Power transmission equipment, power transmission method, and program

Abstract

To improve supply of power to a power reception device that has loss power.SOLUTION: A power transmission device 10 has, for example, a transmission unit 13 that can transmit a first electromagnetic wave being an electromagnetic wave that can supply power to a battery connected with a power reception device, or a second electromagnetic wave that can supply power to a wider range than the first electromagnetic wave; and a power transmission control unit 17B that, when detecting a first power reception device, of power reception devices, in which the amount of power stored in the battery is equal to or less than a predetermined value, transmits the second electromagnetic wave to a second power reception device that is located near the first power reception device and in which the amount of energy stored in the battery is not equal to or less than a predetermined value.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This application relates to a power transmission device, a power transmission method, and a program.

Background Art

[0002] Wireless power transmission is used for power supply to a plurality of power receiving devices. Patent Document 1 discloses a technique for estimating the amount of power required by a power receiving device based on the schedule information of a user using the power receiving device, and generating a power supply schedule based on the estimation result, the power supply history, and the priority of power supply.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The prior art changes the priority of the power transmission schedule according to the usage status of the power receiving device. However, since the user needs to register the schedule of the power receiving device in advance, there is a possibility that the remaining battery level of the power receiving device may be completely depleted. There is room for improvement in the power supply to the power receiving device that has lost power in the conventional wireless power transmission.

Means for Solving the Problems

[0005] A power transmission device according to one aspect includes a transmission unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave capable of supplying power over a wider range than the first electromagnetic wave, and a power transmission control unit that, when detecting a first power receiving device in which the power stored in the battery is below a predetermined level among the power receiving devices, transmits the second electromagnetic wave to a second power receiving device that is located near the first power receiving device and in which the energy stored in the battery is not below the predetermined level.

[0006] A power transmission device according to one embodiment includes a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave; and a power transmission control unit that, when it detects a first power receiving device in which the power stored in the battery is below a predetermined level, transmits the third electromagnetic wave, which is omnidirectional including the installation direction of the power receiving device, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level.

[0007] A power transmission method according to one embodiment involves a power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave. When the power receiving device detects a first power receiving device whose battery has power stored in it below a predetermined level, the power transmission device causes the transmitting unit to transmit the second electromagnetic wave to a second power receiving device located near the first power receiving device, whose battery has energy stored in it that is not below a predetermined level.

[0008] A power transmission method according to one embodiment involves a power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave. When the power receiving device detects a first power receiving device whose battery has power stored in it below a predetermined level, the power transmission device causes the transmitting unit to transmit the third electromagnetic wave, which radiates in all directions including the installation direction of the power receiving device, to a second power receiving device located near the first power receiving device and whose battery has energy stored in it that is not below a predetermined level.

[0009] A program according to one embodiment involves a power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave. The program causes the transmitting unit to transmit the second electromagnetic wave to a second power receiving device located near the first power receiving device, where the power stored in the battery is not below a predetermined level, when it detects a first power receiving device among the power receiving devices whose battery power is below a predetermined level.

[0010] A program according to one embodiment causes a power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, to perform the step of causing the transmitting unit to transmit the third electromagnetic wave, which radiates in all directions including the installation direction of the power receiving device, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below the predetermined level. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a diagram illustrating the outline of a system equipped with a power transmission device according to Embodiment 1. [Figure 2] Figure 2 is a diagram illustrating the overview of a system equipped with a power transmission device according to Embodiment 1. [Figure 3] Figure 3 is a diagram illustrating an abnormality in a system equipped with a power transmission device according to Embodiment 1. [Figure 4] Figure 4 is a diagram illustrating an abnormality in a system equipped with a power transmission device according to Embodiment 1. [Figure 5] Figure 5 shows an example of the configuration of a power transmission device according to Embodiment 1. [Figure 6] Figure 6 shows an example of the management data shown in Figure 5. [Figure 7] Figure 7 shows an example of the schedule data shown in Figure 5. [Figure 8] Figure 8 shows an example of the configuration of a power receiving device according to Embodiment 1. [Figure 9] Figure 9 is a diagram illustrating the power supply schedule of the power transmission device according to Embodiment 1. [Figure 10] Figure 10 is a diagram illustrating an example of changing the beam width of a power transmission device according to Embodiment 1. [Figure 11] Figure 11 is a flowchart showing an example of a processing procedure performed by the power transmission device according to Embodiment 1. [Figure 12] Figure 12 is a diagram illustrating the power supply schedule of the power transmission device according to Embodiment 2. [Figure 13] Figure 13 is a diagram illustrating an example of omnidirectional radiation from a power transmission device according to Embodiment 2. [Figure 14] Figure 14 is a flowchart showing an example of a processing procedure performed by the power transmission device according to Embodiment 2. [Modes for carrying out the invention]

[0012] Multiple embodiments for implementing the power transmission device, power transmission method, program, etc., relating to this application will be described in detail with reference to the drawings. However, the present invention is not limited by the following description. Furthermore, the components described below include those easily conceivable by those skilled in the art, those substantially identical, and those within the so-called equivalent range. Similar components may be denoted by the same reference numerals in the following description. Furthermore, redundant descriptions may be omitted.

[0013] (Embodiment 1) FIG. 1 and FIG. 2 are diagrams for explaining the outline of a system including a power transmission device according to Embodiment 1. The system 1 shown in FIGS. 1 and 2 includes, for example, a wireless power transmission system capable of microwave transmission (space transmission) type wireless power transmission. Wireless power transmission is a mechanism capable of transmitting power, for example, without using cables or plugs. The microwave transmission type system 1 uses electromagnetic waves (microwaves) as energy transmission. Electromagnetic waves are included in radio waves. In the microwave transmission type system 1, multiple frequency bands are available for the frequency of the electromagnetic waves used. For example, in Japan, it includes the 920 MHz band, 2.4 GHz band, 5.7 GHz band, etc. In the present embodiment, the system 1 enables both improving the power supply efficiency suitable for the situation and ensuring safety. The system 1 can be applied to, for example, space solar power generation. Note that in the wireless power transmission system according to the embodiment of the present disclosure, the frequency band of the electromagnetic waves used is not limited to the above microwaves, and electromagnetic waves with a wide range of wavelengths from several meters to several picometers may be used as the wavelength of the electromagnetic waves.

[0014] In the present embodiment, the case where the system 1 includes four power receiving devices 20A, 20B, 20C, and 20D will be described, but the number is not limited to this. In the following description, when the power receiving devices 20A, 20B, 20C, and 20D are not distinguished, they are described as "power receiving device 20", and duplicate explanations are omitted.

[0015] The system 1 includes a power transmission device 10, a plurality of power receiving devices 20, and a management device 30. The power transmission device 10 and the plurality of power receiving devices 20 are configured to be communicable wirelessly. The power transmission device 10 and the management device 30 are configured to be communicable wirelessly or by wire. In the present embodiment, the case where the system 1 includes the management device 30 will be described, but it may be configured not to include the management device 30 or to incorporate the functions of the management device 30 into the power transmission device 10.

[0016] The power transmission device 10 is a device that wirelessly transmits power in System 1. The power transmission device 10 is a device capable of transmitting electromagnetic waves for power supply. Transmitting electromagnetic waves for power supply includes radiating electromagnetic waves from an antenna. The power transmission device 10 can use multiple-input multiple-output (MIMO) antenna technology. In MIMO, antenna elements at each end of the communication circuit are combined to minimize errors and optimize data speed. In the following description, the power transmission device 10 may be referred to as the "own device".

[0017] The plurality of power reception devices 20 are power-receiving devices that receive electromagnetic waves for power supply from the power transmission device 10 in System 1 to obtain power. The power reception devices 20 include, for example, smartphones, tablet terminals, IoT (Internet of Things) sensors, machine tools, notebook personal computers, drones, electric vehicles, electric bicycles, game machines, etc. System 1 may be able to manage the use of electromagnetic waves by time division, frequency division, etc. so as not to interfere with the electromagnetic waves.

[0018] The power reception device 20 may be targeted at a stationary power reception device that does not move, or may be a moving power reception device. Even when the power reception device 20 is stationary, the pilot signal may search the surrounding environment (such as the room situation) in order to transmit the power transmission radio wave. When the power reception device 20 is stationary, instead of transmitting the power transmission radio wave to the position recognized by the power reception device 20 in the past, the power transmission radio wave may be transmitted toward another power reception device that transmits the pilot signal.

[0019] The power reception device 20 may notify the power transmission device 10 and the management device 30 of a decrease in the battery remaining amount. This disclosure can be applied when the power reception device 20 cannot notify of a decrease in the battery remaining amount. For example, there may be cases where the power reception device 20 cannot notify of a decrease in the battery remaining amount, such as when the power consumption of the power reception device 20 suddenly increases.

