Aircraft power system and method for providing regulated voltage and adjusting power fluctuations in a tethered aircraft

Abstract

An aircraft power system for providing regulated voltage and regulating power fluctuations in a tethered aircraft includes a plurality of light-emitting diodes (LEDs) onboard an aircraft having at least one propulsion unit. At least one electrical circuit is onboard the aircraft. The at least one electrical circuit includes a current-amplifying regulator in parallel with a speed controller of the at least one propulsion unit, the current-amplifying regulator in parallel with the speed controller providing the regulated voltage to the speed controller. A tether is connected between the aircraft and a power source located remotely from the aircraft. Power is transmitted via the tether to the aircraft and at least a portion of the plurality of LEDs.

Description

[Technical Field]

[0001] The present disclosure relates generally to electrical power systems, and more particularly to electrical power systems for aircraft, and particularly to related methods for regulating power fluctuations and providing regulated voltages in tethered aircraft without the use of step-down converters. [Background technology]

[0002] Aircraft systems, particularly aircraft, drones, unmanned aircraft systems (UAS), manned aircraft systems, and similar aircraft (collectively referred to herein as air vehicles (AVs)), are becoming increasingly prevalent. In the military, both manned aircraft systems and UASs are commonly used for surveillance, deliveries, and performing tasks. Outside of the military, AVs and drones are also widely used to perform tasks in entertainment, sports, and various industries. In recent years, AVs have been equipped with electronic devices such as cameras, enabling users to capture aerial photographs.

[0003] Similarly, AVs are equipped with onboard lighting to provide aerial or elevated lighting for outdoor spaces. Such illuminated AVs can be used to provide quick, temporary lighting for outdoor spaces in place of more traditional outdoor lighting units, such as permanent lighting poles or trailer-mounted lighting units with elevated temporary lighting. The high-power, wide-area lighting provided by these AVs is typically projected from heights of 25 feet or more and exceeds 10,000 lumens, enabling many activities that would otherwise be impossible outdoors at night, such as construction, sports, and entertainment. Furthermore, advances in both AV and lighting technology now enable AVs to elevate high-power lighting devices to altitudes comparable to or exceeding the height of traditional lighting poles. Currently, power limitations on AVs' onboard batteries limit the practical use of such systems, as most implementations of high-power lighting on untethered AVs can emit less than 12,000 lumens and illuminated flight to less than one hour.

[0004] To provide temporary outdoor lighting for longer periods or to provide higher-intensity lighting, AVs can be equipped with a tether that electrically connects them to a ground power source, such as a battery, generator, or a conventional power source hardwired from a utility power source. Using tethered AVs, it is now possible to provide AVs with continuous power supply indefinitely or nearly indefinitely for high-output lighting exceeding 10,000 lumens. Tethers typically include a wire with a conductor, which may be sheathed or wrapped in a lightweight rope. Power can be supplied from a ground power source via the tether to both the AV's propulsion or flight control system and the AV's onboard lighting system. However, powering both the AV and high-power LEDs via the tether in a weight-efficient manner can often be challenging. Reducing payload weight allows for smaller, lighter, more portable, and less power-consuming AVs to be used for lighting applications. Summary of the Invention [Problem to be solved by the invention]

[0005] Current tethered AVs are designed to power multiple different payloads. Typically, high-voltage DC power delivered via the tether from a ground power source is converted by an onboard DC converter or downconverter to a lower voltage for the drone and accessories, including high-power lighting. If more power is required for the lighting accessory, a larger and heavier DC converter and heat sink are also required. Therefore, as the power requirements for lighting increase, the size of the AV must also increase to accommodate the additional weight. As the total weight increases, so does the power required from the ground power system. Even with AVs that minimize the size and weight of onboard DC converters, there is still a need to provide lighter AVs.

[0006] Additionally, traditional AVs can suffer from complex manufacturing bottlenecks that make it difficult or impossible to obtain components necessary for the AV's operation. For example, DC converters that fit the space and weight constraints of an AV are often difficult to obtain due to market supply shortages. When components are not readily available, AV manufacturers may have to manufacture them themselves, which is inefficient and costly.

