be assigned to T-5.

(81) Upon losing contact with failed physical T-5, physical train T-3 555 informs ABSU-3 559 that a failed physical train is approaching its location. It also provides ABSU-3 with the train signature information for failed train T-5. This enables ABSU-3 to identify physical train T-5 when it approaches its location. It also enables ABSU-3 to determine when all the axles of T-5 have passed its location. Further, upon receiving T-5 failure information, ABSU-3 559 switches to the active mode. Then upon the movement of physical train T-3 555 past its location, ABSU-3 559 assumes the “stop” operating state and acquires the track space vacated by T-3 in the approach to its location. ABSU-3 then holds said vacated track space in abeyance to be relinquished to the next train T-7 551 at a later time. In addition, ABSU-3 starts acquiring the additional track space vacated by T-3 555. Then, upon accumulating track space equal to its associated absolute block track space, ABSU-3 559 authorizes failed physical train T-5 553 to pass its location as explained by the operation shown in FIG. 26. Also, after the movement of T-5 past the location of ABSU-3 559, ABSU-3 creates a new virtual train and relinquishes the track space that was originally assigned to T-5 together with the track space held in abeyance 560 to the new virtual train. The newly created virtual train will operate within the track space occupied by T-5, and will relinquish vacated track space to physical train T-7 551.

(82) In addition to providing a fallback mode of operation during ATCS failures, ABSUs are used to support system and train initialization functions. Upon entering a territory controlled by the Autonomous Train Control System (ATCS), a physical train is initialized to operate in the territory. The physical train initialization process consists of a number of functions, including localization of the physical train, sweeping track space adjacent to the front and back ends of the train (also known as the “sieving function”), establishing communication with the Track Space Controller (TSC), transmitting physical train operating data to the TSC, allocating an initial track space to the physical train, and pairing the physical train with appropriate autonomous train control elements. To establish initial communication with the TSC, the CIC includes a number of memory pairing modules defined as “incubators,” and are used to establish communication between a newly initialized physical train and the TSC. In order to control the initialization process, ABSUs operate in the active mode, wherein they control movement of localized and paired trains into the associated absolute block track space territories. Under the active mode, an ABSU accumulates track space from a paired physical train that is localized. Further, an ABSU receives the sieving status of the localized train moving away from its location, and uses this status as one of the parameters to determine if an approaching physical train should be authorized to move into its associated absolute block track space.

(83) An illustration of the sweeping process is shown in FIG. 28, wherein a localized physical train T-5 563 is sieved at the location of ABSU-7 565. The sieving process ensures that there is no short train hidden in front or in the back of the physical train 563. As such, the sieving process is performed in two steps. In the first step, the front of physical train T-5 563 is sieved when T-5 reaches the location of ABSU-7 while the absolute block track space 564 in its entirety is assigned to ABSU-7 565 (i.e. free of physical trains). Alternatively, the front of T-5 is sieved when it reaches the location of ABSU-7 while ABSU-7 holds part of its associated absolute block track space 564. Similarly, in the second step, the rear end of physical train T-5 563 is sieved when all the axles of T-5 pass the location of ABSU-7 565 while the absolute block track space 562 in its entirety is assigned to ABSU-5 561 (i.e. free of physical trains). To implement this sieving process, it is necessary for ABSU-3 566, ABSU-5 561 and ABSU-7 565 to exchange operational data. It is also necessary to establish communication between ABSU-7 565 and T-5 563 to confirm to T-5 that the sieving process was completed successfully. Further, during the implementation of a sieving process, it is necessary for the ABSUs to coordinate their activities and ensure that train movements do not interfere with the sieving process. For example, ABSU-5 561 prevents trains from entering its associated absolute block track space 562 while the sieving process for T-5 563 is on-going. Similarly, ABSU-7 565 prevents T-5 from entering its associated absolute bock track space 564 until it verifies that at least the near end part of this track space is vacant. This will ensure the successful sieving of T-57 563.

(84) It should be noted that additional autonomous train control elements could be implemented in an ATCS system. For example, an autonomous train control element could be defined and implemented to establish a work zone and to authorize the movement of trains within its boundaries. Since work zones could be implemented at any location on the track, they are classified as a temporary autonomous train control element. In the preferred embodiment, a work zone element is created by the Track Space Controller (TSC) and is allocated an initial track space. Upon its creation, the work zone train control element can create virtual trains to operate within its allocated track space. The work zone element can also relinquish track space to other train control elements, including an approaching physical train, based on predefined rules. A physical train operating within the territory assigned to a work zone element must operate at a reduced speed that is established by the work zone element and communicated to the physical train. In the preferred embodiment, track space that is located within a work zone and vacated by a physical train is relinquished back to the work zone element for reassignment to a virtual train or a following physical train. When the work zone is no longer needed and upon receiving confirmation from a supervisory control system, the TSC will retire the work zone element. The track space assigned to the work zone element will then be reassigned to virtual trains and/or to an approaching physical train as the case may be.

