A method and system for detecting the state of a tab on a winding needle

Abstract

The application provides a winding needle and a tab state detection method and system, the method comprising: adding a thickness detection sensor on the winding needle according to the position of the tab; the thickness detection sensor can continuously or intermittently detect the thickness information at two positions on the tab and one position on the winding core; and the thickness data information at the detected positions is combined and compared to determine whether the tab is missing, the folding degree, the misalignment degree, the misalignment direction and the corresponding layer information. The application solves the technical problems that the misalignment direction of the tab cannot be determined, the misjudgment rate is high in specific scenarios, and the determination effect is restricted by light, assembly space and tab misalignment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery manufacturing, in particular to a winding needle upper tab state detection method and system. BACKGROUND

[0002] Winding is a process in which positive and negative electrode sheets, upper and lower separators are transported by different numbers and types of over rollers, and are wound into a roll core on the winding needle according to a certain arrangement order through the rotation of the winding needle. At this time, the size and shape of the tab on the electrode sheet have been cut by laser. The judgment of the appearance of the roll core is mostly focused on the state of the tab after winding. Common appearance defects include tab misplacement, tab folding, tab damage, and tab loss. These defects will affect the assembly and performance of the roll core to some extent. For example, tab folding may cause the roll core to fail the short circuit test, and tab misplacement may cause insufficient welding area during assembly welding, resulting in process abnormalities. Therefore, how to reduce the tab defects during winding is a problem that battery manufacturers and winding machine manufacturers are focusing on. At the same time, how to effectively identify the tab state defects that have occurred after winding and avoid flowing into the next process is also a problem that needs to be solved.

[0003] The existing patent application document with publication number CN113594556A, entitled "Winding tab misplacement adjustment method and control system", the method includes: calculating the tab misplacement amount according to the linear speed of the winding needle and the time between the front end and the tail end of the detected tab; adjusting the pressure applied by the rubberizing roller in the winding direction according to the tab misplacement amount; and correcting the pressure applied by the rubberizing roller in the winding direction according to the tab misplacement amount detected after the material is discharged. The prior art solution discloses a method for calculating the tab misplacement amount according to the linear speed of the winding needle and the time between the front end and the tail end of the detected tab, but does not describe the determination method of the misplacement direction and is prone to misjudgment when the tab is folded.

[0004] The existing patent application document with the publication number CN114562959A discloses a winding machine device tab folding detection method using a 3D area array camera. The method includes the following steps: S1: preparing the required raw materials; S2: placing the prepared raw materials into the machine; S3: winding the raw materials together by the machine, taking a photo of the tab position, and transmitting the photo to the PLC control board; S4: then pressing and cutting, and then performing glue sticking on the cut product; S5: conveying the glued battery cell to the material taking position; and S6: processing according to the detection result of the PLC control board. However, in the prior art, the detection effect is easily affected by the light condition, and under the back light condition, the detection effect is good, but under the light condition, the tab reflection easily leads to the failure of detection of the folding. Meanwhile, the device occupies a large space. In the existing technology, the width or area of the tab is detected to determine the folding, or the CCD camera is used to analyze the folding and misplacement of the tab on the winding needle. Some technical solutions use color area recognition on the winding needle to determine the folding. These technologies have some defects, such as being suitable for detecting the state of the tab before winding, or being able to detect only one state of the tab, or being easily affected by the external light source environment and the misplacement of the tab. At present, there is no simple and effective method for comprehensively determining the state of the tab on the winding needle through a group of tab data.

[0005] In the prior art, if the width or area of the tab is detected to determine the folding, this solution is only suitable for detecting the state of the tab before winding. If the CCD camera is used to analyze the folding by recognizing the gray scale change of the gray difference in the set edge frame, this solution is affected by the brightness and the clarity of the CCD light source. The brightness is low, the clarity is low, the recognition ability is reduced, and when the tab is seriously mispositioned, the tab folding does not fall into the edge frame, which affects the determination result. If a surface array or linear array camera is used for photographing, such a camera occupies a large volume, is complex to assemble, is difficult to debug, and the detection effect is easily affected by the light condition. If the color area recognition on the winding needle is used to determine the folding, a color recognition sensor is used, the reflectivity difference of different color objects is used as the detection principle, the surface gray scale change of the target object is recognized and compared, and the position is placed at a distance of 5-15 mm from the edge of the separator. This kind of detection has a detection light source, is basically not affected by the environment brightness, but can only detect the case that the tab folding is under the separator area, and the remaining folding cases are missed.

