Wireless power transmission for autonomous vehicles

Abstract

The invention relates to a system comprising a photovoltaic receiver (4) on board a drone (1) and a ground station (2) configured to emit a monochromatic light beam (F1) towards the receiver (4) in order to power an electric battery (3) of the drone (1), in particular when the drone (1) is moving relative to the station (2).

Description

Wireless power transmission for autonomous vehicles

[0001] The present invention relates to the field of vehicle power supply, in particular using on-board power sources comprising an energy storage device such as an electric accumulator battery.

[0002] The invention is of particular interest for autonomous vehicles such as unmanned aircraft, known as "drones", or by the acronyms "RPAS" (from the English "RemotelyPilotedAircraft System"), "UAV" (from the English "UnmannedAerialVehicle"), "UAS" (from the English "UnmannedAir System") or "RPA" (from the English "RemotelyPilotedAircraft").

[0003] The invention relates more specifically to an energy transmission system to power an energy storage device of such a vehicle. State of the art

[0004] Improving the energy autonomy of autonomous vehicles, and in particular drones, is a key objective.

[0005] A drone can typically be equipped with an energy storage device such as an electric battery whose capacity is inherently limited.

[0006] When a drone's battery life is insufficient to continue a mission or begin a new one, it's common practice to recharge the battery on the ground or replace it. Replacing a battery requires having a spare. Furthermore, accessing a drone's battery can be difficult due to safety regulations.

[0007] Another known solution is to replace the drone itself to continue the mission or carry out a new one.

[0008] When the drone performs a mission near its docking station, for example during a surveillance mission, it is known to power the drone via wired connection.

[0009] There is a need to improve traditional powering techniques for autonomous vehicles, particularly drones, in order to increase their flight time.

[0010] The invention relates to a system for powering an energy storage device in a vehicle.

[0011] Without limitation, the vehicle may be an autonomous vehicle such as an unmanned aircraft or a robot.

[0012] The system of the invention comprises: a receiver intended to be carried in the vehicle, the receiver comprising at least one photovoltaic cell configured to produce electrical energy under the action of a light beam in order to power the energy storage device, and an installation comprising a transmitter configured to emit a monochromatic light beam in the direction of the receiver.

[0013] The system of the invention makes it possible to transmit energy remotely, without contact, in a far field.

[0014] The invention thus makes it possible to remedy the disadvantages of the prior art solutions described above, by improving the energy autonomy of autonomous vehicles at a reduced cost.

[0015] In the case of an unmanned aircraft type vehicle, the system of the invention allows the aircraft's energy storage device to be continuously recharged when it is on the ground in a waiting phase, or when the aircraft is hovering, for example during a surveillance mission, or when the aircraft is moving, particularly during landing and takeoff phases which are particularly energy-intensive, especially for a vertical takeoff and landing aircraft.

[0016] Preferably, the emitter can be configured to emit a light beam in the infrared or near-infrared region of the electromagnetic spectrum.

[0017] In one embodiment, the emitter is configured to emit a light beam having a wavelength between 800 nm and 1500 nm.

[0018] As an example, the emitter can be configured to emit a light beam with a wavelength of 976 nm.

[0019] In one embodiment, the emitter is configured to emit a light beam having a power greater than or equal to 20 W.

[0020] By way of non-limitation, the emitter can for example be configured to emit a light beam with a power greater than or equal to 100 W or 200 W or 300 W or 400 W or 500 W or 600 W or 700 W or 800 W or 900 W.

[0021] Without limitation, the emitter can be configured to emit a light beam with a power less than or equal to 1000 W.

[0022] However, a power output greater than 1000 W can be used.

[0023] In one embodiment, at least one photovoltaic cell comprises a semiconductor material having an alloy of copper, indium, gallium and selenium.

[0024] In one embodiment, the installation includes a tracking device configured to track a movement of the receiver and / or the vehicle relative to the installation.

[0025] In one embodiment, the tracking device includes means adapted to detect a position and / or movement of the receiver based on data provided by a satellite geo-positioning receiver module equipping the vehicle.

[0026] Alternatively or complementarily, the tracking device may include means adapted to detect a position and / or a movement of the receiver as a function of a power of the light beam detected by the receiver.

[0027] For this purpose, the receiver may include a means configured to detect the power of a light beam to which it is subjected.

[0028] In one embodiment, the installation includes a control module configured to modify one or more parameters of the beam emitted by the transmitter as a function of a displacement of the receiver detected by the tracking device or estimated by any other means.

[0029] Without limitation, these parameters can be chosen from a list including beam divergence and orientation.

