Method and device for determining state of charge of a battery, test device

Abstract

The application discloses a battery state of charge determination method and device, and test equipment. The method comprises the following steps: collecting a first type of ultrasonic signal of an ultrasonic wave passing through a battery shell water model, and collecting a second type of ultrasonic signal of an ultrasonic wave passing through a battery, wherein the target attribute of the battery shell water model is the same as the target attribute of the battery, and the shell of the battery shell water model is filled with liquid; obtaining a first frequency spectrum corresponding to the first type of ultrasonic signal and a second frequency spectrum corresponding to the second type of ultrasonic signal; determining a frequency band difference curve according to the first frequency spectrum and the second frequency spectrum; and determining the battery state of charge of the battery according to the frequency band difference curve. The application solves the technical problem that the state of charge of a battery with a small open circuit voltage influence on the battery state of charge is not accurately estimated due to the related art estimating the battery state of charge based on the open circuit voltage of the battery.

Description

Technical Field

[0001] This application relates to the field of industrial ultrasonic testing technology, and more specifically, to a method and apparatus for determining the state of charge of a battery, and testing equipment. Background Technology

[0002] With the development of new energy technologies, lithium batteries, widely used in new energy vehicles, consumer electronics, and aerospace, have received widespread attention. The state of charge (SOC) is a crucial monitoring indicator in battery management systems. Accurate SOC estimation facilitates the estimation of lithium-ion battery range, improves charge and discharge efficiency, and extends battery life. Current methods for estimating SOC rely on the relationship between open-circuit voltage (OCV) and SOC. However, for batteries such as lithium iron phosphate and lithium titanate systems, where open-circuit voltage does not significantly affect SOC, accurate SOC estimation is not feasible.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This application provides a method, apparatus, and testing equipment for determining the state of charge (SOC) of a battery, in order to at least solve the technical problem that the SOC estimation of batteries with SOC that is less affected by open-circuit voltage is inaccurate due to the fact that related technologies estimate the SOC based on the open-circuit voltage of the battery.

[0005] According to one aspect of the embodiments of this application, a method for determining the state of charge of a battery is provided, comprising: acquiring a first type of ultrasonic signal of ultrasonic waves passing through a water model of a battery casing, and acquiring a second type of ultrasonic signal of ultrasonic waves passing through the battery, wherein the target properties of the water model of the battery casing are the same as the target properties of the battery, and the interior of the water model of the battery casing is filled with liquid; acquiring a first spectrum corresponding to the first type of ultrasonic signal and a second spectrum corresponding to the second type of ultrasonic signal; determining a frequency band difference curve based on the first spectrum and the second spectrum; and determining the state of charge of the battery based on the frequency band difference curve.

[0006] Optionally, obtaining the first spectrum corresponding to the first type of ultrasound signal and the second spectrum corresponding to the second type of ultrasound signal includes: determining the first average value of the first type of ultrasound signal and the second average value of the second type of ultrasound signal; deleting ultrasound signals in the first type of ultrasound signal whose signal value is equal to the first average value to obtain the third type of ultrasound signal; and deleting ultrasound signals in the second type of ultrasound signal whose signal value is equal to the second average value to obtain the fourth type of ultrasound signal; and processing the third type of ultrasound signal and the fourth type of ultrasound signal respectively to obtain the first spectrum and the second spectrum.

[0007] Optionally, the third type of ultrasound signal and the fourth type of ultrasound signal are processed separately to obtain a first spectrum and a second spectrum; including: determining a first normalization range; normalizing the third type of ultrasound signal and the fourth type of ultrasound signal according to the first normalization range to obtain normalized third type of ultrasound signal and normalized fourth type of ultrasound signal; performing a Fourier transform on the normalized third type of ultrasound signal to obtain the first spectrum, and performing a Fourier transform on the normalized fourth type of ultrasound signal to obtain the second spectrum.

[0008] Optionally, determining the frequency band difference curve based on the first spectrum and the second spectrum includes: determining the upper limit frequency and the lower limit frequency of the frequency band, and determining the second normalization range based on the upper limit frequency and the lower limit frequency of the frequency band; and normalizing the first spectrum and the second spectrum according to the second normalization range to obtain the normalized first spectrum and the normalized second spectrum.

[0009] Optionally, determining the frequency band difference curve based on the normalized first spectrum and the second spectrum includes: determining the ratio of the amplitude of the normalized first spectrum to the normalized second spectrum at the same frequency; determining multiple first coordinate points corresponding to multiple ratios in a coordinate system, and determining the frequency band difference curve based on the multiple first coordinate points, wherein the horizontal axis of the coordinate system is the frequency and the vertical axis of the coordinate system is the ratio.

[0010] Optionally, determining the frequency band difference curve based on the normalized first and second spectra further includes: determining the difference in amplitude between the normalized first and second spectra at the same frequency; determining multiple second coordinate points corresponding to the multiple differences in the coordinate system; and determining the frequency band difference curve based on the multiple second coordinate points.

[0011] Optionally, determining the battery state of charge (SOC) based on the frequency band difference curve includes: determining the slope of the frequency band difference curve and defining the slope as a frequency band difference parameter; determining the battery SOC based on the frequency band difference parameter, wherein the frequency band difference parameter and the battery SOC are directly proportional.

