JP2022006641A - Power transmitting device, control method for power transmitting device, and program - Google Patents

Abstract

To provide a power transmitting device capable of selecting an appropriate power transmission system when transmitting power from the power transmitting device to a plurality of power receiving devices, a control method for the power transmitting device, and a program.SOLUTION: A power transmitting device 100 comprising a plurality of coils 105a-105c selects either a time-division power transmission system for transmitting power using a coil selected from among the plurality of coils in a time-division manner or a parallel power transmission system for transmitting power simultaneously using two or more coils of the plurality of coils. In a case where a plurality of power receiving devices being present in a power transmittable range of the power transmitting device are detected, the power transmitting device determines whether or not a relation obtained from the plurality of power receiving devices satisfies a predetermined condition, and selects either the time-division power transmission system or the parallel power transmission system in accordance with a result of the determination.SELECTED DRAWING: Figure 2

Description

The present invention relates to wireless power transmission technology.

In recent years, technological development of wireless power transmission systems has been widely carried out. Patent Document 1 discloses a power transmission device and a power receiving device conforming to a standard established by the Wireless Power Consortium (WPC), a standardization body for non-contact charging standards. In addition, although the WPC standard stipulates power transmission at 5 watts or less, procedures that enable power transmission over 5 watts are also stipulated in order to realize high-speed charging. According to the WPC standard, a foreign matter detection function is an indispensable condition for a power transmission device when transmitting power exceeding 5 watts. The foreign matter detection function is a function of detecting foreign matter different from that of the power transmission device and the power receiving device, and can reduce the power transmission output or stop the power transmission according to the result.

Further, there is a power transmission device that transmits power to a plurality of power receiving devices by using a plurality of power transmission coils. As a method for transmitting power to multiple power receiving devices, a time-divided power transmission method in which power is transmitted using one coil selected by time division from multiple coils and a parallel power transmission method in which power is transmitted simultaneously using multiple coils. There is.

Japanese Unexamined Patent Publication No. 2016-007116

In a power transmission device having a plurality of power transmission coils, the mounting position of the power receiving device on a surface close to the plurality of power transmission coils (hereinafter, also referred to as a mounting surface) does not have to be strictly determined between the coils. The distance is short, or some parts overlap. Therefore, when a plurality of power receiving devices are placed close to each other, they may be affected by power transmission from adjacent coils. This effect is such that in the power receiving device, the received power value that should be received from the power transmission device becomes larger or smaller than the received power value. The foreign matter detection function in the power transmission device detects foreign matter using the difference between the transmitted power value recognized by the power transmission device and the received power value notified by the power receiving device, and this effect is due to the accuracy of the foreign matter detection function. Causes a decline. As a result, even though there is no foreign matter, an unnecessary power transmission stop, a decrease in power transmission efficiency, or a situation in which foreign matter cannot be detected occurs.

On the other hand, in the parallel power transmission method, the above-mentioned influence may occur, but in the time-division power transmission method, power is always transmitted from only one coil at a time, so that the above-mentioned influence does not occur. Instead, the time-division power transmission method takes time to charge because the power is transmitted in a time-division manner.

For this reason, when multiple power receiving devices are mounted on the mounting surface of the power transmission device, it is possible to appropriately select and switch between the time-division power transmission method and the parallel power transmission method according to the presence or absence of mutual influence. desired. In particular, since it is desirable for the user to have a short time to complete charging, he / she wants to switch to using the parallel power transmission method when there is no mutual influence, and to use the time-division power transmission method in some cases. However, since the user cannot determine whether or not there is mutual influence and whether or not the accuracy of the foreign matter detection function has deteriorated, there is a problem that the time-division power transmission method and the parallel power transmission method cannot be appropriately switched.

The present invention has been made in view of the above problems, and an object of the present invention is to select an appropriate power transmission method when power is transmitted from a power transmission device to a plurality of power receiving devices.

As one means for solving the above problems, the power transmission device of the present invention has the following configuration. That is,
It ’s a power transmission device,
With multiple coils that transmit wirelessly,
A selection means for selecting one of a time-division power transmission method in which power is transmitted using a coil selected by time division from the plurality of coils and a parallel power transmission method in which power is transmitted using two or more of the plurality of coils at the same time.
A power transmission means for transmitting power by the method selected by the selection means, and a power transmission means.
A detection means for detecting one or more power receiving devices existing in the power transmission range of the power transmission device using the coil, and
It has a determination means for determining whether or not a relationship obtained from the plurality of power receiving devices satisfies a predetermined condition when a plurality of power receiving devices are detected by the detecting means.
Depending on the result of the determination by the determination means, the selection means selects either the time-division power transmission method or the parallel power transmission method.

When transmitting power from a power transmitting device to a plurality of power receiving devices, it is possible to select an appropriate power transmission method.

