Method and device for determining an optimal flight trajectory followed by an aircraft

• US 8,825,366 B2
• Filed: 12/01/2011
• Issued: 09/02/2014
• Est. Priority Date: 12/07/2010
• Status: Active Grant

• Current Assignee: Airbus Operations (European Aeronautic Defence and Space Company EADS NV)
• Original Assignee: Airbus Operations (European Aeronautic Defence and Space Company EADS NV)
• Inventors: Giovannini, Andrea, Pastre, Thomas
• Primary Examiner(s): Nguyen, John Q
• Assistant Examiner(s): WHALEN, MICHAEL F
• Application Number:
  US13/309,150
• Publication Number:
  US 20120143505A1
• Time in Patent Office: 1,006 Days
• Field of Search: 701/301, 701/410, 701/528, 701/532, 701/533, 701/540, 701/3, 701/300, 701/411, 701/415, 701/416, 701/466
• US Class Current: 701/301
• CPC Class Codes: G08G 5/0039 Modification of a flight plan
• CPC Class Codes: G08G 5/0052 for cruising combined instruments indicating more than one navigational value G01C23/00
• CPC Class Codes: G08G 5/006 in accordance with predefined flight zones, e.g. to avoid prohibited zones
• CPC Class Codes: G08G 5/0082 for monitoring traffic from a ground station radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: G08G 5/0091 for monitoring atmospheric conditions radar or analogous systems specially adapted for meteorological use G01S13/95; meteorology G01W

Abstract

The device includes processor elements for determining an optimal flight trajectory, which is free of collision with obstacles, which respects constraints of energy, and which links the current position of the aircraft to a target point defined by an operator. The device minimizes additional crew work required to update and validate a new trajectory when an original flight plan needs to be modified to avoid moving obstacles such as storms or other aircraft.

Claims

1. A method for determining an optimum flight trajectory for an aircraft, in particular a transport airplane, the optimum flight trajectory comprising a lateral trajectory and a vertical trajectory and being defined between a current point and a target point, the method comprising:

(a) using at least one obstacle data base relative to obstacles and a reference vertical profile, as well as a set objective received from an operator at a user input device that indicates a target point, and the method further comprising the following automatic steps;

(b) determining with a first processor element a first section of at least one virtual trajectory from the current point, by carrying out the following successive operations;

(b1) generating with a segment generation device at least one straight line segment, with a predetermined length, starting at the current point, the at least one straight line segment defining the first section of the at least one virtual trajectory, each of the at least one virtual trajectory extending from the current point to a downstream end;

(b2) conducting with a segment validation device a trial for validating each generated straight line segment, wherein the trial uses the at least one obstacle database and the reference vertical profile;

(b3) evaluating with a segment score calculator each validated straight line segment to assign a score being representative of an ability of the straight line segment to meet the set objective, the score being based on both (i) a distance remaining between the downstream end of the corresponding virtual trajectory and the target point, and (ii) a heading difference between a heading at the downstream end and a heading target at the target point; and

(b4) recording with a first recording device each straight line segment, with the assigned score, into a storage memory as the first section of the corresponding at least one virtual trajectory;

(c) implementing with a second processor element an iterative processing, comprising the following successive operations, to determine subsequent sections of a chosen virtual trajectory having a best score with respect to the set objective out of all of the at least one virtual trajectory;

(c1) determining with a heading change determination device possible heading changes from the downstream end of the chosen virtual trajectory;

(c2) generating with a subsequent segment generation and validation device for each one of the possible heading changes, a subsequent section of trajectory, starting at the downstream end of the chosen virtual trajectory and comprising at least one of the following elements;

a circle arc and a straight line segment, and then conducting a trial for validating the subsequent section of trajectory using the at least one obstacle database and the reference vertical profile, wherein step (c2) further comprises;

generating a circle arc as a function of speed of the aircraft at the downstream end of the chosen virtual trajectory;

generating a straight line segment, associated with the circle arc; and

combining the circle arc and the straight line segment to produce the subsequent section of trajectory, which is to be validated by conducting the trial;

(c3) forming with a virtual trajectory updating device for each generated and validated subsequent section of trajectory, at least one updated virtual trajectory made up of the chosen virtual trajectory followed by the subsequent section of trajectory, each of the at least one updated virtual trajectory extending from the current point to a downstream end;

(c4) evaluating with a virtual trajectory score calculator each of the at least one updated virtual trajectory to assign the at least one updated virtual trajectory a score being representative of an ability to reach the set objective, the score being based on both (i) a distance remaining between the downstream end of the at least one updated virtual trajectory and the target point, and (ii) a heading difference between a heading at the downstream end of the at least one updated virtual trajectory and a heading target at the target point;

(c5) recording with a second recording device each of the at least one updated virtual trajectory with the score assigned into the storage memory;

(c6) determining with a virtual trajectory score comparison device, amongst all of the recorded at least one updated virtual trajectory, a new chosen virtual trajectory having a best score with respect to the set objective; and

(c7) repeating with the second processor element steps (c1)-(c6) to determine, verify, and evaluate subsequent sections of the new chosen virtual trajectory until the downstream end of the new chosen virtual trajectory determined in step (c6) corresponds to the target point, at which point the second processor element assigns the new chosen virtual trajectory having the best score as the optimum flight trajectory, wherein at each cycle of the iterative processing in steps (c1) through (c6), a single new chosen virtual trajectory is chosen for further processing such that step (c) results in only a single full flight trajectory being generated between the current point and the target point; and

(d) transmitting with at least one transmission device the optimum flight trajectory to a viewing screen and/or external devices.

2. The method according to claim 1, wherein generating with the segment generation device at least one straight line segment in step (b1) further comprises:

determining an altitude of the at least one straight line segment using the reference vertical profile.