[0012] According to another aspect of the embodiments of this application, a method for displaying the state of charge of a battery is also provided, comprising: displaying a first spectrum corresponding to a first type of ultrasonic signal and a second spectrum corresponding to a second type of ultrasonic signal in an interface, wherein the first type of ultrasonic signal is an ultrasonic signal of ultrasonic waves passing through a battery casing water model, the second type of ultrasonic signal is an ultrasonic signal of ultrasonic waves passing through the battery, the target properties of the battery casing water model are the same as the target properties of the battery, and the interior of the battery casing water model is filled with liquid; displaying a frequency band difference curve determined based on the first spectrum and the second spectrum in the interface; and displaying a curve reflecting the state of charge of the battery determined based on the frequency band difference curve in the interface.

[0013] According to another aspect of the embodiments of this application, a testing device is also provided, including: a controller, a first ultrasonic probe, a second ultrasonic probe, and a battery casing water model, wherein the first ultrasonic probe and the second ultrasonic probe are respectively attached to opposite sides of the battery casing water model; the first ultrasonic probe and the second ultrasonic probe are respectively attached to opposite sides of the battery to be tested; the controller is used to execute the above-described method for determining the state of charge of the battery; the target properties of the battery casing water model are the same as the target properties of the battery, and the interior of the battery casing water model is filled with liquid.

[0014] According to another aspect of the embodiments of this application, a device for determining the state of charge of a battery is also provided, comprising: a acquisition module, configured to acquire a first type of ultrasonic signal of ultrasonic waves passing through a water model of a battery casing, and to acquire a second type of ultrasonic signal of ultrasonic waves passing through the battery, wherein the target attribute of the water model of the battery casing is the same as the target attribute of the battery, and the interior of the shell of the water model of the battery casing is filled with liquid; an acquisition module, configured to acquire a first spectrum corresponding to the first type of ultrasonic signal and a second spectrum corresponding to the second type of ultrasonic signal; a first determination module, configured to determine a frequency band difference curve based on the first spectrum and the second spectrum; and a second determination module, configured to determine the state of charge of the battery based on the frequency band difference curve.

[0015] According to another aspect of the embodiments of this application, a non-volatile storage medium is also provided, which stores a computer program, wherein the device containing the non-volatile storage medium executes the above-described method for determining the state of charge of a battery by running the computer program.

[0016] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to execute the above-described method for determining the state of charge of a battery through the computer program.

[0017] In this embodiment, a first type of ultrasonic signal is acquired by collecting ultrasonic waves passing through a water model of a battery casing, and a second type of ultrasonic signal is acquired by collecting ultrasonic waves passing through the battery. The target attributes of the water model of the battery casing are the same as the target attributes of the battery, and the interior of the water model of the battery casing is filled with liquid. A first spectrum corresponding to the first type of ultrasonic signal and a second spectrum corresponding to the second type of ultrasonic signal are obtained. A frequency band difference curve is determined based on the first spectrum and the second spectrum. The battery state of charge (SOC) of the battery is determined based on the frequency band difference curve. By using the ultrasonic signal of ultrasonic waves passing through the water model of the battery casing as a reference signal, the influence of the battery casing on the ultrasonic transmission signal is eliminated when using the ultrasonic signal of ultrasonic waves passing through the battery to estimate the SOC. This achieves the technical effect of accurately estimating the battery SOC, and solves the technical problem of inaccurate SOC estimation for batteries whose SOC is less affected by open circuit voltage due to related technologies that estimate the battery SOC based on the battery open circuit voltage. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 This is a hardware structure block diagram of a computer terminal (or mobile device) for implementing a method for determining the state of charge of a battery, according to an embodiment of this application.

[0020] Figure 2 This is a flowchart of a method for determining the state of charge of a battery according to an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of a frequency band difference curve according to an embodiment of this application;

[0022] Figure 4 This is a flowchart of a method for demonstrating the state of charge of a battery according to an embodiment of this application;

[0023] Figure 5 This is a visual schematic diagram of an ultrasonic signal according to an embodiment of this application;

[0024] Figure 6 This is a schematic diagram of a frequency band difference parameter-battery state of charge curve according to an embodiment of this application;

[0025] Figure 7 This is a structural diagram of a testing device according to an embodiment of this application;

[0026] Figure 8 This is a structural diagram of a battery state of charge determination device according to an embodiment of this application;

[0027] Figure 9 This is a flowchart of a battery state of charge determination device according to an embodiment of this application. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] To better understand the embodiments of this application, the technical terms involved in the embodiments of this application are explained below:

[0031] Battery casing water model: A casing of the same size and material as the battery being tested is used, wherein the casing of the battery casing water model is filled with liquid, for example, water.

[0032] In related technologies, there are two methods for determining the state of charge (SOC) of a battery using ultrasound: 1) Acquiring ultrasonic time-domain signals, processing them by envelope extraction and decomposition, and using the processing results to establish various complex models to determine the SOC; 2) Immersing a pouch battery in water and then using ultrasonic signals to determine the SOC. Method 1) involves very complex time-domain signal processing, making it inconvenient to use. Method 2 can only detect a few waterproof batteries, such as pouch lithium batteries, and cannot be applied to all types of batteries. Therefore, these technologies suffer from the problem of failing to simultaneously achieve simplicity, universality, and accurate estimation of battery SOC. To address this issue, this application provides related solutions, which are detailed below.