[0007] Thus, there exists a heretofore unmet need in the industry to address the aforementioned shortcomings and deficiencies. [Means for solving the problem]

[0008] An embodiment of the present disclosure provides an aircraft electrical power system. Briefly, in terms of structure, one embodiment of the system can be implemented, among other things, as follows: An aircraft has at least one propulsion unit. A plurality of light emitting diodes (LEDs) are mounted on the aircraft. The aircraft has at least one electrical circuit, the at least one electrical circuit including a current boost regulator in parallel with the at least one propulsion unit or a speed controller for the at least one propulsion unit, the current boost regulator in parallel with the at least one propulsion unit or a speed controller for the at least one propulsion unit providing a regulated voltage to the at least one propulsion unit or the speed controller. A tether is connected between the aircraft and a power source located remotely from the aircraft, and power is transmitted via the tether to the aircraft and at least a portion of the plurality of LEDs.

[0009] The present disclosure can also be viewed as providing an aircraft power system. Briefly, in terms of structure, one embodiment of the system can be implemented, among other things, as follows: An aircraft has a plurality of propulsion units. A plurality of light emitting diodes (LEDs) are mounted on the aircraft. The at least one electrical circuit is mounted on the aircraft, the at least one electrical circuit including a plurality of current boost regulators, each in parallel with a respective one of a plurality of speed controllers of the plurality of propulsion units, the current boost regulators in parallel with the plurality of speed controllers providing a regulated voltage to the plurality of speed controllers. A tether is connected between the aircraft and a power source located remotely from the aircraft, and power is transmitted via the tether to the aircraft and at least a portion of the plurality of LEDs.

[0010] The present disclosure can also be viewed as providing a method for regulating power fluctuations and providing a regulated voltage in a tethered aircraft. In this regard, one embodiment of such a method can be broadly summarized by, among other steps, the following steps: providing an aircraft having a plurality of propulsion units and a plurality of light emitting diodes (LEDs) mounted thereon; connecting a tether between the aircraft and a power source located away from the surface of the aircraft; providing at least one electrical circuit onboard the aircraft, the at least one electrical circuit having a plurality of current-boosting regulators each in parallel with a respective one of a plurality of speed controllers of the plurality of propulsion units, the plurality of current-boosting regulators providing a regulated voltage to the plurality of speed controllers of the plurality of propulsion units; and transmitting a quantity of electrical power through the tether, the quantity of electrical power being transmitted through the at least one electrical circuit onboard the aircraft.

[0011] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the disclosure, and be protected by the accompanying claims.

[0012] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Also in the drawings, like reference numbers indicate corresponding parts throughout the several views. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of a tethered aircraft using an aircraft power system according to an exemplary embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram illustrating an example of an aircraft electrical power system, in accordance with an exemplary embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic diagram illustrating an example of an aircraft power system, in accordance with an exemplary embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram of a network of tethered aircraft using an aircraft power system according to an exemplary embodiment of the present disclosure. [Figure 5] FIG. 5 is a flowchart illustrating a method for regulating power fluctuations and providing regulated voltage in a tethered air vehicle according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] Many conventional implementations of tethered aircraft lighting require a relatively heavy and space-consuming DC down converter located on the AV, e.g., mounted on the AV while in flight. The DC converter, also known as a DC down converter or down converter, converts high-voltage power received via the tether to a low voltage usable by the AV's onboard LEDs and the AV's propulsion system (e.g., rotors or similar thrusters). However, the DC converter adds weight and bulk to the AV, limiting the efficiency with which the AV can provide the desired lighting effect.

[0015] The present disclosure improves upon these shortcomings of conventional devices by eliminating the DC converter. Eliminating the DC converter reduces the weight and spatial payload of the AV, resulting in the production and use of lighter, quieter, and less power-consuming AVs. The resulting AV can utilize a tether to provide power to the AV during flight, enabling high-output lighting in excess of 10,000 lumens and extended use, for example, where operational time is limited only by the operational limitations of mechanical flight components.

