Vehicle-mounted wireless charging device and control method thereof

Abstract

The invention provides a vehicle-mounted wireless charging device and a control method thereof, which can be applied to the technical field of radio frequency antennas. The vehicle-mounted wireless charging device comprises a control mainboard, a near field communication antenna and a wireless charging coil, wherein the control mainboard is in control connection with the near field communication antenna and the wireless charging coil; the near field communication antenna comprises a first coil, a second coil and a third coil, the second coil and the third coil are arranged at an interval, the first coil is arranged between the second coil and the third coil, and the first coil is partially overlapped with the second coil and the third coil; the wireless charging coil is arranged below the near field communication antenna. According to the vehicle-mounted wireless charging device, the near-field communication antenna formed by cooperation of the multiple coils is arranged, so that the near-field communication field intensity of the near-field communication antenna can uniformly cover each position of the wireless charging area, and the card reading capability of the vehicle-mounted wireless charging device is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of radio frequency antenna technology, and in particular to a vehicle-mounted wireless charging device and a control method thereof. Background Art

[0002] In the new energy vehicle sector, some models are equipped with WPC (Wireless Power Consortium) wireless charging and NFC (Near Field Communication) card start functions to enhance user convenience and technological experience. These models often have a dedicated wireless charging area in front of the center console armrest. This area supports dual functions: one is to start the vehicle by swiping an NFC card, and the other is to place a wireless charging-capable mobile phone for wireless charging.

[0003] However, in order to facilitate users to charge and swipe cards, the existing in-vehicle wireless charging devices generally have a large area for wireless charging and swiping cards. In addition, the magnetic field distribution of the NFC antenna is uneven, resulting in the NFC field strength of the NFC antenna not evenly covering the entire wireless charging area.

[0004] Therefore, the existing vehicle-mounted wireless charging device has the problem that the NFC card cannot be effectively recognized in areas with weak NFC field strength, which leads to the failure of swiping the card to start the vehicle. Summary of the Invention

[0005] The present application provides an in-vehicle wireless charging device and a control method thereof, which are used to solve the technical problem that the near-field communication field strength of the near-field communication antenna of the existing in-vehicle wireless charging device cannot uniformly cover the entire wireless charging area, resulting in the inability to effectively identify the near-field communication tag.

[0006] According to a first aspect disclosed in the present application, the present application provides a vehicle-mounted wireless charging device, comprising a control mainboard, a near-field communication antenna, and a wireless charging coil, wherein the control mainboard is controlled and connected to the near-field communication antenna and the wireless charging coil respectively;

[0007] The near field communication antenna includes a first coil, a second coil and a third coil, wherein the second coil and the third coil are arranged at intervals, the first coil is arranged between the second coil and the third coil, and the first coil partially overlaps with the second coil and the third coil;

[0008] The wireless charging coil is arranged below the near field communication antenna.

[0009] In a feasible implementation manner, the control main board includes a switch switching circuit, and the switch switching circuit includes a first differential signal output terminal, a second differential signal output terminal and a single-pole triple-throw switch;

[0010] The single-pole triple-throw switch includes a common terminal and a first throw terminal, a second throw terminal, and a third throw terminal, wherein the common terminal is connected to the first differential signal output terminal; the first throw terminal is connected to the first coil, the second throw terminal is connected to the second coil, and the third throw terminal is connected to the third coil;

[0011] The second differential signal output end is connected to the first coil, the second coil and the third coil respectively.

[0012] In a feasible implementation manner, the switch switching circuit further includes a filtering module, and the filtering module includes a first filtering circuit and a second filtering circuit;

[0013] The first filtering circuit includes a first inductor and a first capacitor, wherein a first end of the first inductor is connected to the first differential signal output end, a second end of the first inductor is connected to the first end of the first capacitor, and a second end of the first capacitor is grounded;

[0014] The second filtering circuit includes a second inductor and a second capacitor, a first end of the second inductor is connected to the second differential signal output end, a second end of the second inductor is connected to the first end of the second capacitor, and a second end of the second capacitor is grounded.

