Calibration device for roller surface imaging
By calibrating the attitude of the light source and camera, the problem of uncertain imaging angle caused by the running speed and vibration of the guide roller was solved, thus achieving the accuracy and reliability of roller surface imaging and improving detection efficiency and accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2026-03-13
AI Technical Summary
During the membrane production process, the running speed and vibration of the guide rollers make it difficult to directly determine the actual imaging angle of the imaging equipment, affecting detection efficiency and accuracy, and the imaging angle varies after each setup and adjustment.
A calibration device for roller surface imaging is provided. The device clamps the guide roller with a clamping member, and uses an angle meter and a target to calibrate the attitude of the light source and the camera. This ensures that the center of the beam emitted by the light source intersects the roller surface of the guide roller within the tangent plane of the imaging point. The camera attitude is adjusted according to the imaging area of the target to achieve accuracy and reliability.
This improves the accuracy and reliability of roller surface imaging, ensuring the accuracy and efficiency of subsequent defect detection and providing an accurate imaging basis for subsequent inspections.
Smart Images
Figure CN223992685U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of visual inspection technology, and in particular relates to a calibration device for roller surface imaging. Background Technology
[0002] With the widespread application of machine vision inspection technology, more and more industries are introducing CCD imaging systems to detect defects in production targets to ensure product quality meets standards. In the production and processing of roll-form film materials, cylindrical guide rollers are often used for transportation and handling. However, due to the vibration and shaking of the guide rollers during production, the actual imaging angle of the imaging equipment is difficult to determine directly from its posture angle. Furthermore, the imaging angle varies after each adjustment, making it difficult to maintain consistency and affecting inspection efficiency and accuracy. Utility Model Content
[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a calibration device for roller surface imaging, which can sequentially calibrate the attitude of the light source and the camera, thereby achieving the accuracy and reliability of roller surface imaging, as well as the efficiency and accuracy of the calibration process, providing an accurate imaging basis for subsequent defect detection.
[0004] In a first aspect, this application provides a calibration apparatus for roller surface imaging, comprising:
[0005] The calibration fixture has a symmetrical structure and includes a connecting member and a clamping member. The connecting member has a calibration surface and is used to install a light source. The calibration surface intersects perpendicularly with the symmetrical plane of the calibration fixture. The clamping member is used to clamp the guide roller.
[0006] An angle gauge is used to measure the tilt angle of the calibration surface;
[0007] A target is disposed on the connector, the length of the target extends along the axial direction of the guide roller for contact and engagement with the guide roller, and the target has an imaging area that is mirror-symmetrical with respect to the symmetry plane.
[0008] According to the calibration device for roller imaging of this application, in actual execution, the guide roller is clamped by the clamping member, and the guide roller or calibration fixture is rotated until the angle meter displays the target value. Then, the relative positions between the calibration fixture, the guide roller and the target are fixed. Since the light source is installed on the connecting member, the intersection of the center of the light beam emitted by the light source and the roller surface of the guide roller is located within the tangent of the imaging point, thereby achieving the calibration of the light source attitude. Subsequently, since the target is installed on the connecting member and contacts the guide roller, and the imaging area is mirror-symmetrical with respect to the symmetry plane, the attitude of the camera can be adjusted by comparing the actual image obtained by the camera in the imaging area with the original image of the imaging area until the difference between the actual image and the original image meets the requirements, thereby achieving the calibration of the camera attitude.
[0009] According to one embodiment of this application, the clamping member includes two clamping arms respectively disposed at both ends of the connecting member. Each clamping arm has a clamping surface that is mirror-symmetrical with respect to the plane of symmetry. The clamping surfaces are used to mate with the roller surface of the guide roller.
[0010] The clamping surface is planar, and the distance between the two clamping surfaces gradually increases in the direction away from the connector; or
[0011] The clamping surface is an arc surface, and the center of curvature of the clamping surface is located inside the guide roller.
[0012] According to one embodiment of this application, the connector is provided with a detachable first mounting structure for fixing the light source.
[0013] According to one embodiment of this application, the first mounting structure includes:
[0014] A first mounting component, which protrudes from the calibration surface;
[0015] A second mounting component is used to mount the light source. The second mounting component is angle-adjustably mounted on the first mounting component. The rotation axis of the second mounting component is parallel to the axial direction and located within the plane of symmetry.