[0016] FIG. 1 is a schematic diagram of a tethered AV using an aircraft power system 10 according to an exemplary embodiment of the present disclosure. As shown, the aircraft power system 10, sometimes referred to herein simply as “system 10,” includes an aircraft 20, which may be any type of aircraft, such as a manned aircraft, an unmanned aircraft system (UAS), a drone, or a similar vehicle capable of airborne flight. The AV 20 includes one or more propulsion units 22. The propulsion units 22 may be, for example, rotors, propellers, fans, motors, or similar devices capable of providing thrust to the AV 20. Any number of propulsion units 22 may be used, as may be determined based on the design of the AV 20. A plurality of light-emitting diodes (LEDs) 30 are mounted to the aircraft 20, for example, by mounting one or more LED arrays or similar lighting fixtures to a frame of the AV 20. The LEDs 30 are capable of illuminating a surface 12 or another location with a quantity of light 32 to provide illumination. In one example, the LEDs are high-power LEDs capable of illuminating substantially 20,000 lumens or more.

[0017] At least one electrical circuit 40 is carried onboard the AV 20, and the electrical circuit 40 may often be integrated with the AV 20's own electrical system, thereby communicating with other systems of the AV 20 (e.g., propulsion system, control system, or other systems of the AV 20). As described in connection with FIG. 2 , the electrical circuit 40 can be used to adjust for power fluctuations within the AV 20 and regulate voltage to parallel loads (e.g., speed controller 44). This can be used to improve the performance of the AV 20 and allows for the elimination of DC converters typically required in the operation of tethered AVs. The tether 50 is connected between the AV 20 and a power source 60, which in this example is located on the Earth's surface 12 or a similar location remote from the AV 20, thereby positioning the AV 20 at an elevation H above the Earth's surface 12. Within the scope of the present disclosure, the power source 60 may be located on the Earth's surface, on a land or water vehicle, on another UAS, or any other location remote from the AV 20. Electrical power for powering the LEDs 30 and AVs 20 is transmitted to the AVs 20 and at least a portion of the plurality of LEDs 30 through the tether 50 .

[0018] FIG. 2 is a schematic diagram illustrating an example of an aircraft power system 10 according to an exemplary embodiment of the present disclosure. With reference to FIGS. 1 and 2 , power is supplied to the AV 20 and the LEDs 30 using a tether 50 formed from a two-conductor wire 52 having a positive conductor 52A and a negative (or ground) conductor 52B connected to a positive terminal 62 of the power supply 60 and a negative terminal 64 of the power supply 60. While the power supply 60 may vary, one example is a DC power source and a boost converter that maintains a constant voltage. While using three- or four-conductor wire for the tether 50 is feasible and may be easier to implement as a means of powering the AV 20 and the LEDs 30, the added weight of the additional conductor wire would require the AV 20 to have more power and possibly a higher lift capability compared to a two-conductor tether 50. The use of two-conductor wire allows for a minimal weight of the tether to be achieved, thereby reducing the overall weight of the AV 20 and thereby reducing the power required by the AV 20. In some cases, this may mean that a smaller, less expensive AV 20 can be used. Thus, using two-conductor wire for the tether 50, or for components of the tether 50, ensures that the tether 50 is sufficiently light weight without adding unnecessary weight to the AV 20 payload.

[0019] As shown in FIG. 2, the electrical circuitry 40 onboard the AV 20 includes one or more current-boosting regulators 42 in parallel with a speed controller 44, which regulates the voltage to the speed controller 44, which in turn regulates power fluctuations via the tether 50. FIG. 2 shows four current-boosting regulators 42A-42D, each in parallel with a speed controller 44A-44D. The speed controllers 44A-44D are in electrical communication with the propulsion devices 22, e.g., the motors of the propulsion devices 22A-22D, and each include electronic circuitry that controls and adjusts the speed of the electric motors that drive the propulsion devices 22A-22D. For example, the speed controller may be a device or system of devices that control and / or transmit power to the motors and / or propulsion devices 22, thereby controlling the operation of the propulsion devices 22. In one example, the speed controller 44 may be an electronic speed controller (ESC). In another example, if a brushed motor is used, the speed controller may be a device that provides pulse-width modulation (PWM) to control the throttling of the motor. Thus, any type of speed controller 44 may be used, including a stand-alone device or a device or function contained in another component.

[0020] While the electrical circuit 40 can have any number of current amplifier regulators 42A-42D corresponding to any number of speed controllers 44A-44D, which themselves correspond to any number of propulsion units 22A-22D, Figure 2 shows an example having four of each unit, corresponding to a typical configuration of a quadcopter (e.g., an AV 20 having four propulsion units 22A-22D or four motors corresponding to rotors). For an AV 20 having more or fewer propulsion units 22, the electrical circuit 40 may have more or fewer current amplifier regulators 42A-42D.

