Power supply system, power supply device, and power supply method

Abstract

Provided are a power supply system, a power supply device, and a power supply method with which it is possible to quickly set a phase at which it is possible to increase the power received by a power receiving device. A power supply device includes: a first power transmission control unit that controls phases of power transmission signals of a plurality of first antennas located around a first power receiving device among a plurality of antennas capable of transmitting power; and a second power transmission control unit that controls the phase of a power transmission signal of one or more second antennas other than the plurality of first antennas among the plurality of antennas. The first power transmission control unit changes the phases of the power transmission signals of the plurality of first antennas in time series while maintaining the phase relationship of the power transmission signals of the plurality of first antennas such that the phases of the signals received by the first power receiving device from the plurality of first antennas match. The second power transmission control unit changes the phase of a power transmission signal transmitted by the one or more second antennas to the one or more second power receiving devices in time series.

Description

Technical Field

[0001] The invention relates to a power supply system, a power supply device and a power supply method. Background Art

[0002] Conventionally, there is a power supply device including: a first detection unit that detects the direction of a power receiving device; and a control unit that controls a radiation unit that radiates power supply to perform a first radiation that wirelessly radiates power supply in the direction of the power receiving device detected by the first detection unit, and a second radiation that wirelessly radiates power supply while changing the direction of the power supply within a prescribed range (for example, refer to Patent Document 1).

[0003] <Prior Art Literature>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-083648 Summary of the invention

[0006] <Problems to be Solved by the Invention>

[0007] However, the conventional power supply equipment radiates the power supply electric power to the power receiving device by performing the first radiation and the second radiation, but does not disclose a method for quickly setting a phase capable of increasing the power received by the power receiving device.

[0008] Therefore, an object of the present invention is to provide a power supply system, a power supply device, and a power supply method capable of quickly setting a phase capable of increasing the power received by a power receiving device.

[0009] <Methods used to solve the problem>

[0010] A power supply system according to an embodiment of the present invention is a power supply system including a power supply device and a power receiving device that receives a power transmission signal transmitted from the power supply device, wherein the power supply device includes: an array antenna having a plurality of antennas capable of transmitting electric power; and a power transmission control unit that performs phase control and power transmission control of a power transmission signal transmitted from the plurality of antennas to the power receiving device, wherein the power transmission control unit selects a plurality of first antennas included in the plurality of antennas one by one and performs the following processing: selecting one of the plurality of first antennas, and transmitting a first power transmission signal of a predetermined phase from the selected first antenna while fixing the power transmission phase of a non-selected first antenna among the plurality of first antennas to transmit the first power transmission signal; and transmitting power from the selected first antenna so that the first power transmission signal The power receiving device obtains a differential signal between the first synthetic signal and the second synthetic signal and sends the differential signal to the power transmission control unit, wherein the first synthetic signal is a synthetic signal of the first power transmission signal with the prescribed phase received from the multiple first antennas in the first power transmission processing and the first power transmission signal with the power transmission phase fixed, and the second synthetic signal is a synthetic signal of the first power transmission signal with the inverted phase received from the multiple first antennas in the second power transmission processing and the first power transmission signal with the power transmission phase fixed, and the power transmission control unit controls the phases of the multiple first power transmission signals transmitted by the multiple first antennas based on the multiple differential signals obtained by selecting each of the multiple first antennas.

[0011] <Effects of the Invention>

[0012] It is possible to provide a power supply system, a power supply device, and a power supply method capable of quickly setting a phase capable of increasing the power received by a power receiving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing a power supply device 100 according to an embodiment.

[0014] Figure 2 It is a diagram showing an example of the structure of the specific device 50A.

[0015] Figure 3 It is a diagram showing the structure of the control device 140.

[0016] Figure 4 This is a diagram showing an example of a frame structure.

[0017] Figure 5 This is a diagram for explaining an example of optimization processing.

[0018] Fig. 6AThis is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A.

[0019] Figure 6B This is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A.

[0020] Figure 6C This is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A.

[0021] Fig.6D This is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A.

[0022] Fig. 6E This is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A.

[0023] Figure 7 This is a diagram showing an example of ranking results.

[0024] Figure 8 This is a flowchart showing an example of processing executed by the control device 140 and the specific device 50A of the power supply system 300 .

[0025] Fig. 9 This is a diagram for explaining an example of simulation conditions.

[0026] Fig.10 This is a diagram showing an example of a simulation result regarding received electric power when electric power is transmitted using random beamforming for comparison.

[0027] Fig.11 3 is a diagram showing an example of simulation results of the power supply system 300 .

[0028] Fig.12 It is a diagram for explaining an example of optimization processing in the power supply system 300 according to the modification of the embodiment.

[0029] Fig.13A It is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A in the modification of the embodiment.

[0030] Fig. 13B It is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A in the modification of the embodiment.

[0031] Fig. 13C It is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A in the modification of the embodiment.

[0032] Fig.13D It is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A in the modification of the embodiment.

[0033] Fig.13E It is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A in the modification of the embodiment.

[0034] Fig.14 It is a diagram showing an example of simulation results of a power supply system 300 according to a modification of the embodiment. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of a power supply system, a power supply device, and a power supply method to which the present invention is applied will be described.

[0036] <Implementation Method>

[0037] <Power supply system 300>

[0038] Figure 1 : is a diagram showing a power supply system 300 of an embodiment. The power supply system 300 includes a power supply device 100 and a specific device 50A. The specific device 50A is an example of a power receiving device. The following description uses an XYZ coordinate system. The so-called top view refers to an XY top view. In addition, the power supply system 300 may also include a power supply device 100 and a plurality of devices 50. Among the plurality of devices 50, a specific device 50A and a plurality of non-specific devices 50B other than the specific device 50A are included.

[0039] The power supply device 100 is, for example, disposed in an area 10 of a large-scale facility such as a smart factory, a large-scale workshop, a logistics 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, and supplies power (microwave power supply) to a plurality of devices 50 present in the area 10 in a non-contact manner. The power supply method of the embodiment is a power supply method implemented by the power supply device 100, and is particularly implemented by processing performed by the control device 140.

[0040] When the power supply device 100 supplies power to an indefinite number of multiple devices 50, the array antenna 110 performs power transmission through beamforming. The multiple antenna elements 111 of the array antenna 110 can transmit at the power transmission phase specified by the power transmission control unit described later. If the phase of the power transmission signal output by the multiple antenna elements 111 is changed, a standing wave is generated in the area 10 through the beam formed by the multiple antenna output signals, and the device 50 at the position of the node of the standing wave is hardly supplied with power. In order to avoid such a situation, the power supply device 100 randomly shifts the phase of the multiple power transmission signals output from the multiple antenna elements 111 in a time series so that the node of the standing wave does not occur at a specific position for a long time. In other words, the node of the standing wave is moved within the area 10. The phase of the power transmission signal is shifted according to the time slot. In addition, the so-called power transmission signal is a signal that transmits power (sends) from the antenna element 111, and is an RF (Radio Frequency) signal with a specified power. As an example, the frequency of the power transmission signal is 918MHz.

[0041] Hereinafter, performing power transmission using a beam formed by randomly shifting the phases of a plurality of power transmission signals output from a plurality of antenna elements 111 in each time slot in this manner is referred to as random beamforming.

[0042] In addition, among the multiple devices 50, there may be a device 50 that requires more power to charge the internal battery 54. For example, it is a device 50 that consumes more power than other devices 50 and has less remaining power in the internal battery 54. Such a device 50 that requires more power is called a specific device 50A. Figure 1 , one device 50 at a certain point in time is shown as a specific device 50A.

[0043] The specific device 50A receives power mainly from the plurality of antenna elements 111 included in the antenna subset 110A among the plurality of antenna elements 111. This is because the battery 54 of the specific device 50A can be charged earlier by performing power transmission more intensively than by random beamforming.

[0044] The antenna element 111 included in the antenna subset 110A is an example of the first antenna. The antenna element 111 not included in the antenna subset 110A is an example of the second antenna. In addition, the power transmission signal transmitted by the antenna element 111 included in the antenna subset 110A is an example of the first power transmission signal, and the power transmission signal transmitted by the antenna element 111 not included in the antenna subset 110A is an example of the second power transmission signal.

[0045] The phase of power transmission from the plurality of antenna elements 111 included in the antenna subset 110A to the specific device 50A is set for each frame. Figure 1In FIG. 1 , the antenna subset 110A includes four antenna elements 111. The antenna subset 110A and the phase shift of the power transmission signal to the specific device 50A will be described later.

[0046] The devices 50 other than the specific device 50A are referred to as non-specific devices 50B. All devices 50 may become specific devices 50A depending on the situation. For the specific device 50A, if the charge amount of the battery 54 becomes sufficient, the concentrated power supply from the antenna subset 110A is not performed, and the non-specific device 50B becomes a non-specific device 50B. The non-specific device 50B receives power transmission based on random beamforming from the antenna element 111 including the antenna subset 110A.

