Pressure pad sensor pressure device, pressure pad sensor output value calibration method, and battery cell surface pressure measurement method

Abstract

According to the present invention, it is possible to provide a pressure pad sensor pressure device including: a pressure unit including a node pressure section that is arranged so as to be able to descend from a predetermined height to contact one sensing node, and a weight loading section that is arranged on the upper part of the node pressure section so that the load of a weight is transmitted to the node pressure section; a support frame that supports the pressure unit at a predetermined height; a first drive section that moves the pressure unit in a first direction or its opposite direction; a second drive section that moves the pressure unit in a second direction or its opposite direction; and a third drive section that raises and lowers the pressure unit relative to the pressure pad sensor; and a calibration method that can calibrate the output value of a sensing node to a reliable pressure value using the pressure pad sensor pressure device.

Description

[Technical field]

[0001] The present invention relates to a pressure device and a calibration method for calibrating an output value of a pressure pad sensor used for measuring the swelling pressure of a battery cell to a reliable pressure value, and a method for measuring the surface pressure of a battery cell based on the calibration method.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0183108 filed on December 20, 2021, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference. [Background technology]

[0003] Lithium polymer pouch type secondary batteries are generally manufactured with an electrode assembly built into an aluminum laminate sheet, and therefore have the advantage of a high energy density compared to their small size and light weight, but have the disadvantage of weak mechanical rigidity. In particular, in the case of lithium-polymer pouch type secondary batteries, the electrodes become thick during repeated charging and discharging, or the internal electrolyte decomposes in a side reaction, generating gas, causing the pouch exterior material to swell, resulting in a swelling phenomenon.

[0004] Therefore, for example, when manufacturing a battery module using pouch-type secondary batteries, it is necessary to measure the swelling pressure of the pouch-type secondary battery generated during a charge / discharge test of the pouch-type secondary battery in the initial design step, and to determine the mechanical strength of the module case, etc. based on the results.

[0005] However, in the prior art, there is no suitable technique for measuring the surface pressure of a pouch-type secondary battery, and for example, as disclosed in Korean Patent Publication No. 10-2021-0055363A, a jig including a load cell is used. The jig including the load cell is expensive and bulky, making it difficult to use.

[0006] Therefore, the present applicant has invented a pressure pad sensor (see FIG. 6). The pressure pad sensor has a sheet shape with a size equivalent to one surface of a pouch-type secondary battery, and includes a plurality of sensing nodes for measuring pressure therein. Each sensing node may be configured as a force sensitive resistor (FSR) sensor that utilizes the property that resistance value changes according to physical force or weight. With such a pressure pad sensor, it is possible to measure the surface pressure of each region of the pouch-type secondary battery when the pouch-type secondary battery swells.

[0007] Meanwhile, each sensing node of the pressure pad sensor outputs a numerical value (0 to 255) called ADC, which is a resistance value converted into a digital value. A higher numerical value means a higher pressure. However, it is difficult to manufacture all the sensing nodes constituting the pressure pad sensor to have exactly the same performance. That is, due to manufacturing or assembly errors of the sensing nodes, all the sensing nodes distributed in the pressure pad sensor do not have the same numerical value for the same force.

[0008] Therefore, in order to more accurately measure the swelling pressure distribution of the secondary battery using the pressure pad sensor, it is necessary to calibrate the output values ​​of the plurality of sensing nodes. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2021-0055363A Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above problems, and aims to provide a specialized pressure device that can pressurize each sensing node of a pressure pad sensor while changing the pressure in order to convert the output value of each sensing node of the pressure pad sensor into a reliable pressure value, a method for calibrating the output value of a pressure pad sensor, and a method for measuring the surface pressure of a battery cell using the pressure pad sensor and based on the calibration method.

[0011] However, the technical problems that the present invention aims to solve are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the detailed description of the invention described below. [Means for solving the problem]

[0012] According to one aspect of the present invention, there can be provided a pressure pad sensor pressure device for applying pressure individually to each sensing node in a pressure pad sensor having a plurality of sensing nodes, the pressure pad sensor pressure device including: a pressure unit including a node pressure section that is arranged so as to be able to descend from a predetermined height to contact one of the sensing nodes, and a weight loading section that is arranged on the upper part of the node pressure section so that the load of a weight is transmitted to the node pressure section; a support frame that supports the pressure unit at a predetermined height; a first drive section that moves the pressure unit in a first direction or its opposite direction; a second drive section that moves the pressure unit in a second direction or its opposite direction; and a third drive section that raises and lowers the pressure unit relative to the pressure pad sensor.

[0013] The node pressurizing portion may be configured to have a lower end surface corresponding to one of the sensing nodes.

