Method and system for detecting battery welding quality using vibration signals

Abstract

The application provides a method and system for detecting welding quality of a battery by using a vibration signal. A first vibration signal is applied to a first welding workpiece of a welding component to be detected in the battery. After the first vibration signal is excited, vibration parameters at a first detection position (i.e., a detection position) on the first welding workpiece and a second detection position (i.e., a reference detection position) on a second welding workpiece of the welding component to be detected are detected. A difference between first vibration parameters corresponding to the detection position and second vibration parameters corresponding to the reference detection position is compared with a parameter range determined by a welding component with good welding, so as to determine the welding quality of the welding component to be detected. The vibration of the reference detection position (vibration parameters) is deducted, i.e., the vibration parameters caused by external vibration on the welding component to be detected are deducted. The interference caused by external vibration on the welding component to be detected is reduced, the detection accuracy is improved, and nondestructive detection of the welding component to be detected is realized.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a method and system for detecting battery welding quality using vibration signals. Background Technology

[0002] In the battery manufacturing process of terminal devices, different components often need to be welded together. Improper welding operations can easily lead to incomplete or excessive soldering, severely reducing battery quality and lifespan, causing battery malfunctions during user operation, affecting the user experience, and potentially even impacting user safety.

[0003] Currently, welding tensile tests or tests on battery voltage and internal resistance are commonly used to inspect welding quality. However, these methods cannot accurately, effectively, or promptly detect defects such as incomplete or over-welded welds in welded components. Furthermore, the testing process may damage the welded components being inspected, resulting in low efficiency and accuracy. Therefore, a method is needed that can accurately, effectively, and continuously detect incomplete or over-welded welds in battery components online, thereby ensuring the welding quality of battery components and improving user safety. Summary of the Invention

[0004] This application provides a method and system for detecting the welding quality of a battery using vibration signals. A vibration signal is applied to the welded component to be tested within the battery. Vibration parameters generated at both the detection position and a reference detection position after the vibration signal excitation are detected. The difference between the vibration parameters at the detection position and the reference detection position is compared with a parameter range determined by multiple well-welded components to determine the welding quality of the component to be tested. This application deducts the vibration at the reference detection position, i.e., it deducts the vibration parameters of the welded component caused by external vibrations, reducing interference from external vibrations and improving detection accuracy. Therefore, it can accurately and in real-time detect the welding quality of the component to be tested, effectively screening out defective products. It enables non-destructive testing of the welded component, allows continuous online monitoring of the welding status of the component to be tested, and enables real-time monitoring of the welding effect of all welded components, avoiding defects such as incomplete welds or over-welds.

[0005] In a first aspect, a method for detecting the welding quality of a battery using vibration signals is provided. The battery includes a welded component to be tested, which includes a first welded workpiece and a second welded workpiece. The ratio of the volume of the second welded workpiece to the volume of the first welded workpiece is greater than or equal to 2. The method includes: applying a first vibration signal to a first position on the first welded workpiece; detecting vibration information at at least one first detection position on the first welded workpiece using a first laser probe; detecting vibration information at at least one second detection position on the second welded workpiece using a second laser probe; converting the vibration information at at least one first detection position into a first vibration parameter; and converting the vibration information at at least one second detection position into a second vibration parameter. The second vibration parameter; based on the first vibration parameter and the second vibration parameter, a first value is determined; when the first value is within a predetermined value range, the welding quality of the welded component under test is determined to be good; when the first value is not within the predetermined value range, the welded component under test is determined to have welding defects; wherein, the welding area on the welded component under test is located between a first position and at least one first detection position, and the welding area includes at least one weld point; the predetermined value range is determined based on the vibration parameters corresponding to multiple well-welded welded components, and the structure, size, welding position, and welding process of each well-welded welded component are the same as the structure, size, welding position, and welding process of the welded component under test.

[0006] The first aspect provides a method for detecting battery welding quality using vibration signals. A vibration signal (i.e., a first vibration signal) is applied to a first position on a first welding workpiece of the component to be tested within the battery. Vibration parameters (i.e., the first vibration parameter and the second vibration parameter) generated at a detection position (i.e., the first detection position) on the first welding workpiece and a reference detection position (i.e., the second detection position) on the second welding workpiece after the welding component is excited by the vibration signal are detected. The difference between the vibration parameters corresponding to the detection position and the reference detection position (i.e., the difference between the first vibration parameter and the second vibration parameter) is compared with a parameter range determined by a well-welded component to determine the welding quality of the component to be tested. This application eliminates the vibration at the reference detection position, i.e., it eliminates the vibration parameters of the welding component to be tested caused by external vibrations, reducing the interference of external vibrations on the detection results and improving detection accuracy. Therefore, it can accurately and in real-time detect the welding quality of the component to be tested, effectively screening out defective welds, and achieving non-destructive (or non-destructive) testing of the welding component to be tested. Furthermore, it can continuously detect the welding status of the components under test online, enabling real-time monitoring of the welding effect of all welded components. This ensures the welding quality of the battery, avoids defects such as incomplete welding or over-welding, improves the quality and lifespan of the battery, and thus enhances the user experience when using terminal devices equipped with this battery.

[0007] In this application, the ratio of the volume of the second welded workpiece to the volume of the first welded workpiece is greater than or equal to 2. Both the application position (i.e., the first position) and the detection position (i.e., the first detection position) of the first vibration signal are located on the smaller first welded workpiece, where the vibration caused by the first vibration signal is relatively large. The reference detection position (i.e., the second detection position) is located on the larger second welded workpiece, where the vibration caused by the first vibration signal is relatively small. Simultaneously, both the detection position and the reference detection position experience vibrations caused by external interference. Therefore, the vibration information at the detection position mainly reflects the vibration of the welded component under test caused by the vibration signal excitation and external interference, while the vibration information at the reference detection position mainly reflects the vibration of the welded component under test caused by external interference.

[0008] In the embodiments of this application, the number of laser probes can be one or more.

[0009] In one possible implementation of the first aspect, determining the first value based on the first vibration parameter and the second vibration parameter includes: determining the average value of the first vibration parameter corresponding to at least one first detection position based on the first vibration parameter corresponding to each first detection position; determining the average value of the second vibration parameter corresponding to at least one second detection position based on the second vibration parameter corresponding to each second detection position; and taking the difference between the average value of the first vibration parameter corresponding to at least one first detection position and the average value of the second vibration parameter corresponding to at least one second detection position as the first value. In this implementation, the vibration at the reference detection position is subtracted, i.e., the vibration parameters of the welded component under test caused by external vibration are subtracted, reducing the interference of external vibration on the detection results and improving the detection accuracy.

[0010] In one possible implementation of the first aspect, the distance between the first position and the solder joint is 0.5mm to 50mm, the distance between the first detection position and the solder joint is 0.5mm to 10mm, and the distance between the second detection position and the solder joint is 0.5mm to 10mm. This implementation ensures the accuracy and repeatability of the test results.

[0011] In one possible implementation of the first aspect, if there are multiple weld points in the welding area of ​​the welded component to be tested, and there are multiple detection positions (i.e., first detection positions) and multiple reference detection positions (i.e., second detection positions), then the distance between the first position (i.e., the position where the first vibration signal is applied) and each weld point is between 0.5 mm and 50 mm, the distance between any first detection position (i.e., detection position) and any weld point is between 0.5 mm and 10 mm, and the distance between any second detection position (i.e., reference detection position) and any weld point is between 0.5 mm and 10 mm. In other words, there are multiple different distances between different first detection positions and different weld points, and these multiple different distances are all between 0.5 mm and 10 mm; there are also multiple different distances between different second detection positions and different weld points, and these multiple different distances are all between 0.5 mm and 10 mm.

[0012] For example, the second welded workpiece is an electrode sheet, and the first welded workpiece is an electrode tab. Alternatively, the second welded workpiece is a battery casing, and the first welded workpiece is a nickel sheet.

[0013] In one possible implementation of the first aspect, the method further includes: using an optical fiber sensor to detect uncoated and coated areas on the welded component under test; when the optical fiber sensor detects an uncoated area on the welded component under test, a first laser probe and a second laser probe use a first power to detect vibration information of the uncoated area after applying a first vibration signal; when the optical fiber sensor detects a coated area on the welded component under test, the first laser probe and the second laser probe use a second power to detect vibration information of the coated area after applying the first vibration signal; the second power is less than the first power, and the welded area is located in the uncoated area. During the detection process, the power of the laser probe during operation can be reduced, thereby increasing the lifespan of the laser probe.

