Secondary battery inspection apparatus using mfc

Abstract

This secondary battery inspection apparatus may comprise a sensor module, a detection circuit, a transfer device, a processor, and a memory. The processor may be configured to divide a measured value of a parameter obtained through the detection circuit into a plurality of sections, and identify a defect of a secondary battery for the plurality of sections.

Description

Secondary battery inspection device using MFC

[0001] The descriptions below are about a testing device that uses MFC (magnetic force current).

[0002] A pouch-type secondary battery is a secondary battery in which battery cells are sealed inside a case (pouch), and can have a high energy density. The pouch-type secondary battery may include a lead tab for supplying power. The lead tab serves to electrically connect the electrodes (e.g., the positive and negative electrodes) of the secondary battery to an external device, and power can be supplied through the lead tab.

[0003] A lead tab can be formed by welding a tab portion extending from an electrode to a copper foil. If a defect occurs in the welding condition of the lead tab, power may leak through the lead tab, resulting in a short circuit. Therefore, an inspection of the welding condition of the lead tab may be necessary.

[0004] The above information may be provided as background art to aid in understanding the present disclosure. No claim or determination is made as to whether any of the above is applicable as prior art in connection with the present disclosure.

[0005] The weld condition of the lead tab is directly related to the stable operation of the secondary battery, so inspection of the weld condition may be necessary. Because the welded portion of the lead tab is not visible from the outside, it cannot be observed with the naked eye. Disassembling the secondary battery to inspect the weld condition of the lead tab requires excessive cost and time, and conventional non-destructive equipment is difficult to accurately inspect the weld condition.

[0006] A secondary battery inspection device is provided. The secondary battery inspection device may include a sensor module. The sensor module may include a first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and a second sensor including a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field. The sensor module may include a detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal. The sensor module may include a transport device coupled to the sensor module and configured to transport the sensor module. The sensor module may include a processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one of the plurality of parameters. The sensor module may include a memory that stores instructions and information related to the secondary battery. The instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to select one parameter from among the plurality of parameters, identify a measurement value of the one parameter, distinguish the measurement value of the one parameter with respect to the total number of measurements of the second signal into a plurality of sections including a first section and a second section, identify whether a first defect exists within the first section by comparing a first measurement value included in the first section with a first reference value, identify whether a second defect exists within the second section by comparing a second measurement value included in the second section with a second reference value, and identify a defect in the secondary battery based on identifying at least one of the first defect or the second defect.

[0007] A secondary battery inspection device is provided. The secondary battery inspection device may include a sensor module. The sensor module may include a first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and a second sensor including a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field. The secondary battery inspection device may include a detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal. The secondary battery inspection device may include a transport device coupled to the sensor module and configured to transport the sensor module. The secondary battery inspection device may include a processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one of the plurality of parameters. The secondary battery inspection device may include a memory that stores instructions and information related to the secondary battery. The above instructions, when individually or collectively executed by the processor, may be configured to cause the secondary battery inspection device to select one parameter from among the plurality of parameters, identify a measurement value of the one parameter, distinguish the measurement value of the one parameter into a plurality of sections, and, for each of the plurality of sections, convert the measurement value of the one parameter based on the following [mathematical formula], thereby obtaining a conversion value for the measurement value of the one parameter, and identifying a defect in the secondary battery based on the conversion value.

[0008]

[0009] A secondary battery inspection device is provided. The secondary battery inspection device may include a sensor module. The sensor module may include a first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and a second sensor including a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field. The secondary battery inspection device may include a detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal. The secondary battery inspection device may include a transport device coupled to the sensor module and configured to transport the sensor module. The secondary battery inspection device may include a processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one of the plurality of parameters. The secondary battery inspection device may include a memory that stores instructions and information related to the secondary battery.The instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to select one parameter from among the plurality of parameters, identify a measurement value of the one parameter, distinguish the measurement value of the one parameter for the total number of measurements that measured the second signal into a plurality of sections including a first section and a second section, identify a first skewness, a first kurtosis, and a first difference value corresponding to a difference between maximum and minimum values ​​for a first measurement value within the first section, identify a second skewness, a second kurtosis, and a second difference value corresponding to a difference between maximum and minimum values ​​for a second measurement value within the second section, identify whether a first defect exists within the first section based on the first skewness, the first kurtosis, and the first difference value, identify whether a second defect exists within the second section based on the second skewness, the second kurtosis, and the second difference value, and determine whether at least one of the first defect or the second defect exists. Based on the identification, it can be caused to identify a defect in the secondary battery.

[0010] A secondary battery inspection device according to one embodiment can identify defects within a secondary battery without destruction. The secondary battery inspection device can quickly and accurately identify defects by detecting them based on signals induced by a magnetic field. The secondary battery inspection device according to one embodiment can be installed on a production line to quickly identify defective products in real time.

[0011] FIG. 1A illustrates a secondary battery according to one embodiment.

[0012] Figure 1b is an exploded view of the secondary battery of Figure 1a.

[0013] FIG. 2A is a block diagram of a secondary battery inspection device according to one embodiment.

[0014] Figure 2b schematically illustrates the principle of a secondary battery inspection device according to one embodiment.

[0015] FIGS. 3A and 3B illustrate examples of a transport device of a secondary battery inspection device according to one embodiment.

[0016] Figure 4 is a flow chart showing the operation of a secondary battery inspection device according to one embodiment.

[0017] FIGS. 5A and 5B are graphs showing measured values ​​of parameters obtained through a secondary battery inspection device according to one embodiment.

[0018] Figure 6 is an example of a processor converting parameter values ​​acquired through a detection circuit into a three-dimensional image.

[0019] FIG. 7 is a flowchart showing an operation of a secondary battery inspection device according to one embodiment to identify a defect in a secondary battery by dividing a measurement value into a plurality of sections.

[0020] Figure 8 is a graph showing measurement values ​​for a number of measurements, divided into multiple sections.

[0021] FIG. 9A is a flowchart illustrating an operation of an inspection device according to one embodiment to set a plurality of sections.

[0022] Figure 9b illustrates a graph in which multiple sections are set according to the operation of Figure 9a.

[0023] FIG. 10 is a flowchart showing an operation of a secondary battery inspection device according to one embodiment to identify a defect.

[0024] Figure 11a is a graph showing measurement values ​​for the number of measurements.

[0025] Figure 11b illustrates a process of converting a graph for the measurement values ​​of the first section of Figure 11a.

[0026] Figure 11c shows graphs for the measurement values ​​of the second and fourth sections of Figure 11a.

[0027] Figure 11d shows a graph of the measurement values ​​of the third section of Figure 11a.

[0028] Figure 11e illustrates a process of converting a graph for the measurement values ​​of the fifth section of Figure 11a.

[0029] Figure 12 schematically illustrates a secondary battery inspection device according to one embodiment.

[0030] Fig. 13 is a flowchart showing a process of converting a measurement value by a secondary battery inspection device according to one embodiment.

[0031] Figures 14a, 14b, and 14c illustrate graphs of measurement values ​​according to changes in the distance between the sensor module and the secondary battery.

[0032] Figures 15a, 15b, and 15c illustrate graphs of conversion values ​​for measured values.

[0033] Figure 16a is a graph showing the measured value of one parameter against the number of measurements.

[0034] Figure 16b is a normalized graph of the graph in Figure 16a.

[0035] Figure 17 shows a graph obtained when dispersion occurs.

[0036] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings.

[0037] FIG. 1A illustrates a secondary battery according to one embodiment. FIG. 1B is an exploded view of the secondary battery of FIG. 1A.

[0038] According to one embodiment, the secondary battery (10) is a rechargeable battery and can be used for various electronic devices. For example, the secondary battery (10) mounted in a smart phone can be configured to store power and provide the stored power to electronic components by being charged based on power provided from an external source. The secondary battery (10) can be configured to provide power to electronic components of the smart phone by being controlled by a power management module (e.g., a PMIC, power management integrated circuit) of the smart phone. For example, the secondary battery (10) can include a lithium ion battery.

[0039] According to one embodiment, the secondary battery (10) may include a case (11) defining an exterior surface and components included in the case (11). The components included in the case (11) are illustrated in FIG. 1B. For example,

[0040] According to one embodiment, the secondary battery (10) may be electrically connected to an electrode (e.g., electrode (12) of FIG. 1B) disposed within a case (11) and may include a lead tab (13) for electrical connection with an electronic component. For example, the lead tab (13) may be coupled to an electrode tab (e.g., electrode tab (14) of FIG. 1B) extending from an electrode (e.g., a positive electrode (12-1) and a negative electrode (12-2) of FIG. 1B) within the case (11) and may be electrically connected to the electronic component. The lead tab (13) may be joined to the electrode tab (14) by a method such as resistance welding, ultrasonic welding, or laser welding.

[0041] For example, the lead tab (13) can be electrically connected to an electric circuit, such as a protection circuit module (PCM) for the secondary battery (10). Power stored in the secondary battery (10) can be provided to the outside through the lead tab (13) (discharging), and power provided from the outside to charge the secondary battery (10) can be provided to the secondary battery (10) through the lead tab (13) (charging).

[0042] The lead tab (13) can provide an electrical connection between the electrode (12) disposed within the case (11) and the electronic components outside the secondary battery (10). For example, power provided from the secondary battery (10) to each of the electronic components can be provided through the lead tab (13). For example, power provided from a charging device to the secondary battery (10) can be provided to the secondary battery (10) through the lead tab (13). The lead tab (13) can be coupled to an electrode tab of the electrode (12) disposed within the case (11) (e.g., electrode tab (14) of FIG. 1B). The lead tab (13) may include a first lead tab (13-1) that contacts a first electrode tab (e.g., the first electrode tab (14-1) of FIG. 1B) and a second lead tab (13-2) that contacts a second electrode tab (e.g., the second electrode tab (14-2) of FIG. 3B). A portion of the lead tab (13) may be exposed to the outside of the case (11). A portion of the lead tab (13) that extends from the inside of the case (11) to the outside of the case (11) may be exposed to a side of the case (11). In order to seal the case (11) to which the lead tab (13) is exposed, a terrace seal (15) including an insulating material may be formed on the side of the case (11). The case (11) may include a pouch type case or a cylindrical type case. The case (11) illustrated in FIGS. 1a and 1b is illustrated as a pouch type case, but is not limited thereto.

[0043] Referring to Fig. 1b, components of a secondary battery (10) may be arranged inside a case (11). For example, a positive electrode (12-1), a negative electrode (12-2), a separator (16), and an electrolyte may be arranged inside the case (11). The secondary battery (10) illustrated in Fig. 1b may be a stack-type battery in which positive electrodes (12-1) and negative electrodes (12-2) are alternately laminated, but is not limited thereto. Each of the positive electrode (12-1) and the negative electrode (12-2) may also be referred to as a cathode and an anode based on the discharge of the secondary battery (10).

[0044] According to one embodiment, the electrode (12) may include a cathode (12-2) and a cathode (12-1) having electrically opposite characteristics. The electrode (12) may include an electrode substrate and an electrode active material layer coated on the electrode substrate. For example, the cathode (12-2) may include an anode substrate and an anode active material layer coated on the anode substrate. The anode substrate may collect electrons generated in the anode active material layer according to the electrochemical reaction of the secondary battery (10) or provide electrons required for the electrochemical reaction to the anode active material layer. For example, the anode substrate may be electrically connected to an external circuit, and may provide electrons generated in the anode active material layer to the external circuit during discharge, or may provide electrons supplied through the external circuit to the anode active material layer during charge. For example, the anode substrate may include a second metal. For example, the second metal may include copper. The cathode substrate may be implemented in the form of a copper foil, but is not limited thereto.

[0045] In one embodiment, the negative electrode active material layer can generate or consume electrons based on an electrochemical reaction. For example, during charging, electrons transferred from the negative electrode substrate can be combined with lithium ions in the negative electrode active material layer and consumed. During discharge, electrons can be generated as lithium ions and electrons separate from the negative electrode active material layer.

