GB2618770A

GB2618770A - Airborne vehicle charging

Info

Publication number: GB2618770A
Application number: GB2206748.2A
Authority: GB
Inventors: Thomas Gill James
Original assignee: BAE Systems PLC
Current assignee: BAE Systems PLC
Priority date: 2022-05-09
Filing date: 2022-05-09
Publication date: 2023-11-22

Abstract

The present invention provides a charging apparatus for charging a battery of an aircraft 100 in flight. The charging apparatus comprises a main body; a wire coil (213, fig 3); an energy storage device for generating an electric current in the wire coil (209, fig 3); and a ferromagnetic core (214, fig 3) proximate to a surface of the main body, wherein the wire coil is wrapped around the ferromagnetic core. The charging apparatus may be incorporated into a charging aircraft 200. There is also disclosed an aircraft 100 comprising a main body 202, a motor for generating thrust, and a reachable battery coupled to a coiled electrical wire proximate to the surface of the main body such that when it comes into proximity with a varying magnetic field generated by a charging apparatus, an electrical current is induced in the electrical wire to charge the rechargeable battery. There is also disclosed a pod comprising the charging apparatus, and a system comprising the charging apparatus incorporated into a charging aircraft and a further aircraft to be charged.

Description

AIRBORNE VEHICLE CHARGING

FIELD

The present invention relates to an apparatus for charging batteries of a vehicle in flight. The present invention also relates to an aircraft and system for performing the same.

BACKGROUND

Battery-powered aircraft, which include aircraft with hybrid power units, are becoming prolific. The vast majority of commercial unmanned aerial vehicles (UAVs) are powered exclusively by batteries, such as Lithium-Ion batteries. The maximum operational flight time of these aircraft compared with aircraft powered by combustible fuels is low, for example at time of filing the flight time for a typical commercial UAV carrying a load is approximately 40 minutes. Therefore, battery-powered aircraft must return to land to have their batteries swapped in order to maintain persistent operation, which can leave a gap in observation of a target and increases logistical burden. Further, battery-powered vehicles typically cannot transit long distances while carrying a load. It would be unreasonable to arrange to have spare batteries delivered to waypoints along a vehicle's journey.

It is known to refuel aircraft powered by combustible fuels in flight to increase the length of a sortie. There is a need to provide a similar means for recharging battery-powered aircraft, which despite the aircraft-type being well-known and well-used has not been satisfied.

SUMMARY

According to a first aspect of the present invention, there is provided a charging apparatus for charging a battery of an aircraft in flight, comprising: a main body; a wire coil; an energy storage device for generating an electric current in the wire coil; and a ferromagnetic core proximate to a surface of the main body, wherein the wire coil is wrapped around the ferromagnetic core.

Advantageously, the charging apparatus can be used to recharge a battery-powered vehicle in flight, thereby allowing the battery-powered vehicle to engage in longer sorties without having to land to have its battery recharged or replaced.

The charging apparatus may comprise coupling means for releasably coupling an aircraft to the main body in flight.

The aircraft may be a spacecraft undertaking a space flight.

The charging apparatus may comprise guidance means for guiding an aircraft to the charging apparatus, such that a wire coil of the aircraft can be aligned with the surface of the main body proximate to the ferromagnetic core.

The energy storage device may be a battery, and the charging apparatus may further comprise a power invertor coupled to the battery for generating an alternating current in the wire coil.

The ferromagnetic core may be an iron core. The ferromagnetic core may be a cobalt, magnetite, or nickel core.] The main body may comprise a protrusion extending into the ambient airflow, at least part of the ferromagnetic core being disposed inside the protrusion.

According to a second aspect of the present invention, there is provided a pod for coupling to an aircraft, comprising: an electrical cable extending from a rear end of the pod; and the charging apparatus according to the preceding aspect, wherein one end of the electrical cable is coupled to the energy storage means and the other end comprises the wire coil wrapped around the ferromagnetic core.

Advantageously, the pod can be retrofitted to existing aircraft to enable them to charge the batteries of other aircraft in flight.