It is a block diagram which shows the structural example of a power transmission device. A conceptual diagram of the mounting surface of the power transmission device is shown. An example of mounting a plurality of power receiving devices on the mounting surface of the power transmitting device is shown (proximity pattern). It is a flowchart of the process executed by the power transmission apparatus in Embodiment 1. Another example of mounting multiple power receiving devices on the mounting surface of the power transmitting device is shown (separate pattern). It is a flowchart of the process executed by the power transmission apparatus in Embodiment 2.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential for the invention, and the plurality of features may be arbitrarily combined. Further, in the attached drawings, the same or similar configurations are given the same reference numbers, and duplicate explanations are omitted.

[Embodiment 1]
(Structure of power transmission device)
FIG. 1 is a block diagram showing a configuration example of the power transmission device 100 according to the first embodiment. The power transmission device 100 shall comply with the standard established by the Wireless Power Consortium (WPC), a standardization body for wireless charging standards. The power transmission device 100 can supply power to a power receiving device that also conforms to the WPC standard, and has a capacity to output a maximum of 15 watts of power to a charging unit (not shown) of the power receiving device. In the following description, the power transmission device may be referred to as TX, and the power receiving device may be referred to as RX.

The TX100 transmits electric power via the power transmission coils 105a to 105c. Although three power transmission coils 105a to 105c are shown in FIG. 1, the number of power transmission coils is not limited as long as they are plural. Further, in the following description, the power transmission coils 105a to 105c may be collectively referred to as a power transmission coil 105.

The control unit 101 controls the entire TX100. An example of the control unit 101 is one or more CPUs (Central Processing Units). The control unit 101 instructs the selection unit 106 of the time division power transmission method or the parallel power transmission method. For example, the control unit 101 can give the instruction according to the comparison result (difference) between the received power value in the time-division transmission method and the received power value in the parallel power transmission method acquired by the power receiving power comparison unit 110. Further, the control unit 101 can control / manage the transmitted power value. For example, the control unit 101 determines the power transmission value for the power transmission process performed by the time-division power transmission unit 103 or the parallel power transmission unit 104, and transmits the selection unit 106 to the time-division power transmission unit 103 and the parallel power transmission unit 104. I can tell. Further, the control unit 101 can control the user to give a predetermined notification by using the UI unit 112.
In the time-division power transmission method, different power transmission periods are assigned to each of the plurality of power receiving devices, and power is transmitted to one power receiving device within the assigned power transmission period. On the other hand, in the parallel power transmission method, power is transmitted to a plurality of power receiving devices at the same time within the same power transmission period.

The power supply unit 102 controls the power supply in order to supply the electric power supplied from the outside of the TX100 to the entire TX100. The selection unit 106 gives a selection instruction to either the time-division power transmission unit 103 or the parallel power transmission unit 104 in response to the instruction of the control unit 101.

The time-division power transmission unit 103 operates when it receives a selection instruction from the selection unit 106, and controls to perform power transmission via a plurality of power transmission coils 105 in a time-division power transmission system. Here, the time-division power transmission method is a method of power transmission using one coil selected by time-division from a plurality of power transmission coils 105. The number of coils selected by time division is not limited to one. That is, a plurality of coils may be selected for power transmission in the time-division power transmission system.

The parallel power transmission unit 104 operates when receiving a selection instruction from the selection unit 106, and controls power transmission via a plurality of power transmission coils 105 in a parallel power transmission system. Here, the parallel power transmission method is a method of transmitting power in parallel (for example, at the same time) using some or all of a plurality of power transmission coils 105.

The RX detection unit 107 detects that the RX is placed on the mounting surface (for example, a surface configured to be close to each of the plurality of power transmission coils 105). As a detection method, it is possible to detect an object such as monitoring a change in the voltage value or current value of each of the power transmission coils 105a to 105c, a pressure sensor, an infrared sensor, a magnetic sensor, and monitoring a change in the power transmission load. If so, any method can be used. In addition to such object detection, it may be determined that the object is detected by confirming that it is RX. In the present embodiment, the RX detection unit 107 detects an object by monitoring changes in the voltage value or current value of the power transmission coils 105a to 105c, and then confirms the identification information received from the RX, and then the RX. Can be determined to be detected. In this embodiment, the case where the RX is mounted on the mounting surface of the TX100 will be described as an example, but when the TX100 transmits power to the RX, the RX is within the power transmission range of the TX100. If it exists, it does not have to be placed on the mounting surface. That is, the RX detection unit 107 can detect RX existing in the power transmission range of the TX100.

The communication unit 108 performs non-contact charging control communication based on the WPC standard with the communication unit (not shown) of the RX. The control communication is a so-called in-band communication in which the electromagnetic wave transmitted by the power transmission coil 105 is load-modulated. However, this may be out-band communication using a frequency different from the frequency of the power transmission unit (time-division power transmission unit 103, parallel power transmission unit 104) instead of in-band communication. Out-of-band communication may be NFC (Near Field Communication), RFID (Radio Frequency Identifier), Wi-Fi, or Bluetooth®. For example, when the TX 100 is transmitting power at a certain transmission power value (controlled by the control unit 101), the communication unit 108 periodically sends a power reception notification (notification of the power reception value assumed by the RX) from the RX. receive. As a result, the communication unit 108 receives the received power value and stores it in the memory 111.

