Non-contact steel pipe end face size measuring device

Abstract

The invention provides a non-contact steel pipe end face size measuring device which comprises an equipment box, a lifting mechanism, a camera, a sensor and a data processing module, the lifting mechanism is arranged in the equipment box, the camera is arranged at the lifting end of the lifting mechanism, a shooting opening for the camera to shoot is formed in the equipment box, the sensor is arranged outside the equipment box, and the data processing module is connected with the camera. The camera and the sensor are electrically connected with a data processing module outside the equipment box; the data processing module comprises a binarization module, a filtering module, a convex hull calculation module, a burr judgment module and a thickness calculation module. According to the invention, the steel pipe is prevented from being damaged in the detection process, and the influence of burrs on the measured pipe end size is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of steel pipe production detection equipment, and particularly relates to a non-contact steel pipe end face size measuring device. Background Art

[0002] In modern manufacturing, steel pipes, as an important basic material, are widely used in multiple fields such as construction, transportation, and energy. With the progress of technology and the continuous improvement of industrial demands, the quality and precision requirements for steel pipes are becoming increasingly strict. The end face size of a steel pipe is an important factor affecting its connection performance, sealing property, and overall structural strength. Therefore, accurately measuring the end face size of a steel pipe is particularly important.

[0003] Traditional methods for measuring the end face size of steel pipes mostly use contact measuring tools such as calipers and micrometers. Although these methods can meet the measurement requirements to a certain extent, they have some limitations. First, contact measurement is easily affected by the subjective factors of the operator and cannot exclude the influence of burrs on the results, resulting in instability of the measurement results. Second, contact measurement may cause damage to the object being measured during the measurement process, especially in cases where high precision is required, which may affect the service performance of the steel pipe. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to prevent damage during the detection process and eliminate the influence of burrs.

[0005] The present invention solves the above technical problem by the following technical means:

[0006] A non-contact steel pipe end face size measuring device includes an equipment box, a lifting mechanism, a camera, a sensor, and a data processing module. The lifting mechanism is arranged inside the equipment box, the lifting end of the lifting mechanism is provided with a camera, the equipment box is provided with a shooting port for the camera to take pictures, the sensor is arranged outside the equipment box, and both the camera and the sensor are electrically connected to the data processing module outside the equipment box;

[0007] The data processing module includes a binarization module, a filtering module, a convex hull calculation module, a burr judgment module, and a thickness calculation module;

[0008] Binarization module: Convert the original image of the pipe end taken by the camera into a binary image and use morphological gradient operation to detect the contour, obtain the effective contour points of the pipe end, and judge whether the contour is approximately circular, and then sort the contour to distinguish the inner and outer contour point sets;

[0009] Filtering module: Traverse the original contour points to calculate the average thickness, maximum and minimum thicknesses and their positions, and then filter the original contour points to obtain a contour point set smaller than the distance threshold;

[0010] Convex hull calculation module: According to the set of contour points obtained after filtering, calculate the convex hulls of the large and small contours, perform elliptical fitting on the convex hulls to obtain the fitted ellipse; calculate the average inner and outer diameters and the center point, and calculate the average thickness, maximum and minimum thicknesses and their positions of the filtered contour;

[0011] Burr judgment module: According to the obtained set of convex hull points, draw the positions of each point in the contour point set, and judge whether the distance from the contour point to the contour exceeds the threshold. If it exceeds, it is judged as a burr;

[0012] Thickness calculation module: Calculate the maximum and minimum inner and outer diameters, ellipticity according to the obtained fitted ellipse, and draw the maximum and minimum thickness points.

[0013] The present invention does not need to contact the steel pipe. It only needs to send the original image of the pipe end of the steel pipe taken by the camera to the data processing module. By combining the image edge detection and graphics methods, it identifies the pipe end contour, calculates the positional relationship between the contour points and the contour through the self-developed algorithm, accurately locates the pipe end burr and eliminates the influence of the burr on the measured pipe end size. The present invention not only prevents damage to the steel pipe during the detection process, but also eliminates the influence of the burr on the measured pipe end size.

