Ground Station with Shuttled Drum for Tethered Aerial Vehicles

• US 20150158600A1
• Filed: 12/30/2013
• Published: 06/11/2015
• Est. Priority Date: 12/09/2013
• Status: Active Grant

• Current Assignee: Makani Technologies LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Hachtmann, Brian, Vander Lind, Damon
• Granted Patent: US 9,676,496 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64F 3/00 Ground installations specially adapted for captive aircraft
• CPC Class Codes: B66D 1/39 by means of axially-movable drums or barrels pivotably mounted drums or barrel B66D1/365
• CPC Class Codes: B66D 1/60 adapted for special purposes

Abstract

A system may include an aerial vehicle, a perch platform configured to receive the aerial vehicle, and a ground station coupled to the aerial vehicle via a tether. The ground station may include a winch including a winch drum configured to move laterally and spin in a manner such that the tether is wound onto on the winch drum in a repeating pattern, possibly utilizing a fixed position levelwind. The system may additionally include a tower around which the winch and the perch platform can rotate about a vertical axis relative to the tower. The system may further utilize the tether forces on the levelwind to help move the perch platform around the vertical axis or be driven actively by a motor.

Claims

1. A ground station comprising:

a platform;

a winch drum coupled to the platform, wherein the winch drum is;

(a) rotatable about a central axis and (b) during rotation, configured to move a lateral distance relative to the platform along the direction of the central axis;

a tether adapted to be wound about the winch drum when the winch drum is rotated in a first direction; and

a levelwind rigidly coupled to the platform, wherein the tether passes through the levelwind during winding, and wherein the levelwind is configured to position the tether at a substantially fixed location relative to the platform such that as the tether is wound onto the rotating and laterally moving winch drum, the tether accumulates on the winch drum in a repeating pattern.

2. The ground station of claim 1, further comprising a winch assembly configured to provide lateral movement of the winch drum relative to the platform, wherein the winch assembly comprises:

an axle coupled to the winch drum and about which the winch drum rotates;

one or more support arms, wherein the axle is rotatably coupled to the one or more support arms; and

a winch base, wherein the winch base is coupled to the one or more support arms, and wherein the winch base is slidably coupled to the platform and configured to move the winch drum via the support arms laterally relative to the platform along the direction of the central axis.

3. The ground station of claim 2, further comprising:

at least one restraining device, wherein the at least one restraining device slidably couples the winch base to the platform, and wherein the at least one restraining device is configured to allow lateral movement of the winch base relative to the platform along the direction of the central axis and to restrict movement of the winch base away from the platform and in any other direction relative to the platform; and

a lateral drive mechanism, wherein the lateral drive mechanism is coupled to the winch base and configured to move the winch base laterally relative to the platform along the direction of the central axis.

4. The ground station of claim 3, wherein the at least one restraining device is at least one linear bearing.

5. The ground station of claim 3, wherein the at least one restraining device is at least one dovetail slide.

6. The ground station of claim 3, wherein the lateral drive mechanism comprises:

at least one lead screw nut coupled to the platform;

at least one lead screw coupled to each lead screw nut, wherein each lead screw is further rotatably coupled to the winch assembly, and wherein each lead screw is configured to move the winch base laterally relative to the platform along the direction of the central axis when the lead screw is rotated; and

at least one motor to rotate the at least one lead screw.

7. The ground station of claim 6, wherein the at least one motor is also coupled to the winch drum and is configured to rotate the winch drum and the at least one lead screw.

8. The ground station of claim 3, wherein the lateral drive mechanism comprises a hydraulic cylinder coupled to the winch base and to the platform.

9. The ground station of claim 3, wherein the lateral drive mechanism comprises a pneumatic cylinder coupled to the winch base and to the platform.

10. The ground station of claim 3, wherein the lateral drive mechanism comprises a linear motor coupled to the winch base and to the platform.

