Automatic straightness measurement method and system for thickened end steel pipe

Abstract

The application discloses a kind of straightness automatic measurement method and system of thickened end steel pipe, comprising the following steps: S1, the specification data of current steel pipe is collected;S2, control rotating mechanism drives steel pipe to rotate around axis;S3, the angle value of the current position of steel pipe is measured and the light strip image of surface laser;S4, the surface profile data of steel pipe is calculated;S5, the position and range size of thickened end of steel pipe are calculated by thickened part identification model;S6, the extension profile line of thickened end of steel pipe is calculated by pipe body profile extension model, and the continuous surface profile line data of corrected steel pipe is obtained;S7, the straightness value of steel pipe at current angle position is calculated;S8, in the rotation process of steel pipe, according to steps S3 to S7, obtain multiple straightness values of full length;S9, the maximum straightness value is calculated as the straightness value of thickened end of steel pipe.The application replaces existing manual measurement mode, realizes the straightness of automatic measurement thickened end steel pipe.

Description

Technical Field

[0001] This invention relates to measurement technology in the steel pipe production process, and more specifically, to an automatic method and system for measuring the straightness of thickened end steel pipes. Background Technology

[0002] Steel pipes are one of the most important steel products, occupying a crucial position in industrial production. As a multi-functional and economical cross-section steel material, they are widely used in various industries such as petroleum, chemical, metallurgy, and machinery. Straightness refers to the degree of axial misalignment of the outer surface of a steel pipe. It is a vital indicator for measuring steel pipe quality and one of the most important control parameters in steel pipe production. It is also a key indicator that steel pipe manufacturers prioritize and guarantee to users, with clearly defined technical standards and requirements. With increasingly fierce market competition, customers' requirements for steel pipe straightness are constantly rising. Straightness issues have become one of the main quality concerns raised by customers regarding steel pipe products. Plastic deformation caused by factors such as production, processing, self-weight, collisions during transportation, and temperature changes can lead to irreversible bending of the steel pipe, all of which affect its straightness. Therefore, accurate measurement of steel pipe straightness has become a crucial means for enterprises to control the quality of their steel pipe products.

[0003] Due to the high requirements and precision of measurement, coupled with the influence of large-scale industrial production environments and conditions, measuring the straightness of steel pipes is very difficult. Currently, in actual production, steel pipe straightness is inspected manually, generally by visually judging the degree of bending, combined with offline sampling. Commonly used methods include contact measurements such as the string method and coordinate measuring machine (CMM). This approach is inefficient, labor-intensive, prone to arbitrariness, and cannot cover all steel pipes, posing a risk of exceeding straightness quality standards. Especially for thickened steel pipes, to strengthen the end connections, the outer diameter and wall thickness within a certain range at the end are processed to be larger than the body, creating a step-like transition area between the thickened section and the body, thus altering the continuous contour of the pipe and making end straightness measurement even more difficult. Currently, there is no mature online automatic method for accurately measuring the straightness of thickened end steel pipes. Summary of the Invention

[0004] In view of the above-mentioned defects in the existing technology, the purpose of this invention is to provide an automatic measurement method and system for the straightness of thickened end steel pipes, to replace the existing manual measurement method and realize the automatic measurement of the straightness of thickened end steel pipes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] On the one hand, an automatic method for measuring the straightness of a thickened end steel pipe includes the following steps:

[0007] S1. Collect the specification data of the steel pipe at the current test station;

[0008] S2. Control the rotating mechanism to drive the steel pipe to rotate around the axis;

[0009] S3. Measure the angle value of the current position of the steel pipe and the light band image of the laser on the surface;

[0010] S4. Calculate the surface contour data of the steel pipe based on the light strip image;

[0011] S5. Calculate the position and size of the thickened end of the steel pipe using the thickened part identification model;

[0012] S6. Calculate the extended contour line of the thickened end of the steel pipe using the pipe body contour extension model to obtain the corrected continuous surface contour line data of the steel pipe.

