Strip straightness detection method and detection system

Abstract

The invention discloses a method and a system for detecting the straightness of a strip. The method is used for a strip straightness detection system, and the strip straightness detection system comprises a light source assembly and a light signal receiving assembly. The method comprises the following steps: controlling a light source assembly to emit a light signal to a strip, and obtaining detection data of a light signal receiving assembly on the strip in a detection area; according to the detection data and the mapping matrix, obtaining a plurality of pieces of contour sub-information of the strip, and splicing the plurality of pieces of contour sub-information to form three-dimensional contour information about the strip; and the straightness of the strip is calculated according to the three-dimensional contour information. According to the detection method, straightness detection can be achieved in multiple procedures, rapid calibration can be achieved, the three-dimensional contour information of the strip can be obtained through detection data and the mapping matrix, therefore, accurate detection of the straightness of the strip is achieved, the strip quality control level is improved, and the detection cost can be saved.

Description

Technical Field

[0001] The present application relates to the field of optical detection, and in particular to a strip straightness detection method and detection system. Background Art

[0002] In the field of metal strip processing and manufacturing, the straightness detection device is one of the key detection system equipment for measuring the quality of strip products. Currently, mainstream straightness detection equipment mostly uses non-contact machine vision for detection. It is mostly deployed after the key heating and cooling processes on the production line and before the finished products are unloaded to detect the warping type and degree of the processed strip products.

[0003] At present, the flatness detection equipment of various manufacturers at home and abroad mainly adopts the gantry type, in which the crossbeam part is located directly above the product conveying roller. The crossbeam part carries the core detection instrument. The gantry type flatness detection device is not well suitable for all production line application scenarios. For example, in the operation scenario where there is an overhead crane lifting, the overhead crane will interfere with the gantry, and the incompatibility will make it impossible to install; for example, there is a cooling bed or other mechanism next to the product conveying roller, which makes the gantry unable to be installed; for example, there are other frame structures above the roller, and there is no installation space for the gantry; for example, in high temperature and high heat environments, the thermal insulation requirements for the gantry are high, and maintenance is difficult, etc.

[0004] Furthermore, conventional flatness devices require multiple calibrations using a calibration device before use to establish fitting parameters for calculating flatness. This process is cumbersome and inefficient, and requires personnel to work near the roller table, which is highly dangerous. Therefore, improvements are urgently needed. Summary of the Invention

[0005] The embodiments of the present application provide a method and system for detecting the flatness of a strip. The method and system achieve accurate detection of the flatness of the strip, enable rapid calibration, improve the level of strip quality control, save detection costs, and achieve an upgrade to traditional flatness devices.

[0006] In a first aspect, an embodiment of the present application provides a method for detecting the straightness of a strip. The detection method is used in a strip straightness detection system, and the strip straightness detection system includes a light source component and an optical signal receiving component. The method includes: controlling the light source component to emit an optical signal to the strip, and obtaining detection data of the strip in the detection area by the optical signal receiving component; obtaining multiple contour sub-information of the strip based on the detection data and a mapping matrix, and splicing the multiple contour sub-information to form three-dimensional contour information about the strip; and calculating the straightness of the strip based on the three-dimensional contour information.

[0007] In some optional embodiments, the method for constructing the mapping matrix includes:

[0008] Control the light source in the digital twin to emit light signals to the preset area;

[0009] Obtain the mapping data of the optical signal in the digital twin, and establish a mapping matrix between the mapping data and the corresponding strip profile sub-information; the mapping data is obtained through the perspective of the optical signal receiving component in the digital twin, and the mapping data is a two-dimensional coordinate system; the strip profile sub-information is the spatial position of the light curtain formed by the optical signal in the digital twin, and the strip profile sub-information is a three-dimensional coordinate system.

[0010] In some optional embodiments, obtaining mapping data of the optical signal in the digital twin and establishing a mapping matrix between the mapping data and the corresponding strip profile sub-information includes:

[0011] Based on the light curtain formed by the optical signal in the digital twin, for each point on the light curtain, the projection coordinates (u, v) in the two-dimensional coordinate system are obtained through the perspective of the optical signal receiving component, and the corresponding three-dimensional coordinates (x, y, z) are obtained respectively. The set of projection coordinates is the mapping data, and the set of three-dimensional coordinates is used as the strip profile sub-information;

[0012] Based on the correspondence between the projection coordinates (u, v) in the mapping data and the three-dimensional coordinates (x, y, z) in the strip profile sub-information, all pixel points that intersect with the light signal within the field of view of the optical signal receiving component are traversed to obtain a corresponding set of projection coordinates and three-dimensional coordinates;

[0013] Generate a mapping matrix based on the corresponding set.

[0014] In some optional embodiments, before obtaining mapping data of the optical signal in the digital twin and establishing a mapping matrix between the mapping data and the corresponding strip profile sub-information, the method further includes:

[0015] The first position information and the first posture of the light source assembly and the second position information and the second posture of the input light signal receiving assembly are input into the initial digital twin to adjust the initial digital twin, wherein the first position information includes the vertical height of the light signal from the ground, the vertical distance of the support from the strip roller, and the vertical height of the two ends of the strip roller from the ground; the first posture is used to characterize that the angle between the light signal emitted by the light source and the first direction is α1, and the first direction is the direction perpendicular to the thickness of the strip; the second position information includes the vertical height of the light signal receiving assembly from the ground, and the second posture is used to characterize that the angle between the imaging port of the light signal receiving assembly and the first direction is α2, wherein 0°<(α1+α2)≤45°.

[0016] In some optional embodiments, after inputting the first position information and the first posture of the light source assembly and the second position information and the second posture of the optical signal receiving assembly into the initial digital twin to adjust the initial digital twin, the method further includes:

[0017] The parameters of the optical signal receiving component in the initial digital twin are synchronized, including focal length, sensor size, lens distortion parameters, and imaging resolution, to obtain the digital twin.

[0018] In some optional embodiments, the detection data is a plurality of sets of images; obtaining a plurality of contour sub-information of the strip according to the detection data and the mapping matrix and splicing the plurality of contour sub-information to form three-dimensional contour information about the strip includes:

[0019] Filter multiple groups of images using the median filter function;

[0020] Perform binarization on the filtered image;

[0021] Extract the center line of the optical signal from the binary image and perform coordinate mapping conversion on multiple two-dimensional pixels in multiple groups of images according to the mapping matrix to obtain multiple contour sub-information of the strip;

[0022] Multiple contour sub-information are spliced ​​together to form three-dimensional contour information about the strip.

[0023] In some optional embodiments, laser line centerline extraction and coordinate mapping conversion are performed on the binary image to obtain multiple contour sub-information of the strip, including:

[0024] Scanning pixel columns along the vertical direction of the binary image;

[0025] Calculate the grayscale centroid coordinates of the light signal stripe area in each column;

[0026] According to the grayscale centroid coordinates, the grayscale values ​​are determined by weighted averaging of multiple two-dimensional pixels in multiple groups of images;

[0027] Based on the mapping matrix, the coordinates of the multiple two-dimensional pixels are converted into multiple three-dimensional space coordinates, and the multiple three-dimensional space coordinates are used as multiple contour sub-information of the strip.