[0014] The support frame includes a pair of leg plates arranged parallel to and spaced apart from each other in the second direction, and a support board extending in the second direction and connected to upper ends of the pair of leg plates, and the support board may have a long hole through which the node pressure portion extends downward from above the support board and is configured to move in the second direction.

[0015] The node pressure section may include a pressure block extending through the long hole to the lower part of the support board, and a flange block connected to the pressure block, having a width greater than the long hole, and disposed on the upper part of the support board.

[0016] The weight support portion may be connected to the flange block at a predetermined distance by at least one connecting rod extending vertically upward from the flange block.

[0017] The weight loading portion may include a tray coupled to an upper end of the connecting rod, and one or more weights arranged to be mountable on the tray.

[0018] The first driving unit may include a first guide rail extending along the first direction, a first slide block coupled to a lower portion of each of the leg plates and slidably connected on the first guide rail, a shaft connecting block coupled to one side of the leg plate, a first driving shaft passing through the shaft connecting block and extending in the first direction, and connected to the shaft connecting block such that the shaft connecting block moves in the first direction or the reverse direction when the first driving shaft rotates in the forward or reverse direction, and a first driving motor rotating the first driving shaft in the forward or reverse direction.

[0019] The second driving unit may include a second guide rail extending in a second direction on the support board, a second slide block slidably connected on the second guide rail, a shaft connection frame surrounding the connecting rod and coupled onto the second slide block, a second driving shaft extending in the second direction passing through the shaft connection frame and connected to the shaft connection frame such that the shaft connection frame moves in the second direction or the reverse direction when the second driving shaft rotates in the forward or reverse direction, and a second driving motor rotating the second driving shaft in the forward or reverse direction.

[0020] The third drive unit may include a piston rod extending in the vertical direction, a lever member having one end connected to the weight loading unit and the other end connected to the piston rod, and configured to raise and lower the weight loading unit by a seesaw motion caused by the movement of the piston rod, and a third drive motor that moves the piston rod in the vertical direction.

[0021] The pressure pad sensor pressure device may further include a system unit that records output values ​​of the sensing nodes obtained by individually applying pressure to the plurality of sensing nodes by changing weights, and a display device that can display the output values.

[0022] According to another aspect of the present invention, there may be provided a method for calibrating an output value of a pressure pad sensor, including: a sensor output value measuring step of preparing a pressure pad sensor, pressurizing each sensing node of the pressure pad sensor individually from 1 to n times (n is a natural number equal to or greater than 2) while changing the pressure each time, and storing the output values ​​of each of the sensing nodes from the 1 to n times; and a step of estimating standard pressure data based on the output values ​​for each of the sensing nodes using two or more different pressures applied to each of the sensing nodes, two or more output values ​​resulting therefrom, and an interpolation method.

[0023] The sensor output measuring step may be performed using the pressure pad sensor pressure device described above.

[0024] The method may further include the step of displaying the standard pressure data derived by the standard pressure data estimating step.

[0025] The standard pressure data estimating step may include a step of deriving a linear equation for estimating standard pressure data corresponding to an interval between output values ​​of each of the sensing nodes for the 1st to nth times using a linear interpolation method.

[0026] The linear equation can be expressed as follows:

number

[0027] According to yet another aspect of the present invention, there may be provided a method for measuring a surface pressure of a battery cell when the battery cell is swelling, the method including: disposing a pressure pad sensor, in which a plurality of sensing nodes are arranged in horizontal and vertical directions and which has an area corresponding to one side of the battery cell, between the battery cells and stacking the pressure pad sensor together with the battery cell; and measuring the surface pressure in each region when the battery cell is swelling based on the above-mentioned method for calibrating an output value of the pressure pad sensor. Effect of the Invention

[0028] According to the present invention, the output value according to pressure can be obtained for each sensing node of the pressure pad sensor using a pressure device for the pressure pad sensor, and the output value for each sensing node thus obtained can be calibrated by the output value calibration method of the pressure pad sensor according to the present invention and converted into standard pressure data, thereby solving the problem that the output values ​​are not the same even with the same force due to manufacturing errors of each sensing node.

[0029] That is, according to the present invention, when measuring the swelling pressure distribution of a battery cell using a pressure pad sensor, standard pressure data in which the error is corrected can be used as a measurement value instead of an output value having an error for each sensing node even with the same force. Therefore, it is possible to more accurately and easily measure the surface pressure for each area when the battery cell is swelling by using the pressure pad sensor.

