Non-contact power feed method, non-contact power feed system, non-contact power feed device, and non-contact power reception device

Abstract

To improve the convenience of a system which performs non-contact power feed by using an electromagnetic field between a power reception device mounted in a moving body and a power feed device installed outside the moving body.SOLUTION: A power feed device 2 installed outside a moving body includes a power feed coil 22 and at least one power-feed-side communication device 24 capable of communication in compliance with a UWB wireless communication standard. A power reception device 3 mounted in a moving body includes: a power reception coil 32; and at least one power-reception-side communication device 34 capable of communication with a power-feed-side communication device 24 which is performed in compliance with a UWB wireless communication standard. The control device 6 identifies a positional relation between the power feed coil 22 and the power reception coil 32, based on the communication: and, based on the positional relation, performs a process related to non-contact power feed which is performed from the power feed coil 22 to the power reception coil 32 by means of an electromagnetic field.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a method and system for wireless power supply using an electromagnetic field between a power receiving device mounted on a mobile object and a power supply device installed outside the mobile object. The present disclosure also relates to a wireless power supply device and a wireless power receiving device that can be included in the system. [Background technology]

[0002] Patent Document 1 discloses a system that performs contactless power supply by forming magnetic resonance coupling between a power supply device installed on the ground and a power receiving device mounted on a vehicle, which is an example of a moving object. The contactless power transmission is performed, for example, to charge the battery of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2023-000400 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for improving the convenience of a system that performs contactless power supply using an electromagnetic field between a power receiving device mounted on a mobile object and a power supply device installed outside the mobile object. [Means for solving the problem]

[0005] A first aspect example provided by the present disclosure is a method for contactless power supply using an electromagnetic field between a power receiving device mounted on a moving object and a power supply device installed outside the moving object, the method comprising: Executing communication conforming to the UWB wireless communication standard between at least one first communication device included in the power supply device and at least one second communication device included in the power receiving device; determining a positional relationship between a power supply coil included in the power supply device and a power receiving coil included in the power receiving device based on the communication; A process related to the contactless power supply is performed based on the positional relationship.

[0006] A second embodiment of the present disclosure provides a wireless power supply system, comprising: A power receiving device mounted on a moving object; A power supply device installed outside the moving body; A control device; Contains The power supply device includes: A feeding coil; At least one first communication device capable of communication in accordance with the UWB wireless communication standard; It is equipped with The power receiving device is A receiving coil; At least one second communication device capable of communication with the at least one first communication device in accordance with the UWB wireless communication standard; It is equipped with The control device includes: Identifying a positional relationship between the power supply coil and the power receiving coil based on the communication; Based on the positional relationship, a process related to contactless power supply from the power supply coil to the power receiving coil by utilizing an electromagnetic field is performed.

[0007] In order to suppress the decrease in power transmission efficiency in contactless power supply, the positioning of the power supply device and the power receiving device needs to be performed accurately. According to the configurations of the first and second aspects, whether the power supply coil and the power receiving coil are in an appropriate positional relationship is determined by using UWB wireless communication that can specify the positional relationship between the communication devices with high accuracy, so that the positioning of the power receiving coil mounted on the moving object with respect to the power supply coil can be performed with high accuracy. As a result, the decrease in power transmission efficiency in contactless power supply can be suppressed.

[0008] In addition, since it is possible to determine whether the power supply coil and the power receiving coil are in an appropriate positional relationship without relying on methods such as low power emission (LPE), which involves passing current through the power supply coil, it is possible to reduce power consumption in the contactless power transfer system.

[0009] Furthermore, UWB communication has the advantage of low power consumption and low interference with other communications because the peak value of the transmission power is set lower than the noise level of digital devices that emit radio waves. This can improve the convenience of a system that uses electromagnetic fields to transfer power contactlessly between a power receiving device mounted on a mobile object and a power supply device installed outside the mobile object.

[0010] A third example aspect provided by the present disclosure is a wireless power supply device installed outside a moving object, a power supply coil capable of wirelessly supplying power to a power receiving coil mounted on the moving object by utilizing an electromagnetic field; At least one communication device capable of communication with at least one communication device mounted on the mobile object in accordance with the UWB wireless communication standard; a support body that supports the power supply coil and the at least one communication unit so that their relative positions are invariable; It is equipped with:

[0011] According to the configuration of the third aspect, the position of the communication device relative to the reference position of the power supply coil is fixed, so that information required to specify the positional relationship between the power supply coil and the power receiving coil based on communication conforming to the UWB wireless communication standard can be easily standardized. Therefore, it is possible to improve the installation workability of the power supply device while suppressing a decrease in the positioning accuracy of the power receiving coil mounted on the mobile body relative to the power supply coil. As a result, it is possible to improve the convenience of a system that performs contactless power supply using an electromagnetic field between a power receiving device mounted on the mobile body and a power supply device installed outside the mobile body.