(85) One element of the ATCS is defined as the Track Space Controller (TSC). The TCS manages the interfaces between the various autonomous train control elements, as well as the interfaces between the ATCS elements and other systems in the ATCS operating environment. In addition the TCS manages the creation and retirement of virtual trains and work zone elements. The TCS can be implemented on a dedicated centralized computing environment, or in a network computing environment such as cloud, distributed or virtual network computing. The general architecture of the TCS is demonstrated by the block diagram shown in FIG. 29.

(86) The TCS 599 includes a physical interface module 602 to interface the various TCS elements with physical elements, including physical trains 612, interlocking control elements 616, grade crossing control elements 614 and Absolute Block Signal Units (ABSU) 618. A data communication network 600 is used to interconnect the TCS 599 with the autonomous physical elements. In addition, the TCS 599 includes a diversity of logical and memory modules. Logical modules 634 & 636 are used to provide computing resources for virtual trains, while memory modules 626, 628, 630 & 638 are used to store operational data related to autonomous physical elements.

(87) In the preferred embodiment, the operation of the TCS is controlled by the train controller module 604, which also controls the creation/activation and retirement of virtual trains. To that extent, an address bus 608 and a data bus 632 are used to enable the train controller module 604 to control the operation of the various modules included in the TCS 599. It should be noted that, and as would be understood by a person skilled in the art, a separate TCS processor could be used to control the operation of the TCS. In such an embodiment, the function of the train controller module 604 is limited to the creation/activation and retirement of virtual trains. Upon receiving a request from an autonomous train control element to create or activate a new virtual train, the train controller 604 selects and activates a “spare” logical element 634 to provide the computing resources for the newly created virtual train. The train controller 604 assigns a unique train ID to the newly created virtual train, as well as an initial location that must be confirmed with the autonomous train control element that requested the creation of the new virtual train. Further, the train controller 604 communicates with the Communication Interface Controller CIC 610 via the CIC Interface 620 requesting that the newly created virtual train be paired with the autonomous train control element that requested the creation of the virtual train. In turn, the paired autonomous train control element confirms the location of the new virtual train and relinquishes track space to it.

(88) Alternatively, under certain operating conditions, an autonomous train control element requests the retirement of a virtual train. An example of such operating conditions is during the initialization of a physical train. Typically for the preferred embodiment, a physical train is initialized as a replacement of an existing virtual train, and by acquiring its allocated track space. The virtual train is then switched to a standby mode or state (“standby mode”), its logical element is spared, and the physical train receives an initial movement authority limit associated with the retired virtual train. This movement authority limit is adjusted to account for the length of the physical train. In general, upon receiving a request from an autonomous train control element to retire a virtual train, the train controller 604 acknowledges the request and informs the train control element of a “pending” status of the request. The train control element then acquires the track space assigned to the virtual train, and confirms to the train controller 604 that the virtual train is ready to be retired. Upon receiving such confirmation, the train controller 604 retires the virtual train and assigns a “spare” status to the corresponding logical module 634.

(89) The TSC 599 further includes a Simulation Engine Module 624 that provides nominal operating speeds for the various virtual trains operating in the ATCS territory. The nominal operating speeds are based on the average operating speeds of physical trains 612 operating at various sections of the ATCS territory, as well as civil speed limits. It should be noted that physical trains 612 provide operational data (location, speed, etc.) to corresponding memory modules 638 that reside in the TSC 599.

(90) At the time of a physical train initialization, the train controller 604 assigns a memory module to it. Similarly, each autonomous train control element 614, 616 & 618 is assigned an associated memory module 625, 628 & 630 within the TSC 599. The memory modules stores real time data related to the operational statuses of the corresponding autonomous train control elements, and provide relevant data to the CIC 610. The real time data includes operational and maintenance data and are used to provide train location and status information for the Automatic Train Supervision displays as well as for maintenance functions.

