Wireless charging device

Abstract

The invention relates to a wireless charging device. The wireless charging device is mounted on a vehicle. The wireless charging device includes a control unit. When the control unit detects that an acceleration of a magnitude equal to or greater than a predetermined threshold value has occurred in the horizontal direction during charging of the portable terminal, the control unit estimates the direction of movement of the portable terminal on the wireless charging device on the basis of the direction of the acceleration. Furthermore, the control unit determines the position of the power transmission coil in the wireless charging device on the basis of the estimated movement direction of the portable terminal.

Description

Technical Field

[0001] The present disclosure relates to a wireless charging device mounted on a vehicle. Background Art

[0002] Japanese Patent Application No. 2021-180578 discloses a contactless charging system. The contactless charging system disclosed in Japanese Patent Application No. 2021-180578 includes a drive device and a receiving coil position detection unit. The drive device is capable of moving the position of the relay coil. The receiving coil position detection unit detects or estimates the relative position of the passive coil relative to the power transmission coil. Moreover, the drive device is used to control the position of the relay coil according to the relative position of the passive coil relative to the power transmission coil. Summary of the invention

[0003] An object of the present disclosure is to suppress a decrease in efficiency of charging a portable terminal using a wireless charging device mounted on a vehicle.

[0004] The wireless charging device involved in the present disclosure is a wireless charging device mounted on a vehicle and charging a portable terminal mounted thereon. The wireless charging device includes a control unit that executes:

[0005] When an acceleration having a magnitude greater than a predetermined threshold value is detected in the horizontal direction during charging of the portable terminal, a moving direction of the portable terminal on the wireless charging device is estimated based on the direction of the acceleration; and

[0006] The position of a power transmission coil to be energized for charging the portable terminal in the wireless charging device is determined based on the estimated moving direction of the portable terminal.

[0007] According to the present disclosure, it is possible to suppress a decrease in efficiency of charging a portable terminal using a wireless charging device mounted on a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0009] Figure 1 It is a diagram for explaining the outline of the charging device according to the first embodiment.

[0010] Figure 2 This is a block diagram for explaining the hardware configuration of the charging device according to the first embodiment and various devices mounted on the vehicle.

[0011] Figure 3 This is the flow of the energization control according to the first embodiment.

[0012] Figure 4This is a flow of a process for acquiring the weight of a portable terminal according to a modification of the first embodiment.

[0013] Figure 5 This is the flow of the energization control according to the second embodiment. DETAILED DESCRIPTION

[0014] Wireless charging devices are known that are mounted on vehicles to charge portable terminals of passengers. When charging a portable terminal using a wireless charging device, the portable terminal is placed on the wireless charging device. Then, electromagnetic induction is generated by a power transmission coil provided in the wireless charging device and a power receiving coil provided in the portable terminal to generate power in the portable terminal, thereby charging the battery of the portable terminal.

[0015] However, acceleration occurs during the driving of the vehicle. Furthermore, if horizontal acceleration occurs during the process of charging the portable terminal using the wireless charging device, the portable terminal placed on the wireless charging device may sometimes move. If the portable terminal moves on the wireless charging device, there is a possibility that the position of the power receiving coil of the portable terminal is offset relative to the power transmitting coil of the wireless charging device. As a result, the amount of electric power generated by electromagnetic induction in the portable terminal is reduced, and as a result, there is a possibility that the charging efficiency of the portable terminal is reduced. The present disclosure is completed in view of such problems.

[0016] The wireless charging device involved in the present disclosure is configured to be able to change the position of the power transmission coil. In more detail, for example, the wireless charging device may have multiple power transmission coils. Moreover, the position of the power transmission coil used for charging the portable terminal may be changed by changing the energized power transmission coil during the charging of the portable terminal. In addition, in the wireless charging device, at least one power transmission coil may be configured to be movable. Moreover, the position of the power transmission coil may be changed by moving the energized power transmission coil itself during the charging of the portable terminal.