[0047] In addition, the specific device 50A may be mounted on a mobile body that can be remotely managed, such as an Automatic Guided Vehicle (AGV) or an Autonomous Mobile Robot (AMR) and may be movable. All of the multiple devices 50 may be mounted on such a mobile body and may become the specific device 50A depending on the situation, or only a part of the multiple devices 50 may be mounted on such a mobile body and may become the specific device 50A depending on the situation. The following is an example of a method in which the specific device 50A is mounted on a mobile body and is movable.

[0048] The power supply device 100 is a power supply device that transmits power to the non-specific device 50B using random beamforming and transmits power to the specific device 50A from the antenna subset 110A. In the following, the specific device 50A and the non-specific device 50B are simply referred to as the device 50 unless otherwise specifically distinguished.

[0049] <Configuration of Specific Device 50A>

[0050] Figure 2 Specific device 50A is a diagram showing an example of a structure. Specific device 50A includes antenna 51, switch SW, control unit 52, RF / DC (Direct Current) conversion unit 53, battery 54, orthogonal detection unit 55, calculation unit 56, angle conversion unit 57, and communication unit 58. Communication unit 58 includes antenna 58A.

[0051] The antenna 51 is an antenna for receiving power from one or more antenna elements 111. The antenna 51 outputs the received power to the switch SW. The switch SW is switched by the control unit 52 to switch the connection destination of the antenna 51 to either the RF / DC converter 53 or the orthogonal detector 55.

[0052] The control unit 52 switches the switch SW during the optimization period and the power supply period in each frame. The control unit 52 switches the switch SW to connect to the quadrature detection unit 55 during the optimization period, and switches the switch SW to connect to the RF / DC conversion unit 53 during the power supply period.

[0053] During the optimization period, control unit 52 causes quadrature detection unit 55 , calculation unit 56 , angle conversion unit 57 , and communication unit 58 to perform a process of transmitting data indicating an angle obtained from the differential signal to control device 140 of power supply device 100 .

[0054] Furthermore, during the power supply period, the control unit 52 performs charging control to charge the battery 54 with the power received from the antenna element 111 via the antenna 51 .

[0055] The battery 54 is, for example, a secondary battery or a capacitor, and is charged by the power supplied from the antenna 51. The power charged in the battery 54 is used when the switch SW, the control unit 52, the RF / DC converter 53, the orthogonal detector 55, the calculator 56, the angle converter 57, and the communication unit 58 operate.

[0056] A load that consumes power may also be connected to the battery 54. For example, the load may be a sensor that detects temperature, humidity, etc., in which case the device 50 can be regarded as a sensor device. In addition, the load may be a power source such as a motor or an actuator, and the device 50 may be a device that performs dynamic operations.

[0057] Furthermore, when the device 50 is mounted on a movable object, the electric power charged in the battery 54 can be used as a power source such as a motor of the movable object as a load or as electric power for driving a control unit or the like.

[0058] The RF / DC converter 53 is a converter (conversion circuit) that converts a power transmission signal (RF signal) received (received) by the antenna 51 into direct current power and outputs the direct current power to the battery 54 .

[0059] The quadrature detection unit 55 demodulates the transmission signal received by the antenna 51 to extract phase information and outputs it to the calculation unit 56. The phase information extracted by the quadrature detection unit 55 indicates the phase of the transmission signal received by the antenna 51.

[0060] The calculation unit 56 performs a subtraction process to obtain a difference signal based on the phase indicated by the phase information extracted by the quadrature detection unit 55. The subtraction process will be described later.

[0061] The angle conversion unit 57 converts the differential signal calculated by the calculation unit 56 into an angle in the IQ coordinates, and outputs angle data indicating the angle to the communication unit 58 .

[0062] The communication unit 58 transmits the angle data output from the angle conversion unit 57 to the power supply device 100 via the antenna 58A.

[0063] In addition, although the use of Figure 2 The structure of the specific device 50A has been described, but among the multiple devices 50, the device 50 that will not become the specific device 50A and only functions as the non-specific device 50B may not have the switch SW, the orthogonal detection unit 55, the calculation unit 56, the angle conversion unit 57 and the communication unit 58, and the control unit 52 only needs to control the charging of the battery 54.

[0064] <Array antenna 110>

[0065] Array antenna 110 is an example of a two-dimensional antenna grid, and includes 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, for a total of 256. The 256 antenna elements 111 are located on the XY plane.

[0066] Each antenna element 111 is connected to a microwave generating source 130 via a power transmission cable 130A to supply power in the microwave frequency band. By controlling the control device 140, the four antenna elements 111 selected as the antenna elements 111 constituting the antenna subset 110A among the 256 antenna elements 111 transmit power to the specific device 50A with an optimized phase, but also incidentally supply power to the non-specific device 50B located near the specific device 50A. The antenna elements 111 not included in the antenna subset 110A transmit power to the non-specific device 50B through random beam forming, but also incidentally supply power from the antenna elements 111 located at a relatively close position to the specific device 50A. In addition, the number of antenna elements 111 included in the antenna subset 110A can be any number as long as it is multiple. The antenna element 111 is a patch antenna that is rectangular in a plan view. The antenna element 111 may also have a ground plate maintained at a ground potential on the -Z direction side.

[0067] Furthermore, as the specific device 50A moves, the antenna elements 111 constituting the antenna subset 110A are rearranged for each frame, and the antenna elements 111 included in the antenna subset 110A are selected.

[0068] Each antenna element 111 is installed on a ceiling, a column, etc. of a large-scale facility such as the smart factory. As an example, the interval between each antenna element 111 is equivalent to several wavelengths of the wavelength at the communication frequency of the antenna element 111. As an example, the communication frequency of the antenna element 111 is assumed to be a microwave band, and as an example, it is 918 MHz.

[0069] In addition, Figure 1, as an example, a state in which the specific device 50A receives power from four antenna elements 111 among the 256 antenna elements 111 included in the array antenna 110 is shown. The set of multiple antenna elements 111 selected by the control device 140 to transmit power to the specific device 50A is called an antenna subset 110A. The antenna elements 111 not included in the antenna subset 110A transmit power by random beamforming while shifting the phase of the transmission signal according to the time slot, and the power transmitted by random beamforming is received by the non-specific device 50B, but is also received by the specific device 50A.

[0070] The phase shifter 120 is connected to each antenna element 111 one by one, and is inserted between each antenna element 111 and the power transmission cable 130A. Figure 1 In FIG. 1 , for convenience of explanation, one antenna element 111 , one phase shifter 120 , and one IC chip 125 are shown in an enlarged manner.

[0071] The phase shifter 120 shifts the transmission phase of the power transmitted from the microwave source 130 via the power transmission cable 130A and outputs it to the antenna element 111. The phase shifter 120 is an example of a phase adjustment unit. The IC chip 125 includes a measurement unit for measuring the RSSI (Received Signal Strength Indicator) of the received power and a BLE communication unit, and sends a beacon signal including data indicating the measured RSSI value to the control device 140. The communication unit of the IC chip 125 has an antenna for BLE communication.

[0072] The microwave source 130 is connected to the 256 phase shifters 120 to supply microwaves of a predetermined power. The microwave source 130 is an example of an electric wave source. The frequency of the microwave is 918 MHz as an example. In addition, the power supply device 100 is described here in a manner including the microwave source 130, but it is not limited to microwaves, as long as it is an electric wave of a predetermined frequency.

[0073] The control device 140 is an example of a control unit, and is a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and a nonvolatile memory, and as an example, discrete wavelet multi-tone modulation (DWMT) can be used.

[0074] The control device 140 has an antenna 140A and receives a beacon signal having angle data written therein from the specific device 50A.

[0075] The control device 140 performs selection control (ranking processing) of the antenna elements 111 included in the antenna subset 110A, controls the phases in the 256 phase shifters 120, and controls the output of power from the microwave generator 130. The phase control of the power transmission signal of the antenna element 111 included in the antenna subset 110A and the phase control of the power transmission signal based on random beamforming of the antenna element 111 not included in the antenna subset 110A are realized by controlling the phases in the phase shifters 120.

[0076] <Control device 140>

[0077] Figure 3 1 is a diagram showing 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, the subset selection unit 142, and the power transmission control unit 143 are elements showing the functions of the program executed by the control device 140 as functional blocks. In addition, the memory 144 is an element functionally representing the memory of the control device 140.

[0078] The main control unit 141 is a processing unit that coordinates the processing of the control device 140 , and executes processing other than the processing executed by the subset selection unit 142 and the power transmission control unit 143 .

