Method for calculating width of strip steel by using data measured by scanning pyrometer
By scanning the measurement data of the pyrometer to calculate the strip width, the real-time monitoring of the "neck shrinkage" phenomenon during the coiling process of hot-rolled strip is solved, high-precision width control and parameter optimization are achieved, and production efficiency and safety are improved.
Patent Information
- Application Number
- CN202510510262.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2025-08-15
AI Technical Summary
In the prior art, the "neck shrinkage" phenomenon caused by tension control conversion during the coiling process of hot-rolled strip cannot be monitored in real time, resulting in insufficient width control accuracy and lack of effective real-time adjustment methods.
The scanning pyrometer is used for full scanning measurement, and the boundary points are extracted through temperature difference trend tracking and extraction, and the actual width of the strip is calculated based on the carbon content and thermal expansion coefficient to generate a width curve, which is used to adjust the tension and pressure parameters to optimize the shape of the strip.
High-precision control of strip width is achieved, simplifies operation, reduces costs, and improves production efficiency and safety.
Smart Images
Figure CN120489034A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for calculating the width of a steel strip by using measurement data of a scanning pyrometer, and belongs to the technical field of hot-rolled steel strip production methods in the metallurgical industry. Background Art
[0002] The fierce competition in the steel market makes high-precision control very important in the plate and strip production process. When rolling tinplate, cold-rolled deep-drawing steel, cold-rolled automotive steel and other products, the width control accuracy of hot-rolled raw materials is required to be high. Users generally require the width control accuracy to be within the range of the nominal width size + 7 to 12 mm.
[0003] A major factor affecting the width is that when the strip head enters the coiler and begins to coil, the coiler switches from speed control to tension control. At this time, the strip between the finishing mill end stand and the coiler is stretched under the action of tension, causing the strip width to narrow. This phenomenon is usually called "necking". In hot rolling production lines, width gauges are generally placed at the exit of the finishing mill, and the "necking" position often occurs between the finishing mill exit and the coiling entrance. To reduce costs, the production line rarely installs another width gauge at the coiling entrance. As a result, even if "necking" occurs, the actual location and extent of the occurrence are unknown. It can only be known after the product reaches downstream users. The tension, pressure, necking compensation and other parameter settings when coiling the strip are adjusted based on the feedback of downstream users, which has a large lag and uncertainty. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for calculating the width of a steel strip using the measurement data of a scanning pyrometer. The method is based on the measurement data of the scanning pyrometer and utilizes the temperature difference trend tracking and boundary extraction technology. By processing the measured data of the scanning pyrometer, the actual width value of the steel strip is obtained. By referring to the actual width value, the position and length of the "necking" are understood. According to these data, parameters such as tension, pressure and necking compensation are adjusted, the strip width index is continuously optimized, and the high-precision control of the strip shape is improved. The method is simple and easy to implement, low in cost, high in efficiency, and good in safety, and effectively solves the above-mentioned problems existing in the background technology.
[0005] The technical solution of the present invention is: a method for calculating the width of a steel strip using measurement data of a scanning pyrometer, comprising the following steps: (1) The scanning pyrometer performs full-length scanning measurement on the finished strip, and uses its software archiving function to convert the file format generated after the measurement into a CSV file format; (2) Open the CSV file, find the starting position of the line scan, process each line scan data from the beginning to the end, and obtain the boundary points in the strip width direction of each line scan data; (3) Calculate the hot width of the strip using the position of the boundary points on both sides of the strip: (4) Calculate the cold width of the strip; (5) Save the cold width value and the corresponding strip length position in the row at the same time; (6) Complete the processing of all scan line data, and save the cold width value of each scan line and its position point in the strip length direction in a table, and use the table to generate the strip width curve.
[0006] The specific steps of step (2) are as follows: Based on the total number of sampling points in a line scan, the index position of the middle sampling point is determined; with the position of the middle sampling point as the boundary, a line scan data is divided into two parts, left and right; for the left half, the temperature difference between adjacent temperature points is calculated from right to left; for the right half, the temperature difference between adjacent temperature points is calculated from left to right; the 5 maximum temperature difference values are found in the first 100 temperature differences of the left and right parts respectively, and the average value is calculated as the threshold; when the temperature difference continuously exceeds the threshold and finally falls back to the threshold range, the falling point is determined to be a boundary point; the same applies to the right half.
[0007] In step (3), the specific steps are as follows: Calculate the index position difference of the boundary points on both sides to obtain the actual number of indexes contained in the strip width range, calculate the ratio of the number of indexes to the total number of indexes, and multiply it by the total scanning width; The specific calculation formula is as follows: Wh=(PR-PL) / Ss*Ws Wh hot state width value, PL left boundary point position, PR right boundary point position, Ss line scan total index interval, Ws line scan total width.