[0020] The management device 30 is a server device that provides the function of managing multiple power receiving devices 20. The management device 30 can be implemented as, for example, a personal computer, a tablet terminal, or a smartphone. The management device 30 is configured to communicate with the power transmission device 10 and can send and receive various types of information with the power transmission device 10.

[0021] In the example shown in Figure 1, System 1 consists of power receiving devices 20A, 20B, 20C, and 20D, which are installed at different locations within an installation area such as a factory or facility. The management device 30 has the function of managing management data for each power receiving device 20A, 20B, 20C, and 20D. The management data includes information such as the location of the power receiving device 20, the remaining battery level, and the power consumption of the application being used.

[0022] Each of the power receiving devices 20A, 20B, 20C, and 20D periodically transmits a predetermined signal 1000 to the power transmitting device 10. The predetermined signal 1000 includes, for example, a beacon, a pilot signal, etc. The power receiving devices 20 can transmit the predetermined signal 1000 at different timings within the transmission time period, for example. The power receiving devices 20 can transmit the predetermined signal 1000 with various information added, for example, identification information, battery level information, power consumption information, etc. The power consumption information includes the power consumption of the entire device and the power consumption for each application. The power receiving devices 20 can transmit the predetermined signal 1000 by radiating electromagnetic waves that include the predetermined signal 1000. The predetermined signal 1000 may include the location of the power receiving device 20, information on the application being used, and other arbitrary information.

[0023] The power transmission device 10 has a function to estimate the position of the power receiving device 20 based on the specified signal 1000 upon receiving the specified signal 1000. The power transmission device 10 estimates the position (direction) from itself to the power receiving device 20 based on the received electromagnetic wave intensity of the electromagnetic wave that received the specified signal 1000. The power transmission device 10 calculates a transmission weight (weighting coefficient) for the estimated position of the power receiving device 20. The power transmission device 10 registers the information regarding the power receiving device 20 indicated by the specified signal 1000 with the management device 30 by transmitting the information to the management device 30, associating it with the power receiving device 20.

[0024] As shown in Figure 2, the power transmission device 10 performs directional control by multiplying the antenna by a weighting coefficient and sequentially transmits electromagnetic waves 2000, including the transmission signal for power supply, to each of the power receiving devices 20A, 20B, 20C, and 20D. Transmitting electromagnetic waves 2000 includes, for example, the antenna radiating electromagnetic waves for power supply. Directional control means, for example, controlling the relationship between the radiation direction and radiation intensity of the electromagnetic waves. If the frequencies of the specified signal 1000 and the transmission signal are the same and time variations in the propagation path are ignored, the characteristics of the multiple paths from the power transmission device 10 to the power receiving devices 20 will match the characteristics from the power receiving devices 20 to the power transmission device 10. As a result, the electromagnetic waves 2000 transmitted from the power transmission device 10 will have a radiation pattern (beam) that utilizes not only the path toward the power receiving devices 20, but also the path toward a different direction from the power receiving devices 20. The power transmission device 10 sequentially performs directional control to form electromagnetic waves 2000 to each of the power receiving devices 20A, 20B, 20C, and 20D, and then performs power transmission.

[0025] Figures 3 and 4 are diagrams illustrating an abnormality in system 1 equipped with a power transmission device 10 according to Embodiment 1. As shown in Figure 3, if a battery shortage occurs in the power receiving device 20D, system 1 will be in a state where the power transmission device 10 cannot receive the specified signal 1000 from the power receiving device 20D. Battery shortage includes, for example, states such as the remaining battery level of the power receiving device 20 being below a threshold, having no remaining battery level, or being unable to transmit the specified signal 1000. In this case, the power transmission device 10 can receive the specified signal 1000 from each of the power receiving devices 20A, 20B, and 20C, but cannot receive the specified signal 1000 from power receiving device 20D. The power transmission device 10 detects power receiving device 20D, which does not receive the periodic specified signal 1000, as the first power receiving device with a battery shortage.

[0026] Situations in which the battery of a power receiving device may be lost include when the power supplyable from the power transmission device 10 is less than the power consumed by the power receiving device 20, when the power supplied per unit decreases due to an increase in the number of power receiving devices 20, when the power supplyable to other power receiving devices 20 decreases due to the appearance of a power receiving device 20 with a higher power supply priority, when a power receiving device 20 moves away from the device and the power supplied to that device decreases, or when the power consumption of a power receiving device 20 increases sharply (for example, when frequent communication becomes necessary).

[0027] As shown in Figure 4, the power transmission device 10 performs directional control by multiplying the antenna by a weighting coefficient and sequentially transmits electromagnetic waves 2000, including the transmission signal for power supply, to power receiving devices 20A, 20B, and 20C, respectively, but does not transmit electromagnetic waves 2000 to power receiving device 20D. As a result, System 1 is in a state where the power transmission device 10 does not supply power to power receiving device 20D, which has lost power. Therefore, in this embodiment, System 1 provides a power transmission device 10, etc., that can supply power to power receiving device 20, which has lost power.

[0028] [Configuration of the power transmission device according to Embodiment 1] Figure 5 shows an example of the configuration of the power transmission device 10 according to Embodiment 1. Figure 6 shows an example of the management data shown in Figure 5. Figure 7 shows an example of the schedule data shown in Figure 5.

[0029] As shown in Figure 5, the power transmission device 10 includes an antenna 11, a transmission signal generation unit 12, a transmission unit 13, a receiving unit 14, an estimation unit 15, a storage unit 16, and a control unit 17. The control unit 17 is electrically connected to the transmission signal generation unit 12, the transmission unit 13, the receiving unit 14, the estimation unit 15, the storage unit 16, etc. In this embodiment, for the sake of simplicity, the power transmission device 10 will be described as having an antenna 11 with four antenna elements 11A, but the number of antenna elements 11A is not limited to this.

[0030] Antenna 11 is configured to allow for directional control (beamforming). Antenna 11 is an antenna array equipped with multiple antenna elements 11A. Antenna 11 is configured such that, for example, each of the multiple antenna elements 11A radiates the same electromagnetic wave, and by adjusting their respective phases and power strengths, it is possible to strengthen the electromagnetic wave in a specific direction and weaken it by canceling it out in another direction. Antenna 11 radiates electromagnetic waves 2000 including the transmission signal and receives electromagnetic waves including the signal from the power receiving device 20. Antenna 11 supplies the received signal to the receiving unit 14. The main lobe of Antenna 11 is the direction in which the radiation of electromagnetic waves 2000 is maximized.

[0031] The transmission signal generation unit 12 generates a transmission signal for power supply by converting the current to be transmitted to the power receiving device 20 into electromagnetic waves. The transmission signal is a signal for transmitting electromagnetic waves 2000 capable of supplying power. The transmission signal generation unit 12 generates the transmission signal by converting the current from the power source into electromagnetic waves of the transmission frequency. The power source includes, for example, a commercial power supply, a DC power supply, a battery, etc. The transmission signal generation unit 12 supplies the generated transmission signal to the transmission unit 13.

[0032] The transmitting unit 13 is electrically connected to multiple antenna elements 11A of the antenna 11. The transmitting unit 13 transmits electromagnetic waves 2000, including a transmission signal for power supply, by radiating these electromagnetic waves 2000 from the antenna 11. The transmitting unit 13 radiates the electromagnetic waves 2000 from the multiple antenna elements 11A in a specific direction by applying weights corresponding to the beams that can be formed by the multiple antenna elements 11A. The transmitting unit 13 applies the weights instructed by the control unit 17 to the multiple antenna elements 11A. The transmitting unit 13 transmits the communication signal by radiating radio waves, including the communication signal, from the antenna 11. The transmitting unit 13 transmits the communication signal to the management device 30, other communication devices, etc.

[0033] The receiving unit 14 is electrically connected to multiple antenna elements 11A of the antenna 11, the estimation unit 15, etc. The receiving unit 14 extracts a received signal from the electromagnetic waves received from the power receiving device 20 via the antenna 11. The received signal includes, for example, the specified signal 1000 described above. The receiving unit 14 supplies the extracted received signal to the estimation unit 15, the control unit 17, etc.

[0034] The estimation unit 15 estimates the electromagnetic wave propagation environment from a known specified signal 1000 received from the power receiving device 20. The electromagnetic wave propagation environment includes, for example, the space in which electromagnetic waves propagate between the power transmitting device 10 and the power receiving device 20. The estimation unit 15 estimates, for example, the state of electromagnetic wave propagation in space. The state of electromagnetic wave propagation includes, for example, a state in which direct waves are dominant, a multipath-rich environment in which reflected waves occur, etc. The estimation unit 15 estimates the received response vector (terminal arrival direction) from the received signal. The estimation unit 15 estimates the received response vector by, for example, comparing a known specified signal 1000 included in the received signal with a known reference signal. The estimation unit 15 estimates the propagation environment, terminal arrival direction, distance, etc., using, for example, the received level, sensitivity, received response vector of the specified signal 1000, a reference propagation model, a machine learning program, etc., in order to grasp the state of electromagnetic wave propagation in space. The estimation unit 15 estimates the position of the power receiving device 20 based on the strength of the radio waves, including the specified signal 10000, received from the power receiving device 20, and the estimated direction of arrival of the terminal. The estimation unit 15 supplies the estimation result based on the specified signal 1000 to the control unit 17.