[0012] A fourth example aspect provided by the present disclosure is a non-contact power receiving device mounted on a moving object, a power receiving coil capable of receiving non-contact power supply using an electromagnetic field from a power supply coil installed outside the moving body; At least one communication device capable of communication with at least one communication device installed outside the mobile object in accordance with the UWB wireless communication standard; a support body that supports the receiving coil and the at least one communication unit so that their relative positions are invariable; It is equipped with:

[0013] According to the configuration of the fourth aspect, the position of the power receiving side communication device relative to the reference position of the power receiving coil is fixed, so that information required to specify the positional relationship between the power feeding coil and the power receiving coil based on communication conforming to the UWB wireless communication standard can be easily standardized. Therefore, it is possible to improve the workability of assembling the power receiving device to the mobile body while suppressing a decrease in the positioning accuracy of the power receiving coil mounted on the mobile body relative to the power feeding coil. [Brief description of the drawings]

[0014] [Figure 1] 1 illustrates a configuration of a contactless power supply system according to an embodiment; [Diagram 2] 2 illustrates an example of a functional configuration of the power supply device and the power receiving device of FIG. 1; [Diagram 3] 2 shows the functional configuration of the wireless power supply system in FIG. [Figure 4] 2 shows an example of a flow of processes executed in the contactless power supply system of FIG. [Diagram 5] 3 shows an example of the arrangement of the power supplying side communication device and the power receiving side communication device in FIG. 2. [Figure 6] 3 shows another example of the arrangement of the power supplying communication device and the power receiving communication device of FIG. 2. [Figure 7] 3 shows another example of the arrangement of the power supplying communication device and the power receiving communication device of FIG. 2. [Figure 8] 3 shows another example of the arrangement of the power supplying communication device and the power receiving communication device of FIG. 2. [Figure 9] 13 illustrates another example of the process flow executed by the contactless power supply system of FIG. [Figure 10]2 shows an example of a flow of processes executed in the contactless power supply system of FIG. [Figure 11] 2 shows an example of a flow of processes executed in the contactless power supply system of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described in detail below with reference to the accompanying drawings. In each of the drawings used in the following description, the scale is appropriately changed so that each element can be clearly seen.

[0016] 1 illustrates a configuration of a contactless power supply system 1 according to an embodiment. The contactless power supply system 1 includes a contactless power supply device 2 and a contactless power receiving device 3 (hereinafter, simply referred to as "power supply device 2" and "power receiving device 3"). The power supply device 2 is configured to be able to supply power to the power receiving device 3 contactlessly using an electromagnetic field. Examples of such contactless power supply include a method using magnetic field resonance coupling, a method using electric field resonance coupling, and a method using electromagnetic induction.

[0017] In this example, the power receiving device 3 is mounted on a vehicle 4. The vehicle 4 is an example of a moving body. The power supplying device 2 is buried underground in a parking lot or the like. The underground of a parking lot or the like is an example of the outside of a moving body. The power transmitted from the power supplying device 2 to the power receiving device 3 is used, for example, to charge a battery 41 mounted on the vehicle 4.

[0018] The specific configurations of the power supply device 2 and the power receiving device 3 will be described with reference to FIG.

[0019] The power supply device 2 includes a power supply circuit 21, a power supply coil 22, and a power supply side control unit 23. The power supply circuit 21 is configured to supply power supplied from a power source 5 to a power supply side resonant circuit including the power supply coil 22 and a power supply capacitor (not shown).

[0020] The power source 5 is, for example, a commercial AC power source that supplies single-phase AC power. The power source 5 may be another AC power source that supplies three-phase AC power, or may be a DC power source such as a fuel cell. The power source 5 may be buried underground together with the power supply device 2, or may be installed at an appropriate location above ground.

[0021] When AC power is supplied from the power source 5, the power supply circuit 21 includes a rectifier circuit and an inverter that convert the AC power into DC power. The DC power converted by the rectifier circuit is converted by the inverter into AC power according to the characteristics of the power supply side resonant circuit. The power supply side control unit 23 is configured to control the operation of the inverter.

[0022] The specifications of the power supply coil 22 and the power supply capacitor in the power transmission side power supply circuit are determined so that the resonant frequency of the power transmission side power supply circuit is a predetermined value. When high frequency power supplied from the inverter is applied to the power transmission side power supply circuit, the power supply coil 22 generates an AC magnetic field for power transmission.

[0023] The power receiving device 3 includes a power receiving circuit 31, a power receiving coil 32, and a power receiving side control unit 33. The power receiving circuit 31 is configured to supply, to a battery 41, power received by a power receiving side resonant circuit including the power receiving coil 32 and a power receiving capacitor (not shown).

[0024] The receiver-side resonant circuit has the same configuration as the transmitter-side power supply circuit. The specifications of the receiver coil 32 and the receiver capacitor in the receiver-side power supply circuit are determined so that the resonant frequency of the receiver-side power supply circuit matches that of the transmitter-side power supply circuit, or the difference between the resonant frequencies is within a specified range (for example, within ±20%).

[0025] The vibration of the AC magnetic field generated by the power supply coil 22 is transmitted to the power receiving side resonant circuit that resonates with the resonant frequency of the power transmitting side power supply circuit. As a result, an induced current flows in the power receiving side resonant circuit, generating an induced electromotive force. The power receiving circuit 31 includes a rectifier circuit that converts the AC power supplied from the power receiving side resonant circuit into DC power. The power receiving circuit 31 also includes a conversion circuit that adapts the voltage level of the converted DC power to the specifications of the battery 41. The power receiving side control unit 33 is configured to control the power supply to the battery 41.