[0015] In a feasible implementation manner, the switch switching circuit further includes a matching adjustment module, and the matching adjustment module includes a first matching adjustment circuit and a second matching adjustment circuit;

[0016] The first matching adjustment circuit includes a third capacitor, a fourth capacitor, and a fifth capacitor, wherein a first end of the third capacitor is connected to a second end of the first capacitor, a second end of the third capacitor is connected to a common end of the single-pole triple-throw switch, a first end of the fourth capacitor, and a first end of the fifth capacitor, respectively, and a second end of the fourth capacitor and a second end of the fifth capacitor are grounded;

[0017] The second matching adjustment circuit includes a sixth capacitor, a seventh capacitor and an eighth capacitor, the first end of the sixth capacitor is connected to the second end of the second capacitor, the second end of the sixth capacitor is respectively connected to the near-field communication antenna, the first end of the seventh capacitor and the first end of the eighth capacitor, and the second end of the seventh capacitor and the second end of the eighth capacitor are grounded.

[0018] In a feasible implementation manner, the switch switching circuit further includes a first resistor and a second resistor;

[0019] A first end of the first resistor is connected to the first differential signal output end, and a second end of the first resistor is connected to the common end of the single-pole triple-throw switch;

[0020] A first end of the second resistor is connected to the second differential signal output end, and a second end of the second resistor is connected to the near field communication antenna.

[0021] In a feasible implementation manner, the first pin is connected to the first end of the ninth capacitor, and the second end of the ninth capacitor is grounded;

[0022] The second pin is connected to the first terminal of the tenth capacitor, and the second terminal of the tenth capacitor is grounded;

[0023] The third pin is connected to a first terminal of an eleventh capacitor, and a second terminal of the eleventh capacitor is grounded.

[0024] In a feasible implementation manner, an EMC shielding net is provided between the near-field communication antenna and the wireless charging coil.

[0025] In a feasible implementation manner, at least one NTC resistor is provided between the near-field communication antenna and the wireless charging coil, and the NTC resistor is connected to the control mainboard.

[0026] According to a second aspect disclosed in the present application, the present application provides a control method for an in-vehicle wireless charging device, which is applied to a control mainboard of the in-vehicle wireless charging device described in any one of the first aspects. The method includes:

[0027] When a near-field communication tag is detected within the sensing range of the near-field communication antenna, activation decision parameters of each target coil in the near-field communication antenna are obtained; wherein the activation decision parameters include a geometric coverage weight, an impedance matching degree, a multi-tag conflict index, and a dynamic switching logic decision index; wherein the target coil is the first coil, the second coil, or the third coil;

[0028] For each target coil, if the activation decision parameter of the target coil meets a preset activation condition, the target coil is activated.

[0029] In a feasible embodiment, the method further includes:

[0030] When a near field communication tag is detected within the sensing range of the near field communication antenna, the wireless charging coil is controlled to stop charging.

[0031] Compared with the existing technology, this application has the following beneficial effects:

[0032] The present application provides an on-vehicle wireless charging device and a control method thereof. By providing a near-field communication antenna composed of multiple coils working together, the near-field communication field strength of the near-field communication antenna can evenly cover all positions in the wireless charging area, effectively increasing the card reading range and distance of the near-field communication antenna, eliminating the card reading blind spot in the wireless charging area, and thereby improving the card reading capability of the on-vehicle wireless charging device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] Figure 1 A schematic structural diagram of a vehicle-mounted wireless charging device provided in an embodiment of the present application;

[0035] Figure 2 A schematic diagram of the structure of a near-field communication antenna provided in an embodiment of the present application;

[0036] Figure 3 A schematic diagram of the structure of a switch switching circuit provided in an embodiment of the present application;

[0037] Figure 4 A schematic structural diagram of an EMC shielding net provided in an embodiment of the present application;

[0038] Figure 5 A flow chart of a control method for a vehicle-mounted wireless charging device provided in an embodiment of the present application.

[0039] Description of reference numerals:

[0040] 100-Near Field Communication Antenna;

[0041] 101-first coil;

[0042] 102- second coil;

[0043] 103- third coil;

[0044] 200-wireless charging coil;

[0045] 300-control mainboard;

[0046] 400-EMC shielding mesh.