[0014] For example, when inspecting the welding quality of the electrode and tab online, since the welding area is located in the uncoated area of ​​the electrode, the laser probe power is increased to the normal operating value when the fiber optic sensor detects the uncoated area; when the fiber optic sensor detects the coated area, the laser probe power is reduced to a lower value. This method can reduce the power consumption of the laser during operation and extend the lifespan of the laser probe.

[0015] In one possible implementation of the first aspect, the vibration information includes at least one of vibration displacement information, vibration velocity information, vibration acceleration information, vibration frequency information, vibration amplitude information, vibration energy information, and vibration waveform information; the vibration parameters include at least one of vibration displacement parameters, vibration velocity parameters, vibration acceleration parameters, vibration frequency parameters, vibration amplitude parameters, vibration energy parameters, and vibration waveform parameters.

[0016] In one possible implementation of the first aspect, the predetermined numerical range is obtained by the following method: applying a second vibration signal to a plurality of well-welded welded components, wherein the amplitude and frequency of the first and second vibration signals are the same, and the application position and the first position of the second vibration signal are the same on the plurality of well-welded welded components; detecting the vibration information of each well-welded welded component after the application of the second vibration signal at a third detection position and a fourth detection position on each well-welded welded component, wherein the number and position of the third detection position and the first detection position on the welded component to be tested are the same on different well-welded welded components, and the number and position of the third detection position on each well-welded welded component are the same as the number and position of the first detection position on the welded component to be tested, and the number and position of the fourth detection position on each well-welded welded component are the same as the number and position of the second detection position on the welded component to be tested; converting the vibration information at the third detection position on the plurality of well-welded welded components into a third vibration parameter; converting the vibration information at the fourth detection position on the plurality of well-welded welded components into a fourth vibration parameter; and obtaining the predetermined numerical range based on the third vibration parameter and the fourth vibration parameter.

[0017] In one possible implementation of the first aspect, obtaining the predetermined numerical range based on the third vibration parameter and the fourth vibration parameter includes: determining the average value of the third vibration parameter corresponding to each well-welded welded component; determining the average value of the fourth vibration parameter corresponding to each well-welded welded component; determining the difference between the average value of the third vibration parameter and the average value of the fourth vibration parameter corresponding to each well-welded welded component as the vibration quality parameter of each well-welded welded component; and determining the average value X1 and standard deviation σ of the vibration quality parameters corresponding to the plurality of well-welded welded components respectively based on the vibration quality parameters of each well-welded welded component.

[0018] The predetermined numerical range is as follows:

[0019] [X1-3×σ,X1+3×σ].

[0020] In one possible implementation of the first aspect, the method further includes displaying the vibration parameter on a display. In this implementation, the converted data can be displayed on the display in graphical or numerical form, facilitating comparative analysis of the vibration of different components.

[0021] In a second aspect, a system for detecting the welding quality of a battery using vibration signals is provided. The system includes: a signal generator, a laser probe, a signal converter, and a processor. The laser probe includes a first laser probe and a second laser probe. The battery includes a welding component to be tested, which includes a first welding workpiece and a second welding workpiece. The ratio of the volume of the second welding workpiece to the volume of the first welding workpiece is greater than or equal to 2. At least one second detection position is present on the second welding workpiece, and at least one first detection position is present on the first welding workpiece. The welding area on the welding component to be tested is located between the first position and at least one first detection position. The welding area includes at least one weld point. The system is used to perform the method described in the first aspect above, or any possible implementation of the first aspect.

[0022] For example, the second welded workpiece is an electrode sheet, and the first welded workpiece is an electrode tab. Alternatively, the second welded workpiece is a battery casing, and the first welded workpiece is a nickel sheet.

[0023] Other embodiments of the second aspect correspond to other embodiments of the first aspect, and will not be described in detail here.

[0024] The technical effects corresponding to the second aspect and any implementation thereof can be found in the first aspect and any implementation thereof, and will not be repeated here.

[0025] In one possible implementation of the second aspect, the system further includes: an optical fiber sensor connected in series before a first laser probe and a second laser probe; the optical fiber sensor is used to: detect uncoated and coated areas on the weldment under test; when the optical fiber sensor detects an uncoated area on the weldment under test, the first and second laser probes use a first power to detect vibration information of the uncoated area after applying a first vibration signal; when the optical fiber sensor detects a coated area on the weldment under test, the first and second laser probes use a second power to detect vibration information of the coated area after applying the first vibration signal; the second power is less than the first power, and the weldment is located in the uncoated area. During the detection process, the power of the laser probes during operation can be reduced, thereby increasing the lifespan of the laser probes.

[0026] For example, when inspecting the welding quality of the electrode and tab online, since the welding area is located in the uncoated area of ​​the electrode, the laser probe power is increased to the normal operating value when the fiber optic sensor detects the uncoated area; when the fiber optic sensor detects the coated area, the laser probe power is reduced to a lower value. This method can reduce the power consumption of the laser during operation and extend the lifespan of the laser probe.

[0027] In one possible implementation of the second aspect, the distance between the fiber optic sensor and the first laser probe is less than or equal to 2 mm; the distance between the fiber optic sensor and the second laser probe is less than or equal to 2 mm. This ensures that the fiber optic sensor and the laser probe detect the same non-dressing area or the same dressing area.

[0028] In one possible implementation of the second aspect, the system further includes a display for showing the vibration parameters obtained by the signal converter. In this implementation, the converted data can be displayed on the display in graphical or numerical form, facilitating comparative analysis of the vibration of different components.

[0029] The method and system for detecting battery welding quality using vibration signals provided in this application apply a vibration signal (i.e., a first vibration signal) to a first position of a first welding workpiece in the battery to be welded. After being excited by the vibration signal, the welding workpiece generates vibration information at a detection position (i.e., the first detection position) on the first welding workpiece and a reference detection position (i.e., the second detection position) on the second welding workpiece. After detecting the vibration information by laser probes (a first laser probe and a second laser probe), a signal converter converts the vibration information detected by the laser probes into vibration parameters (the first vibration parameter corresponds to the detection position, and the second vibration parameter corresponds to the reference detection position). The method and system determine the vibration parameters (i.e., the first vibration parameter) corresponding to the detection position (i.e., the first detection position) and the vibration parameters (i.e., the second detection position) corresponding to the reference detection position (i.e., the second detection position). The difference in vibration parameters (i.e., the second vibration parameter) (this difference is the first value) is compared with the difference in vibration parameters corresponding to the detection position and the reference detection position (i.e., the first value) and a parameter range determined by multiple well-welded components (i.e., a predetermined value range) to determine the welding quality of the component to be tested. This application subtracts the vibration parameters of the reference detection position, that is, it subtracts the vibration parameters of the component to be tested caused by external vibration, reducing the interference caused by external vibration on the component to be tested, improving the detection accuracy, accurately detecting the welding quality of the component to be tested, effectively screening out defective welds, realizing non-destructive (or non-destructive) detection of the component to be tested, and can be used to detect the welding quality of welding components with complex mechanisms, showing good versatility. Furthermore, it can continuously detect the welding status of the component to be tested online, realizing real-time monitoring of the welding effect of all welding components, thereby ensuring the welding quality of the battery and avoiding the occurrence of defects such as incomplete welding or over-welding. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a system for detecting battery welding quality using vibration signals, provided in an embodiment of this application.

[0031] Figure 2This is a schematic flowchart illustrating an example of a method for detecting battery welding quality using vibration signals, provided in an embodiment of this application.

[0032] Figure 3 This is a schematic diagram of the structure of a welded component to be tested in a battery, provided in an embodiment of this application.

[0033] Figure 4 This is a schematic diagram of a well-welded component structure in a battery provided in an embodiment of this application.

[0034] Figure 5 This is a schematic diagram of another example of a detection system for detecting battery welding quality using vibration signals, provided in an embodiment of this application.

[0035] Figure 6 This application provides a schematic diagram of a detection system for continuously detecting whether there is poor soldering or over-soldering on the tabs of a battery electrode. Detailed Implementation

[0036] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0037] In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0038] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this embodiment, unless otherwise stated, "a plurality of" means two or more.