[0016] According to one embodiment of this application, the second mounting component includes:
[0017] The first segment, one end of which is angle-adjustably mounted on the first mounting component;
[0018] The second segment is located at the other end of the first segment, and the extension direction of the first segment, the extension direction of the second segment, and the axial direction are perpendicular to each other.
[0019] According to one embodiment of this application, the second segment is provided with an adjustment member for adjusting the mounting position of the light source.
[0020] According to one embodiment of this application, the connector is provided with a detachable second mounting structure for fixing the target.
[0021] According to one embodiment of this application, the second mounting structure includes:
[0022] A third mounting component is disposed on the connector;
[0023] Tensioning assembly, disposed on the third mounting component, is used to tension the target.
[0024] According to one embodiment of this application, the third mounting member includes a main body and two opposing support arms, one end of each support arm being connected to the main body and extending along the axial direction; the tensioning assembly includes:
[0025] The first assembly is installed between the two support arms and spaced apart from the main body, and the first assembly has a first mating surface;
[0026] The second assembly is installed on the first assembly and has a second mating surface, with the end portion of the target located between the first mating surface and the second mating surface.
[0027] According to one embodiment of this application, both the first mating surface and the second mating surface are inclined in a direction away from the main body toward a direction closer to the guide roller.
[0028] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0029] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0030] Figure 1 This is a schematic diagram of the calibration device for roller surface imaging provided in an embodiment of this application;
[0031] Figure 2 This is a schematic diagram of the structure of the calibration device for roller surface imaging and the mating parts provided in the embodiments of this application;
[0032] Figure 3 This is a schematic diagram of the structure of the target and calibration tooling provided in the embodiments of this application;
[0033] Figure 4 This is an exploded view of the tensioning assembly provided in the embodiments of this application;
[0034] Figure 5 This is a schematic diagram of the imaging region of the three targets provided in the embodiments of this application;
[0035] Figure 6 This is a schematic flowchart of a calibration method using a calibration device for roller surface imaging provided in an embodiment of this application.
[0036] Figure label:
[0037] 100. Calibration tooling;
[0038] 110. Connector; 111. Calibration surface; 121. Clamping arm;
[0039] 200. Target; 201. Imaging area;
[0040] 210. Line to target; 211. Triangle; 2121. Sub-segment; 213. Second line;
[0041] 220. Distorted target; 221. Line image;
[0042] 230. White balance target;
[0043] 310. First mounting component; 320. Second mounting component;
[0044] 321. First paragraph; 322. Second paragraph;
[0045] 400. Adjusting component; 410. First part; 420. Second part; 430. Fixing component;
[0046] 500. Second installation structure;
[0047] 510. Third mounting component; 511. Main body; 512. Support arm;
[0048] 520. Tensioning assembly; 521. First assembly; 5211. First mating surface; 522. Second assembly;
[0049] 810. Light source; 820. Camera; 830. Mating parts;
[0050] 900, guide roller; 10, imaging point section. Detailed Implementation
[0051] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0052] The following is for reference. Figures 1-5This application describes a calibration apparatus for roller surface imaging, which includes a calibration fixture 100, an angle meter, and a target 200.
[0053] The calibration fixture 100 has a symmetrical structure and includes a connecting member 110 and a clamping member. The connecting member 110 has a calibration surface 111 for mounting a light source 810. The calibration surface 111 intersects perpendicularly with the plane of symmetry of the calibration fixture 100. The clamping member is used to clamp the guide roller 900. An angle gauge is used to measure the tilt angle of the calibration surface 111. A target 200 is disposed on the connecting member 110. The length of the target 200 extends along the axial direction of the guide roller 900 for contact and engagement with the guide roller 900. The target 200 has an imaging area 201, which is mirror-symmetrical with respect to the plane of symmetry. The target 200 and the guide roller 900 are in line contact or surface contact, that is, the symmetrical planes sequentially penetrate the imaging area 201 of the target 200 and the guide roller 900, so that the contact point between the roller surface and the target 200 is located within the imaging point tangent 10 (the imaging point tangent 10 refers to the tangent formed by the surfaces of the camera 820 and the guide roller 900). The shape of the target 200 includes, but is not limited to, a rectangle.
