Power supply device and power supply method

Abstract

Provided is a power supply device and a power supply method that can supply power to both a plurality of specific power receiving devices that require a large amount of received power and power receiving devices other than the specific power receiving devices. The power supply device repeatedly controls the phases of power transmission signals of a plurality of first antennas located around each of a plurality of first power receiving devices in a frame including a plurality of subframes, in one subframe, maintains the phase relationship of the power transmission signals in a manner that causes one first power receiving device to receive power from the plurality of first antennas located around the one first power receiving device, and changes the phases in time series, in another subframe, maintains the phase relationship of the power transmission signals in a manner that causes another first power receiving device to receive power from the plurality of first antennas located around the another first power receiving device, and changes the phases in time series, and changes the phases of power transmission signals of one or more second antennas in time series.

Description

Technical Field

[0001] This invention relates to a power supply device and a power supply method. Background Technology

[0002] Conventionally, there is a power supply device comprising: a first detection unit for detecting the direction of a powered device; and a control unit for controlling the radiating unit that radiates power to perform a first radiating and a second radiating. The first radiating refers to radiating power wirelessly in the direction of the powered device detected by the first detection unit, and the second radiating refers to radiating power wirelessly while changing the direction of the radiating power within a specified range (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-083648 Summary of the Invention

[0004] <Problem to be solved by this invention>

[0005] On the other hand, conventional power supply devices, when supplying power to multiple power receiving devices, do not take into account both supplying power to a specific power receiving device that requires a large amount of power and supplying power to power receiving devices other than the specific power receiving device.

[0006] Therefore, the object of the present invention is to provide a power supply device and a power supply method that can simultaneously supply power to multiple specific power receiving devices that require a large amount of power and to power receiving devices other than specific power receiving devices.

[0007] <Methods for solving problems>

[0008] The power supply device according to an embodiment of the present invention includes: a power transmission control unit that controls the phase of the power transmission signals of a plurality of first antennas capable of transmitting power, located around each of a plurality of first power receiving devices, and controls the phase of the power transmission signals of one or more second antennas, other than the plurality of first antennas located around each of the plurality of first power receiving devices, wherein the plurality of first antennas located around one of the plurality of first power receiving devices, and the plurality of first antennas located around another of the plurality of first power receiving devices, include at least one common first antenna; the power transmission control unit: repeatedly controls the phase of the power transmission signals of the antennas located around each of the plurality of first power receiving devices. The phase of the power transmission signals of the plurality of first antennas, in one of the plurality of subframes, maintains the phase relationship of the power transmission signals in a manner that makes the phase of the power transmission signals of one of the plurality of first power receiving devices receive power from the plurality of first antennas located around the first power receiving device consistent, while changing the phase in a time sequence; in another of the plurality of subframes, maintains the phase relationship of the power transmission signals in a manner that makes the phase of the power transmission signals of another of the plurality of first power receiving devices receive power from the plurality of first antennas located around the other first power receiving device consistent, while changing the phase in a time sequence, so that the phase of the power transmission signals of the one or more second antennas deliver power changes in a time sequence.

[0009] <The Effects of the Invention>

[0010] It can provide a power supply device and a power supply method that can supply power to multiple specific power receiving devices that require a large amount of power and to power receiving devices other than specific power receiving devices. Attached Figure Description

[0011] Figure 1 This is a diagram showing the power supply device 100 according to an embodiment.

[0012] Figure 2 This is a diagram showing the structure of the control device 140.

[0013] Figure 3 This is a diagram of an example of antenna subset 110A.

[0014] Figure 4 It is a diagram illustrating the phase of the power-receiving signal of a specific device, 250A.

[0015] Figure 5 This is a diagram illustrating a method for determining the phase relationship of the transmission signals of multiple antenna elements 111 in a power monitoring receiving mode.

[0016] Figure 6This is a diagram illustrating the phase index.

[0017] Figure 7 This is a diagram illustrating an example of the phase index PI of the antenna elements assigned to the antenna subset 110A.

[0018] Figure 8 This is a diagram illustrating an example of setting the phase index of antenna element 111 to antenna subset 110A in subset mode.

[0019] Figure 9 This is a flowchart illustrating the process performed by the control device 140.

[0020] Figure 10 This is a graph showing the simulation results of the cumulative distribution function of the received electricity.

[0021] Figure 11 This is a diagram showing an example of multiple antenna subsets 110A1 to 110A5.

[0022] Figure 12 This is a diagram showing the structure of a frame.

[0023] Figure 13 This is a diagram showing the order of data allocation.

[0024] Figure 14 This is a diagram showing the IDs of specific devices SD1 to SD6 assigned to subframes.

[0025] Figure 15 This is a diagram showing the IDs of specific devices SD1 to SD6 assigned to subframes.

[0026] Figure 16 This is a diagram showing the IDs of specific devices SD1 to SD6 assigned to subframes.

[0027] Figure 17 This is a diagram showing the IDs of specific devices SD1 to SD6 assigned to subframes.

[0028] Figure 18 This is a diagram showing the IDs of specific devices SD1 to SD6 assigned to subframes.

[0029] Figure 19 This is a flowchart showing the processes performed by the power transmission control unit 143.

[0030] Figure 20 This is a diagram showing the simulation results after a specific device 250A was assigned to a subframe.

[0031] Figure 21 This is a diagram illustrating an example of driving data. Detailed Implementation

[0032] The following describes the power supply device and embodiments of the power supply method of the present invention.

[0033] <Implementation Method>

[0034] Figure 1 This is a diagram showing the power supply device 100 according to an embodiment. Hereinafter, the explanation will use the XYZ coordinate system. Top view refers to XY top view.

[0035] As an example, the power supply device 100 is configured in area 10 of a large facility such as a smart factory, a large factory, a distribution center, or a warehouse. The power supply device 100 includes an array antenna 110, a phase shifter 120, an IC chip 125, a microwave generator 130, and a control device 140, providing non-contact power (microwave power supply) to multiple devices 250 present in area 10. The power supply method of this embodiment is implemented by the power supply device 100, and particularly by processing performed by the control device 140.

[0036] When powering an unspecified number of devices 250, the power supply device 100 transmits power through beamforming via the array antenna 110. The multiple antenna elements 111 of the array antenna 110 can transmit at the transmission phase specified by the power transmission control unit (described later). When the phase of the transmission signals output by the multiple antenna elements 111 is fixed, a standing wave is generated in region 10 by the beam formed by the output signals from the multiple antennas, providing almost no power to the devices 250 at the nodes of the standing wave. To avoid this, the power supply device 100 randomly shifts the phase of the multiple transmission signals output from the multiple antenna elements 111 in a time sequence to prevent the nodes of the standing wave from appearing for a long time in a specific location. In other words, the nodes of the standing wave move within region 10. The phase of the transmission signals shifts with time slots. Note that the transmission signals are signals transmitted (powered) from the antenna elements 111 and are signals with a predetermined power.

[0037] In the following text, the term "random beamforming" will be used to describe the transmission of power by randomly shifting the phases of multiple transmission signals output from multiple antenna elements 111 with time slots.

[0038] Furthermore, among the multiple devices 250, there may be a device 250 that requires more power to charge its internal battery 253. For example, a device 250 that consumes more power and has less remaining internal battery 253 compared to other devices 250. Such a device 250 that requires more power is referred to as "specific device 250A". Figure 1 In the diagram, a device 250 at a certain point in time is shown as a specific device 250A. Specific device 250A is an example of the first power receiving device.

[0039] The specific device 250A primarily receives power from multiple antenna elements 111 included in antenna subset 110A. This is to charge the battery 253 of the specific device 250A as early as possible by delivering power in a more concentrated manner than random beamforming. The antenna elements 111 included in antenna subset 110A are an example of a first antenna. The antenna elements 111 not included in antenna subset 110A are an example of a second antenna.

[0040] The power transmission from the multiple antenna elements 111 included in the antenna subset 110A to the specific device 250A is also phase-shifted with time slots. Figure 1 In this context, antenna subset 110A includes four antenna elements 111. The phase shift of antenna subset 110A and the power transmission signal to specific device 250A will be described later.

[0041] Devices other than the designated device 250A among the multiple devices 250 are referred to as "non-designated devices 250B". Non-designated device 250B is an example of a second power receiving device. Depending on the situation, all devices 250 can be designated devices 250A. If the battery 253 is sufficiently charged, the designated device 250A ceases to receive centralized power from the antenna subset 110A and becomes a non-designated device 250B. The non-designated device 250B receives power transmitted via random beamforming from the antenna element 111, which includes the antenna subset 110A. Furthermore, among the multiple non-designated devices 250B, there may also be non-designated devices 250B that consume less power than other non-designated devices 250B and designated devices 250A and do not become designated devices 250A.

[0042] The power supply device 100 is a power supply device that can simultaneously supply power to non-specific device 250B via random beamforming and to specific device 250A from antenna subset 110A. Note that in the following text, without specifically distinguishing between specific device 250A and non-specific device 250B, it will be referred to simply as "device 250".