[0079] The subset selection unit 142 is an example of an antenna selection unit. When a differential signal is transmitted from the specific device 50A in each frame and the RSSI values ​​when the differential signal is received by all antenna elements 111 are obtained, the subset selection unit 142 selects the plurality of antenna elements 111 included in the antenna subset 110A based on the ranking of the RSSI values. For details on the selection method based on the ranking of the RSSI values, see Figure 7 This will be described later.

[0080] 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 randomly sets the phase of the power transmission signal of all antenna elements 111 and performs power transmission control (random mode) based on random beamforming that randomly shifts the phase for each time slot. Figure 1 ) The position where the standing wave of the power transmission signal is generated is not fixed in time, so all devices 50 can receive power more evenly.

[0081] When the subset selection unit 142 constructs the antenna subset 110A, the power transmission control unit 143 performs optimization processing during the optimization period in each frame and performs power supply processing during the power supply period in each frame. The optimization processing during the optimization period and the power supply processing during the power supply period will be described later.

[0082] The memory 144 stores data, programs, and the like used when the main control unit 141 , the subset selection unit 142 , and the power transmission control unit 143 execute processes. The memory 144 also stores data indicating the phase of the power transmission signal in each time slot.

[0083] <Frame structure>

[0084] Figure 4 1 is a diagram showing an example of a frame structure. As an example, the frame period is 50 ms. The frame includes an optimization period and a power supply period. The power supply period is provided after the optimization period.

[0085] The optimization period is a period of optimization processing for optimizing the phase (power transmission phase) of the power transmission signal transmitted by the multiple antenna elements 111 included in the antenna subset 110A. Optimizing the phase of the power transmission signal transmitted by the multiple antenna elements 111 means making the phase (power reception phase) of the power transmission signal transmitted by the multiple antenna elements 111 consistent when it is received by the antenna 51 of the specific device 50A. This is because as long as the power reception phases of the multiple power transmission signals are consistent, the power received by the specific device 50A can be maximized. In addition, phase consistency is not limited to the case where the phases are exactly the same, but also includes a state that is roughly equal to the exactly the same state. This is because, in a strict sense, there are sometimes situations where it is not easy to make the phase consistent. For example, as long as the phase deviation is about ±5%, the phase can be considered to be consistent.

[0086] During the optimization period, the phase of the power transmission signal transmitted by the plurality of antenna elements 111 not included in the antenna subset 110A is set to a fixed value. This is because when optimizing the power transmission phase of the antenna elements 111 included in the antenna subset 110A, by fixing the power transmission phase of the plurality of antenna elements 111 not included in the antenna subset 110A, there is no influence of the power transmission signal transmitted by the plurality of antenna elements 111 not included in the antenna subset 110A.

[0087] The power supply period is a period during which the power supply process is performed to transmit power transmission signals from the plurality of antenna elements 111 in a state where the phases of the power transmission signals transmitted by the plurality of antenna elements 111 are optimized by the optimization process in the optimization period. During the power supply period, random beamforming is performed for the plurality of antenna elements 111 included in the antenna subset 110A while maintaining the relationship between the plurality of power transmission phases obtained by the optimization process in the optimization section within the same frame. In addition, for the plurality of antenna elements 111 not included in the antenna subset 110A, random beamforming is performed so that the power transmission phases of the plurality of antenna elements 111 do not have a particular relationship with each other.

[0088] Optimization of power transmission phase

[0089] The four antenna elements 111 included in the antenna subset 110A are divided into antenna elements m1 to m4 , and the optimization of the power transmission phase of the antenna element m1 is described.

[0090] During optimization, power is transmitted with the antenna elements m2 to m4 at the phase set for the antenna element m1 at this time or a specific phase (for example, 0 degrees). The signal received by the specific device 50A becomes a signal synthesized in the antenna 51 of the specific device 50A from the power transmission signals from all antenna elements 111. The power transmission signal r(k) converted from the regenerated carrier to the baseband signal by signal conversion (orthogonal detection) from the radio frequency to the baseband (demodulated by the orthogonal detection unit 55) in the time slot k is expressed by the following equation (1) when the contribution from the antenna element m1 is extracted.

[0091] [Formula 1]

[0092]

[0093] Here, Λ is the entire antenna set, S is the antenna subset, and the first term is the power transmission phase set for the antenna element m1, PR m1 is the received power, ξ m1 is the phase shift between antenna element m1 and antenna 51, and is the remainder (terminal number) when the distance between antenna element m1 and antenna 51 is divided by the wavelength. The second term is the signal component received from antenna elements m2 to m4 other than antenna element m1 in antenna subset 110A. The third term is the signal component received from antenna element 111 which is not included in antenna subset 110A. In the optimization process, the temporal variation of the phase between antenna element 111 and antenna 51 is set to be small enough to be negligible.

[0094] In the next time slot k+1, the power transmission phase of the antenna element m1 is shifted by 180 degrees (π), that is, the phase is reversed, and power is transmitted together with the other antenna elements m2 to m4 included in the antenna subset 110A and the antenna element 111 not included in the antenna subset 110A. The power transmission phase of the antenna element m1 in the time slot k+1 is It is represented by the following formula (2).

[0095] [Formula 2]

[0096]

[0097] Here, in the power transmission phase If it exceeds 360 degrees, it is reduced to the range of 1 to 360 degrees by modular operation. Since the power transmission phases of the other antenna elements m2 to m4 included in the antenna subset 110A and the antenna element 111 not included in the antenna subset 110A do not change, only the power transmission phase of the antenna element m1 changes (inverts).

[0098] In the specific device 50A on the power receiving side, similarly, the signal is converted from the radio frequency to the baseband (orthogonal detection) to a baseband signal. The power transmission signal r(k+1) received in the time slot k+1 is the same as in the time slot k, which is a signal synthesized in the antenna 51 by the power transmission signals transmitted from all antenna elements 111. The power transmission signal r(k+1) is expressed by the following equation (3) when the contribution from the antenna element m1 is extracted and described.

[0099] [Formula 3]

[0100]

[0101] The power transmission signal received in time slot k+1 is subtracted from the power transmission signal received in time slot k. Since power is transmitted in two consecutive time slots k and k+1 from antenna element 111 other than antenna element m1 with the same power transmission phase, the difference is eliminated when the subtraction is performed, and the difference signal is expressed by the following equation (4), and only the signal component from antenna element m1 remains.

[0102] [Formula 4]

[0103]

[0104] The power transmission phase of the power transmission signal transmitted from the antenna element m1 is expressed as follows: The detection is performed and its value is sent to the control device 140.

[0105] [Formula 5]

[0106]

[0107] The control device 140 controls the power transmission phase of the antenna element m1 so as to cancel the received power transmission phase or to make it a specific phase. The transmission phase determined by this phase control is reflected in the power supply period after the time slot k+5.

[0108] [Formula 6]

[0109]

[0110] When the antenna element m1 receives the When the power transmission signal transmitted from the antenna element m1 is received by the antenna 51 of the specific device 50A, the power reception phase Toward the event axis direction, for example, it becomes zero in the following equation (7).

[0111] [Formula 7]

[0112]

[0113] <Optimization Process>

[0114] Figure 5 is a diagram illustrating an example of optimization processing. Figure 5 , the optimization period, power supply period, and time slot in one frame are shown. Here, as an example, it is assumed that the antenna subset 110A includes four antenna elements 111. The optimization process includes the number of time slots obtained by adding 1 to the number of antenna elements 111 included in the antenna subset 110A. Figure 5 In FIG. 1 , since antenna subset 110A includes four antenna elements 111, the number of time slots in the optimization period is five (k to k+4). The power supply period starts from time slot k+5 and is longer than the optimization period, but is simplified here.

[0115] The four antenna elements 111 included in the antenna subset 110A are divided into antenna elements m1 to m4. In addition, a plurality of antenna elements 111 not included in the antenna subset 110A (an example of non-selected first antennas) are referred to as antennas n1, . . .

[0116] In time slot k, the power transmission phase of antenna element m1 is set to The power transmission phase of antenna elements m2 to m4 is set to In this state, power transmission signals are transmitted from antenna elements m1 to m4. For any power transmission phase.

