Method and system for detecting biological foreign matters through wireless charging of electric vehicle

Abstract

The invention discloses an electric vehicle wireless charging biological foreign matter detection method and system. The method comprises the following steps: acquiring a first target parameter variable quantity of a preset first detection coil; performing first preprocessing on the first parameter variable quantity of the first detection coil to obtain a second parameter variable quantity; obtaining an output result of the second parameter variation after the first preprocessing after preset first biological foreign matter invasion judgment logic judgment; and determining whether biological foreign matters invade or not during wireless charging of the electric vehicle according to an output result. And through accurate parameter acquisition and preprocessing, the detection accuracy is effectively improved, and the risk of false operation or missing operation is reduced. By adopting a multi-information detection technology, various parameter changes can be comprehensively considered, so that the existence of biological foreign matters can be more accurately judged, and the safety and the stability of the wireless charging system are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of biological foreign matter detection for wireless charging of electric vehicles, and in particular to a method and system for detecting biological foreign matter for wireless charging of electric vehicles. Background Art

[0002] Compared with the wired charging method of electric vehicles, wireless power transmission technology based on the principle of electromagnetic induction has the characteristics of high safety, small size, convenience and flexibility, and has therefore attracted widespread attention from researchers at home and abroad.

[0003] When the electric vehicle wireless charging system is working, there is a strong electromagnetic coupling area between the transmitting coil and the receiving coil. Therefore, any biological foreign matter entering this area will be affected by the high-intensity magnetic field, which may cause symptoms such as nausea, dizziness, limb weakness and high blood pressure. At the same time, the high-intensity magnetic field will also cause certain damage to the organism's own immune system and nervous system.

[0004] In order to ensure the safe and stable operation of the electric vehicle wireless charging system and the health of the organisms themselves, it is of great significance to study the biological foreign body detection technology in the electric vehicle wireless charging system. At present, the existing biological foreign body detection technology is mostly based on a single amount of information for judgment, and there are problems such as false operation or missed operation. In order to solve the problem of false operation or missed operation in the existing technology and improve the safety of the wireless charging system, a biological foreign body detection technology for electric vehicle wireless charging system based on multiple amounts of information is proposed. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides a method and system for detecting biological foreign matter in wireless charging of electric vehicles, which can solve the problems mentioned in the background technology.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides a method for detecting biological foreign matter in wireless charging of electric vehicles, comprising:

[0010] Obtaining a first target parameter change of a preset first detection coil;

[0011] Performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation;

[0012] Obtaining the output result of the second parameter change amount after the first preprocessing and after the preset first biological foreign body invasion judgment logic judgment;

[0013] It is determined whether there is biological foreign matter intrusion during wireless charging of the electric vehicle according to the output result.

[0014] As a preferred solution of the method for detecting biological foreign matter in wireless charging of electric vehicles described in the present invention, the preset first detection coil is configured at a first target position in the wireless charging area of ​​the electric vehicle.

[0015] As a preferred solution of the electric vehicle wireless charging biological foreign body detection method of the present invention, wherein: the first biological foreign body invasion judgment logic includes:

[0016] Determining the number of logic layers to be determined of the first biological foreign body invasion judgment logic according to the number of parameters of the second parameter change amount;

[0017] The number of logical layers to be determined is at least one.

[0018] As a preferred solution of the electric vehicle wireless charging biological foreign body detection method of the present invention, the step of obtaining the first target parameter change of the preset first detection coil includes:

[0019] The first detection coil generates a target high-frequency electromagnetic field through a target high-frequency excitation power supply;

[0020] The high-frequency electromagnetic field coverage area at least includes the electric vehicle wireless charging area;

[0021] When biological foreign matter invades, the first detection coil generates capacitive coupling with the biological foreign matter, and the value of the first target parameter of the first detection coil changes.

[0022] As a preferred solution of the method for detecting biological foreign matter in wireless charging of electric vehicles described in the present invention, the first detection coil is wound by a single wire, and a bipolar routing method is adopted to achieve mutual decoupling between the first detection coil and the transmitting coil. The area of ​​the first detection coil is larger than that of the transmitting coil, and the first detection coil and the transmitting coil are decoupled from each other.

[0023] As a preferred solution of the method for detecting biological foreign matter in wireless charging of electric vehicles according to the present invention, the first detection coil further includes:

[0024] The first detection coil includes a plurality of small detection coils, and the winding directions of every two adjacent small detection coils are opposite, and the current directions are also opposite, so that the magnetic field directions of adjacent coils are opposite, and the boundary between adjacent coils is the zero-crossing position of the magnetic induction intensity.

[0025] As a preferred solution of the method for detecting biological foreign matter in wireless charging of electric vehicles according to the present invention, wherein: the first pretreatment includes a first transformation and a second transformation;

[0026] The first target parameter variation is subjected to a first transformation using a parallel resonant amplifier circuit, and is subjected to a second transformation through analog-to-digital conversion and digital filtering.