[0043] Device 250 includes a receiving antenna 251, a control unit 252, and a battery 253, such as Figure 1 The image below is enlarged.

[0044] The receiving antenna 251 is an antenna used to receive power from one or more antenna elements 111. The receiving antenna 251 outputs the received power to the control unit 252 and the battery 253.

[0045] The control unit 252 performs charging control by charging the battery 253 with the received power from the antenna element 111 via the receiving antenna 251, and sends an alarm from the antenna 252A to the control device 140 when the charge level of the battery 253 falls below a predetermined value. As an example, the control unit 252 includes a short-range wireless communication unit such as BLE (Bluetooth Low Energy) or EnOcean, and writes alarm data into the BLE beacon signal, which is then sent from the antenna 252A to the control device 140. Furthermore, if the control unit 252 receives a time slot index detection command (described later), it sends index data indicating the time slot index (time slot number) indicating the maximum received power after a predetermined period of power reception to the control device 140. The control unit 252 receives the power transmission command from the control device 140 when the charge level of the battery 253 falls below a predetermined value. As an example, sending power transmission commands and time slot index detection commands from control device 140 to device 250 can be done via BLE-based communication. Note that index data is an example of information used to determine time slots.

[0046] As an example, battery 253 can be a rechargeable battery or capacitor, which is charged by the power supplied by receiving antenna 251. A power-consuming load can be connected to battery 253. For example, the load can be a sensor for detecting temperature, humidity, etc., in which case device 250 can be regarded as a sensor device. In addition, the load can be a power source such as an electric motor or actuator, and device 250 can also be a device that performs dynamic operations.

[0047] Furthermore, when the device 250 is installed on a movable body, the power charged by the battery 253 can be used as a power source for driving an electric motor or control unit that serves as a load on the movable body.

[0048] The array antenna 110 is an example of a two-dimensional antenna grid, comprising antenna elements 111 arranged in a matrix. For example, there are 16 antenna elements 111 in the X direction and 16 in the Y direction, totaling 256. These 256 antenna elements 111 are located in the XY plane.

[0049] Each antenna element 111 is connected to a microwave source 130 via a power transmission cable 130A, supplying power to the microwave band. Controlled by a control device 140, four antenna elements 111 selected from the 256 antenna elements 111 that constitute antenna subset 110A supply power to a specific device 250A, but also provide secondary power to a non-specific device 250B located near the specific device 250A. Antenna elements 111 not included in antenna subset 110A supply power to the non-specific device 250B via random beamforming, but also receive secondary power from antenna elements 111 relatively close to the specific device 250A. Note that the number of antenna elements 111 included in antenna subset 110A can be any number, as long as there are multiple. Antenna elements 111 are rectangular patch antennas when viewed from above. Antenna elements 111 may also have a ground plane maintained at ground potential on the -Z direction side.

[0050] Each antenna element 111 is mounted on the ceiling, columns, or other structures of the aforementioned large-scale facilities such as the smart factory. For example, the spacing between each antenna element 111 corresponds to several wavelengths of the wavelength in the communication frequency of the antenna element 111. The communication frequency of the antenna element 111 is, for example, envisioned as a microwave band, specifically a 920MHz band frequency.

[0051] In addition, Figure 1 As an example, the diagram shows a specific device 250A receiving power from four antenna elements 111 out of the 256 antenna elements 111 included in the array antenna 110. Thus, the set of multiple antenna elements 111 selected by the control device 140 for powering the specific device 250A is referred to as "antenna subset 110A". Antenna elements 111 not included in antenna subset 110A transmit power via random beamforming while the phase shift of the transmitted signal occurs with time slots. The power transmitted via random beamforming is received by a non-specific device 250B, but is also received secondaryly by the specific device 250A.

[0052] One phase shifter 120 is connected to each antenna element 111 and inserted between each antenna element 111 and the power transmission cable 130A. Figure 1 For ease of explanation, an antenna element 111, a phase shifter 120, and an IC chip 125 are shown in an enlarged manner.

[0053] Phase shifter 120 shifts the transmitted phase of the power transmitted from microwave source 130 via power cable 130A and outputs it to antenna element 111. Phase shifter 120 is an example of a phase adjuster. IC chip 125 includes a measurement unit for measuring the received power's RSSI (Received Signal Strength Indicator) and a BLE communication unit, which transmits a beacon signal to control device 140, the beacon signal including data representing the measured RSSI value. The communication unit of IC chip 125 has an antenna for BLE communication.

[0054] Microwave source 130 is connected to 256 phase shifters 120 to provide microwaves with predetermined power. Microwave source 130 is an example of an electromagnetic wave generator. The microwave frequency is, for example, a frequency in the 920MHz band. Note that although the power supply device 100 is described here as including microwave source 130, it is not limited to microwaves; any electromagnetic wave of a specified frequency is acceptable.

[0055] The control device 140 is an example of a control unit, which is a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and non-volatile memory. As an example, discrete wavelet multitone modulation (DWMT) can be used.

[0056] The control device 140 has an antenna 140A, receives a beacon signal with an alarm written to it from the device 250, and receives a beacon signal containing RSSI values ​​from an IC chip 125 connected to each antenna element 111. Furthermore, the control device 140 receives index data representing a time slot index from a specific device 250A. The index data represents the time slot index at which the received power of the specific device 250A reaches its maximum when determining the phase relationship of the transmission signals of the multiple antenna elements 111 included in the antenna subset 110A. Based on the index data received from the specific device 250A, the phase relationship (phase relationship) of the transmission signals of the multiple antenna elements 111 included in the antenna subset 110A is determined. This will be explained in detail later.

[0057] The control device 140 performs selection control of antenna elements 111 included in antenna subset 110A, phase control of the 256 phase shifters 120, and power output control of microwave generator 130. Phase control of the transmission signals of antenna elements 111 included in antenna subset 110A and phase control of transmission signals of antenna elements 111 not included in antenna subset 110A based on random beamforming are achieved through phase control in the phase shifters 120.

[0058] Figure 2 This diagram illustrates the structure of the control device 140. The control device 140 includes a main control unit 141, a subset selection unit 142, a power transmission control unit 143, and a memory 144. The main control unit 141, subset selection unit 142, and power transmission control unit 143 are shown as function blocks representing the functions of the program executed by the control device 140. Furthermore, the memory 144 functionally represents the memory of the control device 140.

[0059] The main control unit 141 is a processing unit that manages the processing of the control device 140 and performs processing other than that performed by the subset selection unit 142 and the power transmission control unit 143.

[0060] When a beacon signal containing an alarm is received from any device 250, the subset selection unit 142 sends a power transmission command to the device 250. The device 250 that sent the beacon signal containing the alarm is the device 250 with a charge level below a predetermined value, and is a candidate device 250 to become a specific device 250A. After sending the power transmission command, the subset selection unit 142 monitors the received power of all antenna elements 111 and selects multiple antenna elements 111 with a received power intensity (RSSI) above a predetermined value as antenna elements 111 included in the antenna subset 110A. Furthermore, when antenna elements 111 included in the antenna subset 110A are selected, the device 250 that is a candidate for specific device 250A is considered as specific device 250A. Multiple antenna elements 111 with a received power intensity (RSSI) above a predetermined value are located around specific device 250A, and are closer to specific device 250A than multiple antenna elements 111 with a received power intensity (RSSI) below a predetermined value. Alternatively, it could be multiple antenna elements 111 in the higher order of RSSI size.

[0061] The power transmission control unit 143 performs power transmission control for transmitting power from all antenna elements 111. When transmitting power from all antenna elements 111, the power transmission control unit 143 performs power transmission control based on random beamforming (random mode), in which the phase of the transmission signal of all antenna elements 111 is randomly set, and the phase shift is randomly performed in each time slot. This allows region 10 (see...) to... Figure 1The position of the standing wave that generates the transmission signal is not fixed in time, which enables all devices to receive power relatively equally.

[0062] Furthermore, the power transmission control unit 143 executes a power reception monitoring mode, wherein when an antenna subset 110A is constructed via the subset selection unit 142, the power reception at a specific device 250A is monitored to switch the power transmission control of the multiple antenna elements 111 included in the antenna subset 110A from a random mode to a subset mode. In the power reception monitoring mode, similar to the random mode, the phases of the power transmission signals of the multiple antenna elements 111 are randomly set within a specified period, and the phases are randomly shifted for each time slot. The specified period is, for example, a period corresponding to 256 time slots. When index data representing a time slot index is received from a specific device 250A after a predetermined period, the power transmission control unit 143 enters a subset mode and performs power transmission control. In this mode, while maintaining the phase relationship (phase relationship) of the power transmission signals of the multiple antenna elements 111 in the time slot represented by the index data, power transmission is performed by randomly shifting the set of phases (the collection of phases of the power transmission signals of the multiple antenna elements 111) of the power transmission signals of each multiple antenna elements 111 in each time slot. The phase relationship refers to the relationship between the phases of the power transmission signals of the multiple antenna elements 111, and is the relationship between the phase differences of the power transmission signals of the multiple antenna elements 111. When a beacon signal containing data indicating that charging is complete is received from the specific device 250A, the power transmission control unit 143 ends the subset mode and restores the power transmission mode of the multiple antenna elements 111 included in the antenna subset 110A to the random mode.

