Rules-based interlocking engine using virtual gates

• US 5,463,552 A
• Filed: 07/30/1992
• Issued: 10/31/1995
• Est. Priority Date: 07/30/1992
• Status: Expired due to Term

• Current Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Original Assignee: AEG Transportation Systems, Inc.
• Inventors: Wilson, Richard A. Jr., Daubner, John M., Jeffers, Frank D.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): PARK, COLLIN
• Application Number:
  US07/921,756
• Time in Patent Office: 1,188 Days
• Field of Search: 346/436, 346/424.01, 246/131, 246/132, 246/133, 246/134, 395/920, 395/902, 395/600, 395/905
• US Class Current: 701/117
• CPC Class Codes: B61L 19/06 Interlocking devices having electrical operation
• CPC Class Codes: B61L 21/04 Electrical locking and release of the route; Electrical repeat locks
• CPC Class Codes: Y10S 706/902 Application using ai with detail of the ai system
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

A method of implementing a computer based interlocking system for automatic train protection includes providing a data base of prestored rule sets for a plurality of guideway objects, the guideway objects being represented as one or more virtual gates of a plurality of virtual gate types, the rule sets defining conditions for a respective guideway object which must be met before entry through a virtual gate of the object is permitted. A high-level description of a guideway layout including all of the guideway objects that form interlocking zones is input and processed using the pre-stored rule sets to form an overall interlocking system definition by locating, retrieving and linking appropriate rule sets corresponding to the respective input guideway objects.

Claims

1. A method of implementing a computer based interlocking system for protecting trains traversing a guideway system, said guideway system comprising guideways comprised of guideway objects which influence movement of trains in the guideway system, comprising:

providing a data base of prestored rule sets for a plurality of guideway objects, said guideway objects defined by entry and exit points, the entry point to at least one guideway object being a virtual gate, the rule sets defining conditions for a respective guideway object which must be met before entry through a virtual gate of said object is permitted;

inputting a high-level description of a guideway system layout including all of the guideway objects that make up guideways in the guideway system;

processing by a computer implemented interlocking engine the high-level description of the guideway system layout using the prestored rule sets to form an internal guideway data model;

supplying status signals from guideway objects and control requests to said interlocking engine;

processing said status signals and control requests by said interlocking engine in real time with reference to said prestored rule sets and said internal guideway data model; and

outputting control signals denying control requests that would result in unsafe conditions.

2. The method according to claim 1, wherein the high-level description of a guideway system layout comprises:

a definition section which describes the entire makeup of the guideway system layout, including the guideways and corresponding guideway objects;

a relation section which defines associations between guideway objects and guideways in the guideway system;

a rules section which states the rules which govern application specific modifications to standard interlocking situations for the guideway objects that make up the guideway system in relation to the current state of those objects; and

an initialization section which permits setting of values for the guideway objects for use during operation of the computer based interlocking system.

3. The method according to claim 1, wherein the step of inputting the high-level description of a guideway system layout comprises:

inputting a definition section which describes the entire makeup of the guideway system layout, including the guideways and corresponding guideway objects;

inputting a relation section which defines associations between the guideway objects and guideways in the guideway system;

inputting a rules section which states the rules which govern application specific modifications to standard interlocking situations for the guideway objects that make up the guideway system in relation to the current state of those objects; and

inputting an initialization section which permits setting of values for the guideway objects for use during operation of the computer based interlocking system.

4. The method according to claim 1, wherein the step of processing to form an internal guideway data model comprises:

parsing the high-level description of a guideway system layout; and

locating, retrieving and linking appropriate rule sets and corresponding respective guideway objects thereby forming an internal guideway data model which includes all of the guideway system objects and their interrelationships.

5. The method according to claim 1, wherein the rule sets are based on the Association of American Railways recommended design practices for design of vital relay based interlocking logic circuits.