[0021] The current-amplifying regulator 42 may be characterized as a resistive device, such as a diode, whose resistance increases as the voltage across it decreases. The current-amplifying regulator 42 may be used in parallel with a load that has a large fluctuation in current demand, such as the speed controller 44. The current-amplifying regulator 42 operates by reducing current and voltage fluctuations across the tether or series circuit (e.g., the tether or tether branch in series with the current-amplifying regulator 42), which may be caused by current fluctuations due to the thrusters 22 or resistance between the power source 60 and the tether or series circuit. The current-amplifying regulator 42 in parallel with the speed controller 44 draws more current and limits voltage rise due to deliberate resistance within the system 10, including the tether 50, allowing the voltage provided by the speed controller 44 to the thrusters 22 to remain below a predetermined maximum or remain relatively constant. For example, when the speed controller 44 draws more current, the current boost regulator 42 draws less current, thereby reducing current fluctuations across the tether 50, and when the speed controller 44 draws less current, the current boost regulator 42 draws more current, thereby reducing current fluctuations across the tether 50. The point at which the parallel current boost regulator 44 draws more current can vary depending on the design of the system 10.

[0022] The current-amplifying regulator 42 may include at least one or more LEDs 46A and / or resistive devices 46B. The LEDs 46A are wired in series and physically attached to the AV 20. The term "LED" may refer to a single LED, parallel LEDs, a series of LEDs, or both. It is also noted that while LEDs are used herein, the system 10 may also function with non-emitting diodes. In one example, each LED 46A is paired with a resistive device 46B, and the combination of the two forms an LED stage of the current-amplifying regulator 42. In this example, the resistive device 46B in each stage is optional and may only be needed to minimize LED flicker or to boost the stage voltage. The wattage of each LED stage may exceed the power requirements of each parallel load, such as the speed controller 44, the power distribution system 54, or the payload device 48 (FIG. 3).

[0023] In the example of FIG. 2 , LED 46A may be used together with LED 30 or separately from LED 30. For example, in one example, LED 30 may be an LED primarily used for lighting applications to provide ground illumination, while LED 46A may be used for current regulation. However, LED 46A can also be used for lighting applications, either in conjunction with LED 30 or, in some circumstances, instead of LED 30, with LED 46A serving as the primary source for both current regulation and lighting, with LED 30 providing supplemental lighting. As shown, LED 46A and resistive device 46B are in parallel with speed controller 44. Each of current-amplifying regulators 42A-42D is in series with one or more additional current-amplifying regulators 42A-42D as shown, and each current-amplifying regulator 42A-42D is typically in parallel with a speed controller 44A-44D or other load, as described in connection with FIG. 3 .

[0024] The electrical circuit 40 may also include an electrical isolator 70, such as an optocoupler, optoisolator, capacitive isolator, or another type of electrical isolator, connected between the speed controller 44 and the flight controller 72 to electrically isolate the speed controller 44 from the flight controller 72. The flight controller 72 is connected to a power distribution module 54 that is in parallel with one of the current-amplifying regulators 42E. As shown in FIG. 2, each speed controller 44A-44D receives a control signal from the flight controller 72 through the electrical isolator 70. The flight controller 72 receives power from the power distribution module 54.

[0025] The speed controllers 44A-44D and the power distribution module 54 may each receive a regulated voltage from a respective parallel current boost regulator 42A-42E, which are connected in series with one another as shown. The positive wire of the tether is connected to a positive terminal 62 of a power source 60 on one side of the electrical circuit 40, and has a ground wire connected to a negative terminal 64 of the power source 60 on the other side.

[0026] In operation, the flight controller 72 may send a control signal to the electrical isolator 70, which in turn transmits the signal to the speed controller 44 without transmitting power, allowing the speed controllers 44A-44D to receive control signals from the flight controller 72 but not power. Because each speed controller 44A-44D is connected to a motor of the propulsion unit 22A-22D, the speed controller 44A-44D can control the speed of the propulsion unit 22A-22D via power supplied via the current amplifier regulator 42 based on the control signal received from the electrical isolator 70. While the speed controllers 44A-44D are electrically isolated from the power distribution module 54, they are still connected to the flight controller 72 to receive control signals, allowing each motor of the propulsion unit 22 to be driven by its corresponding current amplifier regulator 42. This effectively eliminates the need for the speed controllers to include a DC converter, typically connected to a battery via a power distribution module that provides both power and control signals, as commonly used in conventional tethered drones.

