Wireless power supply system

Abstract

A control server 300 according to the present disclosure comprises: an information update function unit 302C which acquires, from an external AP that transmits and receives terminal internal information to and from a power receiver 100, terminal internal information of the power receiver 100, the terminal internal information changing in accordance with the direction of radio waves transmitted from a wireless power transmitter 200; a power receiver position estimation function unit 302D that estimates the position of the power receiver 100 on the basis of the change in the terminal internal information; and a wireless power supply instruction function unit 302B which, on the basis of the estimation result of the position of the power receiver 100 obtained by the power receiver position estimation function unit 302D, transmits, to the wireless power transmitter 200, a power supply instruction according to wireless power supply to the power receiver 100.

Description

Wireless power supply system

[0001] The present disclosure relates to a technology for controlling wireless power feeding to a power receiver.

[0002] In recent years, energy harvesting (EH) technology, which harvests energy from the surrounding environment and uses it to power IoT devices, has been attracting attention. In particular, wireless power supply using wireless communication, which can stably supply power to IoT devices installed in various locations in everyday spaces, has attracted attention.

[0003] Beamforming technology is known as a technology for wirelessly supplying power to IoT terminals. It can increase the received power of the IoT terminal by transmitting radio waves in a pinpoint manner like a beam from a wireless base station or wireless access point (AP), which is the wireless transmission source.

[0004] In order for a base station or AP to perform beamforming, it is necessary to know where an IoT terminal is located in space. As a method for knowing the location of an IoT terminal, Non-Patent Document 1 discloses a method in which channel state information (CSI) or the like is exchanged between a base station or AP and the terminal, and the location of the terminal is known using this information to perform beamforming. Furthermore, Non-Patent Document 2 discloses a method in which the IoT terminal selects the optimal beam from multiple arrival beams and feeds it back to the base station or AP.

[0005] Non-Patent Document 1: Kentaro Nishimori, Takeshi Hirakuri, "Communication Efficiency of Multi-User MIMO and Its Improvement Methods," Journal of the Institute of Image Information and Television Engineers, Vol. 70 (2016), No. 1 Non-Patent Document 2: Koji Takinami, Tomonori Shirakata, Masataka Irie, Kazuaki Takahashi, "Standardization Trends and Elemental Technologies of Millimeter-Wave Wireless LAN Systems," Institute of Electronics, Information and Communication Engineers, Communications Society Magazine, Vol. 10 (2016-2017), No. 2

[0006] However, with the above-mentioned method, if the IoT terminal does not exchange communication data with the base station or AP, the CSI information and beam selection information cannot be shared with the base station or AP, and the location of the IoT device cannot be determined. For this reason, there has been a demand for accurate wireless power supply even to IoT terminals that do not directly communicate with the base station or AP.

[0007] Therefore, in order to solve the above-mentioned problems, the present disclosure aims to provide a control device, a wireless power feeding system, and a wireless power feeding control method that are capable of accurately feeding wireless power to an IoT terminal that is not directly communicating with a base station or an AP.

[0008] In order to achieve the above object, the control device in the wireless power supply system of the present disclosure employs a method of estimating the position of the power receiver based on changes in data acquired from an external AP that transmits and receives data to and from the power receiver.

[0009] Specifically, the control device of the present disclosure includes an information acquisition unit that acquires terminal internal information of a power receiver, which changes depending on the direction of radio waves emitted from a wireless power transmitter, from an external communication device that transmits and receives the terminal internal information to and from the power receiver; a position calculation unit that estimates the position of the power receiver based on the change in the terminal internal information; and a power supply instruction unit that transmits a power supply instruction to the wireless power transmitter via wireless power supply to the power receiver based on the result of the estimation of the position of the power receiver by the position calculation unit.

[0010] The wireless power feeding system of the present disclosure includes the above-described control device, a wireless power transmitter that wirelessly feeds power to a power receiver, and an external communication device that transmits and receives terminal internal information that changes in response to the wireless power feeding between the power receiver and the wireless power transmitter.

[0011] In addition, the wireless power supply control method of the present disclosure includes the steps of: acquiring terminal internal information of a power receiver, which changes depending on the direction of radio waves emitted from a wireless power transmitter, from an external communication device that transmits and receives the terminal internal information to and from the power receiver; estimating the position of the power receiver based on the change in the terminal internal information; and transmitting a power supply instruction to the wireless power transmitter via wireless power supply to the power receiver based on the result of the estimation of the position of the power receiver.

[0012] According to the above configuration, it is possible to wirelessly supply power to a terminal that does not directly transmit or receive data with the wireless power transmitter using a beamforming method from the wireless power transmitter, thereby improving the power generated by wireless power supply.

[0013] It is preferable that the wireless power transmitter wirelessly feeds power to the power receiver by beamforming.

[0014] With this configuration, it is possible to improve the power generated by wireless power supply.

[0015] The above disclosures can be combined as much as possible.

[0016] According to the present disclosure, it is possible to wirelessly supply power to a terminal that does not directly transmit or receive data with a wireless power transmitter using a beamforming method, thereby improving the power generated by wireless power supply.

[0017] FIG. 1 is a diagram illustrating an overview of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating problems of a related wireless power feeding system. FIG. 3 is a diagram illustrating an overall system configuration of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating a configuration of a power receiver of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating a configuration of a wireless power transmitter of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating a configuration of an external AP of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 7 is a diagram illustrating a configuration of an IoT cloud platform of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 8 is a diagram illustrating a configuration of a control server of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 9 is a diagram illustrating a wireless power feeding sequence of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 10 is a flowchart illustrating a processing flow of a power receiver position estimation function unit of a wireless power feeding system according to an embodiment of the present disclosure. FIG. 11 is a diagram illustrating a power receiver position estimation method by a power receiver position estimation function unit. FIG. 12 is a diagram illustrating a power receiver position estimation method by a power receiver position estimation function unit. FIG. 13 is a diagram illustrating a power receiver position estimation method by a power receiver position estimation function unit. FIG. 14 is a diagram illustrating a power receiver position estimation method by a power receiver position estimation function unit. FIG. 15 is a diagram illustrating an overall system configuration of a wireless power feeding system according to a modified embodiment of an embodiment of the present disclosure.