[0117] In time slot k+1, the power transmission phase of antenna element m1 is changed to The power transmission phase of antenna elements m2 to m4 is set to In this state, power transmission signals are transmitted from antenna elements m1 to m4. The power transmission phase of antenna element m1 is changed in time slot k+1. The power transmission phase in time slot k is In the time slots k to k+1, the power transmission phases of antenna elements m2 to m4 are fixed to

[0118] In time slot k+2, the power transmission phase of antenna element m1 is set to The power transmission phase of antenna element m2 is changed to The power transmission phase of antenna elements m3 to m4 is set to In this state, power transmission signals are transmitted from antenna elements m1 to m4. The power transmission phase of antenna element m2 is changed in time slot k+2. The power transmission phase in time slots k to k+1 is In the time slots k+1 to k+2, the power transmission phase of the antenna element m1 is fixed to In time slots k to k+2, the power transmission phases of antenna elements m3 to m4 are fixed to

[0119] In time slot k+3, the power transmission phase of antenna element m1 is set to The power transmission phase of antenna element m2 is set to The power transmission phase of antenna element m3 is changed to The power transmission phase of antenna element m4 is set to In this state, power transmission signals are transmitted from antenna elements m1 to m4. The power transmission phase of antenna element m3 is changed in time slot k+3. The power transmission phase φm3 in the time slots k to k+2 is inverted. In the time slots k+1 to k+3, the power transmission phase of the antenna element m1 is fixed to In time slots k+2 to k+3, the power transmission phase of antenna element m2 is fixed to In time slots k to k+3, the power transmission phase of antenna element m4 is fixed to

[0120] In time slot k+4, the power transmission phase of antenna element m1 is set to The power transmission phase of antenna element m2 is set to The power transmission phase of antenna element m3 is set to The power transmission phase of antenna element m4 is changed to In this state, power transmission signals are transmitted from antenna elements m1 to m4. The power transmission phase of antenna element m4 is changed in time slot k+4. The power transmission phase in time slots k to k+3 is In the time slots k+1 to k+4, the power transmission phase of the antenna element m1 is fixed to In time slots k+2 to k+4, the power transmission phase of antenna element m2 is fixed to In time slots k+3 to k+4, the power transmission phase of antenna element m3 is fixed to +π.

[0121] As described above, during the optimization period of time slots k to k+4, the power transmission phase of the antenna element m1 is optimized in time slots k and k+1, and after time slot k+1, the power transmission phase of the antenna element m1 is fixed to The optimization process in time slot k in which the power transmission phase of the antenna element m1 is set to φm1 and the power transmission signal is transmitted is an example of the first power transmission process for the antenna element m1. The optimization process in the time slot k+1 in which the power transmission signal is transmitted is an example of the second power transmission process for the antenna element m1. The optimization period in which the first power transmission process and the second power transmission process are performed is an example of the preparation period.

[0122] In addition, during the optimization period of time slots k to k+4, the power transmission phase of the antenna element m2 is optimized in time slots k+1 and k+2. In time slots k to k1, the power transmission phase of the antenna element m2 is fixed to After time slot k+2, the power transmission phase of antenna element m2 is fixed to The power transmission phase of antenna element m2 is set to The optimization process in the time slot k+1 for transmitting the power transmission signal is an example of the first power transmission process for the antenna element m2. The power transmission phase of the antenna element m2 is set to The optimization process in the time slot k+2 in which the power transmission signal is transmitted is an example of the second power transmission process for the antenna element m2.

[0123] In addition, during the optimization period of time slots k to k+4, the power transmission phase of the antenna element m3 is optimized in time slots k+2 and k+3. In time slots k to k2, the power transmission phase of the antenna element m3 is fixed to After time slot k+3, the power transmission phase of antenna element m3 is fixed to The power transmission phase of antenna element m3 is set to The optimization process in the time slot k+2 for transmitting the power transmission signal is an example of the first power transmission process for the antenna element m3. The power transmission phase of the antenna element m3 is set to The optimization process in the time slot k+3 in which the power transmission signal is transmitted is an example of the second power transmission process for the antenna element m3.

[0124] In addition, during the optimization period of time slots k to k+4, the power transmission phase of antenna element m4 is optimized in time slots k+3 and k+4. In time slots k to k3, the power transmission phase of antenna element m4 is fixed to In time slot k+4, the power transmission phase of antenna element m4 is changed to The power transmission phase of antenna element m4 is set to The optimization process in the time slot k+3 for transmitting the power transmission signal is an example of the first power transmission process for the antenna element m4. The power transmission phase of the antenna element m4 is set to The optimization process in the time slot k+4 in which the power transmission signal is transmitted is an example of the second power transmission process for the antenna element m4.

[0125] In addition, during the power supply period, the power transmission phases of the antenna elements m1 to m4 are set to the optimized power transmission phases, and the relationship between the four optimized power transmission phases is maintained while random beamforming is performed. In addition, during the optimization period, with respect to the multiple antenna elements 111 not included in the antenna subset 110A (an example of a non-selected first antenna), each of the multiple antenna elements 111 is fixed to an arbitrary phase. In addition, during the power supply period, with respect to the multiple antenna elements 111 not included in the antenna subset 110A, with respect to each of the multiple antenna elements 111, random beamforming is performed so that the power transmission phases of the multiple antenna elements 111 have no particular relationship with each other. The power supply period is an example of a power transmission period.

[0126] <Power receiving phase of power transmission signal of specific device 50A>

[0127] FIG. 6A to FIG. 6E 1 is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A. The I axis is the real axis and the Q axis is the imaginary axis. The four vectors (1) to (4) represent the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 as vectors.

[0128] Assume that the power transmission phases of antenna elements m1 to m4 are The remainders (number of ends) obtained by dividing the distances between the antenna elements m1 to m4 and the antenna 51 by the wavelength are ξm1 to ξm4, respectively.

[0129] like Fig. 6A As shown, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 in the time slot k are respectively These four vectors (1) to (4) are as follows Fig. 6A shown.

[0130] In the time slot k+1, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively The four vectors (1) to (4) are as follows Fig. 6A As shown, vector (1) becomes inverse compared to time slot k.

[0131] When the four vectors (1) to (4) in time slot k+1 are subtracted from the four vectors (1) to (4) in time slot k, vectors (2) to (4) disappear, and only vector (1A) whose length is doubled as that of vector (1) remains as a difference. The signal representing vector (1A) is a differential signal, which is obtained by a subtraction operation by a calculation unit 56. The angle of vector (1A) relative to the I axis is set to α1. Angle α1 is obtained by an angle conversion unit 57. In addition, the four vectors (1) to (4) in time slot k are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+1 are an example of a second synthetic signal.

[0132] like Figure 6B As shown, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 in the time slot k+1 are respectively These four vectors (1) to (4) are as follows Figure 6B shown.

[0133] In the time slot k+2, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively The four vectors (1) to (4) are as follows Figure 6B As shown, vector (2) becomes reversed compared to time slot k+1.

[0134] When the four vectors (1) to (4) in time slot k+2 are subtracted from the four vectors (1) to (4) in time slot k+1, vectors (1), (3) and (4) disappear, and only vector (2A) whose length is doubled as that of vector (2) remains as a difference. The signal representing vector (2A) is a differential signal, which is obtained by a subtraction operation by a calculation unit 56. The angle of vector (2A) relative to the I axis is set to α2. The angle α2 is obtained by an angle conversion unit 57. In addition, the four vectors (1) to (4) in time slot k+1 are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+2 are an example of a second synthetic signal.

[0135] like Figure 6C As shown, in the time slot k+2, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively These four vectors (1) to (4) are as follows Figure 6C shown.

[0136] In the time slot k+3, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively The four vectors (1) to (4) are as follows Figure 6C As shown, vector (3) becomes reversed compared to time slot k+2.

[0137] When the four vectors (1) to (4) in time slot k+3 are subtracted from the four vectors (1) to (4) in time slot k+2, vectors (1), (2) and (4) disappear, and only vector (3A) whose length is doubled as vector (3) remains as a difference. The signal representing vector (3A) is a differential signal, which is obtained by a subtraction operation by a calculation unit 56. The angle of vector (3A) relative to the I axis is set to α3. Angle α3 is obtained by an angle conversion unit 57. In addition, the four vectors (1) to (4) in time slot k+2 are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+3 are an example of a second synthetic signal.

[0138] like Fig.6D As shown, in the time slot k+3, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively These four vectors (1) to (4) are as follows Fig.6D shown.

[0139] In the time slot k+4, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively The four vectors (1) to (4) are as follows Fig.6D As shown, vector (4) becomes reversed compared to time slot k+3.

[0140] When the four vectors (1) to (4) in time slot k+4 are subtracted from the four vectors (1) to (4) in time slot k+3, vectors (1) to (3) disappear, and only vector (4A) whose length is doubled as that of vector (4) remains as a difference. The signal representing vector (4A) is a differential signal, which is obtained by a subtraction operation by a calculation unit 56. The angle of vector (4A) relative to the I axis is set to α4. Angle α4 is obtained by an angle conversion unit 57. In addition, the four vectors (1) to (4) in time slot k+3 are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+4 are an example of a second synthetic signal.

[0141] When the angle conversion unit 57 obtains the angles α1 to α4 of the vectors (1) to (4) as described above, the communication unit 58 transmits angle data indicating the angles α1 to α4 to the power supply device 100 at the last timing of the time slot k+4.

