Camera pose calibration device and camera pose calibration method for roll surface imaging

Abstract

The application discloses a camera pose calibration device and a camera pose calibration method for roll surface imaging, and belongs to the technical field of lithium battery manufacturing. The camera pose calibration device comprises a target which is attached to a guide roller and has a target imaging line parallel to the axial direction of the guide roller; a calibration tool comprising a connecting arm, clamping arms connected to both ends of the connecting arm, and a central mark, the connecting arm having a first plane perpendicular to the symmetry plane of the calibration tool, the two clamping arms having oppositely arranged second planes, the two second planes being mirror-symmetric with respect to the symmetry plane, the distance between the two second planes gradually increasing from the direction close to the connecting arm to the direction away from the connecting arm, the symmetry plane penetrating the central mark, and the two second planes being suitable for clamping the guide roller; and an angle gauge placed on the first plane. Through the arrangement of the target, the calibration tool and the angle gauge, the problem of the lack of a reference for roll surface imaging is solved, thereby ensuring the accuracy of the defect detection of the electrode sheet.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium battery manufacturing, and particularly relates to a camera pose calibration device and a camera pose calibration method for roll surface imaging. BACKGROUND

[0002] In the manufacturing process of a lithium battery, a camera roll surface imaging is used to detect defects on a surface of a pole piece. In the related art, imaging adjustment is performed by an installation and adjustment personnel by adjusting a camera imaging angle and a light source angle until a detection point is illuminated, and the camera can clearly image the surface of the pole piece. However, the inventors have found that, first, due to the roll surface imaging, an imaging point is located on a surface of a circular guide roll, so the camera imaging angle cannot be determined by a pose angle of the camera, thereby leading to inconsistency with a theoretically designed imaging angle, and the camera imaging angle is different each time after installation and adjustment. Second, since most of the defects of the pole piece are three-dimensional defects, a pattern presented by the three-dimensional defects is different when photographed at different angles, which can lead to different shapes and gray scale changes of the same defect on different detection systems, thereby affecting the judgment of a defect type by a software algorithm. SUMMARY

[0003] The application aims to at least solve one of the technical problems in the prior art. To this end, the application provides a camera pose calibration device and a camera pose calibration method for roll surface imaging, which solve the problem that the roll surface imaging has no reference and cannot confirm whether the installation and adjustment are consistent with the design.

[0004] In a first aspect, the application provides a camera pose calibration device for roll surface imaging, comprising:

[0005] a target, the target being used to be attached to a guide roll and having a target imaging line parallel to an axial direction of the guide roll;

[0006] a calibration tool, the calibration tool comprising a connecting arm, clamping arms connected to two ends of the connecting arm, and a center mark, the connecting arm having a first plane perpendicular to a symmetry plane of the calibration tool, the two clamping arms having second planes oppositely arranged, the two second planes being mirror symmetric with respect to the symmetry plane, a distance between the two second planes gradually increasing from a direction close to the connecting arm to a direction away from the connecting arm, the symmetry plane penetrating the center mark, and the two second planes being adapted to clamp the guide roll;

[0007] an angle gauge, the angle gauge being used to be placed on the first plane.

[0008] According to the camera pose calibration device for roll surface imaging provided in the application, the position of the target imaging line on the roll surface is determined according to the target, and then the specific position of the camera imaging point on the roll surface is determined by means of the calibration tool, so that the problem that the roll surface imaging has no reference and the installation is not consistent with the design after adjustment is solved, and the accuracy of the defect detection of the polaroid is ensured.

[0009] According to an embodiment of the application, the calibration tool further comprises:

[0010] A sliding block is slidingly assembled to the connecting arm, and the centering mark is located at the bottom of the sliding block, and the sliding direction of the sliding block is parallel to the central axis of the calibration tool.

[0011] According to an embodiment of the application, the connecting arm comprises:

[0012] A first arm is connected between the two clamping arms, and the first plane is arranged on the first arm.

[0013] A second arm is connected between the two clamping arms, and the second arm is spaced apart from the first arm, and the sliding block is slidingly assembled to the second arm.

[0014] According to an embodiment of the application, the connecting arm further comprises:

[0015] A fixed plate is connected with the second arm and closes the notch.

[0016] According to an embodiment of the application, the connecting arm is provided with a detachable first connecting structure for fixing the angle gauge.

[0017] According to an embodiment of the application, the clamping arm is provided with a detachable second connecting structure for fixing the calibration tool and the guide roller.

[0018] According to an embodiment of the application, the target is rectangular, and the width of the target is equal to the circumference of the guide roller, and the target imaging line is parallel to the long side of the target.

[0019] According to an embodiment of the application, the four corners of the target are provided with alignment marks.