[0008] In the step (4), the specific steps are as follows: calculating the average value of the detection temperature within the range of the left and right boundary points, calculating the corresponding thermal expansion value of the strip steel using the average temperature, carbon content and steel type, dividing the hot width value by the corresponding thermal expansion coefficient, and obtaining the cold width value of the scan line, i.e., the width value at room temperature; The specific formula is as follows: Wl= Wh / Ex; Wl is the cold width value, Wh is the hot width value, and Ex is the thermal expansion coefficient.
[0009] The beneficial effects of the present invention are: based on the measurement data of the scanning pyrometer, the temperature difference trend tracking and boundary extraction technology is used to process the measured data of the scanning pyrometer to obtain the actual width value of the strip, and by referring to the actual width value, the position and length of the "necking" are understood. According to these data, parameters such as tension, pressure and necking compensation are adjusted, the strip width index is continuously optimized, and the high-precision control of the strip shape is improved. It is simple and easy, low cost, high efficiency and good safety. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 is a temperature distribution diagram of a single scan line in an embodiment of the present invention; Figure 2 The left half of the temperature difference diagram in the embodiment of the present invention; Figure 3 The right half of the temperature difference diagram in the embodiment of the present invention; Figure 4 Graph showing calculation results in an embodiment of the present invention. DETAILED DESCRIPTION
[0011] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the invention implementation cases will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0012] A method for calculating strip width using scanning pyrometer measurement data comprises the following steps: (1) The scanning pyrometer performs full-length scanning measurement on the finished strip, and uses its software archiving function to convert the file format generated after the measurement into a CSV file format; (2) Open the CSV file, find the starting position of the line scan, process each line scan data from the beginning to the end, and obtain the boundary points in the strip width direction of each line scan data; (3) Calculate the hot width of the strip using the position of the boundary points on both sides of the strip: (4) Calculate the cold width of the strip; (5) Save the cold width value and the corresponding strip length position in the row at the same time; (6) Complete the processing of all scan line data, and save the cold width value of each scan line and its position point in the strip length direction in a table, and use the table to generate the strip width curve.
[0013] The specific steps of step (2) are as follows: Based on the total number of sampling points in a line scan, the index position of the middle sampling point is determined; with the position of the middle sampling point as the boundary, a line scan data is divided into two parts, left and right; for the left half, the temperature difference between adjacent temperature points is calculated from right to left; for the right half, the temperature difference between adjacent temperature points is calculated from left to right; the 5 maximum temperature difference values are found in the first 100 temperature differences of the left and right parts respectively, and the average value is calculated as the threshold; when the temperature difference continuously exceeds the threshold and finally falls back to the threshold range, the falling point is determined to be a boundary point; the same applies to the right half.
[0014] In step (3), the specific steps are as follows: Calculate the index position difference of the boundary points on both sides to obtain the actual number of indexes contained in the strip width range, calculate the ratio of the number of indexes to the total number of indexes, and multiply it by the total scanning width; The specific calculation formula is as follows: Wh=(PR-PL) / Ss*Ws Wh hot state width value, PL left boundary point position, PR right boundary point position, Ss line scan total index interval, Ws line scan total width.
[0015] In the step (4), the specific steps are as follows: calculating the average value of the detection temperature within the range of the left and right boundary points, calculating the corresponding thermal expansion value of the strip steel using the average temperature, carbon content and steel type, dividing the hot width value by the corresponding thermal expansion coefficient, and obtaining the cold width value of the scan line, i.e., the width value at room temperature; The specific formula is as follows: Wl= Wh / Ex; Wl is the cold width value, Wh is the hot width value, and Ex is the thermal expansion coefficient. Example
[0016] (1) Use a scanning pyrometer to scan and measure the entire strip entering the coiling entrance, and use its system software to convert the special file format generated after the measurement into a CSV file format.
[0017] (2) Open the csv file, find the starting position of the row scan, and process each row scan data. The original data is as follows: Figure 1 As shown, the purpose is to determine the boundary points on both sides of the strip width direction in each line of scanning data.