[0039] With the development of technology, various terminal devices (such as mobile phones, computers, tablets, and various wearable devices) play an important role in people's lives, and the batteries of these electronic devices are particularly important. In the battery production process of terminal devices, different components often need to be welded together. For example, during battery production, the battery tabs need to be welded to the current collector. Furthermore, during battery pack processing, nickel sheets need to be welded onto the finished battery casing. Improper welding operations can easily lead to incomplete or excessive soldering, severely reducing battery quality and lifespan, causing battery malfunctions during user operation, affecting the user experience, and potentially even impacting user safety.

[0040] To check the welding effect, welding tensile tests or tests on battery voltage and internal resistance are commonly used. However, welding tensile tests are destructive tests, and this method can only be used for random checks at the beginning or end of battery production. It cannot monitor the welding effect of all welded components in real time, and cannot detect incomplete or over-welded welds in a timely manner. Therefore, it cannot detect defective products caused by incomplete or over-welded welds in a timely manner. As a result, defective products may flow into subsequent processes, and by the time they are discovered, it may have become a batch problem, causing huge losses.

[0041] To maximize the chances of intercepting defective products with faulty solder joints, battery manufacturers may test the battery's voltage and internal resistance before shipment. However, not all faulty or over-soldered products can be detected through voltage and internal resistance testing. For example, taking laser welding as an example, assuming there are four solder joints under normal conditions, if two of them are faulty while the other two are normal, the battery's internal resistance may also appear normal. Therefore, this method cannot completely and effectively screen out defective products, and the batteries may malfunction when used in end devices.

[0042] In view of this, this application provides a method and system for detecting the welding quality of a battery using vibration signals. A vibration signal is applied to the welded component to be tested within the battery. Vibration parameters generated at both the detection position and a reference detection position after the vibration signal excitation are detected. The difference between the vibration parameters at the detection position and the reference detection position is compared with a parameter range determined by a well-welded component to determine the welding quality of the component to be tested. This application subtracts the vibration at the reference detection position (vibration parameters), thus subtracting the vibration parameters of the welded component caused by external vibrations. This reduces the interference caused by external vibrations on the welded component, improves detection accuracy, and allows for accurate and real-time detection of the welding quality of the component to be tested. It effectively filters out defective welds and enables non-destructive (or non-invasive) testing of the welded component. Furthermore, it can continuously detect the welding status of the components under test online, enabling real-time monitoring of the welding effect of all welded components. This ensures the welding quality of the battery, avoids defects such as incomplete welding or over-welding, improves the quality and lifespan of the battery, and thus enhances the user experience when using terminal devices equipped with this battery.

[0043] The following specific examples illustrate the method for detecting battery welding quality using vibration signals provided in this application.

[0044] Figure 1The diagram shown is a schematic representation of a system for detecting battery welding quality using vibration signals, provided in an embodiment of this application. The method for detecting battery welding quality using vibration signals provided in this application can be applied to… Figure 1 In the detection system shown, such as Figure 1 As shown, the detection system includes:

[0045] The components include a signal generator 101, a welded component under test 102, a laser probe 103, a signal converter 104, and a display 105.

[0046] The signal generator 101 is used to generate a vibration signal (e.g., a first vibration signal or a second vibration signal), the vibration frequency or amplitude of which is fixed. For example, in this embodiment, the vibration signal can be a sound wave signal or a vibration wave signal. It should be understood that in other embodiments of this application, the signal generator 101 can also generate other forms of vibration signals. This application does not limit the specific form of the signal generated by the signal generator 101, as long as the generated signal is a vibration signal.

[0047] The vibration signal generated by the signal generator 101 is applied to the welded component 102 under test. In this embodiment, the welding method of the welded component 102 under test may include laser welding, ultrasonic welding, or resistance welding, etc.; and the welded component 102 under test may include welding between two or more metal workpieces, the metal materials of the different workpieces may be the same material or different materials. This embodiment does not limit the welding method of the welded component 102 under test or whether the welded component under test is welded from two or more workpieces.

[0048] The laser probe 103 is used to detect the vibration information of the welded component 102 under test after a vibration signal is applied. For example, the vibration information includes at least one of the following: vibration displacement information, vibration velocity information, vibration acceleration information, vibration frequency information, vibration amplitude information, vibration energy information, and vibration waveform information. It should be understood that in the embodiments of this application, the vibration information may also include other forms of vibration information, and the embodiments of this application are not limited herein.

[0049] In this embodiment of the application, the number of laser probes 103 can be one or more, and this embodiment of the application does not limit the number of probes.

[0050] The signal converter 104 is connected to the laser probe 103 and is used to convert the vibration information detected by the laser probe 103 into vibration parameters. For example, the signal converter 104 can convert the vibration information detected by the laser probe 103 into sound signals or digital signals, thereby presenting the vibration information detected by the laser probe in a data or digital format.

[0051] The display 105 is used to display the signal converted by the signal converter 104, that is, to display the vibration parameters of the welded component 102 under test after the vibration signal is applied. For example, the converted data can be displayed on the display 105 in the form of charts or numbers, which facilitates the comparative analysis of the vibration of different components.

[0052] It should be understood that, Figure 1 The system shown has an optional display 105. In other words, in this embodiment, the detection system may also exclude the display.

[0053] Optional, in Figure 1 The system shown may also include a processor, which calculates the vibration parameters obtained by the signal converter 104 to obtain a first value, and compares the first value with a predetermined range of values ​​to determine the welding quality of the welded component to be tested.

[0054] It should be understood that, Figure 1 The examples shown are merely structural examples of the detection system provided in this application and do not constitute a limitation on the structure of the detection system. In other embodiments of this application, the detection system may include more or fewer components than shown, or combine certain components, or use different components, etc. This application does not impose any limitations here.

[0055] Figure 2 The diagram shown is a schematic flowchart of an example of a method for detecting battery welding quality using vibration signals, provided by an embodiment of this application. Figure 2 The method shown can be applied to Figure 1 The detection system shown. (As shown in the image) Figure 2 As shown, the method includes: S210 to S240.

[0056] S210, the vibration signal (or the first vibration signal) generated by the signal generator is applied to the first position of the first welded workpiece included in the welded component to be tested. The welded component to be tested includes the first welded workpiece and the second welded workpiece, and the ratio of the volume of the second welded workpiece to the volume of the first welded workpiece is greater than or equal to 2.

[0057] Figure 3 The diagram shown is a schematic representation of the structure of a welded component under test in a battery. Figure 3 As shown, the welded component to be tested includes: welded workpiece 1 (also referred to as the first welded workpiece) and welded workpiece 2 (also referred to as the second welded workpiece). Welded workpiece 1 and welded workpiece 2 are welded together, and the whole assembly of welded workpiece 1 and welded workpiece 2 can be referred to as the welded component to be tested. The volume of welded workpiece 2 is twice or more the volume of welded workpiece 1.

[0058] A vibration signal application position 3 (also referred to as the first position) exists on welding workpiece 1. A first vibration signal generated by a signal generator is applied to vibration signal application position 3. The frequency and amplitude of the first vibration signal are known. The first vibration signal generated by the signal generator propagates on welding workpieces 1 and 2. Multiple weld points exist in the welding areas of welding workpieces 1 and 2. For example, as... Figure 3 As shown, there are four solder joints. Solder joints 4 and 5 are normal solder joints with good soldering, while solder joints 6 and 7 are solder joints with poor soldering or over-soldering.

[0059] S220, vibration information is detected by laser probe at at least one detection position and at least one reference detection position on the welding component to be tested, wherein at least one first detection position exists on the first welding workpiece, at least one second detection position exists on the second welding workpiece, and the welding area on the welding component to be tested is located between the first position and at least one first detection position, and the welding area includes at least one weld point.

[0060] For example, continue to combine Figure 3 The example shown, Figure 3 Position 8 represents the detection position of the laser probe (the first detection position), and position 9 represents the reference detection position of the laser probe (the second detection position), which is equivalent to a reference detection position. Vibration information is detected using the laser probe at both detection position 8 and reference detection position 9. For example, the laser probe includes a first laser probe and a second laser probe. At detection position 8, the first laser probe is used to detect vibration information; at reference detection position 9, the second laser probe is used to detect vibration information.

