Aircraft refueling with sun glare prevention

Patent metadata

Field	Value
Publication number	US-10429857-B2
Application number	US-201715411890-A
Country	US
Kind code	B2
Filing date	Jan 20, 2017
Priority date	Jan 20, 2017
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

Systems and methods for aircraft refueling with sun glare prevention. One embodiment is a method that includes calculating a future time to position a receiver aircraft via an optical sensor with respect to a supply aircraft for an aerial fuel transfer, and calculating a sun position relative to the position of the receiver aircraft for the future time. The method also includes determining that the optical sensor of the receiver aircraft is susceptible to solar interference for the future time based on the sun position relative to the position of the receiver aircraft. The method further includes generating a request for the supply aircraft to move to an alternate position for the future time, and positioning the receiver aircraft via the optical sensor at the future time with respect to the alternate position of the supply aircraft for the aerial fuel transfer.

First claim

What is claimed is:

1. A method comprising:
calculating a future time to position a receiver aircraft via an optical sensor with respect to a supply aircraft for an aerial fuel transfer;
calculating a sun position relative to the position of the receiver aircraft for the future time;
determining that the optical sensor of the receiver aircraft is susceptible to solar interference for the future time based on the sun position relative to the position of the receiver aircraft;
generating a request for the supply aircraft to move to an alternate position for the future time; and
positioning the receiver aircraft via the optical sensor at the future time with respect to the alternate position of the supply aircraft for the aerial fuel transfer.

2. The method of claim 1 further comprising:
determining that the optical sensor of the receiver aircraft is susceptible to solar interference by:
obtaining an interference angle associated with the optical sensor;
calculating a topocentric azimuth angle of the sun for the future time relative to the position of the receiver aircraft;
calculating a topocentric zenith angle of the sun for the future time relative to the position of the receiver aircraft; and
determining whether the topocentric azimuth angle and the topocentric zenith angle define a vector to the receiver aircraft that overlaps with the interference angle.

3. The method of claim 2 further comprising:
calculating the topocentric zenith angle by:
calculating a horizon intercept point on earth surface based on the topocentric azimuth angle;
calculating a topocentric elevation angle of the sun at the horizon intercept point;
calculating an atmospheric refraction correction at the horizon intercept point based on the topocentric elevation angle;
calculating an atmospheric refraction correction with respect to the receiver aircraft by doubling the atmospheric refraction correction at the horizon intercept point;
calculating a corrected topocentric elevation angle of the sun with atmospheric correction with respect to the receiver aircraft by adding the atmospheric refraction correction for the receiver aircraft to the topocentric elevation angle; and
calculating the topocentric zenith angle of the sun at the receiver aircraft by subtracting the corrected topocentric elevation angle from ninety degrees.

4. The method of claim 1 further comprising:
calculating the future time to position the receiver aircraft for the aerial fuel transfer based at least in part on a flight path for the supply aircraft to follow;
generating a request for the supply aircraft to adjust the flight path for the future time in response to a determination that the optical sensor of the receiver aircraft is susceptible to solar interference along the flight path; and
initiating the aerial fuel transfer as the supply aircraft travels in an adjusted flight path.

5. The method of claim 1 further comprising:
calculating the future time to position the receiver aircraft based on a calculated span of time between initiating use of the optical sensor for the aerial fuel transfer and ending use of the optical sensor for the aerial fuel transfer.

6. The method of claim 1 further comprising:
calculating the sun position relative to the position of the receiver aircraft based on a positional constraint for connecting the receiver aircraft with the supply aircraft for the aerial fuel transfer.

7. The method of claim 1 wherein:
the receiver aircraft is an unmanned aerial vehicle.

8. A non-transitory computer readable medium embodying programmed instructions which, when executed by a processor, are operable for performing a method comprising:
calculating a future time to position a receiver aircraft via an optical sensor with respect to a supply aircraft for an aerial fuel transfer;
calculating a sun position relative to the position of the receiver aircraft for the future time;
determining that the optical sensor of the receiver aircraft is susceptible to solar interference for the future time based on the sun position relative to the position of the receiver aircraft;
generating a request for the supply aircraft to move to an alternate position for the future time; and
positioning the receiver aircraft via the optical sensor at the future time with respect to the alternate position of the supply aircraft for the aerial fuel transfer.

9. The medium of claim 8 wherein the method further comprises:
determining that the optical sensor of the receiver aircraft is susceptible to solar interference by:
obtaining an interference angle associated with the optical sensor;
calculating a topocentric azimuth angle of the sun for the future time relative to the position of the receiver aircraft;
calculating a topocentric zenith angle of the sun for the future time relative to the position of the receiver aircraft; and
determining whether the topocentric azimuth angle and the topocentric zenith angle define a vector to the receiver aircraft that overlaps with the interference angle.

10. The medium of claim 9 wherein the method further comprises:
calculating the topocentric zenith angle by:
calculating a horizon intercept point on earth surface based on the topocentric azimuth angle;
calculating a topocentric elevation angle of the sun at the horizon intercept point;
calculating an atmospheric refraction correction at the horizon intercept point based on the topocentric elevation angle;
calculating an atmospheric refraction correction with respect to the receiver aircraft by doubling the atmospheric refraction correction at the horizon intercept point;
calculating a corrected topocentric elevation angle of the sun with atmospheric correction with respect to the receiver aircraft by adding the atmospheric refraction correction for the receiver aircraft to the topocentric elevation angle; and
calculating the topocentric zenith angle of the sun at the receiver aircraft by subtracting the corrected topocentric elevation angle from ninety degrees.

11. The medium of claim 8 wherein the method further comprises:
calculating the future time to position the receiver aircraft for the aerial fuel transfer based at least in part on a flight path for the supply aircraft to follow;
generating a request for the supply aircraft to adjust the flight path for the future time in response to a determination that the optical sensor of the receiver aircraft is susceptible to solar interference along the flight path; and
initiating the aerial fuel transfer as the supply aircraft travels in an adjusted flight path.

12. The medium of claim 8 wherein the method further comprises:
calculating the future time to position the receiver aircraft based on a calculated span of time between initiating use of the optical sensor for the aerial fuel transfer and ending use of the optical sensor for the aerial fuel transfer.

13. The medium of claim 8 wherein the method further comprises:
calculating the sun position relative to the position of the receiver aircraft based on a positional constraint for connecting the receiver aircraft with the supply aircraft for the aerial fuel transfer.

14. The medium of claim 8 wherein:
the receiver aircraft is an unmanned aerial vehicle.

15. A system comprising:
a supply aircraft configured to receive instructions that indicate a flight path for the supply aircraft to follow, and to transfer fuel in-flight to an unmanned air vehicle in an aerial refuel operation; and
a processor configured to determine that the flight path exposes an optical sensor of the unmanned air vehicle to solar i

Assignees

• Boeing Co

Inventors

• Weaver Thomas L
• Wilkins Donald Frank

Classifications

• B64U2201/20

  Remote controls · CPC title

• G08G5/00

  Traffic control systems for aircraft · CPC title

• B64D39/00

  Refuelling during flight · CPC title

• G05D1/104 Primary

  involving a plurality of aircrafts, e.g. formation flying (traffic control systems for aircraft G08G5/00) · CPC title

• B64C2201/146

  Operations & Transport · mapped topic