[0142] In the time slot k+5, the power transmission control unit 143 adjusts the phases of the vectors (1) to (4) to adjust the angles α1 to α4. As a result, Fig. 6E As shown, the directions of vectors (1) to (4) can be made consistent. Fig. 6E In FIG. 1 , the directions of the vectors (1) to (4) are, as an example, directions along the I-axis, but they may have an angle greater than 0 degrees with respect to the I-axis.

[0143] In this way, the angles of the vectors (1) to (4) can be made consistent. That is, the received electric power of the specific device 50A can be maximized.

[0144] During the power supply period after time slot k+5, random beamforming is performed while maintaining the relationship between the four power transmission phases of antenna elements m1 to m4 so that the angles of vectors (1) to (4) are consistent. In addition, for multiple antenna elements 111 not included in antenna subset 110A, random beamforming is performed without any particular relationship between the power transmission phases of the multiple antenna elements 111.

[0145] <Ranking of antenna elements 111 of antenna subset 110A selected>

[0146] The power supply device 100 receives the signal including the angle data through all antenna elements 111, and the IC chip 125 measures the RSSI of the received power. The subset selection unit 142 selects the antenna elements 111 included in the antenna subset 110A by ranking based on the RSSI of the signals including the angle data received by all antenna elements 111.

[0147] Figure 7 is a diagram showing an example of ranking results. Figure 7 , the ranking (RSSI from high to low), RSSI (dBm), and antenna index are shown. As an example, it is assumed that the antenna element 111 is selected until the RSSI is -15 dB relative to the antenna element 111 with the highest RSSI.

[0148] exist Figure 7 In the example, the RSSI of the antenna element 111 with antenna index 5 is the highest, which is -50.0 dBm, and the four antenna elements 111 ranked from 4th to 15 dB below -50.0 dBm (-50.0-15 dB) are selected as the antenna elements 111 included in the antenna subset 110A. In addition, here, the state in which the antenna subset 110A includes four antenna elements 111 is described, but the number of antenna elements 111 included in the antenna subset 110A in each frame is determined by the number of antenna elements 111 from the highest RSSI value to the point where the RSSI drops by 15 dB, so there may be more than four or less than four.

[0149] <Flowchart>

[0150] Figure 81 is a flowchart showing an example of processing executed by the control device 140 and the specific device 50A of the power supply system 300. The control device 140 and the specific device 50A perform processing separately, but here, it is described as a series of processing in the power supply system 300. Figure 8 The processing shown is performed within one frame, and is performed similarly in each frame.

[0151] The power transmission control unit 143 selects the antenna elements 111 included in the antenna subset 110A one by one, and sequentially transmits the power transmission signal and the power transmission signal with the inverted phase (step S1). Figure 5 The processing of time slots k to k+4 is shown.

[0152] The specific device 50A obtains angle data from the differential signal (step S2).

[0153] The specific device 50A transmits a beacon signal storing the angle data to the power supply device 100 (step S3). The processing of step S3 is performed, for example, Figure 5 The last operation shown is in time slot k+4.

[0154] After step S3, the processing of steps S4A and S5A and the processing of steps S4B and S5B are performed in parallel.

[0155] The power transmission control unit 143 causes the plurality of antenna elements 111 included in the antenna subset 110A to transmit power by random beamforming while maintaining the optimized power transmission phase relationship, and causes the antenna elements 111 not included in the antenna subset 110A to transmit power by random beamforming (step S4A). Figure 5 During the power supply period after the time slot k+5 in step S4A, power transmission is performed.

[0156] The specific device 50A receives the power transmission signal transmitted in step S4A (step S5A). Figure 5 Since the power transmission in step S4A is performed in the power supply period after the time slot k+5 in , the specific device 50A receives the power transmission signal in the power supply period.

[0157] The processing of steps S4A and S5A is performed until the frame ends.

[0158] Furthermore, the IC chip 125 of each antenna element 111 measures the RSSI of the beacon signal and transmits it to the control device 140 (step S4B).

[0159] The subset selection unit 142 of the control device 140 selects the antenna element 111 included in the antenna subset 110A based on the ranking result of RSSI (step S5B). The antenna element 111 selected based on the ranking result is used as the antenna element 111 included in the antenna subset 110A in the next frame.

[0160] When the processing of steps S4A and S5A and the processing of steps S4B and S5B are completed, the frame ends (step S6). When the processing within one frame is completed in step S6, the flow returns to step S1.

[0161] <Simulation>

[0162] Fig. 9 1 is a diagram for explaining an example of simulation conditions. As an example, a simulation was performed in which power was supplied to a specific device 50A in a state where 36 antenna elements 111 of 6×6 were arranged in an array. The specific device 50A moved on a dotted circle track at a speed of 2.0 m / sec.

[0163] In the simulation of the power supply system 300, multiple antenna elements 111 included in the antenna subset 110A are selected based on the RSSI ranking result, and the multiple antenna elements 111 included in the antenna subset 110A are made to transmit power through random beamforming while maintaining an optimized power transmission phase relationship, and the antenna elements 111 not included in the antenna subset 110A are made to transmit power through random beamforming, and the amount of power received by the specific device 50A is simulated.

[0164] For comparison, a simulation was also performed on the amount of power received by the specific device 50A when power was transmitted from all (36) antenna elements 111 by random beamforming without setting the antenna subset 110A.

[0165] Fig.10 FIG. 1 is a diagram showing an example of simulation results of received power when power is transmitted by random beamforming for comparison. Fig.10 In , the horizontal axis represents time and the vertical axis represents received power (dBm). When power is transmitted from all (36) antenna elements 111 by random beamforming, the received power fluctuates around 0 (dBm) and varies greatly with time.

[0166] Fig.11 is a diagram showing an example of simulation results of the power supply system 300. Fig.11 The upper side of is shown the time variation pattern of the number of antenna elements 111 included in the antenna subset 110A. Fig.11In the upper graph of , the horizontal axis represents time, and the vertical axis represents the number of antenna elements 111 included in the antenna subset 110A. Fig.11 In the lower graph of , the horizontal axis represents time and the vertical axis represents received power (dBm).

[0167] like Fig.11 As shown in the lower graph, the received power ratio Fig.10 The received power is high, with many periods of 5dBm to 6dBm. The frame period is 50ms, and the period at the beginning of each frame when the received power is low can be considered as the optimization period. In the power supply period after the optimization period, the received power of 5dBm to 6dBm was obtained.

[0168] In addition, observation Fig.11 In the upper curve of , the number of antenna elements 111 included in the antenna subset 110A is 4 to 6. Fig.11 When comparing the upper and lower graphs of , it can be confirmed that the received power is large during the period when the number of antenna elements 111 included in the antenna subset 110A is large.

[0169] <Effect>

[0170] The power supply system 300 is a power supply system 300 including a power supply device 100 and a specific device 50A receiving a power transmission signal transmitted from the power supply device 100. The power supply device 100 includes: an array antenna 110 having a plurality of antenna elements 111 capable of transmitting power; and a power transmission control unit 143, which controls the phase of the power transmission signal transmitted from the plurality of antenna elements 111 to the specific device 50A and controls the power transmission. The power transmission control unit 143 selects a plurality of first antennas one by one while selecting one of the plurality of first antennas included in the plurality of antenna elements 111. In a state where the power transmission phase of a non-selected first antenna among the plurality of first antennas (the antenna element 111 not selected as an object of optimization processing among the antenna elements 111 included in the antenna subset 110A) is fixed to transmit the first power transmission signal, the power transmission control unit 143 selects the first antenna from the selected first antenna (the antenna element 111 not selected as an object of optimization processing among the antenna elements 111 included in the antenna subset 110A). The specific device 50A performs a first power transmission process in which the antenna element 111 selected as the object of optimization processing among the antenna elements 111 included in the set 110A transmits a first power transmission signal of a specified phase, and a second power transmission process in which the first power transmission signal of an inverted phase inverting the specified phase is transmitted from the selected first antenna. The specific device 50A obtains a first composite signal between the first power transmission signal of a specified phase received from the plurality of first antennas in the first power transmission process and the first power transmission signal with a fixed power transmission phase, and a second composite signal between the first power transmission signal of an inverted phase received from the plurality of first antennas in the second power transmission process and the first power transmission signal with a fixed power transmission phase, and transmits the difference signal to the power transmission control unit 143. The power transmission control unit 143 controls the phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals obtained by selecting each of the plurality of first antennas. Therefore, it is possible to quickly set a phase that can increase the received power of the power receiving device.

[0171] Therefore, it is possible to provide the power supply system 300 which can quickly set the phase which can increase the received power of the power receiving device.