[0026] The power supply device 2 includes a power supply side communication device 24. The power receiving device 3 includes a power receiving side communication device 34. The power supply side communication device 24 and the power receiving side communication device 34 are configured to be able to perform two-way communication in accordance with the UWB (Ultra-Wide Band) wireless communication standard. An example of the UWB wireless communication standard is channel number 9 (center frequency: 7987.2 MHz, frequency bandwidth: 499.2 MHz) in IEEE802.15.4a. The power supply side communication device 24 is an example of a first communication device. The power receiving side communication device 34 is an example of a second communication device.

[0027] The power supply side control unit 23 of the power supply device 2 is configured to control the operation of the power supply side communication device 24 in addition to the above operations. The power receiving side control unit 33 of the power receiving device 3 is configured to control the operation of the power receiving side communication device 34 in addition to the above operations.

[0028] In order to suppress a decrease in power transmission efficiency in contactless power supply, it is necessary to accurately position the power receiving coil 32 relative to the power supply coil 22. In other words, it is necessary to accurately park the vehicle 4 equipped with the power receiving device 3 relative to the power supply device 2 buried underground in a parking lot or the like.

[0029] 1, the contactless power supply system 1 includes a control device 6. The control device 6 is configured to identify the positional relationship between the power supply coil 22 and the power receiving coil 32 based on UWB wireless communication performed between a power supply-side communication device 24 and a power receiving-side communication device 34.

[0030] The control device 6 may be installed in a parking lot together with the power supply device 2, or may be installed in a remote location where the control device 6 can communicate with the power supply device 2.

[0031] 3 illustrates an example of the functional configuration of the control device 6. The control device 6 includes an input interface 61, a processor 62, and an output interface 63. The processor 62 outputs a communication control signal CC, which causes the power supply side control unit 23 to control the operation of the power supply side communication device 24, from the output interface 63 configured as a hardware interface.

[0032] The communication control signal CC may be an analog signal or a digital signal depending on the specifications of the power supply device 2. When the communication control signal CC is an analog signal, the output interface 63 includes an appropriate conversion circuit including a D / A converter. This description is similarly applied to other signals that can be output from the output interface 63, which will be described later.

[0033] The power supply-side communication device 24 transmits a trigger signal to the power receiving-side communication device 34 under the control of the power supply-side control unit 23. This triggers an exchange of signals between the power supply-side communication device 24 and the power receiving-side communication device 34 in accordance with the UWB wireless communication standard, and the positional relationship between the power supply-side communication device 24 and the power receiving-side communication device 34 is identified. The expression "positional relationship between A and B" used in this specification includes the meaning of "the distance between A and B." The distance measurement and positioning technology using UWB wireless communication itself is well known, so a detailed description will be omitted.

[0034] The trigger signal may be actively transmitted from the power supply device 2 at regular time intervals, or may be transmitted when an appropriate sensor detects the approach of the vehicle 4 to the power supply device 2. Alternatively, a trigger signal may be transmitted from the power receiving-side communication device 34, and the power supplying-side communication device 24 may receive the trigger signal to start UWB wireless communication.

[0035] The power supply-side control unit 23 is configured to output positional relationship data PR including information corresponding to the identified positional relationship between the power supply-side communication device 24 and the power receiving-side communication device 34. The power supply-side communication device 24 may directly output the positional relationship data PR. The positional relationship data PR may be in the form of analog data or digital data depending on the specifications of the power supply device 2.

[0036] The positional relationship data PR is input to an input interface 61 configured as a hardware interface. Data transmission from the power supply side control unit 23 to the input interface 61 may be performed via wired communication or wireless communication. When the positional relationship data PR is in the form of analog data, the input interface 61 includes an appropriate conversion circuit including an A / D converter. This description is similarly applied to other data that may be input to the input interface 61, which will be described later.

[0037] Alternatively, a trigger signal may be transmitted from the power receiving-side communication device 34, and UWB wireless communication may be started when the power supplying-side communication device 24 receives the trigger signal. In this case, the positional relationship data PR may be acquired by the power receiving-side control unit 33. The acquired positional relationship data PR is transmitted from the power receiving-side control unit 33 or the power receiving-side communication device 34 to the input interface 61 via wireless communication.

[0038] If the positional relationship between the power supplying side communication device 24 and the power supplying coil 22 and the positional relationship between the power receiving side communication device 34 and the power receiving coil 32 are known, the positional relationship between the power supplying coil 22 and the power receiving coil 32 can also be specified based on the positional relationship between the power supplying side communication device 24 and the power receiving side communication device 34 indicated by the positional relationship data PR. The processor 62 determines whether the positional relationship between the power supplying coil 22 and the power receiving coil 32 satisfies a predetermined condition based on the positional relationship data PR.

[0039] For example, it is determined whether the distance between the reference position of the power supply coil 22 and the reference position of the power receiving coil 32 is less than a predetermined value. The reference position can be determined appropriately as long as it is common between the power supply coil 22 and the power receiving coil 32. For example, the center position of the winding can be set as the reference position.

[0040] When it is determined that the positional relationship between the power feeding coil 22 and the power receiving coil 32 satisfies a predetermined condition, the processor 62 outputs, from the output interface 63, a power feeding control signal SC that causes the power feeding side control unit 23 to control the operation of the power feeding circuit 21. The power feeding side control unit 23 causes the power feeding circuit 21 to start feeding power based on the power feeding control signal SC. The process of causing the power feeding device 2 to start wireless power feeding to the power receiving device 3 (power feeding process) is an example of a process related to wireless power feeding.