[0017] In addition, the wireless charging device involved in the present disclosure includes a control unit. Moreover, when the control unit detects that an acceleration of a magnitude greater than a predetermined threshold value has occurred in the horizontal direction during the charging of the portable terminal, the control unit infers the moving direction of the portable terminal on the wireless charging device based on the direction of the acceleration that has occurred. Here, the predetermined threshold value can also be determined as a lower limit value of the magnitude of the acceleration that is accompanied by the occurrence of acceleration and there is a possibility that the portable terminal moves on the wireless charging device. Thus, when an acceleration of a magnitude greater than a predetermined threshold value occurs in the horizontal direction in the vehicle during the process of charging the portable terminal using the wireless charging device, it can be determined that there is a possibility that the portable terminal moves on the wireless charging device.

[0018] Furthermore, the control unit determines the position of the power transmission coil to be energized in the wireless charging device for charging the portable terminal based on the estimated moving direction of the portable terminal. That is, the control unit changes the position of the power transmission coil in a manner that tracks the movement of the portable terminal on the wireless charging device.

[0019] Thus, even if the portable terminal being charged moves due to acceleration in a moving vehicle, the positional relationship between the power transmission coil of the wireless charging device and the power receiving coil of the portable terminal can be quickly corrected to a suitable position. Therefore, the efficiency of charging the portable terminal using the wireless charging device mounted on the vehicle can be suppressed.

[0020] Specific embodiments of the present disclosure are described below with reference to the accompanying drawings. Unless otherwise specified, the technical scope of the present disclosure is not limited to the dimensions, materials, shapes, and relative arrangements of the components described in the present embodiment.

[0021] First Embodiment

[0022] Figure 1 It is a diagram for explaining the outline of the charging device involved in the present embodiment. The charging device 100 is a wireless charging device installed in the cabin of the vehicle 10. For example, the charging device 100 may also be set on the dashboard or center console of the vehicle 10. Moreover, when the portable terminal 200 held by the passenger of the vehicle 10 (the driver or fellow passenger of the vehicle 10) is placed on the placement surface of the charging device 100, the charging device 100 charges the portable terminal 200 wirelessly. The portable terminal 200 may also be, for example, a smart phone, a tablet terminal, a wearable terminal, etc.

[0023] The charging device 100 uses the vehicle battery of the vehicle 10 as a power source. In addition, the charging device 100 charges the portable terminal 200 by electromagnetic induction. Specifically, the portable terminal 200 has a built-in power receiving coil 200a. On the other hand, the charging device 100 has a built-in plurality of (in Figure 1 In addition, by energizing any one of the plurality of power transmission coils 100a in the charging device 100, electromagnetic induction is generated between the energized power transmission coil 100a and the power receiving coil 200a of the portable terminal 200. As a result, electric power is generated in the portable terminal 200, and the battery of the portable terminal 200 is charged.

[0024] Here, in the charging device 100, a plurality of power transmission coils 100a are provided as described above. And, according to the position of the portable terminal 200 on the placement surface of the charging device 100, the power transmission coil 100a to be energized is selected from the plurality of power transmission coils 100a. That is, in the charging device 100, the power transmission coil 100a existing at a position facing the power receiving coil 200a of the portable terminal 200 is selected and energized. Thus, the power transmission coil 100a existing at a position where electromagnetic induction is easily generated with the power receiving coil 200a of the portable terminal 200 is energized. As a result, the portable terminal 200 can be efficiently charged.

[0025] However, horizontal acceleration may occur during the travel of the vehicle 10. Furthermore, when the portable terminal 200 is placed on the placement surface of the charging device 100, that is, when a certain degree of acceleration occurs in the horizontal direction during the charging of the portable terminal 200, the portable terminal 200 may move on the placement surface. As a result, if the relative positional relationship between the power transmission coil 100a energized in the charging device 100 and the power reception coil 200a of the portable terminal 200 is offset, there is a possibility that the charging efficiency of the portable terminal 200 is reduced due to a reduction in the amount of power generated in the portable terminal 200.

[0026] Therefore, in this embodiment, the charging device 100 changes the energized power transmission coil 100a according to the movement of the portable terminal 200 being charged on the placement surface. In addition, at this time, the charging device 100 estimates the moving direction of the portable terminal 200 and the moving amount of the portable terminal 200 according to the direction of the horizontal acceleration generated in the vehicle 10 and the magnitude of the acceleration.

[0027] Hardware structure of charging device

[0028] Figure 2 The charging device 100 includes a control unit 110, a storage unit 120, a charging circuit 130, an in-vehicle communication module 140, and a communication module 150 in addition to the plurality of power transmission coils 100a.