(91) In addition, the TSC 599 includes two memory modules that provide line data necessary for the operation of the autonomous train control elements. The line data memory unit 622 stores track geometry information including data for grades, curves, super elevation, station platforms, civil speed limits, locations of wayside equipment, etc. Similarly, interlocking data memory unit 626 stores data related to interlocking configuration, route and traffic patterns, track switch information, etc. In the preferred embodiment, the line data is downloaded from the Automatic Train Supervision (ATS) system via the ATS interface module 606. In turn, relevant line data is downloaded to physical trains 612 at the time they are initialized in ATCS operation. In addition the ATS system provides itinerary data for each physical train to control and regulate its movement through the ATCS territory. The train itinerary data includes train destination, identity of interlocking routes, required station stops, schedule data, etc. In addition, the ATS system can issue direct commands to physical trains that impact normal scheduled operation. These commands include skip station stop, hold train at station, emergency stop, change itinerary, etc. Further, the ATS system provides line/train regulation data that is sent in the form of performance parameters to physical trains. It should be noted that one design choice is to store the physical train 612 itinerary data, any direct ATS commands and regulation data in the corresponding memory modules 638. In addition, and as disclosed above, operational parameters of virtual trains could be used for the purpose of train regulation.

(92) The physical interface unit 602 provides the needed wireless communications, via wireless communication network 600, between trackside physical elements 612, 614, 616 & 618 and corresponding logical/memory modules 638, 625, 628 & 630. It should be noted that communications between paired and interconnected physical elements do not go through the physical interface 602. However, communications between paired physical elements and virtual trains pass through the physical interface unit 602.

(93) Another element of the ATCS is defined as the Communication Interface Controller (CIC). The CIC's main function is to dynamically manage in real time the pairing of various ATCS elements. In general, the CIC receives location information from the Track Space Controller (TSC), and assigns communication frequencies/channels to paired ATCS elements. Further, in the preferred embodiment, the CIC provides fixed communication links/channels between fixed location ATCS elements. The general CIC architecture proposed for the preferred embodiment is shown in FIG. 31.

(94) The CIC 610 includes a CIC processor 650 that control the operation of the CIC unit, a plurality of pairing memory modules 652, 654, 656, 658, 660, 668, 670, 672 & 674, a data bus 662, an address bus 664, and an interface to the data communication system 600. The main function of a pairing memory module is to store in real time the identity information of the ATCS elements paired together, as well as data related to the communication frequencies/channels used for the paired communications. To that extent, and to facilitate the implementation of the pairing process, the preferred embodiment employs an architecture that includes different types of modules. There are modules that include two cells 652, 656, 658 & 660, which are used for the pairing of two ATCS elements. Further, there are modules that include three cells 654, 668, 670, 672 & 674, which are used for the pairing of three ATCS elements. In general, a three-cell module is used to pair a fixed element (IXL 616, XING 614 & ABSU 618) with physical and/or virtual trains. Also, certain two-cell modules 660 are used to pair or provide communication links between fixed location elements. Other two-cell modules 656 are used to pair moving ATCS elements. Spare modules 658 are provided to accommodate increased traffic conditions. In addition, a number of cells 652 are dedicated for incubator functions to establish initial communication between newly initialized physical trains and the TSC 599.

(95) It should be noted that the preferred embodiment employs cell designations to facilitate the dynamic pairing of ATCS elements. For example, the designations “F” for fixed location, “C” for physical train and “I” for incubator are designed to establish communication for physical elements through the Data Communication Network. Similarly, the designations “V” for virtual train and “t” for Track space controller are designed to establish communication to modules within the TSC. The “s” designation is for spare cells. Preferably, the pairing memory modules could be configured geographically during the application design along individual tracks. It should also be noted that the above CIC architecture is being disclosed for the description of the preferred embodiment. As would be understood by persons skilled in the art, different architectures could be devised to provide the functions for the CIC element. For, example network communication switching could be used to provide the interconnections (pairing) for the various ATCS elements. In addition, pairing memory modules capable of pairing more than three elements could be provided if required by the track configuration warrants it.

(96) As would be understood by those skilled in the art, alternate embodiments could be provided to implement an Autonomous Train Control System based on the new concepts disclosed herein. For example, and as disclosed in the detailed description of an alternate embodiment, physical elements, including physical trains, interlocking control devices, grade crossing control devices and ABSUs could be virtualized and implemented in a network computing environment.

DETAILED DESCRIPTION OF AN ALTERNATE EMBODIMENT

(97) Referring now to the drawings where the illustrations are for the purpose of describing an alternate embodiment of the invention and are not intended to limit the invention hereto, FIG. 32 shows a block diagram of a configuration of the proposed Autonomous Train Control System (ATCS) in accordance with the teachings of the alternate embodiment. This configuration includes physical trains T-1 710 and T-2 112, virtual trains V-3 742, V-6 746 & V-8 744, interlocking element 706, absolute block signal units ABSU2 709 & ABSU3 707. The ATCS also includes centralized computing resources 760 that is implemented in a cloud computing environment, and which includes two main elements: the Track Space Controller (TCS) 700, and the Communication Interface Controller (CIC) 750.

