Autonomous payload recovery system

• US 6,808,144 B1
• Filed: 12/26/2002
• Issued: 10/26/2004
• Est. Priority Date: 08/06/2001
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Robinson, Douglas J., Ramsey, William R. Jr., Nicolai, Leland M.
• Primary Examiner(s): Barefoot, Galen L.
• Application Number:
  US10/331,009
• Time in Patent Office: 670 Days
• Field of Search: 244/139, 244/145, 244/146, 244/152, 244/137.1, 244/138.R, 701/3
• US Class Current: 244/139
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64D 17/025 for gliding chutes
• CPC Class Codes: B64D 17/343 by reefing means
• CPC Class Codes: B64U 2101/60 for transporting passengers; for transporting goods other than weapons
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: B64U 30/10 Wings
• CPC Class Codes: B64U 70/60 Take-off or landing of UAVs from a runway using their own power
• CPC Class Codes: B64U 70/83 using parachutes, balloons or the like
• CPC Class Codes: B64U 80/82 Airborne vehicles
• CPC Class Codes: G05D 1/105 specially adapted for unpowered flight, e.g. glider, parachuting, forced landing parachutes per se B64D17/00

Abstract

A parafoil recovery system capable of autonomously controlling the descent profile of a payload to a recovery area and maneuvering the parafoil to execute a soft landing in the recovery area is disclosed. A descent profile management system determines wind speed and direction, altitude, heading, and position of the payload based on sensor input. The descent profile management system also determines a gliding flight path profile from the launch point to the desired recovery area. A flare and stall maneuver is executed at the end of the landing sequence by braking the parafoil to slow the vertical descent speed and groundspeed for a soft landing. The pitch attitude of the payload can be adjusted by the descent profile management system to prevent nose-first impact with the ground. The parafoil canopy is released from the payload upon touchdown to prevent the canopy from dragging the payload on the ground after landing.

Claims

1. A system for autonomously controlling the glide path and flare landing of a parafoil to recover an airborne payload, comprising:

a processor;

sensors coupled to communicate with the processor, wherein the processor is operable to;

determine at least one of the group of;

wind speed, wind direction, altitude, heading, and position of the payload based on information from the sensors;

determine the pitch attitude of the payload;

determine adjustments to brake lines on the parafoil to execute a glide flight profile to a predetermined altitude, flare the parafoil to slow the descent rate, and stall the parafoil to land the payload; and

determine adjustments to a pitch attitude control line to control the pitch orientation of the payload.

2. The system of claim 1, further comprising a motor functionally coupled with the processor, wherein the motor is operable to adjust the length of a control line, wherein the control line is coupled to a control surface on the parafoil.

3. The system of claim 2, wherein the control surface comprises a flexible trailing edge of the parafoil.

4. The system of claim 1, further comprising a power supply coupled to provide power to the processor and at least a portion of the sensors.

5. The system of claim 1, further comprising a quick release connector coupled between the parafoil and the payload, wherein the release connector is operable to automatically release at least a portion of the parafoil from the payload upon landing.

6. The system of claim 2, wherein the processor further determines when to adjust the control surface to enter a spiral flight path.

7. The system of claim 6, wherein the processor further determines when to adjust the control surface to discontinue the spiral flight path and enter a landing fight path.

8. An apparatus for autonomously controlling the glide path and landing of an airborne payload, wherein the payload is coupled to a parafoil, comprising:

a descent profile management system operable to;

adjust at least one control surface on the parafoil to control the flight path of the payload; and

adjust an attitude line to control the pitch orientation of the payload before touchdown.

9. The apparatus of claim 8, further comprising:

a release mechanism coupled between the parafoil and the payload, wherein the release mechanism is operable to release at least a portion of the parafoil from the payload upon touchdown.

10. The apparatus of claim 8, further comprising:

a sensor system operable to determine at least one of;

wind speed, wind direction, altitude, heading, and position of the payload.

11. The apparatus of claim 8, wherein the processing system is further operable to:

adjust the flight path and the pitch attitude of the payload to flare the payload to a landing.

12. The apparatus of claim 8, wherein the payload is an air vehicle and the descent profile management system is further operable to:

adjust the pitch attitude line to cause the air vehicle to land tail first.

13. The apparatus of claim 10, wherein the processing system is further operable to:

adjust at least one control surface to cause the parafoil to execute a downward spiral flight path;

determine a last spiral in the downward spiral flight path; and

exit the last spiral and glide to a landing with the payload heading into the wind.

14. The apparatus of claim 8, further comprising:

a first actuator to adjust a control line attached to the at least one control surface, wherein operation of the first actuator is controlled by the descent profile management system; and

a second actuator to adjust the attitude line, wherein operation of the second actuator is controlled by the descent profile management system.

