Method for compensating for oil film thickness deviation on both sides of a backup roll

Abstract

The application discloses a method for compensating thickness deviation of oil film on both sides of a supporting roller, and belongs to the technical field of rolling mill control. According to the rolling regulation, the pressure load range and the speed system range of the rolling mill are determined, and the pressure load range is divided into several pressure load intervals. The load pressure is controlled to be in different pressure load intervals, the pressure on both sides of the rolling mill is ensured to be the same, the rotating speed of the supporting roller is changed, and the rotating speed of the supporting roller and the change data of the roller gap on both sides are stored. The mathematical relationship between the oil film thickness, the load pressure and the rotating speed of the supporting roller is established through polynomial fitting. Before the strip enters the rolling, the roller gap deviation pre-compensation value is calculated according to the mathematical relationship to perform pre-compensation. In the rolling process, the real-time compensation value is calculated according to the biting steel mark value to perform real-time compensation. The application realizes segmented closed-loop control, constructs a continuous and smooth oil film thickness response surface, avoids compensation jump at the boundary point, can flexibly adjust the boundary point, improves the compensation precision, and eliminates the cumulative interference of compensation.

Description

Technical Field

[0001] This invention relates to the field of rolling mill control technology, and in particular to a method for compensating for the thickness deviation of the oil film on both sides of a support roll. Background Technology

[0002] In the field of hot strip rolling, in order to ensure the symmetrical stability of the two sides of the rolled plate, the operator usually adjusts the roll gap deviation on both sides based on experience, or the AGC control system makes pre-corrections based on the actual rolling data of the upstream process, and dynamically adjusts the roll gap deviation on both sides based on real-time detection data or current working conditions during the rolling process, so as to ensure the smooth rolling process and the stability of plate shape quality.

[0003] Traditional technical theories generally hold that the difference in oil film thickness between the two support rolls is small and its impact on the strip shape is usually negligible. Therefore, in the above process, existing technologies mostly adopt an overall compensation strategy for roll gap fluctuations caused by changes in the oil film thickness of the support rolls, that is, applying the same compensation amount only to the roll gaps on both sides. As recorded in the literature "Application of Support Roll Oil Film Thickness Compensation Model Based on Field Experiment" and "Method for Determining the Compensation Method for Actual Oil Film Thickness of Strip Mill", the oil film thickness is treated as an overall variable for roll gap compensation, without incorporating the difference in oil film thickness between the two sides into the compensation model separately.

[0004] However, in actual production settings, especially when the characteristics of the rolling mill's foundation equipment are inconsistent, equipment ages unevenly after long-term operation, or the environment and working conditions are harsh, the static differences between the two sides are often quite significant. Therefore, in the actual rolling process, there are indeed significant differences in the oil film thickness on both sides of the support roll.

[0005] Since the oil film thickness cannot be directly detected online, this difference is difficult to eliminate effectively by traditional overall compensation methods. Therefore, this invention proposes a method for compensating the oil film thickness on both sides separately. This method can largely correct the roll gap deviation caused by the difference in oil film thickness on both sides, and has a positive effect on improving the stability of the hot continuous rolling process and product quality. Summary of the Invention

[0006] The purpose of this invention is to provide a method for compensating for the thickness deviation of the oil film on both sides of the support roller in order to solve the above-mentioned problems.

[0007] The present invention achieves the above objectives through the following technical solutions: A method for compensating for the thickness deviation of the oil film on both sides of a support roller specifically includes the following steps: S1. Determine the pressure load range and speed range of the rolling mill according to the rolling procedure, and divide the pressure load range into several corresponding pressure load intervals through n dividing points; S2. Control the load pressure of the rolling mill to be in different pressure load ranges to ensure that the pressure on both sides of the rolling mill is the same, change the speed of the support roller, and store the speed of the support roller and the change in the roll gap on both sides to the computer database. S3. Perform polynomial fitting on the change in the gap between the two sides of the rollers under different load pressures and the rotational speed of the support roller to obtain the mathematical relationship between the thickness of the oil film on both sides and the load pressure and the rotational speed of the support roller. S4. Before the strip enters the rolling mill, the change in oil film thickness on both sides is obtained according to the mathematical relationship, and the pre-compensation value of the roll gap deviation is calculated for pre-compensation. S5. After the strip enters the rolling mill, the real-time change in the thickness of the oil film on both sides and the marked value of the change in the thickness of the oil film on both sides at the moment of steel biting are obtained according to the mathematical relationship, so as to calculate the real-time compensation value for the roll gap deviation and perform real-time compensation. S6. After the strip leaves the rolling mill, the roll gap deviation compensation of the rolling mill is cancelled.

