Formation flight control

• US 8,949,090 B2
• Filed: 01/28/2013
• Issued: 02/03/2015
• Est. Priority Date: 01/28/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Whitehead, Brian T., Bieniawski, Stefan R., Halaas, David, Lavretsky, Eugene
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): Ghajargar, Mohsen
• Application Number:
  US13/752,119
• Publication Number:
  US 20140214243A1
• Time in Patent Office: 736 Days
• Field of Search: 340/958, 701/7
• US Class Current: 703/3
• CPC Class Codes: B64C 19/00 Aircraft control not otherwise provided for
• CPC Class Codes: G05D 1/0202 specially adapted to aircraft
• CPC Class Codes: G05D 1/0825 using mathematical models
• CPC Class Codes: G05D 1/104 involving a plurality of aircrafts, e.g. formation flying traffic control systems for aircraft G08G5/00
• CPC Class Codes: Y02T 50/10 Drag reduction

Abstract

An apparatus for controlling the formation flight of a trailing aircraft relative to a vortex generated by a leading aircraft includes a position module, peak-seeking module, limiter module, and control module. The position module is configured to determine a position of the vortex relative to the trailing aircraft. The peak-seeking module is configured to determine a desired position of the trailing aircraft for providing desired vortex-induced aerodynamic benefits based on the position of the vortex relative to the trailing aircraft and a mapping function of an individual performance metric. The limiter module is configured to modify the desired position of the trailing aircraft to avoid unintended crossings of the trailing aircraft into the vortex. Finally, the control module is configured to control flight of the trailing aircraft based on one of the desired position of the trailing aircraft and modified desired position of the trailing aircraft.

Claims

1. An apparatus for controlling a formation flight of a trailing aircraft relative to a vortex generated by a leading aircraft, comprising

a position module configured to determine a position of the vortex relative to the trailing aircraft based on an estimate of wind conditions and an estimator state vector comprising a velocity of the leading aircraft and a relative position between the vortex and the trailing aircraft, the estimate of wind conditions being based on at least one air data measurement obtained by the leading aircraft and the estimator state vector being based on a first set of measurements, wherein the position module updates the estimator state vector based on a comparison between at least one actual measurement obtained by the trailing aircraft and the position of the vortex relative to the trailing aircraft determined by the position module, the at least one actual measurement differing from the first set of measurements;

a desired position module configured to determine a desired position of the trailing aircraft relative to the vortex for providing desired vortex-induced aerodynamic benefits based on the position of the vortex; and

a control module configured to control flight of the trailing aircraft based on the desired position of the trailing aircraft.

2. The apparatus of claim 1, wherein the at least one air data measurement obtained by the leading aircraft comprises measurements taken from a plurality of angle of attack and sideslip vane sensors on the leading aircraft.

3. The apparatus of claim 1, wherein the estimate of wind conditions is based on at least one of an estimated sideslip angle and an estimated angle of attack of the trailing aircraft.

4. The apparatus of claim 3, wherein the estimated sideslip angle is based on at least one of a position of an aileron of the trailing aircraft, a position of an upper rudder of the trailing aircraft, a position of a lower rudder of the trailing aircraft, a lateral acceleration of the trailing aircraft, a roll rate of the trailing aircraft, and a yaw rate of the trailing aircraft.

5. An apparatus for controlling a formation flight of a trailing aircraft relative to a vortex generated by a leading aircraft, comprising:

a position module configured to determine a position of the vortex relative to the trailing aircraft based on an estimator state vector comprising a relative position between the vortex and trailing aircraft, wherein the position module determines the position of the vortex relative to the trailing aircraft by recursively updating the estimator state vector based on a plurality of sensed measurements, wherein the position module updates the estimator state vector based on a selectable subset of the plurality of sensed measurements each time step;

a desired position module configured to determine a desired position of the trailing aircraft relative to the vortex for providing desired vortex-induced aerodynamic benefits based on the position of the vortex; and

a control module configured to control flight of the trailing aircraft based on the desired position of the trailing aircraft.

