A method and system for evaluating the shape of cold-rolled sheets

Abstract

This invention discloses a method for evaluating the shape of cold-rolled sheets, comprising: detecting the shape UI value of the cold-rolled sheet along the rolling direction using a shape analyzer; performing at least one of the following tests on the cold-rolled sheet based on the detected shape UI value, and displaying the evaluation of the relevant tests; performing out-of-tolerance detection of the shape UI value and asymmetric waviness detection along the length direction of the cold-rolled sheet; performing edge waviness length detection, reverse length detection on both sides, and out-of-tolerance detection of the maximum shape difference on opposite sides on the transmission side and operating side of the cold-rolled sheet; performing out-of-tolerance detection of shape difference fluctuation along the length direction of the cold-rolled sheet; and performing shape detection and out-of-tolerance detection of shape difference in local areas of the cold-rolled sheet. By evaluating the shape command of the cold-rolled sheet from different dimensions, it is determined whether the shape is closed, thereby effectively meeting the requirements of each unit and reducing the risk of scratches, deviations, or even strip breaks caused by shape issues in subsequent processes.

Description

Technical Field

[0001] This invention belongs to the field of sheet shape evaluation technology, and more specifically, this invention relates to a method and system for evaluating the shape of cold-rolled sheets. Background Technology

[0002] The shape of cold-rolled steel sheets is closely related to the deviation, strip breakage, and local scratches of the strip steel in the furnace during subsequent processes. Therefore, the evaluation of the shape of cold-rolled steel sheets is of great significance to the subsequent production of strip steel.

[0003] The application number is CN201711318921.2, and the patent title is: A method for evaluating the shape quality of cold-rolled strip steel, comprising: establishing a shape IU value matrix of the strip steel based on the flatness IU value of the strip steel; performing local waviness detection on the strip steel based on the shape IU value matrix to obtain the feature information of the local waviness; and identifying the pattern of the local waviness according to the feature information of the local waviness.

[0004] The above scheme evaluates the shape of cold-rolled sheets based only on local waviness, which is not comprehensive and cannot accurately evaluate cold-rolled sheets. Summary of the Invention

[0005] This invention provides a method for evaluating the shape of cold-rolled sheets, aiming to improve the above-mentioned problems.

[0006] This invention is implemented as follows: a method for evaluating the shape of cold-rolled sheets, the method being as follows:

[0007] (1) The plate shape instrument detects the UI value of the plate shape along the rolling direction of the cold-rolled plate;

[0008] (2) Perform at least one of the following tests on the cold-rolled sheet based on the detected sheet shape UI value, and display the evaluation of the relevant tests;

[0009] The sheet shape IU value is checked for out-of-tolerance and asymmetric wave detection in sections along the length of the cold-rolled sheet; the edge wave length and reverse length on both sides are checked on the transmission side and operation side of the cold-rolled sheet, and the maximum sheet shape difference on opposite sides is checked for out-of-tolerance; the sheet shape difference fluctuation is checked along the length of the cold-rolled sheet; the sheet shape of the cold-rolled sheet is checked, and the sheet shape difference in local areas of the cold-rolled sheet is checked for out-of-tolerance.

[0010] Furthermore, the out-of-tolerance detection of the sheet shape IU value for each section along the length of the cold-rolled sheet is as follows:

[0011] The cold-rolled sheet is divided into three regions along its length: head, middle, and tail. The length of the sheet shape IU value in each of these three regions that exceeds the corresponding region's IU threshold is calculated, along with the ratio of this length to the total length of the corresponding region. If this ratio is greater than the corresponding region's ratio threshold, the cold-rolled sheet is deemed to have a non-compliant shape, and a warning is issued.

[0012] Furthermore, the specific method for detecting asymmetric waves partitioned along the length of the cold-rolled sheet is as follows:

[0013] The sheet shape analyzer collects a set of sheet shape IU values ​​at different width positions in each length range of the cold-rolled sheet, performs curve fitting on each set of sheet shape IU values, and takes the coefficient b of the first term in all the fitted curves.

[0014] Calculate the integral value of the first term coefficient b of the fitted region line located in the head region, middle region, and tail region of the cold-rolled sheet, respectively. Based on the integral value of ...

[0015] The system detects whether the length of cold-rolled sheet with a linear coefficient b continuously greater than a set coefficient threshold in the head, middle, and tail regions exceeds a set length threshold. If the detection result is yes, it is determined that the corresponding region of the cold-rolled sheet has an asymmetric waviness, and the corresponding region is recorded.

