Battery state determination method and state determination system

Abstract

To provide a battery state determination method and a state determination system capable of improving the accuracy of determining the battery state without increasing the burden of measuring a battery.SOLUTION: A method for determining the state of a battery 60 includes obtaining a measurement value of the magnetic field of the battery 60 mounted in a device 80 measured by a magnetic measurement unit 20, calculating information regarding the relative position of the magnetic measurement unit 20 on the basis of the measurement value of the magnetic field of the battery 60 and a reference value of the magnetic field of the battery 60, and determining the state of the battery 60 on the basis of the information regarding the relative position of the magnetic measurement unit 20.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a battery state determination method and state determination system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known an apparatus for inspecting a battery by comparing the current distribution of the battery to be inspected with a normal current distribution (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-187951 A Summary of the Invention [Problem to be solved by the invention]

[0004] The current distribution of a battery to be compared with the normal current distribution is measured with the current measuring device positioned at the reference position of the battery. The measurement accuracy of the battery current distribution is affected by the misalignment of the measuring device with respect to the reference position of the battery. When judging the battery state based on the measurement result of the battery current distribution, it is required to improve the judgment accuracy without increasing the measurement burden.

[0005] The present disclosure has been made in consideration of the above-mentioned points, and aims to provide a battery state determination method and state determination system that can improve the accuracy of determining the battery state without increasing the burden of measuring the battery. [Means for solving the problem]

[0006] (1) A method for determining the state of a battery according to some embodiments includes acquiring a measurement value of a magnetic field of a battery mounted on a device using a magnetic measurement unit, calculating information on a relative position of the magnetic measurement unit based on the measurement value of the magnetic field of the battery and a reference value of the magnetic field of the battery, and determining the state of the battery based on the information on the relative position of the magnetic measurement unit. In this way, a positional deviation between the battery and the magnetic measurement unit is allowed. As a result, the accuracy of determining the state of the battery is improved even if the battery is measured without being removed from the device.

[0007] (2) The method for determining the state of a battery described in (1) above may include determining that the battery is abnormal when information about the relative position of the magnetic measurement unit satisfies an abnormality determination condition. In this way, the battery is determined to be abnormal without correcting the measurement value. In other words, unnecessary correction operations are omitted. As a result, the operating load of the control device is reduced.

[0008] (3) The method for determining the state of a battery according to (1) or (2) above may include calculating a correction coefficient for the relative position of the magnetic measurement unit as information on the relative position of the magnetic measurement unit, thereby allowing for positional deviation between the battery and the magnetic measurement unit.

[0009] (4) The battery state determination method according to any one of (1) to (3) above may include moving the magnetic measurement unit along one scanning direction to measure the magnetic field of the battery with the magnetic measurement unit. In this way, the control device can measure the distribution of the magnetic field generated by the battery.

[0010] (5) The method for determining the state of a battery described in (4) above may include shifting the magnetic measurement unit to each of a plurality of positions arranged periodically or non-periodically in a direction intersecting the scanning direction, and moving the magnetic measurement unit from each position along the scanning direction. In this way, the control device can measure a planar distribution of a magnetic field generated by the battery.

[0011] (6) The method for determining the state of a battery described in (5) above may include shifting the magnetic measurement unit to each position where the movement in the scanning direction started when the reference value of the magnetic field of the battery was measured, and moving the magnetic measurement unit along the scanning direction from each position. In this way, the control device can compare the reference value and the measured value with high accuracy.

[0012] (7) The battery state determination method according to any one of (4) to (6) above may include acquiring measured values ​​of the magnetic field of the battery by moving the magnetic measurement unit in each of a plurality of directions including at least a first direction and a second direction, and determining the scanning direction based on a first measured value obtained by moving the magnetic measurement unit in the first direction and a second measured value obtained by moving the magnetic measurement unit in the second direction. In this way, the magnetic measurement unit is scanned so that the position of the battery approaches a reference position. As a result, the position or attitude deviation of the battery is reduced.

[0013] (8) The battery state determination method according to any one of (4) to (7) above may include moving the magnetic measurement unit in a scanning range determined based on the type of device in which the battery is mounted. In this way, unnecessary scanning is reduced, and measurement efficiency is improved.

[0014] (9) According to some embodiments, a battery state determination system includes a magnetic measurement unit and the control device according to any one of (1) to (8) above.

[0015] (10) The battery state determination system described in (9) above may further include a moving device that moves the magnetic measurement unit relative to the battery. The moving device may be configured to move between the battery and a surface on which a device having the battery mounted thereon is installed.

[0016] (11) The battery state determination system according to (9) or (10) above may further include a drive device that moves the device mounting the battery relative to the magnetic measurement unit, thereby improving the accuracy of measuring the magnetic field of the battery or the accuracy of determining the state of the battery.

[0017] (12) In the battery state determination system according to any one of (9) to (11) above, the magnetic measurement unit may include one or more magnetic sensors that measure a magnetic field of the battery.

[0018] (13) In the battery state determination system described in (12) above, the magnetic measurement unit may include a plurality of the magnetic sensors arranged in a line or array, thereby reducing the number of scans of the magnetic measurement unit.

[0019] (14) In the battery state determination system described in (12) or (13) above, the magnetic measurement unit may include a plurality of the magnetic sensors arranged in a range covering the entire battery. In this way, scanning of the magnetic measurement unit is omitted.

[0020] (15) In the battery state determination system described in (14) above, the control device may select some of the magnetic sensors from the plurality of magnetic sensors and obtain the measurement values ​​of the selected magnetic sensors. In this way, the magnetic measurement unit is scanned in a pseudo manner. Effect of the Invention

[0021] According to the battery state determination method and state determination system of the present disclosure, the influence of the position of the measuring device is reduced. [Brief description of the drawings]