[0020] In a second aspect, the application provides a camera pose calibration method using any one of the above calibration devices, which comprises:

[0021] The target is attached to the guide roller, and the target imaging line of the target is parallel to the axial direction of the guide roller.

[0022] placing a calibration tool on the guide roller, and aligning a center mark of the calibration tool with the target imaging line;

[0023] mounting an angle gauge on a first plane of the calibration tool;

[0024] synchronously rotating the guide roller, the target, and the calibration tool until the measurement of the angle gauge is equal to a target value;

[0025] keeping the guide roller and the target stationary, and adjusting the pose of the camera based on the target imaging line.

[0026] According to the camera pose calibration method of the present application, through the above steps, the relevant operators can operate according to the standard calibration process steps, and the blindness of the on-site adjustment is reduced, thereby reducing the influence of human factors on the imaging quality.

[0027] According to an embodiment of the present application, the adjusting the pose of the camera based on the target imaging line comprises:

[0028] adjusting the pitch angle of the camera to a design angle;

[0029] horizontally moving the camera to at least one point on the target imaging line in the imaging display;

[0030] adjusting the horizontal angle of the camera to coincide with the target imaging line in the imaging.

[0031] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0032] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0033] Figure 1 is a schematic diagram of a camera pose calibration device for roll surface imaging provided by an embodiment of the present application;

[0034] Figure 2 is a schematic diagram of a target of a camera pose calibration device for roll surface imaging provided by an embodiment of the present application;

[0035] Figure 3 is a schematic diagram of a calibration tool of a camera pose calibration device for roll surface imaging provided by an embodiment of the present application;

[0036] Figure 4Figure 2 is a structural schematic diagram of a second calibration tool of a camera pose calibration device for roll surface imaging provided by an embodiment of the present application;

[0037] Figure 5 Figure 3 is a schematic diagram of installation of a calibration tool of a camera pose calibration device for roll surface imaging and a guide roll provided by an embodiment of the present application;

[0038] Figure 6 Figure 4 is a schematic diagram of installation of a camera pose calibration device for roll surface imaging and a guide roll provided by an embodiment of the present application;

[0039] Figure 7 Figure 5 is a flow schematic diagram of a camera pose calibration method provided by an embodiment of the present application;

[0040] Figure 8 Figure 6 is an operation schematic diagram of step 510 in the camera pose calibration method provided by an embodiment of the present application;

[0041] Figure 9 Figure 7 is an operation schematic diagram of step 520 in the camera pose calibration method provided by an embodiment of the present application;

[0042] Figure 10 Figure 8 is an operation schematic diagram of step 530 in the camera pose calibration method provided by an embodiment of the present application.

[0043] Reference signs:

[0044] Camera pose calibration device 100 for roll surface imaging, angle gauge 140;

[0045] Target 110, target imaging line 111;

[0046] Calibration tool 120, connecting arm 121, first arm 122, second arm 123, clamping arm 124, centering mark 125, symmetry plane 126, first plane 127, second plane 128, sliding block 129, first connecting structure 130, second connecting structure 131, fixed plate 132;

[0047] Guide roll 200;

[0048] Camera position A1, camera normal L1, imaging point tangent m, imaging angle a;

[0049] Camera position A2, camera normal L2, imaging point tangent n, imaging angle b. DETAILED DESCRIPTION

[0050] Embodiments of the present application are described below in the detailed description and illustrated in the accompanying drawings by which like or similar elements, symbols and / or features are referred to by like or similar characters, numbers and / or labels. The embodiments described below are examples for the present application only, and cannot be understood as a limitation of the present application.

[0051] The present application discloses a camera pose calibration device 100 for roll surface imaging.

[0052] Reference is made below to Figures 1-6 and Figures 8-10 A camera pose calibration device 100 for roll surface imaging according to embodiments of the present application is described.

[0053] In some embodiments, as shown in Figures 1-6 and Figures 8-10 The camera pose calibration device 100 for roll surface imaging comprises a target 110, a calibration tool 120 and an angle gauge 140.

[0054] The target 110 is used to be attached to a guide roll 200, and the target 110 has a target imaging line 111 which is parallel to the axial direction of the guide roll 200.

[0055] The target 110 can be used for calibration of the camera imaging line, as shown in Figure 2 In the unfolded state, the shape of the target 110 can be rectangular, the length of the target 110 is equal to the length of the guide roll 200, or the length of the target 110 is slightly smaller than the length of the guide roll 200, for example, in some embodiments, as shown in Figures 8-10 The length of the target 110 is slightly smaller than the length of the guide roll 200.

[0056] The target imaging line 111 can be provided on the target 110, and the target imaging line 111 can be provided with one or more, wherein more means two or more.

