3D Scanning And Appearance Inspection Apparatus For Cylindrical Secondary Battery

Abstract

The present disclosure relates to a 3D scanning and appearance inspection apparatus for a cylindrical secondary battery capable of extracting points for three-dimensional model creation and acquiring a surface image for appearance inspection when rotating the cylindrical secondary battery. According to the present disclosure, a structure for 3D scanning and appearance inspection of a cylindrical secondary battery can be simplified, accurate 3D data can be acquired, and accurate appearance inspection can be performed.

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional (3D) scanning and appearance inspection device for a cylindrical secondary battery, and more particularly, to a device capable of generating 3D data by using two-dimensional (2D) images and performing appearance inspection. Background Art

[0002] Techniques for scanning 3D data of an object are applied to various industrial applications. In some cases, a secondary battery may require 3D scan data to detect physical deformations occurring in the manufacturing process.

[0003] For conventional 3D scan data, techniques such as time-of-flight cameras, stereo vision, laser scanning, and photogrammetry have been used. The problems with these techniques are that it takes a long time to perform 3D scanning on a curved surface and the accuracy is low. Summary of the Invention

[0004] One aspect of the present disclosure provides a device capable of performing fast and accurate 3D scanning on a cylindrical secondary battery and performing appearance inspection simultaneously.

[0005] Exemplary embodiments of the present disclosure provide a 3D scanning device for a cylindrical secondary battery, the 3D scanning device including: a placement unit configured to rotate a secondary battery placed thereon about a longitudinal axis; a backlighting unit configured to emit light toward a side portion of the secondary battery; a camera disposed opposite to the backlighting unit with the secondary battery therebetween; a controller configured to control the placement unit and the camera to acquire an image of the secondary battery each time the secondary battery rotates a predetermined angle; and a calculation unit configured to extract points on the contour of the secondary battery from the image of the secondary battery and reconstruct a three-dimensional model.

[0006] The backlighting unit may be a backlight source of the secondary battery, and the camera may be configured to acquire a projection image of the secondary battery.

[0007] The calculation unit may receive information on a predetermined angle of rotation of the secondary battery and may reconstruct the three-dimensional model based on the diameter of the secondary battery and points on the contour at each angle of the secondary battery.

[0008] The 3D scanning device may further include a driving unit configured to rotate the secondary battery placed thereon in the longitudinal axis direction, wherein the controller controls the driving unit to repeatedly adjust the angle of the secondary battery by a predetermined angle increment until a target angle less than 360 degrees is reached.

[0009] The calculation unit may be configured to extract boundary information of the contour of opposite sides of the secondary battery from the image.

[0010] The rear illumination unit may be configured to be surface-emitting.

[0011] The predetermined angle may be 3 degrees or less.

[0012] The 3D scanning device may further include a coaxial illumination unit configured to emit light coaxially with the camera.

[0013] The calculation unit may generate the length information of the secondary battery by extracting the first edge information closest to the camera and the second edge information farthest from the camera from the image.

[0014] The calculation unit may extract the distance information between the first edge information and the second edge information based on the length information of the secondary battery, and may correct (calibrate) the 3D model of the secondary battery based on the distance information.

[0015] Another exemplary embodiment of the present disclosure provides a 3D scanning method for a cylindrical secondary battery, the 3D scanning method including: obtaining a projection image when emitting light from behind the cylindrical secondary battery; extracting, by a calculation unit, length information, outer diameter information, and side boundary information from the projection image; and creating, by the calculation unit, a three-dimensional model of the secondary battery based on the extracted length information, outer diameter information, and boundary information.

[0016] When obtaining the projection image, the projection image may be obtained by photographing the secondary battery while adjusting the secondary battery at a predetermined angle each time.

[0017] When obtaining the projection image, the projection image may be obtained by rotating the cylindrical secondary battery around the longitudinal axis until a target angle less than 360 degrees is reached.

[0018] When extracting the information, the information of two boundaries of the side portion of the secondary battery may be extracted from the projection image.

[0019] When creating the three-dimensional model, 3D modeling may be performed on a part of the cylindrical secondary battery based on the boundary information extracted at each predetermined angle.

[0020] The obtaining of the projection image may be performed by surface emission together with the emission of light from behind the secondary battery.

[0021] The predetermined angle may be 3 degrees or less.

[0022] The obtaining of the projection image may be performed when additionally emitting light coaxially with the camera.

[0023] The extraction of the information may further include extracting the distance information between the first edge identified by the coaxial light and the second edge identified by the light from the back surface on the upper surface and the lower surface of the secondary battery from the projection image.

[0024] The creation of the three-dimensional model may also include calculating the angle of displacement of the secondary battery based on the length information and the distance information.