[0013] S7. Calculate the straightness value of the steel pipe at the current angular position based on the continuous surface contour data of the steel pipe.

[0014] S8. During the rotation of the steel pipe, multiple straightness values ​​for the 360° full circumference are obtained according to steps S3 to S7.

[0015] S9. The maximum straightness value is the straightness value of the thickened end of the steel pipe.

[0016] Preferably, in step S1, the straightness measurement and control unit obtains the specification data and testing standards of the steel pipe through the signal interface unit.

[0017] Preferably, in step S2, the straightness measurement and control unit controls the rotating support device to rotate the steel pipe via the rotation control device.

[0018] Preferably, in step S3, the laser emitted by the laser is projected onto the surface of the steel pipe to form a light band that completely coincides with the upper edge of the steel pipe;

[0019] The light band image is acquired in real time by an industrial camera and sent to the straightness measurement and control unit;

[0020] The rotation angle of the steel pipe is measured in real time by an angle sensor and sent to the straightness measurement and control unit.

[0021] Preferably, in steps S4 and S5, the straightness measurement and control unit processes and analyzes the light band image:

[0022] In the light strip image, the light strip image within a length range L from the thickened end of the steel pipe is taken, and contour data h1, h2, ..., hn are obtained by sampling at equal intervals;

[0023] For each adjacent data point in the contour data h1, h2, ..., hn, calculate the absolute value of the vertical displacement difference H1 = |h1 - h2| and H2 = |h2 - h3| to obtain H1, H2, ..., Hn-1 displacement difference data. Find the maximum value Hm among them. Then the position corresponding to the contour data point hm is the abrupt change position between the thickened end and the pipe body of the steel pipe, and h1, ..., hm are the contour data of the thickened end of the steel pipe.

[0024] Preferably, in step S6, the abrupt change position hm where the thickened end connects to the pipe body of the steel pipe is used as the dividing line. Several consecutive contour data points hm-1, ..., hm-k are taken on the left side of the thickened end, and the average vertical displacement of these data points is calculated. Similarly, several consecutive contour data points hm+1, ..., hm+k are taken on the right side of the pipe body of the thickened end, and the average vertical displacement of these data points is calculated. The difference between the two average vertical displacements is the displacement difference H between the thickened part and the pipe body.

[0025] The vertical displacement values ​​of all contour data points h1, h2, ..., hm at the thickened end are uniformly reduced by H to obtain the translated contour data f1, f2, ..., fm, which are then connected to the contour data of the pipe body to form the corrected continuous surface contour data f1, f2, ..., fm, hm+1, ..., hn of the steel pipe.

[0026] Preferably, in step S7, the straightness value of the current angular position of the steel pipe is calculated based on the continuous surface contour data f1, f2, ..., fm, hm+1, ..., hn of the steel pipe.

[0027] At a distance L1 from both ends of the steel pipe, two contour points hn and hk with a spacing of L2 are taken on the pipe body as reference points. The straight line connecting these two reference points is the baseline. The straightness value is calculated by measuring the distance between the endpoint f1 and the baseline.

[0028] On the other hand, an automatic straightness measurement system for thickened end steel pipes includes:

[0029] Rotary support device for holding steel pipes;

[0030] A laser is positioned directly above the steel pipe to emit a linear laser beam that illuminates the steel pipe, creating a light band that outlines the surface of the pipe.

[0031] An industrial camera is installed on one side of the steel pipe to capture images of the light band on the steel pipe.

[0032] An angle measuring device is used to measure the rotation angle of the steel pipe;

[0033] A rotation control device is used to control the rotation support device to drive the steel pipe to rotate around the axis;

[0034] The signal interface unit is used to receive and collect the specification data of the steel pipe and the arrival signal of whether the thickened steel pipe has reached the measurement station.

[0035] The straightness measurement and control unit is connected to the laser, the industrial camera, the angle measuring device, the rotation control device, and the signal interface unit. It is used to control the laser and the rotation control device, receive relevant signals and data from the industrial camera, the angle measuring device, and the signal interface unit, and perform straightness calculation.