[0006] In summary, the existing technology has the technical problems of being unable to determine the mispositioning direction of the tab, high misjudgment rate in specific scenarios, and determination effect being restricted by the light, assembly space, and mispositioning of the tab. SUMMARY

[0007] The technical problem to be solved by this invention is how to solve the technical problems in the prior art that cannot determine the direction of electrode misalignment, have a high misjudgment rate in specific scenarios, and whose judgment effect is constrained by lighting, assembly space and electrode misalignment.

[0008] The present invention solves the above-mentioned technical problems by adopting the following technical solution: A method for detecting the state of the upper electrode tab of a wound needle includes:

[0009] S1. At the winding needle, a thickness detection sensor is set according to the location of the tab. The thickness detection sensor is set at the following locations: the first detection point of the winding core, the first detection point of the tab, and the second detection point of the tab.

[0010] S2. Using a thickness detection sensor, detect the thickness information at the locations of the first detection point and the second detection point of the tab, as well as the thickness information at the locations of the monitoring points on the core.

[0011] S3. Compare the thickness data of the detection points on the tab and the monitoring points on the core to determine the tab status. The tab status includes: missing status, degree of folding, degree of misalignment, direction of misalignment, and corresponding layer information.

[0012] This invention utilizes the distributed placement and value detection logic of thickness detection sensors. By comparing thickness information at different locations on the tabs, it can effectively identify the state of each layer of tabs during the winding of the core on the winding needle, determine whether tabs are missing, the degree of folding, and the corresponding layer number information. Simultaneously, it can calculate the degree and direction of misalignment. The thickness detection sensor used in this invention, which can be called a distance sensor, uses laser or infrared technology and is unaffected by the environment.

[0013] In a more specific technical solution, in step S1, the first detection point of the electrode tab is set at the end of the electrode tab away from the diaphragm, and the second detection point of the electrode tab is set at the end of the electrode tab close to the diaphragm.

[0014] In a more specific technical solution, in step S1, the first detection point of the core is set at the root of the upper distance tab of the core.

[0015] In a more specific technical solution, the number of thickness detection sensors is determined based on the positions of the positive and negative electrodes.

[0016] In a more specific technical solution, in step S2, a reflective laser displacement meter is used to detect the height difference between the tab and the core after passing through, with the surface of the winding needle as the origin. Based on the height difference after passing through, the thickness of the tab and the core is measured.

[0017] In a more specific technical solution, the applicable measurement range is selected based on the number of layers of the tab, so as to measure the thickness of the current tab and the core.

[0018] In a more specific technical solution, step S2 includes:

[0019] S21. Determine the start and end points for data recording of the first detection point of the core, the first detection point of the electrode tab, and the second detection point of the electrode tab according to the winding angle;

[0020] S22. Use each thickness detection sensor to detect and obtain the thickness data of each layer of tabs, as well as the thickness data of the first detection point of the core.

[0021] S23. Use the following logic to obtain the value of the thickness data ni:

[0022]

[0023] The thickness data ni is determined by the sensor sampling frequency K and the tab detection width W. m The winding speed S is determined by the winding speed.

[0024] S24. When there is no misalignment in electrode 2, the detection data volume of the two position points is obtained using the following logic:

[0025]

[0026] Among them, the amount of detection data per layer at the two location points is fixed as N1 and N2, and W1 and W2 are the electrode widths at the two location points of the normal electrode.

[0027] This invention comprehensively determines the state of the electrode tabs on the winding needle by using a set of data information of the electrode tabs. It is not affected by light, assembly space, or electrode tab misalignment, thus improving the accuracy of electrode tab state determination.

[0028] In a more specific technical solution, step S3 includes:

[0029] S31. Calculate the thickness range of the corresponding layer tabs based on the thickness information of the first detection point of the core and the winding structure.

[0030] S32. Based on the corresponding layer tab thickness range, compare the thickness of the second detection point of the processed tab to determine the corresponding tab layer number, and obtain the detection data group of the tab state layer to be determined.