[0030] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the present specification and the attached drawings. [Brief description of the drawings]

[0031] [Figure 1] FIG. 2 is a perspective view of a pressure pad sensor compression device according to one embodiment of the present invention; [Diagram 2] 2 is a rear view (in the X direction) of the pressure pad sensor pressure device of FIG. 1. [Diagram 3] 2 is a schematic cross-sectional view of the pressure pad sensor pressing device taken along line AA' in FIG. 1; [Figure 4] 2 is a schematic cross-sectional view of the pressure pad sensor pressing device taken along line BB' in FIG. 1; [Diagram 5] 5 is a view of the pressure pad sensor pressure device of FIG. 4 as seen from another angle. [Figure 6] FIG. 2 illustrates a pressure pad sensor according to one embodiment of the present invention. [Figure 7a]11 is a diagram showing output values ​​of each sensing node obtained by individually pressurizing each sensing node with a first pressure P1 according to an embodiment of the present invention. FIG. [Figure 7b] 13 is a diagram showing output values ​​of each sensing node obtained by individually pressurizing each sensing node with a second pressure P2 according to an embodiment of the present invention. FIG. [Figure 7c] FIG. 11 is a diagram showing output values ​​of each sensing node obtained by individually pressurizing each sensing node with a third pressure P3 according to an embodiment of the present invention. [Figure 7d] FIG. 13 is a diagram showing output values ​​of each sensing node obtained by individually pressurizing each sensing node with a fourth pressure P4 according to an embodiment of the present invention. [Figure 8] 8 is a graph showing an example in which linear interpolation is applied using output values ​​due to pressure changes of one sensing node (C0, R0) shown in FIGS. 7a to 7d. [Figure 9] 1 is a graph showing the relationship between output values ​​of multiple sensing nodes and standard pressure data derived by a calibration method according to an embodiment of the present invention. [Figure 10] FIG. 2 is a diagram showing a pressure pad sensor disposed between battery cells and stacked together with the battery cells according to a method for measuring surface pressure of a battery cell according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as being in accordance with the meaning and concept of the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of the term in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention, and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0033] The pressure pad sensor pressing device according to the present invention described below can be used to pressurize each sensing node in a film-type pressure pad sensor having multiple sensing nodes. However, it should be noted that the scope of the pressure pad sensor pressing device according to the present invention is not limited to the application of pressing the pressure pad sensor.

[0034] FIG. 1 is an oblique view of a pressure pad sensor pressure device according to one embodiment of the present invention, FIG. 2 is a view of the pressure pad sensor pressure device of FIG. 1 from behind (from -X to +X direction), FIG. 3 is a schematic cross-sectional view of the pressure pad sensor pressure device taken along line A-A' in FIG. 1, FIG. 4 is a schematic cross-sectional view of the pressure pad sensor pressure device taken along line B-B' in FIG. 1, and FIG. 5 is a view of the pressure pad sensor pressure device of FIG. 4 from another angle.

[0035] 1. Referring to these drawings, a pressure pad sensor pressing device 10 according to an embodiment of the present invention includes a pressing unit 100, a support frame 200, a first driving section 300, a second driving section 400 and a third driving section 500. As shown in FIG.

[0036] The pressure unit 100 includes a node pressure unit 110 and a weight loading unit 120, and can be configured to move along the X-axis, Y-axis, and Z-axis by operation of the first driving unit 300, the second driving unit 400, and the third driving unit 500, so as to apply uniform pressure to all sensing nodes 21 of the pressure pad sensor 20.

[0037] The node pressurizing unit 110 is installed so as to descend from the vertical upper part of the pressure pad sensor 20 and be capable of making surface contact with one of the sensing nodes 21, and the weight loading unit 120 may be installed on the upper part of the node pressurizing unit 110 so as to pressurize each sensing node 21 while increasing its weight.

[0038] Also, as shown in FIG. 1, the pressure pad sensor pressing device 10 according to this embodiment may further include a base frame 600, a frame cover 700 that covers the upper part of the support frame 200, and a table 800 on which the base frame 600 can be placed or coupled.

[0039] As shown in FIG. 1, the base frame 600 includes a sensor base 610 on which the pressure pad sensor 20 can be placed flat, and rail covers 620 and 630 provided at both end regions along the Y direction.

[0040] The support frame 200 includes a pair of leg plates 210, 220 spaced apart and parallel to each other in a second direction (Y direction), and a support board 230 extending in the second direction and connected to upper ends of the pair of leg plates 210, 220, and is movably installed in a first direction or the opposite direction (±X direction) on the base frame 600. A pressurizing unit 100 is installed on the upper part of the support frame 200.

[0041] A first driving unit 300 is connected to the support frame 200 to move the support frame 200 in a first direction or the opposite direction (±X direction).