[0025] Another exemplary embodiment of the present disclosure provides a 3D scanning device for a cylindrical secondary battery. The 3D scanning device includes: a placement unit configured to rotate the secondary battery placed thereon about the longitudinal axis; a rear illumination unit configured to emit light toward the side of the secondary battery; a camera disposed opposite to the rear illumination unit with the secondary battery interposed therebetween; a front illumination unit configured to emit light toward the side of the secondary battery; a controller configured to control the placement unit and the camera to acquire an image of the secondary battery every time the secondary battery rotates a predetermined angle; and a calculation unit configured to process the image acquired from the camera. The calculation unit is configured to extract points on the contour of the secondary battery from the images at various angles of the secondary battery and reconstruct a three-dimensional model, and is configured to generate an inspection image by extracting the surface portion of the secondary battery from the images at various angles of the secondary battery.

[0026] The front illumination unit may be configured to emit light from at least one different position along the length direction of the secondary battery.

[0027] The controller may be configured to control the placement unit and the camera to acquire a projection image every time the secondary battery rotates a first angle, and may be configured to control the front illumination unit and the camera to acquire a side image every time the secondary battery rotates a second angle.

[0028] The first angle may be less than the second angle.

[0029] The calculation unit may be configured to generate a local inspection image by cropping a part of the side of the secondary battery from the multiple images acquired every time the secondary battery rotates the second angle and combining the cropped parts.

[0030] The calculation unit may be configured to generate a full-side inspection image by combining the local inspection images at each second angle.

[0031] The 3D scanning device may further include a defect detection unit configured to detect appearance defects by analyzing the inspection image of the side of the secondary battery.

[0032] The calculation unit may be configured to extract boundary points of the side from the image and create a three-dimensional model based on the angle and boundary points of the secondary battery.

[0033] The calculation unit may be configured to extract the coordinates of the pixels defining the boundary to extract the boundary points of the side of the secondary battery.

[0034] The controller may set the first angle to be less than the second angle.

[0035] The 3D scanning and appearance inspection device for cylindrical secondary batteries according to the present disclosure has the effect of maximizing inspection efficiency by performing 3D scanning and appearance inspection while rotating the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a perspective view of a 3D scanning device for cylindrical secondary batteries according to a first embodiment of the present disclosure.

[0037] Figure 2A and Figure 2B is a view showing an operating state according to the first embodiment.

[0038] Figure 3 is a view showing an example of an image obtained according to the first embodiment.

[0039] Figure 4 is Figure 3 an enlarged view of region I in

[0040] Figure 5A 、 Figure 5B 、 Figure 5C and Figure 5D are views showing the concept of three-dimensional point modeling.

[0041] Figure 6 is a perspective view of a 3D scanning device for cylindrical secondary batteries according to a second embodiment of the present disclosure.

[0042] Figure 7 is a view showing an example of an image obtained according to the second embodiment of the present disclosure.

[0043] Figure 8 is a view showing the concept of extracting points in region I' in Figure 7 according to the second embodiment to compensate for displacement.

[0044] Figure 9 is a flowchart of a 3D scanning method for cylindrical secondary batteries according to a third embodiment of the present disclosure.

[0045] Figure 10 is a flowchart of a 3D scanning method for cylindrical secondary batteries according to a fourth embodiment of the present disclosure.

[0046] Figure 11 is a perspective view of a 3D scanning and appearance inspection device for cylindrical secondary batteries according to a fifth embodiment of the present disclosure.

[0047] Figure 12 is a view showing a front lighting unit according to the fifth embodiment of the present disclosure.

[0048] Figure 13A , Figure 13B and Figure 13C are views showing the operating state of the front lighting unit according to the fifth embodiment of the present disclosure.

[0049] Figure 14A , Figure 14B and Figure 14C are views showing another operating state of the front lighting unit according to the fifth embodiment of the present disclosure.

[0050] Figure 15 is a conceptual diagram showing the concept of creating a partial inspection image according to the fifth embodiment of the present disclosure.

[0051] Figure 16 is a conceptual diagram showing the concept of generating an inspection image according to the fifth embodiment of the present disclosure. Detailed Description of the Invention

[0052] Hereinafter, a 3D scanning and appearance inspection device for a cylindrical secondary battery according to the present disclosure will be described in detail with reference to the accompanying drawings. In addition, in the following description of the embodiments, the names of the components in the technical field to which the present invention pertains may be different. However, if these components have similarity and identity in function, they may be regarded as equivalent components, although they adopt modified embodiments. In addition, for ease of description, reference numerals assigned to each component are indicated. However, the content of the reference numerals indicated in the drawings does not limit each component to the scope in the drawings. Similarly, although the components in the drawings adopt partially modified embodiments, if these components have similarity and identity in function, they may be regarded as equivalent components. In addition, from the perspective of those of ordinary skill in the art, if an element is considered to be an element that must be naturally included, the description of that element is omitted.