[0008] Furthermore, in step S1, the preferred value range for the number of boundary points n is 3-8, and the value of the nth boundary point is denoted as Fr. n The speed regulation range is 70%-90% of the maximum rotational speed of the support roller.

[0009] Furthermore, in step S2, using n dividing points as values ​​for each pressure load range, the specific method for storing the change in the rotational speed of the support roll and the change in the roll gap on both sides of the mill is as follows: First, the load pressure is controlled to remain constant at Fr1, and the pressure on both sides of the rolling mill is equal. The guaranteed pressure value on one side is Fr1 / 2, in kN. Secondly, the rotational speed of the support roller is controlled to increase from zero speed to 80% of its maximum rotational speed using a uniform acceleration acc. The changes in the roller gap on both sides, the rotational speed of the support roller, and the load pressure data during this acceleration process are stored in the computer database. The preferred value range for acc is 0.1-0.4 m / s. 2 ; Finally, repeat the above process until the load pressure Fr1 is reduced to Fr. n The corresponding data storage is complete.

[0010] Furthermore, the specific process of step S3 includes: S31. Under different load pressures, the change in the gap between the two sides of the rollers and the rotational speed of the support roller are fitted using a cubic equation as the correspondence. The fitting relationship is as follows: Morgoil_Ds_Fr n = a3_Ds· x³ + a 2_Ds· x² + a 1_Ds· x + a0_ Ds , Morgoil_Ws_Fr n = a 3_Ws· x³ + a 2_Ws· x² + a 1_Ws· x + a 0_Ws , Among them, Morgoil_Ds_Fr n Indicated at the load pressure Fr n Under these conditions, the thickness of the oil film on the drive side varies with the rotational speed of the support roller, in mm; x represents the rotational speed of the support roller, in r / min; a0_ Ds - a 3_Ds Indicated at the load pressure Fr n Under certain conditions, the relationship coefficient between the thickness of the oil film on the transmission side and the rotational speed of the support roller; Morgoil_Ws_Fr n Indicated at the load pressure Fr n Under these conditions, the change in oil film thickness on the operating side following the rotational speed of the support roller is expressed in mm; a 0_Ws -a 3_Ws Indicated at the load pressure Fr n Under the given conditions, the relationship coefficient between the oil film thickness on the operating side and the rotational speed of the support roller; S32. After obtaining the relationship between the thickness of the oil film on both sides and the rotational speed of the support roller under different load pressure conditions, the n boundary points are added to the data fitting to obtain the following correspondence between the thickness of the oil film on both sides, the rotational speed of the support roller, and the load pressure: Morgoil_DsComp = P 00_Ds + P 10_Ds· x + P 01_Ds· y + P 20_Ds· x² + P 11_Ds· x · y + P 02_Ds· y², Morgoil_WsComp = P 00_Ws + P 10_Ws· x + P 01_Ws· y + P 20_Ws· x² + P 11_Ws· x · y + P 02_Ws· y², Wherein, Morgoil_DsComp represents the change in oil film thickness on the drive side under different load pressures, following the rotational speed of the support roller and the load pressure; Morgoil_WsComp represents the change in oil film thickness on the operating side under different load pressures, following the rotational speed of the support roller and the load pressure; both units are mm. mn_Ds P represents the polynomial fitting coefficients on the transmission side. mn_Ws The coefficients are the polynomial fitting coefficients on the operating side; x represents the rotational speed of the support roller, in r / min; y represents the load pressure, in kN. S33. Implement data range protection for the load pressure input mentioned in the formula, wherein the protection range is Fr1-Fr n If the input load pressure is not within this range, the critical point protection value is taken.

[0011] Furthermore, the formula for calculating the pre-compensation value of the roll gap deviation is as follows: GapDevComp_MorEmp = (Morgoil_DsCompEmp - Morgoil_WsCompEmp) / 2, Wherein, GapDevComp_MorEmp represents the pre-compensation value of the roll gap deviation before the steel bite, in mm; Morgoil_DsCompEmp is the change in oil film thickness on the drive side before the steel bite, and Morgoil_WsCompEmp is the change in oil film thickness on the operating side before the steel bite, both in mm.

[0012] Furthermore, the formula for calculating the real-time compensation value of the roll gap deviation is as follows: GapDevComp_MorLr = ((Morgoil_DsComp - Morgoil_DsCompLr) (Morgoil_WsComp - Morgoil_WsCompLr)) / 2, Wherein, GapDevComp_MorLr represents the real-time compensation value of the roll gap deviation after steel biting, in mm; Morgoil_DsCompLr is the marked value of the change in oil film thickness on the drive side at the moment of steel biting, Morgoil_DsComp is the real-time change in oil film thickness on the drive side, Morgoil_WsCompLr is the marked value of the change in oil film thickness on the operating side at the moment of steel biting, and Morgoil_WsComp is the real-time change in oil film thickness on the operating side of the mill, all in mm.

