Method and apparatus for measuring large-sized flat products

Abstract

The application provides a large-size plane product measurement method and device, relates to the technical field of large-size component measurement, and comprises the following steps: similarity comparison is performed on a scanning image of a to-be-measured plane product and a preset template image based on a static line scanning module, the to-be-measured size type of the to-be-measured plane product, mark points and pixel position coordinates of the mark points in the scanning image are determined; based on the pixel position coordinates of each mark point in the scanning image and actual pixel position coordinates corresponding to each mark point collected by a dynamic plane array telecentric module driven by a servo device, the pixel distance from each actual pixel position coordinate to the contour line where the corresponding mark point is located is determined, and the physical position coordinates of each mark point are corrected to target physical position coordinates; and the size combination of the to-be-measured plane product is calculated according to the to-be-measured size type and the target physical position coordinates of each mark point, so that the technical problem that the size measurement precision and accuracy of the large-size plane product are not high is relieved.

Description

Technical Field

[0001] This invention relates to the technical field of large-size component measurement, and in particular to a method and apparatus for measuring large-size planar products. Background Technology

[0002] Traditional methods for measuring large-size planar components employ image acquisition technology. This involves capturing a single image of the large planar component to obtain pixel information of the area under test, and then performing measurement using the conversion between pixels and actual physical dimensions. While this method is simple to operate, the large physical size of planar components makes them susceptible to interference from factors such as shooting angle, lens distortion, and ambient lighting during single-image acquisition, leading to significant deviations between the measurement results and the actual dimensions. This lack of measurement accuracy directly affects the assembly precision and overall performance of such large-size planar components during application. Summary of the Invention

[0003] The purpose of this invention is to provide a measurement method and apparatus for large-size planar products, so as to alleviate the technical problem of low accuracy and precision in the measurement of large-size planar products.

[0004] In a first aspect, the present invention provides a method for measuring large-size planar products, which is applied to a size measuring device. The size measuring device includes a test platform for placing the planar product to be measured, a servo device installed on the test platform, a static line scan module and a dynamic area array telecentric module set on the servo device.

[0005] The method includes:

[0006] Based on the similarity comparison between the scanned image of the planar product to be tested obtained by the static line scan module and the preset template image, the test size type, the marker point, and the pixel position coordinates of the marker point in the scanned image are determined;

[0007] Based on the pixel position coordinates of each of the marked points in the scanned image and the actual pixel position coordinates of each of the marked points collected by the dynamic array telecentric module driven by the servo device, the pixel distance from each of the actual pixel position coordinates to the contour line where the corresponding marked point is located is determined, and the physical position coordinates of each of the marked points are corrected to the target physical position coordinates.

[0008] The size combination of the planar product to be tested is calculated based on the size type to be tested and the target physical location coordinates of each of the marked points.

[0009] In an optional implementation, before the step of comparing the scanned image of the planar product under test obtained by the static line scan module with a preset template image to determine the test size type, marker point, and pixel position coordinates of the marker point in the scanned image, the method further includes:

[0010] Based on the scanned images of the test platform with calibrated markers acquired by the static line scan module and the images of the test platform acquired by the dynamic area array telecentric module for each marker, the relationship matrix between the size measuring device in the image coordinate system and the world coordinate system is determined.

[0011] In an optional implementation, the dynamic telecentric array module includes an area array camera and a telecentric lens; the step of determining the relationship matrix between the size measuring device in the image coordinate system and the world coordinate system based on the scanned images of the test platform calibrated with marker points acquired by the static line scan module and the images of the test platform acquired by the dynamic telecentric array module for each marker point includes:

[0012] Based on the size of the test platform, the test platform is divided into multiple squares of preset size, and the center point of each square is marked as an identifier point;

[0013] The test platform for calibrating the marker points is scanned using a static line scan module, and the pixel position coordinates of each marker point are determined from the scanned image after distortion correction.

[0014] Repeat the following steps until the physical position coordinates of the servo device corresponding to each marker point are obtained: Based on the movement of the area scan camera and the telecentric lens driven by the servo device, when the center of the image acquired by the area scan camera and the telecentric lens coincides with the current marker point, determine the physical position coordinates of the servo device corresponding to the current marker point; and take the next marker point as the new current marker point.

[0015] Based on the pixel location coordinates and physical location coordinates of each of the aforementioned marker points, a relation matrix is ​​determined to characterize the transformation relationship between the image coordinate system and the world coordinate system.

[0016] In an optional implementation, the step of performing a similarity comparison between the scanned image of the planar product under test obtained by the static line scan module and a preset template image to determine the test size type, marker points, and pixel position coordinates of the marker points in the scanned image of the planar product under test includes:

[0017] The static line scan module scans the planar product under test to determine the scanned image of the planar product under test.

[0018] The outline of the planar product to be tested in the scanned image is compared with the outline of the planar product in each preset template image;

[0019] If a preset template image exists with a similarity threshold, the model, size type, and identification points of the planar product to be tested are determined based on the preset template image.

[0020] In an optional implementation, the step of performing a similarity comparison between the scanned image of the planar product under test obtained by the static line scan module and a preset template image to determine the test size type, marker point, and pixel position coordinates of the marker point in the scanned image of the planar product under test further includes:

[0021] If no preset template image with a similarity threshold is found, the model, size type, and identification points of the flat product under test are identified based on the scanned image, and a preset template image corresponding to the flat product under test is created.