[0030] In one embodiment, the installation includes a receiving structure capable of receiving the vehicle.

[0031] Without limitation, the receiving structure may form a platform or more generally a structure configured to cooperate with one or more parts of the vehicle in order to support the vehicle.

[0032] In one embodiment, the installation includes a cooling unit.

[0033] Without limitation, the cooling unit may include one or more fans and / or one or more ducts configured to receive a coolant.

[0034] In one embodiment, the cooling unit is configured to be able to lower the receiver temperature when the vehicle is received by the receiving structure.

[0035] Alternatively or in addition, the cooling unit can be configured to lower the temperature of the emitter and / or one or more parts of the installation.

[0036] The invention also relates to an assembly comprising a vehicle and a system as defined above.

[0037] The vehicle in the assembly can be an unmanned aircraft or another vehicle, for example a robot.

[0038] In this document, the term "robot" refers to a device configured to perform one or more predetermined tasks or operations, particularly under the action of an automatic control system.

[0039] The robot can be, but not limited to, an industrial robot, for example to carry out handling and / or assembly operations, a scientific robot, or even a domestic robot.

[0040] Without limitation, the robot can be configured to move by land and / or air and / or sea.

[0041] In the context of the invention, the system receiver is preferably mounted in the vehicle.

[0042] The invention also relates to a method of supplying an energy storage device of a vehicle, in particular a vehicle as defined above, using such a system.

[0043] The method includes emitting, using said emitter, a monochromatic light beam towards said receiver, which is preferably mounted in the vehicle.

[0044] The process can be implemented when the vehicle is in a fixed position relative to the installation or when it is moving relative to the installation.

[0045] For example, when the vehicle is an aircraft, the process can be implemented when the aircraft is received by the facility's receiving structure and / or when the aircraft is hovering and / or when the aircraft is in the landing phase and / or in the takeoff phase and / or in another phase of flight.

[0046] The invention also relates to a computer program comprising executable instructions which, when executed by a computer device, cause the system to implement the process of the invention.

[0047] In one embodiment, the program includes executable instructions which, when executed by a computer device, cause the aforementioned tracking device to follow a movement of said receiver.

[0048] The invention also relates to a computer-readable medium on which the computer program defined above is recorded.

[0049] In general, the invention makes it possible to provide an efficient power transmission system at a reduced manufacturing cost, to reduce the mass of the vehicle and to increase its payload.

[0050] The invention can be implemented in many sectors, including service sectors or missions carried out by drones.

[0051] Other advantages and features of the invention will become apparent from the detailed, non-limiting description that follows. Brief description of the figures

[0052] The detailed description that follows refers to the attached drawings on which: a is a schematic view of a drone in flight and of an installation emitting a light beam towards a photovoltaic receiver on board the drone so as to power an energy storage device on the drone; a is a schematic view of the drone and the installation of the light beam powering the energy storage device in a configuration in which the drone is placed on the installation.

[0053] Common references are used across the different figures to designate identical or analogous elements. Detailed description of implementation methods

[0054] Lamontre schematically represents an assembly consisting of a vehicle 1 and an installation 2 according to the invention.

[0055] In the non-limiting embodiment of the, vehicle 1 is an unmanned aircraft, also called a drone, while installation 2 forms a station intended to remain on the ground during its use.

[0056] In this example, drone 1 is equipped with an energy storage device 3 of the type of electric accumulator battery and a receiver 4 comprising at least one photovoltaic cell.

[0057] As is known, the photovoltaic cell 4 is configured to produce electrical energy under the action of a light beam in order to power the device 3 to store the energy enabling the drone 1 to carry out flight missions.

[0058] Without limitation, cell 4 in this example comprises a semiconductor material having an alloy of copper, indium, gallium and selenium, and is adapted to convert into electrical energy a light beam having a predetermined wavelength.

[0059] In this particular example, receiver 4 is configured to detect a beam whose predetermined wavelength is equal to 976 nm, with a sensitivity that can be between -30 dBm and -40 dBm.

[0060] As an example, receiver 4 can be configured to deliver a continuous output voltage between 20 V and 30 V and the capacity of storage device 3 can be between 5000 mAh and 35000 mAh.

[0061] In one embodiment, the receiver 4 is connected to a maximum power point tracking system (not shown) in order to optimize the efficiency of the energy conversion.

[0062] In one embodiment, the drone 1 carries a cooling unit (not shown) configured to cool the cell 4 during its operation, particularly during flight.