[0016] Furthermore, the specific methods for detecting the edge waviness length on the drive side and operating side of cold-rolled steel sheets are as follows:

[0017] Extract the coefficient b of the first term of all fitted curves within the entire length of the cold-rolled sheet. If the coefficient b is greater than 3, it is considered that there is a transmission side wave. If the coefficient b is less than -3, it is considered that there is an operation side wave. Determine the ratio of the total length of the operation side wave and the transmission side wave to the total length of the cold-rolled sheet. If the ratio is greater than the set ratio threshold, the sheet shape quality of the cold-rolled sheet is considered to be non-compliant.

[0018] Furthermore, the reverse length detection on both sides of the cold-rolled sheet on the drive side and the operating side is as follows:

[0019] Remove the head and tail portions of the cold-rolled sheet. Designate a specified number of detection channels near the transmission side and the operation side of the cold-rolled sheet as the transmission side zone and the operation side zone, respectively. Calculate the mean value of the sheet shape UI of the transmission side zone and the operation side zone for each length interval. Detect whether the mean value of the sheet shape UI of the transmission side zone and the operation side zone is reversed, and whether the absolute value is greater than the set sheet shape IU threshold. If the detection result is yes, it is determined that the transmission side and the operation side are reversed, and the ratio of the reverse length to the total detection length is calculated.

[0020] Furthermore, the specific method for detecting the maximum sheet shape difference on opposite sides of the cold-rolled sheet (drive side and operating side) is as follows:

[0021] Obtain the maximum and minimum values ​​of the plate shape UI value of the transmission side zone and the operation side zone under each length interval, calculate the difference between the maximum and minimum values ​​on the opposite side, and if the difference exceeds the set difference threshold, issue an early warning for the length interval of the corresponding side zone, and count the ratio of the warning length to the total detection length.

[0022] Furthermore, the specific process for detecting out-of-tolerance fluctuations in the sheet shape difference along the length of the cold-rolled sheet is as follows:

[0023] Based on the fitted curve, the UI fitting value of the plate shape for each detection channel in each length interval is calculated; the difference between the plate shape UI detection value and the corresponding plate shape UI fitting value in different length intervals of each detection channel is calculated, and the absolute value of the difference is taken as the plate shape difference at the corresponding position; the inflection point of the plate shape difference of all detection channels in each length interval is determined; the absolute value of the difference between the plate shape difference at the inflection point of any two adjacent length intervals is calculated; if the absolute value of the difference between the plate shape difference at the inflection point is greater than the set plate shape difference threshold, an early warning is issued for the corresponding length interval; if the warning length exceeds the set percentage threshold of the total length of the cold-rolled plate, the plate shape quality of the cold-rolled plate is deemed to be non-compliant.

[0024] Furthermore, the specific procedures for shape inspection of cold-rolled steel sheets are as follows:

[0025] Extract the quadratic coefficients of the fitted curve of the entire length of the cold-rolled sheet, and calculate the mean of the extracted quadratic coefficients. If the mean is greater than zero, the actual shape of the cold-rolled sheet is identified as double-sided wave; if the mean is less than zero, the actual shape of the cold-rolled sheet is medium wave.

[0026] Check whether the actual shape of the cold-rolled sheet matches the set shape. If they do not match, record the discrepancy.

[0027] Furthermore, the specific steps for detecting out-of-tolerance shape differences in localized areas of cold-rolled steel sheets are as follows:

[0028] The cold-rolled sheet is divided into 5 regions along the width of the strip;

[0029] Calculate the shape deviation value of the cold-rolled sheet in the j-th length interval of the s-th region.

[0030] Detecting the shape deviation value of cold-rolled sheet in the j-th length interval of the s-th region. If the detection result is greater than the wavy threshold set for the corresponding area, then it is determined that the cold-rolled plate has a wavy shape in the j-th length interval of the s-th region. The ratio of the length with wavy shape to the total length and the ratio of the number of length intervals with wavy shape in each length interval of each region to the total number are counted.

[0031] This invention is implemented as follows: a method for evaluating the shape of cold-rolled sheets, the system comprising:

[0032] Plate shape analyzer, and PLC controller connected to the plate shape analyzer;

[0033] The shape analyzer detects the UI value of the cold-rolled sheet along the rolling direction and sends it to the PLC controller. The PLC controller evaluates the shape of the cold-rolled sheet based on the above-mentioned cold-rolled sheet shape evaluation method.