[0028] In a second aspect, an embodiment of the present application provides a strip straightness detection system, the strip straightness detection system including a light source component and an optical signal receiving component; the strip straightness detection system also includes: a strip straightness detection device, the strip straightness detection device including:

[0029] A data acquisition module, used to obtain detection data of the strip in the detection area by the optical signal receiving component;

[0030] A mapping module, configured to obtain multiple contour sub-information of the strip according to the detection data and the mapping matrix and to combine the multiple contour sub-information to form three-dimensional contour information about the strip;

[0031] The straightness calculation module is used to calculate the straightness of the strip based on the three-dimensional profile information.

[0032] In some optional embodiments, the strip flatness detection system includes:

[0033] A support member is provided on one side of the strip roller in the width direction;

[0034] The light source assembly and the optical signal receiving assembly are respectively arranged at one end of the support. The light source assembly includes a light source and a light source adjustment member. The light source assembly is used to emit a detection light signal to the strip, and the light source adjustment member is used to adjust the position and direction of the light source on the support; the optical signal receiving assembly is used to obtain the detection data of the strip based on the irradiation result of the light signal on the strip in the detection area.

[0035] In some optional embodiments, the optical signal receiving assembly includes an imaging device and an imaging device adjusting member, and the imaging device adjusting member is used to adjust the position and direction of the imaging device on the supporting member.

[0036] In some optional embodiments, the support member includes a first support member and a second support member that are vertically arranged; the second support member is arranged at one end of the first support member; and the light source assembly and the optical signal receiving assembly are respectively arranged on the second support member.

[0037] In a third aspect, the present application provides an electronic device, which includes: a processor, a memory, and a computer program stored in the memory and runnable on the processor. When the computer program is executed by the processor, the steps of the detection method provided in the first aspect are implemented.

[0038] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the detection method provided in the first aspect are implemented.

[0039] In a fifth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the steps of the detection method provided in the first aspect.

[0040] According to the detection method of the embodiment of the present application, when the light source component emits a light signal to the strip, the detection data of the light signal receiving component on the strip in the detection area is synchronized to the digital twin, and then based on the detection data and the mapping matrix, multiple contour sub-information of the strip is obtained and the multiple contour sub-information is spliced ​​to form three-dimensional contour information about the strip; the straightness of the strip is calculated based on the three-dimensional contour information, which can avoid multiple internal parameter calibrations in traditional detection methods, and also avoid the low flatness accuracy obtained by fitting curve conversion in traditional methods. The detection method of this embodiment can realize flatness detection in multiple processes, and uses the three-dimensional contour information obtained by the detection data and the mapping matrix to improve the detection accuracy of the strip straightness, improve the level of strip quality control, save detection costs, and realize rapid calibration, thereby realizing the upgrade of traditional flatness devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Other features, objects and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features and the accompanying drawings are not drawn to scale.

[0042] Figure 1 A schematic flow chart of a strip steel flatness detection method provided in an embodiment of the present application is shown;

[0043] Figure 2 A schematic diagram of a process for constructing a mapping matrix provided in an embodiment of the present application is shown;

[0044] Figure 3 A schematic diagram of two-dimensional coordinates and three-dimensional coordinates in a mapping matrix provided in an embodiment of the present application is shown;

[0045] Figure 4 A schematic structural diagram of a flatness detection system in another embodiment of the present application is shown;

[0046] Figure 5 A schematic diagram showing the angle between the light signal and the detection viewing angle in a flatness detection system in another embodiment of the present application is shown;

[0047] Figure 6 A schematic structural diagram of a flatness detection device in another embodiment of the present application is shown;

[0048] Figure 7 A schematic diagram of strip 3D profile imaging of a flatness detection system in another embodiment of the present application is shown;

[0049] Figure 8 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0050] Description of reference numerals:

[0051] 100. Strip straightness detection system; 20. Light source assembly; 21. Light source; 22. Light source adjustment member; 30. Optical signal receiving assembly; 31. Imaging device; 32. Imaging device adjustment member; 40. Strip straightness detection device; 41. Data acquisition module; 42. Mapping module; 43. Straightness calculation module; 50. Support member; 60. Strip roller; 70. Strip; 80. Detection area; 81. Boundary line; 90. Light curtain; 801. Processor; 802. Memory; 803. Communication interface; 810. Bus. DETAILED DESCRIPTION

[0052] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0053] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0054] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "on" or "over" another layer or region, it may mean that it is directly on the other layer or region, or that other layers or regions are included between it and the other layer or region. Furthermore, if the component is turned over, the layer or region will be "below" or "beneath" the other layer or region.

[0055] Traditional flatness detection devices require internal and external calibration of the camera and other equipment before use. For example, a calibration device is used to simulate several typical strip thicknesses for calibration. This process records the height offset of the strips at these typical thicknesses in the camera's field of view. The height offset for other thicknesses is then derived through fitting and other methods. Ultimately, a conversion factor is generated to convert the actual object height to the laser line height in the camera image, enabling flatness calculation. For example, during the calibration phase, calibration blocks of different standard thicknesses, such as 10mm and 20mm, are inspected and processed to generate parameters. For thicknesses between 10mm and 20mm, fitting is used to generate parameters for testing. However, in actual production, it is not possible to calibrate every thickness layer. This method, which utilizes the camera's image height position and conversion factor, is limited to situations where the camera is positioned directly above the strip. Furthermore, the derivation of the strip's surface profile height requires multiple calibration and conversion steps, making the process cumbersome and reducing flatness accuracy.

[0056] The embodiments of the present application provide a flatness detection method and a detection system. The various embodiments of the flatness detection method and the detection system will be described below with reference to the accompanying drawings.

[0057] Figure 1 A schematic flow chart of a flatness detection method provided in an embodiment of the present application is shown.

[0058] See also Figure 1 The detection method is used for a strip straightness detection system 100 , which includes a light source component 20 and an optical signal receiving component 30 ; the detection method includes: steps 100 to 300 .

[0059] Step 100 : Control the light source assembly 20 to emit a light signal to the strip 70 , and obtain detection data of the strip 70 in the detection area 80 from the light signal receiving assembly 30 .

[0060] In this step, the detection data can be multiple sets of images, multiple two-dimensional coordinate data of the strip 70 extracted from multiple images, or 2D screen coordinate data of multiple strips 70. The strip 70 can be a steel strip, a copper strip, an aluminum strip, an alloy strip, a plastic strip, a rubber strip, a composite strip, etc. The detection area 80 can be the intersection of the light curtain 90 formed by the light source 21 and the strip 70, for example, the intersection of the laser light curtain and the steel strip.

[0061] In step 200 , a plurality of contour sub-information of the strip 70 is obtained based on the detection data and the mapping matrix, and the plurality of contour sub-information is spliced ​​together to form three-dimensional contour information about the strip 70 .

