System and methods for automatically landing aircraft

• US 9,568,919 B2
• Filed: 10/24/2012
• Issued: 02/14/2017
• Est. Priority Date: 10/24/2012
• Status: Active Grant

• Current Assignee: Aurora Flight Sciences Corporation (The Boeing Co.)
• Original Assignee: Aurora Flight Sciences Corporation (The Boeing Co.)
• Inventors: Lim, Edward
• Primary Examiner(s): MARC-COLEMAN, MARTHE Y
• Application Number:
  US13/659,463
• Publication Number:
  US 20170001732A1
• Time in Patent Office: 1,574 Days
• Field of Search: 701/16, 701/492, 701/503, 701/509, 701/514, 701/519, 701/535, 731/703.1, 244/116
• US Class Current: 1/1
• CPC Class Codes: B63B 35/50 Vessels or floating structures for aircraft aircraft carriers B63G11/00; flying-boat hulls, other flotation means for aircraft B64
• CPC Class Codes: B64D 45/04 Landing aids; Safety measures to prevent collision with earth's surface
• CPC Class Codes: G01S 13/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track G01S13/64 takes precedence
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/865 Combination of radar systems with lidar systems
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 13/913 for landing purposes
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/933 of aircraft or spacecraft
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G05D 1/0684 on a moving platform, e.g. aircraft carrier

Abstract

The present invention is directed to methods of determining a vessel-relative off-deck waypoint (VRODW) location comprising the steps of providing an aircraft in flight; determining vessel range and vessel bearing relative the aircraft; and determining the VRODW location using the range and bearing measurements of the vessel. The present invention is further directed to methods of landing an aircraft on a vessel.

Claims

1. A method of determining a vessel-relative off-deck waypoint (VRODW) location for an aircraft in flight, the method comprising:

determining a vessel range and a vessel bearing of a vessel relative to the aircraft using a sensor;

tracking an altitude of the aircraft relative to the vessel by isolating vertical motion of the vessel from vertical motion of the aircraft, wherein vertical motion of the vessel is isolated using a pseudo-altitude reference value;

determining the VRODW location as a function of the vessel range and the vessel bearing; and

maintaining the aircraft in flight at the VRODW location until the vessel sends to the aircraft a land command through a communications link.

2. The method of claim 1, wherein the VRODW located aft of the vessel.

3. The method of claim 1, wherein the aircraft is a vertical take-off and landing (VTOL) aircraft.

4. The method of claim 1, wherein the aircraft determines the vessel range and vessel bearing.

5. The method of claim 1, further comprising:

determining aircraft groundspeed and aircraft position in a local coordinate frame; and

determining vessel position and vessel velocity in the local coordinate frame from the vessel range, vessel bearing, aircraft groundspeed, and aircraft position determinations.

6. The method of claim 5, wherein aircraft groundspeed is determined using onboard Doppler radar, inertial navigation, satellite navigation, GPS, radio navigation, radio direction finding, or any combination thereof.

7. The method of claim 5, wherein the aircraft position is determined by propagating aircraft groundspeed, inertial navigation, satellite navigation, GPS, radio navigation, radio direction finding, or any combination thereof.

8. The method of claim 5, wherein the vessel position and vessel velocity are determined using an algorithm.

9. The method of claim 8, wherein the algorithm comprises a Kalman filter, extended Kalman filter, unscented Kalman filter, particle filter, least-squares estimator, recursive estimation algorithm, or any combination thereof.

10. The method of claim 5, further comprising determining a vessel velocity vector, wherein the VRODW location is a fixed distance from the vessel along a negative vessel velocity vector.

11. The method of claim 1, wherein the vessel range and vessel bearing is determined using a radar sensor.

12. The method of claim 11, wherein the radar sensor comprises a pulse radar, pulse Doppler radar, high-range resolution radar, pulse-compression radar, synthetic aperture radar, inverse synthetic aperture radar, imaging radar, tracking radar, track-while-scan radar, 3 D radar, phased-array radar, continuous-wave radar, frequency-modulated continuous wave radar, or any combination thereof.

