Method, device and equipment for detecting gas in battery and storage medium
By constructing a matrix of transmitted and reflected echo signals, the system automatically identifies air bubbles inside the battery and their projection areas, solving the problem of relying on human experience in existing technologies and achieving efficient and accurate detection of gas inside the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2026-04-10
AI Technical Summary
Current technologies rely on the experience of researchers to detect gas inside batteries, resulting in low accuracy and efficiency, and making it difficult to achieve automated and efficient bubble identification.
By acquiring the transmitted echo signal on the battery detection surface, a transmission coordinate matrix is constructed, the transmission value attenuation rate is calculated, the target transmission storage cell is screened out, it is determined whether there are bubbles inside the battery and their projection area, and the depth range is calculated by combining the reflected echo signal.
It enables automatic identification and efficient, accurate detection of air bubbles inside batteries, improving detection efficiency and accuracy.
Smart Images
Figure CN121830898A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of battery testing technology, and in particular to a method, apparatus, device, and storage medium for detecting gases inside a battery. Background Technology
[0002] Battery gas generation detection primarily targets abnormal gas generation characteristics, such as excessive gas generation caused by the shedding and regeneration of the electrolyte SEI film, gas generation due to residual gas or moisture inside the battery caused by battery encapsulation problems, gas generation caused by battery micro-short circuits, and gas generation caused by overcharging and over-discharging. Excessive gas generation not only reduces battery capacity but can also, in severe cases, rupture the encapsulation area, leading to leakage and explosion. Therefore, during battery development, it is necessary to regularly detect the gas generation status inside the battery to adjust the battery manufacturing process based on the internal gas generation status, thereby improving battery lifespan.
[0003] Currently, the detection and analysis of gases inside batteries are typically performed by experienced R&D personnel. The accuracy of these tests relies entirely on the R&D experience, and the testing efficiency is low. Therefore, solving these technical problems is a pressing issue for those skilled in the art. Summary of the Invention
[0004] In view of this, the present disclosure proposes a method, apparatus, device and storage medium for detecting gas inside a battery, which can automatically identify air bubbles inside the battery and calculate the projection area of the air bubbles on the detection surface of the battery, thereby improving the detection efficiency and accuracy of air bubbles inside the battery.
[0005] According to a first aspect of this disclosure, a method for detecting gas inside a battery is provided, comprising:
[0006] Acquire the target transmitted echo signal at each detection point on the battery detection surface;
[0007] For each detection point, the maximum transmission value is extracted from the target transmission echo signal, and the maximum transmission value is stored in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix;
[0008] Calculate the maximum transmission value attenuation rate of each transmission storage cell relative to other spatially adjacent transmission storage cells in the transmission coordinate matrix, and select transmission storage cells with a maximum transmission value attenuation rate greater than or equal to the attenuation rate threshold as target transmission storage cells.
[0009] Based on each of the target transmission storage units, determine whether there are bubbles inside the battery and the projection area of the bubbles on the battery detection surface;
[0010] The area of the transmission coordinate matrix is matched with the area of the battery detection surface.
[0011] In one possible implementation, acquiring the target transmitted echo signal at the detection point on the battery detection surface includes:
[0012] The initial transmitted echo signal of the detection point on the battery detection surface is obtained by an ultrasonic transducer.
[0013] The transmitted echo signal located inside the battery is extracted from the initial transmitted echo signal and used as the target transmitted echo signal.
[0014] In one possible implementation, after acquiring the initial transmitted echo signal of the detection point on the battery detection surface via an ultrasonic transducer, the method further includes:
[0015] Determine whether the noise floor amplitude in the initial transmitted echo signal is less than or equal to a preset noise floor threshold;
[0016] When the noise floor amplitude is determined to be less than or equal to the noise floor threshold, the initial transmitted echo signal is determined to be valid.
[0017] If the initial transmitted echo signal is confirmed to be valid, the operation of extracting the transmitted echo signal located inside the battery from the initial transmitted echo signal is then performed as the target transmitted echo signal.
[0018] In one possible implementation, if the initial transmitted echo signal is determined to be valid, the method further includes: normalizing the initial transmitted echo signal.
[0019] In one possible implementation, when acquiring the target transmission echo signal at each detection point on the battery detection surface, the method further includes:
[0020] Acquire the target reflected echo signals at each detection point on the battery detection surface;
[0021] For each detection point, the maximum reflection value is extracted from the target reflected echo signal and the ToF value corresponding to the maximum reflection value is calculated. The ToF value is then stored in the ToF storage unit corresponding to each detection point in the pre-constructed ToF coordinate matrix.
[0022] After obtaining the target transmissive memory cell, the ToF value corresponding to each target transmissive memory cell is extracted from the ToF coordinate matrix;
[0023] Based on the extracted ToF values, the depth range of the projection area is determined.