[0047] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0049] In the new energy vehicle sector, some models are equipped with WPC (Wireless Power Consortium) wireless charging and NFC (Near Field Communication) card start functions to enhance user convenience and technological experience. These models often feature a dedicated wireless charging area in front of the center console armrest, which supports dual functions. On the one hand, users can use NFC cards to start the vehicle, achieving convenient keyless entry and start; on the other hand, users can also place wireless charging-enabled mobile phones in this area to charge, fully utilizing the vehicle's interior space and meeting diverse usage needs.

[0050] However, existing in-vehicle wireless charging devices have exposed some problems in practical applications. To facilitate charging and card swiping, the area used for wireless charging and card swiping is generally large, often reaching 200*100mm. While this large area design has certain advantages from a practical perspective, it also leads to uneven magnetic field distribution of the NFC antenna. As a result, the NFC field strength of the NFC antenna does not evenly cover the entire wireless charging area. This creates a card reading blind spot in areas with weak magnetic fields, preventing NFC cards from being effectively recognized, and thus causing the card swiping to fail to start the vehicle.

[0051] Furthermore, this recognition failure is more likely to occur when users use unusually shaped cards (e.g., cards with irregular shapes, small sizes, or made of unusual materials). Due to their unique shape and structure, unusually shaped cards may not couple well with the NFC antenna's magnetic field, thus affecting signal transmission and recognition.

[0052] In response to the above technical problems, this application proposes a vehicle-mounted wireless charging device and a control method thereof. By setting a near-field communication antenna composed of multiple coils working together, the near-field communication field strength of the near-field communication antenna can evenly cover all positions in the wireless charging area, effectively improving the card reading capability of the vehicle-mounted wireless charging device.

[0053] The following is a detailed description of the technical solutions of the vehicle-mounted wireless charging device and its control method provided by this application through specific embodiments. It should be noted that the following embodiments can exist independently or in combination with each other, and the same or similar content may not be repeated in different embodiments.

[0054] Figure 1 This is a structural diagram of a vehicle-mounted wireless charging device provided in an embodiment of the present application, see Figure 1 and Figure 2 In some embodiments, the vehicle-mounted wireless charging device includes a control motherboard 300, a near-field communication antenna 100 and a wireless charging coil 200. The control motherboard 300 is controlled and connected to the near-field communication antenna 100 and the wireless charging coil 200 respectively; the near-field communication antenna 100 includes a first coil 101, a second coil 102 and a third coil 103, the second coil 102 and the third coil 103 are arranged at intervals, the first coil 101 is arranged between the second coil 102 and the third coil 103, and the first coil 101 partially overlaps with the second coil 102 and the third coil 103; the wireless charging coil 200 is arranged below the near-field communication antenna 100.

[0055] In this embodiment, the traditional near-field communication antenna 100 uses a single coil, which cannot ensure that all positions in the wireless charging area have uniform near-field communication field strength when the wireless charging area is large. This will cause the near-field communication field strength in some areas of the wireless charging area to be very weak. In particular, when near-field communication tags appear on both sides with equal distances, the same amplitude, and opposite current directions, the near-field communication field strength will be weakened, resulting in a card reading blind spot, causing card swiping failure.

[0056] By setting up a near-field communication antenna 100 composed of multiple coils working together, the near-field communication field strength can evenly cover all positions in the wireless charging area, effectively increasing the card reading range and distance of the near-field communication antenna 100, eliminating the card reading blind spot in the wireless charging area, and thus improving the card recognition ability of the vehicle-mounted wireless charging device, and also enabling it to effectively identify special-shaped cards such as access control cards.

[0057] See Figure 2 Specifically, to further improve the uniformity of the near-field communication field strength of the near-field communication antenna 100, the first coil 101, the second coil 102, and the third coil 103 are arranged in an I-shape. The second coil 102 and the third coil 103 are arranged in parallel and spaced apart. The first coil 101 is arranged between the second coil 102 and the third coil 103, and is perpendicular to the second coil 102 and the third coil 103. The first coil 101 partially overlaps with the second coil 102 and the third coil 103.

