Method for improving L1 semi-automatic adjustment of preset control values ​​to improve the deviation of strip steel camber

Abstract

This invention discloses a semi-automatic L1 adjustment method for preset control values ​​to improve the camber deviation of strip steel. A width measuring instrument detects the width centerline deviation of the slab rolled from the roughing mill, and uploads this deviation value to the L1 system. The L1 system then displays the width centerline deviation value on an HMI (Hardware Management Interface). Operators input the tilt value set for each pass of the roughing mill into the HMI based on the displayed width centerline deviation value, thus implementing a semi-automatic camber control process. This invention uses the number of rolling passes in the roughing mill to manually control the camber for each pass semi-automatically, filling the gap where fully automatic systems cannot be implemented. This avoids operators being forced to use manual methods, improving labor efficiency and the control accuracy of the camber.

Description

Technical Field

[0001] This invention relates to the technology of roughing mills in hot rolling equipment, and more specifically, to a method for semi-automatic adjustment of preset control values ​​of L1 to improve the camber deviation of strip steel. Background Technology

[0002] The camber phenomenon that occurs in slabs after rolling is mainly caused by asymmetric deformation during rolling. The main factors contributing to this asymmetric deformation include: temperature distribution along the width of the slab, mill precision, thickness difference between the two sides of the slab along its width, and actual centering precision. Camber is the result of the combined effect of these factors.

[0003] The difficulty in controlling slab warpage lies primarily in the numerous influencing factors, some of which are unmeasurable or difficult to measure accurately. These include factors such as temperature distribution across the slab's width, mill control precision, and slab thickness on both sides. Due to these uncertainties, achieving effective control of slab warpage through theoretical modeling is quite challenging.

[0004] Currently, some patent documents propose using the actual values ​​of rolling forces on both sides of the roughing mill, the actual calculated values ​​of the roll gap, and the bounce parameters on both sides of the stand as inputs. After calculation, the correction of camber and wedge shapes can be achieved by adjusting the size of the roll gap on one or both sides of the mill. Other patent documents propose adjusting the camber of the slab by controlling the position and pressure of the side guide plates.

[0005] Currently, patents related to the upturned button include:

[0006] (1) The Chinese invention patent CN 101934292B, entitled "Automatic Control Method for Sickle and Wedge Shape of Hot-rolled Strip Roughing Mill", mentions that by taking the actual value of the rolling force on both sides of the roughing mill, the actual calculated value of the roll gap, and the bounce parameters on both sides of the stand as inputs, and after precise calculation, the correction of sickle and wedge shape is achieved by adjusting the size of the roll gap on one or both sides of the mill. The control method described in this invention can achieve sickle and wedge shape control without adding any sickle shape detection device for intermediate billets.

[0007] (2) Chinese invention patent CN 102441576B, entitled "Automatic Control Method for Sickle and Wedge Shape of Intermediate Slab in Hot-Rolled Strip Roughing," discloses a novel automatic control method for sickle and wedge shape in intermediate slabs of hot-rolled strip roughing mills. This method is applied to hot-rolled reversible roughing mills. The application discloses two technologies: model control technology and intermediate slab centerline offset feedback control technology. Model control uses the actual rolling force on both sides of the roughing mill, the actual calculated value of the roll gap, and the bounce parameters on both sides of the stand as inputs to accurately calculate the horizontal adjustment amount of the roll gap on one or both sides of the rolling mill. The second technology, centerline offset feedback control, calculates the horizontal adjustment amount on both sides of the mill after special processing of the slab centerline offset signal detected by the width measuring instrument. The reasonable combination of these two technologies can effectively control sickle and wedge shape problems. The control method described in this invention avoids the need for expensive and difficult-to-maintain intermediate slab wedge and sickle shape detection devices.

[0008] (3) A method for controlling the sickle bend of a rough-rolled intermediate billet, which is authorized by Chinese invention patent CN 100566866C. This technical solution adjusts the sickle bend of the billet by controlling the position of the side guide plate and the pressure of the side guide plate.

[0009] (4) The Chinese invention patent CN 103752623B, entitled "Automatic Control Method for Improving the Sickle Curvature of Intermediate Slabs in Roughing Mills," comprises two parts: setting the roll gap tilt adjustment value for the current pass and correcting the roll gap tilt adjustment value for the exit slab ...