[0022] In an optional implementation, the step of determining the pixel distance from each of the marked points to the contour line where the corresponding marked point is located, based on the pixel position coordinates of each marked point in the scanned image and the actual pixel position coordinates corresponding to each marked point acquired by the dynamic area array telecentric module driven by the servo device, and correcting the physical position coordinates of each marked point to the target physical position coordinates, includes:

[0023] Based on the scanned image, determine the pixel position coordinates corresponding to each of the marker points, and convert the pixel position coordinates corresponding to each of the marker points into physical position coordinates according to the relationship matrix;

[0024] Based on the acquired images when the dynamic array telecentric module reaches each of the physical position coordinates, determine the actual pixel position coordinates of each physical position in the acquired images;

[0025] By using the pixel distance between each actual pixel position coordinate and the pixel position coordinate corresponding to each marker point, the physical position coordinates corresponding to each marker point are corrected to the target physical position coordinates.

[0026] In an optional implementation, the step of correcting the physical location coordinates of each marker point to the target physical location coordinates using the pixel distance between each actual pixel location coordinate and the pixel location coordinates corresponding to each marker point includes:

[0027] Based on the pixel distances in the X and Y directions between each actual pixel position coordinate and the pixel position coordinates corresponding to each marker point, the actual distance corresponding to the pixel distance is superimposed on the physical position coordinates corresponding to each marker point to determine the target physical position coordinates corresponding to each marker point;

[0028] or,

[0029] By using the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marker point is located, the actual distance corresponding to the pixel distance is superimposed on the Y direction of the physical position coordinates corresponding to each marker point to determine the target physical position coordinates corresponding to each marker point.

[0030] In an optional implementation, the size combination includes a first type of size and a second type of size; the step of calculating the size combination of the planar product to be measured based on the size type to be measured and the target physical location coordinates of each of the marker points includes:

[0031] Select the corresponding marker point according to the first size type to be measured, and calculate the first type of size of the planar product to be measured, which is used to characterize the contour line;

[0032] Select the corresponding marker point and the outline of the planar product to be measured according to the second size type to be measured, and determine the auxiliary line of the planar product to be measured.

[0033] The second type of dimension of the planar product to be measured is determined based on the intersection of the auxiliary line and the contour line.

[0034] Secondly, the present invention provides a measuring device for large-size planar products, which is applied to a size measuring device. The size measuring device includes a test platform for placing the planar product to be measured, a servo device installed on the test platform, a static line scan module and a dynamic area array telecentric module set on the servo device.

[0035] The device includes:

[0036] The first determining module performs a similarity comparison between the scanned image of the planar product to be tested obtained by the static line scan module and the preset template image to determine the size type, the marker point, and the pixel position coordinates of the marker point in the scanned image of the planar product to be tested.

[0037] The second determining module, based on the pixel position coordinates of each of the marked points in the scanned image and the actual pixel position coordinates of each of the marked points collected by the dynamic array telecentric module driven by the servo device, determines the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marked point is located, and corrects the physical position coordinates of each of the marked points to the target physical position coordinates.

[0038] The calculation module calculates the size combination of the planar product under test based on the size type to be measured and the target physical location coordinates of each of the marked points.

[0039] Thirdly, the present invention provides an electronic device disposed in a dimensional measuring device, comprising a memory, a processor, and a program stored in the memory and capable of running on the processor, wherein the processor executes the program to implement the method as described in any of the foregoing embodiments.

[0040] This invention provides a method and apparatus for measuring large-size planar products. The method utilizes a servo device installed on a test platform, along with a static line scan module and a dynamic telecentric array module, to detect the dimensions of the planar product under test. First, based on the image obtained by the static line scan module scanning the planar product, the most similar preset template image is found. The size type, marker points, and model number of this preset template image are used as the corresponding information for the planar product. The pixel coordinates of each marker point are found based on the scanned image. Then, based on the actual pixel coordinates of each marker point collected by the dynamic telecentric array module driven by the servo device, the pixel distance from the actual pixel coordinates of the same marker point to the contour line containing its corresponding pixel coordinates can be determined. The physical coordinates of each marker point are corrected based on this pixel distance to obtain the target physical coordinates. Finally, based on the size type and target physical coordinates of the planar product under test, various size combinations corresponding to the size type are calculated, thereby achieving accurate size measurement of large-size planar products of various models.

[0041] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1A schematic diagram of a size measuring device provided in an embodiment of the present invention;

[0045] Figure 2 A flowchart illustrating a measurement method for large-size planar products provided in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of a scanned image acquired by a line scan camera, provided in an embodiment of the present invention.

[0047] Figure 4 A schematic diagram of an image acquired by an area scan camera and a circular center lens, provided in an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of an image acquired by another area scan camera and a circular center lens, provided in an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of pixel distance difference provided in an embodiment of the present invention;

[0050] Figure 7 This is a schematic diagram of the dimensions to be measured for a planar product, provided as an embodiment of the present invention.

[0051] Figure 8 A schematic diagram of the functional modules of a measuring device for large-size planar products provided in an embodiment of the present invention;

[0052] Figure 9 This is a schematic diagram of the hardware architecture of an electronic device provided in an embodiment of the present invention.

[0053] Icons: 100 - Planar product under test; 200 - Electrical control cabinet; 300 - Test platform; 400 - Static line scan module; 500 - Servo device; 600 - Dynamic area array telecentric module; 700 - Tricolor lamp. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] With the continuous development of industrial inspection technology, high-precision visual inspection plays an increasingly important role in the manufacturing industry. Modern industrial products have increasingly stringent requirements for dimensional accuracy, especially in fields such as aerospace, precision instruments, and automobile manufacturing, where inspection accuracy often needs to reach 0.1mm or even higher.

[0056] In existing technologies, industrial vision inspection systems typically employ high-resolution industrial cameras combined with backlighting or structured light illumination to acquire image information of the object under test for dimensional measurement. This inspection method is limited by the camera sensor resolution and field of view. When the object to be inspected is large, in order to ensure inspection accuracy, it is usually necessary to use multiple cameras stitched together or to capture images in sections to achieve full-size inspection.