[0014] Preferably, the binarization module includes the following processes:

[0015] Step 1.1: First, convert the image into a binary image by using the inverse binarization method. Secondly, perform morphological gradient operation to highlight the image edge and retrieve all contours. Then, remove small noise contours by calculating the area of the contours and find the rectangle with the smallest area enclosing the contours. After that, select the rectangles with a specific aspect ratio, sort the contours enclosed by the rectangles, and select the largest and the third largest contours as the outer diameter and inner diameter contours and add them to the effective contours, where the resolution of the contour points is the resolution of the original image;

[0016] Step 1.2: According to the two sets of contour points obtained in Step 1.1, denote the zero-order moment of the contour as m 00， representing the area of the contour, the first-order moments of the contour on the x-axis and y-axis are m 10 and m 01 , and the centroid coordinates of the contour are

[0017] Step 1.3: According to the centroid coordinates of the two contours obtained in Step 1.2, calculate the Euclidean distance between the coordinates, and judge whether the distance exceeds the threshold. If it exceeds the threshold, directly return. Otherwise, sort the two contours to distinguish the inner and outer contour point sets.

[0018] Preferably, the filtering module includes the following processes:

[0019] Step 2.1: Traverse the set of original inner diameter contour points obtained in Step 1.1, calculate the distance from each point to the outer diameter contour as the thickness and save it. The maximum distance is the maximum thickness, the minimum distance is the minimum thickness, and save the positions of the maximum and minimum thickness points. Calculate the average of the sum of all distances as the average thickness;

[0020] Step 2.2: According to the set of original contour points obtained in Step 1.1, use the least squares algorithm to find the best-fit ellipse; to filter out contour points that are too far from the contour center, traverse the set of original contour points, record the coordinates of each currently traversed point as p0(x0, y0), take two points at positions N1 points away from the left and right of this point and record them as p1(x1, y1) and p2(x2, y2) respectively, and find the distance dist from point p0 to the line L p1，p2 of p1，p2 The general equation of the line L is: Ax + Bz + C = 0, where A = y1 - y2, B = x2 - x1, C = x1*y2 - y1*x2. The distance from each point p0(x0, y0) to the line L p1，p2 is Similarly, take two points at positions N2 points away from the left and right and connect them to obtain the distance, then calculate the average distance from all points between p1 and p2 to the line connecting the current point and the center point of the fitted ellipse respectively; finally, compare the obtained distances with the set threshold one by one. If it exceeds the threshold, filter the current traversed point; obtain the preliminary filtered set of contour points;

[0021] Step 2.3: Traverse the set of original contour points obtained in Step 1.1, calculate the distance from each point on the point set to the preliminary filtered set of contour points, and mark the points whose distances do not exceed the set threshold as missing points and merge them with the filtered contour again; to ensure that the subsequent traversal order of the contour points is consistent with their position order on the contour, traverse the merged contour. For each traversed contour point, obtain the direction vector from the contour center to this point by subtracting the contour center from the contour point, and normalize this direction vector using the Euclidean norm to obtain the unit vector; take the first unit vector as the initial vector, take the positive x direction as the standard direction, calculate the angles between the initial vector and the unit vector of the current traversed contour point and the positive x direction respectively, and then subtract the two angles to obtain the angle between the direction vector of each contour point and the direction vector of the initial point. Sort these angles in ascending order to obtain the set of contour points with the traversal order consistent with the position order;

[0022] Step 2.4: Similar to Step 2.2, filter the contour again to obtain the filtered set of contour points to ensure that there are no contour points that are too far from the contour center.

[0023] Preferably, the convex hull calculation module includes the following process:

[0024] Step 3.1: To simplify the contour shape, improve the algorithm robustness, and accurately calculate the subsequent pipe end dimensions, based on the final filtered contour point set obtained in Step 2.4, convert the final filtered contour point set into a convex hull and save it through the Graham scan method; use the least squares method to convert the point set saved in the convex hull into a fitted ellipse and obtain the center points of the two fitted ellipses, and calculate the outer diameter and inner diameter values by multiplying the average values of the major and minor axes of the fitted ellipses of the large and small contours by the pixel size respectively;

[0025] Step 3.2: Similar to Step 2.1, obtain the average thickness, maximum and minimum thicknesses of the filtered contour points and their positions;

[0026] Preferably, the burr judgment module includes the following process:

