U.S. patent application number 17/125043 was filed with the patent office on 2021-04-08 for aerial vehicle control using ballast.
This patent application is currently assigned to LOON LLC. The applicant listed for this patent is LOON LLC. Invention is credited to Salvatore J. Candido, Sameera S. Ponda, Jacob Roberts.
Application Number | 20210101667 17/125043 |
Document ID | / |
Family ID | 1000005287705 |
Filed Date | 2021-04-08 |
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United States Patent
Application |
20210101667 |
Kind Code |
A1 |
Ponda; Sameera S. ; et
al. |
April 8, 2021 |
AERIAL VEHICLE CONTROL USING BALLAST
Abstract
A system for controlling an aerial vehicle includes an aerial
vehicle, a ballast coupled to the aerial vehicle, a server
including a processor and a memory, and a wireless communication
link that communicatively couples the aerial vehicle and the
server. the memory stores instructions that, when executed by the
processor, cause the server to receive weather data, determine,
based on the weather data, that the aerial vehicle is experiencing,
or is expected to experience, weather that satisfies a
predetermined criterion, and cause the aerial vehicle to decouple
at least a portion of the ballast based on a result of the
determination.
Inventors: |
Ponda; Sameera S.; (Mountain
View, CA) ; Candido; Salvatore J.; (Mountain View,
CA) ; Roberts; Jacob; (San Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LOON LLC |
Mountain View |
CA |
US |
|
|
Assignee: |
LOON LLC
Mountain View
CA
|
Family ID: |
1000005287705 |
Appl. No.: |
17/125043 |
Filed: |
December 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15850612 |
Dec 21, 2017 |
10875618 |
|
|
17125043 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64B 1/70 20130101; B64B
1/62 20130101; B64B 1/44 20130101 |
International
Class: |
B64B 1/70 20060101
B64B001/70; B64B 1/62 20060101 B64B001/62; B64B 1/44 20060101
B64B001/44 |
Claims
1.-20. (canceled)
21. A method for controlling an aerial vehicle comprising:
receiving weather data from one or both of a data source and a
sensor; determining whether the weather data satisfies a
predetermined criterion; determining whether the aerial vehicle is
expected to experience zero superpressure after determining that
the weather data satisfies the predetermined criterion; determining
whether the aerial vehicle is expected to regain superpressure
after experiencing zero superpressure; and sending a command to the
aerial vehicle, wherein superpressure comprises a pressure in a
balloon envelope that is greater than an ambient pressure.
22. The method of claim 21, wherein the weather data is received by
a transceiver.
23. The method of claim 21, wherein the weather data comprises an
ambient temperature and an upwelling infrared energy condition.
24. The method of claim 23, wherein the ambient temperature
comprises one or both of a current and a future predicted ambient
temperature.
25. The method of claim 23, wherein the upwelling infrared energy
condition comprises one or both of a current and a future predicted
upwelling infrared energy condition.
26. The method of claim 21, wherein the weather data comprises a
predicted solar flux incident.
27. The method of claim 21, wherein the criterion comprises one or
both of a temperature threshold and an upwelling infrared energy
level threshold.
28. The method of claim 21, wherein the command is configured to
cause the aerial vehicle to descend to the ground after determining
the aerial vehicle is not expected to regain superpressure.
29. The method of claim 21, further comprising, in response to
determining that the aerial vehicle is expected to regain
superpressure: determining a descent altitude; determining whether
the descent altitude is less than a threshold altitude; in response
to determining the descent altitude is less than a threshold
altitude, determining whether the aerial vehicle is able to remain
afloat using an altitude control system.
30. The method of claim 29, wherein the command is configured to
cause the aerial vehicle to adjust its altitude using the altitude
control system in response to determining that the aerial vehicle
is able to remain afloat using the altitude control system.
31. The method of claim 29, further comprising, in response to
determining that the aerial vehicle is not able to remain afloat
using the altitude control system: determining an amount of ballast
coupled to the aerial vehicle; determining whether the aerial
vehicle is able to remain afloat using the altitude control system
and decoupling at least a portion of the ballast; and wherein the
command is configured to cause the aerial vehicle to decouple the
portion of the ballast in response to determining the aerial
vehicle is able to remain afloat using the altitude control system
and decoupling at least the portion of the ballast.
32. The method of claim 31, wherein the command further is
configured to cause the aerial vehicle to adjust its altitude using
the altitude control system.
33. The method of claim 31, further comprising, prior to sending
the command configured to cause the aerial vehicle to decouple the
portion of the ballast: receiving new weather data; and determining
that the new weather data satisfies the predetermined
criterion.
34. The method of claim 31, further comprising, after the aerial
vehicle is caused to decouple the portion of the ballast,
determining whether the aerial vehicle is floating at a safe
altitude.
35. The method of claim 34, further comprising sending another
command to the aerial vehicle to cause the aerial vehicle to
decouple another portion of the ballast in response to determining
the aerial vehicle is not floating at a safe altitude and that
there remains at least the another portion of the ballast coupled
to the aerial vehicle.
36. The method of claim 34, further comprising sending another
command to the aerial vehicle to cause the aerial vehicle to
descend to ground in response to determining the aerial vehicle is
not floating at a safe altitude and that there remains less than
the portion of the ballast coupled to the aerial vehicle.
37. A non-transitory computer-readable storage medium storing
instructions which, when executed by a processor, cause a computing
device to implement a method for controlling an aerial vehicle, the
method comprising: receiving weather data from one or both of a
data source and a sensor; determining whether the weather data
satisfies a predetermined criterion; determining whether the aerial
vehicle is expected to experience zero superpressure after
determining that the weather data satisfies the predetermined
criterion; determining whether the aerial vehicle is expected to
regain superpressure after experiencing zero superpressure; and
sending a command to the aerial vehicle, wherein superpressure
comprises a pressure in a balloon envelope that is greater than an
ambient pressure.
Description
BACKGROUND
[0001] Some aerial vehicles float at a preferred altitude by using
a trapped lifting gas to maintain a pressure differential between a
pressure inside the aerial vehicle and an ambient air pressure
outside the aerial vehicle. The pressure differential, however, is
susceptible to ambient weather conditions. In adverse weather
conditions, for example, the internal temperature and pressure of
the aerial vehicle drop and, if they drop low enough, the aerial
vehicle may enter thermal runaway and begin to descend below the
preferred altitude. In some instances, conventional aerial vehicle
lift systems, without more, may be insufficient to compensate for
significant changes in weather conditions. As such, advancements in
aerial vehicle pressure differential management could be beneficial
in improving their resilience in the face of adverse weather
conditions.
SUMMARY
[0002] In one aspect, this disclosure describes a system for
controlling an aerial vehicle. The system includes an aerial
vehicle, a ballast coupled to the aerial vehicle, and a server
communicatively coupled to the aerial vehicle by means of a
wireless communication link, the server including a processor and a
memory. The memory stores instructions which, when executed by the
processor, cause the server to receive weather data, determine,
based on the weather data, that the aerial vehicle is experiencing,
or is expected to experience, weather that satisfies a
predetermined criterion, and cause the aerial vehicle to decouple
at least a portion of the ballast based on a result of the
determination.
