Altitude control via adjustment to mass of air in bladder within lift-gas filled envelope

• US 9,340,272 B1
• Filed: 07/01/2014
• Issued: 05/17/2016
• Est. Priority Date: 09/25/2013
• Status: Active Grant

• Current Assignee: Loon, LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: DeVaul, Richard Wayne, Biffle, Clifford L.
• Primary Examiner(s): O'Hara, Brian M
• Assistant Examiner(s): Dixon, Keith L
• Application Number:
  US14/321,374
• Time in Patent Office: 686 Days
• Field of Search: 244/98
• US Class Current: 1/1
• CPC Class Codes: B64B 1/60 Gas-bags surrounded by separate containers of inert gas
• CPC Class Codes: B64B 1/62 Controlling gas pressure, heating, cooling, or discharging gas
• CPC Class Codes: B64B 1/70 Ballasting arrangements

Abstract

This disclosure relates to the use of a method for adjusting an altitude of variable-buoyancy vehicle, such as an aerostatic balloon. The method includes determining a target mass for a variable-buoyancy vehicle, where the target mass is based on a target altitude for the variable-buoyancy vehicle. Additionally, the method includes adding a first mass to the variable-buoyancy vehicle. The mass added is less than a difference between the target mass and a current mass. The method also includes adding a second mass to the variable-buoyancy vehicle in response to a decrease in an internal pressure of the variable-buoyancy vehicle caused by adding the first mass. Further, adding the second mass makes a current mass of the variable-buoyancy vehicle approximately equal to the target mass.

Claims

1. A method for adjusting a variable-buoyancy vehicle comprising:

determining a target mass for a variable-buoyancy vehicle having an initial internal pressure and an initial altitude, based on a target altitude for the variable-buoyancy vehicle, wherein the target altitude is lower than the initial altitude;

adding a first mass of air to the variable-buoyancy vehicle, wherein the mass added is less than a difference between the target mass and an initial mass, and wherein the mass added causes an internal pressure of the variable-buoyancy vehicle to increase; and

in response to in the internal pressure of the variable-buoyancy vehicle decreasing below the initial internal pressure based on a current altitude of the variable-buoyancy vehicle being lower than the initial altitude, adding a second mass of air to the variable-buoyancy vehicle, wherein the pressure of the variable-buoyancy vehicle decreased based on the first adding mass, wherein the second mass added makes a current mass of the variable-buoyancy vehicle approximately equal to the target mass.

2. The method of claim 1, further comprising determining the internal pressure of the variable-buoyancy vehicle after adding the first mass.

3. The method of claim 1, wherein the decrease in the internal pressure has an associated delay time.

4. The method of claim 3, wherein the second mass is added after the delay time.

5. The method of claim 2, wherein the second mass is added in response to the internal pressure falling below a threshold.

6. The method of claim 5, wherein the threshold is selected based on a power consumption of a pump of the variable-buoyancy vehicle.

7. The method of claim 5, wherein the threshold is selected based on an inflection point of a pressure curve of the internal pressure of the variable-buoyancy vehicle.

8. A balloon comprising:

an envelope configured to hold air;

a bladder configured to hold lift gas, wherein the bladder is located within the envelope;

a control unit configured to add or remove air from the envelope in order to change a mass of air in the envelope; and

a processing unit configured to;

determine a target mass for the balloon, based on a target altitude for the balloon;

cause the control unit to add a first mass of air to the balloon, wherein the mass added is less than a difference between the target mass and a current mass; and

in response to a decrease in an internal pressure of the balloon, cause the control unit to add a second mass of air to the balloon, wherein the pressure of the balloon decreased based on the first adding mass, wherein the second mass of air added makes a current mass of the balloon approximately equal to the target mass.

9. The balloon of claim 8, wherein the processing unit is further configured to determine the internal pressure of the aerostatic balloon after adding the first mass of air.

10. The balloon of claim 8, wherein the decrease in ihe internal pressure has an associated delay time.

11. The balloon of claim 10, wherein the processing unit causes the second mass of air to be added after the delay time.

12. The balloon of claim 9, wherein the processing unit causes the second mass of air to be added in response to the internal pressure falling below a threshold.

13. The balloon of claim 12, wherein the threshold is selected based on a power consumption of the control unit of the balloon.

14. An article of manufacture including a non-transitory computer-readable medium having stored thereon program instructions that, if executed by a processor in a balloon-control system, cause the balloon-control system to perform operations comprising:

determining a target mass for a variable-buoyancy vehicle, based on a target altitude for the variable-buoyancy vehicle;

adding a first mass of air to the variable-buoyancy vehicle, wherein the mass added is less than a difference between the target mass and a current mass; and

in response to a decrease in an internal pressure of the variable-buoyancy vehicle, adding a second mass of air to the variable-buoyancy vehicle, wherein the pressure of the variable-buoyancy vehicle decreased based on the first adding mass, wherein the second mass of air added makes a current mass of the variable-buoyancy vehicle approximately equal to the target mass.

15. The article of manufacture of claim 14, further comprising determining the internal pressure of the variable-buoyancy vehicle after adding the first mass of air.

16. The article of manufacture of claim 14, wherein the decrease in the internal pressure has an associated delay time.

17. The article of manufacture of claim 16, wherein the second mass of air is added after the delay time.

18. The article of manufacture of claim 15, wherein the second mass of air is added in response to the internal pressure falling below a threshold.

19. The article of manufacture of claim 18, wherein the threshold is selected based on a power consumption of a pump of the variable-buoyancy vehicle.

20. The article of manufacture of claim 14, wherein the variable-buoyancy vehicle is an aerostatic balloon.