[0031] S33. Compare the difference between the data before and after in the detection data group of the second detection point of the electrode tab, compare the detection data volume of the monitoring data group with the preset data volume, and detect the thickness value fluctuation of the first detection point of the core during the corresponding detection period to determine the missing state and degree of folding of the electrode tab.

[0032] S34. Based on the processing of the detection data group, the change trend of the thickness data of the second detection point of the electrode is obtained, and the misalignment direction of the electrode is determined accordingly.

[0033] S35. Calculate the difference between the layer detection width and the normal width of the electrode at the second detection point of the electrode using the detection data of the second detection point of the electrode, and take the maximum value of the difference as the electrode misalignment amount.

[0034] This invention determines the direction of tab misalignment, avoiding misjudgment when tabs are folded. This invention can identify abnormal tab conditions in advance for interception, reducing the risk of undetected abnormalities due to tab conditions or missed detection during manual visual inspection.

[0035] In a more specific technical solution, step S32 includes:

[0036] S321. Calculate the median thickness data of the first detection point of the core for the m-th layer tab. Based on the stacking order of the electrode sheet and diaphragm during winding, subtract the corresponding design thickness from the median thickness data to obtain the theoretical thickness of the corresponding layer tab.

[0037] S322. Analyze the thickness data of the second detection point of the electrode tab in the m-th layer, and take the continuous data group whose thickness data is greater than the preset threshold as the detection data group of the electrode tab state layer to be determined.

[0038] In a more specific technical solution, step S33 includes:

[0039] S331. Calculate the difference T1m between the data before and after the test data set. ni -T1m n(i-1) T2m ni -T2m n(i-1) ;

[0040] S332, The difference T1m between the data before and after ni -T1m n(i-1) T2m ni -T2m n(i-1) When the absolute values ​​of all values ​​are less than the thickness of the single electrode, and the amount of data in the data group is the same as the amount of data detected, N1 and N2, it is determined that the electrode of the current layer has no folding or missing values.

[0041] S333. When the amount of data in the detection data group is 0, and the absolute value of the difference between the data before and after the detection thickness data of the first detection point of the core in the same detection interval is less than the thickness of the single tab, it is determined that the tab of the current layer is missing.

[0042] S334. If the absolute value of the difference between the data of the first detection point of the core within the same tab thickness detection range is greater than the thickness of a single tab, and the absolute value of the difference between the thickness data of the first detection point and the second detection point of the tab is greater than the thickness of a single tab, and the amount of detection data is abnormal, it is determined that the tab has been folded into the core; otherwise, it is determined that the tab has been folded.

[0043] This invention is applicable to detecting the state of tabs before, after, and during winding, and can detect the missing state, degree of folding, degree of misalignment, and direction of misalignment of tabs. Furthermore, this invention avoids the judgment errors caused by external light source environmental factors and tab misalignment that exist in existing technologies.

[0044] In a more specific technical solution, a system for detecting the state of the upper tab of a winding needle includes:

[0045] The sensor setting module is used to set a thickness detection sensor at the winding needle according to the location of the tab. The setting positions of the thickness detection sensor include: the first detection point of the winding core, the first detection point of the tab, and the second detection point of the tab.

[0046] Each monitoring point thickness detection module is used to detect the thickness information at the location of the first detection point and the second detection point of the tab, as well as the thickness information at the location of the monitoring point on the core, using a thickness detection sensor. Each monitoring point thickness detection module is connected to the sensor setting module.

[0047] The tab state determination module is used to compare the thickness data of the detection points on the tab and the monitoring points on the core to determine the tab state. The tab state includes: missing state, degree of folding, degree of misalignment, direction of misalignment, and corresponding layer information. The tab state determination module is connected to the thickness detection module of each monitoring point.

[0048] Compared with existing technologies, this invention has the following advantages: By utilizing the distributed arrangement and value detection logic of thickness detection sensors, and comparing thickness information at different locations on the tabs, this invention can effectively identify the state of each layer of tabs during the winding of the core on the winding needle, determine whether tabs are missing, the degree of folding, and the corresponding layer number, and simultaneously calculate the degree and direction of misalignment. This invention uses a thickness detection sensor, which can be called a ranging sensor, and uses laser or infrared technology, making it unaffected by the environment.