[0063] This cooling unit may include one or more heat sinks configured to dissipate a thermal load that can typically reach up to 150 W.

[0064] In this example, drone 1 is also equipped with a satellite geo-positioning receiving module (not shown), also called a GPS module.

[0065] In the embodiment of the, the installation 2 forms a ground station for the drone 1.

[0066] In this non-limiting example, the installation 2 includes a drone 1 reception platform 10, also called a receiving structure, a transmitter 11, a transmitter 11 control module 12, a cooling unit 13, a tracking device (not shown), and a power supply module 14.

[0067] The receiving structure 10 is configured to receive the drone 1, as illustrated in the figure, for example before and / or after a flight mission.

[0068] The emitter 11 includes a light beam generator and optical components configured to focus the beam formed by the generator.

[0069] In this non-limiting example, the emitter 11 is configured to emit a temporally coherent light beam having a wavelength of 976 nm and a power of 500 W, i.e. a high-power laser beam in the near-infrared region of the electromagnetic spectrum.

[0070] Without limitation, the optical components of the emitter 11 may include one or more lenses having a focal length between 50 mm and 100 mm and one or more collimators defining a divergence angle of less than 1 mrad.

[0071] The control module 12 is configured to be able to modify one or more parameters of the beam emitted by the transmitter 11, in particular to modify the beam divergence and / or the beam orientation.

[0072] For this purpose, the emitter 11 in this example includes an optical adaptation system which may, for example, include lenses of different focal lengths. Alternatively or complementarily, the emitter 11 may include a mechanism configured to modify the orientation of one or more mirrors onto which the beam is reflected.

[0073] With reference to the, module 14 is configured to supply electrical power to installation 2 and, more specifically, to emitter 11, control module 12 and cooling unit 13.

[0074] The power supply module 14 may include a battery of electrical accumulators and / or means of connection to a power source which may be formed by a distribution network and / or a vehicle alternator.

[0075] Module 14 may also include one or more components configured to convert an alternating input current, which typically has a voltage between 120 V and 240 V, into direct current with a voltage that typically has a voltage between 300 V and 400 V, and one or more components configured to lower this voltage to a value that typically has a voltage of 12 V, 24 V or 48 V.

[0076] The cooling unit 13 of the installation 2 is in this example configured to lower the temperature of the emitter 11 and more generally of the installation 2 when the emitter 11 emits a beam.

[0077] The cooling unit 13 may include one or more fans and / or one or more conduits through which a coolant circulates, in order to dissipate a thermal load that can typically be up to 200 W.

[0078] The cooling unit 13 can also be configured to lower the temperature of the receiver 4 when the drone 1 is received by the structure 10 of the installation 2.

[0079] The installation 2 tracking device in this example includes means adapted to detect a position and / or a movement of the receiver 4 based on data provided by the GPS module equipping the drone 1 and / or a power of the light beam detected by the receiver 4.

[0080] In this example, the tracking device incorporates an artificial intelligence model trained to detect drone 1 and / or receiver 4 in images.

[0081] Installation 2 in this example is equipped with a computer device and a computer-readable medium on which is recorded a computer program which includes executable instructions which, when executed by the computer device, allow the installation 2 to be controlled and, in this particular example, the tracking device.

[0082] According to the invention, the installation 2 and the receiver 4 on board the drone 1 form a power supply system for the energy storage device 3 of the drone 1.

[0083] In operation, a monochromatic light beam F1 / F2 is emitted by the transmitter 11 of the installation 2 towards the receiver 4 on board the drone 1, so that the receiver 4 can convert this beam into electrical energy to power the device 3.

[0084] According to a first type of implementation represented in the figure, the beam F1 is emitted when drone 1 is at a distance from installation 2, in this example while drone 1 is in flight.

[0085] When drone 1 is moving relative to installation 2, for example during landing or takeoff, the tracking device of installation 2 can be implemented to follow the movement of receiver 4 relative to installation 2. The control module 12 can modify one or more parameters of beam F1 according to the movement detected by the tracking device, in order to continue pointing beam F1 at receiver 4 when drone 1 is moving relative to installation 2.

[0086] As a non-limiting example, tracking can be achieved using drone 1 position data provided by the GPS module and implementing the artificial intelligence model to detect drone 1 in an image, zoom in on drone 1, detect receiver 4 in an image of the thus enlarged drone 1, zoom in on receiver 4, and implement a feedback loop to ensure tracking.

[0087] In this example, beam F1 is considered to be correctly pointing at receiver 4 when receiver 4 detects a beam power that exceeds a predetermined threshold. For reference, this predetermined threshold could be 10 W.