[0054] It should be noted that the angle meter displays the measured value of the angle formed between the calibration surface 111 and the horizontal plane. Since the calibration surface 111 is perpendicular to the plane of symmetry of the calibration fixture 100, the angle value displayed by the angle meter is also equal to the angle between the plane of symmetry and the vertical plane. Furthermore, since the centerline of the calibration fixture 100 is within the plane of symmetry, the displayed angle value is also equal to the angle between the centerline of the calibration fixture 100 and the vertical plane. For example, when the angle meter displays an angle of 0 between the calibration surface 111 and the horizontal plane, it indicates that the target 200 is placed directly above the guide roller 900, meaning that the imaging point tangent 10 is parallel to the horizontal plane, and the normal corresponding to the imaging point tangent 10 is located within the plane of symmetry and parallel to the vertical plane. The angle meter can be installed on the calibration surface 111 or outside the calibration fixture 100, as long as it can measure the tilt angle between the calibration surface 111 and the horizontal plane. This embodiment does not impose specific limitations on this.
[0055] For ease of understanding, during inspection, the light source 810 and camera 820 are located on the same side of the guide roller 900 and on both sides of the normal corresponding to the imaging point tangent 10. The intersection of the beam center emitted by the light source 810 and the roller surface of the guide roller 900 should also be located within the imaging point tangent 10, so as to improve the imaging effect, enhance imaging accuracy and the accuracy of defect detection.
[0056] Understandably, in actual execution, the guide roller 900 is clamped by the clamping device, and the guide roller 900 or the calibration fixture 100 is rotated until the angle meter displays the target value. Then, the relative positions of the calibration fixture 100, the guide roller 900, and the target 200 are fixed. Since the light source 810 is installed on the connector 110, the intersection of the beam center emitted by the light source 810 and the roller surface of the guide roller 900 is located within the imaging point tangent 10, thereby achieving the calibration of the attitude of the light source 810. Subsequently, since the target 200 is installed on the connector 110 and contacts and engages with the guide roller 900, and the imaging area 201 is mirror-symmetrical with respect to the symmetry plane, the attitude of the camera 820 can be adjusted by comparing the actual image obtained by the camera 820 from the imaging area 201 with the calibration image of the imaging area 201, until the difference between the actual image and the calibration image meets the requirements, thereby achieving the calibration of the attitude of the camera 820.
[0057] The calibration device for roller surface imaging provided in this application embodiment, through the relative fixation between the calibration fixture 100 and the target 200, first uses an angle meter to measure the tilt angle of the calibration surface 111 to calibrate the attitude of the light source 810, and then calibrates the attitude of the camera 820 according to the imaging area 201 on the target 200. This achieves the accuracy and reliability of roller surface imaging, as well as the efficiency and accuracy of the calibration process, providing an accurate imaging basis for subsequent defect detection.
[0058] In some embodiments, such as Figures 1 to 3 As shown, the clamping member includes two clamping arms 121 respectively disposed at both ends of the connector 110. Both clamping arms 121 have clamping surfaces that are mirror-symmetrical with respect to the symmetry plane. The clamping surfaces are used to cooperate with the roller surface of the guide roller 900.
[0059] Understandably, the two opposing clamping arms 121 can tightly fit against the roller surface of the guide roller 900, ensuring that the calibration fixture 100 is more firmly and stably fixed on the guide roller 900, thus providing a reliable physical basis for the calibration of the light source 810 and the camera 820. That is, the clamping surface and the roller surface of the guide rail are tangent. Combining the geometric principle of "three points determine a circle", the contact points between the two clamping surfaces and the roller surface of the guide roller 900 are used to determine the imaging point tangent plane 10. This ensures that the symmetry plane can penetrate the calibration surface 111 and the central axis of the guide roller 900, so as to accurately determine the position and orientation of the calibration fixture 100 on the guide roller 900, thereby achieving the subsequent accurate calibration of the light source 810 and the camera 820.
[0060] In some embodiments, such as Figures 1 to 3 As shown, the clamping surfaces are planar, and the distance between the two clamping surfaces gradually increases in the direction away from the connector 110. It should be noted that the tilt angle and size of the clamping surfaces can be designed according to actual needs; this embodiment is symmetrical and not specifically limited.