[0027] In a second aspect, the present invention provides a biological foreign body detection system for wireless charging of electric vehicles, comprising:

[0028] A parameter acquisition module, used to acquire a first target parameter change of a preset first detection coil;

[0029] A preprocessing module, used for performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation;

[0030] A first judgment module is used to obtain the output result of the second parameter change after the first preprocessing after the first biological foreign body invasion judgment logic is preset;

[0031] The second judgment module is used to determine whether there is biological foreign matter intrusion during wireless charging of the electric vehicle according to the output result.

[0032] In a third aspect, the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned method when executing the computer program.

[0033] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method described above when executed by a processor.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a method and system for detecting biological foreign matter in wireless charging of electric vehicles, obtaining a first target parameter change of a preset first detection coil; performing a first preprocessing on the first parameter change of the first detection coil to obtain a second parameter change; obtaining the output result of the second parameter change after the first preprocessing after the preset first biological foreign matter invasion judgment logic; determining whether there is biological foreign matter invasion during wireless charging of the electric vehicle according to the output result. Through accurate parameter acquisition and preprocessing, the accuracy of detection is effectively improved, and the risk of false operation or missed operation is reduced. The multi-information detection technology adopted can comprehensively consider multiple parameter changes, thereby more accurately judging the presence of biological foreign matter and ensuring the safety and stability of the wireless charging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0036] Figure 1 A method flow chart of a method and system for detecting biological foreign matter in wireless charging of an electric vehicle provided by one embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the system structure of a method and system for detecting biological foreign matter in wireless charging of an electric vehicle provided by one embodiment of the present invention;

[0038] Figure 3 A structural diagram of a first detection coil of a method and system for detecting biological foreign matter in wireless charging of an electric vehicle provided by one embodiment of the present invention;

[0039] Figure 4 An equivalent circuit model of a first detection coil before and after biological foreign matter invasion of a biological foreign matter detection method and system for wireless charging of an electric vehicle provided by an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of FPGA signal filtering of a biological foreign body detection method and system for wireless charging of electric vehicles provided by one embodiment of the present invention;

[0041] Figure 6 A resonant amplification circuit diagram of a method and system for detecting biological foreign matter in wireless charging of an electric vehicle provided by one embodiment of the present invention;

[0042] Figure 7An experimental waveform diagram of the output voltage of the resonant amplifier circuit before and after the biological foreign matter invasion of a biological foreign matter detection method and system for wireless charging of an electric vehicle provided by one embodiment of the present invention;

[0043] Figure 8 A schematic diagram of the BP neural network biological foreign body classification principle of a method and system for detecting biological foreign bodies in wireless charging of electric vehicles provided by one embodiment of the present invention;

[0044] Fig. 9 A flow chart of a method and system for detecting biological foreign matter in wireless charging of an electric vehicle based on multi-information provided by one embodiment of the present invention;

[0045] Fig.10 An internal structural diagram of a computer device of a method and system for detecting biological foreign matter in wireless charging of an electric vehicle provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0047] Example 1

[0048] Reference Figure 1-Figure 10 , which is the first embodiment of the present invention, provides a method and system for detecting biological foreign matter in wireless charging of electric vehicles, comprising:

[0049] Before describing the embodiments of the present application in detail, some related concepts are first explained for the sake of clarity.

[0050] Wireless charging for electric vehicles: This refers to the technology that can charge electric vehicle batteries without physical contact. The charging process is to transfer energy through the electromagnetic field between the charging plate on the ground (transmitter) and the receiving device installed on the bottom of the car.

[0051] Foreign biological matter: in this context refers to any living matter, such as a human, animal or other organism, that accidentally enters the working area of ​​a wireless charging device and may pose a potential health risk due to the presence of electromagnetic fields.

[0052] Transmitter coil: In a wireless charging system, the transmitter coil is located in a ground station or a fixed device and is responsible for generating an electromagnetic field to transmit energy. It generates a changing magnetic field through alternating current, thereby achieving wireless energy transmission.

[0053] Receiver coil: This is the part of the electric vehicle that is designed to capture the electromagnetic field from the transmitter coil. The receiver coil converts the received energy into electrical energy, which is then fed into the vehicle's battery for charging. The receiver coil needs good electromagnetic coupling with the transmitter coil to effectively complete the energy transfer.

[0054] There are some problems and challenges in the existing related technologies, such as insufficient detection accuracy, high risk of false or missed actions, and inability to effectively distinguish biological and non-biological foreign objects. These problems may threaten the safety and stability of the wireless charging system, thus affecting the user experience and the reliability of the device.