[0003] In embodiments, the determining that the aerial vehicle is
experiencing, or is expected to experience, weather that satisfies
the predetermined criterion includes determining that a temperature
metric included in the weather data is below a predetermined
threshold.
[0004] In embodiments, the instructions, when executed by the
processor, further cause the server to determine the portion of the
ballast to decouple based on an amount by which the temperature
metric is below the predetermined threshold.
[0005] In embodiments, the determining of the portion of the
ballast to decouple is further based on an altitude of the aerial
vehicle.
[0006] In embodiments, the predetermined threshold is determined
based on an altitude of the aerial vehicle and an amount of gas
inside the aerial vehicle.
[0007] In embodiments, the determining that the aerial vehicle is
experiencing, or is expected to experience, weather that satisfies
the predetermined criterion includes determining that a temperature
of gas inside the aerial vehicle is expected to cause the aerial
vehicle to experience zero superpressure.
[0008] In embodiments, determining that the temperature of gas
inside the aerial vehicle is expected to cause the aerial vehicle
to experience zero superpressure includes determining that a level
of infrared radiation experienced at an altitude of the aerial
vehicle is expected to cause a temperature of the gas inside the
aerial vehicle to drop below a predetermined threshold.
[0009] In embodiments, the predetermined threshold is determined
based on an amount of gas inside the aerial vehicle.
[0010] In embodiments, the instructions, when executed by the
processor, further cause the server to determine the portion of the
ballast to decouple based on an amount of gas inside the aerial
vehicle.
[0011] In embodiments, the determining of the portion of the
ballast to decouple is further based on the altitude of the aerial
vehicle.
[0012] In embodiments, the instructions, when executed by the
processor, further cause the server to determine whether the aerial
vehicle is expected to recover from experiencing zero
superpressure.
[0013] In embodiments, the instructions, when executed by the
processor, further cause the server to determine an altitude to
which the aerial vehicle is expected to descend while the aerial
vehicle experiences zero superpressure.
[0014] In embodiments, the instructions, when executed by the
processor, further cause the server to determine whether the
altitude to which the aerial vehicle is expected to descend while
the aerial vehicle experiences zero superpressure is above a
minimum altitude.
[0015] In embodiments, the instructions, when executed by the
processor, further cause the server to cause the aerial vehicle to
descend to the ground prior to experiencing zero superpressure in
response to a determination that the altitude to which the aerial
vehicle is expected to descend while the aerial vehicle experiences
zero superpressure is not above the minimum altitude.
[0016] In embodiments, the weather data is received from an
external source.
[0017] In embodiments, the weather data is received from a sensor
coupled to the aerial vehicle.
[0018] In embodiments, the aerial vehicle includes a balloon.
[0019] In embodiments, the ballast is composed of a granular
substance.
[0020] In another aspect, the present disclosure describes a method
for controlling an aerial vehicle. The method includes receiving
weather data, determining, based on the weather data, that an
aerial vehicle is experiencing, or is expected to experience,
weather that satisfies a predetermined criterion, and causing the
aerial vehicle to decouple at least a portion of a ballast coupled
to the aerial vehicle based on a result of the determination.
[0021] In another aspect, the present disclosure describes a
non-transitory computer-readable storage medium storing
instructions which, when executed by a processor, cause a computing
device to receive weather data, determine, based on the weather
data, that an aerial vehicle is experiencing, or is expected to
experience, weather that satisfies a predetermined criterion, and
cause the aerial vehicle to decouple at least a portion of a
ballast coupled to the aerial vehicle based on a result of the
determination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Various aspects and features of the present systems and
methods for controlling an aerial vehicle are described herein
below with references to the drawings, wherein:
[0023] FIG. 1 is a schematic diagram of an illustrative aerial
vehicle system, in accordance with an embodiment of the present
disclosure;
[0024] FIG. 2 is a schematic diagram showing additional aspects of
the aerial vehicle system of FIG. 1, in accordance with an
embodiment of the present disclosure;
[0025] FIG. 3 is a schematic block diagram of an illustrative
embodiment of a computing device that may be employed in various
embodiments of the present system, for instance, as part of the
system or components of FIG. 1 or 2, in accordance with an
embodiment of the present disclosure;
[0026] FIGS. 4A and 4B (collectively, FIG. 4) are a flowchart
showing an illustrative method for controlling an aerial vehicle
from the perspective of a computing device of FIG. 1, in accordance
with an embodiment of the present disclosure; and
[0027] FIG. 5 is a flowchart showing an illustrative method for
controlling an aerial vehicle from the perspective of the aerial
vehicle of FIG. 1, in accordance with an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0028] The present disclosure is directed to systems and methods
for controlling vertical movement of an aerial vehicle using a
combination of an air-gas lift mechanism and a ballast. In one
aspect, the systems and methods of the present disclosure enable an
aerial vehicle to compensate for changes in ambient weather
conditions by adjusting the air-gas lift mechanism and/or
decoupling ballast to effect a vertical maneuver and maintain a
desired pressure differential, thereby ensuring safe operation of
the aerial vehicle, even in the face of adverse weather. In some
examples, the systems and methods of the present disclosure
facilitate maneuvers that enable the aerial vehicle to evade
adverse weather that might otherwise prevent the aerial vehicle
from remaining airborne, thereby extending the operational airborne
lifetime of the aerial vehicle. The systems and methods of the
present disclosure, in some aspects, enable a control system of an
aerial vehicle to determine, based on predicted and/or detected
weather conditions, whether the aerial vehicle will be able to
maintain a safe altitude during flight. The control system of the
aerial vehicle may further determine whether the aerial vehicle has
sufficient lifting gas and/or ballast remaining to maintain a safe
altitude during predicted weather conditions, and cause the aerial
vehicle to make a controlled descent to the ground if it is
determined that the aerial vehicle does not have sufficient lifting
gas and/or ballast remaining to maintain the safe altitude.
[0029] While various types and forms of aerial vehicles are
envisioned by the present disclosure, including balloons,
dirigibles, blimps, other vehicles that maintain altitude at least
in part by using buoyancy, and/or the like, the present disclosure
will use a superpressure balloon as an illustrative aerial vehicle.
Superpressure balloons are designed to float at an altitude in the
atmosphere where the density of the balloon system is equal to the
density of the atmosphere. Higher atmospheric levels have lower
density, and lower atmospheric levels have higher density. On the
other hand, the balloon's density corresponds to the mass of the
balloon system (including everything coupled to it) divided by the
total volume of the balloon. Additionally, for a superpressure
balloon to float, the pressure inside the balloon must be greater
than the pressure outside the balloon (referred to hereinbelow as
the "ambient pressure") such as to generate a force pushing outward
on the balloon's structure to retain the balloon's volume at a
roughly constant level. If the pressure inside the balloon is not
greater than the pressure outside the balloon, the volume of the
balloon will contract and the density of the balloon system will
increase, thus causing the balloon to lose altitude and drop to an
atmospheric level where the balloon system again has the same
density as the surrounding air. This condition is referred to
hereinbelow as the balloon experiencing "zero superpressure."