[0049] This invention comprehensively determines the state of the electrode tabs on the winding needle by using a set of data information of the electrode tabs. It is not affected by light, assembly space, or electrode tab misalignment, thus improving the accuracy of electrode tab state determination.

[0050] This invention determines the direction of tab misalignment, avoiding misjudgment when tabs are folded. This invention can identify abnormal tab conditions in advance for interception, reducing the risk of undetected abnormalities due to tab conditions or missed detection during manual visual inspection.

[0051] This invention is applicable to detecting the state of tabs before, during, and after winding, and can detect the missing state, degree of folding, degree of misalignment, and direction of misalignment of tabs. Simultaneously, this invention avoids the judgment errors caused by external light source environmental factors and tab misalignment in existing technologies. This invention solves the technical problems of existing technologies, such as the inability to determine the direction of tab misalignment, high misjudgment rate in specific scenarios, and the limitation of judgment effect by lighting, assembly space, and tab misalignment. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the basic steps of a method for detecting the state of the upper electrode tab of a winding needle according to Embodiment 1 of the present invention;

[0053] Figure 2 This is a schematic diagram illustrating the specific steps of thickness information detection in Embodiment 1 of the present invention;

[0054] Figure 3 This is a schematic diagram illustrating the specific steps of combining and comparing thickness data information in Embodiment 1 of the present invention;

[0055] Figure 4 This is a schematic diagram of the distribution of detection position points and detection range of the thickness detection sensor in Embodiment 2 of the present invention;

[0056] Figure 5 This is a schematic diagram illustrating the comprehensive comparative analysis of thickness detection data at various detection points in Embodiment 2 of the present invention, showing the absence of tabs and abnormal folding.

[0057] Figure 6 This is a schematic diagram illustrating the comprehensive comparative analysis of the thickness detection data at each detection point in Embodiment 2 of the present invention, showing the direction and degree of electrode misalignment. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Example 1

[0060] like Figure 1 As shown, the method for detecting the state of the upper electrode tab of a winding needle provided by the present invention includes the following basic steps:

[0061] S1. Add a thickness detection sensor at the coil needle 3 according to the location of the tab 2;

[0062] S2. The thickness detection sensor can continuously or intermittently detect the thickness information at two points on the tab 2 and the thickness information at the first detection point 11 on the core 1.

[0063] S3. Based on the combination and comparison of thickness data at the detected points, determine whether the tab 2 is missing, the degree of folding, the degree of misalignment, the direction of misalignment, and the corresponding number of layers.

[0064] In this embodiment, a reflective laser displacement meter is used. The surface of the winding needle 3 is taken as the origin. After the tab 2 and the winding core 1 pass through, a height difference is formed to measure the current thickness of the tab 2 and the winding core 1. The measurement range is selected according to the number of layers of the tab 2.

[0065] In this embodiment, the thickness detection sensor detects the thickness information at the second detection point 22 of the tab 2 and the first detection point 11 of the core 1. In this embodiment, the inspection method of the thickness detection sensor includes, but is not limited to, continuous and intermittent methods. The distribution of the second detection point 22 of the tab 2: The first detection point 21 is set at tab k1h, in this embodiment, the first detection point 21 is far from the diaphragm end, h is the tab height, and k1≤1 / 4; the second detection point 22 is set at k2h, in this embodiment, the second detection point 22 is close to the diaphragm end, and k2≥3 / 4. The first detection point 11 of the core is set at k3h on the core 1 from the root of the tab 2, and k3≤1 / 4. The detection points can be concentrated on one detection sensor. In this embodiment, the arrangement of the detection sensors also includes using no less than two independent detection sensors. In this embodiment, the number of detection sensors is determined according to the positions of the positive and negative tabs.

[0066] like Figure 2 As shown, in this embodiment, step S2 further includes the following specific steps:

[0067] The start and end of data recording at points S21 and 3 are determined based on the winding angle. The thickness of the surface of the winding needle 3 is recorded as 0.

[0068] In this embodiment, except for the value of 0, the angle setting satisfies the following conditions: the amount of data detected at the first detection point 11 of the core is greater than or equal to the amount of data detected at the position of the second detection point 22 of the electrode tab is greater than or equal to the amount of data detected at the position of the first detection point 21 of the electrode tab.

[0069] S22. Use the detection sensors at each location point to detect and obtain the thickness data of each layer tab 2, and detect and obtain the thickness data at the first detection point 11 of the core.

