Non-contact power supply method, non-contact power supply system, non-contact power supply device, non-contact power reception device, position identification method for mobile body, position identification system for mobile body, and mobile body

Abstract

This power supply device (2) installed outside a mobile body comprises a power supply coil (22) and at least one power supply-side communication apparatus (24) that can perform communication conforming to the UWB wireless communication standard. This power reception device (3) mounted on the mobile body comprises: a power reception coil (32); and at least one power reception-side communication apparatus (34) that can perform communication, which conforms to the UWB wireless communication standard, with the power supply-side communication apparatus (24). A control device (6) identifies the positional relationship between the power supply coil (22) and the power reception coil (32) on the basis of the communication, and, on the basis of the positional relationship, causes non-contact power supply to be performed by using an electromagnetic field from the power supply coil (22) to the power reception coil (32).

Description

Non-contact power supply method, non-contact power supply system, non-contact power supply device, non-contact power receiving device, mobile body position specifying method, mobile body position specifying system, and mobile body

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

[0002] The present disclosure also relates to a moving object and a method and system for determining the position of the moving object relative to a reference position.

[0003] Japanese Patent Application Publication No. 2023-000400 discloses a system for wireless 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 wireless power transmission is performed, for example, to charge the vehicle's battery.

[0004] There is a demand for improving the convenience of a system that uses an electromagnetic field to perform contactless power supply between a power receiving device mounted on a mobile object and a power supply device installed outside the mobile object (first demand).

[0005] There is a demand for improving the convenience of a system for identifying the position of a mobile object relative to a reference position (second demand).

[0006] A first example embodiment provided by the present disclosure in order to meet the first requirement is a method for contactless power supply using an electromagnetic field between a power receiving device mounted on a mobile body and a power supply device installed outside the mobile body, 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; identifying 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; and performing processing related to the contactless power supply based on the positional relationship.

[0007] A second example aspect provided by the present disclosure to meet the first requirement is a contactless power supply system including: a power receiving device mounted on a mobile body; a power supply device installed outside the mobile body; and a control device, wherein the power supply device includes a power supply coil and at least one first communication device capable of communication in accordance with the UWB wireless communication standard; the power receiving device includes a power receiving coil and at least one second communication device capable of communication in accordance with the UWB wireless communication standard with the at least one first communication device; and the control device identifies a positional relationship between the power supply coil and the power receiving coil based on the communication, and causes processing related to contactless power supply from the power supply coil to the power receiving coil using an electromagnetic field based on the positional relationship.

[0008] To prevent a decrease in power transmission efficiency in contactless power transfer, it is necessary to accurately position the power transfer device and the power receiving device. According to the configurations of the first and second aspects, whether the power transfer coil and the power receiving coil are in an appropriate positional relationship is determined using UWB wireless communication, which can accurately identify the positional relationship between communication devices. This allows the power receiving coil mounted on a mobile object to be positioned with respect to the power transfer coil with high accuracy. As a result, it is possible to prevent a decrease in power transmission efficiency in contactless power transfer.

[0009] In addition, because it is possible to determine whether the power supply coil and the power receiving coil are in an appropriate positional relationship without relying on techniques 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.

[0010] Furthermore, UWB wireless 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 systems that use electromagnetic fields to perform contactless power transfer between a power receiving device mounted on a mobile object and a power transfer device installed outside the mobile object.

[0011] A third example aspect provided by the present disclosure in order to meet the first requirement is a contactless power supply device installed outside a mobile body, comprising: a power supply coil capable of contactlessly supplying power to a power receiving coil mounted on the mobile body by using an electromagnetic field; at least one communication device capable of communicating with at least one communication device mounted on the mobile body in accordance with the UWB wireless communication standard; and a support body that supports the power supply coil and the at least one communication device so that their relative positions are invariable.

[0012] 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, and therefore, information required to identify the positional relationship between the power supply coil and the power receiving coil based on communication compliant with the UWB wireless communication standard can be easily standardized. Therefore, the efficiency of installing the power supply device can be improved 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, the convenience of a system that uses an electromagnetic field to perform contactless power supply between a power receiving device mounted on the mobile body and a power supply device installed outside the mobile body can be improved.