[0036] The automatic straightness measurement system for the thickened end steel pipe is used to realize the automatic straightness measurement method for the thickened end steel pipe.

[0037] The present invention provides an automatic method and system for measuring the straightness of thickened end steel pipes. The method adopts a non-contact measurement method, which is suitable for implementation in industrial production sites. It can realize the automatic measurement of the straightness of the end of thickened steel pipes online, which greatly improves the measurement efficiency and accuracy of straightness, can detect straightness exceeding the standard in a timely manner, and improves the quality control capability. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating an embodiment of the automatic straightness measurement method for thickened end steel pipes of the present invention;

[0039] Figure 2 This is a schematic diagram illustrating the calculation principle of an embodiment of the automatic straightness measurement method for thickened end steel pipes of the present invention;

[0040] Figure 3 This is a schematic diagram of the framework of an embodiment of the automatic straightness measurement system for thickened end steel pipes of the present invention. Detailed Implementation

[0041] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0042] Combination Figure 1As shown, this invention provides an automatic method for measuring the straightness of a thickened end steel pipe. The thickened steel pipe to be inspected is placed horizontally on a measuring station. A laser is placed directly above the axis of the steel pipe. The laser beam emitted by the laser is projected onto the surface of the thickened steel pipe, forming a light band that completely coincides with the upper edge of the steel pipe. This light band is the surface contour line of the steel pipe at that location. An image of this light band is captured by a high-resolution industrial camera, obtaining the contour curve data represented by the light band. The position and length of the thickened part are determined using a thickened part identification model. Then, the extended contour line of the pipe body at the thickened part is calculated using a pipe body contour extension model. Finally, the true straightness value at the current position is calculated based on the corrected contour data. A rotating mechanism on the measuring station drives the steel pipe to rotate around its axis, measuring the straightness values ​​corresponding to various angles around the circumference of the steel pipe. The value with the largest offset is the straightness value of the thickened steel pipe end. Specifically, the method includes the following steps:

[0043] S1. Collect the specification data of the steel pipe at the current test station to obtain the outer diameter and other dimensional data;

[0044] S2. Control the rotating mechanism to drive the steel pipe to rotate around the axis;

[0045] S3. Measure the angle value of the current position of the steel pipe and the light band image of the laser on the surface;

[0046] S4. Calculate the surface contour data of the steel pipe based on the laser beam pattern;

[0047] S5. After obtaining the surface contour data of the steel pipe, calculate the position and range of the thickened end of the steel pipe through the thickened part identification model;

[0048] S6. Calculate the extended profile of the thickened end of the steel pipe using the pipe body profile extension model to obtain the corrected continuous surface profile data of the steel pipe.

[0049] S7. Calculate the straightness value of the steel pipe at the current angular position based on the continuous surface contour data of the steel pipe.

[0050] S8. During the rotation of the steel pipe, obtain multiple straightness values ​​for the 360° full circumference according to steps S3 to S7.

[0051] S9. The maximum straightness value is the straightness value of the thickened end of the steel pipe.

[0052] By following the steps above, the straightness of the thickened steel pipe end can be measured online in a non-contact manner.

[0053] In step S1 above, the straightness measurement and control unit obtains the specification data and testing standards of the steel pipe through the signal interface unit.

[0054] In step S2 above, the straightness measurement and control unit controls the rotating support device to drive the steel pipe to rotate through the rotation control device.

[0055] In step S3 above, the laser emitted by the laser is projected onto the surface of the steel pipe to form a light band that completely coincides with the upper edge of the steel pipe;

[0056] An industrial camera captures light band images in real time and sends them to the straightness measurement and control unit.

[0057] An angle sensor measures the rotation angle of the steel pipe in real time and sends it to the straightness measurement and control unit.

