Wireless power supply system

Abstract

To provide a wireless power supply system capable of suppressing reduction in power supply efficiency caused by variations of a peripheral environment of a power transmission device.SOLUTION: A wireless power supply system supplies power from a power transmission device 30 to a drone 20 via wireless power supply. The drone 20 includes a power reception unit 22 for receiving power transmitted from the power transmission device 30. The power transmission device 30 includes a power transmission antenna 31, a detection unit 33, and a control unit 32. The power transmission antenna 31 transmits a power transmission signal to the drone 20. The detection unit 33 detects a position of the drone 20 and a position of an obstacle around the power transmission device 30. The control unit 32 controls actuation of the power transmission antenna 31 on the basis of the position of the drone 20 and the position of the obstacle that are detected by the detection unit 33.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless power feeding system that feeds power from a power transmitting device to a mobile object through wireless power feeding. [Background technology]

[0002] Patent Document 1 proposes a wireless power supply system that supplies power to an unmanned aerial vehicle (so-called drone) by wireless power supply from a power transmission device installed on the ground. In this wireless power supply system, the position of the drone is acquired by a GPS (Global Positioning System). The position of the power transmission device is registered in advance. Then, the operation of the power transmission device is controlled based on the position of the drone and the position of the power transmission device, thereby wirelessly supplying power from the power transmission device to the drone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-162391 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the surrounding environment of the power transmission device may change. For example, if the power transmission device is installed in a mountainous area, there is a risk that trees may grow around the power transmission device or fall. Also, if the power transmission device is installed in an urban area (or its suburbs), high-rise buildings and other structures may be constructed around the power transmission device.

[0005] Such changes in the surrounding environment of the power transmitting device cannot be ascertained from the drone's position information acquired by GPS or the preregistered position information of the power transmitting device. Therefore, in the wireless power supply system described in Patent Document 1, when the surrounding environment of the power transmitting device changes, a part between the power transmitting device and the drone may be blocked by an obstacle, which may result in a decrease in power supply efficiency.

[0006] The above-mentioned inconveniences caused by changes in the surrounding environment of the power transmitting device may also occur in a wireless power feeding system that supplies power to moving bodies (such as ships and vehicles) other than aircraft through wireless power feeding. [Means for solving the problem]

[0007] A wireless power supply system for solving the above problem is a wireless power supply system that supplies power to a mobile body from a power transmission device via wireless power supply, wherein the mobile body has a power receiving unit that receives power transmitted from the power transmission device, and the power transmission device has a power transmission unit that transmits power to the mobile body, a mobile body detection unit that detects the position of the mobile body, a surrounding detection unit that detects the position of an obstacle in the vicinity of the power transmission device, and a control unit that controls operation of the power transmission unit based on the position of the mobile body detected by the mobile body detection unit and the position of the obstacle detected by the surrounding detection unit.

[0008] According to the above configuration, when transmitting power from the power transmission unit, the surrounding environment of the power transmission device (such as the arrangement of structures, the arrangement of natural objects, and the topography) can be detected, including changes in the surrounding environment (such as overgrown trees and fallen trees). This makes it possible to grasp the actual situation of the surrounding environment of the power transmission device. Therefore, it is possible to execute operation control of the power transmission unit according to the position of the moving body while grasping the positions of obstacles that may impede power transmission from the power transmission unit. This makes it possible to select an execution mode that enables highly efficient wireless power transmission in accordance with the change, and execute power transmission from the power transmission unit, even if the surrounding environment of the power transmission device changes. According to the above configuration, it is thus possible to suppress a decrease in power supply efficiency caused by changes in the surrounding environment of the power transmission device.

[0009] In the above wireless power supply system, the power transmission devices are arranged at intervals and have a communication unit that performs data communication with the other power transmission devices, and the position of the moving body detected by the moving body detection unit is shared among the multiple power transmission devices through data communication by the communication unit.

[0010] According to the above configuration, each power transmission device can prepare for future power transmission to the moving object based on the location information of the moving object obtained from the other power transmission devices through data communication. Since the multiple power transmission devices can be linked in this way, wireless power supply to the moving object using the power transmission devices can be smoothly performed.

[0011] In the wireless power supply system, the power transmitting device includes a route estimating unit that estimates a moving route of the moving object based on a position of the moving object that is shared. According to the above configuration, each power transmission device can estimate the moving route of the moving object based on the position information acquired from the other power transmission devices, and prepare for the subsequent transmission of power to the moving object.

[0012] In the wireless power feeding system, the power transmitting device includes a passing period estimation unit configured to estimate a period during which the moving object passes through a range in which power can be transmitted by the power transmitting unit, based on a position of the moving object that is shared.

[0013] According to the above configuration, each power transmission device can estimate a period during which a moving object will pass through an area in which power can be transmitted, based on location information acquired from other power transmission devices, and prepare for the subsequent transmission of power to the moving object.

[0014] In the above wireless power supply system, the power transmission device has a mode selection unit that selects a normal mode when the position of the moving body is detected by the moving body detection unit, and selects a power saving mode that operates with less power than when the normal mode is selected when the position of the moving body is not detected by the moving body detection unit.