[0013] A fourth example aspect provided by the present disclosure in order to meet the first requirement is a contactless power receiving device mounted on a mobile body, comprising: a receiving coil capable of receiving contactless power supply using an electromagnetic field from a power supply coil installed outside the mobile body; at least one communication device capable of communication in accordance with the UWB wireless communication standard with at least one communication device installed outside the mobile body; and a support body that supports the receiving coil and the at least one communication device so that their relative positions are invariable.

[0014] 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 identify the positional relationship between the power feeding coil and the power receiving coil based on communication compliant with 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 object while suppressing a decrease in the positioning accuracy of the power receiving coil mounted on the mobile object relative to the power feeding coil.

[0015] A fifth example aspect provided by the present disclosure to meet the second requirement is a method for determining the position of a mobile body, comprising: performing communication conforming to the UWB wireless communication standard between a first communication device mounted on the mobile body and a second communication device installed outside the mobile body; determining a positional relationship between the first communication device and the second communication device based on the communication; and determining a position of the mobile body relative to a reference position based on the positional relationship.

[0016] A sixth example aspect provided by the present disclosure to meet the second requirement is a position determination system for a mobile body, including: a first communication device mounted on the mobile body; a second communication device installed outside the mobile body; and a control device that determines the positional relationship between the first communication device and the second communication device based on communication compliant with the UWB wireless communication standard executed between the first communication device and the second communication device, and determines the position of the mobile body relative to a reference position based on the positional relationship.

[0017] A seventh example aspect provided by the present disclosure to meet the second requirement is a mobile body comprising: a first communication device capable of performing communication compliant with the UWB wireless communication standard with a second communication device installed outside the mobile body; and a control unit that determines the positional relationship between the first communication device and the second communication device based on the communication, and determines the position of the mobile body relative to a reference position based on the positional relationship.

[0018] According to the configurations of the fifth to seventh aspects, the positional relationship between the first and second communication devices can be determined with high accuracy using UWB wireless communication, thereby enabling highly accurate positioning of a moving object relative to a reference position. In addition, UWB wireless communication has the advantage of low power consumption and low interference with other communications because the peak value of transmission power is set lower than the noise level of digital devices that emit radio waves. Therefore, the convenience of the system for determining the position of a moving object relative to a reference position can be improved.

[0019] 2 illustrates an example of a configuration of a contactless power transfer system according to an embodiment. It illustrates an example of a functional configuration of the power transfer device and the power receiving device of FIG. 1. It shows a functional configuration of the contactless power transfer system of FIG. 1. It shows an example of a processing flow executed in the contactless power transfer system of FIG. 1. It shows an example of an arrangement of the power transfer side communication device and the power receiving side communication device of FIG. 2. It shows another ... a processing flow executed by the contactless power transfer system of FIG. 1. It shows an example of a processing flow executed in the contactless power transfer system of FIG. 1. It shows an example of a processing flow executed in the contactless power transfer system of FIG. 1.

[0020] The following detailed description of exemplary embodiments will be given with reference to the accompanying drawings. In the drawings used in the following description, the scale has been changed appropriately so that each element can be clearly seen.

[0021] 1 illustrates the 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 methods include a method using magnetic field resonance coupling, a method using electric field resonance coupling, and a method using electromagnetic induction.

[0022] In this example, the power receiving device 3 is mounted on a vehicle 4. The vehicle 4 is an example of a mobile body. The power supply device 2 is buried underground in a parking lot or the like. The underground space of a parking lot or the like is an example of the outside of a mobile body. The power transmitted from the power supply device 2 to the power receiving device 3 is used, for example, to charge a battery 41 mounted on the vehicle 4.

[0023] Specific configurations of the power supply device 2 and the power receiving device 3 will be described with reference to FIG.

[0024] 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 the power source 5 to the power supply coil 22 and a power supply-side resonant circuit including a power supply capacitor (not shown).

[0025] The power supply 5 is, for example, a commercial AC power supply that supplies single-phase AC power. The power supply 5 may be another AC power supply that supplies three-phase AC power, or a DC power supply such as a fuel cell. The power supply 5 may be buried underground together with the power supply device 2, or may be installed at an appropriate location above ground.

[0026] When AC power is supplied from power source 5, power supply circuit 21 includes a rectifier circuit and an inverter that converts the AC power to DC power. The DC power converted by the rectifier circuit is then converted by the inverter into AC power that matches the characteristics of the power supply-side resonant circuit. Power supply-side control unit 23 is configured to control the operation of the inverter.