[0024] In one possible implementation, after extracting the maximum reflection value from the target reflected echo signal for each detection point and calculating the ToF value corresponding to the maximum reflection value, and storing the ToF value corresponding to the maximum reflection value in the ToF storage unit corresponding to each detection point in the pre-constructed ToF coordinate matrix, the method further includes:
[0025] Calculate the ToF value shift rate of each ToF storage cell in the ToF coordinate matrix relative to other spatially adjacent ToF storage cells, and select the ToF storage cells whose ToF value shift rate is within a preset first range as target ToF storage cells;
[0026] Based on each of the target ToF storage cells, a first verification projection area of the bubble is determined on the battery detection surface;
[0027] Determine whether the first verification projection area is consistent with the projection area. If they are consistent, extract the ToF value corresponding to each target transmission storage unit from the ToF coordinate matrix. Based on the extracted ToF values, determine the depth range of the projection area.
[0028] In one possible implementation, the method further includes:
[0029] The maximum reflection value corresponding to each detection point is stored in the pre-constructed reflection coordinate matrix and the reflection storage unit corresponding to each detection point;
[0030] Calculate the maximum reflection value growth rate of each reflection storage unit in the reflection coordinate matrix relative to other spatially adjacent reflection storage units, and select the reflection storage units whose maximum reflection value growth rate is within a preset second range as target reflection storage units;
[0031] Based on each of the target reflection storage units, a second verification projection area of the bubble on the battery detection surface is determined;
[0032] Determine whether the second verification projection area is consistent with the projection area. If they are consistent, extract the ToF value corresponding to each of the target transmission storage units from the ToF coordinate matrix. Based on the extracted ToF values, determine the depth range of the projection area.
[0033] According to a second aspect of this disclosure, a device for detecting gas inside a battery is provided, comprising:
[0034] The transmission echo signal acquisition module is used to acquire the target transmission echo signal of each detection point on the battery detection surface;
[0035] The transmission coordinate matrix construction module is used to extract the maximum transmission value from the target transmission echo signal for each detection point, and store the maximum transmission value in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix;
[0036] The target transmission storage cell screening module is used to calculate the maximum transmission value attenuation rate of each transmission storage cell in the transmission coordinate matrix relative to other spatially adjacent transmission storage cells, and to screen out the transmission storage cells with a maximum transmission value attenuation rate greater than or equal to the attenuation rate threshold as target transmission storage cells.
[0037] A bubble detection module is used to determine, based on each of the target transmission storage units, whether there are bubbles inside the battery and the projection area of the bubbles on the battery detection surface.
[0038] The area of the transmission coordinate matrix is matched with the area of the battery detection surface.
[0039] According to a third aspect of this disclosure, a device for detecting gas inside a battery is provided, comprising: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to perform the method described in the first aspect of this disclosure.
[0040] According to a fourth aspect of this disclosure, a non-volatile computer-readable storage medium is provided that stores computer program instructions thereon, wherein the computer program instructions, when executed by a processor, implement the method described in the first aspect of this disclosure.
[0041] This disclosure provides a method for detecting gases inside a battery, comprising: acquiring target transmission echo signals at each detection point on the battery detection surface; for each detection point, extracting the maximum transmission value from the target transmission echo signal and storing the maximum transmission value in a pre-constructed transmission coordinate matrix corresponding to each detection point in a transmission storage unit; calculating the attenuation rate of the maximum transmission value stored in each transmission storage unit in the transmission coordinate matrix relative to other spatially adjacent transmission storage units, and selecting transmission storage units with a maximum transmission value attenuation rate greater than or equal to an attenuation rate threshold as target transmission storage units; and determining, based on each target transmission storage unit, whether bubbles exist inside the battery and the projection area of the bubbles on the battery detection surface; wherein the area of the transmission coordinate matrix matches the area of the battery detection surface. This method can automatically identify bubbles inside the battery and calculate the projection area of the bubbles on the battery detection surface, thereby improving the detection efficiency and accuracy of bubbles inside the battery.
[0042] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description
[0043] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.
[0044] Figure 1 A flowchart illustrating a method for detecting gas inside a battery according to an embodiment of the present disclosure is shown.
[0045] Figure 2 A schematic diagram showing the positional relationship between an ultrasonic transducer and a battery according to an embodiment of the present disclosure is shown.
[0046] Figure 3 A schematic diagram showing the detection points and scanning trajectory on a detection surface according to an embodiment of the present disclosure is provided.
[0047] Figure 4 A schematic diagram of a transmission coordinate matrix according to an embodiment of the present disclosure is shown;
[0048] Figure 5 A schematic diagram of a target transmission memory cell according to an embodiment of the present disclosure is shown;
[0049] Figure 6 A schematic diagram of a ToF coordinate matrix according to an embodiment of the present disclosure is shown;
[0050] Figure 7 A schematic block diagram of a battery internal gas detection device according to an embodiment of the present disclosure is shown.
[0051] Figure 8 A schematic block diagram of a device for detecting gas inside a battery according to an embodiment of the present disclosure is shown. Detailed Implementation
[0052] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.