[0033] According to an embodiment of this application, a method embodiment for determining the state of charge of a battery is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0034] The methods and embodiments provided in this application can be executed on mobile terminals, computer terminals, or similar computing devices. Figure 1 A hardware block diagram of a computer terminal (or mobile device) for implementing a method for determining the state of charge of a battery is shown. Figure 1 As shown, the computer terminal 10 (or mobile device 10) may include one or more processors 102 (shown as 102a, 102b, ..., 102n in the figure) 102 (processor 102 may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0035] It should be noted that the aforementioned one or more processors 102 and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be embodied, in whole or in part, in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be integrated, in whole or in part, into any other element within the computer terminal 10 (or mobile device). As involved in the embodiments of this application, the data processing circuits serve as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0036] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the battery state of charge determination method in this embodiment. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the aforementioned battery state of charge determination method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0037] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the computer terminal 10. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0038] The display may be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10 (or mobile device).

[0039] This application provides a method for determining the state of charge of a battery in the above-described operating environment. Figure 2 A flowchart of a method for determining the state of charge of a battery according to an embodiment of this application is shown below. Figure 2 As shown, the method includes the following steps:

[0040] Step S202: Collect a first type of ultrasonic signal of ultrasonic waves passing through the battery casing water model, and collect a second type of ultrasonic signal of ultrasonic waves passing through the battery. The target properties of the battery casing water model are the same as the target properties of the battery, and the interior of the battery casing water model is filled with liquid.

[0041] The battery state of charge determination method provided in this application uses the ultrasonic signal of ultrasound passing through a battery casing water model as a reference signal. The battery casing water model and the battery under test are made of the same material and have the same dimensions (i.e., the target properties of the battery casing water model and the target properties of the battery are the same). The battery casing water model is filled with a liquid of any known sound velocity, such as water or an ultrasonic coupling fluid. In step S202, probes attached to both sides of the battery casing water model collect the ultrasonic signal of ultrasound passing through the battery casing water model (i.e., the first type of ultrasonic signal), and probes attached to both sides of the battery collect the ultrasonic signal of ultrasound passing through the battery (i.e., the second type of ultrasonic signal).

[0042] It should be noted that, in the method provided in this embodiment, the ultrasonic signal of the collected ultrasonic waves passing through the water model of the battery casing can be saved for subsequent reuse.

[0043] Step S204: Obtain the first spectrum corresponding to the first type of ultrasound signal and the second spectrum corresponding to the second type of ultrasound signal.

[0044] In step S204, the ultrasonic signals of the ultrasonic waves passing through the water model of the battery casing (i.e., the first type of ultrasonic signal) and the ultrasonic signals of the ultrasonic waves passing through the battery (i.e., the second type of ultrasonic signal) obtained in step S202 are processed respectively to obtain the spectrum of the ultrasonic signals of the ultrasonic waves passing through the water model of the battery casing (i.e., the first spectrum) and the spectrum of the ultrasonic signals of the ultrasonic waves passing through the battery (i.e., the second spectrum).

[0045] Step S206: Determine the frequency band difference curve based on the first spectrum and the second spectrum.

[0046] In step S206, after obtaining the spectrum of the ultrasonic signal passing through the water model of the battery casing (i.e., the first spectrum) and the spectrum of the ultrasonic signal passing through the battery (i.e., the second spectrum), the two spectra are normalized and processed to obtain the frequency band difference curve of the two spectra.

[0047] Step S208: Determine the battery state of charge based on the frequency band difference curve.

[0048] In step S208, the frequency band difference curve obtained in step S204 is processed to obtain a curve that reflects the state of charge of the battery under test, so as to determine the state of charge of the battery under test.

[0049] Through the above steps, the influence of the battery casing on the measurement results can be eliminated when using ultrasonic waves to measure the state of charge of a battery, thereby improving the accuracy of the measurement results. In addition, the method provided in this application embodiment is applicable to any type and specification of battery, and has universality. Furthermore, the method provided in this application embodiment only requires one Fourier transform during the processing of ultrasonic signals, making it easy to use.

[0050] According to an optional embodiment of this application, obtaining a first spectrum corresponding to a first type of ultrasound signal and a second spectrum corresponding to a second type of ultrasound signal includes: determining a first average value of the first type of ultrasound signal and a second average value of the second type of ultrasound signal; deleting ultrasound signals in the first type of ultrasound signal whose signal value is equal to the first average value to obtain a third type of ultrasound signal; and deleting ultrasound signals in the second type of ultrasound signal whose signal value is equal to the second average value to obtain a fourth type of ultrasound signal; and processing the third type of ultrasound signal and the fourth type of ultrasound signal respectively to obtain the first spectrum and the second spectrum.