[0053] Figure 1 is a perspective view of a 3D scanning device 1 for a cylindrical secondary battery 1000 according to the first embodiment of the present disclosure.

[0054] Referring to Figure 1 , the 3D scanning device 1 for a cylindrical secondary battery 1000 according to the first embodiment of the present disclosure may include a placement unit 100, a driving unit (not shown), a rear lighting unit 200, a camera 300, a controller (not shown), and a calculation unit (not shown).

[0055] The 3D scanning device 1 for a cylindrical secondary battery 1000 according to the first embodiment of the present disclosure may be configured to: when irradiating the secondary battery 1000 from the back, acquire a contour image of the projected secondary battery 1000.

[0056] The placement unit 100 is configured such that the cylindrical secondary battery 1000 placed thereon is in a lying position. The placement unit 100 can be configured in such a way that when the camera 300 captures an image, the placement unit 100 is set within the area where the secondary battery 1000 is projected. That is to say, the placement unit 100 can be configured such that when the camera 300 captures an image, the placement unit 100 does not appear in the image.

[0057] The driving unit can be configured to rotate the cylindrical secondary battery 1000 placed on the placement unit 100 about the longitudinal axis. Here, the driving unit is configured to repeatedly adjust the angle of the secondary battery 1000 by a predetermined angle. The driving unit can be configured to rotate the secondary battery 1000 by 0.1 degree to 3 degrees for each operation.

[0058] The rear illumination unit 200 and the camera 300 can be arranged on opposite sides with respect to the placement unit 100. The rear illumination unit 200 is configured to emit light toward the secondary battery 1000 placed on the placement unit 100. The rear illumination unit 200 is configured to be surface-emitting. That is to say, the rear illumination unit 200 can be used as a backlight for the secondary battery 1000.

[0059] The camera 300 is configured to obtain a projected image when the light emitted by the rear illumination unit 200 is blocked by the secondary battery 1000. The camera 300 can be configured as an area camera 300 to obtain a planar image.

[0060] Although not shown, the 3D scanning device 1 for the cylindrical secondary battery 1000 according to the first embodiment of the present disclosure may further include a controller and a calculation unit.

[0061] The controller is configured to control the overall operation of the device. Specifically, the controller is configured to make the rear illumination unit 200 and the camera 300 operate synchronously with each other. In addition, the controller is configured to control the driving unit to adjust the angle of the secondary battery 1000. Therefore, the camera 300 is configured to capture an image each time the angle of the secondary battery 1000 changes when the backlight is turned on.

[0062] The calculation unit is configured to extract boundary points from the multiple images obtained by the camera 300 and perform 3D modeling. The dimensions of the secondary battery 1000 to be 3D scanned can be input into the calculation unit in advance. That is to say, the dimension information (such as the outer diameter and length) of the secondary battery 1000 can be determined in advance during the manufacturing stage and input into the 3D scanning device 1 according to the embodiment of the present disclosure.

[0063] The calculation unit can change the scale of the points displayed on the image and perform modeling based on the information of the secondary battery 1000 input in advance.

[0064] Figure 2A and Figure 2B is a view showing the operating state according to the first embodiment. For ease of explanation, these figures only depict the postures of the secondary battery 1000 and the rear lighting unit 200.

[0065] Referring to Figure 2A , in the first embodiment of the present disclosure, when the second battery 1000 is turned off, the rear lighting unit 200 is turned on to obtain an image. At this time, a projection image of the secondary battery 1000 is obtained. The coordinates of the farthest points P1 and P2 on the curve in the cross-section can be found from the projection image. In addition, the boundary coordinates of the top surface and the bottom surface can also be confirmed.

[0066] Referring to Figure 2B , the controller rotates the secondary battery 1000 by a predetermined angle and then turns on the rear lighting unit 200 to obtain an image. In this case, when the secondary battery 1000 is projected, the points P3 and P4 obtained from the side peripheral boundary are 180 degrees apart. The scanning device 1 according to the present disclosure rotates the secondary battery 1000 by 180 degrees while repeating the processes shown in Figure 2A and Figure 2B several times to hundreds of times. Since points are extracted from the opposite boundaries parallel to each other as the secondary battery 1000 rotates 180 degrees, points can be extracted from the entire boundary around the side, covering the entire 360-degree angle.

[0067] Figure 3 is a view showing an example of the image obtained according to the first embodiment.

[0068] Referring to Figure 3 , in the first embodiment, a simple projection image of the secondary battery 1000 can be obtained when the backlight is turned on. In this case, points P Figure 3 can be extracted from the right boundary according to the rotation angle θ extracted from the side boundary shown in the upper part of θR . In addition, points P θL can be extracted from the left boundary.