(98) The TCS 700 includes logical modules that provide virtualization of physical train control elements. More specifically, the TCS 700 includes logical modules that are defined as “Avatar” trains A-1 745 & A-2 743, and which correspond to physical trains T-1 710 and T-2 712. Also, the TCS 700 includes a logical module VIXL-1 730 that virtualizes the interlocking control unit 714. In addition, the TCS 700 includes logical modules VABSU-2 732 and VABSU-3 728 that virtualize Absolute Block Signal Units ABSU-2 709 and ABSU-3 707. It should be noted that if the physical train control installation includes a grade crossing control device, then the ATCS will also include a virtual grade crossing control element that performs the required grade crossing functions in the context of an Autonomous Train Control System.

(99) In the alternate embodiment, the main functions performed by the TCS 700 include the management of virtual trains 742, 744 & 746, the management of logical modules that provide virtual train control elements that correspond to physical elements, management of interfaces 716 and communications between virtual train control elements and corresponding physical elements, and the management of interfaces with external systems 720. In effect, the main concept used in the alternate embodiment is for the virtual train control elements (avatar trains, virtual trains, virtual interlocking control elements, virtual Absolute Block Signal Units, and virtual grade crossing control units) to operate autonomously from each other, exchange virtual track space that corresponds to the physical track space within the ATCS territory, receive status information from corresponding physical elements and transmit control data to corresponding physical elements.

(100) Similar to the preferred embodiment, the main function of the CIC 750 is to pair the virtual train control elements together based on location and operational data received from the TCS 700. As such, for the ATCS configuration shown in FIG. 32, and for the relative positions of trains shown, virtual train V6 724 is paired with avatar train A-1 745, virtual train V-8 744 is also paired with A-1 745. In turn, V-8 744 is also paired with avatar train A-2 743 and virtual absolute block signal unit VABU-2 732. Further, avatar train A-2 743 is paired with virtual interlocking control element VIXL-1 730. In addition, virtual train V-3 742 is paired with VIXL-1 730 and ABSU3 728. It should be noted that avatar trains A-1 and A-2 continuously reflect the movements of associated physical trains T-1 and T-2. It should also be noted that as the relative positions of avatar (physical) trains and virtual trains change, the pairing of train control elements change. This is a dynamic process based train locations and operational data.

(101) Referring now to FIG. 33, where the illustrations are for the purpose of describing the alternate embodiment of the invention and are not intended to limit the invention hereto, FIG. 33 is a conceptual diagram of the proposed ATCS, showing virtual track space 800, and the various autonomous virtual train control elements, including avatar trains 802, virtual interlocking control elements 803, virtual grade crossing control elements 804, virtual trains 805, virtual Absolute Block Signal Units (ABSU) 806 & any other virtual train control element 811. The virtual track space 800 corresponds to the track space within the ATCS territory. Similar to the preferred embodiment, the main concept for the operation of the alternate embodiment is for the various virtual train control elements to acquire virtual track space, then operate autonomously within that space in accordance with predefined rules. As part of normal ATCS operation, virtual train control elements exchange virtual track space 807 with paired elements. Similar to the preferred embodiment, the initial allocation of virtual track space 809 to the virtual train control elements is made during system and/or train initialization, and is based on predefined rules.

(102) With respect to the autonomous operation of an avatar train, it is similar to the operation of the physical train described in the preferred embodiment. As such, an avatar train acquires and relinquishes virtual track space from/to other virtual train control elements. More specifically, and as shown in FIG. 34, an avatar train 821 can acquire track space from another avatar train 820, a virtual train 822, a virtual interlocking control element 824, a virtual grade crossing control element 826, or a virtual absolute block signal unit (ABSU) 828. The acquisition of virtual track space takes place as a train ahead (avatar 820 or virtual 822) vacates virtual track space, in response to a route request to a virtual interlocking control element 824, in response to a request for virtual track space to a virtual grade crossing control element 826, or during a failure condition, wherein a virtual ABSU 828 relinquishes the virtual track space associated with its absolute signal block (ASB) after ensuring that the ASB is vacant. It should be noted that to proceed through a grade crossing section, it is necessary for the avatar train to acquire track space directly from the grade crossing. A train (avatar or virtual) moving ahead of the avatar train must relinquish/release vacated virtual track space to the virtual grade crossing element for reassignment to the following avatar train.