According to a third aspect of the present invention, there is provided a charging aircraft comprising the charging apparatus according to the first aspect, or the pod according to the second aspect.

The charging aircraft may be an unmanned aerial vehicle. Alternatively, the charging aircraft may be a manned aircraft. The charging aircraft may be a spacecraft. The charging aircraft may be a multicopter. Alternatively, the charging aircraft may be a fixed-wing aircraft.

The charging aircraft may comprise a controller for determining a remaining energy level of the energy storage means, and, if the remaining energy level is less than a minimum threshold, directing the charging aircraft to land.

The charging aircraft may comprise a motor for generating thrust, and first 5 and second energy storage means, wherein the first energy storage means is for driving the motor and the second energy storage means is for powering the charging coil.

According to a fourth aspect of the present invention, there is provided an aircraft comprising: a main body; at least one motor for generating thrust; a rechargeable battery coupled to a coiled electrical wire, the electrical wire arranged proximate to the surface of the main body such that when it comes into proximity with a varying magnetic field generated by a charging apparatus, an electrical current is induced in the electrical wire to charge the rechargeable battery.

The aircraft may be a manned aircraft. Alternatively, the aircraft may be an unmanned aircraft. The aircraft may be spacecraft.

The aircraft may comprise a receptacle for receiving a protrusion from a charging apparatus according to the first aspect, wherein the coil is wrapped around the wall of the receptacle.

The aircraft may comprise a controller configured to determine a capacity of the rechargeable battery, and if the capacity is below a threshold, locate and fly towards a charging apparatus.

The aircraft may comprise a user input.

The aircraft may comprise a controller configured to determine when an electrical current is being induced in the coiled electrical wire. The controller may be arranged to transmit an indication to the operator of the aircraft. The indication may be audible, visual and/or haptic. Where the aircraft is operated by artificial intelligence, the indication may be the activation of a software subroutine, which causes the aircraft to maintain its position relative to the charging aircraft. The aircraft may comprise a haptic feedback mechanism to indicate to the operator when an electrical current is being induced in the coiled electrical wire. The aircraft may be configured to maintain its position relative to the charging apparatus when the controller determines an electrical current is being induced in the coiled wire. This tends to ensure consistent charging of the aircraft's battery.

The aircraft may be an unmanned aircraft. Alternatively, the aircraft may be a manned aircraft. The aircraft may be a spacecraft.

According to a fifth aspect of the present invention, there is provided a system for charging a battery of an aircraft in flight, the system comprising: the aircraft according to the fourth aspect; and the charging aircraft according to the third aspect, wherein the aircraft and charging aircraft are arranged such that when the aircraft and charging aircraft come into proximity with each other an electrical current is induced in the electrical wire of the aircraft to charge the rechargeable battery.

It will be appreciated that features described in relation to one aspect of the present disclosure can be incorporated into other aspects of the present disclosure.

For example, an apparatus of the disclosure can incorporate any of the features described in this disclosure with reference to a method, and vice versa. Moreover, additional embodiments and aspects will be apparent from the following description, drawings, and claims. As can be appreciated from the foregoing and following description, each and every feature described herein, and each and every combination of two or more of such features, and each and every combination of one or more values defining a range, are included within the present disclosure provided that the features included in such a combination are not mutually inconsistent.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will now be described by way of example only with reference to the figures, in which: Figure 1 shows perspective view of a system for charging a battery-powered aircraft according to embodiments; Figure 2 is a schematic drawing of a charging aircraft and a battery-powered aircraft that requires recharging according to embodiments; and Figure 3 is a schematic drawing of system for charging a battery-powered aircraft battery according to embodiments.

DETAILED DESCRIPTION

Generally, the embodiments described herein relate to an apparatus for charging an aircraft in flight. The apparatus includes an inductive charging device that generates a magnetic field. Battery-powered aircraft are provided with a wire coil in which an electric current is induced to charge a rechargeable battery when it is positioned appropriately within the generated magnetic field. The apparatus may be installed within an aircraft, or may be attached to an aircraft. Herein, "flight" encompasses "space flight".