[0046] According to one embodiment, the negative electrode active material layer may include a negative electrode active material involved in the electrochemical reaction of the above-described negative electrode (12-2), a conductive material for improving electrical conductivity within the negative electrode (12-2), and a binder so that the negative electrode active material layer can be easily attached to the negative electrode substrate. In one embodiment, the negative electrode active material may include, but is not limited to, graphite, lithium titanate (LTO), silicon (Si), germanium (Ge), tin (Sn), or lithium oxide (Li2O). For example, a polymer material such as polyvinylidene fluoride (PVDF), polyacrylic acid (PAA), styrene-butadiene rubber (SBR), and carboxymethylcellulose (CMC) may be used as the binder of the negative electrode active material layer.

[0047] In one embodiment, a separator (16) may be interposed between the negative electrode (12-2) and the positive electrode (12-1). The separator (16) may provide a passage for lithium ions to pass through and may prevent physical contact (or direct electrical short-circuit) between the positive electrode (12-1) and the negative electrode (12-2).

[0048] According to one embodiment, the positive electrode (12-1) may include a positive electrode substrate and a positive electrode active material layer. For example, the positive electrode substrate may be connected to the external circuit to supply electrons generated during a charging or discharging process to the outside or inside of the positive electrode active material layer. For example, the positive electrode substrate may be electrically connected to the external circuit to provide electrons generated in the positive electrode active material layer to the external circuit during charging, or to provide electrons supplied through the external circuit to the positive electrode active material layer during discharging. For example, the positive electrode substrate may include a first metal. For example, the first metal may include aluminum. The positive electrode substrate may be implemented in the form of an aluminum foil, but is not limited thereto.

[0049] According to one embodiment, the positive electrode active material layer can generate or consume electrons according to the electrochemical reaction of the secondary battery (10). For example, when charging, electrons may be generated as lithium compounds are ionized in the positive electrode active material layer, and when discharging the secondary battery (10), electrons supplied through the external circuit may be combined with lithium ions in the positive electrode active material layer and consumed.

[0050] According to one embodiment, the positive electrode active material layer may include a positive electrode active material involved in the electrochemical reaction of the positive electrode (12-1) described above, a conductive material for improving electrical conductivity within the positive electrode (12-1), and a binder so that the positive electrode active material layer can be easily attached to the positive electrode substrate. For example, the positive electrode active material may include, but is not limited to, LiCoO2, LiNiCoMnO2, LiNiCoAlO2, LiTiS2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiCo2O4, LiFePO4, LiMnPO4, LiCoPO4, LiFeSO4F, or LiVPO4F. According to one embodiment, a polymer material such as polyvinylidene fluoride (PVDF) may be used as the binder of the positive electrode active material layer.

[0051] According to one embodiment, the electrolyte may provide a path through which lithium ions can move between the negative electrode (12-2) and the positive electrode (12-1). For example, the electrolyte may include a liquid electrolyte or a gel electrolyte. For example, when charging the secondary battery (10), lithium ions may be deintercalated from the positive electrode active material layer and may move to the negative electrode active material layer through the electrolyte and the separator (16). The lithium ions that have moved to the negative electrode active material layer may be intercalated into the negative electrode active material layer as a reduction reaction occurs. Electrons generated during the deintercalation of lithium ions may move to the negative electrode active material layer through the external circuit. For example, when discharging the secondary battery (10), lithium ions inserted into the negative electrode active material layer are deintercalated and ionized into the electrolyte, and the ionized lithium ions may move to the positive electrode active material layer through the electrolyte and the separator (16). Electrons generated in the negative active material layer by the desorption of lithium ions can move to the positive active material layer through the external circuit. Lithium ions can be inserted into the positive active material layer by meeting electrons and causing a reduction reaction. When the secondary battery (10) is discharged, electrons passing through the external circuit can perform work.

[0052] According to one embodiment, the electrode (12) may include an electrode tab (14). For example, the electrode tab (14) may include a first electrode tab (14-1) extending from the anode (12-1) and a second electrode tab (14-2) extending from the cathode (12-2). The first electrode tab (14-1) may be referred to as the anode (12-1) tab, and the second electrode tab (14-2) may be referred to as the cathode (12-2) tab.

[0053] The lead tab (13) may be exposed to the outside of the case (11) by extending through the terrace seal (15) of the case (11). The lead tab (13) may be electrically connected to an external circuit, or may be electrically connected to another battery to form a battery module or a battery pack. As described above, the lead tab (13) may include a conductive material so that power may be transmitted through the lead tab (13). For example, the lead tab (13) may include a metal. A portion of the lead tab (13) may be exposed to the outside of the case (11), and an electrode tab (14) extending from the electrode (12) may extend toward another portion of the lead tab (13) located within the case (11). The electrode tab (14) may be at least partially bent so as to be coupled with the lead tab (13).

[0054] The electrode tab (14) can extend from the electrode (12) and be connected to the lead tab (13). When the secondary battery (10) is discharged, power provided from the electrode (12) can be transmitted to the lead tab (13) through the electrode tab (14) and, through the lead tab (13), can be provided to an external circuit electrically connected to the lead tab (13). When the secondary battery (10) is charged, power provided from the charging device can be transmitted to the electrode tab (14) through the lead tab (13) and, through the electrode tab (14), to the electrode (12).

[0055] When a plurality of electrodes (12) are stacked, the electrode tabs (14) of each of the plurality of electrodes (12) may be coupled to a lead tab (13). According to one embodiment, the bonding force between the lead tab (13) and the electrode tab (14) may be affected by the difference in the physical properties of the lead tab (13) and the electrode tab (14). As described above, the lead tab (13) may include a conductive material (e.g., metal). If the electrode tab (14) coupled to the lead tab (13) includes a non-conductive material (e.g., polymer), the bonding force may be weakened due to the difference in the physical properties of the conductive material of the lead tab (13) and the non-conductive material of the electrode tab (14).

[0056] Since the lead tab (13) provides an electrical connection between the electronic components located on the upper portion of the secondary battery (10) and the secondary battery (10) and provides a power transmission path, it may be required that the lead tab (13) be stably connected to the electrode tab (14). For example, if a defect (e.g., a crack) occurs between the lead tab (13) and the electrode tab (14), a leakage current may be caused during charging and / or discharging of the secondary battery (10), thereby deteriorating the quality of the secondary battery (10) and causing a safety accident. If a defect occurs inside the case (11), it may be difficult to determine whether or not the defect exists because the defect is not observed from the outside.

[0057] Therefore, even if a defect (e.g., a crack) occurs inside the secondary battery (10), it may be difficult to identify the presence or absence of the crack due to the case (11). In order to identify the crack in the secondary battery (10), a non-destructive inspection device using X-ray imaging may be used. In general, secondary battery inspection devices have a long inspection time for identifying cracks and low resolution, making accurate identification difficult. In addition, since the volume of conventional secondary battery inspection devices is large, mass production is difficult, and thus they may not be suitable as inspection devices for inspecting cracks in small pouch-type secondary batteries. In addition, since cracks may occur in a specific area of ​​the secondary battery (10), X-ray photography of the entire area of ​​the secondary battery (10) may be required in order to identify the presence or absence of cracks in the secondary battery (10) as a whole.

[0058] A secondary battery inspection device (e.g., a secondary battery inspection device (100) of FIG. 2A) according to one embodiment can identify a crack that has occurred in a secondary battery (10) of a secondary battery (10) using a magnetic force current (MFC). The magnetic force current may include a current formed by an induced magnetic field (e.g., an eddy current). In the present specification, the magnetic force current may be referred to as a current formed by a magnetic field. A secondary battery inspection device (100) according to one embodiment is a non-destructive inspection device that can identify a crack using the magnetic force current (e.g., an eddy current), and can identify a crack in a secondary battery (10) through a simplified structure. Hereinafter, the secondary battery inspection device (100) will be described with reference to the drawings.

[0059] Fig. 2a is a block diagram of a secondary battery inspection device according to one embodiment. Fig. 2b schematically illustrates the principle of a secondary battery inspection device according to one embodiment.

[0060] Referring to FIG. 2A, a secondary battery inspection device (100) according to one embodiment may include a sensor module (110), a detection circuit (120), a processor (130), a transport device (140), and / or a memory (150).

[0061] Referring to FIG. 2B, the sensor module (110) may include a first sensor (111) and a second sensor (112). The first sensor (111) may include a first coil (111a). The second sensor (112) may include a second coil (112a). The first coil (111a) may be wound around the first sensor (111), and the second coil (112a) may be wound around the second sensor (112).

[0062] For example, in a state where the sensor module (110) is disposed adjacent to the surface of the secondary battery (10), a first signal may be applied to the first coil (111a). As the first signal is applied to the first coil (111a), it may be configured to form a first magnetic field (M1). For example, when a high-frequency alternating current flows along the coil, a first magnetic field (M1), which is an alternating magnetic field, may be formed. The first magnetic field (M1) may induce a current (E) (e.g., an eddy current) on the surface of the secondary battery (10) adjacent to the sensor module (110). For example, since the case (11) includes a conductive material (e.g., a metal), an induced electromotive force may be formed on the surface of the case (11), which is a conductor, and a current (E) may be formed by the induced electromotive force.

[0063] For example, a current (E) formed on the surface of a secondary battery (10) can form a second magnetic field (M2). The second magnetic field (M2) can interact with a second coil (112a) of an adjacent second sensor (112). For example, the second coil (112a) can be positioned closer to the secondary battery (10) than the first coil (111a) to interact with the second magnetic field (M2). However, the present invention is not limited thereto. For example, if a defect (e.g., a crack) exists inside the secondary battery (10), the discontinuity caused by the defect can change the amplitude and pattern of the current (E). The change in the current (E) can cause a change in the second magnetic field (M2). The change in the second magnetic field (M2) can affect the movement of electrons flowing along the second coil (112a) by changing the impedance of the second coil (112a). According to one embodiment, the second coil (112a) may be configured to generate a second signal by interacting with the second magnetic field (M2).

[0064] According to one embodiment, the second signal generated through the second coil (112a) may include a signal regarding a current and / or voltage applied to the second coil (112a) by the second magnetic field (M2). For example, the second magnetic field (M2) formed by the current (E) may induce a current flowing along the second coil (112a). The second coil (112a) may be configured to generate a signal in the form of a sine wave regarding the current.

[0065] Referring again to FIG. 2A, according to one embodiment, the detection circuit (120) may be configured to acquire a second signal via the second coil (112a). The detection circuit (120) may be configured to acquire a plurality of parameters. For example, the detection circuit (120) may include a lock-in amplifier configured to detect a signal reflecting a change in current (E) due to a defect in a noisy environment. For example, the detection circuit (120) may be configured to detect the amplitude and phase of an input signal relative to a periodic reference signal using a low pass filter (LPF).

[0066] According to one embodiment, the detection circuit (120) can measure the change in characteristics of the second signal due to the change in impedance in the second coil (112a). For example, since the second signal changes depending on the size, shape, location, material inhomogeneity, conductivity, or permeability of a defect, the characteristics can be identified based on the size and shape of the signal. The detection circuit (120) can utilize a process of finding solutions for each boundary condition in Maxwell's equations to interpret the second signal according to the current, and in particular, can utilize signal analysis using the finite element method in consideration of the geometric shape and material characteristics of the secondary battery (10) which is the subject of the analysis. For example, analytical methods and numerical methods can be used for signal analysis to interpret electromagnetic fields and model currents, and finite difference method (FDM), finite element method (FEM), boundary element method (BEM), and volume integral method (VIM) can be used.

[0067] According to one embodiment, the measurement values ​​of a plurality of parameters acquired through the detection circuit (120) may be provided to the processor (130). The detection circuit (120) may be configured to acquire a second signal from the second sensor (112) and provide the measurement values ​​of the plurality of parameters acquired based on the second signal to the processor (130).

[0068] According to one embodiment, the plurality of parameters may include a first parameter and a second parameter. For example, the first parameter may include a voltage difference between the first signal and the second signal, and a phase difference between the first signal and the second signal, as a primary sensing parameter obtained through the detection circuit (120). For example, the second parameter may include a resistance of the second coil (112a) and an impedance of the second coil (112a), which are calculated based on the first parameter. However, the present invention is not limited thereto. For example, the voltage difference may be expressed as an amplitude due to a potential difference.

