Patent Application
20200144866
The present disclosure relates, in general, to airships and, more particularly, to remote power transmission to an airship.
The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art.
An airship provides a platform that contains a lifting gas, which provides lift and enables vehicle operations. Flight platforms such as airships can carry payloads that provide capabilities such as surveillance or communications over a geographic region. These platforms can be unmanned and are capable of extended flight of weeks to months to years, with the ability to fly back and be recovered and reused. These platforms have distinct advantages over existing systems, such as satellites or ground-based solutions. For instance, such platforms can maintain position over a particular area for extended periods, using various energy architectures, such as, but not limited to solar regenerative systems to capture solar energy during daytime and store excess energy in batteries, capacitors or other energy storage mediums for use at night for propulsion and payload power. With this power such airships can overcome the normally benign winds to effectively hold a specific position.
Methods and systems are described for, among other things, an energy collection device for an airship and a power transmission system for remotely and wirelessly transmitting power to the energy collection device via one or more laser beams.
According to some implementations, a system can include an airship that has an outer casing with an exterior surface and containing a gas therein. The airship can include an energy storage system having one or more energy storage devices, an energy distribution and control system electrically coupled to the energy storage system and configured to distribute power from the energy storage system to one or more systems of the airship, and an energy collection system coupled to the exterior surface of the outer casing. The energy collection system can include a laser tolerant layer, an insulation layer, a plurality of photovoltaic cells arranged in an array and electrically coupled to the energy storage system, and one or more retroreflectors positioned adjacent the array of photovoltaic cells. The system can also include a power transmission system. The power transmission system can include plurality of power transmission lasers, a beam control system for the plurality of power transmission lasers, one or more control link lasers, and a controller. The controller can be configured to establish a control link between the power transmission system via the one or more control link lasers and the retroreflectors of the airship and control the plurality of power transmission lasers to transmit power to the airship. The laser beams of the plurality of power transmission lasers can overlap to achieve a substantially uniform irradiance level and power distribution spatial profile at the plurality of photovoltaic cells of the airship.
According to some implementations, an airship can include an outer casing, an energy storage system having one or more energy storage devices, an energy distribution and control system electrically coupled to the energy storage system and configured to distribute power from the energy storage system to one or more systems of the airship, and an energy collection system positioned outside the outer casing. The energy collection system can include a plurality of photovoltaic cells arranged in an array and electrically coupled to the energy storage system and one or more control link components positioned adjacent the array of photovoltaic cells. The one or more control link components can be configured to establish a control link between the airship and a power transmission system. The plurality of photovoltaic cells can be configured to transfer laser beam transmitted energy from the power transmission system to the energy storage system.
According to some implementations, a power transmission system can include plurality of power transmission lasers, a beam control system for the plurality of power transmission lasers, one or more control link lasers, and a controller. The controller can be configured to establish a control link between the power transmission system and an airship via the one or more control link lasers and one or more control link components of the airship and control the plurality of power transmission lasers to transmit power to the airship. The laser beams of the plurality of power transmission lasers can overlap to achieve a substantially uniform irradiance level and power distribution spatial profile at a plurality of photovoltaic cells of the airship.
According to some implementations, an energy collection system can include a plurality of photovoltaic cells arranged in an array and electrically coupled to an energy storage system and one or more control link components positioned adjacent the array of photovoltaic cells. The one or more control link components can be configured to establish a control link with a power transmission system. The plurality of photovoltaic cells can be configured to transfer laser beam transmitted energy from the power transmission system to the energy storage system.
According to some implementations, an energy collection system can include a plurality of thermo-electrical cells arranged in an array and electrically coupled to an energy storage system and one or more control link components positioned adjacent the array of thermo-electrical cells. The one or more control link components can be configured to establish a control link with a power transmission system. The plurality of thermo-electrical cells can be configured to transfer laser beam transmitted energy from the power transmission system to the energy storage system.
According to some implementations, an energy collection system can include a plurality of photothermal cells arranged in an array and electrically coupled to an energy storage system and one or more control link components positioned adjacent the array of photothermal cells. The one or more control link components can be configured to establish a control link with a power transmission system. The plurality of photothermal cells can be configured to transfer laser beam transmitted energy from the power transmission system to the energy storage system.
According to some implementations, an energy collection system can include a plurality of pyroelectrical cells arranged in an array and electrically coupled to an energy storage system and one or more control link components positioned adjacent the array of pyroelectrical cells. The one or more control link components can be configured to establish a control link with a power transmission system. The plurality of pyroelectrical cells can be configured to transfer laser beam transmitted energy from the power transmission system to the energy storage system.