[0027] The specifications of the power supply coil 22 and 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.

[0028] 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 power received by a power receiving side resonant circuit including the power receiving coil 32 and a power receiving capacitor (not shown) to a battery 41.

[0029] The receiver-side resonant circuit has a configuration similar to that of 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 so that the difference between the resonant frequencies is within a specified range (for example, ±20%).

[0030] The oscillation of the AC magnetic field generated by the power supply coil 22 is transmitted to the power receiving resonant circuit, which resonates with the resonant frequency of the power transmitting power supply circuit. This causes an induced current to flow in the power receiving 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 resonant circuit into DC power. The power receiving circuit 31 also includes a converter circuit that adapts the voltage level of the converted DC power to the specifications of the battery 41. The power receiving control unit 33 is configured to control the power supply to the battery 41.

[0031] 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 bidirectional 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.

[0032] In addition to the above operations, the power supply-side control unit 23 of the power supply device 2 is configured to also 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 also control the operation of the power receiving-side communication device 34.

[0033] To prevent a decrease in power transmission efficiency in contactless power transfer, it is necessary to accurately position the power receiving coil 32 relative to the power transfer 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 transfer device 2 buried underground in a parking lot or the like.

[0034] 1 , the contactless power transfer system 1 includes a control device 6. The control device 6 is configured to identify the positional relationship between the power transfer 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.

[0035] 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 that can communicate with the power supply device 2.

[0036] 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, which is configured as a hardware interface.

[0037] 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 also applies to other signals that can be output from the output interface 63, which will be described later.

[0038] 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 also means "the distance between A and B." Distance measurement and positioning technology using UWB wireless communication is well known, so a detailed description will be omitted.

[0039] 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 that the vehicle 4 is approaching the power supply device 2. 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 signal.

[0040] 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.

[0041] 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 via wired communication or wireless communication. If the positional relationship data PR is in the form of analog data, the input interface 61 has an appropriate conversion circuit including an A / D converter. This description also applies to other data that can be input to the input interface 61, as described below.

[0042] 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.

[0043] 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 determined 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.

[0044] For example, it is determined whether the distance between the reference position of the power feeding coil 22 and the reference position of the power receiving coil 32 is less than a predetermined value. The reference position can be set appropriately as long as it is the same between the power feeding coil 22 and the power receiving coil 32. For example, the center position of the winding can be set as the reference position.

[0045] If it is determined that the positional relationship between power feeding coil 22 and power receiving coil 32 satisfies a predetermined condition, processor 62 outputs, from output interface 63, a power feeding control signal SC that causes power feeding-side controller 23 to control the operation of power feeding circuit 21. Power feeding-side controller 23 causes power feeding circuit 21 to start feeding power based on the power feeding control signal SC. The process of causing power feeding device 2 to start wireless power feeding to power receiving device 3 (power feeding process) is an example of a process related to wireless power feeding.

[0046] If 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 that causes 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 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 of causing the notification device 7 to make a notification (the notification process) is an example of a process related to contactless power supply.

[0047] As one 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.

[0048] In addition to or instead of the above-described notification process, when it is determined that the positional relationship between the power feeding coil 22 and the power receiving coil 32 does not satisfy a predetermined condition, the processor 62 outputs a limit control signal RC from the output interface 63 to cause the power feeding-side controller 23 to execute a process (limiting process) to limit power feeding. The limiting process is an example of a process related to contactless power feeding.

[0049] Examples of the restriction process performed by power supply-side control unit 23 based on the restriction control signal RC include a process to prevent contactless power supply and a process to reduce the power transmission output below normal.

[0050] 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.

[0051] First, UWB wireless communication is established between the power supplying communication device 24 and the power receiving communication device 34, thereby starting to identify the positional relationship between the power supplying coil 22 and the power receiving coil 32 (STEP 11). Identification of the positional relationship continues at least until power supply is started.

[0052] Next, it is determined whether the specified positional relationship between the power supply coil 22 and the power receiving coil 32 satisfies a predetermined condition (STEP 12).

[0053] If it is determined that the identified positional relationship between the 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 the 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.

[0054] For example, if it is determined that the positional relationship between the identified power supply coil 22 and power receiving coil 32 does not satisfy a predetermined condition due to an inappropriate parking position of the vehicle 4 (NO in STEP 12), the user of the vehicle 4 is notified of this fact via the alarm device 7 (STEP 14).