[0069] According to one embodiment, the processor (130) may obtain measurement values ​​of a plurality of parameters obtained from the detection circuit (120). The processor (130) may represent the measurement values ​​for each of the plurality of parameters in a graph. The processor (130) may be configured to identify a defect in the secondary battery (10) based on at least some of the plurality of parameters. The processor (130) may be configured to generate a three-dimensional image of the secondary battery (10) based on at least some of the plurality of parameters. From the three-dimensional image, the state of the secondary battery (10) may be intuitively identified. For example, from the three-dimensional image of the lead tab (13), the welding state of the lead tab (13) may be easily identified. For example, the processor (130) may select one parameter from among the plurality of parameters and generate a two-dimensional image and / or a three-dimensional image for coordinates of the surface of the secondary battery (10) using the selected one parameter. When the state of the secondary battery (10) is abnormal (for example, when a defect exists), the two-dimensional image and three-dimensional image of the area of ​​the abnormal state may appear as images indicating abnormal values.

[0070] According to one embodiment, the transport device (140) may be configured to transport the sensor module (110). The transport device (140) may be coupled with the sensor module (110) and configured to transport the sensor module (110) along at least a portion of a surface of the secondary battery (10) (e.g., the surface of the lead tab (11)). The sensor module (110) may be transported along at least a portion of an area of ​​the secondary battery (10) while being coupled to the transport device (140). The transport device (140) may adjust the distance between the sensor module (110) and the secondary battery (10). For example, the transport device (140) may be configured to transport the sensor module (110) in an up-and-down direction relative to the secondary battery (10). However, the present invention is not limited thereto, and the transport device (140) may be implemented in the form of a transport stage configured to transport the secondary battery (10).

[0071] According to one embodiment, the memory (150) may store instructions executable by the processor (130). The processor (130) may be configured to control the operation of the secondary battery inspection device (100). The instructions, when executed by the processor (130), may be configured to cause the operation of the secondary battery inspection device (100). Any function or operation described in the present disclosure may be processed by one processor or a combination of processors. One processor or a combination of processors is a circuit that performs processing, and may include an application processor (AP, e.g., a central processing unit (CPU)), a communication processor (CP, e.g., a modem), a graphics processing unit (e.g., a GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a wireless-fidelity (Wi-Fi) chip, and a Bluetooth TMThe memory (150) may include a chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display drive integrated circuit (DDI), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or a similar circuit. According to one embodiment, the memory (150) may store instructions. Each of the flow charts described below may be performed by instructions executable by a computer being executed by the processor (130).

[0072] According to one embodiment, the memory (150) can store information related to the secondary battery (10). For example, the memory (150) can store information on the size of the secondary battery (10), information on the position of the lead tab (13), information on the manufacturer of the secondary battery (10), information on the specifications (e.g., capacity) of the secondary battery (10), etc.

[0073] FIGS. 3A and 3B illustrate examples of a transport device of a secondary battery inspection device according to one embodiment.

[0074] Referring to FIGS. 3A and 3B, the transport device (140) may include a first transport device (141) and a second transport device (142). The first transport device (141) may be configured to be coupled with the sensor module (110) and transport the sensor module (110) along the secondary battery (10). The second transport device (142) may be configured to transport the secondary battery (10). The second transport device (142) may be implemented in the form of a transport stage or a conveyor belt. In the case of the first transport device (141), the sensor module (110) may be moved, and in the case of the second transport device (142), the secondary battery (10) may be moved.

[0075] Referring to FIG. 3A, the first transport device (141) may be coupled with the sensor module (110). The first transport device (141) may be configured to move the sensor module (110) over the secondary battery (10). The sensor module (110) may be configured to apply a first signal and acquire a second signal according to the first signal while moving over the secondary battery (10) by the first transport device (141). When a defect exists at a specific location of the secondary battery (10), the second signal acquired by the sensor module (110) when the sensor module (110) is placed near the specific location may indicate the defect.

[0076] According to one embodiment, the first transport device (141) may be configured to move the sensor module (110) in an up-and-down direction (e.g., a direction parallel to the z-axis) with respect to the secondary battery (10). For example, the first transport device (141) may be configured to be able to adjust the distance between the secondary battery (10) and the sensor module (110). The first transport device (141) may be configured to move the sensor module (110) on the same plane. For example, the first transport device (141) may be configured to move the sensor module (110) in a direction parallel to the x-axis and a direction parallel to the y-axis.

[0077] Referring to FIG. 3B, the second transport device (142) can fix the sensor module (110) to a designated position and move the secondary battery (10) under the sensor module (110). For example, the sensor module (110) can be fixed to a designated position on a conveyor belt (142a) on which the secondary battery (10) moves. The second transport device (142) can drive the conveyor belt (142a). The secondary battery (10) can be placed on the conveyor belt (142a). When the conveyor belt (142a) is driven in one direction, the secondary battery (10) placed on the conveyor belt (142a) can be transported in the one direction. When the secondary battery (10) is transported, passing under the sensor module (110), the sensor module (110) can be configured to acquire a second signal.

[0078] According to one embodiment, the sensor module (110) can be fixed at a position corresponding to the lead tab (13) of the secondary battery (10). The second transport device (142) can position the sensor module (110) so as to face the lead tab (13) of the secondary battery (10) placed on the conveyor belt (142a).

[0079] According to one embodiment, the processor (130) may be configured to control the first transfer device (141) and the second transfer device (142) based on information about the secondary battery (10) stored in the memory (150). For example, size information about the secondary battery (10) and position information about the lead tab (13) may be stored in the memory (150).

[0080] According to one embodiment, the processor (130) may use the information to control the first transfer device (141). For example, in order to determine at which location of the secondary battery (10) the second signal acquired by the sensor module (110) is acquired, coordinates may be assigned to the location of the secondary battery (10). The secondary battery (10) may identify at which location of the secondary battery (10) the second signal acquired through the sensor module (110) is acquired by controlling the first transfer device (141) based on the assigned coordinates. For example, the processor (130) may control the first transfer device (141) to position the sensor module (110) at the (a, b) location assigned to the secondary battery (10), and may identify that the second signal is a signal acquired at the (a, b) location by acquiring the second signal at the (a, b) location.

[0081] According to one embodiment, the processor (130) may use the information to control the second transport device (142). For example, the second transport device (142) may be controlled so that the sensor module (110) can obtain a second signal at a location corresponding to the lead tab (13) of the secondary battery (10). For example, information on the location and size of the first lead tab (13-1) and the second lead tab (13-2) of the secondary battery (10) may be stored in the memory (150). The processor (130) may obtain the information corresponding to the secondary battery (10) placed on the conveyor belt (142a). The processor (130) can control the second transport device (142) so that when the secondary battery (10) passes under the sensor module (110) by driving the conveyor belt (142a), the sensor module (110) is placed at a position corresponding to the position of the lead tab (13). For example, when the secondary battery (10) placed on the conveyor belt (142a) is changed, the processor (130) can obtain the information related to the changed secondary battery (10). The processor (130) can be configured to control the second transport device (142) so that the sensor module (110) is placed at a position corresponding to the lead tab (13) of the changed secondary battery (10).

[0082] According to one embodiment, the processor (130) may be configured to control the driving speed of the conveyor belt (142a) of the second transport device (142). For example, if the driving speed is too fast, the transport speed of the secondary battery (10) may be too fast, making it difficult for the sensor module (110) to identify a defect in the secondary battery (10). For example, if the driving speed is too slow, the transport speed of the secondary battery (10) may be too slow, making the sensor module (110) obtain too many second signals within a narrow area of ​​the secondary battery (10), and when the number of secondary batteries (10) to be detected is large, the sensing speed may be too slow.

[0083] According to one embodiment, the processor (130) may obtain a plurality of parameters based on a second signal obtained through the sensor module (110) from the detection circuit (120). The processor (130) may be configured to adjust the driving speed of the second transport device (142) based on the measured values ​​of the plurality of parameters obtained from the detection circuit (120).

[0084] According to one embodiment, when the area of ​​the secondary battery (10) corresponding to the interval between the measured values ​​of the plurality of parameters is less than the designated area, the processor (130) may be configured to control the second transport device (142) so as to reduce the driving speed. The designated area of ​​the area of ​​the secondary battery (10) corresponding to the interval between the measured values ​​of the plurality of parameters may be based on the driving speed of the conveyor belt (142a) of the second transport device (142). If the conveying speed is too fast, the area of ​​the secondary battery (10) may be reduced, making it difficult to determine a defect. The processor (130) may compare the area of ​​the secondary battery (10) with the designated area and reduce the driving speed so that the area of ​​the secondary battery (10) corresponds to the designated area.

[0085] According to one embodiment, the processor (130) may be configured to control the second transport device (142) to increase the driving speed when the area of ​​the secondary battery (10) corresponding to the interval between the measured values ​​of the plurality of parameters exceeds the designated area. If the transport speed is too slow, the area of ​​the secondary battery (10) may increase, making it difficult to distinguish the plurality of parameters based on the second signal, and the sensing speed of the secondary battery (10) may be slow. The processor (130) may compare the area of ​​the secondary battery (10) with the designated area, and increase the driving speed so that the area of ​​the secondary battery (10) corresponds to the designated area.

[0086] Fig. 4 is a flow chart illustrating the operation of a secondary battery inspection device according to one embodiment. Figs. 5a and 5b are graphs illustrating measured values ​​of parameters obtained through a secondary battery inspection device according to one embodiment.

[0087] The operations described in FIG. 4 may be referred to as operations caused by the secondary battery inspection device (100) when instructions stored in the memory (150) are executed by the processor (130).

[0088] Referring to FIG. 4, in operation 401, a processor (e.g., processor (130) of FIG. 2A) may select one parameter from among a plurality of parameters obtained from a detection circuit (e.g., detection circuit (120) of FIG. 2A).

[0089] According to one embodiment, the detection circuit (120) may be configured to detect a plurality of parameters within the second signal. For example, the detection circuit (120) may include a lock-in amplifier configured to detect a signal reflecting a change in current (E) (e.g., eddy current) due to a defect in a noisy environment. The detection circuit (120) may mix a reference signal having the same frequency as the measurement signal (e.g., the second signal) with the second signal, and pass the mixed signal through a low-pass filter to extract only the desired frequency components. The detection circuit (120) may amplify the extracted signal to a level that is easy to measure.

[0090] In one embodiment, the plurality of parameters may include a first parameter and a second parameter. For example, the first parameter may include a difference between the voltage of the first signal and the voltage of the second signal and a difference between the phase of the first signal and the phase of the second signal. For example, the difference in voltage may be referred to as an amplitude, which is a potential difference. The second parameter may be obtained through calculation from the first parameter. For example, the second parameter may include a resistance of the second coil (110b) and an impedance of the second coil (110b).

[0091] According to one embodiment, the processor (130) may be configured to generate a graph representing a measurement value for one parameter.

[0092] In one embodiment, the graph may include a graph representing a difference between the voltage of the first signal and the voltage of the second signal according to the number of measurements. For example, the voltage of the first signal provided to the first coil (110a) may be different from the voltage of the second signal received by the second coil (110b). The second magnetic field (M2) formed by the induced electromotive force phenomenon may induce a voltage applied to the second coil (110b), and the voltage of the second signal may be lower than the voltage of the first signal. The difference in voltage may generate an amplitude, which is a potential difference. The graph may be acquired by the detection circuit (120) detecting the difference in voltage.

[0093] In one embodiment, the graph may include a graph representing the phase difference between the first signal and the second signal according to the number of measurements. Due to reactance, a delay may occur in the second signal with respect to the first signal, and the delay may cause a phase difference. By detecting the phase difference using the detection circuit (120), the second graph may be obtained. If a defect exists, the phase difference may increase.

[0094] According to one embodiment, the resistance and reactance of the second coil (110b) can be obtained based on the difference in voltage and the difference in phase that can be obtained through the detection circuit (120). For example, the detection circuit (120) can obtain the electrical parameters of resistance and reactance through an impedance plane for the second coil (110b). The impedance plane can be referred to as a plane in which the reactance and resistance of the circuit are expressed as measured values ​​or vectors on two axes that are perpendicular to each other. The processor (130) can obtain the second parameter that can be obtained secondarily based on the first parameter that can be obtained primarily from the detection circuit (120). For example, the processor (130) can obtain the resistance and reactance based on the voltage and phase.