[0022] [Figure 1] 10 is a side view showing an example of the positional relationship between a battery and a magnetic measurement unit. FIG. [Diagram 2] 10 is a plan view showing an example of the positional relationship between a battery and a magnetic measurement unit. FIG. [Diagram 3]1 is a block diagram showing an example of the configuration of a state determination system according to an embodiment; [Figure 4] 10 is a flowchart illustrating an example of a procedure for determining the state of a battery. [Diagram 5] 11 is a diagram showing an example in which a battery is arranged so that the arrangement of the battery cells is aligned with the scanning direction of a magnetic measurement unit. FIG. [Figure 6] 11 is a diagram showing an example in which a battery is arranged so that the arrangement of the battery cells is inclined with respect to the scanning direction of a magnetic measurement unit. FIG. [Figure 7] 13 is a diagram showing an example in which a battery is arranged so that the arrangement plane of the battery cells is parallel to the scanning plane of a magnetic measurement unit. FIG. [Figure 8] 11 is a diagram showing an example in which a battery is arranged so that the arrangement plane of the battery cells is inclined with respect to the scanning plane of a magnetic measurement unit. FIG. [Figure 9] 11 is a diagram showing an example in which the battery is arranged so that the distance between the arrangement of the battery cells and the scanning path of the magnetic measurement unit changes. FIG. [Figure 10] 11 is a graph showing an example of the waveform of a magnetic field measurement value measured by a magnetic measurement unit when the position of a battery is shifted in the scanning direction of the magnetic measurement unit. [Figure 11] 13 is a graph showing an example of the waveform of a magnetic field measurement value measured by a magnetic measurement unit when the battery position is shifted so that the distance between the arrangement of the battery cells and the scanning path of the magnetic measurement unit is increased. [Figure 12] 13 is a graph showing an example of the waveform of a magnetic field measurement value measured by the magnetic measurement unit when the battery is misaligned so that the arrangement surface of the battery cells rotates around a rotation axis in a direction intersecting the scanning direction of the magnetic measurement unit. [Figure 13] 11 is a three-dimensional graph showing an example of the waveform of a magnetic field measurement value for each scanning path measured by scanning a magnetic measurement unit along a plurality of scanning paths. [Figure 14] FIG. 13 is a diagram showing an example of scanning a magnetic measurement unit in two intersecting directions for preliminary checking of the arrangement of battery cells. [Figure 15] 11 is a side view showing an example of a moving device that moves a magnetic measurement unit in a scanning direction. FIG. [Figure 16]FIG. 2 is a plan view showing an example of a drive device for moving a vehicle equipped with a battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] A magnetic field is generated when a charge / discharge current flows through a secondary battery. The state of the battery may be inspected by measuring the magnetic field generated by charging / discharging the secondary battery. The battery for which the magnetic field is measured is, for example, a battery having an electrode body in which a positive electrode active material layer and a negative electrode active material layer are stacked with an insulating layer interposed therebetween, and an exterior that houses the electrode body. Hereinafter, an embodiment of a battery state determination method and state determination system 1 (see FIG. 3) according to the present disclosure will be described in comparison with a comparative example.

[0024] (Comparative Example) The device of the comparative example acquires data on the current distribution of a battery in a normal state in advance by placing a battery in a reference position and using a magnetic measurement unit to measure the magnetic field when a reference current is passed through the battery in the normal state.The device of the comparative example acquires data on the current distribution of a battery to be inspected by placing a battery to be inspected in a reference position and using a magnetic measurement unit to measure the magnetic field when a reference current is passed through the battery to be inspected.The device of the comparative example determines the condition of the battery to be inspected by comparing the data on the current distribution of the battery to be inspected with data on the current distribution of a battery in a normal state.

[0025] Here, deviation of the battery being inspected from the reference position causes an error in the current distribution data of the battery being inspected. The error in the current distribution data reduces the inspection accuracy of the battery condition. In other words, deviation of the position of the battery being inspected affects the inspection accuracy of the battery condition.

[0026] However, in the device according to the comparative example, it is not always possible to accurately position the battery to be inspected at the reference position. For example, when the battery to be inspected is mounted on an electric vehicle, it is difficult to accurately reproduce the position and posture of the vehicle. If the battery to be inspected is removed from the vehicle in order to accurately reproduce the position and posture of the battery, the task of removing the battery from the vehicle increases the workload and cost of inspecting the battery. Therefore, it is necessary to determine the state of the battery by taking into account the effect of the deviation in the position of the battery to be inspected.

[0027] Therefore, the battery state determination method and state determination system 1 (see FIG. 3) according to the present disclosure determine the state of the battery by taking into consideration the positional deviation of the battery being inspected when the magnetic field of the battery is measured without removing the battery from an electric vehicle or other device. The battery state determination method and state determination system 1 according to an embodiment of the present disclosure will be described below.

[0028] (One embodiment of the present disclosure) 1 and 2, a battery 60 to be inspected in a state determination system 1 according to an embodiment of the present disclosure is mounted on a vehicle 80. The vehicle 80 has tires 82 that are in contact with the ground 70. In this embodiment, the ground 70 is assumed to be along the XY plane. The normal direction (vertical direction) of the ground 70 corresponds to the Z axis. The vertical upward direction is assumed to be the positive direction of the Z axis.

[0029] The battery 60 has cells 62 (see FIG. 5 ) arranged in a lattice pattern as described below. The battery 60 is mounted on the vehicle 80 so that the plane on which the cells 62 are arranged is along the ground 70. The magnetic measurement unit 20 is installed on the ground 70 and measures the magnetic field generated by the battery 60. The magnetic measurement unit 20 may be configured to be movable on the ground 70 along the ground 70, that is, along the arrangement direction of the cells of the battery 60. The vehicle 80 may be configured to be movable relative to the magnetic measurement unit 20 along the ground 70, that is, along the arrangement direction of the cells of the battery 60.

[0030] (Example of configuration of state determination system 1) As shown in FIG. 3, the state determination system 1 according to an embodiment of the present disclosure includes a control device 10 and a magnetic measurement unit 20. The control device 10 includes an acquisition unit 11, a calculation unit 12, a determination unit 13, and a scanning unit 14. The acquisition unit 11 acquires a measurement result of the magnetic field of the battery 60 from the magnetic measurement unit 20. The magnetic measurement unit 20 scans the battery 60, so that the acquisition unit 11 can acquire a distribution of the measurement result of the magnetic field of the battery 60. The calculation unit 12 calculates a current distribution of the battery 60 based on the measurement result of the magnetic field of the battery 60. The determination unit 13 determines the state of the battery 60 based on the current distribution of the battery 60. When the magnetic measurement unit 20 is configured to be movable, the scanning unit 14 controls the position of the magnetic measurement unit 20 so as to cause the magnetic measurement unit 20 to scan the battery 60. The scanning unit 14 scans the magnetic measurement unit 20 by moving it along one scanning direction, thereby measuring the magnetic field of the battery 60.