[0041] When it is determined that the positional relationship between the power supply coil 22 and the power receiving coil 32 does not satisfy a predetermined condition, the processor 62 outputs, from the output interface 63, a notification control signal NC for causing the notification device 7 to execute a notification process. Based on the notification control signal NC, the notification device 7 notifies the user of the vehicle 4 of the fact that the conditions for starting power supply are not satisfied. The notification can be made through at least one of a visual notification, an auditory notification, and a tactile notification. The process for causing the notification device 7 to make a notification (notification process) is an example of a process related to contactless power supply.

[0042] As an example, the notification device 7 may be a stationary device installed in a parking lot. As another example, the notification device 7 may be a device installed in the passenger compartment of the vehicle 4. As another example, the notification device 7 may be a mobile device that can be carried by the user of the vehicle 4. The notification control signal NC may be a signal used for wired communication or a signal used for wireless communication, depending on the specifications of the notification device 7.

[0043] In addition to or instead of the above-described notification process, when it is determined that the positional relationship between the power supply coil 22 and the power receiving coil 32 does not satisfy a predetermined condition, the processor 62 outputs a limit control signal RC for causing the power supply side control unit 23 to execute a process for limiting power supply (limitation process) from the output interface 63. The limit process is an example of a process related to contactless power supply.

[0044] Examples of the limiting process performed by power supply-side control unit 23 based on limit control signal RC include a process for preventing contactless power supply, a process for reducing the power transmission output below normal, and the like.

[0045] FIG. 4 shows an example of the flow of a contactless power supply method that can be executed by the contactless power supply system 1 configured as above.

[0046] First, UWB wireless communication is performed between the power supplying side communication device 24 and the power receiving side communication device 34, and thus the positional relationship between the power supplying coil 22 and the power receiving coil 32 is determined (STEP 11). The determination of the positional relationship continues at least until power supply is started.

[0047] Next, it is determined whether the identified positional relationship between the power supply coil 22 and the power receiving coil 32 satisfies a predetermined condition (STEP 12).

[0048] When it is determined that the positional relationship between the identified power supply coil 22 and the power receiving coil 32 satisfies a predetermined condition (YES in STEP 12), contactless power supply from the power supply device 2 to the power receiving device 3 is started (STEP 13). Note that power supply may be started automatically, or the fact that power supply is permitted may be notified to a user of the vehicle 4 via the notification device 7, and power supply may be started in response to an instruction input by the user.

[0049] For example, if it is determined that the positional relationship between the power supply coil 22 and the power receiving coil 32 identified due to an inappropriate parking position of the vehicle 4 does not satisfy a predetermined condition (NO in STEP 12), the user of the vehicle 4 is notified of this fact via the alarm device 7 (STEP 14).

[0050] The user who has received the notification can redo the stop positioning of the vehicle 4. Next, it is determined whether such a redo has been performed (STEP 15). Specifically, the processor 62 of the control device 6 starts timing when the notification control signal NC is output. When the stop positioning is redoed, the vehicle 4 moves, and therefore a change occurs in the positional relationship between the power supply coil 22 and the power receiving coil 32. That is, a change occurs in the positional relationship data PR. The processor 62 determines whether the stop positioning has been redoed based on whether a change occurs in the positional relationship data PR before the elapsed time from the start of timing reaches a threshold value.

[0051] If it is determined that the parking position has been retried (YES in STEP 15), the process returns to STEP 12, and it is determined whether the parking position resulting from the retried process is appropriate.

[0052] If no change occurs in the positional relationship data PR until the time corresponding to the threshold value has elapsed, it is determined that the parking positioning has not been redone (NO in STEP 15), and a process of limiting the power supply is executed (STEP 16).

[0053] According to the configuration of this embodiment, whether the power supply coil 22 and the power receiving coil 32 are in an appropriate positional relationship is determined by using UWB wireless communication that can specify the positional relationship between communication devices with high accuracy, so that the position of the power receiving coil 32 relative to the power supply coil 22 when the vehicle 4 is stopped can be accurately determined. As a result, a decrease in power transmission efficiency in contactless power supply can be suppressed. For example, when the power transmitted as in this embodiment is used to charge the battery 41 mounted on the vehicle 4, an increase in charging time associated with a decrease in power transmission efficiency can be suppressed. This makes it possible to suppress the occurrence of a situation in which an expected amount of charging has not been performed after a predetermined time has elapsed.

[0054] In addition, since it is possible to determine whether the power supply coil 22 and the power receiving coil 32 are in an appropriate positional relationship without relying on a method such as low power emission (LPE) that involves passing current through the power supply coil 22, power consumption in the contactless power supply system 1 can be reduced.

[0055] Furthermore, UWB communication has the advantage of low power consumption and low interference with other communications because the peak value of the transmission power is set lower than the noise level of digital devices that emit radio waves. This improves the convenience of the system that uses an electromagnetic field to perform contactless power supply between the power receiving device 3 mounted on the vehicle 4 and the power supply device 2 installed outside the vehicle 4.