[0069] Figure 4 is Figure 3 an enlarged view of region I in

[0070] Referring to Figure 4 , the calculation unit identifies the boundary points pixel by pixel from the image obtained at the first angle θ1. When checking the enlarged region I at the first angle, the right boundary can be identified pixel by pixel. The x coordinate and y coordinate of each pixel can be found. The calculation unit extracts the boundary points on the left and right boundaries pixel by pixel in each obtained image. The process of the calculation unit extracting the boundary points can be performed in each of the multiple images.

[0071] For example, if the controller rotates the secondary battery 1000 in 1-degree increments, 180 images can be acquired by the camera 300. The calculation unit extracts the points on the left and right boundaries of each of the 180 images.

[0072] Figure 5A 、 Figure 5B 、 Figure 5C and Figure 5D are views showing the concept of three-dimensional point modeling.

[0073] Referring to Figure 5A , the calculation unit extracts the boundary points for the first angle. The extracted points can be three-dimensionally represented as shown in Figure 5A . The point P 1R (x, y) extracted from the right boundary for the first angle can be represented. In addition, the point extracted from the left boundary can be represented in the three-dimensional space. At this time, the scale of the three-dimensional space can be adjusted according to the diameter of the secondary battery 1000 input in advance. The scale adjustment can be performed by matching the radius D / 2 starting from the rotation center of the secondary battery 1000, the rotation coordinate system for each rotation angle, and the extracted points.

[0074] Referring to Figure 5B , when the secondary battery 1000 is placed at the second angle, the points P 1R (x, y) and P 2R (x, y) can be extracted from the right boundary and represented in the three-dimensional space. Similarly, the points extracted from the left boundary that are 180 degrees apart from the points on the right boundary can also be represented in the three-dimensional space.

[0075] Referring again to Figure 5A and Figure 5B 's description and referring to Figure 5C , three-dimensional points are generated along the rotation angle. The points P 1R (x, y), P 2R (x, y), P 3R (x, y) and P 4R (x, y) extracted from the right boundary can be represented at positions spaced apart from the central axis by a predetermined angular interval (the rotation angle of the secondary battery 1000).

[0076] Referring to Figure 5D , since the point extraction process is completed by rotating the secondary battery 1000 by only 180 degrees, the calculation unit can generate three-dimensional data for the entire 360-degree angle.

[0077] As described above, in the present disclosure, three-dimensional scanning of the secondary battery 1000 can be performed by creating a three-dimensional model using the points extracted from the projection image. In this case, the points extracted using a single camera 300 can be combined into 3D data, thereby simplifying the device.

[0078] Although this embodiment has been described by way of an example of creating three-dimensional data by rotating the secondary battery 1000 by 180 degrees, this embodiment can be modified and implemented in such a way as to create three-dimensional data by rotating the secondary battery 1000 by more than 360 degrees.

[0079] In addition, although this embodiment has been described by way of an example of obtaining a single cylindrical battery, this is merely an example, and according to the scanning device 1 of the present disclosure, it can be modified and implemented in such a way that different numbers of secondary batteries 1000 are rotated simultaneously and obtained simultaneously.

[0080] The calculation unit can perform appearance defect detection by using the three-dimensional information of the generated secondary battery 1000.

[0081] Hereinafter, with reference to Figures 6 to 8 the 3D scanning device 1 for the cylindrical secondary battery 1000 according to the second embodiment of the present disclosure will be described. The 3D scanning device 1 according to this embodiment may include the same components as those in the foregoing first embodiment. It should be noted that, in order to avoid redundant description, the description of the same components will be omitted, and only the differences will be described in detail.

[0082] If there is no coaxial illumination (which depends on the cylindrical geometry), the image may be acquired symmetrically, which makes it impossible to determine which direction the secondary battery 1000 is turning. In addition, even if the secondary battery 1000 is misaligned (for example, deflected), on the projected image, the points along the side surface boundary may not seem to be different. Therefore, the second embodiment is implemented in such a way as to detect the misalignment of the secondary battery 1000 and create and correct (calibrate) the 3D model based on the detected rotation.

[0083] Figure 6 is a perspective view of the 3D scanning device 1 for the cylindrical secondary battery 1000 according to the second embodiment of the present disclosure.

[0084] With reference to Figure 6 , the 3D scanning device 1 for the cylindrical secondary battery 1000 according to the second embodiment of the present disclosure may further include a mirror unit 500 and a coaxial illumination unit 400. The coaxial illumination unit 400 may include a beam splitter and an illumination module.

[0085] The mirror unit 500 may be disposed in the shooting area of the camera 300, and the camera 300 may acquire a projected image of the secondary battery when the secondary battery 1000 is reflected by the mirror unit 500.