The foreign matter detection unit 109 detects the presence of foreign matter between the power transmission coil 105 and the power receiving coil (not shown) of the RX during power transmission from the TX100 to the RX. A foreign substance is a conductive object such as a piece of metal, which is different from a power receiving device. Specifically, as described above, when the TX 100 is transmitting power at a certain transmission power value, the communication unit 108 periodically receives the power reception value measured by the RX from the RX. The foreign matter detection unit 109 compares the transmitted power value with the received received power value, and determines that the foreign matter is present when the difference exceeds a predetermined range. If foreign matter is present, the difference between the transmitted power value and the received power value can be large because the notified power received power value becomes small because it is attenuated by the foreign matter. Therefore, the foreign matter detection unit 109 can detect the foreign matter. The foreign matter detection unit 109 can detect foreign matter that is not between the power transmission coil 105 and the power receiving coil of the RX by comparing the power transmission power value and the power reception power value.

The received power comparison unit 110 compares a plurality of received power values received from RX stored in the memory 111. Specifically, the received power comparison unit 110 acquires (for example, calculates) the difference between the received power value in the time-division transmission method and the received power value in the parallel power transmission method for a certain RX. The received power comparison unit 110 outputs the difference as a comparison result to the control unit 101. When the difference (comparison result) is larger than the predetermined range, the control unit 101 determines that there is an influence in the parallel power transmission method, and when it is small, it determines that there is no influence. A predetermined value may be used instead of the predetermined range. The predetermined range can be stored in the memory 111 in advance. The control unit 101 gives an instruction according to the determination to the selection unit 106.

The memory 111 stores the program and data of the TX100, the information of the setting and the state, and the received power value received from the RX via the communication unit 108. Further, the memory 111 can store the center position (for example, coordinate information on the mounting surface) and the radius of each of the power transmission coils 105a to 105c. The UI unit 112 is a user interface. In the present embodiment, the UI unit 112 is a liquid crystal panel (display unit), but other configurations may be used as long as it is a means for notifying the user or a means operated by the user. For example, the UI unit 112 may be an LED, a speaker, a microphone, a vibration generating circuit, a display, or a combination thereof.

In FIG. 1, the control unit 101, the time-division power transmission unit 103, the parallel power transmission unit 104, the selection unit 106, the RX detection unit 107, the communication unit 108, the foreign matter detection unit 109, the power received power comparison unit 110, and the memory 111 are described as separate bodies. However, any plurality of these may be mounted on the same chip. Further, one block may be divided into a plurality of blocks.

(Communication for power transmission / reception control based on WPC standard)
The power transmission device and the power reception device according to the present embodiment perform communication for power transmission / reception control based on the WPC standard. The WPC standard defines a plurality of phases, including a Power Transfer phase in which power transmission is executed and one or more phases before actual power transmission is performed, and is used for power transmission / reception control required in each phase. Communication takes place. The phase before power transmission may include a Selection phase, a Ping phase, an Identity and Configuration phase, a Negotiation phase, and a Calibration phase. In the following, the Identity and Configuration phase will be referred to as the I & C phase. Here, TX100 and RX200, 201 (FIGS. 3 and 5) as RX will be described as an example.

In the Selection phase, the TX100 intermittently transmits Analog Ping to detect that an object is placed on the TX100 (for example, RX200, 201, a conductor piece, etc. are placed on the mounting surface of the TX100). .. The TX100 detects at least one of the voltage value and the current value of the power transmission antenna when the Analog Ping is transmitted, and determines that an object exists when the voltage value falls below a certain threshold value or the current value exceeds a certain threshold value. Then, the transition to the Ping phase occurs.

In the Ping phase, the TX100 transmits a Digital Ping with a larger power than the Analog Ping. The size of the Digital Ping is sufficient power to activate the control unit (not shown) of the RX200 and 201 mounted on the TX100. The RX200 and 201 notify the TX100 of the magnitude of the received voltage. In this way, the TX100 recognizes that the object detected in the Selection phase is the RX200, 201 by receiving the response from the RX200, 201 that received the Digital Ping. Upon receiving the notification of the received voltage value, the TX100 transitions to the I & C phase.

In the I & C phase, the TX100 identifies the RX200 and 201 and acquires device configuration information (capacity information) from the RX200 and 201. Therefore, RX200 and 201 transmit the Identity Packet (ID Packet) and the Configuration Packet to the TX100. The ID Packet includes the identifier information of the RX200 and 201, and the Configuration Packet contains the device configuration information (capacity information) of the RX200 and 201. Upon receiving the ID Packet and the Configuration Packet, the TX100 responds with an acknowledge (ACK, acknowledgment). Then, the I & C phase ends.