[0172] In addition, the power transmission control unit 143 sets the power transmission phase to the reverse phase for the first antenna (the antenna element 111 selected as the object of optimization processing among the antenna elements 111 included in the antenna subset 110A) selected in the first power transmission process, thereby providing a power supply system 300 that can more quickly set the phase that can increase the power received by the power receiving device. By fixing the reverse phase for the antenna element 111 selected as the object of optimization processing among the antenna elements 111 included in the antenna subset 110A, the phase that can increase the power received by the power receiving device can be set more quickly without performing additional processing.

[0173] The power transmission control unit 143 fixes the power transmission phases of one or more second antennas (antenna elements 111 not included in the antenna subset 110A) other than the plurality of first antennas (antenna elements 111 included in the antenna subset 110A) among the plurality of antenna elements 111 in the first power transmission process and the second power transmission process.

[0174] Therefore, a plurality of differential signals can be obtained while suppressing the influence of the power transmission signals of one or more second antennas (antenna elements 111 not included in antenna subset 110A), thereby providing a power supply system 300 that can more accurately and quickly set the phase that can increase the power received by the power receiving device.

[0175] Furthermore, it is possible to provide a power supply system 300 capable of providing both power supply to a specific power receiving device (specific equipment 50A) requiring a larger power receiving amount and power supply to power receiving devices other than the specific power receiving device.

[0176] The power supply device 100 further includes: a subset selection unit 142 that selects a plurality of antenna elements 111 whose reception strength of a signal transmitted from the power receiving device is greater than a predetermined strength as a plurality of first antennas (antenna elements 111 included in the antenna subset 110A), and selects one or more antenna elements 111 whose reception strength is less than the predetermined strength as one or more second antennas (antenna elements 111 not included in the antenna subset 110A).

[0177] Therefore, multiple antenna elements 111 having a reception strength above a specified strength (ranked above a specified order) can be selected as antenna elements 111 included in the antenna subset 110A. By using the antenna subset 110A composed of multiple antenna elements 111 close to the specific device 50A, power can be efficiently supplied to the specific device 50A.

[0178] Furthermore, since the signal transmitted from the power receiving device is a signal representing a differential signal, it is possible to use a signal including angle data representing the differential signal to simultaneously transmit the angle data and measure the RSSI for ranking, thereby providing a power supply system 300 that can quickly and efficiently set a phase that can increase the power received by the power receiving device.

[0179] In addition, the power transmission control unit 143 repeatedly performs frame processing including a preparation period (optimization period) for performing the first power transmission processing and the second power transmission processing, and a power transmission period (power supply period) for transmitting power from the multiple first antennas (antenna elements 111 included in the antenna subset 110A) to the specific device 50A by controlling the phases of the multiple first power transmission signals transmitted by the multiple first antennas (antenna elements 111 included in the antenna subset 110A) based on the multiple differential signals, and uses the multiple first antennas selected by the subset selection unit 142 from the multiple antenna elements 111 based on the reception strength (RSSI) of the signal representing the differential signal (beacon signal storing angle data) as the multiple first antennas in the next frame of the frame.

[0180] Therefore, the antenna elements 111 included in the antenna subset 110A in the next frame can be selected based on the received strength (RSSI) of the signal representing the differential signal (the beacon signal storing the angle data).

[0181] Since the specific device 50A is movable, it is possible to provide a power supply system 300 that can quickly set a phase that can increase the received power of the specific device 50A even if the specific device 50A moves and the phase of the received power transmission signal changes.

[0182] In addition, the power transmission control unit 143 controls the power transmission phases of the multiple first power transmission signals transmitted by the multiple first antennas based on the multiple differential signals so that the power reception phases of the multiple first power transmission signals received by the specific device 50A from the multiple first antennas are consistent. Therefore, the power transmission phases of the first power transmission signals can be controlled so that the power received by the specific device 50A is maximized, and the power received by the specific device 50A can be reliably increased.

[0183] The power supply device 100 is a power supply device 100 that transmits a power transmission signal to a specific device 50A, and includes: an array antenna 110, which has a plurality of antenna elements 111 that can transmit electric power; and a power transmission control unit 143, which controls the phase of the power transmission signal transmitted from the plurality of antenna elements 111 to the specific device 50A and controls the power transmission, the power transmission control unit 143 selects a plurality of first antennas one by one, and selects one of the plurality of first antennas included in the plurality of antenna elements 111, and in a state where the power transmission phase of a non-selected first antenna among the plurality of first antennas (the antenna element 111 included in the antenna subset 110A that is not selected as an object of optimization processing) is fixed to transmit the first power transmission signal, and then transmits the first power transmission signal from the selected first antenna (the antenna element 111 included in the antenna subset 110A). The first power transmission processing of transmitting a first power transmission signal of a specified phase, and the second power transmission processing of transmitting a first power transmission signal of a reversed phase in which the specified phase is reversed from the selected first antenna, and the phases of the multiple first power transmission signals transmitted by the multiple first antennas are controlled based on the multiple differential signals obtained by selecting each of the multiple first antennas, the differential signal being a first composite signal of the first power transmission signal of the specified phase and the first power transmission signal with a fixed power transmission phase received by the specific device 50A from the multiple first antennas in the first power transmission processing, and a second composite signal of the first power transmission signal of the reversed phase and the first power transmission signal with a fixed power transmission phase received by the multiple first antennas in the second power transmission processing. Therefore, the phase that can increase the received power of the power receiving device can be quickly set.

[0184] Therefore, it is possible to provide the power supply device 100 that can quickly set a phase that can increase the received power of the power receiving device.

[0185] The power supply method is a power supply method in a power supply system 300 including a power supply device 100 and a specific device 50A receiving a power transmission signal transmitted from the power supply device 100, wherein the power supply device 100 includes: an array antenna 110 having a plurality of antenna elements 111 capable of transmitting a certain amount of power; and a power transmission control unit 143, which controls the phase of the power transmission signal transmitted from the plurality of antenna elements 111 to the specific device 50A and controls the power transmission, wherein the power transmission control unit 143 selects a plurality of first antennas one by one while selecting one of the plurality of first antennas included in the plurality of antenna elements 111, and in a state where the power transmission phase of a non-selected first antenna among the plurality of first antennas (the antenna element 111 included in the antenna subset 110A that is not selected as an object of optimization processing) is fixed to transmit the first power transmission signal, the power transmission control unit 143 controls the phase of the power transmission signal transmitted from the plurality of antenna elements 111 to the specific device 50A and controls the power transmission, wherein the power transmission control unit 143 selects one of the plurality of first antennas included in the plurality of antenna elements 111 while selecting one of the plurality of first antennas included in the plurality of first antennas. The specific device 50A performs a first power transmission process in which the antenna element 111 selected as the object of optimization processing among the antenna elements 111 included in the subset 110A transmits a first power transmission signal of a specified phase, and a second power transmission process in which the first power transmission signal of an inverted phase inverting the specified phase is transmitted from the selected first antenna. The specific device 50A obtains a first composite signal between the first power transmission signal of a specified phase received from the plurality of first antennas in the first power transmission process and the first power transmission signal with a fixed power transmission phase, and a second composite signal between the first power transmission signal of an inverted phase received from the plurality of first antennas in the second power transmission process and the first power transmission signal with a fixed power transmission phase, and transmits the difference signal to the power transmission control unit 143. The power transmission control unit 143 controls the phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals obtained by selecting each of the plurality of first antennas. Therefore, it is possible to quickly set a phase that can increase the received power of the power receiving device.

[0186] Therefore, it is possible to provide a power supply method capable of quickly setting a phase capable of increasing the received power of the power receiving device.

[0187] <Modification>

[0188] Fig.12 It is a diagram for explaining an example of optimization processing in the power supply system 300 according to the modification of the embodiment. Fig.12 and Figure 5 Similarly, the optimization period, power supply period, and time slot in one frame are shown. Here, as an example, it is assumed that the antenna subset 110A includes four antenna elements 111. The optimization process includes time slots that are twice the number of antenna elements 111 included in the antenna subset 110A. Fig.12 In FIG. 1 , since antenna subset 110A includes four antenna elements 111, the optimization period has eight time slots (k to k+7). The power supply period starts from time slot k+8 and is longer than the optimization period, but is simplified here.

[0189] In the optimization process of the modified example, the power transmission control unit 143 sets the power transmission phase of the non-selected first antenna (antenna elements 111 included in the antenna subset 110A that are not selected as the target of the optimization process) to the same value in the first power transmission process and the second power transmission process.

[0190] More specifically, the power transmission phase of the antenna element m1 is set to The optimization process of transmitting the power transmission signal (an example of the second power transmission process for the antenna element m1) and the power transmission phase of the antenna element m2 are set to The optimization process for transmitting the power transmission signal (an example of the first power transmission process for the antenna element m2) is performed in different time slots k+1 and k+2.