6. In a digital computer, a rules based interlocking system for automatic train protection of a guideway comprising:

a guideway data model comprising a plurality of data entries specifying guideway objects, at least one of the guideway objects corresponding to guideway hardware devices, the guideway data model specifying relationships between the guideway objects;

a data base comprising rule sets for a plurality of guideway objects, said guideway objects defined by entry and exit points, the entry point to at least one guideway object being a virtual gate, the rule sets defining conditions for a respective guideway object which must be met before entry of a train through a virtual gate of said object is permitted;

a user input guideway definition file comprising a high-level description of the guideway, including the guideway objects;

a data model parser for parsing the guideway definition file and producing the guideway data model using the data base comprising the rule sets;

an interlocking engine for processing status signals in real time to produce control signals; and

I/O control means for sending said control signals to the guideway hardware devices and for receiving said status signals from the guideway hardware devices based on the guideway data model and sensed status signals.

7. A method of implementing a computer based interlocking system for automatic train protection, comprising:

providing a data base of prestored rule sets for a plurality of guideway objects, the guideway objects being represented as at least one virtual gate of a plurality of virtual gate types, the rule sets defining conditions for a respective guideway object which must be met before entry through a virtual gate of said object is permitted;

inputting a high-level description of a guideway layout including all of the guideway objects that form interlocking zones; and

processing the high-level description using the pre-stored rule sets to form an overall interlocking system definition by locating, retrieving and linking appropriate rule sets corresponding to the respective input guideway objects.

8. The method according to claim 7, wherein the objects include simple switches, turntables and scissors crossovers.

9. The method according to claim 7, wherein three types of virtual gates are used to represent a simple switch object, the three types of virtual gates corresponding to a respective direction of approach to the switch, the direction of approach being one of normal, reverse and tangent.

10. The method according to claim 9, wherein a rule set for a simple switch object includes a plurality of conditions for each virtual gate type which must be met for entry through the virtual gate, the conditions comprising:

an object state condition defining a switch position in which entry through the virtual gate is allowed;

at least one opposing gates state condition defining at least one states that the other virtual gate of the switch must be in for entry through the virtual gate to be allowed;

at least one object occupancy state condition defining at least one occupancy state of the switch in which entry through the virtual gate is allowed;

at least one adjoining object occupancy state condition defining at least one occupancy state any adjoining objects must be in for entry through the virtual gate to be allowed; and

at least one adjoining object direction of travel state condition defining at least one travel direction state any adjoining objects must be in for entry through the virtual gate to be allowed.

11. The method according to claim 7, wherein the rule sets are based on the Association of American Railways recommended design practices for design of vital relay based interlocking logic circuits.

12. In a digital computer, a rules based interlocking system for automatic train protection of a guideway comprising:

a guideway data model comprising a plurality of data entries specifying guideway objects, at least one of the guideway objects corresponding to guideway hardware devices, the guideway objects being represented as at least one virtual gate of a plurality of virtual gate types, the guideway data model specifying relationships between the guideway objects;

a database comprising rule sets for a plurality of guideway objects, the rule sets defining conditions for a respective guideway object which must be met before entry of a train through a virtual gate of said object is permitted;

a user input guideway definition file comprising a high-level description of the guideway, including the guideway objects;

a data model parser for parsing the guideway definition file and producing the guideway data model using the database comprising the rule sets; and

I/O control means for sending control signals to the guideway hardware devices and for receiving status signals from the guideway hardware devices based on the guideway data model and sensed status signals.

13. A method of forming a database representing a guideway in a computer based interlocking system, comprising:

dividing a guideway into a plurality of guideway objects;

for each of the plurality of guideway objects, representing each entry point into the guideway object as a virtual gate of a plurality of virtual gate types;

storing a rule set for each virtual gate type, the rule sets specifying virtual gate entry condition requirements; and

associating the rule sets with the respective virtual gates of the plurality of guideway objects.