[0058] Specifically, the first coil 101 is the central, vertically positioned coil, the second coil 102 is the horizontally positioned coil above, and the third coil 103 is the horizontally positioned coil below. The smaller inner coil of the centrally positioned first coil 101 effectively enhances the near-field communication field strength at the center of the wireless charging area.

[0059] Each of the first coil 101 , the second coil 102 and the third coil 103 is wound three times in one direction, and the coil self-inductance Ls is about 1 uH, which is conducive to the debugging of the resonant capacitor.

[0060] Specifically, the wireless charging coil 200 is an A13 coil.

[0061] See Figure 4 Optionally, an EMC shielding net 400 is provided between the near field communication antenna 100 and the wireless charging coil 200 .

[0062] Among them, assuming that the oscillation frequency of the electromagnetic field used for energy transmission between the transmitter and the receiver of the wireless charging coil 200 during the wireless charging process is 128 kHz, then the doubled frequency signal of the 128 kHz interference will be directly radiated to the near-field communication antenna 100 through the wireless charging coil 200, thereby affecting the normal operation of the near-field communication antenna 100.

[0063] By providing an EMC (Electromagnetic Compatibility) shielding net 400, the low-frequency electromagnetic radiation of the wireless charging coil 200 can be effectively shielded and isolated, thereby allowing the wireless charging signal to pass through while shielding EMC radiation interference, ensuring the normal operation of the near-field communication antenna 100.

[0064] Specifically, the EMC shielding net 400 is grounded on one side and has an open structure on the other side. The conductive network constructed of metal materials blocks the propagation path of electromagnetic waves, thereby effectively shielding and isolating the low-frequency electromagnetic radiation of the wireless charging coil 200.

[0065] Optionally, at least one NTC resistor is provided between the near field communication antenna 100 and the wireless charging coil 200 , and the NTC resistor is connected to the control mainboard 300 .

[0066] Among them, the NTC resistor is arranged above the wireless charging coil 200 and connected to the control mainboard 300. The temperature of the wireless charging device can be detected by the NTC resistor and fed back to the control mainboard 300, thereby monitoring the operating status of the wireless charging device to ensure the normal operation of the wireless charging device.

[0067] Specifically, the near-field communication antenna 100, EMC shielding mesh 400, and NTC resistor can be placed on a single PCB. This PCB is divided into two layers: the upper layer houses the NFC antenna coil, and the lower layer houses the NTC resistor and EMC shielding mesh 400. The PCB is then connected to the control motherboard 300 via a connector. Below the PCB is the wireless charging coil 200, which is mounted on the control motherboard 300 via ferrite and metal steel sheets. This ensures upward radiation and shields some low-frequency signals radiated by the control motherboard 300. Furthermore, the entire wireless charging device is enclosed in a metal housing to facilitate EMC shielding and enhance structural strength. A plastic exterior is added to the top for placing a mobile phone, making it easier to collect and charge the device.

[0068] See Figure 3 In some embodiments, the control main board 300 includes a switch switching circuit, which includes a first differential signal output terminal RF01, a second differential signal output terminal RF02 and a single-pole three-throw switch; the single-pole three-throw switch includes a common terminal and a first throw terminal RF1, a second throw terminal RF2, and a third throw terminal RF3, and the common terminal is connected to the first differential signal output terminal RF01; the first throw terminal RF1 is connected to the first coil 101, the second throw terminal RF2 is connected to the second coil 102, and the third throw terminal RF3 is connected to the third coil 103; the second differential signal output terminal RF02 is respectively connected to the first coil 101, the second coil 102 and the third coil 103.