In the negotiation phase, the GP value is determined based on the GP value required by the RX200 and 201, the power transmission capacity of the TX100, and the like. Further, the TX100 executes a foreign matter detection process using the Q value measurement method in accordance with the requests from the RX200 and 201. Further, the WPC standard stipulates a method of once shifting to the Power Transfer phase and then performing the same processing as the Negotiation phase again at the request of RX200 and 201. The phase in which these processes are performed by migrating from the Power Transfer phase is called the Regency phase.

In the calibration phase, the RX200 and 201 notify the TX100 of the predetermined received power value (received power value in the light load state / received power value in the maximum load state) based on the WPC standard, and the TX100 efficiently transmits power. Make adjustments. The received power value notified to the TX100 can be used for foreign matter detection processing by the power loss method specified in the WPC standard (a method of detecting foreign matter by the difference between the transmitted power in the TX100 and the received power in the RX200 and 201). ..

In the Power Transfer phase, control is performed for starting and continuing power transmission, and stopping power transmission due to an error or full charge. The TX100, RX200, and 201 use the same power transmission antenna (power transmission coil) and power reception antenna (power reception coil) used when performing wireless power transmission based on the WPC standard for these power transmission / reception control. Communication is performed by superimposing a signal on an electromagnetic wave transmitted from a power transmitting antenna or a power receiving antenna. The range in which communication based on the WPC standard is possible between the TX100 and the RX200 and 201 is almost the same as the transmission range of the TX100.

(Process flow)
Subsequently, the processing of the power transmission device in this embodiment will be described. First, the arrangement of RX200 and 201 with respect to TX100 will be described. FIG. 2 is a conceptual diagram of the mounting surface of the TX100. In FIG. 2, the power transmission coils 105a to 105c are adjacent to each other, and some of them are arranged so as to overlap each other. There is no large gap between adjacent coils. Therefore, the user can place the power receiving device for charging at any place on the mounting surface of the TX100.

FIG. 4 shows a flowchart of the process executed by the power transmission device in the present embodiment. First, as shown in FIG. 3, assuming that the RX200 and 201 are placed close to each other on the mounting surface of the TX100 as the power receiving device, the process of FIG. 4 will be described. FIG. 3 shows an example of mounting RX200 and 201 on the mounting surface of TX100.

An example of RX200 and 201 is a smartphone, and an example of TX100 is an accessory device for charging the smartphone. The RX200, 201 and TX100 may be a storage device such as a tablet, a hard disk device or a memory device, or an information processing device such as a personal computer (PC). Further, the RX200, 201 and TX100 may be, for example, an image input device such as an image pickup device (camera, video camera, etc.) or a scanner, or may be an image output device such as a printer, a copy machine, or a projector. .. Further, the TX100 may be a smartphone. In this case, RX200 and 201 may be another smartphone or wireless earphones. Further, the TX100 may be a charger installed on a console or the like in an automobile.

The TX100 performs the following processing before starting the processing shown in FIG. First, after being activated, the control unit 101 instructs the selection unit 106 of the time-division power transmission method. Upon receiving the instruction, the selection unit 106 gives a selection instruction to the time-division power transmission unit 103. In this example, it is described that the time-division power transmission method is used after the control unit 101 is activated, but at this point, there is no problem even if the parallel power transmission method is used. Upon receiving the selection instruction, the time-division power transmission unit 103 starts the above-mentioned operation conforming to the WPC standard. Specifically, in the Selection phase, the time-division power transmission unit 103 transmits analog pings via the power transmission coils 105a to 105c. The Analog Ping is a signal of minute electric power for detecting an object existing in the vicinity of the power transmission coils 105a to 105c. When the transmission of Analog Ping is started, the TX100 starts the process of FIG.

The RX detection unit 107 monitors the voltage value or current value of the power transmission coils 105a to 105c when the analog ping is transmitted in order to monitor the number of RXs mounted on the mounting surface of the TX100 (S401). .. When the RX200 and 201 are placed as shown in FIG. 3, the voltage value falls below a certain threshold value or the current value exceeds a certain threshold value. The RX detection unit 107 determines that an object (RX) has been detected due to this event, and the power transmission coil 105 (one or more of the power transmission coils 105a to 105c) in which at least one of the voltage value and the current value has changed). Transition to the Ping phase in the transmission path corresponding to. Here, it is assumed that there is a change in at least one of the voltage value and the current value in the power transmission coils 105a and 105b with reference to FIG.

In the Ping phase, the time-division transmission unit 103 transmits Digital Ping larger than the Analog Ping from the transmission coils 105a and 105b. The size of the Digital Ping is sufficient power to activate the respective control units of the RX200 and 201 existing in the vicinity of the power transmission coils 105a and 105b.