[0191] In the optimization process of the modified example, the power transmission phase of the antenna element m2 is set to The optimization process of transmitting the power transmission signal (an example of the second power transmission process for the antenna element m2) and the power transmission phase of the antenna element m3 are set to The optimization process for transmitting the power transmission signal (an example of the first power transmission process for the antenna element m3) is performed in different time slots k+3 and k+4.

[0192] In the optimization process of the modified example, the power transmission phase of the antenna element m3 is set to The optimization process of transmitting the power transmission signal (an example of the second power transmission process for the antenna element m3) and the power transmission phase of the antenna element m4 are set to The optimization process for transmitting the power transmission signal (an example of the first power transmission process for the antenna element m4) is performed in different time slots k+5 and k+6.

[0193] Then, the power transmission phase of the antenna element m4 is set to The optimization process for transmitting the power transmission signal (an example of the second power transmission process for the antenna element m4) is performed in the time slot k+7.

[0194] Therefore, the optimization process of the modified example is Figure 5 The optimization process shown takes slightly longer than necessary.

[0195] The power transmission phase of antenna elements m1 to m4 is as follows: Fig.12 As shown, after optimization, the optimized power transmission phase is fixed and remains unchanged during the power supply period, but when entering the power supply period, random beamforming can be performed while maintaining the relationship between the optimized power transmission phases. The optimized power transmission phase of antenna elements m1 to m4 is an example of a phase based on a differential signal.

[0196] <Power Receiving Phase of Power Transmission Signal of Specific Device 50A in Modification of Embodiment>

[0197] FIG. 13A to FIG. 13E This is a diagram for explaining the power receiving phase of the power transmission signal received by the specific device 50A in the modified example of the embodiment. The I axis is the real axis and the Q axis is the imaginary axis. The four vectors (1) to (4) represent the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 in the form of vectors.

[0198] The power transmission phases of antenna elements m1 to m4 are The remainders (number of ends) obtained when the distances between the antenna elements m1 to m4 and the antenna 51 are divided by the wavelength are ξm1 to ξm4, respectively.

[0199] like Fig.13A As shown, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 in the time slot k are respectively These four vectors (1) to (4) are as follows Fig.13A shown.

[0200] In the time slot k+1, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m4 are respectively The four vectors (1) to (4) are as follows Fig.13A As shown, vector (1) becomes reversed compared to time slot k.

[0201] When the four vectors (1) to (4) in time slot k+1 are subtracted from the four vectors (1) to (4) in time slot k, vectors (2) to (4) disappear, and only vector (1A) whose length is doubled as that of vector (1) remains as a difference. The signal representing vector (1A) is a differential signal, which is obtained by a subtraction operation by the calculation unit 56. The angle of vector (1A) relative to the I axis is set to α1. The angle α1 is obtained by the angle conversion unit 57. At this point in time, a beacon signal storing the angle α1 is sent to the power supply device 100 via the communication unit 58. In addition, the four vectors (1) to (4) in time slot k are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+1 are an example of a second synthetic signal.

[0202] like Fig. 13B As shown, in the time slot k+2, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna element m1 is 0 degrees, and the power receiving phases of the power transmission signals received from the antenna elements m2 to m4 are respectively These four vectors (1) to (4) are as follows Fig. 13BWhen the beacon signal storing the angle α1 is not transmitted to the power supply device 100 via the communication unit 58 in the time slot k+1, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna element m1 in the time slot k+2 becomes α1 degrees.

[0203] In time slot k+3, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna element m1 is 0 degrees, and the power receiving phases of the power transmission signals received from the antenna elements m2 to m4 are respectively The four vectors (1) to (4) are as follows Fig. 13B As shown, vector (2) becomes reversed compared to time slot k+2.

[0204] When the four vectors (1) to (4) in time slot k+3 are subtracted from the four vectors (1) to (4) in time slot k+2, vectors (1), (3) and (4) disappear, and only vector (2A) whose length is doubled as that of vector (2) remains as a difference. The signal representing vector (2A) is a differential signal, which is obtained by a subtraction operation by a calculation unit 56. The angle of vector (2A) relative to the I axis is set to α2. The angle α2 is obtained by an angle conversion unit 57. In addition, the four vectors (1) to (4) in time slot k+2 are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+3 are an example of a second synthetic signal.

[0205] like Fig. 13C As shown, in time slot k+4, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna elements m1 and m2 is 0 degrees, and the power receiving phase of the power transmission signal received from the antenna elements m3 to m4 is respectively These four vectors (1) to (4) are as follows Fig. 13C In addition, when the beacon signal storing the angles α1 and α2 is not transmitted to the power supply device 100 via the communication unit 58 in the time slots k+1 and k+3, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 and m2 in the time slot k+4 become α1 degrees and α2 degrees.

[0206] In time slot k+5, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna elements m1 and m2 is 0 degrees, and the power receiving phase of the power transmission signal received by the specific device 50A from the antenna elements m3 to m4 is respectively The four vectors (1) to (4) are as follows Fig. 13C As shown, vector (3) becomes reversed compared to time slot k+4.

[0207] When the four vectors (1) to (4) in time slot k+5 are subtracted from the four vectors (1) to (4) in time slot k+4, vectors (1), (2) and (4) disappear, and only vector (3A) whose length is doubled as vector (3) remains as a difference. The signal representing vector (3A) is a differential signal, which is obtained by a subtraction operation by a calculation unit 56. The angle of vector (3A) relative to the I axis is set to α3. Angle α3 is obtained by an angle conversion unit 57. In addition, the four vectors (1) to (4) in time slot k+4 are an example of a first synthetic signal, and the four vectors (1) to (4) in time slot k+5 are an example of a second synthetic signal.

[0208] like Fig.13D As shown, in time slot k+6, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna elements m1 to m3 is 0 degrees, and the power receiving phase of the power transmission signal received from the antenna element m4 is These four vectors (1) to (4) are as follows Fig.13D In addition, when the beacon signal storing the angles α1 to α3 is not transmitted to the power supply device 100 via the communication unit 58 in the time slots k+1, k+3, and k+5, the power receiving phases of the power transmission signal received by the specific device 50A from the antenna elements m1 to m3 in the time slot k+6 are α1 degrees to α3 degrees, respectively.

[0209] In time slot k+7, the power receiving phase of the power transmission signal received by the specific device 50A from the antenna elements m1 to m3 is 0 degrees, and the power receiving phase of the power transmission signal received from the antenna element m4 is The four vectors (1) to (4) are as follows Fig.13D As shown, vector (4) becomes reversed compared to time slot k+6.

[0210] When the four vectors (1) to (4) in time slot k+7 are subtracted from the four vectors (1) to (4) in time slot k+6, vectors (1) to (3) disappear, and only vector (4A) whose length is doubled as that of vector (4) remains as a difference. The signal representing vector (4A) is a difference signal, which is obtained by subtraction processing by the calculation unit 56. In addition, the four vectors (1) to (4) in time slot k+6 are an example of the first composite signal, and the four vectors (1) to (4) in time slot k+7 are an example of the second composite signal.

[0211] The angle of the vector (4A) with respect to the I-axis is α4. The angle α4 is obtained by the angle conversion unit 57. The communication unit 58 transmits the beacon signal storing the angle α4 to the power supply device 100.

[0212] In addition, when the beacon signal storing the angles α1 to α3 is not transmitted to the power supply device 100 via the communication unit 58 in the time slots k+1, k+3, and k+5, the communication unit 58 may transmit the angle data indicating the angles α1 to α4 to the power supply device 100 at the end of the time slot k+7. The RSSI for ranking may be measured when the power supply device 100 receives any beacon signal.

[0213] In the time slot k+8, the power transmission control unit 143 adjusts the phases of the vectors (1) to (4) in order to adjust the angles α1 to α4. As a result, Fig.13E As shown, the directions of vectors (1) to (4) can be made consistent. Fig.13E In FIG. 1 , the directions of the vectors (1) to (4) are, as an example, directions along the I-axis, but they may have an angle greater than 0 degrees with respect to the I-axis.

[0214] In this way, the angles of the vectors (1) to (4) can be made consistent. That is, the received electric power of the specific device 50A can be maximized.

[0215] During the power supply period after time slot k+8, if Fig.13E As shown, power transmission can be performed while maintaining the optimized four power transmission phases of the antenna elements m1 to m4. In addition, during the power supply period, random beamforming can be performed while maintaining the relationship between the four power transmission phases of the antenna elements m1 to m4 in a manner that the angles of the vectors (1) to (4) are consistent. In addition, for the multiple antenna elements 111 not included in the antenna subset 110A, random beamforming is performed without any particular relationship between the power transmission phases of the multiple antenna elements 111.