[0069] In this embodiment, the single-pole, three-throw switch is a switching device having one input terminal (common terminal) and three output terminals (throw terminals). By operating the switch, the common terminal can be connected to any one of the three throw terminals to achieve signal or circuit switching. In the switch switching circuit, the single-pole, three-throw switch is controlled to switch the differential structure of the NFC coil, so that the first differential signal output terminal RF01 and the second differential signal output terminal RF02 can be connected to the first coil 101, the second coil 102, or the third coil 103, respectively, thereby activating the first coil 101, the second coil 102, or the third coil 103, avoiding the simultaneous activation of multiple coils, which would cause the tag current to cancel each other during identification, thereby ensuring that the NFC tag can be properly identified.

[0070] Specifically, the single-pole three-throw switch also has a control end, which is used to control the connection switching between the common end and different throw ends through electrical signals (such as voltage, current). By connecting the control end to the control main board 300, the control main board 300 can control the connection between the common end and any one of the three throw ends to achieve the activation of different coils.

[0071] See Figure 3Optionally, the switching circuit also includes a filtering module, the filtering module includes a first filtering circuit and a second filtering circuit; the first filtering circuit includes a first inductor L1 and a first capacitor C1, the first end of the first inductor L1 is connected to the first differential signal output terminal RF01, the second end of the first inductor L1 is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is grounded; the second filtering circuit includes a second inductor L2 and a second capacitor C2, the first end of the second inductor L2 is connected to the second differential signal output terminal RF02, the second end of the second inductor L2 is connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is grounded.

[0072] Among them, the first filtering circuit composed of the first inductor L1 and the first capacitor C1 filters the differential signal output by the first differential signal output terminal RF01, and the second filtering circuit composed of the second inductor L2 and the second capacitor C2 filters the differential signal output by the second differential signal output terminal RF02.

[0073] Among them, the inductor uses its "passing DC and blocking AC" characteristics to prevent high-frequency interference signals from passing through, while allowing low-frequency useful signals to be transmitted smoothly, playing a role in suppressing high-frequency noise. The capacitor uses its "passing AC and blocking DC" characteristics to provide a low-impedance path for high-frequency interference signals, bypassing them to the ground, while preventing the loss of DC or low-frequency signals. The two work together to filter out stray frequency components and noise interference in the differential signal, achieve screening and purification of signals in specific frequency bands, and ensure that the differential signal transmitted from the differential output end to the coil is pure and stable, thereby improving the quality and reliability of near-field communication and ensuring the stable operation of the near-field communication antenna 100.

[0074] See Figure 3 Optionally, the switch switching circuit also includes a matching adjustment module, which includes a first matching adjustment circuit and a second matching adjustment circuit; the first matching adjustment circuit includes a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5, the first end of the third capacitor C3 is connected to the second end of the first capacitor C1, the second end of the third capacitor C3 is respectively connected to the common end of the single-pole three-throw switch, the first end of the fourth capacitor C4 and the first end of the fifth capacitor C5, and the second end of the fourth capacitor C4 and the second end of the fifth capacitor C5 are grounded; the second matching adjustment circuit includes a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8, the first end of the sixth capacitor C6 is connected to the second end of the second capacitor C2, the second end of the sixth capacitor C6 is respectively connected to the near-field communication antenna 100, the first end of the seventh capacitor C7 and the first end of the eighth capacitor C8, and the second end of the seventh capacitor C7 and the second end of the eighth capacitor C8 are grounded.

[0075] The first matching adjustment circuit formed by the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 is used to adjust the impedance matching between the first differential signal output terminal RF01 and the near-field communication antenna 100, and the second matching adjustment circuit formed by the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 is used to adjust the impedance matching between the second differential signal output terminal RF02 and the near-field communication antenna 100. The first matching adjustment circuit and the second matching adjustment circuit are thus used to optimize the impedance matching between the near-field communication antenna 100 and the front-end circuit, thereby reducing signal reflection and energy loss, ensuring efficient transmission of differential signals, and improving the communication performance and stability of near-field communication.

[0076] The third and sixth capacitors C3 and C6, connected in series, adjust the circuit's equivalent impedance, changing the phase and amplitude characteristics of the differential signal to better match the characteristics of the near-field communication antenna 100. The fourth and fifth capacitors C4, C5, and the seventh and eighth capacitors C7 and C8, connected in parallel, provide additional capacitive loads, adjusting the circuit's resonant frequency and bandwidth and further optimizing impedance matching. Together, they enable the near-field communication antenna 100 to achieve optimal performance under varying operating conditions.