[0057] In actual implementation, the above-mentioned target 110 is wrapped on the surface of the guide roll 200. At this time, the target 110 is wound into a cylinder, and the target 110 is tightly attached to the roll surface of the guide roll 200, and the target imaging line 111 on the target 110 after being attached is parallel to the axial direction of the guide roll 200.

[0058] By setting the above-mentioned target 110, the target imaging line 111 on the target 110 is marked and fixed more accurately.

[0059] The calibration fixture 120 includes a connecting arm 121, a clamping arm 124, and a centering mark 125. The clamping arm 124 is connected to both ends of the connecting arm 121. The connecting arm 121 has a first plane 127 perpendicular to the symmetry plane 126 of the calibration fixture 120. The two clamping arms 124 have opposing second planes 128. The two second planes 128 are mirror-symmetrical with respect to the symmetry plane 126. The distance between the two second planes 128 gradually increases from the direction closer to the connecting arm 121 to the direction farther away from the connecting arm 121. The symmetry plane 126 passes through the centering mark 125. The two second planes 128 are suitable for clamping the guide roller 200.

[0060] Calibration fixture 120 can be used for calibrating camera imaging points, such as... Figures 3-5 As shown, the calibration fixture 120 can have two clamping arms 124, which are spaced apart and connected by a connecting arm 121 of the calibration fixture 120. The two clamping arms 124 and the connecting arm 121 can be integrally formed. A V-shaped opening can be formed below the two clamping arms 124, which can be used to place the guide roller 200.

[0061] like Figure 5 As shown, the two clamping arms 124 are mirror-symmetrical about the symmetry plane 126 of the calibration fixture 120. The first plane 127 of the calibration fixture 120 is perpendicular to the symmetry plane 126. The two clamping arms 124 can clamp the guide roller 200 covering the target 110. The two clamping arms 124 can abut against the roller surface of the guide roller 200. The two clamping arms 124 are tangent to the roller surface of the guide roller 200. The two tangent planes of the two clamping arms 124 and the guide roller 200 are the two second planes 128.

[0062] It is understandable that the larger the angle of the V-shaped opening of the two clamping arms 124, the closer the guide roller 200 is to the connecting arm 121 of the calibration fixture 120. Similarly, the smaller the angle of the V-shaped opening of the two clamping arms 124, the further the guide roller 200 is from the connecting arm 121 of the calibration fixture 120.

[0063] In actual execution, the calibration fixture 120 clamps the guide roller 200 covering the target 110. At this time, the two clamping arms 124 of the calibration fixture 120 stop against the roller surface of the guide roller 200. The guide roller 200 is rotated so that the target imaging line 111 on the roller surface is aligned with the center mark 125 of the calibration fixture 120.

[0064] By setting the calibration fixture 120 as described above, the alignment of the target imaging line 111 with the center mark 125 is achieved after the clamping fixture and guide roller 200 are fixed.

[0065] An angle gauge 140 is used to be placed on the first plane 127.

[0066] Angle gauge 140 can be used to measure the angle between calibration fixture 120 and the horizontal plane, such as Figure 6 As shown, the angle gauge 140 can be arranged above the calibration fixture 120, and the contact surface between the angle gauge 140 and the calibration fixture 120 is the first plane 127.

[0067] In actual operation, when the calibration fixture 120 starts to rotate, the position of the symmetry plane 126 and the first plane 127 of the calibration fixture 120 in space is deflected. The angle meter 140 displays the angle between the first plane 127 of the calibration fixture 120 and the horizontal plane. Since the first plane 127 of the calibration fixture 120 is perpendicular to the symmetry plane 126 of the calibration fixture 120, the displayed angle value is also equal to the angle between the symmetry plane 126 of the calibration fixture 120 and the vertical plane. Also, since the centerline of the calibration fixture 120 is within the symmetry plane 126, the displayed angle value is also equal to the angle between the centerline of the calibration fixture 120 and the vertical plane.

[0068] By setting the angle gauge 140 as described above, precise control of the levelness of the calibration fixture 120 is achieved.

[0069] It should be noted that, as Figure 1 As shown, when the camera is in camera position A1, the tangent formed by the surface of the camera and the guide roller 200 is the imaging point tangent m. At this time, the normal corresponding to the imaging point is the camera normal L1, and the angle between the camera normal L1 and the imaging line of the camera at this time is the imaging angle α. When the camera is in camera position A2, the tangent formed by the surface of the camera and the guide roller 200 is the imaging point tangent n. At this time, the normal corresponding to the imaging point is the camera normal L2, and the angle between the camera normal L2 and the imaging line of the camera at this time is the imaging angle β. The camera position A1, camera normal L1, imaging point tangent m, and imaging angle α mentioned above do not correspond one-to-one with the camera position A2, camera normal L2, imaging point tangent n, and imaging angle β.