The RX200 and 201 each receive the Digital Ping from the TX100 via the power receiving coil, and when the control unit (not shown) is activated, the RX200 and 201 transition to the I & C phase (Identification and Configuration phase). Then, RX200 and 201 each transmit an ID Packet. When the communication unit 108 receives the ID Packet from the RX200 and 201, the RX detection unit 107 determines that the RX200 and RX201 have been detected (S402). In response to the RX detection by the RX detection unit 107, the control unit 101 counts the number of detected RXs. When the RX200 and RX201 are mounted as shown in FIG. 3 from the state where nothing is mounted on the mounting surface of the TX100 (FIG. 2), the control unit 101 changes the count value from 0 to 2. Let me. Although not shown, when one RX (RX200 or 201) is mounted on the mounting surface of the TX100 and two RXs (RX200 and RX201) are mounted, the control unit 101 counts. Is changed from 1 to 2. When the power transmission is completed or the RX is removed from the mounting surface of the TX100, the control unit 101 decrements the count value. That is, for example, when the state in which three RXes are mounted changes to the state in which two RXes are mounted (FIG. 3), the control unit 101 changes the count value from 3 to 2. When the count value changes from the previous value (for example, the default value), the control unit 101 confirms whether the changed count value becomes 2 or more (S403). The confirmation may be performed when the count value is stable, when a predetermined time has elapsed from S401, when a predetermined operation is performed by the user, and the like.

In the case of FIG. 3, the number of RXs mounted is 2, but when the number of RXs is less than 2 (that is, 1) (No in S403), the following processing is performed. That is, the TX100 advances the operation conforming to the WPC standard as the processing after the mounting detection of the RX, and transitions to the Negotiation phase, the Calibration phase, and the Power Transfer phase. The control unit 101 instructs the selection unit 106 of the time-division power transmission method, the selection unit 106 gives the selection instruction to the time-division power transmission unit 103 in response to the instruction, and the time-division power transmission unit 103 transmits power. At this time, since there is only one RX mounted on the mounting surface of the TX100, although it is a time-division transmission method, it is actually a single power transmission without time-division (S414). Of course, there is no problem even if the parallel power transmission unit 104 is selected instead of the time-division power transmission unit 103, and the same power transmission process can be realized.

As shown in FIG. 3, when the number of RXs mounted is 2 (Yes in S403), the process proceeds to S404. As a process after the RX placement detection, the TX100 advances the operation conforming to the WPC standard in each of the transmission coils 105a and 105b that have detected the RX placement, and transitions to the Negotiation phase, the Calibration phase, and the Power Transfer phase. .. The control unit 101 instructs the selection unit 106 of the time-division power transmission method, the selection unit 106 gives the selection instruction to the time-division power transmission unit 103 in response to the instruction, and the time-division power transmission unit 103 transmits power (S404). ). At this time, the time-division power transmission unit 103 uses the two power transmission coils 105a and 105b in a time-division manner to transmit power to the RX200 and RX201. When the power transmission is started, the notification of the received power value is periodically transmitted from each of the RX200 and RX201. The communication unit 108 receives the received power value (S405). The received power value can be used for the foreign matter detection process by the foreign matter detection unit 109. Further, the communication unit 108 distinguishes the received received power value for each RX (distinguished by RX200 and RX201) and stores it in the memory 111 (S406).

When the power received power values from the RX200 and RX201 are stored (recorded) in the memory 111 (Yes in S406), the control unit 101 instructs the selection unit 106 to switch to the parallel power transmission method. The selection unit 106 stops the selection instruction to the time-division power transmission unit 103, and gives the selection instruction to the parallel power transmission unit 104. In response to the selection instruction, the parallel power transmission unit 104 performs an operation conforming to the WPC standard. That is, since it is the Power Transfer phase at this point, the parallel power transmission unit 104 transmits power to the RX200 and RX201 from the two power transmission coils 105a and 105b as the Power Transfer phase (S407). Then, similarly to S405, the communication unit 108 distinguishes each received power value received from RX200 and RX201 for each RX and stores it in the memory 111 (S408).

When the TX100 first receives the received power value from the RX200 and RX201 via the parallel power transmission method, the TX100 receives power from the RX200 and RX201 via the time-divided power transmission method after the reception and storage in the memory 111. The power value is received and stored in the memory 111.

When the power received power values from the RX200 and RX201 in the time-division transmission method and the parallel power transmission method are stored (recorded) in the memory 111 (Yes in S409), the relationship obtained from the RX200 and RX201 satisfies the predetermined condition for the TX100. Check if it is. Here, the TX100 confirms whether or not there is any influence on the parallel power transmission system in each RX. Specifically, first, the received power comparison unit 110 acquires (calculates) the difference between the received power value in the time-division transmission method and the received power value in the parallel power transmission method in each RX stored in the memory 111. (S410). Next, the control unit 101 determines whether or not the difference acquired by the received power comparison unit 110 is within a predetermined range (S411). In the example of FIG. 3, RX200 and RX201 are placed close to each other and are influenced by each other, so that the difference between the received power values is larger than the predetermined range (No in S411). That is, in at least one of RX200 and RX201, the difference between the received power value received in S405 and the received power value received in S408 becomes larger than the predetermined range. In this case, the control unit 101 determines that there is an influence in the parallel power transmission method, and controls to perform power transmission in the time-division power transmission method. Specifically, the control unit 101 instructs the selection unit 106 to switch to the time-division power transmission system. The selection unit 106 stops the selection instruction to the parallel power transmission unit 104 and gives the selection instruction to the time-division power transmission unit 103. In response to the selection instruction, the time-division power transmission unit 103 transmits power from the power transmission coils 105a and 105b to the RX200 and RX201 by the time-division power transmission method (S413). In S411, the determination may be made using a predetermined value instead of the predetermined range (for example, if the difference between the received power values is larger than the predetermined value, the process proceeds to S413, and in other cases, the process proceeds to S413. Proceed to S412).