[0063] Furthermore, when multiple antenna subsets 110A are constructed through the subset selection unit 142, the power transmission control unit 143 also performs the function to be used later. Figures 11 to 21 The processing of the description.

[0064] The memory 144 stores data, programs, etc., used by the main control unit 141, subset selection unit 142, and power transmission control unit 143 during processing. Data representing the phase of the power transmission signal in each time slot is also stored in the memory 144.

[0065] Figure 3 This is an example of antenna subset 110A. Figure 3 Twenty of the 256 antenna elements 111 are shown. As an example, antenna subset 110A includes four antenna elements 111 with antenna grid indices of (4,4), (4,5), (5,4), and (5,5). The antenna grid indices indicate the antenna element 111 in region 10 (see [reference]). Figure 1The index of the position in the antenna grid (4,4), (4,5), (5,4), and (5,5) is located approximately near the center of the antenna subset 110A. The four antenna elements 111 at antenna grid indices (4,4), (4,5), (5,4), and (5,5) are located around the specific device 250A and are closer to the specific device 250A than the multiple antenna elements 111 outside of antenna grid indices (4,4), (4,5), (5,4), and (5,5).

[0066] Figure 4 This is a diagram illustrating the phase of the received signal of a specific device 250A. The I-axis is the real axis, and the Q-axis is the imaginary axis. The four vectors shown as (4,4), (4,5), (5,4), and (5,5) are vectors representing the signals received by the specific device 250A from the antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5).

[0067] If the phase of the signal received by a specific device 250A from the four antenna elements 111 is synchronized, then when the signals received from the antenna elements 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) are added together, a linear vector A is obtained. Vector A represents the maximum received power achieved by synchronizing the phase of the signal received by the specific device 250A from the antenna elements 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5).

[0068] Thus, if the signals received by a specific device 250A from antenna elements 111 with grid indices (4,4), (4,5), (5,4), and (5,5) included in antenna subset 110A are phase-consistent, the composite vector of the four received signals can be maximized. Here, phase consistency is not limited to the case of completely identical phases, but also includes states that are approximately equal to completely identical phases. This is because, sometimes, strict phase consistency is not easy to achieve; for example, if the phase deviation is around ±5%, phase consistency is considered acceptable.

[0069] If the phase relationship of the power transmission signals from antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) is maintained while the phase of the four power transmission signals is shifted, then vector A rotates relative to the I-axis and Q-axis. If the phase relationship of the four power transmission signals is maintained while the phase of the four power transmission signals is shifted, then the maximum power received by the specific device 250A can be maintained, and the specific device 250A can be charged efficiently in a shorter time.

[0070] Furthermore, around antenna subset 110A, multiple antenna elements 111 not included in antenna subset 110A transmit power in a random mode, thus the specific device 250A receives a power transmission signal based on the random mode. The received power based on the random mode received by the specific device 250A is less than the received power received from the multiple antenna elements 111 included in antenna subset 110A. This is because the specific device 250A is closer to the antenna elements 111 within antenna subset 110A compared to the antenna elements 111 outside antenna subset 110A. Here, the power based on the random mode received by the specific device 250A is represented by vector B. Since the phase is shifted by the random mode in each time slot, vector B rotates randomly by 360 degrees as shown by the dashed arrow.

[0071] That is, in region 10 (see Figure 1 When transmitting power based on random and subset modes within a given area, the 250A received power of a specific device becomes determined by... Figure 4 The received power represented by the composite vector of vectors A and B shown, although containing variations in random patterns, is dominated by the contribution of vector A in the power received signal of a specific device 250A, which can increase the received power.

[0072] Figure 5 This is a diagram illustrating a method for determining the phase relationship of the transmission signals of multiple antenna elements 111 in a power monitoring receiving mode. Figure 5 The table on the upper side is divided into time slots horizontally, with time slot indices ranging from 1 to L, for example, L being 256. Furthermore, the table shows antenna grid indices vertically, illustrating the phases of the transmission signals for antenna elements 111 at (4,4), (4,5), (5,4), and (5,5). The phases of the four transmission signals are randomly set among antenna elements 111 within each time slot and are randomly shifted over each time slot.

[0073] Figure 5 The lower side shows the received power (dBm) of a specific device 250A in time slot indices 1 to L. The specific device 250A can store the received power in each time slot in the memory within the control unit 252, or it can compare the received power and update it to the time index where the received power has reached its maximum up to the current time. Figure 5As an example, the following situation illustrates that in power reception from time slot indices 1 to L, the maximum received power occurs at time slot index 4, where the phase indices of the transmission signals of antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) are 29, 11, 3, and 24. In this case, the device 250A sends index data indicating time slot index 4 to the control device 140. The phase index is represented by a value that normalizes the phase; the larger the value, the larger the phase value. Note that the device 250A can start counting time slots using the timing of transmitting beacon signals or during periods when no power is being transmitted from the array antenna 110. If such timing is used, the device 250A can easily use it as a trigger to start counting time slots. Furthermore, when the device 250A and the control device 140 share time slot information, for example, counting time slots can begin at the timing of detecting the frame header of a frame containing time slot indices 1 to L.

[0074] In this way, by informing the control device 140 of the time slot index when the received power of a specific device 250A is at its maximum using index data, the phase relationship of the transmitted signal when the received power is at its maximum can be communicated from the specific device 250A to the control device 140, enabling power transmission with a phase relationship that allows for efficient power reception. Since the index data only needs to be data that can determine one of the 256 time slot indices, an 8-bit data size is sufficient.

[0075] When the phase of the transmission signal of antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), (5,5) is maintained at a phase relationship with phase differences of 29, 11, 3, and 24, the received power of specific device 250A reaches its maximum. If this phase difference relationship is maintained, the received power of specific device 250A is as follows: Figure 4 As shown, four states with consistent (or nearly consistent) power receiving vectors are obtained, enabling efficient power receiving.

[0076] Therefore, while maintaining the phase relationship, the power supply device 100 randomly shifts the phase of the transmission signal of the antenna element 111 with antenna grid index (4,4), (4,5), (5,4), (5,5) in each time slot to supply power from the antenna subset 110A to the specific device 250A.

[0077] Figure 6 This is a diagram illustrating the phase index. In Figure 6As an example, the diagram shows the phase index obtained by dividing 360 degrees into 64 parts. When the phase index is 1, the phase is 0 degrees; each time the phase index increases, the phase increases by 360 degrees / 64. This phase index is obtained using PSK (Phase Shift Keying).

[0078] Figure 7 This diagram illustrates an example of the phase index PI assigned to antenna elements 111 of antenna subset 110A. The transmission phase index PI of the transmission signals for antenna elements 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) is set to 29, 11, 3, and 24, respectively. Power supply device 100 supplies power from antenna subset 110A to specific device 250A while randomly shifting the phase of the transmission signals in each time slot while maintaining the phase relationship.

[0079] Figure 8 This is a diagram illustrating an example of setting the phase index of antenna element 111 to antenna subset 110A in subset mode. (See diagram for example.) Figure 8 As shown, when the time slot index is 1, the phase index PI of the transmission signal of the antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) is set to 29, 11, 3, and 24. Furthermore, the phase index PI of the transmission signal of the antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) and a time slot index of 2 or higher is randomly shifted while maintaining the phase relationship as when the time slot index is 1.

[0080] When the time slot index is 1, the phase index PI of the transmission signal of antenna element 111 with antenna grid indices (4,4) and (4,5) is 29 and 11, with a difference of 18. When the time slot index is 1, the phase index PI of the transmission signal of antenna element 111 with antenna grid indices (4,4) and (5,4) is 29 and 3, with a difference of 26. When the time slot index is 1, the phase index PI of the transmission signal of antenna element 111 with antenna grid indices (4,4) and (5,5) is 29 and 24, with a difference of 5.

[0081] The phase index PI of the transmission signal of antenna element 111 with a time slot index of 2 or higher and antenna grid indices of (4,4), (4,5), (5,4), and (5,5) is randomly shifted while maintaining the phase difference described above. For example, when the time slot index changes from 1 to 2, each of the four phase indices increases by 30. When the time slot index changes from 2 to 3, each of the four phase indices decreases by 40. Note that, as an example, the phase index is represented by values ​​from 1 to 64. Therefore, when the time slot index changes from 2 to 3, the phase index PI of the transmission signal of antenna element 111 with antenna grid index (5,4) is 33 - 40 = -7, represented as 57 (-7 plus 64). This phase relationship of the four phase indices remains the same after the time slot index changes from 3 to 4.

