Vehicle-mounted wireless charging device and foreign matter detection method thereof

Abstract

The invention discloses a vehicle-mounted wireless charging device and a foreign matter detection method thereof. The vehicle-mounted wireless charging device comprises a charging cavity, a wireless charging coil arranged in the charging cavity, a multicolor LED array, a plurality of photosensitive sensors, a control chip and an optical shielding cover. A PCB (Printed Circuit Board) is arranged in the charging cavity and is positioned at the bottom of the charging cavity; the wireless charging coil is arranged on the PCB; the multi-color LED array is arranged above the wireless charging coil; the plurality of photosensitive sensors are arranged on the PCB and distributed around the wireless charging coil, and the optical shielding cover covers the multicolor LED array and the plurality of photosensitive sensors and is fixed at the edge of the charging cavity; and the control chip is arranged on the PCB. According to the device, optical signals with specific wavelengths are emitted through the multi-color LED array, and the intensity of reflected light is synchronously acquired by using the plurality of photosensitive sensors, so that the accuracy and reliability of foreign matter detection are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle-mounted electronic equipment, and in particular to a vehicle-mounted wireless charging device and a foreign object detection method thereof. Background Art

[0002] In-vehicle wireless charging technology provides a convenient way to charge mobile devices through electromagnetic induction. However, in practice, foreign objects may be present on the charging device, affecting charging, causing overheating, or loss of efficiency. Foreign Object Detection (FOD) is a key technology to prevent metallic or non-metallic foreign objects from interfering with the charging process, causing overheating or loss of efficiency. The reliability and accuracy of FOD are directly related to the safety and user experience of in-vehicle wireless charging systems.

[0003] Traditional technologies mainly use two detection methods. One is the Q-value detection method based on the change of the coil's electromagnetic parameters. This method is insensitive to non-metallic foreign objects and is easily affected by electromagnetic interference. The other is the traditional optical detection method that relies on ambient light or a simple infrared light source. This method usually has a signal-to-noise ratio of less than 10 times in a strong vehicle light environment of 0-1000 Lux. It is difficult to distinguish between the background, foreign objects and charging equipment, making it difficult to detect foreign objects and affecting the reliability of detection.

[0004] In summary, traditional technologies perform poorly in resisting ambient light interference and are prone to misjudgment or missed judgment in strong light environments. Secondly, the functional integration of in-vehicle wireless charging devices is insufficient, and the charger and ambient lighting system usually adopt a separate design, which not only increases hardware costs but also takes up valuable space in the vehicle. Summary of the Invention

[0005] The object of the present invention is to provide a vehicle-mounted wireless charging device and a foreign object detection method thereof, which can improve the anti-interference ability of ambient light, enhance functional integration and reduce hardware costs.

[0006] To solve the above technical problems, the present invention provides an in-vehicle wireless charging device and a foreign object detection method thereof. The in-vehicle wireless charging device includes a charging chamber, a wireless charging coil arranged in the charging chamber, a multi-color LED array, multiple photosensors and a control chip, and an optical shielding cover;

[0007] A PCB board is provided in the charging cavity and is located at the bottom of the charging cavity;

[0008] The wireless charging coil is arranged on the PCB board; the multi-color LED array is arranged above the wireless charging coil; the multiple photosensors are arranged on the PCB board and distributed around the wireless charging coil; the optical shielding cover covers the multi-color LED array and the multiple photosensors and is fixed on the edge of the charging cavity, and a charging area is formed on the optical shielding cover for placing the charging device that needs to be charged; the control chip is arranged on the PCB board and is electrically connected to the multi-color LED array, the multiple photosensors and the wireless charging coil.

[0009] Furthermore, the multiple photosensors are photosensors with narrowband filters, and there are at least three of them; the multiple photosensors are installed at an angle of 10° to 15° relative to the PCB board.

[0010] Furthermore, the optical shielding cover is a fence-type structure.

[0011] Furthermore, it also includes a super capacitor and an accelerometer, and the super capacitor and the accelerometer are both arranged on one side of the PCB board.

[0012] The present invention also provides a foreign object detection method for an on-vehicle wireless charging device, based on the above-mentioned on-vehicle wireless charging device, comprising:

[0013] S1. The control chip alternately executes the foreign object detection mode and the atmosphere lighting mode. When executing the foreign object detection mode, the multi-color LED array is controlled to emit detection light, and the reflected light signal of the charging area is collected by multiple photosensors;

[0014] S2. analyzing the spatial distribution characteristics of the reflected light signal according to a pattern recognition algorithm;

[0015] S3, determining the charging area status based on the spatial distribution characteristics, controlling the wireless charging coil to perform related operations, and the ambient lighting function of the multi-color LED array;

[0016] The charging area status includes an idle state, a normal charging device placement state, and an abnormal state; the abnormal state includes the presence of foreign objects on the surface of the vehicle-mounted wireless charging device or improper placement of the charging device.