[0030] The mass of the balloon is adjustable by way of an altitude
control system (ACS) configured to pump a gas, such as air, into
the balloon and out of the balloon, as described below. Thus, the
density of the balloon, and correspondingly the altitude at which
the balloon will float, is adjustable, at least to some extent, by
way of the ACS. In some instances, a balloon experiencing zero
superpressure will lose altitude but remain afloat at a lower
atmospheric level where the density of the balloon system and the
density of the surrounding air is again matched, i.e., the balloon
would regain superpressure at that lower atmospheric level. During
severe weather conditions, for example during severely cold ambient
temperatures and/or in conditions where upwelling infrared energy
from the surface of the Earth is obstructed by severe cloud cover,
the air inside the balloon may compress by such a large amount that
the volume of the balloon can no longer be maintained, and the
density of the balloon system increases beyond a level where the
balloon is able to stay afloat at a safe altitude. Such situations
are referred to hereinbelow as a "thermal runaway," and this may
cause the balloon system to drop below a safe altitude or even all
the way to the ground. In such situations where the air inside the
balloon is colder than the ambient air temperature, the ACS may be
used to decrease the amount of gas inside the balloon (e.g.,
decrease an amount of air inside ballonets) to decrease the mass
and density of the balloon system to repressurize and the balloon
to float at a higher altitude.
[0031] The volume of any given quantity (e.g., a mole) of gas
depends in part on the temperature of the gas. For example,
assuming a pressure of the gas remains constant, increasing the
temperature of the gas causes the volume of the gas to expand.
Similarly, assuming the pressure of the gas remains constant,
decreasing the temperature of the gas causes the volume of the gas
to contract. This is taken into consideration when determining the
amount of lifting gas needed to maintain superpressure in a
balloon, because if the temperature of the lifting gas is
decreased, the volume of the lifting gas will contract, and thus
more lifting gas will be needed to maintain superpressure in the
balloon. The pressure inside a balloon, or inside the portion of a
balloon occupied by a lifting gas, can be determined according to
the laws of thermodynamics, such as by using the ideal gas law,
i.e., the formula PV=nRT, where P is the pressure inside the
portion of the balloon occupied by a lifting gas (measured in
Pascals, for example), n is the amount of lifting gas inside the
balloon (measured in moles, for example), R is a constant (for this
example, 8.3144621 Joules/(moles*Kelvin), T is the absolute
temperature of the lifting gas inside the balloon (measured in
units Kelvin, for example) and V is the volume of the portion of
the balloon (measured in cubic meters, for example) occupied by the
lifting gas. By solving for the various variables in this formula,
the pressure of the lifting gas inside the balloon, the amount of
gas inside the balloon, the volume of the balloon, and/or the
temperature of the gas inside the balloon may be calculated for
various temperatures, pressures, and/or amounts of gas. The
altitude at which the balloon floats depends the volume of the
balloon and the mass of the total balloon system temperature of the
air inside the balloon, which causes the air inside the balloon
expand or compress, thereby increasing or decreasing the density of
the balloon system. The ambient pressure at a particular altitude
varies day to day and based on location due to differences in the
density of the atmosphere. The ambient pressure at a particular
altitude may be determined based on barometric measurements, and/or
may be calculated based various models of atmospheric pressure,
such as, for example, the International Standard Atmosphere model.
Thus, the altitude at which the balloon will float may also be
calculated based on the above-noted formula by first solving for
the temperature of the air inside the balloon, determining, based
on the temperature of the air inside the balloon, whether the
pressure of the air inside the balloon is sufficient to maintain
the balloon at maximum volume (i.e. will the balloon maintain
superpressure), and then calculating the corresponding altitude at
which the density of the balloon system will be equal to the
ambient air density.
[0032] With reference to FIG. 1, an illustrative aerial vehicle
control system 100 includes an aerial vehicle 102, one or more
computing devices 104, and one or more data sources 106, not drawn
to scale. The aerial vehicle 102 and the computing devices 104 are
communicatively coupled to one another by way of a wireless
communication link 108, and the computing devices 104 and the data
sources 106 are communicatively coupled to one another by way of
wired and/or wireless communication link 110. In some aspects, the
aerial vehicle 102 is configured to be launched into and moved
about the atmosphere, and the computing devices 104 cooperate as a
ground-based distributed array to perform their functions described
herein. The data sources 106 may include airborne data sources,
such as airborne weather balloons, additional airborne aerial
vehicles 102, and/or the like, and/or ground-based data sources,
such as publicly available and/or proprietary databases, examples
of which are the Global Forecast System (GFS) operated by the
National Oceanic and Atmospheric Administration (NOAA), as well as
databases maintained by the European Center for Medium-range
Weather Forecasts (ECMWF). Although the present disclosure is
provided in the context of an embodiment where the system 100
includes multiple computing devices 104 and multiple data sources
106, in other embodiments the system 100 may include a single
computing device 104 and a single data source 106. Further,
although FIG. 1 shows a single aerial vehicle 102, in various
embodiments the system 100 includes a fleet of multiple aerial
vehicles 102 that are positioned at different locations throughout
the atmosphere and that are configured to communicate with the
computing devices 104, the data sources 106, and/or one another by
way of the communication links 108 and/or 110.
[0033] In various embodiments, the aerial vehicle 102 may be
configured to perform a variety of functions or provide a variety
of services, such as, for instance, telecommunication services
(e.g., long term evolution (LTE) service), hurricane monitoring
services, ship tracking services, services relating to imaging,
astronomy, radar, ecology, conservation, and/or other types of
functions or services. Computing devices 104 control the position
(also referred to as location) and/or movement of the aerial
vehicles 102 throughout the atmosphere or beyond, to facilitate
effective and efficient performance of their functions or provision
of their services, as the case may be. As described in further
detail herein, the computing devices 104 are configured to obtain a
variety of types of data from a variety of sources and, based on
the obtained data, communicate messages to the aerial vehicle 102
to control its position and/or movement during flight.
[0034] With continued reference to FIG. 1, the aerial vehicle 102
includes a lift gas balloon 112, one or more ballonets 116, and a
payload or gondola 114, which is suspended beneath the lift gas
balloon 112 and/or the ballonets 116 while the aerial vehicle 102
is in flight. The ballonets 116, as described in further detail
below, are used to control the buoyancy, and thereby the altitude,
of the aerial vehicle 102 during flight. In some aspects, the
ballonets 116 include air and the lift gas balloon 112 includes a
lifting gas that is lighter than air. As shown in FIG. 1, the
ballonets 116 may be positioned inside the lift gas balloon 112
and/or outside the lift gas balloon 112. An altitude controller 126
controls a pump and a valve (neither of which are shown in FIG. 1)
to pump air into the ballonets 116 (from air outside the aerial
vehicle 102) to increase the mass of the aerial vehicle 102 and
lower its altitude, or to release air from the ballonets 116 (into
the atmosphere outside the aerial vehicle 102) to decrease the mass
of the aerial vehicle 102 and increase its altitude. The
combination of the altitude controller 126, the lift gas balloon
112, the ballonets 116, and the valves and pumps (not shown in FIG.
1) may be referred to as an air-gas altitude control system
(ACS).