[0088] The system of the invention thus makes it possible to transmit electromagnetic energy in a far field and continuously, in particular without wired connection and in the absence of physical contact between the installation 2 and the drone 1.

[0089] According to a second type of implementation represented in the figure, the F2 beam can be emitted when the drone 1 is placed on the receiving structure 10 of the installation 2.

[0090] The system of the invention therefore also makes it possible to recharge the battery 3 of the drone 1 on the ground, when the drone 1 is placed on the structure 10 of the installation 2, by transmission of energy through the air.

[0091] The preceding description is of course not limiting, the transmitter-receiver system of the invention and / or the vehicle carrying the receiver and / or the installation comprising the transmitter may have many variations compared to the embodiment of figures 1 and 2.

[0092] For example, the receiver of the system of the invention may comprise one or more photovoltaic cells made of an alloy different from that described above. More generally, the receiver may comprise several photovoltaic cells forming a photovoltaic panel, the surface area of ​​which may be determined, in particular, according to the vehicle carrying this panel.

[0093] As another example, the transmitter-receiver system can be adapted for a wavelength other than 976 nm and / or a power other than 500 W. Without limitation, the wavelength can be chosen from a range of 800 nm to 1500 nm, or more generally in the infrared or near-infrared region of the electromagnetic spectrum. The system can also be configured so that the power of the emitted beam is greater than or equal to 20 W, for example, greater than 100 W, and / or less than or equal to 1000 W.

[0094] Furthermore, the receiver of the system of the invention can be fitted to another type of aircraft or, more generally, to an autonomous vehicle, for example, an industrial or domestic robot, and / or the transmitter of the system of the invention can be fitted to an installation that is not intended to be installed on the ground and / or to remain static. For example, the transmitter can be part of an installation mounted on another vehicle, which may be a motor vehicle or an aircraft.

[0095] In one embodiment, not shown, the invention can be implemented while the installation including the transmitter is moving relative to a terrestrial reference frame, the installation may or may not be moving relative to the vehicle carrying the receiver.

Claims

System intended to power an energy storage device (3) of a vehicle (1) such as an unmanned aircraft or a robot, the system comprising: a receiver (4) intended to be carried in the vehicle (1), the receiver (4) comprising at least one photovoltaic cell configured to produce electrical energy under the action of a light beam in order to power the energy storage device (3), and an installation (2) comprising a transmitter (11) configured to emit a monochromatic light beam (F1, F2) in the direction of the receiver (4). System according to claim 1, wherein: the emitter (11) is configured to emit a light beam (F1, F2) having a wavelength between 800 nm and 1500 nm, for example 976 nm, and / or a power greater than or equal to 20 W, for example 100 W or 1000 W, and / or at least one photovoltaic cell comprises a semiconductor material having an alloy of copper, indium, gallium and selenium. System according to claim 1 or 2, wherein the installation (2) comprises a tracking device configured to track a displacement of the receiver (4) relative to the installation (2). System according to claim 3, wherein the tracking device includes means adapted to detect a position and / or a displacement of the receiver (4) as a function of data provided by a satellite geo-positioning receiver module equipping the vehicle (1) and / or as a function of a light beam power detected by the receiver (4). System according to claim 3 or 4, wherein the installation (2) comprises a control module (12) configured to modify one or more parameters of the beam (F1, F2) emitted by the transmitter (11) as a function of a displacement of the receiver (4) detected by the tracking device, said parameters being able to be selected from a list including the divergence of the beam (F1, F2) and its orientation. System according to any one of claims 1 to 5, wherein the installation (2) comprises a receiving structure (10) capable of receiving the vehicle (1) and a cooling element (13) configured to be able to lower the temperature of the receiver (4) when the vehicle (1) is received by the receiving structure (10), the cooling element (13) comprising, for example, one or more fans and / or one or more conduits configured to receive a coolant. Assembly comprising a vehicle (1), for example an unmanned aircraft or a robot, and a system according to any one of claims 1 to 6, said receiver (4) of the system being carried in the vehicle (1). Method of supplying an energy storage device (3) of a vehicle (1) such as an unmanned aircraft or a robot, using a system according to any one of claims 1 to 6, comprising emitting, using said emitter (11), a monochromatic light beam (F1, F2) towards said receiver (4) mounted in the vehicle (1). Computer program comprising executable instructions which, when executed by a computing device, cause the tracking device of a system according to any one of claims 3 to 5 to follow a displacement of said receiver (4). Computer-readable medium on which the computer program of claim 9 is recorded.

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