[0095] In one embodiment, the processor (130) may select one parameter from among a plurality of parameters. For example, the processor (130) may select one parameter that best represents a defect in the secondary battery (10) within the frequencies of the first signal and / or the second signal.

[0096] For example, among the multiple parameters acquired through the detection circuit (120), if the difference between the voltage of the first signal and the voltage of the second signal is clear, the processor (130) may be configured to select the difference in voltage.

[0097] For another example, a parameter may be specified that is selected based on the frequency. According to one embodiment, the processor (130) may be configured to select one parameter from among a plurality of parameters based on the frequency band of the first signal applied to the first coil (110a). For example, when the frequency band of the first signal is within a range of about 400 kHz to about 500 kHz, the processor (130) may be configured to select the phase difference between the first signal and the second signal from among the plurality of parameters. If the frequency of the first signal is too low, it may be difficult to detect a defect. In particular, when a defect occurs at the edge of the secondary battery (10), the first signal in the low frequency band may have difficulty identifying the defect. In addition, if the frequency of the first signal is too high, the current may not reach the battery cells arranged inside the case (210) and may be formed only on the surface of the case (210), making it difficult to identify a defect generated in the battery cell. According to one embodiment, the frequency of the first signal may be about 400 kHz to about 500 kHz. The processor (130) may be configured to, in response to identifying the first signal on the frequency band, select a phase difference between the first signal and the second signal, and identify a defect occurring in the secondary battery (10) based on the phase difference.

[0098] In operation 402, the processor (130) can compare the measured value of one selected parameter with the value of a reference parameter for a normal state secondary battery (10) corresponding to the one parameter.

[0099] A secondary battery (10) in a normal state may be referred to as a secondary battery (10) in a state without any physical defects such as defects. The reference parameter may be referred to as a parameter that can be obtained from the secondary battery (10) in a normal state. The reference parameter corresponding to the above-mentioned one parameter may be referred to as a parameter corresponding to a selected parameter among the parameters for the secondary battery (10) in a normal state. For example, if the selected one parameter is a voltage difference, the corresponding reference parameter may be a voltage difference in a normal state.

[0100] In operation 403, the processor (130) may be configured to identify a defect in the secondary battery (10) based on the comparison result.

[0101] According to one embodiment, the processor (130) may be configured to identify a defect in the secondary battery (10) based on identifying that a difference between the first parameter and a reference parameter exceeds a specified threshold value when the first parameter is selected.

[0102] In one embodiment, the processor (130) may identify maximum and minimum values ​​among the parameter values ​​to detect abnormal values. For example, the processor (130) may identify peaks and valleys within the acquired amplitude.

[0103] Fig. 5a is a first graph (510) for the measured values ​​of parameters that can be obtained from a secondary battery (10) in a normal state. Fig. 5b is a second graph (520) for the measured values ​​of parameters that can be obtained from a secondary battery (10) in an abnormal state. Figs. 5a and 5b may be measured values ​​of one parameter for the number of measurements of a second signal measured through a sensor module (110). For example, the graphs of Figs. 5a and 5b may be graphs for the phase for the number of measurements. The number of measurements refers to the number of times the sensor module (110) obtained the second signal, and the total number of measurements may represent the total number of times the sensor module (110) measured the second signal.

[0104] For example, the processor (130) may select, from among a plurality of parameters, the difference between the phase of the first signal, which is a first parameter, and the phase of the second signal. The first graph (510) of FIG. 5A may be referred to as a graph representing the difference in phase that can be obtained from a secondary battery (10) in a normal state. The second graph (520) of FIG. 5B may be referred to as a graph representing the difference in phase that can be obtained from a secondary battery (10) in which a defect exists.

[0105] According to one embodiment, the processor (130) may obtain a measurement value for the difference in phase, such as between the first graph (510) and the second graph (520), through the detection circuit (120). When the first graph (510) and the second graph (520) are compared, the amplitude due to the potential difference may be lowered within the area A. Due to the defect, the second magnetic field (M2) may be affected, and thus an abnormal value that cannot be exhibited in the secondary battery (10) in a normal state may be obtained. According to one embodiment, the processor (130) may determine that a defect has occurred in the secondary battery (10) based on comparing the measurement value within the area A of the second graph (520) with a reference measurement value and identifying that the difference exceeds a threshold value.

[0106] A secondary battery inspection device (100) according to one embodiment can simply identify a defect in a secondary battery (10) through a sensor module (110). According to one embodiment, in order to determine the presence or absence of a defect, the processor (130) can select one parameter from among a plurality of parameters acquired from the detection circuit (120). For example, the processor (130) can accurately identify a defect in the secondary battery (10) by selecting a parameter that can clearly express a physical defect in the secondary battery (10) in a signal of a specific frequency. The processor (130) can identify a defect in a method based on the selected one parameter. In the case of the first parameter, peaks and / or valleys of signals that occur locally in the measured signal can be identified, and whether the identified peaks or valleys indicate abnormal values ​​can be identified. For example, the occurrence of a defect can be identified based on whether a difference between a peak or valley of a reference parameter and the identified peak or valley exceeds a threshold value. For the second parameter, the processor (130) can identify the occurrence of a fault based on whether data falling within a specified range indicating an abnormal value exists. For example, the processor (130) can obtain impedance based on the second parameter, resistance and reactance, and identify the occurrence of a fault if the obtained impedance falls within a specified range.

[0107] Figure 6 is an example of a processor converting parameter values ​​acquired through a detection circuit into a three-dimensional image.

[0108] Referring to FIG. 6, the processor (130) can generate a three-dimensional image (600) showing measured values ​​of parameters for the secondary battery (10). The three-dimensional image (600) can include an x-axis, a y-axis, and a z-axis. The x-axis represents the x-axis of the secondary battery (10). The y-axis represents the y-axis of the secondary battery (10). For example, x, y coordinates can be assigned to the entire surface of the secondary battery (10), and the assigned x, y coordinates can be displayed as x, y values ​​of the three-dimensional image (600). The z-axis represents the measured values ​​of the selected parameters.

[0109] According to one embodiment, x, y values ​​can be determined according to x, y coordinates assigned to the entire surface of the secondary battery (10). For example, if the coordinates of one position are (a, b), and the measurement value of the selected parameter for the one position is e, a three-dimensional image (600) can be generated at (a, b, e). For example, if the coordinates of another position are (c, d), and the measurement value of the selected parameter for the other position is f, a three-dimensional image (600) can be generated at (c, d, f). As the measurement values ​​of the selected parameter for the entire surface area of ​​the secondary battery (10) are generated, a three-dimensional image (600) as illustrated in FIG. 6 can be acquired.

[0110] According to one embodiment, the three-dimensional image (600) can indicate the presence or absence of a defect in the secondary battery (10).

[0111] For example, the processor (130) may select, among a plurality of parameters, the difference between the phase of the first signal, which is a first parameter, and the phase of the second signal.

[0112] According to one embodiment, the processor (130) can obtain the phase difference through the detection circuit (120). Due to a defect, the second magnetic field (M2) is affected, so that an abnormal value that cannot be exhibited in a normal secondary battery (10) can be obtained. In other words, if a sudden change in phase due to a potential difference is measured within a specific area, it can be determined that a defect has occurred in the secondary battery (10). The z-axis may be the phase difference between the first signal and the second signal. If the processor (130) selects the phase difference between the first signal and the second signal among a plurality of parameters based on the frequency band and / or the second frequency band of the first signal, a three-dimensional image (600) for the phase difference between the first signal and the second signal can be generated according to the coordinates for the entire area of ​​the secondary battery (10). Referring to FIG. 6, an area B where the phase difference is abruptly lowered can be identified.

[0113] In order to closely observe the state of a defect (e.g., shape, size, location, etc.) in the measurement results measured through the detection circuit (120), the processor (130) can separate the measurement results into low-frequency components and high-frequency components through FFT (Fast Fourier Transform). For example, the filter used for frequency separation is a Gaussian function, and the Gaussian function can be defined by the following [Mathematical Formula 1].

[0114]

[0115] If the above measurement result is defined as z(x, y), the FFT for the measurement result can be expressed as Z(m, n). The processor (130) can separate the frequency components using [Mathematical Formula 2] below.

[0116]

[0117] The above [Mathematical Formula 2] can be referenced as a formula for extracting the frequency of low-frequency components from measurement results using a Gaussian function filter. The results of the low-frequency components can be obtained through the following [Mathematical Formula 3] using the inverse FFT transform.

[0118]

[0119] Additionally, from the measurement results, the processor (130) can separate high-frequency components through [Mathematical Formula 4] below.

[0120]

[0121] The processor (130) can extract high-frequency components from the measurement results and express colors differently according to the high-frequency components using the x, y coordinates assigned to the secondary battery (10). In the three-dimensional image (600), the state of the defect can be observed in detail. For example, referring to area B of the image (600) in FIG. 6, the location where the defect occurred, the shape of the defect, and the size and degree of the defect can be intuitively identified.

[0122] Area B of FIG. 6 can be referred to as a three-dimensional image of area A of FIG. 5b. Area B can be caused by a phase shift due to a defect in the secondary battery (10). Through the coordinates of the area, the location of the area where the defect has occurred among the entire area of ​​the secondary battery (10) can be identified. For example, through the coordinates of area B where the phase difference rapidly decreases, it is possible to identify not only the presence or absence of a defect, but also the area in which the defect has occurred and the general shape of the defect. Since the three-dimensional image can represent the actual physical state of the secondary battery (10) rather than the simulation result, it can intuitively represent the exact state of the secondary battery (10).

[0123] A secondary battery inspection device (100) according to one embodiment can provide a three-dimensional image (600) to intuitively identify whether a crack has occurred in a secondary battery (10). Through the three-dimensional image (600), the presence or absence of a defect, the size of the defect, and the area where the defect has occurred can be identified without destroying the secondary battery (10). The secondary battery inspection device (100) can provide a three-dimensional image (600) that can indicate not only the presence or absence of a defect, but also the area where the defect has occurred, the approximate shape of the defect, and the location of the defect, by moving the sensor module (110) along the entire area of ​​the surface of the secondary battery (10).

[0124] FIG. 7 is a flowchart illustrating an operation of a secondary battery inspection device according to one embodiment of the present invention to identify defects in a secondary battery by dividing measurement values ​​into multiple sections. FIG. 8 is a graph illustrating measurement values ​​for a number of measurements, each of which is divided into multiple sections.

[0125] The operations described in FIG. 7 may be operations caused by the secondary battery inspection device when instructions stored in the memory (150) are executed by the processor (130).

[0126] Referring to FIG. 7, in operation 701, the processor (130) may be configured to identify a first value and a second value among measurement values ​​of one parameter selected from among a plurality of parameters.

[0127] According to one embodiment, the processor (130) may cause the secondary battery inspection device to identify a first value and a second value among the measured values ​​of one parameter when executing instructions stored in the memory (150).

[0128] For example, the measurement values ​​for one parameter may be multiple. The parameter obtained based on the second signal measured by the sensor module (110) may be expressed as a measurement value for the number of measurements of the sensor module (110). Here, the first value may be referred to as the smallest value among the measurement values ​​of one parameter, and the second value may be referred to as the smallest value among the remaining measurement values ​​excluding the first value, and as a value next to the first value. The processor (130) may be configured to identify the first value and the second value with respect to the entire measurement values ​​for the inspection results provided from the detection circuit (120).

[0129] In operation 702, the processor (130) may be configured to identify an interval between a first measurement number corresponding to a first value and a second measurement number corresponding to a second value.

[0130] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to identify an interval between a first measurement number corresponding to a first value and a second measurement number corresponding to a second value.

[0131] For example, the processor (130) may be configured to identify a first measurement number corresponding to a first value and a second measurement number corresponding to a second value in order to divide the measurement values ​​for the total number of measurements into a plurality of sections. As illustrated in FIGS. 3A and 3B , the transport device (140) may move the sensor module (110) over the secondary battery (10) (e.g., the first transport device of FIG. 3A ) or transport the secondary battery (10) under the fixed sensor module (110). At this time, the second signal acquired by the sensor module (110) while the sensor module (110) is positioned at a position corresponding to the secondary battery (10) may be a second signal capable of determining a defect in the secondary battery (10). For example, since the sensor module (110) operates even at a location that does not correspond to the secondary battery (10), such as when the sensor module (110) is not on the secondary battery (10) but outside the secondary battery (10), a second signal unrelated to the secondary battery (10) may be acquired. The second signal acquired at a location that does not correspond to the secondary battery (10) may be noise because it is unrelated to the secondary battery (10).