[0035] The aerial vehicle 102 also has one or more solar panels 134
affixed thereto. As shown in FIG. 1, the solar panels 134 may be
affixed to an upper portion of the lift gas balloon 112 that
absorbs sunlight, when available, and generate electrical energy
from the absorbed sunlight. Alternatively, or in addition, the
solar panels 134 may be affixed to the gondola 114 or elsewhere to
aerial vehicle 102 (not shown in FIG. 1). The solar panels 134
provide, by way of power paths such as power path 136, the
generated electrical energy to the various components of the aerial
vehicle 102, such as components housed within the gondola 114, for
utilization during flight.
[0036] The gondola 114 includes a variety of components, some of
which may or may not be included, depending upon the application
and/or needs. Although not expressly shown in FIG. 1, the various
components of the aerial vehicle 102 in general, and/or of the
gondola 114 in particular, may be coupled to one another for
communication of power, data, and/or other signals or information.
The example gondola 114 shown in FIG. 1 includes one or more
sensors 128, an energy storage module 124, a power plant 122, an
altitude controller 126, a transceiver 132, and other on-board
equipment 130. The transceiver 132 is configured to wirelessly
communicate data between the aerial vehicle 102 and the computing
devices 104 and/or data sources 106 by way of the wireless
communication link 108 and/or the communication link 110,
respectively.
[0037] In addition to the aforementioned components, the gondola
114 also has affixed or otherwise coupled to it a ballast 120. The
configuration of the ballast 120 suspended from the center of
gravity at the bottom of the gondola 114 shown in FIG. 1 is
provided by way of example and not limitation. Other configurations
of coupling the ballast 120 to the aerial vehicle 102 are
contemplated. For instance, in other embodiments, the ballast 120
may be coupled directly to the aerial vehicle 102 and/or may be
coupled to various portions of the gondola 114. Further, while
shown as a single component, the ballast 120 may be distributed
into multiple separate components coupled to various positions
and/or portions of the gondola 114 and/or the aerial vehicle 102.
The ballast 120 may include or be composed of various materials,
including small steel sand, other granular substances, liquids,
and/or the like. As described further below, the computing devices
104 may cause the aerial vehicle 102 to decouple all or a portion
of the ballast 120 during flight. For that purpose, the ballast 120
may include a valve, door, and/or any other relevant decoupling
mechanism known to those skilled in the art.
[0038] In some embodiments, the sensors 128 include a global
positioning system (GPS) sensor that senses and outputs location
data, such as latitude, longitude, and/or altitude data
corresponding to a latitude, longitude, and/or altitude of the
aerial vehicle 102 in the Earth's atmosphere. The sensors 128 are
configured to provide the location data to the computing devices
104 by way of the wireless transceiver 132 and the wireless
communication link 108 for use in controlling the aerial vehicle
102, as described in further detail below.
[0039] The energy storage module 124 includes one or more batteries
that store electrical energy provided by the solar panels 134 for
use by the various components of the aerial vehicle 102. The power
plant 122 obtains electrical energy stored by the energy storage
module 124 and converts and/or conditions the electrical energy to
a form suitable for use by the various components of the aerial
vehicle 102.
[0040] The altitude controller 126 is configured to control the
ballonets 116 to adjust the buoyancy of the aerial vehicle 102 to
assist in controlling its position and/or movement during flight.
As described in further detail below, in various embodiments the
altitude controller 126 is configured to control the ballonets 116
based at least in part upon an altitude command that is generated
by, and received from, the computing devices 104 by way of the
wireless communication link 108 and the transceiver 132. In some
examples, the altitude controller 126 is configured to implement
the altitude command by causing the actuation of the ACS based on
the altitude command.
[0041] The on-board equipment 130 may include a variety of types of
equipment, depending upon the application or needs, as outlined
above. For example, the on-board equipment 130 may include LTE
transmitters and/or receivers, weather sensors, imaging equipment,
and/or any other suitable type of equipment. In some embodiments,
the on-board equipment may further include one or more processors,
controllers, or entire computing devices similar to the computing
devices 104.
[0042] Having provided an overview of the aerial vehicle control
system 100 in the context of FIG. 1, reference is now made to FIG.
2, which shows certain operations of the aerial vehicle control
system 100, in accordance with an embodiment of the present
disclosure. In particular, FIG. 2 illustrates an example embodiment
of how functionality and corresponding components are allocated
among the aerial vehicle 102, the computing devices 104, and/or the
data sources 106, to control a position and/or movement of the
aerial vehicle 102. Although more detailed aspects of how the
system 100 implements control of the aerial vehicle 102 are
provided below in the context of FIG. 4, FIG. 2 provides an
overview of the functionality and component allocation. The
arrangement of components depicted in FIG. 2 is provided by way of
example and not limitation. Other arrangements of components and
allocations of functionality are contemplated, for instance, with
the aerial vehicle 102 including components that implement
functionality shown in FIG. 2 as being implemented by the computing
devices 104, or vice versa. However, in the example shown in FIG.
2, a majority of the components and functionality are allocated to
the computing devices 104 instead of to the aerial vehicle 102,
which decreases the amount of energy required to operate the
components of the aerial vehicle 102 and thus enables the
components of the aerial vehicle 102 to utilize a greater portion
of the available energy than would be possible if more components
and functionality were allocated to the aerial vehicle 102. This
increases the capabilities of the aerial vehicle 102 for
implementing functionality and/or providing services for a given
amount of available energy.
[0043] In addition to certain components that were introduced above
in connection with FIG. 1, FIG. 2 shows a weather analyzer module
202, a navigation module 204, and a flight control module 206 that
are included within the computing devices 104. Once the aerial
vehicle 102 is in flight in the atmosphere, the sensors 128 are
configured to periodically transmit to the weather automation
module 202, by way of the transceiver 132 and the wireless
communication link 108, location data, such as timestamped GPS
positions and altitudes of the aerial vehicle 102 at corresponding
times. The weather analyzer module 202 utilizes the location data
obtained from the sensors 128 and weather data, including ambient
temperature conditions and/or predictions as well as current and/or
expected upwelling infrared energy conditions, obtained from other
data sources 106 (such as National Oceanic and Atmospheric
Administration (NOAA) data sources, European Centre for
Medium-Range Weather Forecasts (ECMWF) data sources, and/or the
like) to infer or estimate the weather conditions in which the
aerial vehicle 102 is flying or is expected to be flying. Weather
data, including ambient temperature conditions as well as current
upwelling infrared energy conditions, may also be obtained by
sensors 128 and transmitted to the weather automation module 202,
by way of the transceiver 132 and the wireless communication link
108. In particular, weather data are stored in the weather analyzer
module 202, which constructs a kernel function, such as a Gaussian
Process kernel function that assists the navigation module 204 in
determining how to navigate the aerial vehicle 102 based on the
inferred or estimated weather conditions, according to one or more
predetermined navigation algorithms. Examples of types of
navigation algorithms that may be implemented by the navigation
module 204 are described in U.S. patent application Ser. Nos.
15/662,940, 15/662,968, 15/663,000, and 15/663,030, all entitled
SYSTEMS AND METHODS FOR CONTROLLING AERIAL VEHICLES, filed on Jul.
28, 2017, by Candido et al., the entire contents of each of which
are incorporated herein by reference. Depending upon the navigation
algorithm being implemented, the navigation module 204 generates a
flight plan, which is a set of locations (e.g., altitudes, latitude
coordinates, and/or longitude coordinates) that the aerial vehicle
102 should attempt to attain at corresponding times. Based on the
temperature and/or upwelling infrared energy predictions, the
navigation module 204 may determine adjustments to the flight plan,
as further described below. The navigation module 204 then
registers the flight plan with the flight control module 206.