3. The method according to claim 1, wherein, for carrying out a trial in steps (b2) or (c2) for validating a section of trajectory with either the segment validation device or the subsequent segment generation and validation device, the following steps are automatically performed:

determining a protective shell around the section of trajectory;

comparing the protective shell to obstacles issued from the at least one obstacle database relative to obstacles; and

determining that the section of trajectory is considered to be validated if no obstacle is located in said protective shell.

4. The method according to claim 3, wherein comparing the protective shell to obstacles further comprises:

for mobile obstacles, comparing the protective shell to extrapolated positions of the mobile obstacles.

5. The method according to claim 1, wherein evaluating with the virtual trajectory score calculator each of the at least one updated virtual trajectory in step (c4) further comprises:

determining a distance remaining to be covered from the downstream end of the at least one updated virtual trajectory, for reaching the target point;

determining a heading difference between a heading at the downstream end and a heading target at the target point; and

calculating the score to be assigned to the at least one updated virtual trajectory as a function of the distance remaining to be covered and of the heading difference.

6. The method according to claim 1, wherein determining with the heading change determination device possible heading changes in step (c1) further comprises:

identifying a plurality of successive headings, according to a predetermined pitch, from a current heading at the downstream end to a maximum heading, and this, on either side of the current heading.

7. The method according to claim 1, wherein generating the circle arc in step (c2) further comprises:

forming the circle arc so as to have a smallest radius able to be followed by the aircraft flying at a predicted speed.

8. The method according to claim 1, wherein the segment generation device or the subsequent segment generation and validation device each determine a straight line segment similarly.

9. A device for determining an optimum flight trajectory for an aircraft, in particular a transport airplane, the flight trajectory comprising a lateral trajectory and a vertical trajectory and being defined between a current point and a target point, wherein the device comprises:

at least one obstacle database relative to obstacles;

a user input device allowing an operator to enter an objective indicating at least the target point;

a first processor element for determining at least one first section of flight trajectory from the current point, the first processor element comprising;

a segment generation device that generates at least one straight line segment with a predetermined length starting at the current point, the at least one straight line segment defining the first section of the at least one virtual trajectory, each of the at least one virtual trajectory extending from the current point to a downstream end;

a segment validation device that conducts a trial for validating each generated straight line segment, wherein the trial uses the at least one obstacle database and a reference vertical profile;

a segment score calculator that evaluates each generated and validated straight line segment, and assigns each straight line segment a score being representative of an ability to reach the set objective, the score being based on both (i) a distance remaining between the downstream end of the corresponding virtual trajectory and the target point, and (ii) a heading difference between a heading at the downstream end and a heading target at the target point; and

a first recording device that records, in a storage memory, each straight line segment as the first section of the corresponding at least one virtual trajectory, with the assigned score;

a second processor element that implements an iterative processing to determine subsequent sections of a chosen virtual trajectory having a best score with respect to the set objective out of all of the at least one virtual trajectory, the second processor element comprising;

a heading change determination device that determines possible heading changes from the downstream end of the chosen virtual trajectory;

a subsequent segment generation and validation device that generates, for each one of the possible heading changes, a subsequent section of trajectory starting at the downstream end of the chosen virtual trajectory and comprising at least one of the following elements;

a circle arc and a straight line segment, and the subsequent segment generation and validation device then conducts a validation trial on the subsequent section using the at least one obstacle database and the reference vertical profile, wherein the subsequent segment generation and validation device is programmed to perform the following steps automatically;

generate a circle arc as a function of speed of the aircraft at the downstream end of the chosen virtual trajectory;

generate a straight line segment, associated with the circle arc; and

combine the circle arc and the straight line segment to produce the subsequent section of trajectory, which is to be validated by conducting the validation trial;

a virtual trajectory updating device that forms, for each generated and validated subsequent section of trajectory, at least one updated virtual trajectory consisting of the chosen virtual trajectory followed with the subsequent section of trajectory, each of the at least one updated virtual trajectory extending from the current point to a downstream end;

a virtual trajectory score calculator that evaluates each of the at least one updated virtual trajectory, and assigns the at least one updated virtual trajectory a score being representative of an ability to reach the set objective, the score being based on both (i) a distance remaining between the downstream end of the updated virtual trajectory and the target point, and (ii) a heading difference between a heading at the downstream end and a heading target at the target point;

a second recording device that records, in the storage memory, each of the at least one updated virtual trajectory with the assigned score; and

a virtual trajectory score comparison device that determines, amongst all the virtual trajectories recorded in the storage memory, a new chosen virtual trajectory having a best score with respect to the set objective;

wherein the second processor element repeats the iterative processing to determine, verify, and evaluate subsequent sections of the new chosen virtual trajectory until the downstream end of the new chosen virtual trajectory having the best score corresponds to the target point, at which point the second processor element assigns the new chosen virtual trajectory having the best score as the optimum flight trajectory, wherein at each cycle of the iterative processing by the second processor element, a single new chosen virtual trajectory is chosen for further processing such the iterative processing results in only a single full flight trajectory being generated between the current point and the target point; and

at least one transmission device that transmits the optimum flight trajectory to a viewing screen user devices and/or external devices.

10. The device according to claim 9, further comprising:

the viewing screen of the aircraft, for displaying the optimum flight trajectory.

11. The device according to claim 9, wherein the at least one transmission device comprises a communication device for transmitting the optimum flight trajectory to devices being external to the device.

12. The device according to claim 9, wherein the at least one obstacle database includes at least one data base relative to stationary obstacles and at least one data base relative to mobile obstacles.

13. An aircraft, characterized in that it comprises a device such as specified in claim 9.