[0070] Therefore, since the imaging point is located on the circumferential roller surface, changes in the camera position will also affect the imaging angle. Even if the camera's own angle does not change, but only the spatial position of the camera shifts, it will cause a large deviation in the camera's imaging angle. Therefore, it is necessary to use certain installation and adjustment methods to ensure that the position of the imaging point on the roller surface is consistent with the design position, so as to ensure that the imaging angle is consistent with the design value.

[0071] In actual implementation, the target 110 is wrapped on the guide roller 200, the target imaging line 111 parallel to the axial direction of the guide roller 200 is calibrated, the guide roller 200 wrapped with the target 110 is clamped by the calibration tool 120, the central identification 125 of the calibration tool 120 is aligned with the target imaging line 111 on the roller surface after the guide roller 200 is rotated, the calibration tool 120, the guide roller 200 and the target 110 are synchronously rotated, the rotation is stopped when the angle gauge 140 displays a set value, and the calibration tool 120, the guide roller 200 and the target 110 are fixed, at this time, the central identification 125 is still aligned with the target imaging line 111 on the roller surface, finally, the camera is adjusted according to the target imaging line 111 at this time, the camera can take a photo of the surface of the pole roll on the guide roller 200, and thus the detection of the surface defects of the pole roll is completed.

[0072] The camera pose calibration device 100 for roller surface imaging provided by the embodiment of the application is configured by the target 110, the calibration tool 120 and the angle gauge 140, the position of the target imaging line on the roller surface is determined according to the target, the specific position of the camera imaging point on the roller surface is further determined by means of the calibration tool, and thus the problem that there is no reference for roller surface imaging and whether the adjustment is consistent with the design after adjustment cannot be confirmed is solved, and the accuracy of the defect detection of the pole piece is ensured.

[0073] In some embodiments, as shown in Figures 3-4 and Figure 6 , the calibration tool 120 can further include a sliding block 129.

[0074] The sliding block 129 can be slidingly assembled to the connecting arm 121, and the central identification 125 can be located at the bottom of the sliding block 129, and the sliding direction of the sliding block 129 can be parallel to the central axis of the calibration tool 120.

[0075] The sliding block 129 can be used to help the central identification 125 to move, as shown in Figures 3-4 and Figure 6 , the sliding block 129 can include two lugs and a block, one lug can be arranged above the block, and the other lug can be arranged below the block, the cross-sectional area of the two lugs can be greater than the cross-sectional area of the block, the block can slide up and down on the connecting arm 121, and the central identification 125 can be arranged on the lug below the block.

[0076] In actual implementation, when the slider 129 drives the center mark 125 thereon to press downward, the lug below the block contacts the roll surface of the guide roller 200, the center mark 125 on the lug below the block is aligned with the target imaging line 111 on the roll surface, at this time, the lug above the block abuts against the connecting arm 121 of the calibration tool 120, preventing the slider 129 from continuing to descend; when the slider 129 drives the center mark 125 thereon to ascend, the lug below the block is disengaged from the roll surface of the guide roller 200 until the lug below the block abuts against the connecting arm 121 of the calibration tool 120.

[0077] Through the above-mentioned arrangement of the slider 129, the alignment of the center mark 125 on the calibration tool 120 with the position of the target imaging line 111 on the roll surface can be realized, and in combination with the design of the structure of the slider 129, the structure reliability of the camera pose calibration device 100 for roll surface imaging is not affected, and the center mark 125 is ensured to move within a controllable range, facilitating operation.

[0078] In some embodiments, as shown in Figures 3-4 and as shown in Figure 6 , the connecting arm 121 can include a first arm 122 and a second arm 123.

[0079] The first arm 122 can be connected between the two clamping arms 124, and the first plane 127 can be arranged on the first arm 122.

[0080] The first arm 122 can be used to mount the angle gauge 140, as shown in Figures 3-4 and as shown in Figure 6 , the upper top surface of the first arm 122 can be the first plane 127 of the calibration tool 120, and the angle gauge 140 can be arranged on the upper top surface of the first arm 122, that is, the connecting surface of the angle gauge 140 and the first arm 122 of the connecting arm 121 is the first plane 127 of the calibration tool 120.

[0081] The second arm 123 can be connected between the two clamping arms 124, and the second arm 123 can be spaced apart from the first arm 122, and the slider 129 can be slidingly assembled on the second arm 123.

[0082] The second arm 123 can be used to mount the slider 129, as shown in Figure 3 , the first arm 122 and the second arm 123 can be integrally formed, the first arm 122 can be arranged above the second arm 123, and the middle region formed after the first arm 122 and the second arm 123 are arranged apart can be a region for sliding of the slider 129.