[0062] In this step, the mapping matrix includes multiple preset correspondences between strip 70 inspection data and the strip's spatial coordinates. This can be understood as multiple preset correspondences between the strip's 2D coordinates and the strip's spatial coordinates. By converting the inspection data into spatial coordinates, multiple sub-profiles of the strip 70 are obtained. These sub-profiles are then combined to form 3D profile information about the strip 70. This system then generates the strip's complete spatial position data.

[0063] Step 300: Calculate the straightness of the strip 70 based on the three-dimensional profile information.

[0064] In this step, the straightness of the strip 70 can be calculated based on the three-dimensional profile information using existing methods or methods described in embodiments of the present application. For example, a longitudinal cross-sectional curve can be extracted from the three-dimensional profile data. The curve is composed of contour points distributed along the length of the strip 70. A reference plane fit is performed on the longitudinal cross-sectional curve, and the deviation of each contour point from the reference plane is calculated. A straightness index is then output based on the statistical distribution or extreme values ​​of the deviation values. The straightness index can include at least one of waviness, warpage, or relative curvature.

[0065] This detection method is based on the triangulation arrangement of the optical signal, the optical signal receiving assembly 30 and the strip 70 during detection, and is therefore called a triangulation method.

[0066] According to the detection method of the embodiment of the present application, when the light source component 20 emits a light signal to the strip 70, the light signal receiving component 30 obtains detection data of the strip 70 in the detection area 80 based on the light signal, and synchronizes it to the digital twin, and then obtains multiple contour sub-information of the strip 70 according to the detection data and the mapping matrix, and splices the multiple contour sub-information to form three-dimensional contour information about the strip 70; the straightness of the strip 70 is calculated according to the three-dimensional contour information, which can avoid multiple internal parameter calibrations in traditional detection methods, and also avoid the low precision of the traditional flatness calculation using fitting parameters. The detection method can realize flatness detection in a variety of application scenarios or processes; the straightness of the strip 70 is calculated according to the three-dimensional contour information, which improves the detection accuracy of the straightness of the strip 70, improves the quality control level of the strip 70, and can save detection costs and realize rapid calibration, thereby realizing the upgrade of traditional flatness devices.

[0067] In some optional embodiments, in step 200, the method for constructing the mapping matrix includes:

[0068] Control the light source 21 in the digital twin to emit light signals to a preset area;

[0069] Obtain the mapping data of the optical signal in the digital twin, and establish a mapping matrix between the mapping data and the corresponding strip 70 contour sub-information; wherein the mapping data is obtained through the perspective of the optical signal receiving component 30 in the digital twin, and the mapping data is a two-dimensional coordinate system; the strip 70 contour sub-information is the spatial position of the light curtain 90 formed by the optical signal in the digital twin, and the strip 70 contour sub-information is a three-dimensional coordinate system.

[0070] In the digital twin, the light source assembly 20 and the optical signal receiving assembly 30 are simulated accordingly. The strip 70 and the strip roller 60 supporting the strip 70 can also be simulated.

[0071] By simulating the light signal emitted by the light source assembly 20, a correspondence is established between the two-dimensional coordinates of all possible spatial positions of the strip 70 and the three-dimensional coordinate system of the spatial position. This correspondence can be understood as the correspondence between the two-dimensional coordinates that the actual strip 70 may present and the three-dimensional coordinates of the contour sub-information of the strip 70, that is, the mapping matrix.

[0072] The flatness detection system may include a storage device for persistently storing the mapping matrix. For example, the mapping matrix may be stored in a hard disk or cloud storage device in the form of a binary file, a database table, or a structured data format.

[0073] Figure 2 This is a flowchart of a mapping matrix construction method provided in an embodiment of the present application.

[0074] See Figure 2 , the construction method of the mapping matrix includes:

[0075] Step 201: Based on the light curtain 90 formed by the optical signal in the digital twin, for each point on the light curtain 90, the projection coordinates (u, v) in the two-dimensional coordinate system are obtained through the perspective of the optical signal receiving component 30, and the corresponding three-dimensional coordinates (x, y, z) are obtained respectively. The set of projection coordinates is the mapping data, and the set of three-dimensional coordinates is used as the strip 70 profile sub-information;

[0076] Step 202 , based on the correspondence between the projection coordinates (u, v) in the mapping data and the three-dimensional coordinates (x, y, z) in the strip 70 profile sub-information, traverse all pixel points that intersect with the light signal within the field of view of the optical signal receiving component 30 to obtain a corresponding set of projection coordinates and three-dimensional coordinates;

[0077] Step 203: Generate a mapping matrix according to the corresponding set.

[0078] In an embodiment of the present application, a set of corresponding relationships between mapping data and contour sub-information of the strip 70 is established in the digital twin, and a mapping matrix is ​​obtained, which avoids the prior art of measuring the two-dimensional coordinates of the strip multiple times at different positions or under different process conditions, and establishing a curve through the two-dimensional coordinates to achieve flatness calculation; thereby, manpower is saved, operation is convenient and simple, efficiency is improved, and the quality of the strip 70 can be better controlled.

[0079] Compared to the existing technology, which uses a laser line formed by a laser emitter striking the surface of strip 70 of various thicknesses, several typical thicknesses are calibrated to achieve conversion and calculate the flatness of strip 70. In this method, strip 70 is always within light curtain 90, so the mapping matrix covers data for all thickness specifications. This workload is almost impossible to complete in reality, avoiding tedious operations. Therefore, by replacing real-world calibration with calibration in the digital twin, this almost impossible task can be accomplished, thereby improving the accuracy of flatness.

[0080] In some optional embodiments, the method further includes: constructing an initial digital twin based on the flatness detection system.

[0081] The initial digital twin can be understood as a virtual space within a simulation system or software, or as part of a flatness detection device. The support member 50, light source assembly 20, and optical signal receiving assembly 30 are correspondingly positioned within the initial digital twin. The initial digital twin may also include the strip 70 to be inspected and the strip roller 60.

[0082] After inputting the initial data, the digital twin can automatically generate a mapping matrix, avoiding the need for multiple calibrations of parameters using a calibration device before use in other existing methods or traditional flatness devices. The operation is cumbersome and inefficient, and requires personnel to work near the roller, which is highly dangerous. Therefore, this method achieves rapid calibration.

[0083] It is understandable that the posture and position of the aforementioned devices or equipment within the digital twin must be consistent with the actual physical world. This allows the calibration work required by existing technologies to be performed within the digital twin, allowing calibration to be performed for each thickness layer to be inspected, avoiding errors that may be introduced by fitting operations. This significantly reduces workload and improves efficiency compared to traditional methods.