[0132] According to one embodiment, the processor (130) may be configured to identify an interval between a first measurement number corresponding to a first value and a second measurement number corresponding to a second value as a valid interval.

[0133] Referring to FIG. 8, a graph (810) for a measurement value of one parameter for the total number of measurements is illustrated. The graph (810) can be obtained by having the detection circuit (120) convert the second signal measured by the sensor module (110) into measurement values ​​for each of a plurality of parameters, and having the processor (130) represent this as a graph (810) for the total number of measurements. The total number of measurements illustrated in FIG. 8 can be, for example, 371. The fact that the total number of measurements is 371 means that the sensor module (110) performed a measurement operation 371 times to obtain the second signal.

[0134] In the graph (810) illustrated in FIG. 8, a first value and a second value may be identified. For example, the first value may be a measurement value obtained when the number of measurements is c, and the second value may be a measurement value obtained when the number of measurements is d. According to one embodiment, the processor (130) may identify the first measurement number corresponding to the first value as d, and the second measurement number corresponding to the second value as c. In other words, the first measurement number corresponding to the first value may be d, and the second measurement number corresponding to the second value may be c. The processor (130) may be configured to identify an interval between c and d.

[0135] In operation 703, the processor (130) may be configured to divide an interval between a first measurement number and a second measurement number into a plurality of intervals.

[0136] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to distinguish an interval between a first measurement number and a second measurement number into a plurality of intervals.

[0137] In one embodiment, the processor (130) may be configured to divide the measured values ​​of one parameter for the total number of measurements of the second signal into a plurality of intervals including a first interval and a second interval. For example, the processor (130) may divide the interval between the first measurement number and the second measurement number into a plurality of intervals including a first interval and a second interval.

[0138] Referring to FIG. 8, the processor (130) may be configured to divide the section between c and d into a plurality of sections. For example, the plurality of sections may include five sections. According to one embodiment, the first section (801), the second section (802), the third section (803), the fourth section (804), and the fifth section (805) may be sequentially set according to the number of measurements. The first section (801), the second section (802), the third section (803), the fourth section (804), and the fifth section (805) may each be referred to as sections that border each other. For example, the second section (802) may be between the first section (801) and the third section (803), and the fourth section (804) may be between the third section (803) and the fifth section (805). According to one embodiment, the processor (130) may be configured to compare the measured values ​​of the parameters with reference values, thereby dividing the entire section into a plurality of sections, and identifying defects for the entire section and each of the plurality of sections.

[0139] In operation 704, the processor (130) may be configured to compare a measurement value included in an interval between the first measurement number and the second measurement number and a measurement value included in each of the plurality of intervals with a reference value.

[0140] According to one embodiment, the processor (130) may cause the secondary battery inspection device to compare a measurement value included in an interval between the first measurement number and the second measurement number and a measurement value included in each of the plurality of intervals with a reference value when executing instructions stored in the memory (150).

[0141] For example, the processor (130) may inspect the entire section to identify a defect in the secondary battery (10). The processor (130) may be configured to compare the measurement values ​​included in the entire section with a reference value. Here, the measurement values ​​included in the entire section may refer to measurement values ​​included in the section between the first measurement number and the second measurement number, rather than the entire measurement values ​​for the entire number of measurements. That is, the processor (130) may not perform an inspection on measurement values ​​included in a section excluded from the entire section (e.g., section A and section B of FIG. 8) because they are classified as noise unrelated to the secondary battery (10).

[0142] For example, the processor (130) may inspect each of a plurality of sections to identify a defect in the secondary battery (10). The processor (130) may be configured to compare a measurement value included in each of the plurality of sections with a reference value. For example, the processor (130) may be configured to identify the presence of a first defect in the first section (801) by comparing a first measurement value included in the first section (801) with a first reference value. For example, the processor (130) may be configured to identify the presence of a second defect in the second section (802) by comparing a second measurement value included in the second section (802) with a second reference value. Each of the plurality of sections including the first section (801) and the second section (802) may correspond to different regions of the secondary battery (10), and thus may have different reference values. According to one embodiment, the processor (130) may independently assign a reference value to each of a plurality of sections. For example, the second section (802) and the fourth section (804) of FIG. 8 may be sections corresponding to the lead tabs (13) of the secondary battery (10) (e.g., the first lead tab (13-1) and the second lead tab). In the case of the lead tab (13), since it is a section where welding exists between the electrode tab and the lead tab (13), the reference value may be set according to the presence of welding. For example, since the change in the physical properties at the welding portion is large, the amount of change in the measured value included in the second section (802) and the fourth section (804) may be greater than the amount of change in the measured value included in other sections. Accordingly, the reference values ​​assigned to the sections corresponding to the lead tab (13) (e.g., the second section (802) and the fourth section (804)) may be different from the reference values ​​assigned to other sections (e.g., the first section (801), the third section (803), and the fifth section (805)).

[0143] In operation 705, the processor (130) may be configured to identify a defect in the secondary battery (10) for each of the plurality of sections based on the comparison result. Operation 705 may substantially correspond to operation 503.

[0144] According to one embodiment, the secondary battery inspection device can precisely identify a defect by performing an inspection on the entire section and each of a plurality of sections. If the defect is identified only within the entire section, accurate analysis of the measurement values ​​within the section may be difficult. In order to precisely detect a defect, the secondary battery inspection device may be configured to divide the entire section into a plurality of sections, as well as the entire section, and to perform an inspection on each of the plurality of sections. When a defect is identified for the entire section or a plurality of sections, the processor (130) may determine a defect in the secondary battery (10). The processor (130) may be configured to identify, based on the comparison result, whether a first defect exists within a first section (801) and whether a second defect exists within a second section (802).

[0145] According to one embodiment, the secondary battery inspection device may be configured to identify a defect in the secondary battery (10) when a defect is identified in any one of a plurality of sections. For example, the secondary battery (10) may be configured to identify a defect based on identifying at least one of a first defect in a first section (801) or a second defect in a second section (802). The secondary battery inspection device may precisely identify a defect by determining a defect when a defect exists in any one of the plurality of sections.

[0146] FIG. 9A is a flowchart illustrating an operation of a test device according to one embodiment to set multiple sections. FIG. 9B illustrates a graph in which multiple sections are set according to the operation of FIG. 9A.

[0147] Although the plurality of sections (801, 802, 803, 804, 805) illustrated in FIG. 8 have been described as sections whose boundaries are adjacent to each other, the secondary battery inspection device may set the plurality of sections so that they partially overlap when setting the plurality of sections. The operations described in FIG. 9A may be operations caused by the secondary battery inspection device when instructions stored in the memory (150) are executed by the processor (130).

[0148] Referring to FIG. 9A, in operation 901, the processor (130) may be configured to obtain information related to a secondary battery (10) stored in a memory (150).

[0149] According to one embodiment, when the processor (130) executes instructions stored in the memory (150), the secondary battery inspection device may cause the secondary battery inspection device to obtain information related to the secondary battery (10) stored in the memory (150).

[0150] According to one embodiment, the memory (150) can store information related to the secondary battery (10) to be inspected. For example, the memory (150) can store information related to the secondary battery (10). For example, the memory (150) can store size information of the secondary battery (10), position information of the lead tab (13), manufacturer information of the secondary battery (10), specification (e.g., capacity) information of the secondary battery (10), etc. The position information of the lead tab (13) can include first position information corresponding to the first lead tab (13-1) and second position information corresponding to the second lead tab (13-2).

[0151] In operation 902, the processor (130) may be configured to obtain first location information corresponding to the first lead tab (13-1) and second location information corresponding to the second lead tab (13-2).

[0152] According to one embodiment, when the processor (130) executes instructions stored in the memory (150), the secondary battery inspection device may cause the secondary battery inspection device to obtain first location information corresponding to the first lead tab (13-1) and second location information corresponding to the second lead tab (13-2).

[0153] According to one embodiment, the first position information corresponding to the first lead tab (13-1) may be referenced as the coordinates of the secondary battery (10) where the first lead tab (13-1) is positioned, and the second position information corresponding to the second lead tab (13-2) may be referenced as the coordinates of the secondary battery (10) where the second lead tab (13-2) is positioned. Depending on the type and size of the secondary battery (10), the position of the lead tab (13) may be different. Within the secondary battery (10), the lead tab (13) may be a part where defects easily occur because it is welded with the electrode tab. The processor (130) may obtain the first position information and the second position information stored in the memory (150) to set a plurality of sections based on the position of the first lead tab (13-1) and the position of the second lead tab (13-2).

[0154] In operation 903, the processor (130) may be configured to identify a third measurement number obtained at a timing when the sensor module (110) is positioned at a position corresponding to the first location information and a fourth measurement number obtained at a timing when the sensor module (110) is positioned at a position corresponding to the first location information.

[0155] According to one embodiment, the processor (130) may cause the secondary battery inspection device to identify a third measurement number obtained at a timing when the sensor module (110) is located at a position corresponding to the first location information and a fourth measurement number obtained at a timing when the sensor module (110) is located at a position corresponding to the second location information when executing instructions stored in the memory (150).

[0156] According to one embodiment, the position corresponding to the first position information may be referred to as a position where the sensor module (110) is placed on the first lead tab (13-1), and the position corresponding to the second position information may be referred to as a position where the sensor module (110) is placed on the second lead tab (13-2). For example, when the transport device (140) transports the sensor module (110) (e.g., the first transport device (141)), the positions may be referred to as positions where the sensor module (110) is placed at a position overlapping the first lead tab (13-1) or the second lead tab (13-2) when the sensor module (110) is transported. For example, the above positions may be referenced as positions where the sensor module (110) is placed in a position overlapping the first lead tab (13-1) or the second lead tab (13-2) when the secondary battery (10) is being transported by the transport device (140) (e.g., the second transport device (142)). The third measurement number may be referenced as the number of measurements at which the sensor module (110) acquires (or measures) the second signal at the timing (e.g., the first timing) at which the sensor module (110) is placed on the first lead tab (13-1), and which measurement number is the measurement number acquired at the first timing among the total number of measurements. The fourth measurement number is a measurement number at which the sensor module (110) acquires (or measures) the second signal at a timing (e.g., the second timing) at which the sensor module (110) is placed on the second lead tab (13-2), and can be referred to as the measurement number among the total number of measurements at which the measurement number acquired at the timing (e.g., the second timing) is. Since the processor (130) acquires the first location information and the second location information from the memory (150), the processor (130) can identify the third measurement number acquired (or measured) at a location corresponding to the first location information and the fourth measurement number acquired (or measured) at a location corresponding to the second location information.

[0157] Referring to FIG. 9B, a graph (910) is shown for the measurement values ​​of one parameter for the total number of measurements described above. The x-axis of the graph (910) can be normalized by dividing each measurement number by the total number of measurements. For example, if the total number of measurements is 371, as in the graph (910)(810) illustrated in FIG. 8, each measurement number can be normalized from 0 to 1 by dividing each measurement number by 371. For example, the first measurement number can be 1 / 371, the 30th measurement number can be 30 / 371, and the 371st measurement number can be 371 / 371. The normalization will be described later.

[0158] Referring to FIG. 9B, the processor (130) can identify the third measurement number and the fourth measurement number. For example, the processor (130) can identify the third measurement number measured when the sensor module (110) coupled to the transport device (140) corresponds to the first lead tab (13-1) based on the first location information, and can identify the fourth measurement number measured when the sensor module (110) coupled to the transport device (140) corresponds to the second lead tab (13-2) based on the second location information. In the graph (910) of FIG. 9B, the third measurement number may be a, and the fourth measurement number may be b. The first location information and the second location information may vary depending on the secondary battery (10), and the third measurement number and the fourth measurement number may also vary depending on the secondary battery (10).

[0159] In operation 904, the processor (130) may be configured to set the plurality of sections to partially overlap.