[0055] The user who receives 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, causing a change in the positional relationship between the power supply coil 22 and the power receiving coil 32. In other words, 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 has occurred in the positional relationship data PR before the elapsed time from the start of timing reaches a threshold value.

[0056] If it is determined that the parking position has been re-tried (YES in STEP 15), the process returns to STEP 12, where it is determined whether the parking position as a result of the re-tried is appropriate.

[0057] 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 processing to limit the power supply is executed (STEP 16).

[0058] According to the configuration of this embodiment, UWB wireless communication, which can accurately identify the positional relationship between communication devices, is used to determine whether the power supply coil 22 and the power receiving coil 32 are in an appropriate positional relationship, so that the position of the power receiving coil 32 relative to the power supply coil 22 can be accurately determined when the vehicle 4 is stopped. As a result, a decrease in power transmission efficiency in contactless power transfer 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 due to a decrease in power transmission efficiency can be suppressed. This can prevent the battery from not being charged to the expected amount after a predetermined time has elapsed.

[0059] 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 techniques 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.

[0060] Furthermore, UWB wireless 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 performs contactless power transfer using an electromagnetic field between the power receiving device 3 mounted on the vehicle 4 and the power transfer device 2 installed outside the vehicle 4.

[0061] In addition, if the parking lot in which the contactless power supply system 1 is installed has 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.

[0062] The number of power supplying-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 as appropriate. When UWB wireless communication is performed between a single power supplying-side communication device 24 and a single power receiving-side communication device 34 as illustrated in Fig. 5, the positional relationship between the power supplying coil 22 and the power receiving coil 32 that is identified is the distance between them.

[0063] 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, 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.

[0064] 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.

[0065] Increasing the number of power-receiving-side communication devices 34 allows for more accurate identification of the 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.

[0066] 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.

[0067] 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), 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 ).

[0068] As an example, the processor 62 of the control device 6 can output a request control signal QC from the output interface 63, causing the power supply-side control unit 23 of the power supply device 2 to perform processing to request 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.

[0069] 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 device (not shown). The storage device 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.

[0070] The power supply-side control unit 23, which has received the authentication information ID through the power supply-side communication device 24, compares the received information with authentication information previously stored in a storage device (not shown). If the two pieces of information match, the processor 62 determines that authentication has been established. If it is determined that authentication has been established (YES in STEP 22 of 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).

[0071] 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 that causes the notification device 7 to execute a process of notifying the user of the vehicle 4 that the authentication has not been established (STEP 23). Then, the process ends.

[0072] According to this configuration, the process of specifying the positional relationship is started only for vehicles 4 whose authentication information ID has been pre-registered, thereby reducing unnecessary power consumption in the contactless power transfer system 1. In particular, in a configuration in which the control device 6 transmits authentication request signals RQ to multiple power transfer devices 2, when a specific power transfer device 2 receives a response from the power receiving device 3 mounted on the vehicle 4 to be parked, it becomes possible to perform a process in which the control device 6 stops transmitting the authentication request signals RQ to power transfer devices 2 other than the specific power transfer device 2. Even in this case, unnecessary power consumption in the contactless power transfer system 1 can be reduced.

[0073] 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, thereby reducing unnecessary power consumption in the contactless power supply system 1.

[0074] 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 in which, for example, a fee according to the amount of power supplied is charged to the 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.

[0075] 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.

[0076] 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, from the power receiving device 3, 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 (STEP 31). The position information PS can be generated through measurements before shipping 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 device (not shown) included in the power receiving device 3.

[0077] 3 , when UWB wireless 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 positional information PS (STEP 11), and generates positional relationship data PR.

[0078] In a configuration in which the power receiving-side control unit 33 generates the positional relationship data PR, the power receiving device 3 acquires, from the power supplying device 2, 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. The position information PS can be generated through measurements before shipping 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 device (not shown) included in the power supplying device 2.

[0079] Specifically, when UWB wireless 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 supplying-side communication device 24. The power receiving-side control unit 33 performs processing to identify the positional relationship between the power supplying coil 22 and the power receiving coil 32 while referring to the positional information PS (STEP 11), and generates positional relationship data PR.