[0084] Figure 3This is a schematic diagram illustrating the formation of two-dimensional and three-dimensional coordinates in a mapping matrix provided by an embodiment of the present application. When the light source assembly 20 transmits a light signal to the strip 70, the light signal receiving assembly 30 generates the two-dimensional coordinates of the strip 70's position. These two-dimensional coordinates are synchronized to the digital twin. Through the mapping matrix, the corresponding three-dimensional coordinates of the strip 70 in the digital twin are obtained. These three-dimensional coordinates are then concatenated in the digital twin to obtain the corresponding three-dimensional profile information of the strip. This facilitates the subsequent calculation of the strip 70's straightness.

[0085] In some optional embodiments, before obtaining mapping data of the optical signal in the digital twin and establishing a mapping matrix between the mapping data and corresponding strip 70 profile sub-information, the method further includes:

[0086] Step 150, input the first position information and the first posture of the light source assembly 20 and the second position information and the second posture of the input optical signal receiving assembly 30 into the initial digital twin to adjust the initial digital twin, wherein the first position information includes the vertical height of the optical signal from the ground, the vertical distance of the support 50 from the strip roller 60, and the vertical height of the two ends of the strip roller 60 from the ground; the first posture is used to characterize that the angle between the light signal emitted by the light source and the first direction is α1, and the first direction is the direction perpendicular to the thickness of the strip 70; the second position information includes the vertical height of the optical signal receiving assembly 30 from the ground, and the second posture is used to characterize that the angle between the imaging port of the optical signal receiving assembly 30 and the first direction is α2, wherein 0°<(α1+α2)≤45°, which can be optionally 15°≤(α1+α2)≤40°.

[0087] In this embodiment, the position and posture of the light source component 20 and the optical signal receiving component 30 in the digital twin are corrected, so that the detection data measured by the actual optical signal receiving component 30 can be converted into the digital twin to obtain the three-dimensional contour information of the strip 70, thereby calculating the flatness, which is beneficial to improving the accuracy of the flatness measurement.

[0088] The angle will affect the displacement of the light signal imaging on the object being measured. The smaller the angle, the smaller the displacement and the smaller the change in flatness. A higher resolution of the detection camera is required. When the light source remains unchanged, the error increases and the cost increases.

[0089] On the contrary, the larger the angle, the greater the displacement, but the light will diverge more on the surface of the object being measured, the light intensity performance will deteriorate, affecting the accuracy, and the need to increase the light power, which increases the cost; therefore, the above range of α1+α2 can achieve detection, but the appropriate angle can control costs and reduce errors.

[0090] In some optional embodiments, after inputting the first position information and the first posture of the light source assembly 20 and the second position information and the second posture of the optical signal receiving assembly 30 into the initial digital twin to adjust the initial digital twin, the method further includes:

[0091] Step 160 , synchronize the parameters of the optical signal receiving component 30 in the initial digital twin, the parameters including focal length, sensor size, lens distortion parameters and imaging resolution, to obtain a digital twin.

[0092] In this embodiment, the parameters of the optical signal receiving component 30 in the digital twin are corrected. By setting the parameters of the actual optical signal receiving component 30 in the digital twin, the detection data measured by the actual optical signal receiving component 30 is converted in the digital twin to obtain the three-dimensional contour information of the strip 70, thereby calculating the flatness, which is conducive to improving the accuracy of the flatness measurement.

[0093] In some optional embodiments, the detection data is a plurality of sets of images; step 200, based on the detection data and the mapping matrix, obtains a plurality of contour sub-information of the strip 70 and splices the plurality of contour sub-information to form three-dimensional contour information about the strip 70, including:

[0094] Step 210, filtering the multiple groups of images using a median filter function;

[0095] In this step, a median filter (nonlinear filtering) is used to sort the grayscale values ​​within each pixel's neighborhood and take the median value. This effectively suppresses noise while preserving edge sharpness. This eliminates image noise (such as sensor noise and ambient light interference), preserves edge information, and avoids distortion in subsequent contour extraction. For example, if the surface of strip 70 has reflective spots, median filtering can eliminate these isolated noise points, preventing them from being mistakenly identified as contour edges during binarization.

[0096] Step 220, performing binarization processing on the filtered image;

[0097] After binarization, since the laser line itself also has a certain width, it is necessary to extract the center line first. The steps for extracting the center line are: obtain the upper edge vertical coordinate v0 and the lower edge coordinate v1 of the white laser line at the horizontal coordinate u position, then the center line vertical coordinate v of the laser line at the horizontal coordinate u position is v=v0+v1-v0, and this method is used to traverse the image horizontally to obtain the center line vertical coordinates of each horizontal coordinate position to form a 2D coordinate set and record it.

[0098] In this step, a threshold (such as the automatic threshold using the Otsu algorithm) is set to classify pixel grayscale values ​​into two categories, such as 0 or 255, to separate the strip 70 area from the background. This converts the grayscale image into a black-and-white binary image, highlighting the contrast between the strip 70 and the background and facilitating contour segmentation. For example, in low light conditions during the process, the background of the image interface is gray. Binarization can convert the strip 70 against the gray background into a white area and the background into black, creating a clear boundary.

[0099] Step 230 , extracting the centerline of the optical signal from the binary image and performing coordinate mapping conversion on multiple two-dimensional pixels in the multiple groups of images according to a mapping matrix to obtain multiple contour sub-information of the strip 70 ;

[0100] In this step, a pre-calibrated mapping matrix (camera-laser coordinate system conversion relationship) is used to convert the projection coordinates (u, v) into three-dimensional coordinates (x, y, z), thereby accurately extracting the center line of the edge of the strip 70 (sub-pixel accuracy) and converting the two-dimensional image coordinates into three-dimensional space coordinates, thereby improving the accuracy of the contour sub-information and achieving the effect of improving the flatness accuracy.

[0101] In this step, centerline extraction can be performed using a light stripe method (such as the Steger algorithm) to detect the center of the laser light stripe and obtain sub-pixel edges. For example, the edge of strip 70 appears as a curved light strip in the image. Centerline extraction can produce a continuous curve, which, after mapping, is mapped to a 3D contour point cloud in real space. This facilitates accurate extraction of the centerline of the strip 70 edge (with sub-pixel accuracy) and improves the accuracy of straightness.

[0102] In step 240 , the plurality of contour sub-information are spliced ​​together to form three-dimensional contour information about the strip 70 .

[0103] In this step, multiple sub-profile information is stitched together to form a 3D profile of strip 70. This can be achieved by unifying coordinates (e.g., using the ICP point cloud registration algorithm) or synchronizing motion platform data. This allows for the stitching of multiple frames of profile data, eliminating overlap errors, and fusing scan data from different viewing angles or positions into a complete 3D profile. For example, after scanning strip 70 in segments, the 3D points of each segment are stitched together to reconstruct the overall profile, such as fully revealing any flatness defects in strip 70.