[0027] Step 4.1: Based on the point set saved in the form of a convex hull obtained in Step 3, draw the contour points included in the point set for subsequent confirmation of the burr point positions;

[0028] Step 4.2: Based on the point set saved in the form of a convex hull obtained in Step 3, traverse the large and small contours respectively, and judge whether the point is inside the contour and the distance from the point to the contour through the ray projection method; for the large contour point set, judge whether the distance from the point outside the contour to the contour exceeds the threshold, and if it exceeds the distance, judge it as a burr point and draw it on the image; for the small contour point set, judge whether the distance from the point inside the contour to the contour exceeds the threshold, and if it exceeds the distance, judge it as a burr point and draw it on the image;

[0029] Preferably, the thickness calculation module includes the following process:

[0030] According to the fitted ellipse obtained in Step 3.1, the major axis and minor axis of the fitted ellipse of the large contour are denoted as a1 and b1 respectively, the major axis and minor axis of the fitted ellipse of the small contour are denoted as a2 and b2 respectively, and the pixel size is denoted as pix, Maximum outer diameter = a1 * pix, minimum outer diameter = b1 * pix, maximum inner diameter = a2 * pix, minimum inner diameter = b2 * pix. Draw the maximum and minimum thickness points according to the positions of the maximum and minimum thicknesses obtained in Step 3.2.

[0031] Preferably, the lifting mechanism includes a driving mechanism, a worm and worm gear transmission component, and a fixed seat. The driving mechanism is fixed inside the equipment box, the output end of the driving mechanism is connected to the fixed seat through the worm and worm gear transmission component, the camera is fixed on the fixed seat, and driving the driving mechanism drives the fixed seat to move up and down through the worm and worm gear transmission component.

[0032] Preferably, the lifting mechanism further includes a guide rod and a guide seat inside the equipment box. One end of the guide rod is vertically fixed at the bottom of the fixed seat, and the other end passes through the guide seat and can slide vertically on the guide seat.

[0033] The advantages of the present invention are as follows:

[0034] The present invention does not need to contact the steel pipe. Only the original image of the pipe end of the steel pipe needs to be taken by a camera and sent to the data processing module. By combining the image edge detection and graphics methods, the pipe end contour is recognized, and the position relationship between the contour points and the contour is calculated by a self-developed algorithm, so as to accurately locate the burrs at the pipe end and eliminate the influence of the burrs on the measured pipe end size. The present invention not only prevents damage to the steel pipe during the detection process, but also eliminates the influence of burrs on the measured pipe end size. Description of the Drawings

[0035] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0036] Figure 2 is a schematic partial structural diagram of an embodiment of the present invention;

[0037] Figure 3 is a flowchart of an embodiment of the present invention;

[0038] Figure 4 is an enlarged view of the outer diameter contour in an embodiment of the present invention;

[0039] Figure 5 is a diagram of the original detection data and the detection result in an embodiment of the present invention. Detailed Embodiments

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0041] Refer to Figure 1 and Figure 2 , the present invention provides a non-contact steel pipe end face size measuring device, including an equipment box 1, a lifting mechanism 2, a camera 3, a sensor 4, and a data processing module (not shown in the figure). The lifting mechanism 2 is arranged inside the equipment box 1. The lifting end of the lifting mechanism 2 is provided with a camera 3. The equipment box 1 is provided with a shooting port for the camera 3 to take pictures. The sensor 4 is arranged outside the equipment box 1. Both the camera 3 and the sensor 4 are electrically connected to the data processing module outside the equipment box 1.

[0042] The lifting mechanism 2 includes a driving mechanism 21, a worm and worm gear transmission assembly 22, a fixed seat 23 and a guide rod 24. The driving mechanism 21 is fixed inside the equipment box 1. The output end of the driving mechanism 21 is connected to the fixed seat 23 through the worm and worm gear transmission assembly 22. The camera 3 is fixed on the fixed seat 23. Driving the driving mechanism 21 drives the fixed seat 23 to move up and down through the worm and worm gear transmission assembly 22. There is a guide seat 11 inside the equipment box 1. One end of the guide rod 24 is vertically fixed at the bottom of the four corner ends of the fixed seat 23, and the other end penetrates through the guide seat 11 and can slide vertically on the guide seat 11.

