An automatic identification method for side bending of rolled parts in the strip production process

Abstract

This invention belongs to the field of strip and plate production technology, specifically an automatic identification method for side bending of rolled pieces in the strip and plate production process. The method includes the following steps: S1: The rolled piece exits the furnace, and initial parameters are obtained, mainly including the rolled piece grade, inlet thickness, inlet width, and inlet temperature; S2: Production begins, after the rolled piece passes through the mill stand, the outlet thickness, outlet width, and rolling speed are obtained. The rolled piece moves along the rolling direction via the roller conveyor. This invention's automatic identification method for side bending eliminates the need for traditional manual inspection, reducing labor costs and increasing automation in the inspection process. Based on the relative distance signal from the rangefinders on the transmission and operation sides, the degree of side bending at the rolling centerline is obtained after processing. This solves the problem of relying on manual visual judgment of side bending on-site and provides accurate side bending data, improving the accuracy of side bending identification and providing guidance for subsequent supply and demand adjustments, thereby improving product quality.

Description

Technical Field

[0001] This invention belongs to the field of strip production technology, specifically a method for automatic identification of side bending of rolled parts in the strip production process. Background Technology

[0002] In hot deformation processes such as strip rolling, uneven temperature distribution across the width of the rolled piece, wedge-shaped initial billet, deviations during the piece's bite, and differences in stiffness on both sides of the mill result in varying reduction rates across the width of the rolled piece. This leads to uneven extension along the length of the rolled piece, causing it to lose its straightness and become asymmetrical along the width, bending towards the operating or transmission side, exhibiting a lateral bending pattern. Lateral bending not only reduces yield but, if not addressed promptly, can also disrupt the rolling process and lead to production accidents. Therefore, identifying lateral bending in strip rolling is crucial. Currently, most production processes rely on manual visual inspection for lateral bending, which is both inaccurate and inefficient.

[0003] Theoretical modeling, finite element simulation, and machine vision are often used to predict and identify side bending during strip rolling. Based on the equations of roll gap rigidity tilt, exit piece wedge shape, piece thickness distribution, unit width rolling force distribution, force balance, and moment balance, a mathematical model for the side bending and its control at the exit of the rolled piece was established. The influence of temperature difference on both sides of the rolled piece and roll tilt on side bending during rolling was studied using the finite element method. Chinese patent "CN 104438354 A A method to overcome side bending during rough rolling of sheet metal" uses image processing to process the edges of the obtained rolled piece image, thereby obtaining the morphology of the side bending of a certain pass of the rolled piece.

[0004] In existing technologies, long-term observation has revealed that theoretical modeling is often based on numerous assumptions, which differ from actual production. The finite element method struggles to obtain accurate boundary conditions and has a long solution time, making it unsuitable for online application. Meanwhile, machine vision-based detection methods are easily affected by environmental factors such as moisture and dust, leading to errors in the measurement results.

[0005] Therefore, the present invention provides an automatic identification method for side bending of rolled parts in the strip production process. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, the present invention proposes an automatic identification method for side bending of rolled parts in the strip production process.

[0007] The technical solution adopted by this invention to solve its technical problem is: an automatic identification method for side bending of rolled parts in the strip production process, comprising the following steps:

[0008] S1: The rolled piece exits the furnace, and the initial parameters of the rolled piece are obtained;

[0009] This mainly includes the rolled product grade, inlet thickness, inlet width, and inlet temperature;

[0010] S2: At the start of the production process, after the workpiece is rolled out through the stand, data such as the exit thickness, exit width, and rolling speed of the workpiece are obtained. The workpiece moves along the rolling direction via the roller table, and the rolling speed of the mill is recorded.

[0011] S3: When the head of the rolled piece reaches the measurement position, the operating side distance meter and the transmission side distance meter perform distance detection on the rolled piece;

[0012] S3.1: Determine whether the workpiece has reached the distance measuring instrument position, and start distance measurement and data upload;

[0013] First, based on the judgment criteria (a comprehensive judgment based on two rangefinders and the actual width), it is determined whether the head of the rolled piece has reached the detection position. If the criteria are met, counting starts from zero, and the operation side distance data l1(t) and transmission side distance data l2(t) are continuously uploaded to the data processing server. If the criteria are not met, the judgment continues. The judgment formula is as follows:

[0014] l1(t)+l2(t)+w≤L1+L2+ΔL(t=0,1,2…,n)

[0015] Where l1(t) is the distance from the transmission side distance measuring instrument to the edge of the rolled piece, l2(t) is the distance from the transmission side distance measuring instrument to the edge of the rolled piece, w is the target width value, and ΔL is the target width tolerance value;

[0016] S3.2: When the workpiece head is determined to have reached the distance measuring instrument position, data is uploaded according to a fixed communication cycle, transmitting the roll speed and roller conveyor speed to the data processing server.