[0058] In step 5 above, the difference between the thickened steel pipe and the ordinary steel pipe lies in the fact that the wall thickness and outer diameter of the thickened steel pipe within a certain range at its end are larger than those of the pipe body, and the surface contour has a raised step shape, thus changing the continuous contour shape of the pipe body. The thickened part identification model is used to determine the location and range of the thickened part. First, it traverses all sampling points on the contour line, calculates the distance difference between adjacent sampling points in the direction perpendicular to the axis of the thickened pipe, and finds the maximum distance difference. If the distance difference is greater than the reference threshold, the corresponding horizontal position is the abrupt change position from the pipe body to the thickened part. Then, the range from the end of the steel pipe to this abrupt change position is the thickened part of the thickened steel pipe.

[0059] In step 6 above,

[0060] The calculation method for the pipe body contour extension model is described as follows: First, calculate the contour curves of the thickened part and the pipe body respectively. Then, calculate the distance deviation between the thickened part and the pipe body in the direction perpendicular to the axis of the thickened pipe. Then, translate the contour curve of the thickened part as a whole in the direction of the axis according to the distance deviation and connect it with the contour curve of the pipe body to obtain continuous pipe body surface contour line data.

[0061] Combination Figure 3 As shown, the present invention also provides an automatic straightness measurement system for thickened end steel pipes, comprising:

[0062] The rotating support device 1 is used to place the steel pipe 2 horizontally and can drive the steel pipe 2 to rotate around the axis.

[0063] Laser 3 is a laser emitting device located directly above steel pipe 2, used to emit a straight laser beam that illuminates the steel pipe 2 to create a light strip that outlines the surface.

[0064] Industrial camera 4 is an image acquisition device, located on one side of steel pipe 2, used to acquire the light strip image on steel pipe 2;

[0065] Angle measuring device 5 is an angle sensor used to measure the rotation angle of steel pipe 2;

[0066] The rotation control device 6 is a driving device used to control the rotation support device 1 to drive the steel pipe 2 to rotate around the axis;

[0067] Signal interface unit 7 is a data signal acquisition and communication device used to receive and acquire the current steel pipe specification data and whether it is in place signal;

[0068] The straightness measurement and control unit 8 is a computer device connected to the laser 3, industrial camera 4, angle measuring device 5, rotation control device 6 and signal interface unit 7. It is used to control the laser 3 and rotation control device 6, receive relevant signals and data from the industrial camera 4, angle measuring device 5 and signal interface unit 7, and realize straightness calculation.

[0069] The present invention provides an automatic straightness measurement system for thickened end steel pipes to realize the automatic straightness measurement method for thickened end steel pipes of the present invention.

[0070] In summary, in view of the current status and existing problems of the technology for measuring the straightness of thickened steel pipe ends, this invention proposes an automatic method and system for measuring the straightness of thickened steel pipe ends. This method is based on the principle of laser profile measurement. By projecting a laser line onto the axial position of the surface of the steel pipe being measured, surface profile data is captured by image measurement to identify the accurate position and length of the thickened part. The extended profile line of the pipe body in the thickened part is reconstructed using a profile extension calculation model, thereby calculating the true straightness value of the pipe end.

[0071] Example 1

[0072] refer to Figures 1 to 3 As shown in Example 1, an automatic method for measuring the straightness of a thickened end steel pipe is proposed. The specific steps are as follows:

[0073] S1. The straightness measurement control unit 8 detects whether the thickened steel pipe 2 has reached the measurement station through the signal interface unit 7. If yes, proceed to step S2; otherwise, continue to detect and wait.

[0074] S2, the straightness measurement and control unit 8 obtains the specification data and testing standards of the thickened steel pipe 2 through the signal interface unit 7;

[0075] S3, Straightness measurement and control unit 8 controls the rotation support device 1 to drive the thickened steel pipe 2 to rotate through rotation control device 6;

[0076] S4, Industrial camera 4 acquires the laser strip image on the surface of thickened steel pipe 2 in real time and sends it to straightness measurement control unit 8, Angle sensor 5 measures the rotation angle value of thickened steel pipe 2 in real time and sends it to straightness measurement control unit 8;

[0077] S5 and the straightness measurement and control unit 8 process and analyze the light strip image to obtain contour data and calculate the straightness value of the end of the thickened steel pipe 2 at this angle position.