[0029] In addition, the vehicle 10 includes a vehicle ECU 11, an acceleration sensor 12, and a vehicle battery 13. The vehicle ECU 11 is an electronic control unit (Electric Central Unit (ECU)) that controls the behavior of the vehicle 10 based on the detection values ​​of various sensors provided in the vehicle 10. The acceleration sensor 12 is a sensor that detects the acceleration of the vehicle 10. The acceleration sensor 12 detects the acceleration generated in the vehicle 10 in three axes, namely, the X-axis direction, the Y-axis direction, and the Z-axis direction. The detection value of the acceleration sensor 12 is input to the vehicle ECU 11. The vehicle battery 13 is a power source that supplies power to various devices provided in the vehicle 10, such as the vehicle ECU 11 and the acceleration sensor 12.

[0030] The control unit 110 has a function of performing arithmetic processing for controlling the charging device 100. The control unit 110 includes a processor such as a central processing unit (CPU), a main storage device such as a random access memory (RAM), and an auxiliary storage device such as a read-only memory (ROM). In addition, the CPU is an example of a processor resource. In addition, the RAM and the ROM are examples of memory resources. The control unit 110 can perform arbitrary information processing according to various programs and various data. However, part or all of the functions of the control unit 110 can also be implemented by hardware circuits such as ASIC and FPGA. The storage unit 120 is composed of arbitrary storage devices such as RAM, ROM, and flash memory. In the storage unit 120, programs executed by the control unit 110 and various data used in the execution of the programs are stored.

[0031] The charging circuit 130 converts DC power supplied from the vehicle battery 13 into AC power of appropriate amplitude and frequency. The charging circuit 130, which is a circuit for supplying the converted AC power to the power transmission coil 100a to be energized, includes, for example, a DC-DC converter, an inverter, and the like.

[0032] The in-vehicle communication module 140 is an interface for the charging device 100 to communicate with other devices provided in the vehicle 10 using a predetermined in-vehicle communication standard. As the predetermined in-vehicle communication standard, a controller area network (CAN) or a local interconnect network (LIN) can be exemplified. In addition, the charging device 100 communicates with the vehicle ECU 11 via the in-vehicle communication module 140. For example, the charging device 100 receives information about the direction and magnitude of the horizontal acceleration occurring in the vehicle 10, which is calculated by the vehicle ECU 11 based on the detection value of the acceleration sensor 12, from the vehicle ECU 11 at a predetermined period.

[0033] The communication module 150 is an interface for the charging device 100 to directly communicate with the portable terminal 200 placed on the placement surface using a predetermined short-range wireless communication standard. As the predetermined short-range wireless communication standard, the Bluetooth (registered trademark) Low Energy standard or WiFi (registered trademark) can be exemplified. The charging device 100 communicates with the portable terminal 200 being charged via the communication module 150. For example, the charging device 100 periodically receives the status of the portable terminal 200 including the power (power generation) generated by electromagnetic induction in the portable terminal 200 from the portable terminal 200 at a predetermined period.

[0034] In addition, the portable terminal 200 has a processor such as a central processing unit (CPU), a main storage device such as a random access memory (RAM), and an auxiliary storage device such as a read-only memory (ROM). Furthermore, the portable terminal 200 has a communication module that uses the same standard as the short-range wireless communication standard used by the communication module 150 of the charging device 100.

[0035] Power-on control process

[0036] Next, according to Figure 3 , a flow of power-on control executed in charging device 100 will be described. Figure 3 This is a flow of power-on control according to the present embodiment. This flow is executed by the control unit 110 when the portable terminal 200 is placed on the placement surface of the charging device 100 , that is, when the portable terminal 200 is being charged by the charging device 100 .

[0037] In this process, first, in S101, the direction and magnitude Va of the acceleration in the horizontal direction occurring in the vehicle 10, which are sent from the vehicle ECU 11, are received. Next, in S102, it is determined whether the magnitude Va of the acceleration received in S101 (i.e., the absolute value of the acceleration) is above a predetermined threshold value Va0. Here, the predetermined threshold value Va0 may also be determined as a lower limit value of the magnitude of the acceleration at which there is a possibility that the portable terminal 200 moves on the charging device 100 with the occurrence of acceleration. In addition, an acceleration sensor capable of detecting the direction and magnitude of the acceleration in the horizontal direction may also be provided in the charging device 100. In this case, the charging device 100 can grasp the acceleration occurring in the vehicle 10 without communicating with the vehicle ECU 11.