[0057] For single-image detection schemes, accuracy primarily depends on the matching relationship between the camera's pixel resolution and field of view. According to optical imaging principles, detection accuracy can be calculated using the physical size represented by a single pixel. For example, when the required detection accuracy is 0.1mm, the accuracy of edge detection under backlighting conditions is approximately 6 pixels, which requires a single-pixel accuracy of 0.01666mm / pixel. For a 5m long object, this means the camera's long side resolution needs to reach 300 x 120 pixels.

[0058] However, the resolution of existing industrial cameras falls far short of this requirement. The highest resolution industrial camera currently on the market, with 604 megapixels, has a long-side resolution of only 28,416 pixels, far short of the required 300,120 pixels. Furthermore, such ultra-high-resolution cameras are already very expensive, further limiting their application in industrial inspection. Therefore, under current technological conditions, achieving high-precision inspection of large workpieces through single-image capture faces significant technical challenges and equipment cost limitations.

[0059] Based on this, the present invention provides a measurement method and apparatus for large-size planar products, which can achieve high-precision detection by arbitrarily placing the large-size planar products on the test platform.

[0060] To facilitate understanding of this embodiment, the dimension measuring equipment used in the measurement method for large-size planar products disclosed in this embodiment will first be described in detail, such as... Figure 1 As shown, the dimensional measuring device includes a test platform 300 for placing the planar product 100 to be measured, a servo device 500 mounted on the test platform 300, a static line scan module 400 and a dynamic area array telecentric module 600 set on the servo device 500; it also includes a three-color light 700 for indicating the detection status and an electrical control cabinet 200 for controlling the dimensional measurement; wherein, the planar product to be measured can be understood as a product component with a large size and a length greater than 3 meters that extends in a sheet-like shape on a plane, and may include large-size planar components such as silicon steel sheets.

[0061] Based on the foregoing embodiments, a method for measuring large-size planar products disclosed in the embodiments of the present invention will be described in detail again. This method can be specifically applied to control equipment in which size measuring equipment is integrated into an electrical control cabinet.

[0062] Figure 2 A flowchart illustrating a measurement method for a large-size planar product provided in an embodiment of the present invention.

[0063] Reference Figure 2 As shown, the method includes the following steps:

[0064] Step S102: Based on the similarity comparison between the scanned image of the planar product to be tested obtained by the static line scan module and the preset template image, the test size type, the marker point, and the pixel position coordinates of the marker point in the scanned image are determined.

[0065] Here, the preset template image pre-sets the size type and identification points of each model of planar product to be tested; based on the comparison similarity between the scanned image and the preset template image, the preset template image that matches the current planar product to be tested can be determined, and then the model, identification points and size type to be tested corresponding to the matching preset template image can be obtained;

[0066] For example, step S102 can be implemented by the following steps, specifically including:

[0067] Step 1.1: Scan the planar product under test using the static line scan module to determine the scanned image of the planar product under test.

[0068] The static line scan module can be understood as a line scan camera, which is relatively stationary on the servo device. This allows the servo device to move along with the line scan camera to scan the flat product to be tested, which is stationary on the test platform. As an optional embodiment, the image is processed to remove distortion, thereby obtaining a distortion-free scan image.

[0069] Step 1.2: Compare the outline of the planar product to be tested in the scanned image with the outline of the planar product in each preset template image.

[0070] Here, edge detection operators such as the Canny operator can be used to identify pixels in the scanned image / preset template image whose pixel values ​​change beyond a preset pixel threshold, i.e., edge pixels. Then, the outline of the planar product formed by connecting the pixels can be measured. By comparing the shape and trend of the outline, the similarity between the planar product under test and each preset template can be determined.

[0071] Step 1.3: If there is a preset template image with a similarity that reaches a preset threshold, then the model, size type, and identification points of the planar product to be tested are determined based on the preset template image.

[0072] Here, it can be understood that if the similarity between the scanned image of the flat product to be tested and a certain preset template image reaches a preset threshold, then the flat product to be tested and the preset template belong to the same model, size type to be tested, and identification point. It should be noted that if the similarity between the scanned image of the flat product to be tested and multiple preset template images all reach the preset threshold, then the flat product to be tested selects the model, size type to be tested, and identification point corresponding to the preset template with the highest similarity.

[0073] The type of dimension to be measured can be understood as the type of dimension that needs to be measured, such as the length, width, position of each vertex of the product, the size of the hole, and the type of dimension to be measured.

[0074] Step 1.4: If there is no preset template image with a similarity threshold, the model, size type and identification points of the flat product to be tested are identified based on the scanned image, and a preset template image corresponding to the flat product to be tested is created.

[0075] In practical applications, if no preset template image with a similarity threshold is found, then no preset template exists for the planar product under test. In this case, the size type and marker points of the planar product under test are directly detected. The detection results are used to create a preset template image for the planar product under test. This template includes a scanned image of the planar product under test, along with its model number, size type under test, and marker points. The model number of the planar product determines its corresponding size type under test, while marker points can be understood as virtual or physical markers on the scanned image, indicating the location points known to the executing device (such as a host computer or control device). These marker points are used to calculate the size of large-size planar products for each size type under test.

[0076] Step S104: Based on the pixel position coordinates of each marker point in the scanned image and the actual pixel position coordinates of each marker point acquired by the dynamic array telecentric module driven by the servo device, determine the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marker point is located, and correct the physical position coordinates of each marker point to the target physical position coordinates.

[0077] Among them, the outline of the planar product to be tested can be understood as being composed of multiple outline lines connected end to end; while the outline line where the marker point is located can be understood as the product outline line where the marker point is located, which is one of the product outlines.