[0017] Furthermore, the step S1 includes:

[0018] The multi-color LED array uses time division multiplexing to alternately execute the foreign object detection mode and the atmosphere lighting mode. When in the foreign object detection mode, the control chip controls the multi-color LED array to emit light of a specific wavelength;

[0019] The time division multiplexing method includes:

[0020] In the ambient lighting mode, the multi-color LED array is controlled by a PWM signal to generate ambient lighting;

[0021] The atmosphere lighting mode is periodically paused and switched to the foreign object detection mode, so that the multi-color LED array emits detection light and collects reflection signals.

[0022] Furthermore, the S2 includes:

[0023] S21. The control chip collects signal vectors of multiple photosensors to form a comprehensive signal vector S, where the comprehensive signal vector S = [S0, S1, ..., Sn], where S0 is the signal vector of the first photosensor, S1 is the signal vector of the second photosensor, ..., Sn is the signal vector of the nth photosensor;

[0024] S22. Calculate the characteristic vector F of the signal vector, wherein the characteristic vector F = [Savg, Smax, Smin, Svar], wherein Savg is the average value of the plurality of photosensitive sensor signal vectors, Smax is the maximum value of the plurality of photosensitive sensor signal vectors, Smin is the minimum value of the plurality of photosensitive sensor signal vectors, and Svar is the variance of the plurality of photosensitive sensor signal vectors.

[0025] S23. Compare the feature vector F with a pre-stored or online learned reference pattern library. If the average value Savg of the multiple photosensor signal vectors and the variance Svar of the multiple photosensor signal vectors are lower than the average value and variance of the reference pattern library, it indicates that the vehicle-mounted wireless charging device is in an idle state.

[0026] If the variance Svar of the signal vectors of the multiple photosensors is lower than the variance of the reference pattern library, it indicates that the charging device is placed normally;

[0027] If the variance Svar of the plurality of photosensitive sensor signal vectors is higher than the variance of the reference pattern library, or higher than the maximum value of the plurality of photosensitive sensor signal vectors, it indicates that the charging device is in an abnormal state.

[0028] Furthermore, the S3 includes:

[0029] When the control chip determines that the vehicle-mounted wireless charging device is in an idle state, it controls the multi-color LED array to switch to the ambient lighting mode;

[0030] When the control chip determines that the charging device is in a normal placement state, it starts the wireless charging coil to perform a charging operation and controls the multi-color LED array to provide ambient lighting in a first preset mode;

[0031] When the control chip determines that it is in an abnormal state, the wireless charging coil is prohibited from performing a charging operation, and the multi-color LED array is controlled to provide warning lighting in a second preset mode.

[0032] Furthermore, the S3 further includes:

[0033] When the state of the charging area changes from a normal placement state of the charging device to an abnormal state, the control chip controls the wireless charging coil to immediately stop the wireless charging operation;

[0034] When the state of the charging area changes from an abnormal state to a normal placement state of the charging device, the control chip controls the wireless charging coil to resume the wireless charging operation after a preset delay.

[0035] Furthermore, the foreign body detection method further includes:

[0036] The vehicle's posture is monitored through an accelerometer and the vehicle's tilt angle is calculated. When the vehicle's tilt angle is detected to exceed a preset threshold, the wireless charging operation is suspended and a visual prompt is issued through a multi-color LED array.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects:

[0038] The in-vehicle wireless charging device proposed in the present invention transmits light signals of specific wavelengths through a multi-color LED array, and uses multiple tilted photosensors to synchronously collect the reflected light intensity. Combined with the physical blocking effect of the optical shielding cover, it suppresses ambient light interference while detecting foreign objects, thereby improving the accuracy and reliability of foreign object detection. The foreign object detection light source and ambient light functions are integrated into the same multi-color LED array, and the coordinated switching of the two functions is achieved through a control chip, reducing hardware redundancy and optimizing PCB space and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is an exploded diagram of a vehicle-mounted wireless charging device according to one embodiment of the present invention;

[0040] Figure 2 A schematic diagram of a portion of the structure of a vehicle-mounted wireless charging device according to an embodiment of the present invention;

[0041] Figure 3 A schematic structural diagram of an optical shielding cover according to an embodiment of the present invention;

[0042] Figure 4 This is a general schematic diagram of a vehicle-mounted wireless charging device according to an embodiment of the present invention;

[0043] Figure 5 Flowchart of a foreign body detection method according to an embodiment of the present invention;

[0044] Figure 6A signal strength comparison diagram according to an embodiment of the present invention;

[0045] Figure 7 FIG. 4 is a comparison diagram of the reflected signal and noise in one embodiment of the present invention.