11. The ground station of claim 1, further comprising a winch assembly configured to provide lateral movement of the winch drum, wherein the winch assembly comprises:

an axle coupled to the winch drum, wherein the axle is configured for the winch drum to rotate about the axle and for the winch drum to move laterally relative to the platform along the axle;

one or more support arms, wherein the axle is rotatably coupled to the one or more support arms;

a winch base, wherein the winch base is rigidly coupled to the one or more support arms and rigidly coupled to the platform; and

a lateral drive mechanism, wherein the lateral drive mechanism is coupled to the winch drum and configured to move the winch drum along the axle within the winch assembly in a lateral direction relative to the platform.

12. The winch assembly of claim 11, wherein the lateral drive mechanism comprises a lead screw and a lead screw nut.

13. The winch assembly of claim 11, wherein the lateral drive mechanism comprises a hydraulic cylinder.

14. The winch assembly of claim 11, wherein the lateral drive mechanism comprises a pneumatic cylinder.

15. The winch assembly of claim 11, wherein the lateral drive mechanism comprises a linear motor.

16. The ground station of claim 1, further comprising a control station, wherein the control station is configured to dynamically control the lateral distance the winch drum moves during rotation of the winch drum.

17. The ground station of claim 1,

wherein the winch drum further includes a convoluted surface about which the tether winds, and wherein the lateral distance moved by the winch drum during rotation is based in part on the distance between convolutions on the convoluted surface.

18. The ground station of claim 1, wherein the levelwind comprises a levelwind horn.

19. The ground station of claim 1, wherein the levelwind comprises a levelwind pulley.

20. The ground station of claim 1, further comprising:

a vertical tower; and

a rotating member, wherein the rotating member couples the platform to the tower, and wherein the rotating member is configured to permit the platform to rotate about a vertical axis relative to the tower.

21. The ground station of claim 20, wherein the levelwind is configured such that a lateral bias from the tether on the levelwind from a change in the azimuth angle of the tether relative to a planar axis normal to the winch drum causes the platform to rotate around the vertical axis towards the direction of the lateral bias.

22. The ground station of claim 1, further comprising:

a bias sensor coupled to the levelwind, wherein the bias sensor is configured to determine the lateral bias exerted by the tether on the levelwind from a change in the azimuth angle of the tether relative to an axis normal to the winch drum;

a control station, wherein the control station is configured to causes the platform to rotate around the vertical axis towards the direction of the lateral bias.

23. A method comprising:

rotating a winch drum in a first direction, wherein the rotating causes a tether to wind onto the winch drum, and wherein the tether passes through a levelwind before winding onto the winch drum;

moving the winch drum a lateral distance relative to the levelwind along the direction of the winch drum'"'"'s central axis of rotation during rotation of the winch drum.

24. A system comprising:

an aerial vehicle;

a perch coupled to a platform and configured to receive the aerial vehicle in a perched configuration;

a vertical tower;

a rotating member, wherein the rotating member couples the platform to the tower, and wherein the rotating member is configured to permit the platform to rotate about a vertical axis relative to the tower,

a winch drum coupled to the platform, wherein the winch drum is;

(a) rotatable about a central axis and (b) during rotation, configured to move a lateral distance relative to the platform along the direction of the central axis;

a tether adapted to be wound about the winch drum when the winch drum is rotated in a first direction, wherein the tether includes a proximate portion coupled to the winch drum and a distal portion that extends outwardly from the winch drum and is coupled to the aerial vehicle; and

a levelwind rigidly coupled to the platform, wherein the tether passes through the levelwind during winding, and wherein the levelwind is configured to position the tether at a substantially fixed location relative to the platform such that as the tether is wound onto the rotating and laterally moving winch drum, the tether accumulates on the winch drum in a repeating pattern; and

wherein the levelwind is also configured such that lateral bias from the tether on the levelwind from a change in the azimuth angle of the tether relative to a planar axis normal to the winch drum causes the platform to rotate around the vertical axis towards the direction of the lateral bias.