Optimal altitude controller for super pressure aerostatic balloon

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

determining a target variable-buoyancy vehicle state for a variable-buoyancy vehicle in flight, wherein the target variable-buoyancy vehicle state includes at least one of a target mass, a target altitude and a target velocity;

determining a current variable-buoyancy vehicle state for the variable-buoyancy vehicle, wherein the current variable-buoyancy vehicle state includes a current mass, a current altitude and a current velocity;

performing a state-change optimization to determine (1) a control policy configured to reduce power usage of the variable-buoyancy vehicle, and (2) a fill-rate control plan based on the control policy to move the variable-buoyancy vehicle from the current variable-buoyancy vehicle state to the target variable-buoyancy vehicle state, wherein the fill-rate control plan comprises a plurality of fill rates for a bladder of the variable-buoyancy vehicle and timing information indicating when each fill rate should be utilized by the variable-buoyancy vehicle; and

communicating the fill-rate control plan to the variable-buoyancy vehicle.

2. The method of claim 1 , wherein the variable-buoyancy vehicle state further includes a global location.

3. The method of claim 1 , wherein communicating the fill-rate control plan further comprises communicating instructions for changing the variable-buoyancy vehicle state.

4. The method of claim 3 , wherein the instructions for changing the variable-buoyancy vehicle state comprise instructions for operating an impeller.

5. The method of claim 4 , wherein the impeller is powered by renewable energy.

6. The method of claim 1 , wherein the communicating is performed wirelessly.

7. The method of claim 1 , further comprising:

determining a revised variable-buoyancy vehicle state for the variable-buoyancy vehicle, wherein the revised variable-buoyancy vehicle state includes a revised mass, a revised altitude and a revised velocity;

performing a revised state-change optimization to determine a revised fill-rate control plan to move the variable-buoyancy vehicle from the revised variable-buoyancy vehicle state to the target variable-buoyancy vehicle state, wherein the revised fill-rate control plan comprises a plurality of fill rates for a bladder of the variable-buoyancy vehicle and timing information indicating when each fill rate should be utilized by the variable-buoyancy vehicle; and

communicating the revised fill-rate control plan to the variable-buoyancy vehicle.

8. The method of claim 1 , wherein the state-change optimization is performed based on a calculation including at least one of adding ambient air to or removing ambient air from the variable-buoyancy vehicle, wherein the adding ambient air to or removing ambient air adjusts the mass.

9. An aerostatic 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 current balloon state for the balloon in flight, wherein the current balloon state includes a current mass, a current altitude and a current velocity;

perform a state-change optimization to determine (1) a control policy configured to reduce power usage of the variable-buoyancy vehicle, and (2) a fill-rate control plan based on the control policy to move the balloon from the current balloon state to a target balloon state, wherein the fill-rate control plan comprises a plurality of fill rates for an envelope of the balloon and timing information indicating when each fill rate should be utilized by the balloon;

wherein the control unit is further configured to adjust the mass of air in the envelope based on the fill-rate control plan.

10. The aerostatic balloon of claim 9 , further comprising a communication module configured to:

transmit data indicative of a current balloon state to the processing unit, wherein the processing unit is located at central control system; and

subsequently receive the fill-rate control plan that indicates at least one intermediate balloon state and a final balloon state.

11. The aerostatic balloon of claim 10 , wherein the communication module is further configured to transmit and receive data wirelessly.

12. The aerostatic balloon of claim 10 , wherein the communication module is further configured to transmit data relating to a current balloon state at periodic intervals.

13. The aerostatic balloon of claim 9 , wherein the control unit is powered by a renewable energy source.

14. The aerostatic balloon of claim 13 , wherein the renewable energy source is solar power.

15. The aerostatic balloon of claim 9 , wherein the control unit further comprises an impeller configured to change the mass of the aerostatic balloon.

16. The aerostatic balloon of claim 9 , wherein each balloon state comprises an altitude, a system mass, and a vertical velocity.

17. The aerostatic balloon of claim 16 , wherein the current balloon state further comprises a global location.

18. The aerostatic balloon of claim 9 , wherein the processor is further configured to determine both the at least one intermediate balloon state and the final balloon state.

19. The aerostatic balloon of claim 9 , wherein the air is ambient air in the balloon environment.

20. The aerostatic balloon of claim 9 , wherein the processor is configured to operate the control unit in one of a power-efficient mode, a time-efficient mode, and a damped-controlled mode.

21. 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 balloon state for a balloon, wherein the target balloon state includes at least one of a target mass, a target altitude and a target velocity;

determining a current balloon state for the balloon in flight, wherein the current balloon state includes a current mass, a current altitude and a current velocity;

perform a state-change optimization to determine (1) a control policy configured to reduce power usage of the variable-buoyancy vehicle, and (2) a fill-rate control plan based on the control policy to move the balloon from the current balloon state to the target balloon state, wherein the fill-rate control plan comprises a plurality of fill rates for a bladder of the balloon and timing information indicating when each fill rate should be utilized by the balloon; and

communicating the fill-rate control plan to the balloon.

22. The article of manufacture of claim 21 , wherein the balloon state further includes a global location.

23. The article of manufacture of claim 21 , wherein communicating the fill-rate control plan further comprises communicating instructions for changing the balloon state.

24. The article of manufacture of claim 23 , wherein the instructions for changing the balloon state comprise instructions for operating an impeller.

25. The article of manufacture of claim 24 , wherein the impeller is powered by renewable energy.

26. The article of manufacture of claim 21 , wherein the communicating is performed wirelessly.