(103) Similarly, an avatar train 821 can relinquish virtual track space to another avatar train 830, a virtual train 832, a virtual interlocking control element 834 a virtual grade crossing control element 836, or a virtual absolute block signal unit (ABSU) 838. The relinquishing of virtual track space takes place after avatar train 821 vacates virtual track space upon its movement in the indicated direction 825.

(104) FIGS. 35 & 36 show certain characteristics of the autonomous operation for avatar trains. Each avatar train establishes a movement authority limit (MAL) based on the available virtual track space it has acquired from paired elements. The MAL is then transmitted to the associated physical train. In turn, the physical train establishes a stopping profile that is based on the MAL received from the avatar train. Similar to the preferred embodiment, to the extent possible, it is desirable to provide an “optimum” virtual track space to an avatar train in order for the associated physical train to operate at the maximum allowable operating speed within the ATCS territory. As such, FIG. 35 reflects an operating scenario, wherein the current virtual track space and associated MAL 840 for an avatar train 839 is less than the required optimum virtual track space 842. Based on the premise that avatar trains have an assigned level of virtual track space acquisition priority that is higher than that of virtual trains, the autonomous operation of avatar trains includes a rule wherein an avatar train 839 acquires more track space from a paired virtual train 846 to satisfy its optimum virtual track space requirements. As such, in FIG. 35, avatar train 839 requests virtual track space from paired front virtual train 846 to satisfy the requirement for an optimized virtual track space 842. In the event the needed virtual track space 844 is more that the virtual track space 845 allocated to the virtual train 846, the process is repeated until the optimized virtual track space 842 is satisfied. Alternatively, if the needed virtual track space 844 is less than the track space 845 allocated to the virtual train 846, then the virtual train 846 will relinquish the needed track space 844 to the avatar train 839. However, if the remaining virtual track space for the virtual train 846 is less than a certain threshold, the entire virtual track space 845 assigned to the virtual train 846 is relinquished to the avatar train 839. In such a case, the virtual train 846 is retired.

(105) A second characteristic of the avatar train autonomous operation is associated with the operating scenario depicted in FIG. 36, wherein the virtual track space 852 allocated to an avatar train 855 exceeds a maximum virtual track space threshold 852. Similar to the preferred embodiment, it is not desirable for an avatar train to acquire virtual track space way in excess of its optimum virtual track space. As such, one autonomous operation characteristics of avatar train is to relinquish virtual track space when its allocated space exceeds a maximum threshold. An example of an operational scenario that results in excess virtual track space 856 occurs when a physical train (and associated avatar train) is delayed, and wherein the avatar train keeps accumulating virtual track space from a train ahead that is moving away from its location. In FIG. 36, when the virtual track space allocated to avatar train 855 exceeds the maximum virtual track space threshold 852, the avatar train relinquishes the excess virtual track space 856 for the creation or activation of a new virtual train 851.

(106) As indicated above, the autonomous operation of an avatar train in the alternate embodiment is similar to the autonomous operation of a physical train in the preferred embodiment. As such, additional operational scenarios that involve an avatar train are similar to the operational scenarios disclosed in the preferred embodiment. For example, the operational scenario described in FIG. 6, wherein a physical train relinquishes track space to a paired autonomous train control element that has a higher assigned level of track space acquisition priority.

(107) With respect to the autonomous operation of an avatar train during a failure condition in the associated physical train, the avatar train detects such failure and communicates the failure information to other train control elements. The failure is detected either based on self-diagnostics of the failed physical train or by loss of communication between the avatar train and the physical train. Failure information, including the identity and characteristics of the failed physical train are propagated within the ATCS using daisy chain communication by paired virtual train control elements. Similar to the preferred embodiment, the alternate embodiment identifies a physical train by a “train signature.” FIG. 7 shows various design options to provide physical train signature for a train consist 161. The various design options are described and explained in the preferred embodiment.

(108) As in the preferred embodiment, virtual trains are logical elements that represent free/unassigned virtual track space, but have a similar operational behavior to avatar trains. These logical elements are implemented as part of the TSC and operate autonomously based on predefined rules. In addition, the autonomous operation of virtual trains in the alternate embodiment is similar to the autonomous operation of virtual trains in the preferred embodiment, except that virtual trains have to interact with avatar trains in lieu of physical trains. In that respect, the autonomous rules that govern the operation of a virtual train in both the preferred and alternate embodiments are similar. Further, the characteristics of the virtual train autonomous operation are similar in both embodiments.