[0044] The flight control module 206 generates flight commands,
such as altitude commands (e.g., an altitude to which the altitude
of the aerial vehicle 102 should be adjusted), and sequentially
transfers each flight command to the altitude controller 126 for
implementation according to the corresponding times indicated in
the flight plan. In particular, the flight control module 206
transmits to the transceiver 132, by way of the wireless
communication link 108, an altitude command (for example, which may
be specified as a barometric pressure, which may be equivalent to
pressure altitude, and which indicates a desired altitude for the
aerial vehicle 102 to maintain within some tolerance band) and/or a
decouple command (for example, which may be a command to decouple
all or a specified portion of the ballast 120). The altitude
controller 126 is configured to execute an altitude loop whereby
the altitude controller 126 periodically receives the altitude
command and/or the decouple command from the computing devices 104
and executes those commands to control the altitude of the aerial
vehicle 102.
[0045] FIG. 3 is a schematic block diagram of a computing device
300 that may be employed in accordance with various embodiments
described herein. Although not explicitly shown in FIG. 1 or FIG.
2, in some embodiments, the computing device 300, or one or more of
the components thereof, may further represent one or more
components (e.g., the computing device 104, components of the
gondola 114, the data sources 106, and/or the like) of the system
100. The computing device 300 may, in various embodiments, include
one or more memories 302, processors 304, display devices 306,
network interfaces 308, input devices 310, and/or output modules
312. The memory 302 includes non-transitory computer-readable
storage media for storing data and/or software that is executable
by the processor 304 and which controls the operation of the
computing device 300. In embodiments, the memory 302 may include
one or more solid-state storage devices such as flash memory chips.
Alternatively, or in addition to the one or more solid-state
storage devices, the memory 302 may include one or more mass
storage devices connected to the processor 304 through a mass
storage controller (not shown in FIG. 3) and a communications bus
(not shown in FIG. 3). Although the description of computer
readable media included herein refers to a solid-state storage, it
should be appreciated by those skilled in the art that
computer-readable storage media may be any available media that can
be accessed by the processor 304. That is, computer readable
storage media includes non-transitory, volatile and non-volatile,
removable and non-removable media implemented in any method or
technology for storage of information such as computer-readable
instructions, data structures, program modules or other data.
Examples of computer-readable storage media include RAM, ROM,
EPROM, EEPROM, flash memory or other solid state memory technology,
CD-ROM, DVD, Blu-Ray or other optical storage, magnetic cassettes,
magnetic tape, magnetic disk storage or other magnetic storage
devices, or any other medium which may be used to store the desired
information and which can be accessed by computing device 300.
[0046] In some embodiments, the memory 302 stores data 314 and/or
an application 316. In some aspects the application 316 includes a
user interface component 318 that, when executed by the processor
304, causes the display device 306 to present a user interface, for
example a graphical user interface (GUI) (not shown in FIG. 3). The
network interface 308, in some embodiments, is configured to couple
the computing device 300 and/or individual components thereof to a
network, such as a wired network, a wireless network, a local area
network (LAN), a wide area network (WAN), a wireless mobile
network, a Bluetooth network, the Internet, and/or another type of
network. The input device 310 may be any device by means of which a
user may interact with the computing device 300. Examples of the
input device 310 include without limitation a mouse, a keyboard, a
touch screen, a voice interface, and/or the like. The output module
312 may, in various embodiments, include any connectivity port or
bus, such as, for example, a parallel port, a serial port, a
universal serial bus (USB), or any other similar connectivity port
known to those skilled in the art.
[0047] Turning now to FIG. 4, there is shown a flowchart depicting
an illustrative method 400 for controlling an aerial vehicle from
the perspective of the computing devices 104 of the system 100, in
accordance with an embodiment of the present disclosure. As
described above, the computing device 104 include various
components, including processors, memories, and various other
modules. As will be appreciated by those skilled in the art, the
processes described below may be performed and/or executed by a
variety of these components. As such, the description that follows
will refer to the processes being performed by the computing
devices 104, but those skilled in the art will recognize that one
or more of the above-described components of the computing devices
104 are used by the computing devices 104 to perform and/or execute
these processes. Further, those skilled in the art will recognize
that the processes described below may be a sub-process forming
part of a bigger process for controlling aerial vehicles, and thus
various other processes and steps may be performed in addition to
the below-described steps and processes. While the processes
described below are organized into an illustrative ordered sequence
of steps, those skilled in the art will appreciate that various of
these steps may be performed in a different order or sequence,
repeated, and/or omitted without departing from the scope of the
present disclosure.
[0048] A process for controlling an aerial vehicle, such as the
aerial vehicle 102, using ballast may start at block 402, where the
computing device 104 receives weather data from the data sources
106 and/or the sensors 128, by way of the transceiver 132. The
weather data includes a predicted current and/or future ambient
temperature as well as current and/or future upwelling infrared
energy conditions, such as severe cloud cover, that the aerial
vehicle 102 is expected to experience (as received from the data
sources 106), and/or an actual temperature and/or upwelling
infrared energy conditions being experienced by the aerial vehicle
102 (as received from the sensors 128). The weather data may
further include predictions of solar flux incident on the aerial
vehicle 102, as measured by the sensors 128.
[0049] At block 404, the computing devices 104 determine whether
the weather data received at block 402, and particularly the
ambient temperature and/or upwelling infrared energy conditions
included in the weather data, satisfies a criterion. In
embodiments, the criterion may be a threshold, such as a minimum
temperature and/or upwelling infrared energy level at which the
aerial vehicle 102 is able to maintain a preferred altitude. For
example, the criterion may be a threshold temperature and/or
infrared energy level corresponding to a lower end of a range of
normal temperatures and/or infrared energy levels typically
experienced by the aerial vehicle 102 during flight. If the
computing devices 104 determine that the weather data does not
satisfy the criterion ("NO" at block 404), processing returns to
block 402 where the computing devices 104 receive new weather data.
Alternatively, if the computing devices 104 determine that the
weather data satisfies the criterion ("YES" at block 404),
processing proceeds to block 406.
[0050] At block 406, the computing devices 104 determine whether
the aerial vehicle 102 is expected to experience zero
superpressure. As noted above, zero superpressure is a condition
where the pressure that the atmospheric gas exerts on the outside
of the lift gas balloon 112 and/or the ballonets 116 of the aerial
vehicle 102 is greater than or equal to the pressure exerted by the
lifting gas inside the lift gas balloon 112 and/or the air inside
the ballonets 116. The computing devices 104 may determine whether
the aerial vehicle 102 is expected to experience zero superpressure
by using various formulas such as, for example, the formula
described above. For example, the computing devices 104 may
calculate a pressure of the lifting gas inside the aerial vehicle
102 based on the predicted temperature and/or upwelling infrared
energy level included in the weather data received at block 402. If
the computing devices 104 determine that the aerial vehicle 102 is
not expected to experience zero superpressure ("NO" at block 406),
processing returns to block 402, where the computing devices 104
again receive new weather data. Alternatively, if the computing
devices 104 determine that the aerial vehicle 102 is expected to
experience zero superpressure ("YES" at block 406), processing
proceeds to block 408.