[0046] Figure numbers: 1. Charging chamber; 2. Wireless charging coil; 3. Multi-color LED array; 4. Photosensor; 5. Charging device; 6. Control chip; 7. Supercapacitor; 8. Accelerometer; 9. Voice chip; 10. Optical shielding cover; 11. PCB board. DETAILED DESCRIPTION

[0047] Based on the teachings of this specification, those skilled in the art may form new technical solutions by cross-combining different implementation methods without generating technical contradictions. Such variations should be deemed to fall within the scope of protection of this patent.

[0048] The following is a more detailed description of a vehicle-mounted wireless charging device and foreign object detection method of the present invention, with reference to schematic diagrams. These diagrams illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art may modify the present invention described herein while still achieving the beneficial effects of the present invention. Therefore, the following description should be understood as a general guideline for those skilled in the art and not as a limitation of the present invention.

[0049] The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are greatly simplified and not to exact scale, and are provided solely for the purpose of assisting in the description of the embodiments of the present invention.

[0050] Example 1

[0051] like Figure 1-Figure 4 As shown, an embodiment of the present invention proposes an in-vehicle wireless charging device, including a charging cavity 1, a wireless charging coil 2 arranged in the charging cavity 1, a multi-color LED array 3, multiple photosensors 4 and a control chip 6, and an optical shielding cover 10.

[0052] Specifically, a PCB 11 is disposed within the charging chamber 1 and located at the bottom of the chamber. The charging chamber 1 provides mounting space for internal components and forms an electromagnetic shielding environment, and may be constructed of an injection-molded housing. The PCB 11 provides circuit connections and physical support for the wireless charging assembly.

[0053] The wireless charging coil 2 is mounted on the PCB 11; the multi-color LED array 3 is mounted above the wireless charging coil 2; and the multiple photosensors 4 are mounted on the PCB 11 and distributed around the wireless charging coil 2. The multiple photosensors 4, positioned at an angle, are used to synchronously collect reflected light intensities at different locations within the charging area, providing information for status analysis. The optical shield 10 covers the multi-color LED array 3 and the multiple photosensors 4 and is secured to the edge of the charging chamber 1. The optical shield 10 transmits both detection light and ambient light from the multi-color LED array 3 while preventing interference from external ambient light on the photosensors 4. A charging area is formed on the optical shield 10 for placing the charging device 5 to be charged. The control chip 6 is mounted on the PCB 11 and electrically connected to the multi-color LED array 3, the multiple photosensors 4, and the wireless charging coil 2. The control chip 6 utilizes a high-performance microprocessor capable of processing multi-sensor data in real time and executing complex pattern recognition algorithms.

[0054] The in-vehicle wireless charging device creates a controlled optical detection environment through the spatial arrangement of the multi-color LED array 3 and the photosensors 4, combined with the physical isolation provided by the optical shield 10. The multi-color LED array 3 emits detection light, which is reflected by the charging area and received by the multiple, angled photosensors 4. The control chip 6 analyzes the spatial distribution of the reflected light signal, determines the charging area status, and controls the wireless charging coil charging and the ambient lighting function of the multi-color LED array 3. This improves the stability of the foreign object detection signal-to-noise ratio and reduces hardware redundancy through light source reuse.

[0055] In a specific embodiment, the multi-color LED array 3 adopts an RGB LED 8*8 array, which can achieve lighting effects of red, green, blue and their mixed colors, and has the dual functions of detection light emission and ambient light illumination, so that the foreign object detection light source and atmosphere lighting functions can be realized simultaneously by switching the light emission mode.