13. The method of claim 11, wherein the radar sensor is mounted onboard the aircraft.

14. The method of claim 1, wherein the aircraft performs autonomous landing.

15. The method of claim 1, wherein a barometric altimeter provides the pseudo-altitude reference value.

16. A method of landing an aircraft in flight at a vessel-relative off-deck waypoint (VRODW) location aft of a vessel, the method comprising:

determining a vessel velocity vector;

approaching the vessel from the VRODW location along the vessel velocity vector after the aircraft receives a land command from the vessel through a communications link;

identifying a landing area of the vessel using a sensor;

hovering the aircraft above the landing area;

tracking an altitude of the aircraft relative to the landing area by filtering vertical motion of the vessel from vertical motion of the aircraft, wherein vertical motion of the vessel is filtered using a pseudo-altitude reference value;

descending to the landing area as a function of said pseudo-altitude reference value; and

landing the aircraft on the vessel.

17. The method of claim 16, wherein the aircraft is a vertical take-off and landing (VTOL) aircraft.

18. The method of claim 16, wherein determining the vessel velocity vector comprises:

determining vessel range and vessel bearing;

determining aircraft groundspeed and aircraft position in a local coordinate frame; and

determining vessel position and vessel velocity in the local coordinate frame using the vessel range, vessel bearing, aircraft groundspeed and aircraft position.

19. The method of claim 16, wherein a barometric altimeter provides the pseudo-altitude reference value.

20. A method of landing an aircraft in flight at a vessel-relative off-deck waypoint (VRODW) location aft of a vessel, the method comprising:

navigating the aircraft to the vessel from the VRODW location in response to a land command from the vessel to the aircraft through a communications link;

identifying a landing area of the vessel using LIDAR;

hovering the aircraft above the landing area;

filtering vertical motion of the vessel from vertical motion of the aircraft, wherein vertical motion of the vessel is filtered using a pseudo-altitude reference value;

descending the aircraft to the landing area as a function of said pseudo-altitude reference value; and

landing the aircraft on the vessel at the landing area.

21. The method of claim 20, wherein the aircraft is a vertical take-off and landing (VTOL) aircraft.

22. The method of claim 20, wherein the LIDAR is scanning or flash LIDAR.

23. The method of claim 20, wherein the landing area is designated on the vessel by a symbol.

24. The method of claim 23, wherein the symbol is a circle, a cross, a H-shape, or other conventional symbols used on vessels to designate a landing area.

25. The method of claim 20, further comprising identifying a touchdown marker within the landing area.

26. The method of claim 20, wherein a barometric altimeter provides the pseudo-altitude reference value.

28. The method of claim 24, wherein the aircraft is a vertical take-off and landing (VTOL) aircraft.

27. A method of landing an aircraft on a vessel comprising:

determining a vessel range and a vessel bearing of the vessel using a sensor;

identifying a vessel-relative off-deck waypoint (VRODW) location using the vessel range and vessel bearing;

navigating the aircraft to the VRODW location;

determining a vessel velocity vector;

maintaining the aircraft in flight at the VRODW location until the vessel sends a land command to the aircraft through a communications link;

approaching the vessel from the VRODW location along the vessel velocity vector upon receipt of the land command through the communications link;

identifying a landing area on the vessel using LIDAR;

tracking an altitude of the aircraft relative to the landing area by filtering vertical motion of the vessel from vertical motion of the aircraft, wherein vertical motion of the vessel is filtered using a pseudo-altitude reference value;

hovering the aircraft above the landing area at a first altitude;

descending the aircraft from the first altitude to a second altitude at a first descent speed;

hovering the aircraft above the landing area at the second altitude;

descending the aircraft from the second altitude to the landing area at a second descent speed; and

landing the aircraft on the vessel at the landing area.

29. The method of claim 27, wherein the aircraft performs the method autonomously.