[0051] In this embodiment, the ultrasonic signals passing through the battery casing water model (i.e., the first type of ultrasonic signal) and the ultrasonic signals passing through the battery (i.e., the second type of ultrasonic signal) are processed as follows to obtain the spectrum of the ultrasonic signal passing through the battery casing water model (i.e., the first spectrum) and the spectrum of the ultrasonic signal passing through the battery (i.e., the second spectrum). The average signal amplitude (i.e., the first average value) of the ultrasonic signals passing through the battery casing water model (i.e., the first type of ultrasonic signal) is determined, and signals with signal amplitudes equal to the (first) average value are filtered out. Similarly, the average signal amplitude (i.e., the second average value) of the ultrasonic signals passing through the battery (i.e., the second type of ultrasonic signal) is determined, and signals with signal amplitudes equal to the (second) average value are filtered out. After the average value is filtered out, the signal undergoes a Fourier transform, resulting in a power value of zero at zero frequency, which facilitates signal analysis. By processing the ultrasonic signals passing through the water model of the battery casing after filtering out the mean (i.e., the third type of ultrasonic signal) and the ultrasonic signals passing through the battery after filtering out the mean (i.e., the fourth type of ultrasonic signal), the spectrum of the ultrasonic signal passing through the water model of the battery casing (i.e., the first spectrum) and the spectrum of the ultrasonic signal passing through the battery (i.e., the second spectrum) can be obtained.

[0052] According to the previous embodiment, the third type of ultrasonic signal and the fourth type of ultrasonic signal are processed respectively to obtain a first spectrum and a second spectrum; including the following steps: determining a first normalization range; normalizing the third type of ultrasonic signal and the fourth type of ultrasonic signal according to the first normalization range to obtain normalized third type of ultrasonic signal and normalized fourth type of ultrasonic signal; performing Fourier transform on the normalized third type of ultrasonic signal to obtain the first spectrum, and performing Fourier transform on the normalized fourth type of ultrasonic signal to obtain the second spectrum.

[0053] In this embodiment, the method for obtaining the spectrum (i.e., the first spectrum) and the spectrum (i.e., the second spectrum) of the ultrasonic signal passing through the battery casing water model from the mean-filtered ultrasonic signal passing through the battery casing water model (i.e., the third type of ultrasonic signal) and the mean-filtered ultrasonic signal passing through the battery (i.e., the fourth type of ultrasonic signal) is as follows: First, a predefined (first) normalization range is determined, and the mean-filtered ultrasonic signal passing through the battery casing water model (i.e., the third type of ultrasonic signal) and the mean-filtered ultrasonic signal passing through the battery (i.e., the fourth type of ultrasonic signal) are normalized so that the signal values ​​of the processed signals are all within the (first) normalization range. Then, a Fourier transform is performed on the normalized ultrasonic signal passing through the battery casing water model (i.e., the third type of ultrasonic signal) and the normalized ultrasonic signal passing through the battery (i.e., the fourth type of ultrasonic signal) respectively to obtain the spectrum of the ultrasonic signal passing through the battery casing water model. (i.e., the first spectrum) and the spectrum of the ultrasonic signal passing through the battery. (i.e., the second spectrum).

[0054] According to another optional embodiment of this application, determining the frequency band difference curve based on the first spectrum and the second spectrum includes the following steps: determining the upper limit frequency and the lower limit frequency of the frequency band, and determining a second normalization range based on the upper limit frequency and the lower limit frequency of the frequency band; normalizing the first spectrum and the second spectrum according to the second normalization range to obtain the normalized first spectrum and the normalized second spectrum.

[0055] In this embodiment, the frequency band difference curve is determined by the following method: First, a predefined upper limit frequency is determined. and the predefined lower limit frequency , increase the upper limit frequency and lower limit frequency This interval is defined as the (second) normalization range, where the upper frequency is required to be... The upper limit frequency should be less than or equal to three times the center frequency of the ultrasound probe. For example, if you choose an ultrasound probe with a center frequency of 1.2 MHz, then the upper limit frequency should be less than or equal to three times the center frequency of the ultrasound probe. It should be less than or equal to 3.6MHz; while the lower limit frequency... As long as it is greater than zero. The spectrum of the ultrasonic signal passing through the water model of the battery casing obtained through the above embodiments. (i.e., the first spectrum) and the spectrum of the ultrasonic signal passing through the battery. (i.e., the second spectrum) is normalized so that the normalized spectrum is The signal values ​​and normalized values ​​in the first spectrum (i.e., the first spectrum) The signal values ​​in the second spectrum (i.e., the upper frequency range) are all within the range of the upper frequency range. and lower limit frequency Within the defined (second) normalization range.

[0056] According to some optional embodiments of this application, determining the frequency band difference curve based on the normalized first spectrum and the normalized second spectrum includes: determining the ratio of the amplitude of the normalized first spectrum and the normalized second spectrum at the same frequency; determining multiple first coordinate points corresponding to multiple ratios in a coordinate system, and determining the frequency band difference curve based on the multiple first coordinate points, wherein the horizontal axis of the coordinate system is the frequency, and the vertical axis of the coordinate system is the ratio.