[0013] Further, step S6 specifically includes: The steel bite signal of the rolling mill is monitored in real time. When a steel throwing signal is detected in the current stand, the roll gap deviation compensation amount is immediately set to 0.

[0014] The beneficial effects are as follows: The method for compensating the oil film thickness deviation on both sides of the support roller described in this invention adopts a segmented compensation method, realizes a complete closed-loop control strategy in the time dimension, fully considers the nonlinear law of oil film thickness change, ensures high-precision control in the rolling process, and avoids the cumulative interference of the compensation strategy on subsequent rolling cycles. By introducing the mathematical relationship of multivariate fitting, the relationship between roll gap change and mill speed is fitted with a 1×n order polynomial in different load pressure ranges to obtain the fitting coefficients under each pressure. These coefficients are then used as input to further perform n×n order polynomial fitting, constructing a continuous and smooth oil film thickness response surface covering the entire pressure and speed range. This avoids the compensation jump or non-smoothness that may occur at the boundary points in traditional piecewise fitting, making the compensation value continuous with pressure and speed changes, and significantly improving the accuracy of pre-compensation and real-time compensation for oil film thickness changes. The number and density of the dividing points can be flexibly adjusted according to the specific capabilities of the on-site equipment, the rigidity characteristics of the rolling mill, the working limits of the oil film bearing, and the actual production needs, thereby flexibly adjusting the system complexity and model resolution. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the execution of a method for compensating for the thickness deviation of the oil film on both sides of a support roller as described in this invention. Figure 2 The method for compensating for the oil film thickness deviation on both sides of the support roller described in this invention is a three-dimensional surface plot of the oil film thickness on the transmission side, the rotational speed, and the pressure fitted by MATLAB. Figure 3 The method for compensating for the thickness deviation of the oil film on both sides of the support roller described in this invention is a three-dimensional surface plot of the oil film thickness on the operating side, the rotational speed, and the pressure fitted by MATLAB. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The following combination Figure 1 - Figure 3 To further illustrate the embodiments of the invention, a method for compensating for the thickness deviation of the oil film on both sides of a support roller specifically includes the following steps: S1. Determine the pressure load range and speed range of the rolling mill according to the rolling procedure, and divide the pressure load range into n-1 corresponding pressure load intervals through n dividing points; The rolling mill in question is an oil film bearing supported roll mill. The selection of the boundary points is determined based on the specific capabilities of the on-site equipment, the rigidity characteristics of the rolling mill, the working limits of the oil film bearings, and actual production requirements. For scenarios with strong equipment capabilities and high control precision requirements, the density of boundary points can be increased to improve model resolution. For scenarios with limited equipment capabilities or relatively stable rolling processes, the number of boundary points can be appropriately reduced to decrease system complexity. After multiple experimental optimizations, the optimal range for the number of boundary points n is 3-8, and the value of the nth boundary point is denoted as Fr. n The speed regulation range is 70%–90% of the maximum rotational speed of the support roller.

[0018] In this embodiment, taking n as 4 as an example, Fr1-Fr4 are denoted as 3000kN, 6000kN, 9000kN, and 11000kN respectively. The pressure load range is divided into 3000kN-6000kN, 6000kN-9000kN, and 9000kN-11000kN.

[0019] S2. Control the load pressure of the rolling mill to be in different pressure load ranges to ensure that the pressure on both sides of the rolling mill is the same, change the speed of the support roll, and store the speed of the support roll and the change in the roll gap on both sides to the computer database.

[0020] In this embodiment, taking n dividing points as the values ​​for each pressure load range as an example, the specific method for storing the change in the rotational speed of the support roll and the change in the roll gap on both sides of the mill is as follows: First, the load pressure is controlled to remain constant at Fr1, and the pressure on both sides of the rolling mill is equal. The guaranteed pressure value on one side is Fr1 / 2, in kN. Secondly, the rotational speed of the support roller is controlled to increase from zero speed to 80% of its maximum rotational speed using a uniform acceleration acc. The changes in the roller gap on both sides, the rotational speed of the support roller, and the load pressure data during this acceleration process are stored in the computer database. The preferred value range for acc is 0.1-0.4 m / s. 2 In this embodiment, acc = 0.2 m / s 2 Perform calculations; Finally, repeat the above process until the corresponding data under the load pressures Fr1 to Fr4 have been stored.