[0010] (5) The Chinese invention patent CN 104162549B, entitled "Automatic Control Method and System for the Sickle Curve of Intermediate Billet in Hot Continuous Rolling Mill," describes a technical solution that obtains the centerline offset of the intermediate billet by measuring with a slab width measuring instrument; calculates the side length L1 and L2 of the first side of the intermediate billet exit using the side length calculation formula based on the centerline offset; substitutes L1 and L2 into the conversion formula to obtain the first thickness deviation Δh1 and the second thickness deviation Δh2 on both sides of the intermediate billet exit; substitutes Δh1 and Δh2 into the roll gap leveling value formula to obtain the roll gap leveling value Δs; and adjusts the roll gap value between the mill work rolls based on the roll gap leveling value Δs, so that the mill work rolls can effectively control the sickle curve shape of the intermediate billet during the next rolling pass of the intermediate billet.

[0011] (6) Chinese Patent Application No. 201910810128.7 discloses a camber control method based on the analysis of slab centerline deviation. The method includes installing a camber measuring instrument before and after a reciprocating mill; detecting the slab centerline curve using the camber measuring instrument; determining the bending direction and degree of bending based on the centerline deviation data curve; calculating the roll gap correction amount; correcting the roll gap correction amount based on the current pass width and reduction; adjusting the roll gap difference on both sides of the horizontal roll according to the roll gap correction amount data (L1); and performing subsequent passes based on this, thereby achieving automatic feedback control of the camber. By analyzing the centerline deviation data after slab rolling, it automatically calculates the roll gap difference setpoint on both sides of the horizontal roll in subsequent passes, thereby reducing the degree of camber, ensuring slab straightness, reducing the labor intensity of roughing mill operators, and improving the automation rate of roughing mill production.

[0012] The aforementioned patents (1) and (2) calculate the adjustment amount of the roll gap on one or both sides of the horizontal roll based on the actual values ​​of the rolling force, roll gap, and mill bounce on both sides of the horizontal roll. The shortcoming is that the mill stiffness is required in the calculation of mill bounce, but the roughing rolling usually uses electric pressing, so stiffness testing cannot be performed. Therefore, it is not realistic to obtain very accurate stiffness data, which leads to the inaccuracy of the calculated bounce data. Patent (3) controls the camber by using the side guide plates on both sides of the mill, which is to adjust the camber by mechanical equipment. The shortcoming of this method is that correcting the camber by the side guide plates is extremely risky and can easily cause steel jamming. Patent (4) also calculates the camber adjustment amount by using a theoretical model based on the rolling data. The shortcoming is the same as that of patents (1) and (2), which is that the stiffness calculation is inaccurate. Patent (5) calculates the side lengths on both sides of the slab, calculates the difference in extension on both sides, and calculates the camber adjustment amount by using a model. This method is relatively complicated and does not consider the influence of slab pressing amount and slab width on camber control. Patent (6) solves the problem of L2 automatic control issuing roll gap correction amount in roughing mill camber control technology, but for L1, there is still only one manual mode. That is, the operator manually adjusts the roll gap inclination value of the horizontal roll according to the roll gap correction amount issued by the L2 automatic control of the rolling line, visually observes the plate shape through monitoring video, or according to the slab centerline deviation data fed back by the instrument side width meter, so as to achieve the purpose of adjusting the camber at the mill exit.

[0013] Currently, the 1580 production line in the steel plant has three heating furnaces, each with a different type and distance from the rolling line. This results in varying temperatures of the slabs extracted from each furnace, leading to different camber patterns after rough rolling. For example, slabs from furnace #1 camber ...

[0014] When the 1580 production line adopted the Sickle Bend L1 fully automatic control mode, the above-mentioned problems were significantly improved. This method achieves an automation rate of approximately 85%. However, the conditions for applying the Sickle Bend L1 fully automatic control mode are often significantly affected by external factors. For example, the width gauge data can be distorted or discontinuous due to the influence of external descaling moisture, leading to the inability to execute fully automatically. Additionally, there are issues such as inaccurate model learning calculations. Summary of the Invention

[0015] To address the shortcomings of existing technologies, the purpose of this invention is to provide a semi-automatic L1 adjustment preset control value method for improving strip camber deviation. This method uses the number of rolling passes on the roughing mill to manually control the camber for each pass in a semi-automatic manner, filling the gap where fully automatic systems cannot be implemented. This avoids operators having to resort to manual methods, thereby improving labor efficiency and the control accuracy of the camber.