[0057] In some optional embodiments, the frequency band difference curve is obtained by the following method: first, after normalization processing... Extracting the frequency band of the ultrasonic signal from the battery casing water model (i.e., the first spectrum). (i.e., the first frequency band), and after normalization processing Extracting the frequency band of the ultrasonic signal from the battery (i.e., the second spectrum). (i.e., the second frequency band), wherein the upper limit frequency of the signal in the two frequency bands extracted above (i.e., the first frequency band and the second frequency band) is... The lower limit frequency of the signal is In other words, the two frequency bands extracted above (i.e., the first frequency band and the second frequency band) are two different signal frequency bands within the same range. When visualizing the frequency bands, a horizontal axis is established with the signal frequency value as the horizontal axis and a vertical axis is established with the signal amplitude as the vertical axis. A Cartesian coordinate system is then established using the horizontal and vertical axes to represent the frequency bands of the ultrasonic signals from the battery casing water model. (i.e., the first frequency band) and the frequency band of the battery's ultrasonic signal (i.e., the second frequency band) is represented on the coordinate axis. According to the formula... The frequency band of the ultrasonic signal of the battery casing water model (i.e., the first frequency band) and the frequency band of the battery's ultrasonic signal Dividing the amplitude values ​​at the same frequency (i.e., the second frequency band) by the amplitude values ​​at the same frequency yields the frequency band difference curve. . Figure 3This is a schematic diagram of the frequency band difference curve, such as... Figure 3 As shown, a horizontal axis is established using signal frequency values ​​such as 0.8MHz, 1MHz, 1.2MHz, 1.4MHz, 1.6MHz, 1.8MHz, 2MHz, 2.2MHz, 2.4MHz, and 2.6MHz as horizontal axis markers. A vertical axis is established using the ratio of the amplitudes of two frequency bands (i.e., the first and second frequency bands) at the same frequency, such as 0, 1, 2, 3, 4, 5, and 6 as vertical axis markers. A Cartesian coordinate system is established using the horizontal and vertical axes, with the frequency value of each signal as the horizontal axis and the first frequency band as the vertical axis. The ratio of the amplitude of the signal in the first frequency band at that frequency value to the amplitude of the signal in the second frequency band at that frequency value is used as the vertical axis. A (first) coordinate point is determined by the horizontal and vertical axes, and multiple (first) coordinate points are determined by the same method. The curve composed of these multiple (first) coordinate points is represented on the coordinate axis. The curve fitted by these multiple (first) coordinate points is the frequency band difference curve.

[0058] According to some alternative embodiments of this application, determining the frequency band difference curve based on the normalized first spectrum and the normalized second spectrum further includes: determining the difference in amplitude between the normalized first spectrum and the normalized second spectrum at the same frequency; determining multiple second coordinate points corresponding to multiple differences in a coordinate system; and determining the frequency band difference curve based on the multiple second coordinate points.

[0059] In some alternative embodiments, the frequency band difference curve can also be obtained by the following method: according to the formula The frequency band of the ultrasonic signal of the battery casing water model (i.e., the first frequency band) and the frequency band of the battery's ultrasonic signal Subtracting the amplitudes corresponding to the same frequency value in the second frequency band (i.e., the second frequency band) yields the frequency band difference curve. When visualizing the frequency band difference curve, a horizontal axis is established with the signal frequency value as the abscissa, and a vertical axis is established with the difference in amplitude between the two frequency bands (i.e., the first and second frequency bands) at the same frequency as the ordinate. A Cartesian coordinate system is then established using the horizontal and vertical axes, with the frequency value of each signal as the abscissa and the first frequency band as the ordinate. The difference between the amplitude of the signal in the first frequency band and the amplitude of the signal in the second frequency band at the same frequency is used as the vertical axis. A (second) coordinate point is determined by the horizontal and vertical axes, and multiple (second) coordinate points are determined by the same method. The curve formed by these multiple (second) coordinate points is represented on a coordinate axis with the frequency of the signal as the horizontal axis and the difference in amplitude of the two different signals at the same frequency as the vertical axis. The curve fitted by these multiple (second) coordinate points is the frequency band difference curve.

[0060] According to an optional embodiment of this application, determining the battery state of charge (SOC) of a battery based on a frequency band difference curve includes: determining the slope of the frequency band difference curve and defining the slope as a frequency band difference parameter; determining the battery SOC of the battery based on the frequency band difference parameter, wherein the frequency band difference parameter and the battery SOC of the battery are directly proportional.

[0061] In this embodiment, when determining the battery state of charge (SOC) using the frequency band difference curve obtained in the above embodiments, firstly, the slope of the frequency band difference curve is obtained as the frequency band difference parameter. Since the trend of the frequency band difference curve obtained under different battery states of charge (SOC) is different, the slope of the obtained frequency band difference curve is also different. Therefore, the slope of the frequency band difference curve can reflect the battery's state of charge (SOC). Specifically, there is a direct proportional relationship between the battery state of charge (SOC) and the slope of the frequency band difference curve (i.e., the frequency band difference parameter). A larger frequency band difference parameter results in a larger SOC value, and a smaller frequency band difference parameter results in a smaller SOC value.

[0062] Figure 4 This is a flowchart illustrating a method for demonstrating the state of charge of a battery according to an embodiment of this application, such as... Figure 4 As shown, the method includes the following steps:

[0063] Step S402: Display the first spectrum corresponding to the first type of ultrasonic signal and the second spectrum corresponding to the second type of ultrasonic signal in the interface. The first type of ultrasonic signal is the ultrasonic signal of ultrasonic waves passing through the battery shell water model, and the second type of ultrasonic signal is the ultrasonic signal of ultrasonic waves passing through the battery. The target properties of the battery shell water model are the same as the target properties of the battery, and the shell of the battery shell water model is filled with liquid.