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0019] (Embodiment 1) [System Overview] A wireless power feeding system according to the present disclosure will be described with reference to Figs. 1 and 2. In this embodiment, an overview of the wireless power feeding system will be described. Fig. 1 is a diagram illustrating an overview of a wireless power feeding system 91 according to this embodiment. The wireless power feeding system 91 is a wireless power feeding system that feeds power to a power receiver 10 by combining wireless power transfer and other energy harvesting (EH) technologies. However, the scope of the present disclosure is not limited to feeding power to the power receiver 10 by combining wireless power feeding and other EH technologies, and the power receiver 10 may be fed with power only by wireless power feeding.

[0020] The wireless power feeding system 91 includes a plurality of power receivers 10, a wireless power transmitter 20, a wireless power feeding controller 32, a data storage unit 31, and an external AP 40. The external AP 40 functions as an "external communication device" according to the present disclosure. Each of the plurality of power receivers 10 includes an IoT terminal 11, a wireless power feeding unit 12, a power generation unit 13, and a capacitor 14. In this embodiment, an example is shown in which there are N plurality of power receivers 10. The wireless power feeding system 91 estimates the position of each power receiver 100 using a binary search method, which is one of search algorithms. Specifically, the wireless power feeding system 91 is a closed-loop wireless power feeding system using search beamforming, in which a wireless power feeding beam is transmitted from the wireless power transmitter 20 in a predetermined direction and whether the power receiver 10 is present in the predetermined direction is estimated based on the magnitude of the power generated by wireless power feeding in the power receiver 10. The wireless power feeding controller 32 functions as a "control device" according to the present disclosure.

[0021] Specifically, the wireless power feeding system 91 includes the wireless power feeding controller 32, a wireless power transmitter 20 that wirelessly feeds power to the power receiver 10, and an external AP 40 that transmits and receives terminal internal information that changes depending on the wireless power feeding between the power receiver 10 and the wireless power transmitter 20.

[0022] The functions of each component are described below. The IoT terminal 11 consumes the power stored in the power receiver 10, repeatedly activating, sending data, and powering off. IoT terminals can be broadly classified into terminals with sensing functions (e.g., temperature sensors), terminals with data processing functions (e.g., microcomputers), and terminals with data transmission functions (e.g., BLE communication modules). The IoT terminal 11 must have at least one terminal corresponding to each of these three functions, and may have multiple terminals corresponding to each of these three functions, or may have terminals with completely different functions.

[0023] The IoT terminal 11 transmits data to the external AP 40. The data transmitted by the IoT terminal 11 may be any data, such as sensing data and internal terminal information. The IoT terminal 11 may transmit the internal terminal information to the external AP 40 as metadata. The IoT terminal 11 is configured to transmit predetermined data to the external AP within a predetermined time interval. For example, the IoT terminal 11 may transmit sensing data and metadata at least once a day, and transmit metadata once every few hours. In this manner, the requirements defined for each IoT terminal are referred to as terminal requirements in the present disclosure. Each IoT terminal must store the amount of power required to transmit data defined in the terminal requirements by the scheduled transmission time defined in the terminal requirements.

[0024] In the present embodiment, as shown in the figure, the IoT terminal 11 is incorporated inside the power receiver 10, and the power receiver 10 and the IoT terminal 11 are integrated. However, the scope of the present disclosure is not limited thereto. The IoT terminal 11 may be provided outside the power receiver 10, and the IoT terminal 11 and the power receiver 10 may be connected to each other. In any case, it is sufficient that either the IoT terminal 11 or the power receiver 10 has a function to transmit sensing data and metadata. When the power receiver 10 transmits sensing data and metadata, the power receiver 10 transmits the sensing data and metadata to the external AP 40 in accordance with the terminal requirements of the IoT terminal 11. Furthermore, if the power receiver 10 is capable of supplying power to multiple external IoT terminals, the power receiver 10 transmits the sensing data and metadata to the external AP 40 in accordance with the terminal requirements of the multiple IoT terminals.

[0025] The wireless power transmitter 20 is a device capable of wirelessly communicating with the power receiver 10 using radio waves. By transmitting radio waves from the wireless power transmitter 20 to the power receiver 10, wireless power can be supplied from the wireless power transmitter 20 to the power receiver 10. Any type of wireless communication using radio waves can be used, and existing wireless communication devices can be used, such as wireless communication base stations that require various licenses, such as 4G / 5G and local 5G / LPWA (Low Power Wide Area), or unlicensed wireless communication base stations such as Wi-Fi access points. Furthermore, the wireless power transmitter 20 is a device that only transmits radio waves, and a wireless power supply source in a wireless power transmission system specified by the Ministry of Internal Affairs and Communications can be used.

[0026] The wireless power supply unit 12 is a functional unit that converts radio waves for wireless power transmission from the wireless power transmitter 20 into electric power and stores the power in the capacitor 14. More specifically, this technology receives radio waves with an antenna, cleans them in an electric / electronic circuit, and then uses them as electric power, and is generally collectively called a rectenna. The antenna that receives the radio waves may be one specific to wireless power transmission.

[0027] The power generation unit 13 is any means for generating power using energy other than radio waves. The power generation method used by the power generation unit 13 can be any method other than wireless power transmission, including various energy harvesting technologies such as solar cells, small wind power generation, and vibration power generation. While the figure shows a situation in which one power generation unit 13 is provided in the power receiver 10, the scope of the present disclosure is not limited to this. A combination of multiple power generation units 13 may be provided for one power receiver 10 depending on the application.