[0055] The present application provides a method that can effectively solve the above-mentioned problems. Next, multiple embodiments will be combined to explain in detail how to implement the electric vehicle wireless charging biological foreign body detection method;

[0056] Figure 1 A method flow chart of a method and system for detecting biological foreign matter in wireless charging of electric vehicles is shown, including:

[0057] S101, obtaining a first target parameter change of a preset first detection coil;

[0058] In the embodiment of the present application, the preset first detection coil is configured at a first target position in the wireless charging area of ​​the electric vehicle.

[0059] In the embodiment of the present application, the first detection coil is configured in the wireless charging area of ​​the electric vehicle directly above the transmitting coil, so that the presence of biological foreign matter can be more effectively monitored. Because when biological foreign matter invades, the influence of the area directly above on the electromagnetic field will be more obvious.

[0060] In an optional embodiment, the first target position can be any position on the transmitting coil set in the wireless charging area of ​​the electric vehicle. The transmitting coil can be set in any position in the wireless charging area of ​​the electric vehicle, for example, on or near the ground charging plate. When the electric vehicle is parked on the charging plate, electromagnetic coupling is formed between the transmitting coil and the receiving coil to achieve wireless energy transmission. And the first detection coil can sense the electromagnetic field changes caused by the invasion of biological foreign matter, thereby triggering the detection mechanism.

[0061] In the embodiment of the present application, obtaining the first target parameter change of the preset first detection coil includes:

[0062] The first detection coil generates a target high-frequency electromagnetic field through a target high-frequency excitation power supply;

[0063] The high-frequency electromagnetic field coverage area at least includes the electric vehicle wireless charging area;

[0064] When biological foreign matter invades, the first detection coil generates capacitive coupling with the biological foreign matter, and the value of the first target parameter of the first detection coil changes.

[0065] In an optional embodiment, the first target parameter of the first detection coil may be an inductance value or a resistance value, and changes in these parameters can reflect the presence of biological foreign matter. When biological foreign matter invades the wireless charging area, due to its interaction with the electromagnetic field, the inductance or resistance of the coil will be changed, thereby causing the parameters of the detection coil to change. By monitoring the changes in these parameters, it can be determined whether there is biological foreign matter intrusion.

[0066] In the embodiment of the present application, a 3 MHz sinusoidal wave excitation is input to the first detection coil through a high-frequency excitation power supply, thereby forming a high-frequency electromagnetic field in the area above the first detection coil. After the biological foreign matter invades, capacitive coupling is formed between the detection coil, causing the coil impedance parameters to change.

[0067] In an optional embodiment, other high-frequency excitation power supplies can also be selected, and sine wave power supplies of different frequencies can be selected, or high-frequency excitation sources with non-sinusoidal waveforms can be used, such as square waves, triangle waves, or other waveforms suitable for exciting the detection coil and capable of effectively detecting biological foreign bodies. When selecting different excitation frequencies or waveforms, it should be considered whether the new excitation source will affect the sensitivity, selectivity, and overall performance of the detection system, and it is also necessary to ensure that the new excitation source complies with relevant safety standards and does not interfere with the operation of the wireless charging system. This choice can be based on the size, shape, and electromagnetic properties of the biological foreign body that the user or technician wants to detect to optimize the detection sensitivity and accuracy. In this application, considering the size, shape, and electromagnetic properties of humans, 3Mhz sine wave excitation is selected. Other relevant personnel can select different excitation power supplies according to specific needs. For example, when small animals need to be considered, a lower frequency excitation power supply can be selected to adapt to the electromagnetic properties of small animals. For example, a 1MHz square wave excitation can be used. This waveform is more sensitive to the detection of small animals because their electromagnetic properties are different from those of humans. Lower frequency excitation can better couple with the biological electromagnetic field of small animals, thereby improving the sensitivity of detection.

[0068] In an optional embodiment, if the method of the present application is used in other different scenarios, for example, in a hospital or laboratory environment, it may be encountered that the biological foreign matter to be detected has different electromagnetic properties. At this time, it may be considered to use an excitation source of a specific frequency to optimize the detection effect. For example, for certain specific microorganisms or cells, an excitation source in the microwave frequency band may be used, because the electromagnetic properties of these organisms may have a more obvious response in the microwave frequency band. In addition, the waveform and intensity of the excitation source can be adjusted according to the size and shape of the biological foreign matter to achieve more accurate detection.

[0069] When implementing the electric vehicle wireless charging biological foreign body detection method and system of the present invention, it is also possible to consider arranging multiple detection coils at different positions to form a detection network. This not only improves the coverage of the detection, but also allows the specific location of the biological foreign body to be located by the changes in the parameters of the multiple coils. For example, one set of detection coils can be arranged at the bottom of the electric vehicle, and the other set can be arranged on the ground charging plate. By comparing the parameter changes of the two sets of coils, the location and size of the biological foreign body can be more accurately determined.