(109) In the alternate embodiment, the virtual interlocking control element (V-IXL) provides the control logic functions for trackside interlocking equipment. The V-IXL communicates with a physical interlocking interface unit through a data communication network. In turn, the interlocking interface unit provides local control functions for the track side interlocking equipment based on control data received from the V-IXL. Further, the interface unit receives status information from the interlocking trackside equipment, and transmits this information to the V-IXL. The characteristics of the autonomous operation of the V-IXL are similar to the characteristics of the autonomous operation of the interlocking control element in the preferred embodiment. Some of the characteristics are related to operating scenarios, wherein the V-IXL acquires virtual track space from paired elements. Other characteristics are related to operating scenarios, wherein the V-IXL relinquishes virtual track space to paired elements. During these operating scenarios, the V-IXL performs various interlocking functions (modify a route, establish new route, modify traffic direction, etc.). Examples of the operating scenarios are shown in FIGS. 13, 14, 16, 17, 18, 19 & 20, and are described in the preferred embodiment.

(110) The alternate embodiment could also includes a virtual grade crossing control element (V-XING). The V-XING provides the control logic functions for physical grade crossing equipment. The V-XING communicates with a physical grade crossing interface unit through a data communication network. In turn, the grade crossing interface unit provides local control/activation functions for the physical grade crossing equipment based on activation data received from the V-XING. Further, the interface unit receives status information from the grade crossing equipment, and transmits this information to the V-XING. The characteristics of the autonomous operation of the V-XING are similar to the characteristics of the autonomous operation of the grade crossing control element in the preferred embodiment. These characteristics are related to operating scenarios, wherein the V-XING relinquishes/recaptures virtual track space (physical track space in the preferred embodiment) from paired elements. During these operating scenarios, the main function of the V-XING is to provide safe operation of vehicle and rail traffic at an intersection. In general, and as described in the preferred embodiment, the V-XING maintains virtual track space in the approach to and at the associated intersection to allow vehicle traffic to proceed. The V-XING relinquishes virtual track space to paired avatar trains to allow associated physical trains to proceed through the intersection. Further, the V-XING relinquishes virtual track space to other paired elements to allow them to perform various autonomous functions. Examples of the operating scenarios during which virtual track space is exchanged between the V-XING and other virtual train control elements are shown in FIGS. 22 & 23, and are described in the preferred embodiment.

(111) The alternate embodiment also includes an optional virtual Automatic Block Signal Unit (VABSU). The VABSU provides the control logic functions for physical ABSU equipment. The VABSU communicates with a physical ABSU interface unit through a data communication network. In turn, the physical ABSU interface unit provides local control functions for the physical ABSU equipment based on control data received from the VABSU. Further, the interface unit receives status and monitoring data from the physical ABSU equipment, and transmits this information to the VABSU. The characteristics of the autonomous operation of the VABSU are similar to the characteristics of the autonomous operation of the ABSU element in the preferred embodiment. These characteristics are related to operating scenarios, wherein the V-XING relinquishes/recaptures virtual track space from paired elements. During these operating scenarios, the main function of the V-XING is to provide system initialization functions and to support a backup mode of operation during system failures. Further, the interactions between a VABSU and other virtual autonomous train control elements are similar to those described in the preferred embodiment.

(112) The configuration of physical ABSU equipment is similar to the ABSU configuration described in the preferred embodiment and shown in FIG. 24. As in the preferred embodiment, the VABSU operates in a plurality of modes. During a passive mode, the VABSU monitors train movements during normal train operation without any impact on train service. During a failure condition (active VABSU mode), the VABSU provides control function that ensures safe train separation for a failed physical train. During its autonomous mode of operation, the VABSU acquires virtual track space from an avatar train or a virtual train moving away from its location. The VABSU controls the physical ABSU equipment to hold a failed physical train, and allows it to proceed only after ensuring that its associated absolute signal block is vacant. FIGS. 26 & 27 and associated descriptions in the preferred embodiment provide examples of operational scenarios that demonstrate the characteristics of the autonomous operation of ABSUs. The VABSU also provides control functions during system initialization. More specifically, a VABSU controls the movement of an avatar train and associated physical train into its associated signal block to enable the performance of track sweep, and the initialization of a physical/avatar train into ATCS operation. FIG. 28 and associated description in the preferred embodiment provide an example of operational scenario for system initialization.