[0018] The specific method is as follows: Determine the position of the middle sampling point based on the number of line scan sampling points. Use the middle sampling point position as the boundary to divide a line scan data into two parts, left and right. For the left half, calculate the temperature difference between adjacent temperature points from right to left; for the right half, calculate the temperature difference between adjacent temperature points from left to right; the average value of the 5 maximum temperature differences in the first 100 temperature differences in the left and right parts is 1.9°C as the threshold. When the temperature difference exceeds the threshold continuously and finally falls back to the threshold range, the falling point is identified as the boundary point; the same applies to the right half; (3) The boundary points in the strip width direction obtained in step (2) are used to calculate the hot width of the strip using the positions of the boundary points on both sides of the strip: First, calculate the index position difference of the boundary points on both sides to obtain the actual number of indexes within the strip width. Calculate the ratio of the number of indexes to the total number of indexes and multiply it by the total scan width. Take the 176th scan line as an example: The specific calculation formula is as follows: Wh=(PR-PL) / Ss*Ws Wh is the hot state width value, PL is the left boundary point position, PR is the right boundary point position, Ss is the total index interval of the line scan, and Ws is the total width of the line scan; Wh=(774-324) / 1000*3352=1508.4mm.
[0019] (4) Using the result of step (3), calculate the cold width of the strip The specific method is as follows: Calculate the average temperature of the detection points within the left and right boundary points. Use the average temperature, carbon content, and material code to calculate the corresponding thermal expansion value of the strip. Divide the hot width value by the corresponding thermal expansion coefficient to obtain the cold width value of the scan line (i.e., the width value at room temperature). Tave = 590.47℃; carbon content of this steel: 0.0771%; thermal expansion coefficient = 1.0086 Wl= Wh / Ex =1508.4 / 1.0086=1495.5mm.
[0020] (5) Save the cold width value and the corresponding strip length position (24.686 meters) in the row at the same time.
[0021] (6) Use steps (2) to (5) to complete the processing of all scan line data, and save the cold width value of each scan line and its position point in the strip length direction into a table. The strip width curve can be generated using this table.
[0022] The present invention overcomes the problem that the hot rolling production line is not equipped with a width meter at the coiling entrance, and is unable to grasp the change in the actual width value of the strip after entering the coiler. Based on the measurement data of the scanning pyrometer, the temperature difference trend tracking and boundary extraction technology is used to process the measured data of the scanning pyrometer to obtain the actual width value of the strip. The invention is simple, easy, low-cost, highly efficient and safe.
Claims
1. A method for calculating strip width using scanning pyrometer measurement data, characterized in that The following steps are involved: (1) The scanning pyrometer performs full-length scanning measurement on the finished strip, and uses its software archiving function to convert the file format generated after the measurement into a CSV file format; (2) Open the CSV file, find the starting position of the line scan, process each line scan data from the beginning to the end, and obtain the boundary points in the strip width direction of each line scan data; (3) Calculate the hot width of the strip using the position of the boundary points on both sides of the strip: (4) Calculate the cold width of the strip; (5) Save the cold width value and the corresponding strip length position in the row at the same time; (6) Complete the processing of all scan line data, and save the cold width value of each scan line and its position point in the strip length direction in a table, and use the table to generate the strip width curve.
2. The method for calculating strip width using scanning pyrometer measurement data according to claim 1, characterized in that: The specific steps of step (2) are as follows: Based on the total number of sampling points in a line scan, the index position of the middle sampling point is determined; with the position of the middle sampling point as the boundary, a line scan data is divided into two parts, left and right; for the left half, the temperature difference between adjacent temperature points is calculated from right to left; for the right half, the temperature difference between adjacent temperature points is calculated from left to right; the 5 maximum temperature difference values are found in the first 100 temperature differences of the left and right parts respectively, and the average value is calculated as the threshold; when the temperature difference continuously exceeds the threshold and finally falls back to the threshold range, the falling point is determined to be a boundary point; the same applies to the right half.
3. The method for calculating strip width using scanning pyrometer measurement data according to claim 1, characterized in that: In step (3), the specific steps are as follows: Calculate the index position difference of the boundary points on both sides to obtain the actual number of indexes contained in the strip width range, calculate the ratio of the number of indexes to the total number of indexes, and multiply it by the total scanning width; The specific calculation formula is as follows: Wh=(PR-PL) / Ss*Ws Wh hot state width value, PL left boundary point position, PR right boundary point position, Ss line scan total index interval, Ws line scan total width.
4. The method for calculating strip width using scanning pyrometer measurement data according to claim 1, characterized in that: In the step (4), the specific steps are as follows: calculating the average value of the detection temperature within the range of the left and right boundary points, calculating the corresponding thermal expansion value of the strip steel using the average temperature, carbon content and steel type, dividing the hot width value by the corresponding thermal expansion coefficient, and obtaining the cold width value of the scan line, i.e., the width value at room temperature; The specific formula is as follows: Wl= Wh / Ex; Wl is the cold width value, Wh is the hot width value, and Ex is the thermal expansion coefficient.