15. An autonomous air vehicle comprising:

a navigation system; and

a control system functionally coupled to the navigation system, wherein the control system includes instructions operable to;

determine when the air vehicle is in the vicinity of a predetermined recovery area based on information from the navigation system;

deploy a parafoil when the air vehicle is in the vicinity of the recovery area, wherein the parafoil is coupled to the air vehicle with a quick release buckle to release at least a portion of the parafoil upon landing, and the parafoil includes a control line coupled to the control system;

control the parafoil to descend and land substantially near the recovery area; and

adjust a pitch attitude line to change the pitch orientation of the air vehicle.

16. The air vehicle of claim 15, wherein the control system further comprises instructions operable to:

determine wind speed and wind direction relative to the air vehicle during a spiral descent flight path to the landing location.

17. The air vehicle of claim 16, wherein the control system further comprises instructions operable to:

flare the parafoil at a predetermined height above the ground.

18. The air vehicle of claim 15, further comprising

a reel motor, wherein the pitch attitude line is coupled at one end to the reel motor and at another end to an attach point remote from the reel motor along the longitudinal axis of the air vehicle, and the reel motor is operable to wind and unwind the pitch attitude line to raise and lower the nose of the air vehicle.

19. The air vehicle of claim 18, wherein the control system further comprises instructions operable to:

raise the nose of the air vehicle during landing when the air vehicle reaches a predetermined height above the ground.

20. A system for autonomously controlling the glide path and flare landing of a parafoil to recover an airborne payload, comprising:

a processor;

sensor means coupled to communicate with the processor, wherein the processor is operable to;

determine at least one of the group of;

wind speed, wind direction, altitude, heading, and position of the payload based on information from the sensors;

control the pitch attitude orientation of the payload; and

determine adjustments to brake lines on the parafoil to execute a glide flight profile, a flare, and stall of the parafoil to land the payload.

21. The system of claim 20, further comprising means for adjusting a control line coupled to a control surface on the parafoil.

22. The system of claim 21, wherein the control surface comprises a flexible trailing edge of the parafoil.

23. The system of claim 20, further comprising power supply means for providing power to the processor.

24. The system of claim 20, further comprising release means for automatically releasing at least a portion of the parafoil from the payload upon landing.

25. The system of claim 21, wherein the processor further determines when to adjust the control surface to enter a spiral flight path.

26. The system of claim 20, wherein the processor further determines when to adjust the control surface to discontinue the spiral flight path and enter a landing flight path.

27. A payload recovery system comprising:

a navigation system; and

a control system functionally coupled to the navigation system, wherein the control system includes instructions operable to;

steer the payload to the vicinity of a recovery area;

deploy a parafoil, wherein the parafoil is coupled to the payload with a release mechanism to release at least a portion of the parafoil upon landing;

adjust a control line coupled to the parafoil to control the descent profile of the payload; and

adjust an attitude control line to change the pitch attitude orientation of the payload.

28. The system of claim 27, wherein the control system further comprises instructions operable to:

determine wind speed and direction relative to the payload during a spiral descent flight path to the landing location.

29. The system of claim 28, wherein the control system further comprises instructions operable to:

flare the parafoil at a predetermined height above the ground; and

stall the parafoil at another predetermined height above the ground.

30. The system of claim 27, further comprising:

a reel motor positioned along the longitudinal axis of the payload, wherein the pitch attitude line is coupled at one end to the reel motor and at another end to an attach point remote from the reel motor along the longitudinal axis of the payload, and the reel motor is operable to wind and unwind the pitch attitude line to raise and lower a portion of the payload.

31. The system of claim 30, wherein the control system further comprises:

instructions operable to raise the front portion of the payload during landing when the payload reaches a predetermined height above the ground.

32. A method for recovering a payload, the method comprising:

deploying a parafoil coupled to the payload;

adjusting at least one control surface on the parafoil to control the descent of the payload;

executing a spiral descent until the payload is within a determined height above ground;

adjusting the pitch orientation of the payload to avoid impacting the ground with the front portion of the payload on touchdown;

flaring the parafoil to slow the descent rate of the payload; and

stalling the parafoil when the payload is within a second height above the ground.

33. The method of claim 32 further comprising:

determining when to stop the spiral descent to establish a final glide path segment heading in to the wind before touchdown.

34. The method of claim 32 further comprising:

adjusting the at least one control surface to position the payload near the desired recovery point before touchdown.

35. The method of claim 32 further comprising:

releasing the parafoil from the payload upon touchdown.