Method and a device for avoiding an object by detecting its approach to an aircraft

• US 10,643,481 B2
• Filed: 08/30/2018
• Issued: 05/05/2020
• Est. Priority Date: 08/31/2017
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Airbus Helicopters
• Inventors: Salesse-Lavergne, Marc
• Primary Examiner(s): Moyer, Dale
• Application Number:
  US16/117,807
• Publication Number:
  US 20190088146A1
• Time in Patent Office: 614 Days
• CPC Class Codes: G05D 1/106 Change initiated in response to external conditions, e.g. avoidance of elevated terrain or of no-fly zones
• CPC Class Codes: G05D 1/1064 specially adapted for avoiding collisions with other aircraft
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/30241 Trajectory
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G08G 5/0008 with other aircraft
• CPC Class Codes: G08G 5/0021 located in the aircraft
• CPC Class Codes: G08G 5/0078 for monitoring traffic from the aircraft radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• 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 method and a device for avoiding an object by detecting its approach to an aircraft. After detecting an object in the vicinity of an aircraft and detecting its approach, a first track for the object and a second track for the aircraft are estimated from successive first states for the object and successive second states for the aircraft. Thereafter, a minimum distance (d_m) between the first track and the second track is estimated and a warning is triggered as soon as the minimum distance is less than a first threshold so as to warn a crew of the aircraft of a risk of collision. Finally, if the minimum distance is less than a second threshold, an avoidance maneuver is performed automatically by the aircraft in order to move away from the first track, and thereby avoid any risk of collision with the object.

Claims

1. A method of avoiding an object by detecting its approach to an aircraft, the aircraft including a detector device and a positioning device, wherein the method comprises the following steps:

detecting an object approaching the aircraft, the object being detected by the detector device;

making a first estimate of successive first states for the object, the successive first states for the object being estimated by the detector device, the first states being constituted by a position, a speed, and/or an acceleration of the object;

making a second estimate of successive second states for the aircraft, the successive second states for the aircraft being estimated by the positioning device, the second states being constituted by a position, a speed, and/or an acceleration of the aircraft;

making a first characterization of a first track for the object as a set of equations as a function of time;

making a second characterization of a second track for the aircraft as a set of equations as a function of time;

making a third estimate of a distance between the first track for the object and the second track for the aircraft;

making a fourth estimate of a minimum distance (d_m) between the first track for the object and the second track for the aircraft;

triggering a warning when the minimum distance (d_m) is less than a first threshold;

the aircraft performing an avoidance maneuver for avoiding the object as soon as the minimum distance (d_m) is less than a second threshold, the second threshold being less than the first threshold, the avoidance maneuver being performed with a particular acceleration of the aircraft serving to maximize the distance between the first track for the object and the second track for the aircraft corresponding to a particular time value associated with the minimum distance (d_m);

wherein the first track for the object and the second track for the aircraft are defined respectively from the successive first states for the object and from the successive second states for the aircraft, and are characterized by respective sets of three equations as a function of time, and the distance between the first track for the object and the second track for the aircraft is characterized by a polynomial function of time defined from the two sets of three equations; and

wherein the object and the aircraft are considered as having acceleration that is constant, and the first track for the object and the second track for the aircraft are characterized by respective sets of three second order equations such that the distance between the first track for the object and the second track for the aircraft is characterized by a polynomial function of fourth degree.

2. The method according to claim 1, wherein the detector device is formed by an electromagnetic wave detector system, an optical detector system, an imaging system having at least one camera, or indeed an imaging system having at least one camera in combination with an electromagnetic wave detector system or with an optical detector system.

3. The method according to claim 1, wherein the positioning device is formed by at least one GNSS receiver and/or at least one inertial unit.

4. The method according to claim 1, wherein the fourth estimate of the minimum distance (d_m) between the first track for the object and the second track for the aircraft is performed by differentiating relative to time the distance between the first track and the second track and by searching for the time value that minimizes the distance.

5. The method according to claim 1, wherein the method includes an additional step of displaying the object on a display device.

6. The method according to claim 1, wherein the particular acceleration is estimated by applying a set of equations determining the distance between the first track for the detected object and the second track for the aircraft and by calculating an acceleration vector for the aircraft that maximizes the minimum distance (d_m).

7. The method according to claim 6, wherein the acceleration vector for the aircraft is written in a second reference frame attached to the aircraft.

8. The method according to claim 1, wherein the avoidance maneuver is performed by acting on a roll attitude of the aircraft, a pitch attitude of the aircraft, a load factor of the aircraft, and a variation of the heading of the aircraft induced by the aircraft performing a roll action.

9. The method according to claim 1, wherein the avoidance maneuver is performed:

by coordinating a roll action of the aircraft with a variation of the heading of the aircraft

and with an action on the collective pitch of the aircraft.