[0086] The coaxial illumination unit 400 is configured to emit light toward the side of the secondary battery 1000 that is shot by the camera 300.

[0087] The controller is configured to control the coaxial illumination unit 400, the rear illumination unit 200, the camera 300, and the driving unit. When the coaxial illumination unit 400 and the rear illumination unit 200 emit light toward the secondary battery 1000 simultaneously, the controller can control the camera 300 to acquire an image.

[0088] In this embodiment, the boundary information obtained when light is emitted from behind the secondary battery 1000 and the boundary information of half of the side surface of the side surface of the secondary battery 1000 facing the camera 300 can be extracted. If the boundary points on the front half surface and the boundary points on the rear half surface are different, the calculation unit can calculate the displacement information and correct the three-dimensional model information based on the calculated displacement information.

[0089] It should be noted that although this embodiment provides the mirror unit 500 as an additional component, the mirror unit can be omitted.

[0090] Figure 7 is a view showing an example of an image obtained according to the second embodiment of the present disclosure.

[0091] Refer to Figure 7 , in the second embodiment, the edge of the front half surface (the surface facing the camera 300) of the secondary battery 1000 can be detected by using coaxial illumination.

[0092] Therefore, in this embodiment, an image is obtained when light is emitted by using coaxial illumination. The calculation unit can extract the points on the edges of the upper surface and the lower surface facing the camera 300 in the obtained image.

[0093] Figure 8 is a view showing the concept of extracting points in region I' according to the second embodiment to compensate for displacement. Figure 7 in

[0094] Refer to Figure 8 , the calculation unit extracts the point Pe1 closest to the camera 300 on the first edge from among the points identified by the coaxial illumination. In addition, the calculation unit extracts the point Pe2 farthest from the camera 300 on the second edge from among the points identified by the rear illumination unit 200. In this case, the point closest to the camera 300 or the point farthest from the camera 300 can be selected as the point on the boundary intersecting the horizontal axis.

[0095] The calculation unit calculates how many degrees the secondary battery 1000 is misaligned toward the camera 300 by using the pre-input information, that is, the diameter of the upper surface or the lower surface of the secondary battery 1000 and the distance between the first edge and the second edge. Based on the misalignment angle of the secondary battery 1000, the 3D data of the secondary battery 1000 described in the first embodiment will be corrected.

[0096] Hereinafter, reference will be made toFigure 9 A 3D scanning method for a cylindrical secondary battery according to a third embodiment of the present disclosure will be described in detail.

[0097] Figure 9 is a flowchart of a 3D scanning method for a cylindrical secondary battery according to a third embodiment of the present disclosure.

[0098] Referring to Figure 9 According to a third embodiment of the present disclosure, a 3D scanning method for a cylindrical secondary battery may include: a step S110 of acquiring a projection image when light is emitted from the rear of the cylindrical secondary battery; a step S120 of extracting length information, outer diameter information, and side boundary information from the projection image; and a step S130 of creating a three-dimensional model of the secondary battery.

[0099] The step S110 of acquiring a projection image when light is emitted from the rear of the cylindrical secondary battery may be performed by emitting light from the rear of the secondary battery and acquiring an image using a camera on the other side. This step may be repeatedly performed by rotating the secondary battery at a predetermined angle. That is, through this step, dozens or hundreds of images of the secondary battery can be acquired.

[0100] The step S120 of extracting length information, outer diameter information, and side boundary information from the projection image corresponds to a step of obtaining the length information, outer diameter information, and side boundary information of the secondary battery by extracting boundary points from the projection image. These projection images may be acquired when the secondary battery is fixed at the same position. Therefore, the pixel size recognized from the image based on a pre-input reference value can match the actual size. Based on this, information on the length and outer diameter of the secondary battery can be extracted, and information on the boundaries (two lines) around the side can be extracted.

[0101] The step S130 of creating a three-dimensional model of the secondary battery corresponds to a step of performing three-dimensional modeling based on the extracted length information, outer diameter information, and side boundary information. In this step, points are extracted as the cylindrical secondary battery rotates, so the side boundary points extracted for each predetermined angle can be three-dimensionally reconstructed.

[0102] Hereinafter, a 3D scanning method for a cylindrical secondary battery according to a fourth embodiment of the present disclosure will be described in detail with reference to Figure 10 In the present embodiment, the term "projection image" may refer to an image acquired when light is emitted from the front and from the back.

[0103] Figure 10 is a flowchart of a 3D scanning method for a cylindrical secondary battery according to a fourth embodiment of the present disclosure.