[0082] Figure 9 This is a flowchart illustrating the process executed by the control device 140. When the process begins, the power transmission control unit 143 transmits power from all antenna elements 111 in a random mode (step S1). In the random mode, the power transmission control unit 143 performs power transmission control by random beamforming, wherein the phase of the power transmission signal of all antenna elements 111 is randomly set, and the phase is randomly shifted in each time slot.

[0083] The subset selection unit 142 determines whether a beacon signal containing an alarm has been received from any device 250 (step S2). Devices 250 whose battery 253's charge level is below a predetermined value write alarm data into their BLE beacon signals and send it to the control device 140. Step S2 involves determining whether a beacon signal containing such an alarm has been received. Since the beacon signal contains the ID (Identifier) ​​of each device 250, the device 250 that is the source of the signal can be identified through the beacon signal. When a beacon signal containing an alarm is received, the subset selection unit 142 detects that a device 250 has a charge level below a predetermined value.

[0084] When it is determined that a beacon signal containing an alarm has been received (S2: Yes), the subset selection unit 142 sends a power transmission command to the corresponding device 250 to perform power transmission (step S3).

[0085] The subset selection unit 142 monitors the received power of all antenna elements 111 and determines whether there are multiple antenna elements 111 whose received signal RSSI value is above a specified value (step S4).

[0086] When it is determined that there are multiple antenna elements 111 with RSSI values ​​of receiving signals above a specified value (S4: Yes), the subset selection unit 142 selects multiple antenna elements 111 with RSSI values ​​above the specified value and constructs an antenna subset 110A using these multiple antenna elements 111 (step S5).

[0087] When antenna subset 110A is set via subset selection unit 142, power transmission control unit 143 sends a time slot index detection command to specific device 250A (step S6). The time slot index detection command is a command that performs the following processing within a specified period and detects that the time slot index in specific device 250A reaches its maximum power reception. The processing refers to... Figure 5 The phase of the transmission signal of the multiple antenna elements 111 of the antenna subset 110A is randomly set, and the phase of the transmission signal is randomly shifted in each time slot.

[0088] The power transmission control unit 143 executes the power receiving monitoring mode (step S7), in which the phase of the transmission signals of the multiple antenna elements 111 of the antenna subset 110A is randomly set within a specified period, and the phase shift is randomly performed in each time slot to transmit power. Thus, it has... Figure 5 The phase indexed transmission signal shown is transmitted from multiple antenna elements 111 of antenna subset 110A.

[0089] The power transmission control unit 143 determines whether it has received index data representing the time slot index from the specific device 250A (step S8). The specific device 250A sends the time slot index where the received power reaches its maximum during the specified period in step S7 as index data to the power transmission control unit 143.

[0090] When it is determined that index data has been received (S8: Yes), the power transmission control unit 143 performs power transmission control (step S9), wherein, while maintaining the phase relationship in the time slot represented by the index data, power transmission is performed while shifting the phase of the transmission signals of the multiple antenna elements 111 of the antenna subset 110A in each time slot. Thus, the subset mode is executed: while maintaining the phase relationship in the time slot represented by the index data, power transmission is performed while shifting the phase of the transmission signals of the multiple antenna elements 111 of the antenna subset 110A in each time slot. Figure 8 When the received power reaches the maximum phase relationship, the phase shift of the transmission signal of the multiple antenna elements 111 of the antenna subset 110A is adjusted in each time slot.

[0091] The power transmission control unit 143 determines whether the charging of the specific device 250A is complete (step S10). When a beacon signal containing data indicating that charging is complete is received from the specific device 250A, the power transmission control unit 143 determines that the charging of the specific device 250A is complete.

[0092] When it is determined that charging of a specific device 250A is complete (S10: Yes), the power transmission control unit 143 terminates the subset mode, causing the power transmission mode of the multiple antenna elements 111 included in the antenna subset 110A to return to the random mode (step S11). This concludes the series of processes (end).

[0093] Note that if it is determined in step S2 that no beacon signal containing an alarm has been received (S2: No), the subset selection unit 142 returns the process to step S1 and continues in random mode. This is because there is no device 250 to be charged by constructing antenna subset 110A.

[0094] Furthermore, if in step S4 it is determined that there are no multiple antenna elements 111 with RSSI values ​​above a predetermined value for receiving a power signal (S4: No), the subset selection unit 142 returns the process to step S3. This is to power on the corresponding device 250 and to search for antenna elements 111 that form the antenna subset 110A again. Note that in step S4 after returning the process to step S3, if the subset selection unit 142 determines that there are no multiple antenna elements 111 with RSSI values ​​above a predetermined value for receiving a power signal (S4: No), the series of processes can also be terminated (end). This is to restart from the beginning.

[0095] Furthermore, if it is determined in step S8 that no index data has been received (S8: No), the power transmission control unit 143 returns the process to step S6. This is to repeat the processing of steps S6 and S7. Note that if, after repeating the processing of steps S6 and S7, it is again determined in step S8 that no index data has been received (S8: No), the series of processes can also be terminated (end). This is to restart from the beginning.

[0096] Furthermore, if it is determined in step S10 that charging of a specific device 250A is incomplete (S10: No), the power transmission control unit 143 returns the process to step S9. This is to continue charging.

[0097] Figure 10 This is a graph showing the simulation results of the cumulative distribution function (CDF) of the received electricity. Figure 10 In the diagram, the dashed line represents the power distribution of a specific device 250A when power is received in subset mode with the number of antenna elements 111 of antenna subset 110A set to 4, the number of time slot indices L in power reception monitoring mode set to 256, and the time slot index feedback after maximizing power reception. Note that it is also affected by antenna elements 111 in the random mode from the surrounding area outside the antenna elements 111 of antenna subset 110A. The solid line represents the power distribution of a specific device 250A when power is received in subset mode with the number of antenna elements 111 of antenna subset 110A set to 4 and the phase of the transmission signal based on conventional technology fully optimized. Furthermore, the double-dotted line represents the power distribution of a specific device 250A when power is delivered from all antenna elements 111 in random mode.

[0098] In the double-dotted random mode, the received power varies considerably between -40dBm and -5dBm. On the other hand, in the dashed subset mode, with a CDF of 0.5, the received power increases by approximately 5dBm, and the variation in received power is reduced. In subset mode, within a defined area of ​​the plurality of antenna elements 111 included in the antenna subset 110A, compared to the random mode, the received power can be increased at the cost of slightly fixing the position of the standing wave that generates the transmission signal in time.

[0099] In subset mode, received power can be increased even when the time slot index L is small. That is, in subset mode, received power can be increased even when the time slot index L is small. Furthermore, the phase relationship of the optimal transmission signal that increases received power can be detected with a shorter search time (or number of attempts) that reduces the time slot index L.

[0100] Similarly, the improvement in power reception is minimal in the solid-line subset mode compared to the dashed-line subset mode. Phase optimization of the transmission signal in the solid-line subset mode is a conventional technique where the phase of the transmission signal is optimized based on the phase of the received signal in the antenna array of a power supply device, which transmits pilot signals from a specific device to each antenna array using a method such as Channel State Information (CSI) feedback. In conventional techniques, each antenna array requires hardware for detecting the phase of the received signal, increasing the size of the power supply device. That is, the subset mode enables miniaturization of the power supply device.

[0101] Additionally, the control device 140 may sometimes receive alarms from multiple devices 250. In this case, multiple specific devices 250A will appear, and multiple antenna subsets 110A will be constructed through the subset selection unit 142.

[0102] Figure 11 This diagram illustrates one example of multiple antenna subsets 110A1 to 110A5. Figure 11 As an example, an array antenna 110 comprising 24 antenna elements 111 is shown, wherein 4 are arranged longitudinally and 6 are arranged laterally. Although Figure 11 The diagram shows 24 antenna elements 111, but the array antenna 110 may include more antenna elements 111. Furthermore, in Figure 11 In this design, the 24 antenna elements 111 are distinguished by being assigned numbers 25–30, 33–38, 41–46, and 49–54. These numbers are antenna grid indices. Figure 11 The antenna grid index shown is Figures 3 to 5 , Figure 7 as well as Figure 8The antenna grid indices shown are labeled in different ways, but they have the same meaning.

[0103] Figure 11 The diagram shows six specific devices 250A(SD1) to 250A(SD6) and six antenna subsets 110A1 to 110A6. In the following text, specific devices 250A(SD1) to 250A(SD6) are sometimes simply referred to as "SD1 to SD6". Furthermore, unless otherwise specified, antenna subsets 110A1 to 110A6 are simply referred to as "antenna subset 110A".

[0104] For specific device SD1, antenna subset 110A1 was constructed, which includes four antenna elements 111: 26, 33, 34, and 35. For specific device SD2, antenna subset 110A2 was constructed, which includes four antenna elements 111: 37, 38, 45, and 46.