[0104] In some optional embodiments, step 230 is to perform laser line centerline extraction and coordinate mapping conversion on the binary image to obtain multiple contour sub-information of the strip 70, including:

[0105] Step 231, scanning pixel columns along the vertical direction of the binary image;

[0106] In this step, pixels are scanned column by column along the vertical direction of the image (assuming the laser line is projected horizontally), detecting the continuous non-zero pixel regions (i.e., laser streaks) within each column. This allows for column-by-column analysis of the binary image and localization of the laser streak distribution within each column, providing the data foundation for subsequent centerline extraction. For example, if the laser line appears as a horizontal bright band in the image, scanning the 100th column of pixels reveals that the pixels in rows 50-70 are white with a grayscale of 255, this column is identified as a streak region.

[0107] Step 232, calculating the grayscale centroid coordinates of the light signal stripe area in each column;

[0108] In this step, the grayscale centroid of the stripe area for each column of pixels can be calculated. For example, the formula yc = ∑(yi·Ii) / ∑Ii can be used, where yi is the row coordinate and Ii is the grayscale value. This allows for sub-pixel positioning of the laser stripe center, improving the accuracy of contour measurement and enabling clearer extraction of edge pixels compared to a simple binary image. For example, if a stripe column covers rows 50-70, with the grayscale highest on row 60 and decreasing on adjacent rows, the grayscale centroid might be calculated as row 62.3 (sub-pixel accuracy).

[0109] Step 233, determining a plurality of two-dimensional pixels in the plurality of groups of images by weighted averaging the grayscale values ​​according to the grayscale centroid coordinates;

[0110] As the strip 70 passes through the measured area at a constant speed, multiple sets of images are obtained, and finally, when the strip 70 leaves the measured area, the coordinate sets can be summarized.

[0111] In this step, multiple scans of the same location are weighted and averaged according to grayscale value weights (confidence levels) to obtain the final 2D pixel coordinates. This integrated multi-frame image data reduces random errors through weighted averaging, improving the stability of centerline coordinates. For example, if the center of gravity coordinates of the same location in three frames are 62.1, 62.3, and 62.0, the weighted average output is 62.15, suppressing single-frame noise.

[0112] In step 234 , based on the mapping matrix, the plurality of two-dimensional pixel coordinates are converted into a plurality of three-dimensional space coordinates, and the plurality of three-dimensional space coordinates are used as a plurality of contour sub-information of the strip 70 .

[0113] In this step, the mapping relationship in the mapping matrix is ​​used to accurately measure the 2D image to 3D dimensions. For example, the 3D coordinates can be (10.2, 0.5, 25.3 mm), and this point is used as the contour sub-information for subsequent splicing to form the 3D contour information.

[0114] Figure 4 A structural schematic diagram of a flatness detection system in another embodiment of the present application is shown.

[0115] See also Figure 4 The strip straightness detection system 100 includes a light source component 20 and an optical signal receiving component 30 ; the strip straightness detection system 100 also includes: a strip straightness detection device 40 .

[0116] The straightness detection system may include: a support member 50, which is arranged on one side of the strip roller 60 in the width direction; a light source assembly 20 and an optical signal receiving assembly 30 are respectively arranged at one end of the support member 50, the light source assembly 20 includes a light source 21 and a light source adjustment member 22, the light source assembly 20 is used to emit a detection light signal to the strip 70, and the light source adjustment member 22 is used to adjust the position and direction of the light source 21 on the support member 50; the optical signal receiving assembly 30 is used to obtain detection data of the strip 70 based on the irradiation result of the light signal on the strip 70 in the detection area 80.

[0117] The light source 21 may include a laser, an infrared emitter, etc. The laser light emitted by the laser has a narrow spectral bandwidth and can generate a continuous and stable light source 21. The light source 21 emitted by the light source 21 may be a laser, an infrared light, etc. For example, a laser emitter can continuously emit a linear laser, and the light curtain 90 emitted is irradiated on the object to be measured to form a laser line. The light signal emitted by the light source 21 can form a light curtain 90, please refer to Figure 4 From the figure, it can be observed that the light curtain 90 reaches the strip 70 and illuminates the strip 70 in the detection area 80. The edge of the detection area 80 has a boundary line 81. For example, multiple laser lines can form the light curtain 90.

[0118] The light source adjustment member 22 may be a laser adjustment beam, which may be fixed to one end of the support member 50 and may be connected to the laser mounting frame.

[0119] Figure 4 In the figure, x represents the cross-sectional direction of the roller, y represents the running direction of the roller, and z represents the vertical direction. The support member 50 can be a mounting column, which can serve as a base support for the light source assembly 20 and the optical signal receiving assembly 30. The bottom can be fixed vertically to the ground by bolts, welding, etc.

[0120] Since different processing and manufacturing companies have different production line layouts, the gantry-type flatness detection system is not well suited to all production line application scenarios. For example, in the operation scenario where there is an overhead crane lifting, the overhead crane will interfere with the gantry, and the incompatibility will make it impossible to install. For example, there is a cooling bed or other structure next to the product conveying roller, which makes it impossible to install the gantry. For example, there are other frame structures above the roller, and there is no installation space for the gantry. For example, in high temperature and high heat environments, the thermal insulation requirements for the gantry are high, and maintenance is difficult.

[0121] In order to solve the problem that the gantry-type flatness detection system is not well suited for all production line application scenarios, the support member 50 is set on one side of the strip roller 60 in the width direction; the light source component 20 and the optical signal receiving component 30 are respectively set at one end of the support member 50.

[0122] Therefore, the light source component 20 and the optical signal receiving component 30, such as the detection camera and laser transmitter, not only have y-axis rotation changes, but also x-axis rotation changes. Due to the angle problem, the optical signal is no longer a horizontal line in the 2D space during imaging detection, but an oblique line from near to far in the 3D space. At this time, the changes in the optical signal lines at different strip 70 heights become complicated, and will also be more affected by the fisheye distortion of the lens. Therefore, traditional calibration and detection methods are no longer applicable.

[0123] According to an embodiment of the present application, the support member 50 is arranged on one side in the width direction of the strip roller 60, and the light source component 20, the optical signal receiving component 30 and the support member 50 are simulated in the digital twin. According to the detection data of the optical signal receiving component 30, the three-dimensional contour information of the strip is generated using the mapping matrix. This detection method is convenient and fast, and the detection system is suitable for various scenarios, and also avoids the problem of fisheye distortion of the lens.

[0124] The flatness detection system includes a support 50, a light source assembly 20, an optical signal receiving assembly 30, and a flatness detection device. The flatness detection system may include a data acquisition module 41, a mapping module 42, and a flatness calculation module 43. The light source assembly 20 is located on the support 50 and emits an optical signal toward the strip 70 in the detection area 80 within the strip roller 60. The light source assembly 20 includes an optical signal. The detection optical signal emitted by the optical signal is an optical signal with different spectral bandwidths. The optical signal reaches the optical signal receiving assembly 30, which converts the optical signal on the strip 70 in the detection area 80 into detection data. The mapping module 42 obtains the detection data through the mapping matrix to obtain the three-dimensional contour information of the strip 70; the flatness calculation module 43 can calculate the straightness of the strip 70 based on the three-dimensional contour information. The flatness detection system of the present application can perform flatness detection on the strip 70 at various process positions, and replaces the real space calibration with calibration in virtual space or digital twin, thereby achieving tasks that are almost impossible to complete in reality, realizing the effects of rapid calibration, cost savings, and convenient maintenance of the system, thereby realizing the upgrade of traditional flatness devices.