[0077] See Figure 3 Optionally, the switching circuit also includes a first resistor R1 and a second resistor R2; the first end of the first resistor R1 is connected to the first differential signal output terminal RF01, and the second end of the first resistor R1 is connected to the common end of the single-pole triple-throw switch; the first end of the second resistor R2 is connected to the second differential signal output terminal RF02, and the second end of the second resistor R2 is connected to the near-field communication antenna 100.

[0078] The first resistor R1 and the second resistor R2 play an impedance adjustment role. The debugging values ​​can be changed according to actual conditions to help adjust the input impedance of the circuit to reduce signal reflection and improve signal transmission efficiency.

[0079] See Figure 3 Optionally, the first throw terminal RF1 is connected to the first end of the ninth capacitor C9, and the second end of the ninth capacitor C9 is grounded; the second throw terminal RF2 is connected to the first end of the tenth capacitor C10, and the second end of the tenth capacitor C10 is grounded; the third throw terminal RF3 is connected to the first end of the eleventh capacitor C11, and the second end of the eleventh capacitor C11 is grounded.

[0080] In switching circuits, single-pole, triple-throw (SPTH) switches are used to switch between different circuit paths. However, switching transients such as voltage spikes, current surges, and residual energy can cause power supply noise, impacting near-field communication (NFC) signal quality and even interfering with NFC circuit performance and electromagnetic compatibility.

[0081] Therefore, a resonant circuit is formed by the ninth capacitor C9 connected in parallel with the first throw terminal RF1, the tenth capacitor C10 connected in parallel with the second throw terminal RF2, the eleventh capacitor C11 connected in parallel with the third throw terminal RF3, and the parasitic inductance of the single-pole three-throw switch, thereby establishing an energy recovery and buffering path to improve system stability and reliability.

[0082] By optimizing the resonant circuit parameters, the residual energy regeneration efficiency during switching is increased to 90%, effectively recovering most of the residual energy and improving energy utilization efficiency. The resonant circuit effectively suppresses power supply noise generated by switching transients, reducing it to below -70dBm and improving near-field communication signal quality. By reducing power supply noise and transient effects, interference with the near-field communication circuit and overall electromagnetic compatibility performance is minimized.

[0083] Specifically, parasitic inductance (about 2 nH), which exists inside a single-pole triple-throw switch, is one of the main causes of switching transients.

[0084] Specifically, the ninth capacitor C9, the tenth capacitor C10, and the eleventh capacitor C11 are used to store and release energy, and together with the parasitic inductance form a resonant circuit.

[0085] Figure 5 This is a flow chart of a control method for a vehicle-mounted wireless charging device provided in an embodiment of the present application, see Figure 5 In some embodiments, the control method of the vehicle-mounted wireless charging device is applied to the control mainboard 300 of the vehicle-mounted wireless charging device, and the process includes the following steps:

[0086] S501, when a near-field communication tag is detected within the sensing range of the near-field communication antenna 100, the activation decision parameters of each target coil in the near-field communication antenna 100 are obtained; wherein the activation decision parameters include geometric coverage weight, impedance matching, multi-tag conflict index and dynamic switching logic decision index; wherein the target coil is the first coil 101, the second coil 102 or the third coil 103.

[0087] Among them, if a near-field communication tag is detected, the geometric coverage weight between the near-field communication tag and the target coil, the impedance matching of the RF differential signal input by the target coil, and the multi-tag conflict index of the target coil are obtained, and then the dynamic switching logic decision index is determined based on the geometric coverage weight, impedance matching and multi-tag conflict index.

[0088] Specifically, near field communication tags include NFC cards and other RFID (Radio Frequency Identification) tags.

[0089] Specifically, to monitor the NFC tag, the NFC antenna 100 activates the first coil 101 by default.