[0160] According to one embodiment, the processor (130) may cause the secondary battery inspection device to set a plurality of sections to partially overlap when executing instructions stored in the memory (150).

[0161] Referring to Fig. 9b, multiple sections whose boundaries are in contact can be adjusted to partially overlap. For example, a second section (912) can be set based on the first lead tab (13-1), and a fourth section (914) can be set based on the second lead tab (13-2).

[0162] According to one embodiment, the processor (130) may be configured to set the boundary of the second section (912) outside a first range specified from the third measurement number such that the second section (912) overlaps with the first section (911). The first range may be pre-specified by the user or may be set based on information related to the secondary battery (10). For example, the first range may be set such that the boundary of the second section (912) may be included within the first section (911). The processor (130) may be configured to set the boundary of the fourth section (914) outside a second range specified from the fourth measurement number such that the fourth section (914) overlaps with the fifth section (915). The second range may be pre-specified by the user or may be set based on information related to the secondary battery (10). For example, the second range may be set such that the boundary of the fourth section (914) can be included within the fifth section (915). The processor (130) may be configured to set the third section (913) to be between the third measurement number and the fourth measurement number.

[0163] Referring to FIG. 9B, a first section (911) may overlap a second section (912), a third section (913) may overlap a second section (912) and a fourth section (914), and a fourth section (914) may overlap a fifth section (915). If a plurality of sections do not overlap, and a measurement value indicating a defect exists on a boundary between the plurality of sections, it may be difficult to identify the defect. For example, if a measurement value indicating a defect exists on a boundary between the first section (911) and the second section (912), it may be difficult to determine a defect from the measurement value within the first section (911) and the measurement value within the second section (912) based on the boundary. According to an embodiment, a secondary battery inspection device can accurately identify a defect by setting a plurality of sections to partially overlap, even if a measurement value indicating a defect is located on a boundary between the sections.

[0164] FIG. 10 is a flowchart showing an operation of a secondary battery inspection device according to one embodiment to identify a defect.

[0165] The operations described in FIG. 10 may be operations caused by the secondary battery inspection device when instructions stored in the memory (150) are executed by the processor (130).

[0166] Referring to FIG. 10, in operation 1001, the processor (130) may be configured to divide the measurement values ​​of one parameter for the total number of measurements into a plurality of intervals.

[0167] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to divide the measurement values ​​of one parameter for the total number of measurements into a plurality of intervals. For example, the processor (130) may be configured to divide the measurement values ​​of one parameter for the total number of measurements into a plurality of intervals. The plurality of intervals may include a first interval and a second interval.

[0168] In operation 1002, the processor (130) may be configured to identify a difference value corresponding to the skewness, kurtosis, and maximum and maximum value difference for each of the plurality of intervals.

[0169] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to identify a difference value corresponding to the asymmetry, kurtosis, and maximum and minimum value difference for each of the plurality of sections.

[0170] According to one embodiment, the processor (130) may be configured to identify skewness, kurtosis, and difference between maximum and maximum values, respectively. The processor (130) may identify skewness, kurtosis, and difference between maximum and maximum values, respectively, for each of a plurality of intervals. The processor (130) may be configured to identify a first difference value corresponding to a first skewness, a first kurtosis, and a difference between maximum and minimum values ​​for a first measured value within a first interval. The processor (130) may be configured to identify a second skewness, a second kurtosis, and a difference between maximum and minimum values ​​for a second measured value within a second interval, respectively.

[0171] According to one embodiment, skewness is a measure of how symmetrical the distribution of measured values ​​is. For example, if the distribution of measured values ​​is completely symmetrical, the skewness is 0. If a physical defect exists in the secondary battery (10), the skewness can be reduced because the measured values ​​appear symmetrical about the defect. The skewness of the measured values ​​of the parameters obtained from the secondary battery (10) including the defect can be smaller than the reference value for the skewness corresponding to the normal state. The skewness can be calculated based on the following [Mathematical Formula 5].

[0172]

[0173] In one embodiment, kurtosis is a measure of how peaked or flat a distribution of measured values ​​is. For example, the kurtosis of a normal distribution is 0. If the distribution of measured values ​​is peaked more than a normal distribution, the kurtosis is greater than 0, and if the distribution of measured values ​​is flatter than a normal distribution, the kurtosis is less than 0. In other words, the higher the kurtosis (kurtosis value), the more peaked the distribution of measured values ​​can be. Kurtosis can quantify the peak of measured values. The kurtosis of measured values ​​of parameters obtained from a secondary battery (10) including a defect can be higher than a reference value for kurtosis corresponding to a normal state. Kurtosis can be calculated based on the following [Mathematical Formula 6].

[0174]

[0175] In one embodiment, a difference value corresponding to the difference between the maximum and minimum values ​​of measured values ​​within an interval may be used to control over-detection. The difference value may be obtained by calculating the difference between the maximum and minimum values ​​within a specific interval. The difference value of the measured values ​​of the parameters obtained from a secondary battery (10) including a defect may be greater than the reference value for the difference value corresponding to a normal state.

[0176] When the plurality of intervals include a first interval and a second interval, according to one embodiment, in operation 1002, the processor (130) may be configured to identify a first skewness, a first kurtosis, and a first difference value for a first measurement value within the first interval. The processor (130) may be configured to identify a second skewness, a second kurtosis, and a second difference value for a second measurement value within the second interval.

[0177] In operation 1003, the processor (130) may be configured to identify a defect in the secondary battery (10) based on the asymmetry, kurtosis, and maximum and difference values.

[0178] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to identify a defect in the secondary battery (10) based on the asymmetry, kurtosis, and maximum and difference values.

[0179] According to one embodiment, the processor (130) may be configured to compare the first skewness with a first reference value of the skewness, compare the first kurtosis with a second reference value of the kurtosis, and compare the first difference value with a third reference value of the difference value. The processor (130) may be configured to identify the first defect based on identifying the first skewness being less than the first reference value, the first kurtosis being greater than the second reference value, and the first difference value being greater than the third reference value. In other words, the first defect within the first interval may be identified when the first skewness, the first kurtosis, and the first difference value each deviate from their corresponding reference values. The above description may be equally applicable to the second interval. If a defect is determined based on only one of the asymmetry, kurtosis, and difference values, an incorrect judgment may be made regarding the defect due to an inaccurate judgment. According to one embodiment, when all three factors are abnormal, the processor (130) can identify that the measured value within the first section indicates an abnormal defect and identify the first defect. Accordingly, the presence or absence of a defect can be accurately identified. Since the ease of identifying a defect based on the asymmetry, kurtosis, and difference values ​​varies depending on the type and shape of the defect, the secondary battery inspection device can determine the presence of a defect if the results for each of the asymmetry, kurtosis, and difference values ​​are determined to be abnormal.

[0180] Fig. 11a is a graph showing measurement values ​​for the number of measurements. Fig. 11b illustrates a process for converting a graph for measurement values ​​of the first section of Fig. 11a. Fig. 11c illustrates graphs for measurement values ​​of the second and fourth sections of Fig. 11a. Fig. 11d illustrates a graph for measurement values ​​of the third section of Fig. 11a. Fig. 11e illustrates a process for converting a graph for measurement values ​​of the fifth section of Fig. 11a.

[0181] Referring to FIG. 11A, a measurement value for a single parameter may be represented as a graph (1100) for the number of measurements. As described above, the processor (130) may divide the measurement value into multiple sections. For example, the multiple sections may include a first section (1101), a second section (1102), a third section (1103), a fourth section (1104), and a fifth section (1105).

[0182] According to one embodiment, the processor (130) may inspect each of the multiple sections to identify a defect. If inspection is performed on the entire section, it may be difficult to determine the defect. For example, if a defect is detected in a section where a curve slope of the graph exists, the defect reduces the asymmetry, making it difficult to accurately determine the defect based on the asymmetry of the entire section. The secondary battery inspection device may divide the entire section into multiple sections and set a separate detection method for each section.

[0183] Referring to FIG. 11b, in order to identify a defect (e.g., a first defect) within the first section (1101), the processor (130) may transform a graph within the first section (1101). For example, the graph (1101a) of FIG. 11b is a graph displayed within the first section (1101). To facilitate detection of the defect, in order to adjust the slope of the graph (1101a), the processor (130) may generate a straight line graph (1110) having an average rate of change for the measured values ​​within the graph (1101a). The processor (130) may subtract a value corresponding to the straight line graph (1110) from the measured values ​​within the first section (1101) to obtain a graph (1101b). Referring to the graph (1101b), peaks and valleys may be expressed more clearly. The processor (130) can acquire a graph (1101c) by acquiring a certain section based on a minimum value within the graph (1101b). The processor (130) can be configured to identify a first defect by acquiring kurtosis for the graph (1101c). Since a measurement value indicating a defect, which is difficult to detect within the graph (1101a), can be clearly identified within the graph (1101c), the secondary battery inspection device can accurately identify the first defect within the first section (1101). For example, the processor (130) can calculate kurtosis for the graph (1101c) of the first section (1101). Since peaks and valleys are clearly expressed, defect determination based on kurtosis can be facilitated.

[0184] Referring to FIG. 11c, in order to identify a defect (e.g., a second defect) in the second section (1102) and a defect (e.g., a fourth defect) in the fourth section (1104), the processor (130) may calculate asymmetry for the second section (1102) and the fourth section (1104). The graph (1102a) of FIG. 11c is a graph displayed in the second section (1102). The graph (1104a) of FIG. 11c is a graph displayed in the fourth section (1104). The second section (1102) and the fourth section (1104) may correspond to the lead tap (13). The second section (1102) may correspond to the first lead tap (13-1), and the fourth section (1104) may correspond to the second lead tap (13-2). In the case of the lead tab (13), since the change in physical properties due to welding with the electrode tab is significant, the symmetry may be high. If a defect exists around the electrode tab, the symmetry may become weak, and thus the asymmetry value may increase. According to one embodiment, the processor (130) can identify the presence of the second defect and the fourth defect by calculating the asymmetry for the second section (1102) and the fourth section (1104).

[0185] The graph (1103a) of FIG. 11D is a graph displayed within the third section (1103). Referring to FIG. 11D, in order to identify a defect (e.g., a third defect) within the third section (1103), the processor (130) may calculate an asymmetry for the third section (1103). The third section (1103) is a section between the second section (1102) and the fourth section (1104), and may correspond between the first lead tab (13-1) and the second lead tab (13-2). The third section (1103) may have high symmetry. If a defect exists within an area of ​​the secondary battery (10) corresponding to the section, the asymmetry value may increase because the symmetry may become weak. According to one embodiment, the processor (130) may identify the presence or absence of the third defect by calculating an asymmetry for the third section (1103).

[0186] Referring to FIG. 11e, in order to identify a defect (e.g., a fifth defect) within the fifth section (1105), the processor (130) may transform a graph within the fifth section (1105). The process of FIG. 11e may be substantially the same as or similar to the process of FIG. 11b. For example, the graph (1105a) of FIG. 11b is a graph displayed within the fifth section (1105). In order to adjust the slope of the graph (1105a) to facilitate detection of the defect, the processor (130) may generate a straight line graph (1130) having an average rate of change for the measured values ​​within the graph (1105a). The processor (130) may subtract a value corresponding to the straight line graph (1130) from the measured values ​​within the first section (1101) to obtain a graph (1105b). In the case of the fifth section (1105), since it may be difficult to clearly detect peaks and valleys, the processor (130) may convert the graph (1105b) into a graph (1105c) once more by repeating the same process. The processor (130) may obtain a graph (1105d) by obtaining a certain section based on a minimum value within the graph (1105c). The processor (130) may be configured to identify the first defect by obtaining kurtosis for the graph (1105d). Since the measurement value indicating a defect, which is difficult to detect within the graph (1105a), can be clearly identified within the graph (1105d), the secondary battery inspection device can accurately identify the fifth defect within the fifth section (1105). Since the peaks and valleys are clearly expressed, defect determination based on kurtosis may be easy.

[0187] As described above, the secondary battery inspection device according to one embodiment can accurately identify defects and enable rapid inspection by selecting different inspection methods for each section.

[0188] Fig. 12 schematically illustrates a secondary battery inspection device according to one embodiment. Fig. 13 is a flowchart illustrating a process of converting a measurement value by a secondary battery inspection device according to one embodiment.