[0061] Understandably, the two clamping arms 121 can abut against the roller surface of the guide roller 900, meaning that the two clamping surfaces are tangent to the roller surface of the guide roller 900. A V-shaped opening for placing the guide roller 900 can be formed between the two clamping surfaces, so as to utilize the inclined setting of the clamping surfaces to accommodate guide rollers 900 of different diameters, and to provide stable support during clamping, while facilitating installation and disassembly. That is, the larger the angle of forming the V-shaped opening, the closer the guide roller 900 is to the connecting member 110 of the calibration fixture 100, and the smaller the angle, the further the guide roller 900 is from the connecting member 110 of the calibration fixture 100.
[0062] In other embodiments, the clamping surface is an arc surface, and the center of curvature of the clamping surface is located within the guide roller 900.
[0063] Understandably, the center of curvature of the clamping surface is located inside the guide roller 900, which makes the clamping surface fit more closely with the roller surface of the guide roller 900, increases the contact area, provides better contact stability and clamping accuracy, and makes the calibration fixture 100 more firmly and stably fixed on the guide roller 900.
[0064] In some embodiments, such as Figure 2 As shown, to ensure that the positions of the calibration fixture 100 and the guide roller 900 remain unchanged during the calibration process, a mating part 830 is provided on the outer side of the guide roller 900. The mating part 830 is fixedly connected to the connecting part 110 to provide external clamping, thereby improving the accuracy and reliability of the calibration. This connection can be achieved through threaded connection, snap-fit, plug-in, or other mechanical connection methods to ensure that there is no relative displacement between the two during the calibration process.
[0065] In some embodiments, such as Figures 1 to 3 As shown, the connector 110 is provided with a detachable first mounting structure for fixing the light source 810. Exemplarily, the first connection structure may be a detachable connector 110, which may include, but is not limited to, a threaded connector 110, a snap-fit connector 110, or other connectors 110.
[0066] Understandably, after the calibration fixture 100 is placed on the roller surface, the light source 810 can be mounted to the connector 110 through the first mounting structure described above. During the subsequent rotation of the calibration fixture 100, an angle meter is used to measure the angle between the calibration surface 111 and the horizontal plane until it equals a preset angle. After the inspection is completed, the first mounting structure can be disassembled, thereby removing the light source 810 from the calibration fixture 100. This improves the overall flexibility of the calibration device used for roller surface imaging, and the easy-to-disassemble design also facilitates subsequent maintenance, upkeep, and storage of the device.
[0067] In some embodiments, such as Figures 1 to 3As shown, the first mounting structure includes a first mounting member 310 and a second mounting member 320. The first mounting member 310 protrudes from the calibration surface 111. The second mounting member 320 is used to mount the light source 810. The second mounting member 320 is mounted on the first mounting member 310 at an adjustable angle. The rotation axis of the second mounting member 320 is parallel to the axial direction and located in the plane of symmetry.
[0068] Understandably, the first mounting member 310 is disposed on the connector 110 and protrudes from the calibration surface 111, serving as a basic support structure for mounting the light source 810 and ensuring the stability of the relative position between the light source 810 and the calibration surface 111. The second mounting member 320 is adjustablely mounted on the first mounting member 310, allowing the angle between the intersection of the beam center emitted by the light source 810 and the roller surface of the guide roller 900 and the normal corresponding to the imaging point tangent plane 10 to be adjusted according to actual needs before calibrating the light source 810. The rotation axis of the second mounting member 320 is parallel to the axial direction of the guide roller 900 and is located on the plane of symmetry of the calibration fixture 100, ensuring that when the clamping member holds the guide roller 900, the intersection of the beam center of the light source 810 and the roller surface of the guide roller 900 is exactly within the imaging point tangent plane 10, enhancing the versatility, flexibility, and reliability of the calibration device for roller surface imaging.
[0069] In some embodiments, such as Figure 1 and Figure 2 As shown, the second mounting component 320 includes a first segment 321 and a second segment 322. One end of the first segment 321 is installed at an adjustable angle on the first mounting component 310. The second segment 322 is located at the other end of the first segment 321, and the extension direction of the first segment 321, the extension direction of the second segment 322, and the axial direction are perpendicular to each other.