[0070] In an embodiment of the present application, the first detection coil is wound by a single wire, and a bipolar routing method is adopted to achieve mutual decoupling between the first detection coil and the transmitting coil. The area of ​​the first detection coil is larger than that of the transmitting coil, and the first detection coil and the transmitting coil are decoupled from each other.

[0071] In an embodiment of the present application, the first detection coil also includes: the first detection coil includes a plurality of small detection coils, the winding directions of every two adjacent small detection coils are opposite, and the current directions are also opposite, so that the magnetic field directions of adjacent coils are opposite, and the boundary between adjacent coils is the zero-crossing position of the magnetic induction intensity.

[0072] Specifically, Figure 2 The figure shows the structure of the first detection coil, with the black color representing the top wiring and the gray color representing the bottom wiring. The entire detection coil is wound by a single wire with a wire width of 2 mm, and the number of small detection coils is M × N. In order to make the detection coil generate a bipolar detection excitation magnetic field, the winding directions of every two adjacent small coils are opposite, and the current directions are also opposite, so that the magnetic field directions of adjacent coils are opposite, and the boundary of adjacent coils is the zero-crossing position of the magnetic induction intensity.

[0073] It should be noted that this bipolar wiring method can effectively reduce the electromagnetic interference of the transmitting coil to the detection coil and improve the accuracy of detection. In addition, since the area of ​​the first detection coil is larger than that of the transmitting coil, it can cover a wider area, thereby increasing the sensitivity and coverage of the detection.

[0074] In an optional embodiment, the detection performance can also be optimized by adjusting the number M×N of small detection coils to accommodate biological foreign bodies of different sizes and shapes. For example, when the biological foreign body to be detected is large in volume, the number of small detection coils can be increased to improve the sensitivity of the detection. On the contrary, if the target biological foreign body is small, the number of small detection coils can be reduced to enhance the resolution of the detection. In addition, the accuracy and efficiency of the detection can be further improved by optimizing the layout of the small detection coils. For example, non-uniformly distributed small detection coils can be used to increase the density of the detection coils in areas where biological foreign bodies may appear, and reduce the density of the detection coils in areas where biological foreign bodies are unlikely to appear, thereby reducing the complexity and cost of the system while ensuring the detection effect.

[0075] It should be noted that the single-wire winding detection coil in the present invention only requires a single-layer detection coil, avoiding the high cost and severe crosstalk caused by the traditional multi-layer detection coil. At the same time, since the detection coil is wound with a single wire, there is no need to switch the coil and an excitation magnetic field with a larger detection area can be generated.

[0076] S102, performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation;

[0077] In the embodiment of the present application, the first preprocessing includes a first transformation and a second transformation;

[0078] The first target parameter variation is subjected to a first transformation using a parallel resonant amplifier circuit, and is subjected to a second transformation through analog-to-digital conversion and digital filtering.

[0079] In an optional embodiment, when the first parameter change is the impedance change of the first detection coil, the corresponding first transformation is to use a parallel resonant amplifier circuit to transform the impedance change of the first detection coil into a voltage change, and the corresponding second transformation is to obtain a voltage U after being collected by an ADC module and processed by FPGA digital filtering. k The amplitude, phase and frequency changes of the current are obtained. When the first parameter change is the current change, the corresponding first transformation is to convert the current change into a voltage change through a parallel resonant amplifier circuit, and the second transformation is to convert the voltage change into a digital signal through an analog-to-digital converter (ADC), and obtain the amplitude, phase and frequency changes of the current change after digital filtering. This processing method can effectively extract characteristic signals related to biological foreign matter, thereby improving the accuracy and reliability of detection.

[0080] It should be noted that if the relevant technical personnel select other first target parameter changes and obtain the corresponding second target parameter changes through preprocessing means, and the subsequent threshold judgment operations are the same, then the method adopted by the relevant technical personnel should be within the scope of our protection.

[0081] In the embodiment of the present application, the first parameter change is the impedance change of the first detection coil. Figure 4 Shown Figure 4 is the equivalent circuit model of the detection coil before and after biological foreign bodies invade. Since the detection coil is wound by a wire and contains multiple small coils connected in series in reverse order, such as Figure 4 As shown in (a), when biological foreign matter has not invaded, it can be equivalent to a resistor connected in series with multiple inductors, and the impedance expression is:

[0082] Z noLO =R D +jωL D

[0083] Among them, L D is the total inductance of multiple small coils in series, R D To detect the internal resistance of the coil, Z noLO is the impedance of the detection coil when there is no biological foreign body invading, and ω is the high-frequency excitation frequency of the detection coil.

[0084] Furthermore, after the biological foreign matter invades, it will produce capacitive coupling with the detection coil, increasing the stray capacitance of the detection coil, such as Figure 4 As shown in (b), the impedance expression of the detection coil is:

[0085]

[0086] Among them, Z LO is the impedance of the detection coil after the invasion of biological foreign matter, C LO It is the stray capacitance of the detection coil after the invasion of biological foreign matter.