10. The method according to claim 1, wherein the particular acceleration of the aircraft for maximizing the distance between the first track for the object and the second track for the aircraft is estimated by differentiating the minimum distance (d_m) relative to each of the components of an acceleration vector of the aircraft.

11. The method according to claim 1, wherein when the particular acceleration is greater than a limited acceleration, the avoidance maneuver is performed with the limited acceleration.

12. The method according to claim 1, wherein the aircraft has an autopilot and the avoidance maneuver for avoiding the object by the aircraft is performed by the autopilot, avoidance orders being supplied to the autopilot.

13. An assembly for avoiding an object by detecting its approach to an aircraft, the assembly being for fitting to the aircraft, the assembly comprising:

a detector device for detecting the object and supplying successive first states for the object, the successive first states being constituted by a position, a speed, and/or an acceleration of the object;

a positioning device for positioning the aircraft and providing successive second states for the aircraft, the successive second states being constituted by a position, a speed, and/or an acceleration of the object;

at least one memory for storing calculation instructions, the successive first states for the object, and the successive second states for the aircraft;

at least one calculation device suitable for executing the calculation instructions to make a first characterization of a first track for the object as a set of equations as a function of time, make a second characterization of a second track for the aircraft as a set of equations as a function of time, make a third estimate of a distance between the first track for the object and the second track for the aircraft, and make a fourth estimate of a minimum distance (d_m) between the first track for the object and the second track for the aircraft; and

at least one warning device connected to the calculation device to trigger a warning when the minimum distance (d_m) is less than a first threshold;

wherein the first track for the object and the second track for the aircraft are defined respectively from the successive first states for the object and from the successive second states for the aircraft, and are characterized by respective sets of three equations as a function of time, and the distance between the first track for the object and the second track for the aircraft is characterized by a polynomial function of time defined from the two sets of three equations; and

wherein the object and the aircraft are considered as having acceleration that is constant, and the first track for the object and the second track for the aircraft are characterized by respective sets of three second order equations such that the distance between the first track for the object and the second track for the aircraft is characterized by a polynomial function of fourth degree.

14. The assembly according to claim 13, wherein the detector device is formed by an electromagnetic wave detector system, an optical detector system, an imaging system having at least one camera, or indeed an imaging system having at least one camera in combination with an electromagnetic wave detector system or with an optical detector system.

15. The assembly according to claim 13, wherein the positioning device is formed by at least one GNSS receiver and/or at least one inertial unit.

16. An aircraft comprising:

a detector device for detecting an object approaching the aircraft and supplying successive first states for the object, the successive first states being constituted by a position, a speed, and/or an acceleration of the object;

a positioning device for positioning the aircraft and providing successive second states for the aircraft, the successive second states being constituted by a position, a speed, and/or an acceleration of the object;

at least one memory for storing calculation instructions, the successive first states for the object, and the successive second states for the aircraft;

at least one calculation device suitable for executing the calculation instructions to make a first characterization of a first track for the object as a set of equations as a function of time, make a second characterization of a second track for the aircraft as a set of equations as a function of time, make a third estimate of a distance between the first track for the object and the second track for the aircraft, and make a fourth estimate of a minimum distance (d_m) between the first track for the object and the second track for the aircraft;

at least one warning device connected to the calculation device to trigger a warning when the minimum distance (d_m) is less than a first threshold;

an autopilot configured to control the aircraft to perform an avoidance maneuver for avoiding the object as soon as the minimum distance (d_m) is less than a second threshold, the second threshold being less than the first threshold, the avoidance maneuver being performed with a particular acceleration of the aircraft serving to maximize the distance between the first track for the object and the second track for the aircraft corresponding to a particular time value associated with the minimum distance (d_m);

wherein the first track for the object and the second track for the aircraft are defined respectively from the successive first states for the object and from the successive second states for the aircraft, and are characterized by respective sets of three equations as a function of time, and the distance between the first track for the object and the second track for the aircraft is characterized by a polynomial function of time defined from the two sets of three equations; and

wherein the object and the aircraft are considered as having acceleration that is constant, and the first track for the object and the second track for the aircraft are characterized by respective sets of three second order equations such that the distance between the first track for the object and the second track for the aircraft is characterized by a polynomial function of fourth degree.

17. The aircraft according to claim 16, wherein the detector device is formed by an electromagnetic wave detector system, an optical detector system, an imaging system having at least one camera, or indeed an imaging system having at least one camera in combination with an electromagnetic wave detector system or with an optical detector system.

18. The aircraft according to claim 16, wherein the positioning device is formed by at least one GNSS receiver and/or at least one inertial unit.