[0043] Specifically, the steel pipe is conveyed towards the equipment box 1 until it is sensed by the sensor 4 and then the conveying stops. Then, the lifting mechanism 2 is driven to drive the camera 3 to move vertically until the center of the camera 3 coincides with the center of the steel pipe and the lifting stops. Then, the camera 3 takes a picture of the pipe end of the steel pipe and sends the original image of the taken pipe end to the data processing module.

[0044] The data processing module includes a binarization module, a filtering module, a convex hull calculation module, a burr judgment module and a thickness calculation module. As Figure 3 shown, the specific process of the data processing module is as follows:

[0045] The binarization module converts the original image of the pipe end taken by the camera 3 into a binary image and uses morphological gradient operation to detect the contour to obtain the effective contour points of the pipe end and judge whether the contour is approximately circular. Then, the contour is sorted to distinguish the inner and outer contour point sets. Specifically, the binarization module includes the following processes:

[0046] Step 1.1: First, the image is converted into a binary image by using the inverse binarization method. Secondly, the morphological gradient operation is performed to highlight the image edges and retrieve all contours. Then, small noise contours are removed by calculating the area of the contours, and the rectangle with the smallest area enclosing the contours is found. After that, the rectangles with a specific aspect ratio are screened out. The contours enclosed by the rectangles are sorted, and the largest and the third largest contours are selected as the outer diameter and inner diameter contours and added to the effective contours. The resolution of the contour points is the resolution of the original image. It should be noted here that there are two layers of pixel contours for the outer diameter and inner diameter of the steel pipe end face. The outermost layer of the outer diameter and the outermost layer of the inner diameter contours are taken, so they are the largest and the third largest contours. As Figure 4 shown, it is an enlarged view of the outer diameter contour.

[0047] Step 1.2: According to the two contour point sets obtained in Step 1.1, the zero-order moment of the contour is denoted as m 00， representing the area of the contour. The first-order moments of the contour on the x-axis and y-axis are m 10 and m 01 respectively, and the centroid coordinates of the contour are

[0048] Step 1.3: Calculate the Euclidean distance between the two contour centroid coordinates obtained in Step 1.2, and determine whether the distance exceeds the threshold. If it exceeds the threshold, return directly; otherwise, sort the two contours to distinguish the inner and outer contour point sets.

[0049] The filtering module traverses the original contour points to calculate the average thickness, maximum and minimum thicknesses, and their positions, and then filters the original contour points to obtain a contour point set smaller than the distance threshold; specifically, the filtering module includes the following processes:

[0050] Step 2.1: Traverse the inner diameter original contour point set obtained in Step 1.1, calculate the distance from each point to the outer diameter contour as the thickness, obtain the maximum distance as the maximum thickness, the minimum distance as the minimum thickness, and save the positions of the maximum and minimum thickness points. Calculate the average of the sum of all distances as the average thickness;

[0051] Step 2.2: According to the original contour point set obtained in Step 1.1, use the least squares algorithm to find the best-fit ellipse; to filter the contour points that are too far from the contour center, traverse the original contour point set, record the coordinates of each currently traversed point as p0(x0, y0), and take two points at positions N1 points to the left and right of this point and record them as p1(x1, y1) and p2(x2, y2) respectively. Calculate the distance dist from point p0 to the line L p1，p2 of, and the general equation of the line L p1，p2 is: Ax + Bz + C = 0, where A = y1 - y2, B = x2 - x1, C = x1 * y2 - y1 * x2. The distance from each point to p0(x0, y0) to the line L p1，p2 is Similarly, connect two points at positions N2 points to the left and right to obtain the distance, and then calculate the average distance between all points between p1 and p2 to the line connecting the current point and the center point of the fitted ellipse; finally, compare the obtained distances with the set threshold one by one. If it exceeds the threshold, filter the currently traversed point; obtain a preliminary filtered contour point set;

[0052] Step 2.3: Traverse the set of original contour points obtained in Step 1.1, calculate the distance from each point in the point set to the preliminarily filtered contour point set, and mark the points whose distances do not exceed the set threshold as missing points and merge them with the filtered contour again; to ensure that the subsequent traversal order of the contour points is consistent with their position order on the contour, traverse the merged contour. For each traversed contour point, subtract the contour center from the contour point to obtain the direction vector from the contour center to this point, and normalize this direction vector using the Euclidean norm to obtain a unit vector; use the first unit vector as the initial vector and the positive x - direction as the standard direction. By calculating the angles between the initial vector and the unit vector of the current traversed contour point and the positive x - direction respectively, and then subtracting the two angles, the angle between the direction vector of each contour point and the initial point direction vector can be obtained. Sort these angles in ascending order to obtain a contour point set with the traversal order consistent with the position order.