[0083] In actual implementation, the angle gauge 140 is arranged on the first plane 127, and when the calibration tool 120 starts to rotate, the angle gauge 140 can measure the included angle between the first plane 127 and the horizontal plane. During the process that the slider 129 is pressed to contact the guide roller 200, the slider 129 drives the centering mark 125 on it to move downward until the lug above the block abuts against the second arm 123 of the connecting arm 121. At this time, the slider 129 abuts against the guide roller 200, and the centering mark 125 on the lug below the block is aligned with the target imaging line 111 on the roller surface.

[0084] Through the first arm 122 and the second arm 123, the installation of the angle gauge 140 and the sliding assembly of the slider 129 are realized. First, the separate arrangement of the first arm 122 and the second arm 123 provides sufficient sliding space for the slider 129, which provides a premise for the subsequent alignment of the centering mark 125 with the target imaging line 111, and at the same time, in cooperation with the structural design of the slider 129, the limiting effect of the slider 129 is also achieved. Second, the structure is simple and clear in layers, which reduces the use threshold of the camera pose calibration device 100 for roller surface imaging and facilitates the assembly of relevant personnel.

[0085] In some embodiments, as shown in Figure 3 The connecting arm 121 can further include a fixed plate 132.

[0086] The second arm 123 is provided with a notch, the slider 129 is slidingly assembled in the notch, the fixed plate 132 is connected with the second arm 123, and the notch is closed.

[0087] The fixed plate 132 can be used to fix the second arm 123 and the slider 129, that is, to ensure that the slider 129 and the second arm 123 remain in a sliding connection state, so that the slider 129 and the second arm 123 do not come out of contact, as shown in Figure 3 The fixed plate 132 can be embedded in the second arm 123, and the connection mode of the fixed plate 132 and the connecting arm 121 can include, but is not limited to, bolt connection, rivet connection or pin shaft connection, etc. For example, in some embodiments, the connection mode of the fixed plate 132 and the connecting arm 121 is bolt connection.

[0088] The notch can be used to accommodate the slider 129, as shown in Figure 3 The notch can be a square groove, and the notch can be arranged between the fixed plate 132 and the second arm 123. The slider 129 can be arranged in the notch, that is, the slider 129 is arranged between the fixed plate 132 and the second arm 123, and the slider 129 forms a sliding fit with the fixed plate 132 and the second arm 123.

[0089] In actual implementation, as shown in Figure 3As shown, the process of assembling the calibration tool 120, the slider 129 is installed into the notch of the second arm 123, and then the fixed plate 132 is embedded into the second arm 123, while blocking the notch where the slider 129 is installed, drilling holes at both ends of the fixed plate 132 and the corresponding positions of the second arm 123, and finally installing two bolts into the above-mentioned holes, thereby realizing the fixed connection between the fixed plate 132 and the second arm 123. After installation, the lug above the block of the slider 129 is arranged above the fixed plate 132 and the second arm 123, and the lug below the block is arranged below the fixed plate 132 and the second arm 123.

[0090] Through the above-mentioned setting of the fixed plate 132, the sliding assembly of the slider 129 and the second arm 123 is realized, and the structure design and embedded assembly design of the slider 129 are matched to limit the sliding range of the slider 129 in the second arm 123, while realizing the lightweight of the structure and improving the reliability of the structure.

[0091] In some embodiments, as shown, Figure 3 The connecting arm 121 is provided with a detachable first connecting structure 130 for fixing the angle instrument 140.

[0092] The first connecting structure 130 can be a detachable connecting piece, which can be a threaded connecting piece, a buckle connecting piece or other connecting pieces. For example, in some embodiments, the first connecting structure 130 is a threaded connecting piece.

[0093] As shown, Figure 3 The first connecting structure 130 can be provided on the first arm 122 of the connecting arm 121, and the first connecting structure 130 can be provided in multiple, where multiple means two or more than two, for example, in some embodiments, as shown, Figure 3 Two first connecting structures 130 are arranged on the first arm 122 of the connecting arm 121.

[0094] It can be understood that after the calibration tool 120 is placed on the roll surface and the centering mark 125 on the slider 129 of the calibration tool 120 is aligned with the target imaging line 111 mark, the angle instrument 140 can be installed on the first arm 122 of the calibration tool 120 through the above-mentioned first connecting structure 130. The installed angle instrument 140 can measure the included angle between the first plane 127 and the horizontal plane during the subsequent rotation of the calibration tool 120. After use, the first connecting structure 130 can be disassembled, so that the angle instrument 140 can be removed from the calibration tool 120.

[0095] Through the setting of the first connecting structure 130, detachable connection of the angle gauge 140 and the calibration tool 120 is realized, the overall flexibility of the camera pose calibration device 100 for roll surface imaging is improved, and the easy-to-disassemble design also provides convenience for subsequent maintenance and storage of the device.