[0056] In this embodiment, the multiple photosensors 4 are photosensors 4 with narrowband filters, and there are at least three of them, for example, three, and four are shown in the figure. The passband wavelength of the narrowband filter matches the wavelength of the detection light emitted by the multi-color LED array 3, which can effectively filter out ambient light interference and improve the signal-to-noise ratio. For example, the 650nm red light band is selected, and each sensor is equipped with a 650nm narrowband pass filter with a bandwidth within ±5nm, so that the multiple photosensors 4 can efficiently transmit the 650nm signal light and attenuate non-650nm ambient light. The number of the photosensors 4 is configured to be three or more, distributed in a ring array around the wireless charging coil 2, so that the optical characteristics of the charging area can be collected from multiple angles, improving the accuracy and reliability of the detection.

[0057] The multiple photosensors 4 are installed at an angle of 10° to 15° relative to the PCB 11. The tilted installation of the multiple photosensors 4 can better capture the reflected light characteristics of objects in the charging area, thereby improving detection sensitivity. Preferably, the multiple photosensors 4 are installed at an angle of 12° relative to the PCB 11.

[0058] In this embodiment, if Figure 3 As shown, the optical shield 10 is a fence-like structure. This structural design not only defines the boundaries of the charging area, guiding users to correctly place the charging device, but also physically blocks both high- and low-angle external ambient light from entering the charging area, reducing interference with the photosensor 4. The fence-like structure also prevents the charging device 5 from sliding out of the charging area due to inertia while the vehicle is in motion, improving charging stability and safety.

[0059] In this embodiment, the vehicle-mounted wireless charging device further includes a supercapacitor 7 and an accelerometer 8, both of which are disposed on one side of the PCB board 11. The supercapacitor 7 can provide a stable high-peak current (10A) within 1-5ms. Utilizing the high power density characteristics of the supercapacitor 7, the wireless charging coil 2 is provided with stable power when the power supply fluctuates, thereby avoiding charging interruptions or reduced efficiency. The accelerometer 8 is used to monitor the vehicle's posture in real time and calculate the vehicle's tilt angle. When the vehicle's tilt angle is too large, the vehicle-mounted wireless charging device can suspend the charging operation to prevent a decrease in charging efficiency or safety issues caused by the displacement of the charging device 5.

[0060] In a specific operation process, the accelerometer 8 samples at a set frequency and calculates the three-axis acceleration to obtain the tilt angle θ, which is the angle between the incident light and the normal of the photosensor 4. When the tilt angle θ is greater than 15° (such as a sharp turn or a ramp), the control chip 6 controls the wireless charging coil 2 to suspend charging to prevent the charging device 5 from shifting, resulting in a decrease in charging efficiency or overheating. The calculation formula for the tilt angle θ is:

[0061]

[0062] Among them, ax, ay, az are the accelerations of the X-axis, Y-axis, and Z-axis respectively.

[0063] In another specific embodiment, the vehicle-mounted wireless charging device further includes a voice chip 9, which is disposed on the PCB board 11 and electrically connected to the control chip 6. The voice chip 9 is used to provide voice prompts when the charging status changes, thereby enhancing the interactive experience between the device and the user. For example, when it is detected that the charging device 5 is placed normally, the voice chip 9 will play a prompt tone of "charging has started"; when a foreign object is detected or the charging device 5 is improperly placed, the voice chip 9 will play a prompt tone of "foreign object detected, please clean the charging area"; when the vehicle tilt angle is too large, the voice chip 9 will play a prompt tone of "charging has been paused". This voice prompt function is combined with LED visual feedback to form a multi-sensory human-computer interaction system, allowing the driver to know the charging status through hearing without having to distract his attention to check the charging area, effectively improving driving safety and user experience.

[0064] In addition, the voice chip 9 also supports multi-language settings and volume adjustment, which can adapt to the needs of different users and the noise levels of different driving environments.

[0065] Example 2

[0066] like Figure 2 As shown, this second embodiment proposes a foreign object detection method for a vehicle-mounted wireless charging device based on the first embodiment, and the foreign object detection method includes:

[0067] S1. The control chip 6 alternately executes the foreign object detection mode and the atmosphere lighting mode. When executing the foreign object detection mode, the multi-color LED array 3 is controlled to emit detection light, and the reflected light signal of the charging area is collected through the multiple photosensors 4.

[0068] S2. Analyze the spatial distribution characteristics of the reflected light signal according to a pattern recognition algorithm.

[0069] S3. Determine the charging area status based on the spatial distribution characteristics, control the wireless charging coil 2 to perform related operations, and control the ambient lighting function of the multi-color LED array 3.

[0070] The charging area status includes an idle state, a normal placement state of the charging device 5 and an abnormal state; the abnormal state includes the presence of foreign objects on the surface of the vehicle-mounted wireless charging device or improper placement of the charging device 5.