[0035] The storage unit 16 can store programs and data. The storage unit 16 may include any non-transient storage medium such as a semiconductor storage medium and a magnetic storage medium. The storage unit 16 may include a combination of a storage medium such as a memory card, optical disk, or magneto-optical disk and a storage medium reader. The storage unit 16 may include a storage device used as a temporary storage area such as RAM.

[0036] The memory unit 16 can store programs 16A, weight data 16B, management data 16C, schedule data 16D, etc. Program 16A can provide functions to realize various operations of the power transmission device 10. Program 16A can provide various functions related to wireless power transmission. Weight data 16B includes, for example, data showing multiple weights (weighting coefficients) for adjusting the amplitude and phase of signals radiated from multiple antenna elements 11A of the antenna 11 for each of multiple directional patterns. Weight data 16B includes, for example, data showing combinations of multiple antenna elements 11A corresponding to directional patterns. Weight data 16B includes, for example, data showing weights obtained by estimating the time variation of the received response vector, focusing on the fact that a weight vector (weighting coefficient vector) can be uniquely represented by the received response vector at each antenna element 11A.

[0037] Management data 16C is data used for managing multiple power receiving devices 20. For example, as shown in Figure 6, management data 16C has items such as identification information, location information, power consumption information, and history information. The identification information item contains information for identifying power receiving devices 20A, 20B, 20C, and 20D. The location information item contains information indicating the location P1 of power receiving device 20A, the location P2 of power receiving device 20B, the location P3 of power receiving device 20C, and the location P4 of power receiving device 20D. The location information includes, for example, the location of the power receiving device 20 and the direction from the power transmitting device 10 (direction of terminal arrival). The power consumption information item contains information indicating the power W1 of power receiving device 20A, the power W2 of power receiving device 20B, the power W3 of power receiving device 20C, and the power W4 of power receiving device 20D. In this embodiment, the power consumption information includes, for example, the total power consumption of the power receiving device 20, the power consumption of each application installed on the power receiving device 20, etc. The history information items are set to show the history H1 of power receiving device 20A, the history H2 of power receiving device 20B, the history H3 of power receiving device 20C, and the history H4 of power receiving device 20D. The history information includes, for example, the reception history of a specified signal 1000 from the power receiving device 20, the history of the remaining battery level of the power receiving device 20, etc.

[0038] Schedule data 16D contains data indicating the power supply schedule of the power transmission device 10 to power receiving devices 20A, 20B, 20C, and 20D. For example, as shown in Figure 7, schedule data 16D shows the time-division power supply schedule SC for power transmission to power receiving devices 20A, 20B, 20C, and 20D. In Figure 7, the horizontal direction represents time. In the example shown in Figure 7, schedule data 16D shows the power supply schedule SC for two cycles of power receiving devices 20A, 20B, 20C, and 20D. Schedule data 16D shows the power supply schedule SC for power transmission TA of power receiving device 20A, power transmission TB of power receiving device 20B, power transmission TC of power receiving device 20C, and power transmission TD of power receiving device 20D. Power transmission TA, power transmission TB, power transmission TC, and power transmission TD indicate, for example, the transmission time, amount of power, etc., which are set according to the power consumption of the power receiving device 20, the remaining battery level, etc.

[0039] As shown in Figure 5, the control unit 17 includes one or more arithmetic units. The arithmetic units include, but are not limited to, a CPU (Central Processing Unit), a SoC (System-on-a-Chip), an MCU (Micro Control Unit), an FPGA (Field-Programmable Gate Array), and a coprocessor. The control unit 17 realizes various operations related to the power transmission device 10 by having the arithmetic units execute program 16A. The control unit 17 may realize at least one part of the functions provided by program 16A using a dedicated IC (Integrated Circuit).

[0040] When the control unit 17 executes program 16A and detects that one of the multiple power receiving devices 20 has a low battery, it modifies the second electromagnetic wave that supplies power to the second power receiving device near the first power receiving device so that it can supply power to both the first and second power receiving devices, and then sends it to the transmitting unit 13. Based on the estimation results of the estimation unit 15, the control unit 17 controls the directionality of the electromagnetic wave 2000.

[0041] For example, the control unit 17 has functional units such as a detection unit 17A and a power transmission control unit 17B. The control unit 17 functions as a functional unit such as the detection unit 17A and the power transmission control unit 17B by executing program 16A.

[0042] The detection unit 17A detects a power receiving device 20 that cannot receive the specified signal 1000 as a first power receiving device with insufficient battery power. The detection unit 17A detects a power receiving device 20 as a first power receiving device with insufficient battery power if it can no longer receive the specified signal 1000 from a power receiving device 20 that was able to receive the specified signal 1000 during the previous transmission period. The detection unit 17A detects a power receiving device 20 as a first power receiving device with insufficient battery power if it cannot receive the specified signal 1000 from the power receiving device 20 for a predetermined judgment period. As a result, the power transmitting device 10 can wait for obstacles between it and the power receiving device 20 to pass or move, thereby improving the accuracy of detecting insufficient battery power.

[0043] The detection unit 17A detects a second power receiving device near a first power receiving device among a plurality of power receiving devices 20 if it detects that the first power receiving device has insufficient battery power. Based on the location information of the management data 16C and the detection conditions, the detection unit 17A detects a second power receiving device that is close to the position, direction, etc., of the first power receiving device. The detection conditions include, for example, conditions for determining proximity based on the position, direction, etc., of the first power receiving device. The detection conditions include, for example, a range of directions for the second power receiving device relative to the direction of the first power receiving device from the machine, and a threshold or range to compare with the distance between the first power receiving device and the second power receiving device. For example, the detection unit 17A detects the power receiving device 20 closest to the first power receiving device as the second power receiving device.

[0044] The power transmission control unit 17B, based on the weight data 16B, applies a weight to the transmission unit 13 that directs the main lobe of the transmission signal toward the receiving device 20 to be powered, thereby causing the electromagnetic wave 2000 to be radiated in a specific direction from multiple antenna elements 11A. Based on the schedule data 16D, the power transmission control unit 17B controls the transmission signal generation unit 12 to generate a transmission signal corresponding to the power transmission and transmit it from the transmission unit 13. Based on the power supply schedule SC for the multiple receiving devices 20, the power transmission control unit 17B controls the transmission of either a first electromagnetic wave or a second electromagnetic wave to the multiple receiving devices 20. The first electromagnetic wave is an electromagnetic wave used for supplying power to the multiple receiving devices 20. The second electromagnetic wave is an electromagnetic wave used for supplying power to a second receiving device located near the first receiving device.

[0045] When the power transmission control unit 17B detects that one of the multiple power receiving devices 20 has a low battery, it modifies the second electromagnetic wave that supplies power to the second power receiving device near the first power receiving device so that it can supply power to both the first and second power receiving devices, and then transmits it to the transmission unit 13. The power transmission control unit 17B modifies the second electromagnetic wave that supplies power to the second power receiving device detected by the detection unit 17A so that it can supply power to both the first and second power receiving devices, and then transmits it to the transmission unit 13. As the second electromagnetic wave, the power transmission control unit 17B transmits an electromagnetic wave with a wider beam width than the first electromagnetic wave to the transmission unit 13.

[0046] The power transmission control unit 17B generates or modifies the power supply schedule SC based on a specified signal 1000 received from the power receiving device 20. When the power transmission control unit 17B receives a specified signal 1000 from multiple power receiving devices 20, it generates a power supply schedule SC for the multiple power receiving devices 20 and sets it in the schedule data 16D. When the power transmission control unit 17B detects that one of the multiple power receiving devices 20 has a low battery, it modifies the power supply schedule SC to transmit the second electromagnetic wave. When the power transmission control unit 17B detects that one of the multiple power receiving devices 20 has a low battery, it stops the power supply schedule SC for the first power receiving device and then causes the second electromagnetic wave to be transmitted to the transmission unit 13 for the second power receiving device. The power transmission control unit 17B causes the second electromagnetic wave to be transmitted to the transmission unit 13 during the time period of the power supply schedule SC for the first power receiving device with a low battery. The power transmission control unit 17B terminates the transmission of the second electromagnetic wave when it receives a specified signal 1000 from the first power receiving device after transmitting the second electromagnetic wave to the transmitting unit 13.