[0042] 3, the first driving unit 300 includes a first guide rail 310 located under the rail covers 620 and 630 of the base frame 600 and extending along a first direction (X direction), a first slide block 320 coupled to a lower portion of the leg plates 210 and 220 and slidably coupled on the first guide rail 310, a shaft connecting block 330 coupled to one side of the leg plates 210 and 220, a first driving shaft 340 extending in the first direction (X direction) passing through the shaft connecting block 330 and coupled to the shaft connecting block 330 such that the shaft connecting block 330 moves in the first direction or the reverse direction (±X direction) when rotated in the forward or reverse direction, and a driving motor 350 rotating the first driving shaft 340 in the forward or reverse direction. Although not shown in the drawings for convenience of illustration, the first driving motor 350 may be coupled to one end of the first driving shaft 340 by a timing belt.

[0043] The first drive shaft 340 and the shaft connection block 330 are connected to be capable of relative rotation, for example, by a ball screw method, so that when the first drive shaft 340 rotates in the forward or reverse direction, the shaft connection block 330 can move along the first drive shaft 340 in a first direction or the reverse direction.

[0044] As shown in FIG. 3, the shaft connection block 330 is fixedly coupled to one side of one leg plate 210 so that the support frame 200 can be moved together with the shaft connection block 330 in a first direction or the opposite direction.

[0045] The pair of leg plates 210, 220 of the support frame 200 pass through the upper surfaces of the cut-out rail covers 620, 630, and the lower ends thereof are fixedly coupled to the first slide block 320, which is slidably connected to the first guide rail 310 and can move smoothly and precisely along the first guide rail 310. The pressure unit 100 is installed on the support board 230 of the support frame 200 and can move together with the support frame 200 in the first direction or the opposite direction.

[0046] Meanwhile, referring to FIG. 1, FIG. 4 and FIG. 5, the second driving unit 400 according to an embodiment of the present invention includes a second guide rail 410 extending along a second direction (Y direction) on the support board 230, a second slide block 420 slidably connected on the second guide rail 410, a shaft connection frame 430 surrounding a connection rod 130 connected between the node pressurizing unit 110 and the weight loading unit 120 and connected on the second slide block 420, a second driving shaft 440 extending in the second direction passing through a body of the shaft connection frame 430 (Y direction) and connected to the shaft connection frame 430 such that the shaft connection frame 430 moves in the second direction or the opposite direction when rotated in the forward or reverse direction, and a second driving motor 450 rotating the second driving shaft 440 in the forward or reverse direction.

[0047] 5, the support board 230 has a long hole 231 provided in a long hole shape in the second direction (Y direction). The long hole 231 can have a width corresponding to the widest part of the node pressurizing part 110 and can be provided in a long hole shape in the second direction. Since such a long hole 231 is provided in the support board 230, the node pressurizing part 110 of the pressurizing unit 100 can be vertically arranged from above to below the support board 230 and can move in the second direction or the opposite direction (±Y direction) in this state.

[0048] The second guide rails 410 may be provided at both end regions in the width direction (X direction) of the support board 230 across the slot 231. A second slide block 420 is connected to the top of each second guide rail 410, and at least one side of a shaft connection frame 430 is fixedly connected to an upper portion of the second slide block 420.

[0049] As shown in FIG. 5, the shaft connection frame 430 may be provided in a form in which it covers the upper part of the node pressurizing unit 110 and has four connecting rods 130 that vertically connect the node pressurizing unit 110 and the weight loading unit 120 penetrating the body in the vertical direction.

[0050] With the above-mentioned configuration, when the shaft connection frame 430 moves in the ±Y direction along the second guide rail 410 together with the second slide block 420, the pressurizing unit can also move together.

[0051] Similarly to the first driving unit 300, a second driving shaft 440 is connected to the shaft connecting frame 430 for relative rotation, for example, by a ball screw method, and a second driving motor 450 is connected to one end of the second driving shaft 440.

[0052] Therefore, when the second driving motor 450 is controlled to rotate the second driving shaft 440 in a forward or reverse direction, the shaft connection frame 430 moves in the second direction or the reverse direction (±Y direction). At this time, since the pressurizing unit 100 is connected to the shaft connection frame 430, the pressurizing unit 100 moves together with the shaft connection frame 430.

[0053] According to the configuration of the first driving unit 300 and the second driving unit 400 of this embodiment, the first driving motor 350 and the second driving motor 450 are controlled to move the pressure unit 100 in ±X and ±Y directions so that the pressure unit 100 is located vertically above the location of the sensing node 21 to be pressed. For example, the pressure pad sensor 20 according to this embodiment includes a plurality of sensing nodes arranged in 5 rows (R0 to R4) and 24 columns (C0 to C23) at a predetermined interval from each other, and after pressing any one sensing node 21, when pressing the sensing node 21 in the next row or column, the first driving motor 350 and / or the second driving motor 450 can be controlled to precisely move the pressure unit 100 to a desired position.