[0028] The capacitor 14 is a functional unit that stores the power generated by the wireless power supply unit 12 and the power generation unit 13 and uses the power as power for transmitting sensing data and internal terminal information. The capacitor 14 is a physical battery generally collectively referred to as a capacitor and having a relatively long life, but may also be a secondary battery using a chemical reaction and having a relatively short life. When a certain amount of power is stored in the capacitor 14, the power receiver 10 and the IoT terminal 11 are powered on and power is supplied to each functional unit in the IoT terminal 11. After data transmission by the IoT terminal 11 is completed, the power receiver 10 and the IoT terminal 11 are powered off and remain in the power-off state until a certain amount of power is stored in the capacitor 14 again.

[0029] As described above, in this embodiment, wireless power feeding is performed by the wireless power transmitter 20, but as a prerequisite for this, it is necessary to know the location of the power receiver 10. To achieve this, the wireless power feeding system 91 includes an external AP 40, a data storage unit 31, and a wireless power feeding controller 32. The functions of each component for knowing the location of the power receiver 10 will be described below.

[0030] The external AP 40 receives sensing data and terminal internal information from the IoT terminal 11 (power receiver 10). The external AP 40 transmits the sensing data and terminal internal information to the data storage unit 31. There are no fundamental limitations on the technology that can be adopted for the external AP 40, but in utilizing EH technology, it is preferable to adopt an access point that conforms to a low-power wireless communication standard that actually exchanges data with the power receiver. Examples of such technologies include BLE (Bluetooth (registered trademark) Low Energy) and LPWA (Low Power Wide Area) / Sigfox (registered trademark).

[0031] The data storage unit 31 acquires and stores sensing data and terminal internal information from the external AP 40. In other words, the data storage unit 31 is a physical device that holds information groups sent from the external AP 40. The data storage unit 31 provides various information to the wireless power supply controller 32 in response to a request from the wireless power supply controller 32. The data storage unit 31 is also a so-called database that successively accumulates and updates information groups sent from the external AP 40.

[0032] Here, the internal terminal information includes power information that enables the wireless power feeding controller 32 to determine whether to feed power wirelessly. The power information is, for example, the amount of power (mWs) stored in the capacitor 14, i.e., the remaining amount of power, and the amount of power (mWs) generated by the power generation unit 13, i.e., the amount of power generated.

[0033] Furthermore, each IoT terminal 11 has defined terminal requirements for data transmission, such as the frequency of sensing data transmission and the amount of data to be transmitted. Therefore, the terminal internal information may include information about the IoT terminal to which power is supplied by the power receiver 10, such as the terminal requirements. Since the terminal internal information includes the information about the IoT terminal, the amount of power generated and consumed by each power receiver 10 can be predicted, and the wireless power supply controller 32 can predict whether each power receiver satisfies the requirements and is operable.

[0034] The wireless power supply controller 32 executes a process of estimating the position of a terminal that requires wireless power supply among the plurality of power receivers 10. The information acquisition unit of the wireless power supply controller 32 acquires terminal internal information from the data storage unit 31.

[0035] The wireless power feeding controller 32 identifies a terminal that requires wireless power feeding from among the multiple power receivers 10 based on the terminal internal information. Specifically, the wireless power feeding controller 32 determines whether a predetermined amount of power can be satisfied during an intermittent operation cycle defined as a requirement for the power receiver, based on the remaining amount of stored power and the amount of generated power in the capacitor 14 of each power receiver 10 obtained from the power information included in the terminal internal information. If the wireless power feeding controller 32 determines that the predetermined amount of power cannot be satisfied during the intermittent operation cycle of the power receiver 10, it determines that wireless power feeding to the corresponding power receiver 10 is required.

[0036] The wireless power feeding controller 32 also estimates the position of the power receiver 10 that requires wireless power feeding. Specifically, a position calculation unit of the wireless power feeding controller 32 appropriately determines the spatial position (direction) of the power receiver 10 as seen from the wireless power transmitter 20, and a power feeding instruction unit transmits a power feeding instruction to the wireless power transmitter 20 in that direction. For example, the wireless power feeding controller 32 transmits a power feeding instruction to the wireless power transmitter 20 in a direction of any 180 degrees within 360 degrees measured from the wireless power transmitter 20 as the center. The wireless power feeding controller 32 may also transmit a power feeding instruction to the wireless power transmitter 20 in a direction of any angle within a solid angle measured from the wireless power transmitter 20 as the center. The wireless power transmitter 20 transmits wireless radio waves in a predetermined direction in accordance with the instruction from the wireless power feeding controller 32, thereby wirelessly feeding power to the power receiver 10. Specifically, the wireless power transmitter 20 forms a beam in the direction in which the power receiver 10 is located and transmits the beam (beamforming), thereby wirelessly feeding power to the power receiver 10 .

[0037] The wireless power supply controller 32 also checks the power generated by wireless power supply from the internal terminal information stored in the data storage unit 31. If the power generated in the power receiver 10 is smaller than a predetermined value, it is determined that the power receiver 10 is located in a direction different from the initially determined direction. On the other hand, if the power generated in the power receiver 10 is greater than a predetermined value, it is determined that the power receiver 10 is located in the initially determined direction. In either case, the wireless power supply controller 32 can roughly estimate the direction in which the power receiver 10 is located. Then, by narrowing the range and repeating the above procedure to identify the position of the power receiver 10 in detail, wireless power supply by beamforming is realized. In other words, the wireless power supply controller 32 estimates the position of the power receiver 10 using a binary search method. In this way, the wireless power supply controller 32 does not accurately estimate the position of the power receiver 10 by transmitting a beam only once, but accurately estimates the position of the power receiver 10 based on changes in the generated power due to multiple beam transmissions.

[0038] Thereafter, the wireless power transmitter 20 continuously transmits radio waves in a predetermined direction in accordance with an instruction from the wireless power feeding controller 32, thereby wirelessly feeding power to the power receiver 10. Specifically, the wireless power transmitter 20 forms and transmits a beam (beamforming) in the direction (angle) in which the power receiver 10 is located, thereby wirelessly feeding power to the power receiver 10. This can improve the power generated by wireless power feeding.