[0034] This invention provides a method for evaluating the shape of cold-rolled steel sheets. The method evaluates the shape of cold-rolled steel sheets from different dimensions, thereby determining whether the shape is closed, which effectively meets the requirements of each unit and reduces the risk of scratches, deviations or even strip breaks caused by the shape of the sheets in subsequent processes. Attached Figure Description

[0035] Figure 1 A flowchart of a method for evaluating the shape of cold-rolled sheet provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the cold-rolled sheet shape evaluation system provided in an embodiment of the present invention. Detailed Implementation

[0037] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0038] Figure 1 A flowchart of the cold-rolled sheet shape evaluation method provided in an embodiment of the present invention is shown below:

[0039] (1) The plate shape instrument detects the UI value of the plate shape along the rolling direction of the cold-rolled plate;

[0040] (2) Perform at least one of the following tests on the cold-rolled sheet based on the detected sheet shape UI value, and display the evaluation of the relevant tests;

[0041] The sheet shape IU value is checked for out-of-tolerance and asymmetric wave detection in sections along the length of the cold-rolled sheet; the edge wave length and reverse length on both sides are checked on the transmission side and operation side of the cold-rolled sheet, and the maximum sheet shape difference on opposite sides is checked for out-of-tolerance; the sheet shape difference fluctuation is checked along the length of the cold-rolled sheet; the sheet shape of the cold-rolled sheet is checked, and the sheet shape difference in local areas of the cold-rolled sheet is checked for out-of-tolerance.

[0042] The detection methods described above are as follows:

[0043] (a) Perform out-of-tolerance IU value detection along the length of the cold-rolled sheet in sections;

[0044] The strip shape analyzer has multiple detection channels arranged sequentially along the width of the cold-rolled strip. Each channel detects the shape IU value of the strip within its corresponding width range, and the detection area of ​​all channels covers the entire strip. The cold-rolled strip is divided into three regions along its length: head, middle, and tail. The length of each region where the shape IU value exceeds the corresponding region's IU threshold is calculated, along with the ratio of this length to the total length of the corresponding region. If this ratio is greater than the corresponding region's ratio threshold, the cold-rolled strip is deemed to have a non-compliant shape, and a warning is issued.

[0045] (1) Evaluation of sheet shape quality based on the length of the out-of-tolerance IU value in the head region of cold-rolled sheet:

[0046] Obtain the shape IU value of the head region of the cold-rolled sheet. Divide the shape IU value of the head region of the cold-rolled sheet into segments along the length (rolling) direction of the cold-rolled sheet. Calculate the average shape IU value of each segment. Calculate the segment length L1 where the average shape IU value is greater than the shape IU threshold of the head region of the cold-rolled sheet. Calculate the ratio of segment length L1 to the total length of the head region of the cold-rolled sheet. If this ratio is greater than the set proportional threshold c1 for the head region of the cold-rolled sheet, then the shape of the cold-rolled sheet is deemed unacceptable, and a warning is issued.

[0047] (2) Evaluation of plate shape quality based on the length of plate shape IU value exceeding the tolerance in the tail region of cold-rolled plate;

[0048] Obtain the shape IU value of the tail region of the cold-rolled sheet. Divide the shape IU value of the tail region of the cold-rolled sheet into segments along the length (rolling) direction of the cold-rolled sheet. Calculate the average shape IU value of each segment. Calculate the segment length L3 where the average shape IU value is greater than the shape IU threshold of the tail region of the cold-rolled sheet. Calculate the ratio of segment length L3 to the total length of the tail region of the cold-rolled sheet. If this ratio is greater than the ratio threshold c3 set for the head region of the cold-rolled sheet, then the shape of the cold-rolled sheet is deemed to be non-compliant, and a warning is issued.

[0049] (3) Evaluation of plate shape quality based on the length of plate shape IU value exceeding the tolerance in the middle region of cold-rolled plate;

[0050] The area outside the head and tail regions of the cold-rolled sheet is called the middle region of the cold-rolled sheet. The shape IU value of the middle region of the cold-rolled sheet is obtained. The shape IU value of the middle region of the cold-rolled sheet is divided into segments along the length (rolling) direction of the cold-rolled sheet. The average shape IU value of each segment is calculated. The length L2 of the segment whose average shape IU value is greater than the shape IU threshold of the middle region of the cold-rolled sheet is calculated. The ratio of the segment length L2 to the total length of the middle region of the cold-rolled sheet is calculated. When this ratio is greater than the set proportional threshold c2 of the middle region of the cold-rolled sheet, the shape of the cold-rolled sheet is considered to be non-compliant and a warning is issued.