[0053] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.
[0054] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.
[0055] <Method Implementation>
[0056] Figure 1 A flowchart illustrating a method for detecting gas inside a battery according to an embodiment of the present disclosure is shown. Figure 1 As shown, the method includes steps S1100-S1400.
[0057] S1100 acquires the target transmitted echo signal at each detection point on the battery detection surface.
[0058] In one possible implementation, acquiring the target transmission echo signal at each detection point on the detection surface may include the following steps:
[0059] First, the initial transmission echo signal of each detection point on the battery detection surface is acquired using an ultrasonic transducer. This initial transmission echo signal is the original transmission echo signal acquired by the ultrasonic transducer.
[0060] It should be noted that when testing the battery, one of the four sides of the battery will be randomly selected as the testing surface. An ultrasonic transducer 1 for emitting sound waves is placed at one end of this testing surface, and an ultrasonic transducer 2 for receiving sound waves is placed at the opposite end of the testing surface, as detailed below. Figure 2 As shown, the target transmitted echo signal at each detection point on the detection surface is obtained by using two ultrasonic transducers arranged opposite to each other.
[0061] When acquiring the initial transmitted echo signals of each detection point on the detection surface using two ultrasonic transducers positioned opposite each other, it is necessary to first input the dimensions of the battery detection surface into both ultrasonic transducers to define the scanning range of the transducers. This scanning range is determined based on the dimensions of the battery detection surface. For example, if the dimensions of the battery detection surface are m*n, the ultrasonic transducers will scan within the m*n dimension range. After determining the scanning range, the detection surface within the scanning range can be scanned according to a preset scanning trajectory. The scanning trajectory can be as follows: Figure 3The Z-shaped trajectory shown can also be other linear trajectories, which are not specifically limited here. It should be noted that this scanning trajectory includes multiple trajectory points. At each trajectory point, the ultrasonic transducer emits an acoustic signal onto the detection surface according to the configured pulse repetition frequency (PRF). This acoustic signal allows the acquisition of the initial transmitted echo signal of the corresponding detection point on the detection surface. After the acoustic signal reaches the detection surface, it forms a patch area on the detection surface; this patch area is the detection point corresponding to the trajectory point. In other words, at each trajectory point, the initial transmitted echo signal of a corresponding detection point on the detection surface will be acquired. After the scan is completed, the initial transmitted echo signals of all detection points on the detection surface will be obtained. The sum of the areas of all detection points equals the area of the battery detection surface. For example, after scanning a 4mm*4mm battery detection surface according to the preset Z-shaped trajectory, the following will be obtained: Figure 3 The initial transmitted echo signals are shown for the 16 detection points (A1-A16). The acoustic wave forms a 1mm x 1mm patch on the detection surface, effectively dividing the battery detection surface into multiple 1mm x 1mm regions.
[0062] Second, the target transmitted echo signal is extracted from the initial transmitted echo signal, specifically the transmitted echo signal located inside the battery. This extraction is based on a pre-configured rule for finding the starting point of the transmitted echo extraction and the sound path of the acoustic signal within the battery. Specifically, after acquiring the initial transmitted echo signal at the detection point, the starting point is found using the rule. Then, starting from this point, a transmitted echo signal with the same duration as the sound path is extracted from the initial transmitted echo signal; this extracted transmitted echo is the target transmitted echo signal located inside the battery. The rule for finding the starting point can be based on the origin of the initial transmitted echo signal. The sound path of the acoustic signal within the battery can be calculated based on the battery thickness and the sound velocity inside the battery. The specific calculation formula is shown below.
[0063]
[0064] It should be noted that a high noise floor in the initial transmitted echo signal will affect the accuracy of bubble detection. Therefore, to improve the accuracy of bubble detection, one possible implementation includes the following steps after acquiring the initial transmitted echo signal of the detection point on the battery detection surface via an ultrasonic transducer: determining whether the noise floor amplitude in the initial transmitted echo signal is less than or equal to a preset noise floor threshold; confirming the validity of the initial transmitted echo signal if the noise floor amplitude is less than or equal to the noise floor threshold; and, if the initial transmitted echo signal is confirmed to be valid, then extracting the transmitted echo signal located inside the battery from the initial transmitted echo signal as the target transmitted echo signal. The noise floor threshold can be set to 10% of the initial transmitted echo signal amplitude. For example, when the initial transmitted echo signal amplitude is 1V, the noise floor threshold can be set to 100mV. When the noise floor amplitude is determined to be greater than the noise floor threshold, it indicates that the initial transmitted echo signal contains significant noise. Therefore, it is necessary to filter out the noise floor in the initial transmitted echo signal before extracting the transmitted echo signal located inside the battery from the initial transmitted echo signal as the target transmitted echo signal. How to filter out the noise floor from the initial transmitted echo signal is common knowledge in the field and will not be elaborated upon here.