[0070] It should be noted that the extension direction of the second segment 322 is parallel to the direction emitted from the center of the light beam of the light source 810.
[0071] It is understandable that the second segment 322 is located at the end of the first segment 321 that is far away from the first mounting member 310, and the extension direction of the first segment 321, the extension direction of the second segment 322, and the axis are perpendicular to each other. That is, the second mounting member 320 is L-shaped, which ensures that the installation position and angle of the light source 810 remain stable during the calibration process and reduces the possibility of imaging deviation.
[0072] In some embodiments, such as Figure 1 As shown, the second section 322 is provided with an adjusting member 400 for adjusting the installation position of the light source 810 to accommodate guide rollers 900 and light sources 810 of different specifications, thereby enhancing the versatility and adaptability of the calibration device for roller surface imaging.
[0073] In some embodiments, such as Figure 1As shown, the light source 810 is installed in an adjustable position on the second section 322 along the extension direction of the second section 322, so that the light source 810 is closer to or farther away from the guide roller 900, thereby adjusting the irradiation intensity of the light beam.
[0074] In some embodiments, such as Figure 1 As shown, the adjusting member 400 includes a first part 410, which is connected to the light source 810 and forms a first groove. The second segment 322 extends into the first groove at one end away from the first segment 321. One of the first groove and the second segment 322 forms a first elongated hole, and the other forms multiple spaced first mounting holes. By using different first mounting holes and first elongated holes in combination, the light source 810 can be adjusted in position along the extension direction of the second segment 322. Of course, in other embodiments, a threaded adjusting device, elastic support, or other mechanical adjusting mechanism can also be used; this embodiment does not impose specific limitations on this.
[0075] In some embodiments, such as Figure 1 As shown, the light source 810 is axially mounted in the second segment 322, thereby adjusting the illumination angle and range of the beam.
[0076] In some embodiments, such as Figure 1 As shown, the adjusting member 400 also includes a second part 420 connected to the light source 810. The second part 420 and the first part 410 are axially slidably engaged, and the first part 410 forms a second mounting hole. One end of the fixing member 430 passes through the second mounting hole and is threadedly connected to the second part 420. That is, after the first part 410 and the second part 420 are slid relative to each other to a suitable position, the fixing member 430 is used to lock the second part 420 in that position. The fixing member 430 includes, but is not limited to, screws or bolts. Of course, in other embodiments, a threaded adjusting device, elastic support, or other mechanical adjusting mechanism can also be used, and this embodiment does not impose specific limitations on this.
[0077] In some embodiments, such as Figure 1 As shown, in order to ensure that the target 200 fits tightly with the guide roller 900 and that the light source 810 is installed stably, two calibration fixtures 100 are arranged at intervals along the axial direction at both ends of the guide roller 900, and the first mounting structure and the calibration fixture 100 correspond one-to-one.
[0078] In some embodiments, such as Figure 3 and Figure 4 As shown, the connector 110 is provided with a detachable second mounting structure 500 for fixing the target 200.
[0079] It is understood that the second mounting structure 500 and the calibration fixture 100 correspond one-to-one. After the calibration fixture 100 is placed on the roller surface, the target 200 can be installed onto the connector 110 through the second mounting structure 500. During the subsequent rotation of the calibration fixture 100, an angle meter is used to measure the angle between the calibration surface 111 and the horizontal plane until it equals a preset angle. After calibration, the second mounting structure 500 can be disassembled, allowing the target 200 to be removed from the calibration fixture 100, reducing the possibility of interference with the product wound on the roller surface. This improves the overall flexibility of the calibration device used for roller surface imaging, and the easy-to-disassemble design also facilitates subsequent maintenance, upkeep, and storage of the device.
[0080] It should be noted that the products include, but are not limited to, lithium battery film, plastic film, or roll paper.
[0081] In some embodiments, such as Figure 3 As shown, the second mounting structure 500 includes a third mounting member 510, which is disposed on the connector 110; the tensioning assembly 520 is disposed on the third mounting member 510 and is used to tension the target 200.