[0105] For the specific device SD3, an antenna subset 110A3 was constructed, which includes antenna elements 111 numbered 44, 45, 52, and 53. For the specific device SD4, an antenna subset 110A4 was constructed, which includes four antenna elements 111 numbered 41, 42, 49, and 50.

[0106] For the specific device SD5, an antenna subset 110A5 was constructed, which includes four antenna elements 111: 35, 36, 43, and 44. For the specific device SD6, an antenna subset 110A6 was constructed, which also includes four antenna elements 111: 35, 36, 43, and 44.

[0107] Thus, antenna element 111 (number 35) included in antenna subset 110A1 is shared with antenna element 111 (number 35) included in antenna subsets 110A5 and 110A6. Antenna element 111 (number 45) included in antenna subset 110A2 is shared with antenna element 111 (number 45) included in antenna subset 110A3. Antenna element 111 (number 44) included in antenna subset 110A3 is shared with antenna element 111 (number 44) included in antenna subsets 110A5 and 110A6.

[0108] For antenna subset 110A4, which does not include antenna element 111 shared with other antenna subsets 110A1, 110A2, 110A3, 110A5 and 110A6, centralized power supply in subset mode for specific device SD4 can be achieved as long as the phase relationship of the power transmission signal is maintained in a way that makes the phase of the power transmission signal transmitted from the four antenna elements 111 consistent in specific device SD4, and the phase is changed in a time sequence.

[0109] However, when multiple antenna subsets 110A, such as antenna subsets 110A1, 110A2, 110A3, 110A5, and 110A6, include at least one common antenna element 111, it is difficult to maintain the phase relationship of the transmission signal in the same time slot while simultaneously changing the phase sequentially over time. Therefore, when multiple antenna subsets 110A include at least one common antenna element 111, the timing of centralized power supply from the antenna subsets 110A in subset mode is staggered.

[0110] Figure 12 This is a diagram illustrating the structure of a frame. A frame is a data packet used by the storage control device 140 to cause the antenna element 111 to transmit a data packet as a power transmission signal. A frame contains multiple subframes. Each subframe has multiple time slots 1 to L. In this embodiment, for multiple antenna subsets 110A that include at least one common antenna element 111, power is transmitted from the antenna subset 110A in subset mode in different subframes. Furthermore, for multiple antenna subsets 110A that do not include the common antenna element 111, power is transmitted from the antenna subset 110A in subset mode in the same subframe.

[0111] That is, for Figure 11 The antenna subsets 110A1 to 110A6 shown, for example, can perform subset-mode-based power transmission within the same subframe because antenna subsets 110A1 and 110A2 do not share an antenna element 111. Similarly, subset-mode-based power transmission can also be performed within the same subframe for antenna subsets 110A1 and 110A3. Furthermore, subset-mode-based power transmission can also be performed within the same subframe for antenna subsets 110A1 and 110A4.

[0112] Furthermore, power transmission based on subset pattern can also be performed within the same subframe for antenna subsets 110A2 and 110A4. Similarly, power transmission based on subset pattern can also be performed within the same subframe for antenna subsets 110A2 and 110A5. Finally, power transmission based on subset pattern can also be performed within the same subframe for antenna subsets 110A2 and 110A6.

[0113] Furthermore, power transmission based on subset pattern can also be performed within the same subframe for antenna subsets 110A3 and 110A4. Similarly, power transmission based on subset pattern can also be performed within the same subframe for antenna subsets 110A4 and 110A5. Finally, power transmission based on subset pattern can also be performed within the same subframe for antenna subsets 110A4 and 110A6.

[0114] On the other hand, for antenna subsets 110A1 and 110A5, since antenna element 111 (number 35) is shared, power transmission based on subset pattern is performed in different subframes. Here, the subframe in antenna subset 110A1 that performs subset pattern power transmission to a specific device SD1 is an example of one of multiple subframes contained in one frame. The specific device SD1 that performs subset pattern power transmission through antenna subset 110A1 is an example of one of the multiple specific devices SD1 to SD6, specifically a first power receiving device. The four antenna elements 111 included in antenna subset 110A1 are an example of multiple first antennas located around a first power receiving device.

[0115] Furthermore, antenna subset 110A5, which performs subset-mode-based power transmission in a subframe different from antenna subset 110A1, is shown below. The subframe in antenna subset 110A5 that performs subset-mode-based power transmission for a specific device SD5 is an example of another subframe among multiple subframes contained within a single frame. The specific device SD5 that performs subset-mode-based power transmission via antenna subset 110A5 is an example of another first power receiving device among multiple specific devices SD1 to SD6. The four antenna elements 111 included in antenna subset 110A5 are an example of multiple first antennas located around another first power receiving device.

[0116] Furthermore, for antenna subsets 110A1 and 110A6, subset-mode-based power transmission is also performed in different subframes. For antenna subsets 110A2 and 110A3, subset-mode-based power transmission is also performed in different subframes. For antenna subsets 110A3 and 110A5, subset-mode-based power transmission is also performed in different subframes. For antenna subsets 110A3 and 110A6, subset-mode-based power transmission is also performed in different subframes. For antenna subsets 110A5 and 110A6, subset-mode-based power transmission is also performed in different subframes.

[0117] In subframes other than those where subset-mode power transmission is performed via antenna subsets 110A1 to 110A6, specific devices SD1 to SD6 primarily receive power transmission signals based on random beamforming. That is, in specific devices SD1 to SD6, in subframes other than those where subset-mode power transmission is performed via antenna subsets 110A1 to 110A6, power reception is significantly reduced due to the lack of subset-mode power transmission, and therefore they wait for subset-mode power transmission in the next subframe.

[0118] Here, although the number of subframes can be increased within a frame, the frame length is limited. Therefore, the side with fewer subframes has a shorter waiting time for subset-based power transmission in the subframes waiting for the next frame, which enables efficient subset-based power transmission to a specific device 250A.

[0119] On the other hand, if too many specific devices 250A receive power based on subset patterns in a subframe, the number of antenna elements 111 included in antenna subset 110A increases, and the power of the random beamforming power transmission signal that powers non-specific devices 250B decreases.

[0120] Therefore, considering the power received by the non-specific device 250B through random beamforming, it is preferable that the number of subframes in a frame is set to be as small as possible.

[0121] Furthermore, if the difference in the number of specific devices 250A receiving power based on subset pattern transmission in each subframe is large, the difference in the amount of power received by each specific device 250A through subset pattern transmission in each frame will increase. Therefore, it is preferable that the number of specific devices 250A receiving power through subset pattern transmission in each subframe is equalized.

[0122] Therefore, in this embodiment, antenna subsets 110A1 to 110A6 are assigned to subframes as follows.

[0123] Figure 13 This is a diagram showing the allocation order data. Here, the scoring method and allocation order determination method for specific devices SD1 to SD6 are explained using the allocation order data. The processing of scoring specific devices SD1 to SD6 and the processing of determining the allocation order are handled by the transmission control unit 143 (see...). Figure 2 )implement.

[0124] The IDs of specific devices SD1 through SD6 in the allocation order data are 1 through 6, respectively. The leftmost column of the allocation order data table shows the IDs (1 through 6) of specific devices SD1 through SD6 from top to bottom. In addition, the top row shows the IDs (1 through 6) of specific devices SD1 through SD6 from left to right.

[0125] The allocation order data represents the number of antenna elements 111 shared by the antenna subset 110A corresponding to each of the specific devices SD1 to SD6 and the antenna elements 111 shared by the antenna subset 110A corresponding to other specific devices 250A.

[0126] For example, in the case of a specific device SD1, the number of antenna elements 111 shared by the corresponding antenna subset 110A1 and the antenna elements 111 shared by the antenna subset 110A2 corresponding to another specific device SD2 is 0. Therefore, the number of antenna elements 111 shared by specific devices SD1 and SD2 is 0. Furthermore, the number of antenna elements 111 shared by specific devices SD1 and SD3 is 0. Similarly, the number of antenna elements 111 shared by specific devices SD1 and SD4 is 0.

[0127] Furthermore, the number of shared antenna elements 111 for specific devices SD1 and SD5 is 1, and the number of shared antenna elements 111 for specific devices SD1 and SD6 is 1. This is because antenna element 111 is shared by all devices.

[0128] The number of shared antenna elements 111 for specific devices SD2 and SD3 is 1. This is because antenna element 111, number 45, is shared in antenna subsets 110A2 and 110A3. The number of shared antenna elements 111 for specific devices SD2 and SD4–SD6 is 0.

[0129] The number of shared antenna elements 111 for specific devices SD4 and SD5-SD6 is 0. The number of shared antenna elements 111 for specific devices SD5 and SD6 is 4. This is because antenna elements 111 35, 36, 43, and 44 are shared.