[0047] The above describes an example of the functional configuration of the power transmission device 10 according to this embodiment. Note that the above configuration described using Figure 5 is merely an example, and the functional configuration of the power transmission device 10 according to this embodiment is not limited to this example. The functional configuration of the power transmission device 10 according to this embodiment can be flexibly modified according to specifications and operation.

[0048] [Configuration of the power receiving device according to Embodiment 1] Figure 8 shows an example of the configuration of a power receiving device 20 according to Embodiment 1. As shown in Figure 8, the power receiving device 20 includes an antenna 21, a generation unit 22, a conversion unit 23, and a battery 24.

[0049] Antenna 21 is electrically connected to the generation unit 22 and the conversion unit 23. Antenna 21 radiates electromagnetic waves including, for example, a specified signal 1000, and receives electromagnetic waves including a signal from the power transmission device 10. Antenna 21 supplies the received electromagnetic waves to the conversion unit 23.

[0050] The generation unit 22 generates a specified signal 1000 and causes the antenna 21 to radiate electromagnetic waves including the specified signal 1000. The generation unit 22 generates the specified signal 1000 at a predetermined timing. The predetermined timing includes, for example, a timing after a certain period of time has elapsed, a specified timing, etc. The generation unit 22 may be configured to generate a signal different from the specified signal 1000. In this embodiment, the generation unit 22 generates a specified signal 1000 to which various information such as identification information, battery 24 remaining charge information, and power consumption information is added.

[0051] The conversion unit 23 is electrically connected to the battery 24. The conversion unit 23 converts the electromagnetic waves received by the antenna 21 into a direct current and uses this direct current to charge the battery 24. The conversion unit 23 converts the electromagnetic waves into a direct current using, for example, a known rectifier circuit.

[0052] The battery 24 is electrically connected to the conversion unit 23. The battery 24 includes a rechargeable battery. The battery 24 includes, for example, a battery compatible with Qi (an international standard for wireless power transfer). The battery 24 can supply the stored power to various parts of the power receiving device 20 that require power.

[0053] The above describes an example of the functional configuration of the power receiving device 20 according to this embodiment. Note that the above configuration described with reference to Figure 8 is merely an example, and the functional configuration of the power receiving device 20 according to this embodiment is not limited to this example. The functional configuration of the power receiving device 20 according to this embodiment can be flexibly modified according to specifications and operation.

[0054] In this embodiment, the power receiving device 20 is described as generating and transmitting a specified signal 1000 to which various information such as identification information, battery level information 24, and power consumption information has been added, but it is not limited to this. For example, the power receiving device 20 may be configured to include a position detection means such as a GPS (Global Positioning System) receiver and to add position information indicating the current location to the specified signal 1000.

[0055] [Example of power supply operation of the power transmission device according to Embodiment 1] Figure 9 is a diagram illustrating the power supply schedule of the power transmission device 10 according to Embodiment 1. Figure 10 is a diagram illustrating an example of changing the beam width of the power transmission device 10 according to Embodiment 1. In Figures 9 and 10, it is assumed that the power transmission device 10 transmits electromagnetic waves 2000 for power transmission to the four power receiving devices 20A, 20B, 20C, and 20D mentioned above.

[0056] When the power transmission device 10 receives a specified signal 1000 from power receiving devices 20A, 20B, 20C, and 20D, it sequentially transmits electromagnetic waves 2000 for power transmission based on the power supply schedule SC1 shown in Figure 9. Specifically, the power transmission device 10 transmits electromagnetic waves 2000 containing a transmission signal corresponding to power transmission TA, electromagnetic waves 2000 containing a transmission signal corresponding to power transmission TB, electromagnetic waves 2000 containing a transmission signal corresponding to power transmission TC, and electromagnetic waves 2000 containing a transmission signal corresponding to power transmission TD. As a result, the power transmission device 10 performs wireless power transmission using electromagnetic waves 2000 with an appropriate amount of power for each of the power receiving devices 20A, 20B, 20C, and 20D.

[0057] Subsequently, the receiving device 20D experiences a battery shortage and becomes unable to transmit the specified signal 1000 to the transmitting device 10. In this case, the transmitting device 10 can receive the specified signal 1000 from each of the receiving devices 20A, 20B, and 20C, but cannot receive the specified signal 1000 from the receiving device 20D, and therefore detects the receiving device 20D as the first receiving device with a battery shortage. Of the receiving devices 20A, 20B, and 20C, the transmitting device 10 detects the receiving device 20C closest to the receiving device 20D as the second receiving device. The transmitting device 10 changes the power supply schedule SC1 to power supply schedule SC2, which does not transmit power to the receiving device 20D. In this embodiment, the power supply schedule SC2 has a blank space for the power transmission TD portion of the power supply schedule SC1, but the time can be shortened or the power transmission time of the power receiving devices 20A, 20B, and 20C can be lengthened.

[0058] Based on the modified power supply schedule SC2, the power transmission device 10 sequentially transmits electromagnetic waves 2000 for power transmission corresponding to the power receiving devices 20A, 20B, and 20C. As a result, the power transmission device 10 does not transmit electromagnetic waves 2000 in the direction of the power receiving device 20D, thus ensuring safety in the event that people or animals are present in that direction.

[0059] If the power transmission device 10 continues to be unable to receive the specified signal 1000 from the power receiving device 20D, it changes the power supply schedule SC2 to power supply schedule SC3, which changes the beam width of the electromagnetic waves to the second power receiving device, power receiving device 20C, and transmits power. Based on the changed power supply schedule SC3, the power transmission device 10 transmits electromagnetic waves 2000 for power transmission to power receiving devices 20A and 20B. Then, as shown in Figure 10, the power transmission device 10 changes the beam width 2100 of the electromagnetic waves 2000 to power receiving device 20C and transmits electromagnetic waves 2000 including a transmission signal corresponding to the power transmission TCD. In this embodiment, the power transmission device 10 shifts the direction of the main lobe of the electromagnetic wave 2000 from the power receiving device 20C to the power receiving device 20D, and widens the beam width 2100 toward the power receiving device 20D, thereby enabling the electromagnetic wave 2000 intended for the power receiving device 20C to be received by the power receiving device 20D as well. As a result, the power transmission device 10 causes the electromagnetic wave 2000 intended for the power receiving device 20C to also arrive at the power receiving device 20D, allowing the power receiving device 20D, which is low on battery power, to receive the electromagnetic wave 2000 and charge its battery 24.

[0060] When the power receiving device 20D charges the battery 24, it transmits a specified signal 1000 to the power transmitting device 10. When the power transmitting device 10 receives the specified signal 1000 from the power receiving device 20D, it determines that the battery shortage in the power receiving device 20D has been resolved and changes the power supply schedule SC3 to the normal power supply schedule SC1. Subsequently, when the power transmitting device 10 receives the specified signal 1000 from power receiving devices 20A, 20B, 20C, and 20D, it sequentially transmits electromagnetic waves 2000 for power transmission based on the power supply schedule SC1.

[0061] As described above, when the periodic prescribed signal 1000 from the power receiving device 20D ceases, the power transmission device 10 transmits power using electromagnetic waves 2000 (first electromagnetic wave) to all power receiving devices 20A, 20B, and 20C, excluding power receiving device 20D. Furthermore, the power transmission device 10 can transmit power to power receiving devices 20C near power receiving device 20D using electromagnetic waves 2000 (second electromagnetic wave) with a widened beam width 2100 of the first electromagnetic wave. This allows the power transmission device 10 to charge power receiving devices 20 with insufficient battery power by transmitting electromagnetic waves 2000 to the other power receiving devices 20, thereby improving the power supply to power receiving devices 20 that have lost power.

[0062] Furthermore, the power transmission device 10 modifies the second electromagnetic wave that is supplied to the detected second power receiving device so that it can supply power to both the first and second power receiving devices, and transmits it from the transmission unit 13. As a result, the power transmission device 10 can use the electromagnetic wave 2000 that is supplied to the power receiving device 20 that is not experiencing a battery shortage, eliminating the need to transmit the electromagnetic wave 2000 to the power receiving device 20 that is experiencing a battery shortage, thereby improving safety.

[0063] Furthermore, the power transmission device 10 detects a power receiving device 20 that cannot receive the specified signal 1000 as a first power receiving device with insufficient battery power. As a result, the power transmission device 10 can detect a power receiving device 20 with insufficient battery power in the communication configuration by using the last received specified signal 1000, thereby suppressing an increase in the number of devices in the configuration.

[0064] Furthermore, if the power transmission device 10 detects that the power receiving device 20 is low on battery power, it transmits a second electromagnetic wave, 2000, which has a wider beam width 2100 than the first electromagnetic wave. This increases the likelihood that the power transmission device 10 can charge the power receiving device 20 with low battery power using the electromagnetic wave 2000 with a wider beam width 2100, thereby improving the power supply to the power receiving device 20 that has lost power.