[0080] The configuration of this example makes use of the characteristics of UWB wireless communication, which is capable of not only ranging and positioning but also data communication. At least one of the position of the power supplying 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 communication device 34 relative to the reference position of the power receiving coil 32 is referenced, so the positional relationship between the power supplying coil 22 and the power receiving coil 32 can be determined more precisely.

[0081] At least one of the power supplying communication device 24 and the power receiving communication device 34 may have a UWB radar function (ranging function). Specifically, if the time it takes for a pulse signal emitted from the power supplying 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 illustrated in FIG. 1 is detected. The foreign object F may be a living or non-living object. Similarly, if the time it takes for a pulse signal emitted from the power receiving 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 if a moving foreign object F is present 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. Therefore, the distance to the foreign object F can be detected based on the time it takes for the frequency-shifted pulse signal to return.

[0082] 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 to restrict the execution of contactless power supply when the input interface 61 receives the detection signal DT.

[0083] 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 flows described with reference to Figs. 9 and 10.

[0084] 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 from the output interface 63 to cause the power supply device 2 or the power receiving device 3 to execute a foreign object detection process (see FIG. 3 ). When the processor 62 determines 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 processor 62 executes the power supply process (STEP 13).

[0085] If it is determined that a foreign object has been detected (YES in STEP 41), the fact is notified to the user of vehicle 4 via notification device 7 (STEP 14). The user who has received the notification can reset the power supply environment by removing the foreign object. Next, it is determined whether the foreign object has been removed (STEP 15). Specifically, it is determined whether the output of detection signal DT from power supply-side controller 23 or power receiving-side controller 33 has been stopped within a predetermined time.

[0086] 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).

[0087] 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 a situation in which the living body is exposed to the electromagnetic field used for contactless power supply.

[0088] A technology is known for locking and unlocking the doors of a vehicle 4 by authenticating the user through UWB wireless 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 via UWB wireless communication. An authentication device (not shown) mounted on the vehicle 4 compares the authentication information received by the communication device with authentication information pre-stored in a storage device (not shown). If a match between the two pieces of information is confirmed, the authentication device determines that the authentication process is successful. The power receiving communication device 34 included in the power receiving device 3 mounted on the vehicle 4 can be used for the authentication process in addition to the wireless power supply described above. The authentication information transmitted from the mobile device may be used as the authentication information ID for the wireless power supply described above.

[0089] According to this configuration, the contactless power supply system 1 can be constructed by effectively utilizing the resources for UWB wireless communication installed in the vehicle 4 .

[0090] 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 device 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 device 34 so that their relative positions are invariable.

[0091] With 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, which makes it easy to standardize information required to identify the positional relationship between the power supply coil 22 and the power receiving coil 32. This can improve the installation workability 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.

[0092] 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 identify the positional relationship between the power feeding coil 22 and the power receiving coil 32. This makes it possible to improve the workability 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.

[0093] 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.

[0094] Alternatively, each of the power supply-side controller 23, the power receiving-side controller 33, and the processor 62 may be realized by a general-purpose microprocessor operating 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 portion of the program stored in the ROM, expands it on the RAM, and executes the above-described processing in cooperation with the RAM.

[0095] 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.

[0096] 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.

[0097] The configurations described above are merely examples to facilitate understanding of the present disclosure. Each configuration example can be appropriately modified and combined with other configuration examples without departing from the spirit of the present disclosure.

[0098] The "UWB wireless communication standard" used in the above-described embodiment originates from a standard conforming to IEEE 802.15. However, this expression is not intended to be limited to this standard. Any derivative or alternative short-range wireless communication standard that has the advantages of being able to identify the positional relationship between communication devices with high accuracy and having low power consumption and interference with other communications may be adopted.

[0099] In the above embodiment, the power supply device 2 is buried 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 buried in a wall laterally facing the vehicle 4. Alternatively, the power supply device 2 may be mounted on a portable object that can be positioned as appropriate relative to the vehicle 4.

[0100] 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.

[0101] 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, flying objects, ships, etc. The moving object may not require a driver.

[0102] The above-described embodiment can also be regarded as a system that accurately determines the position of the vehicle 4 relative to the power supply device 2 based on UWB wireless communication executed between the power supplying-side communication device 24 and the power receiving-side communication device 34. In particular, by utilizing the distance measurement function of UWB wireless communication, the positional relationship between the power receiving-side communication device 34 mounted on the vehicle 4 and the power supplying-side communication device 24 installed outside the vehicle 4 can be accurately determined.