According to some implementations, an energy collection system can include a plurality of optical rectennas arranged in an array and electrically coupled to an energy storage system and one or more control link components positioned adjacent the array of optical rectennas. The one or more control link components can be configured to establish a control link with a power transmission system. The plurality of optical rectennas can be configured to transfer laser beam transmitted energy from the power transmission system to the energy storage system.
According to some implementations, an energy collection system can include means for establishing a control link with a power transmission system and means for converting and transferring laser beam transmitted energy from the power transmission system to an energy storage system.
According to some implementations, a power transmission system can include means for establishing a control link with an energy collection system of an airship and means for transmitting power to the airship responsive to establishing the control link.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the following drawings and the detailed description.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims, in which:
It will be recognized that some or all of the figures are schematic representations for purposes of illustration. The figures are provided for the purpose of illustrating embodiments with the explicit understanding that they will not be used to limit the scope or the meaning of the claims.
Stratospheric flight platforms, such as airships, provide capabilities such as surveillance or communications over a large geographic region. These platforms can be unmanned and are capable of extended flight of weeks to months to years, with the ability to fly back and be recovered and reused. These platforms have advantages over existing systems, such as satellites or ground-based solutions as such platforms can maintain position over a particular area for extended periods, using various energy architectures, such as but not limited to solar regenerative systems, to capture solar energy during daytime and store excess for use at night for propulsion and payload power. With this power such airships can overcome the normally benign winds at high altitudes to effectively hold a specific position. However, there are limitations on energy storage and/or acquisition under certain conditions, such as high latitudes, short daytime hours with long nights during winter seasons, and occasional high wind events. Under such conditions the volume and mass constraints of a stratospheric platform can limit the amount of energy that can be gathered and stored. Thus, provided herein are systems and methods to remotely power the platform using an energy transmission system, such as a laser transmission system.
Such a system can include a ground-, sea-, or aircraft-based laser transmission system, an airship-based collection system, and a control and feedback system that aligns the lasers to focus on the airship-based collection system and can provide beam control and optimization functions. Such power transmission systems can provide power for an airship that has a malfunctioning and/or otherwise reduced output power system to maneuver to a destination. In other instances, such a system can be used to assist in launching or otherwise initially positioning the airship. In further instances, such a system can be used to provide supplemental power to the airship to overcome high wind periods, or to execute other high energy maneuvers.
The gas-filled membrane 110 may be formed from a film capable of creating a suitable gas barrier, which can be used for airships and aerostats to retain the gasses with which they are filled. In some cases, the material from which the gas-filled membrane 110 is formed may vary depending on the type of gas intended to be used with the gas-filled membrane 110. The gas-filled membrane 110 may be filled with any suitable gas, such helium, hydrogen, or other gases.
The solar array 120 is electrically coupled to an energy storage system 140 to transmit energy produced from the photovoltaic cells to one or more energy storage devices 142. The one or more energy storage devices 142 can include batteries, capacitors, etc. In some implementations, the energy storage devices 142 include lithium-ion cells formed into battery modules. The energy storage system 140 is electrically coupled to an energy distribution and control system 150. The energy distribution and control system 150 can include a power distribution unit, an array control unit, a controller, and/or any other components utilized for power distribution from the energy storage system 140 and/or to control components of the power subsystem of the airship 100, such as the solar array 120. In some implementations, the power distribution unit can provide power management and control of electrical loads to components of the power subsystem and/or other systems of the airship 100 (e.g., power to actuators for control surfaces, propulsion systems, etc.). An array control unit can monitor photovoltaic performance of the solar array 120 and/or individual photovoltaic components and can monitor, control, and route energy transmitted by the solar array 120 or components thereof. The airship 100 can further include one or more auxiliary systems 190, such as surveillance systems, sensor systems, communications systems, etc.
As noted above, in situations where the energy produced from the solar array 120 is reduced (e.g., winter reduced daylight hours, high latitude or polar regions, etc.) or provides insufficient power (e.g., high wind conditions, high power consumption auxiliary systems, etc.), the airship 100 can include a separate energy collection system 130. The energy collection system 130 is also electrically coupled to the energy storage system 140 for transmitting energy received from a remote power transmission system to the one or more energy storage devices 142. In the implementations described herein, a laser-based energy collection system 130 is described. The energy collection system 130 can include one or more photovoltaic cells configured to receive transmitted energy from a remote power transmission system as will be described in greater detail herein. In some implementations, an array of photovoltaic cells can be arranged on an exterior surface of the gas-filled membrane 110 and/or on an exterior structure (e.g., a tail fin, an exterior mount, and/or other structure).