[0061] like Figure 3 As shown, detection position 8 is located on welding workpiece 1, and reference detection position 9 is located on welding workpiece 2.

[0062] Optionally, in this embodiment, if the dimensions of welding workpiece 1 and welding workpiece 2 differ significantly, for example, the volume of welding workpiece 2 is twice or more the volume of welding workpiece 1, then the detection position 8 and the vibration signal application position 3 can both be set on the smaller welding workpiece 1, and the reference detection position 9 can be set on the larger welding workpiece 2. For example, welding workpiece 2 is an electrode sheet, and welding workpiece 1 is an electrode tab. Alternatively, welding workpiece 2 is a battery casing, and welding workpiece 1 is a nickel sheet.

[0063] Optionally, in the embodiments of this application, such as Figure 3As shown, the welding area 10 needs to be located between the vibration signal application position 3 and the detection position 8. The welding area 10 includes a number of weld points (e.g., weld points 4 to 7), including well-welded weld points as well as weld points with poor welds or over-welded welds. The welding area 13 is set between the vibration signal application position 3 and the detection position 8. After the first vibration signal is applied at the vibration signal application position 3, the first vibration signal is attenuated by the welding area 10 and then transmitted to the detection position 8. Thus, the attenuated first vibration signal can be detected at the detection position 8 using a laser probe.

[0064] In this embodiment of the application, when determining the reference detection position, it is necessary to ensure that the external disturbance vibration conditions of the reference detection position and the detection position are basically the same, and that the reference detection position is less affected by the applied vibration signal.

[0065] In this embodiment, since the ratio of the volume of welding workpiece 2 to the volume of welding workpiece 1 is greater than or equal to 2, the application position (i.e., the first position) and the detection position (i.e., the first detection position) of the first vibration signal are both located on the smaller welding workpiece 1, and the vibration caused by the first vibration signal is relatively large at the detection position. The reference detection position (i.e., the second detection position) is located on the larger welding workpiece 2, and the vibration caused by the first vibration signal is relatively small at the reference detection position (i.e., the second detection position). At the same time, both the detection position and the reference detection position are subject to vibration caused by external interference. Therefore, the vibration information at the detection position mainly reflects the vibration of the welding component under test caused by the vibration signal excitation and external interference, while the vibration information at the reference detection position mainly reflects the vibration of the welding component under test caused by external interference.

[0066] For example, such as Figure 3 As shown, the reference detection position 9 can be set around the welding area 10. For example, the reference detection position 9 can be set at... Figure 3 The area 11 surrounding the welding area shown in the figure is shown in the middle.

[0067] For example, the location of the reference detection position 9 needs to be as close as possible to the welding workpiece 1 (i.e., the part where the vibration signal is applied), and to a location where it is less affected by the applied vibration signal. For example, such as Figure 3 As shown, the reference detection position 9 is located on the welded workpiece 2 (i.e., the part where the vibration signal is not applied) and is located in the area 11 surrounding the welded area.

[0068] For example, combining Figure 3In the example shown, two laser probes are used to measure vibration signals at detection position 8 and reference detection position 9, respectively. For example, the vibration signal may include at least one of the following: vibration displacement signal, vibration velocity signal, vibration acceleration signal, vibration frequency signal, vibration amplitude signal, vibration energy signal, vibration waveform signal, etc.

[0069] After the vibration signal is applied, welding workpiece 1 and welding workpiece 2 will vibrate, and the vibration wave will propagate along the solid. Vibration will also exist at the detection position 8 and the reference detection position 9. The vibration signal of the vibration wave can be detected by the laser probe.

[0070] Optionally, in this embodiment, the distance between the first position (i.e., the vibration signal application position) and the solder joint is between 0.5 mm and 50 mm, the distance between the first detection position (i.e., the detection position) and the solder joint is between 0.5 mm and 10 mm, and the distance between the second detection position (i.e., the reference detection position) and the solder joint is between 0.5 mm and 10 mm. This ensures the accuracy and repeatability of the test results.

[0071] In this embodiment of the application, if there are multiple solder joints in the welding area (e.g.) Figure 3 Solder joints 4, 5, 6, and 7 shown in the diagram), and there are multiple probe positions and reference probe positions. In this case, the first position (e.g., Figure 3 The distance between the vibration signal application position 3 and each solder joint shown is between 0.5 mm and 50 mm. The distance between any first detection position (i.e., the detection position) and any solder joint is between 0.5 mm and 10 mm. The distance between any second detection position (i.e., the reference detection position) and any solder joint is also between 0.5 mm and 10 mm. In other words, there are multiple different distances between different first detection positions and different solder joints, all of which are between 0.5 mm and 10 mm; there are also multiple different distances between different second detection positions and different solder joints, all of which are between 0.5 mm and 10 mm.

[0072] S230, determine the difference in vibration parameters corresponding to at least one detection position and at least one reference detection position.

[0073] For example, combining Figure 3In the example shown, the signal converter converts the vibration information detected by the two laser probes into vibration parameters. Assuming the vibration parameter (or first vibration parameter) corresponding to probe position 8 is B1, and the vibration parameter (or second vibration parameter) corresponding to the reference probe position 9 is B2, the difference between B1 and B2 is the difference between the vibration parameters corresponding to the probe position and the reference probe position. This difference can also be called the first value or vibration quality parameter. This difference reflects the welding quality of the welded component under test. By subtracting the vibration from the reference probe position (i.e., the vibration parameter), the interference caused by external vibrations on the welded component under test is reduced, improving the accuracy of detecting the welding quality. By comparing the difference between the vibration parameters corresponding to the probe position and the reference probe position with a parameter range (or vibration quality parameter range) determined by multiple well-welded components, the welding quality of the welded component under test can be determined.

[0074] For example, in Figure 3 In the example shown, the volume of welded workpiece 2 is twice or more than the volume of welded workpiece 1. Furthermore, the vibration signal application position 3 and the detection position 8 are both located on welded workpiece 1, while the reference detection position 9 is located on welded workpiece 2. Detection position 8 and the reference detection position 9 are relatively independent positions. The vibration information detected by the laser probe at the reference detection position 9 reflects the vibration information caused by external interference to the welded component under test. The vibration information detected by the laser probe at detection position 8 reflects the vibration information caused by both external interference and the applied vibration signal to the welded component under test. The difference between the vibration parameters corresponding to detection position 8 and the vibration parameters corresponding to reference detection position 9 represents the vibration information truly caused by the vibration signal applied by the signal generator. Figure 3 In the example shown, vibration signal application position 3 and detection position 8 are located on the same welded workpiece 1, while reference detection position 9 is located on the welded workpiece 2. Both detection position 8 and reference detection position 9 are affected by external interference. When a vibration signal is applied at vibration signal application position 3, detection position 8 vibrates due to the vibration signal, while reference detection position 9, located on the larger welded workpiece 2, vibrates almost unaffected by the vibration signal. The difference between the vibration parameters corresponding to detection position 8 and the vibration parameters corresponding to reference detection position 9 reflects the vibration impact on the welded component under test due to the application of an additional vibration signal.

[0075] It should be understood that in the above example, only one detection position and one reference detection position are used for illustration. In other embodiments of this application, there can be multiple detection positions and multiple reference detection positions.

[0076] For example, if there are multiple detection locations and only one reference detection location, one possible implementation is to calculate the average value of multiple vibration parameters obtained from the multiple detection locations (this average value can also be called the average value of the first vibration parameter), use this average value as the vibration parameter corresponding to the detection location, and use the difference between this average value and the vibration parameter corresponding to the reference detection location (at this time, the vibration parameter corresponding to the reference detection location is equivalent to the average value of the second vibration parameter) as the difference between the vibration parameters corresponding to the detection location and the reference detection location respectively (this difference in vibration parameters can also be called the first value). Another possible implementation is to first calculate the difference between the vibration parameter corresponding to the reference detection location and the vibration parameter corresponding to each detection location, obtain multiple differences, calculate the average value of these multiple differences, and use this average value as the difference between the vibration parameters corresponding to the detection location and the reference detection location respectively (this difference in vibration parameters can also be called the first value).