[0051] The specific IU threshold and proportional threshold for the three regions of cold-rolled steel are shown in Table 1 below:

[0052] Serial Number area Plate-shaped IU threshold proportional threshold 1 Head area 8 20％ 2 Central region 5 15％ 3 Tail area 8 20％

[0053] (ii) Asymmetric wave detection is performed in sections along the length of the cold-rolled sheet;

[0054] The shape analyzer collects a set of shape IU values ​​of the cold-rolled plate at different width positions within the current length range. The shape analyzer collects multiple sets of shape IU values ​​along the length direction of the cold-rolled plate, performs curve fitting on each set of shape IU values, and takes the coefficient b of the first-order term in all the fitted curves.

[0055] (1) Evaluation of sheet shape quality based on asymmetric waves in the head region of cold-rolled sheet;

[0056] Calculate the shape integral value of the coefficient b of the first term of the fitted region line in the head region of the cold-rolled sheet. The larger the shape integral value, the more obvious the asymmetric waviness in the head region of the cold-rolled sheet. The shape of the head region of the cold-rolled sheet is rated based on the shape integral value, as shown in the table below.

[0057] Plate integral of the head region Plate shape rating of the head area Color Alarm 0 < Flatness integral of the head region <= 1.5 A green 1.5 < Flatness integral of partial area <= 2.5 B yellow 2.5 < flatness integral of partial area <= 3.5 C orange color 3.5 Shape integral of the partial area D red

[0058] Among them, grade A indicates that the head region has a good shape, and grade D indicates that the head region has a poor shape.

[0059] The system detects whether the length of the cold-rolled sheet with a linear coefficient b continuously greater than a set coefficient threshold in the head region exceeds the set length threshold. If the detection result is yes, it is determined that there is an asymmetric waviness in the corresponding region of the cold-rolled sheet, and this is recorded.

[0060] (2) Evaluation of sheet shape quality based on asymmetric waves in the middle region of cold-rolled sheet;

[0061] Calculate the shape integral value of the coefficient b of the first term of the fitted region line in the middle region of the cold-rolled sheet. The larger the shape integral value, the more obvious the asymmetric waviness in the middle region of the cold-rolled sheet. The shape of the middle region of the cold-rolled sheet is rated based on the shape integral value, as shown in the table below.

[0062] Plate integral in the central region Central region plate shape rating Color Alarm 0 < Flatness integral of the central region <= 1 A green 1 < Flatness integration of the central region ≤ 2 B yellow 2 < Flatness integral of the central region <= 3 C orange color 3 <Mid-plate shape integral value D red

[0063] Among them, grade A indicates that the central region has a good plate shape, and grade D indicates that the central region has a poor plate shape.

[0064] The system detects whether the length of a cold-rolled sheet in the central region where the coefficient b of the first term is continuously greater than a set coefficient threshold exceeds the set length threshold. If the detection result is yes, it is determined that there is an asymmetric waviness in the corresponding region of the cold-rolled sheet, and this is recorded.

[0065] (3) Evaluation of sheet shape quality based on asymmetric waves in the tail region of cold-rolled sheet;

[0066] Calculate the shape integral value of the coefficient b of the first term of the fitted region line in the tail region of the cold-rolled sheet. The larger the shape integral value, the more obvious the asymmetric waviness in the tail region of the cold-rolled sheet. The shape of the tail region of the cold-rolled sheet is rated based on the shape integral value, as shown in the table below.

[0067] Plate integral of the tail region Tail area plate shape rating Color Alarm 0 < Tail plate shape integral value <= 1.5 A green 1.5 < Tail plate shape integral value <= 2.5 B yellow 2.5 < Tail plate shape integral value <= 3.5 C orange color 3.5 < Tail plate shape integral value D red

[0068] Among them, grade A indicates that the tail region has a good plate shape, and grade D indicates that the tail region has a poor plate shape.

[0069] The system detects whether the length of the cold-rolled sheet with a linear coefficient b continuously greater than a set coefficient threshold in the tail region exceeds the set length threshold. If the detection result is yes, it is determined that there is an asymmetric waviness in the corresponding region of the cold-rolled sheet, and this is recorded.