[0053] Step 2.4: Similar to Step 2.2, filter the contour again to obtain a filtered contour point set, ensuring that there are no contour points that are too far from the contour center.

[0054] The convex hull calculation module calculates the convex hulls of the large and small contours based on the filtered contour point set, performs elliptical fitting on the convex hulls to obtain the fitted ellipses; calculates the average outer and inner diameters and the center points, and calculates the average thickness, maximum and minimum thicknesses and their positions of the filtered contour; specifically, the convex hull calculation module includes the following processes:

[0055] Step 3.1: To simplify the contour shape and improve the robustness of the algorithm, and to accurately calculate the subsequent pipe end dimensions, based on the final filtered contour point set obtained in Step 2.4, convert the final filtered contour point set into a convex hull and save it through the Graham scan method; use the least - squares method to convert the point set saved in the convex hull into a fitted ellipse and obtain the center points of the two fitted ellipses. Calculate the average values of the major and minor axes of the fitted ellipses of the large and small contours and multiply them by the pixel size to obtain the values of the outer and inner diameters.

[0056] Step 3.2: Similar to Step 2.1, obtain the average thickness, maximum and minimum thicknesses and their positions of the filtered contour points.

[0057] The burr judgment module draws the positions of each point in the contour point set according to the obtained convex hull point set, and judges whether the distance from the contour point to the contour exceeds the threshold. If it exceeds, it is judged as a burr; specifically, the burr judgment module includes the following processes:

[0058] Step 4.1: According to the point set saved in the form of a convex hull obtained in Step 3, draw the contour points included in the point set for subsequent confirmation of the burr point positions.

[0059] Step 4.2: Based on the point set saved in the form of a convex hull obtained in Step 3, traverse the large and small contours respectively, and use the ray projection method to determine whether a point is inside the contour and the distance from the point to the contour; for the large contour point set, determine whether the distance from the points outside the contour to the contour exceeds the threshold, and if it exceeds the distance, determine it as a burr point and draw it on the image; for the small contour point set, determine whether the distance from the points inside the contour to the contour exceeds the threshold, and if it exceeds the distance, determine it as a burr point and draw it on the image.

[0060] The thickness calculation module calculates the maximum and minimum inner and outer diameters, ellipticity based on the obtained fitted ellipse, and draws the maximum and minimum thickness points; specifically, the thickness calculation module includes the following process:

[0061] Based on the fitted ellipse obtained in Step 3.1, the major axis and minor axis of the large contour fitted ellipse are denoted as a1 and b1 respectively, the major axis and minor axis of the small contour fitted ellipse are denoted as a2 and b2 respectively, and the pixel size is denoted as pix. The maximum outer diameter = a1 * pix, the minimum outer diameter = b1 * pix, the maximum inner diameter = a2 * pix, and the minimum inner diameter = b2 * pix. Based on the maximum and minimum thickness positions obtained in Step 3.2, draw the maximum and minimum thickness points.

[0062] As Figure 5 shown, Figure 5 In each row of figures, the left figure is the original data, the aperture in the figure is the end face of the steel pipe, and the right figure is the test result report. The purple points in the report represent the minimum thickness positions, and the yellow points represent the maximum thickness positions. Since no comparison standard was set during the test, all the displayed results are unqualified. This does not affect the effectiveness of the method in this embodiment.