[0065] Furthermore, the power transmission device 10 detects the second power receiving device near the first power receiving device based on the last specified signal 1000 received from the first power receiving device. For example, if the battery is low, the power receiving device 20 is likely to remain in that location. As a result, the power transmission device 10 can increase the likelihood of charging the power receiving device 20 with a low battery by transmitting electromagnetic waves 2000 with a widened beam width 2100 to the second power receiving device, thereby improving the power supply to the power receiving device 20 that has lost power.

[0066] Furthermore, the power transmission device 10 controls the transmission of either the first or second electromagnetic wave to the multiple power receiving devices 20 based on the power supply schedule SC for the multiple power receiving devices 20. As a result, the power transmission device 10 can use the schedules of the first and second power receiving devices to transmit an electromagnetic wave 2000 with a wider beam width 2100 to the second power receiving device, thereby further increasing the possibility of charging a power receiving device 20 with insufficient battery power.

[0067] Furthermore, the power transmission device 10 generates or modifies a power supply schedule based on a specified signal 1000 received from the power receiving device 20. This allows the power transmission device 10 to generate or modify the schedule of the power receiving device 20 that has received the specified signal 1000, enabling it to supply power to multiple power receiving devices 20 with a schedule suitable for the installation environment. In addition, if the power transmission device 10 detects a power receiving device 20 with insufficient battery power, it can temporarily change the schedule to supply power to the power receiving device and also supply power to the power receiving device with insufficient battery power.

[0068] Furthermore, the power transmission device 10 transmits the second electromagnetic wave to the transmission unit 13 during the power supply schedule period (one cycle) of the first power receiving device that is experiencing battery depletion. This allows the power transmission device 10 to minimize changes to the power supply schedule even when transmitting electromagnetic waves 2000 to multiple power receiving devices, thereby minimizing the impact on other power receiving devices 20 and enabling power supply to power receiving devices experiencing battery depletion.

[0069] Furthermore, after transmitting the second electromagnetic wave to the transmitting unit 13, the power transmission device 10 terminates the transmission of the second electromagnetic wave when it receives a specified signal 1000 from the first power receiving device. This allows the power transmission device 10 to confirm that the first power receiving device's battery is low and return to its normal schedule, thus eliminating the need for maintenance.

[0070] Furthermore, if the power transmission device 10 continues to be unable to receive the specified signal 1000 from the power receiving device 20D, even though it has sent the electromagnetic wave 2000 intended for the power receiving device 20C to the power receiving device 20D, it will notify the power receiving device 20D that it has determined to have a low battery. For example, the power transmission device 10 generates notification information indicating the power receiving device 20D that it has determined to have a low battery and transmits it to the management device 300, thereby causing the notification information to be output to the administrator or other relevant parties. In this way, the power transmission device 10 can recognize the power receiving device 20 with a low battery among multiple power receiving devices 20, thereby contributing to the rapid response of that power receiving device 20.

[0071] In the example shown in Figure 9, the power transmission device 10 is described as being used in the order of power supply schedule SC1, power supply schedule SC2, and power supply schedule SC3, but it is not limited to this. For example, when the power transmission device 10 detects that the first power receiving device has insufficient battery power, it may be configured to transmit the second electromagnetic wave based on power supply schedule SC3 without using power supply schedule SC2.

[0072] [Processing procedure of the power transmission device according to Embodiment 1] Figure 11 is a flowchart showing an example of a processing procedure performed by the power transmission device 10 according to this embodiment. The processing procedure shown in Figure 11 is realized by the control unit 17 of the power transmission device 10 executing program 16A. The processing procedure shown in Figure 11 is repeatedly executed by the control unit 17.

[0073] As shown in Figure 11, the control unit 17 of the power transmission device 10 receives a specified signal 1000 from a plurality of power receiving devices 20 via the receiving unit 14 (step S101). For example, during the transmission period, the control unit 17 acquires the specified signal 1000 from the electromagnetic waves received by the antenna 11. When the processing in step S101 is completed, the control unit 17 proceeds to step S102.

[0074] The control unit 17 determines whether or not it has received the specified signal 1000 from all the power receiving devices 20 (step S102). For example, the control unit 17 determines that it has received the specified signal 1000 from all the power receiving devices 20 if the identification information indicated by all the received specified signals 1000 matches the identification information in the management data 16C. If the control unit 17 determines that it has received the specified signal 1000 from all the power receiving devices 20 (Yes in step S102), it proceeds to step S103.

[0075] The control unit 17 controls power transmission to the multiple power receiving devices 20 based on the power supply schedule SC (step S103). For example, for each power receiving device 20 indicated by the power supply schedule SC, the control unit 17 sets a weight corresponding to the power receiving device 20 in the transmitting unit 13 and causes the antenna 11 to radiate electromagnetic waves 2000 including the transmission signal generated by the transmission signal generation unit 12. As a result, the transmitting unit 13 sequentially transmits electromagnetic waves 2000 for power supply to the multiple power receiving devices. When the processing in step S103 is completed, the control unit 17 terminates the processing procedure shown in Figure 11.

[0076] Furthermore, if the control unit 17 determines that it has not received the specified signal 1000 from any of the power receiving devices 20 (No in step S102), it proceeds to step S104. The control unit 17 detects the first power receiving device with insufficient battery power (step S104). For example, the control unit 17 detects as the first power receiving device the power receiving device 20 among the multiple power receiving devices 20 that has not received the specified signal 1000 during the transmission period. Once the processing in step S104 is completed, the control unit 17 proceeds to step S105.

[0077] The control unit 17 detects a second power receiving device in the vicinity of the first power receiving device (step S105). For example, based on the location information of the management data 16C, the control unit 17 detects the power receiving device 20 closest to the first power receiving device detected in step S104 as the second power receiving device. When the processing in step S105 is completed, the control unit 17 proceeds to step S106.

[0078] The control unit 17 modifies the second electromagnetic wave supplied to the second power receiving device so that it can supply power to both the first and second power receiving devices (step S106). For example, based on the positional relationship between the first and second power receiving devices, the control unit 17 modifies the beam width 2100 of the second electromagnetic wave so that the first power receiving device can receive power with the second electromagnetic wave supplied to the second power receiving device. The control unit 17 modifies the power supply schedule SC so that the time for which the second electromagnetic wave is emitted is longer than before the modification, in order to supply power to both the first and second power receiving devices with the second electromagnetic wave. After the control unit 17 modifies the power supply schedule SC based on the modification of the second electromagnetic wave, it proceeds to step S107.

[0079] The control unit 17 controls power transmission to multiple power supply devices based on the modified power supply schedule SC (step S107). For example, for each power receiving device 20 indicated by the modified power supply schedule SC, the control unit 17 sets a weight corresponding to the power receiving device 20 in the transmitting unit 13 and causes the antenna 11 to radiate electromagnetic waves 2000 including the transmission signal generated by the transmission signal generation unit 12. As a result, the transmitting unit 13 transmits a second electromagnetic wave with a widened beam width 2100 to the first and second power receiving devices, and sequentially transmits electromagnetic waves 2000 corresponding to each of the other power receiving devices 20. When the processing in step S107 is completed, the control unit 17 proceeds to step S108.

[0080] The control unit 17 determines whether or not it has received the specified signal 1000 from the first power receiving device (step S108). For example, the control unit 17 determines that it has received the specified signal 1000 from the first power receiving device if the identification information of the specified signal 1000 received by the receiving unit 14 matches the identification information of the first power receiving device. If the control unit 17 determines that it has received the specified signal 1000 from the first power receiving device (Yes in step S108), it proceeds to step S109.

[0081] The control unit 17 restores the modified second electromagnetic wave and power supply schedule SC to their original values ​​(step S109). For example, the control unit 17 restores the beam width 2100 and power supply schedule SC of the second electromagnetic wave, which were modified in step S106, to their original values. Once the processing in step S109 is complete, the control unit 17 terminates the processing procedure shown in Figure 11.

[0082] Furthermore, if the control unit 17 determines that it has not received the specified signal 1000 from the first power receiving device (No in step S108), it proceeds to step S110. The control unit 17 determines whether or not the determination time has elapsed (step S110). For example, the control unit 17 determines that the determination time has elapsed if the time since the transmission of the second electromagnetic wave in step S107 is equal to or greater than the set determination time. If the control unit 17 determines that the determination time has not elapsed (No in step S110), it returns to step S108, which has already been described, and continues processing. Also, if the control unit 17 determines that the determination time has elapsed (Yes in step S110), it proceeds to step S111.

[0083] The control unit 17 performs a notification process for the detected low-battery power receiving device 20 (step S111). The notification process includes, for example, generating notification information to notify the detected low-battery power receiving device 20, and transmitting the notification information to the management device 300, etc. By performing the notification process, the control unit 17 notifies the management device 300, etc. of the detected low-battery power receiving device 20. When the process in step S111 is completed, the control unit 17 terminates the processing procedure shown in Figure 11.