6. The apparatus of claim 5, wherein the relative position between the vortex and trailing aircraft comprises a relative lateral position of the vortex with respect to the trailing aircraft and a relative vertical position of the vortex with respect to the trailing aircraft.

7. The apparatus of claim 6, wherein the estimator state vector comprises a velocity of the leading aircraft in a lateral direction and a velocity of the leading aircraft in a vertical direction.

8. The apparatus of claim 7, wherein the estimator state vector comprises a wind gust component on the vortex in a lateral direction and a wind gust component on the vortex in a vertical direction.

9. The apparatus of claim 8, wherein the estimator state vector comprises a delay constant and a strength of the vortex.

10. The apparatus of claim 5, wherein the position module is configured to determine the position of the vortex relative to the trailing aircraft based on a measurement vector comprising the plurality of sensed measurements.

11. The apparatus of claim 5, wherein the plurality of sensed measurements comprises a longitudinal position of the leading aircraft relative to the trailing aircraft, a time-delayed lateral position of the leading aircraft relative to the trailing aircraft, a time-delayed vertical position of the leading aircraft relative to the trailing aircraft, a wind gust component acting on the trailing aircraft in a lateral direction, and a wind gust component acting on the trailing aircraft in a vertical direction.

12. The apparatus of claim 5, wherein the position module recursively updates the estimator state vector using a Kalman filter recursion technique and the subset of the plurality of sensed measurements comprises one of the plurality of sensed measurements.

13. The apparatus of claim 5, wherein the position module determines the position of the vortex relative to the trailing aircraft based on an estimated vortex-induced component of total body-axes forces acting on the trailing aircraft and an estimated vortex-induced component of a total body-axes moment acting on the trailing aircraft.

14. The apparatus of claim 5, wherein the position module is configured to update the estimator state vector based on a comparison between the position of the vortex relative to the trailing aircraft determined by the position module and at least one actual measurement of the relative position of the trailing aircraft with respect to the vortex.

15. The apparatus of claim 14, wherein the at least one actual measurement is obtained from output signals of a plurality of angle of attack vanes secured to the trailing aircraft.

16. The apparatus of claim 5, wherein the control module is configured to control the flight of the trailing aircraft based on a proportional-integral-derivative architecture.

17. The apparatus of claim 5, wherein the control module is configured to control the flight of the trailing aircraft based on a crosstrack rate feedback value.

18. The apparatus of claim 5, wherein the control module is configured to control the flight of the trailing aircraft based on at least one of a roll feedback value, a rudder feedback value, and a sideslip feedback value.

19. The apparatus of claim 5, wherein the position of the vortex comprises a lateral position component and a vertical position component.

20. An apparatus for controlling a formation flight of a trailing aircraft relative to a vortex generated by a leading aircraft, comprising:

a position module configured to determine a position of the vortex relative to the trailing aircraft based on an estimate of wind conditions at the leading aircraft and an estimator state vector comprising a relative position between the vortex and the trailing aircraft, the estimator state vector being based on a first set of measurements, wherein the position module updates the estimator state vector based on a comparison between at least one actual measurement obtained by the trailing aircraft and the position of the vortex relative to the trailing aircraft determined by the position module, the at least one actual measurement differing from the first set of measurements;

a peak-seeking module configured to determine a desired position of the trailing aircraft for providing desired vortex-induced aerodynamic benefits based on the position of the vortex relative to the trailing aircraft and a mapping function of an individual performance metric;

a limiter module configured to monitor the desired position of the trailing aircraft and modify the desired position of the trailing aircraft into a modified desired position of the trailing aircraft to avoid unintended crossings of the trailing aircraft into the vortex; and

a control module configured to control flight of the trailing aircraft based on one of the desired position of the trailing aircraft and modified desired position of the trailing aircraft.