[0031] The acquiring unit 11 includes a communication device for connecting to the magnetic measuring unit 20 in a wired or wireless manner so as to be able to communicate with the magnetic measuring unit 20. The communication device may include a communication module that transmits and receives data based on a data communication standard such as RS-232C or RS-485. The communication device may include a communication module that supports a mobile communication standard such as 4G (4th Generation), LTE (Long Term Evolution), or 5G (5th Generation). The communication device is not limited to the communication module exemplified above, and may include various other devices or modules.

[0032] The calculation unit 12, the determination unit 13, or the scanning unit 14 may be configured to include a processor such as a CPU (Central Processing Unit). The calculation unit 12, the determination unit 13, or the scanning unit 14 may realize a predetermined function by causing the processor to execute a predetermined program. The calculation unit 12, the determination unit 13, or the scanning unit 14 may be configured as an integrated unit of at least a partial combination, or may be configured as separate units. Hereinafter, the calculation unit 12, the determination unit 13, or the scanning unit 14 is also collectively referred to as a control unit. The control unit may include a storage unit. The storage unit may store various information used in the operation of the control unit, or programs for realizing the functions of the control unit. The storage unit may function as a work memory for the control unit. The storage unit may be configured, for example, of a semiconductor memory. The storage unit may be configured to include a volatile memory or a non-volatile memory. The storage unit may be included in the control unit, or may be configured as a separate unit from the control unit.

[0033] The magnetic measurement unit 20 may include a magnetic sensor that measures a magnetic field. The number of magnetic sensors included in the magnetic measurement unit 20 may be one or more. The magnetic measurement unit 20 may be configured by arranging a plurality of magnetic sensors in a line or an array. When the magnetic measurement unit 20 scans the battery 60 as described above, the number of scans is reduced by arranging the magnetic sensors in a line or an array. The reduction in the number of scans shortens the measurement time of the magnetic field of the battery 60.

[0034] The magnetic measurement unit 20 may be configured by arranging a plurality of magnetic sensors in a range covering the entire battery 60. By arranging a plurality of magnetic sensors in a range covering the entire battery 60, scanning of the battery 60 by the magnetic measurement unit 20 is omitted. The magnetic measurement unit 20 may select a specific magnetic sensor from the multiple magnetic sensors arranged in a range covering the entire battery 60, and obtain the measurement value of the selected specific magnetic sensor. In other words, the magnetic measurement unit 20 may select some of the multiple magnetic sensors arranged in a range covering the entire battery 60, and obtain the measurement value of the selected part of the magnetic sensors. By obtaining the measurement value of some of the magnetic sensors, the operation of scanning the magnetic sensors is reproduced in a pseudo manner. The specific magnetic sensor may be selected from the magnetic sensors arranged at equal intervals, or may be selected from the magnetic sensors arranged at any interval that is not equal.

[0035] The magnetic sensor may be configured to measure the magnetic field in one axis, or may be configured to measure the magnetic field in three axes simultaneously. Regardless of the direction of the measurement axis of the magnetic sensor, it is desirable to arrange the magnetic sensor so that the magnetic sensing surface is perpendicular to the magnetic field generated by the battery 60. The reason for arranging the magnetic sensor so that the magnetic sensing surface is perpendicular to the magnetic field generated by the battery 60 is to make it easier to obtain a magnetic field distribution that reflects the orientation or arrangement of the battery 60 by making the macro current of the battery 60 perpendicular to the magnetic sensing surface.

[0036] The magnetic sensor may include at least one magnetic element. The magnetic element may be an analog element or a digital element. The magnetic element may include, for example, a Hall element, a magnetoresistance element such as anisotropic magnetoresistance effect (AMR), giant magnetoresistance effect (GMR), or tunnel magnetoresistance effect (TMR). The magnetic element may include, for example, a magnetic impedance element such as magneto-impedance (MI) or a fluxgate. The magnetic element may include, for example, a thin-film magnetic element based on the anomalous Hall effect using a topological magnetic material. When an alternating current flows through the measurement target, a pickup coil may be used as the magnetic element.

[0037] The magnetic measurement section 20 is not limited to a magnetic sensor, and may have various other configurations capable of measuring a magnetic field.

[0038] (Example of operation of state determination system 1) The state determination system 1 according to an embodiment of the present disclosure measures the magnetic field of the battery 60 to determine the state of the battery 60. The control device 10 may execute a state determination method for the battery 60 including the steps of a flowchart illustrated in Fig. 4. The state determination method for the battery 60 may be realized as a state determination program executed by a processor constituting the control device 10. The state determination program may be stored in a non-transitory computer-readable medium.

[0039] The control device 10 acquires a reference value of the magnetic field of the battery 60 (step S1). The reference value is a measurement value of the magnetic field obtained by scanning the magnetic measurement unit 20 with the battery 60 installed in a reference position when it is known that the battery 60 is in a normal state.

[0040] As illustrated in FIG. 5, the battery 60 has cells 62 arranged in a lattice pattern along each of the X-axis direction and the Y-axis direction. In other words, the cells 62 are arranged on an arrangement surface along the XY plane. In this embodiment, the magnetic measurement unit 20 is scanned in the X-axis direction. That is, the scanning direction 22 of the magnetic measurement unit 20 corresponds to the X-axis direction. The magnetic measurement unit 20 is scanned multiple times by shifting the start point of scanning in the Y-axis direction. In other words, the control device 10 may scan the magnetic measurement unit 20 by moving the magnetic measurement unit 20 along the scanning direction 22 from each of a plurality of positions that are periodically or non-periodically arranged in a direction intersecting the scanning direction 22. The reference position of the battery 60 is the installation position of the battery 60 when the arrangement direction of the cells 62 coincides with the scanning direction 22 of the magnetic measurement unit, as shown in FIG. 5.

[0041] 6, the battery 60 may be positioned such that the arrangement direction of the cells 62 is inclined with respect to the X-axis direction and the Y-axis direction. That is, the scanning direction 22 of the magnetic measurement unit 20 is inclined with respect to the arrangement direction of the cells 62. In this case, the installation position of the battery 60 is shifted from the reference position. Therefore, the position and attitude of the battery 60 or the device in which the battery 60 is mounted, or the scanning direction of the magnetic measurement unit 20 is adjusted so that the position of the battery 60 becomes the reference position.