[0065] In one possible implementation, if the initial transmitted echo signal is determined to be valid, the method further includes: normalizing the initial transmitted echo signal, and after normalizing the initial transmitted echo signal, extracting the transmitted echo signal located inside the battery from the initial transmitted echo signal as the target transmitted echo signal.
[0066] S1200 extracts the maximum transmission value from the target transmission echo signal for each detection point and stores the maximum transmission value in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix.
[0067] Specifically, the extraction of the maximum transmission value from the target transmitted echo signal can be achieved using a greedy algorithm. The calculation formula for the greedy algorithm is as follows.
[0068] X0 = argmax(f(x))
[0069] In the formula, X0 is the maximum transmission value extracted from the target transmitted echo signal, and f(x) is the target transmitted echo signal.
[0070] After extracting the maximum transmission value from the target transmitted echo signal, the maximum transmission value can be stored in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix.
[0071] Before performing this step, a transmission coordinate matrix that matches the area of the battery detection surface needs to be constructed. Specifically, the area of the transmission coordinate matrix is considered to match the area of the battery detection surface if the area of the transmission coordinate matrix is equal to or proportional to the area of the battery detection surface.
[0072] When constructing a transmission coordinate matrix with the same area as the battery detection surface, it is based on the size of the battery detection surface and the size of the patch. Specifically, a Cartesian coordinate system is constructed. Starting from point O of the Cartesian coordinate system, and using the patch size as the unit length, a first side of the same length as the bottom edge of the battery detection surface is drawn on the x-axis of the Cartesian coordinate system, and a second side of the same length as the left side of the battery detection surface is drawn on the y-axis. A coordinate region with the same area as the battery detection surface is constructed based on the first and second sides. Further, this coordinate region is divided into multiple storage units of equal area based on the unit length, thus obtaining the transmission coordinate matrix with the same area as the battery detection surface. Each storage unit that makes up the transmission coordinate matrix is a transmission storage unit, and each transmission storage unit corresponds to a detection point on the battery detection surface.
[0073] For example, when scanning a 4mm*4mm battery detection surface according to a preset Z-shaped trajectory, the result is as follows: Figure 3 In the example of the 16 detection points shown, a system will be constructed as follows: Figure 4 The transmission coordinate matrix is shown. In the transmission coordinate matrix, the coordinate (1, 1) corresponds to transmission memory cell B1, which is related to... Figure 3 The detection point A1 corresponds to this value, and it is used to store the maximum transmission value corresponding to detection point A1. The coordinate (2, 1) in the transmission coordinate matrix corresponds to transmission storage unit B2, which is related to... Figure 3 The corresponding detection point A2 is used to store the maximum transmission value corresponding to detection point A2. And so on, which will not be elaborated here.
[0074] After constructing the transmission coordinate matrix, the maximum transmission value of each detection point is obtained and stored in the corresponding transmission storage unit in the transmission coordinate matrix. This process continues until the scanning is complete, at which point the maximum transmission values of each detection point are stored in the corresponding transmission storage unit in the transmission coordinate matrix.
[0075] After the scan is completed, step S1300 can be executed to calculate the maximum transmission value attenuation rate of each transmission memory cell in the transmission coordinate matrix relative to other spatially adjacent transmission memory cells, and select transmission memory cells with a maximum transmission value attenuation rate greater than or equal to an attenuation rate threshold as target transmission memory cells. Preferably, the attenuation rate threshold can be set to 30%. The formula for calculating the maximum transmission value attenuation rate of the current transmission memory cell relative to other spatially adjacent transmission memory cells can be as follows:
[0076]
[0077] It should be noted here that the spatially adjacent region includes at least one adjacent region located above, below, to the left, and to the right of the current region in the transmission coordinate matrix. When there are multiple transmission memory cells spatially adjacent to the current transmission memory cell, the maximum transmission value attenuation rate between the current transmission memory cell and each of the other spatially adjacent transmission memory cells will be calculated separately. If any of the calculated maximum transmission value attenuation rates is greater than or equal to the attenuation rate threshold, the current transmission memory cell can be selected as the target transmission memory cell.
[0078] For example, regarding Figure 4 In the case of transmission storage cell B1, other transmission storage cells adjacent to it include transmission storage cell B2 to its right and transmission storage cell B8 above it. Therefore, the maximum transmission value in transmission storage cell B1 is first extracted as the maximum transmission value (i.e., maximum transmission amplitude) of the current region. 当前区域 Extract the maximum transmission value stored in transmission storage unit B2 as the maximum transmission value (i.e., maximum transmission amplitude) of the spatially adjacent region. 空间相邻区域 By substituting both values into the formula for calculating the maximum transmission attenuation rate, the maximum transmission attenuation rate of the current transmission memory cell B1 relative to its spatially adjacent transmission memory cell B2 can be obtained. Similarly, the maximum transmission attenuation rate of the current transmission memory cell B1 relative to its spatially adjacent transmission memory cell B8 can be calculated. If either of the two calculated maximum transmission attenuation rates is greater than or equal to 30%, then transmission memory cell B1 can be selected as the target transmission memory cell.