[0077] For example, if there is one detection position and multiple reference detection positions, one possible implementation is to calculate the average value of multiple vibration parameters obtained at multiple reference detection positions (this average value can also be called the average value of the second vibration parameter), use this average value as the vibration parameter corresponding to the reference detection position, and use the difference between this average value and the vibration parameter corresponding to the detection position (at this time, the vibration parameter corresponding to the detection position is equivalent to the first vibration parameter) as the difference between the vibration parameters corresponding to the detection position and the reference detection position respectively (this difference between vibration parameters can also be called the first value); another possible implementation is to first calculate the difference between the vibration parameter corresponding to the detection position and the vibration parameter corresponding to each reference detection position, obtain multiple differences, calculate the average value of these multiple differences, and use this average value as the difference between the vibration parameters corresponding to the detection position and the reference detection position respectively.

[0078] For example, if there are multiple detection positions and multiple reference detection positions, and the number of detection positions is different from the number of reference detection positions, then the vibration parameters corresponding to the multiple reference detection positions can be obtained separately, and the average value of these multiple vibration parameters can be calculated (this average value can also be called the average value of the second vibration parameter); and the vibration parameters corresponding to the multiple detection positions can be obtained, and the average value of these multiple vibration parameters can be calculated (this average value can also be called the average value of the first vibration parameter); the difference between the average value of the first vibration parameter and the average value of the second vibration parameter can be calculated, and this difference can be used as the difference between the vibration parameters corresponding to the detection position and the reference detection position respectively (this difference in vibration parameters can also be called the first value).

[0079] For example, if there are multiple detection positions and multiple reference detection positions, and the number of detection positions is the same as the number of reference detection positions, one possible implementation is as follows: Vibration parameters corresponding to multiple reference detection positions can be obtained separately, and the average value of these multiple vibration parameters (this average value can also be called the average value of the second vibration parameter) can be calculated; vibration parameters corresponding to multiple detection positions can be obtained, and the average value of these multiple vibration parameters can also be called the average value of the first vibration parameter; the difference between the average value of the multiple detection positions and the average value of the multiple reference detection positions (i.e., the difference between the average value of the first vibration parameter and the average value of the second vibration parameter) can be calculated, and this difference can be used as the difference between the vibration parameters corresponding to the detection position and the reference detection position respectively (this difference in vibration parameters can also be called the first value). Another possible implementation is as follows: First, the difference between the vibration parameter corresponding to a detection position and the vibration parameter at the reference detection position corresponding to that detection position can be calculated, thus obtaining multiple differences. The average value of these multiple differences can be calculated and used as the difference between the vibration parameters corresponding to the detection position and the reference detection position respectively (this difference in vibration parameters can also be called the first value). In this method, the correspondence between the detection position and the reference detection position can be set in advance, that is, a one-to-one correspondence between the detection position and the reference detection position can be set.

[0080] It should also be understood that the above examples are only illustrative examples of one or more reference detection points and one or more detection points. In other embodiments of this application, a reference detection area (or a second detection area) and a detection area (or a first detection area) can be set in advance, and are not limited to setting one or more detection points. In this case, multiple points can be detected in the reference detection area and the detection area respectively, and the vibration information corresponding to each detection point can be obtained. The vibration parameters obtained after conversion by the signal converter can be used to obtain the vibration parameters corresponding to multiple detection points. The average value of the vibration parameters corresponding to the reference detection area and the average value of the vibration parameters corresponding to the detection area are calculated, and the difference between the two average values ​​is used as the first value.

[0081] For example, in the embodiments of this application, the vibration parameters can be any one of the following: vibration displacement, vibration velocity, vibration acceleration, vibration frequency, vibration amplitude, vibration energy, etc. The specific form of the vibration parameters is not limited in the embodiments of this application.

[0082] S240, by comparing the difference in vibration parameters with a predetermined range of vibration parameter differences, the welding quality of the welded component to be tested is determined.

[0083] S230 and S240 can be executed by a processor.

[0084] The following describes the process of determining the range of the predetermined difference. In the embodiments of this application, the predetermined range of the difference can also be referred to as the predetermined numerical range.

[0085] In this embodiment, prior to S210, multiple well-welded components are first manually selected. These well-welded components are identical to the actual welded component to be tested, sharing the same structure, dimensions, welding positions, and welding processes. For example, each well-welded component includes a first welded component and a second welded component. In other words, compared to the welded component to be tested, the multiple well-welded components are identical except for any defective welds (e.g., cold welds, over-welding).

[0086] After obtaining multiple well-welded components, for each well-welded component, a vibration signal (or a second vibration signal) generated by a signal generator is applied to the well-welded component. Each well-welded component has at least one detection position (also called a third detection position) and at least one reference detection position (also called a fourth detection position). Vibration information is detected at the third and fourth detection positions on each well-welded component using laser probes (e.g., multiple laser probes). The vibration information detected by the laser probes is converted into vibration parameters by a signal converter. The vibration parameter corresponding to each third detection position on the well-welded component can be called a third vibration parameter, and the vibration parameter corresponding to each fourth detection position on the well-welded component can be called a fourth vibration parameter. The difference between the vibration parameters corresponding to the detection positions and the reference detection positions (i.e., the difference between the third and fourth vibration parameters) is then determined. In other words, for each well-welded component, steps S210 to S230 are performed to obtain the difference in vibration parameters corresponding to each well-welded component (this difference in vibration parameters can also be called the vibration quality parameter of each well-welded component).

[0087] It should be understood that the vibration frequency or amplitude of the vibration signals applied to the multiple well-welded welded components are the same. In other words, the magnitude, form, and application location of the second vibration signal applied to each well-welded welded component are the same. Furthermore, the magnitude, form, and application location of the second vibration signal applied to each well-welded welded component are also the same as the magnitude, form, and application location of the first vibration signal applied to the welded component under test. That is, the same vibration signals are applied to the multiple well-welded welded components and the welded component under test.

[0088] It should also be understood that for different well-welded welded parts, the number and position of the detection positions (third detection position) and the reference detection positions (fourth detection position) are the same.

[0089] It should also be understood that the number and position of the detection positions (third detection positions) on each well-welded component are the same as the number and position of the detection positions (first detection positions) on the component to be tested; the number and position of the reference detection positions (fourth detection positions) on each well-welded component are also the same as the number and position of the reference detection positions (second detection positions) on the component to be tested.

[0090] For example, combining Figure 3 The example shown, Figure 3 This is a schematic diagram of the structure of the welded component to be tested. Figure 4 The diagram shown is a schematic of a well-welded component structure corresponding to the component to be tested. Figure 4 As shown, the well-welded component also includes: welded workpiece 1a and welded workpiece 2a, which are welded together. The assembly of welded workpiece 1a and welded workpiece 2a can be called a welded component. A vibration signal application position 3a exists on welded workpiece 1a, and a vibration signal generated by a signal generator is applied to the vibration signal application position 3a. Multiple weld points exist in the welding area of ​​welded workpiece 1a and welded workpiece 2a. For example, as... Figure 4 As shown, there are four solder joints, namely solder joint 4a, solder joint 5a, solder joint 6a and solder joint 7a. All four solder joints are normal solder joints with good soldering.

[0091] Figure 4 The welding workpiece 1a, welding workpiece 2a, detection position 8a, vibration signal application position 3a, reference detection position 9a, welding area 10a, and area surrounding the welding area 11a shown are... Figure 3 The locations of the welding workpiece 1 and welding workpiece 2, including the detection position 8, vibration signal application position 3, reference detection position 9, welding area 10, and the area surrounding the welding area 11, are all identical. In other words, Figure 3 and Figure 4 Compared to the structures shown, except Figure 3 Apart from defective solder joints 6 and 7, everything else (including structure, size, welding position, welding process, etc.) is the same. Furthermore, the magnitude and form (e.g., amplitude and frequency) of the second vibration signal applied by the signal generator to vibration signal application position 3a and the first vibration signal applied to vibration signal application position 3 are identical.

[0092] exist Figure 4In the structure shown, after executing steps S210 to S230, the difference between the vibration parameters corresponding to the detection position (i.e., the third detection position) and the reference detection position (i.e., the fourth detection position) on each well-welded welded component can be calculated (i.e., the difference between the third vibration parameter and the fourth vibration parameter). The difference between the third vibration parameter and the fourth vibration parameter corresponding to each well-welded welded component can also be called the vibration quality parameter of each well-welded welded component. By obtaining the difference in vibration parameters (vibration quality parameters) corresponding to multiple well-welded welded components, a predetermined range of difference values ​​can be obtained.