[0021] The change in the roll gap on both sides is the change in the roll gap on the operating side and the change in the roll gap on the transmission side. The stored data includes the change in the roll gap on the operating side, the change in the roll gap on the transmission side, the rotational speed of the support roller, and the load pressure, for a total of 4×n sets of data.

[0022] S3. Perform polynomial fitting on the changes in the gap between the two sides of the rollers under different load pressures and the rotational speed of the support roller to obtain the mathematical relationship between the oil film thickness on both sides and the load pressure and the rotational speed of the support roller. The specific method is as follows: S31. Under different load pressures, the changes in the gap between the two sides of the rollers and the rotational speed of the support roller are fitted with data using a cubic equation as the correspondence, such as: Morgoil_Ds_Fr n = a 3_Ds· x³ + a 2_Ds· x² + a 1_Ds· x + a0_ Ds , Morgoil_Ws_Fr n = a 3_Ws· x³ + a 2_Ws· x² + a 1_Ws· x + a 0_Ws , Among them, Morgoil_Ds_Fr n Indicated at the load pressure Fr n Under these conditions, the thickness of the oil film on the drive side varies with the rotational speed of the support roller, in mm; x represents the rotational speed of the support roller, in r / min; a0_ Ds - a 3_Ds Indicated at the load pressure Fr n Under certain conditions, the relationship coefficient between the thickness of the oil film on the transmission side and the rotational speed of the support roller; Morgoil_Ws_Fr n Indicated at the load pressure Fr n Under these conditions, the change in oil film thickness on the operating side following the rotational speed of the support roller is expressed in mm; a 0_Ws -a 3_Ws Indicated at the load pressure Fr n Under certain conditions, the relationship coefficient between the oil film thickness on the operating side and the rotational speed of the support roller.

[0023] In this embodiment, data was sampled and calculated under the condition that the support roller rotates at 70 r / min, and detailed data as shown in Table 1 below was obtained: Table 1 S32. After obtaining the relationship between the thickness of the oil film on both sides and the rotational speed of the support roller under different load pressure conditions, the n boundary points are added to the data fitting to obtain the common correspondence between the thickness of the oil film on both sides, the rotational speed of the support roller, and the load pressure (see details). Figure 2 , Figure 3 (The changing relationships in the text), such as: Morgoil_DsComp = P 00_Ds + P 10_Ds· x + P 01_Ds· y + P 20_Ds· x² + P 11_Ds· x · y + P 02_Ds· y², Morgoil_WsComp = P 00_Ws + P 10_Ws· x + P 01_Ws· y + P 20_Ws· x² + P 11_Ws· x · y + P 02_Ws· y², Wherein, Morgoil_DsComp represents the change in oil film thickness on the drive side under different load pressures, following the rotational speed of the support roller and the load pressure; Morgoil_WsComp represents the change in oil film thickness on the operating side under different load pressures, following the rotational speed of the support roller and the load pressure; both units are mm. mn_Ds P represents the polynomial fitting coefficients on the transmission side. mn_Ws y represents the polynomial fitting coefficients on the operating side; x represents the rotational speed of the support roller, in r / min; y represents the load pressure, in kN.

[0024] Data from the drive side and the operating side under the same rolling condition were sampled and calculated when the load pressure was 10000kN and the support roller speed was 80 r / min. The detailed data is shown in Table 2 below. Table 2 S33. Perform data range protection on the load pressure input in the formula, wherein the protection range is Fr1-Fr4. When the input load pressure is not within this range, the critical point protection value is taken.

[0025] S4. Before the strip enters the rolling mill, the change in oil film thickness on both sides is obtained according to the mathematical relationship between the oil film thickness, the rotational speed of the support roll, and the load pressure, and the roll gap deviation on both sides is pre-compensated.

[0026] Before the strip enters the rolling mill, the change in oil film thickness on both sides can be calculated based on the current load pressure of the rolling mill and the rotation speed of the support roll, which are respectively Morgoil_DsComp and Morgoil_WsComp. Since there is no load pressure before the strip bites in, the load pressure calculation input value takes the critical point Fr1 as the effective value.

[0027] The formula for calculating the pre-compensation amount for roll gap deviation is: GapDevComp_MorEmp = (Morgoil_DsCompEmp - Morgoil_WsCompEmp) / 2, Wherein, GapDevComp_MorEmp represents the pre-compensation amount for the roll gap deviation before the rolling mill bites the steel, in mm. The roll gap deviation is defined as the deviation of the operating side roll gap minus the deviation of the drive side roll gap; Morgoil_DsCompEmp is the change in oil film thickness on the drive side before the steel bites the steel, and Morgoil_WsCompEmp is the change in oil film thickness on the operating side before the steel bites the steel, both in mm.