[0079] After selecting the target transmissive storage cells, step S1400 can be executed to determine whether bubbles exist inside the battery and the projection area of the bubbles on the battery detection surface based on each target transmissive storage cell. Specifically, if the selected target transmissive storage cells are not empty, it means that bubbles exist inside the battery. Simultaneously, the area where the target transmissive storage cells are located is the projection area of the bubbles on the battery detection surface. For example, when the target transmissive storage cells are B7, B8, and B9, then the target transmissive storage cells are the gray area composed of B7, B8, and B9 (e.g., ...). Figure 5 (As shown) is the projection area of the bubble on the battery detection surface. The battery internal bubble detection method of this disclosure can determine whether bubbles exist inside the battery and the projection area of the bubbles on the battery detection surface.
[0080] In one possible implementation, after determining the projection area of the bubble on the battery detection surface, the method further includes determining the depth range of the bubble projection area. This determination of the depth range can be based on the target reflected echo signal, and specifically includes the following steps:
[0081] First, acquire the target reflected echo signals at each detection point on the battery detection surface. Acquiring the target reflected echo signals at each detection point includes the following steps:
[0082] First, the initial reflected echo signals at each detection point on the battery detection surface are acquired using an ultrasonic transducer. These initial reflected echo signals are the original reflected echo signals obtained by the ultrasonic transducer.
[0083] Then, the reflected echo signal located inside the battery is extracted from each initial reflected echo signal as the target reflected echo signal. This extraction is based on a pre-configured rule for finding the starting point of the reflected echo extraction and the sound path of the sound wave signal within the battery. Specifically, after acquiring the initial reflected echo signal at the detection point, the starting point for the reflected echo extraction is found using the rule. Then, starting from this starting point, a reflected echo of the same duration as the sound path is extracted from the initial reflected echo signal; this extracted reflected echo is the target reflected echo signal located inside the battery. The rule for finding the starting point can be the starting point of the initial reflected echo signal; the formula for calculating the sound path is described above and will not be repeated here.
[0084] Second, for each detection point, the maximum reflection value is extracted from the target reflected echo signal and the corresponding ToF value is calculated. The ToF value is then stored in the ToF storage unit corresponding to each detection point in the pre-constructed ToF coordinate matrix.
[0085] First, it should be noted that before performing this step, a ToF coordinate matrix with the same area as the battery detection surface needs to be constructed. The specific construction steps are detailed in the section on constructing the transmission coordinate matrix and will not be repeated here. For example, after scanning a 4mm*4mm detection surface according to a preset Z-shaped trajectory, the following results are obtained: Figure 3 In the example of the 16 detection points shown, a system will be constructed as follows: Figure 6 The ToF coordinate matrix is shown. In the ToF coordinate matrix, the coordinate (1, 1) corresponds to the ToF storage unit ToF1. This ToF storage unit ToF1 is related to... Figure 3 The detection point A1 corresponds to the ToF value corresponding to the maximum reflection value of detection point A1. The coordinate (2, 1) in the ToF coordinate matrix corresponds to the ToF storage unit ToF2, which is related to... Figure 3 Corresponding to detection point A2, the Time-of-Flight (ToF) value corresponding to the maximum reflectance value of detection point A2 is stored. And so on, without further explanation.
[0086] After constructing the Time-of-Flight (ToF) coordinate matrix, the ToF value corresponding to the maximum reflectance value of each detection point is obtained and stored in the ToF storage unit corresponding to the detection point in the ToF coordinate matrix. This process continues until the scanning is complete, at which point the ToF values corresponding to the maximum reflectance values of each detection point are stored in the ToF storage unit corresponding to each detection point in the ToF coordinate matrix.
[0087] When extracting the maximum reflection value from the target's reflected echo signal, the greedy algorithm described above can be used, which will not be elaborated here.
[0088] While using a greedy algorithm to extract the maximum reflection value from the target reflected echo signal, the sampling point index corresponding to the maximum reflection value can also be determined simultaneously. This allows the Time-of-Flight (ToF) value corresponding to the maximum reflection value to be calculated based on the sampling point index. The formula for calculating the ToF value is as follows:
[0089]
[0090] For example, when the sampling rate of the ultrasonic transducer is 80 MHz Sa / s, 80 data points will be collected from the detection point within 1 µs. These 80 data points constitute the initial reflected echo signal. Further, when extracting the target reflected echo signal from the initial reflected echo signal, data points 10-70 are extracted. A greedy algorithm determines that the maximum reflection value of the target reflected echo signal occurs at the 20th data point. Therefore, the ToF value = 20 / 80 = 0.25 µs.
[0091] Third, after obtaining the target transmission memory cells, the ToF value corresponding to each target transmission memory cell is extracted from the ToF coordinate matrix.