A charging system 10 including a battery-powered aircraft 100 and a charging aircraft 200 is shown in Figure 1. Here, the battery-powered aircraft 100 is an unmanned aircraft, with a multicopter (i.e. specifically a quadcopter) configuration.

However, in alternative embodiments, the battery-powered aircraft 100 is a manned aircraft. The battery-powered aircraft 100 may take an alternative configuration; for example, it may be a fixed-wing aircraft, an airship or a helicopter. The battery-powered aircraft 100 may be a spacecraft. The term "battery-powered" includes hybrid power.

The battery-powered aircraft 100 includes a main body 102. The main body 102 is, for example, a fuselage. Propulsion devices 103 are coupled externally to the main body 102. Here, the propulsion devices 103 include motors for driving rotor blades, where the rotor blades provide lift and thrust for the battery-powered aircraft 100. In alternative embodiments, for example where the battery-powered aircraft 100 is a fixed-wing aircraft, the propulsion device(s) 103 may be installed at least partially within the main body 102. The main body 102 is a container that protects flight control systems, an inductive charging system, and other components from damage. The main body 102 may be aerodynamically shaped.

In the illustrated embodiment, the main body 102 is provided with a receptacle 101 into which a protrusion that is part of a charging apparatus can be inserted temporarily. The receptacle 101 is a depression in the main body 102 of the aircraft 100.

The battery-powered aircraft 100 may be arranged to carry a payload, such as 30 a package for delivery, an observation system, or a weapon.

The charging aircraft 200 in this embodiment takes substantially the same form as the battery-powered aircraft 100. However, the configurations of the two aircraft 100, 200 may be different. For example, the battery-powered aircraft 100 may be a quadcopter as illustrated, while the charging aircraft 200 may be an airship or fixed-wing aircraft. In alternative embodiments, for example where the charging aircraft 200 is a fixed-wing aircraft, the propulsion device(s) 203 may be installed at least partially within the main body 202. The charging aircraft 200 may be a space craft.

The charging aircraft 200 has a main body 202 and at least one propulsion device 203. The main body 202 comprises a protrusion 201 extending into the airflow outside the main body 202. As illustrated, the protrusion 201 is arranged on the upper (i.e. dorsal) surface of the main body 202, i.e. facing away from the ground when the aircraft 200 is flying straight and level. This allows it to cooperate with a receptacle 101 on the lower (i.e. ventral) side of the battery-powered aircraft 100. However, in alternative embodiments, the protrusion 101 and receptacle 201 may take any position on their respective aircraft 100/200 that provides engagement of the pair without interference from the propulsion devices 102/203. The protrusion 201 is sized to fit inside a receptacle 101 on the battery-powered aircraft 100 (or vice versa).

The charging aircraft 200 may be configured to transport a large high capacity battery with which to charge other aircraft 100 in flight (that is, both aircraft 100, 200 are in flight while the charging system 10 is in use to charge the aircraft's 100 battery). The charging aircraft 200 may transport a plurality of batteries. Alternatively, the charging aircraft 200 may generate electricity for charging other aircraft 100 using an on-board generator, such as an electrical generator powered by combustion or chemical reaction.

The charging system 10 may include a coupling mechanism to temporarily secure (i.e. attach) the battery-powered aircraft 100 to the charging aircraft 200. For example, the coupling mechanism may include an electronically-actuated mechanical catch on one of the aircraft 100/200 for hooking on to a corresponding connection member present on the other one of the aircraft 100/200. Alternatively, the battery-powered aircraft 100 may include a magnetic metal plate, which is attracted to the magnetic field generated by the charging aircraft 200. The metal plate may be an electromagnet that can be selectively activated The metal plate may be a permanent magnet.

The charging system 10 may include a guidance apparatus for guiding the battery-powered aircraft 100 towards the charging aircraft 200. The guidance apparatus may be configured to align the battery-powered aircraft 100 with the charging aircraft 200 such that a current is induced in wiring in the battery-powered aircraft 100 to charge its battery. Examples of guidance systems can be found in granted patents GB3294629 and GB2538241.