[0039] [Comparison with Related Art] Next, a comparison is made between the wireless power feeding method of the wireless power feeding system 91 and the wireless power feeding method of a wireless power feeding system 91A according to related art. FIG. 2 is a diagram illustrating a problem of the wireless power feeding system 91A according to related art. The wireless power feeding system 91A includes a plurality of power receivers 10A, a wireless power transmitter 20A, and an external AP 40A. Each of the plurality of power receivers 10A includes a functional unit for wireless power feeding and an existing IoT wireless sensor terminal. The wireless power transmitter 20A wirelessly feeds power to the plurality of power receivers 10A. The external AP 40 exchanges sensing data with the IoT wireless sensor terminal. In the wireless power feeding system 91A, other than wireless power feeding, no information is exchanged between the wireless power transmitter 20A and each power receiver 10A.

[0040] Here, information about the spatial location of the power receiver from the perspective of the wireless power transmitter is important for wireless communication and wireless power supply. This is because if the location of the power receiver can be determined, a method can be adopted in which the wireless power transmitter forms a beam in the direction of the power receiver (beamforming) and transmits it in that direction, rather than transmitting radio waves in a concentric pattern (spherical waves in three dimensions). This allows wireless communication to be performed over long distances with low power consumption, and wireless power supply can increase the received power at the power receiver compared to when transmitting radio waves using spherical waves.

[0041] However, in the wireless power feeding system 91A, information is not exchanged between the wireless power transmitter 20A and each power receiver 10A, and sensing data and internal terminal information are exchanged between each power receiver 10A and the external AP 40A. Therefore, information about the position of the power receiver 10A and feedback of wireless radio waves cannot be transmitted from the power receiver 10A to the wireless power transmitter 20A. Therefore, the wireless power feeding system 91A cannot grasp the position of each power receiver 10A, and therefore cannot perform wireless power feeding using the beamforming method.

[0042] In contrast, in the wireless power feeding system 91 according to the present embodiment, it is possible to wirelessly feed power after estimating the position of each power receiver 10 based on a binary search method while checking the terminal internal information stored in the data storage unit 31 via the external AP 40. As a result, in the present embodiment, it is possible to wirelessly feed power by the beamforming method to the power receiver 10 that does not communicate with the wireless power transmitter 20, which is the wireless supply source, and it is possible to improve the generated power.

[0043] (Embodiment 2) [Overall System Configuration] A wireless power feeding system according to the present disclosure will be described with reference to Figs. 3 to 14. In this embodiment, the configuration of the wireless power feeding system will be described. Fig. 3 is a diagram illustrating the overall system configuration of a wireless power feeding system 92 according to this embodiment. In this embodiment, a power receiver 100 is provided instead of the power receiver 10. The power receiver 100 is a power receiver incorporating an EH hybrid IoT terminal that operates using wireless power transmission and energy harvesting other than wireless power transmission as a power source.

[0044] This embodiment also includes a control server 300 having a data storage unit 301 and a wireless power supply controller 302. The wireless power supply controller 302 is software that executes a process for estimating the location of a terminal that requires wireless power supply among multiple power receivers 100. The wireless power supply controller 302 functions as a "control device" according to the present disclosure. The data storage unit 301 is a so-called database that sequentially stores and updates information groups sent from the external AP 400. The data stored in the data storage unit 301 is referenced by the wireless power supply controller 302 during wireless power supply. However, it is not essential that the data storage unit 301 be provided within the control server 300; the wireless power supply controller 302 may be configured to acquire the data from another data storage such as a cloud whenever necessary. In either case, there are no limitations on the format of information acquisition and storage.

[0045] In addition, in this embodiment, a wireless power transmitter 200 is provided instead of the wireless power transmitter 20. The wireless power transmitter 200 is a relay device for transmitting received communication data to a destination. In addition, in this embodiment, an external AP 400 is provided instead of the external AP 40. The external AP 400 communicates with the power receiver 100 and also communicates with the IoT cloud platform 500. The external AP 400 functions as an "external communication device" according to the present disclosure.

[0046] The IoT cloud infrastructure 500 is a platform for storing, updating, and utilizing sensing data and the like transmitted from the power receiver 100 via the external AP 400. The IoT cloud infrastructure 500 may be, for example, a cloud-connected data center or a general-purpose server device.

[0047] In this embodiment as well, the wireless power feeding system 92 can estimate the position of each power receiver 100 based on the binary search method while checking the terminal internal information stored in the data storage unit 31 via the external AP 400, and then wirelessly feed power to the power receiver 100. This allows wireless power feeding by the beamforming method to be performed even to the power receiver 100 that does not communicate with the wireless power transmitter 200, which is the wireless power supply source, and can improve the generated power.

[0048] Specifically, the wireless power feeding controller 302 includes an information update function unit 302C that acquires, from an external AP 400 that transmits and receives terminal internal information to and from the power receiver 100, the terminal internal information of the power receiver 100, which changes depending on the direction of the radio waves emitted from the wireless power transmitter 200; a power receiver position estimation function unit 302D that estimates the position of the power receiver 100 based on the change in the terminal internal information; and a wireless power feeding instruction function unit 302B that transmits a power feeding instruction to the wireless power transmitter 200 via wireless power feeding to the power receiver 100 based on the result of the estimation of the position of the power receiver 100 by the power receiver position estimation function unit 302D.

[0049] The wireless power feeding system 92 also includes the wireless power feeding controller 302, a wireless power transmitter 200 that wirelessly feeds power to the power receiver 100, and an external AP 400 that transmits and receives terminal internal information that changes depending on the wireless power feeding between the power receiver 100 and the power receiver 100. More specifically, the wireless power transmitter 200 wirelessly feeds power to the power receiver 100 by beamforming.

[0050] The configuration of each component of the wireless power feeding system 92 will be described in more detail below. Fig. 4 shows an example configuration of the power receiving device 100. The power receiving device 100 has a wireless power supply unit 101, a power generation unit 102, a power storage / discharge function unit 103, and a power utilization unit 104. In this embodiment, the wireless power supply unit 101 functions as the wireless power feeding unit 12, the power generation unit 102 functions as the power generation unit 13, the power storage / discharge function unit 103 functions as the capacitor 14, and the power utilization unit 104 functions as the IoT terminal 11. The power utilization unit 104 has an internal information function unit 104A, a detection unit 104B, a data transmission function unit 104C, and a communication function unit 104D.