[0071] In this embodiment, step S1 includes:

[0072] The multi-color LED array 3 alternately executes the foreign object detection mode and the atmosphere lighting mode through time division multiplexing. When in the foreign object detection mode, the control chip 6 controls the multi-color LED array 3 to emit light of a specific wavelength.

[0073] In a specific embodiment, in the foreign body detection mode, the control chip 6 controls the multi-color LED array 3 to emit 650nm red light pulses (frequency is 10Hz, pulse width is 1-5ms). There are many considerations for selecting red light with a wavelength of 650nm as the detection light source: first, light with a wavelength of 650nm has good reflection characteristics for foreign bodies of different materials; second, compared with other visible light wavelengths, 650nm red light is less irritating to the human eye; finally, light sensors with a wavelength of 650nm are low-cost and easy to obtain. The pulse frequency of 10Hz can ensure the real-time detection without placing too much burden on the device. The pulse width of 1-5ms can provide sufficient light energy for detection while minimizing interference with ambient lighting.

[0074] Among them, the time division multiplexing method includes controlling the multi-color LED array 3 to generate atmosphere lighting through a PWM signal in the atmosphere lighting mode; periodically pausing the atmosphere lighting mode and switching to the foreign object detection mode, so that the multi-color LED array 3 emits detection light and collects reflection signals.

[0075] By employing time-division multiplexing, a single piece of hardware (i.e., the multi-color LED array 3) achieves dual functionality, enabling it to serve as both a light source for foreign object detection and interior ambient lighting. This significantly simplifies the device structure, reducing costs and space requirements. The switching frequency and time ratio of the time-division multiplexing can be set according to actual needs, ensuring efficient execution of both functions with minimal interference.

[0076] In this embodiment, step S2 includes:

[0077] S21. The control chip 6 collects signal vectors of multiple photosensors to form a comprehensive signal vector S, where the comprehensive signal vector S = [S0, S1, ..., Sn], where S0 is the signal vector of the first photosensor, S1 is the signal vector of the second photosensor, ..., Sn is the signal vector of the nth photosensor.

[0078] S22. Calculate the characteristic vector F of the signal vector, wherein the characteristic vector F = [Savg, Smax, Smin, Svar], wherein Savg is the average value of the plurality of photosensitive sensor signal vectors, Smax is the maximum value of the plurality of photosensitive sensor signal vectors, Smin is the minimum value of the plurality of photosensitive sensor signal vectors, and Svar is the variance of the plurality of photosensitive sensor signal vectors.

[0079] S23. Compare the feature vector F with a pre-stored or online learned reference pattern library. If the average value Savg of the multiple photosensitive sensor signal vectors and the variance Svar of the multiple photosensitive sensor signal vectors are lower than the average value and variance of the reference pattern library, it indicates that the vehicle-mounted wireless charging device is in an idle state; if the variance Svar of the multiple photosensitive sensor signal vectors is lower than the variance of the reference pattern library, it indicates that the charging device 5 is placed normally; if the variance Svar of the multiple photosensitive sensor signal vectors is higher than the variance of the reference pattern library, or higher than the maximum value among the multiple photosensitive sensor signal vectors, it indicates that the charging device 5 is in an abnormal state.

[0080] Light signals are based on optical models: Pulse power density P = 10,000 W / m 2 , ρ is the reflectivity, the reflectivity of the foreign body ρ fod =0.7, background reflectivity ρ bg =0.15, sensor efficiency η = 0.01, detection distance d = 5mm detection distance. Figure 3 As shown in the figure, according to the optical model calculation, the foreign object signal Sobject ≈ 8000 LSB, the background signal Sbackground ≈ 200 LSB, and the ambient noise Snoise ≈ 50 LSB, making the actual signal-to-noise ratio approximately 20 times, far exceeding the 10-fold threshold of traditional optical FOD systems, making the device detection highly reliable. The optical model is based on the Lambert diffuse reflection model, assuming that the charging area is a uniform diffuse reflection surface and ignoring the multiple reflection effects. In actual use, the distributed spatial sampling of multiple sensors compensates for the model simplification error and maintains the robustness of the non-uniform light field.

[0081] Step S2 utilizes the spatial characteristics of distributed sensors and identifies different charging area states by comparing the feature vector F with a pre-stored or online learned reference pattern library. This not only improves the sensitivity and accuracy of detection, but also enhances the device's ability to detect low-reflectivity or transparent foreign objects, especially in complex lighting environments. It effectively solves the problems of low signal-to-noise ratio and high misjudgment rate of traditional optical FOD methods under strong ambient light.