A charging system 20 according to an alternative embodiment is illustrated in Figure 2. Here, the charging aircraft 200 includes an inductive charging apparatus, which is arranged wholly outside of the main body 202. The charging aircraft 200 is a fixed-wing aircraft, and here the main body 202 is the fuselage of the aircraft 200. The aircraft 200 comprises wing members 204 extending from the fuselage to provide lift in flight.

The aircraft 200 comprises a pod 205 coupled to a wing member 204 of the aircraft 200. The pod 205 is for housing the inductive charging apparatus, or at least a part thereof. The pod 205 may be attached to a hardpoint of the wing member 204, and so may be readily detachable and replaceable. Alternatively, the pod 205 may be integrally formed with the wing member 204. The pod 205 may be a nacelle. The pod 205 may be installed in a weapons bay of the aircraft 200.

The pod 205 is aerodynamically shaped to reduce drag in flight.

The pod 205 comprises a cable spool having a length of electrical cable 206 wrapped around it. In use, the cable 206 plays out, or extends, behind the aircraft 200. The cable 206 is drawn out into the airflow behind the aircraft 200 (i.e. the cable 206 is drawn out of the rear end of the pod 205, which is that end opposite that onto which airflow predominantly impinges when the aircraft 200 is moving). The cable 206 may be coated in a non-conductive sheath for protection.

One end of the cable 206 may be electrically coupled to the electrical system of the aircraft 200. In other words, the power source for the inductive charging apparatus may be, at least indirectly, the charging aircraft's 200 main engines.

Alternatively, the pod 205 may comprise a self-contained electrical power source, such as a battery or electrical generator.

The other end of the cable 206 extends into a secondary housing 208. The secondary housing 208 comprises a wire coil wrapped around an iron core, as will be explained with reference to Figure 3. As described with reference to Figure 1, the secondary housing 208 comprises a protrusion 201 for communicating with a receptacle 101 in the main body 102 of the battery-powered aircraft 100. The wire coil is electrically coupled to the power source by the cable 206.

A drogue 207 is used to stabilise the secondary housing 208 in flight, which tends to make coupling of the aircraft 100 easier. Further, the deployment of the drogue 207 may be used to draw the cable 206 out of the pod 205.

It would therefore be understood that, in this embodiment, an inductive charging device can be coupled to an aircraft 200 without significantly modifying the aircraft 200, in order to charge the battery of another aircraft 100 in flight.

The charging system 10 of Figure 1 will now be explained in more detail with reference to the system diagram of Figure 3.

The battery-powered aircraft 100 includes at least a controller 111, a rechargeable battery 109 and associated charging circuitry, and a propulsion device 103. The rechargeable battery 109 may, for example, be a Lithium Ion or a Lithium Ion or Sodium Ion battery. For non-autonomous operation, the aircraft 100 may also include a user input device 112. The user input device 112 may include a control column, where the aircraft 100 is manned. While illustrated as being directly coupled to the controller 111, this may not be the case; instead the user input device 112 may be remote from the main body 102 and therefore coupled to the controller 111 by way of wireless (e.g.) radio transceiver. In other words, the aircraft 100 may be remotely controlled/operated.

The aircraft 100 may also include an optical system for allowing a remote pilot to control the aircraft 100 visually.

The controller 111 may take any suitable form. For instance, it may be a microcontroller, plural microcontrollers, a processor, or plural processors.

The rechargeable battery 109 is coupled to a wire 113 forming a charging circuit. The wire 113 is wrapped in the form of a coil around the internal walls of the receptacle 101. A current is induced in the wire 113 to charge the battery 109, when the wire 113 interacts with a changing magnetic field. The more loops in the coil of wire 113, the greater the inductive effect and therefore greater the rate of charging The controller 111 may comprise a battery level sensor. The controller 111 may be arranged to detect the remaining capacity of the battery 109. If the current charge falls below threshold, the controller 111 may transmit a warning to a user, or automatically control the battery-powered aircraft 100 to fly towards a charging aircraft 200. If the battery capacity is full, the controller 111 may control the aircraft 100 to continue with its mission, or transmit a warning to the end user that the aircraft 100 is ready to leave the charging aircraft 200.