[0216] <Simulation results>

[0217] Fig.14 FIG. 1 is a diagram showing an example of simulation results of a power supply system 300 according to a modification of the embodiment. Fig.14 The upper side of is shown the time variation pattern of the number of antenna elements 111 included in the antenna subset 110A. Fig.14 In the upper graph of , the horizontal axis represents time, and the vertical axis represents the number of antenna elements 111 included in the antenna subset 110A. Fig.14 In the lower graph of , the horizontal axis represents time and the vertical axis represents received power (dBm).

[0218] like Fig.14 As shown in the lower graph, the received power ratio Fig.10The received power is high, with many periods of 5dBm to 6dBm. The frame period is 50ms, and the period at the beginning of each frame when the received power is low can be considered as the optimization period. In the power supply period after the optimization period, the received power of 5dBm to 6dBm was obtained.

[0219] In addition, observation Fig.14 In the upper curve of , the number of antenna elements 111 included in the antenna subset 110A is 4 to 6. Fig.14 When comparing the upper and lower graphs of , it can be confirmed that the received power is large during the period when the number of antenna elements 111 included in the antenna subset 110A is large.

[0220] In the modification of the embodiment, it is also possible to quickly set a phase that can increase the received power of the power receiving device. Therefore, it is possible to provide a power supply system 300 according to the modification of the embodiment that can quickly set a phase that can increase the received power of the power receiving device.

[0221] Furthermore, it is possible to provide a power supply system 300 according to a modification of the embodiment that can provide both power supply to a specific power receiving device (specific equipment 50A) requiring a large power receiving amount and power supply to power receiving devices other than the specific power receiving device.

[0222] Although the power supply system, power supply device, and power supply method according to exemplary embodiments of the present invention have been described above, the present invention is not limited to the specifically disclosed embodiments, and various modifications and changes can be made without departing from the scope of the claims.

[0223] In addition, the present international application claims priority based on Japanese patent application No. 2022-163333 filed on October 11, 2022, the entire contents of which are incorporated herein by reference.

[0224] Explanation of symbols

[0225] 10: Region

[0226] 50: Equipment

[0227] 50A: Specific equipment

[0228] 50B: Non-specific device

[0229] 51: Antenna

[0230] SW: Switch

[0231] 52: Control Department

[0232] 53: RF / DC conversion unit

[0233] 54: Battery

[0234] 55: Quadrature detection unit

[0235] 56: Computing Department

[0236] 57: Angle conversion unit

[0237] 58: Ministry of Communications

[0238] 100: Power supply device

[0239] 110: Array antenna

[0240] 110A: Antenna subset

[0241] 111: Antenna element

[0242] 120: Phase Shifter

[0243] 125: IC chip

[0244] 130: Microwave source

[0245] 140: Control device

[0246] 141: Main control unit

[0247] 142: Subset selection

[0248] 143: Power transmission control unit

[0249] 144: Memory.

Claims

1. A power supply system, comprising: Power supply device; as well as a power receiving device for receiving a power transmission signal transmitted from the power supply device, The power supply device comprises: an array antenna having a plurality of antennas capable of transmitting power; and a power transmission control unit that performs phase control of power transmission signals transmitted from the plurality of antennas to the power receiving device and power transmission control, The power transmission control unit selects a plurality of first antennas included in the plurality of antennas one by one and performs the following processing: selecting one of the plurality of first antennas, and transmitting a first power transmission signal of a predetermined phase from the selected first antenna in a state where a power transmission phase of a non-selected first antenna among the plurality of first antennas is fixed to transmit a first power transmission signal; and a second power transmission process of transmitting power from the selected first antenna by inverting the predetermined phase to obtain a first power transmission signal with an inverted phase, The power receiving device obtains a differential signal between a first composite signal and a second composite signal and transmits the differential signal to the power transmission control unit, wherein the first composite signal is a composite signal of the first power transmission signal of the specified phase received from the plurality of first antennas in the first power transmission process and the first power transmission signal with the power transmission phase fixed, and the second composite signal is a composite signal of the first power transmission signal of the reverse phase received from the plurality of first antennas in the second power transmission process and the first power transmission signal with the power transmission phase fixed, The power transmission control unit controls phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals obtained by selecting each of the plurality of first antennas.

2. The power supply system according to claim 1, wherein: The power transmission control unit sets the power transmission phase of the non-selected first antenna to the same value in the first power transmission process and the second power transmission process.

3. The power supply system according to claim 1 or 2, wherein: The power transmission control unit sets the power transmission phase to the reverse phase for the first antenna selected in the first power transmission process in the second power transmission process.

4. The power supply system according to claim 1 or 2, wherein: The power transmission control unit sets a power transmission phase to a phase based on the differential signal for the first antenna selected in the first power transmission process in the second power transmission process.

5. The power supply system according to any one of claims 1 to 4, wherein: The power transmission control unit fixes the power transmission phase of one or more second antennas other than the plurality of first antennas among the plurality of antennas in the first power transmission process and the second power transmission process.

6. The power supply system according to claim 5, wherein: The power supply device further includes an antenna selection unit that selects a plurality of antennas whose reception strength of a signal transmitted from the power receiving device is greater than a predetermined strength as the plurality of first antennas, and selects one or more antennas whose reception strength is less than the predetermined strength as the one or more second antennas.

7. The power supply system according to claim 6, wherein: The signal transmitted from the power receiving device is a signal representing the differential signal.

8. The power supply system according to claim 7, wherein: The power transmission control unit, repeatedly performing a frame process including a preparation period and a power transmission period, wherein the preparation period is a period during which the first power transmission process and the second power transmission process are performed, and the power transmission period is a period during which power is transmitted from the plurality of first antennas to the power receiving device by controlling the phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals, And the plurality of first antennas selected by the antenna selection unit based on the reception strength of the signal representing the differential signal among the plurality of antennas are used as the plurality of first antennas in a frame next to the frame.

9. The power supply system according to any one of claims 1 to 8, wherein: The power receiving device is movable.

10. The power supply system according to any one of claims 1 to 9, wherein: The power transmission control unit controls the power transmission phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals so that the power reception phases of the plurality of first power transmission signals received by the power receiving device from the plurality of first antennas coincide with each other.

11. A power supply device for transmitting a power transmission signal to a power receiving device, comprising: an array antenna having multiple antennas capable of delivering power; as well as a power transmission control unit that performs phase control of power transmission signals transmitted from the plurality of antennas to the power receiving device and power transmission control, The power transmission control unit, While selecting a plurality of first antennas included in the plurality of antennas one by one, the following processing is performed: selecting one of the plurality of first antennas, and transmitting a first power transmission signal of a predetermined phase from the selected first antenna in a state where a power transmission phase of a non-selected first antenna among the plurality of first antennas is fixed to transmit a first power transmission signal; and a second power transmission process of transmitting power from the selected first antenna by inverting the predetermined phase to obtain a first power transmission signal with an inverted phase, and controlling the phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals obtained by selecting each of the plurality of first antennas, The differential signal is a differential signal between a first synthesized signal and a second synthesized signal, the first synthesized signal being a synthesized signal of the first power transmission signal of the prescribed phase and the first power transmission signal with the power transmission phase fixed, which is received by the power receiving device from the plurality of first antennas in the first power transmission process, and the second synthesized signal being a synthesized signal of the first power transmission signal of the inverted phase and the first power transmission signal with the power transmission phase fixed, which is received by the power receiving device from the plurality of first antennas in the second power transmission process.

12. A power supply method is a power supply method in a power supply system, the power supply system comprising: Power supply device; as well as a power receiving device for receiving a power transmission signal transmitted from the power supply device, The power supply device comprises: an array antenna having a plurality of antennas capable of transmitting power; and a power transmission control unit that performs phase control of power transmission signals transmitted from the plurality of antennas to the power receiving device and power transmission control, The power transmission control unit selects a plurality of first antennas included in the plurality of antennas one by one and performs the following processing: selecting one of the plurality of first antennas, and transmitting a first power transmission signal of a predetermined phase from the selected first antenna in a state where a power transmission phase of a non-selected first antenna among the plurality of first antennas is fixed to transmit a first power transmission signal; and a second power transmission process of transmitting power from the selected first antenna by inverting the predetermined phase to obtain a first power transmission signal with an inverted phase, The power receiving device obtains a differential signal between a first composite signal and a second composite signal and transmits the differential signal to the power transmission control unit, wherein the first composite signal is a composite signal of the first power transmission signal of the specified phase received from the plurality of first antennas in the first power transmission process and the first power transmission signal with the power transmission phase fixed, and the second composite signal is a composite signal of the first power transmission signal of the reverse phase received from the plurality of first antennas in the second power transmission process and the first power transmission signal with the power transmission phase fixed, The power transmission control unit controls phases of the plurality of first power transmission signals transmitted by the plurality of first antennas based on the plurality of differential signals obtained by selecting each of the plurality of first antennas.

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