[0056] In addition, when the parking lot in which the contactless power supply system 1 is installed is equipped with multiple power supply devices 2, the control device 6 may be associated one-to-one with each of the multiple power supply devices 2, or one control device 6 may be associated with multiple power supply devices 2.

[0057] The number of power supply side communication devices 24 mounted on the power supply device 2 and the number of power receiving side communication devices 34 mounted on the power receiving device 3 can be determined appropriately. When UWB wireless communication is performed between a single power supply side communication device 24 and a single power receiving side communication device 34 as illustrated in Fig. 5, the positional relationship between the power supply coil 22 and the power receiving coil 32 that is specified is the distance between them.

[0058] 6, when UWB wireless communication is performed between two power supplying-side communication devices 24 and a single power receiving-side communication device 34, the position of the power receiving-side communication device 34 along the arrangement direction D of the two power supplying-side communication devices 24, as indicated by the dashed line, can be identified based on the phase difference of the radio waves received by each power supplying-side communication device 24. When UWB wireless communication is performed between three power supplying-side communication devices 24 and a single power receiving-side communication device 34, as indicated by the dashed line, the two-dimensional position of the power receiving-side communication device 34 can be identified.

[0059] As illustrated in Figure 7, when UWB wireless communication is performed between two power supply side communication devices 24 and two power receiving side communication devices 34, if the arrangement direction D1 of the two power supply side communication devices 24 and the arrangement direction D2 of the two power receiving side communication devices 34 are non-parallel, the two-dimensional positions of each power supply side communication device 24 and each power receiving side communication device 34 can be identified.

[0060] By increasing the number of the power receiving-side communication devices 34, it is possible to identify a more accurate position of the power supplying-side communication device 24 as seen from the power receiving device 3. Therefore, as illustrated in Fig. 8, it is preferable that the power supplying device 2 includes at least three power supplying-side communication devices 24, and the power receiving device 3 includes at least three power receiving-side communication devices 34.

[0061] Fig. 9 shows another example of the flow of a contactless power supply method that can be executed by the contactless power supply system 1. Processing elements that are substantially the same as those in the example shown in Fig. 4 are given the same reference numerals, and repeated explanations will be omitted.

[0062] In this example, prior to the process of identifying the positional relationship between the power supply coil 22 and the power receiving coil 32 (STEP 11), an authentication process for the vehicle 4 is executed (STEP 21). In this case, authentication information ID for authenticating the vehicle 4 or the user of the vehicle 4 is transmitted and received between the power supply-side communication device 24 of the power supply device 2 and the power receiving-side communication device 34 of the power receiving device 3 (see FIG. 3).

[0063] As an example, the processor 62 of the control device 6 may output a request control signal QC from the output interface 63, which causes the power supply-side control unit 23 of the power supply device 2 to perform a request process for authentication information. Upon receiving the request control signal QC, the power supply-side control unit 23 causes the power supply-side communication device 24 to transmit an authentication request signal RQ. The authentication request signal RQ is received by the power receiving-side communication device 34 of the power receiving device 3.

[0064] The power-receiving-side control unit 33, which has received the authentication request signal RQ through the power-receiving-side communication device 34, causes the power-receiving-side communication device 34 to transmit authentication information ID stored in a storage (not shown). The storage may be provided in the power receiving device 3, or may be provided at an appropriate location in the vehicle 4 in which the power receiving device 3 is mounted. The authentication information ID is received by the power-supplying-side communication device 24.

[0065] The power supply side control unit 23, which has received the authentication information ID through the power supply side communication device 24, collates it with authentication information previously stored in a storage device (not shown). If the two pieces of information match, the processor 62 determines that the authentication has been established. If it is determined that the authentication has been established (YES in STEP 22 in FIG. 9), the processor 62 starts the process of identifying the positional relationship between the power supply coil 22 and the power receiving coil 32 (STEP 11).

[0066] If it is determined that the authentication has not been established (NO in STEP 22), the processor 62 outputs, from the output interface 63, a notification control signal NC for causing the notification device 7 to execute a process of notifying the user of the vehicle 4 of the fact that the authentication has not been established (STEP 23). Then, the process ends.

[0067] According to this configuration, the process of specifying the positional relationship is started only for the vehicle 4 whose authentication information ID has been preregistered, thereby suppressing unnecessary power consumption in the contactless power supply system 1. In particular, in a configuration in which the control device 6 transmits an authentication request signal RQ to a plurality of power supply devices 2, when a specific power supply device 2 receives a response from the power receiving device 3 mounted on the vehicle 4 to be parked, the process of stopping the transmission of the authentication request signal RQ to the power supply devices 2 other than the specific power supply device 2 becomes possible. Even in this case, unnecessary power consumption in the contactless power supply system 1 can be suppressed.

[0068] As another example, a configuration may be adopted in which an authentication request signal RQ is transmitted from the power receiving side communication device 34 of the power receiving device 3 mounted on the vehicle 4. The authentication request signal RQ may include authentication information ID. Even with such a configuration, the authentication process is started only in the specific power supply device 2 that has received the authentication request signal RQ, so that unnecessary power consumption in the contactless power supply system 1 can be suppressed.