[0078] Specifically, the physical position coordinates are obtained based on the pixel position transformation of the marker points in the scanned image; when the servo device moves to the physical position coordinates, the array image acquired by the dynamic array telecentric module is the acquired image; such as Figure 6As shown, the center of the acquired image, i.e. the hollow circle, represents the actual pixel position coordinates. However, the acquired image can identify the ideal pixel position coordinates of the marker point, i.e. the solid circle, as well as its contour line. Based on the pixel distance from the hollow circle to the contour line of the solid circle, the purpose of correcting the physical position coordinates of the marker point can be achieved.

[0079] Here, the dynamic telecentric array module includes an area scan camera and a telecentric lens. The image obtained by the line scan camera has slightly lower accuracy than the image acquired by the dynamic telecentric array module; for example, the scanned image of a triangular planar product under test is as follows: Figure 3 As shown; Figure 4 This can be used as an image acquisition tool for the triangular test plane product by a dynamic telecentric array module. Figure 5 The image is acquired by the dynamic telecentric array module for a single marker point; it can be seen that the image acquired by the dynamic telecentric array module has higher accuracy than the image scanned by the line scan camera.

[0080] In some embodiments, step S104 can correct the physical location corresponding to the actual marker point by using the pixel difference determined by the high-precision dynamic area array telecentric module and the coarse-precision line scan camera. For example, it includes:

[0081] Step 2.1: Determine the pixel position coordinates corresponding to each marker point based on the scanned image, and convert the pixel position coordinates corresponding to each marker point into physical position coordinates according to the relationship matrix.

[0082] As can be seen from the foregoing embodiments, the pixel position coordinates of each marker point in the image coordinate system can be obtained based on the scanned image, and the physical position coordinates of each marker point in the world coordinate system can be obtained under the action of the relation matrix.

[0083] It should be noted that the relationship matrix can be determined in advance. Before step S102, the relationship matrix between the dimensional measuring device in the image coordinate system and the world coordinate system can be determined based on the scanned images of the test platform with calibrated markers acquired by the static line scan module and the images of the test platform acquired by the dynamic area array telecentric module for each marker. This includes:

[0084] Step 3.1: Based on the size of the test platform, divide the test platform into multiple squares of preset size, and mark the center point of each square as an identifier point.

[0085] Here, the size of the test platform determines the number of squares it is divided into; that is, the larger the size, the more squares it is divided into. The size of each square can be set according to the size of the test platform. The center point of each square is defined as the marker point.

[0086] Step 3.2: Scan the test platform for calibrated marker points using the static line scan module, and determine the pixel position coordinates of each marker point from the scanned image after distortion correction.

[0087] Here, the pixel coordinates of each marker point are identified from the scanned images acquired by the line scan camera.

[0088] Step 3.3: Repeat the following steps until the physical location coordinates of the servo device corresponding to each marker point are obtained:

[0089] Based on the servo device driving the area scan camera and telecentric lens to move, when the center of the image acquired by the area scan camera and telecentric lens coincides with the current marker point, the physical position coordinates of the servo device corresponding to the current marker point are determined; the next marker point is taken as the new current marker point.

[0090] It should be noted that the dynamic telecentric module, i.e., the area scan camera and the telecentric lens, can move relative to the servo device under the control axis of the servo device, thereby driving the acquisition of data by the area scan camera and the telecentric lens. Figure 5 When the center of the acquired image coincides with the center of the marker point, the two coincide. At this time, the physical position coordinates of the servo device are used as the physical position coordinates of the marker point in the world coordinate system. The servo device controls the dynamic array telecentric module to move to the next marker point and repeats this process until the physical position coordinates of each marker point in the world coordinate system are determined.

[0091] Step 3.4: Based on the pixel location coordinates and physical location coordinates of each marker point, determine the relationship matrix used to characterize the transformation relationship between the image coordinate system and the world coordinate system.

[0092] Understandably, based on the mapping relationship between the pixel position coordinates and physical position coordinates of each marker point, the relationship matrix between the current test platform in the image coordinate system and the world coordinate system can be determined.

[0093] Step 2.2: Based on the acquired images when the dynamic array telecentric module reaches the coordinates of each physical position, determine the actual pixel position coordinates of each physical position in the acquired image.

[0094] In particular, when the dynamic array telecentric module moves according to the physical position coordinates obtained by converting the pixel position coordinates of each marker point, errors often occur; for example... Figure 6As shown, the hollow dot is the target point of the dynamic array telecentric module after it moves according to the physical position coordinates of each marker point (the actual pixel position coordinates corresponding to the marker point on the acquired image). However, based on the acquired image of the dynamic array telecentric module, the ideal pixel position of the marker point (the position of the solid dot) can be known. That is, the position of the solid dot is the pixel position coordinate (ideal pixel position coordinate) that the dynamic array telecentric module expects to reach after moving according to the physical position coordinates converted from the pixel position coordinates of the marker point.

[0095] Step 2.3: Using the pixel distance between each actual pixel position coordinate and the pixel position coordinate corresponding to each marker point, correct the physical position coordinates corresponding to each marker point to the target physical position coordinates.

[0096] As an optional embodiment, the actual distance corresponding to the pixel distance can be determined based on the pixel distance between each actual pixel position coordinate and the pixel position coordinate corresponding to each marker point in the X and Y directions, respectively, under the action of the aforementioned relationship matrix. This actual distance is then superimposed on the physical position coordinates corresponding to each marker point to determine the target physical position coordinates corresponding to each marker point.

