Method for determining the horizontal profile of a flight plan complying with a prescribed vertical flight profile

• US 8,090,526 B2
• Filed: 11/11/2006
• Issued: 01/03/2012
• Est. Priority Date: 12/07/2005
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Marty, Nicolas, Francois, Gilles, Bitar, Elias
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Nguyen, Bao Long T
• Application Number:
  US12/094,656
• Publication Number:
  US 20080306680A1
• Time in Patent Office: 1,879 Days
• Field of Search: None
• US Class Current: 701/201
• CPC Class Codes: G08G 5/0034 Assembly of a flight plan

Abstract

The present invention relates to the definition, in a flight plan, of the horizontal profile of an air route with vertical flight and speed profile prescribed on departure and/or on arrival, by a stringing together of check-points and/or turn points associated with local flight constraints and called “D-Fix” because they are not listed in a published navigation database like those called “Waypoints”. It consists in charting, on curvilinear distance maps, a direct curvilinear path joining the departure point to the destination point of the air route while complying with vertical flight and speed profiles prescribed on departure and/or on arrival and while guaranteeing a circumnavigation of the surrounding reliefs and compliance with regulated overfly zones, then in approximating the series of points of the direct curvilinear path by a sequence of straight segments complying with an arbitrary maximum deviation threshold relative to the points of the series and an arbitrary minimum lateral deviation threshold relative to the set of obstacles to be circumnavigated and in adopting as “D-Fix” points the points of the intermediate intersections of the rectilinear segments.

Claims

1. A method for determining the horizontal profile of an aircraft flight plan route leading from a departure point to a destination point, complying with vertical flight and speed profiles prescribed on departure and/or on arrival and taking account of the relief and of regulated overfly zones, said method implemented by an onboard device and comprising the following steps:

creating two curvilinear distance maps covering a maneuver zone containing the departure point and destination point and including one and the same set of obstacles to be circumnavigated taking into account the relief, the regulated overfly zones and the vertical flight and speed profiles prescribed on departure and/or on arrival, the first having the departure point as the origin of the distance measurements and the second, the destination point as the origin of the distance measurements,

creating, a third curvilinear distance map by summation, for each of its points, of the curvilinear distances that are assigned to them in the first and second curvilinear distance maps,

charting, in the third curvilinear distance map, a connected set of iso-distance points forming a sequence of parallelograms and/or of points linking the departure point and destination point,

selecting, from the charted connected set of iso-distance points, a series of consecutive points going from the departure point to the destination point via diagonals of its parallelograms, the series being called direct path,

approximating the series of points of the direct path by a sequence of straight segments complying with an arbitrary maximum deviation threshold relative to the points of the series and an arbitrary minimum lateral deviation threshold relative to the set of obstacles to be circumnavigated, and

choosing points of the intermediate junctions of the straight segments as check-points or turn points in the flight plan.

2. The method as claimed in claim 1, wherein, when there is only one vertical flight and speed profile prescribed on departure, the first curvilinear distance map having the departure point as the origin of the distance measurements is created by taking account of the static constraints due to the relief and to the regulated overfly zones and the dynamic constraint due to the vertical flight and speed profile prescribed on departure whereas the second curvilinear distance map having the destination point as the origin of the distance measurements is created from the set of obstacles to be circumnavigated appearing in the first curvilinear distance map.

3. The method as claimed in claim 1, wherein, when there is only one vertical flight and speed profile prescribed on arrival, the second curvilinear distance map having the destination point as the origin of the distance measurements is created by taking account of the static constraints due to the relief and to the regulated overfly zones and the dynamic constraint due to the vertical flight and speed profile prescribed on arrival whereas the first curvilinear distance map having the point of departure as the origin of the distance measurements is created from the set of obstacles to be circumnavigated appearing in the second curvilinear distance map.