[0015] According to the above configuration, when a moving body is not detected by the power transmitting device, i.e., when power transmission from the power transmitting device to the moving body is not necessary, the power transmitting device can be operated in a power saving mode while maintaining necessary functions by restricting the power supply to the power transmitting unit, etc. Moreover, when a moving body is detected by the power transmitting device, i.e., when there is a possibility of transmitting power to the moving body, the restriction on the power supply can be lifted and the power transmitting device can be operated in a normal mode. Effect of the Invention

[0016] According to the present invention, it is possible to suppress a decrease in power supply efficiency caused by a change in the surrounding environment of the power transmitting device. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic configuration diagram of a wireless power supply system according to a first embodiment. [Diagram 2] 1 is a schematic diagram showing an arrangement of a plurality of power transmitting devices; [Diagram 3] 1 is a schematic diagram showing the movement of a drone as seen from a power transmission device. [Figure 4] FIG. 2 is an explanatory diagram for explaining an operation of the wireless power supply system according to the first embodiment. [Diagram 5] 1 is an explanatory diagram for explaining an example of a change in the surrounding environment of a power transmitting device; [Figure 6] 11 is an explanatory diagram for explaining another example of a change in the surrounding environment of the power transmitting device. FIG. [Figure 7] 5 is a flowchart showing an execution procedure of a power transmission control process according to the first embodiment. [Figure 8] FIG. 11 is an explanatory diagram for explaining an operation of the wireless power supply system according to the second embodiment. [Figure 9] 1 is a schematic diagram of the detection range when a drone is not entering, as viewed from the power transmission device. [Figure 10] 1 is a schematic diagram of the detection range when a drone enters, as viewed from a power transmission device. [Figure 11]A simplified diagram of a drone stopped at a power supply position as seen from a power transmission device. [Figure 12] A simplified diagram of a drone viewed from a power transmission device just before it leaves the detection range. [Figure 13] 10 is a flowchart showing an execution procedure of a power transmission control process according to a second embodiment. [Figure 14] 13 is a schematic diagram showing an arrangement of power transmitting devices in a wireless power feeding system according to another embodiment, together with the movement of an unmanned small boat to be fed with power. [Figure 15] 13 is a schematic diagram showing an arrangement of power transmitting devices in a wireless power feeding system according to another embodiment, together with a state of movement of an unmanned small vehicle to be fed with power. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] (First embodiment) A first embodiment of a wireless power feeding system will be described below with reference to Fig. 1 to Fig. 7. The wireless power feeding system of this embodiment feeds power from a power transmitting device to an unmanned aerial vehicle (a so-called drone) as a moving body through wireless power feeding.

[0019] <Drone 20> As shown in Figs. 1 and 2, the drone 20 of this embodiment is a balloon type having a balloon section 201 and an operating section 202. The balloon section 201 is filled with helium gas that generates buoyancy. The operating section 202 has a propeller that generates a propulsive force for movement and a control device that controls the rotation speed and direction of the propeller. The drone 20 is assumed to be used to deliver packages in depopulated areas such as mountainous regions.

[0020] As shown in FIG. 1, the drone 20 has a storage battery 21, a power receiving unit 22, and a control unit 23. The storage battery 21 is a secondary battery. The storage battery 21 is used as a power source for the drone 20.

[0021] The power receiving unit 22 constitutes a part that receives power transmitted from the power transmitting device 30 by wireless power supply using radio waves (microwaves). The power receiving unit 22 has a power receiving antenna 221 and a conversion unit 222. The power receiving antenna 221 is used for various communications with the power transmitting device 30. More specifically, the power receiving antenna 221 is used for receiving a power transmission signal transmitted from the power transmitting device 30 and for transmitting and receiving various data related to wireless communications with the power transmitting device 30. The conversion unit 222 constitutes a part that converts the power transmission signal received by the power receiving antenna 221 into DC power. The conversion unit 222 has a rectifier circuit and a transformer circuit. In this embodiment, the DC power converted by the conversion unit 222 is supplied to the storage battery 21, thereby charging the storage battery 21.

[0022] The control unit 23 may be, for example, a microcontroller unit. The control unit 23 includes a processor and a storage unit. The storage unit includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The control unit 23 executes various controls related to the operation control of the drone 20. The control unit 23 controls the power receiving antenna 221. This allows the control unit 23 to receive a power transmission signal transmitted from the power transmitting device 30 and to transmit and receive a data signal to and from the power transmitting device 30. The control unit 23 executes operation control of the operating unit 202. This allows the rotation speed and orientation of the propeller to be controlled.

[0023] In this embodiment, before the departure of the drone 20, a basic flight route RTb to the destination is stored in the control unit 23 of the drone 20. The control unit 23 basically executes the operation control of the operation unit 202 so that the drone 20 moves along the basic flight route RTb.

[0024] <Power transmission device 30> The power transmitting device 30 includes a power transmitting antenna 31 , a control unit 32 , and a detection unit 33 . The power transmitting antenna 31 is used for various communications with the drone 20. The power transmitting antenna 31 is used for transmitting a power transmission signal and transmitting and receiving data through wireless communication. In this embodiment, the power transmitting antenna 31 corresponds to a power transmitting unit.