[0027] In the system 10, the current-amplifying regulators 42A-42E, and in particular the LEDs 46A or resistive devices 46B of the current-amplifying regulators 42A-42E, function as voltage dividers or voltage references to provide regulated voltages to parallel-arranged loads. The LEDs 46A of the current-amplifying regulators 42A-42E are arranged in series with each other. Each LED 46A of the current-amplifying regulators 42A-42E provides regulated power to a parallel load, such as a speed controller 44A-44D for the current-amplifying regulators 42A-42D or a power distribution module 54 for the current-amplifying regulator 42E.

[0028] Each speed controller 44A-44D receives an electrically isolated signal from the flight controller 72, and electrical isolation of the flight control signal to the speed controller 44A-44D is achieved by disposing an electrical isolator 70A-70D between the flight controller 72 and each speed controller 44A-44D. In this configuration, the speed controller 44A-44D is connected to the receiving side of the electrical isolator 70A-70D, and the receiving side of the electrical isolator 70A-70D is powered by the 5 volt output (BEC) of the speed controller 44A-44D or a separate power source that is electrically isolated from the flight controller 72.

[0029] It is noted that in other examples, only the LED 46A and one of the optional resistive devices 46B of the current amplifier regulator 42 may be used to drive the entire AV 20, including all of the speed controllers 44 and the power distribution module 54. If this is the case, electrical isolation may not be necessary if only one LED stage is used to drive the speed controllers 44 and the power distribution module 54. It is also noted that while all of the speed controllers 44 and the power distribution module 54 are described herein as receiving power from the tether 50, some or all of the speed controllers 44 or the power distribution module 54 may be capable of receiving power from another power source, such as an on-board battery.

[0030] Among the many advantages of the system 10, one is the ability to operate an airborne lighting system for extended periods or indefinitely with illumination capabilities that meet or exceed required applications. Additionally, the system 10 minimizes the likelihood of AV20 and LED 30 operation being interrupted by fluctuations in the power supplied to the AV20 via the tether 50. For example, during certain phases of AV20 flight, such as initial startup and takeoff, the AV20 may consume significantly more power than during steady-state flight. Similarly, certain maneuvering maneuvers of the AV20 may cause the AV20 to consume more power than when stationary. Because the LED 30 and the AV20 are powered from the same power source 60 via the tether 50, these power draws by the AV20 may cause the LED 30 to flicker or similar undesirable events. The system 10 can accommodate these power fluctuations from the AV20 via the tether 50 to minimize fluctuations in light output from the LED 30.

[0031] In a tethered drone system designed to provide illumination, the system 10 reduces the weight of the AV 20 by eliminating the need for the AV 20 to include a DC or step-down converter to convert the high voltage received via the tether 50 to the low-voltage DC required by the AV 20 and any payload. The use of current-boost regulators 42A-42E in the described configuration eliminates the need for DC converters, enabling a significant reduction in the weight of the AV 20. Eliminating the need for DC converters significantly reduces weight, thereby reducing thrust and energy requirements and acoustic output. Furthermore, eliminating the need for DC converters means that the AV 20 costs less to manufacture than conventional devices, since gains comparable to DC converters can be achieved using current-boost regulators 42A-42E, which are less expensive to acquire or manufacture.

[0032] Figure 3 is a schematic diagram illustrating an example of an aircraft electrical power system 10 in accordance with an exemplary embodiment of the present disclosure. In particular, Figure 3 illustrates an example similar to the electrical circuit 40 of Figure 2, shown with optional aspects. The components and features of Figure 2 included in Figure 3 are the same as those described in connection with Figure 2, unless otherwise noted.