[0082] In this embodiment, step S3 includes:

[0083] When the control chip 6 determines that the vehicle-mounted wireless charging device is in an idle state, it controls the multi-color LED array 3 to switch to an ambient lighting mode.

[0084] When the control chip 6 determines that the charging device 5 is in a normal placement state, it starts the wireless charging coil 2 to perform a charging operation and controls the multi-color LED array 3 to provide ambient lighting in a first preset mode.

[0085] When the control chip 6 determines that the state is abnormal, the wireless charging coil 2 is prohibited from performing the charging operation, and the multi-color LED array 3 is controlled to provide warning lighting in the second preset mode.

[0086] The three preset modes not only have beautiful visual effects, but more importantly, they convey system status information to users through intuitive color changes. This visual feedback mechanism greatly improves the user experience.

[0087] In a specific embodiment, the ambient lighting mode can be low-brightness blue or a multi-color mixture, indicating a standby state; the first preset mode is a stable green breathing effect, indicating normal charging; the second preset mode is a red flashing effect, warning of an abnormal state.

[0088] In this embodiment, step S3 further includes:

[0089] When the state of the charging area changes from a normal placement state of the charging device 5 to an abnormal state, the control chip 6 controls the wireless charging coil 2 to immediately stop the wireless charging operation.

[0090] When the charging area status changes from an abnormal status to a normal placement status of the charging device 5 , the control chip 6 controls the wireless charging coil 2 to resume the wireless charging operation after a preset delay.

[0091] This state transition mechanism takes safety into full consideration. When an abnormal state is detected, the device will immediately stop charging to prevent possible safety hazards. When the abnormal state is eliminated, the device will wait for a preset period of time (usually 2-3 seconds) before resuming charging. This delay mechanism effectively prevents frequent charging state switching due to instantaneous interference and improves the stability of the device.

[0092] In this embodiment, the foreign body detection method further includes:

[0093] The vehicle posture is monitored by the accelerometer 8, and the vehicle tilt angle is calculated. When it is detected that the vehicle tilt angle exceeds a preset threshold, the wireless charging operation is suspended and a visual prompt is issued through the multi-color LED array 3 to prevent the charging device 5 from shifting, resulting in a decrease in charging efficiency or overheating.

[0094] Accelerometer 8 provides real-time monitoring of the vehicle's dynamic posture, making it suitable for situations such as mountain driving or tight turns. When the vehicle's tilt angle exceeds a preset threshold (typically 15°), charging device 5 may slip or shift within the charging area, leading to reduced charging efficiency, overheating, and even safety hazards. The device then pauses charging and automatically resumes charging once the vehicle returns to normal posture, significantly improving the safety and reliability of the on-board wireless charging device under complex road conditions.

[0095] Example 3

[0096] Based on the first and second embodiments, this third embodiment proposes a specific implementation method.

[0097] In this embodiment, there are four light sensors 4, evenly distributed around the wireless charging coil 2, and all installed at an angle of 12° relative to the PCB 11. In addition, each light sensor 4 is configured with a 650nm narrowband bandpass filter.

[0098] The multicolor LED array 3 utilizes an 8x8 array of RGB LEDs, with 650nm red light used for FOD pulses and the three RGB colors used for ambient lighting. The shield, measuring 1.5mm in height and 1.0mm in thickness, covers the multicolor LED array 3 and the photosensor 4, limiting the incident angle of ambient light to within ±30°, effectively blocking interference from side-incident ambient light. Combined with a 650nm narrowband filter, ambient light noise is reduced to 50LSB, significantly lower than the 200LSB of traditional optical FODs.

[0099] The foreign object detection process of the vehicle-mounted wireless charging device is described in detail below with reference to the first and second embodiments.

[0100] After charging, the control chip 6 performs a self-test to ensure normal operation of the vehicle-mounted wireless charging device. The control chip 6 alternates between a foreign object detection mode and an ambient lighting mode. When in the foreign object detection mode, the control chip 6 controls the multi-color LED array 3 to emit 650nm red light pulses at a frequency of 10Hz, with a pulse width of 1-5ms. When in the ambient lighting mode, the control chip 6 independently drives the R / G / B channels via a 1kHz PWM signal to produce an ambient lighting effect, while consuming less than 100mW.