[0069] 9, in this example where authentication processing is performed, billing processing may be executed for the vehicle 4 to which contactless power has been supplied (STEP 24). The billing processing is processing for charging a fee according to the amount of power supplied, for example, to a user associated with the authentication information ID. The fee may be collected, for example, through a payment machine installed in the parking lot, by cash or cashless payment, or may be debited from an account associated with the authentication information ID.

[0070] Fig. 10 shows another example of the flow of a contactless power supply method that can be executed by the contactless power supply system 1. Processing elements that are substantially the same as those in the example shown in Fig. 4 are given the same reference numerals, and repeated explanations will be omitted. The processing flow according to this example can be executed in addition to or instead of the processing flow described with reference to Fig. 9.

[0071] In this example, prior to the process of specifying the positional relationship between the power supply coil 22 and the power receiving coil 32 (STEP 11), the power supply device 2 acquires position information PS indicating the position of the power receiving side communication device 34 relative to the reference position of the power receiving coil 32 from the power receiving device 3 (STEP 31). The position information PS can be generated through measurement before shipping of the power receiving device 3. Alternatively, the position information PS can be information indicating a standardized position of the power receiving side communication device 34 relative to the reference position of the power receiving coil 32. The position information PS is stored in a storage (not shown) provided in the power receiving device 3.

[0072] 3, when UWB communication is started between the power supplying side communication device 24 and the power receiving side communication device 34, position information PS is transmitted from the power receiving side communication device 34. The power supplying side control unit 23 performs a process of specifying the positional relationship between the power supplying coil 22 and the power receiving coil 32 while referring to the position information PS (STEP 11), and generates positional relationship data PR.

[0073] In a configuration in which the power receiving side control unit 33 generates the positional relationship data PR, the power receiving device 3 acquires position information PS indicating the position of the power supplying side communication device 24 relative to the reference position of the power supplying coil 22 from the power supplying device 2. The position information PS can be generated through measurement before shipping of the power supplying device 2. Alternatively, the position information PS can be information indicating a standardized position of the power supplying side communication device 24 relative to the reference position of the power supplying coil 22. The position information PS is stored in a storage (not shown) provided in the power supplying device 2.

[0074] Specifically, when UWB communication is started between the power supply side communication device 24 and the power receiving side communication device 34, position information PS is transmitted from the power supply side communication device 24. The power receiving side control unit 33 performs a process of specifying the positional relationship between the power supply coil 22 and the power receiving coil 32 while referring to the positional information PS (STEP 11), and generates positional relationship data PR.

[0075] According to the configuration of this example, which makes use of the characteristics of UWB communication, which enables not only ranging and positioning but also data communication, at least one of the position of the power supplying side communication device 24 relative to the reference position of the power supplying coil 22, which may differ between products, and the position of the power receiving side communication device 34 relative to the reference position of the power receiving coil 32, is referenced, so that the positional relationship between the power supplying coil 22 and the power receiving coil 32 can be determined more precisely.

[0076] At least one of the power supplying side communication device 24 and the power receiving side communication device 34 may have a UWB radar function. Specifically, when the time it takes for the pulse signal emitted from the power supplying side communication device 24 to be reflected by the bottom of the vehicle 4 and return is shorter than an expected value, the presence of a foreign object F between the power supplying device 2 and the power receiving device 3 as exemplified in FIG. 1 is detected. The foreign object F may be a living object or a non-living object. Similarly, when the time it takes for the pulse signal emitted from the power receiving side communication device 34 to be reflected by the ground and return is shorter than an expected value, the presence of the foreign object F is detected. Note that when a moving foreign object F exists between the power supplying device 2 and the power receiving device 3, the frequency of the pulse signal reflected by the foreign object F shifts, and therefore the distance to the foreign object F can also be detected based on the time it takes for the frequency-shifted pulse signal to return.

[0077] When a foreign object F is detected, the power supply-side controller 23 or the power receiving-side controller 33 is configured to output a detection signal DT. The detection signal DT is input to the input interface 61 of the control device 6. The processor 62 can be configured to perform a process of restricting the execution of contactless power supply when the input interface 61 receives the detection signal DT.

[0078] Fig. 11 shows another example of the flow of a contactless power supply method that can be executed by the contactless power supply system 1 configured as described above. Processing elements that are substantially the same as those in the example shown in Fig. 4 are given the same reference numerals, and repeated explanations will be omitted. The processing flow according to this example can be executed in addition to or instead of the processing flow described with reference to Figs. 9 and 10.

[0079] In this example, when the processor 62 determines that the positional relationship between the power supply coil 22 and the power receiving coil 32 satisfies a predetermined condition (YES in STEP 12), the processor 62 outputs a detection control signal DC for causing the power supply device 2 or the power receiving device 3 to execute a foreign object detection process from the output interface 63 (see FIG. 3). When it is determined that no foreign object has been detected as a result of the foreign object detection process performed by the above-described method (NO in STEP 41), the power supply process is executed (STEP 13).

[0080] If it is determined that a foreign object has been detected (YES in STEP 41), the fact is notified to the user of the vehicle 4 via the notification device 7 (STEP 14). The user who has received the notification can reset the power supply environment by removing the foreign object. Then, it is determined whether the foreign object has been removed (STEP 15). Specifically, it is determined whether the output of the detection signal DT from the power supply side control unit 23 or the power receiving side control unit 33 has been canceled within a predetermined time.