[0063] This embodiment does not require contacting the steel pipe. It only needs to capture the original image of the pipe end of the steel pipe by the camera 3 and send it to the data processing module. By combining image edge detection and graphics methods, it identifies the pipe end contour, calculates the positional relationship between the contour points and the contour through a self-developed algorithm, accurately locates the pipe end burrs, and eliminates the influence of the burrs on the measured pipe end dimensions. The present invention not only prevents damage to the steel pipe during the detection process but also eliminates the influence of burrs on the measured pipe end dimensions.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A non-contact measuring device for the end face dimensions of steel pipes, characterized in that, It includes an equipment box, a lifting mechanism, a camera, a sensor and a data processing module. The lifting mechanism is arranged inside the equipment box. The lifting end of the lifting mechanism is provided with a camera. The equipment box is provided with a shooting port for the camera to take pictures. The sensor is arranged outside the equipment box. Both the camera and the sensor are electrically connected to the data processing module outside the equipment box; The data processing module includes a binarization module, a filtering module, a convex hull calculation module, a burr judgment module and a thickness calculation module; Binarization module: Convert the original image of the pipe end taken by the camera into a binary image, use morphological gradient operation to detect the contour, obtain the effective contour points of the pipe end, and judge whether the contour is approximately circular. Then sort the contours to distinguish the inner and outer contour point sets; Filtering module: Traverse the original contour points to calculate the average thickness, maximum and minimum thicknesses and their positions, and then filter the original contour points to obtain a contour point set with distances less than the distance threshold; Convex hull calculation module: According to the contour point set obtained after filtering, calculate the convex hulls of the large and small contours, perform ellipse fitting on the convex hulls to obtain the fitted ellipse; calculate the average inner and outer diameters and the center point, and calculate the average thickness, maximum and minimum thicknesses and their positions of the filtered contour; Burr judgment module: According to the obtained convex hull point set, draw the positions of each point in the contour point set, and judge whether the distance from the contour point to the contour exceeds the threshold. If it exceeds, it is judged as a burr; Thickness calculation module: Calculate the maximum and minimum inner and outer diameters and the ellipticity according to the obtained fitted ellipse, and draw the maximum and minimum thickness points.

2. The non-contact steel pipe end face dimension measuring device according to claim 1, characterized in that, The binarization module includes the following process: Step 1.1: First, convert the image into a binary image by using the inverse binarization method. Secondly, perform morphological gradient operation to highlight the image edges and retrieve all contours. Then, remove small noise contours by calculating the area of the contours, find the rectangle with the smallest area enclosing the contours, and screen out rectangles with a specific aspect ratio. Sort the contours enclosed by the rectangle and select the largest and the third largest contours as the outer diameter and inner diameter contours and add them to the effective contours. The resolution of the contour points is the resolution of the original image; Step 1.2: According to the two contour point sets obtained in Step 1.1, denote the zero-order moment of the contour as m 00， which represents the area of the contour. The first-order moments of the contour on the x-axis and y-axis are m 10 and m 01 respectively, and the centroid coordinates of the contour are Step 1.3: According to the centroid coordinates of the two contours obtained in Step 1.2, calculate the Euclidean distance between the coordinates, and judge whether the distance exceeds the threshold. If it exceeds the threshold, return directly. Otherwise, sort the two contours to distinguish the inner and outer contour point sets.

3. The non-contact steel pipe end face dimension measuring device according to claim 2, wherein The filtering module includes the following process: Step 2.1: Traverse the inner diameter original contour point set obtained in Step 1.1, calculate the distance from each point to the outer diameter contour as the thickness and save it. The maximum distance is the maximum thickness, the minimum distance is the minimum thickness, and save the positions of the maximum and minimum thickness points. Calculate the average of the sum of all distances as the average thickness; Step 2.2: According to the original contour point set obtained in Step 1.1, use the least squares algorithm to find the best-fit ellipse; to filter out the contour points that are too far from the contour center, traverse the original contour point set, record the coordinates of each currently traversed point as p0(x0, y0), and take the two points at positions N1 points away from the left and right sides of this point and record them as p1(x1, y1) and p2(x2, y2) respectively. Calculate the distance dist from point p0 to the line L p1，p2 of, and the general equation of the line L p1，p2 is: Ax + Bz + C = 0, where A = y1 - y2, B = x2 - x1, C = x1*y2 - y1*x2. The distance from each point to p0(x0, y0) to the line L p1，p2 is Similarly, take the two points at positions N2 points away from the left and right sides and connect them to obtain the distance, and then calculate the average distance between all the points between p1 and p2 and the line connecting the current point and the center point of the fitted ellipse; finally, compare the obtained distances with the set threshold one by one. If it exceeds the threshold, filter the currently traversed point; obtain the preliminary filtered contour point set; Step 2.3: Traverse the set of original contour points obtained in Step 1.1, calculate the distance from each point in the point set to the preliminarily filtered contour point set, and mark the points whose distances do not exceed the set threshold as missing points and merge them with the filtered contour again; to ensure that the subsequent traversal order of the contour points is consistent with their position order on the contour, traverse the merged contour. For each traversed contour point, subtract the contour center from the contour point to obtain the direction vector from the contour center to this point, and normalize this direction vector using the Euclidean norm to obtain a unit vector; use the first unit vector as the initial vector and the positive x - direction as the standard direction. By calculating the angles between the initial vector and the unit vector of the current traversed contour point and the positive x - direction respectively, and then subtracting the two angles, the angle between the direction vector of each contour point and the direction vector of the initial point can be obtained. Sort these angles in ascending order to obtain a contour point set with a traversal order consistent with the position order. Step 2.4: Similar to Step 2.2, filter the contour again to obtain a filtered contour point set, ensuring that there are no contour points that are too far from the contour center.