[0038] If the determination in S102 is negative, that is, if the magnitude Va of the acceleration is smaller than the predetermined threshold value Va0, it is assumed that the portable terminal 200 has not moved on the charging device 100. In this case, the execution of this flow is temporarily terminated.

[0039] On the other hand, if the determination in S102 is positive, that is, if the magnitude Va of the acceleration is greater than or equal to the predetermined threshold value Va0, it is assumed that the portable terminal 200 has moved on the charging device 100. In this case, the process of S103 is executed next. In S103, the moving direction of the portable terminal 200 on the charging device 100 is estimated based on the direction of the acceleration received in S101.

[0040] Next, in S104, the movement amount of the portable terminal 200 on the charging device 100 is estimated based on the magnitude of the acceleration received in S101. Here, the greater the magnitude of the acceleration received in S101, the greater the estimated movement amount of the portable terminal 200 on the charging device 100.

[0041] Next, in S105, the power transmission coil 100a to be energized is selected from among the plurality of power transmission coils 100a based on the moving direction of the portable terminal 200 and the moving amount of the portable terminal 200 estimated in S103. At this time, if it is determined that the power transmission coil 100a existing at a position facing the power receiving coil 200a of the portable terminal 200 due to the movement of the portable terminal 200 becomes a different power transmission coil 100a from that before the acceleration occurs, the energized power transmission coil 100a is changed. On the other hand, if the power transmission coil 100a existing at a position facing the power receiving coil 200a of the portable terminal 200 is the same as that before the acceleration occurs even after the portable terminal 200 moves, the same power transmission coil 100a continues to be energized. After that, the execution of this process is temporarily terminated.

[0042] According to the above process, even if the position of the power receiving coil 200a of the portable terminal 200 is offset relative to the power transmitting coil 100a energized in the charging device 100 due to acceleration in the vehicle 10, the power transmitting coil 100a to be energized can be quickly corrected to a suitable coil. In other words, the position of the power transmitting coil 100a energized in the charging device 100 for charging the portable terminal 200 can be quickly changed in a manner tracking the movement of the portable terminal 200. Therefore, the efficiency of charging the portable terminal 200 by the charging device 100 can be suppressed from being reduced.

[0043] Modifications

[0044] Next, a modification of the present embodiment is described. As described above, if a certain degree of acceleration occurs in the horizontal direction in the vehicle 10 during charging of the portable terminal 200, the portable terminal 200 may move on the charging device 100. In this case, even if the magnitude of the acceleration is the same, the amount of movement of the portable terminal 200 may vary depending on the weight of the portable terminal 200. Therefore, in this modification, the control unit 110 of the charging device 100 estimates the amount of movement of the portable terminal 200 on the charging device 100 based not only on the magnitude of the acceleration in the horizontal direction but also on the weight of the portable terminal 200.

[0045] More specifically, in this modification, a database (hereinafter referred to as a "portable terminal database") in which information related to the weight of each model of a portable terminal that may be charged is input is stored in the storage unit 120 of the charging device 100. In addition, model information indicating the model of the portable terminal 200 placed on the charging device 100 is transmitted from the portable terminal 200 to the charging device 100. Furthermore, when the portable terminal 200 is placed on the charging device 100, the control unit 110 executes a process for obtaining the weight of the portable terminal 200.

[0046] Figure 4 This is a flow of a process for obtaining the weight of a portable terminal according to this modification. This flow is executed by the control unit 110 when the portable terminal 200 is placed on the placement surface of the charging device 100 .

[0047] In this process, first, in S201, the model information of the portable terminal 200 sent from the portable terminal 200 is received. Next, in S202, the weight of the portable terminal 200 corresponding to the model information received in S201 is extracted from the portable terminal database. Next, in S203, the weight of the portable terminal 200 currently placed on the charging device 100 extracted in S202 is stored in the storage unit 120. After that, the execution of this process is temporarily terminated. In addition, when the portable terminal 200 is picked up from the charging device 100, the weight of the portable terminal 200 stored in the storage unit 120 is deleted from the storage unit 120.