[0092] For example, in the target transmission storage unit is Figure 5 When targeting B7, B8, and B9, the coordinates of these three target transmission storage units (2, 2), (1, 2), and (1, 3) are obtained sequentially. The ToF storage unit ToF7, located at (2, 2), is selected from the ToF coordinate matrix, and its stored ToF value is extracted as the ToF value corresponding to target transmission storage unit B7. Similarly, the ToF storage unit ToF8, located at (1, 2), is selected from the ToF coordinate matrix, and its stored ToF value is extracted as the ToF value corresponding to target transmission storage unit B8. Finally, the ToF storage unit ToF9, located at (1, 3), is selected from the ToF coordinate matrix, and its stored ToF value is extracted as the ToF value corresponding to target transmission storage unit B9.
[0093] Fourth, based on the extracted ToF values, the depth range of the projection area is determined. Specifically, for each extracted ToF value, its corresponding depth value can be calculated using the depth value calculation formula. The minimum value among all depth values is taken as the minimum value of the depth range, and the maximum value is taken as the maximum value of the depth range. This allows the depth range of the projection area to be determined. The depth value calculation formula is as follows:
[0094]
[0095] In the formula, V 材料 S is the speed of sound propagation in the battery, S is the depth value corresponding to the ToF value, and t is the time corresponding to the distance between the ultrasonic transducer probes. This time t is equal to the distance between the ultrasonic transducer probes divided by the speed of sound propagation in the battery.
[0096] It should be noted that due to improper probe spacing settings of the ultrasonic transducer, resulting in the probe focal point being far from the battery surface, and incorrect probe frequency selection causing a sharp attenuation of ultrasonic energy inside the battery, the accuracy of the acquired target reflected echo signal is poor. Therefore, when using the target reflected echo signal to determine the depth range of the bubble projection area, the following steps are also included:
[0097] First, calculate the ToF value shift rate of each ToF memory cell relative to its spatially adjacent ToF memory cells in the ToF coordinate matrix, and select ToF memory cells with ToF value shift rates within a preset first range as target ToF memory cells. The preset first range can be 30%-80%. The formula for calculating the ToF value shift rate is as follows:
[0098]
[0099] It should be noted here that spatially adjacent regions include at least one adjacent region located above, below, to the left, or to the right of the current region in the ToF coordinate matrix. When there are multiple ToF memory cells spatially adjacent to the current ToF memory cell, the ToF value shift rate between the current ToF memory cell and each of the other spatially adjacent ToF memory cells will be calculated separately. If any of the calculated ToF value shift rates is within the range of 30%-80%, the current ToF memory cell can be selected as the target ToF memory cell.
[0100] For example, regarding Figure 6 In a ToF storage unit ToF1, the ToF storage units adjacent to it include ToF storage units ToF2 to its right and ToF storage unit ToF8 to its top. Therefore, the ToF value in ToF storage unit ToF1 is first extracted as the ToF value (i.e., the ToF value) of the current region. 当前区域 Extract the ToF value stored in the ToF storage unit ToF2 as the ToF value (i.e., the toF value) of the spatially adjacent region. 空间相邻区域 Substituting these two values into the ToF value shift rate calculation formula, we can obtain the ToF value shift rate of the current ToF storage cell D1 relative to its spatially adjacent ToF storage cell ToF2. Similarly, we can calculate the ToF value shift rate of the current ToF storage cell ToF1 relative to its spatially adjacent ToF storage cell ToF8. If one of the two calculated ToF value shift rates falls within the range of 30%-80%, the current ToF storage cell ToF1 can be selected as the target ToF storage cell.
[0101] Second, based on each target ToF storage cell, the first verification projection area of the bubble on the battery detection surface is determined. The specific method is described above for determining the projection area, and will not be repeated here. It is then determined whether the first verification projection area matches the projection area. If they match, the ToF values corresponding to each target transmission storage cell are extracted from the ToF coordinate matrix. Based on the extracted ToF values, the depth range of the projection area is determined.
[0102] For example, the first verification projection area is determined as follows: Figure 6 The determined projection area is the region where ToF7, ToF8, and ToF9 are located. Figure 5 If the regions where B7, B8, and B9 are located are found, then it can be determined that the first verification projection region is consistent with the projection region.
[0103] It should be noted here that if the first verification projection area matches the actual projection area, it indicates that the target reflected echo signal is accurate. Only when the target reflected echo signal is accurate will the ToF values in the ToF coordinate matrix be more accurate, thereby improving the accuracy of calculating the depth range of the projection area.