[0033] It is noted that motor power fluctuations can cause undesirable voltage fluctuations at the corresponding LEDs 46A of the current-amplifying regulators 42A-42E. To improve motor power output stability, a control signal from the flight controller 72 may be throttled to compensate for voltage fluctuations across one or more of the speed controllers 44A-44B. This may be accomplished by a device such as a signal throttle 56 connected between the speed controllers 44A-44D and the power distribution module 54 or incorporated within the speed controllers 44A-44B. For example, in the speed controller 44A corresponding to the current-amplifying regulator 42A, the signal throttle 56 is integrated into the speed controller 44A, while in the ESD 44B corresponding to the current-amplifying regulator 42B, the signal throttle 56 is a separate device located between the speed controller 44B and the power distribution module 54.

[0034] The throttle signal input from the flight controller 72 to each speed controller 44A-44B may be adjusted to compensate for voltage fluctuations between the speed controllers 44A-44B. For example, if the reference LED stage voltage is 12 volts and the voltage from the LED 46A of the current amplifier regulators 42A-42B to the speed controllers 44A-44B decreases to 10.8 volts (a 10% decrease from reference), the signal to the speed controllers 44A-44B would increase the throttle signal by 1 / (1-0.1), or 11%. This is expected to result in a more consistent wattage to the motors of the thrusters 22, even when the voltage at the LED 46A of the current amplifier regulators 42A-42B fluctuates. The signal throttle 56 can receive the throttle signal from the flight controller 72, receive voltage measurements from the LED 46A of the current amplifier regulators 42A-42B, calculate the necessary adjustment, and send the adjusted throttle signal to the speed controllers 44A-44B.

[0035] 3 also illustrates the option of using a current boost regulator 44 to provide voltage-regulated power to a payload device 48 that is not part of the propulsion system. For example, in an AV 20 carrying a camera, sensor, or other equipment, the payload device 48 may be placed in parallel with current boost regulators 42C-42D as shown. If a payload device 48 is used, it may receive control signals from a controller 58 that is separate from or integrated into the flight controller 72, as shown. Any type of payload device 48 or accessory having an electrical load may be included.

[0036] 2-3, it should be noted that system 10 may require calculations to determine the voltage required from the tether power supply or base station. For example, the base station voltage supplied to tether 50 may be calculated to balance the voltage to each LED stage of current amplifier regulator 42 so that it remains within a required range. This can be summarized by the following equation: V ベース電源電圧 =V ドロップテザー +V 合計LED段 +V 補助LED where V ベース電源電圧 is the reference voltage from the power supply, V ドロップテザー is the voltage drop across the tether, V 合計LED段 is the voltage applied to all LED stages of the current amplifier regulator 42, V 補助LED is the voltage of any auxiliary LED. A voltage range based on expected current variations may be considered in this calculation. This calculation assumes that the voltage from the base station power supply is set according to this calculation and that the supply voltage to tether 50 is constant.

[0037] Additionally, various steps and considerations may be used to balance the system 10. In one example, the following steps are used: 1. Steps to determine the minimum and maximum voltages and currents for (a) any drone power distribution, (b) the speed controller, (c) the current amplifier regulator LED stage and any auxiliary LEDs; 2. Calculating the maximum voltage required across the tether when the system is at full load; 3. Ensuring that the maximum current through the tether does not exceed the rating of the auxiliary LED or the rating of the LEDs in each stage of the LED power system; 4. Powering the system and testing to ensure the drone maintains power from power off to full power and that the LEDs light up as expected; and 5. Performing repeated iterations to update parameters as needed and retesting through various drone power and LED settings until the LED and drone operate as desired.

[0038] As an illustration of system 10, a first embodiment is shown in which a quadcopter drone is designed for tether power, eliminating the need for an on-board battery or DC converter. Six 12V LEDs are wired in series and physically attached to the drone. The first, second, third, and fourth LEDs are each wired in parallel with one of the quadcopter's four electronic speed controllers (ESCs). Each ESC receives a signal from an electrical isolator. Each electrical isolator receives a signal from the flight controller. The fifth LED is wired in parallel with the power distribution module. The sixth LED is added solely to provide additional illumination. A 10-foot, two-wire tether is attached to the drone. The positive lead of the tether is connected to the positive terminal of the first LED. The negative lead of the tether is connected to the negative terminal of the sixth LED. A constant power supply provides 75 volts (12V x 6 LEDs + 3V tether resistor) and enough current for the LEDs, ESC, and drone system power to maintain power and voltage regulation throughout all phases of drone flight and lighting.