[0070] (iii) Detect the edge waviness length on the transmission side and the operating side of the cold-rolled sheet;

[0071] Extract the first-order coefficient b of all fitted curves along the entire length of the cold-rolled sheet (including the head, middle, and tail). The first-order coefficient b represents the asymmetric wave pattern, and the larger the first-order coefficient b, the more severe the asymmetric wave at the corresponding position. Based on empirical values, ±3 is selected as the edge wave judgment threshold. When the first-order coefficient b is greater than 3, it is identified as a transmission side edge wave, and when the first-order coefficient b is less than -3, it is identified as an operation side edge wave. Determine the ratio of the total length of the operation side edge wave and the transmission side edge wave to the total length of the cold-rolled sheet. If this ratio is greater than the set ratio threshold (5%), the sheet shape quality of the cold-rolled sheet is considered to be unacceptable.

[0072] (iv) Detect the deviation of the plate shape difference along the length of the cold-rolled plate;

[0073] Based on the fitted curve, the UI fitting value of the plate shape for each detection channel in each length interval is calculated; the difference between the plate shape UI detection value and the corresponding plate shape UI fitting value in different length intervals of each detection channel is calculated, and the absolute value of the difference is taken as the plate shape difference at the corresponding position; the inflection point of the plate shape difference of all detection channels in each length interval is determined; the absolute value of the difference between the plate shape difference at the inflection point of any two adjacent length intervals is calculated; if the absolute value of the difference between the plate shape difference at the inflection point is greater than the set plate shape difference threshold, an early warning is issued for the corresponding length interval; if the warning length exceeds the set percentage threshold of the total length of the cold-rolled plate, the plate shape quality of the cold-rolled plate is deemed to be non-compliant.

[0074] (v) Detect the reverse length of the cold-rolled sheet on the drive side and the operating side;

[0075] Remove the head and tail portions of the cold-rolled sheet. Designate a specified number of detection channels near the transmission side and the operation side of the cold-rolled sheet as the transmission side side zone and the operation side side zone, respectively. Calculate the mean value of the sheet shape UI of the transmission side side zone and the operation side side zone for each length interval. Check whether the mean values ​​of the sheet shape UI of the transmission side side zone and the operation side side zone are reversed and whether the absolute value is greater than the set sheet shape IU threshold (1IU). If the detection result is yes, issue an early warning for the length interval of the corresponding side zone and count the ratio of the warning length to the total detection length.

[0076] (vi) Detect out-of-tolerance based on the maximum difference in plate shape between the transmission side and the operation side of the cold-rolled plate;

[0077] Remove the head and tail portions of the cold-rolled sheet. Designate a specified number of detection channels near the transmission side and the operation side of the cold-rolled sheet as the transmission side side zone and the operation side side zone, respectively. Obtain the maximum and minimum values ​​of the sheet shape UI value of the transmission side side zone and the operation side side zone under each length interval. Calculate the difference between the maximum and minimum values ​​on opposite sides. If the difference exceeds the set difference threshold (10 IU), issue an early warning for the length interval of the corresponding side zone. Calculate the ratio of the warning length to the total detection length.

[0078] (vii) Inspect the shape of the cold-rolled sheet;

[0079] Extract the quadratic coefficients of the fitted curve of the entire length of the cold-rolled sheet, and calculate the mean of the extracted quadratic coefficients. If the mean is greater than zero, the actual shape of the cold-rolled sheet is identified as double-sided wave; if the mean is less than zero, the actual shape of the current cold-rolled sheet is medium wave. Check whether the actual shape of the cold-rolled sheet is consistent with the set shape. If they are inconsistent, record the result.

[0080] (viii) Detecting excessive deviations in the shape of cold-rolled steel sheets in localized areas;

[0081] The cold-rolled sheet is divided into five regions along the width direction of the strip: the operating side edge region and the drive side edge region corresponding to the edge wave of the strip shape; the operating side 1 / 4 region and the drive side 1 / 4 region corresponding to the 1 / 4 wave of the strip shape; and the middle region of the strip corresponding to the middle wave of the strip shape. The operating side edge region is defined as extending from the operating side edge of the strip to 1 / 6 of the width of the strip on the operating side. The operating side 1 / 4 region is defined as extending from 1 / 6 to 1 / 3 of the width of the strip on the operating side. The middle region of the strip is defined as extending from 1 / 3 of the width of the strip on the operating side to 1 / 3 of the width of the strip on the drive side. The drive side edge region is defined as extending from the drive side edge of the strip to 1 / 6 of the width of the strip on the drive side. The drive side 1 / 4 region is defined as extending from 1 / 6 to 1 / 3 of the width of the strip on the drive side.