[0097] It should be noted that the acquired image (area scan image) is generated by the area scan camera moving and capturing images based on the physical position coordinates converted from the pixel position coordinates corresponding to the marked points in the line scan image. At this time, the image center of the area scan image is... Figure 6 The hollow circle is the actual pixel position coordinate of the marker point when the area scan camera actually reaches the actual physical position; then, taking the image center of the area scan image as the reference, we look at the centroid coordinates of the marker point (solid circle) captured on the area scan image, and calculate the pixel distances of the centroid coordinates from the image center in the X and Y directions, respectively.

[0098] As another optional embodiment, the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marker point is located can be used to determine the actual distance corresponding to the pixel distance under the action of the aforementioned relationship matrix. This actual distance is then superimposed on the Y direction of the physical position coordinates corresponding to each marker point to determine the target physical position coordinates corresponding to each marker point.

[0099] Here, the image contour recognition algorithm based on the foregoing embodiments can determine, as follows: Figure 6The outline of the marker point is shown. By calculating the distance from the actual pixel position coordinates to this outline, a correction value can be determined, which is used to correct the actual physical position coordinates to the target physical position coordinates. Specifically, based on the single-pixel accuracy and the pixel distance in the X and Y directions, the actual physical distances in the X and Y directions can be directly calculated and added to the X and Y physical position coordinates of the area scan camera. The coordinates at this point are the actual coordinates of the marker point in the mechanism (target physical position coordinates).

[0100] Step S106: Calculate the size combination of the planar product to be measured based on the size type to be measured and the target physical location coordinates of each marker point.

[0101] The size combination includes a first type of size and a second type of size; step S106 may include:

[0102] Step 4.1: Select the corresponding marker point according to the first size type to be measured, and calculate the first type of size of the planar product to be measured to characterize the contour line.

[0103] like Figure 7 As shown, based on the first type of dimension to be measured, the physical coordinates of marker point 1 and marker point 2, the dimension of the outline L of the planar product to be measured, i.e., the first type of dimension, can be calculated. The first type of dimension to be measured can be understood as the dimension that is expected to be measured.

[0104] Step 4.2: Select the corresponding marker points and the outline of the planar product to be measured according to the second size type to be measured, and determine the auxiliary lines of the planar product to be measured.

[0105] like Figure 7 As shown, based on the second dimension to be measured, the physical coordinates of marker 1, marker 2, marker 3, and marker 4, and the contour line L, the auxiliary line (center line) between contour line 12 and contour line 34 can be determined. This auxiliary line (center line) is as follows: Figure 7 The midpoint is indicated by the dashed line. The second type of dimension to be measured can be understood as the second type of dimension that is expected to be measured. The second type of dimension can be understood as a dimension that is not the product outline but still needs to be measured.

[0106] Step 4.3: Determine the second type of dimension of the planar product to be measured based on the intersection of the auxiliary lines and the outline.

[0107] Based on the intersection of the auxiliary line (center line) and the aforementioned marker points, the distance L0 between the two points is calculated, thereby obtaining the second type of dimension of the planar product to be measured.

[0108] like Figure 7As shown, this size combination may include product length dimensions L and L0, product widths B and B / 2, and vertex position dimension PA0. Figure 7 The figure shows a case where the vertex position degree is 45°.

[0109] In a preferred embodiment of practical application, the dimensions of the planar product under test on the test platform are detected using a servo device installed on the test platform, along with a static line scan module and a dynamic telecentric array module. First, the most similar preset template image is found based on the image obtained by the static line scan module scanning the planar product under test. The size type, marker points, and model number of this preset template image are used as the corresponding information for the planar product under test. The pixel coordinates of each marker point are found based on the scanned image. Then, based on the actual pixel coordinates of each marker point collected by the dynamic telecentric array module driven by the servo device, the pixel distance from the actual pixel coordinates of the same marker point to the contour line containing its corresponding pixel coordinates can be determined. The physical coordinates of each marker point are corrected based on this pixel distance to obtain the target physical coordinates. Finally, based on the size type and target physical coordinates of the planar product under test, various size combinations corresponding to the size type are calculated, thereby achieving accurate size measurement of larger-sized planar products of various models.

[0110] In practical applications, this invention also provides another method for measuring large-size planar products, including:

[0111] 1. A marble test platform can be used. Divide the test platform into nine squares evenly in different directions according to its size, and mark nine markers in the center of each square.

[0112] 2. Use a line scan camera to scan the test platform and its nine marker points, and use an algorithm to correct the image distortion to obtain the corrected scan image (subsequent steps are all calculated on the corrected scan image).

[0113] 3. Calculate the centroid coordinates (pixel coordinates on the line scan) of the nine marker points on the scanned image.

[0114] 4. Using a three-axis servo device, along with an area scan camera and a telecentric lens, locate these nine marker points. When the center of a marker point is in the center of the image captured by the area scan camera, record the physical position coordinates (X, Y) of the servo device at this time as the physical position coordinates of the marker point. Repeat this process until the physical position coordinates of all nine marker points are determined.

[0115] 5. Currently, the pixel coordinates of nine marker points on the scanned image and the physical position coordinates of the servo device in the time coordinate system have been obtained. The relationship matrix between the scanned image and the physical position coordinates can be obtained through nine-point calibration, which is called the nine-point calibration matrix.

[0116] 6. Place the flat product to be tested on the test platform, take a picture with a line scan camera to create a preset template image, so that different flat products to be tested can be distinguished by product type to determine the corresponding model, marking points and the type of size to be tested.

[0117] 7. If a corresponding preset template image exists for the flat product to be tested, the scanned image can be matched with the preset template image to identify the product model, and then the identification points to be tested and the dimensions to be known for different product models can be determined.