[0082] Understandably, the third mounting component 510 is disposed on the connector 110 to serve as a basic support structure for the installation of the target 200, ensuring that the target 200 remains fixed during the calibration process. Simultaneously, the tensioning component 520 is used to fix the end of the target 200, ensuring that the target 200 remains as flat and stable as possible during the calibration process, reducing the possibility of partial deformation of the target 200 affecting imaging.
[0083] In some embodiments, such as Figure 1 , Figure 3 and Figure 4 As shown, the third mounting component 510 includes a main body 511 and two opposing support arms 512. One end of each support arm 512 is connected to the main body 511 and extends axially. The tensioning assembly 520 includes a first mounting part 521 and a second mounting part 522. The first mounting part 521 is mounted between the two support arms 512 and spaced apart from the main body 511, and has a first mating surface 5211. The second mounting part 522 is mounted on the first mounting part 521 and has a second mating surface. The end portion of the target 200 is located between the first mating surface 5211 and the second mating surface. The connection between the first mounting part 521 and the second mounting part 522 includes, but is not limited to, a threaded connection.
[0084] Understandably, one end of the support arm 512 is connected to the main body 511, and the other end extends axially, thereby forming a U-shaped opening in the third mounting member 510 to accommodate the tensioning assembly 520 while facilitating the tensioning operation of the target 200. The first mounting member 521 is installed between the two support arms 512 and spaced apart from the main body 511, providing a stable and convenient platform. Through the clamping action between the first mating surface 5211 and the second mating surface, adjusting the preload between the second mounting member 522 and the first mounting member 521 can achieve tensioning of the target 200, reducing imaging errors caused by unevenness of the target 200 surface, thereby improving calibration accuracy.
[0085] In some embodiments, such as Figure 4 As shown, both the first mating surface 5211 and the second mating surface are inclined in a direction away from the main body 511 towards the guide roller 900.
[0086] It is understandable that the first mating surface 5211 and the second mating surface are inclined so that the target 200 will be subjected to an inward clamping force when it is clamped, thereby ensuring that it remains stable during the calibration process and reducing the possibility of the target 200 loosening or shifting due to vibration or external force.
[0087] In some embodiments, such as Figure 5 As shown, target 200 includes line-pair target 210, and the imaging area 201 of line-pair target 210 has a geometric combination image to adjust the distance and angle of camera 820 relative to target 200 during calibration. It should be noted that the number and specific distribution of conventional geometric images can be designed according to actual needs, and this embodiment does not impose specific limitations on this. For example, multiple geometric combination images are distributed at intervals along the axial direction.
[0088] In some embodiments, such as Figure 5 As shown, the geometric composite image includes two symmetrically arranged sub-images. Each sub-image includes two triangles 211 symmetrically arranged along the axis, and multiple first lines and second lines 213. The multiple first lines are located between the triangles 211 and the second lines 213 along the axis. That is, the two sub-images are symmetrically arranged along the width direction of the target 210, and the triangles 211, first lines, and second lines 213 are used to provide rich and uniform feature points for camera 820 calibration, thereby improving the robustness of the calibration process and the stability and accuracy of the calibration results. For example, triangle 211 is a right triangle.
[0089] In some embodiments, such as Figure 5As shown, the first line includes two segments 2121 that are spaced apart along the width direction of the line-target 210. One segment 2121 gradually increases in length along the width direction of the line-target 210 towards the second line 213, and the other segment 2121 gradually decreases in length along the width direction of the line-target 210 towards the second line 213.
[0090] Understandably, the sub-segment 2121, which consists of one addition and one subtraction, provides unique geometric features for the line-pair target 210, increasing the redundancy of feature points. This improves the fault tolerance of the calibration process and allows it to better adapt to different environmental conditions, such as changes in illumination, reflection interference, or cluttered backgrounds. This enhances the recognition effect and reduces the complexity and computation time of feature extraction during the calibration process.
[0091] In some embodiments, such as Figure 5 As shown, the target 200 also includes a distortion target 220. The imaging area 201 of the distortion target 220 has multiple line images 221. That is, by comparing the line width of each line in the line image 221 in the actual image with the line width of each line in the line image 221 in the calibration image, the distortion coefficient of the camera 820 can be adjusted in the calibration.