[0078] As attached Figure 2 As shown in S51, in the light strip image, take the light strip image within a length range L from the end of the thickened steel pipe 2, and obtain the contour data h1, h2, ..., hn by sampling at equal intervals. The length range L can be set according to industry standard requirements. For example, for thickened steel pipes such as casing and oil pipe, L = 1.8 meters.

[0079] S52. Calculate the absolute value of the vertical displacement difference between two adjacent data points of the contour data h1, h2, ..., hn, H1 = |h1 - h2|, H2 = |h2 - h3|, to obtain H1, H2, ..., Hn-1 displacement difference data. Find the maximum value Hm among them. Then the position corresponding to the contour data point hm is the abrupt change position where the thickened part connects with the pipe body, and h1, ..., hm are the contour data of the thickened part.

[0080] S53. Using the abrupt change point hm where the thickened part meets the pipe body as the dividing line, take several consecutive contour data points hm-1, ..., hm-k on the left side of the thickened part, and calculate the average vertical displacement of these data points; similarly, take several consecutive contour data points hm+1, ..., hm+k on the right side of the pipe body, and calculate the average vertical displacement of these data points. The difference between the two average vertical displacements is the displacement difference H between the thickened part and the pipe body. Subtract H from the vertical displacement values ​​of all contour data points h1, h2, ..., hm of the thickened part to obtain the translated contour data f1, f2, ..., fm, and connect them with the pipe body contour data to form the corrected continuous surface contour data f1, f2, ..., fm, hm+1, ..., hn of the pipe body;

[0081] S54. According to the industry standard requirements and methods for straightness measurement, calculate the straightness value at the current angular position based on the contour data f1, f2, ..., fm, hm+1, ..., hn. The industry standard specifies the following method for measuring end straightness: At a distance L1 from the end of the thickened steel pipe 2, take two contour points hn and hk with a spacing of L2 on the pipe body as reference points. The straight line connecting these two reference points is the baseline. The distance from the endpoint f1 to this baseline is the straightness value. The lengths L1 and L2 can be set according to industry standard requirements. For example, for thickened steel pipes such as casing and tubing, L1 and L2 are taken as 1.5 meters and 0.3 meters, respectively.

[0082] S6. Repeat steps S4 to S5;

[0083] S7. The straightness measurement control unit 8 determines whether the 360° full circumference measurement of the thickened steel pipe 2 has been completed. If yes, then execute step S8; otherwise, return to step S3.

[0084] S8, the straightness measurement and control unit 8 compares the straightness values ​​at all angle positions and selects the maximum value as the straightness value at the end of the thickened steel pipe 2;

[0085] S9. Straightness measurement control unit 8 determines whether the measurement has ended. If yes, the measurement ends; otherwise, it returns to step S1.

[0086] Example 2

[0087] refer to Figures 1 to 3 As shown in Example 2, an automatic method for measuring the straightness of a thickened end steel pipe is proposed. The specific steps are as follows:

[0088] S1. The straightness measurement control unit 8 detects whether the thickened steel pipe 2 has reached the measurement station through the signal interface unit 7. If yes, proceed to step S2; otherwise, continue to detect and wait.

[0089] S2. The straightness measurement and control unit 8 obtains the specification data and testing standards of the thickened steel pipe 2 through the signal interface unit 7. In this embodiment, the outer diameter of the thickened section of the thickened steel pipe 2 is 110mm, the outer diameter of the pipe body is 98mm, and the testing standard is that the deviation distance within a 1.0m length range of the pipe end should not exceed 4mm.