[0103] More generally, communication conforming to the UWB wireless communication standard is performed between a first communication device mounted on a mobile body and a second communication device installed outside the mobile body. A positional relationship between the first communication device and the second communication device is determined based on the communication, and the position of the mobile body relative to a reference position is determined based on the positional relationship. The determination of the positional relationship and the position of the mobile body are performed by a control device. The location where the control device is installed is not particularly limited, but it is preferably mounted on the mobile body.

[0104] With this configuration, the positional relationship between the first and second communication devices can be determined with high accuracy using UWB wireless communication, allowing for highly accurate positioning of the moving object relative to the reference position. In addition, UWB wireless communication has the advantage of low power consumption and low interference with other communications, since 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 for determining the position of the moving object relative to the reference position.

[0105] The contents of Japanese Patent Application No. 2023-169750 filed on September 29, 2023 are incorporated by reference as part of this disclosure.

Claims

1. A method for contactless power supply using an electromagnetic field between a power receiving device mounted on a mobile body and a power supply device installed outside the mobile body, 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; identifying 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; and performing processing related to the contactless power supply based on the positional relationship.

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

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

4. The contactless power supply method according to claim 1, further comprising the step of: performing authentication processing of the moving object via the communication prior to identifying the positional relationship.

5. The contactless power supply method according to claim 4, further comprising the step of: performing a billing process for the contactless power supply when the authentication process is successful.

6. A contactless power supply method according to any one of claims 1 to 5, wherein prior to identifying the positional relationship, the power supply device acquires information indicating the position of the second communication device relative to a reference position of the power receiving coil.

7. A contactless power supply method according to claim 1, wherein, prior to identifying the positional relationship, the power receiving device acquires information indicating a position of the first communication device relative to a reference position of the power supply coil.

8. A contactless power supply method according to any one of claims 1 to 7, further comprising the steps of: 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; and performing at least one of a process of restricting the contactless power supply and a process of notifying the user when the foreign object is detected.

9. The contactless power supply method according to any one of claims 1 to 8, wherein the second communication device is also used for authentication processing for locking and unlocking the mobile object.

10. A contactless power supply system comprising: a power receiving device mounted on a mobile body; a power supplying device installed outside the mobile body; and a control device, wherein the power supplying device comprises a power supply coil and at least one first communication device capable of communication in accordance with the UWB wireless communication standard; the power receiving device comprises a power receiving coil and 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; and the control device identifies a positional relationship between the power supplying coil and the power receiving coil based on the communication, and performs processing related to contactless power supply from the power supplying coil to the power receiving coil using an electromagnetic field based on the positional relationship.

11. A contactless power supply device installed outside a moving body, comprising: a power supply coil capable of contactlessly supplying power to a power receiving coil mounted on the moving body by utilizing an electromagnetic field; at least one communication device capable of communicating with at least one communication device mounted on the moving body in accordance with the UWB wireless communication standard; and a support body that supports the power supply coil and the at least one communication device so that their relative positions are invariant.

12. A contactless power receiving device mounted on a moving body, comprising: a receiving coil capable of receiving contactless power supply using an electromagnetic field from a power supply coil installed outside the moving body; at least one communication device capable of communication in accordance with the UWB wireless communication standard with at least one communication device installed outside the moving body; and a support body that supports the receiving coil and the at least one communication device so that their relative positions are invariant.

13. A method for determining the position of a mobile body, comprising: carrying out communication conforming to the UWB wireless communication standard between a first communication device mounted on the mobile body and a second communication device installed outside the mobile body; determining a positional relationship between the first communication device and the second communication device based on the communication; and determining a position of the mobile body relative to a reference position based on the positional relationship.

14. A system for determining the position of a mobile body, comprising: a first communication device mounted on the mobile body; a second communication device installed outside the mobile body; and a control device that determines the positional relationship between the first communication device and the second communication device based on communication conforming to the UWB wireless communication standard performed between the first communication device and the second communication device, and determines the position of the mobile body relative to a reference position based on the positional relationship.

15. A mobile body comprising: a first communication device capable of communicating with a second communication device installed outside the mobile body in accordance with the UWB wireless communication standard; and a control unit that determines the positional relationship between the first communication device and the second communication device based on the communication, and determines the position of the mobile body relative to a reference position based on the positional relationship.

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