[0042] 7, the battery 60 is installed in a vehicle 80 so that the cells 62 are arranged along the XY plane. The magnetic measurement unit 20 is scanned in the depth direction of the paper. The reference position of the battery 60 is the installation position of the battery 60 when the distance in the Z-axis direction between the magnetic measurement unit 20 and the arrangement surface of the cells 62 is constant when the magnetic measurement unit 20 is scanned.

[0043] As illustrated in FIGS. 8 and 9, when the vehicle 80 carrying the battery 60 is inclined with respect to the ground 70, the battery 60 may be positioned such that the arrangement surface of the cells 62 is inclined with respect to the XY plane. In the example of FIG. 8, the arrangement surface of the cells 62 rotates around the X axis. In other words, the arrangement surface of the cells 62 is parallel to the X axis and inclined with respect to the Y axis direction. In the example of FIG. 9, the arrangement surface of the cells 62 rotates around the Y axis. In other words, the arrangement surface of the cells 62 is parallel to the Y axis and inclined with respect to the X axis direction. In these cases, the installation position of the battery 60 is deviated from the reference position. Therefore, the position and attitude of the battery 60 or the device carrying the battery 60, or the scanning direction of the magnetic measurement unit 20 is adjusted so that the position of the battery 60 is in the reference position.

[0044] The reference value may be a measurement value of the magnetic field when the battery 60 is mounted on the device, or may be a measurement value of the magnetic field when the battery 60 is removed from the device. The reference value may be expressed as a waveform of continuous magnetic field measurement values ​​along the scanning direction of the magnetic measurement unit 20 (see, for example, the graph in FIG. 10). The reference value may be expressed as a set of magnetic field measurement values ​​at discrete positions along the scanning direction of the magnetic measurement unit 20. In this embodiment, the reference value is expressed as a continuous waveform. The waveform representing the reference value changes with a period corresponding to the interval between the cells 62. The waveform representing the reference value may be, for example, a sine wave or a waveform approximated by a sine wave. The waveform representing the reference value is not limited to a sine wave, and may be various other waveforms having periodicity, such as a triangular wave or a pulse wave.

[0045] The waveform representing the reference value is not limited to a waveform with a constant amplitude such as a sine wave, but may include a waveform with a variable amplitude. In the arrangement of the poles of the battery 60, when one positive pole and one negative pole are alternately arranged in a certain direction, the amplitude of the waveform representing the reference value may be constant. On the other hand, in the arrangement of the poles of the battery 60, when the positive poles and the negative poles are not alternately arranged in a certain direction, the number of positive poles or negative poles may be biased in a limited section. For example, when the poles of the battery 60 are arranged in the order of positive pole, positive pole, negative pole, negative pole, positive pole, the waveform measured by taking out only the section where the first two positive poles are arranged has a different amplitude from the waveform measured including the other sections. In other words, the amplitude of the waveform is not constant depending on the section to be measured. Therefore, the waveform representing the reference value is not limited to a sine wave or a waveform approximated by a sine wave, but may be a waveform approximated by a polynomial of degree 2 or higher. In other words, the waveform representing the reference value may be a waveform that does not have periodicity in at least a part of the section.

[0046] The control device 10 may acquire a reference value prepared in advance by the acquisition unit 11. The reference value of the magnetic field of the battery 60 may be prepared in advance as an external database. The reference value of the magnetic field of the battery 60 may be organized in a database for each type of battery 60. The reference value of the magnetic field of the battery 60 may be organized in a database for each device in which the battery 60 is mounted. The control device 10 may acquire the reference value by scanning the magnetic measurement unit 20 with the scanning unit 14 and acquiring the magnetic field measurement results from the magnetic measurement unit 20 with the acquisition unit 11 while a battery 60 known to be in a normal state is placed in a reference position.

[0047] Returning to the flowchart of Fig. 4, the control device 10 measures the magnetic field of the battery 60 to be measured (step S2). It is assumed that the device, such as the vehicle 80 on which the battery 60 is mounted, is installed in a position where the magnetic field of the battery 60 can be measured by the magnetic measurement unit 20. If the magnetic measurement unit 20 is configured to be movable, the control device 10 scans the magnetic measurement unit 20 with the scanning unit 14, and acquires the measurement results of the magnetic field generated from each part of the battery 60 with the acquisition unit 11. If the device on which the battery 60 is mounted is configured to be movable, the control device 10 controls the position of the device and acquires the measurement results of the magnetic field generated from each part of the battery 60 with the acquisition unit 11.

[0048] The control device 10 may scan the magnetic measurement unit 20 multiple times by shifting the start point of scanning in the Y-axis direction in order to measure the magnetic field of the battery 60 to be measured. In other words, the control device 10 may scan the magnetic measurement unit 20 by moving the magnetic measurement unit 20 along the scanning direction 22 from each of a plurality of positions that are periodically or non-periodically arranged in a direction intersecting the scanning direction 22. The control device 10 may shift the magnetic measurement unit 20 to each position where the movement in the scanning direction started when the reference value of the magnetic field of the battery 60 was measured, and move the magnetic measurement unit 20 along the scanning direction from each position. In other words, the control device 10 may scan the magnetic measurement unit 20 in accordance with the start point of scanning when the reference value of the magnetic field of the battery 60 was measured. By aligning the start point of scanning for measuring the magnetic field of the battery 60 to the start point of scanning when the reference value of the magnetic field of the battery 60 was measured, the control device 10 can compare the reference value and the measured value with high accuracy.

[0049] The control device 10 determines whether the difference between the reference value and the measured value of the magnetic field of the battery 60 satisfies a matching condition (step S3) using the calculation unit 12. The matching condition includes that the reference value and the measured value of the magnetic field of the battery 60 match, or that the difference between the reference value and the measured value of the magnetic field of the battery 60 is small.

[0050] 10, 11, and 12 show examples of waveforms of measured values ​​of battery 60 when the installation position of battery 60 is deviated from the reference position. The horizontal axis of each graph in Fig. 10 to Fig. 12 is the X-coordinate position corresponding to the position in the X-axis direction. The vertical axis is the measured magnetic field value at each position. The solid line waveform represents the reference value. The dashed dotted line waveform represents the measured value.