[0054] Meanwhile, the main configuration of the pressurizing unit 100 according to one embodiment of the present invention will be described in detail with reference to Figures 4 and 5. The pressurizing unit 100 includes a node pressurizing section 110 and a weight loading section 120, and the node pressurizing section 110 and the weight loading section 120 are configured to be connected by at least one connecting rod 130.

[0055] The node pressurizing unit 110 includes a pressurizing block 111 and a flange block 113. The pressurizing block 111 protrudes downward from the support board 230 through an elongated hole 231 of the support board 230, and a lower end surface of the pressurizing block 111 may be provided with a size corresponding to the surface area of ​​one sensing node 21. Here, the lower end surface of the pressurizing block 111 refers to a portion that comes into direct surface contact with the sensing node 21.

[0056] The pressure block 111 may be provided as a whole, or may be configured in a form in which a plurality of parts are assembled. The pressure block 111 of this embodiment belongs to the latter type, and is provided with a replaceable contact point block 111a at its lower end. The lower end surface of the contact point block 111a may be manufactured in various shapes according to the shape of the sensing node 21 to be pressed. That is, as shown in FIG. 6, since the sensing node 21 of this embodiment is square, the lower end surface of the contact point block 111a may also be provided in a square corresponding to the area of ​​the square sensing node. Unlike this embodiment, if the sensing node 21 is circular or polygonal, the lower end surface of the contact point block 111a may also be provided in a shape corresponding thereto.

[0057] The flange block 113 may have a predetermined thickness, may be in the form of a plate-like body horizontally extended at the upper end of the pressure block 111, may be disposed on the upper part of the support board 230, and may be provided to have a width larger than that of the slot 231. Therefore, the pressure block 111 may be positioned below the support board 230 until the flange block 113 contacts the upper surface of the support board 230.

[0058] The weight loading unit 120 includes a tray 121 and a weight 122. The tray 121 may be provided in the shape of a shelf or a box on which the weight 122 can be placed, and various types of weights, for example, 1 kg to 10 kg, may be used as the weight 122.

[0059] The node pressurizing unit 110 and the weight loading unit 120 are connected by at least one connecting rod 130, and can maintain a certain distance in the vertical direction. The connecting rod 130 is a rod-shaped rod having a predetermined length and can be vertically disposed between the flange block 113 and the tray 121. In order to minimize friction with the shaft connection frame 430 when the connecting rod 130 moves up and down, a bearing structure can be applied to an area where the connecting rod 130 passes through the shaft connection frame 430. In addition, it is preferable that a total of four connecting rods 130 are provided, one at each of the four corners of the flange block 113, so that the tray 121 is stably positioned on the upper part of the flange block 113 and the load of the weight 122 can be applied to the flange block 113 without being biased to either side.

[0060] The third driving part 500 is configured to support the pressurizing unit 100 as described above and to move it up and down.

[0061] Referring again to Figures 1, 4 and 5, the third driving unit 500 includes a piston rod 510 extending in the vertical direction, a lever member 520 having one end connected to the weight loading unit 120 and the other end connected to the piston rod 510 and configured to perform a seesaw motion by the movement of the piston rod 510, and a third driving motor 530 that moves the piston rod 510 in the vertical direction.

[0062] The lever member 520 has one end connected to the tray 121 and the other end connected to the piston rod 510, and is provided to perform a seesaw motion based on a central fixed axis. When the piston rod 510 is lowered by the operation of the third driving motor 530, and the other end of the lever member 520 is lowered, the one end of the lever member 520 rises, and the tray 121 of the weight loading unit 120 also rises in the +Z direction. At this time, the node pressurizing unit 110 connected to the weight loading unit 120 by the connecting rod 130 as described above also rises in the +Z direction.

[0063] Conversely, when the piston rod 510 rises and the other end of the lever member 520 is pulled in the +Z direction, one end of the lever member 520 descends, and accordingly, the weight loading portion 120 and the node pressure applying portion 110 also descend together in the -Z direction.

[0064] In this manner, the pressurizing unit 100 can be moved in the ±Z directions by the third driving section 500 .

[0065] Meanwhile, when applying a load to each sensing node 21, the pressurizing block 111 is moved to a position close to the sensing node 21, and the operations of the first to third driving motors 350, 450, 530 are all stopped. Then, the sensing node 21 may be pressurized by the weight of the pressurizing unit 100 itself. For example, when the load of the pressurizing unit 100 without weights 122 is 5 kgf, by adding weights 122 of 5 kg one by one to the upper part of the tray 121, the load of the pressurizing unit 100 may be increased to 10 kgf, 15 kgf, and 20 kgf.