[0051] At block 408, the computing devices 104 determine whether
the aerial vehicle 102 is expected to regain superpressure. As
noted above, superpressure is the condition where the pressure
exerted by the lifting gas inside the lift gas balloon 112 and/or
the pressure exerted by the air inside the ballonets 116 is greater
than the pressure exerted by the atmospheric gas on the outside of
the lift gas balloon 112 and/or the ballonets 116, respectively.
The computing devices 104 may determine whether the aerial vehicle
102 is expected to regain superpressure by comparing the pressure
of the lifting gas inside the aerial vehicle 102 calculated at
block 406 to an ambient pressure at one or more threshold
altitudes. Examples of threshold altitudes include sea level,
relative ground level, and/or one or more altitudes above ground
level, etc. If the pressure calculated at block 406 is greater than
the ambient pressure at the threshold altitude, the computing
devices 104 may determine that the aerial vehicle 102 is expected
to regain superpressure. If the computing devices 104 determine
that the aerial vehicle 102 is not expected to regain superpressure
("NO" at block 408), processing proceeds to block 410, where the
computing devices 104 send a command to the aerial vehicle 102, via
the communication link 108 and the transceiver 132, to descend to
the ground, whereafter processing of the method 400 ends.
Alternatively, if the computing devices 104 determine that the
aerial vehicle 102 is expected to regain superpressure ("YES" at
block 408), processing proceeds to block 412.
[0052] At block 412, the computing devices 104 determine whether an
altitude to which the aerial vehicle is expected to descend (the
"descent altitude") while experiencing zero superpressure is
greater (higher) than a threshold altitude. The computing devices
104 may first determine the descent altitude by using various
formulas such as, for example, the formula described above. For
example, the computing devices 104 may calculate an altitude at
which the pressure of the lifting gas inside the lift gas balloon
112 and/or the air inside the ballonets 116 will again be greater
than the pressure exerted by the atmospheric gas on the outside of
the lift gas balloon 112 and/or the ballonets 116, respectively.
The computing devices 104 may then compare the descent altitude to
the threshold altitude. The threshold altitude may be a
predetermined lower limit altitude at which the aerial vehicle 102
may safely operate. For example, the threshold altitude may be
60,000 feet above sea level, which is the upper limit of controlled
airspace for commercial aircraft. If the computing devices 104
determine that the descent altitude is greater (higher) than the
threshold altitude ("YES" at block 412), processing returns to
block 402, where the computing devices 104 again receive new
weather data. Alternatively, if the computing devices 104 determine
that the descent altitude is not greater (that is, if the descent
altitude is lower) than the threshold altitude ("NO" at block 412),
processing proceeds to block 414.
[0053] At block 414, the computing devices 104 determine whether
the aerial vehicle 102 is expected to be able to remain afloat at a
safe altitude by using only the ACS. In embodiments, the safe
altitude may be any altitude that is higher than the threshold
altitude. The computing devices 104 may determine whether the
aerial vehicle 102 is able to remain afloat at the safe altitude
using only the ACS by using various formulas such as, for example,
the ideal gas law formula described above. For example, the
computing devices 104 may calculate an amount of lifting gas
necessary for the aerial vehicle 102 to float at the safe altitude.
The computing devices 104 may then calculate a difference between
the amount of lifting gas necessary to float at the safe altitude
and the amount of lifting gas currently inside the aerial vehicle.
Thereafter, the computing devices 104 may determine whether the
aerial vehicle 102, using the ACS, is expected to be able to pump
an amount of air corresponding to the determined difference into
the ballonets 116 before a time at which the aerial vehicle 102 is
expected to descend below the threshold altitude, and thus keep the
aerial vehicle 102 afloat at a safe altitude. If the computing
devices 104 determine that the aerial vehicle 102 is expected to be
able to remain afloat at a safe altitude using only the ACS ("YES"
at block 414), processing proceeds to block 416. Alternatively, if
the computing devices 104 determine that the aerial vehicle 102 is
not expected to be able to remain afloat at a safe altitude using
only the ACS ("NO" at block 414), processing proceeds to block
418.
[0054] At block 416, the computing devices 104 send a command, via
the communication link 108 and the transceiver 132, to the altitude
controller 126 of the aerial vehicle 102 to adjust the altitude of
the aerial vehicle 102 using the ACS. In embodiments, the command
may include a pressure to which the pressure of the lifting gas
inside the aerial vehicle 102 should be increased. Additionally or
alternatively, the command may include an amount of gas (e.g., air)
which the ACS should pump into the ballonets 116 regardless of the
pressure currently exerted by the lifting gas because that pressure
is expected to decrease as the temperature of the air inside the
ballonets 116 and/or the lifting gas inside the lifting gas balloon
112 decreases. In other embodiments, the computing devices 104 may
not send a command at all, and instead the altitude controller 126
of the aerial vehicle 102 may determine to pump air into the
ballonets 116 as the pressure of the air inside the ballonets 116
and/or the lifting gas inside the lifting gas balloon 112 starts to
decrease as the temperature of the air inside the ballonets 116
and/or the lifting gas inside the lifting gas balloon 112
decreases. In some embodiments, the computing devices 104 may wait
a predetermined or dynamically determined period of time before
sending the command. Thereafter, processing proceeds to block
432.
[0055] At block 418, the computing devices 104 determine an amount
of the ballast 120 that is coupled to the aerial vehicle 102. The
determination may be based on a weight of the ballast 120 and/or a
record of how much ballast was coupled to the aerial vehicle 102 at
launch and how much of the ballast 120 has been previously
decoupled during the flight of the aerial vehicle 102. Thereafter,
processing proceeds to block 420.
[0056] At block 420, the computing devices 120 determine whether
the aerial vehicle 102 is expected to be able to remain afloat at a
safe altitude by using the ACS and by decoupling at least a portion
of the ballast 120. The computing devices 104 may determine whether
the aerial vehicle 102 is able to remain afloat at the safe
altitude using the ACS decoupling a portion of the ballast 120 by
using various formulas such as, for example, the formula described
above. For example, the computing devices 104 may first determine
how much of the ballast 120 can be decoupled before a time at which
the aerial vehicle 102 is expected to descend below the threshold
altitude, and may then determine a difference between the pressure
of the lifting gas inside the aerial vehicle 102 with the ballast
120 unchanged and the expected pressure of the lifting gas inside
the aerial vehicle 102 with the ballast 120 decoupled. For example,
each kilogram (kg) of the ballast 120 decoupled may increase the
pressure of the lifting gas inside the aerial vehicle 102 by an
amount approximately equal to the pressure added by pumping an
additional 40 moles of air into the ballonets 116. The computing
devices 104 may then determine whether the expected increase in
pressure of the lifting gas inside the aerial vehicle 102 resulting
from decoupling the ballast 120, in combination with the amount of
air the aerial vehicle 102, using the ACS, is expected to be able
to pump into the ballonets 116 before a time at which the aerial
vehicle 102 is expected to descend below the threshold altitude, as
determined at block 414, is expected to keep the aerial vehicle 102
afloat at a safe altitude. If the computing devices 104 determine
that the aerial vehicle 102 is expected to be able to remain afloat
at a safe altitude using the ACS and by decoupling at least a
portion of the ballast 120 ("YES" at block 420), processing
proceeds to block 422. Alternatively, if the computing devices 104
determine that the aerial vehicle 102 is not expected to be able to
remain afloat at a safe altitude using the ACS and by decoupling
the ballast 120 ("NO" at block 420), processing proceeds to block
410.