[0087] Furthermore, after the invasion of biological foreign matter, the equivalent resistance and equivalent inductance of the detection coil will increase, thereby affecting the voltage amplitude, phase, and frequency parameters. Figure 5 This is the schematic diagram of FPGA signal filtering, using a non-recursive (FIR) filter, also known as a finite length unit impulse filter. The relationship between the output of the FIR filter of length N and the time series x(n) is given in the form of a finite convolution sum, as follows:

[0088]

[0089] Among them, y(n) is the filter output signal, h(k) is the unit impulse response sequence, and k is the unit impulse response sequence number.

[0090] Furthermore, the input signal of the FIR filter is time-dependent and changes with time. The final output signal of the filter is the input at each moment multiplied by the corresponding weight, and then superimposed and output.

[0091] Furthermore, Figure 6 It is a resonant amplifier circuit diagram, which is essentially a reverse amplifier circuit. ex is the high frequency excitation power supply, R 1 is the amplification matching resistor, L D and R D To detect the equivalent inductance and equivalent resistance of the coil, C LO The stray capacitance added to the detection coil after biological foreign bodies invade, C r The detection coil series resonant compensation capacitor, U k is the output voltage of the resonant amplifier circuit. When biological foreign matter invades, the detection coil and the series resonant compensation capacitor will deviate from the resonant state, resulting in the output voltage U k change.

[0092] Furthermore, Figure 7 The output voltage experimental waveform of the resonant amplifier circuit before and after the invasion of biological foreign matter. Among them, Uref is the output voltage reference waveform before the invasion of biological foreign matter, and Uk is the output voltage waveform after the invasion of biological foreign matter. It can be seen that after the invasion of biological foreign matter, the amplitude of the output voltage of the resonant amplifier circuit decreases, the phase increases, and the frequency decreases, so it can effectively detect biological foreign matter in the electric vehicle wireless charging system.

[0093] It should be noted that the benefit of performing a first preprocessing on the first parameter variation of the first detection coil to obtain the second parameter variation is that the response speed and accuracy of the detection system can be significantly improved. Through this preprocessing method, the system can quickly identify the presence of biological foreign matter and accurately locate its position. In addition, due to the use of a parallel resonant amplifier circuit, the system can effectively reduce noise interference and improve the signal-to-noise ratio when processing signals, thereby further enhancing the reliability of detection.

[0094] In practical applications, this detection method and system can be widely used in wireless charging stations for electric vehicles to provide a safe charging environment for vehicles. By real-time monitoring of biological foreign matter during the charging process, the system can issue an alarm in time to prevent charging accidents caused by foreign matter interference and ensure the safety and stability of the charging process.

[0095] S103, obtaining an output result of the second parameter variation after the first preprocessing and judging it through a preset first biological foreign body invasion judgment logic;

[0096] In the embodiment of the present application, the first biological foreign body invasion judgment logic includes:

[0097] Determining the number of logic layers to be determined of the first biological foreign body invasion judgment logic according to the number of parameters of the second parameter change amount;

[0098] The number of logical layers to be determined is at least one.

[0099] In the embodiment of the present application, because the impedance change of the first detection coil is selected, the number of parameters of the second parameter change is three, namely, the amplitude, phase, and frequency change, so the number of logic layers to be judged of the first biological foreign body invasion judgment logic is set to 3 layers;

[0100] In an optional embodiment, the number of parameters of the second parameter change can also be other numbers. If the number of parameters of the second parameter change is four, for example, including amplitude, phase, frequency and resonance point offset, then the number of logic layers to be judged of the first biological foreign body invasion judgment logic is correspondingly set to 4 layers. Each layer of logic is responsible for processing the change of a parameter and judging whether there is a biological foreign body by comparing the actual measured value with the preset threshold. For example, the first layer of logic is responsible for judging whether the amplitude change exceeds the set threshold, the second layer of logic is responsible for judging the phase change, and so on. When all logic layers confirm the presence of biological foreign bodies, the system will output an alarm signal for biological foreign body invasion.

[0101] In the embodiment of the present application, three specific judgment thresholds corresponding to the number of logic layers to be judged are set, which are recorded as the first voltage amplitude threshold, the second voltage phase threshold and the third voltage frequency threshold, and the logic judgment is performed in the order of the first, second and third. The reason for judging in the order of amplitude, phase and frequency is that the changes of these three parameters when biological foreign bodies invade have a certain order and correlation. First, the invasion of biological foreign bodies will cause the change of the impedance of the detection coil, which is mainly reflected in the change of amplitude. When the foreign body approaches or contacts the coil, due to the principle of electromagnetic induction, the impedance of the coil will increase, resulting in a decrease in the current passing through the coil, thereby causing a decrease in amplitude. Therefore, the amplitude is the primary parameter for judging the invasion of foreign bodies. Secondly, as the foreign body approaches further, the phase of the coil will also change. This is because the foreign body changes the electromagnetic field distribution of the coil, thereby affecting the phase of the current. The change in phase usually occurs after the change in amplitude, so it serves as the second judgment logic layer. Finally, the change in frequency is due to the change in the resonant frequency of the coil by the foreign body. When the foreign body is coupled with the coil, the resonant frequency of the coil will deviate from the original value, resulting in a change in frequency. Since the change of frequency usually takes a certain amount of time to accumulate, it serves as the third judgment logic layer.