Next, as shown in FIG. 5, it is assumed that the RX200 and 201 are separately mounted on the mounting surface of the TX100 as the power receiving device, and the process of FIG. 4 will be described. FIG. 5 shows another example of mounting RX200, 201 on the mounting surface of TX100. In the processing after S411 in FIG. 4, a processing different from the case of FIG. 3 will be described.

The control unit 101 determines whether or not the difference acquired by the power receiving power comparison unit 110 is within a predetermined range (S411). In the example of FIG. 5, it is assumed that RX200 and RX201 are placed apart from each other and do not affect each other. Therefore, the difference between the received power values is within a predetermined range (Yes in S411). That is, in all of the RX200 and RX201, the difference between the received power value received in S405 and the received power value received in S408 is within a predetermined range. In this case, the control unit 101 determines that there is no influence in the parallel power transmission method, and controls to continue the power transmission in the parallel power transmission method (S412).

When the difference between the received power values is within a predetermined range (No in S411), before and after S413, the control unit 101 indicates (notifies) that the UI unit 112 is transmitting power by the time division transmission method, and the user. You may let me know. By doing so, the user can recognize that the current method of mounting the RX200 and RX201 takes a long time to charge. That is, the TX100 will be able to give the user an opportunity to relocate the RX200 and RX201.

Further, since the control unit 101 can grasp the power transmission coil that can be used when the time-division power transmission method is transmitted through the processing of S411, the time-division power transmission method is applied to the UI unit 112 at which power transmission coil (location / position). It may indicate whether to do it. That is, the control unit 101 may notify the user of information on one or more power transmission coils capable of performing power transmission using the time-division power transmission method, depending on the result of S411. By doing so, the user can obtain knowledge on where on the mounting surface the RX is placed to be charged by the time-division power transmission method. In this embodiment, three power transmission coils have been described and described, but it is a TX in which more power transmission coils are arranged in a two-dimensional manner, and it seems that the two or three adjacent coils are affected. This is a particularly useful finding in cases.

Further, when the power value transmitted by the TX100 is small, it becomes possible to transmit power by the parallel power transmission method without affecting the adjacent power transmission coils. Therefore, when the transmission power value is smaller than the predetermined value, the TX100 may always select the parallel power transmission method without selecting the time-division power transmission method.

As described above, the power transmission device according to the present embodiment can select and transmit an appropriate power transmission method according to the presence or absence of mutual influence when a plurality of power receiving devices are mounted. In the example of FIG. 3, the number of RXs mounted on the mounting surface of the TX100 is two, but the process of FIG. 4 is the same even when three or more power receiving devices are mounted. Can be applied to. In this case, in S411, when the difference between the received power value received in S405 and the received power value received in S408 is larger than a predetermined range in at least one of the plurality of power receiving devices, the process proceeds to S413, and the other If so, the process may proceed to S412. Further, as described above, the process of FIG. 4 can be applied even when a plurality of RXs exist within the power transmission range of the TX100, and the same effect can be obtained.

[Embodiment 2]
As the second embodiment, a method of more efficiently carrying out the process described in the first embodiment will be described. Hereinafter, the differences from the first embodiment will be described. In the present embodiment, it is assumed that the memory 111 stores the center position (for example, coordinate information with a predetermined point (on the mounting surface) as the origin) and the radius of each of the power transmission coils 105a to 105c. Therefore, it is assumed that the control unit 101 can obtain the distance between the power transmission coils (for example, the distance from one coil edge to the other coil edge). The distance itself between the power transmission coils may be stored in the memory 111.

FIG. 6 shows a flowchart of the process executed by the power transmission device in the present embodiment. The description of the same processing as in FIG. 4 will be omitted. First, as shown in FIG. 3, assuming that the RX200 and 201 are placed close to each other on the mounting surface of the TX100 as the power receiving device, the process of FIG. 6 will be described.

The control unit 101 confirms that the number of RX detected by the RX detection unit 107 is 2 or more (Yes in S403), and the process proceeds to S601. In S601, the control unit 101 confirms which of the transmission coils 105a to 105c has detected the RX200 and RX201. In the case of FIG. 3, it is confirmed that RX200 and RX201 are detected by using the power transmission coil 105a and the power transmission coil 105b. Subsequently, the control unit 101 obtains the values of the center positions and radii of the power transmission coil 105a and the power transmission coil 105b from the memory 111, and obtains the distance between the coils (distance from one coil edge to the other coil edge). ) Is calculated. When there are three or more power transmission coils that have detected RX, the distance between each power transmission coil or the distance between adjacent (adjacent) power transmission coils can be obtained. If the coils overlap, the distance will be negative. In addition to this, it is the same even if the distance between coils related to the influence from power transmission in adjacent coils is defined and used.