[0048] Furthermore, in this modification, the control unit 110 executes Figure 3 In the process of S104 of the illustrated flow of power-on control, the weight of the portable terminal 200 is acquired from the storage unit 120. Then, the control unit 110 estimates the movement amount of the portable terminal 200 based on the magnitude of the horizontal acceleration and the weight of the portable terminal 200.

[0049] According to this modification, the movement amount of the mobile terminal 200 when it moves on the charging device 100 due to the horizontal acceleration generated in the vehicle 10 can be estimated with higher accuracy. Therefore, the power transmission coil 100a to be energized can be selected more appropriately.

[0050] Second Embodiment

[0051] In the present embodiment, the configurations of the charging device 100 and the portable terminal 200 are also the same as those in the first embodiment. In addition, in the present embodiment, when a horizontal acceleration is generated in the vehicle 10 during the charging of the portable terminal 200, the moving direction of the portable terminal 200 and the moving amount of the portable terminal 200 are estimated. And, based on the estimated moving direction of the portable terminal 200 and the moving amount of the portable terminal 200, the power transmission coil 100a to be energized is selected in the charging device 100. However, in the present embodiment, when a horizontal acceleration is generated in the vehicle 10 during the charging of the portable terminal 200, unlike the first embodiment, the moving amount of the portable terminal 200 is estimated based on the change in the amount of power generated in the portable terminal 200.

[0052] More specifically, the charging device 100 periodically receives information related to the amount of power generated in the portable terminal 200 at a predetermined period during the charging of the portable terminal 200. Furthermore, when an acceleration of a magnitude greater than a predetermined threshold value Va0 is generated in the horizontal direction of the vehicle 10 during the charging of the portable terminal 200, the control unit 110 of the charging device 100 calculates the amount of change in the amount of power generated in the portable terminal 200 being charged before and after the acceleration occurs.

[0053] In addition, as described above, if the relative positional relationship between the power transmission coil 100a energized in the charging device 100 and the power receiving coil 200a of the portable terminal 200 is offset during the charging of the portable terminal 200, the amount of power generated in the portable terminal 200 is reduced. At this time, for example, if the position of the power receiving coil 200a relative to the power transmission coil 100a energized before the acceleration is the position where the power generation in the portable terminal 200 is the maximum, the greater the offset amount of the relative positional relationship between the two coils 100a, 200a after the acceleration occurs, the greater the reduction amount of the power generation in the portable terminal 200. Therefore, the movement amount of the portable terminal 200 can be calculated based on the amount of change in the power generation in the portable terminal 200 before and after the acceleration occurs.

[0054] Power-on control process

[0055] Below, according to Figure 5 , a flow of power supply control executed in charging device 100 according to the present embodiment will be described. Figure 5 This is the process of power-on control involved in this embodiment. When the portable terminal 200 is placed on the placement surface of the charging device 100, that is, when the portable terminal 200 is charged by the charging device 100, the control unit 110 executes this process. Figure 3 The example in which S104 of the flow of the energization control according to the first embodiment is replaced with S304 and S305 is shown. Therefore, the processing in S304 and S305 will be described below, and the description of the processing in other steps will be omitted.

[0056] In this flow, the process of S304 is executed after S103. In S103, the change amount dPt of the power generation amount in the portable terminal 200 before and after the acceleration of a magnitude greater than the predetermined threshold value Va0 is calculated. At this time, the control unit 110 calculates the change amount dPt of the power generation amount based on the power generation amount received from the portable terminal 200 immediately before the acceleration occurs and the power generation amount received from the portable terminal 200 just after the acceleration occurs.

[0057] Next, in S305, the movement amount of the portable terminal 200 on the charging device 100 is estimated based on the change amount dPt of the power generation amount in the portable terminal 200 calculated in S304. Here, the greater the decrease amount of the power generation amount in the portable terminal 200, the greater the movement amount of the portable terminal 200 on the charging device 100 is estimated to be. Then, S305 executes the process of S105.