[0057] At block 422, the computing devices 104 determine a portion
of the ballast 120 to decouple. In embodiments, the computing
devices 104 may determine a minimum portion or amount of the
ballast 120 to decouple which, in combination with the amount of
air expected to be pumped into the ballonets 116 by the ACS, is
expected to keep the aerial vehicle 102 afloat at a safe
altitude.
[0058] Thereafter, at block 424, the computing devices 104 send a
command, via the communication link 108 and the transceiver 132, to
the altitude controller 126 of the aerial vehicle 102 to adjust the
altitude of the aerial vehicle 102 using the ACS. The command may
be similar to the command described above with reference to block
416. And similar to block 416, in some embodiments, the computing
devices 104 may not send a command at all, and instead the altitude
controller 126 of the aerial vehicle 102 may determine to pump air
into the ballonets 116 as the pressure of the lifting gas inside
the balloon starts to decrease as the temperature of the air inside
the ballonets 116 and/or the lifting gas inside the lift gas
balloon 112 decreases. In some embodiments, the computing devices
104 may wait a predetermined or dynamically determined period of
time before sending the command. Thereafter, processing proceeds to
block 426.
[0059] At block 426, the computing devices 104 determine whether it
is time to decouple the portion of the ballast 120 determined at
block 422. In embodiments, the computing devices 104 may be
configured to delay decoupling of the portion of the ballast 120
for a period of time. For example, the computing devices 104 may
delay decoupling the portion of the ballast 120 until a time
whereafter decoupling of the portion of the ballast 120 will no
longer be sufficient to keep the aerial vehicle afloat at a safe
altitude. If the computing devices 104 determine that it is not
time to decouple the portion of the ballast 120 ("NO" at block
426), processing proceeds to block 428. Alternatively, if the
computing devices 104 determine that it is time to decouple the
portion of the ballast 120 ("YES" at block 426), processing
proceeds to block 430.
[0060] At block 428, the computing devices 104 receive new weather
data and determine whether the new weather data satisfies the
criterion. The new weather data may be received from the data
sources 106 and may reflect updated weather predictions.
Additionally or alternatively, the weather data may be received
from the sensors 128, for example temperature sensors and/or
infrared energy sensors, coupled to the aerial vehicle 102, and may
reflect a current ambient temperature and/or amount of upwelling
infrared energy experienced by the aerial vehicle 102. The
determination may be similar to the determination described above
with reference to block 404. If the computing devices 104 determine
that the new weather data satisfies the criterion ("YES" at block
428), processing returns to block 426, where the computing devices
104 again determine whether it is time to decouple the portion of
the ballast 120. Alternatively, if the computing devices 104
determine that the new weather data does not satisfy the criterion
("NO" at block 428), processing returns to block 402.
[0061] At block 430, the computing devices 104 send a command, via
the communication link 108 and the transceiver 132, to the altitude
controller 126 of the aerial vehicle 102 to decouple the portion of
the ballast 120 determined at block 422. Thereafter, processing
proceeds to block 432.
[0062] At block 432, the computing devices 104 determine whether
the aerial vehicle 102 is floating at a safe altitude. For example,
the computing devices 104 may determine whether the pressure of the
lifting gas inside the aerial vehicle 102 corresponds to an ambient
pressure at a safe altitude. If the computing devices 104 determine
that the aerial vehicle 102 is floating at a safe altitude ("YES"
at block 432), processing proceeds to block 434. Alternatively, if
the computing devices 104 determine that the aerial vehicle 102 is
not floating at a safe altitude ("NO" at block 432), processing
proceeds to block 436.
[0063] At block 434, the computing devices 104 again receive new
weather data and determine whether the new weather data satisfies
the criterion. Similar to block 428, the new weather data may be
received from the data sources 106 and may reflect updated weather
predictions. Additionally or alternatively, the weather data may be
received from the sensors 128, for example temperature sensors
and/or infrared energy sensors, coupled to the aerial vehicle 102,
and may reflect a current ambient temperature and/or amount of
upwelling infrared energy experienced by the aerial vehicle 102.
The determination may be similar to the determination described
above with reference to block 404. If the computing devices 104
determine that the new weather data does not satisfy the criterion
("NO" at block 434), processing returns to block 402.
Alternatively, if the computing devices 104 determine that the new
weather data satisfies the criterion ("YES" at block 434),
processing returns to block 432.
[0064] At block 436, the computing devices 104 determine whether at
least a portion of the ballast 120 remains coupled to the aerial
vehicle. If the computing devices 104 determine that at least a
portion of the ballast 120 remains coupled to the aerial vehicle
102 ("YES" at block 436), processing returns to block 422.
Alternatively, if the computing devices 104 determine that none of
the ballast 120 remains coupled to the aerial vehicle 102,
processing proceeds to block 410.
[0065] FIG. 5 is a flowchart showing an illustrative method 500 for
controlling an aerial vehicle, from the perspective of the aerial
vehicle 102, in accordance with an embodiment of the present
disclosure. As described above with reference to FIG. 4, those
skilled in the art will recognize that the processes described
below may be a sub-process forming part of a bigger process for
controlling aerial vehicles, and thus various other processes and
steps may be performed in addition to the below-described steps and
processes. While the processes described below are organized into
an illustrative ordered sequence of steps, those skilled in the art
will appreciate that various of these steps may be performed in a
different order or sequence, repeated, and/or omitted without
departing from the scope of the present disclosure.
[0066] At block 502, the aerial vehicle 102 receives, by way of the
wireless communication link 108 and the transceiver 132, navigation
data from the flight control module 206 of the computing device
104. The aerial vehicle 102 periodically receives multiple
transmissions of navigation data from the computing device 104, as
described above. The navigation data may include a target
altitude.
[0067] At block 504, the altitude controller 126 determines whether
the aerial vehicle 102 is floating at the target altitude. In
embodiments, the altitude controller 126 obtains from the sensors
128 location data, including altitude data, indicating a current
altitude, of the aerial vehicle 102. As described above, the
altitude of the aerial vehicle 102 may correspond to, and thus be
determined based on, a pressure of the lifting gas inside the
aerial vehicle 102. As such, in some embodiments, the altitude
controller 126 may receive data from the sensors 128 indicating the
pressure of the lifting gas inside the aerial vehicle 102, and may
determine the altitude of the aerial vehicle 102 based on the
pressure data. If the altitude controller 126 determines that the
aerial vehicle 102 is floating at the target altitude ("YES" at
block 504), processing proceeds to block 512. Alternatively, if the
altitude controller 126 determines that the aerial vehicle 102 is
not floating at the target altitude ("NO" at block 504), processing
proceeds to block 506.