[0064] Figure 5 This is a visual schematic diagram of an ultrasonic signal. In step S402, when the method provided in this embodiment is applied to a computer or other electronic device that supports software applications, such as... Figure 5As shown, the electronic device displays the (first) spectrum of the ultrasonic signal passing through the battery casing water model (i.e., the first type of ultrasonic signal) and / or the (second) spectrum of the ultrasonic signal passing through the battery (i.e., the second type of ultrasonic signal) as curves in a coordinate system with the number of sampling points as the horizontal axis and the signal amplitude as the vertical axis. For example, taking a battery with a state of charge of 40% as an example, when the number of sampling points is set to 0~450 when visualizing the frequency band difference curve, the amplitude of the collected signal is in the range of -1.5~1. At this time, 0, 50, 100, 150, 200, 250, 300, 350, 400, 450 are used as horizontal axis markers, and -1.5, -1, -0.5, 0, 0.5, 1 are used as vertical axis markers to display the spectrum of the signal on the electronic device's display interface.

[0065] Step S404: Display the frequency band difference curve determined based on the first and second spectra in the interface.

[0066] In step S404, a spectral difference curve is determined based on the (first) spectrum of the ultrasonic signal passing through the battery casing water model (i.e., the first type of ultrasonic signal) obtained in step S402 and the (second) spectrum of the ultrasonic signal passing through the battery (i.e., the second type of ultrasonic signal). Specifically, an abscissa is established using the frequency values ​​of the signals in the first and second spectra as the abscissa, and a ordinate is established using the ratio of the signal amplitudes in the two spectra at the same frequency or the difference in the signal amplitudes in the two spectra as the ordinate. The spectral difference curve is then displayed as a curve on the display interface of the electronic device in the coordinate system determined by the abscissa and ordinate axes.

[0067] Step S406: Display the curve reflecting the state of charge of the battery, determined based on the frequency band difference curve, on the interface.

[0068] In step S406, firstly, the slope of the frequency band difference curve obtained in step S404 is obtained, and the slope of the frequency band difference curve is used as the frequency band difference parameter. The curve reflecting the relationship between the frequency band difference parameter and the battery state of charge is displayed on the display interface of the electronic device, so as to determine the battery state of charge of the battery under test according to the frequency band difference parameter-battery state of charge curve. Figure 6 This is a schematic diagram of the frequency band difference parameter-battery state of charge curve, such as... Figure 6As shown, batteries with state of charge (SOC) of 0%, 20%, 40%, 60%, 80%, and 100% were measured using the above method. The measurement results show that the bandwidth difference parameter is -4.1 when SOC is 0%; -3.7 when SOC is 20%; -3.6 when SOC is 40%; -3.1 when SOC is 60%; -2.9 when SOC is 80%; and -2.8 when SOC is 100%. Therefore, the curve reflecting the battery's state of charge is displayed in a coordinate system with 0, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% as the horizontal axis markers, and -4.2, -4, -3.8, -3.6, -3.4, -3.2, -3, and -2.8 as the horizontal axis markers. Figure 6 It can be concluded that there is a positive proportional relationship between battery SOC and frequency band difference parameters.

[0069] Figure 7 This is a structural diagram of a testing device provided in an embodiment of this application, such as... Figure 7As shown, the testing equipment includes a controller 70, a first ultrasonic probe 72, a second ultrasonic probe 74, and a battery casing water model 76. When using the first ultrasonic probe 72 and the second ultrasonic probe 74 to collect ultrasonic signals (type 1) as ultrasound passes through the battery casing water model 76, the first ultrasonic probe 72 and the second ultrasonic probe 74 are respectively attached to opposite sides of the battery casing water model 76. The first ultrasonic probe 72 is controlled by an ultrasonic transmitting system to emit ultrasonic signals, and the second ultrasonic probe 74 is controlled by an ultrasonic transmitting and receiving system to receive ultrasonic signals, thus completing the acquisition of type 1 ultrasonic signals. When using the first ultrasonic probe 72 and the second ultrasonic probe 74 to collect ultrasonic signals (type 2) as ultrasound passes through the battery, the battery casing water model is replaced with the battery under test, and the first ultrasonic probe 72 and the second ultrasonic probe 74 are respectively attached to opposite sides of the battery under test. The first ultrasonic probe 72 is controlled by an ultrasonic transmitting system to emit ultrasonic signals, and the second ultrasonic probe 74 is controlled by an ultrasonic transmitting and receiving system to receive ultrasonic signals, thus completing the acquisition of type 2 ultrasonic signals. The controller 70 is used to execute the above-described method for determining the state of charge of the battery. When executing this method, it controls the ultrasonic transmitting system to emit ultrasonic signals using the first ultrasonic probe 72, and simultaneously controls the ultrasonic transmitting and receiving system to receive ultrasonic signals using the second ultrasonic probe. When visualizing the acquired ultrasonic signals and the signal spectrum determined from them, the controller 70 can be connected to an electronic device and displayed on its interface; for example, it can be connected to a computer and displayed on its interface. Since the method provided in this application acquires the signal of ultrasonic waves passing through the battery casing water model to avoid the influence of the battery casing water model on the detection results and to improve the accuracy of the measurement results, the material and size (i.e., target attributes) of the battery casing water model are the same as the material and size (i.e., target attributes) of the battery under test, and the interior of the battery casing water model is filled with liquid.