[0092] In some embodiments, such as Figure 5 As shown, the target 200 also includes a white balance target 230, the imaging area 201 of which has a solid color block image. That is, by comparing the image grayscale values in the actual image with the image grayscale values in the calibration image, the camera 820 is normally corrected during calibration. For example, the color of the solid color block image is white.
[0093] It should be noted that after the attitude of the light source 810 is calibrated, the line pair target 210, the distortion target 220 and the white balance target 230 can be fixedly set on the guide roller 900 respectively through the second mounting structure 500, so as to achieve the calibration of the pose and parameters of the camera 820.
[0094] This application also provides a calibration method using the above-described calibration device for roller imaging.
[0095] like Figure 6 As shown, the calibration method includes steps 710 and 720.
[0096] Step 710: The calibration fixture 100 and the light source 810 are fixed relative to each other and the calibration fixture 100 clamps the guide roller 900, and the measured value of the angle meter is equal to the target value.
[0097] In actual execution, the two clamping arms 121 of the calibration fixture 100 are engaged with the roller surface of the guide roller 900, and the guide roller 900 is rotated so that the angle between the calibration surface 111 measured by the angle meter and the horizontal plane is equal to the target value, thereby completing the calibration of the attitude of the light source 810.
[0098] It should be noted that the light source 810 can be first fixedly mounted on the calibration fixture 100 via the first mounting structure, and then the clamping arm 121 can be engaged with the roller surface of the guide roller 900. Alternatively, the light source 810 can be fixedly mounted on the calibration fixture 100 after the guide roller 900 is rotated to make the angle meter's measured value equal to the target value. This embodiment does not impose specific limitations on this.
[0099] Step 720: Keep the calibration fixture 100 and guide roller 900 in place, and adjust the pose of camera 820 with the imaging area 201 of target 200 as a reference.
[0100] In actual execution, the state of the guide roller 900 and the target 200 remains unchanged. Based on the current position of the imaging area 201 of the target 200, the attitude of the camera 820 is adjusted accordingly by comparing the actual image with the calibration image of the imaging area 201.
[0101] It should be noted that the target 200 can be relatively fixedly installed on the connector 110 by the third mounting part 510 after the orientation of the light source 810 is calibrated; or it can be relatively fixedly installed on the connector 110 before the clamping arm 121 of the calibration fixture 100 is engaged with the roller surface stop. This embodiment does not impose any specific restrictions on this.
[0102] According to the calibration method provided in the embodiments of this application, by using the above-mentioned calibration device for roller surface imaging in conjunction with steps 710 and 720, relevant operators can operate according to the standard calibration process steps, reducing the blindness of on-site assembly and adjustment, thereby reducing the impact of human factors on imaging quality.
[0103] In some embodiments, step 720 includes:
[0104] Adjust the pitch, yaw, and roll angles of camera 820 respectively until the actual image coincides with the calibration image.
[0105] It is understandable that adjusting the pitch angle of camera 820 is to adjust the imaging angle of camera 820 by tilting camera 820 up and down; moving camera 820 horizontally is to adjust the spatial position of camera 820; adjusting the yaw angle of camera 820 is to adjust the imaging angle of camera 820 by tilting camera 820 left and right; and adjusting the roll angle of camera 820 is to adjust the imaging angle of camera 820 by tilting camera 820 back and forth.
[0106] In this way, the spatial position and attitude of the camera 820 can be adjusted through the above design. Combined with the imaging area 201 calibrated by the target 200, the problem of uncertain imaging angle in roller imaging is solved, the positioning accuracy of the camera 820 is improved, the error caused by human factors is greatly reduced, and the quality of defect detection of subsequent products is improved.
[0107] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0108] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0109] In the description of this application, "first feature" and "second feature" may include one or more of the features.
[0110] In the description of this application, "multiple" means two or more.
[0111] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.
[0112] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.