[0102] Specifically, when the voltage amplitude is less than the first voltage amplitude threshold, it is necessary to re-perform biological foreign body intrusion detection. When the voltage amplitude is greater than the first voltage amplitude threshold, the second level of judgment, namely, voltage phase judgment, is performed. If the voltage phase is less than the second voltage phase threshold, it is necessary to re-perform biological foreign body intrusion detection. When the voltage phase is greater than the second voltage phase threshold, the third level of judgment, namely, voltage frequency judgment, is performed. If the voltage frequency is less than the third voltage frequency threshold, it is necessary to re-perform biological foreign body intrusion detection. When the voltage frequency is greater than the third voltage frequency threshold, it is determined that biological foreign body intrusion has occurred, and the electric vehicle wireless charging device is turned off at this time.

[0103] In an optional embodiment, other technicians may not perform the operations in this order.

[0104] It should be noted that if the first preprocessing step is not required, the first parameter change amount is the second parameter change amount, which is one layer.

[0105] S104, determining whether there is any biological foreign matter intrusion during wireless charging of the electric vehicle based on the output result.

[0106] In an embodiment of the present application, when the voltage amplitude is less than the first voltage amplitude threshold, it is necessary to re-perform biological foreign body intrusion detection. When the voltage amplitude is greater than the first voltage amplitude threshold, the second level of judgment, i.e., voltage phase judgment, is performed. If the voltage phase is less than the second voltage phase threshold, it is necessary to re-perform biological foreign body intrusion detection. When the voltage phase is greater than the second voltage phase threshold, the third level of judgment, i.e., voltage frequency judgment, is performed. If the voltage frequency is less than the third voltage frequency threshold, it is necessary to re-perform biological foreign body intrusion detection. When the voltage frequency is greater than the third voltage frequency threshold, it is determined that biological foreign body intrusion has occurred, and the electric vehicle wireless charging device is turned off at this time.

[0107] In summary, the present invention proposes a biological foreign body detection method for wireless charging of electric vehicles, which includes obtaining a first target parameter change of a preset first detection coil; performing a first preprocessing on the first parameter change of the first detection coil to obtain a second parameter change; obtaining the output result of the second parameter change after the first preprocessing after being judged by a preset first biological foreign body invasion judgment logic; and determining whether there is biological foreign body invasion during wireless charging of the electric vehicle according to the output result. Through accurate parameter acquisition and preprocessing, the accuracy of detection is effectively improved, and the risk of false operation or missed operation is reduced. The multi-information detection technology adopted can comprehensively consider multiple parameter changes, thereby more accurately judging the presence of biological foreign bodies and ensuring the safety and stability of the wireless charging system.

[0108] This embodiment also provides an electric vehicle wireless charging biological foreign body detection system, including:

[0109] A parameter acquisition module, used to acquire a first target parameter change of a preset first detection coil;

[0110] A preprocessing module, used for performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation;

[0111] A first judgment module is used to obtain the output result of the second parameter change after the first preprocessing after the first biological foreign body invasion judgment logic is preset;

[0112] The second judgment module is used to determine whether there is biological foreign matter intrusion during wireless charging of the electric vehicle according to the output result.

[0113] The above-mentioned unit modules may be embedded in or independent of the processor in the computer device in the form of hardware, or may be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0114] This embodiment also provides a computer device, which may be a terminal, and its internal structure diagram may be as shown in FIG. Fig.10 As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a method for detecting biological foreign matter in wireless charging of an electric vehicle is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0115] This embodiment further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0116] Obtaining a first target parameter change of a preset first detection coil;

[0117] Performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation;

[0118] Obtaining the output result of the second parameter change amount after the first preprocessing and after the preset first biological foreign body invasion judgment logic judgment;

[0119] Based on the output results, it is determined whether there is biological foreign matter intrusion during wireless charging of electric vehicles.