[0084] (Embodiment 2) System 1 according to Embodiment 2 comprises a power transmission device 10, a plurality of power receiving devices 20, and a management device 30, similar to Embodiment 1. The basic configuration of the power transmission device 10 and power receiving devices 20 is the same as that of the power transmission device 10 and power receiving devices 20 of Embodiment 1. The following description will focus on configurations that differ from those of Embodiment 1.

[0085] The power transmission device 10 comprises the antenna 11, transmission signal generation unit 12, transmission unit 13, receiving unit 14, estimation unit 15, storage unit 16, and control unit 17 shown in Figure 5 above. The control unit 17 has functional units for detection unit 17A and power transmission control unit 17B. In the power transmission device 10 according to Embodiment 2, the power transmission control unit 17B has the following functions.

[0086] The power transmission control unit 17B, when it detects a first power receiving device 20 with insufficient battery power, transmits a third electromagnetic wave radiating in all directions, including the installation direction of the first power receiving device, to the transmission unit 13. The power transmission control unit 17B, when the detection unit 17A detects the first power receiving device, transmits a third electromagnetic wave radiating in all directions, including the installation direction of the first power receiving device, to the transmission unit 13. The power transmission control unit 17B controls the transmission of the first or third electromagnetic wave to the multiple power receiving devices 20 based on the power supply schedule SC for the multiple power receiving devices 20. The power transmission control unit 17B, when it detects a first power receiving device 20 with insufficient battery power, stops the power supply schedule SC for the first power receiving device and then transmits a third electromagnetic wave radiating in all directions, including the installation direction of the first power receiving device, to the transmission unit 13. The power transmission control unit 17B transmits the third electromagnetic wave to the transmission unit 13 during the power supply schedule SC time period for the first power receiving device with insufficient battery power.

[0087] Thus, in this disclosure, even if the power receiving device 20 moves, power can be supplied to the power receiving device 20 with a low battery by widening the beam width to a nearby power receiving device 20, minimizing the impact on other power receiving devices 20 that are being supplied. Furthermore, if the power receiving device 20 that has lost its battery moves, its location cannot be determined by pilot signals or other means. In response to this, a camera is installed on the power transmitting side, and the power receiving devices 20 that are being supplied are recognized within the range visible to the camera. The camera then identifies the location of the power receiving device 20 that has lost its battery, and by widening the beam width to a nearby power receiving device 20 that is being supplied, power can be supplied to the power receiving device 20 that has lost its battery even if it has moved.

[0088] Furthermore, in this disclosure, if a camera cannot be installed, or if the power receiving device 20, whose battery has been lost, is located outside the camera's field of view even if a camera is installed, the beam width can be widened based on the information registered in the management device 30 (recording device) to expand the range over which radio waves are emitted, thereby supplying radio wave energy to the power receiving device 20 even in areas not visible to the camera.

[0089] In this disclosure, when supplying power to a power receiving device 20 whose battery has lost by widening the beam width, a time limit (e.g., 10 seconds) can be set, and the beam width can be widened sequentially for multiple power receiving devices 20 that are currently being supplied with power. Furthermore, in this disclosure, priority is given to control in a way that does not affect the overall system as much as possible, and if there is no response from the power receiving device 20 whose battery has lost within the time limit, the power receiving device 20 to which the beam width is widened is switched sequentially, and if there is still no response from the power receiving device 20 whose battery has lost, power is transmitted using the time interval of omnidirectional radiation.

[0090] [Example of power supply operation of the power transmission device according to Embodiment 2] Figure 12 is a diagram illustrating the power supply schedule SC of the power transmission device 10 according to Embodiment 2. Figure 13 is a diagram illustrating an example of omnidirectional radiation of the power transmission device 10 according to Embodiment 2. In Figures 12 and 13, it is assumed that the power transmission device 10 transmits electromagnetic waves 2000 for power transmission to the four power receiving devices 20A, 20B, 20C, and 20D described above.

[0091] The omnidirectional radiation of this disclosure may include electromagnetic waves radiated in a spherical state from the power transmission device 10. That is, the omnidirectional radiation of this disclosure may include electromagnetic waves that are spherically symmetric with respect to a three-dimensional transmission origin, or electromagnetic waves that are axially symmetric with respect to a predetermined z-axis direction passing through a two-dimensional transmission origin. For spherically symmetric electromagnetic waves, if we define spherical coordinates with mutually orthogonal axes as the x-axis, y-axis, and z-axis, and the distance from the origin as r, the angle with the z-axis as θ, and the angle with the x-axis in the xy-plane as φ, then the electromagnetic wave E at coordinate (r,θ,φ) may be defined as an electromagnetic wave E(r) that depends only on r.

[0092] Furthermore, the omnidirectional radiation of the transmitted electromagnetic wave may be defined as radiation in which the beamforming direction of the transmitted electromagnetic wave changes from 0 to 2π in the φ direction with a predetermined period T, where the axes perpendicular to each other are the x-axis, y-axis, and z-axis, the distance from the origin is r, the angle with the z-axis is θ, and the angle with the x-axis in the xy-plane is φ. In this case, the beamforming direction of the electromagnetic wave may change discretely or continuously from 0 to 2π in the φ direction with a predetermined period T.

[0093] When the power transmission device 10 receives a specified signal 1000 from the power receiving devices 20A, 20B, 20C, and 20D, it sequentially transmits electromagnetic waves 2000 for power transmission based on the power supply schedule SC1 shown in Figure 12. As a result, the power transmission device 10 performs wireless power transmission using electromagnetic waves 2000 with an appropriate amount of power for each of the power receiving devices 20A, 20B, 20C, and 20D.

[0094] Subsequently, the receiving device 20D experiences a battery shortage and is unable to transmit the specified signal 1000 to the transmitting device 10. In this case, the transmitting device 10 can receive the specified signal 1000 from each of the receiving devices 20A, 20B, and 20C, but cannot receive the specified signal 1000 from the receiving device 20D, and therefore detects the receiving device 20D as the first receiving device with a battery shortage. Of the receiving devices 20A, 20B, and 20C, the transmitting device 10 detects the receiving device 20C closest to the receiving device 20D as the second receiving device. The transmitting device 10 changes the power supply schedule SC1 to power supply schedule SC2, which does not transmit power to the receiving device 20D. Based on the modified power supply schedule SC2, the power transmission device 10 sequentially transmits electromagnetic waves 2000 for power transmission corresponding to the power receiving devices 20A, 20B, and 20C.

[0095] If the power transmission device 10 continues to be unable to receive the specified signal 1000 from the power receiving device 20D, it changes the power supply schedule SC2 to power supply schedule SC4, which transmits omnidirectional third electromagnetic waves to the second power receiving device, power receiving device 20C. Based on the changed power supply schedule SC4, the power transmission device 10 sequentially transmits the electromagnetic waves 2000 for power transmission to power receiving devices 20A, 20B, and 20C. Power supply schedule SC4 is a modified version of power supply schedule SC1 where the power transmission TD portion is changed to an omnidirectional schedule. Therefore, the power transmission device 10 controls the transmission of omnidirectional electromagnetic waves as follows.

[0096] As shown in Figure 13, the power transmission device 10 transmits an omnidirectional third electromagnetic wave 2300, including the installation direction 2200 of the battery-depleted power receiving device 20D. The installation direction 2200 includes, for example, the direction from the device itself to the battery-depleted power receiving device 20D. The installation direction 2200 is estimated based on the position information of the power receiving device 20D indicated by the management data 16C. In this embodiment, the third electromagnetic wave 2300 is omnidirectional, directed from the device itself to all of the multiple power receiving devices 20, but is not limited to this. The third electromagnetic wave 2300 may be, for example, an electromagnetic wave that radiates in an omnidirectional manner in a 360-degree direction centered on the device itself. The power transmission device 10 transmits the omnidirectional third electromagnetic wave 2300 by, for example, increasing the power of a predetermined antenna element in the antenna 11. As a result, the power transmission device 10 also sends the third electromagnetic wave 2300 to the power receiving device 20D, allowing the power receiving device 20D, which is low on battery power, to receive the electromagnetic wave 2000 and charge its battery 24.

[0097] When the power receiving device 20D charges the battery 24, it transmits a specified signal 1000 to the power transmitting device 10. When the power transmitting device 10 receives the specified signal 1000 from the power receiving device 20D, it determines that the battery shortage in the power receiving device 20D has been resolved and changes the power supply schedule SC3 to the normal power supply schedule SC1. Subsequently, when the power transmitting device 10 receives the specified signal 1000 from power receiving devices 20A, 20B, 20C, and 20D, it sequentially transmits electromagnetic waves 2000 for power transmission based on the power supply schedule SC1.