[0025] For example, a micro control unit is used as the control unit 32. The control unit 32 includes a processor and a storage unit. The storage unit includes a ROM and a RAM. The control unit 32 executes various controls related to communication with the drone 20. The control unit 32 controls the power transmission antenna 31 to transmit a data signal to the drone 20 and to receive a data signal transmitted by the drone 20. The control unit 32 converts power supplied from a power supply device (not shown) into a power transmission signal, and transmits the power transmission signal using the power transmission antenna 31.

[0026] A LiDAR (Laser Imaging Detection and Ranging) is used as the detection unit 33. An output signal of the detection unit 33 is input to the control unit 23. The detection unit 33 detects the surrounding environment of the power transmission device 30 and the position of the drone 20. Detection by the detection unit 33 is performed based on the following idea. First, the detection unit 33 detects the shape and distance of an object at a distant location. Then, a three-dimensional map of the surrounding environment of the power transmission device 30 is generated based on the detection data of the detection unit 33. Based on this three-dimensional map, the surrounding topography, the positions of obstacles (overgrown trees, fallen trees, large trucks, etc.), and the position of the drone 20 are identified and detected. In this embodiment, the detection unit 33 corresponds to a moving object detection unit and a surrounding detection unit.

[0027] <Arrangement of power transmitting device 30> 2, a plurality of power transmission devices 30 are arranged at intervals. In this embodiment, each power transmission device 30 is installed in a mountainous area.

[0028] <Communications Division 34> As shown in Fig. 1, each power transmission device 30 has a communication unit 34. The multiple power transmission devices 30 are connected via a communication network (e.g., the Internet). The communication unit 34 of each power transmission device 30 performs data communication with the other power transmission devices 30 via the communication network. In this embodiment, the position of the drone 20 detected by the detection unit 33 of any of the power transmission devices 30 is shared among the multiple power transmission devices 30 through data communication by the communication unit 34 of each power transmission device 30. The control of the communication unit 34 is performed by the control unit 32.

[0029] The control unit 32 of the power transmitting device 30 has, as its functional units, a path estimating unit 321, a passing period estimating unit 322, and a mode selecting unit 323. <Route Estimation Unit 321> The route estimation unit 321 estimates a movement route RT of the drone 20 based on the position information of the drone 20 shared among the power transmission devices 30. This movement route RT is stored in the storage unit of the control unit 32.

[0030] <Transit period estimation unit 322> The passing period estimation unit 322 estimates the passing periods T1 and T2 based on the position information of the drone 20 shared among the power transmission devices 30. The passing period T1 is the period during which the drone 20 passes through a range SD where the detection unit 33 can detect it. The passing period T2 is the period during which the drone 20 passes through a range ST where the power transmission device 30 can transmit power. These passing periods T1 and T2 are stored in the storage unit of the control unit 32.

[0031] When it is expected that the drone 20 will pass through the detection range SD or the power transmission range ST based on the movement route RT and the passing periods T1, T2, each power transmission device 30 can prepare for the passage of the drone 20. Furthermore, when it is determined that the drone 20 will not pass through the detection range SD or the power transmission range ST of the power transmission device 30 based on the movement route RT and the passing periods T1, T2, it is possible to prevent the power transmission device 30 from operating unnecessarily by, for example, reducing the frequency of detection by the detection unit 33.

[0032] <Mode selection unit 323> The power transmission device 30 has two operation modes: a normal mode in which all functions are performed, and a power saving mode in which some functions (such as the power transmission function) are stopped. In the power saving mode, at least the detection function of the detection unit 33 and the communication function of the communication unit 34 are performed. The power consumption of the power transmission device 30 in the power saving mode is less than the power consumption of the power transmission device 30 in the normal mode.

[0033] When the drone 20 has entered the detection range SD of the detection unit 33 of the power transmitting device 30 and the position of the drone 20 has been detected by the detection unit 33, the mode selection unit 323 selects and sets the normal mode as the operation mode of the power transmitting device 30. On the other hand, when the drone 20 has not entered the detection range SD and the position of the drone 20 has not been detected by the detection unit 33, the mode selection unit 323 selects and sets the power saving mode. When the power saving mode is selected in the power transmitting device 30, power consumption is reduced by stopping unused functions.

[0034] <Power supply to drone 20> Hereinafter, the manner in which wireless power supply from the power transmitting device 30 to the drone 20 is performed will be described with reference to Fig. 3 and Fig. 4. In Fig. 4, the size of the power transmission range ST relative to the size of the detection range SD is shown larger than the actual size in order to facilitate understanding.

[0035] <Before entering detection range SD> 3 and 4, when the drone 20 is not within the detection range SD of the power transmission device 30, the power transmission device 30 operates in a power saving mode. At this time, the power transmission device 30 detects the detection range SD by the detection unit 33 and performs data communication with other power transmission devices 30 by the communication unit 34 at a predetermined cycle.

[0036] <Position T11> 4, when the drone 20 enters the detection range SD of the power transmitting device 30 (position T11), the detection unit 33 detects the position of the drone 20 and the surrounding environment of the power transmitting device 30. In addition, the operation mode of the power transmitting device 30 is switched to the normal mode.

[0037] Based on the position of the drone 20 detected by the detection unit 33 and the surrounding environment of the power transmission device 30, the power transmission device 30 calculates the flight route TR1 of the drone 20 and a power supply position TA1 where wireless power supply from the power transmission device 30 will be performed.