[0104] In one possible implementation, the embodiment of acquiring target reflected echo signals at each detection point on the battery detection surface; for each detection point, extracting the maximum reflection value from the target reflected echo signal and calculating the ToF value corresponding to the maximum reflection value, and storing the ToF value corresponding to the maximum reflection value in the ToF storage unit corresponding to each detection point in a pre-constructed ToF coordinate matrix, may further include:
[0105] The maximum reflection value corresponding to each detection point is stored in the pre-constructed reflection coordinate matrix and the corresponding reflection storage unit. The maximum reflection value growth rate of each reflection storage unit in the reflection coordinate matrix relative to other spatially adjacent reflection storage units is calculated, and reflection storage units with maximum reflection value growth rates within a preset second range are selected as target reflection storage units. Based on each target reflection storage unit, the second verification projection area of the bubble on the battery detection surface is determined. It is determined whether the second verification projection area is consistent with the projection area. If they are consistent, it indicates that the target reflected echo signal is accurate. Then, the ToF value corresponding to each target transmission storage unit is extracted from the ToF coordinate matrix. Based on the extracted ToF values, the depth range of the projection area is determined, thereby improving the accuracy of the depth range calculation. The preset second range can be 30%-80%. The formula for calculating the maximum reflection value growth rate is as follows:
[0106]
[0107] It should be noted that the calculation process for the second verification projection area is described in the section on the calculation process of the projection area above, and will not be repeated here.
[0108] In another possible implementation, the first and second verification projection regions are first calculated. Then, it is determined whether the first and second verification projection regions are consistent with the previously calculated projection regions. If they are consistent, the depth range is then calculated. This can further improve the accuracy of the depth range calculation.
[0109] This disclosure provides a method for detecting gases inside a battery, comprising: acquiring target transmission echo signals at each detection point on the battery detection surface; for each detection point, extracting the maximum transmission value from the target transmission echo signal and storing the maximum transmission value in a pre-constructed transmission coordinate matrix corresponding to each detection point in a transmission storage unit; calculating the attenuation rate of the maximum transmission value stored in each transmission storage unit in the transmission coordinate matrix relative to other spatially adjacent transmission storage units, and selecting transmission storage units with a maximum transmission value attenuation rate greater than or equal to an attenuation rate threshold as target transmission storage units; and determining, based on each target transmission storage unit, whether bubbles exist inside the battery and the projection area of the bubbles on the battery detection surface; wherein the area of the transmission coordinate matrix matches the area of the battery detection surface. This method can automatically identify bubbles inside the battery and calculate the projection area of the bubbles on the battery detection surface, thereby improving the detection efficiency and accuracy of bubbles inside the battery.
[0110] <Device Embodiment>
[0111] Figure 7 A schematic block diagram of a battery internal gas detection device according to an embodiment of the present disclosure is shown. Figure 7 As shown, the device 100 includes:
[0112] The transmission echo signal acquisition module 110 is used to acquire the target transmission echo signal of each detection point on the battery detection surface.
[0113] The transmission coordinate matrix construction module 120 is used to extract the maximum transmission value from the target transmission echo signal for each detection point, and store the maximum transmission value in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix.
[0114] The target transmission storage unit filtering module 130 is used to filter at least two spatially adjacent transmission storage units from the transmission coordinate matrix and whose stored maximum transmission value is less than or equal to a preset transmission threshold as target transmission storage units.
[0115] The bubble detection module 140 is used to determine whether there are bubbles inside the battery and the projection area of the bubbles on the battery detection surface based on each of the target transmission storage units.
[0116] The area of the transmission coordinate matrix is matched with the area of the battery detection surface.
[0117] <Equipment Example>
[0118] Figure 8 A schematic block diagram of a battery internal gas detection device according to an embodiment of the present disclosure is shown. Figure 8As shown, the battery internal gas detection device 200 includes a processor 210 and a memory 220 for storing executable instructions of the processor 210. The processor 210 is configured to implement any of the aforementioned battery internal gas detection methods when executing the executable instructions.
[0119] It should be noted here that the number of processors 210 can be one or more. Furthermore, the battery internal gas detection device 200 of this embodiment may also include an input device 230 and an output device 240. The processors 210, memory 220, input device 230, and output device 240 can be connected via a bus or other means, which are not specifically limited here.
[0120] The memory 220, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and various modules, such as the program or module corresponding to the battery internal gas detection method of this disclosure embodiment. The processor 210 executes various functional applications and data processing of the battery internal gas detection device 200 by running the software program or module stored in the memory 220.
[0121] Input device 230 can be used to receive input digital numbers or signals. These signals may include key signals related to user settings and function control of the device / terminal / server. Output device 240 may include a display device such as a screen.
[0122] <Storage Medium Examples>
[0123] According to a fourth aspect of this disclosure, a non-volatile computer-readable storage medium is also provided, having stored thereon computer program instructions that, when executed by processor 210, implement the method for detecting internal gas in a battery as described above.