4. The method as claimed in claim 1, wherein, when there are vertical flight and speed profiles prescribed on departure and on arrival, the first and second curvilinear distance maps are created from a set of obstacles to be circumnavigated appearing in two outlines of these curvilinear distance maps:

an outline of the first curvilinear distance map having the departure point as the origin of the distance measurements created by taking account of the static constraints due to the relief and to the regulated overfly zones and the dynamic constraint due to the vertical flight and speed profile prescribed on departure, and

an outline of the second curvilinear distance map having the destination point as the origin of the distance measurements being created by taking account of the static constraints due to the relief and to the regulated overfly zones and the dynamic constraint due to the vertical flight and speed profile prescribed on arrival.

5. The method as claimed in claim 1, wherein the set of obstacles to be circumnavigated taken into account in the curvilinear distance maps is complemented by the points of the first and second maps assigned estimations of curvilinear distance showing discontinuities in relation to those assigned to points in the near vicinity.

6. The method as claimed in claim 1, wherein the set of obstacles to be circumnavigated taken into account in the curvilinear distance maps is complemented by lateral safety margins dependent on the flat turn capabilities of the aircraft in its configuration of the moment, when approaching the relief and/or the regulated overfly zone concerned, resulting from following the prescribed vertical flight and speed profile.

7. The method as claimed in claim 6, wherein the lateral safety margins added to the set of listed obstacles to be circumnavigated are determined from a curvilinear distance map having the set of obstacles to be circumnavigated as the origin of the distance measurements.

8. The method as claimed in claim 6, wherein the local thickness of a lateral safety margin takes account of the local wind.

9. The method as claimed in claim 6, wherein the local thickness of a lateral safety margin takes account of the change of heading needed to circumnavigate a relief and/or a regulated overfly zone.

10. The method as claimed in claim 6, wherein the local thickness of a lateral safety margin corresponds to the minimum flat turn radius allowed for the aircraft in the configuration of the moment.

11. The method as claimed in claim 1, wherein the maximum deviation threshold of the sequence of straight segments in relation to the series of points of the direct path is of the order of a minimum flat turn half-radius allowed for the aircraft in its configuration of the moment.

12. The method as claimed in claim 1, wherein the curvilinear distance maps are created by means of a propagation distance transform.

13. The method as claimed in claim 1, wherein the approximation of the series of points of the direct path by a sequence of rectilinear segments is obtained by a progressive construction during which the departure point or respectively destination point of the direct path is taken as the origin of a first segment that is enlarged by adding one by one consecutive points as long as it does not penetrate into the set of obstacles to be circumnavigated and that its deviation relative to the points of the direct path that it short-circuits complies with the arbitrary maximum deviation allowed threshold, other rectilinear segments constructed in the same way being added to the series as long as the destination point, or respectively departure point, of the direct path is not reached.

14. The method as claimed in claim 1, wherein the approximation of the series of points of the direct path by stringing together rectilinear segments is obtained by a dichotomic construction during which the departure point and the destination point of the direct path are initially linked by a rectilinear segment that is replaced, when it penetrates into the set of obstacles to be circumnavigated or its deviation relative to the points of the direct path that it short-circuits exceeds the arbitrary maximum deviation allowed threshold, with a stringing together of two rectilinear segments intersecting at the point of the direct path that is furthest away out of those that it short-circuits, each new segment being in turn replaced by a stringing together of two new segments intersecting at the point of the direct path that is furthest away out of the short-circuited points when it penetrates into the set of obstacles to be circumnavigated or its deviation relative to the points of the direct path that it short-circuits exceeds the arbitrary maximum deviation allowed threshold.

15. The method as claimed in claim 1, implemented in a system for reaching a fallback airport in the event of engine failure.

16. The method as claimed in claim 1, implemented in a flight plan discontinuity management system.

17. The method as claimed in claim 1, implemented in a system for automatically reaching predetermined positions for pilotless aircraft.

18. The method as claimed in claim 1, implemented, in a security context, in a system for automatically reaching predetermined positions for piloted aircraft out of control.

19. The method as claimed in claim 1, implemented on preparing military or civil security missions.

20. The method as claimed in claim 1, implemented during a flight, on a “

Dir-to”

request to reach a geographic point made by the crew to the flight management computer of the aircraft.