[0038] In this embodiment, the flight route TR1 and power supply position TA1 are calculated based on the following concept. First, based on the surrounding environment of the power transmission device 30, a place in the power transmission range ST with good visibility from the power transmission device 30, that is, a place where the power transmission signal transmitted from the power transmission device 30 is not blocked and therefore power can be supplied with high efficiency (hereinafter, A area) is determined. Then, a route including A area is determined, and this route is set as the flight route TR1. Furthermore, A area included in this flight route TR1 is set as the power supply position TA1.

[0039] In the wireless power supply system of the present embodiment, when the surrounding environment of the power transmission device 30 changes, a part between the power transmission device 30 and the drone 20 may be blocked by an obstacle, which may result in a decrease in power supply efficiency. Examples of such changes in the surrounding environment of the power transmission device 30 include the parking of a large truck C as shown in Fig. 5 and the occurrence of a fallen tree W as shown in Fig. 6.

[0040] According to this embodiment, when calculating the flight route TR1 and the power supply position TA1, places with poor visibility from the power transmission device 30 are excluded from the above-mentioned area A. Therefore, the above-mentioned power supply position TA1, which is the period passing through the area A, does not include places where the power transmission device 30 and the drone 20 are blocked by obstacles (such as a large truck C [see FIG. 5] or a fallen tree W [see FIG. 6]). Note that the places shown by areas AA1 and AA2 in FIG. 4 are examples of places where the power transmission device 30 and the drone 20 are blocked by obstacles.

[0041] The power transmission device 30 transmits a data signal including the flight route TR1 and the position of the drone 20 to the drone 20 via wireless communication. The drone 20 receives this data signal and executes operation control of the operating unit 202 to fly along the flight route TR1 based on the flight route TR1 included in the data signal and the position of the drone 20. The operation control of the operating unit 202 is executed, for example, by feedback controlling the operation amount of the operating unit 202 (more specifically, the direction of the propellers and the rotation speed of the propellers) in accordance with the deviation between the flight route TR1 and the position of the drone 20 to match them.

[0042] <Position T12~Position T13> As shown by the arrow A2 in FIG. 4, when the drone 20 enters the power transmission range ST of the power transmission device 30 and reaches the power supply position TA1 (position T12 to position T13), it is determined that highly efficient power supply is possible, and wireless power supply from the power transmission device 30 to the drone 20 is executed. At the power supply position TA1, specifically, the operation of the power transmission antenna 31 is controlled based on the position of the drone 20 detected by the detection unit 33 and the flight route TR1. As a result, the power transmission signal transmitted from the power transmission device 30 at the power supply position TA1 is constantly irradiated to the drone 20 moving along the flight route TR1. Then, this power transmission signal is received by the power receiving antenna 221 of the drone 20. In this way, wireless power supply from the power transmission device 30 to the drone 20 and charging of the storage battery 21 of the drone 20 are performed.

[0043] <After passing position T13> As shown by arrow A3 in FIG. 4, when the drone 20 passes the power supply position TA1, it is determined that efficient power supply is no longer possible, and power supply from the power transmission device 30 to the drone 20 is stopped.

[0044] <After passing position T14> Thereafter, as shown by an arrow A4 in Fig. 4, when the drone 20 moves out of the detection range SD of the power transmitting device 30 (when it passes through position T14 in Fig. 4), the position of the drone 20 can no longer be detected by the detection unit 33. This causes the operation mode of the power transmitting device 30 to be switched to the power saving mode.

[0045] <Processing Related to Operation Control of Power Transmission Device 30> Hereinafter, a detailed description will be given of the process (power transmission control process) related to the operation control of the power transmitting device 30. Fig. 7 shows the procedure for executing the power transmission control process. A series of processes shown in the flowchart of Fig. 7 is executed by the control unit 32 of the power transmitting device 30 as a process at a predetermined cycle.

[0046] 7, in this process, first, the position of the drone 20 and the surrounding environment of the power transmission device 30 are detected by the detection unit 33 (step S11). In detail, the detection data detected by the detection unit 33 is analyzed. Then, based on the analysis result, when the drone 20 enters the detection range SD of the detection unit 33, the position of the drone 20 is detected, and the positions of obstacles (terrain, large trucks, fallen trees, etc.) around the power transmission device 30 are detected.

[0047] Then, in the process of step S11, it is determined whether or not the position of the drone 20 has been detected (step S12). If the position of the drone 20 has not been detected (step S12: NO), it is determined that the drone 20 has not entered the detection range SD of the detection unit 33, and the operation mode of the power transmission device 30 is set to the power saving mode (step S13).

[0048] On the other hand, if the position of the drone 20 is detected in the processing of step S11 (step S12: YES), it is determined that the drone 20 has entered the detection range SD of the detection unit 33, and the operating mode of the power transmission device 30 is set to the normal mode (step S14).

[0049] In this case, the flight route TR1 and the power supply position TA1 are calculated based on the position of the drone 20 detected by the detection unit 33 and the surrounding environment of the power transmission device 30 (step S15). The flight route TR1 and the power supply position TA1 are stored in the memory unit of the control unit 32.