[0090] Specifically, the geometric coverage weight satisfies the following formula:

[0091]

[0092] Among them, W g represents the geometric coverage weight, A overlap A represents the overlapping effective area between the NFC tag and the target coil, total represents the total area of ​​the target coil, and d represents the distance between the NFC tag and the center of the target coil.

[0093] Specifically, the impedance matching satisfies the following formula:

[0094]

[0095] Among them, Z match represents the impedance matching, and VSVR represents the voltage standing wave ratio of the RF differential output of the target coil.

[0096] Specifically, the multi-label conflict index satisfies the following formula:

[0097]

[0098] Among them, C m represents the multi-tag conflict index, N represents the number of times the NFC tag phase is read, Δφ k represents the difference between the kth and expected phases, δ represents the Dirac function, t represents the number of signal detections, and t k Indicates the number of phase collisions.

[0099] Specifically, the dynamic switching logic decision function satisfies the following formula:

[0100] S=a·W g +b·Z match +c·(1-C m )

[0101] Where S represents the dynamic switching logic decision coefficient, and a, b, and c represent weight coefficients.

[0102] S502 : For each target coil, if the activation decision parameter of the target coil meets a preset activation condition, the target coil is activated.

[0103] Among them, when the activation decision parameters of the target coil meet the preset activation conditions, it indicates that the signal strength between the target coil and the near-field communication tag is the largest. At this time, the target coil is activated to communicate with the near-field communication tag to obtain better communication effect.

[0104] See Figure 2 In this way, when the near-field communication tag is placed horizontally at the top, the second coil 102 arranged horizontally at the top and the first coil 101 arranged vertically in the middle can choose which coil to switch according to the actual placement position to avoid the card current cancellation; when the near-field communication tag is placed horizontally at the middle, the three coils can choose which coil to switch according to the actual placement position to avoid the card current cancellation; when the near-field communication tag is placed horizontally at the bottom, the third coil 103 arranged horizontally at the bottom and the first coil 101 arranged vertically in the middle can choose which coil to switch according to the actual placement position to avoid the card current cancellation; when the card is placed vertically, the three coils can choose which coil to switch according to the actual placement position to avoid the card current cancellation.

[0105] Specifically, when S1>S2+0.2 and S1>S3+0.3, the activation condition of the first coil 101 is met, which indicates that the signal strength of the first coil 101 is the highest, and the first coil 101 is activated.

[0106] Specifically, when C m >0.6 or Z match When <0.8, the activation condition of the second coil 102 is met, which indicates that the signal strength of the second coil 102 is the highest, and the second coil 102 is activated.

[0107] Specifically, when W g >0.7 or C m When <0.1, the activation condition of the third coil 103 is met, which indicates that the signal strength of the third coil 103 is the highest, and the third coil 103 is activated.

[0108] In some embodiments, the control method of the vehicle-mounted wireless charging device further includes controlling the wireless charging coil 200 to stop charging when a near-field communication tag is detected within the sensing range of the near-field communication antenna 100 .

[0109] In this embodiment, if an NFC tag is detected while the wireless charging coil 200 is operating, the tag could be coupled to the high charging current of the wireless charging coil 200, potentially burning the wireless charging coil 200. Therefore, if an NFC tag is detected within the sensing range of the NFC antenna 100 while the wireless charging coil 200 is operating, the wireless charging coil 200 is controlled to stop charging, thus protecting the NFC tag from burning.

[0110] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0112] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0113] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0114] In the above embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a particular embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined in any way. To keep the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the appended claims.

[0116] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A vehicle-mounted wireless charging device, characterized in that: It includes a control mainboard, a near-field communication antenna and a wireless charging coil, wherein the control mainboard is respectively connected to the near-field communication antenna and the wireless charging coil; The near field communication antenna includes a first coil, a second coil and a third coil, wherein the second coil and the third coil are arranged at intervals, the first coil is arranged between the second coil and the third coil, and the first coil partially overlaps with the second coil and the third coil; The wireless charging coil is arranged below the near field communication antenna.