[0051] The internal information function unit 104A acquires the amount of power currently generated by the wireless power supply unit 101 and the power generation unit 102 and the amount of power stored in the power storage / discharge function unit 103, and passes this information as power information to the data transmission function unit 104C. As described above, the power information is an example of terminal internal information.

[0052] The detection unit 104B is a sensing function unit that detects predetermined information. The information detected by the detection unit 104B is passed to the data transmission function unit 104C as sensing data in the power utilization unit 104. Here, the predetermined information may be, for example, one or more pieces of arbitrary information, such as temperature and humidity, that are determined for each power utilization unit 104. The predetermined information may also include metadata acquired by the power utilization unit 104.

[0053] The data transmission function unit 104C is a function unit for transmitting the terminal internal information and sensing data acquired from the internal information function unit 104A and the detection unit 104B via the communication function unit 104D. The data transmission function unit 104C may collectively transmit the terminal internal information and sensing data as one piece of data at the same time, or may transmit the terminal internal information and sensing data at separate times.

[0054] The communication function unit 104D is a function unit that communicates with external communication devices. In particular, in this embodiment, the communication function unit 104D communicates with the external AP 400.

[0055] 5 shows an example of the configuration of the wireless power transmitter 200. The wireless power transmitter 200 includes a communication function unit 201. The communication function unit 201 is a function unit that communicates with an external communication device.

[0056] Specifically, the communication function unit 201 exchanges data with the control server 300. For example, the communication function unit 201 provides power transmitter position information relating to the position of the wireless power transmitter 200 when communicating with the control server 300. The communication function unit 201 also wirelessly feeds power to each power receiver 100 using beamforming. The communication function unit 201 achieves Wireless Power Transfer / Transmission (WPT) by delivering communication data addressed to a power receiver that requires wireless power feeding, which is transmitted from the wireless power feeding controller 302, to the power receiver 100.

[0057] 6 shows an example of the configuration of the external AP 400. The external AP 400 includes a communication function unit 401. The communication function unit 401 is a function unit that communicates with external communication devices. The external AP 400 receives sensing data and terminal internal information from each power receiver 100. The communication function unit 401 transmits the sensing data and terminal internal information received from each power receiver 100 to the IoT cloud platform 500.

[0058] 7 shows an example of the configuration of the IoT cloud platform 500. The IoT cloud platform 500 holds information sent from the external AP 400 and provides this information in response to a request from the control server 300. Specifically, the IoT cloud platform 500 holds a terminal internal information group 501 and a sensing data group 502. In these information groups, each terminal internal information and each sensing data are linked to correspond to each power receiver 10.

[0059] 8 shows an example of the configuration of the control server 300. The control server 300 includes a data storage unit 301 functioning as the data storage unit 31, a wireless power supply controller 302 functioning as the wireless power supply controller 32, and a communication function unit 303. The communication function unit 303 is a function unit for communicating with external communication devices. The wireless power supply controller 302 includes a power supply determination function unit 302A, a wireless power supply instruction function unit 302B, an information update function unit 302C, and a power receiver position estimation function unit 302D. The wireless power supply controller 302 can be configured using software of a general-purpose server.

[0060] The data storage unit 301 holds the internal information of the terminal. The data storage unit 301 may or may not store the sensing data. Furthermore, when the internal information of the terminal is updated, the data storage unit 301 associates information indicating that the internal information of the terminal has been updated with the internal information of the terminal and stores the information.

[0061] The information update function unit 302C updates the terminal internal information stored in the data storage unit 301. For example, the information update function unit 302C periodically acquires the terminal internal information stored in the IoT cloud platform 500. The information update function unit 302C compares the terminal internal information acquired from the IoT cloud platform 500 with the terminal internal information stored in the data storage unit 301. If the information update function unit 302C determines that the terminal internal information has been updated in the IoT cloud platform 500, it updates the terminal internal information in the data storage unit 301. In this way, when the terminal internal information is updated in the IoT cloud platform 500, the information update function unit 302C has the function of updating the data sent from the IoT cloud platform 500 to the data storage unit 301 when the IoT cloud platform 500 initiates transmission of data to the control server 300. The information update function unit 302C functions as an "information acquisition unit" according to the present disclosure.

[0062] It should be noted that the control server 300 may acquire information directly from the IoT cloud platform 500 without providing the data storage unit 301, that is, without storing various data in the data storage unit 301. In this case, the data storage unit 301 does not exist, and therefore the information update function unit 302C is not necessary.

[0063] The power supply determination function unit 302A determines which power receiver 100 requires wireless power supply based on the internal terminal information of the power receiver 100. If the data storage unit 301 is not provided, the control server 300 may directly acquire the internal terminal information of the power receiver 100 from the IoT cloud platform 500 and make a determination based on the internal terminal information.

[0064] The wireless power feeding instruction function unit 302B transmits a power feeding instruction to the wireless power transmitter 200 so as to wirelessly feed power to the power receiver 100. For example, the wireless power feeding instruction function unit 302B intentionally creates new communication data and unilaterally transmits it using the communication function unit 303. The wireless power feeding instruction function unit 302B functions as a "power feeding instruction unit" according to the present disclosure.

[0065] The power receiver position estimation function unit 302D estimates the direction of the power receiver 100 that requires power supply based on a binary search method while checking internal terminal information. In this embodiment, the result of the position estimation of the power receiver 100 by the power receiver position estimation function unit 302D is stored in the data storage unit 301 as "position estimation information." Here, the position estimation information includes information on the direction in which the power receiver 100 is located as seen from the wireless power transmitter 200 and information on the range within which the power receiver 100 is located in that direction. Note that if the data storage unit 301 is not provided, the power receiver position estimation function unit 302D may be provided with a memory that stores the position estimation information. The power receiver position estimation function unit 302D functions as a "position calculation unit" according to the present disclosure.