[0113] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0114] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A calibration device for roll surface imaging, characterized by, The utility model relates to a kind of calibration tool (100), angle gauge, target (200) and the related method for calibrating the angle of inclination of the calibration surface (111) of the calibration tool (100) and the angle of inclination of the calibration surface (111) of the calibration tool (100) are measured. The calibration tool (100) is symmetrical structure, and the calibration tool (100) includes connected connecting piece (110) and clamping piece, the connecting piece (110) has calibration surface (111) and is used to install light source (810), the calibration surface (111) is perpendicular to the intersection of symmetry plane of the calibration tool (100), and the clamping piece is used to clamp guide roller (900); Angle gauge is used to measure the inclination angle of the calibration surface (111); Target (200) is arranged in the connecting piece (110), the length of the target (200) extends along the axial direction of the guide roller (900), is used to contact with the guide roller (900), and the target (200) has imaging area (201), and the imaging area (201) is mirror-symmetrical relative to the symmetry plane.
2. The calibration device for imaging of a roll surface according to claim 1, characterized in that The clamping piece includes two clamping arms (121) arranged at two ends of the connecting piece (110) respectively, and the two clamping arms (121) are mirror-symmetrical relative to the symmetry plane, and the clamping surface is used to cooperate with the roll surface of the guide roller (900); Wherein, The clamping surface is a plane, and the distance between the two clamping surfaces gradually increases in the direction away from the connecting piece (110);Or 3. The calibration device for imaging of a roll surface according to claim 1, characterized in that The clamping surface is a curved surface, and the center of curvature of the clamping surface is located in the guide roller (900).
4. The calibration device for imaging of a roll surface according to claim 3, characterized in that The connecting piece (110) is provided with a detachable first mounting structure for fixing the light source (810). The first mounting structure includes: First mounting piece (310), the first mounting piece (310) is protruded on the calibration surface (111); 5. The calibration device for imaging of a roll surface according to claim 4, characterized in that Second mounting piece (320) is used to install the light source (810), and the second mounting piece (320) is adjustably mounted on the first mounting piece (310), and the rotation axis of the second mounting piece (320) is parallel to the axial direction and is located in the symmetry plane. The second mounting piece (320) includes: First section (321), one end of the first section (321) is adjustably mounted on the first mounting piece (310); 6. The calibration device for imaging of a roll surface according to claim 5, characterized in that Second section (322) is arranged at the other end of the first section (321), and the extension direction of the first section (321), the extension direction of the second section (322) and the axial direction are perpendicular to each other.
7. The calibration device for imaging of a roll surface according to claim 1, characterized in that The second section (322) is provided with adjusting member (400) for adjusting the installation position of the light source (810).
8. The calibration device for imaging of a roll surface according to claim 7, characterized in that The connecting piece (110) is provided with a detachable second mounting structure (500) for fixing the target (200). The second mounting structure (500) includes: Third mounting piece (510) is arranged in the connecting piece (110); Tensioning assembly (520) is arranged in the third mounting piece (510) and is used to tension the target (200).
9. The calibration device for imaging of a roll surface according to claim 8, characterized in that The third mounting member (510) comprises a main body (511) and two oppositely arranged supporting arms (512), one end of the supporting arms (512) being connected with the main body (511) and extending along the axial direction; the tensioning assembly (520) comprises: a first assembly member (521) installed between the two supporting arms (512) and spaced apart from the main body (511), and the first assembly member (521) has a first matching surface (5211); a second assembly member (522) installed on the first assembly member (521) and having a second matching surface, and an end portion of the target (200) is located between the first matching surface (5211) and the second matching surface.
10. The calibration device for imaging of a roll surface according to claim 9, characterized in that The first matching surface (5211) and the second matching surface are both inclined in a direction away from the main body (511) and towards the guide roller (900).
11. A calibration device for imaging a roll surface according to any one of claims 1-10, characterized in that The target (200) comprises a line pair target (210), and an imaging area (201) of the line pair target (210) has a combined image of geometric figures, the combined image of geometric figures comprising two symmetrically arranged sub-images, and the sub-images comprising two axially symmetrically arranged triangles (211), a plurality of first lines and second lines (213), and the plurality of first lines being located between the triangles (211) and the second lines (213) in the axial direction.
12. The calibration device for imaging of a roll surface according to claim 11, characterized in that The first lines comprise two sub-segments (2121) spaced apart along the width direction of the line pair target (210), one of the sub-segments (2121) gradually increasing in length along the width direction of the line pair target (210) and towards the second lines (213), and the other sub-segment (2121) gradually decreasing in length along the width direction of the line pair target (210) and towards the second lines (213).