The control unit 101 determines whether or not the inter-coil distance thus calculated or the inter-coil distance stored in the memory 111 is equal to or less than a predetermined value (S602). The process corresponds to a process of confirming whether or not the relationship obtained from the RX200 and the RX201 satisfies a predetermined condition. When the number of power transmission coils that have detected RX is three or more, it can be determined whether or not the distance between each power transmission coil or the distance between adjacent (adjacent) power transmission coils is a predetermined value or less.

The predetermined value may be stored in the memory 111 in advance. The predetermined value may be set to the maximum value of the distance between the coils that is expected to affect between a plurality of power receiving devices mounted on the mounting surface. In this example, it is assumed that the predetermined value is set so as to be greater than or equal to the distance between the transmission coil 105a and the transmission coil 105b and less than the distance between the transmission coil 105a and the transmission coil 105c. Therefore, the distance between the coils with respect to the power transmission coil 105a and the power transmission coil 105b is equal to or less than a predetermined value (Yes in S602). In this case, the control unit 101 determines that the RX200 and the RX201 affect each other, and the process proceeds to S404. Since the processing after S404 is the same as that in FIG. 4, the description thereof will be omitted.

Next, as shown in FIG. 5, it is assumed that the RX200 and 201 are separately mounted on the mounting surface of the TX100 as the power receiving device, and the process of FIG. 6 will be described. The control unit 101 confirms that the number of RX detected by the RX detection unit 107 is 2 or more (Yes in S403), and the process proceeds to S601. In S601, the control unit 101 detects the power transmission coil 105a and the power transmission coil 105c as the coils that have detected the RX200 and RX201. Next, the control unit 101 obtains the distance between the coils of the power transmission coil 105a and the power transmission coil 105c and compares it with a predetermined value (S602). As described above, in this example, the predetermined value is set so as to be greater than or equal to the distance between the transmission coil 105a and the transmission coil 105b and less than the distance between the transmission coil 105a and the transmission coil 105c. Therefore, the distance between the coils with respect to the power transmission coil 105a and the power transmission coil 105c becomes larger than a predetermined value (No in S602). In this case, the control unit 101 determines that the RX200 and the RX201 do not affect each other, and the process proceeds to S412. Since the processing of S412 is the same as that of FIG. 4, the description thereof will be omitted.

In FIG. 6, the method of making a judgment using the distance between the coils as an index has been described, but the judgment may be made using the pattern of the combination of the power transmission coils as an index. For example, the memory 111 stores in advance a combination pattern of coils that is expected to affect between a plurality of power receiving devices mounted on the mounting surface. For example, when the power transmission coils 105a to 105 are arranged as shown in FIGS. 3 to 5.
-Pattern 1: Power transmission coil 105a and power transmission coil 105b
-Pattern 2: Power transmission coil 105b and power transmission coil 105c
-Pattern 3: Power transmission coil 105a, power transmission coil 105b, power transmission coil 105c,
These three patterns are stored in the memory 111 in advance.

When the control unit 101 confirms that the number of RX detected by the RX detection unit 107 is 2 or more (Yes in S403), which of the power transmission coils 105a to 105c has detected RX200 or RX201? Is confirmed (S601). The process corresponds to a process of confirming whether or not the relationship obtained from the RX200 and the RX201 satisfies a predetermined condition. The control unit 101 confirms whether the combination of the power transmission coils that have detected the RX200 and RX201 matches the pattern stored in the memory 111. If there is a pattern that matches the combination, the process may proceed to S404, and if not, the process may proceed to S412.

As described above, the power transmission device according to the present embodiment can more efficiently select and transmit an appropriate power transmission method according to the presence or absence of mutual influence when a plurality of power receiving devices are mounted. become. As described above, the process of FIG. 6 can be applied even when a plurality of power receiving devices exist within the power transmission range of the power transmission device, and the same effect can be obtained.

[Other embodiments]
The power transmission method of the wireless power transmission system in this embodiment is not particularly limited. A magnetic field resonance method may be used in which power is transmitted by coupling of a magnetic field between a TX resonator (resonance element) and an RX resonator (resonance element) by resonance (resonance). Further, an electromagnetic induction method, an electric field resonance method, a microwave method, a power transmission method using a laser or the like may be used.

Further, at least a part of the flowcharts shown in FIGS. 4 and 6 may be realized by hardware. When it is realized by hardware, for example, by using a predetermined compiler, a dedicated circuit may be automatically generated on the FPGA from the program for realizing each step. FPGA is an abbreviation for Field Programmable Gate Array. Further, a Gate Array circuit may be formed in the same manner as the FPGA and realized as hardware.

Further, the flowchart shown in FIG. 4 and / or FIG. 6 can be started when the power is turned on to the control unit. The flowchart shown in FIG. 4 and / or FIG. 6 can be realized by the control unit 101 executing the program stored in the memory 111 of the TX100. Further, a configuration may be configured in which a part or all of the steps shown in the flowchart shown in FIGS. 4 and / or 6 is realized by hardware such as ASIC.