4. The non-contact steel pipe end face dimension measuring device according to claim 3, characterized in that, The convex hull calculation module includes the following process: Step 3.1: To simplify the contour shape, improve the algorithm robustness, and accurately calculate the subsequent pipe end dimensions, according to the finally filtered contour point set obtained in Step 2.4, convert the finally filtered contour point set into a convex hull and save it through the Graham scan method; use the least - squares method to convert the point set saved in the convex hull into a fitted ellipse and obtain the center points of the two fitted ellipses. Calculate the average values of the major and minor axes of the fitted ellipses of the large and small contours respectively, and multiply by the pixel size to obtain the outer diameter and inner diameter values. Step 3.2: Similar to Step 2.1, obtain the average thickness, maximum and minimum thicknesses of the filtered contour points and their positions.

5. The non-contact steel pipe end face dimension measuring device according to claim 4, characterized in that The burr judgment module includes the following process: Step 4.1: According to the point set saved in the form of a convex hull obtained in Step 3, draw the contour points included in the point set for subsequent confirmation of the burr point positions. Step 4.2: According to the point set saved in the form of a convex hull obtained in Step 3, traverse the large and small contours respectively, and use the ray projection method to judge whether the point is inside the contour and the distance from the point to the contour; for the large contour point set, judge whether the distance from the point outside the contour to the contour exceeds the threshold. If the distance exceeds, it is judged as a burr point and drawn on the image; for the small contour point set, judge whether the distance from the point inside the contour to the contour exceeds the threshold. If the distance exceeds, it is judged as a burr point and drawn on the image.

6. The non-contact steel pipe end face dimension measuring device according to claim 4, characterized in that, The thickness calculation module includes the following process: For the fitted ellipse obtained in step 3.1, the major axis and minor axis of the large contour fitted ellipse are denoted as a1 and b1 respectively, the major axis and minor axis of the small contour fitted ellipse are denoted as a2 and b2 respectively, and the pixel size is denoted as pix, obtaining Maximum outer diameter = a1 * pix, minimum outer diameter = b1 * pix, maximum inner diameter = a2 * pix, minimum inner diameter = b2 * pix. According to the maximum and minimum thickness positions obtained in step 3.2, draw the maximum and minimum thickness points.

7. A non-contact steel pipe end face dimension measuring device according to claim 1, characterized in that, The lifting mechanism includes a driving mechanism, a worm - and - worm - gear transmission component, and a fixed seat. The driving mechanism is fixed inside the equipment box. The output end of the driving mechanism is connected to the fixed seat through the worm - and - worm - gear transmission component. The camera is fixed on the fixed seat, and driving the driving mechanism drives the fixed seat to move up and down through the worm - and - worm - gear transmission component.

8. The non-contact steel pipe end face dimension measuring device according to claim 7, characterized in that, The lifting mechanism also includes a guide rod and a guide seat inside the equipment box. One end of the guide rod is vertically fixed at the bottom of the fixed seat, and the other end passes through the guide seat and can slide vertically on the guide seat.

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