[0189] As described above, the transport device (140) may be configured to be coupled with the sensor module (110) and transport the sensor module (110). Referring to FIG. 12, the transport device (140) may transport the sensor module (110) relative to the secondary battery (10). The processor (130) may be configured to control the transport device (140).

[0190] According to one embodiment, the transport device (140) may transport the sensor module (110) horizontally or vertically along the surface of the secondary battery (10). The transport device (140) may be configured to adjust the distance between the sensor module (110) and the secondary battery (10). For example, the transport device (140) may decrease the distance between the sensor module (110) and the secondary battery (10) so that the sensor module (110) is positioned closer to the secondary battery (10). For example, the transport device (140) may increase the distance between the sensor module (110) and the secondary battery (10) so that the sensor module (110) is positioned farther away from the secondary battery (10).

[0191] According to one embodiment, the intensity of the second signal obtained may vary depending on the distance between the sensor module (110) and the secondary battery (10). The intensity of the second signal may change the intensity of the measured values ​​for a plurality of parameters. If the distance between the sensor module (110) and the secondary battery (10) is too far, the intensity of the second signal may be weak, and thus the intensity of the measured values ​​may be weak. If the intensity is weak, it may be difficult to determine a defect from a graph of the measured values.

[0192] Referring to FIG. 13, in operation 1301, the processor (130) may be configured to obtain a measurement value of one parameter among a plurality of parameters.

[0193] According to one embodiment, the processor (130) may cause the secondary battery inspection device to obtain a measurement value of one parameter among a plurality of parameters when executing instructions stored in the memory (150).

[0194] In operation 1302, the processor (130) may be configured to divide the measurement value of the one parameter into a plurality of intervals.

[0195] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to distinguish the measured value of the one parameter into a plurality of sections.

[0196] In operation 1303, the processor (130) may be configured to obtain a conversion value for a measurement value for each of the plurality of sections.

[0197] According to one embodiment, the processor (130), when executing instructions stored in the memory (150), may cause the secondary battery inspection device to obtain a conversion value for a measurement value for each of a plurality of sections.

[0198] According to one embodiment, the processor (130) can obtain a conversion value by converting a measurement value of one parameter so that it represents a measurement value of a constant intensity independently of the distance between the sensor module (110) and the secondary battery (10). The processor (130) can obtain a conversion value for the measurement value based on the following [Mathematical Formula 7].

[0199]

[0200] The conversion value can be obtained for the measurement value included in each of the plurality of intervals.

[0201] In operation 1304, the processor (130) may be configured to identify a defect in the secondary battery (10) based on the conversion value.

[0202] According to one embodiment, the processor (130) may cause the secondary battery inspection device to identify a defect in the secondary battery (10) based on the conversion value when executing instructions stored in the memory (150).

[0203] According to one embodiment, the processor (130) may be configured to compare a conversion value with a designated reference value and identify a defect in the secondary battery (10) based on the comparison. The reference value may be designated for the conversion value. For example, the processor (130) may obtain a first conversion value for a first measurement value within a first interval and compare the first conversion value with a first reference value. For example, the processor (130) may identify that a defect exists within the first interval if a difference between the first conversion value and the first reference value is outside a designated range.

[0204] According to one embodiment, the processor (130) can accurately identify a defect in the secondary battery (10) by converting the measurement value to identify the defect. When the intensity of the measurement value is weak depending on the distance between the sensor module (110) and the secondary battery (10), the processor (130) can obtain a conversion value and determine a defect. For example, the processor (130) may be configured to obtain the measurement value of one parameter within a state where the distance between the sensor module (110) and the secondary battery (10) is a first distance. The processor (130) may be configured to obtain a conversion value based on identifying that the difference between the maximum value and the minimum value of the measurement value of one parameter is less than a reference value. For example, the measurement value may vary depending on the number of measurements. When the distance is too far and the intensity of the second signal is weak, the difference between the maximum value and the minimum value among the measurement values ​​may be small because the intensity of the measurement value is small. The processor (130) may calculate a conversion value if the difference is less than the reference value. If the difference is greater than the reference value, the processor (130) may not calculate a conversion value because a defect can be determined from the measured value of the parameter.

[0205] According to one embodiment, the processor (130) may be configured to adjust the transfer device (140) to change the first distance to a second distance smaller than the first distance based on identifying that a difference between a maximum value and a minimum value of the measured value of the one parameter is less than a reference value. As the first distance changes to the second distance, the intensity of the second signal may increase, and the intensity of the measured value of the parameter may increase. As the intensity of the measured value of the parameter increases, a graph may be obtained more clearly, thereby facilitating the determination of a defect.

[0206] Figures 14a, 14b, and 14c illustrate graphs of measured values ​​according to changes in the distance between the sensor module and the secondary battery. Figures 15a, 15b, and 15c illustrate graphs of converted values ​​for measured values.

[0207] Referring to FIGS. 14A, 14B, and 14C, the shape of the graph may change depending on the distance between the sensor module (110) and the secondary battery (10). For example, when the distance changes, although the shape of the graph is maintained, the intensity of the measured value changes, so the difference between the maximum and minimum values ​​may change. As the distance gets closer, the intensity of the measured value increases, so the difference between the maximum and minimum values ​​of the graph increases, and the shape of the graph can be clearly distinguished. As the distance gets longer, the intensity of the measured value decreases, so the difference between the maximum and minimum values ​​of the graph decreases, and the shape of the graph may be difficult to distinguish.

[0208] The graph (1410) of FIG. 14a is a graph showing the measurement value of one parameter against the number of measurements when the distance between the sensor module (110) and the secondary battery (10) is about 1 mm. The graph (1420) of FIG. 14b is a graph showing the measurement value of one parameter against the number of measurements when the distance between the sensor module (110) and the secondary battery (10) is about 0.75 mm. The graph (1430) of FIG. 14c is a graph showing the measurement value of one parameter against the number of measurements when the distance between the sensor module (110) and the secondary battery (10) is about 0.5 mm. Comparing the graphs (1410, 1420, 1430), as the distance between the sensor module (110) and the secondary battery (10) increases, the difference between the maximum and minimum values ​​of the graphs may decrease. For example, within the graph (1410) of FIG. 14a, the difference (1401) between the maximum and minimum values ​​may be smaller than the difference (1402) between the maximum and minimum values ​​within the graph (1420) of FIG. 14b and the difference (1403) between the maximum and minimum values ​​within the graph (1430) of FIG. 14c. With reference to this, when the distance increases, it may be difficult to determine a defect because the measured values ​​are not clearly distinguished.

[0209] The graph (1510) of Fig. 15a is a graph obtained by converting the measurement values ​​of the graph (1410) of Fig. 14a. The graph (1520) of Fig. 15b is a graph obtained by converting the measurement values ​​of the graph (1420) of Fig. 14b. The graph (1530) of Fig. 15c is a graph obtained by converting the measurement values ​​of the graph (1430) of Fig. 14c. Comparing the above graphs (1510, 1520, 1530), even if the distance between the sensor module (110) and the secondary battery (10) changes, the difference between the maximum and minimum values ​​of the graphs can be substantially maintained. For example, in the graph (1510) of FIG. 15a, the difference (1501) between the maximum and minimum values, in the graph (1520) of FIG. 15b, the difference (1502) between the maximum and minimum values, and in the graph (1530) of FIG. 15c, the difference (1503) between the maximum and minimum values ​​may be similar or substantially the same. When a graph is obtained through a converted value based on the above [Mathematical Formula 7], the converted values ​​represented by the graph can be clearly distinguished, so that the determination of a defect can be performed accurately.

[0210] Figure 16a is a graph showing the measured value of one parameter against the number of measurements. Figure 16b is a normalized graph of the graph of Figure 16a.

[0211] According to one embodiment, the processor (130) may normalize a graph for the measured values. For example, depending on the operation of the transport device (140), the speed at which the sensor module (110) is transported along the secondary battery (10) or the secondary battery (10) is transported below the sensor module (110) may be different. For example, in the case of the second transport device (142), when the conveyor belt (142a) is operated, since the speed has not yet reached the maximum speed in the initial section, a large number of measurements may be performed within a narrow area of ​​the secondary battery (10), and since the speed is reduced in the later section, a large number of measurements may be performed within a narrow area of ​​the secondary battery (10). In this case, since the graph for the measured values ​​shows a distribution concentrated in a specific area, it may be difficult to determine a defect.

[0212] A secondary battery inspection device according to one embodiment can normalize a measurement result and divide the normalized result into a plurality of sections. Referring to FIG. 16A, the x-axis of a graph (1610) for a measurement value represents the number of measurements. For example, if the sensor module (110) performs 371 measurements on a secondary battery (10), the x-axis of the graph (1610) may have a range of 0 to 371. In this case, in the initial section (e.g., 0 to 40) and the later section (e.g., 330 to 371), since the transport speed of the sensor module (110) or the transport speed of the secondary battery (10) is slow, the measurement values ​​may be concentrated within a narrow area. Therefore, the graph for the parameter may be distorted, making it difficult to identify a defect in the secondary battery (10).

[0213] Referring to FIG. 16B, the processor (130) can provide a graph (1620) that is a conversion of the graph (1610) of FIG. 16A. The processor (130) can provide a graph (1620) of conversion values ​​by converting measurement values ​​for a plurality of sections. According to one embodiment, the x-axis of the graph (1620) can have a range between 0 and 1. The processor (130) can obtain the converted graph (1620) based on the following [Mathematical Formula 8].

[0214]

[0215] According to one embodiment, a secondary battery inspection device can obtain a conversion value for a measurement value and provide a graph (1620) based on the conversion value. Since the graph (1620) is a graph based on a normal distribution of the number of measurements, a defect can be accurately determined.

[0216] Figure 17 shows a graph obtained when dispersion occurs.

[0217] According to one embodiment, in the case of the second transport device (142), the secondary battery (10) may be transported on a conveyor belt (142a). If the secondary battery (10) is incorrectly placed on the conveyor belt (142a), scattering may occur. The scattering refers to a case where the secondary battery (10) is inspected while incorrectly placed on the conveyor belt (142a). In this case, distorted results may be obtained, as in the graph (1700) illustrated in FIG. 17.

[0218] According to one embodiment, when dispersion occurs, the processor (130) can divide the graph (1700) into a plurality of sections (1710, 1720, 1730) and perform an inspection only on the remaining sections (1710, 1720) excluding some sections (1720). For example, the processor (130) can divide the graph (1700) in which dispersion occurs into a first section (1710), a second section (1720), and a third section (1730). The processor (130) can identify the presence of a defect by calculating kurtosis for the first section (1710) and the third section (1730). In the case of the second section (1720), since the degree of distortion is severe, it is difficult to determine the defect, so only in the first section (1710) and the third section (1730), by determining elements that can be determined, such as kurtosis, it is possible to identify the defect of the secondary battery (10).

[0219] A secondary battery inspection device is provided. The secondary battery inspection device may include a sensor module. The sensor module may include a first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and a second sensor including a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field. The sensor module may include a detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal. The sensor module may include a transport device coupled to the sensor module and configured to transport the sensor module. The sensor module may include a processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one of the plurality of parameters. The sensor module may include a memory that stores instructions and information related to the secondary battery. The instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to select one parameter from among the plurality of parameters, identify a measurement value of the one parameter, distinguish the measurement value of the one parameter with respect to the total number of measurements of the second signal into a plurality of sections including a first section and a second section, identify whether a first defect exists within the first section by comparing a first measurement value included in the first section with a first reference value, identify whether a second defect exists within the second section by comparing a second measurement value included in the second section with a second reference value, and identify a defect in the secondary battery based on identifying at least one of the first defect or the second defect.

[0220] In one embodiment, the instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to identify, among the measurement values ​​of the one parameter, a smallest first value and a second value next to the first value, identify an interval between a first measurement number corresponding to the first value and a second measurement number corresponding to the second value, and distinguish an interval between the first measurement number and the second measurement number into the plurality of intervals.

[0221] According to one embodiment, the instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to compare the measured value of the one parameter included in the interval between the first measured number and the second measured number with a reference value, and to identify the defect in the secondary battery based on the comparison.