(113) Similar to the preferred embodiment, the alternate embodiment employs a Track Space Controller (TSC), which includes logical elements that provide the autonomous operations for various virtual train control elements. The TCS is implemented in a cloud computing environment to provide a very high level of reliability/availability. The TSC manages the interfaces between virtual train control elements, between virtual elements and associated physical elements, and between virtual elements and external elements in the ATCS operating environment (for example ATS). FIG. 37 shows a block diagram of the architecture for the TCS in accordance with the alternate embodiment. The TCS 899 includes elements that are similar to elements included in the TCS of the preferred embodiment. A physical interface module 902 performs the function of interfacing the various virtual TCS elements with associated physical elements, including physical trains 912, interlocking control elements 916, grade crossing control elements 914 and Absolute Block Signal Units (ABSU) 918. A data communication network 900 is used to interconnect the TCS 899 with the physical elements. In addition, the TCS 899 includes a diversity of logical modules 925, 928, 930, 936 & 938 that are used to provide computing resources for virtual crossing elements, virtual interlocking controllers, virtual ABSUs, virtual trains and avatar trains.

(114) In the alternate embodiment, the operation of the TCS is controlled by the train controller module 904, which also controls the creation/activation and retirement of virtual trains, as well as the management of avatar trains. To that extent, an address bus 908 and a data bus 932 are used to enable the train controller module 904 to control the operation of the various modules included in the TCS 899. It should be noted, and as would be understood by a person skilled in the art, that a separate TCS processor could be used to control the operation of the TCS. In such an embodiment, one of the main functions of the train controller module 904 is to create/activate and retire of virtual trains. Upon receiving a request from a virtual train control element to create or activate a new virtual train, the train controller 904 selects and activates a “spare” logical element 934 to provide the computing resources for the newly created virtual train. The train controller 904 assigns a unique train ID to the newly created virtual train, as well as an initial location that must be confirmed with the virtual autonomous train control element that requested the creation of the new virtual train. Further, the train controller 904 communicates with the Communication Interface Controller CIC 910 via the CIC Interface 920 requesting that the newly created virtual train be paired with the virtual autonomous train control element that requested the creation of the virtual train. In turn, the paired virtual autonomous train control element confirms the location of the new virtual train and relinquishes virtual track space to it.

(115) Alternatively, under certain operating conditions, a virtual autonomous train control element requests the retirement of a virtual train. An example of such operating conditions is during the initialization of a physical/avatar train. Typically for the preferred embodiment, a physical/avatar train is initialized as a replacement of an existing virtual train, and by acquiring its allocated virtual track space. The virtual train is then switched to a standby mode or state (“standby mode”), its logical element is spared, and the avatar train receives an initial movement authority limit associated with the retired virtual train. This movement authority limit is adjusted to account for the length of the associated physical train. In general, upon receiving a request from a virtual autonomous train control element to retire a virtual train, the train controller 904 acknowledges the request and informs the virtual train control element of a “pending” status of the request. The virtual train control element then acquires the virtual track space assigned to the virtual train, and confirms to the train controller 904 that the virtual train is ready to be retired. Upon receiving such confirmation, the train controller 904 retires the virtual train and assigns a “spare” status to the corresponding logical module 934.

(116) Further, the TSC 899 has the function of initializing a new avatar train when a physical train enters or is activated in the ATCS territory. When a new physical train establishes communication with the TSC 899, the train controller 904 assigns a spare logical module 939 to operate as an avatar train it. In addition, at the time the ATCS system is configured, fixed location physical elements are assigned logical elements within the TSC 899. For example, a physical interlocking element 916 is assigned a logical module 928 to operate as a virtual interlocking control element, a physical ABSU element 918 is assigned a logical element 928 to act as a virtual ABSU, and a physical grade crossing element 914 is assigned a logical element 925 to act as a virtual grade crossing control element. In addition to providing autonomous control functions, the logical elements store real time data related to the operational statuses of the corresponding physical train control elements. Also, the logical elements provide relevant data to the CIC 910 to effect the pairing process. The real time data includes operational and maintenance data related to physical/virtual elements and is used to provide train location and status information for the Automatic Train Supervision displays as well as for maintenance functions.