[0051] In FIG. 10, the phase of the waveform of the measurement value is shifted by ΔT in the X-axis direction with respect to the phase of the waveform of the reference value. In this case, the installation position of the battery 60 is shifted in the X-axis direction from the reference position. The calculation unit 12 may determine that the matching condition is satisfied when ΔT, which is the difference between the phase of the waveform of the measurement value and the phase of the waveform of the reference value, is less than the phase threshold. Conversely, the calculation unit 12 may determine that the matching condition is not satisfied when ΔT, which is the difference between the phase of the waveform of the measurement value and the phase of the waveform of the reference value, is equal to or greater than the phase threshold. The phase threshold may be set appropriately. As described above, the shift in the X-axis direction of the battery 60 without changing its attitude in the reference position is detected as a shift in the phase of the waveform.

[0052] In FIG. 11, the amplitude (A') of the waveform of the measurement value is smaller than the amplitude (A) of the waveform of the reference value. In this case, the battery 60 is separated from the magnetic measurement unit 20 without changing its posture in the reference position. In other words, the installation position of the battery 60 is shifted in the Z-axis direction from the reference position while the arrangement surface of the cells 62 is kept along the XY plane. The calculation unit 12 may determine that the matching condition is satisfied when the difference between the amplitude of the waveform of the measurement value and the amplitude of the waveform of the reference value is less than the amplitude threshold. Conversely, the calculation unit 12 may determine that the matching condition is not satisfied when the difference between the amplitude of the waveform of the measurement value and the amplitude of the waveform of the reference value is equal to or greater than the amplitude threshold. The amplitude threshold may be set appropriately. As described above, the displacement of the battery 60 in the Z-axis direction without changing its posture in the reference position is detected as a change in the amplitude of the waveform.

[0053] In FIG. 12, the period (T') of the waveform of the measurement value is shorter than the period (T) of the waveform of the reference value. Moreover, the amplitude (A') of the waveform of the measurement value increases as it moves in the positive direction of the X-axis. Conversely, the amplitude (A') of the waveform of the measurement value decreases as it moves in the negative direction of the X-axis. The amplitude of the waveform is represented as a dashed line connecting the peaks of the waveform. In this case, the arrangement surface of the cells 62 of the battery 60 rotates around the Y-axis as exemplified in FIG. 9. The calculation unit 12 may determine that the matching condition is satisfied when the difference between the period of the waveform of the measurement value and the period of the waveform of the reference value is less than the period threshold. Conversely, the calculation unit 12 may determine that the matching condition is not satisfied when the difference between the period of the waveform of the measurement value and the period of the waveform of the reference value is equal to or greater than the period threshold. The period threshold may be set as appropriate. Moreover, the calculation unit 12 may determine that the matching condition is satisfied when the rate of change in the amplitude of the waveform of the measurement value with respect to the X-coordinate is less than the amplitude change threshold. Conversely, the calculation unit 12 may determine that the matching condition is not satisfied when the rate of change in the amplitude of the waveform of the measurement value with respect to the X-coordinate is equal to or greater than the amplitude change threshold. The amplitude change threshold may be set appropriately. As described above, the rotation of the battery 60 around the Y-axis is detected as a change in the period of the waveform or a rate of change in the amplitude with respect to the X-axis coordinate.

[0054] As described above, positional deviations in the X-axis and Z-axis directions, as well as rotation around the Y-axis, are detected.

[0055] In addition, the positional deviation in the Y-axis direction and the rotation around the X-axis and Z-axis are detected. In order to detect these positional deviations and rotations, the control device 10 scans the magnetic measurement unit 20 in a planar manner by scanning the magnetic measurement unit 20 in a plurality of scanning paths. The control device 10 can measure the planar distribution of the magnetic field generated by the battery 60 by scanning the magnetic measurement unit 20 in a plurality of scanning paths. For example, when the scanning unit 14 of the control device 10 scans the magnetic measurement unit 20 with the X-axis direction as the scanning direction, the scanning unit 14 may scan the magnetic measurement unit 20 in a plurality of scanning paths with the scanning start point shifted in the Y-axis direction. The scanning start point is the start point of the scanning path of the magnetic measurement unit 20, and is the position where the magnetic measurement unit 20 starts to move in the scanning direction. In other words, the scanning unit 14 may set the scanning start point at each of a plurality of positions that are periodically or non-periodically arranged in a direction intersecting the scanning direction, and move the magnetic measurement unit 20 along the scanning direction from each position.

[0056] Each position that is the scanning start point is set to be the same as the scanning start point when the reference value of the magnetic field of the battery 60 is measured. In other words, the multiple scanning paths may be set to be the same when measuring the reference value and when measuring the battery 60 to be evaluated. The magnetic measurement unit 20 may be shifted to each position where it started moving in the scanning direction when the reference value of the magnetic field of the battery 60 was measured, and moved along the scanning direction from each position. In this way, the control device 10 can compare the reference value and the measured value with high accuracy.

[0057] The multiple scanning paths may be set to different paths when measuring the reference value and when measuring the target battery 60. In this case, the control device 10 may compare the measured value with the reference value by complementing the measured value between the multiple scanning paths.

[0058] Specifically, as illustrated in FIG. 13, multiple waveforms 51 to 55 of measurement values ​​are obtained by scanning in the X-axis direction from each of multiple starting points shifted in the Y-axis direction. The graph in FIG. 13 is a three-dimensional graph showing the magnitude of the magnetic field measurement value at each position on the XY plane. Each waveform in the graph in FIG. 13 shows the result of scanning in the X-axis direction. In the three-dimensional graph in FIG. 13, an envelope is generated that connects the magnetic field measurement values ​​aligned in the Y-axis direction at a specific X coordinate. The envelope corresponds to the result of scanning in the Y-axis direction with the X coordinate as the starting point. The envelope can be represented as a periodic waveform when the interval between the starting points shifted in the Y-axis direction is sufficiently shorter than the period in the Y-axis direction. For example, the interval between the starting point of the scan for measuring the waveform 51 and the starting point of the scan for measuring the waveform 52 is W1 in the Y-axis direction. Also, the interval between the starting point of the scan for measuring the waveform 52 and the starting point of the scan for measuring the waveform 53 is W2 in the Y-axis direction. By further shortening W1 or W2, the envelope can be represented as a waveform having periodicity. W1 and W2 may be set to the same value or different values. Also, the distance in the Y-axis direction between waveforms 53 and 54, or the distance in the Y-axis direction between waveforms 54 and 55, may be set to the same value or different values. The distance by which the scanning start points are shifted in the Y-axis direction may be set to the same value or different values.