[0050] After that, a data signal including the flight route TR1 and the position of the drone 20 is transmitted to the drone 20 via wireless communication (step S16). In the drone 20, the operation control of the operation unit 202 is executed based on the flight route TR1 and the position of the drone 20 received via wireless communication. As a result, the drone 20 flies the flight route TR1.

[0051] Thereafter, it is determined whether the position of the drone 20 is at the power supply position TA1 (step S17). If the position of the drone 20 is not at the power supply position TA1 (step S17: NO), this process ends without executing wireless power supply from the power transmission device 30 to the drone 20 (step S18). On the other hand, if the position of the drone 20 is at the power supply position TA1 (step S17: YES), wireless power supply from the power transmission device 30 to the drone 20 is executed (step S19).

[0052] <Action and effect> The effects of the wireless power supply system of this embodiment will be described below. (1-1) The drone 20 has a power receiving unit 22 that receives power transmitted from a power transmitting device 30. The power transmitting device 30 has a power transmitting antenna 31 that transmits a power transmission signal to the drone 20, and a detection unit 33 that detects the position of the drone 20 and the surrounding environment of the power transmitting device 30. A control unit 32 of the power transmitting device 30 controls the operation of the power transmitting antenna 31 based on the position of the drone 20 detected by the detection unit 33 and the surrounding environment of the power transmitting device 30.

[0053] According to this embodiment, when transmitting a power transmission signal from the power transmitting antenna 31, the surrounding environment (such as the layout of structures and topography) of the power transmitting device 30, including changes in the surrounding environment (such as a parked large truck or a fallen tree), can be detected. This makes it possible to grasp the actual situation of the surrounding environment of the power transmitting device 30.

[0054] Therefore, the flight route TR1 and the power supply position TA1 can be set after grasping the positions of obstacles that may impede the transmission of the power transmission signal from the power transmission antenna 31. This allows wireless power supply from the power transmission device 30 to the drone 20 to be performed only in places with good visibility, not in places with poor visibility from the power transmission device 30.

[0055] According to this embodiment, even if the surrounding environment of the power transmitting device 30 changes, a location (power supply position TA1) where highly efficient wireless power supply is possible in response to the change can be selected, and a power transmission signal can be transmitted from the power transmitting antenna 31. Therefore, a decrease in power supply efficiency caused by a change in the surrounding environment of the power transmitting device 30 can be suppressed.

[0056] (1-2) A plurality of power transmission devices 30 are arranged at intervals. Each power transmission device 30 has a communication unit 34 that executes data communication with the other power transmission devices 30. Through data communication by the communication unit 34, the position of the drone 20 detected by the detection unit 33 of any of the power transmission devices 30 is shared among the plurality of power transmission devices 30.

[0057] Each power transmission device 30 can prepare for future power transmission to the drone 20 by estimating the movement route of the drone 20 based on the position information of the drone 20 acquired from the other power transmission devices 30 through data communication. According to the present embodiment, since the multiple power transmission devices 30 can be linked in this manner, wireless power supply to the drone 20 using those power transmission devices 30 can be smoothly executed.

[0058] (1-3) The path estimation unit 321 of the power transmission device 30 estimates the movement path RT of the drone 20 based on the position information of the drone 20 shared among the power transmission devices 30. When the movement path RT indicates that the drone 20 will pass through the detection range SD of the detection unit 33, each power transmission device 30 can prepare for future power transmission to the drone 20. Furthermore, when the movement path RT indicates that the drone 20 will not pass through the detection range SD of the detection unit 33, the frequency of detection by the detection unit 33 can be reduced, for example, to prevent the power transmission device 30 from operating unnecessarily.

[0059] (1-4) The passing period estimation unit 322 of the power transmission device 30 estimates the passing periods T1, T2 based on the position information of the drone 20 shared between each power transmission device 30. When it is expected that the drone 20 will pass through the detection range SD or the power transmission range ST, each power transmission device 30 can wait in an operating state suitable for the passage of the drone 20 based on the passing periods T1, T2. Furthermore, when it is determined that the drone 20 will not pass through the detection range SD or the power transmission range ST of the power transmission device 30, the frequency of detection by the detection unit 33 can be reduced, for example, to prevent the power transmission device 30 from operating unnecessarily.

[0060] (1-5) When the detection unit 33 detects the position of the drone 20, the mode selection unit 323 of the power transmission device 30 selects and sets the normal mode as the operation mode of the power transmission device 30. On the other hand, when the detection unit 33 does not detect the position of the drone 20, the mode selection unit 323 selects and sets the power saving mode.

[0061] According to this embodiment, when the position of the drone 20 is not detected by the detection unit 33, i.e., when wireless power supply from the power transmission device 30 to the drone 20 is not necessary, the power transmission function can be stopped, etc., so that the power transmission device 30 can be operated in a power saving mode with low power consumption. Moreover, when the position of the drone 20 is detected by the detection unit 33, i.e., when there is a possibility that wireless power supply from the power transmission device 30 to the drone 20 will be performed, the function restrictions can be released and the power transmission device 30 can be operated in a normal mode.

[0062] Second embodiment Hereinafter, the second embodiment of the wireless power supply system will be described with reference to Figs. 8 to 13, focusing on the differences from the first embodiment.

[0063] In the following description, the same components as those in the wireless power supply system of the first embodiment illustrated in FIGS. 1 to 7 are denoted by the same reference numerals (or corresponding reference numerals), and detailed description of these components will be omitted.