[0118] 8. For example Figure 7 As shown, on the scanned image captured by the line scanning camera, by using an edge (contour) finding algorithm, lines L12 and L14 are located, and the intersection of these lines yields corner point 1. Similarly, corner points 2, 3, and 4 can be obtained. These are then converted to physical position coordinates (X, Y) using a nine-point calibration matrix, and these coordinate values ​​are sequentially returned to the servo device. For example, the pixel position of each marker point (such as corner points 1, 2, 3, and 4) on the scanned image is calculated. Then, the physical position coordinates (X, Y) converted using the nine-point calibration matrix are used. The physical position coordinates converted from the line scanning camera image are coarsely located, and the servo device moves to this coarsely located position accordingly.

[0119] 9. The servo device controls the area array camera to take pictures of each marker point at the physical location coordinates of the scanned image converted from the online scanning camera image. Here, a total of four images are taken: A, B, C, and D, corresponding to corner points 1, 2, 3, and 4, respectively. The image taken at each corner point can be as follows: Figure 4 As shown, that is Figure 4 This refers to any one of the four images captured previously. For example, the servo device can control the area scan camera to first capture the corner point 1 position based on the physical position coordinates converted from the scan image of the line scan camera.

[0120] 10. Then, a servo device is used to drive the area scan camera and telecentric lens for precise positioning. This achieves high-precision measurement. For example, the edge-finding algorithm described above is used to identify the intersection point 1 (corner point 1) of the edge contour lines from images A, B, C, and D. The difference between intersection point 1 and the center of the image circle is calculated and compensated to the physical position coordinates (X1, Y1). The record is saved as point MZ_1, with coordinates (MZ_X1, MZ_Y1). Here, the center of the image circle is the center of the image captured by the area scan camera and telecentric lens, which is the reference point. The difference between intersection point 1 and the center of the image circle is the distance from the center point of the image to the perpendicular point of the edge line or the center of the hole. It should be noted that the difference can be split into X-axis and Y-axis components, or the Y-axis component of the difference in the Y direction can be obtained. Then, the above components are converted into actual distances, and the physical position coordinates are corrected according to the X-axis and Y-axis directions corresponding to the components. The coordinates of this embodiment of the invention can be pre-established in a large coordinate system, and then various dimensions of the product can be calculated based on the coordinates in the large coordinate system. As an optional implementation, theoretically, when the servo moves over, the position of intersection point 1 should be at the center of the image. However, the actual movement of the servo device has deviations, the nine-point matrix conversion has deviations, and the corner point 1 obtained from the line scan image also has deviations. Therefore, a grating ruler with higher movement accuracy is used to read the coordinates of the servo device's movement in real time, which is more accurate, and the movement accuracy can reach 0.015mm.

[0121] 11. Then, the servo device, carrying the area scan camera, moves to the physical coordinates of corner point 2 provided by the line scan camera. For example, at this time, the servo's coordinates are fed back to the algorithm in real time, denoted as (X2, Y2). Similarly, the line intersection point 2 (corner point 2) is obtained through the edge finding algorithm, and the difference between intersection point 2 and the center of the image circle is calculated and compensated to the servo coordinates (X2, Y2). The record is saved as point MZ_2, with coordinates (MZ_X2, MZ_Y2).

[0122] 12. Similarly, the coordinates of corner point 3 (MZ_X3, MZ_Y3) and corner point 4 (MZ_X4, MZ_Y4) can be obtained.

[0123] 13. The dimension L to be measured for this product can be obtained by using the point-to-point distance from points MZ_1 and MZ_2. The dimension L0 to be measured for this product can be obtained by using points MZ_1 and MZ_2 to obtain line L12, and points MZ_3 and MZ_4 to obtain line L34. The midline of lines L12 and L34 is then calculated. This midline intersects with lines L14 and L23 at two points. The distance between these two intersection points is then calculated to determine the dimension L0.

[0124] In this embodiment of the invention, a line scan camera is first used for coarse positioning, and then an area scan camera with a telecentric lens is used for precise positioning. At the same time, a grating ruler is used to provide real-time feedback of the physical position coordinates, thereby achieving high-precision measurement of large-size planar products for automatic detection.

[0125] In some embodiments, such as Figure 8 As shown, this embodiment of the invention provides a measuring device for large-size planar products, which is applied to a size measuring device. The size measuring device includes a test platform for placing the planar product to be measured, a servo device installed on the test platform, a static line scan module and a dynamic area array telecentric module set on the servo device.

[0126] The device includes:

[0127] The first determining module performs a similarity comparison between the scanned image of the planar product to be tested obtained by the static line scan module and the preset template image to determine the size type, the marker point, and the pixel position coordinates of the marker point in the scanned image of the planar product to be tested.

[0128] The second determining module, based on the pixel position coordinates of each of the marked points in the scanned image and the actual pixel position coordinates of each of the marked points collected by the dynamic array telecentric module driven by the servo device, determines the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marked point is located, and corrects the physical position coordinates of each of the marked points to the target physical position coordinates.

[0129] The calculation module calculates the size combination of the planar product under test based on the size type to be measured and the target physical location coordinates of each of the marked points.

[0130] Due to current limitations in camera resolution and the cost of high-precision cameras, high-precision dimensional measurement of large-size planar products is not feasible. Therefore, a line scan camera is first used for coarse positioning, followed by a planar array camera with a telecentric lens for precise positioning. A grating ruler provides real-time feedback of physical coordinates for calculation.

[0131] Furthermore, before the step of comparing the similarity between the scanned image of the planar product under test obtained by the static line scan module and the preset template image to determine the size type, marker point, and pixel position coordinates of the marker point in the scanned image of the planar product under test, the device is also used to determine the relationship matrix between the size measuring device in the image coordinate system and the world coordinate system based on the scanned image of the test platform calibrated with marker points acquired by the static line scan module and the image of the test platform acquired by the dynamic array telecentric module for each marker point.