[0101] After the vehicle-mounted wireless charging device self-checks, it enters ambient lighting mode. Every 100ms (i.e., 10Hz), the control chip 6 pauses the PWM signal output and switches to foreign object detection mode. At this time, the control chip 6 outputs 1-5ms 650nm red light pulses, and the photosensor 4 synchronously collects the signals.

[0102] The photosensor 4 transmits the collected signal to the control chip 6 , which calculates the characteristic vector F=[Savg, Smax, Smin, Svar] of multiple photosensor signals and compares the characteristic vector F with a reference pattern library to determine the charging area status.

[0103] If the average value Savg of the multiple photosensitive sensor signal vectors and the variance Svar of the multiple photosensitive sensor signal vectors are lower than the average value and variance of the reference pattern library, it indicates that the vehicle-mounted wireless charging device is in an idle state; if the variance Svar of the multiple photosensitive sensor signal vectors is lower than the variance of the reference pattern library, it indicates that the charging device 5 is placed normally; if the variance Svar of the multiple photosensitive sensor signal vectors is higher than the variance of the reference pattern library, or higher than the maximum value among the multiple photosensitive sensor signal vectors, it indicates that the charging device 5 is in an abnormal state.

[0104] If the vehicle-mounted wireless charging device is in an idle state, the control chip 6 switches to an ambient lighting mode.

[0105] If the charging device 5 is placed normally, the control chip 6 controls the wireless charging coil 2 to charge, and the color of the atmosphere light switches to a stable green breathing effect.

[0106] If the charging device 5 is in an abnormal state, the control chip 6 will not charge, the ambient light will switch to a red flashing effect, and / or a corresponding prompt tone will be played through the voice chip 9. The status will be continuously monitored until the abnormal condition is resolved.

[0107] During charging, the control chip 6 reads data from the accelerometer 8 at a frequency of 100 Hz to calculate the vehicle's tilt angle θ. If the tilt angle θ exceeds 15°, the control chip 6 controls the wireless charging coil 2 to suspend charging. Normal charging is resumed when the tilt angle θ reaches 15° or less.

[0108] like Figure 4 As shown in the figure, the reflected signal intensity comparison of the reflected LED pulse signal and the reflected ambient light (noise) is shown. The peak value of the 10Hz pulse signal is 7000LSB, and the reflected ambient noise is 350LSB, which verifies the high signal-to-noise ratio performance of the wireless charging device in the vehicle environment (SNR≈20 times). This value reflects the synergistic effect of the pulse light source (10Hz), distributed sensor (12° tilt) and pattern recognition algorithm, which is far more than 10 times that of the traditional optical FOD. Although this value is different from the theoretical SNR≈160 times, these differences are due to actual test conditions (noise 350LSB, signal 7000LSB) and hardware limitations (optical path loss), but 20 times still has a significant advantage.

[0109] To sum up, the vehicle-mounted wireless charging device provided by the present invention transmits a light signal of a specific wavelength through a multi-color LED array, and uses multiple tilted photosensors to synchronously collect the reflected light intensity, combined with the physical blocking effect of the optical shielding cover, to suppress ambient light interference while detecting foreign objects, thereby improving the accuracy and reliability of foreign object detection; the foreign object detection light source and the atmosphere light function are integrated on the same multi-color LED array, and the coordinated switching of the two functions is realized through the control chip, which reduces hardware redundancy and optimizes PCB space and cost.

[0110] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A vehicle-mounted wireless charging device, characterized in that: It includes a charging cavity, a wireless charging coil, a multi-color LED array, a plurality of light-sensitive sensors and a control chip, and an optical shielding cover arranged in the charging cavity; A PCB board is provided in the charging cavity and is located at the bottom of the charging cavity; The wireless charging coil is arranged on the PCB board; the multi-color LED array is arranged above the wireless charging coil; the multiple photosensors are arranged on the PCB board and distributed around the wireless charging coil; the optical shielding cover covers the multi-color LED array and the multiple photosensors and is fixed on the edge of the charging cavity, and a charging area is formed on the optical shielding cover for placing the charging device that needs to be charged; the control chip is arranged on the PCB board and is electrically connected to the multi-color LED array, the multiple photosensors and the wireless charging coil.

2. The vehicle-mounted wireless charging device according to claim 1, wherein: The multiple photosensors are photosensors with narrowband filters, and there are at least three of them; the multiple photosensors are installed at an angle of 10° to 15° relative to the PCB board.

3. The vehicle-mounted wireless charging device according to claim 1, wherein: The optical shielding cover is a fence-type structure.