[0090] S3, Straightness measurement and control unit 8 controls the rotation support device 1 to drive the thickened steel pipe 2 to rotate through rotation control device 6;

[0091] S4, Industrial camera 4 acquires the laser strip image on the surface of thickened steel pipe 2 in real time and sends it to straightness measurement control unit 8, Angle sensor 5 measures the rotation angle value of thickened steel pipe 2 in real time and sends it to straightness measurement control unit 8;

[0092] S5 and the straightness measurement and control unit 8 process and analyze the light strip image to obtain contour data and calculate the straightness value of the end of the thickened steel pipe 2 at this angle position.

[0093] As attached Figure 2 As shown in S51, in the light strip image, take the light strip image within a length range of L = 1 meter from the end of the thickened steel pipe 2, and obtain 101 contour data h1, h2, ..., h101 by sampling at equal intervals of 10 mm.

[0094] S52. Calculate the absolute value of the vertical displacement difference between adjacent data points h1, h2, ..., h101 in sequence: H1 = |h1 - h2|, H2 = |h2 - h3|. This yields 100 displacement difference data points: H1 = 0.02mm, H2 = 0mm, ..., H11 = 6.01mm, H12 = 0.1mm, ..., H100 = 0.03mm. Find the maximum value H11 among them. The position corresponding to the contour data point h11 is the abrupt change position where the thickened part connects to the pipe body, and h1, ..., h11 are the contour data of the thickened part.

[0095] S53. Using the abrupt change point hm where the thickened part meets the pipe body as the dividing line, take 5 consecutive contour data points h10, h9, h8, h7, and h6 on the left side of the thickened part, and calculate the average vertical displacement of these data points; similarly, take 5 consecutive contour data points h12, h13, h14, h15, and h16 on the right side of the pipe body, and calculate the average vertical displacement of these data points. The difference between the two average vertical displacements is the displacement difference H between the thickened part and the pipe body, which is 6 mm. Subtract H from the vertical displacement values ​​of all contour data points h1, h2, ..., h11 of the thickened part to obtain the translated contour data f1, f2, ..., f11, and connect them with the pipe body contour data to form the corrected continuous surface contour data f1, f2, ..., f11, h12, ..., h101 of the pipe body;

[0096] S54. According to the industry standard requirements and methods for straightness measurement, based on the contour data f1, f2, ..., f11, h12, ..., h101, calculate the straightness value of 3.2mm at the current angular position. The industry standard specifies the following method for measuring end straightness: At a distance of L1 = 0.8 meters from the end of the thickened steel pipe 2, take two contour points h101 and h80 on the pipe body with a spacing of L2 = 0.2 meters as reference points. The straight line connecting these two reference points is the baseline. The distance from the endpoint f1 to this baseline is the straightness value.

[0097] S6. Repeat steps S4 to S5;

[0098] S7. The straightness measurement control unit 8 determines whether the 360° full circumference measurement of the thickened steel pipe 2 has been completed. If yes, then execute step S8; otherwise, return to step S3.

[0099] S8, the straightness measurement and control unit 8 compares the straightness values ​​at all angle positions and selects the maximum value as the straightness value at the end of the thickened steel pipe 2;

[0100] S9. Straightness measurement control unit 8 determines whether the measurement has ended. If yes, the measurement ends; otherwise, it returns to step S1.