2. The vehicle-mounted wireless charging device according to claim 1, characterized in that: The control main board includes a switch switching circuit, and the switch switching circuit includes a first differential signal output terminal, a second differential signal output terminal and a single-pole triple-throw switch; The single-pole triple-throw switch includes a common terminal and a first throw terminal, a second throw terminal, and a third throw terminal, wherein the common terminal is connected to the first differential signal output terminal; the first throw terminal is connected to the first coil, the second throw terminal is connected to the second coil, and the third throw terminal is connected to the third coil; The second differential signal output end is connected to the first coil, the second coil and the third coil respectively.

3. The vehicle-mounted wireless charging device according to claim 2, characterized in that: The switch switching circuit further includes a filtering module, and the filtering module includes a first filtering circuit and a second filtering circuit; The first filtering circuit includes a first inductor and a first capacitor, wherein a first end of the first inductor is connected to the first differential signal output end, a second end of the first inductor is connected to the first end of the first capacitor, and a second end of the first capacitor is grounded; The second filtering circuit includes a second inductor and a second capacitor, a first end of the second inductor is connected to the second differential signal output end, a second end of the second inductor is connected to the first end of the second capacitor, and a second end of the second capacitor is grounded.

4. The vehicle-mounted wireless charging device according to claim 3, characterized in that: The switch switching circuit further includes a matching adjustment module, and the matching adjustment module includes a first matching adjustment circuit and a second matching adjustment circuit; The first matching adjustment circuit includes a third capacitor, a fourth capacitor, and a fifth capacitor, wherein a first end of the third capacitor is connected to a second end of the first capacitor, a second end of the third capacitor is connected to a common end of the single-pole triple-throw switch, a first end of the fourth capacitor, and a first end of the fifth capacitor, respectively, and a second end of the fourth capacitor and a second end of the fifth capacitor are grounded; The second matching adjustment circuit includes a sixth capacitor, a seventh capacitor and an eighth capacitor, the first end of the sixth capacitor is connected to the second end of the second capacitor, the second end of the sixth capacitor is respectively connected to the near-field communication antenna, the first end of the seventh capacitor and the first end of the eighth capacitor, and the second end of the seventh capacitor and the second end of the eighth capacitor are grounded.

5. The vehicle-mounted wireless charging device according to claim 4, characterized in that: The switch switching circuit further includes a first resistor and a second resistor; A first end of the first resistor is connected to the first differential signal output end, and a second end of the first resistor is connected to the common end of the single-pole triple-throw switch; A first end of the second resistor is connected to the second differential signal output end, and a second end of the second resistor is connected to the near field communication antenna.

6. The vehicle-mounted wireless charging device according to claim 2, characterized in that: The first pin is connected to the first end of the ninth capacitor, and the second end of the ninth capacitor is grounded; The second pin is connected to the first terminal of the tenth capacitor, and the second terminal of the tenth capacitor is grounded; The third pin is connected to a first terminal of an eleventh capacitor, and a second terminal of the eleventh capacitor is grounded.

7. The vehicle-mounted wireless charging device according to any one of claims 1 to 6, characterized in that: An EMC shielding net is provided between the near-field communication antenna and the wireless charging coil.

8. The vehicle-mounted wireless charging device according to any one of claims 1 to 6, characterized in that: At least one NTC resistor is provided between the near field communication antenna and the wireless charging coil, and the NTC resistor is connected to the control mainboard.

9. A control method for a vehicle-mounted wireless charging device, characterized in that: The method applied to the control mainboard of the vehicle-mounted wireless charging device according to any one of claims 1 to 8 comprises: When a near-field communication tag is detected within the sensing range of the near-field communication antenna, activation decision parameters of each target coil in the near-field communication antenna are obtained; wherein the activation decision parameters include a geometric coverage weight, an impedance matching degree, a multi-tag conflict index, and a dynamic switching logic decision index; wherein the target coil is the first coil, the second coil, or the third coil; For each target coil, if the activation decision parameter of the target coil meets a preset activation condition, the target coil is activated.

10. The control method of the vehicle-mounted wireless charging device according to claim 9, characterized in that: The method further comprises: When a near field communication tag is detected within the sensing range of the near field communication antenna, the wireless charging coil is controlled to stop charging.

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