4. The vehicle-mounted wireless charging device according to claim 1, wherein: It also includes a super capacitor and an accelerometer, and the super capacitor and the accelerometer are both arranged on one side of the PCB board.

5. A foreign object detection method for a vehicle-mounted wireless charging device, based on the vehicle-mounted wireless charging device according to any one of claims 1 to 4, characterized in that: include: S1. The control chip alternately executes the foreign object detection mode and the ambient lighting mode. When executing the foreign object detection mode, the multi-color LED array is controlled to emit detection light, and the reflected light signal of the charging area is collected through multiple photosensors; S2. analyzing the spatial distribution characteristics of the reflected light signal according to a pattern recognition algorithm; S3, judging the state of the charging area based on the spatial distribution characteristics, controlling the wireless charging coil to perform related operations, and the ambient lighting function of the multi-color LED array; The charging area status includes an idle state, a normal charging device placement state, and an abnormal state; the abnormal state includes the presence of foreign objects on the surface of the vehicle-mounted wireless charging device or improper placement of the charging device.

6. The foreign object detection method for a vehicle-mounted wireless charging device according to claim 5, wherein: Said S1 comprises: The multi-color LED array uses time division multiplexing to alternately execute the foreign object detection mode and the atmosphere lighting mode. When in the foreign object detection mode, the control chip controls the multi-color LED array to emit light of a specific wavelength; The time division multiplexing method includes: In the ambient lighting mode, the multi-color LED array is controlled by a PWM signal to generate ambient lighting; The atmosphere lighting mode is periodically paused and switched to the foreign object detection mode, so that the multi-color LED array emits detection light and collects reflection signals.

7. The foreign object detection method for a vehicle-mounted wireless charging device according to claim 6, wherein: The S2 includes: S21, the control chip collects signal vectors of multiple photosensors to form a comprehensive signal vector S, wherein the comprehensive signal vector S = [S0, S1, ..., Sn], where S0 is the signal vector of the first photosensor, S1 is the signal vector of the second photosensor, ..., Sn is the signal vector of the nth photosensor; S22. Calculate the characteristic vector F of the signal vector, wherein the characteristic vector F = [Savg, Smax, Smin, Svar], wherein Savg is the average value of the plurality of photosensitive sensor signal vectors, Smax is the maximum value of the plurality of photosensitive sensor signal vectors, Smin is the minimum value of the plurality of photosensitive sensor signal vectors, and Svar is the variance of the plurality of photosensitive sensor signal vectors. S23. Compare the feature vector F with a pre-stored or online learned reference pattern library. If the average value Savg of the multiple photosensor signal vectors and the variance Svar of the multiple photosensor signal vectors are lower than the average value and variance of the reference pattern library, it indicates that the vehicle-mounted wireless charging device is in an idle state. If the variance Svar of the signal vectors of the multiple photosensors is lower than the variance of the reference pattern library, it indicates that the charging device is placed normally; If the variance Svar of the plurality of photosensitive sensor signal vectors is higher than the variance of the reference pattern library, or higher than the maximum value of the plurality of photosensitive sensor signal vectors, it indicates that the charging device is in an abnormal state.

8. The foreign object detection method for a vehicle-mounted wireless charging device according to claim 7, wherein: The S3 includes: When the control chip determines that the vehicle-mounted wireless charging device is in an idle state, it controls the multi-color LED array to switch to the ambient lighting mode; When the control chip determines that the charging device is in a normal placement state, it starts the wireless charging coil to perform a charging operation and controls the multi-color LED array to provide ambient lighting in a first preset mode; When the control chip determines that it is in an abnormal state, the wireless charging coil is prohibited from performing a charging operation, and the multi-color LED array is controlled to provide warning lighting in a second preset mode.

9. The foreign object detection method for a vehicle-mounted wireless charging device according to claim 8, wherein: Said S3 further comprises: When the state of the charging area changes from a normal placement state of the charging device to an abnormal state, the control chip controls the wireless charging coil to immediately stop the wireless charging operation; When the state of the charging area changes from an abnormal state to a normal placement state of the charging device, the control chip controls the wireless charging coil to resume the wireless charging operation after a preset delay.

10. The foreign object detection method for a vehicle-mounted wireless charging device according to claim 5, wherein: The foreign body detection method further includes: The vehicle's posture is monitored through an accelerometer and the vehicle's tilt angle is calculated. When the vehicle's tilt angle is detected to exceed a preset threshold, the wireless charging operation is suspended and a visual prompt is issued through a multi-color LED array.

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