[0016] To achieve the above objectives, the present invention adopts the following technical solution:

[0017] A method for semi-automatic adjustment of preset control values ​​using L1 to improve the deviation of strip steel camber:

[0018] The width centerline deviation of the slab rolled out by the roughing mill is detected by a width measuring instrument and uploaded to the L1 system. The L1 system then displays the width centerline deviation on the HMI. The operator uses the width centerline deviation displayed on the HMI to input the tilt value setting for each pass of the roughing mill, thus performing a semi-automatic control process for the sickle bend.

[0019] Preferably, the semi-automatic control process for the sickle bend specifically includes the following steps:

[0020] S1. The operator sets the tilt value based on the rolling pass by using the curve formed by the width centerline deviation value displayed on the HMI.

[0021] S2, Preset the roll gap inclination value for the current pass;

[0022] S3. Determine whether the execution time of step S2 exceeds the set time. If yes, display an alarm on the HMI. If no, proceed to step S4.

[0023] S4. The working side of the roughing mill performs the preset tilt value of the roll gap;

[0024] S5. The roughing mill begins to feed steel for rolling.

[0025] Preferably, the semi-automatic control process for the sickle bend further includes:

[0026] S6. Determine whether the steel type and specifications of the subsequent slab have changed. If they have changed, exit the semi-automatic sickle bend control process and enter the fully automatic sickle bend control process. If they have not changed, proceed to step S7.

[0027] S7. The width measuring instrument detects the width centerline deviation value of the slab rolled out by the roughing mill and uploads the width centerline deviation value to the L1 system.

[0028] S8. The L1 system displays the width centerline deviation value on the HMI and then executes step S1.

[0029] S9. Repeat steps S1 to S8.

[0030] Preferably, the time in step S3 is set to 20 seconds.

[0031] This invention provides a method for semi-automatic adjustment of preset control values ​​using the L1 method to improve strip camber deviation. Previously, semi-automatic control of the camber was performed manually for each roughing mill pass. However, this method is problematic in two situations: the width gauge data is affected by external descaling moisture, leading to data distortion or discontinuity, which prevents fully automatic operation; or the fully automatic control is ineffective due to inaccurate model learning calculations, causing operators to disable the fully automatic function. This invention effectively fills the gap where fully automatic operation is not feasible, preventing operators from resorting to manual methods and improving labor efficiency and camber control accuracy. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating the L1 semi-automatic adjustment of preset control values ​​method of the present invention;

[0033] Figure 2 This is a schematic diagram of the system architecture of the L1 semi-automatic adjustment of preset control values ​​method of the present invention. Detailed Implementation

[0034] 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.

[0035] Combination Figure 1 and Figure 2 As shown, the present invention provides a method for semi-automatic adjustment of the preset control value of L1 to improve the deviation of the camber of the strip:

[0036] The width centerline deviation of the slab rolled out by the roughing mill is detected by the width measuring instrument 1 (installed behind the roughing mill). The width centerline deviation value is uploaded to the L1 system 2 (basic automation system). The L1 system 2 then displays the width centerline deviation value on the HMI3 (human-machine interface) and highlights the part that exceeds the standard in red. The operator uses the width centerline deviation value displayed on the HMI3 to input the tilt value setting value of each pass of the roughing mill on the HMI to carry out the semi-automatic control process of the sickle bend.

[0037] In the HMI3 of L1 system 2, an input mode screen for tilt value setting is added. Selecting AUTO on the screen enables the L2 ALL function, where all tilt value settings for the three passes are issued and set by the L2 system (process calculation system), which is the fully automatic control of the sickle bend L1. Alternatively, selecting AUTO on the screen enables the L1 ALL function, which is the semi-automatic control of the sickle bend L1. If the operator needs to directly adjust the tilt amount manually, the mode automatically switches from AUTO to MAN (fully manual mode).

[0038] Add an input mode screen for tilt value settings to HMI3 in L1 system 2. Specifically, add one column of data input value, two columns of data display value, and two columns of status display to the L1 system 2 pass planning screen. These correspond to the tilt value input and display for the three passes of the R1 mill (typically, R1 rolling is done in three passes). The first column shows the tilt value setting data issued by the L2 system; the second column shows the tilt value setting value manually entered by the operator through the current HMI screen; the third column, the Ref data column, displays the tilt value data finally selected by the L1 system; the other two columns indicate whether the data for the current pass originates from the L2 or L1 system.

[0039] The semi-automatic control process for the sickle-shaped bend includes the following steps:

[0040] S1. The staff sets the tilt value based on the curve formed by the width centerline deviation value displayed on the HMI3, according to the rolling pass.