[0104]

[0105] Figure 10 ​​, the 3D scanning method for a cylindrical secondary battery according to the fourth embodiment of the present disclosure may include: step S210 of obtaining a projection image when coaxial light emission is performed with the back surface of the cylindrical secondary battery and a camera; step S220 of extracting length information, outer diameter information, and side boundary information from the projection image; step S230 of calculating the angle of displacement of the secondary battery; and step S240 of creating a three-dimensional model of the secondary battery. Here, the steps of extracting information and creating the three-dimensional model may be performed by a computing unit including a processor.

[0106] Step S210 of obtaining a projection image when coaxial light emission is performed with the back surface of the cylindrical secondary battery corresponds to the step of emitting light from the front and back surfaces of the secondary battery and obtaining an image.

[0107] Step S220 of extracting length information, outer diameter information, and side boundary information corresponds to the step of extracting the coordinates of pixels on the boundary by processing the image. In this step, the edge of the upper surface or the lower surface irradiated by the light from the front surface of the secondary battery can be identified.

[0108] In particular, if the secondary battery rotates toward the camera, the points on the edge of the upper surface or the lower surface irradiated by the light from the front surface and the points on the edge of the upper surface or the lower surface irradiated by the light from the back surface can be simultaneously identified. In this case, the computing unit can extract the point on the edge farthest from the camera and the point on the edge closest to the camera, and obtain the information on the distance between the two points. However, unless the secondary battery is placed in the correct position without displacement, these points may not be extracted, and the distance information may be zero.

[0109] Step S230 of calculating the angle of displacement of the secondary battery is a step of calculating the amount of displacement of the secondary battery toward the camera by using the outer diameter information and the distance information of the secondary battery.

[0110] Step S240 of creating a three-dimensional model of the secondary battery corresponds to the step of correcting the three-dimensional model of the side of the secondary battery based on the angle of displacement of the secondary battery. Through this step, even if the secondary battery is not placed in the correct position toward the camera, the angle of displacement can be easily obtained. In addition, an accurate three-dimensional model can be created based on the angle of displacement of the secondary battery.

[0111] As described above, the 3D scanning device and the 3D scanning method for a cylindrical secondary battery according to the present disclosure enable an accurate three-dimensional model of the cylindrical secondary battery to be reconstructed by a simple structure using a single camera.

[0112] Hereinafter, reference will be made to Figures 11 to 16A 3D scanning and appearance inspection device for a secondary battery according to a fifth embodiment of the present disclosure will be described in detail. The 3D scanning and appearance inspection device according to this embodiment may include the same components as the foregoing embodiments. It should be noted that, in order to avoid redundant descriptions, the descriptions of the same components will be omitted, and only the differences will be described in detail.

[0113] Figure 11 is a perspective view of a 3D scanning and appearance inspection device for a cylindrical secondary battery according to a fifth embodiment of the present disclosure. Figure 12 is a view showing a front illumination unit according to a fifth embodiment of the present disclosure.

[0114] Referring to Figure 11 and Figure 12 , a 3D scanning and appearance inspection device for a secondary battery according to a fifth embodiment of the present disclosure may include a front illumination unit 600. The front illumination unit 600 may be configured to emit light toward the secondary battery coaxially with the camera. The front illumination unit 600 may include a beam splitter 620 and a front illumination module 610. The beam splitter may be disposed at a position where the optical axis of the camera intersects the optical axis of the front illumination module 610.

[0115] The front illumination module 610 may include a plurality of illumination units 611, 612,..., 618. The plurality of illumination units may be sequentially disposed along the length direction of the secondary battery. Each illumination unit may be manufactured with a predetermined width. In addition, each of the illumination units 611, 612,..., 618 may be configured to be independently controlled by a controller. Although the front illumination module 610 is shown by way of example to include eight illumination units, this is merely an example, and the number of illumination units may vary.

[0116] In a fifth embodiment of the present disclosure, the controller may control the secondary battery to rotate in increments of a predetermined angle. The controller may control the camera to acquire a projection image each time the secondary battery rotates by a first angle for 3D scanning. In addition, the controller may control the camera to acquire a surface image each time the secondary battery 1000 rotates by a second angle. The controller may set the first angle to be less than the second angle. That is, the images acquired for 3D scanning may be controlled in a manner of extracting points more frequently to create an accurate 3D model.

[0117] The calculation unit may extract boundary points of the side portion of the secondary battery from the acquired projection images and create a 3D model based on these boundary points. However, the functions or methods described in the foregoing first to fourth embodiments may be used by the calculation unit in association with the creation of the 3D model.

[0118] It should be noted that, although this embodiment provides the mirror unit 500 as an additional component, the mirror unit may be omitted.

[0119] In this embodiment, the computing unit can generate an inspection image by photographing the side of the secondary battery at various angles and combining the photographed images. In addition, the appearance inspection device can detect defects of the side of the secondary battery by analyzing the generated inspection image. Examples of defects may include scratches, dents, contamination, foreign matter, and leakage.