[0066] [Operation Sequence] The sequence of the wireless power supply system of this embodiment will be described with reference to the sequence diagram of Figure 9. When a certain amount of power is stored in the power storage / discharge function unit 103, the power receivers #1 to #N are activated at the scheduled transmission time specified in the terminal requirements of each IoT terminal, and transmit sensing data and terminal internal information to the external AP 400 (S11). As described above, the data transmission function unit 104D of the power receiver 100 may simultaneously transmit the terminal internal information and sensing data as a single piece of data, or may transmit the terminal internal information and sensing data at separate times. The external AP 400 transmits the sensing data and terminal internal information to the IoT cloud platform 500 (S12).

[0067] S13 to S17 indicated by S1 in the figure are a series of processes performed by the information update function unit 302C of the control server 300. The information update function unit 302C periodically or at random times refers to and acquires internal terminal information of all power receivers 100 in the IoT cloud platform 500 (S13, S14).

[0068] The information update function unit 302C refers to and acquires the internal terminal information of all the power receivers 100 stored in the data storage unit 301 (S15, S16). The information update function unit 302C compares the internal terminal information acquired from the IoT cloud platform 500 with the internal terminal information acquired from the data storage unit 301 for each power receiver 100, and if it determines that there is a change, updates the internal terminal information in the data storage unit 301 (S17).

[0069] Although not shown in the figure, the power supply determination function unit 302A of the control server 300 identifies a terminal that requires wireless power supply from among the multiple power receivers 100 based on the terminal internal information. Specifically, the power supply determination function unit 302A determines whether the remaining amount of power stored in the power storage / discharge function unit 103 of each power receiver 100, obtained from the power information included in the terminal internal information, has fallen below a predetermined threshold. When the power supply determination function unit 302A determines that the remaining amount of power stored in the power storage / discharge function unit 103 has fallen below the predetermined threshold, it determines that wireless power supply to the corresponding power receiver 100 is required.

[0070] S18 to S20, indicated by S2 in the figure, are a series of processes performed by the power receiver position estimation function unit 302D of the control server 300. The power receiver position estimation function unit 302D periodically refers to and acquires internal terminal information from the data storage unit 301, and estimates the spatial position (direction) of the power receiver 100 as seen from the wireless power transmitter 200 based on the internal terminal information (S18, S19). Specifically, the power receiver position estimation function unit 302D estimates the position of each power receiver 100 based on a binary search method while grasping changes in power generated by wireless power feeding from the terminal position information. The power receiver position estimation function unit 302D updates the position estimation information in the data storage unit 301 based on the estimation result (S20).

[0071] The wireless power feeding instruction function unit 302B of the wireless power feeding controller 302 transmits the position estimation information and a power feeding instruction to the wireless power transmitter 200 via the communication function unit 303 (S21). The wireless power transmitter 200 transmits wireless radio waves in a predetermined direction based on the position estimation information and the power feeding instruction, and wirelessly feeds power to the power receiver 100. Specifically, the wireless power transmitter 200 forms and transmits a beam in the direction where the power receiver 100 is located (beamforming), and wirelessly feeds power to the power receiver 100 (S22).

[0072] [Processing Flow] The processing flow of the power receiver position estimation function unit 302D will be described with reference to the flowchart in Fig. 10. First, the power receiver position estimation function unit 302D sets a counter variable i to 1 (step S101). Here, the counter variable i indicates the number of searches for the power receiver 100. In step S101, the variable i is set to 1, which indicates that this search by wireless power feeding is the first (initial) search. In this embodiment, the search by wireless power feeding is performed four times.

[0073] Next, the power receiver position estimation function unit 302D roughly estimates the spatial position (direction) of the power receiver 100 as seen from the wireless power transmitter 200 at a coarse granularity. In the following description, information about the position of the power receiver 100 estimated by the power receiver position estimation function unit 302D is referred to as "estimated information." The power receiver position estimation function unit 302D registers the estimated information as position estimation information in the data storage unit 301 (step S102). For example, the power receiver position estimation function unit 302D estimates that the power receiver 100 is located within a range of any 180 degrees out of 360 degrees measured from the wireless power transmitter 200 as the center.

[0074] Next, the power receiver position estimation function unit 302D provides the assumed information to the wireless power feeding instruction function unit 302B so that the wireless power feeding instruction function unit 302B issues a power feeding instruction based on the assumed information (S103). The wireless power feeding instruction function unit 302B transmits the assumed information and a power feeding instruction to the wireless power transmitter 200 via the communication function unit 303. The wireless power transmitter 200 transmits radio waves at a coarse granularity in a predetermined direction and range based on the assumed information and the power feeding instruction, and wirelessly feeds power to the power receiver 100.

[0075] The power receiver position estimation function unit 302D acquires the terminal internal information from the data storage unit 301 (step S104). Here, the terminal internal information in the data storage unit 301 is updated in response to an increase or decrease in the amount of remaining power in the power storage / discharge function unit 103. In particular, when power is stored in the power storage / discharge function unit 103 by wireless power feeding or the power generation unit 102, the data storage unit 301 acquires the terminal internal information reflecting this increase in power via the external AP, thereby updating the terminal internal information in the data storage unit 301. Then, as described above, when the terminal internal information is updated, the data storage unit 301 associates information indicating that the terminal internal information has been updated with the terminal internal information and stores it. Therefore, the power receiver position estimation function unit 302D can determine whether the terminal internal information has been updated in the data storage unit 301 (step S105).

[0076] If it is determined that the terminal internal information has not been updated (step S105: No), the power receiver position estimation function unit 302D puts the function to sleep and waits for a certain period of time (step S106), and thereafter repeats the processing of steps S104 to S106.

[0077] When it is determined that the terminal internal information has been updated (step S105: Yes), the power receiver position estimation function unit 302D performs a position estimation calculation based on the power information included in the terminal internal information (step S107).