[0222] According to one embodiment, the information related to the secondary battery may include first position information corresponding to a first lead tab of the secondary battery and second position information corresponding to a second lead tab. The instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to identify a third measurement number obtained at a timing when the sensor module is positioned at a position corresponding to the first position information and a fourth measurement number obtained at a timing when the sensor module is positioned at a position corresponding to the second position information, and to sequentially set the plurality of sections into five sections including the first section, the second section, the third section, the fourth section, and the fifth section according to the measurement numbers.

[0223] In one embodiment, the instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to set a boundary of the second section outside a first range specified from the third measurement number so that the second section overlaps the first section, set a boundary of the fourth section outside a second range specified from the fourth measurement number so that the fourth section overlaps the fifth section, and set the third section between the third measurement number and the fourth measurement number.

[0224] A secondary battery inspection device is provided. The secondary battery inspection device may include a sensor module. The sensor module may include a first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and a second sensor including a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field. The secondary battery inspection device may include a detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal. The secondary battery inspection device may include a transport device coupled to the sensor module and configured to transport the sensor module. The secondary battery inspection device may include a processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one of the plurality of parameters. The secondary battery inspection device may include a memory that stores instructions and information related to the secondary battery.The instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to select one parameter from among the plurality of parameters, identify a measurement value of the one parameter, distinguish the measurement value of the one parameter for the total number of measurements that measured the second signal into a plurality of sections including a first section and a second section, identify a first skewness, a first kurtosis, and a first difference value corresponding to a difference between maximum and minimum values ​​for a first measurement value within the first section, identify a second skewness, a second kurtosis, and a second difference value corresponding to a difference between maximum and minimum values ​​for a second measurement value within the second section, identify whether a first defect exists within the first section based on the first skewness, the first kurtosis, and the first difference value, identify whether a second defect exists within the second section based on the second skewness, the second kurtosis, and the second difference value, and determine whether at least one of the first defect or the second defect exists. Based on the identification, it can be caused to identify a defect in the secondary battery.

[0225] According to one embodiment, the asymmetry can be calculated based on the above [Mathematical Formula 5].

[0226] According to one embodiment, the kurtosis can be calculated based on the above [Mathematical Formula 6].

[0227] According to one embodiment, the instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to compare the measured value of the one parameter for the total number of measurements with a reference value, and to identify, based on the comparison, whether a third defect in the secondary battery for the total number of measurements exists.

[0228] In one embodiment, the instructions, when individually or collectively executed by the processor, may cause the secondary battery inspection device to identify the first defect based on comparing the first asymmetry with a first reference value of the asymmetry, comparing the first kurtosis with a second reference value of the kurtosis, comparing the first difference value with a third reference value of the difference value, and identifying the first asymmetry being less than the first reference value, the first kurtosis being greater than the second reference value, and the first difference value being greater than the third reference value.

[0229] A secondary battery inspection device is provided. The secondary battery inspection device may include a sensor module. The sensor module may include a first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and a second sensor including a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field. The secondary battery inspection device may include a detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal. The secondary battery inspection device may include a transport device coupled to the sensor module and configured to transport the sensor module. The secondary battery inspection device may include a processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one of the plurality of parameters. The secondary battery inspection device may include a memory that stores instructions and information related to the secondary battery. The above instructions, when individually or collectively executed by the processor, may be configured to cause the secondary battery inspection device to select one parameter from among the plurality of parameters, identify a measurement value of the one parameter, distinguish the measurement value of the one parameter into a plurality of sections, and, for each of the plurality of sections, convert the measurement value of the one parameter based on [Mathematical Formula 7], thereby obtaining a conversion value for the measurement value of the one parameter, and identifying a defect in the secondary battery based on the conversion value.

[0230] In one embodiment, the transport device may be configured to adjust the distance between the sensor module and the secondary battery. The processor may be configured to obtain the measured value of the one parameter while the distance between the sensor module and the secondary battery is the first distance, and to obtain the converted value based on identifying that a difference between a maximum value and a minimum value of the measured value of the one parameter is less than a reference value.

[0231] In one embodiment, the processor may be configured to adjust the transport device to change the first distance to a second distance less than the first distance based on identifying that a difference between a maximum value and a minimum value of the measured values ​​of the one parameter is less than a reference value.

[0232] According to one embodiment, the processor may be configured to obtain a graph based on the above [Mathematical Formula 8] and to divide the graph into the plurality of sections in order to normalize the measured value of the one parameter with respect to the total number of measurements.

[0233] According to one embodiment, the plurality of parameters may include a first parameter including a difference between a voltage of the first signal and a voltage of the second signal and a difference between a phase of the first signal and a phase of the second signal; and a second parameter including a resistance of the second coil and an impedance of the second coil obtained from the first parameter.

[0234] The terms described in this document are not limited to specific examples, and can be readily understood by those skilled in the art to have substantially identical equivalents. For example, a specific term may be understood to include terms that are understood as equivalents by those skilled in the art. In this document, unless specifically limited to the singular, terms described in the singular should be construed to include both the singular and the plural. Furthermore, in this document, terms such as "first" and "second" are used to distinguish components and do not indicate the order or importance of the components.

[0235] The devices described above may be implemented as hardware components, software components, and / or a combination of hardware components and software components. For example, the devices and components described in the embodiments may be implemented using one or more general-purpose computers or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding. For ease of understanding, the processing unit is sometimes described as being used alone, but one of ordinary skill in the art will recognize that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors, or one processor and one controller.

[0236] The method according to the embodiment may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program commands, data files, data structures, etc., alone or in combination. The program commands recorded on the medium may be those specially designed and configured for the embodiment or may be those known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program commands, such as ROMs, RAMs, and flash memories. Examples of the program commands include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiment, and vice versa.

[0237] Although the embodiments described above have been described by way of limited examples and drawings, those skilled in the art will appreciate that various modifications and variations can be made based on the above teachings. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0238] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. In the secondary battery inspection device, A sensor module, said sensor module comprising: A first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and A second sensor comprising a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field; A detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal; A transport device coupled to the sensor module and configured to transport the sensor module; A processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one parameter among the plurality of parameters; and Includes a memory that stores instructions and information related to the secondary battery, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Among the above multiple parameters, select one parameter, Identify the measurement value of the above one parameter, The measurement values ​​of the one parameter for the total number of measurements measuring the second signal are divided into a plurality of sections including a first section and a second section, By comparing a first measurement value included in the first section with a first reference value, the presence or absence of a first defect within the first section is identified, By comparing the second measurement value included in the second section with the second reference value, the presence or absence of a second defect within the second section is identified, Identifying a defect in the secondary battery based on identifying at least one of the first defect or the second defect, Secondary battery testing device.

2. In paragraph 1, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Among the measured values ​​of the above one parameter, identify a first smallest value and a second smallest value next to the first value, Identifying an interval between a first measurement number corresponding to the first value and a second measurement number corresponding to the second value, Causing the interval between the first measurement number and the second measurement number to be distinguished into the plurality of intervals, Secondary battery testing device.

3. In paragraph 2, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: From the first measurement number, the measurement value of the one parameter included in the interval between the second measurement number is compared with a reference value, Based on the above comparison, causing the defect of the secondary battery to be identified, Secondary battery testing device.

4. In paragraph 1, Information related to the above secondary battery is: Includes first position information corresponding to the first lead tab of the secondary battery and second position information corresponding to the second lead tab, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Identifying a third measurement number obtained at a timing when the sensor module is located at a position corresponding to the first location information and a fourth measurement number obtained at a timing when the sensor module is located at a position corresponding to the second location information; Causing the above plurality of sections to be sequentially set into five sections including the first section, the second section, the third section, the fourth section, and the fifth section according to the number of measurements. Secondary battery testing device.

5. In paragraph 4, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: The boundary of the second section is set outside the first range specified from the third measurement number so that the second section overlaps with the first section, The boundary of the fourth section is set outside the second range specified from the fourth measurement number so that the fourth section overlaps with the fifth section, causing the third section to be set between the third measurement number and the fourth measurement number, Secondary battery testing device.

6. In the secondary battery inspection device, A sensor module, said sensor module comprising: A first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and A second sensor comprising a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field; A detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal; A transport device coupled to the sensor module and configured to transport the sensor module; A processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one parameter among the plurality of parameters; and Includes a memory that stores instructions and information related to the secondary battery, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Among the above multiple parameters, select one parameter, Identify the measurement value of the above one parameter, The above measurement value of the above one parameter is divided into a plurality of intervals, For each of the above multiple sections, by converting the measured value of the one parameter based on [Mathematical Formula 1] below, a converted value for the measured value of the one parameter is obtained, Based on the above conversion value, configured to identify a defect in the secondary battery, Secondary battery testing device.

7. In paragraph 6, The above transport device, configured to adjust the distance between the sensor module and the secondary battery, The above processor, In a state where the distance between the sensor module and the secondary battery is the first distance, the measurement value of the one parameter is obtained, Based on identifying that the difference between the maximum value and the minimum value of the measured value of the above one parameter is less than a reference value, the conversion value is obtained, Secondary battery testing device.

8. In paragraph 7, The above processor, Based on identifying that the difference between the maximum and minimum values ​​of the measured values ​​of the one parameter is less than a reference value, the transport device is configured to adjust the first distance to a second distance smaller than the first distance. Secondary battery testing device.

9. In paragraph 6, The above processor, In order to normalize the above measurement value of the above one parameter to the total number of measurements, a graph based on the following [Mathematical Formula 2] is obtained, The above graph is configured to be divided into the above plurality of sections, Secondary battery testing device.

10. In paragraph 6, The above multiple parameters are, A first parameter including a difference between the voltage of the first signal and the voltage of the second signal and a difference between the phase of the first signal and the phase of the second signal; and A second parameter including the resistance of the second coil and the impedance of the second coil obtained from the first parameter, Secondary battery testing device.

11. In the secondary battery inspection device, A sensor module, said sensor module comprising: A first sensor including a first coil that applies an induced magnetic field to the secondary battery based on a first signal, and A second sensor comprising a second coil configured to measure a second signal based on the induced magnetic field by interacting with the induced magnetic field; A detection circuit configured to obtain the second signal from the second sensor and obtain measurement values ​​of each of a plurality of parameters based on the second signal; A transport device coupled to the sensor module and configured to transport the sensor module; A processor configured to control the transport device, obtain the measurement values ​​from the detection circuit, and identify a crack in the secondary battery based on one parameter among the plurality of parameters; and Includes a memory that stores instructions and information related to the secondary battery, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Among the above multiple parameters, select one parameter, Identify the measurement value of the above one parameter, The measurement values ​​of the one parameter for the total number of measurements measuring the second signal are divided into a plurality of sections including a first section and a second section, Identifying a first skewness, a first kurtosis, and a first difference value corresponding to the maximum and minimum difference values ​​for the first measurement value within the first interval, Identifying a second skewness, a second kurtosis, and a second difference value corresponding to the maximum and minimum difference values ​​for the second measurement value within the second interval, Based on the first asymmetry, the first kurtosis, and the first difference value, identifying whether a first defect exists within the first section; Based on the second asymmetry, the second kurtosis, and the second difference value, the presence or absence of a second defect within the second section is identified, Identifying a defect in the secondary battery based on identifying at least one of the first defect or the second defect, Secondary battery testing device.

12. In paragraph 11, The above asymmetry is, Calculated based on [Mathematical Formula 3] below, Secondary battery testing device.

13. In paragraph 11, The above kurtosis is, Calculated based on [Mathematical Formula 4] below, Secondary battery testing device.

14. In paragraph 11, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Compare the measured value of the above one parameter for the above total number of measurements with a reference value, Based on the above comparison, causing the presence or absence of a third defect in the secondary battery for the total number of measurements to be identified, Secondary battery testing device.

15. In paragraph 11, The above instructions, when individually or collectively executed by the processor, cause the secondary battery inspection device to: Comparing the first asymmetry with the first reference value of the asymmetry, Compare the first kurtosis with the second reference value of the kurtosis, Compare the first difference value with the third reference value of the difference value, Identifying the first defect based on identifying the first skewness that is less than the first reference value, the first kurtosis that is greater than the second reference value, and the first difference value that is greater than the third reference value, Secondary battery testing device.

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