The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

The invention is not limited to the above embodiment, and various modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, a claim is attached to publicize the scope of the invention.

100 power transmission device

Claims (14)

It ’s a power transmission device,
With multiple coils that transmit wirelessly,
A selection means for selecting one of a time-division power transmission method in which power is transmitted using a coil selected by time division from the plurality of coils and a parallel power transmission method in which power is transmitted using two or more of the plurality of coils at the same time.
A power transmission means for transmitting power by the method selected by the selection means, and a power transmission means.
A detection means for detecting one or more power receiving devices existing in the power transmission range of the power transmission device using the coil, and
It has a determination means for determining whether or not a relationship obtained from the plurality of power receiving devices satisfies a predetermined condition when a plurality of power receiving devices are detected by the detecting means.
The power transmission device is characterized in that the selection means selects either the time-division power transmission method or the parallel power transmission method according to the result of the determination by the determination means. When the determination means determines that the predetermined condition is satisfied, the selection means selects the parallel power transmission method, and the determination means determines that the predetermined condition is not satisfied. The power transmission device according to claim 1, wherein a divided power transmission method is selected. When a plurality of power receiving devices are detected by the detection means, the first power received, which is the power received value when the power transmitting means is transmitting power by the time-divided power transmission method from the plurality of power receiving devices. Further having a receiving means for receiving the value and the second received power value which is the received power value when the power is transmitted by the parallel power transmission method by the power transmission means.
The determination means determines that the predetermined condition is satisfied when the difference between the first received power value and the second received power value is within a predetermined range for the plurality of power receiving devices. 2. The power transmission device according to claim 2. Further, it has an acquisition means for acquiring a distance between a plurality of coils that have detected the plurality of power receiving devices when a plurality of power receiving devices are detected by the detecting means.
The power transmission device according to claim 2, wherein when all of the distances are larger than a predetermined value, it is determined that the predetermined condition is satisfied. When a plurality of power receiving devices are detected by the detecting means, it is the first power received value when power is transmitted from each of the plurality of power receiving devices by the power transmission means in the time-divided power transmission method. Further having a receiving means for receiving the received power value and the second received power value which is the received power value when the power transmission means is transmitting power by the parallel power transmission method.
Any of the distances is equal to or less than the predetermined value, and the difference between the first received power value and the second received power value in any of the plurality of power receiving devices is within a predetermined range. The power transmission device according to claim 4, wherein the determination means determines that the predetermined condition is satisfied. Further, it has an acquisition means for acquiring a combination of a plurality of coils that have detected the plurality of power receiving devices when a plurality of power receiving devices are detected by the detecting means.
The second aspect of claim 2, wherein it is determined that the predetermined condition is satisfied when the combination does not match a predetermined pattern that is expected to affect between a plurality of preset power receiving devices. Power transmission device. When a plurality of power receiving devices are detected by the detecting means, it is the first power received value when power is transmitted from each of the plurality of power receiving devices by the power transmission means in the time-divided power transmission method. Further having a receiving means for receiving the received power value and the second received power value which is the received power value when the power transmission means is transmitting power by the parallel power transmission method.
When the combination matches the predetermined pattern and the difference between the first received power value and the second received power value in any of the plurality of power receiving devices is within a predetermined range. The power transmission device according to claim 6, wherein the determination means determines that the predetermined condition is satisfied. The power transmission device according to any one of claims 1 to 7, wherein when the power transmitted by the power transmission means is equal to or less than a predetermined value, the selection means selects the parallel power transmission method. The power transmission device according to any one of claims 1 to 8, wherein the plurality of power receiving devices are mounted on a mounting surface configured to be close to each of the plurality of coils. .. 10. The power transmission device according to any one. A second notification means for notifying the user of information on one or more coils capable of transmitting power using the time-division power transmission method among the plurality of coils according to the result of the determination by the determination means. The power transmission device according to any one of claims 1 to 10, further comprising. The power transmission device according to any one of claims 1 to 11, wherein the power transmission device and the plurality of power reception devices are devices conforming to a WPC (Wiress Power Consortium) standard. A power transmission device with multiple coils that transmit power wirelessly.
A selection step of selecting one of a time-division power transmission method in which power is transmitted using a coil selected by time division from the plurality of coils and a parallel power transmission method in which power is transmitted using two or more of the plurality of coils at the same time.
A power transmission process that transmits power by the method selected in the selection process, and
A detection step of detecting one or more power receiving devices existing in the power transmission range of the power transmission device using the coil, and a detection step.
Including a determination step of determining whether or not a relationship obtained from the plurality of power receiving devices satisfies a predetermined condition when a plurality of power receiving devices are detected in the detection step.
A control method comprising selecting either the time-division power transmission method or the parallel power transmission method in the selection step according to the result of the determination in the determination step. A program for operating a computer as a power transmission device according to any one of claims 1 to 12.

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