[0120] Figure 13A , Figure 13B and Figure 13C is a view showing an operating state of a front lighting portion according to a fifth embodiment of the present disclosure. Figure 14A , Figure 14B and Figure 14C 2 is a view showing another operating state of the front lighting portion according to the fifth embodiment of the present disclosure.

[0121] Reference Figure 13A , Figure 13B and Figure 13C , the front lighting module 610 includes a plurality of lighting units, which can be arranged continuously along the length direction of the secondary battery. In this case, the lighting units can be controlled in a manner such as turning on two adjacent lighting units in a predetermined area at the same time. Every two adjacent lighting units can be controlled in the following order: Figure 13A , Figure 13B and Figure 13C That is, the first lighting unit 611 and the second lighting unit 612 may be turned on first, and then the third lighting unit 613 and the fourth lighting unit 614 may be turned on. Thereafter, the fifth lighting unit 615 and the sixth lighting unit 616 may be turned on. The camera may acquire an image at each phase shift of the lighting on position.

[0122] Reference Figure 14A , Figure 14B and Figure 14C , the front lighting module can operate in various modes and in a phase-shifted manner. Figure 14A As shown, the first lighting unit 611 and the fifth lighting unit 615 can be turned on at the same time. Thereafter, the second lighting unit 612 and the sixth lighting unit 616 are turned on at the same time in a manner that the turned-on lighting units are phase-shifted. Thereafter, as shown Figure 14C As shown, the third lighting unit 613 and the seventh lighting unit 617 can be turned on at the same time. In this way, at each phase shift in the front lighting module, the camera can be activated to capture an image of the secondary battery.

[0123] However, referring to Figures 13A to 14CThe configuration of the front lighting module described is merely an example, and different numbers of lighting units can be configured in various patterns. That is, the lighting units can be arranged in a 1×N array or an N×M array. In addition, it should be taken into account that the operating mode of the lighting units can be modified into various modes capable of phase shift.

[0124] Figure 15 is a conceptual diagram showing the concept of creating a partial inspection image according to the fifth embodiment of the present disclosure.

[0125] Referring to Figure 15 , when the secondary battery stops operating, the above front lighting module can complete one cycle. In each cycle, the camera can acquire images by taking pictures of the secondary battery at each phase shift of the on-position of the lighting units.

[0126] Therefore, at a specific angle, as many images of the secondary battery as the number of phase shifts can be acquired. For example, as Figure 15 shown, when the secondary battery is at the first angle, the first phase image I1-1, the second phase image I1-2, and the third phase image I1-3 can be acquired.

[0127] The calculation unit can crop the flattest part from each of these three images and extract that flattest part. Here, the flattest part can correspond to a part of the center of the image.

[0128] The calculation unit can generate a partial inspection image i1 by combining the extracted partial phases. Since such a partial inspection image is generated based on the images acquired when the front lighting module undergoes phase shift, it can represent accurate information about the level of a part of the surface (able to evaluate surface irregularities, imperfections, etc.). That is, once the calculation unit generates the partial inspection image i1, an image with depth information displayed on a plane, such as a 2.5D image, can be acquired.

[0129] Meanwhile, although the above process of generating a partial inspection image is described by taking the generation of a partial inspection image based on three images acquired at three lighting phases as an example, this is only an example, and the camera can be controlled to acquire multiple images at multiple or dozens of phases.

[0130] The controller can operate the front lighting unit and the camera in this way every time the secondary battery rotates by a second angle. In addition, the calculation unit can generate a partial inspection image every time the second battery rotates by a second angle.

[0131] Figure 16 is a conceptual diagram showing the concept of generating an inspection image according to the fifth embodiment of the present disclosure.

[0132] Referring to Figure 16, in the first embodiment, the calculation unit can generate partial inspection images I1, I2, ……, In at respective second angles. This process can be continuously executed until the secondary battery completes a 360-degree rotation. The partial inspection images obtained at a certain angle can be merged side by side with the partial inspection images obtained at subsequent angles. Finally, the calculation unit can generate an inspection image Iside that completely shows the side portion of the secondary battery.

[0133] Although not shown, the defect inspection unit can detect appearance defects from the side portion of the secondary battery based on the inspection image.

[0134] In addition, in the foregoing fifth embodiment, the controller is described as extracting a contour by rotating the secondary battery, obtaining a projection image for each first angle, and obtaining a surface image for each second angle. In this case, at least one of the projection image and the surface image can be obtained according to the magnitudes of the first angle and the second angle. That is to say, in some cases, when the secondary battery is at a specific angle, only the projection image can be obtained, and at another angle, only the surface image can be obtained. In addition, in some cases, the projection image and the surface image of the secondary battery can be obtained simultaneously.