[0070] In this embodiment, the thickness data of the first layer of electrode 2 detected by the first detection point 21 is recorded as T111, T112, ..., T11 n1The thickness data of the first layer of electrode 2 detected at the second detection point 22 is recorded as T211, T212, ..., T21 n2 And so on, the thickness data of the m-th layer of the electrode detected by the first detection point 21 is recorded as T1m1, T1m2, ..., T1m n3 The thickness data of the m-th electrode layer detected at the second detection point 22 is recorded as T2m1, T2m2, ..., T2m ni The thickness data at the first detection point 11 of the core is recorded as T31, T32, ..., T3 j ;

[0071] S23. Use the following logic to obtain the value of the thickness data ni:

[0072]

[0073] The thickness data ni is determined by the sensor sampling frequency K and the tab detection width W. m The winding speed S is determined by the winding speed.

[0074] In this embodiment, due to the misalignment and irregular size of the tab 2, the detection width W of the layer tab 2 is affected. m They are not equal, therefore, the thickness data ni values ​​measured at each layer and at each point are not equal;

[0075] S24. When there is no misalignment in electrode 2, the detection data volume of the two position points is obtained using the following logic:

[0076]

[0077] Among them, the amount of detection data per layer at the two location points is fixed as N1 and N2, and W1 and W2 are the electrode widths at the two location points of the normal electrode.

[0078] like Figure 3 As shown, in this embodiment, the specific steps for combining and comparing thickness data information in step S3 include:

[0079] S31. Based on the thickness information at the first detection point 11 of the core and the winding structure, calculate the theoretical thickness range of the corresponding layer tab 2.

[0080] S32. Compare the thickness at the second detection point 22 of the electrode to determine the number of electrode layers corresponding to the data, and find the detection data group of the electrode state layer that needs to be determined.

[0081] S33. By comparing the difference between the data before and after the detection data group at the second detection point 22 of the electrode tab and the data volume with the theoretical data volume, and combining the thickness value fluctuation at the first detection point 11 of the core during the corresponding detection period, it is determined whether the electrode tab 2 is missing or folded.

[0082] S34. Determine the misalignment direction of electrode 2 based on the thickness data change trend at the second detection point 22 of the electrode.

[0083] S35. Calculate the difference between the layer detection width and the normal width of the electrode at the second detection point 22 of the electrode using the detection data at the second detection point 22 of the electrode, and take the maximum value of the two difference data as the electrode misalignment amount.

[0084] In this embodiment, during the process of determining whether the tab 2 is missing, its degree of folding, its degree of misalignment, its misalignment direction, and the corresponding layer number, the median thickness data T3a at the first detection point 11 of the core is calculated for the m-th layer tab. Based on the stacking order of the electrode sheet and diaphragm during winding, the corresponding design thickness is subtracted from T3a to calculate the theoretical thickness Tm of the corresponding layer tab. The thickness data at two points on the m-th layer tab are analyzed to find a continuous data set that satisfies greater than 90% of Tm. This data set is recorded as the two-point detection data set of the current tab state layer. T1m within the data set is calculated. ni -T1m n(i-1) T2m ni -T2m n(i-1) If the absolute value of the difference between the preceding and following data is less than the thickness of the single tab and the amount of data in the data group is the same as N1 and N2, it indicates that the tab in the current layer is not folded or missing. If the amount of data in the data group is 0 and the absolute value of the difference between the preceding and following thickness data of the first detection point 11 of the core in the same detection interval is less than the thickness of the single tab, it indicates that the tab in the current layer is missing. If the absolute value of the difference between the preceding and following thickness data of the first detection point 11 of the core in the same tab thickness detection interval is greater than the thickness of the single tab and the absolute value of the difference between the preceding and following thickness data of the other two points is greater than the thickness of the single tab and the amount of data is different from the corresponding N1 and N2, it indicates that the tab is folded into the core. In other cases, it is determined that the tab 2 is folded.

[0085] The direction of electrode misalignment is determined based on the thickness data change trend at the second detection point 22 of the electrode tab. If the data gradually increases from small to large, it indicates misalignment in the reverse winding direction, and if it decreases from large to small, it indicates misalignment in the forward winding direction. The difference between the layer detection width and the normal width of the electrode tab at the second detection point 22 of the last layer is calculated by measuring the detection data at the second detection point 22 of the last layer electrode tab. The maximum value of the two difference data is taken as the misalignment amount of the core electrode tab.