[0130] If the number of shared antenna elements 111 for specific devices SD1 to SD6 is calculated in this way, then the scores for specific devices SD1 to SD6 are calculated. As an example, for each specific device 250A, the score is the sum of the number of antenna elements 111 shared by it and other specific devices 250A. The score is an example of the degree of sharing, representing the extent to which multiple antenna elements 111 included in the antenna subset 110A corresponding to two specific devices 250A share antenna elements 111 with each other. The more shared antenna elements 111, the higher the score (degree of sharing). The scores for specific devices SD1 to SD6 are 2, 1, 3, 0, 6, and 6, respectively.

[0131] If a score is calculated for specific devices SD1 to SD6, it is determined in which of the multiple subframes within a single frame will the specific device 250A be powered from antenna subset 110A based on a subset pattern. Here, subframes are allocated to specific devices SD1 to SD6 sequentially, starting with the one with the highest score.

[0132] The order in which subframes are allocated to specific devices SD1 through SD6 is called the allocation order. Thus, the allocation order determined by the score is an example of an order based on the degree of sharing. The allocation orders for specific devices SD1 through SD6 are 4, 5, 3, 6, 1, 2, respectively. Here, since specific devices SD5 and SD6 both have a score of 6, as an example, the allocation order for specific device SD5, which has the smaller ID number, is set before that of specific device SD6.

[0133] Figures 14 to 18 It indicates the ID of the specific device SD1 to SD6 assigned to the subframe. Figures 14 to 18 The diagram illustrates, in stages, the allocation of subframes for specific devices SD1 to SD6 according to the allocation order. This process is handled by the transmission control unit 143 (see [link]). Figure 2 )implement.

[0134] In order to Figure 11 The antenna subsets 110A1 to 110A6 shown do not overlap and require at least 3 subframes. Here, for specific devices SD1 to SD6, the ideal number of subframes is 3, taking into account the balance to minimize the number of subframes and to equalize the number of specific devices 250A receiving subset-based power transmission in each subframe.

[0135] exist Figures 14 to 18 The leftmost column shows the subframe index. The subframe index represents the number of multiple subframes within a frame, with subframe index 1 being the first subframe. Subframe indices are numbered sequentially starting from the first subframe.

[0136] In addition, Figures 14 to 18 In the diagram, the four numbers enclosed in parentheses below the IDs of specific devices SD1 to SD6 are the antenna grid indices of the four antenna elements 111 included in the antenna subsets 110A1 to 110A6 corresponding to specific devices SD1 to SD6. For the antenna grid indices of the four antenna elements 111, as an example, they are labeled from left to right in the order of the antenna element 111 with the highest RSSI value of the power transmission command sent by specific devices SD1 to SD6, up to the fourth highest value.

[0137] First, such as Figure 14As shown, the specific device SD5, which is the first in the allocation order, is assigned to the subframe with subframe index 1. Here, as an example, in the case where there are multiple subframes with no specific device 250A assigned, the allocation starts from the subframe with the smaller subframe index number.

[0138] Next, as Figure 15 As shown, because specific device SD5 and antenna element 111 are duplicated (shared), specific device SD6, which is the second in the allocation order, avoids the first subframe for specific device SD5 and is allocated to the second subframe. Furthermore, in Figure 15 In the process, for a specific device SD3, which is the 3rd in the allocation order, it is assigned to the 3rd subframe, bypassing the 1st and 2nd subframes, because it has an antenna element 111 shared with specific devices SD5 and SD6.

[0139] Next, as Figure 16 As shown, for the specific device SD1, which is the 4th in the allocation order, although it shares antenna element 111 with specific devices SD5 and SD6, it is allocated to subframe 3 instead of subframes 1 and 2 because it does not share antenna element 111 with specific device SD3. From the perspective of equalization, it would be ideal for the remaining specific devices SD2 and SD4 to be allocated one antenna element each in subframes 1 and 2.

[0140] Next, as Figure 17 As shown, for the specific device SD2, which is the 5th device in the allocation order, although it shares antenna element 111 with the specific device SD3, it can be allocated to subframe 1 or 2 by avoiding subframe 3 because it does not share antenna element 111 with the specific devices SD5 and SD6. Here, in the case where there are multiple subframes that can be allocated, as an example, it is allocated to the one with the smaller subframe index number. Therefore, the specific device SD2 is allocated to subframe 1.

[0141] Finally, for the specific device SD4, which is the 6th device in the allocation order, since there is no antenna element 111 shared with other specific devices SD1-SD3, SD5, and SD6, it can also be allocated to any subframe from 1 to 3. Here, based on the two viewpoints of minimizing the number of subframes and equalizing the number of specific devices 250A receiving subset-mode power transmission in each subframe, as... Figure 18 As shown, the specific device SD4 is assigned to subframe 2.

[0142] As a result, a combination of specific devices 250A that balances minimizing the number of subframes and equalizing the number of specific devices 250A receiving subset-based power transmissions in each subframe is determined.

[0143] Furthermore, since subframes are allocated starting with specific devices 250A with higher allocation order, it is possible to determine subframes starting with specific devices 250A that share a large number of antenna elements 111 with other specific devices 250A. Therefore, it is easier to perform the process of allocating all specific devices 250A to multiple subframes. This is because if subframe allocation starts with specific devices 250A that share fewer antenna elements 111 with other specific devices 250A, it would be difficult to find a subframe that can ultimately be allocated to specific devices 250A that share a large number of antenna elements 111 with other specific devices 250A.

[0144] Figure 19 This is a flowchart illustrating the processing performed by the power transmission control unit 143. As a prerequisite, it is assumed that multiple specific devices 250A exist, and multiple antenna subsets 110A are constructed by the subset selection unit 142.

[0145] When processing begins, the power transmission control unit 143 creates a subframe with subframe index 1 in the frame (step S21).

[0146] The power transmission control unit 143 determines the allocation order for each specific device 250A (step S22). The power transmission control unit 143 calculates a score for each specific device 250A and determines the allocation order based on the score. This generates... Figure 13 The data shown includes the allocation order, which contains scores and allocation order.

[0147] The power transmission control unit 143 reads the highest-level specific device 250A among the specific devices 250A that have not been allocated a subframe in the allocation sequence data created in step S22 (step S23).

[0148] The power transmission control unit 143 performs a cyclic comparison between the specific device 250A read in step S23 and the specific device 250A already allocated to a subframe, and detects specific devices 250A with shared antenna elements 111 and subframes that have allocated such specific devices 250A (step S24). Note that for specific devices 250A that are allocated in the first position, since there are no specific devices 250A already allocated to a subframe, the shared antenna elements 111 are not detected.

[0149] The power transmission control unit 143 determines whether there is a subframe of antenna element 111 that is not shared with the specific device 250A read in step S23 (step S25).

[0150] When it is determined that there is a subframe in which there is no shared antenna element 111 (S25: Yes), the power transmission control unit 143 allocates the specific device 250A read in step S23 to the subframe with the smallest allocation number of specific device 250A and the smallest subframe index among the subframes in step S25 where there is no shared antenna element 111 (step S26A). That is, the power transmission control unit 143 allocates the specific device 250A read in step S23 based on the two viewpoints of minimizing the number of subframes and equalizing the number of specific devices 250A receiving power transmission based on subset pattern in each subframe.

[0151] Furthermore, when it is determined that there is no subframe in which a shared antenna element 111 does not exist (step S25: No), the power transmission control unit 143 adds a new subframe to the frame and assigns the added subframe to the specific device 250A read in step S23 (step S26B).

[0152] When the processing of step S26A or S26B is completed, the power transmission control unit 143 determines whether the allocation of subframes has been completed for all specific devices 250A included in the allocation sequence data (step S27).

[0153] When it is determined that subframe allocation has not been completed for all specific devices 250A (S27: No), the power transmission control unit 143 returns the process to step S23. As a result, the processing of steps S23 to S26 is repeated for the remaining specific devices 250A.

[0154] Furthermore, when it is determined in step S27 that subframe allocation has been completed for all specific devices 250A (S27: Yes), the power transmission control unit 143 terminates a series of processes (end).

[0155] Figure 20 This is a diagram showing the simulation results after a specific device 250A was assigned to a subframe. Figure 20 (A) shows the result of allocating a specific device 250A to a subframe using allocation order data. Figure 20 (B) shows the result of allocating the specific device 250A to the subframe sequentially, starting from the smaller of the numbers of the IDs of the specific device 250A, without using allocation order data, using the same allocation steps.

[0156] exist Figure 20 (A) and Figure 20 In (B), for each subframe index, a gray-filled grid frame indicates the number of IDs assigned to a specific device 250A within the subframe. Note that in Figure 20 (A) and Figure 20 In (B), the number of specific devices 250A is 30.

[0157] like Figure 20 As shown in (A), with the allocation order data used, six specific devices 250A are allocated to each of the five subframes. The number of specific devices 250A allocated to all subframes is equal.

[0158] On the other hand, such as Figure 20 As shown in (B), without using allocation order data, specific device 250A was allocated to 7 subframes, but the number of specific device 250A allocated to each subframe varied. Although 6 specific devices 250A were allocated to subframe with subframe index 1, 5 specific devices A were allocated to subframes 3 and 6, 4 specific devices A were allocated to subframes 2, 4, and 5, and 2 specific devices A were allocated to subframe 7.