[0064] <Drone 40> First, a drone applied to the wireless power supply system of the present embodiment will be described. As shown in FIG. 8, the drone 40 of this embodiment is a rotorcraft (so-called multicopter). The drone 40 has an operating unit 401, the storage battery 21, the power receiving unit 22, and a control unit 23. The operating unit 401 has a plurality of rotors and a control device that controls the rotation speed and orientation of the rotors. The control unit 23 executes operation control of the operating unit 401. In this embodiment, the rotation speed and orientation of the rotors are controlled through the operation control of the operating unit 401.

[0065] <Power supply to drone 40> Hereinafter, the manner in which wireless power supply from the power transmitting device 30 to the drone 40 is performed will be described with reference to Figs. 8 to 12.

[0066] <Position T21> 8 and 9, when the drone 40 is not within the detection range SD of the power transmission device 30 (position T21), the power transmission device 30 operates in a power saving mode. At this time, the power transmission device 30 detects the detection range SD by the detection unit 33 and performs data communication with other power transmission devices 30 by the communication unit 34 at a predetermined cycle.

[0067] <Position T22> 8 and 10, when the drone 40 enters the detection range SD of the power transmitting device 30 (position T22), the detection unit 33 detects the position of the drone 40 and the surrounding environment of the power transmitting device 30. In addition, the operation mode of the power transmitting device 30 is switched to the normal mode.

[0068] Based on the position of the drone 40 detected by the detection unit 33 and the surrounding environment of the power transmission device 30, the power transmission device 30 calculates the flight route TR2 of the drone 40 and a power supply position TA2 where wireless power supply from the power transmission device 30 will be performed.

[0069] In this embodiment, the flight route TR2 and the power supply position TA2 are calculated based on the following idea. First, based on the surrounding environment of the power transmission device 30, a place in the power transmission range ST with good visibility from the power transmission device 30, that is, a place where the power transmission signal transmitted from the power transmission device 30 is not blocked and therefore power can be supplied with high efficiency (hereinafter, point B) is obtained. Then, a route including point B is obtained, and this route is set as the flight route TR2. Furthermore, point B included in this flight route TR2 is set as the power supply position TA2.

[0070] According to this embodiment, when calculating the flight route TR2 and the power supply position TA2, locations with poor visibility from the power transmission device 30 are excluded from the point B. Therefore, the point B (the power supply position TA2) is a location where the space between the power transmission device 30 and the drone 40 is not blocked by obstacles (such as a large truck C or a fallen tree W).

[0071] The power transmitting device 30 transmits a data signal including the flight route TR2 and the position of the drone 40 to the drone 40 via wireless communication. The drone 40 receives the data signal and performs operation control of the operating unit 401 to fly the flight route TR2 based on the flight route TR2 and the position of the drone 40 included in the data signal. The operation control of the operating unit 401 is performed, for example, by feedback controlling the operation amount of the operating unit 401 (more specifically, the orientation of the rotor and the rotation speed of the rotor) in accordance with the deviation between the flight route TR2 and the position of the drone 40 to match them.

[0072] <Position T23> As shown in FIG. 8 and FIG. 11, when the drone 40 enters the power transmission range ST of the power transmission device 30 and reaches the power supply position TA2 (position T23), it is determined that highly efficient power supply is possible, and wireless power supply from the power transmission device 30 to the drone 40 is executed. Specifically, the drone 40 stops moving (more specifically, hovers) for a predetermined period at the power supply position TA2. The power transmission device 30 controls the operation of the power transmission antenna 31 to transmit a power transmission signal toward the power supply position TA2 for a predetermined period. As a result, a power transmission signal is transmitted from the power transmission device 30 to the drone 40. Then, this power transmission signal is received by the power receiving antenna 221 of the drone 40. In this manner, wireless power supply from the power transmission device 30 to the drone 40, and thus charging of the storage battery 21 of the drone 40 is performed.

[0073] <After passing position T23> When wireless power supply from the power transmission device 30 to the drone 40 at the power supply position TA2 is performed for a predetermined period, the wireless power supply is stopped. Also, as shown in Fig. 8 and Fig. 12, the drone 40 starts moving (arrow B1 in Fig. 8) and leaves the power supply position TA2.

[0074] <Position T24> Thereafter, when the drone 40 moves out of the detection range SD of the power transmitting device 30 (passes through position T24 in FIG. 8), the position of the drone 40 can no longer be detected by the detection unit 33. As a result, the operation mode of the power transmitting device 30 is switched to the power saving mode.

[0075] <Processing Related to Operation Control of Power Transmission Device 30> The process (power transmission control process) for controlling the operation of the power transmitting device 30 will be described in detail below. Fig. 13 shows the procedure for executing the power transmission control process. Note that a series of processes shown in the flowchart of Fig. 13 is executed by the control unit 32 of the power transmitting device 30 as processes at predetermined intervals. Also, the processes of steps S11 to S14 in the power transmission control process are similar to the processes of steps S11 to S14 in the power transmission control process of the first embodiment shown in Fig. 7 above, and therefore detailed description thereof will be omitted below.

[0076] 13, in this process, first, the detection unit 33 detects the position of the drone 40 and the surrounding environment of the power transmitting device 30 (step S11). Then, in the process of step S11, it is determined whether or not the position of the drone 40 has been detected (step S12).