[0093] For example, assuming 32 well-welded welded components are used, after performing steps S210 to S230 for each well-welded component, the difference in vibration parameters corresponding to each well-welded component can be obtained. Figure 4 In the example shown, the difference between the third and fourth vibration parameters corresponding to each well-welded welded component can also be called the vibration quality parameter of each well-welded welded component. That is, 32 data points (i.e., 32 vibration quality parameters) are obtained. After removing outliers from the 32 data points, the remaining data are used as the basic data and a normal distribution is made to obtain the mean (denoted as X1) and standard deviation σ of the remaining data. The values ​​of the standard deviations above and below the mean X1 are selected as a1 and a2. In this way, the normal range of the vibration parameter difference corresponding to the well-welded welded component can be obtained as (a1, a2), which is [X1-3×σ, X1+3×σ]. That is, the predetermined difference range is [X1-3×σ, X1+3×σ].

[0094] It should be understood that if for multiple well-welded components, each well-welded component has multiple detection positions and reference detection positions, then the method for calculating the difference in vibration parameters corresponding to different welded components is the same.

[0095] For example, assuming that each well-welded component has two detection positions (i.e., two third detection positions) and two reference detection positions (i.e., two fourth detection positions), then for any well-welded component, the average value of the two vibration parameters corresponding to the two detection positions (i.e., the two third vibration parameters) can be calculated (the average value of the vibration parameters corresponding to these two detection positions can also be called the average value of the third vibration parameters). Similarly, the average value of the two vibration parameters corresponding to the two reference detection positions (i.e., the two fourth vibration parameters) can be calculated (the average value of the vibration parameters corresponding to these two reference detection positions can also be called the average value of the fourth vibration parameters). The difference between the average value of the third vibration parameters and the average value of the fourth vibration parameters is taken as the vibration quality parameter of this well-welded component.

[0096] It should also be understood that the method for calculating the difference in vibration parameters is the same for each well-welded component and the component under test.

[0097] By using the above method, a predetermined range of differences can be obtained from the well-welded welded parts.

[0098] The difference (i.e., the first value) of the vibration parameters of the welded component to be tested calculated in S230 is compared with the predetermined difference range.

[0099] If the difference in vibration parameters of the welded component under test is within the predetermined range, it proves that the quality of the welded component under test is good and that it is a qualified welded component.

[0100] If the difference in vibration parameters of the welded component under test is not within the predetermined range, it proves that the quality of the welded component under test is poor, and there are false welds or over-welds, indicating that the welded component is of unsuitable quality.

[0101] The method for detecting battery welding quality using vibration signals provided in this application applies a vibration signal (i.e., a first vibration signal) to the vibration signal application position (i.e., a first position) of the welding workpiece 1 (i.e., the first welding workpiece) of the welding component under test in the battery. After being excited by the vibration signal, the welding component under test generates vibration information at the detection position (i.e., the first detection position) on the welding workpiece 1 and the reference detection position (i.e., the second detection position) on the welding workpiece 2 (i.e., the second welding workpiece). After detecting the vibration information by laser probes (a first laser probe and a second laser probe), the vibration information is converted into vibration parameters (the detection position corresponds to the first vibration parameter, and the reference detection position corresponds to the second vibration parameter). The difference between the vibration parameters corresponding to the reference detection position and the reference detection position (i.e., the difference between the first vibration parameter and the second vibration parameter) is compared with the parameter range determined by the well-welded welded component to determine the welding quality of the welded component to be tested. This application deducts the vibration of the reference detection position, that is, it deducts the vibration parameters of the welded component to be tested caused by external vibration, reducing the interference of external vibration on the welded component to be tested, improving the detection accuracy, accurately detecting the welding quality of the welded component to be tested, effectively screening out defective welded products, realizing non-destructive (or non-destructive) detection of the welded component to be tested, and can be used to detect the welding quality of welded components with complex mechanisms, showing good versatility. Furthermore, it can continuously detect the welding status of the component to be tested online, realizing real-time monitoring of the welding effect of all welded components, thereby ensuring the welding quality of the battery and avoiding the occurrence of defects such as incomplete welding or over-welding.

[0102] Optionally, in some other embodiments of this application, to further increase the lifespan of the laser probe, an optical fiber and a laser probe can be used together. For example, an optical fiber sensor can be connected in series before the laser probe. Figure 5 The diagram shown is a schematic of another example of a system for detecting battery welding quality using vibration signals, provided in an embodiment of this application. The method for detecting battery welding quality using vibration signals provided in this application can also be applied to… Figure 5 The detection system shown. (As shown in the image) Figure 5 As shown, the system includes:

[0103] The components include a signal generator 501, a welded component under test 502, a fiber optic sensor 506, a rheostat 507, a laser probe 503, a signal converter 504, a display 505, and a power supply 508.

[0104] The descriptions of the signal generator 501, the welded component under test 502, the laser probe 503, the signal converter 504, and the display 505 can be found in [reference]. Figure 1 For the sake of brevity, the specific details will not be elaborated here.

[0105] Power supply 508 powers the fiber optic sensor 506, rheostat 507, and laser probe 503. The fiber optic sensor 506 and laser probe 503 are connected to the weldment under test 502. The fiber optic sensor 506 can sense the coated areas (e.g., the electrode coating area in a battery, also known as the current collector coating area) and uncoated areas (e.g., the uncoated electrode area, also known as the uncoated current collector area) of the weldment under test 502. When the fiber optic sensor 506 detects an uncoated area on the weldment under test 502, the internal resistance of the rheostat 507 decreases, the current in the circuit increases, and the power of the laser probe 503 increases to its normal operating value. When the fiber optic sensor 506 detects a coated area on the weldment under test 502, the internal resistance of the rheostat 507 increases, the current in the circuit decreases, and the power of the laser probe 503 decreases to a lower value. In this way, the power consumption of the laser probe 503 during operation can be reduced, extending its lifespan.

[0106] Optional, Figure 5 The laser probe shown includes: laser probes corresponding to the detection position and the reference detection position, respectively. Figure 5 The laser probe shown includes multiple laser probes, and in this case, the rheostat and the multiple laser probes are connected in series.

[0107] Optional, in Figure 5 The system shown may further include a processor, which calculates the vibration parameters obtained from the signal converter 504 to obtain a first value, and compares the first value with a predetermined range of values ​​to determine the welding quality of the welded component under test. In other words, the processor is mainly used to perform calculations and processing on the vibration parameters, and compares the processed data (i.e., the difference between the vibration parameters corresponding to the detection position and the reference detection position) with a predetermined range of values ​​to determine the welding quality of the welded component under test.

[0108] It should be understood that, Figure 5 In the system shown, display 505 is optional.

[0109] The following specific examples illustrate the method for detecting battery welding quality using vibration signals provided in this application.

[0110] Figure 6 The diagram shown is a schematic representation of a detection system provided in this application for continuously detecting whether there is poor soldering or over-soldering on the tabs of a battery electrode. Figure 6 As shown, the detection system includes:

[0111] The components include a signal generator 601, a welded component under test 602, a fiber optic sensor 603, a variable resistor 604, a laser probe 605, a signal converter 606, a display 607, and a power supply 608.

[0112] The welding component 602 to be tested includes: a tab 602a, a non-coated area of ​​the electrode (or a non-coated area of ​​the current collector) 602b, and a coated area of ​​the electrode (or a coated area of ​​the current collector) 602c.

[0113] Power supply 608 is used to power fiber optic sensor 603, rheostat 604 and laser probe 605. Fiber optic sensor 603 and laser probe 605 are not in contact with the welded component 602 under test.

[0114] Optionally, in this embodiment, the signal generator 601 and the welded component 602 under test may or may not be in contact.

[0115] Optionally, in this embodiment, the distance between the fiber optic sensor 603 and the laser probe 605 is less than 2mm, so as to ensure that the fiber optic sensor and the laser probe detect the same non-dressing area or the same dressing area.

[0116] In this embodiment of the application, if the laser probe 605 includes multiple laser probes, the distance between the fiber optic sensor and each laser probe is less than 2 mm.