[0125] In some optional embodiments, the optical signal receiving assembly 30 includes an imaging device 31 and an imaging device adjusting member 32 , and the imaging device adjusting member 32 is used to adjust the position and direction of the imaging device 31 on the supporting member 50 .

[0126] Exemplarily, the imaging device 31 in the optical signal receiving component 30 can be a detection camera for capturing the laser line profile image, which can be connected to the imaging device adjustment member 32, such as a camera adjustment bracket, to capture the roller area image, and the shooting range is defined as the measured area.

[0127] For example, the light source adjustment member 22 in the optical signal receiving assembly 30 may include a camera adjustment beam fixed to one side of the top of the mounting post for supporting the camera device. The light source adjustment member 22 may also include a camera adjustment bracket that connects the camera adjustment beam and the detection camera and has y-axis and z-axis rotation adjustment capabilities.

[0128] In some optional embodiments, the support member 50 includes a first support member 50 and a second support member 50 disposed vertically; the second support member 50 is disposed at one end of the first support member 50; the light source assembly 20 and the optical signal receiving assembly 30 are respectively disposed on the second support member 50. The first support member 50 and the second support member 50 can be disposed at an angle, for example, perpendicularly.

[0129] Optionally, the support member 50 can be set in the strip 70 production line, such as in an operation scenario where there is an overhead crane lifting operation, for easy installation; in a narrow space where there is a cooling bed or other mechanism next to the conveying roller of the strip 70 production line and other frame structures above the strip roller 60; in a high temperature and high heat environment, with high requirements for gantry insulation and difficult maintenance.

[0130] The light source assembly 20 and the optical signal receiving assembly 30 can be respectively disposed on the second support member 50. The light source assembly 20 can be located above or on a side of the strip 70. The optical signal emitted by the light source assembly 20 can be a laser, an infrared light source 21, etc. The optical signal receiving assembly 30 can be located above or on a side of the strip 70.

[0131] The receiving port of the optical signal receiving component 30 and the optical signal sent by the light source 21 form a certain angle relationship, so that the light curtain 90 formed by the optical signal is irradiated on the surface of the strip 70, and the optical signal is within the field of view or signal receiving range of the optical signal receiving component 30, that is, within the detection area 80. The relationship between the angle α between the two is as follows: Figure 5 shown.

[0132] Figure 5 A schematic diagram showing the angle between the light signal and the detection viewing angle in a flatness detection system in another embodiment of the present application is shown; Figure 5In the figure, (a) shows that the light signal emitted by light source 21 is perpendicular to the strip 70 along the z-axis, and the imaging port of light signal receiving assembly 30 is tilted along the z-axis at an angle of α1; (b) shows that the imaging port of imaging device 31 is perpendicular to the strip 70 along the z-axis, and the light signal emitted by light source 21 is tilted along the z-axis at an angle of α2; (c) shows that the imaging port of light signal receiving assembly 30 and the light signal emitted by light source 21 act on strip 70, respectively, at angles α1 and α2 relative to the z-axis normal. As can be seen from the figure, the angle between the imaging port of light signal receiving assembly 30 and the first direction is α1, and the angle between the light signal emitted by light source 21 and the first direction is α2. The first direction is perpendicular to the thickness of strip 70, and 0°≤(α1+α2)≤45°, which can be 15°≤(α1+α2)≤45°.

[0133] Accordingly, when detecting the straightness of the strip 70, the first position information and the first posture of the light source assembly 20 can be adjusted. The first posture is used to characterize that the angle between the emitted light of the light source 21 and the first direction is α1, and the first direction is the direction perpendicular to the thickness of the strip 70; the second position information and the second posture of the data acquisition module 41 are adjusted to adjust the initial digital twin to obtain the digital twin; the second posture is used to characterize that the angle between the imaging port of the optical signal receiving assembly 30 and the first direction is α2. Based on α1 and α2, the detection area 80 of the strip 70 is determined.

[0134] Furthermore, the flatness detection system is equipped with an electrical box with a built-in network communication module and power supply module for transmitting detection data and connecting various devices to the power supply and / or network. An image processing server can be provided within the data acquisition module 41. The image processing server can be connected to the optical signal receiving component 30 (camera) via an Ethernet network for data acquisition and processing of raw images.

[0135] Figure 6 A schematic structural diagram of a flatness detection device in another embodiment of the present application is shown.

[0136] See Figure 6 , the strip straightness detection device 40 comprises:

[0137] The data acquisition module 41 is used to obtain the detection data of the strip 70 in the detection area 80 by the optical signal receiving component 30;

[0138] A mapping module 42 is configured to obtain a plurality of contour sub-information of the strip 70 based on the detection data and the mapping matrix and to combine the plurality of contour sub-information to form three-dimensional contour information of the strip 70;

[0139] The straightness calculation module 43 is used to calculate the straightness of the strip 70 based on the three-dimensional profile information. This module is also a software module. It receives the three-dimensional profile information from the mapping module 42 and calculates the strip's straightness parameters by analyzing the height variations at different locations on the strip surface. These parameters can include indicators such as waviness, edge waviness, center waviness, and quarter waviness, which quantify the flatness of the strip surface. The straightness calculation module 43 can use mathematical methods such as least squares and Fourier analysis to generate a straightness evaluation result that meets industry standards.

[0140] In some optional embodiments, the mapping module 42 includes a stored mapping matrix. The implementation means of the mapping matrix may include:

[0141] The analog optical signal module permanently controls the light source 21 in the digital twin to emit optical signals to the preset areas;

[0142] The mapping matrix determination module is used to obtain the mapping data of the optical signal in the digital twin and establish a mapping matrix between the mapping data and the corresponding strip 70 contour sub-information; wherein the mapping data is obtained through the perspective of the optical signal receiving component 30 in the digital twin, and the mapping data is a two-dimensional coordinate system; the strip 70 contour sub-information is the spatial position of the light curtain 90 formed by the optical signal in the digital twin, and the strip 70 contour sub-information is a three-dimensional coordinate system.

[0143] In some optional embodiments, the mapping matrix determination module specifically includes:

[0144] A coordinate acquisition module is used to generate a light curtain 90 based on the optical signal in the digital twin. For each point on the light curtain 90, the projected coordinates (u, v) in the two-dimensional coordinate system are obtained through the perspective of the optical signal receiving component 30, and the corresponding three-dimensional coordinates (x, y, z) are obtained respectively. The set of projected coordinates is the mapping data, and the set of three-dimensional coordinates is used as the strip 70 profile sub-information.