[0078] An overview of the position estimation calculation by the power receiver position estimation function unit 302D will be described below. Here, the power generated by the previous wireless power feeding is defined as "P1," and the power generated by wireless power feeding obtained from the internal terminal information at the current time is defined as "P2." Note that there is no P1 by the previous wireless power feeding that corresponds to P2 by the first wireless power feeding. In this case, the power generated by radio waves leaking from the periphery is defined as P1. These generated power values ​​may be temporarily stored in the data storage unit 301 until the processing shown in the flow is completed. In this case, the power receiver position estimation function unit 302D acquires the generated power values ​​before and after the update from the data storage unit 301, in addition to the internal terminal information.

[0079] If P1<P2, it can be inferred that the currently assumed wireless power feeding direction and range are correct, and that the power generated by the currently assumed wireless power feeding has been stored in the power storage / discharge function unit 103. Therefore, the power receiver position estimation function unit 302D infers that the power receiver 100 is located in the currently assumed wireless power feeding direction and range. On the other hand, if P1>P2, it can be inferred that the currently assumed wireless power feeding direction and range are incorrect. Therefore, the power receiver position estimation function unit 302D infers that the power receiver 100 is located in the opposite direction to the currently assumed wireless power feeding direction. In either case, the power receiver position estimation function unit 302D can roughly estimate the direction in which the power receiver 10 is located.

[0080] The power receiver position estimation function unit 302D updates the position estimation information in the data storage unit 301 based on the result of estimating the position of the power receiver 100 in step S107 (step S108).

[0081] The power receiver position estimation function unit 302D increments the counter variable i by 1 (step S109). Furthermore, the power receiver position estimation function unit 302D narrows the range to a higher granularity than the previous time and estimates the spatial position (direction) of the power receiver 100 as seen from the wireless power transmitter 200. For example, while referring to the previous position estimation result, the power receiver position estimation function unit 302D estimates that the power receiver 100 is present within a range of any 90 degrees within the previous 180 degrees or any 90 degrees outside the previous 180 degrees within 360 degrees measured from the wireless power transmitter 200 as the center. The previous position estimation result is used to determine whether the power receiver 100 is within or outside the previous 180 degrees.

[0082] The power receiver position estimation function unit 302D provides new assumed information to the wireless power feeding instruction function unit 302B so that the wireless power feeding instruction function unit 302B issues a power feeding instruction based on the new assumed information (S109). The wireless power feeding instruction function unit 302B transmits the new assumed information and a power feeding instruction to the wireless power transmitter 200 via the communication function unit 303. Based on the new assumed information and the power feeding instruction, the wireless power transmitter 200 transmits wireless radio waves in a predetermined direction and range with higher granularity than in the previous wireless power feeding, and wirelessly feeds power to the power receiver 100.

[0083] The power receiver position estimation function unit 302D determines whether the value set in the counter variable i is less than C (step S110). Here, C represents the number of searches by wireless power feeding. In this embodiment, the power receiver position estimation function unit 302D performs four searches for one power receiver 100. That is, the power receiver position estimation function unit 302D repeats the processes of steps S105 to S110 until the value of the variable i becomes 4 (step S110: Yes). Note that the number of searches by wireless power feeding is arbitrary, and the more the number of searches, the more precisely the position of the power receiver 100 can be estimated. In this way, the wireless power feeding system 92 can estimate the position of the power receiver 100 by a binary search method and then wirelessly feed power. As a result, in this embodiment, wireless power feeding by the beamforming method can be performed even for a power receiver 100 that does not communicate with the wireless power transmitter 200, which is the wireless power source, thereby improving the generated power.

[0084] When the power receiver position estimation function unit 302D determines that the counter variable i is set to 4 (step S110: No), it registers the most recent position estimation result in the data storage unit 301 as final power receiver position estimation information. Furthermore, the power receiver position estimation function unit 302D instructs the wireless power feeding instruction function unit 302B to continuously instruct the wireless power transmitter 200 to feed power thereafter based on the final position estimation information. Thereafter, the power receiver position estimation function unit 302D stops functioning. Based on the instruction from the power receiver position estimation function unit 302D, the wireless power feeding instruction function unit 302B transmits a power feeding instruction to the wireless power transmitter 200. The wireless power transmitter 200 continuously performs wireless power feeding based on the power feeding instruction.

[0085] Furthermore, the power receiver position estimation function unit 302D can estimate the positions of all of the power receivers #1 to #N by executing the flow shown in the figure for the multiple power receivers #1 to #N.

[0086] A method for estimating the position of the power receiver 100 by the power receiver position estimation function unit 302D will be described with reference to FIGS. 11 to 14 . As in the description of the flowchart above, the power receiver position estimation function unit 302D performs four searches (=C) for one power receiver 100. FIG. 11 shows a method for estimating the position of the power receiver 100 by the power receiver position estimation function unit 302D when performing the first search (i=1). As shown in the figure, the power receiver 100 is assumed to be located to the lower right of the wireless power transmitter 200 in a plan view. When performing the first search, the power receiver position estimation function unit 302D assumes that the power receiver 100 is located in the "wireless power feeding direction at i=1" (to the left of the wireless power transmitter 200 in the figure). The power receiver 100 is assumed to be located to the left of the wireless power transmitter 200 in the figure. However, in reality, the power receiver 100 is located to the right of the wireless power transmitter 200, and therefore the result of P1>P2 is obtained for the generated power. From this result, the power receiver position estimation function unit 302D estimates that the power receiver 100 is located to the right, not to the left, of the wireless power transmitter 200. Here, since the counter variable i is set to 1≠C (=4), the power receiver position estimation function unit 302D narrows the range and performs a search.

[0087] FIG. 12 shows a method for estimating the position of the power receiver 100 by the power receiver position estimation function unit 302D when performing a second search (i=2). When performing the second search, the power receiver position estimation function unit 302D assumes that the power receiver 100 is located in the "wireless power feeding direction at i=2" (to the upper right of the wireless power transmitter 200) shown in the figure. However, in reality, the power receiver 100 is located to the lower right of the wireless power transmitter 200, and therefore, the result of P1>P2 is obtained for the generated power. From this result, the power receiver position estimation function unit 302D estimates that the power receiver 100 is located to the lower right of the wireless power transmitter 200, not to the upper right. Here, because the counter variable i is set to 2≠C (=4), the power receiver position estimation function unit 302D performs a search with a narrower range.