[0124] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A method for detecting gas inside a battery, characterized in that, include: Acquire the target transmitted echo signal at each detection point on the battery detection surface; For each detection point, the maximum transmission value is extracted from the target transmission echo signal, and the maximum transmission value is stored in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix; Calculate the maximum transmission value attenuation rate of each transmission storage cell relative to other spatially adjacent transmission storage cells in the transmission coordinate matrix, and select transmission storage cells with a maximum transmission value attenuation rate greater than or equal to the attenuation rate threshold as target transmission storage cells. Based on each of the target transmission storage units, determine whether there are bubbles inside the battery and the projection area of the bubbles on the battery detection surface; The area of the transmission coordinate matrix is matched with the area of the battery detection surface.
2. The method according to claim 1, characterized in that, When acquiring the target transmitted echo signal at the detection point on the battery detection surface, the following steps are included: The initial transmitted echo signal of the detection point on the battery detection surface is obtained by an ultrasonic transducer. The transmitted echo signal located inside the battery is extracted from the initial transmitted echo signal and used as the target transmitted echo signal.
3. The method according to claim 2, characterized in that, After acquiring the initial transmitted echo signal of the detection point on the battery detection surface using an ultrasonic transducer, the method further includes: Determine whether the noise floor amplitude in the initial transmitted echo signal is less than or equal to a preset noise floor threshold; When the noise floor amplitude is determined to be less than or equal to the noise floor threshold, the initial transmitted echo signal is determined to be valid. If the initial transmitted echo signal is confirmed to be valid, the operation of extracting the transmitted echo signal located inside the battery from the initial transmitted echo signal is then performed as the target transmitted echo signal.
4. The method according to claim 1, characterized in that, If the initial transmitted echo signal is determined to be valid, the method further includes: normalizing the initial transmitted echo signal.
5. The method according to claim 1, characterized in that, When acquiring the target transmitted echo signal at each detection point on the battery detection surface, the following is also included: Acquire the target reflected echo signals at each detection point on the battery detection surface; For each detection point, the maximum reflection value is extracted from the target reflected echo signal and the ToF value corresponding to the maximum reflection value is calculated. The ToF value is then stored in the ToF storage unit corresponding to each detection point in the pre-constructed ToF coordinate matrix. After obtaining the target transmissive memory cell, the ToF value corresponding to each target transmissive memory cell is extracted from the ToF coordinate matrix; Based on the extracted ToF values, the depth range of the projection area is determined.
6. The method according to claim 5, characterized in that, After extracting the maximum reflection value from the target reflected echo signal for each detection point and calculating the ToF value corresponding to the maximum reflection value, and storing the ToF value in the ToF storage unit corresponding to each detection point in the pre-constructed ToF coordinate matrix, the method further includes: Calculate the ToF value shift rate of each ToF storage cell in the ToF coordinate matrix relative to other spatially adjacent ToF storage cells, and select the ToF storage cells whose ToF value shift rate is within a preset first range as target ToF storage cells; Based on each of the target ToF storage cells, a first verification projection area of the bubble is determined on the battery detection surface; Determine whether the first verification projection area is consistent with the projection area. If they are consistent, extract the ToF value corresponding to each target transmission storage unit from the ToF coordinate matrix. Based on the extracted ToF values, determine the depth range of the projection area.
7. The method according to claim 5, characterized in that, Also includes: The maximum reflection value corresponding to each detection point is stored in the pre-constructed reflection coordinate matrix and the reflection storage unit corresponding to each detection point; Calculate the maximum reflection value growth rate of each reflection storage unit in the reflection coordinate matrix relative to other spatially adjacent reflection storage units, and select the reflection storage units whose maximum reflection value growth rate is within a preset second range as target reflection storage units; Based on each of the target reflection storage units, a second verification projection area of the bubble on the battery detection surface is determined; Determine whether the second verification projection area is consistent with the projection area. If they are consistent, extract the ToF value corresponding to each of the target transmission storage units from the ToF coordinate matrix. Based on the extracted ToF values, determine the depth range of the projection area.
8. A device for detecting gas inside a battery, characterized in that, include: The transmission echo signal acquisition module is used to acquire the target transmission echo signal of each detection point on the battery detection surface; The transmission coordinate matrix construction module is used to extract the maximum transmission value from the target transmission echo signal for each detection point, and store the maximum transmission value in the transmission storage unit corresponding to each detection point in the pre-constructed transmission coordinate matrix; The target transmission storage cell screening module is used to calculate the maximum transmission value attenuation rate of each transmission storage cell in the transmission coordinate matrix relative to other spatially adjacent transmission storage cells, and to screen out the transmission storage cells with a maximum transmission value attenuation rate greater than or equal to the attenuation rate threshold as target transmission storage cells. A bubble detection module is used to determine, based on each of the target transmission storage units, whether there are bubbles inside the battery and the projection area of the bubbles on the battery detection surface. The area of the transmission coordinate matrix is matched with the area of the battery detection surface.
9. A device for detecting gas inside a battery, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to implement the method of any one of claims 1 to 7 when executing the executable instructions.
10. A non-volatile computer-readable storage medium storing computer program instructions thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the method described in any one of claims 1 to 7.