[0132] Furthermore, the dynamic telecentric array module includes an area array camera and a telecentric lens; before the step of comparing the scanned image of the planar product under test acquired by the static line scan module with a preset template image to determine the test size type, marker point, and pixel position coordinates of the marker point in the scanned image, the device is specifically used to: divide the test platform into multiple squares of preset size according to the size of the test platform, and mark the center point of each square as a marker point; scan the test platform marked with the marker point based on the static line scan module, and from distortion correction... In the processed scanned image, determine the pixel position coordinates of each of the marker points; repeat the following steps until the physical position coordinates of the servo device corresponding to each marker point are obtained: based on the servo device driving the area scan camera and the telecentric lens to move, when the center of the image acquired by the area scan camera and the telecentric lens coincides with the current marker point, determine the physical position coordinates of the servo device corresponding to the current marker point; take the next marker point as the new current marker point; based on the pixel position coordinates and physical position coordinates of each marker point, determine the relationship matrix used to characterize the transformation relationship between the image coordinate system and the world coordinate system.

[0133] Furthermore, the first determining module is specifically used to scan the planar product to be tested based on the static line scanning module to determine the scanned image of the planar product to be tested; compare the outline of the planar product to be tested in the scanned image with the outline of the planar product in each preset template image; if there is a preset template image with a similarity reaching a preset threshold, then determine the model, size type and identification points of the planar product to be tested based on the preset template image.

[0134] Furthermore, the first determining module is specifically used to, if there is no preset template image with a similarity reaching a preset threshold, identify the model, size type and identification points of the planar product to be tested based on the scanned image, and create a preset template image corresponding to the planar product to be tested.

[0135] Furthermore, the second determining module is specifically used to: determine the pixel position coordinates corresponding to each of the marker points based on the scanned image, and convert the pixel position coordinates corresponding to each of the marker points into physical position coordinates according to the relationship matrix; determine the actual pixel position coordinates corresponding to each physical position in the acquired image based on the acquired image when the dynamic array telecentric module reaches each of the physical position coordinates; and correct the physical position coordinates corresponding to each marker point to the target physical position coordinates using the pixel distance between each of the actual pixel position coordinates and the pixel position coordinates corresponding to each of the marker points.

[0136] Furthermore, the second determining module is specifically used to determine the target physical location coordinates of each marker point by superimposing the actual distance corresponding to the pixel distance onto the physical location coordinates of each marker point in the X and Y directions, respectively, based on the pixel distance between each actual pixel location coordinate and the pixel location coordinates corresponding to each marker point; or, by using the pixel distance from each actual pixel location coordinate to the contour line where the corresponding marker point is located, superimposing the actual distance corresponding to the pixel distance onto the Y direction of the physical location coordinates of each marker point, respectively, to determine the target physical location coordinates of each marker point.

[0137] Furthermore, the size combination includes a first type of size and a second type of size; the detection module is specifically used to: select the corresponding marker point according to the first size type to be measured, calculate the first type of size of the planar product to be measured for characterizing the contour line; select the corresponding marker point and the contour line of the planar product to be measured according to the second size type to be measured, determine the auxiliary line of the planar product to be measured; and determine the second type of size of the planar product to be measured based on the intersection of the auxiliary line and the contour line.

[0138] The present invention provides an embodiment of an electronic device. In this embodiment, the electronic device may be, but is not limited to, a personal computer (PC), a laptop computer, a monitoring device, a server, or other computer device with analysis and processing capabilities.

[0139] As an exemplary embodiment, see [reference]. Figure 9 The electronic device 110 includes a communication interface 111, a processor 112, a memory 113, and a bus 114. The processor 112, the communication interface 111, and the memory 113 are connected via the bus 114. The memory 113 is used to store a computer program that supports the processor 112 in executing the above-described method. The processor 112 is configured to execute the program stored in the memory 113.

[0140] It is understood that the specific operation methods of each functional module in this embodiment can be referred to the detailed description of the corresponding steps in the above method embodiment, and will not be repeated here.

[0141] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0142] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0143] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0144] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention.

Claims

1. A method for measuring large-size planar products, characterized in that, The device is applied to a size measuring equipment, which includes a test platform for placing a planar product to be measured, a servo device mounted on the test platform, and a static line scan module and a dynamic area array telecentric module set on the servo device. The method includes: performing a similarity comparison between the scanned image of the planar product to be tested obtained by the static line scan module and a preset template image to determine the test size type, the marker point, and the pixel position coordinates of the marker point in the scanned image of the planar product to be tested; Based on the pixel position coordinates of each of the marked points in the scanned image and the actual pixel position coordinates of each of the marked points collected by the dynamic array telecentric module driven by the servo device, the pixel distance from each of the actual pixel position coordinates to the contour line where the corresponding marked point is located is determined, and the physical position coordinates of each of the marked points are corrected to the target physical position coordinates. Calculate the size combination of the planar product to be tested based on the size type to be tested and the target physical location coordinates of each of the marked points; First, the static line scan module is used to coarsely locate the pixel position coordinates of each of the marker points. Then, the dynamic area array telecentric module is used to precisely locate the actual pixel position coordinates of each of the marker points, and the pixel distance used to correct the physical position coordinates is determined.

2. The method according to claim 1, characterized in that, Before the step of comparing the scanned image of the planar product under test obtained by the static line scan module with a preset template image to determine the test size type, marker point, and pixel position coordinates of the marker point in the scanned image, the method further includes: Based on the scanned images of the test platform with calibrated markers acquired by the static line scan module and the images of the test platform acquired by the dynamic area array telecentric module for each marker, the relationship matrix between the size measuring device in the image coordinate system and the world coordinate system is determined.