[0077] Then, if the position of the drone 40 is not detected (step S12: NO), it is determined that the drone 20 has not entered the detection range SD of the detection unit 33, and the operating mode of the power transmission device 30 is set to a power saving mode (step S13).

[0078] On the other hand, if the position of the drone 40 is detected in the processing of step S11 (step S12: YES), it is determined that the drone 40 has entered the detection range SD of the detection unit 33, and the operating mode of the power transmission device 30 is set to the normal mode (step S14).

[0079] In this case, the flight route TR2 and the power supply position TA2 are calculated based on the position of the drone 40 detected by the detection unit 33 and the surrounding environment of the power transmission device 30 (step S25). The flight route TR2 and the power supply position TA2 are stored in the storage unit of the control unit 32.

[0080] After that, a data signal including the flight route TR2 and the position of the drone 40 is transmitted to the drone 40 via wireless communication (step S26). In the drone 40, the operation control of the operation unit 401 is executed based on the flight route TR2 and the position of the drone 40 received via wireless communication. As a result, the drone 40 flies the flight route TR2.

[0081] Thereafter, it is determined whether or not the drone 40 is stopped at the power supply position TA2 (step S27). If the drone 40 is not at the power supply position TA2 or is not stopped at the power supply position TA2 (step S27: NO), this process ends without wirelessly supplying power from the power transmitting device 30 to the drone 40 (step S28). On the other hand, if the drone 40 is stopped at the power supply position TA2 (step S27: YES), wirelessly supplying power from the power transmitting device 30 to the drone 40 is executed (step S29).

[0082] <Action and effect> According to the wireless power supply system of the present embodiment, in addition to the same advantageous effects as those described in (1-2) to (1-5) above, the advantageous effect described in the following (2-1) can be obtained.

[0083] (2-1) The drone 40 has a power receiving unit 22 that receives power transmitted from the power transmitting device 30. The power transmitting device 30 has a power transmitting antenna 31 that transmits a power transmission signal to the drone 40, and a detection unit 33 that detects the position of the drone 40 and the surrounding environment of the power transmitting device 30. The control unit 32 of the power transmitting device 30 controls the operation of the power transmitting antenna 31 based on the position of the drone 40 detected by the detection unit 33 and the surrounding environment of the power transmitting device 30.

[0084] According to this embodiment, when transmitting a power transmission signal from the power transmitting antenna 31, the surrounding environment (such as the layout of structures and topography) of the power transmitting device 30 can be detected, including changes in the surrounding environment (such as a parked large truck or a fallen tree). This makes it possible to grasp the actual situation of the surrounding environment of the power transmitting device 30.

[0085] Therefore, the flight route TR2 and the power supply position TA2 can be set after grasping the positions of obstacles that may impede the transmission of the power transmission signal from the power transmission antenna 31. Therefore, wireless power supply from the power transmission device 30 to the drone 40 can be performed only in places with good visibility, not in places with poor visibility from the power transmission device 30.

[0086] According to this embodiment, even if the surrounding environment of the power transmitting device 30 changes, a location (power supply position TA2) where highly efficient wireless power supply is possible can be selected in response to the change, and the drone 40 can be guided to the power supply position TA2 and stopped there. Then, at the power supply position TA2, a power transmission signal can be transmitted from the power transmitting antenna 31 to the drone 40. Therefore, a decrease in power supply efficiency caused by a change in the surrounding environment of the power transmitting device 30 can be suppressed.

[0087] <Example of change> The above-described embodiments may be modified as follows: The above-described embodiments and the following modifications may be combined with each other to the extent that no technical contradiction occurs.

[0088] In the first embodiment, the movement speed of the drone 20 at the power supply position TA1 may be set to a speed lower than the movement speed of the drone 20 at a movement position other than the power supply position TA1. According to the above configuration, the drone 20 is decelerated when it reaches the power supply position TA1, so the power supply time to the drone 20 at the power supply position TA1 can be extended compared to when the drone 20 is not decelerated. In addition, a power transmission signal can be transmitted from the power transmission device 30 to the drone 20 moving at a relatively low speed. Therefore, the transmission of the power transmission signal from the power transmission device 30 can be performed with high accuracy toward the moving drone 20 while suppressing deviation of the transmission position.

[0089] The wireless power supply system according to the first embodiment can also be applied to a wireless power supply system that uses a rotorcraft as a drone. In the second embodiment, in order to stop the movement of the drone 40 at the power supply position TA2, instead of hovering the drone 40 at the power supply position TA2, the drone 40 may be temporarily landed at the power supply position TA2.

[0090] The wireless power supply system according to the second embodiment can also be applied to a wireless power supply system that supplies power to a balloon-type drone. In each embodiment, the method of detecting the position of the drone 20, 40 by the power transmitting device 30 is not limited to a method using LiDAR as the detection unit 33, and can be changed as desired. For example, the power transmitting device 30 can detect the position of the drone 20, 40 by receiving a position signal (such as a beacon signal) emitted from the drone 20, 40. If the drone 20, 40 has acquired its own position information by GPS or the like, the power transmitting device 30 may detect the position of the drone 20, 40 by receiving this position information from the drone 20, 40 through wireless communication.