[0117] exist Figure 6 In the detection system shown, a signal generator 601 generates a vibration signal, which is transmitted to the welded component 602 under test. A fiber optic sensor 603, a variable resistor 604, and a laser probe 605 are connected in series. The welded component 602 under test is movable relative to the fiber optic sensor 603, the variable resistor 604, and the laser probe 605. In other words, the welded component 602 under test can move in one direction, while the positions of the fiber optic sensor 603, the variable resistor 604, and the laser probe 605 remain relatively unchanged. This allows for continuous online measurement of the welding condition of the welded component 602.

[0118] When the fiber optic sensor 603 detects the non-coated area 602b of the electrode on the component 602 to be welded, the internal resistance of the variable resistor 604 decreases, the current in the circuit increases, and the power of the laser probe 605 increases to its normal operating value. When the fiber optic sensor 603 detects the coated area 602c of the electrode on the component 602 to be welded, the internal resistance of the variable resistor 604 increases, the current in the circuit decreases, and the power of the laser probe 605 decreases to a lower power value. This method can reduce the power consumption of the laser probe during operation and extend its service life.

[0119] The laser probe 605 can detect vibration information at the detection position and the reference detection position on the welding component 602, respectively. After acquiring the vibration information detected by the laser probe 605, the signal converter 606 converts the vibration information into vibration parameters. For example, the signal converter 606 can convert the vibration information detected by the laser probe 605 into an acoustic signal or a digital signal. Further, based on the vibration parameters converted by the signal converter 606, the difference in vibration parameters corresponding to the detection position and the reference detection position can be determined using the steps in S230 above. Then, using the steps in S240 above, the difference in vibration parameters is compared with a predetermined range of vibration parameter differences to determine the welding quality of the welding component 602 under test. The display 607 can display the signal converted by the signal converter 606, that is, the vibration parameters of the welding component 602 under test after the vibration signal is applied. For example, the converted data can be displayed on the display 607 in the form of a graph or numbers, which is convenient for comparative analysis of the vibration of different components.

[0120] The method for detecting battery welding quality using vibration signals provided in this application applies a vibration signal (i.e., a first vibration signal) to the welding workpiece 1 (i.e., the first welding workpiece) of the welding component to be tested in the battery. After being excited by the vibration signal, the welding component to be tested generates vibration information at the detection position (i.e., the first detection position) on the welding workpiece 1 and the reference detection position (i.e., the second detection position) on the welding workpiece 2 (i.e., the second welding workpiece). After detecting the vibration information by laser probes (a first laser probe and a second laser probe), the vibration information is converted into vibration parameters (the detection position corresponds to the first vibration parameter, and the reference detection position corresponds to the second vibration parameter). The vibration parameters corresponding to the detection position and the reference detection position are respectively... The difference between the first and second vibration parameters is compared with the parameter range determined by the well-welded component to determine the welding quality of the component to be tested. Vibration at the reference detection position (vibration parameters) is subtracted, meaning the vibration parameters caused by external vibrations are deducted, reducing interference from external vibrations and improving detection accuracy. This allows for accurate detection of the welding quality of the component under test, achieving non-destructive (or non-invasive) inspection. Continuous online monitoring of the welding status of the component under test is possible, enabling real-time monitoring of the welding effect of all components in the battery and avoiding defects such as incomplete or over-welded welds. Furthermore, a fiber optic sensor is placed before the laser probe to control its power, extending the probe's lifespan.

[0121] This application also provides a system for detecting battery welding quality using vibration signals. The system includes: a signal generator, a laser probe, a signal converter, and a display.

[0122] The signal generator is used to generate vibration signals, and the vibration frequency or vibration amplitude of the vibration signals is fixed.

[0123] A vibration signal (i.e., a first vibration signal) generated by a signal generator is applied to the welding component under test. A laser probe (e.g., including a first laser probe and a second laser probe) is used to detect the vibration information generated by the welding component under test at the detection position (first detection position) and the reference detection position (second detection position) after the vibration signal is applied. For example, the vibration information includes at least one of vibration displacement, vibration velocity, vibration acceleration, vibration frequency, vibration amplitude, vibration energy, and vibration waveform. A signal converter is connected to the laser probe and is used to convert the vibration information detected by the laser probe into vibration parameters (the detection position corresponds to the first vibration parameter, and the reference detection position corresponds to the second vibration parameter). For example, the signal converter can convert the vibration information detected by the laser probe into an acoustic signal or a digital signal, thereby presenting the vibration information detected by the laser probe in a data or digital format. A display is used to display the signal converted by the signal converter, that is, to display the vibration parameters of the welding component under test after the vibration signal is applied. For example, the converted data can be displayed on the display in the form of a graph or numbers, which is convenient for comparing and analyzing the vibration of different components. For example, the structure of the system for determining the welding quality of a battery using vibration signals provided in this application can be as follows: Figure 1 shown.

[0124] It should be understood that, Figure 1 In the system shown, the display 105 is optional. In other words, the system provided in this embodiment may also exclude the display.

[0125] Optional, in Figure 2 The system shown may also include a processor, which calculates the difference between the vibration parameters obtained by the signal converter and the reference detection position (also known as the vibration quality parameter or the first value), and compares the first value with a predetermined value range (or a predetermined value range) to determine the welding quality of the welded component to be tested.

[0126] Optionally, the system for determining battery welding quality using vibration signals provided in this application may not include... Figure 1 The welding component to be tested.

[0127] It should be understood that in the embodiments of this application, the number of laser probes may be one or more.

[0128] The system for detecting battery welding quality using vibration signals provided in this application can be referenced in the process of detecting the welding quality of the welded component under test. Figure 1 as well as Figure 2 For the sake of brevity, the corresponding descriptions will not be repeated here.

[0129] The system for detecting battery welding quality using vibration signals provided in this application generates a vibration signal (i.e., a first vibration signal) through a signal generator. This vibration signal is applied to the welding workpiece 1 (i.e., the first welding workpiece) of the component to be tested. The welding component under test generates vibration information at the detection position (i.e., the first detection position) on the welding workpiece 1 and the reference detection position (i.e., the second detection position) on the welding workpiece 2 (i.e., the second welding workpiece). After detecting the vibration information through a laser probe, a signal converter converts the vibration information detected by the laser probe into vibration parameters (the detection position corresponds to the first vibration parameter, and the reference detection position corresponds to the second vibration parameter). The detection position and... The difference in vibration parameters corresponding to the reference detection positions (i.e., the difference between the first vibration parameter and the second vibration parameter) is compared with the parameter range determined by the well-welded welded components to determine the welding quality of the welded component to be tested. This application subtracts the vibration condition at the reference detection position, that is, it subtracts the vibration parameters caused by external vibration to the welded component under test, reducing the interference of external vibration on the test results, improving the test accuracy, and can accurately detect the welding quality of the welded component under test, effectively screening out defective welded products. It realizes non-destructive testing of the welded component under test, and can be used to test the welding quality of welded components with complex mechanisms, showing good versatility. Furthermore, it can continuously detect the welding status of the component under test online, realizing real-time monitoring of the welding effect of all welded components, thereby ensuring the welding quality of the battery and avoiding the occurrence of defects such as incomplete welding or over-welding.

[0130] Optionally, in another possible implementation, based on the system for detecting battery welding quality using vibration signals provided in this application, the system may further include an optical fiber sensor connected in series before the laser probe. For example, the structure of the system for detecting battery welding quality using vibration signals provided in this application can be as follows: Figure 5 As shown, for example, when the welding quality of the electrode and the tab is detected online, since the welding area is located in the uncoated area of ​​the electrode, when the fiber optic sensor detects the uncoated area of ​​the electrode, the power of the laser probe is increased to the normal operating value; when the fiber optic sensor detects the coated area of ​​the electrode, the power of the laser probe is reduced to a smaller power value, which can reduce the power of the laser probe during operation and improve the service life of the laser probe.

[0131] Optionally, in this embodiment, the distance between the fiber optic sensor and the laser probe is less than 2 mm to ensure that the fiber optic sensor and the laser probe detect the same non-dressing area or the same dressing area.

[0132] In this embodiment of the application, if the system includes multiple laser probes, the distance between the fiber optic sensor and each laser probe is less than 2 mm.

[0133] It should be understood that, Figure 5 In the system shown, the display 505 is optional. In other words, the system provided in this embodiment may also exclude the display.