In the implementation shown, the energy collection system 130 includes a laser tolerant layer 610, an insulation layer 612, one or more photovoltaic cells 614, and one or more interconnects 616 electrically coupling the one or more photovoltaic cells 614. The laser tolerant layer 610 is a layer of material capable of continuous irradiance by a laser beam 330 that results from spillover from the laser beams 330. The laser tolerant layer 610 can be made of polyimide. In some implementations, the laser tolerant layer 610 can be integrated into the exterior surface 600 of the airship or can be omitted entirely. In some implementations, the laser tolerant layer 610 is capable of continuous irradiation from a laser energy of above 500 W/m2, above 1000 W/m2, such as 1355 W/m2 (i.e., a typical solar radiation level), or above 1500 W/m2 to protect the underlying exterior surface 600 of the airship. In some implementations, the laser tolerant layer 610 is capable of continuous irradiation from a laser energy of above 10,000 W/m2. For example, a 500 kW received laser power impinging on a 50 m2 collection array would have an average irradiance of 10,000 W/m2.
An insulation layer 612 is provided between the one or more photovoltaic cells 614 and the laser tolerant layer 610. The insulation layer 612 is a layer of material capable of thermal and/or irradiance insulation to limit heat transfer and/or irradiance resulting from the laser beams 330 directed at the one or more photovoltaic cells 614. The insulation later 612 can be made of expanded polyimide foams. In some implementations, the insulation later 612 can be integrated into the exterior surface 600 of the airship or can be omitted entirely.
The one or more photovoltaic cells 614 are shown coupled to the exterior surface 600 of the airship via the insulation layer 612 and the laser tolerant layer 610. In implementations where two or more photovoltaic cells 614 are provided, an interconnect 616 can electrically couple a photovoltaic cell 614 to another photovoltaic cell 614. The interconnect 616 provides for high current electrical coupling between photovoltaic cells 614. The one or more photovoltaic cells 614 can be arranged in series, in parallel, or in both series and parallel. The one or more photovoltaic cells 614 convert the transmitted laser beam 330 energy to DC electrical power that is used and/or stored in one or more energy storage devices, such as energy storage devices 142 of
As shown in
In some implementations, a lens, filter, or other optical device can be positioned above one or more of the one or more photovoltaic cells 614 such that the path and/or content of the laser beam can be modified. For instance, a Fresnel lens can be implemented to redirect received laser beam light to a perpendicular path to the one or more photovoltaic cells 614.
In some implementations, temperature control devices, such as thermal monitors, insulation, heaters, etc., can be implemented with the energy collection system 130 to adjust and/or maintain operating characteristics of the optical-to-electrical conversion devices, such as photovoltaic cells 614, optical rectennas, thermo-electrical components, photothermal components, pyroelectrical components, and/or combinations thereof.
In some implementations, the energy collection system 130 and/or the airship can include optical sensors and/or thermal sensors to measure a spatial distribution of received laser beams 330 on the energy collection system 130 and/or adjacent portions of exterior surface 600 of the airship.
In implementations with retroreflectors, one or more control laser beams can be used to detect the retroreflector via the reflection of the control laser beam(s) back to the power transmission system. The control laser beams can be mechanically or optically co-aligned with the transmitted power transfer laser beam(s). Such retroreflectors passively provide the area of the array 710 for the power transmission system such that the power transmission system can adjust and/or maintain the direction of the irradiation from the laser beams for the photovoltaics of the array 710. In some implementations, the position of the retroreflector, the number of retroreflectors, the shape of the retroreflector, and/or the composition of the reflected control laser beam can be used to determine information about the airship and/or the energy collection system 700, such as the shape of the array 710, the size of the array 710, the curvature of the array 710, etc.
The controller 810 is communicatively coupled to the laser 840 and/or beam control system 850 to control operation thereof. The controller 810 is configured to adjust the intensity of power transmission of the laser 840 and/or the orientation of the laser 840, either directly or through the beam control system 850, to achieve a desired irradiance level and/or a spatial profile at an energy collection system of an airship. In some implementations, the controller 810 can control several lasers 840 and/or beam control system 850 to superimpose and/or offset the angle of the one or more lasers 840 to achieve a desired irradiance level and/or power distribution spatial profile at the energy collection system of the airship.
In some implementations, the controller 810 can be configured to modify operation of the laser 840 responsive to control link component feedback from an airship. For instance, for retroreflector control link components, the controller 810 may be configured to pause or turn off the laser 840 responsive to an interruption of the control link. For instance, if an object enters between the power transmission system and the airship that blocks the control link laser, the controller 810 can pause or turn off the laser 840 and/or operate the beam control system 850 to block the laser beam transmission. In some implementations, the controller 810 is configured to adjust the power output and/or spatial profile such that irradiated power outside the array and/or beyond the array on the airship is low or non-existent to minimize potential damage to other equipment and/or entities.