[0017] If the workpiece has not yet completely passed through the mill at this time, record and upload the roll speed v. R (t), when the rolled piece has completely passed through the mill, the recorded upload roller speed v is recorded. r (t), and upload the workpiece vi representation as the workpiece speed processing;

[0018] S3.3: When the end of the rolled piece reaches the detection position, data recording and uploading are completed. The judgment conditions are as follows:

[0019] l1(t)+l2(t)+w≥L1+L2+ΔL(t=0,1,2…,n)

[0020] The final data processor obtains two direct data curves, which are further processed to achieve side bending identification of the rolled piece;

[0021] S4: Processing and conversion of rolled piece inspection data;

[0022] S4.1: Processing of rolled product inspection data;

[0023] With the plane of the operating side as the X-axis, the data uploaded by the sensor ultimately yields two distance curves that change over time, which require further processing to accurately represent the side bending of the rolled piece.

[0024] The function representing the change of the operating side distance over time is expressed as:

[0025] y1(t)=L1+L2-l1(t)

[0026] The function of the transmission side distance changing with time is:

[0027] y2(t)=L2-l2(t)

[0028] The relationship between the midline data and time is then obtained, denoted as , and calculated using the following formula:

[0029]

[0030] S4.2: Conversion of rolled piece inspection data;

[0031] Data curves stored according to time, based on a fixed communication period ΔT. Converted into a data curve Y(s) stored by length:

[0032] Sampling points converted to length points

[0033] Where n is the number of sampling points, and v(t) is the speed transmitted by the speed sensor;

[0034] Wherein: the number of sampling points remains unchanged, still n;

[0035] S5: Calculation of side bending parameters of rolled parts;

[0036] S5.1: Curve data fitting;

[0037] A quartic curve was used to fit Y(s), and the curve structure is as follows:

[0038] Y(s)=k1s 4 +k2s 3 +k3s 2 +k4s+k5

[0039] Calculate the first and second derivatives of this curve:

[0040] The first derivative is: Y′(s)=4k1s 3 +3k2s 2 +2k3s+k4

[0041] The second derivative is: Y″(s)=12k1s 2 +6k2s+2k3

[0042] S5.2: Calculate the radius of curvature of the rolled piece;

[0043] The formula for calculating the radius of curvature is shown below:

[0044]

[0045] In the formula, R is the radius of curvature, and K is the curvature;

[0046] Write a program to take Y(s) as input, calculate the radius of curvature of each sampling point, compare the maximum radius of curvature, and then obtain the corresponding position of the rolled piece.

[0047] S5.3: Calculate the bending amount of the rolled piece;

[0048] Calculate the coordinates of the starting point A and ending point B of Y(s), denoted as (0,Y0)A and (n,Y0)B, respectively. S B, obtain the straight line l containing the starting and ending points. A,B The equation is:

[0049] If the coordinates of a point on the centerline of the rolled piece are (s i ,Y(s i Then, connect this point with l A,B The distance between them is d i The amount of bending is calculated using the following formula:

[0050]

[0051] The bending amount at each sampling point is further calculated, and the maximum bending amount is obtained by comparison, thus determining the corresponding position of the rolled piece.

[0052] S7: Completes the side bending measurement process of the rolled piece, and outputs the rolled piece curve, the radius of curvature of the rolled piece, and the bending amount.

[0053] The beneficial effects of this invention are as follows:

[0054] 1. The present invention provides an automatic identification method for side bending of rolled pieces in the strip production process, which eliminates the traditional manual inspection method, reduces labor costs for enterprises, and improves the automation level of the inspection process. By processing the relative distance signals from the rangefinders on the transmission side and the operation side, the degree of side bending at the rolling centerline position is obtained, solving the problem of relying on manual visual judgment of side bending on site, and obtaining accurate side bending data, thereby improving the accuracy of side bending identification, providing guidance for subsequent supply and demand adjustments, and improving product quality. Attached Figure Description

[0055] The invention will now be further described with reference to the accompanying drawings.

[0056] Figure 1 This is a schematic diagram of the detection position in this invention;

[0057] Figure 2 This is a flowchart from the present invention;

[0058] Figure 3 This is a schematic diagram of online measurement of the side bending morphology of the rolled piece in this invention;

[0059] Figure 4 This is a schematic diagram of the side bending parameters of the rolled piece in this invention;

[0060] Figure 5 This is a schematic diagram of the side bending of the rolled piece in this invention.