[0082] In the description of the regional plate shape, they are identified by the numbers 1, 2, 3, 4, and 5, respectively. The plate shape channel values ​​of the above-mentioned regions are calculated using the mean square error method. Therefore, the plate shape deviation value of the cold-rolled plate in the j-th length interval of the s-th region is... The calculation formula is as follows:

[0083]

[0084] in, This represents the shape deviation value of the cold-rolled sheet in the j-th length interval of the s-th region, where s = 1,...,5. This represents the UI value of the plate shape detected by the i-th detection channel in the j-th length interval of the s-th region of the cold-rolled sheet. b represents the target plate shape UI value of the i-th detection channel in the s-th region of the cold-rolled sheet in the j-th length interval. i The width of the i-th measurement channel of the plate shape analyzer is represented by , and m and k represent the detection channel number corresponding to the start position and end position of the s-th region, respectively.

[0085] Detecting the shape deviation value of cold-rolled sheet in the j-th length interval of the s-th region. If the detection result is greater than the wavy threshold set for the corresponding area, then it is determined that the cold-rolled plate has a wavy shape in the j-th length interval of the s-th region. The ratio of the length with wavy shape to the total length and the ratio of the number of length intervals with wavy shape in each length interval of each region to the total number are counted.

[0086] Figure 2 This is a schematic diagram of the structure of the cold-rolled sheet shape evaluation system provided in an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown. The system includes:

[0087] Plate shape analyzer, and PLC controller connected to the plate shape analyzer;

[0088] The shape analyzer detects the UI value of the cold-rolled sheet along the rolling direction and sends it to the PLC controller. The PLC controller evaluates the shape of the cold-rolled sheet based on the above-mentioned cold-rolled sheet shape evaluation method.

[0089] The present invention has been described by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A method for evaluating the shape of cold-rolled sheets, characterized in that, The method is as follows: (1) The plate shape instrument detects the UI value of the plate shape along the rolling direction of the cold-rolled plate; (2) Perform at least one of the following tests on the cold-rolled sheet based on the detected sheet shape UI value, and display the evaluation of the relevant tests; The sheet shape IU value is checked for out-of-tolerance and asymmetric wave detection in sections along the length of the cold-rolled sheet; the edge wave length, reverse length on both sides, and maximum sheet shape difference on opposite sides are checked for out-of-tolerance detection on the transmission side and operation side of the cold-rolled sheet; the sheet shape difference fluctuation is checked for out-of-tolerance detection along the length of the cold-rolled sheet; the sheet shape is checked and the sheet shape difference in local areas of the cold-rolled sheet is checked for out-of-tolerance detection. The specific method for detecting asymmetric waves partitioned along the length of cold-rolled sheet is as follows: The sheet shape analyzer collects a set of sheet shape IU values ​​at different width positions in each length range of the cold-rolled sheet, performs curve fitting on each set of sheet shape IU values, and takes the coefficient b of the first term in all the fitted curves. Calculate the integral value of the first term coefficient b of the fitted region line located in the head region, middle region, and tail region of the cold-rolled sheet, respectively. Based on the integral value of ... The system detects whether the length of cold-rolled sheet in the head, middle, and tail regions where the coefficient b of the first term is continuously greater than a set coefficient threshold exceeds a set length threshold. If the detection result is yes, it is determined that there is an asymmetric waviness in the corresponding region of the cold-rolled sheet, and the corresponding region is recorded. The specific methods for detecting the edge waviness length on the drive side and operating side of cold-rolled steel sheets are as follows: Extract the first-order coefficient b of all fitted curves within the entire length of the cold-rolled sheet. If the first-order coefficient b is greater than 3, it is considered that there is a transmission side wave. If the first-order coefficient b is less than -3, it is considered that there is an operation side wave. Determine the ratio of the total length of the operation side wave and the transmission side wave to the total length of the cold-rolled sheet. If the ratio is greater than the set ratio threshold, it is considered that the sheet shape quality of the cold-rolled sheet does not meet the requirements. The specific process for detecting out-of-tolerance fluctuations in the sheet shape difference along the length of the cold-rolled sheet is as follows: The plate shape UI fitting value of each detection channel in each length interval is calculated based on the fitting curve; the difference between the plate shape UI detection value and the corresponding plate shape UI fitting value in different length intervals of each detection channel is calculated, and the absolute value of the difference is taken as the plate shape difference at the corresponding position; the inflection point of the plate shape difference of all detection channels in each length interval is determined. Calculate the absolute value of the difference in plate shape at the inflection point of any two adjacent length intervals; if the absolute value of the difference in plate shape at the inflection point is greater than the set plate shape difference threshold, an early warning is issued for the corresponding length interval; if the warning length exceeds the set percentage threshold of the total length of the cold-rolled plate, the plate shape quality of the cold-rolled plate is deemed to be non-compliant.