[0098] As described above, when the periodic prescribed signal 1000 from the power receiving device 20D ceases, the power transmission device 10 can transmit power to all power receiving devices 20A, 20B, 20C, and 20D using the third electromagnetic wave 2300. This allows the power transmission device 10 to charge the power receiving devices 20 with insufficient battery power using the omnidirectional third electromagnetic wave 2300, thereby improving the power supply to the power receiving devices 20 that have lost power.

[0099] Furthermore, when the power transmission device 10 detects the first power receiving device, it transmits a third electromagnetic wave 2300 that radiates in all directions, including the installation direction 2200 of the first power receiving device, to the transmission unit 13. As a result, the power transmission device 10 can use the omnidirectional third electromagnetic wave 2300 to increase the likelihood of charging the power receiving device 20 with insufficient battery power, thereby improving the power supply to the power receiving device 20 that has lost power.

[0100] Furthermore, the power transmission device 10 controls the transmission of the first or third electromagnetic wave 2300 to the multiple power receiving devices 20 based on the power supply schedule SC for the multiple power receiving devices 20. As a result, the power transmission device 10 can use the schedules of the first and second power receiving devices to transmit the omnidirectional third electromagnetic wave 2300 to the second power receiving device, thereby further increasing the possibility of charging power receiving devices 20 with insufficient battery power.

[0101] Furthermore, the power transmission device 10 transmits the third electromagnetic wave 2300 to the transmission unit 13 during the power supply schedule period (1 cycle) of the first power receiving device that is experiencing battery depletion. This allows the power transmission device 10 to minimize changes to the power supply schedule even when transmitting electromagnetic waves 2000 to multiple power receiving devices 20, thereby minimizing the impact on other power receiving devices 20 and enabling power supply to power receiving devices 20 experiencing battery depletion.

[0102] Furthermore, after the power transmission device 10 has transmitted the third electromagnetic wave 2300 to the transmission unit 13, it terminates the transmission of the third electromagnetic wave 2300 when it receives a specified signal 1000 from the first power receiving device. This allows the power transmission device 10 to confirm that the first power receiving device is out of battery and return to its normal schedule, thus eliminating the need for maintenance.

[0103] Furthermore, if the power transmission device 10 continues to be unable to receive the specified signal 1000 from the power receiving device 20D despite having sent the omnidirectional third electromagnetic wave 2300 to the power receiving device 20D, it will notify the power receiving device 20D that it has determined to have a low battery. In this way, the power transmission device 10 can help administrators and others recognize which power receiving device 20 among the multiple power receiving devices 20 has a low battery, thereby contributing to the rapid response of that power receiving device 20.

[0104] [Processing procedure of the power transmission device according to Embodiment 2] Figure 14 is a flowchart showing an example of a processing procedure performed by the power transmission device 10 according to Embodiment 2. The processing procedure shown in Figure 14 is realized by the control unit 17 of the power transmission device 10 executing program 16A. The processing procedure shown in Figure 14 is repeatedly executed by the control unit 17.

[0105] In the processing procedure shown in Figure 14, steps that are substantially the same as those shown in Figure 11 are denoted by the same reference numerals. In the processing procedure shown in Figure 14, steps S101 to S104 and steps S107 to S111 are the same as steps S101 to S104 and steps S108 to S111 in Figure 11, so their explanation is omitted.

[0106] As shown in Figure 14, if the control unit 17 of the power transmission device 10 determines that it has not received the specified signal 1000 from all power receiving devices 20 (No in step S102), it proceeds to step S104. The control unit 17 detects the first power receiving device with insufficient battery power (step S104). Once the processing in step S104 is complete, the control unit 17 proceeds to step S120.

[0107] The control unit 17 modifies the power supply schedule SC to include omnidirectional radiation (step S120). For example, the control unit 17 changes the schedule of the first power receiving device in the power supply schedule SC to an omnidirectional radiation schedule. When the processing in step S120 is completed, the control unit 17 proceeds to step S121.

[0108] The control unit 17 controls power transmission to multiple power supply devices based on the modified power supply schedule SC (step S121). For example, for each power receiving device 20 indicated by the modified power supply schedule SC, the control unit 17 sets a weight corresponding to the power receiving device 20 other than the first power receiving device in the transmitting unit 13, and sequentially radiates electromagnetic waves 2000, including the transmission signal generated by the transmission signal generation unit 12, from the antenna 11. Then, the control unit 17 sets a weight corresponding to omnidirectional radiation in the transmitting unit 13, and radiates a third electromagnetic wave 2300, which is omnidirectional and includes the transmission signal generated by the transmission signal generation unit 12, from the antenna 11. When the processing in step S121 is completed, the control unit 17 proceeds to step S108.

[0109] The control unit 17 determines whether or not it has received the specified signal 1000 from the first power receiving device (step S108). If the control unit 17 determines that it has received the specified signal 1000 from the first power receiving device (Yes in step S108), it proceeds to step S109.

[0110] The control unit 17 restores the modified second electromagnetic wave and power supply schedule SC to their original values ​​(step S109). For example, the control unit 17 restores the beam width 2100 of the second electromagnetic wave and the power supply schedule SC, which were modified in step S106, to their original values. Once the processing in step S109 is complete, the control unit 17 terminates the processing procedure shown in Figure 14.

[0111] Furthermore, if the control unit 17 determines that it has not received the specified signal 1000 from the first power receiving device (No in step S108), it proceeds to step S110. The control unit 17 determines whether the determination time has elapsed (step S110). If the control unit 17 determines that the determination time has not elapsed (No in step S110), it returns to step S108, which has already been described, and continues processing. Also, if the control unit 17 determines that the determination time has elapsed (Yes in step S110), it proceeds to step S111.

[0112] The control unit 17 performs a notification process for the detected low-battery power receiving device 20 (step S111). By performing the notification process, the control unit 17 notifies the management device 300, etc., of the detected low-battery power receiving device 20. Once the process in step S111 is completed, the control unit 17 terminates the processing procedure shown in Figure 14.

[0113] In Embodiments 1 and 2 described above, System 1 was described as a case where the power transmission device 10 is an independent power supply device, but it is not limited to this. The electronic equipment may be implemented as, for example, a control device that controls a power supply device capable of radiating power supply electromagnetic waves, or a computer built into the power supply device. Furthermore, although System 1 was described as a wireless power transmission system, it is not limited to this. For example, System 1 can be applied to systems that perform wireless communication in an electromagnetic wave propagation environment.

[0114] Characteristic embodiments have been described in order to fully and clearly disclose the technology relating to the attached claims. However, the attached claims should not be limited to the above embodiments, but should be configured to embody all modifications and alternative configurations that a person skilled in the art may create within the scope of the fundamental matters presented herein. The contents of this disclosure can be modified in various ways by a person skilled in the art. Therefore, these modifications and adaptations are within the scope of this disclosure. For example, in each embodiment, each functional part, each means, each step, etc. can be added to or replaced with each functional part, each means, each step, etc. of other embodiments in a logically consistent manner. Also, in each embodiment, multiple functional parts, each means, each step, etc. can be combined into one or divided into two. Furthermore, each embodiment of this disclosure described above is not limited to being implemented strictly according to the respective embodiments described, but can be implemented by combining or omitting features as appropriate.