[0101] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. An automatic method for measuring the straightness of a thickened end steel pipe, characterized in that, Includes the following steps: S1. Collect the specification data of the steel pipe at the current test station; S2. Control the rotating mechanism to drive the steel pipe to rotate around the axis; S3. Measure the angle value of the current position of the steel pipe and the light band image of the laser on the surface; S4. Calculate the surface contour data of the steel pipe based on the light strip image; S5. Calculate the position and size of the thickened end of the steel pipe using the thickened part identification model; S6. Calculate the extended contour line of the thickened end of the steel pipe using the pipe body contour extension model to obtain the corrected continuous surface contour line data of the steel pipe. S7. Calculate the straightness value of the steel pipe at the current angular position based on the continuous surface contour data of the steel pipe. S8. During the rotation of the steel pipe, multiple straightness values ​​for the 360° full circumference are obtained according to steps S3 to S7. S9. The maximum straightness value is the straightness value of the thickened end of the steel pipe. In steps S4 and S5, the straightness measurement and control unit processes and analyzes the light band image: In the light strip image, the light strip image within a length range L from the thickened end of the steel pipe is taken, and contour data h1, h2, ..., hn are obtained by sampling at equal intervals; For each adjacent data point in the contour data h1, h2, ..., hn, calculate the absolute value of the vertical displacement difference: H1 = |h1 - h2|, H2 = |h2 - h3|, obtaining H1, H2, ..., Hn-1 displacement difference data. Find the maximum value Hm among them. Then, the position corresponding to the contour data point hm is the abrupt change position where the thickened end connects to the pipe body of the steel pipe, and h1, ..., hm are the contour data of the thickened end of the steel pipe. In step S6, taking the abrupt change position hm where the thickened end connects to the pipe body of the steel pipe as the dividing line, several consecutive contour data points hm-1, ..., hm-k are taken on the left side of the thickened end, and the average vertical displacement of these data points is calculated; similarly, several consecutive contour data points hm+1, ..., hm+k are taken on the right side of the pipe body of the thickened end, and the average vertical displacement of these data points is calculated. The difference between the two average vertical displacements is the displacement difference H between the thickened part and the pipe body. The vertical displacement values ​​of all contour data points h1, h2, ..., hm at the thickened end are uniformly reduced by H to obtain the translated contour data f1, f2, ..., fm, which are then connected to the contour data of the pipe body to form the corrected continuous surface contour data f1, f2, ..., fm, hm+1, ..., hn of the steel pipe.

2. The automatic straightness measurement method for thickened end steel pipes according to claim 1, characterized in that: In step S1, the straightness measurement and control unit obtains the specification data and testing standards of the steel pipe through the signal interface unit.

3. The automatic straightness measurement method for thickened end steel pipes according to claim 2, characterized in that: In step S2, the straightness measurement and control unit controls the rotating support device to rotate the steel pipe through the rotation control device.

4. The automatic straightness measurement method for thickened end steel pipes according to claim 2, characterized in that: In step S3, the laser emitted by the laser is projected onto the surface of the steel pipe to form a light band that completely coincides with the upper edge of the steel pipe. The light band image is acquired in real time by an industrial camera and sent to the straightness measurement and control unit; The rotation angle of the steel pipe is measured in real time by an angle sensor and sent to the straightness measurement and control unit.

5. The automatic straightness measurement method for thickened end steel pipes according to claim 1, characterized in that, In step S7, the straightness value of the current angular position of the steel pipe is calculated based on the continuous surface contour data f1, f2, ..., fm, hm+1, ..., hn of the steel pipe. At a distance L1 from both ends of the steel pipe, two contour points hn and hk with a spacing of L2 are taken on the pipe body as reference points. The straight line connecting these two reference points is the baseline. The straightness value is calculated by measuring the distance between the endpoint f1 and the baseline.

6. An automatic straightness measurement system for thickened end steel pipes, characterized in that, include: Rotary support device for holding steel pipes; A laser is positioned directly above the steel pipe to emit a linear laser beam that illuminates the steel pipe, creating a light band that outlines the surface of the pipe. An industrial camera is installed on one side of the steel pipe to capture images of the light band on the steel pipe. An angle measuring device is used to measure the rotation angle of the steel pipe; A rotation control device is used to control the rotation support device to drive the steel pipe to rotate around the axis; The signal interface unit is used to receive and collect the specification data of the steel pipe and the arrival signal of whether the thickened steel pipe has reached the measurement station. The straightness measurement and control unit is connected to the laser, the industrial camera, the angle measuring device, the rotation control device, and the signal interface unit. It is used to control the laser and the rotation control device, receive signals and data from the industrial camera, the angle measuring device, and the signal interface unit, and perform straightness calculation. The automatic straightness measurement system for the thickened end steel pipe is used to implement the automatic straightness measurement method for the thickened end steel pipe as described in any one of claims 1-5.

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