2. The method for evaluating the shape of cold-rolled sheet as described in claim 1, characterized in that, The specific steps for detecting out-of-tolerance IU values ​​of the sheet shape along the length of the cold-rolled sheet are as follows: The cold-rolled sheet is divided into three regions along its length: head, middle, and tail. The length of the sheet shape IU value in each of these three regions that exceeds the corresponding region's IU threshold is calculated, along with the ratio of this length to the total length of the corresponding region. If this ratio is greater than the corresponding region's ratio threshold, the cold-rolled sheet is deemed to have a non-compliant shape, and a warning is issued.

3. The evaluation method for cold-rolled sheet shape as described in claim 1, characterized in that, The specific details of the reverse length detection on both sides of the transmission side and the operating side of the cold-rolled sheet are as follows: Remove the head and tail portions of the cold-rolled sheet. Designate a specified number of detection channels near the transmission side and the operation side of the cold-rolled sheet as the transmission side zone and the operation side zone, respectively. Calculate the mean value of the sheet shape UI of the transmission side zone and the operation side zone for each length interval. Detect whether the mean value of the sheet shape UI of the transmission side zone and the operation side zone is reversed, and whether the absolute value is greater than the set sheet shape IU threshold. If the detection result is yes, it is determined that the transmission side and the operation side are reversed, and the ratio of the reverse length to the total detection length is calculated.

4. The evaluation method for cold-rolled sheet shape as described in claim 1, characterized in that, The specific method for detecting the maximum sheet shape difference on opposite sides of the transmission and operation sides of cold-rolled steel sheets is as follows: Obtain the maximum and minimum values ​​of the plate shape UI value of the transmission side zone and the operation side zone under each length interval, calculate the difference between the maximum and minimum values ​​on the opposite side, and if the difference exceeds the set difference threshold, issue an early warning for the length interval of the corresponding side zone, and count the ratio of the warning length to the total detection length.

5. The evaluation method for cold-rolled sheet shape as described in claim 1, characterized in that, The specific procedures for shape inspection of cold-rolled steel sheets are as follows: Extract the quadratic coefficients of the fitted curve of the entire length of the cold-rolled sheet, and calculate the mean of the extracted quadratic coefficients. If the mean is greater than zero, the actual shape of the cold-rolled sheet is identified as double-sided wave; if the mean is less than zero, the actual shape of the cold-rolled sheet is medium wave. Check whether the actual shape of the cold-rolled sheet matches the set shape. If they do not match, record the discrepancy.

6. The method for evaluating the shape of cold-rolled sheet as described in claim 1, characterized in that, The specific steps for detecting out-of-tolerance shape differences in localized areas of cold-rolled steel sheets are as follows: The cold-rolled sheet is divided into 5 regions along the width of the strip; Calculate the shape deviation value of the cold-rolled sheet in the j-th length interval of the s-th region. Detecting the shape deviation value of cold-rolled sheet in the j-th length interval of the s-th region. If the detection result is greater than the wavy threshold set for the corresponding area, then it is determined that the cold-rolled plate has a wavy shape in the j-th length interval of the s-th region. The ratio of the length with wavy shape to the total length and the ratio of the number of length intervals with wavy shape in each length interval of each region to the total number are counted.

7. An evaluation system for cold-rolled sheet shape, characterized in that, The system includes: Plate shape analyzer, and PLC controller connected to the plate shape analyzer; The shape analyzer detects the UI value of the cold-rolled sheet along the rolling direction and sends it to the PLC controller. The PLC controller evaluates the shape of the cold-rolled sheet based on the cold-rolled sheet shape evaluation method according to any one of claims 1 to 6.

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