[0135] As described above, the 3D scanning and appearance inspection device for a cylindrical secondary battery according to the present disclosure has the effect of maximizing inspection efficiency by performing 3D scanning and appearance inspection while rotating the secondary battery.

Claims

1. A 3D scanning device for a cylindrical secondary battery, the 3D scanning device comprising: A placement unit configured to rotate a secondary battery placed thereon about a longitudinal axis; A rear illumination unit configured to emit light toward a side portion of the secondary battery; A camera disposed opposite to the rear illumination unit, with the secondary battery being between the camera and the rear illumination unit; A controller configured to control the placement unit and the camera to acquire an image of the secondary battery each time the secondary battery rotates by a predetermined angle; And A calculation unit configured to extract points on the contour of the secondary battery from the image of the secondary battery and reconstruct a three-dimensional model.

2. The 3D scanning device according to claim 1, wherein The rear illumination unit is a backlight of the secondary battery, and the camera is configured to acquire a projection image of the secondary battery.

3. The 3D scanning device according to claim 2, wherein, The calculation unit receives information on the predetermined angle of rotation of the secondary battery and reconstructs the three-dimensional model based on the diameter of the secondary battery and the points on the contour at each angle of the secondary battery.

4. The 3D scanning device according to claim 3, further comprising a driving unit configured to rotate the secondary battery placed thereon in the longitudinal axis direction, Among them, The controller controls the driving unit to repeatedly adjust the angle of the secondary battery according to the predetermined angle until a target angle below 360 degrees is reached.

5. The 3D scanning device according to claim 4, wherein, The calculation unit is configured to extract boundary information of the contour of the opposite sides of the secondary battery from the image.

6. The 3D scanning device according to claim 5, wherein, The rear illumination unit is configured to be surface-emitting.

7. The 3D scanning device according to claim 6, wherein, The predetermined angle is 3 degrees or less.

8. The 3D scanning device according to claim 1, further comprising a coaxial illumination unit configured to emit light coaxially with the camera.

9. The 3D scanning device according to claim 8, wherein, The calculation unit generates length information of the secondary battery by extracting first edge information closest to the camera and second edge information farthest from the camera from the image.

10. The 3D scanning device according to claim 9, wherein, The calculation unit extracts distance information between the first edge information and the second edge information based on the length information and corrects the 3D model information of the secondary battery based on the distance information.

11. A 3D scanning device for a cylindrical secondary battery, the 3D scanning device comprising: A placement unit configured to rotate a secondary battery placed thereon about a longitudinal axis; A rear illumination unit configured to emit light toward a side portion of the secondary battery; A camera disposed opposite to the rear illumination unit, with the secondary battery being between the camera and the rear illumination unit; A front illumination unit configured to emit light toward the side portion of the secondary battery; A controller configured to control the placement unit and the camera to acquire an image of the secondary battery each time the secondary battery rotates by a predetermined angle; And A calculation unit configured to process the image acquired from the camera, wherein the calculation unit is configured to extract points on the contour of the secondary battery from images at various angles of the secondary battery and reconstruct a three-dimensional model, and is configured to generate an inspection image by extracting a surface portion of the secondary battery from images at various angles of the secondary battery.

12. The 3D scanning device according to claim 11, wherein, The front illumination unit is configured to emit light from at least one different position along the longitudinal direction of the secondary battery.

13. The 3D scanning device according to claim 12, wherein, The controller is configured to control the placement unit and the camera to obtain a projection image each time the secondary battery rotates by a first angle, and is configured to control the front illumination unit and the camera to obtain a side image each time the secondary battery rotates by a second angle.

14. The 3D scanning device according to claim 13, wherein, The first angle is less than the second angle.

15. The 3D scanning device according to claim 14, wherein, The calculation unit is configured to generate a partial inspection image by cropping a part of the side of the secondary battery from a plurality of images obtained each time the secondary battery rotates by the second angle and combining the cropped parts.

16. The 3D scanning device according to claim 15, wherein, The calculation unit is configured to generate a full side inspection image by combining the partial inspection images at each second angle.

17. The 3D scanning device according to claim 16, further comprising a defect detection unit configured to detect an appearance defect by analyzing the inspection image of the side of the secondary battery.

18. The 3D scanning device according to claim 13, wherein, The calculation unit is configured to extract boundary points of the side from the image and create a three-dimensional model based on the angle of the secondary battery and the boundary points.

19. The 3D scanning device according to claim 18, wherein, The calculation unit is configured to extract coordinates of pixels defining the boundary to extract boundary points of the side of the secondary battery.

20. The 3D scanning device according to claim 13, wherein, The controller sets the first angle to be less than the second angle.

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