[0115] [Note 1] A transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider area than the first electromagnetic wave, When a power receiving device detects a first power receiving device whose battery has stored power below a predetermined level, the power transmission control unit transmits the second electromagnetic wave to a second power receiving device located near the first power receiving device, whose battery has stored energy that is not below a predetermined level. A power transmission device having a power transmission device. [Note 2] The second electromagnetic wave is an electromagnetic wave capable of supplying power to the battery connected to the first power receiving device and the battery connected to the second power receiving device. The power transmission equipment described in Appendix 1. [Note 3] A receiving unit capable of receiving a specified signal transmitted by the aforementioned power receiving device, A detection unit determines that the power stored in the battery is below a predetermined level if the transmission of the specified signal cannot be confirmed in the power receiving device, A power transmission device as described in Appendix 1, having the following features. [Note 4] The power transmission control unit transmits an electromagnetic wave with a wider beam width than the first electromagnetic wave as the second electromagnetic wave. The power transmission equipment described in Appendix 3. [Note 5] The detection unit detects the second power receiving device based on the specified signal last received from the first power receiving device. The power transmission equipment described in Appendix 4. [Note 6] The power transmission control unit controls the transmission of the first electromagnetic wave or the second electromagnetic wave to the power receiving device based on a power supply schedule that defines the order or timing of transmitting the first electromagnetic wave to the power receiving device. The power transmission equipment described in Appendix 5. [Note 7] The power transmission control unit generates or modifies the power supply schedule based on the specified signal received from the power receiving device. The power transmission equipment described in Appendix 6. [Note 8] When the power transmission control unit detects the first power receiving device, it stops transmitting the first electromagnetic wave to the first power receiving device according to the power supply schedule and instructs the second power receiving device to transmit the second electromagnetic wave to the transmission unit. The power transmission equipment described in Appendix 7. [Note 9] The power transmission control unit causes the second electromagnetic wave to be transmitted to the transmission unit at the transmission timing specified in the power supply schedule of the first power receiving device. The power transmission equipment described in Appendix 8. [Note 10] The power transmission control unit terminates the transmission of the second electromagnetic wave after transmitting the second electromagnetic wave to the transmitting unit and receiving the specified signal from the first power receiving device. The power transmission equipment described in Appendix 9. [Note 11] The first power receiving device is located within a range in which power can be supplied to the battery by the second electromagnetic wave transmitted to the second power receiving device. The power transmission equipment described in Appendix 1. [Note 12] A transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, When a power receiving device is detected among the power receiving devices in which the power stored in the battery is below a predetermined level, a power transmission control unit transmits the third electromagnetic wave, which radiates in all directions including the installation direction of the power receiving device, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level. A power transmission device having a power transmission device. [Note 13] A receiving unit capable of receiving specified signals transmitted by multiple of the aforementioned power receiving devices, If the specified signal is not received from the power receiving device, the detection unit detects the power receiving device as the first power receiving device with insufficient battery power. Furthermore, When the detection unit detects the first power receiving device, the power transmission control unit causes the transmission unit to transmit the third electromagnetic wave, which radiates in all directions including the installation direction of the first power receiving device. The power transmission equipment described in Appendix 12. [Note 14] The power transmission control unit controls the transmission of the first electromagnetic wave or the third electromagnetic wave to the plurality of power receiving devices based on the power supply schedule to the plurality of power receiving devices. The power transmission equipment described in Appendix 13. [Note 15] When the power transmission control unit detects that the first power receiving device among the multiple power receiving devices is experiencing battery depletion, it stops the power supply schedule to the first power receiving device and then transmits the third electromagnetic wave, which radiates in all directions including the installation direction of the first power receiving device, to the transmission unit. The power transmission equipment described in Appendix 14. [Note 16] The power transmission control unit, during the time period of the power supply schedule for the first power receiving device when the battery is low, causes the third electromagnetic wave to be transmitted to the transmitting unit. The power transmission equipment described in Appendix 15. [Note 17] The power transmission control unit terminates the transmission of the third electromagnetic wave after transmitting the third electromagnetic wave to the transmitting unit and receiving the specified signal from the first power receiving device. The power transmission equipment described in Appendix 15. [Note 18] A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider area than the first electromagnetic wave, A power transmission method in which, when a first power receiving device is detected among the power receiving devices in which the power stored in the battery is below a predetermined level, the transmitting unit transmits the second electromagnetic wave to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level. [Note 19] A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, A power transmission method in which, when a first power receiving device is detected among the power receiving devices in which the power stored in the battery is below a predetermined level, the transmitting unit transmits the third electromagnetic wave, which radiates in all directions including the installation direction of the power receiving device, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level. [Note 20] A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, A program that, when it detects a first power receiving device among the power receiving devices in which the power stored in the battery is below a predetermined level, causes the program to transmit the second electromagnetic wave to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level. [Note 21] A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, A program that, when it detects a first power receiving device among the power receiving devices in which the power stored in the battery is below a predetermined level, causes the program to transmit the third electromagnetic wave, which radiates in all directions including the direction in which the power receiving device is installed, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level. [Note 22] Power transmission equipment and Multiple power receiving devices that are supplied with power by electromagnetic waves received from the aforementioned power transmission device, Equipped with, The aforementioned power transmission device is A transmitting unit capable of supplying power to multiple power receiving devices by transmitting a first electromagnetic wave capable of supplying power, A power transmission control unit, which, when it detects that one of the multiple power receiving devices has a low battery, modifies the second electromagnetic wave that supplies power to the second power receiving device near the first power receiving device so that power can be supplied to both the first and second power receiving devices, and then transmits the power to the transmission unit, A system that includes these features. [Note 23] Power transmission equipment and Multiple power receiving devices that are supplied with power by electromagnetic waves received from the aforementioned power transmission device, Equipped with, The aforementioned power transmission device is A transmitting unit capable of supplying power to multiple power receiving devices by transmitting a first electromagnetic wave capable of supplying power, A power transmission control unit, which, when it detects that one of the multiple power receiving devices has insufficient battery power, transmits a third electromagnetic wave that radiates in all directions, including the installation direction of the first power receiving device, to the transmission unit, A system that includes these features. [Explanation of Symbols]

[0116] 1 System 10 Power transmission equipment 11 Antennas 12. Transmission signal generation unit 13 Transmitter 14 Receiving Unit 15 Estimation part 16 Memory section 16A Program 16B Weight Data 16C Management Data 16D Schedule Data 17 Control Unit 17A Detection Unit 17B Power transmission control unit 20 Power receiving equipment 21 Antennas 22 Generation part 23 Conversion section 24 batteries 30 Management device 1000 regulated signal 2000 Electromagnetic Waves 2100 beam width 2200 Installation direction 2300 Third Electromagnetic Wave SC Power Supply Schedule

Claims

1. A transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider area than the first electromagnetic wave, When a power receiving device is detected among the power receiving devices in which the power stored in the battery is below a predetermined level, a power transmission control unit transmits the second electromagnetic wave to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level. A power transmission device having a power transmission device.

2. The second electromagnetic wave is an electromagnetic wave capable of supplying power to the battery connected to the first power receiving device and the battery connected to the second power receiving device. The power transmission device according to claim 1.

3. A receiving unit capable of receiving a specified signal transmitted by the aforementioned power receiving device, A detection unit determines that the power stored in the battery is below a predetermined level if the transmission of the specified signal cannot be confirmed in the power receiving device, A power transmission device according to claim 1, having the following features.

4. The power transmission control unit transmits an electromagnetic wave with a wider beam width than the first electromagnetic wave as the second electromagnetic wave. The power transmission device according to claim 3.

5. The detection unit detects the second power receiving device based on the specified signal last received from the first power receiving device. The power transmission device according to claim 4.

6. The power transmission control unit controls the transmission of the first electromagnetic wave or the second electromagnetic wave to the power receiving device based on a power supply schedule that defines the order or timing of transmitting the first electromagnetic wave to the power receiving device. The power transmission device according to claim 5.

7. The power transmission control unit generates or modifies the power supply schedule based on the specified signal received from the power receiving device. The power transmission device according to claim 6.

8. When the power transmission control unit detects the first power receiving device, it stops transmitting the first electromagnetic wave to the first power receiving device according to the power supply schedule and instructs the second power receiving device to transmit the second electromagnetic wave to the transmission unit. The power transmission device according to claim 7.

9. The power transmission control unit causes the second electromagnetic wave to be transmitted to the transmission unit at the transmission timing specified in the power supply schedule of the first power receiving device. The power transmission device according to claim 8.

10. The power transmission control unit terminates the transmission of the second electromagnetic wave after transmitting the second electromagnetic wave to the transmitting unit and receiving the specified signal from the first power receiving device. The power transmission device according to claim 9.

11. The first power receiving device is located within a range in which power can be supplied to the battery by the second electromagnetic wave transmitted to the second power receiving device. The power transmission device according to claim 1.

12. A transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider area than the first electromagnetic wave, When a power receiving device detects a first power receiving device whose battery has power below a predetermined level, a power transmission control unit transmits the third electromagnetic wave, which radiates in all directions including the installation direction of the power receiving device, to a second power receiving device located near the first power receiving device and whose battery has energy not below a predetermined level. A power transmission device having a power transmission device.

13. A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider area than the first electromagnetic wave, A power transmission method in which, when a first power receiving device is detected among the power receiving devices in which the power stored in the battery is below a predetermined level, the transmitting unit transmits the second electromagnetic wave to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level.

14. A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, A power transmission method in which, when a first power receiving device is detected among the power receiving devices in which the power stored in the battery is below a predetermined level, the transmitting unit transmits the third electromagnetic wave, which radiates in all directions including the direction in which the power receiving device is installed, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level.

15. A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a second electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, A program that, when it detects a first power receiving device among the power receiving devices in which the power stored in the battery is below a predetermined level, causes the program to transmit the second electromagnetic wave to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level.

16. A power transmission device having a transmitting unit capable of transmitting a first electromagnetic wave, which is an electromagnetic wave capable of supplying power to a battery connected to a power receiving device, or a third electromagnetic wave, which is capable of supplying power over a wider range than the first electromagnetic wave, A program that, when it detects a first power receiving device among the power receiving devices in which the power stored in the battery is below a predetermined level, causes the program to transmit the third electromagnetic wave, which radiates in all directions including the direction in which the power receiving device is installed, to a second power receiving device located near the first power receiving device and in which the energy stored in the battery is not below a predetermined level.

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