[0134] Optional, in Figure 5 The system shown may also include a processor, which calculates the vibration parameters obtained by the signal converter 504 to obtain the difference between the vibration parameters corresponding to the detection position and the reference detection position (also known as the vibration quality parameter or the first value), and compares the first value with a predetermined value range (or a predetermined value range) to determine the welding quality of the welded component to be tested.

[0135] It should be understood that, Figure 5 The examples shown are merely structural examples of the detection system provided in this application and do not constitute a limitation on the structure of the detection system. In other embodiments of this application, the detection system may include more or fewer components than those shown in the figures; for example, it may not include any components. Figure 5 The power supply and / or the soldered component under test, or a combination of certain components, or different components, etc., are not limited herein.

[0136] The system for detecting battery welding quality using vibration signals provided in this application generates a vibration signal (i.e., a first vibration signal) through a signal generator. This vibration signal is applied to the welding workpiece 1 (i.e., the first welding workpiece) of the welding component under test. The welding component under test generates vibration information at the detection position (i.e., the first detection position) on the welding workpiece 1 and the reference detection position (i.e., the second detection position) on the welding workpiece 2 (i.e., the second welding workpiece). After the vibration information is detected by a laser probe, a signal converter converts the vibration information detected by the laser probe into vibration parameters (the detection position corresponds to the first vibration parameter, and the reference detection position corresponds to the second vibration parameter). The difference between the vibration parameters corresponding to the detection position and the reference detection position (i.e., the difference between the first vibration parameter and the second vibration parameter) is compared with the parameter range determined by the well-welded welding component to determine the welding quality of the welding component under test. This application connects a fiber optic sensor in series before the laser probe, which can reduce the power consumption of the laser probe during operation, increase the service life of the laser probe, and improve the service life and stability of the system. Furthermore, this application deducts the vibration at the reference detection position, that is, it deducts the vibration parameters caused by external vibration to the welded component under test, reducing the interference of external vibration on the detection results, improving the detection accuracy, accurately detecting the welding quality of the welded component under test, effectively screening out defective welded products, realizing non-destructive (or non-destructive) detection of the welded component under test, continuously detecting the welding status of the component under test online, realizing real-time monitoring of the welding effect of all welded components in the battery, avoiding the occurrence of defects such as false welding or over-welding, and improving the service life and stability of the system.

[0137] It should be understood that the above description is merely to help those skilled in the art better understand the embodiments of this application, and is not intended to limit the scope of the embodiments of this application. Based on the examples given above, those skilled in the art can obviously make various equivalent modifications or changes. For example, some steps in the various methods described above may be unnecessary, or new steps may be added. Alternatively, any combination of two or more of the above embodiments may be used. Such modifications, changes, or combinations also fall within the scope of the embodiments of this application.

[0138] It should also be understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0139] It should also be understood that, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0140] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing embodiments, and will not be repeated here.

[0141] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for detecting battery welding quality using vibration signals, characterized in that, The battery includes a welded component to be tested, the welded component to be tested includes a first welded workpiece and a second welded workpiece, the ratio of the volume of the second welded workpiece to the volume of the first welded workpiece is greater than or equal to 2, and the method includes: The first vibration signal is applied to a first position on the first welded workpiece; The vibration information at at least one first detection position on the first welded workpiece is detected using a first laser probe. The vibration information at at least one second detection position on the second welded workpiece is detected using a second laser probe. The vibration information at at least one first detection location is converted into a first vibration parameter; The vibration information at at least one second detection location is converted into a second vibration parameter; The first value is determined based on the first vibration parameter and the second vibration parameter; When the first value is within a predetermined range, the welding quality of the welded component under test is determined to be good. If the first value is not within a predetermined range, it is determined that the welded component under test has a welding defect. Wherein, the welding area on the welding component to be tested is located between the first position and the at least one first detection position, and the welding area includes at least one weld point; The predetermined numerical range is determined based on the vibration parameters corresponding to multiple well-welded components. The structure, size, welding position, and welding process of each well-welded component are the same as those of the component to be tested. The non-coated and coated areas on the welding component under test are detected using an optical fiber sensor, which is connected in series before the first laser probe and the second laser probe. When the fiber optic sensor detects an uncoated area on the welded component under test, the first laser probe and the second laser probe use a first power to detect the vibration information of the uncoated area after the first vibration signal is applied; When the fiber optic sensor detects the coating area on the welding component to be tested, the first laser probe and the second laser probe use the second power to detect the vibration information of the coating area after the first vibration signal is applied; The second power is less than the first power, and the welding area is located in the non-coated area; Determining the first value based on the first vibration parameter and the second vibration parameter includes: Based on the first vibration parameter corresponding to each of the first detection positions, determine the average value of the first vibration parameter corresponding to the at least one first detection position; Based on the second vibration parameter corresponding to each second detection position, determine the average value of the second vibration parameter corresponding to the at least one second detection position; The difference between the average value of the first vibration parameter and the average value of the second vibration parameter is taken as the first value.

2. The method according to claim 1, characterized in that, The distance between the first position and the solder joint is 0.5mm to 50mm, the distance between the first detection position and the solder joint is 0.5mm to 10mm, and the distance between the second detection position and the solder joint is 0.5mm to 10mm.

3. The method according to claim 1 or 2, characterized in that, The vibration information includes at least one of the following: vibration displacement information, vibration velocity information, vibration acceleration information, vibration frequency information, vibration amplitude information, vibration energy information, and vibration waveform information. The vibration parameters include at least one of the following: vibration displacement parameters, vibration velocity parameters, vibration acceleration parameters, vibration frequency parameters, vibration amplitude parameters, vibration energy parameters, and vibration waveform parameters.

4. The method according to claim 1 or 2, characterized in that, The predetermined numerical range is obtained through the following method: The second vibration signal is applied to the plurality of well-welded welded parts respectively. The amplitude and frequency of the first vibration signal and the second vibration signal are the same. The application position of the second vibration signal on the plurality of well-welded welded parts is the same as that of the first vibration signal. At the third and fourth detection positions on each well-welded welded component, vibration information of each well-welded welded component after the second vibration signal is applied is detected. The number and position of the third detection positions on different well-welded welded components are the same, the number and position of the fourth detection positions on different well-welded welded components are the same, the number and position of the third detection positions on each well-welded welded component are the same as the number and position of the first detection positions on the welded component to be tested, and the number and position of the fourth detection positions on each well-welded welded component are the same as the number and position of the second detection positions on the welded component to be tested. The vibration information at the third detection position on the multiple well-welded components is converted into a third vibration parameter; The vibration information at the fourth detection position on the plurality of well-welded components is converted into a fourth vibration parameter; The predetermined numerical range is obtained based on the third vibration parameter and the fourth vibration parameter.

5. The method according to claim 4, characterized in that, The step of obtaining the predetermined numerical range based on the third vibration parameter and the fourth vibration parameter includes: Determine the average value of the third vibration parameter corresponding to each well-welded welded component; Determine the average value of the fourth vibration parameter corresponding to each well-welded welded component; The difference between the average value of the third vibration parameter and the average value of the fourth vibration parameter corresponding to each well-welded welded component is determined as the vibration quality parameter of each well-welded welded component. Based on the vibration quality parameters of each well-welded component, determine the average value X1 and standard deviation of the vibration quality parameters corresponding to the plurality of well-welded components. ; The predetermined numerical range is: 。 6. The method according to claim 1 or 2, characterized in that, The first welding workpiece is an electrode tab, and the second welding workpiece is an electrode sheet.

7. A system for detecting battery welding quality using vibration signals, characterized in that, The system includes: a signal generator, an optical fiber sensor, a laser probe, a signal converter, and a processor. The laser probe includes a first laser probe and a second laser probe. The optical fiber sensor is connected in series before the first laser probe and the second laser probe. The battery includes a welded component to be tested. The welded component to be tested includes a first welded workpiece and a second welded workpiece. The ratio of the volume of the second welded workpiece to the volume of the first welded workpiece is greater than or equal to 2. The system is used to perform the method for detecting the welding quality of a battery using vibration signals as described in any one of claims 1 to 6.

8. The system according to claim 7, characterized in that, The distance between the fiber optic sensor and the first laser probe is less than or equal to 2 mm; The distance between the fiber optic sensor and the second laser probe is less than or equal to 2 mm.

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