[0059] In other words, the intervals of the scanning measurements may be periodic or random. Whether the measurements are performed at periodic intervals or at random intervals, different waveforms due to the structure of the battery 60 are obtained in each measurement. For example, when measuring the front of the module, the measured value is dominated by the magnetic field generated from the cell 62 or module located directly in front. However, by measuring the middle point of the module, the measured value is influenced by the modules on both sides. In view of the above, the control device 10 may periodically measure the front of the module based on the structure of the device, or may alternately measure the front and the middle. The control device 10 may measure the magnetic field anywhere where it can measure the magnetic field generated by the module. However, the magnetic field measurement position is the same position as the position specified when measuring the reference value.

[0060] The position shift in the Y-axis direction is expressed as a difference between the phase of the waveform of the envelope in the Y-axis direction of the three-dimensional graph of the reference value and the phase of the waveform of the envelope in the Y-axis direction of the measurement value. The calculation unit 12 may determine that the matching condition is satisfied when the difference between the phase of the waveform of the envelope in the Y-axis direction of the measurement value and the phase of the waveform of the envelope in the Y-axis direction of the reference value is less than the phase threshold. Conversely, the calculation unit 12 may determine that the matching condition is not satisfied when the difference between the phase of the waveform of the envelope in the Y-axis direction of the measurement value and the phase of the waveform of the envelope in the Y-axis direction of the reference value is equal to or greater than the phase threshold. The phase threshold may be set to the same value in the X-axis direction and the Y-axis direction, or may be set to different values.

[0061] The rotation around the X-axis is represented as a difference between the amplitude of the envelope waveform in the Y-axis direction of the three-dimensional graph of the reference value and the amplitude of the envelope waveform in the Y-axis direction of the three-dimensional graph of the measurement value. The calculation unit 12 may determine that the matching condition is satisfied when the difference between the amplitude of the envelope waveform in the Y-axis direction of the measurement value and the amplitude of the envelope waveform in the Y-axis direction of the reference value is less than the amplitude threshold. Conversely, the calculation unit 12 may determine that the matching condition is not satisfied when the difference between the amplitude of the envelope waveform in the Y-axis direction of the measurement value and the amplitude of the envelope waveform in the Y-axis direction of the reference value is equal to or greater than the amplitude threshold. The amplitude threshold may be set to the same value in the X-axis direction and the Y-axis direction, or may be set to different values.

[0062] The rotation around the Z-axis is represented as an angle that a ridgeline 50 connecting the peaks of waveforms 51-55 in the three-dimensional graph of the measurement values ​​makes with the Y-axis direction. The calculation unit 12 may determine that the matching condition is met when the angle of the ridgeline 50 with respect to the Y-axis is less than the angle threshold. Conversely, the calculation unit 12 may determine that the matching condition is not met when the angle of the ridgeline 50 with respect to the Y-axis is equal to or greater than the angle threshold. The angle threshold may be set as appropriate.

[0063] As described above, the matching conditions are set so that the positional and attitude deviations of the battery 60 from the reference position are less than the determination thresholds.

[0064] Returning to the flowchart of FIG. 4, if the difference between the reference value and the measured value of the magnetic field of the battery 60 satisfies the comparison condition (step S3: YES), the control device 10 proceeds to the procedure of step S7. If the difference between the reference value and the measured value of the magnetic field of the battery 60 does not satisfy the comparison condition (step S3: NO), the control device 10 causes the calculation unit 12 to calculate information on the relative position of the magnetic measurement unit 20 (step S4). If the state of the battery 60 is normal and the same current flows as when measured at the reference position, the difference between the waveform of the measured value of the magnetic field of the battery 60 and the waveform of the reference value is caused by the difference in the relative position between the battery 60 or the device equipped with the battery 60 and the magnetic measurement unit 20. In other words, the calculation unit 12 may calculate the magnitude of the positional deviation of the battery 60 in the X-axis, Y-axis, or Z-axis direction based on the difference between the reference value and the measured value of the magnetic field of the battery 60 as information on the relative position of the magnetic measurement unit 20. Furthermore, the calculation unit 12 may calculate the angle of rotation about the X-axis, the Y-axis, or the Z-axis of the battery 60 as the information on the relative position of the magnetic measurement unit 20. The angle of rotation about the X-axis, the Y-axis, or the Z-axis of the battery 60 represents the magnitude of the attitude deviation of the battery 60.

[0065] The calculation unit 12 may calculate a correction coefficient as information regarding the relative position of the magnetic measurement unit 20. The correction coefficient is used to correct a position shift or an attitude shift of the battery 60. The correction coefficient may be used to correct a waveform of a measurement value of the magnetic field of the battery 60 to a waveform when the battery 60 is placed in a reference position.

[0066] The calculation unit 12 may calculate a pattern representing the difference between the waveform of the reference value and the waveform of the measurement value of the magnetic field of the battery 60 as information on the relative position of the magnetic measurement unit 20. The calculation unit 12 may calculate a pattern representing the difference between the three-dimensional waveform of the reference value and the three-dimensional waveform of the measurement value. In other words, the calculation unit 12 may recognize the difference between the waveform of the reference value and the waveform of the measurement value as a pattern.

[0067] The control device 10 determines whether the information on the relative position of the magnetic measurement unit 20 satisfies an abnormality determination condition using the determination unit 13 (step S5). The abnormality determination condition is set to be satisfied when the state of the battery 60 is not normal. For example, even if the measured value does not match the reference value or is significantly deviated from the reference value, the determination unit 13 may determine that the state of the battery 60 is normal as long as it can identify how the battery 60 is deviated from the reference position.