[0096] In some embodiments, as shown in Figure 3 The clamping arm 124 is provided with a detachable second connecting structure 131 for fixing the calibration tool 120 and the guide roller 200.

[0097] As shown in Figure 3 The second connecting structure 131 can be a connecting groove, which can be divided into a first section and a second section. The first section is a cylinder with a large inner cross-sectional area, and the second section is a cuboid with a small outer cross-sectional area. The second connecting structure 131 can be arranged on the clamping arm 124 of the calibration tool 120. Multiple first connecting members can be provided, where multiple means two or more, for example, in some embodiments, as shown in Figure 3 Two second connecting structures 131 are arranged on the calibration tool 120, i.e., one second connecting structure 131 is arranged on each of the two clamping arms 124 of the calibration tool 120.

[0098] In actual implementation, the second connecting structure 131 can be detachably connected with other tooling that fixes the guide roller 200. When the two are coupled, the other tooling that fixes the guide roller 200 can be arranged with a corresponding connecting member, which can form a fit with the second connecting structure 131. Because the cross-sectional area of the first section of the second connecting structure 131 is larger than that of the second section, the part of the connecting member that couples with the first section cannot break through the block of the second section, thereby forming a clamping connection between the connecting member and the second connecting structure 131. However, the connecting member can slide vertically relative to the second connecting structure 131, thereby realizing detachable connection between the connecting member and the second connecting structure 131.

[0099] Through the setting of the second connecting structure 131, detachable connection of the guide roller 200 and the calibration tool 120 is realized. While ensuring the calibration accuracy of the calibration tool 120, the process of camera pose calibration is faster and more convenient, thereby improving the calibration efficiency.

[0100] In some embodiments, as shown in Figure 2 The unfolded target 110 can be rectangular, and the width of the target 110 can be equal to the circumference of the guide roller 200. The target imaging line 111 can be parallel to the long side of the target 110.

[0101] The rectangular target 110 includes two long sides and two short sides. The two long sides are parallel to each other, the two short sides are parallel to each other, the target imaging line 111 can be parallel to the two long sides, and the length of the short side of the target 110, i.e., the width of the target 110, can be equal to the circumference of the cross section of the guide roller 200.

[0102] It can be understood that, as Figure 8 shown, the target 110 is wrapped on the surface of the guide roller 200. At this time, the target 110 is wound into a cylinder, and the target 110 is tightly attached to the roller surface of the guide roller 200. Because the width of the target 110 is equal to the circumference of the cross section of the guide roller 200, at this time, the target 110 is just one turn around the guide roller 200, and the two long sides of the target 110 coincide at this time. Because the target imaging line 111 is parallel to the long side of the target 110, according to the self-correcting property of a rectangle, i.e., assuming that a number of horizontal lines parallel to the upper and lower edges are arranged on a rectangle, then the lines on the rectangle must be parallel to the center line of the cylinder. This property is used to ensure that the target imaging line 111 on the target 110 is parallel to the axial direction of the guide roller 200 after the target 110 is pasted.

[0103] Through the shape and size design of the target 110, the mathematical theorem is used to avoid the inclination of the target imaging line 111 on the roller surface of the guide roller 200, and the calibration accuracy of the target imaging line 111 is improved.

[0104] In some embodiments, as Figure 2 shown, the four corners of the target 110 are provided with alignment marks.

[0105] As Figure 2 shown, the rectangular target 110 can include a left upper vertex, a left lower vertex, a right upper vertex, and a right lower vertex. The left upper vertex, the left lower vertex, the right upper vertex, and the right lower vertex are sequentially connected and closed to form the rectangular target 110. The left upper vertex, the left lower vertex, the right upper vertex, and the right lower vertex can each be provided with a corresponding alignment mark.

[0106] In actual implementation, as Figure 8 shown, the target 110 is wrapped on the surface of the guide roller 200. At this time, the target 110 is wound into a cylinder, and the target 110 is tightly attached to the roller surface of the guide roller 200. The alignment mark of the left upper vertex of the target 110 coincides with the alignment mark of the left lower vertex of the target 110, and the alignment mark of the right upper vertex of the target 110 coincides with the alignment mark of the right lower vertex of the target 110. According to the self-correcting property of a rectangle, i.e., assuming that a number of horizontal lines parallel to the upper and lower edges are arranged on a rectangle, then the lines on the rectangle must be parallel to the center line of the cylinder. This property is used to ensure that the target imaging line 111 on the target 110 is parallel to the axial direction of the guide roller 200 after the target 110 is pasted.

[0107] Through the setting of the alignment marks, the four point positions of the target 110 are accurately positioned, and the calibration accuracy of the target imaging line 111 is further improved, thereby reducing the error rate of the pole piece detection system.