[0039] In another example, two 12V LEDs are wired in series and physically attached to the drone. One 12V LED is wired in parallel with a power distribution module. The power distribution module provides power to components including the flight controller and ESCs. The second LED is added solely to provide additional lighting. A 10-foot tether is attached, with its positive lead connected to the positive terminal of the first LED. The negative lead of the tether is connected to the negative terminal of the second LED. A constant power supply provides 27 volts (2 x 12V LEDs + 3 volt tether resistor) and sufficient current for the drone's power distribution throughout all phases of drone flight and lighting.

[0040] FIG. 4 is a schematic diagram of a network of tethered aircraft using an aircraft power system 10 according to an exemplary embodiment of the present disclosure. As shown, using the system 10 described in connection with FIGS. 1-3 may enable AVs 20 to be connected in series and be powered by tethers connected to other AVs 20. For example, in FIG. 4, a first AV 20A includes a tether 50A connected to a power source 60 located on the Earth's surface 12, with the first AV 20A located at height H above the Earth's surface 12. A second AV 20B can be located in an airborne location above the Earth's surface 12, e.g., at height H or another height, with an airborne tether 50B connected between the first and second AVs 20A, 20B. A third AV 20C can be located in an airborne location with an airborne tether 50C between the second and third AVs 20B, 20C. A fourth AV 20D can be located in an airborne position, with an airborne tether 50D located between the third and fourth AVs 20C, 20D. Any additional number of AVs and airborne tethers can also be included.

[0041] In this example, as described in connection with Figures 2-3, the electrical circuitry 40 of each AV allows for simultaneous powering and flight of multiple AVs 20A-20D by wiring the AVs 20A-20D in series. Flying the AVs 20A-20D in series rather than individually reduces the overall weight of the wiring, further improving efficiency and reducing acoustic output. The series connection of AVs 20A-20D is made possible by the present system 10 by creating a nearly constant current throughout the system 10.

[0042] 5 is a flowchart illustrating a method for providing a regulated voltage to a tethered aircraft and regulating power fluctuations within the tethered aircraft according to an exemplary embodiment of the present disclosure. Note that any process description or block in the flowchart should be understood to represent a module, segment, portion of code, or step containing one or more instructions for implementing a specific logical function in the process. Also, alternative embodiments are included within the scope of the present disclosure in which functions may be performed in an order different from that illustrated or described (e.g., substantially simultaneously or in reverse order), depending on the function, as would be understood by one skilled in the art.

[0043] As shown in block 102, an aircraft having multiple propulsion units is provided, the aircraft having multiple light emitting diodes (LEDs) mounted thereon. A tether is connected between the aircraft and a power source located off the aircraft surface (block 104). At least one electrical circuit is onboard the aircraft, the at least one electrical circuit having multiple current-boosting regulators, each current-boosting regulator in parallel with a respective one of multiple speed controllers for the multiple propulsion units, the multiple current-boosting regulators providing regulated voltages to the multiple speed controllers for the multiple propulsion units (block 106). A quantity of power is transmitted through the tether, and the quantity of power is transmitted through at least one electrical circuit onboard the aircraft (block 108). Any number of additional steps, functions, processes, or variations thereof may be included in the method, including those disclosed in connection with other figures of this disclosure.

[0044] It should be emphasized that the above-described embodiments of the present disclosure, particularly any "preferred" embodiments, are merely exemplary implementations set forth for a clear understanding of the principles of the present disclosure. Many changes and modifications can be made to the above-described embodiments of the present disclosure without substantially departing from the spirit and principles of the present disclosure. All such changes and modifications are intended to be included herein within the scope of this disclosure and this specification, and are protected by the following claims.

Claims

1. an aircraft having at least one propulsion unit; a plurality of light emitting diodes (LEDs) mounted on the aircraft; at least one electrical circuit onboard the aircraft, the at least one electrical circuit having a current boost regulator in parallel with the at least one propulsion unit or a speed controller of the at least one propulsion unit, the current boost regulator in parallel with the at least one propulsion unit or the speed controller of the at least one propulsion unit providing a regulated voltage to the at least one propulsion unit or the speed controller; a tether connected between the aircraft and a power source located remotely from the aircraft, the tether transmitting power to the aircraft and at least a portion of the plurality of LEDs. Aircraft power systems.

