Automatic train control system and method

• US 5,828,979 A
• Filed: 05/15/1997
• Issued: 10/27/1998
• Est. Priority Date: 09/01/1994
• Status: Expired due to Term

• Current Assignee: GE Global Sourcing LLC (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Matheson, William L., Polivka, Alan L.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Walker, Tyrone V.
• Application Number:
  US08/856,754
• Time in Patent Office: 530 Days
• Field of Search: 701/117, 701/50, 246/5, 246/167 R
• US Class Current: 701/117
• CPC Class Codes: B61L 2205/04 Satellite based navigation systems, e.g. global positioning system [GPS]
• CPC Class Codes: B61L 27/12 Preparing schedules
• CPC Class Codes: B61L 27/14 Following schedules
• CPC Class Codes: B61L 27/16 Trackside optimisation of vehicle or train operation
• CPC Class Codes: G06Q 10/047 Optimisation of routes or paths, e.g. travelling salesman problem
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management

Abstract

A system and method for controlling the movement of plural freight trains through a multiple route railway system with improved efficiency and safety. Freight train movements are precisely monitored and orchestrated in accordance with a dynamic schedule that is determined through an evaluation of delivery requirements, coordination among all trains, speed restrictions and the effects of the track topography and train consist on train response to brake and power application.

Claims

1. A method of control of a plural freight trains with varying numbers of cars and varying loads over a pre-determined track layout, the method comprising the steps of:

(a) providing a railway with both periodic and non-periodic freight train service;

(b) providing a realizable movement plan for all trains over the track layout, the plan including ETAs and ETDs at all stations of significance calculated on the basis of track parameters, train handling constraints, actual train position and velocity data, wind data to the extent available, and track condition data to the extent available to cause the freight trains to operate on the trajectories indicated by the plan;

(c) updating the movement plan in response to unplanned or deviant movements of freight trains over the track layout; and

(d) alternatively displaying commands (to comply with the movement timeline profile derived from the updated movement plan) to the train engineer or automatically executing power and brake settings for the locomotive in response thereto for immediate execution of the updated movement plan.

2. The method of claim 1 including the step of selectively manually overriding any automatically executed commands.

3. A method of adjusting the planned movement of plural trains traveling on a network of track in response to addition of a previously unplanned train to the network of track, or to an anomaly in the trains or in the network of track which affects movement of the trains there across, the method comprising the steps of:

(a) storing train characteristics for each of the planned trains in a central computer for the network of track, the train characteristics including the number of cars and train handling constraints;

(b) storing track characteristics for the network of track in a central computer, the track characteristics including the topography of the network of track and track parameters;

(c) providing to a central computer from each of the planned trains the locations of their respective beginning of train;

(d) revising the planned movement of the planned trains in response to an unplanned train or an anomaly, the revised planned movement including a planned movement for the previously unplanned train (if present) and a new planned movement for the planned trains, the revised planned movement taking into consideration (i) the locations of the planned and unplanned trains, (ii) the topography of the network of track along which the planned and unplanned trains are to move, and (iii) an effect of the topography on speed adjustment points in consideration of locations of the beginnings of the trains and of their respective cars; and

(e) communicating the revised planned movements to the trains for immediate execution.

4. The method of claim 3 wherein the effect of the topography on the speed adjustment points is determined by the method comprising the steps of:

(a) determining an initial brake application point in consideration of brake factors comprising train velocity, position, consist, brake force, and aerodynamic data and the track topography in the vicinity of the initial brake application point; and

(b) updating the initial brake application point in view of updated brake factors so as to achieve a desired train velocity at a predetermined location.

5. The method of claim 4 wherein the brake factors further comprise the locations of the cars in the trains.

6. The method of claim 5 wherein the brake factors further comprise the effect of topography-induced stretching and compression on the locations of the cars.

7. The method of claim 3 wherein the effect of the topography on the speed adjustment points is determined by the method comprising the step of evaluating the change of potential energy of a train to be braked between the train'"'"'s beginning and end-of-braking points by considering the track topography at the locations of each of the cars in the train when the beginning of the train is at the beginning-of-braking versus at the end-of-braking points.

8. The method of claim 7 further comprising the step of determining the potential energy of each of the cars in the one train by multiplying its mass times its altitude.

9. The method of claim 8 wherein the locations of the cars in the one train are determined in consideration of the effect of topography-induced stretching and compression on the locations of the cars.

10. A method for precisely controlling the movement of plural trains along a network of track according to a predetermined movement plan comprising:

(a) providing to each of the plural trains its respective portion of the movement plan (i.e., its "trip plan") before departure on the planned movement;

(b) determining the position of each train along the track;

(c) evaluating the adherence of each train to its trip plan;

(d) determining trip plan and/or speed adjustments needed by any train not adhering to its trip plan, taking into consideration the effects of the topography of the track on the adjustments; and

(e) communicating the trip plan adjustments to each train.

11. The method of claim 10 wherein trip plan and/or speed adjustments are determined based on the step of evaluating an effect of the topography on train brake application points in consideration of locations of the beginnings of the trains and of their respective cars.