[0070] Figure 8 This is a structural diagram of a battery state of charge determination device according to an embodiment of this application, as shown below. Figure 8 As shown, the device includes: a data acquisition module 80, used to acquire a first type of ultrasonic signal of ultrasonic waves passing through a battery casing water model, and to acquire a second type of ultrasonic signal of ultrasonic waves passing through the battery, wherein the target attribute of the battery casing water model is the same as the target attribute of the battery, and the interior of the battery casing water model is filled with liquid; an acquisition module 82, used to acquire a first spectrum corresponding to the first type of ultrasonic signal and a second spectrum corresponding to the second type of ultrasonic signal; a first determination module 84, used to determine a frequency band difference curve based on the first spectrum and the second spectrum; and a second determination module 86, used to determine the battery state of charge based on the frequency band difference curve.

[0071] Figure 9This is a flowchart of the process for determining the battery state of charge, such as... Figure 9 As shown, the device starts working, acquiring ultrasonic signals (type 1) from the ultrasonic waves passing through the water model of the battery casing and ultrasonic signals (type 2) from the ultrasonic waves passing through the battery under test via acquisition module 80; acquiring module 82 performs a Fourier transform on the ultrasonic signals (type 1) from the ultrasonic waves passing through the water model of the battery casing and ultrasonic signals (type 2) from the ultrasonic waves passing through the battery under test, respectively, to obtain the (first) spectrum of the ultrasonic signals (type 1) from the ultrasonic waves passing through the water model of the battery casing and the (second) spectrum of the ultrasonic signals (type 2) from the ultrasonic waves passing through the battery under test; the first determining module 84 selects frequency bands from the first spectrum and the second spectrum, respectively, wherein the two selected frequency bands belong to the same range, and the frequency band selected from the (first) spectrum of the ultrasonic signals (type 1) from the ultrasonic waves passing through the water model of the battery casing will be saved and reused. A frequency band difference curve is determined based on the selected frequency bands; finally, the second determining module 86 determines the spectral difference parameters based on the frequency band difference curve, and determines the state of charge (SOC) of the battery under test based on the spectral parameters.

[0072] It should be noted that, Figure 8 Preferred embodiments of the shown examples can be found in [reference needed]. Figure 2 The relevant descriptions of the embodiments shown will not be repeated here.

[0073] This application also provides a non-volatile storage medium storing a computer program, wherein the device containing the non-volatile storage medium executes the above-described method for determining the state of charge of a battery by running the computer program.

[0074] The aforementioned non-volatile storage medium is used to store a program that performs the following functions: acquiring a first type of ultrasonic signal from an ultrasonic wave passing through a battery casing water model, and acquiring a second type of ultrasonic signal from an ultrasonic wave passing through the battery, wherein the target properties of the battery casing water model are the same as the target properties of the battery, and the interior of the battery casing water model is filled with liquid; acquiring a first spectrum corresponding to the first type of ultrasonic signal and a second spectrum corresponding to the second type of ultrasonic signal; determining a frequency band difference curve based on the first spectrum and the second spectrum; and determining the battery state of charge based on the frequency band difference curve.

[0075] This application also provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor is configured to execute the above-described method for determining the state of charge of a battery through the computer program.

[0076] The processor in the aforementioned electronic device is used to run a program that performs the following functions: acquiring a first type of ultrasonic signal of ultrasonic waves passing through a battery casing water model, and acquiring a second type of ultrasonic signal of ultrasonic waves passing through the battery, wherein the target properties of the battery casing water model are the same as the target properties of the battery, and the interior of the battery casing water model is filled with liquid; acquiring a first spectrum corresponding to the first type of ultrasonic signal and a second spectrum corresponding to the second type of ultrasonic signal; determining a frequency band difference curve based on the first spectrum and the second spectrum; and determining the battery state of charge based on the frequency band difference curve.

[0077] It should be noted that each module in the above-mentioned battery state of charge determination device can be a program module (for example, a set of program instructions to implement a certain function) or a hardware module. For the latter, it can be manifested in the following forms, but is not limited to them: each of the above modules is manifested as a processor, or the functions of each of the above modules are implemented by a processor.

[0078] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0079] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0080] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0081] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0082] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0083] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0084] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for determining the state of charge of a battery, characterized in that, include: A first type of ultrasonic signal is acquired when ultrasonic waves pass through a water model of a battery casing, and a second type of ultrasonic signal is acquired when the ultrasonic waves pass through the battery. The target properties of the water model of the battery casing are the same as the target properties of the battery, and the interior of the water model of the battery casing is filled with liquid. Obtain the first spectrum corresponding to the first type of ultrasonic signal and the second spectrum corresponding to the second type of ultrasonic signal; Determine the frequency band difference curve based on the first spectrum and the second spectrum; Determining the battery state of charge (SOC) of the battery based on the frequency band difference curve includes: determining the slope of the frequency band difference curve and defining the slope as a frequency band difference parameter; determining the battery SOC of the battery based on the frequency band difference parameter, wherein the frequency band difference parameter and the battery SOC of the battery are directly proportional.