[0159] Compare Figure 20 (A) and Figure 20 As can be seen from (B), by using allocation order data, in step S26A, the specific device 250A read in step S23 is allocated to the subframe with the smallest allocation number of specific device 250A and the smallest subframe index in the subframe where there are no shared antenna elements, thereby suppressing the increase in the number of subframes and making the number of specific devices 250A allocated to each subframe equal. Figure 20 As shown in (A), the method of this embodiment enables equalized spatial multiplexing by allocating an equal number of specific devices 250A to each subframe. In other words, the method of this embodiment enables time-space scheduling, which enables efficient frame-time power transmission to multiple specific devices 250A based on a subset pattern.

[0160] Figure 21 This diagram illustrates an example of the drive data. The drive data is the data used by the power transmission control unit 143 when driving the array antenna 110 on a per-frame basis. The drive data includes the IDs and antenna grid indices of specific devices SD1 to SD6 assigned to the subframe, as well as the antenna grid index of the antenna element 111 that transmits the power transmission signal for random beamforming. In addition, the drive data includes the subframe with subframe index 0. Figure 21 The driving data shown is for Figure 18 The data shown includes data appended to subframe 0 and the antenna grid index of antenna element 111 used for random beamforming in subframes 1 to 3.

[0161] As an example, in subframe 0, the antenna grid indexes of all antenna elements 111 included in the array antenna 110 are registered. In subframe 0, all antenna elements 111 transmit power signals for random beamforming. Furthermore, in subframe 0, the following is performed: Figure 9The processes shown are steps S1 to S8. Therefore, in subframe 0, the specific device 250A is determined through the process in step S8, and then... Figure 19 The processing steps S21 to S27 shown are as follows.

[0162] In subframes 1 through 3, antenna elements 111 included in antenna subset 110A corresponding to specific device 250A transmit transmission signals for subset-based power transmission, and other antenna elements 111 transmit transmission signals for random beamforming. In subframes 1 through 3, for antenna elements 111 included in antenna subset 110A, [the following is performed / conducted / etc.] Figure 9 The processing steps S9 to S11 are shown. Furthermore, for other antenna elements 111, the same processing as in subframe 0 is performed.

[0163] exist Figure 21 In the driving data shown, in subframe 1, the antenna grid indices 35, 43, 36, 44, 45, 37, 46, and 38 of the antenna elements 111 included in the antenna subsets 110A5 and 110A2 corresponding to specific devices SD5 and SD2 are registered. Therefore, the antenna grid indices of the other antenna elements 111 are the numbers obtained by removing antenna grid indices 35, 43, 36, 44, 45, 37, 46, and 38 from the antenna grid indices of all antenna elements 111 included in the array antenna 110.

[0164] In subframe 1, the antenna elements 111 included in the antenna subsets 110A6, 110A4, 110A3 and 110A1 corresponding to specific devices SD6, SD4, SD3 and SD1 transmit power signals for random beamforming.

[0165] Furthermore, in subframe 2, the antenna grid indices 36, 35, 44, 43, 42, 50, 41, and 49 of the antenna elements 111 included in the antenna subsets 110A6 and 110A4 corresponding to specific devices SD6 and SD4 are registered. Therefore, the antenna grid indices of the other antenna elements 111 are the numbers obtained by removing antenna grid indices 36, 35, 44, 43, 42, 50, 41, and 49 from the antenna grid indices of all antenna elements 111 included in the array antenna 110.

[0166] In subframe 2, the antenna elements 111 included in the antenna subsets 110A5, 110A2, 110A3 and 110A1 corresponding to specific devices SD5, SD2, SD3 and SD1 transmit power signals for random beamforming.

[0167] Furthermore, in subframe 3, the antenna grid indices 53, 45, 52, 44, 34, 26, 35, and 33 of the antenna elements 111 included in the antenna subsets 110A3 and 110A1 corresponding to specific devices SD3 and SD1 are registered. Therefore, the antenna grid indices of the other antenna elements 111 are the numbers obtained by removing the antenna grid indices 53, 45, 52, 44, 34, 26, 35, and 33 from the antenna grid indices of all antenna elements 111 included in the array antenna 110.

[0168] In subframe 3, the antenna elements 111 included in the antenna subsets 110A5, 110A2, 110A6 and 110A4 corresponding to specific devices SD5, SD2, SD6 and SD4 transmit power signals for random beamforming.

[0169] As described above, the power supply device 100 supplies power to a specific device 250A in a subset mode from antenna elements 111 included in antenna subset 110A, and supplies power to a non-specific device 250B in a random mode from antenna elements 111 not included in antenna subset 110A. In subset mode, while maintaining the phase relationship of the power supply signal that maximizes the power received in the specific device 250A, the phase set of the power supply signals of the multiple antenna elements 111 included in antenna subset 110A is randomly shifted per time slot. Furthermore, in random mode, the phase of the power supply signal supplying power to the non-specific device 111B is randomly shifted per antenna element 111 and per time slot.

[0170] In addition, each frame is divided into multiple subframes, including antenna subsets 110A of the shared antenna element 111. In order to transmit power based on subset patterns in mutually different subframes, the phase relationship of the transmission signals is maintained in such a way that the phase of the transmission signal for receiving power by a particular device 250A is consistent, while the phase changes in a time sequence.

[0171] Therefore, a power supply device 100 and a power supply method can be provided, which can simultaneously supply power to multiple specific devices 250A that require a large amount of power and to non-specific devices 250B. Furthermore, in subset mode, while maintaining the phase relationship of the transmission signals of the multiple antenna elements 111 included in antenna subset 110A, the phase of the transmission signals of the multiple antenna elements 111 is randomly shifted in each time slot. Therefore, the random effects on power transmission caused by the random patterns of antenna elements 111 outside antenna subset 110A are not reduced, and subset modes within antenna subset 110A and random modes outside antenna subset 110A can be efficiently balanced.

[0172] Furthermore, since the antenna element 111 included in the antenna subset 110A performs random mode power transmission in subframes other than the subframes that become subset modes, it is possible to efficiently perform random mode power transmission to devices 250 located near a specific device 250A that do not have an antenna subset 110A constructed.

[0173] Furthermore, since power transmission in random mode is based on the subframes that power supply in subset mode, a smooth transition to specific device 250A is possible when the charge level of battery 253 of device 250 that has not built antenna subset 110A falls below a specified value.

[0174] Furthermore, since specific devices 250A are allocated to subframes according to the allocation order, it is easy to perform the process of allocating all specific devices 250A to multiple subframes. In particular, since specific devices 250A with higher allocation order are allocated to subframes first, it is easier to perform the process of allocating all specific devices 250A to multiple subframes.

[0175] Furthermore, since the specific device 250A is assigned to the subframe with the smallest number of specific devices 250A and the smallest subframe index in the subframe in which there is no shared antenna element 111, it is possible to minimize the number of subframes and balance the number of specific devices 250A receiving power transmission based on subset pattern in each subframe.

[0176] Furthermore, in the absence of a subframe in which there is no shared antenna element 111, since a new subframe is added to the frame and a specific device 250A is assigned to the added subframe, each specific device 250A can be powered in subset mode in a subframe in which there is no shared antenna element 111 with other specific devices 250A.

[0177] Furthermore, when power is transmitted from antenna element 111, which is included in antenna subset 110A, to specific device 250A, digital phase modulation such as QPSK (Quadrature Phase Shift Keying) can be applied to the transmission signal to notify information from antenna element 111 to specific device 250A via the transmission signal. For example, differential encoding of the transmission signal can be performed by setting the phase change of the transmission signal to ±π / 2 or ±π to notify information from antenna element 111 to specific device 250A.

[0178] Furthermore, the above describes the method of sending index data to the control device 140, indicating the time slot index when the received power of a specific device 250A reaches its maximum. Phase relationship is one such relationship.

[0179] However, power transmission can also be performed by a specific device 250A detecting multiple time slot indices where the received power reaches a specified value, while switching the phase relationships of multiple transmission signals in multiple time slot indices. For example, when the phase indices of the transmitted power of antenna element 111 with antenna grid indices (4,4), (4,5), (5,4), and (5,5) are 29, 11, 3, and 24, and the phase indices of the transmitted signals are 32, 46, 15, and 59, and the received power of the specific device 250A reaches a specified value or higher, power transmission can also be performed by switching the phase relationships of the transmitted signals with phase differences of 29, 11, 3, and 24 and the phase relationships of the transmitted signals with phase differences of 32, 46, 15, and 59 in a time sequence.

[0180] In this case, when the phase indices of the transmission signals are 29, 11, 3, and 24, it is an example of the first timing, and the phase relationship with phase differences of 29, 11, 3, and 24 is an example of the first phase relationship. When the phase indices of the transmission signals are 32, 46, 15, and 59, it is an example of the second timing, and the phase relationship with phase differences of 32, 46, 15, and 59 is an example of the second phase relationship.