[0068] At block 506, the altitude controller 126 determines whether
the aerial vehicle 102 should end its flight and descend to the
ground. For example, the altitude controller 126 may determine
whether the aerial vehicle 102 has reached the end of its flight,
or is unable to maintain the target altitude. If the altitude
controller 126 determines that the aerial vehicle 102 should end
its flight ("YES" at block 506), processing ends and a controlled
descent is initiated in the manner described above. Alternatively,
if the altitude controller 126 does not determine that the aerial
vehicle 102 should end its flight ("NO" at block 506), processing
proceeds to block 508.
[0069] At block 508, the altitude controller 126 determines whether
the aerial vehicle 102 can attain the target altitude received at
block 502 by adjusting (for example by pumping air into or out of)
the ballonets 116. If the altitude controller 126 determines that
the aerial vehicle 102 can attain the target altitude by adjusting
the amount of air in the ballonets 116 ("YES" at block 508),
processing proceeds to block 510. Alternatively, if the altitude
controller 126 determines that the aerial vehicle 102 cannot attain
the target altitude by adjusting the amount of air in the ballonets
116 ("NO" at block 504), processing proceeds to block 520.
[0070] At block 510, the altitude controller 126 operates the pump
and/or valve coupled to the ballonets 116 to adjust the amount of
air in the ballonets 116. Thereafter, processing returns to block
504.
[0071] At block 512, the aerial vehicle 102, via the transceiver
132 and the communication link 108, sends position data, including
altitude data, to the computing devices 104. Thereafter, at block
514, the altitude controller 126 determines whether the aerial
vehicle 102 should end its flight and descend to the ground. For
example, the altitude controller 126 may determine whether the
aerial vehicle 102 has reached the end of its flight. If the
altitude controller 126 determines that the aerial vehicle 102
should end its flight ("YES" at block 514), processing ends.
Alternatively, if the altitude controller 126 does not determine
that the aerial vehicle 102 should end its flight ("NO" at block
514), processing proceeds to block 516.
[0072] At block 516, the altitude controller 126 determines whether
the aerial vehicle 102 has received a new command to adjust its
altitude. If the altitude controller 126 determines that the aerial
vehicle 102 has received a new command to adjust its altitude
("YES" at block 516), processing returns to block 502.
Alternatively, if the altitude controller 126 determines that the
aerial vehicle 102 has not received a new command to adjust its
altitude ("NO" at block 516), processing proceeds to block 518.
[0073] At block 518, the altitude controller 126 determines whether
the aerial vehicle 102 has received a command to adjust the amount
of air in the ballonets 116. If the altitude controller 126
determines that the aerial vehicle 102 has received a command to
adjust the amount of air in the ballonets 116 ("YES" at block 518),
processing proceeds to block 510. Alternatively, if the altitude
controller 126 determines that the aerial vehicle 102 has not
received a command to adjust the amount of air in the ballonets 116
("NO" at block 518), processing proceeds to block 520.
[0074] At block 520, the altitude controller 126 determines whether
the aerial vehicle 102 has received a command to decouple a portion
of the ballast 120. If the altitude controller 126 determines that
the aerial vehicle 102 has received a command to decouple a portion
of the ballast 120 ("YES" at block 520), processing proceeds to
block 522 where the altitude controller 126 operates a valve, door,
or other decoupling mechanism, to decouple the portion of the
ballast 120. Thereafter, or if the altitude controller 126
determines that the aerial vehicle 102 has not received a command
to decouple a portion of the ballast 120 ("NO" at block 520),
processing returns to block 504.
[0075] As can be appreciated in view of the present disclosure, the
systems and methods described herein provide advancements in aerial
vehicle pressure differential management that enable aerial
vehicles to be more resilient and withstand adverse weather
conditions, thereby increasing their usable lifetime. The
embodiments disclosed herein are examples of the present systems
and methods and may be embodied in various forms. For instance,
although certain embodiments herein are described as separate
embodiments, each of the embodiments herein may be combined with
one or more of the other embodiments herein. Specific structural
and functional details disclosed herein are not to be interpreted
as limiting, but as a basis for the claims and as a representative
basis for teaching one skilled in the art to variously employ the
present information systems in virtually any appropriately detailed
structure. Like reference numerals may refer to similar or
identical elements throughout the description of the figures.
[0076] The phrases "in an embodiment," "in embodiments," "in some
embodiments," or "in other embodiments" may each refer to one or
more of the same or different embodiments in accordance with the
present disclosure. A phrase in the form "A or B" means "(A), (B),
or (A and B)." A phrase in the form "at least one of A, B, or C"
means "(A); (B); (C); (A and B); (A and C); (B and C); or (A, B,
and C)."
[0077] The systems and/or methods described herein may utilize one
or more controllers to receive various information and transform
the received information to generate an output. The controller may
include any type of computing device, computational circuit, or any
type of processor or processing circuit capable of executing a
series of instructions that are stored in a memory. The controller
may include multiple processors and/or multicore central processing
units (CPUs) and may include any type of processor, such as a
microprocessor, digital signal processor, microcontroller,
programmable logic device (PLD), field programmable gate array
(FPGA), or the like. The controller may also include a memory to
store data and/or instructions that, when executed by the one or
more processors, causes the one or more processors to perform one
or more methods and/or algorithms. In example embodiments that
employ a combination of multiple controllers and/or multiple
memories, each function of the systems and/or methods described
herein can be allocated to and executed by any combination of the
controllers and memories.
[0078] Any of the herein described methods, programs, algorithms or
codes may be converted to, or expressed in, a programming language
or computer program. The terms "programming language" and "computer
program," as used herein, each include any language used to specify
instructions to a computer, and include (but is not limited to) the
following languages and their derivatives: Assembler, Basic, Batch
files, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, machine
code, operating system command languages, Pascal, Perl, PL1,
scripting languages, Visual Basic, metalanguages which themselves
specify programs, and all first, second, third, fourth, fifth, or
further generation computer languages. Also included are database
and other data schemas, and any other meta-languages. No
distinction is made between languages which are interpreted,
compiled, or use both compiled and interpreted approaches. No
distinction is made between compiled and source versions of a
program. Thus, reference to a program, where the programming
language could exist in more than one state (such as source,
compiled, object, or linked) is a reference to any and all such
states. Reference to a program may encompass the actual
instructions and/or the intent of those instructions.
[0079] Any of the herein described methods, programs, algorithms or
codes may be contained on one or more non-transitory
computer-readable or machine-readable media or memory. The term
"memory" may include a mechanism that provides (in an example,
stores and/or transmits) information in a form readable by a
machine such a processor, computer, or a digital processing device.
For example, a memory may include a read only memory (ROM), random
access memory (RAM), magnetic disk storage media, optical storage
media, flash memory devices, or any other volatile or non-volatile
memory storage device. Code or instructions contained thereon can
be represented by carrier wave signals, infrared signals, digital
signals, and by other like signals.
[0080] The foregoing description is only illustrative of the
present systems and methods. Various alternatives and modifications
can be devised by those skilled in the art without departing from
the disclosure. Accordingly, the present disclosure is intended to
embrace all such alternatives, modifications and variances. The
embodiments described with reference to the attached drawing
figures are presented only to demonstrate certain examples of the
disclosure. Other elements, steps, methods, and techniques that are
insubstantially different from those described above and/or in the
appended claims are also intended to be within the scope of the
disclosure.
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