[0145] A coordinate set corresponding module is used to traverse all pixel points that intersect with the light signal within the field of view of the optical signal receiving component 30 based on the corresponding relationship between the projected coordinates (u, v) in the mapping data and the three-dimensional coordinates (x, y, z) in the strip 70 profile sub-information to obtain a corresponding set of projected coordinates and three-dimensional coordinates;

[0146] The mapping matrix generation module is used to generate a mapping matrix according to the corresponding set.

[0147] In some optional embodiments, the strip straightness detection device 40 further includes:

[0148] The adjustment module is used to input the first position information and the first posture of the light source component 20 and the second position information and the second posture of the input optical signal receiving component 30 into the initial digital twin to adjust the initial digital twin.

[0149] In some optional embodiments, the strip straightness detection device 40 further includes:

[0150] The optical signal receiving component 30 adjustment module synchronizes the parameters of the optical signal receiving component 30 in the initial digital twin, including focal length, sensor size, lens distortion parameters and imaging resolution, to obtain the digital twin.

[0151] In some optional embodiments, the detection data is a plurality of sets of images; the mapping module 42 specifically includes:

[0152] A filtering processing module, used for performing filtering processing on multiple groups of images using a median filter function;

[0153] A binarization processing module, used for performing binarization processing on the filtered image;

[0154] A mapping conversion module is used to extract the center line of the optical signal from the binary image and perform coordinate mapping conversion on multiple two-dimensional pixels in multiple groups of images according to the mapping matrix to obtain multiple contour sub-information of the strip 70;

[0155] The three-dimensional contour information determination module is used to splice multiple contour sub-information to form three-dimensional contour information about the strip 70.

[0156] In some optional embodiments, the mapping conversion module specifically includes:

[0157] A pixel column scanning module is used to scan pixel columns along the vertical direction of the binary image;

[0158] A grayscale centroid coordinate calculation module is used to calculate the grayscale centroid coordinates of the light signal stripe area in each column;

[0159] A two-dimensional pixel weighting module is used to determine multiple two-dimensional pixels in multiple groups of images by weighted averaging the grayscale values ​​according to the grayscale centroid coordinates;

[0160] The contour sub-information determination module is used to convert multiple two-dimensional pixel coordinates into multiple three-dimensional space coordinates based on the mapping matrix, and the multiple three-dimensional space coordinates are used as multiple contour sub-information of the strip 70.

[0161] As an example, the strip straightness detection system 100 of this embodiment is deployed at the quenching machine outlet of the plate roller hearth furnace production line to detect the flatness of the plate after heat treatment. The width of the plate roller hearth furnace production line is 4500mm, and the maximum width of the plate is 4000mm. The strip straightness detection system 100 is installed on the left side of the roller and in the production direction. The support column is 3500mm high. The laser emitter uses 405nm blue light with a power of 4W. The laser line width is less than 5mm, and the line width covers the roller width; the detection camera uses a 4K resolution industrial camera with an exposure setting of 15000μs to ensure that the laser lines are clearly visible. The angle between the laser emitter and the industrial camera along the y-axis is 30°; the image processing server uses an NVIDIA graphics card and uses OPENCV+CUDA for processing acceleration; the digital twin design tool uses the current mainstream 3D engine tool Unity3D.

[0162] After the above-mentioned devices are prepared, they are measured and calibrated. Auxiliary tools such as handheld laser rangefinders and electronic levels are used to determine the relative positions of the laser emitter, detection camera, and roller conveyor. Then, a consistent digital twin is created in Unity3D. The parameters of the camera in the virtual space or digital twin are adjusted to keep them completely consistent with the physical detection camera. This solution uses an area array industrial camera with a focal length of 16mm, a sensor size of 14×10.5, a lens distortion of 0.33%, and a resolution of 4096×3000.

[0163] Once the digital twin is ready, create the mapping matrix. For example, you can use the Screen Point To Ray method in Unity3D to create a transmission line from the camera screen coordinate system or 2D coordinate system to the world coordinate system or 3D coordinate system. Using the Physics.Raycast method, capture the relative coordinates of each 3D coordinate point on the laser light curtain in the world coordinate system to the screen coordinate system. Use transform.position to extract this coordinate information and save it to the mapping matrix. This completes the construction of the mapping matrix.

[0164] Application part of the strip flatness detection system 100: The detection camera acquires multiple sets of images of the running strip steel, which are loaded into the mapping matrix in the memory. The acquired images are then filtered to eliminate noise and smooth the laser line. This can be done through the cuda:createMedianFilter median filter function of OPENCV+CUDA. Binarization is then performed using the cuda:threshold binarization function. Finally, the center line of the laser line is extracted and the coordinate mapping is converted from the binarized image. This is done using a self-written cuda kernel function. The function algorithm principle refers to the center line extraction mentioned above. Finally, the coordinate set of the three-dimensional contour information of the frame image is obtained. The actual on-site measurement is close to the detection result, with an error of less than 2mm and a single frame processing time of less than 50ms. The effect is ideal and meets the application requirements.

[0165] Figure 7 FIG2 is a schematic diagram of strip 3D contour imaging of a strip straightness detection system 100 in another embodiment. As can be seen from the figure, based on the strip contour sub-information, the strip 3D contour information is formed and imaged in the digital twin.

[0166] The strip straightness detection system 100 and detection method of the embodiment of the present application have the following advantages over conventional straightness detection systems and detection methods:

[0167] 1. This strip straightness detection method can be easily installed and arranged without occupying the space above the roller table, and is suitable for various working scenarios.

[0168] 2. The strip flatness detection method does not require complex on-site system calibration. The main operations are implemented or completed in the digital twin, which reduces on-site labor intensity and avoids unexpected errors caused by calibration.

[0169] 3. The coordinate mapping matrix obtained in the digital twin fully covers the possible location information of strip products of various thickness specifications, making up for the deficiency of traditional calibration methods that can only be calibrated by sampling, and improving the detection accuracy and effect;

[0170] 4. Compared with traditional methods, the strip flatness detection system has lower overall cost and lower maintenance difficulty.

[0171] The specific implementation of each step of the above detection method has been described in detail above when introducing the flatness detection system, and can achieve its corresponding technical effects. For the sake of brevity, it will not be repeated here.

[0172] Based on the detection method provided in the above embodiment, the present application also provides a specific implementation of the electronic device. Please refer to the following embodiment.

[0173] Figure 8A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0174] The electronic device may include a processor 801 and a memory 802 storing computer program instructions.

[0175] Specifically, the processor 801 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0176] The memory 802 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 802 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 802 may include removable or non-removable (or fixed) media. Where appropriate, the memory 802 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 802 is a non-volatile solid-state memory.

[0177] In certain embodiments, the memory 802 may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0178] The processor 801 reads and executes computer program instructions stored in the memory 802 to implement any one of the flatness detection methods in the above embodiments.

[0179] In one example, the electronic device may further include a communication interface 803 and a bus 810. Figure 7 As shown, the processor 801, the memory 802, and the communication interface 803 are connected via a bus 810 and communicate with each other.