3. The method according to claim 2, characterized in that, The dynamic telecentric array module includes an area array camera and a telecentric lens; the step of determining the relationship matrix between the size measuring device in the image coordinate system and the world coordinate system based on the scanned images of the test platform with calibrated markers acquired by the static line scan module and the images of the test platform acquired by the dynamic telecentric array module for each marker point includes: Based on the size of the test platform, the test platform is divided into multiple squares of preset size, and the center point of each square is marked as an identifier point; The test platform for calibrating the marker points is scanned using a static line scan module, and the pixel position coordinates of each marker point are determined from the scanned image after distortion correction. Repeat the following steps until the physical position coordinates of the servo device corresponding to each marker point are obtained: Based on the movement of the area scan camera and the telecentric lens driven by the servo device, when the center of the image acquired by the area scan camera and the telecentric lens coincides with the current marker point, determine the physical position coordinates of the servo device corresponding to the current marker point; and take the next marker point as the new current marker point. Based on the pixel location coordinates and physical location coordinates of each of the aforementioned marker points, a relation matrix is ​​determined to characterize the transformation relationship between the image coordinate system and the world coordinate system.

4. The method according to claim 1, characterized in that, The steps of comparing the scanned image of the planar product under test obtained by the static line scan module with a preset template image to determine the test size type, marker point, and pixel position coordinates of the marker point in the scanned image include: The static line scan module scans the planar product under test to determine the scanned image of the planar product under test. The outline of the planar product to be tested in the scanned image is compared with the outline of the planar product in each preset template image; If a preset template image exists with a similarity threshold, the model, size type, and identification points of the planar product to be tested are determined based on the preset template image.

5. The method according to claim 4, characterized in that, The step of comparing the scanned image of the planar product under test obtained by the static line scan module with a preset template image to determine the test size type, the marker point, and the pixel position coordinates of the marker point in the scanned image further includes: If no preset template image with a similarity threshold is found, the model, size type, and identification points of the flat product under test are identified based on the scanned image, and a preset template image corresponding to the flat product under test is created.

6. The method according to claim 1, characterized in that, Based on the pixel position coordinates of each marker point in the scanned image and the actual pixel position coordinates corresponding to each marker point acquired by the dynamic area array telecentric module driven by the servo device, the step of determining the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marker point is located, and correcting the physical position coordinates of each marker point to the target physical position coordinates, includes: Based on the scanned image, determine the pixel position coordinates corresponding to each of the marker points, and convert the pixel position coordinates corresponding to each of the marker points into physical position coordinates according to the relationship matrix; Based on the acquired images when the dynamic array telecentric module reaches each of the physical position coordinates, determine the actual pixel position coordinates of each physical position in the acquired images; By using the pixel distance between each actual pixel position coordinate and the pixel position coordinate corresponding to each marker point, the physical position coordinates corresponding to each marker point are corrected to the target physical position coordinates.

7. The method according to claim 6, characterized in that, The step of correcting the physical location coordinates of each marker point to the target physical location coordinates using the pixel distance between each actual pixel location coordinate and the pixel location coordinates corresponding to each marker point includes: Based on the pixel distances in the X and Y directions between each actual pixel position coordinate and the pixel position coordinates corresponding to each marker point, the actual distance corresponding to the pixel distance is superimposed on the physical position coordinates corresponding to each marker point to determine the target physical position coordinates corresponding to each marker point; or, By using the pixel distance from each actual pixel position coordinate to the contour line of the corresponding marker point, the actual distance corresponding to the pixel distance is superimposed on the Y direction of the physical position coordinates corresponding to each marker point to determine the target physical position coordinates corresponding to each marker point.

8. The method according to claim 1, characterized in that, The size combination includes a first type of size and a second type of size; the step of calculating the size combination of the planar product to be measured based on the size type to be measured and the target physical location coordinates of each of the marked points includes: Select the corresponding marker point according to the first size type to be measured, and calculate the first type of size of the planar product to be measured, which is used to characterize the contour line; Select the corresponding marker point and the outline of the planar product to be measured according to the second size type to be measured, and determine the auxiliary line of the planar product to be measured. The second type of dimension of the planar product to be measured is determined based on the intersection of the auxiliary line and the contour line.

9. A measuring device for large-size planar products, characterized in that, The device is applied to a size measuring equipment, which includes a test platform for placing a planar product to be measured, a servo device mounted on the test platform, and a static line scan module and a dynamic area array telecentric module set on the servo device. The device includes: The first determining module performs a similarity comparison between the scanned image of the planar product to be tested obtained by the static line scan module and the preset template image to determine the test size type, the marker point, and the pixel position coordinates of the marker point in the scanned image of the planar product to be tested. The second determining module, based on the pixel position coordinates of each of the marked points in the scanned image and the actual pixel position coordinates of each of the marked points collected by the dynamic array telecentric module driven by the servo device, determines the pixel distance from each actual pixel position coordinate to the contour line where the corresponding marked point is located, and corrects the physical position coordinates of each of the marked points to the target physical position coordinates. The calculation module calculates the size combination of the planar product under test based on the size type to be measured and the target physical location coordinates of each of the marked points; The device first uses the static line scan module to coarsely locate the pixel position coordinates of each of the marker points, and then uses the dynamic area array telecentric module to precisely locate the actual pixel position coordinates of each of the marker points, thereby determining the pixel distance used to correct the physical position coordinates.

10. An electronic device, characterized in that, The device is configured to measure dimensions and includes a memory, a processor, and a program stored in the memory and capable of running on the processor, wherein the processor executes the program to implement the method as described in any one of claims 1 to 8.

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