When the battery-powered aircraft 100 is appropriately positioned relative to the inductive charging apparatus, the controller (i.e. operator) of the battery-powered aircraft 100 and/or the charging aircraft 200 may be sent a warning (i.e. an indication).

This indicates to the operator that the battery 109 is being charged with the battery-powered aircraft 200 and charging aircraft 200 (or a charging apparatus thereof) in their present relative positions. Here, the controller may be a human operator, or may be a processor 111 executing stored programming where the aircraft 100/200 is autonomous. The aircraft 100 may be operated by artificial intelligence. The warning may be haptic, audible and/or visual, or alternatively may trigger a software subroutine to cause the controller 111 to control the battery-powered aircraft 100 to maintain its position relative to the charging aircraft 200. Where one or both of the aircraft 100/200 is autonomous, the warning may be a signal that executes a software subroutine. For example, when the protrusion 201 of the charging aircraft 100 is disposed within the receptacle 101 the battery-powered aircraft 100, a haptic device in a flight control input 112 provides feedback indicating as much to the operator. The controller 111 may be configured to detect when the battery 109 is being charged (i.e. when the battery-powered aircraft 100 and the inductive charging apparatus are appropriately positioned), which triggers the warning (i.e. indication) to be transmitted.

The charging aircraft 200 comprises a power source 209. The power source 209 is directly or indirectly coupled to a wire 213 in the form of a coil, such that it can provide that wire 213 with a varying electric field. The power source 209 may be an electrical generator, powered by internal combustion. In other words, the power source 209 may generate alternating current. Alternatively, the power source 209 may generate direct current. For example, the power source 209 may be a battery or a plurality of batteries. Where the power source 209 generates direct current, the charging circuit includes a power inverter 210 to provide the wire 213 with an alternating current.

The wire 213 is wrapped around a ferromagnetic core 214 so as to create a varying magnetic field. The ferromagnetic core 214 may be an iron core. Alternatively, the ferromagnetic core 214 may be made of cobalt, nickel, steel or an alloy thereof.

The charging aircraft 200 may include a first power source 209 for energising the wire 213, and a second power source for powering the propulsion device(s) 203. Alternatively, the power source 209 may power both the inductive charging apparatus and the propulsion device(s) 203.

The controller 211 may take any suitable form. For instance, it may be a microcontroller, plural microcontrollers, a processor, or plural processors.

The controller 211 may comprise a sensor for determining the amount of fuel, for example, battery capacity, remaining for the power source 209. In the case where the power source 209 drives both the propulsion device(s) 203 and the charging circuit, the aircraft 200 will require fuel in order to move to a suitable landing site.

Therefore, the controller 211 may be configured to detect when the remaining fuel supply (e.g. battery charge) has reached a minimum threshold. When that threshold is reached, the controller 211 may automatically land the aircraft 200 or send a warning to the operator.

For non-autonomous operation, the charging aircraft 200 may also include a user input device 212. The user input device 212 may include a control signal receiver for receiving a control input from a remote joystick or the like. Alternatively, the user input device 212 may include a control column, where the charging aircraft 200 is manned.

The charging aircraft 200 may also include an optical system for allowing a remote pilot to control the aircraft 200 visually.

While as illustrated the charging aircraft 200 includes a protrusion 201 for aiding coupling of the battery-powered aircraft 100 and increasing the magnetic field strength present inside the battery-powered aircraft 100, the charging aircraft 200 may instead be provided with a planar "charging pad" area, with the primary coil 213 located proximate to that area. Here, the battery-powered aircraft 100 has a planar region, with the secondary coil 113 arranged in proximity to that planar region.

