Method for generating conflict resolutions for air traffic control of free flight operations

• US 6,604,044 B1
• Filed: 02/14/2002
• Issued: 08/05/2003
• Est. Priority Date: 02/14/2002
• Status: Active Grant

• Current Assignee: Mitre Corporation
• Original Assignee: Mitre Corporation
• Inventors: Kirk, Daniel B.
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US10/073,956
• Time in Patent Office: 537 Days
• Field of Search: 701/120, 701/121, 701/122, 701/1, 701/3, 701/14
• US Class Current: 701/120
• CPC Class Codes: G08G 5/0043 Traffic management of multiple aircrafts from the ground G08G5/003 takes precedence; data processing specially designed for resource management, e.g. scheduling or allocating time, human or machine resources G06Q10/06
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

A computationally efficient method for automatically generating lateral resolutions for air traffic control problems for a given aircraft allows for prediction and evaluation of required separation between aircraft, between aircraft and airspace, and problems with assigned metering time. Upon a possible problem being predicted, lateral resolutions are created which provide plans to re-route the original flight trajectory of the aircraft in order to avoid a possible problem by examining the space surrounding the aircraft, iteratively adding data on each conflict encountered into a conflict database, calculating and probing maneuver trajectories for all conflicts in the conflict database, and selecting the most appropriate of the created maneuver trajectories.

Claims

1. A method for generating problem resolutions for free flight operations in air traffic control, comprising the steps of:

selecting a subject aircraft to be maneuvered;

iteratively examining continuous space enveloping said subject aircraft for potential aircraft problems for a predetermined look-ahead time interval defining a plurality of examination passes;

in each iterative examination pass, generating resolutions in response to all problems encountered in said examined continuous space, each resolution proposing a predefined type of maneuver for said subject aircraft;

calculating parameters of requested maneuvers based on relative motion geometry, and

probing each said generated resolution by examining said continuous space enveloping said subject aircraft affected by each requested maneuver applied thereto.

2. The method of claim 1, wherein said proposed maneuver includes a lateral maneuver chosen from the group consisting of a Direct to Maneuver End Point, a Minimum Off-Angle, and a Fixed Off-Angle.

3. The method of claim 2, further comprising the steps of:

creating a conflict data base including first and second conflict databases for generating maneuvers to the left and right turn of the initial conflict, respectively, said conflict data base containing an initial problem,

during each examination pass of said continuous space, adding data of newly discovered conflicts to a respective one of said first and second databases, and

generating a resolution requesting the lateral maneuver to avoid each conflict stored in said first and second conflict databases.

4. The method of claim 3, further comprising the steps of:

determining a maneuver start point (MSP) for a minimum off-angle (MOA) maneuver by;

(a) determining an initial MOA MSP starting at a parameter time in the future,

(b) for each conflict within said conflict database, calculating a set of MSP prohibited turn intervals,

(c) selecting the smallest MSP turn angle outside of said set of MSP prohibited intervals,

(d) moving said initial MSP down trajectory of said subject aircraft if said selected smallest MSP turn angle exceeds a predefined angle value, and

(e) repeating said steps (b)-(d) for all encountered conflicts stored in said conflict database until said selected smallest MSP turn angle meets said predefined angle value.

5. The method of claim 4, further comprising the steps of:

determining a maneuver turn point (MTP) and a maneuver end point (MEP) for the MOA maneuver by;

(f) determining an initial MEP for the MOA maneuver, said MOA maneuver being the next fix downstream of the end of said initial conflict,

(g) calculating a set of MSP and MTP prohibited turn intervals for each conflict in said conflict database,

(h) selecting the MSP and MTP turn angles outside said set of MSP and MTP prohibited turn intervals, and

(i) moving said initial MEP for the MOA maneuver down trajectory of said subject aircraft if said selected MTP or resultant MEP turn angles exceed predefined limits.

6. The method of claim 5, further comprising the steps of:

determining MSP, MTP and MEP for a fixed off-angle (FOA) maneuver by;

(j) determining an initial FOA MSP starting at a parameter time in the future,

(k) determining an initial MEP for the FOA maneuver, said FOA maneuver being the next fix downstream of the start of said initial conflict,

(l) calculating a set of MTP prohibited turn intervals for each conflict in said conflict database,

(m) moving the MSP downstream until outside of said set of MTP prohibited turn intervals,

(n) selecting the MTP turn angles outside said set of MTP prohibited turn intervals, and

(o) moving said initial MEP for the FOA maneuver down the trajectory of said subject aircraft if said selected MTP or resultant MEP turn angles exceed predefined limits.

7. The method of claim 6, further comprising the steps of:

selecting a better of said MOA and FOA maneuvers based on predefined criteria,

creating the selected maneuver trajectory,

probing said created trajectory of said selected maneuver for problems, and

acknowledging said created maneuver trajectory as the most appropriate if said maneuver trajectory is conflict free.

8. The method of claim 7, further comprising the steps of:

adding to said conflict database the information of each conflict encountered during said probing of said created maneuver trajectory,

moving said MEP calculated for the MOA and FOA maneuvers past the last conflict in said conflict database, and

repeating said steps (a)-(o) until said created maneuver trajectory is problem free.

9. The method of claim 1, further comprising the steps of:

generating resolutions to meet assigned metering time constraints for said subject aircraft by including MTPs violating the metering constraint in the set of MTP prohibited turn intervals, and

reducing the size of the resultant delay maneuver by reducing the speed of the aircraft.

10. The method of claim 1, further comprising the steps of:

defining a conflict free path constraint for said subject aircraft comprising at least one straight line flight segment, defining start point, end point, turn point, and off-angle of the maneuver, and

re-routing said subject aircraft through a series of fixes respective to said flight segment in predefined off-angle parameter increments starting at said start point, turning said subject aircraft at said turn point, and returning said subject aircraft to said flight segment at said end point of the maneuver.

11. The method of claim 1, further comprising the steps of:

assigning to said subject aircraft a specific maneuver and evaluating the merits of said specific maneuver by generating said plurality of resolutions in response thereto.

12. The method of claim 1, further comprising the steps of:

(a) forming a problem summary structure,

(b) collecting data including;

said subject aircraft'"'"'s headings, speeds, and transitioning states at the current time;

the encountered problem'"'"'s start and end times, and predicted headings, speeds, and transitioning states of said subject aircraft at said start and end times;

minimum and maximum altitudes and true airspeeds of said subject aircraft; and

sector and facility currently controlling said subject aircraft;

(c) storing said data in said problem summary structure, and

(d) processing said data for generating and ranking the resolutions.

13. The method of claim 1, wherein said maneuvers are compatible with the operational performance envelope of said subject aircraft.

14. The method of claim 1, wherein the maneuver'"'"'s parameters include:

turn angles of said maneuvers calculated and displayed in predefined magnitude increments.

15. The method of claim 1, wherein each said generated resolution, upon completing said maneuver, returns said subject aircraft to a pre-conflict route or destination.