[0108] The application further discloses a camera pose calibration method using any one of the calibration devices.

[0109] Reference will be made to the accompanying drawings Figures 7-10 The camera pose calibration method according to the embodiments of the application is described.

[0110] In some embodiments, as Figure 7 shown, the camera pose calibration method comprises steps 510, 520, 530, 540 and 550.

[0111] Step 510, the target 110 is attached to the guide roller 200, and the target imaging line 111 of the target 110 is parallel to the axial direction of the guide roller 200.

[0112] In actual implementation, as Figure 8 shown, the target 110 is wrapped around the guide roller 200, so that the alignment mark of the left upper vertex of the target 110 coincides with the alignment mark of the left lower vertex of the target 110, and the alignment mark of the right upper vertex of the target 110 coincides with the alignment mark of the right lower vertex of the target 110, while ensuring that the target 110 has no relative motion with the guide roller 200 under no external force, and then the target 110 and the guide roller 200 are bonded with an adhesive, and after the subsequent calibration is completed, the residual adhesive on the roller surface can be wiped clean using a degreasing agent.

[0113] Step 520, the calibration tool 120 is placed on the guide roller 200, and the centering mark 125 of the calibration tool 120 is aligned with the target imaging line 111.

[0114] In actual implementation, as Figure 9 shown, the two clamping arms 124 of the calibration tool 120 are placed on the roller surface of the guide roller 200, the guide roller 200 is rotated so that the target imaging line 111 on the roller surface is aligned with the centering mark 125 of the calibration tool 120, and after confirming that the target imaging line 111 on the roller surface is aligned with the centering mark 125 of the calibration tool 120, the guide roller 200 and the calibration tool 120 are fixed through the second connecting structure 131.

[0115] Step 530, the angle gauge 140 is installed on the first plane 127 of the calibration tool 120.

[0116] In actual implementation, as Figure 10As shown, the angle gauge 140 is detachably connected to the first arm 122 of the connecting arm 121 of the calibration tool 120 through the first connecting structure 130, at this time, the angle gauge 140 is arranged on the first plane 127 of the calibration tool 120, after the angle gauge 140 is installed, the included angle between the first plane 127 and the horizontal plane can be measured, since the first plane 127 is perpendicular to the symmetry plane 126 of the calibration tool 120, and the center line of the calibration tool 120 is in the symmetry plane 126, the displayed angle value is equal to the included angle between the center line of the calibration tool 120 and the vertical plane, and the center line passes through the center of the guide roller 200, if the central mark 125 on the calibration tool 120 is aligned with the target imaging line 111, then the center line is the imaging normal line.

[0117] Step 540, synchronously rotate the guide roller 200, the target 110 and the calibration tool 120, until the measurement value of the angle gauge 140 is equal to the target value.

[0118] In actual execution, after the angle gauge 140 is installed, the target 110, the calibration tool 120 and the guide roller 200 are synchronously rotated, that is, the directions and angles of rotation of the target 110, the calibration tool 120 and the guide roller 200 are all equal, until the value displayed by the angle gauge 140 is consistent with the designed included angle between the imaging normal line and the vertical plane, then the target 110, the calibration tool 120 and the guide roller 200 all stop rotating.

[0119] Step 550, keep the guide roller 200 and the target 110 still, and adjust the pose of the camera based on the target imaging line 111.

[0120] In actual execution, after the target 110, the calibration tool 120 and the guide roller 200 all stop rotating, the state of the guide roller 200 and the target 110 is kept unchanged, and the position and attitude of the camera are adjusted according to the position of the target imaging line 111 at this time.

[0121] The camera pose calibration method provided by the embodiment of the application, through the settings of steps 510, 520, 530, 540 and 550, the camera pose calibration device is used in cooperation, relevant operating personnel operate according to the standard calibration process steps, the blindness of on-site assembly and adjustment is reduced, and the influence of human factors on imaging quality is reduced.

[0122] In some embodiments, step 550, adjusting the pose of the camera based on the target imaging line 111, includes:

[0123] adjusting the pitch angle of the camera to the designed angle; horizontally moving the camera to at least one point on the target imaging line 111; and adjusting the horizontal angle of the camera to make the imaging coincide with the target imaging line 111.

[0124] It can be understood that adjusting the pitch angle of the camera, i.e. adjusting the posture of the camera itself, changes the imaging angle of the camera by tilting the camera up and down; horizontally moving the camera, i.e. adjusting the spatial position of the camera, changes the horizontal distance between the camera and the guide roller 200 by moving the camera as a whole; adjusting the horizontal angle of the camera, i.e. adjusting the posture of the camera itself, changes the yaw angle of the camera relative to the guide roller 200 by tilting the camera left and right.