[0086] In this embodiment, the direction of electrode misalignment is determined based on the thickness data change trend at the second detection point 22 of the electrode tab. If the data gradually increases from small to large, it indicates misalignment in the reverse winding direction, and if it decreases from large to small, it indicates misalignment in the forward winding direction. The difference between the layer detection width and the normal width of the electrode tab at the second detection point 22 of the last layer is calculated by the detection data at the second detection point 22 of the last layer, and the maximum value of the two difference data is taken as the core electrode tab misalignment amount.

[0087] Example 2

[0088] like Figure 4 As shown, in this embodiment, the core tabs are distributed on both sides. The core tabs are distributed on both sides and have the same shape and size. Since the detection position points on the tabs 2 and the core 1 are set in the same way, the data processing method and judgment are the same, only the collected data are different. This case only uses the positive tab side as an illustration.

[0089] In this embodiment, the core tab is known to be an isosceles trapezoid, with a height h = 20 mm for the positive tab, a top width of 23 mm, a bottom width of 35 mm, and a single-layer tab thickness of 13 μm. The first detection point 21 is set at a position 5 mm from the top of the tab, i.e., 1 / 4 of the tab height. The second detection point 22 is set at a position 15 mm from the top of the tab. In this embodiment, the second detection point 22 is located near the diaphragm end, i.e., 3 / 4 of the tab height. Point 1 on the core is set at a position 5 mm from the diaphragm. Therefore, the tab width detected by the first detection point 21 is W1 = 26 mm, and the tab width detected by the second detection point 22 is W2 = 32 mm.

[0090] In this embodiment, the core 1 is designed with a separator thickness of d1 = 22 μm, a positive electrode thickness of d2 = 117 μm, and a negative electrode thickness of d3 = 139 μm. The winding structure, from the inside out, consists of a negative electrode, a separator, a positive electrode, and a separator. Theoretically, starting from the second layer, the thickness difference between the tab layers is (2*d1+d2+d3) = 300 μm. Compared with the thickness data detected at two points on the positive electrode tab layer, the data detected on the corresponding core is 74 μm smaller.

[0091] like Figure 5 As shown, in this embodiment, the thickness detection sensor independently detects thickness data at three locations, with a sampling frequency K of 6000 times / second, a resolution of 0.3μm, and a sampling repeatability of 0.1μm. The single core has a fixed winding speed S = 1000mm / s. Based on the sensor and winding speed data, excluding the value of 0, the theoretical data quantity N1 detected at the first detection point 21 of the tab is 156, and the theoretical data quantity N2 detected at the second detection point 22 of the tab is 192. Due to the large amount of detected data, the data from the first four layers of tabs are used to illustrate the comparison between the data and the corresponding tab states.

[0092] like Figure 6As shown, in this embodiment, the median value of the data detected at the first detection point 11 of the core corresponding to the first layer tab is 0.3389 mm. Therefore, the detection data set at the two points on the first layer tab 2 is determined to be continuous data with a value greater than (0.3389-0.074)*0.9=0.2384. The data volume of the detection data set at the two points on the first layer tab 2 is equal to N1 and N2 respectively, and the difference between the data before and after the data in the set is less than 0.013 mm. Therefore, the first layer tab is determined to be in normal condition, without folding or missing parts. The median value of the data detected at the first detection point 11 of the core corresponding to the second layer tab is 0.6446 mm, and the difference between the data before and after the data is less than 0.013 mm. Therefore, the detection data set at the two points on the second layer tab is determined to be continuous data with a value greater than 0.5135 mm. However, the actual detected thickness data is less than 0.5135 mm. The measured data is the thickness data of the first layer tab. Therefore, the second layer tab is determined to be missing. The median value of the data detected at the first detection point 11 of the core corresponding to the third layer tab is 0.9386mm. Therefore, the detection data group at the two points on the third layer tab is determined to be continuous data with a value greater than 0.7781mm. However, the actual thickness data detected at the first detection point 21 of the tab is less than 0.7781mm. The measured data is still the thickness data of the first layer tab. The amount of data in the continuous data group with a value greater than 0.7781mm at the second detection point 22 of the tab is the same as that in N2. However, there is a fluctuation of more than 0.013mm in the difference between the data before and after the data in the data group. At the same time, there is also a fluctuation of more than 0.013mm in the difference between the data before and after the detection point 11 of the core. Therefore, it is determined that the third layer tab is folded over and folded into the diaphragm area. The median value of the data detected at the first detection point 11 of the core corresponding to the fourth layer tab is 1.2380mm. Therefore, the detection data group at the two points on the third layer tab is determined to be continuous data with a value greater than 1.0476mm. The number of data in the continuous data group with a thickness value greater than 1.0476mm at the first detection point 21 of the tab is 135, which is less than N1 and the difference between the data before and after is also greater than 0.013mm. The number of data in the continuous data group with a thickness greater than 1.0476mm at the second detection point 22 of the tab is the same as N2, and the difference between the data before and after is not greater than 0.013mm. At the same time, the difference between the data before and after the detection at the first detection point 11 of the core is also not greater than 0.013mm. Therefore, it is determined that the fourth layer tab 2 is slightly folded and has not folded into the diaphragm area.