Where, in the foregoing description, integers or elements are mentioned that have known, obvious, or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present disclosure, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the disclosure that are described as optional do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, while of possible benefit in some embodiments of the disclosure, may not be desirable, and can therefore be absent, in other embodiments

Claims

CLAIMS1. A charging apparatus for charging a battery of an aircraft in flight, comprising: a main body; a wire coil; an energy storage device for generating an electric current in the wire coil; and a ferromagnetic core proximate to a surface of the main body, wherein the wire coil is wrapped around the ferromagnetic core.
2. The charging apparatus according to claim 1, comprising coupling means for releasably coupling an aircraft to the main body in flight.
3. The charging apparatus according to claim 1 or claim 2, comprising guidance means for guiding an aircraft to the charging apparatus, such that a wire coil of the aircraft can be aligned with the surface of the main body proximate to the ferromagnetic core.
4. The charging apparatus according to any one of the preceding claims, wherein the energy storage device is a battery, and wherein the charging apparatus further comprises a power invertor coupled to the battery for generating an alternating current in the wire coil.
5. The charging apparatus according to any one of the preceding claims, 25 wherein the ferromagnetic core is an iron core.
6. The charging apparatus according to any one of the preceding claims, wherein the main body comprises a protrusion extending into the ambient airflow, at least part of the ferromagnetic core being disposed inside the protrusion.
7 A pod for coupling to an aircraft, comprising: an electrical cable extending from a rear end of the pod; and the charging apparatus according to any one of the preceding claims, wherein one end of the electrical cable is coupled to the energy storage means and the other end comprises the wire coil wrapped around the ferromagnetic core.
8. A charging aircraft comprising the charging apparatus according to any one of claims 1 to 6, or the pod according to claim 7.
9. The charging aircraft according to claim 8, wherein the charging aircraft is an unmanned aerial vehicle.
10. The charging aircraft according to claim 8 or claim 9, wherein the aircraft is a spacecraft.
11. The charging aircraft according to claim 8, claim 9 or claim 10, comprising a controller for determining a remaining energy level of the energy storage means, and, if the remaining energy level is less than a minimum threshold, directing the charging aircraft to land.
12. The charging aircraft according to claim 8, claim 9 or claim 10, comprising a motor for generating thrust, and first and second energy storage means, wherein the first energy storage means is for driving the motor and the second energy storage means is for powering the charging coil.
13. An aircraft comprising: a main body; at least one motor for generating thrust; a rechargeable battery coupled to a coiled electrical wire, the electrical wire arranged proximate to the surface of the main body such that when it comes into proximity with a varying magnetic field generated by a charging apparatus, an electrical current is induced in the electrical wire to charge the rechargeable battery.
14. The aircraft according to claim 13, comprising a receptacle for receiving a protrusion from a charging apparatus according to claim 6, wherein the coil is wrapped around the wall of the receptacle.
15. The aircraft according to claim 13 or claim 14, comprising a controller configured to determine a capacity of the rechargeable battery, and if the capacity is below a threshold, locate and fly towards a charging apparatus.
16. The aircraft according to any one of claims 13 to 15, comprising a controller configured to determine when an electrical current is being induced in the coiled electrical wire.
17. The aircraft according to claim 16, comprising a haptic feedback mechanism to indicate to the operator when an electrical current is being induced in the coiled electrical wire.
18. The aircraft according to claim 16, wherein the aircraft is configured to maintain its position relative to the charging apparatus when the controller determines an electrical current is being induced in the coiled wire.
19. The aircraft according to any one of claims 13 to 18, wherein the aircraft is an unmanned aerial vehicle.
20. The aircraft according to any one of claims 13 to 19, wherein the aircraft is a 25 spacecraft.
21. A system for charging a battery of an aircraft in flight, the system comprising: the aircraft according to any one of claims 13 to 20; and the charging aircraft according to any one of claims 8 to 12, wherein the aircraft and charging aircraft are arranged such that when the aircraft and charging aircraft come into proximity with each other an electrical current is induced in the electrical wire of the aircraft to charge the rechargeable battery.