[0120] Example 2

[0121] Reference Figure 2-Figure 9 , which is an embodiment of the present invention, provides a method and system for detecting biological foreign matter in wireless charging of electric vehicles. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0122] like Figure 2 As shown, the present invention proposes a biological foreign body detection method for wireless charging of electric vehicles based on multi-information, characterized by: comprising a biological foreign body detection algorithm 1, a parallel resonant amplifier circuit 2, a single-wire winding detection coil 3 (i.e., a first detection coil), and a high-frequency excitation power supply 4. The detection method is as follows: the single-wire winding detection coil 3 is wound by a single PCB wire, and a bipolar routing method is adopted, and a 3Mhz sine wave excitation is input to it through a high-frequency excitation power supply 4, so that a high-frequency electromagnetic field is formed in the area above the first detection coil. After the biological foreign body invades, a capacitive coupling is formed between the first detection coil, so that the coil impedance parameter changes. Then, the parallel resonant amplifier circuit 2 converts the coil impedance change into a voltage change, and the amplitude, phase, and frequency change of the voltage Uk are obtained after being collected by the ADC module and processed by the FPGA digital filter. In the BP neural network, it is compared with the set threshold to determine whether there is biological foreign body invasion.

[0123] Figure 3 It is a single-wire winding detection coil structure (i.e., the first detection coil structure), black is the top wiring, gray is the bottom wiring, the entire detection coil is wound by a single wire, the wire width is 2 mm, and the number of small detection coils is M × N. In order to make the detection coil generate a bipolar detection excitation magnetic field, the winding direction of every two adjacent small coils is opposite, and the current direction is also opposite, so that the magnetic field directions of adjacent coils are opposite, and the boundary of adjacent coils is the zero-crossing position of the magnetic induction intensity.

[0124] Figure 4 is the equivalent circuit model of the detection coil before and after biological foreign bodies invade. Since the detection coil is wound by a wire and contains multiple small coils connected in series in reverse order, such as Figure 4 As shown in (a), when biological foreign matter has not invaded, it can be equivalent to a resistor connected in series with multiple inductors, and the impedance expression is:

[0125] Z noLO =R D +jωL D

[0126] Among them, LD is the total inductance of multiple small coils in series, R D To detect the internal resistance of the coil, Z noLO is the impedance of the detection coil when there is no biological foreign body invading, and ω is the high-frequency excitation frequency of the detection coil.

[0127] After biological foreign matter invades, it will produce capacitive coupling with the detection coil, increasing the stray capacitance of the detection coil, such as Figure 4 As shown in (b), the impedance expression of the detection coil is:

[0128]

[0129] Among them, Z LO is the impedance of the detection coil after the invasion of biological foreign matter, C LO It is the stray capacitance of the detection coil after the invasion of biological foreign matter.

[0130] It can be seen that after the invasion of biological foreign matter, the equivalent resistance and equivalent inductance of the detection coil will increase, thereby affecting the voltage amplitude, phase, and frequency parameters.

[0131] Figure 5 This is the schematic diagram of FPGA signal filtering, using a non-recursive (FIR) filter, also known as a finite length unit impulse filter. The relationship between the output of the FIR filter of length N and the time series x(n) is given in the form of a finite convolution sum, as follows:

[0132]

[0133] Among them, y(n) is the filter output signal, h(k) is the unit impulse response sequence, and k is the unit impulse response sequence number.

[0134] It can be seen that the input signal of the FIR filter is time-dependent and changes with time. The final output signal of the filter is the input at each moment multiplied by the corresponding weight, and then superimposed and output.

[0135] Figure 6 It is a resonant amplifier circuit diagram, which is essentially a reverse amplifier circuit. ex is the high frequency excitation power supply, R 1 is the amplification matching resistor, L D and R D To detect the equivalent inductance and equivalent resistance of the coil, C LO The stray capacitance added to the detection coil after biological foreign bodies invade, C r The detection coil series resonant compensation capacitor, U k is the output voltage of the resonant amplifier circuit. When biological foreign matter invades, the detection coil and the series resonant compensation capacitor will deviate from the resonant state, resulting in the output voltage U kchange.

[0136] Table 1 shows the detection coil and circuit parameters, where the detection coil excitation voltage frequency f ex is 1.02Mhz, high frequency excitation voltage U ex Amplitude 50mV

[0137] Table 1 Detection coil and circuit parameters

[0138]

[0139] Figure 7 It is the experimental waveform of the output voltage of the resonant amplifier circuit before and after the invasion of biological foreign matter. ref is the output voltage reference waveform before biological foreign matter invades, U k This is the output voltage waveform after biological foreign matter invades. It can be seen that after biological foreign matter invades, the amplitude of the output voltage of the resonant amplifier circuit decreases, the phase increases, and the frequency decreases, so biological foreign matter in the electric vehicle wireless charging system can be effectively detected.

[0140] Figure 8 This is the principle of biological foreign body classification using BP neural network. BP neural network is a multi-layer network including input layer, hidden layer and output layer. After the biological foreign body detection system starts working, the output voltage amplitude, phase and frequency change of the resonance amplifier circuit are input into the BP neural network as three characteristic parameters. The input parameters are propagated to the output layer through the hidden layer. If the actual output value is too far from the expected value, the gradient descent method is used to reversely propagate from the output layer, and the weighted values ​​in the hidden layer are adjusted iteratively until the output error is reduced to an acceptable level.