[0066] When the sensing node 21 is pressurized while increasing the load as described above, the resistance value of the sensing node 21 can be output as a digital value each time. Although not shown, a (flat flexible) cable can be connected to the connector unit 22 of the pressure pad sensor 20 in FIG. 1, and the digital value obtained by pressing each sensing node 21 can be transmitted to a system unit (not shown) via the cable. Here, the system unit can refer to a device including a memory for recording the digital value, a microprocessor for performing a calculation according to a method for calibrating the output value of the pressure pad sensor 20, which will be described later, based on the digital value, and the like. In addition, the digital value can be displayed on a display device 900 as an output value in the range of 1 to 255, for example.

[0067] According to the pressure pad sensor pressure device 10 of one embodiment of the present invention described above, it is possible to apply a constant pressure uniformly to each sensing node 21 of the pressure pad sensor 20, and it is also possible to grasp how the output value of each sensing node 21 changes when the applied pressure is changed.

[0068] A method for calibrating the output value of each sensing node 21 obtained by using the pressure pad sensor pressure device 10 to standard pressure data will now be described.

[0069] The method for calibrating the output value of the pressure pad sensor 20 according to the present invention includes a step of measuring the sensor output value and a step of estimating standard pressure data.

[0070] The sensor output value measurement step is a step of preparing a pressure pad sensor 20, pressurizing each sensing node 21 of the pressure pad sensor 20 individually from 1 time to n times (n is a natural number greater than or equal to 2) while changing the pressure each time, and storing the output values ​​of each sensing node 21 from the 1st to nth times.

[0071] The sensor output value measuring step may be performed using the pressure pad sensor pressing device 10 according to the present invention. By using the pressure pad sensor pressing device 10, pressure can be applied uniformly to each sensing node 21, and an output value of each sensing node 21 for a specific pressure can be accurately obtained. Therefore, it is most preferable to perform the sensor output value measuring step using the pressure pad sensor pressing device 10. However, the scope of the rights of the output value calibrating method of the pressure pad sensor 20 according to the present invention is not limited by whether or not the pressing device according to the present invention is used. That is, the sensor output value measuring step may be performed by an alternative means other than the pressing device of the present invention.

[0072] In this embodiment, each sensing node 21 was pressurized while changing the pressure to P1, P2, P3, and P4 from 1st to 4th times (meaning P1=5kgf, P2=10kgf, P3=15kgf, and P4=20kgf in this embodiment), and the results are shown in Figures 7a to 7d.

[0073] 7a to 7d, it can be seen that the output values ​​are not the same even when the same pressure is applied to each sensing node 21. For example, the output value of the first sensing node (C0, R0) and the output value of the 120th sensing node (C23, R4) in response to pressure P2 are 89 and 80, respectively, which are not the same.

[0074] That is, the pressure pad sensor 20 having multiple sensing nodes may not obtain the same output value at each sensing node 21 even if the same force is applied as described above. Therefore, if the output value for each region of the pressure pad sensor 20 is used as is during swelling of the battery cell, a large pressure measurement error may occur. Therefore, it is necessary to calibrate the output value for each sensing node 21.

[0075] Said calibration may be performed as follows through a standard pressure data estimation step according to the present invention.

[0076] The standard pressure data estimation step is a step of estimating standard pressure data based on the output value for each of the sensing nodes 21 using two or more different pressures applied to each of the sensing nodes 21 and two or more output values ​​resulting therefrom, and an interpolation method.

[0077] Specifically, the standard pressure data estimation step according to this embodiment includes:

[0078] The method includes a step of deriving a linear equation for estimating standard pressure data corresponding to an interval between the output values ​​of each of the sensing nodes 21 for the first to nth times using a linear interpolation method.

[0079] The linear equation can be expressed as follows:

number

[0080] For example, in the standard pressure data estimation step, a linear equation for each section is derived using a predetermined pressure value and an output value of the sensing node (Cx, Ry) obtained by pressurizing the sensing node (Cx, Ry) that is the predetermined pressure value.

[0081] If the linear equation is derived as described above, when an unknown arbitrary pressure value is applied to the certain sensing node (Cx, Ry), the specific output value represented by the certain sensing node (Cx, Ry) can be substituted for the X value of the linear equation to obtain standard pressure data. The standard pressure data thus obtained can be used as a measure of the strength of the arbitrary pressure value.

[0082] FIG. 8 is a graph showing an example in which linear interpolation is applied using output values ​​due to pressure changes of one sensing node (C0, R0) shown in FIGS. 7a to 7d.

[0083] More specifically, in FIG. 8, if the linear equation for the interval between (K1, P1) and (K2, P2) is F1(X), the linear equation for the interval between (K2, P2) and (K3, P3) is F2(X), and the linear equation for the interval between (K3, P3) and (K4, P4) is F3(X), the linear equation for each interval can be derived as follows. F1(X)=X / 6-29 / 6 F2(X)=5X / 16-285 / 16 F3(X)=5X / 12-345 / 12

[0084] When an arbitrary pressure is applied to the sensing node (C0, R0) and the output value at that time is 79, 50 / 6 kgf [F1(79)] can be obtained as the standard pressure data value by substituting 79 for X. Therefore, the intensity of the arbitrary pressure can be displayed as a pressure of 50 / 6 kgf, rather than the output value of 79 of the sensing node (C0, R0).