2. 2. The system of claim 1, wherein when the at least one propulsion unit or the speed controller of the at least one propulsion unit draws a larger current, the current amplification regulator draws a smaller current, thereby reducing current fluctuations across the tether, and when the at least one propulsion unit or the speed controller of the at least one propulsion unit draws a smaller current, the current amplification regulator draws a larger current, thereby reducing current fluctuations across the tether.

3. 3. The system of claim 1, further comprising an electrical isolator connected between the at least one propulsion device or the speed controller of the at least one propulsion device and a flight controller, wherein the at least one propulsion device or the speed controller of the at least one propulsion device is electrically isolated from the flight controller.

4. The system of claim 3 , wherein the flight controller is connected to a power distribution module.

5. an aircraft having multiple propulsion systems; a plurality of light emitting diodes (LEDs) mounted on the aircraft; at least one electrical circuit onboard the aircraft, the at least one electrical circuit having a plurality of current boost regulators each in parallel with a respective one of a plurality of speed controllers of the plurality of propulsion units, the current boost regulators in parallel with the plurality of speed controllers providing regulated voltages to the plurality of speed controllers; a tether connected between the aircraft and a power source located remotely from the aircraft, the tether transmitting power to the aircraft and at least a portion of the plurality of LEDs. Aircraft power systems.

6. 6. The system of claim 5, wherein when one of the speed controllers draws a larger current, a corresponding current multiplier regulator draws a smaller current, thereby reducing voltage fluctuations across the one of the speed controllers and also reducing current fluctuations across the tether or series circuit, and when the one of the speed controllers draws a smaller current, the corresponding current multiplier regulator draws a larger current, thereby reducing voltage fluctuations across the one of the speed controllers and also reducing current fluctuations across the tether or series circuit.

7. 7. The system of claim 5 or 6, further comprising an electrical isolator connected between each of the speed controllers and a flight controller, wherein each of the speed controllers is electrically isolated from the flight controller.

8. 8. The system of claim 5, wherein the flight controller is connected to a power distribution module, the power distribution module being connected in parallel to one of the plurality of current multiplying regulators, and wherein a control signal sent from the flight controller to one or more of the plurality of speed controllers is throttled to compensate for voltage variations across the one or more speed controllers.

9. The system of claim 8 further comprising a signal throttle connected between each of the speed controllers and the power distribution module or integrated into each of the speed controllers.

10. 10. The system of claim 5, further comprising at least one device on board the aircraft, the at least one device being connected in parallel with one of the plurality of current amplifier regulators.

11. 1. A method for regulating power fluctuations and providing regulated voltage in a tethered aircraft, comprising: providing an aircraft having a plurality of propulsion units and having a plurality of light emitting diodes (LEDs) mounted thereon; connecting a tether between the aircraft and a power source located away from the surface of the aircraft; providing at least one electrical circuit onboard the aircraft, the at least one electrical circuit having a plurality of current boost regulators each in parallel with a respective one of a plurality of speed controllers of the plurality of propulsion units, the plurality of current boost regulators providing regulated voltages to the plurality of speed controllers of the plurality of propulsion units; and 10. A method comprising: transmitting an amount of power through the tether, the amount of power being transmitted through the at least one electrical circuit onboard the aircraft.

12. 12. The method of claim 11, wherein when one of the speed controllers draws a larger current, a corresponding current multiplier regulator draws a smaller current, thereby reducing voltage fluctuations across the one of the multiple speed controllers and also reducing current fluctuations across the tether or series circuit, and when the one of the speed controllers draws a smaller current, the corresponding current multiplier regulator draws a larger current, thereby reducing voltage fluctuations across the one of the multiple speed controllers and also reducing current fluctuations across the tether or series circuit.

13. The method of claim 11 or 12, wherein the plurality of propulsion devices further comprise a plurality of rotors each.

14. 14. The method of claim 11, further comprising electrically isolating each of the speed controllers from the flight controller using an electrical isolator connected between each of the speed controllers and the flight controller.

15. connecting the flight controller to a power distribution module, the power distribution module being connected in parallel to one of the plurality of current-boost regulators; and 15. The method of claim 14, further comprising throttling a control signal sent from the flight controller to the one or more of the speed controllers to compensate for voltage fluctuations across the one or more of the speed controllers.

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