2. The method according to claim 1, characterized in that, Obtaining the first spectrum corresponding to the first type of ultrasound signal and the second spectrum corresponding to the second type of ultrasound signal includes: Determine the first average value of the first type of ultrasound signal and the second average value of the second type of ultrasound signal, delete the ultrasound signals in the first type of ultrasound signal whose signal value is equal to the first average value to obtain the third type of ultrasound signal, and delete the ultrasound signals in the second type of ultrasound signal whose signal value is equal to the second average value to obtain the fourth type of ultrasound signal; The third type of ultrasonic signal and the fourth type of ultrasonic signal are processed respectively to obtain the first spectrum and the second spectrum.

3. The method according to claim 2, characterized in that, The third type of ultrasound signal and the fourth type of ultrasound signal are processed respectively to obtain the first spectrum and the second spectrum; including: Determine the first normalization range; The third type of ultrasound signal and the fourth type of ultrasound signal are normalized according to the first normalization range to obtain the normalized third type of ultrasound signal and the normalized fourth type of ultrasound signal. The normalized third type of ultrasound signal is subjected to Fourier transform to obtain the first spectrum, and the normalized fourth type of ultrasound signal is subjected to Fourier transform to obtain the second spectrum.

4. The method according to claim 1, characterized in that, Determining the frequency band difference curve based on the first spectrum and the second spectrum includes: Determine the upper limit frequency and the lower limit frequency of the frequency band, and determine the second normalization range based on the upper limit frequency and the lower limit frequency of the frequency band; The first spectrum and the second spectrum are normalized according to the second normalization range to obtain the normalized first spectrum and the normalized second spectrum.

5. The method according to claim 4, characterized in that, The frequency band difference curve is determined based on the normalized first spectrum and the second spectrum, including: Determine the ratio of the amplitude of the normalized first spectrum to the amplitude of the normalized second spectrum at the same frequency; In a coordinate system, a plurality of first coordinate points corresponding to the plurality of ratios are determined, and the frequency band difference curve is determined based on the plurality of first coordinate points, wherein the horizontal axis of the coordinate system is the frequency, and the vertical axis of the coordinate system is the ratio.

6. The method according to claim 5, characterized in that, Determining the frequency band difference curve based on the normalized first and second spectra also includes: Determine the difference in amplitude between the normalized first spectrum and the normalized second spectrum at the same frequency; In the coordinate system, a plurality of second coordinate points corresponding to the plurality of differences are determined, and the frequency band difference curve is determined based on the plurality of second coordinate points.

7. A method for displaying the state of charge of a battery, characterized in that, include: The interface displays the first spectrum corresponding to the first type of ultrasonic signal and the second spectrum corresponding to the second type of ultrasonic signal. The first type of ultrasonic signal is the ultrasonic signal of ultrasonic waves passing through the battery shell water model, and the second type of ultrasonic signal is the ultrasonic signal of the ultrasonic waves passing through the battery. The target properties of the battery shell water model are the same as the target properties of the battery, and the shell of the battery shell water model is filled with liquid. The interface displays a frequency band difference curve determined based on the first spectrum and the second spectrum; and, The interface displays a curve reflecting the state of charge of the battery, determined based on the frequency band difference curve.

8. A testing device, characterized in that, include: The controller, the first ultrasonic probe, the second ultrasonic probe, and the battery casing water model, wherein, The first ultrasonic probe and the second ultrasonic probe are respectively attached to opposite sides of the water mold of the battery casing; The first ultrasonic probe and the second ultrasonic probe are respectively attached to opposite sides of the battery under test; A controller for performing the method for determining the state of charge of a battery as described in any one of claims 1-7; The target properties of the battery casing water model are the same as the target properties of the battery, and the interior of the battery casing water model is filled with liquid.

9. A device for determining the state of charge of a battery, characterized in that, include: The acquisition module is used to acquire a first type of ultrasonic signal of ultrasonic waves passing through the battery shell water model, and to acquire a second type of ultrasonic signal of ultrasonic waves passing through the battery, wherein the target property of the battery shell water model is the same as the target property of the battery, and the interior of the battery shell water model is filled with liquid; The acquisition module is used to acquire the first spectrum corresponding to the first type of ultrasound signal and the second spectrum corresponding to the second type of ultrasound signal; The first determining module is used to determine the frequency band difference curve based on the first spectrum and the second spectrum; The second determining module is used to determine the battery state of charge of the battery based on the frequency band difference curve, including: determining the slope of the frequency band difference curve and determining the slope as a frequency band difference parameter; determining the battery state of charge of the battery based on the frequency band difference parameter, wherein the frequency band difference parameter has a positive proportional relationship with the battery state of charge of the battery.

10. A non-volatile storage medium, characterized in that, The non-volatile storage medium stores a computer program, wherein the device containing the non-volatile storage medium executes the method for determining the state of charge of a battery according to any one of claims 1 to 6 by running the computer program.

11. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method for determining the state of charge of a battery according to any one of claims 1 to 6 through the computer program.

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