[0041] S2. The current pass begins to preset the roll gap inclination value. The pressing electromagnetic clutch is opened, the clutch between the high-speed pressing and low-speed pressing on the drive side is disengaged, and the clutch between the high-speed pressing and low-speed pressing on the working side is engaged. The working side pressing mechanism uses the low-speed pressing motor to execute the inclination value setting.

[0042] S3. Determine whether the execution time of step S2 exceeds the set time (20 seconds). If yes, display an alarm on the HMI and the staff should intervene manually. If no, proceed to step S4.

[0043] S4. The electromagnetic clutch is closed, the pneumatic clutches on both sides are opened, the low-speed pressing motor is disengaged, and the two high-speed pressing motors on both sides of the roughing mill work side execute the preset inclination value of the back roll gap.

[0044] S5. The roughing mill begins feeding steel for rolling.

[0045] The semi-automatic control process for the sickle bend also includes:

[0046] S6. Determine whether the steel type and specifications of the subsequent slabs have changed. If they have changed, exit the semi-automatic sickle bend control process and enter the fully automatic sickle bend control process. If they have not changed, proceed to step S7.

[0047] S7. Width measuring instrument 1 detects the width centerline deviation value of the slab rolled out by the roughing mill and uploads the width centerline deviation value to L1 system 2.

[0048] S8, L1 system 2 displays the width centerline deviation value on HMI3, and then executes step S1;

[0049] S9. Repeat steps S1 to S8.

[0050] The L1 semi-automatic adjustment method for preset control values ​​of this invention is indispensable as a supplement to the L2 fully automatic control mode on the 1580 production line. This is because the application of fully automatic control is often greatly affected by external factors: for example, the width gauge data is affected by external descaling moisture, which can easily distort or discontinuous the data, causing the fully automatic system to fail; in addition, there are also issues such as inaccurate model learning calculations. Therefore, using the L1 semi-automatic adjustment method for preset control values ​​of this invention to precisely adjust the control values ​​for each pass of the relevant rolling mill based on the operator's experience is indeed a good approach. Moreover, once the preset values ​​for each pass are manually entered, for subsequent plans involving slabs of the same steel grade and specifications, within the permissible deviation range, the operator does not need to manually input and adjust the preset values ​​for each slab.

[0051] When the L1 semi-automatic adjustment preset control value method of the present invention is adopted, the automatic control rate (fully automatic + semi-automatic) of the training is increased to 99%, which further improves the labor efficiency of the operator.

[0052] The table below compares the monthly average of the maximum deviation of the centerline of the third pass exit width of R2 before and after the implementation of this invention:

[0053]

[0054] As can be seen from the table above, after adopting the present invention, the maximum deviation of the center line of the exit width of the third pass of R2 is significantly reduced, the control of the sickle shape of the exit of R2 is greatly improved, and the large sickle bend phenomenon and accidents are effectively eliminated.

[0055] 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. A method for semi-automatic adjustment of preset control values ​​for L1 to improve the deviation of strip steel camber, characterized in that: The width centerline deviation of the slab rolled from the roughing mill is detected by a width measuring instrument and uploaded to the L1 system. The L1 system then displays the width centerline deviation on the HMI. Operators use the width centerline deviation displayed on the HMI to input the tilt value set for each pass of the roughing mill, thus implementing a semi-automatic control process for the sickle bend. The semi-automatic control process for the sickle-shaped bend specifically includes the following steps: S1. The operator sets the tilt value based on the rolling pass by using the curve formed by the width centerline deviation value displayed on the HMI. S2, Preset the roll gap inclination value for the current pass; S3. Determine whether the execution time of step S2 exceeds the set time. If yes, display an alarm on the HMI. If no, proceed to step S4. S4. The working side of the roughing mill performs the preset tilt value of the roll gap; S5. The roughing mill begins to feed steel for rolling; S6. Determine whether the steel type and specifications of the subsequent slab have changed. If they have changed, exit the semi-automatic sickle bend control process and enter the fully automatic sickle bend control process. If they have not changed, proceed to step S7. S7. The width measuring instrument detects the width centerline deviation value of the slab rolled out by the roughing mill and uploads the width centerline deviation value to the L1 system. S8. The L1 system displays the width centerline deviation value on the HMI and then executes step S1. S9. Repeat steps S1 to S8.

2. The method for semi-automatic adjustment of the preset control value of L1 to improve the deviation of the camber of the strip steel according to claim 1, characterized in that: The time set in step S3 is 20 seconds.

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