[0093] In this embodiment, under the same parameter conditions, Figure 6The image shows the thickness measurement data for the last tab of a core. It can be seen that the last tab has no folds or gaps. The thickness measurement data at the second measurement point 22 of the last tab shows a gradually increasing trend, indicating that the winding is misaligned in the reverse winding direction. The measurement data at the second measurement point 22 of the last tab are 186 and 222 respectively, and the calculated layer widths are 31mm and 37mm respectively. The difference between these two widths and the normal tab width at point 2 is 5mm. Taking the larger of the two differences as the tab misalignment, the misalignment between core 1 and tab 2 is 5mm.

[0094] In summary, this invention utilizes the distributed arrangement and value detection logic of thickness detection sensors to effectively identify the state of each layer of tabs during the winding of the core on the winding needle by comparing thickness information at different locations on the tabs. It can also determine whether tabs are missing, the degree of folding, and the corresponding layer number, while simultaneously calculating the degree and direction of misalignment. The thickness detection sensors used in this invention, which can be called distance sensors, utilize laser or infrared technology and are unaffected by environmental conditions.

[0095] This invention comprehensively determines the state of the electrode tabs on the winding needle by using a set of data information of the electrode tabs. It is not affected by light, assembly space, or electrode tab misalignment, thus improving the accuracy of electrode tab state determination.

[0096] This invention determines the direction of tab misalignment, avoiding misjudgment when tabs are folded. This invention can identify abnormal tab conditions in advance for interception, reducing the risk of undetected abnormalities due to tab conditions or missed detection during manual visual inspection.

[0097] This invention is applicable to detecting the state of tabs before, during, and after winding, and can detect the missing state, degree of folding, degree of misalignment, and direction of misalignment of tabs. Simultaneously, this invention avoids the judgment errors caused by external light source environmental factors and tab misalignment in existing technologies. This invention solves the technical problems of existing technologies, such as the inability to determine the direction of tab misalignment, high misjudgment rate in specific scenarios, and the limitation of judgment effect by lighting, assembly space, and tab misalignment.

[0098] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the state of the upper electrode tab of a wound needle, characterized in that, The method includes: S1. At the winding needle, a thickness detection sensor is set according to the location of the tab. The thickness detection sensor is set at the following locations: the first detection point of the winding core, the first detection point of the tab, and the second detection point of the tab. S2. Using a thickness detection sensor, detect the thickness information at the locations of the first detection point and the second detection point of the tab, as well as the thickness information at the locations of the monitoring points on the core. S3. Compare the thickness data of the detection points on the tab and the monitoring points on the core to determine the tab status. The tab status includes: missing status, degree of folding, degree of misalignment, direction of misalignment, and corresponding layer information. S3 includes: S31. Calculate the thickness range of the corresponding layer tabs based on the thickness information of the first detection point of the core and the winding structure. S32. Based on the corresponding layer tab thickness range, compare the thickness of the second detection point of the processed tab to determine the corresponding tab layer number, and obtain the detection data group of the tab state layer to be determined. S33. Compare the difference between the data before and after in the detection data group of the second detection point of the electrode tab, compare the detection data volume of the monitoring data group with the preset data volume, and detect the thickness value fluctuation of the first detection point of the core during the corresponding detection period to determine the missing state and degree of folding of the electrode tab. S34. Based on the processing of the detection data group, the change trend of the thickness data of the second detection point of the electrode is obtained, and the misalignment direction of the electrode is determined accordingly. S35. Calculate the difference between the layer detection width and the normal width of the electrode at the second detection point of the electrode using the detection data of the second detection point of the electrode, and take the maximum value of the difference as the electrode misalignment amount.

2. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, In step S1, the first detection point of the electrode tab is set at the end of the electrode tab away from the diaphragm, the second detection point of the electrode tab is set at the end of the electrode tab close to the diaphragm, and the first detection point of the core is set at the upper part of the core from the root of the electrode tab.

3. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, The number of thickness detection sensors is determined based on the positions of the positive and negative electrodes.

4. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, In step S2, a reflective laser displacement meter is used to detect the height difference between the tab and the core after they pass through, with the surface of the winding needle as the origin. Based on the height difference after they pass through, the thickness of the tab and the core is measured.

5. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, Based on the number of layers of the tab, an applicable measurement range is selected to measure the thickness of the tab and the core.

6. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, Step S2 includes: S21. Determine the start and end points of data recording for the first detection point of the core, the first detection point of the electrode tab, and the second detection point of the electrode tab according to the winding angle; S22. Use the thickness detection sensors to detect and obtain the thickness data of each layer tab and the thickness data of the first detection point of the core. S23. Obtain thickness data using the following logic. The possible values ​​of: Among them, thickness data The value is determined by the sensor sampling frequency. Layer tab detection width Winding speed Decide; S24. When there is no misalignment of the electrode tabs, the detection data at the two position points is obtained using the following logic: The amount of detection data per layer at each of the two location points is fixed at 1. and , , The width of the electrode at two normal electrode locations.

7. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, Step S32 includes: S321. Calculate the median thickness data of the first detection point of the core for the m-th layer tab. Based on the stacking order of the electrode sheet and diaphragm during winding, subtract the corresponding design thickness from the median thickness data to obtain the theoretical thickness of the corresponding layer tab. S322. Analyze the thickness data of the second detection point of the electrode in the m-th layer, and take the continuous data group whose thickness data is greater than a preset threshold as the detection data group of the current electrode state layer to be determined.

8. The method for detecting the state of the upper electrode tab of a winding needle according to claim 1, characterized in that, Step S33 includes: S331. Calculate the difference between the data before and after the detection data group. ； S332, the difference before and after the data The absolute values ​​are all less than the thickness of the monopole, and the amount of data within the data group is less than the amount of the detected data. If they are the same, it is determined that the tabs of the current layer are neither folded nor missing. S333. When the amount of data in the detection data group is 0, and the absolute value of the difference between the data before and after the detection thickness data of the first detection point of the core in the same detection interval is less than the thickness of the single tab, it is determined that the tab of the current layer is missing. S334. If the absolute value of the difference between the data of the first detection point of the core within the same electrode thickness detection range is greater than the thickness of a single electrode, and the absolute value of the difference between the thickness data of the first detection point of the electrode and the second detection point of the electrode is greater than the thickness of a single electrode, and the amount of detection data is abnormal, it is determined that the electrode is folded into the core; otherwise, it is determined that the electrode is folded.

9. A system for detecting the state of the upper tab of a winding needle, used to execute the method for detecting the state of the upper tab of a winding needle according to any one of claims 1 to 8, characterized in that, The system includes: The sensor setting module is used to set a thickness detection sensor at the winding needle according to the location of the tab, wherein the setting positions of the thickness detection sensor include: the first detection point of the winding core, the first detection point of the tab, and the second detection point of the tab. Each monitoring point thickness detection module is used to detect the thickness information at the locations of the first detection point of the tab and the second detection point of the tab, as well as the thickness information at the locations of the monitoring points on the core, using the thickness detection sensor. Each monitoring point thickness detection module is connected to the sensor setting module. The tab state determination module is used to compare the thickness data of the detection points on the tab and the monitoring points on the core to determine the tab state. The tab state includes: missing state, degree of folding, degree of misalignment, direction of misalignment, and corresponding layer information. The tab state determination module is connected to the thickness detection module of each monitoring point.

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