[0081] If the foreign object is removed, the process returns to STEP 12. Since the predetermined condition is satisfied (YES in STEP 12) and no foreign object is present (NO in STEP 41), the power supply process is executed. If the foreign object is not removed before the predetermined time has elapsed, the process of limiting the power supply is executed (STEP 16).

[0082] This configuration can prevent a situation in which the power transmission efficiency in contactless power supply is reduced due to the presence of a foreign object between the power supply device 2 and the power receiving device 3. In addition, if the foreign object is a living body, it can prevent the living body from being exposed to the electromagnetic field used for contactless power supply.

[0083] There is known a technique for locking and unlocking the doors of the vehicle 4 by performing a process for authenticating the user through UWB communication between a mobile device carried by a user of the vehicle 4 and a communication device mounted on the vehicle 4. Specifically, authentication information for authenticating the user or the mobile device is transmitted from the mobile device to the communication device through UWB communication. An authentication device (not shown) mounted on the vehicle 4 compares the authentication information received by the communication device with authentication information previously stored in a storage device (not shown). If the two pieces of information match, the authentication device determines that the authentication process is successful. The power receiving side communication device 34 included in the power receiving device 3 mounted on the vehicle 4 can be used in common to perform the authentication process in addition to the above-mentioned contactless power supply. The above-mentioned authentication information transmitted from the mobile device may be used as an authentication information ID for the above-mentioned contactless power supply.

[0084] According to such a configuration, the contactless power supply system 1 can be constructed by effectively utilizing the resources for UWB communication mounted on the vehicle 4.

[0085] 5 to 8, the power supply device 2 may include a support 25. The support 25 supports the power supply coil 22 and at least one power supply-side communication unit 24 so that their relative positions are invariable. Similarly, the power receiving device 3 may include a support 35. The support 35 supports the power receiving coil 32 and at least one power receiving-side communication unit 34 so that their relative positions are invariable.

[0086] According to this configuration, the position of the power supply side communication device 24 relative to the reference position of the power supply coil 22 is fixed, so that it is possible to easily standardize information required to specify the positional relationship between the power supply coil 22 and the power receiving coil 32. Therefore, it is possible to improve the ease of installation of the power supply device 2 while suppressing a decrease in the positioning accuracy of the power receiving coil 32 relative to the power supply coil 22 when the vehicle 4 is stopped.

[0087] Similarly, since the position of the power receiving side communication device 34 relative to the reference position of the power receiving coil 32 is fixed, it is possible to easily standardize information required to specify the positional relationship between the power feeding coil 22 and the power receiving coil 32. This makes it possible to improve the ease of assembling the power receiving device 3 to the vehicle 4 while suppressing a decrease in the positioning accuracy of the power receiving coil 32 relative to the power feeding coil 22 when the vehicle 4 is stopped.

[0088] Each of the power supply side control unit 23 of the power supply device 2, the power receiving side control unit 33 of the power receiving device 3, and the processor 62 of the control device 6, which have the various functions described above, can be realized by a dedicated integrated circuit such as a microcontroller, ASIC, or FPGA, which has a memory element in which a computer program for realizing the function is pre-installed.

[0089] Alternatively, each of the power supply side control unit 23, the power receiving side control unit 33, and the processor 62 may be realized by a general-purpose microprocessor that operates in cooperation with a general-purpose memory. Examples of the general-purpose microprocessor include a CPU, an MPU, and a GPU. Examples of the general-purpose memory include a ROM and a RAM. In this case, a computer program for realizing the corresponding function may be stored in the ROM. The general-purpose microprocessor specifies at least a part of the program stored in the ROM, expands it on the RAM, and executes the above-mentioned process in cooperation with the RAM.

[0090] Each of the power supply side controller 23, the power receiving side controller 33, and the processor 62 may be realized by a combination of a general-purpose microprocessor and a dedicated integrated circuit.

[0091] The functions of the processor 62 do not necessarily have to be realized by a single device. For example, some of the functions of the processor 62 may be shared between a device installed in a parking lot together with the power supply device 2 and a device installed in a location remote from the parking lot.

[0092] The configurations described above are merely examples for facilitating understanding of the present disclosure. Each configuration example may be appropriately modified and combined with other configuration examples without departing from the spirit of the present disclosure.

[0093] The "UWB wireless communication standard" used in the above embodiment originates from a standardization standard conforming to IEEE802.15. However, this expression is not intended to be limited to this standard. As long as it is a short-range wireless communication standard that has the advantages of being able to specify the positional relationship between communication devices with high accuracy and having low power consumption and interference with other communications, an appropriate derived standard or alternative plan may be adopted.

[0094] In the above embodiment, the power supply device 2 is embedded in the ground facing the bottom of the vehicle 4. However, the location of the power supply device 2 can be changed as appropriate depending on the expected positional relationship with the power receiving device 3. For example, the power supply device 2 may be embedded in a wall laterally facing the vehicle 4. Alternatively, the power supply device 2 may be mounted on a portable body that can be positioned appropriately with respect to the vehicle 4.

[0095] In the above embodiment, the vehicle 4 on which the power receiving device 3 is mounted has four wheels. However, the number of wheels may be any number equal to or greater than two.