In some implementations, the power transmission system 800 includes control link lasers and control link beam control systems in addition to the power transmission lasers 840. The controller 810 can also control the control link lasers that are directed towards the control link component of the airship. In some implementations, the power transmission system 800 further includes control link receivers configured to monitor the transmitted and/or retro-reflected control signals from the airship.
In some implementations, data responsive to the control link can be communicated to a power transmission system, such as via a retroreflected control link laser beam and/or through the communication link. Such data can include a size, spatial profile, and/or other data indicative of an energy collection system of the airship.
The process 1000 includes activating a power transmission laser system responsive to establishing a control link (block 1020). The power transmission laser system can be configured in accordance with the system 800 described in reference to
In some implementations, if the airship drifts or one or more control links become misaligned, the power transmission system can be configured to adjust a power and/or direction of an output laser beam of the power transmission system, either directly or through a beam control system.
In some implementations, the process 1000 can include detecting an interruption in the control link (block 1030). An interruption in the control link can include an object, such as an aircraft, an animal, a person, or any other object, entering between or otherwise disrupting the control link laser beam and a control link component. In other instances, the interruption in the control link can include the airship moving or otherwise becoming misaligned.
Responsive to the interruption, the process 1000 can include turning off or pausing the laser and/or operating a beam control system to block the laser beam transmission (block 1040).
The processing system 1102 may be implemented using software, hardware, or a combination of both. By way of example, the processing system 1102 may be implemented with one or more processors. A processor may be a general-purpose microprocessor, a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a state machine, gated logic, discrete hardware components, or any other suitable device that can perform calculations or other manipulations of information.
A machine-readable medium may be one or more machine-readable media, including no-transitory or tangible machine-readable media. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code).
Machine-readable media (e.g., 1119) may include storage integrated into a processing system such as might be the case with an ASIC. Machine-readable media (e.g., 1110) may also include storage external to a processing system, such as a Random Access Memory (RAM), a flash memory, a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable PROM (EPROM), registers, a hard disk, a removable disk, a CD-ROM, a DVD, or any other suitable storage device. Those skilled in the art will recognize how best to implement the described functionality for the processing system 1102. According to one aspect of the disclosure, a machine-readable medium may be a computer-readable medium encoded or stored with instructions and may be a computing element, which provides structural and functional interrelationships between the instructions and the rest of the system, which permit the instructions' functionality to be realized. Instructions may be executable, for example, by the processing system 1102 or one or more processors. Instructions can be, for example, a computer program including code for performing methods of some of the embodiments.
A network interface 1116 may be any type of interface to a network (e.g., an Internet network interface), and may reside between any of the components shown in
A device interface 1118 may be any type of interface to a device and may reside between any of the components shown in
The foregoing description is provided to enable a person skilled in the art to practice the various configurations described herein. While the subject technology has been particularly described with reference to the various figures and configurations, it should be understood that these are for illustration purposes only and should not be taken as limiting the scope of the subject technology. In some aspects, the subject technology may be used in various markets, including for example and without limitation, advanced sensors and mobile space platforms.
There may be many other ways to implement the subject technology. Various functions and elements described herein may be partitioned differently from those shown without departing from the scope of the subject technology. Various modifications to these embodiments may be readily apparent to those skilled in the art, and generic principles provided herein may be applied to other embodiments. Thus, many changes and modifications may be made to the subject technology, by one having ordinary skill in the art, without departing from the scope of the subject technology.
Phrases such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, a configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof and alike are for convenience and do not imply that a disclosure relating to such phrase(s) is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. A disclosure relating to such phrase(s) may apply to all configurations, or one or more configurations. A disclosure relating to such phrase(s) may provide one or more examples. A phrase such as an aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to other foregoing phrases. Every combination of components described or exemplified can be used to practice the embodiments, unless otherwise stated. Some embodiments can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the embodiments. Additionally, while various embodiments of the disclosure have been described, it is to be understood that aspects of the disclosure may include only some of the described embodiments. Accordingly, the disclosure is not to be seen as limited by the foregoing description.
A reference to an element in the singular is not intended to mean “one and only one” unless specifically stated, but rather “one or more.” The term “some” refers to one or more. Underlined and/or italicized headings and subheadings are used for convenience only, do not limit the subject technology, and are not referred to in connection with the interpretation of the description of the subject technology. All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the subject technology. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.