[0058] In this embodiment, the magnitude Va of the horizontal acceleration occurring in the vehicle 10 is also received in S101 . Therefore, the control unit 110 may estimate the movement amount of the portable terminal 200 on the charging device 100 based on the magnitude Va of the acceleration and the change dPt of the power generation amount in the portable terminal 200 .

[0059] The power receiving coil 200a of the portable terminal 200 may be displaced relative to the power transmitting coil 100a energized in the charging device 100 due to acceleration in the vehicle 10. Even in such a case, the power transmitting coil 100a to be energized can be quickly corrected to an appropriate coil by the above process.

[0060] In addition, in the above-mentioned first embodiment and second embodiment, the charging device 100 includes a plurality of power transmission coils 100a. Moreover, in the charging device 100, since the power transmission coil 100a that is energized is changed, the position of the power transmission coil 100a used for charging the portable terminal 200 is changed. However, the structure of the charging device involved in the present disclosure is not limited to such a structure having a plurality of power transmission coils. For example, as the structure of the charging device 100, a structure in which a single power transmission coil 100a is movably configured in the charging device 100 may also be adopted. In this case, in the charging device 100, the position of the power transmission coil 100a itself is controlled by moving the power transmission coil 10a through the control unit 110. In this case, the position of the power transmission coil 100a that is energized itself is changed, thereby changing the position of the power transmission coil 100a used for charging the portable terminal 200.

[0061] Other Implementations

[0062] The above-mentioned embodiment is only an example, and the present disclosure can be implemented with appropriate changes within the scope of the gist thereof. In addition, the processes and units described in the present disclosure can be implemented in combination as long as no technical contradiction occurs.

[0063] In addition, a process described as being performed by one device may be shared and executed by multiple devices. Alternatively, a process described as being performed by different devices may be executed by one device. In a computer system, it is possible to flexibly change what hardware structure (server structure) is used to implement each function.

[0064] The present disclosure can also be implemented by supplying a computer program equipped with the functions described in the above embodiments to a computer, and one or more processors of the computer reading and executing the program. Such a computer program can be provided to the computer via a non-temporary computer-readable storage medium that can be connected to the system bus of the computer, or provided to the computer via a network. Non-temporary computer-readable storage media include, for example, any type of disk (floppy disk (registered trademark), hard disk drive (HDD)), optical disk (CD-ROM, DVD disk, Blu-ray disk, etc.), read-only memory (ROM), random access memory (RAM), EPROM, EEPROM, magnetic card, flash memory, or any type of medium suitable for storing electronic commands such as an optical card.

Claims

1. A wireless charging device, mounted on a vehicle, for charging a portable terminal mounted thereon, the wireless charging device comprising a control unit, the control unit executing: When an acceleration having a magnitude greater than a predetermined threshold value is detected in the horizontal direction during charging of the portable terminal, a moving direction of the portable terminal on the wireless charging device is estimated based on the direction of the acceleration; and The position of a power transmission coil to be energized in the wireless charging device for charging the portable terminal is determined based on the estimated moving direction of the portable terminal.

2. The wireless charging device according to claim 1, wherein: The control unit further executes: when an acceleration having a magnitude greater than the predetermined threshold value is detected in the horizontal direction during charging of the portable terminal, estimating the movement amount of the portable terminal on the wireless charging device according to the magnitude of the acceleration, The control unit determines the position of the power transmission coil based on the estimated moving direction of the portable terminal and the estimated moving amount of the portable terminal.

3. The wireless charging device according to claim 2, wherein: The control unit further executes: obtaining the weight of the portable terminal being charged, The control unit estimates a movement amount of the portable terminal on the wireless charging device based on a magnitude of the acceleration and a weight of the portable terminal.

4. The wireless charging device according to claim 3, wherein: The control unit further executes: receiving model information of the portable terminal from the portable terminal being charged, The control unit acquires the weight of the portable terminal corresponding to the received model information of the portable terminal.

5. The wireless charging device according to claim 1, wherein: The control unit further executes: when an acceleration of a magnitude greater than the predetermined threshold value is detected in the horizontal direction during charging of the portable terminal, an estimation of the movement amount of the portable terminal on the wireless charging device is made based on the amount of change in the amount of power generated in the portable terminal during charging before and after the acceleration occurs, The control unit determines the position of the power transmission coil based on the estimated moving direction of the portable terminal and the estimated moving amount of the portable terminal.

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