(117) The TSC 899 further includes a Simulation Engine Module 924 that provides nominal operating speeds for the various virtual trains operating in the ATCS territory. The nominal operating speeds are based on the average operating speeds of avatar trains 938, which receive operational data from associated physical trains 912 operating at various sections of the ATCS territory, as well as civil speed limits. In addition, the TSC 899 includes two memory modules that provide line data necessary for the operation of the autonomous virtual train control elements. The line data memory unit 922 stores track geometry information including data for grades, curves, super elevation, station platforms, civil speed limits, locations of wayside equipment, etc. Similarly, interlocking data memory unit 926 stores data related to interlocking configuration, route and traffic patterns, track switch information, etc. In the alternate embodiment, the line data is downloaded from the Automatic Train Supervision (ATS) system via the ATS interface module 906. In turn, relevant line data is provided to avatar trains 938, which in turn download relevant data to associated physical trains 912 at the time they are initialized in ATCS operation. In addition the ATS system provides itinerary data for each avatar train to control and regulate its movement through the ATCS territory. The train itinerary data includes train destination, identity of interlocking routes, required station stops, schedule data, etc. Further, the ATS system can issue direct commands to avatar trains that impact normal scheduled operation. These commands include skip station stop, hold train at station, emergency stop, change itinerary, etc. Also, the ATS system provides line/train regulation data that is sent in the form of performance parameters to avatar trains, and then transmitted to associated physical trains. In addition, and as disclosed above, operational parameters of virtual trains could be used for the purpose of train regulation.

(118) The physical interface unit 902 provides the needed wireless communication interfaces, via wireless communication network 900, between trackside physical elements 912, 914, 916 & 918 and corresponding logical modules 938, 925, 928 & 930. It should be noted that communications between paired virtual train control elements are managed by the Communication Interface Controller 910 based on operational data provided by the TSC 899. Also, the CIC 910 provides initial communication links for physical trains as they enter the ATCS territory.

(119) Similar to the preferred embodiment, the alternate embodiment includes an ATCS element defined as the Communication Interface Controller (CIC). The CIC's main function is to dynamically manage in real time the pairing of various virtual ATCS elements. In general, the CIC receives location information from the Track Space Controller (TSC), and assigns communication channels to paired virtual ATCS elements. Further, in the alternate embodiment, the CIC manages the allocation of fixed communication links between virtual train control elements that are associated with fixed location physical elements. The general CIC architecture proposed for the alternate embodiment is shown in FIG. 38. It should be noted, and unlike the preferred embodiment, the communication channels needed for communications between the virtual train control elements reside within the TSC 899. As such, one design choice is for the CIC to provide addressing information for the various logical modules to communicate in dynamic pairing configurations.

(120) The CIC 910 includes a CIC processor 950 that control the operation of the CIC unit, a plurality of pairing memory modules 952, 954, 956, 958, 960, 968, 970, 972 & 974, a data bus 962, an address bus 964, and an interface to the data communication network 900. The main function of a pairing memory module is to store in real time the identity (or address) information of the virtual ATCS elements paired together, as well as data related to the communication links used for the paired communications. To that extent, and to facilitate the implementation of the pairing process, the alternate embodiment employs an architecture that includes different types of modules. There are modules that include two cells 952, 956, 958 & 960, which are used for the pairing of two virtual ATCS elements. Further, there are modules that include three cells 954, 968, 970, 972 & 974, which are used for the pairing of three virtual ATCS elements. In general, a three-cell module is used to pair a fixed location element (VIXL 916, VXING 914 & VABSU 918) with avatar and/or virtual trains. Also, certain two-cell modules 960 are used to pair or provide communication links between fixed location virtual elements. Other two-cell modules 956 are used to pair moving virtual ATCS elements. Spare modules 958 are provided to accommodate increased traffic conditions. In addition, a number of cells 952 are dedicated for incubator functions to establish initial communication between newly initialized physical trains and the TSC 899. It should be noted that in the alternate embodiment, one design choice is to integrate the CIC 910 as part of the TSC architecture 899. In such configuration, the TSC performs the functions performed by the CIC.

(121) It should be noted that the foregoing detailed descriptions of the preferred and alternate embodiments have been given to demonstrate the various disclosed concepts and functions. As would be understood by a person skilled in the art, there are different design choices to implement the concepts presented herein. It should also be noted that the various autonomous elements disclosed in the preferred and alternate embodiments can utilize alternate vital programs to implement the described autonomous train control functions. Obviously these programs will vary from one another in some degree. However, it is well within the skill of the signal engineer to provide particular programs for implementing vital algorithms to achieve the functions described herein. In addition, it is to be understood that the foregoing detailed descriptions of the preferred and alternate embodiments have been given for clearness of understanding only, and are intended to be exemplary of the invention while not limiting the invention to the exact embodiment shown. Obviously certain subsets, modifications, simplifications, variations and improvements will occur to those skilled in the art upon reading the foregoing. It is, therefore, to be understood that all such modifications, simplifications, variations and improvements have been deleted herein for the sake of conciseness and readability, but are properly within the scope and spirit of the following claims.