[0091] In each embodiment, in addition to an electromagnetic wave sensor that uses electromagnetic waves such as microwaves, a laser sensor, a sound wave sensor, etc. can be used as the detection unit 33. In short, the detection unit 33 may be anything that can detect the shape and distance of an object located at a distance.

[0092] In each embodiment, the condition for switching the operation mode of the power transmission device 30 can be changed arbitrarily. For example, the operation mode of the power transmission device 30 may be switched from the power saving mode to the normal mode on the condition that the drone 20, 40 approaches the power transmission device 30. The approach of the drone 20, 40 to the power transmission device 30 can be determined based on the position information shared by multiple power transmission devices 30, the movement route RT, and the passing periods T1, T2. In addition, it is also possible to set the normal mode for the power transmission device 30 whose flight route of the drone 20, 40 passes through the detection range SD, while setting the power saving mode for the power transmission device 30 whose flight route does not pass through the detection range SD.

[0093] In each embodiment, the mode selection unit 323 may be omitted. In this case, the power transmitting device 30 may be constantly operated in an operation mode corresponding to the selection of the normal mode in which all functions are exercised.

[0094] In each embodiment, one or both of the path estimation unit 321 and the transit time estimation unit 322 may be omitted. In each embodiment, the communication unit 34 for performing data communication between a plurality of power transmitting devices 30 can be omitted.

[0095] In each embodiment, the installation location of the power transmission device 30 is not limited to mountainous areas, but can be set arbitrarily, such as in urban areas or suburban areas. Even in such a configuration, it is possible to suppress a decrease in power supply efficiency caused by changes in the surrounding environment of the power transmission device 30. When the power transmission device 30 is installed in an urban area or suburban area, changes in the surrounding environment of the power transmission device 30 include "the construction (or demolition) of a high-rise building" and "the growth (or cutting) of trees in a park."

[0096] In each embodiment, the power transmission device 30 may supply power to the drones 20 and 40 through wireless power supply using electromagnetic induction, in addition to wireless power supply using radio waves (such as microwaves).

[0097] The wireless power supply system according to each embodiment can also be applied to a wireless power supply system that supplies power from a power transmitting device 30 to an unmanned small boat 50 (such as a barge or a carrier) via wireless power supply, as shown in an example in Fig. 14. In this configuration, the unmanned small boat 50 corresponds to a moving body.

[0098] The wireless power supply system according to each embodiment can also be applied to a wireless power supply system that supplies power from a power transmitting device 30 to an unmanned small vehicle 60 (such as a dolly or small mobility vehicle) via wireless power supply, as shown in an example in Fig. 15. In this configuration, the unmanned small vehicle 60 corresponds to a moving body. [Explanation of symbols]

[0099] 20. Drone 201…Balloon Club 202...Operating part 21…Battery 22…Power receiving section 221…Receiving antenna 222…Conversion section 23...Control section 30...Power transmission device 31...Transmission antenna 32...Control section 321…Route Estimation Unit 322...Transit period estimation section 323…Mode selection section 33…Detection unit 34…Communications Department 40…Drone 401...Operating part 50...Unmanned small ship 60...Unmanned small vehicle

Claims

1. A wireless power supply system for supplying power from a power transmitting device to a mobile object through wireless power supply, the moving object has a power receiving unit that receives power transmitted from the power transmitting device, The power transmitting device is A power transmission unit that transmits power to the moving object; A moving object detection unit that detects the position of the moving object; a surrounding detection unit that detects a position of an obstacle in the vicinity of the power transmitting device; a control unit that controls an operation of the power transmission unit based on a position of the moving object detected by the moving object detection unit and a position of the obstacle detected by the surroundings detection unit, The power transmitting device is A plurality of the electrodes are arranged at intervals, and A communication unit that performs data communication with another power transmitting device, a position of the moving object detected by the moving object detection unit is shared among the plurality of power transmission devices through data communication by the communication unit; The power transmitting device is a wireless power supply system including a path estimating unit that estimates a moving path of the moving object based on a position of the moving object that is shared.

2. A wireless power supply system for supplying power from a power transmission device to a mobile object through wireless power supply, the moving object has a power receiving unit that receives power transmitted from the power transmitting device, The power transmitting device is A power transmission unit that transmits power to the moving object; A moving object detection unit that detects the position of the moving object; a surrounding detection unit that detects a position of an obstacle in the vicinity of the power transmitting device; a control unit that controls an operation of the power transmission unit based on a position of the moving object detected by the moving object detection unit and a position of the obstacle detected by the surroundings detection unit, The power transmitting device is A plurality of the electrodes are arranged at intervals, and A communication unit that performs data communication with another power transmitting device, a position of the moving object detected by the moving object detection unit is shared among the plurality of power transmission devices through data communication by the communication unit; The power transmission device includes a passing period estimation unit that estimates a period during which the moving object passes through a range in which power can be transmitted by the power transmission unit, based on a position of the moving object that is shared.

3. 3. The wireless power supply system according to claim 1, wherein the power transmitting device has a mode selection unit that selects a normal mode when the position of the moving body is detected by the moving body detection unit, and selects a power saving mode that operates with less power than when the normal mode is selected when the position of the moving body is not detected by the moving body detection unit.

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