[0085] For example, assuming there is a pressure pad sensor 20 having six sensing nodes 21, according to the present invention, the six sensing nodes 21 can be displayed in a graph showing the relationship between output values ​​and the resulting standard pressure data as shown in FIG.

[0086] Referring to FIG. 9, when a certain pressure is uniformly applied to the six sensing nodes 21, the output values ​​of the six sensing nodes may be different, but the standard pressure data values ​​corresponding to the different output values ​​are the same.

[0087] As in the case of the six sensing nodes, the relationship between the output value of each sensing node (21) from the first sensing node (C0, R0) to the 120th sensing node (C23, R3) and the resulting standard pressure data can be displayed in a graph for the 120 sensing nodes in Fig. 6. When an arbitrary pressure is applied to the first to 120th sensing nodes, the standard pressure data is the same as Px even if the output values ​​of the first to 120th sensing nodes are different.

[0088] Therefore, by converting the output value of each sensing node 21 into standard pressure data and using it according to the output value calibration method of the pressure pad sensor 20 of the present invention, the problem of the pressure pad sensor 20 (the problem that the output values ​​of the sensing nodes differ even at the same pressure due to manufacturing tolerances, etc.) can be solved.

[0089] FIG. 10 is a diagram showing a pressure pad sensor 20 disposed between battery cells 30 and stacked together with the battery cells in accordance with a method for measuring a surface pressure of a battery cell according to an embodiment of the present invention.

[0090] Next, a method for measuring a surface pressure of a battery cell according to an embodiment of the present invention will be described.

[0091] The method for measuring the surface pressure of the battery cell is a method for measuring the surface pressure of each region when the battery cell 30 swells, and includes a step of disposing a pressure pad sensor 20 having a plurality of sensing nodes 21 arranged in horizontal and vertical directions and an area corresponding to one surface of the battery cell between the battery cells and stacking the pressure pad sensor together with the battery cells as shown in FIG. 10.

[0092] In this embodiment, the battery cell 30 is a pouch-type battery cell, but instead of the pouch-type battery cell, for example, a rectangular parallelepiped prismatic battery cell can be used. Also, the pressure pad sensor 20 is a pressure pad sensor having a plurality of sensing nodes 21 as shown in FIG. 6, and may be a plurality of sensing nodes.

[0093] In addition, the method for measuring a surface pressure of a battery cell according to an embodiment of the present invention further includes a step of measuring a surface pressure in each region during swelling of the battery cell 30 based on the above-described method for calibrating the output value of the pressure pad sensor 20 according to the present invention.

[0094] According to this method for measuring surface pressure of a battery cell, the pressure distribution during swelling can be grasped through the sensing nodes 21 distributed over the entire surface of the battery cell 30. In addition, by displaying standard pressure data obtained by calibrating the output values ​​of the sensing nodes 21, rather than the output values ​​of the individual sensing nodes 21, as values ​​indicating the strength of pressure, the pressure distribution for each region of the battery cell can be accurately grasped.

[0095] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical concept of the present invention and the scope of the claims.

[0096] Meanwhile, although directional terms such as up, down, left, right, front, and back can be used in this specification, it will be obvious to those skilled in the art of the present invention that these terms are used merely for convenience of explanation and may vary depending on the position of the object in question or the position of the observer, etc.

Claims

1. 1. A pressure pad sensor pressure applying device for applying pressure to each sensing node individually in a pressure pad sensor having a plurality of sensing nodes, comprising: a pressure unit including a node pressure unit that is provided so as to be capable of descending from a predetermined height to come into contact with one of the sensing nodes, and a weight loading unit that is provided above the node pressure unit so that the load of a weight is transmitted to the node pressure unit; A support frame that supports the pressurizing unit at a predetermined height; A first drive unit that moves the pressurizing unit in a horizontal first direction or an opposite direction; A second drive unit that moves the pressurizing unit in a horizontal second direction perpendicular to the first direction or in the opposite direction; a third drive unit that raises and lowers the pressure unit relative to the pressure pad sensor; A pressure pad sensor pressure device comprising: the support frame includes a pair of leg plates spaced apart and parallel to each other in the second direction, and a support board extending in the second direction and connected to upper ends of the pair of leg plates, the support board includes a slot in which the node pressurizing portion extends downward from above the support board and is configured to be movable in the second direction; The second driving unit moves the pressure unit along the long hole in the second direction, and the first driving unit moves the pressure unit together with the support frame in the first direction or the reverse direction.