[0141] Fig. 9 The flowchart of biological foreign body detection based on multi-information electric vehicle wireless charging is shown in FIG. After the electric vehicle wireless charging system starts to transmit electric energy at rated power, the biological foreign body detection system also starts to work, and determines whether there is biological foreign body invasion by continuously comparing the voltage amplitude, phase, and frequency parameters with the threshold. If it is determined that there is biological foreign body, the electric vehicle wireless charging system is immediately shut down. Specifically, the electric vehicle starts wireless charging at rated power 200, the biological foreign body detection system starts to work 201, and enters the judgment link 202 to determine whether the voltage amplitude change exceeds the threshold. If it exceeds, it enters 203 to determine whether the voltage phase change exceeds the threshold. If not, it returns to 201. If the voltage phase change exceeds the threshold, it enters 204 to determine whether the voltage frequency change exceeds the threshold. If not, it returns to 201. If it exceeds, it is determined that biological foreign body invasion occurs, and the electric vehicle shuts down the wireless charging system.

[0142] In summary, the present invention proposes a biological foreign body detection method for wireless charging of electric vehicles, which obtains the first target parameter change of a preset first detection coil; performs a first preprocessing on the first parameter change of the first detection coil to obtain a second parameter change; obtains the output result of the second parameter change after the first preprocessing after the preset first biological foreign body invasion judgment logic; and determines whether there is biological foreign body invasion during wireless charging of the electric vehicle according to the output result. Through accurate parameter acquisition and preprocessing, the accuracy of detection is effectively improved and the risk of false operation or missed operation is reduced. The multi-information detection technology adopted can comprehensively consider multiple parameter changes, thereby more accurately judging the presence of biological foreign bodies and ensuring the safety and stability of the wireless charging system.

[0143] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0144] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0145] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0146] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0148] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0149] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for detecting biological foreign matter in wireless charging of electric vehicles, characterized in that: include: Obtaining a first target parameter change of a preset first detection coil; Performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation; Obtaining the output result of the second parameter change amount after the first preprocessing and after the preset first biological foreign body invasion judgment logic judgment; It is determined whether there is biological foreign matter intrusion during wireless charging of the electric vehicle according to the output result.

2. The method for detecting biological foreign matter in wireless charging of electric vehicles according to claim 1, characterized in that: The preset first detection coil is configured at a first target position in the wireless charging area of ​​the electric vehicle.

3. The method for detecting biological foreign matter in wireless charging of electric vehicles according to claim 2, characterized in that: The first biological foreign body invasion judgment logic includes: Determining the number of logic layers to be determined of the first biological foreign body invasion judgment logic according to the number of parameters of the second parameter change amount; The number of logical layers to be determined is at least one.

4. The method for detecting biological foreign matter in wireless charging of electric vehicles according to claim 3, characterized in that: The obtaining of the first target parameter change of the preset first detection coil comprises: The first detection coil generates a target high-frequency electromagnetic field through a target high-frequency excitation power supply; The high-frequency electromagnetic field coverage area at least includes the electric vehicle wireless charging area; When biological foreign matter invades, the first detection coil generates capacitive coupling with the biological foreign matter, and the value of the first target parameter of the first detection coil changes.

5. The method for detecting biological foreign matter in wireless charging of electric vehicles as claimed in claim 4, characterized in that: The first detection coil is wound by a single wire and adopts a bipolar routing method to achieve mutual decoupling between the first detection coil and the transmitting coil. The area of ​​the first detection coil is larger than that of the transmitting coil, and the first detection coil and the transmitting coil are decoupled from each other.

6. The method for detecting biological foreign matter in wireless charging of electric vehicles as claimed in claim 5, characterized in that: The first detection coil also includes: The first detection coil includes a plurality of small detection coils, and the winding directions of every two adjacent small detection coils are opposite, and the current directions are also opposite, so that the magnetic field directions of adjacent coils are opposite, and the boundary between adjacent coils is the zero-crossing position of the magnetic induction intensity.

7. The method for detecting biological foreign matter in wireless charging of electric vehicles according to claim 6, characterized in that: The first pretreatment includes a first transformation and a second transformation; The first target parameter variation is subjected to a first transformation using a parallel resonant amplifier circuit, and is subjected to a second transformation through analog-to-digital conversion and digital filtering.

8. A biological foreign body detection system for wireless charging of electric vehicles, characterized in that: include: A parameter acquisition module, used to acquire a first target parameter change of a preset first detection coil; A preprocessing module, used for performing a first preprocessing on the first parameter variation of the first detection coil to obtain a second parameter variation; A first judgment module is used to obtain the output result of the second parameter change after the first preprocessing after the first biological foreign body invasion judgment logic is preset; The second judgment module is used to determine whether there is biological foreign matter intrusion during wireless charging of the electric vehicle according to the output result.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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