[0068] Specifically, the difference between the measured value and the reference value of the magnetic field when the state of the battery 60 is normal is caused by the difference in the relative position of the magnetic measurement unit 20. That is, the difference between the measured value and the reference value is caused by the positional deviation or the attitude deviation of the battery 60. In this case, the correction coefficient is calculated as a value proportional to the positional deviation or the attitude deviation of the battery 60. Then, the determination unit 13 may determine that the state of the battery 60 is normal when the magnitude of the positional deviation or the attitude deviation determined based on the correction coefficient is, for example, within the inside of the device in which the battery 60 is mounted. Conversely, the determination unit 13 may determine that the state of the battery 60 is not normal when the magnitude of the positional deviation or the attitude deviation determined based on the correction coefficient is physically impossible, such as when it exceeds the size of the device in which the battery 60 is mounted. The determination unit 13 may determine that the battery 60 is normal when the correction coefficient is less than the determination threshold, and may determine that the battery 60 is not normal when the correction coefficient is equal to or greater than the determination threshold. In other words, the abnormality determination condition may be that the correction coefficient is equal to or greater than the determination threshold. The determination threshold value may be set appropriately based on, for example, the size of the device in which the battery 60 is mounted.

[0069] When the determination unit 13 calculates a pattern representing the difference between the waveform of the reference value and the waveform of the measurement value as information on the relative position of the magnetic measurement unit 20, the determination unit 13 may determine whether the pattern corresponds to a pattern when the state of the battery 60 is normal or an abnormal pattern. The determination unit 13 may determine the state of the battery 60 by pattern matching. The determination unit 13 may determine the state of the battery 60 by using a model that outputs the state of the battery 60 when a pattern is input. In other words, the abnormality determination condition may be that the pattern representing the difference between the waveform of the reference value and the waveform of the measurement value is different from the pattern when the state of the battery 60 is normal.

[0070] When the measurement value of the magnetic field of the battery 60 is an impossible result based on the structure of the device in which the battery 60 is mounted, the determination unit 13 may determine that the state of the battery 60 is abnormal regardless of the correction coefficient. For example, when the measurement value does not match a reference value stored in a database, when the correction coefficient cannot be calculated, or when the correction coefficient falls outside a predetermined range, the determination unit 13 may determine that the state of the battery 60 is abnormal. In other words, the abnormality determination conditions may include a case where the measurement value does not match a reference value stored in a database, when the correction coefficient cannot be calculated, or when the correction coefficient falls outside a predetermined range.

[0071] Cases in which the condition of the battery 60 is not normal may include, for example, cases in which the battery 60 installed in the device is not genuine, cases in which the battery 60 is broken, or cases in which the position of the battery 60 is outside the range in which the magnetic field can be measured by the magnetic measurement unit 20.

[0072] When the information on the relative position of the magnetic measurement unit 20 does not satisfy the abnormality determination condition (step S5: NO), the control device 10 causes the calculation unit 12 to correct the measurement value of the magnetic field of the battery 60 (step S6). Specifically, the calculation unit 12 corrects the measurement value of the magnetic field of the battery 60 based on the information on the relative position of the magnetic measurement unit 20. The calculation unit 12 may correct the measurement value of the magnetic field of the battery 60 based on a correction coefficient.

[0073] If the matching condition is satisfied in the procedure for determining the matching condition in step S3, or if the abnormality determination condition is not satisfied in the procedure for determining the abnormality determination condition in step S5, the control device 10 executes the procedure in step S6 and then determines that the state of the battery 60 is normal (step S7). On the other hand, if the abnormality determination condition is satisfied in the procedure for determining the abnormality determination condition in step S5 (step S5: YES), the control device 10 determines that the state of the battery 60 is abnormal (step S8). After executing the procedure in step S7 or S8, the control device 10 ends the execution of the procedure in the flowchart of FIG. 4.

[0074] When the abnormality determination condition is satisfied in the determination procedure of the abnormality determination condition in step S5 of the flowchart in Fig. 4, the control device 10 determines that the battery 60 is abnormal without correcting the measured magnetic field value. In this way, unnecessary correction operations are omitted. As a result, the operating load of the control device 10 is reduced.

[0075] (summary) As described above, according to the method for determining the state of the battery 60 according to the present embodiment, information on the relative position of the battery 60 is calculated based on the difference between the reference value and the measured value of the magnetic field of the battery 60, and the measured value is corrected. In this way, a positional or attitude shift of the battery 60 with respect to the magnetic measurement unit 20 is permitted. As a result, even if it is difficult to adjust the position of the battery 60 with respect to the magnetic measurement unit 20 while the battery 60 is mounted on the device, the magnetic field of the battery 60 is measured with high accuracy without removing the battery 60 from the device. For example, when the battery 60 is mounted on an electric vehicle, etc., it is difficult to remove the battery 60 from the device, and the method for determining the state of the battery 60 according to the present disclosure is effective. By determining the state of the battery 60 while the battery 60 is mounted on the device, the accuracy of determining the state of the battery is improved without increasing the burden of measuring the battery.

[0076] (Other embodiments) Hereinafter, a system 1 and a method for determining a state of a battery 60 according to another embodiment will be described.

[0077] <Pre-examination> The arrangement of the cells 62 of the battery 60 may be unknown. In this case, the control device 10 may preliminarily scan the magnetic measurement unit 20 in each of the scanning direction 22X along the X-axis and the scanning direction 22Y along the Y-axis, as illustrated in FIG. 14, to obtain the measured values ​​in each scanning direction. The control device 10 may estimate the arrangement of the cells 62 of the battery 60 based on the measured values ​​in each scanning direction, and determine the scanning direction of the magnetic measurement unit 20 according to the estimated arrangement. By determining the scanning direction of the magnetic measurement unit 20 based on the preliminarily measurement, the magnetic measurement unit 20 is scanned so that the position of the battery 60 approaches the reference position. As a result, the position or attitude deviation of the battery 60 is reduced. The sensor used to preliminarily measure the magnetic field of the battery 60 may be the same as or different from the magnetic measurement unit 20 used to obtain the measured values ​​of the magnetic field for determining the state of the battery 60.

[0078] In other words, the control device 10 may obtain the measured values ​​of the magnetic field of the battery 60 by moving the magnetic measurement unit 20 in each of a plurality of directions including at least a first direction and a second direction. Here, the first direction may correspond to the X-axis direction. The second direction may correspond to the Y-axis direction. The control device 10 may estimate the arrangement of the cells 62 based on a first measured value obtained by moving the magnetic measurement unit 20 in the first direction and a second measured value obtained by moving the magnetic measurement unit 20 in the second direction, and may determine the scanning direction of the magnetic measurement unit 20.