[0181] The power supply device and power supply method of the present invention have been described above according to exemplary embodiments. However, the present invention is not limited to the specific disclosed embodiments, and various modifications or alterations can be made without departing from the scope of the claims.

[0182] Note that this international application claims priority based on Japanese Patent Application 2021-084702, filed on May 19, 2021, the entire contents of which are incorporated herein by reference.

[0183] Explanation of reference numerals in the attached figures

[0184] 10 regions

[0185] 100 power supply unit

[0186] 110 array antenna

[0187] 110A, 110A1~110A6 antenna subsets

[0188] 111 Antenna Components

[0189] 120 phase shifter

[0190] 130 Microwave Generator

[0191] 140 Control device

[0192] 141 Main Control Unit

[0193] 142 Subset Selection Department

[0194] 143 Transmission Control Department

[0195] 144 memory

[0196] 250 devices

[0197] 250A Specific Equipment

[0198] 250B Non-specific equipment.

Claims

1. A power supply device, comprising: The power transmission control unit controls the phase of the power transmission signals of a plurality of first antennas located around each of a plurality of first power receiving devices, and controls the phase of the power transmission signals of one or more second antennas other than the plurality of first antennas located around each of the plurality of first power receiving devices, wherein... A plurality of first antennas located around one of the plurality of first power receiving devices, and a plurality of first antennas located around another of the plurality of first power receiving devices, including at least one common first antenna. The power transmission control unit: Repeated frames containing multiple subframes are used to control the phase of the transmission signals of the multiple first antennas located around each of the multiple first power receiving devices. In one of the plurality of subframes, while maintaining the phase relationship of the transmission signal so that the transmission signal for one of the plurality of first power receiving devices to receive power from the plurality of first antennas located around the first power receiving device is consistent, the phase is changed in a time sequence. In another subframe of the plurality of subframes, while maintaining the phase relationship of the transmission signal so that the transmission signal for another first power receiving device among the plurality of first power receiving devices receives power from the plurality of first antennas located around the other first power receiving device is consistent, the phase is changed in a time sequence. The phase of the power transmission signal that supplies power to the one or more second antennas changes in a time sequence.

2. The power supply device according to claim 1, wherein, In subframes other than the aforementioned subframe, the power transmission control unit causes the phase of the power transmission signal transmitted by a plurality of first antennas located around the first power receiving device to change in a time sequence.

3. The power supply device according to claim 1, wherein, In subframes other than the other subframe, the power transmission control unit causes the phase of the power transmission signal supplied by the plurality of first antennas located around the other first power receiving device to change in a time sequence.

4. The power supply device according to any one of claims 1 to 3, wherein, The power transmission control unit causes the phase of the power transmission signal transmitted by the one or more second antennas to change in a time sequence according to the plurality of subframes.

5. The power supply device according to any one of claims 1 to 3, wherein, For the plurality of first power receiving devices that do not have a first antenna shared with the plurality of first antennas located around the first power receiving device, the power transmission control unit, in a subframe, maintains the phase relationship of the power transmission signal in a manner that makes the phase of the power transmission signal received by the first power receiving device from the plurality of first antennas located around the first power receiving device consistent, while changing the phase in a time sequence.

6. The power supply device according to claim 5, wherein, The power transmission control unit, in subframes other than the first subframe, causes the phase of the power transmission signal that supplies power to multiple first antennas that do not share power with multiple first antennas located around the first power receiving device to change in a time sequence.

7. The power supply device according to any one of claims 1 to 3, wherein, For the first power receiving devices among the plurality of first power receiving devices that do not have a first antenna shared with a plurality of first antennas located around the other first power receiving device, the power transmission control unit, in the other subframe, maintains the phase relationship of the power transmission signal in a manner that makes the phase of the power transmission signal received by the first power receiving device from the plurality of first antennas located around the first power receiving device consistent, while changing the phase in a time sequence.

8. The power supply device according to claim 7, wherein, The power transmission control unit, in subframes other than the other subframe, causes the phase of the power transmission signal that supplies power to multiple first antennas that do not share power with multiple first antennas located around the other first power receiving device to change in a time sequence.

9. The power supply device according to any one of claims 1 to 3, wherein, For each of the plurality of first receiving devices, the power transmission control unit calculates the degree of sharing, which indicates the extent to which the plurality of first antennas located around it share a first antenna, and determines which subframe among the plurality of subframes to allocate to it according to the order corresponding to the degree of sharing of each of the first receiving devices.

10. The power supply device according to claim 9, wherein, The power transmission control unit determines the subframes to be allocated sequentially, starting from the first power receiving device with the highest degree of sharing.

11. The power supply device according to any one of claims 1 to 3, wherein, The power transmission control unit assigns the first power receiving device among the plurality of first power receiving devices, wherein the plurality of first antennas located around it do not share a first antenna with each other, to the same subframe.

12. The power supply device according to any one of claims 1 to 3, wherein, For a first power receiving device that has a first antenna shared by multiple first antennas located around one or more of the first power receiving devices that are assigned to one or more of the subframes, the power transmission control unit adds a new subframe to the frame and assigns the first power receiving device to the new subframe.

13. The power supply device according to any one of claims 1 to 3, wherein, The power transmission control unit assigns a first power receiving device that does not share a first antenna with a plurality of first antennas located around a plurality of first power receiving devices already assigned to the plurality of subframes to a subframe in which the number of first power receiving devices already assigned is less than that of other subframes.

14. The power supply device according to any one of claims 1 to 3, wherein, The power transmission control unit determines the combination of the first power receiving devices allocated in each subframe in a manner that reduces the number of the multiple subframes.

15. The power supply device according to any one of claims 1 to 3, wherein, The power transmission control unit determines the combination of the first power receiving devices allocated in each subframe in a manner that balances the number of first power receiving devices allocated in each subframe.

16. The power supply device according to any one of claims 1 to 3, wherein, The phase relationship is the relationship between the phases of the power transmission signals of the plurality of first antennas when the phases of the power transmission signals of the plurality of first antennas are randomly changed in a time sequence by the power transmission control unit, and when the power received by the first power receiving device reaches or exceeds a predetermined threshold.

17. The power supply device according to any one of claims 1 to 3, wherein, The power transmission control unit maintains the phase relationship of the power transmission signals of the plurality of first antennas for each of one or more time slots, while simultaneously causing the phase of the power transmission signals of the plurality of first antennas to change sequentially over time. The first power receiving device notifies the power transmission control unit of the time slot when the received power reaches or exceeds a specified threshold. The power transmission control unit sets the phase of the power transmission signals of the plurality of first antennas in the time slot determined by the notified information as the phase relationship.

18. The power supply device according to claim 16, wherein, The phase relationship includes a first phase relationship when the phase of the transmission signal of the plurality of first antennas is randomly changed in a time sequence by the power transmission control unit, and when the received power of the first receiving device reaches or exceeds a predetermined threshold at a first timing, and a second phase relationship when the received power of the first receiving device reaches or exceeds the predetermined threshold at a second timing. The power transmission control unit switches the phase of the power transmission signals of the plurality of first antennas between the first phase relationship and the second phase relationship in a time sequence.

19. The power supply device according to any one of claims 1 to 3, wherein, The plurality of first antennas are those antennas in which the received power is above a specified value when the first powered device transmits a signal.

20. The power supply device according to any one of claims 1 to 3, wherein, While maintaining the phase relationship of the power transmission signals of the plurality of first antennas, the power transmission control unit changes the phase of the power transmission signals of the plurality of first antennas in a time sequence, sets the amount of phase change of the power transmission signals of the plurality of first antennas to ±π / 2 or ±π, performs differential encoding of the power transmission signals, and thereby notifies the first power receiving device of information.

21. A power supply method, comprising: The phase of the power transmission signal of a plurality of first antennas located around each of a plurality of first power receiving devices is controlled, and the phase of the power transmission signal of one or more second antennas other than the plurality of first antennas located around each of the plurality of first power receiving devices is also controlled, wherein, A plurality of first antennas located around one of the plurality of first power receiving devices, and a plurality of first antennas located around another of the plurality of first power receiving devices, including at least one common first antenna. The power supply method: Repeated frames containing multiple subframes are used to control the phase of the transmission signals of the multiple first antennas located around each of the multiple first power receiving devices. In one of the plurality of subframes, while maintaining the phase relationship of the transmission signal so that the transmission signal for one of the plurality of first power receiving devices to receive power from the plurality of first antennas located around the first power receiving device is consistent, the phase is changed in a time sequence. In another subframe of the plurality of subframes, while maintaining the phase relationship of the transmission signal so that the transmission signal for another first power receiving device among the plurality of first power receiving devices receives power from the plurality of first antennas located around the other first power receiving device is consistent, the phase is changed in a time sequence. The phase of the power transmission signal that supplies power to the one or more second antennas changes in a time sequence.

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