[0061] In the diagram: 1. Rolled workpiece; 2. Roll; 3. Speed ​​measuring instrument; 4. Drive-side distance measuring instrument; 5. Operator-side distance measuring instrument. Detailed Implementation

[0062] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0063] like Figures 1 to 2 As shown in the embodiment of the present invention, an automatic identification method for side bending of rolled parts in the strip production process includes the following steps:

[0064] Step 1: The rolled piece exits the furnace, and the initial parameters of the rolled piece are obtained;

[0065] The initial parameters of the rolled piece mainly include the rolled piece grade, inlet thickness, inlet width, and inlet temperature;

[0066] Step 2: After the workpiece deforms as it passes through the rolling mill, it continues to move along the rolling direction;

[0067] The data collected based on the above process are shown in Table 1;

[0068]

[0069] Step 3: Once the rolled piece arrives at the inspection area, measurement begins, and the speed and distance data are uploaded;

[0070] Step 3.1: First, based on the judgment conditions (a comprehensive judgment based on two rangefinders and the actual width), determine whether the head of the rolled piece has reached the detection position. If the conditions are met, start counting from zero and continuously upload the operating side distance data and the transmission side distance data to the data processing server; if the conditions are not met, continue the judgment process. The judgment formula is as follows:

[0071] l1(t)+l2(t)+w≤L1+L2+ΔL(t=0,1,2…,n)

[0072] Where l1(t) is the distance from the transmission-side distance measuring instrument to the edge of the rolled piece; l2(t) is the distance from the transmission-side distance measuring instrument to the edge of the rolled piece; w is the target width value; ΔL is the target width tolerance value;

[0073] Step 3.2: Transmit the speed sensor data v(t) to the data processing server according to a fixed communication cycle;

[0074] Step 3.3: Once the tail of the rolled piece reaches the detection position, data recording and uploading are complete. The judgment conditions are as follows:

[0075] l1(t)+l2(t)+w≥L1+L2+ΔL(t=0,1,2…,n)

[0076] Step 4: Processing and conversion of rolled piece inspection data;

[0077] Step 4.1: Processing of rolled piece inspection data;

[0078] With the plane of the operating side as the X-axis, the data uploaded by the sensor ultimately yields two distance curves that change over time, which require further processing to accurately represent the side bending of the rolled piece.

[0079] The function representing the change of the operating side distance over time is expressed as:

[0080] y1(t)=L1+L2-l1(t)

[0081] The function of the transmission side distance changing with time is:

[0082] y2(t)=L2-l2(t)

[0083] This leads to the relationship between the midline data and time, which is then calculated as follows: Calculated by the following formula:

[0084]

[0085] Step 4.2: Convert rolling mill inspection data;

[0086] Data curves stored according to time, based on a fixed communication period ΔT. Converted into a data curve Y(s) stored by length:

[0087] Sampling point t is converted into length point

[0088] The number of sampling points remains unchanged at n.

[0089] Step 5: Calculation of side bending parameters of the rolled piece;

[0090] Step 5.1: Curve data fitting;

[0091] A fourth-order curve was used to fit Y(s), and the curve structure was: Y(s) = k1s 4 +k2s 3 +k3s 2 +k4s+k5

[0092] The parameters of the thickness curve fitted by the data processor are shown in the table below:

[0093]

[0094]

[0095] Calculate the first and second derivatives of this curve:

[0096] The first derivative is: Y′(s)=4k1s 3 +3k2s 2 +2k3s+k4

[0097] The second derivative is: Y″(s)=12k1s 2 +6k2s+2k3

[0098] Step 5.2: Calculate the radius of curvature of the rolled piece;

[0099] The formula for calculating the radius of curvature is shown below:

[0100]

[0101] In the formula, R is the radius of curvature, K is the curvature; Y′(s) represents the first derivative of Y(s), and Y″(s) represents the second derivative of Y(s).

[0102] Input Y(s) to further calculate the radius of curvature of each sampling point. The maximum radius of curvature is found to be 1.46084E8, and the corresponding position of the rolled piece is obtained.

[0103] Step 5.3: Calculate the bending amounts A(0,Y0) and B(n,Y0) of the rolled piece. S);

[0104] Calculate the coordinates of the starting point A and the ending point B of Y(s), denoted as A(0,3500) and B(14250,3430), to obtain the straight line l containing the starting and ending points. A,B The equation is:

[0105]

[0106] If the coordinates of a point on the centerline of the rolled piece are (s i ,Y(s i Then, the point will be intersected by the line l. A,B Distance d between i The bending amount is calculated using the following formula:

[0107]

[0108] The bending amount at each sampling point was further calculated, and the maximum bending amount was found to be 48.31 mm. The corresponding position of the rolled piece was then obtained.

[0109] Step 7: Complete the side bending measurement process of the rolled piece, and output the rolled piece curve, the radius of curvature of the rolled piece, and the bending amount.