[0180] The communication interface 803 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0181] Bus 810 comprises hardware, software or both, couples the parts of electronic equipment to each other.For example, and not limitation, bus can comprise accelerated graphics port (AGP) or other graphics bus, enhanced industry standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industry standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations.In suitable cases, bus 810 can comprise one or more buses.Although the present application embodiment describes and shows specific bus, the application considers any suitable bus or interconnection.

[0182] The electronic device can execute the flatness detection method in the embodiment of the present application.

[0183] In addition, in conjunction with the flatness detection method in the above embodiments, embodiments of the present application may provide a computer-readable storage medium for implementation. The computer-readable storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the flatness detection methods in the above embodiments is implemented.

[0184] In combination with the flatness detection method in the above embodiment, an embodiment of the present application may provide a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes any one of the above flatness detection methods.

[0185] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0186] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0187] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0188] Aspects of the present disclosure have been described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit. It is also understood that each box in the block diagram and / or flowchart and the combination of the boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0189] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the scope of protection of the present application.

Claims

1. A method for detecting the straightness of a strip, characterized in that: The method is used in a strip straightness detection system, which includes a light source component and an optical signal receiving component; the method includes: Controlling the light source component to emit a light signal to the strip, and obtaining detection data of the strip in the detection area by the light signal receiving component; According to the detection data and the mapping matrix, a plurality of contour sub-information of the strip is obtained and the plurality of contour sub-information is spliced ​​together to form three-dimensional contour information about the strip; The straightness of the strip is calculated based on the three-dimensional profile information.

2. The method according to claim 1, characterized in that The method for constructing the mapping matrix includes: Control the light source in the digital twin to emit light signals to the preset area; Obtain mapping data of the optical signal in the digital twin, and establish a mapping matrix between the mapping data and the corresponding strip profile sub-information; wherein the mapping data is obtained through the perspective of the optical signal receiving component in the digital twin, and the mapping data is a two-dimensional coordinate system; the strip profile sub-information is the spatial position of the light curtain formed by the optical signal in the digital twin, and the strip profile sub-information is a three-dimensional coordinate system.

3. The method according to claim 2, characterized in that The obtaining of mapping data of the optical signal in the digital twin and establishing a mapping matrix between the mapping data and the corresponding strip profile sub-information includes: Based on the light curtain formed by the optical signal in the digital twin, for each point on the light curtain, the projection coordinates (u, v) in the two-dimensional coordinate system are obtained through the perspective of the optical signal receiving component, and the corresponding three-dimensional coordinates (x, y, z) are obtained respectively. The set of projection coordinates is the mapping data, and the set of three-dimensional coordinates is used as the strip profile sub-information; Based on the correspondence between the projection coordinates (u, v) in the mapping data and the three-dimensional coordinates (x, y, z) in the strip profile sub-information, traverse all pixel points that intersect with the light signal within the field of view of the optical signal receiving component to obtain a corresponding set of projection coordinates and three-dimensional coordinates; A mapping matrix is ​​generated according to the corresponding set.

4. The method according to claim 2, characterized in that Before obtaining the mapping data of the optical signal in the digital twin and establishing a mapping matrix between the mapping data and the corresponding strip profile sub-information, the method further includes: The first position information and the first posture of the light source component and the second position information and the second posture of the input light signal receiving component are input into the initial digital twin to adjust the initial digital twin, wherein the first position information includes the vertical height of the light signal from the ground, the vertical distance of the support from the strip roller, and the vertical height of the two ends of the strip roller from the ground; the first posture is used to characterize that the angle between the light signal emitted by the light source and the first direction is α1, and the first direction is the direction perpendicular to the thickness of the strip; the second position information includes the vertical height of the light signal receiving component from the ground, and the second posture is used to characterize that the angle between the imaging port of the light signal receiving component and the first direction is α2, wherein 0°<(α1+α2)≤45°.

5. The method according to claim 4, characterized in that After inputting the first position information and the first posture of the light source assembly and the second position information and the second posture of the optical signal receiving assembly into the initial digital twin to adjust the initial digital twin, the method further includes: Synchronize parameters of the optical signal receiving component in the initial digital twin, wherein the parameters include focal length, sensor size, lens distortion parameters, and imaging resolution, to obtain a digital twin.

6. The detection method according to claim 1, characterized in that The detection data is a plurality of sets of images; obtaining a plurality of contour sub-information of the strip according to the detection data and the mapping matrix and splicing the plurality of contour sub-information to form three-dimensional contour information about the strip includes: Filter multiple groups of images using the median filter function; performing a binarization process on the filtered image to obtain a binarized image; Extracting the center line of the optical signal from the binary image and performing coordinate mapping conversion on multiple two-dimensional pixels in multiple groups of images according to a mapping matrix to obtain multiple contour sub-information of the strip; Multiple contour sub-information are spliced ​​together to form three-dimensional contour information about the strip.

7. The detection method according to claim 6, characterized in that The laser line centerline extraction and coordinate mapping conversion are performed on the binary image to obtain multiple contour sub-information of the strip, including: Scanning pixel columns along the vertical direction of the binary image; Calculate the grayscale centroid coordinates of the light signal stripe area in each column; Determine a plurality of two-dimensional pixels in a plurality of groups of images by weighted averaging the grayscale values ​​according to the grayscale centroid coordinates; Based on the mapping matrix, the coordinates of the plurality of two-dimensional pixels are converted into a plurality of three-dimensional space coordinates, and the plurality of three-dimensional space coordinates are used as a plurality of contour sub-information of the strip.

8. A strip straightness detection system, characterized in that: The strip flatness detection system includes a light source component and an optical signal receiving component; The strip straightness detection system further includes: a strip straightness detection device, the strip straightness detection device including: A data acquisition module, configured to acquire detection data of the strip within the detection area by the optical signal receiving component; a mapping module, configured to obtain a plurality of contour sub-information of the strip according to the detection data and the mapping matrix, and to combine the plurality of contour sub-information to form three-dimensional contour information about the strip; The straightness calculation module is used to calculate the straightness of the strip according to the three-dimensional profile information.

9. The flatness detection system according to claim 8, characterized in that: The strip straightness detection system comprises: A support member, the support member being arranged on one side in the width direction of the strip roller; The light source assembly and the optical signal receiving assembly are respectively arranged at one end of the support member, the light source assembly includes a light source and a light source adjustment member, the light source assembly is used to emit a detection light signal to the strip, and the light source adjustment member is used to adjust the position and direction of the light source on the support member; the optical signal receiving assembly is used to obtain detection data of the strip based on the result of the light signal irradiating the strip in the detection area.

10. The flatness detection system according to claim 9, characterized in that: The optical signal receiving assembly includes an imaging device and an imaging device adjusting member, wherein the imaging device adjusting member is used to adjust the position and direction of the imaging device on the supporting member; The support member includes a first support member and a second support member that are vertically arranged; the second support member is arranged at one end of the first support member; the light source assembly and the optical signal receiving assembly are respectively arranged on the second support member.

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