12. The method of claim 11 wherein the effect of the topography on the train brake application points is evaluated by the method comprising the step of evaluating the change of potential energy of a train to be braked between the train'"'"'s beginning-of-braking and end-of-braking points by considering the track topography at the locations of each of the cars in the train when the beginning of the train is at the beginning-of-braking and end-of-braking points.

13. The method of claim 12 wherein the locations of the cars in the train are determined in consideration of the effect of topography-induced stretching and compression on the locations of the cars.

14. The method of claim 10 wherein the step of determining the trip plan and/or speed adjustments comprises the step of evaluating an effect of the topography on train power application points in consideration of locations of the beginnings of the trains and of their respective cars.

15. The method of claim 10 including the further step of modifying the speed adjustments so as to asymptotically approach the trip plan.

16. The method of claim 10 wherein each train'"'"'s portion of the movement plan (i.e., its trip plan) is provided to a selectively installed onboard computer which derives and provides instructions for implementing the trip plan when installed therein.

17. The method of claim 16 further comprising the step of communicating the trip plan from a central computer associated with or comprising the train dispatch system to the onboard computer.

18. The method of claim 17 wherein the onboard computer automatically makes the speed adjustments.

19. A system for precisely controlling the movement of plural trains along a network of track according to a predetermined movement plan comprising:

(a) means for providing to each of the plural trains its trip plan before departure on the planned movement;

(b) means for determining the position of each of the plural trains along the track;

(c) means for evaluating the adherence of each of the plural trains to the predetermined movement plan (its trip plan);

(d) means for determining the movement plan adjustments needed by any of the plural trains not adhering to the predetermined movement plan and all others affected, said means comprising means for determining the effects of the topography of the track on the adjustments; and

,

(e) means for communicating said trip plan adjustments to the plural trains.

20. The system of claim 19 wherein the means for determining the movement plan or speed adjustments comprises means for evaluating an effect of the topography on train brake application points in consideration of locations of the beginnings of the trains and of their respective cars.

21. The system of claim 19 wherein the means for evaluating the effect of the topography on the train brake application points comprises one of three possible algorithms for determining the braking distance:

(a) Given the track profile and an estimate of the total braking force a reasonable estimate of the braking distance can be obtained by the conservation of energy method.

(b) Using the conservation of energy method to obtain an initial estimate of the stopping distance, a differential equation method which models all the forces on the train is used to provide a more precise estimate.

(c) Using only the differential equation method described above, a precise estimate of the stopping distance can be made with the expense of more processing. This last method is much more robust than the above methods in that it is totally adaptive in nature sensing only the throttle position, the brake pipe pressure, the acceleration and the track profile to recursively update the model of the train and then use the differential method to predict the stopping distance.

22. The system of claim 21 further comprising means for determining the effect of topography-induced stretching and compression on the locations of the cars.

23. The system of claim 19 wherein the means for determining the movement plan or speed adjustments comprises means for evaluating an effect of the topography on train power application points in consideration of locations of the beginnings of the trains and of their respective cars.

24. The system of claim 19 further comprising an onboard computer selectively installed in the plural trains for storing each train'"'"'s trip plan thereto and for deriving and providing instructions for implementing the train'"'"'s trip plan when installed therein.

25. The system of claim 24 further comprising a data radio attached to said onboard computer for communicating the trip plan adjustments from a train dispatcher to said onboard computer.

26. The system of claim 25 wherein said onboard computer is connected to train speed controls so as to automatically make the speed adjustments.

27. The system of claim 19 wherein said means for evaluating comprises moving block control.

28. The system of claim 19 further comprising a computer aided dispatch system remote from the plural trains for overriding the control of the trains.

29. A method of controlling movement of a freight train having a multiplicity of cars over a track having a known topography, the method comprising the steps of:

(a) providing a trip plan for the train which takes into account the effect of the track topography on train speed adjustment points;

(b) revising the trip plan in response to deviations from the movement plan, the revisions taking into account the effect of the track topography on train speed adjustment points; and

(c) wherein the effect of track topography is determined by the method comprising the step of evaluating the effect of track topography on each of the cars in the train.

30. The method of claim 29 further comprising the step of considering the effect of topography-induced stretching and compression on the locations of the cars.

31. The method of claim 29 wherein the effect of the topography on the cars in the train is evaluated by the method comprising the step of evaluating the change of potential energy of each of the cars between the car'"'"'s location at the beginning of the speed adjustment and the location at the end of the speed adjustment.

32. The method of claim 31 further comprising the step of determining the potential energy of each of the cars by multiplying its mass times its altitude.

33. A method of controlling plural freight trains moving over a network of tracks, comprising the steps of:

(a) determining a movement plan of operating the plural trains over the track;

(b) communicating the relevant portion of the movement plan (i.e. the trip plan) to each one of the trains;

(c) generating planned trajectories for each of the trains in accordance with its determined trip plan;

(d) determining throttle and brake settings related to the first planned movement timeline profile;

(e) controlling the one train in accordance with said settings;

(f) communicating a second trip plan before the one train reaches the end of the first trip plan; and

(g) repeating steps (c), (d) and (e) for the second planned movement timeline profile.

34. The method of claim 33 wherein said determining is performed on the basis of track parameters.

35. The method of claim 33 wherein said determining is performed on the basis of train handling constraints.