[0088] FIG. 13 shows a method for estimating the position of the power receiver 100 by the power receiver position estimation function unit 302D when performing a third search (i=3). When performing the third search, the power receiver position estimation function unit 302D assumes that the power receiver 100 is located in the "wireless power feeding direction at i=3" (inside the octant in the figure) shown in the figure. In this case, since the power receiver 100 is actually located within the octant shown in the figure, the result of P1<P2 is obtained for the generated power. From this result, the power receiver position estimation function unit 302D estimates that the power receiver 100 is located within the octant in the figure. Here, since the counter variable i is set to 3≠C (=4), the power receiver position estimation function unit 302D performs a search with a narrower range.

[0089] FIG. 14 shows a method for estimating the position of the power receiver 100 by the power receiver position estimation function unit 302D when performing the fourth search (i=4). When performing the fourth search, the power receiver position estimation function unit 302D assumes that the power receiver 100 is located in the "wireless power feeding direction at i=4" (within the hexagon in the figure) shown in the figure. In this case, since the power receiver 100 is actually located within the hexagon shown in the figure, the result P1<P2 is obtained for the generated power. From this result, the power receiver position estimation function unit 302D estimates that the power receiver 100 is located within the hexagon in the figure. Here, since the counter variable i is set to 4=C (=4), the power receiver position estimation function unit 302D registers the final position estimation result in the data storage unit 301 as the final position direction of the power receiver 100.

[0090] The power receiver position estimation function unit 302D thereafter instructs the wireless power feeding instruction function unit 302B to continuously instruct the wireless power transmitter 200 to feed power based on the final position estimation information. The wireless power feeding instruction function unit 302B transmits a power feeding instruction to the wireless power transmitter 200 based on the instruction from the power receiver position estimation function unit 302D. The wireless power transmitter 200 continuously performs wireless power feeding based on the power feeding instruction.

[0091] In this manner, in the present embodiment, the position of the power receiver 100 is estimated by the binary search method, but the scope of the present disclosure is not limited to this. The power receiver position estimation function unit 302D can estimate the position of the power receiver 100 by any search method or search algorithm other than the binary search method, based on changes in the terminal internal information.

[0092] As described above, the wireless power feeding control method of the present disclosure includes the steps of: acquiring, from an external AP that transmits and receives the terminal internal information of the power receiver 100, the terminal internal information of the power receiver 100, which changes depending on the direction of the radio waves emitted from the wireless power transmitter 200; estimating the position of the power receiver 100 based on the change in the terminal internal information; and transmitting, to the wireless power transmitter 200, a power feeding instruction to the power receiver 100 via wireless power feeding based on the result of the estimation of the position of the power receiver 100 by the power receiver position estimation function unit 302D.

[0093] (Modification of Embodiment 2) A modification of the wireless power supply system of the present disclosure will be described with reference to FIG. 15 . FIG. 15 is a diagram illustrating the overall system configuration of a wireless power supply system according to a modification of the embodiment of the present disclosure. Unlike the wireless power supply system 92, a wireless power supply system 92A according to this modification does not include an IoT cloud platform 500 outside the control server 300. In this way, the functional unit that stores various information transmitted from the external AP 400 does not need to be a cloud, and a functional unit having the same function as the IoT cloud platform 500 may be provided in the control server 300. For example, the data storage unit 301 in the control server 300 may function as a functional unit having the same function as the IoT cloud platform 500.

[0094] The device of the present invention can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network. The program of the present disclosure is a program for causing a computer to realize each function of the device according to the present disclosure, and a program for causing a computer to execute each procedure of the method executed by the device according to the present disclosure.

[0095] 10, 10A, 100: Power receiver 11: IoT terminal 12: Wireless power supply unit 13: Power generation unit 14: Capacitor 101: Wireless power supply unit 102: Power generation unit 103: Power storage / discharge function unit 104: Power utilization unit 104A: Internal information function unit 104B: Detection unit 104C: Wireless information acquisition function unit 104D: Data transmission function unit 104E, 201, 303, 303A, 401: Communication function unit 20, 20A, 200: Wireless power transmitter 300, 300A: Control server 31, 301: Data storage unit 32, 302: Wireless power supply controller 302A: Power supply determination function unit 302B: Wireless power supply instruction function unit 302C: Information update function unit 302D: Power receiver position estimation function unit 40, 40A, 400, 400A: External AP 500: IoT cloud platform 501: Terminal internal information group 502: Sensing data group 91, 91A, 92, 92A: Wireless power supply system

Claims

1. A control device comprising: an information acquisition unit that acquires internal terminal information of a power receiver, which changes depending on the direction of radio waves emitted from a wireless power transmitter, from an external communication device that transmits and receives the internal terminal information to and from the power receiver; a position calculation unit that estimates the position of the power receiver based on the change in the internal terminal information; and a power supply instruction unit that transmits a power supply instruction to the wireless power transmitter via wireless power supply to the power receiver based on the result of the estimation of the position of the power receiver by the position calculation unit.

2. The control device according to claim 1, wherein the wireless power transmitter wirelessly supplies power to the power receiver by beamforming.

3. A wireless power supply system comprising: a control device according to claim 1 or 2; a wireless power transmitter that wirelessly supplies power to a power receiver; and an external communication device that transmits and receives internal terminal information that changes in response to the wireless power supply between the power receiver and the wireless power transmitter.

4. A wireless power supply control method comprising: a step of acquiring internal terminal information of a power receiver, the internal terminal information changing according to the direction of radio waves emitted from a wireless power transmitter, from an external communication device which transmits and receives the internal terminal information between the power receiver and the wireless power transmitter; a step of estimating a position of the power receiver based on the change in the internal terminal information; and a step of transmitting, to the wireless power transmitter, an instruction to supply power via wireless power supply to the power receiver based on the result of the estimation of the position of the power receiver.

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