[0079] When the battery 60 is mounted on a vehicle, the position of the battery 60 and the arrangement of the cells 62 are determined for each vehicle model. The control device 10 may identify the vehicle model based on an image of the vehicle in which the battery 60 is mounted, and determine the scanning direction and scanning range of the magnetic measurement unit 20 based on the position of the battery 60 and the arrangement of the cells 62. In other words, the control device 10 may move the magnetic measurement unit 20 within a scanning range determined based on the type of device in which the battery 60 is mounted. In this way, unnecessary scanning is reduced. As a result, measurement efficiency is improved.

[0080] <Position adjustment> In the above-described embodiment, when the position of the battery 60 is deviated from the reference position, the control device 10 responds by correcting the measurement value without adjusting the position of the battery 60 or the magnetic measurement unit 20. In another embodiment, the position of the battery 60 or the magnetic measurement unit 20 may be adjusted.

[0081] As illustrated in Fig. 15, the condition determination system 1 may further include a moving device 30. The magnetic measurement unit 20 may be mounted on the moving device 30. The moving device 30 is configured to move along a ground surface 70, for example. The moving device 30 may be configured to move in a vertical direction. The control device 10 may move the magnetic measurement unit 20 by controlling the scanning direction of the magnetic measurement unit 20 by the scanning unit 14 in accordance with the positional deviation or attitude deviation of the battery 60, so that the magnetic measurement unit 20 is moved to the same scanning range as that of the magnetic measurement unit 20 when the battery 60 is placed at the reference position.

[0082] 16, the state determination system 1 may further include a driving device 40. The driving device 40 is configured to drive a device equipped with a battery 60, such as a vehicle 80, relative to a ground surface 70. In the example of FIG. 16, the driving device 40 drives the attitude of the battery 60 from a state in which the arrangement of the cells 62 is inclined with respect to the X-axis and Y-axis to a state in which the arrangement is aligned with the X-axis and Y-axis by moving tires 82 of the vehicle 80 along the ground surface 70. The driving device 40 adjusts the position and attitude of the battery 60 relative to the magnetic measurement unit 20.

[0083] The control device 10 may re-measure the magnetic field of the battery 60 by scanning the magnetic measurement unit 20 after adjusting the positions of the battery 60 and the magnetic measurement unit 20 as described above. In other words, the control device 10 may re-measure the magnetic field after physically correcting the relative position of the magnetic measurement unit 20. In this way, the accuracy of measuring the magnetic field or the accuracy of determining the state of the battery 60 is improved.

[0084] If the equipment mounting the battery 60 is a low-floor vehicle 80, the magnetic measurement unit 20 may be installed so as to scan the bottom of the vehicle 80 in a space hollowed out in the ground 70 that is lower than the contact surface of the tires 82.

[0085] The control device 10 may use a distance measuring sensor to calculate the relative position between the battery 60 and the magnetic measurement unit 20.

[0086] Although the embodiments according to the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to be logically inconsistent, and multiple components or steps can be combined or divided into one. [Explanation of symbols]

[0087] 1. Status Judgment System 10 control device (11: acquisition unit, 12: calculation unit, 13: judgment unit, 14: scanning unit) 20 Magnetic measurement unit (22, 22X, 22Y: scanning direction) 30 Moving device (32: moving direction of magnetic measurement unit) 40 Driving device (42: Vehicle driving direction) 50 Ridgeline 51~55 Magnetic field measurement waveform 60 Battery (62: Cell) 70 ground 80 Vehicles (82: Tires)

Claims

1. Obtaining a measurement value obtained by measuring a magnetic field of a battery mounted in the device using a magnetic measurement unit; Calculating information regarding a relative position of the magnetic measurement unit based on a measured value of the magnetic field of the battery and a reference value of the magnetic field of the battery; determining a state of the battery based on information regarding the relative position of the magnetic measurement unit; A method for determining a state of a battery, comprising:

2. The method of claim 1 , further comprising determining that the battery is abnormal when the information relating to the relative position of the magnetic measurement unit satisfies an abnormality determination condition.

3. The method of claim 2 , further comprising: calculating a correction coefficient for the relative position of the magnetic measurement unit as information regarding the relative position of the magnetic measurement unit.

4. The method for determining a state of a battery according to claim 1 , further comprising moving the magnetic measurement unit along one scanning direction to measure a magnetic field of the battery with the magnetic measurement unit.

5. The battery state determination method of claim 4, further comprising shifting the magnetic measurement unit to each of a plurality of positions arranged periodically or non-periodically in a direction intersecting the scanning direction, and moving the magnetic measurement unit from each position along the scanning direction.

6. 6. The method for determining the state of a battery as described in claim 5, further comprising shifting the magnetic measurement unit to each position where it started to move in the scanning direction when a reference value of the magnetic field of the battery was measured, and moving the magnetic measurement unit along the scanning direction from each position.

7. Moving the magnetic measurement unit in each of a plurality of directions including at least a first direction and a second direction to obtain a measurement value of a magnetic field of the battery; determining the scanning direction based on a first measurement value obtained by moving the magnetic measurement unit in the first direction and a second measurement value obtained by moving the magnetic measurement unit in the second direction; The method of claim 4 , further comprising:

8. 5. The method of claim 4, further comprising moving the magnetic measuring unit within a scanning range determined based on the type of device in which the battery is mounted.

9. A battery state determination system comprising: a magnetic measurement unit; and a control device that executes the battery state determination method according to any one of claims 1 to 3.

10. The magnetic measuring device further includes a moving device that moves the magnetic measuring unit relative to the battery. The battery state determination system according to claim 9 , wherein the moving device is configured to move between a surface on which a device having the battery mounted thereon is placed and the battery.

11. The battery state determination system according to claim 9 , further comprising a driving device that moves a device having the battery mounted thereon relative to the magnetic measurement unit.

12. The battery state determination system according to claim 9 , wherein the magnetic measurement unit includes one or more magnetic sensors that measure a magnetic field of the battery.

13. The battery state determination system according to claim 12 , wherein the magnetic measurement unit includes a plurality of the magnetic sensors arranged in a line or an array.

14. The battery state determination system according to claim 12 , wherein the magnetic measurement unit includes a plurality of the magnetic sensors arranged in a range covering the entire battery.

15. The battery state determination system according to claim 14 , wherein the control device selects some of the plurality of magnetic sensors and obtains the measurement values ​​of the selected magnetic sensors.

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