[0110] Working principle: After the rolled piece exits the furnace, its initial parameters are obtained. After the rolled piece deforms as it passes through the rolling mill, parameters such as the exit thickness of the rolled piece are obtained. The rolled piece continues to move along the rolling direction. When the rolled piece reaches the detection area, measurement begins, and speed and distance data are uploaded. The rolled piece detection data is then processed and converted. The parameters of the rolled piece side bending are then calculated according to the formula. The calculated data is fitted to the curve data to calculate the bending amount of the rolled piece. Finally, the side bending measurement process of the rolled piece is completed, and the rolled piece curve, the radius of curvature of the rolled piece, and the bending amount are output.

[0111] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic identification method for side bending of rolled products in the strip production process; characterized in that: The method for automatic identification of side bending of rolled parts in the strip production process includes the following steps: S1: The rolled piece exits the furnace, and the initial parameters of the rolled piece are obtained; This mainly includes the grade of the rolled piece, the inlet thickness, the inlet width, and the inlet temperature; S2: At the start of the production process, after the workpiece is rolled out through the stand, the exit thickness, exit width, and rolling speed data of the workpiece are obtained. The workpiece moves along the rolling direction via the roller table, and the rolling speed of the mill is recorded. S3: When the head of the rolled piece reaches the measurement position, the operating side distance meter and the transmission side distance meter perform distance detection on the rolled piece; S3.1: Determine whether the workpiece has reached the distance measuring instrument position, and start distance measurement and data upload; First, based on a combined assessment of the two rangefinders and the actual width, it is determined whether the head of the rolled piece has reached the detection position. If the condition is met, the count starts from zero, and the distance data from the operating side is continuously uploaded. and transmission side distance data If the conditions are not met at the data processing server, the process continues with the following judgment formula: （ =0,1,2...,n） in l 1 (t) represents the distance from the transmission-side distance measuring instrument to the edge of the rolled piece. l 2 (t) represents the distance from the transmission-side distance measuring instrument to the edge of the rolled piece. This is the distance from the transmission-side distance measuring instrument to the rolling center line; The distance from the operating side rangefinder to the rolling center line, The target width value. This represents the target tolerance value for width. S3.2: When the workpiece head is determined to have reached the distance measuring instrument position, data is uploaded according to a fixed communication cycle, transmitting the roll speed and roller conveyor speed to the data processing server. If the workpiece has not yet completely passed through the mill at this time, record and upload the roll speed. v R (t), when the rolled piece has completely passed through the mill, the speed of the uploaded roller table is recorded. v r (t), and upload the workpiece vi representation as the workpiece speed processing; S3.3: When the end of the rolled piece reaches the detection position, data recording and uploading are completed. The judgment conditions are as follows: （ =0,1,2...,n） The final data processor obtains two direct data curves, which are further processed to achieve side bending identification of the rolled piece; S4: Processing and conversion of rolled piece inspection data; S4.1: Processing of rolled product inspection data; With the plane of the operating side as the X-axis, the data uploaded by the sensor ultimately yields two distance curves that change over time, which require further processing to accurately represent the side bending of the rolled piece. The function representing the change of the operating side distance over time is expressed as: The function of the transmission side distance changing with time is: The relationship between the midline data and time is then obtained, denoted as , and calculated using the following formula: S4.2: Conversion of rolled piece inspection data; Based on a fixed communication cycle Data curves stored by time Convert into data curves stored by length : Sampling points converted to length points Where n is the number of sampling points, The speed transmitted by the speed sensor; Wherein: the number of sampling points remains unchanged, still n; S5: Calculation of side bending parameters of rolled parts; S5.1: Curve data fitting; Using a four-fold form Curve fitting was performed, and the curve structure is as follows: Calculate the first and second derivatives of this curve: The first derivative is: The second derivative is: S5.2: Calculate the radius of curvature of the rolled piece; The formula for calculating the radius of curvature is shown below: In the formula, Let be the radius of curvature. For curvature; express The first derivative, express The second derivative; Write a program to Input, further calculate the radius of curvature of each sampling point, compare to obtain the maximum radius of curvature, and further obtain the corresponding position of the rolled piece; S5.3: Calculate the bending amount of the rolled piece; calculate The coordinates corresponding to the starting point A and the ending point B are denoted as follows: A and B, obtain the straight line containing the starting and ending points. The equation is: If the coordinates of a point on the centerline of the rolled piece are ( , Then the point and the line The distance between them is used as The amount of bending is calculated using the following formula: The bending amount at each sampling point is further calculated, and the maximum bending amount is obtained by comparison, thus determining the corresponding position of the rolled piece. S6: Completes the side bending measurement process of the rolled piece, and outputs the rolled piece curve, the radius of curvature of the rolled piece, and the bending amount.

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