[0096] The power receiving device 3 may be mounted on a moving object other than the vehicle 4. Examples of such moving objects include trains, airplanes, ships, etc. The moving object may not require a driver.

[0097] Each of the configurations listed below also constitutes part of this disclosure. Item 1: A method for wireless power supply using an electromagnetic field between a power receiving device mounted on a moving object and a power supply device installed outside the moving object, comprising: Executing communication conforming to the UWB wireless communication standard between at least one first communication device included in the power supply device and at least one second communication device included in the power receiving device; determining a positional relationship between a power supply coil included in the power supply device and a power receiving coil included in the power receiving device based on the communication; performing a process related to the contactless power supply based on the positional relationship; Non-contact power supply method. Item 2: The number of at least one of the first communication devices and the second communication devices is plural. Item 1. A contactless power supply method. Item 3: the number of at least one of the first communication devices and the second communication devices is at least three; 3. The contact power supply method according to item 2. Item 4: performing an authentication process for the mobile object via the communication before specifying the positional relationship; 4. The contactless power supply method according to any one of items 1 to 3. Item 5: performing a billing process related to the contactless power supply when the authentication process is successful; 5. The contactless power supply method according to item 4. Item 6: Prior to identifying the positional relationship, the power supply device acquires information indicating a position of the second communication device with respect to a reference position of the power receiving coil. 6. The contactless power supply method according to any one of items 1 to 5. Item 7: Prior to identifying the positional relationship, the power receiving device acquires information indicating a position of the first communication device with respect to a reference position of the power supply coil. 6. The contactless power supply method according to any one of items 1 to 5. Item 8: detecting a foreign object located between the moving body and the outside based on radio waves emitted from at least one of the first communication device and the second communication device; performing at least one of a process of limiting the non-contact power supply and a process of notifying the user when the foreign object is detected; 8. The contactless power supply method according to any one of items 1 to 7. Item 9: The second communication device is used in common for authentication processing for locking and unlocking the mobile body. 9. The contactless power supply method according to any one of items 1 to 8. [Explanation of symbols]

[0098] 1: non-contact power supply system, 2: power supply device, 22: power supply coil, 24: power supply side communication device, 25: support, 3: power receiving device, 32: power receiving coil, 34: power receiving side communication device, 35: support, 4: vehicle, 6: control device, F: foreign object, PS: position information

Claims

1. A method for wireless power supply using an electromagnetic field between a power receiving device mounted on a moving object and a power supply device installed outside the moving object, comprising: executing communication conforming to an UWB wireless communication standard between at least one first communication device included in the power supply device and at least one second communication device included in the power receiving device; determining a positional relationship between a power supply coil included in the power supply device and a power receiving coil included in the power receiving device based on the communication; performing a process related to the contactless power supply based on the positional relationship; Non-contact power supply method.

2. The number of at least one of the first communication devices and the second communication devices is plural. The contactless power supply method according to claim 1 .

3. the number of at least one of the first communication devices and the second communication devices is at least three; The contact power supply method according to claim 2.

4. performing an authentication process for the mobile object via the communication before specifying the positional relationship; The contactless power supply method according to claim 1 .

5. performing a billing process related to the contactless power supply when the authentication process is successful; The contactless power supply method according to claim 4.

6. Prior to identifying the positional relationship, the power supply device acquires information indicating a position of the second communication device with respect to a reference position of the power receiving coil. The contactless power supply method according to claim 1 .

7. Prior to identifying the positional relationship, the power receiving device acquires information indicating a position of the first communication device with respect to a reference position of the power supply coil. The contactless power supply method according to claim 1 .

8. detecting a foreign object located between the moving body and the outside based on a signal emitted from at least one of the first communication device and the second communication device; performing at least one of a process of limiting the non-contact power supply and a process of notifying the user when the foreign object is detected; The contactless power supply method according to claim 1 .

9. The second communication device is used in common for authentication processing for locking and unlocking the mobile body. The contactless power supply method according to claim 1 .

10. A power receiving device mounted on a moving object; A power supply device installed outside the moving body; A control device; Contains The power supply device includes: A feeding coil; At least one first communication device capable of communication in accordance with the UWB wireless communication standard; Equipped with The power receiving device is A receiving coil; at least one second communication device capable of communication with the at least one first communication device in accordance with the UWB wireless communication standard; Equipped with The control device includes: Identifying a positional relationship between the power supply coil and the power receiving coil based on the communication; performing a process related to contactless power supply from the power supply coil to the power receiving coil using an electromagnetic field based on the positional relationship; Contactless power supply system.

11. A non-contact power supply device installed outside a moving object, a power supply coil capable of contactlessly supplying power to a power receiving coil mounted on the moving object by utilizing an electromagnetic field; At least one communication device capable of communication with at least one communication device mounted on the mobile object in accordance with the UWB wireless communication standard; a support body that supports the power supply coil and the at least one communication unit so that their relative positions are invariable; Equipped with Non-contact power supply device.

12. A non-contact power receiving device mounted on a moving object, a power receiving coil capable of receiving non-contact power supply using an electromagnetic field from a power supply coil installed outside the moving body; At least one communication device capable of communication with at least one communication device installed outside the mobile object in accordance with the UWB wireless communication standard; a support body that supports the receiving coil and the at least one communication unit so that their relative positions are invariable; Equipped with Non-contact power receiving device.

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