[0125] In actual implementation, after step 540, the imaging angle of the camera is first changed by tilting the camera up and down until the angle of the camera is consistent with the value of the angle instrument 140, the up-and-down tilting is stopped, and the pitch posture of the camera at this time is locked, then the horizontal distance between the camera and the guide roller 200 is changed by horizontally moving the camera as a whole until the imaging of the camera displays at least part of the target imaging line 111, the movement of the camera is stopped, the spatial position of the camera at this time is fixed, and finally the yaw angle of the camera relative to the guide roller 200 is changed by tilting the camera left and right until the imaging of the camera displays the entire target imaging line 111, the left-and-right tilting is stopped, and the yaw posture of the camera at this time is locked.

[0126] In this way, by the design of the above scheme, the spatial position and the posture of the camera are adjusted, which, in cooperation with the calibrated target imaging line 111, solves the problem that the imaging angle cannot be determined in the roller surface imaging, and at the same time, the multiple separate adjustments of the camera position and posture improve the positioning accuracy of the camera, greatly reduce the error caused by human factors, and thus improve the wafer quality in the subsequent defect detection process of the wafer.

[0127] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and are not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the objects before and after are in an "or" relationship.

[0128] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0129] In the description of the application, "first feature" and "second feature" can include one or more of the features.

[0130] In the description of the application, "a plurality of" means two or more.

[0131] In the description of the application, "above" or "below" the first feature of the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them.

[0132] In the description of the application, "above", "over" and "on" the first feature of the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher than the second feature in horizontal height.

[0133] In the description of the application, the description referring to the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description of the application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0134] Although embodiments of the application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the application, and the scope of the application is defined by the claims and their equivalents.

Claims

1. A camera pose calibration device for roller surface imaging, characterized in that, include: A target, which is used to be attached to a guide roller and has a target imaging line adapted to be parallel to the axial direction of the guide roller; A calibration fixture includes a connecting arm, clamping arms connected to both ends of the connecting arm, and a centering mark. The connecting arm has a first plane perpendicular to the plane of symmetry of the calibration fixture. The two clamping arms have opposing second planes. The two second planes are mirror-symmetrical with respect to the plane of symmetry. The distance between the two second planes gradually increases from the direction closer to the connecting arm to the direction farther from the connecting arm. The plane of symmetry passes through the centering mark. The two second planes are adapted to clamp the guide roller. An angle gauge, which is used to place on the first plane.

2. The camera pose calibration device for roller surface imaging according to claim 1, characterized in that, The calibration fixture also includes: The slider is slidably mounted on the connecting arm, and the centering mark is located at the bottom of the slider. The sliding direction of the slider is parallel to the central axis of the calibration fixture.

3. The camera pose calibration device for roller surface imaging according to claim 2, characterized in that, The connecting arm includes: A first arm, the first arm being connected between the two clamping arms, and the first plane being disposed on the first arm; The second arm is connected between the two clamping arms and is spaced apart from the first arm. The slider is slidably mounted on the second arm.

4. The camera pose calibration device for roller surface imaging according to claim 3, characterized in that, The connecting arm also includes: The fixed plate has a notch in the second arm, the slider is slidably fitted into the notch, the fixed plate is connected to the second arm, and the notch is closed.

5. The camera pose calibration device for roller surface imaging according to claim 1, characterized in that, The connecting arm is provided with a detachable first connecting structure for fixing the angle gauge.

6. The camera pose calibration device for roller surface imaging according to claim 1, characterized in that, The clamping arm is provided with a detachable second connection structure for fixing the calibration fixture to the guide roller.

7. The camera pose calibration device for roller surface imaging according to any one of claims 1-6, characterized in that, The target is rectangular, and the width of the target is equal to the circumference of the guide roller. The target imaging line is parallel to the long side of the target.

8. The camera pose calibration device for roller surface imaging according to claim 7, characterized in that, The target has alignment marks at its four corners.

9. A camera pose calibration method using the calibration apparatus as described in any one of claims 1-8, characterized in that, include: The target is attached to the guide roller, and the target imaging line of the target is parallel to the axis of the guide roller; The calibration fixture is placed on the guide roller, and the center mark of the calibration fixture is aligned with the target imaging line; The angle meter is mounted on the first plane of the calibration fixture; The guide roller, the target, and the calibration fixture are rotated synchronously until the measured value of the angle meter equals the target value; Keeping the guide roller and the target stationary, adjust the camera's pose using the target imaging line as a reference.

10. The camera pose calibration method of the calibration device according to claim 9, characterized in that, The step of adjusting the camera pose based on the target imaging line includes: Adjust the camera's tilt angle to the designed angle; The camera is moved horizontally until it is positioned such that at least one point on the target imaging line is displayed. Adjust the horizontal angle of the camera until the image coincides with the target's imaging line.

Images