2. The pressure pad sensor pressing device according to claim 1 , wherein the node pressing portion has a lower end surface corresponding to one of the sensing nodes.

3. The node pressurizing unit is 2. The pressure pad sensor pressure device of claim 1, comprising: a pressure block extending through the slot to the bottom of the support board; and a flange block connected to the pressure block, having a width greater than the slot, and disposed on the top of the support board.

4. 4. The pressure pad sensor pressing device according to claim 3, wherein the weight carrying portion is connected to the flange block at a predetermined distance by at least one connecting rod extending vertically upward from the flange block.

5. The weight loading unit is 5. The pressure pad sensor pressing device according to claim 4, further comprising: a tray coupled to an upper end of the connecting rod; and one or more weights mounted on the tray.

6. The first driving unit is A first guide rail extending along the first direction; a first slide block coupled to a lower portion of each of the leg plates and slidably connected on the first guide rail; a shaft connecting block coupled to one side of the leg plate; a first drive shaft that passes through the shaft connection block and extends in the first direction, and is connected to the shaft connection block such that the shaft connection block moves in the first direction or the reverse direction when the first drive shaft rotates in a forward or reverse direction; 2. The pressure pad sensor compression apparatus of claim 1, further comprising: a first drive motor for rotating said first drive shaft in forward and reverse directions.

7. The second drive unit is a second guide rail extending along a second direction on the support board; a second slide block slidably connected on the second guide rail; a shaft connecting frame surrounding the connecting rod and coupled onto the second slide block; a second drive shaft that passes through the shaft connection frame and extends in the second direction, and is connected to the shaft connection frame such that, when the second drive shaft rotates in a forward or reverse direction, the shaft connection frame moves in the second direction or the reverse direction; 5. The pressure pad sensor compression apparatus of claim 4, further comprising: a second drive motor for rotating said second drive shaft in forward and reverse directions.

8. The third drive unit is A piston rod extending in the vertical direction; a lever member having one end connected to the weight support portion and the other end connected to the piston rod, the lever member being configured to raise and lower the weight support portion by a seesaw motion caused by the movement of the piston rod; 5. The pressure pad sensor pressing device of claim 4, further comprising: a third drive motor for moving the piston rod in an up and down direction.

9. 2. The pressure pad sensor pressure device of claim 1, further comprising: a system unit that records output values ​​of the sensing nodes obtained by individually pressurizing the plurality of sensing nodes by changing weights; and a display device that can display the output values.

10. A method for calibrating the output value of a pressure pad sensor in which the output values ​​of each sensing node are different even with the same pressure, a sensor output value measurement step of preparing a pressure pad sensor, pressurizing each sensing node of the pressure pad sensor individually from 1 to n times (n is a natural number of 2 or more) while changing the pressure each time, and storing the output values ​​of each sensing node from the 1st to nth times; estimating standard pressure data according to output values ​​for each of the sensing nodes using two or more different pressures applied to each of the sensing nodes and two or more output values ​​corresponding thereto and an interpolation method; Including, 2. A method for calibrating an output value of a pressure pad sensor, wherein the sensor output value measuring step is performed using a pressure pad sensor pressing device according to claim 1.

11. 11. The method of claim 10, further comprising the step of displaying the standard pressure data derived by the step of estimating the standard pressure data.

12. The step of estimating standard pressure data comprises:

11. The method for calibrating the output value of a pressure pad sensor as described in claim 10, further comprising a step of deriving a linear equation for estimating standard pressure data corresponding to an interval between the output values ​​of each of the sensing nodes for the first to nth times using a linear interpolation method.

13. 13. The method for calibrating an output value of a pressure pad sensor according to claim 12, wherein the linear equation is expressed by the following formula: [0010] (In the formula, the first applied pressure is P １ The second applied pressure is P ２ . . ., the m-1th applied pressure is P ｍ－１ The m-th applied pressure is P ｍ and m=n≧2. P １ The output value of the sensing node for K １ Let P ２ The output value of the sensing node for K ２ , . . ., then P ｍ－１ The output value of the sensing node for ｍ－１ And P ｍ The output value of the sensing node for ｍ It is. F ｍ－１ (X) is the standard pressure data value, and X is the output value of the sensing node.

14. A method for measuring a surface pressure of a battery cell when the battery cell is swelling, comprising: A pressure pad sensor having a plurality of sensing nodes arranged in a horizontal and vertical direction and an area corresponding to one surface of the battery cell is disposed between the battery cells and stacked together with the battery cells; Measuring a surface pressure in each area during swelling of the battery cell based on the output value calibration method of the pressure pad sensor according to any one of claims 10 to 13; A method for measuring surface pressure of a battery cell, comprising:

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