14. A method of representing a simple switch as a guideway object in a computer based guideway control system, wherein the simple switch is divided into a plurality of virtual gates, comprising for each virtual gate type:

storing an object state condition defining a switch position in which entry through the virtual gate is allowed;

storing at least one opposing gates state condition defining at least one state that other virtual gates of the switch must be in for entry through the virtual gate to be allowed;

storing at least one object occupancy state condition defining at least one occupancy state of the switch in which entry through the virtual gate is allowed;

storing at least one adjoining object occupancy state condition defining at least one occupancy state any adjoining objects must be in for entry through the virtual gate to be allowed; and

storing at least one adjoining object direction of travel state condition defining at least one travel direction state any adjoining objects must be in for entry through the virtual gate to be allowed.

15. A computer implemented interlocking system protecting trains traversing a guideway system, said guideway system comprised of guideway objects which influence movement of trains in the system comprising:

a computer;

a guideway data model stored in said computer comprising a plurality of data entries specifying said guideway objects, said guideway objects defined by entry and exit points, the entry point to at least one guideway object being a virtual gate, at least one of the guideway objects corresponding to guideway hardware devices, the guideway data model specifying relationships between the guideway objects;

a data base stored in said computer comprising rule sets for a plurality of guideway objects, the rule sets defining conditions for a respective guideway object which must be met before entry of a train through a virtual gate of said object is permitted;

a computer implemented interlocking engine for processing status signals with reference to said data model and said rule sets in real time to produce control signals with reference to said data model and said rule sets; and

input/output (I/O) control means for sending said control signals to the guideway hardware devices and for receiving said status signals from the guideway hardware devices.

16. A computer implemented interlocking system protecting trains traversing a guideway system, said guideway system comprised of guideway objects which influence movement of trains in the system comprising:

a computer;

a guideway data model stored in said computer comprising a plurality of data entries specifying said guideway objects, said guideway objects defined by entry and exit points, the entry point to at least one guideway object being a virtual gate, at least one of the guideway objects corresponding to guideway hardware devices, the guideway data model specifying relationships between the guideway objects;

a data base stored in said computer comprising rule sets for a plurality of guideway objects, the rule sets defining conditions for a respective guideway object which must be met before entry of a train through a virtual gate of said object is permitted;

a computer implemented interlocking engine for processing status signals with reference to said data model and said rule sets in real time to produce control signals with reference to said data model and said rule sets;

a computer implemented speed code selection engine for processing said status signals in real time with reference to the data model and rule sets to produce speed control signals;

input/output (I/O) control means for sending said control signals to the guideway hardware devices and said speed control signals to trains and for receiving said status signals from the guideway hardware devices.

17. A computer implemented interlocking system protecting trains traversing a guideway system, said guideway system comprised of guideway objects which influence movement of trains in the system comprising:

a computer;

a guideway data model stored in said computer comprising a plurality of data entries specifying said guideway objects, said guideway objects defined by entry and exit points, the entry point to at least one guideway object being a virtual gate, at least one of the guideway objects corresponding to guideway hardware devices, the guideway data model specifying relationships between the guideway objects;

a data base stored in said computer comprising rule sets for defining protection zones for gateway objects, there being rules for a plurality of gateway objects, the rule sets defining conditions for a respective gateway object which must be met before entry of a train is permitted into a protection zone for said object;

a computer implemented interlocking engine for processing status signals with reference to said data model and said rule sets in real time to produce control signals with reference to said data model and said rule sets; and

input/output (I/O) control means for sending said control signals to the guideway hardware devices and for receiving said status signals from the guideway hardware devices.

18. The interlocking system according to claim 17 wherein the rule set data base comprises rules for dynamically expanding and contracting the extent of protection zones along the guideway depending upon current state of the guideway.

19. The interlocking system according to claim 17 wherein the rule set data base comprises rules for dynamically adding and subtracting protection zones depending on current state of the guideway.