[0028] Since there is no load pressure before the strip is bitten in this embodiment, the load pressure is calculated using data at the critical point Fr1 of 3000 kN and the support roller speed is 80 r / min, and the detailed data shown in Table 3 are obtained: Table 3 S5. After the strip enters the rolling mill, the deviation of the roll gap on both sides is compensated in real time according to their corresponding relationship.

[0029] The changes in oil film thickness on both sides at the moment of steel biting are marked as Morgoil_DsCompLr and Morgoil_WsCompLr, respectively. The real-time changes in oil film thickness on both sides during the rolling process are subtracted from the marked values ​​of the changes in oil film thickness on both sides at the moment of steel biting, and the real-time compensation value of roll gap deviation during the rolling process is calculated by the difference between the two values.

[0030] The formula for calculating the real-time compensation value of the roll gap deviation during the rolling process is as follows: GapDevComp_MorLr = ((Morgoil_DsComp - Morgoil_DsCompLr) (Morgoil_WsComp - Morgoil_WsCompLr)) / 2, Wherein, GapDevComp_MorLr represents the real-time compensation amount of the roll gap deviation after steel biting, in mm. The roll gap deviation is defined as the deviation of the roll gap on the operating side of the mill minus the deviation of the roll gap on the drive side of the mill; Morgoil_DsCompLr is the marked value of the change in oil film thickness on the drive side at the moment of steel biting, Morgoil_DsComp is the real-time change in oil film thickness on the drive side, Morgoil_WsCompLr is the marked value of the change in oil film thickness on the operating side at the moment of steel biting, and Morgoil_WsComp is the real-time change in oil film thickness on the operating side of the mill, all in mm.

[0031] In this embodiment, when marking the change in oil film thickness on both sides at the moment of steel biting, the roll speed is 30 r / min and the load pressure is 3000 kN; when calculating the oil film thickness on both sides at the current moment during rolling, the roll speed is 80 r / min and the load pressure is 10000 kN, and the detailed data obtained are shown in Table 4: Table 4 S6. After the strip leaves the rolling mill, the roll gap deviation compensation of the rolling mill is cancelled.

[0032] Specifically, the steel bite signal of the rolling mill is monitored in real time. When a steel throwing signal is detected in the current stand, the roll gap deviation compensation amount of the oil film thickness of the current stand is immediately set to 0.

[0033] In this embodiment, the method pre-compensates the roll gaps on both sides based on a fitted model before the strip enters the rolling mill, eliminating the influence of initial oil film changes. During strip rolling, the roll gaps on both sides are dynamically corrected based on real-time collected pressure and speed data to achieve process compensation. After the strip leaves the rolling mill, the compensation is promptly canceled to prevent excessive adjustment under no-load conditions. It achieves a complete closed-loop control strategy in the time dimension, employing a segmented compensation method that fully considers the nonlinearity of oil film thickness changes, ensuring high-precision control during rolling while avoiding cumulative interference from the compensation strategy in subsequent rolling cycles.

[0034] By introducing the mathematical relationship of multivariate fitting, the relationship between the roll gap change and the mill speed is fitted with a 1×n order polynomial in different load pressure ranges to obtain the fitting coefficients under each pressure. These coefficients are then used as input to further perform n×n order polynomial fitting, constructing a continuous and smooth oil film thickness response surface covering the entire pressure and speed range. This avoids the compensation jump or non-smoothness that may occur at the boundary points in traditional piecewise fitting, making the compensation value continuous with pressure and speed changes, and significantly improving the accuracy of pre-compensation and real-time compensation for oil film thickness changes.

[0035] The number and density of the dividing points can be flexibly adjusted according to the specific capabilities of the on-site equipment, the rigidity characteristics of the rolling mill, the working limits of the oil film bearing, and the actual production needs, thereby flexibly adjusting the system complexity and model resolution.

[0036] 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 present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for compensating for the thickness deviation of the oil film on both sides of a support roller, characterized in that, Includes the following steps: S1. Determine the pressure load range and speed range of the rolling mill according to the rolling procedure, and divide the pressure load range into several corresponding pressure load intervals through n dividing points; S2. Control the load pressure of the rolling mill to be in different pressure load ranges to ensure that the pressure on both sides of the rolling mill is the same, change the speed of the support roller, and store the speed of the support roller and the change in the roll gap on both sides to the computer database. S3. Perform polynomial fitting on the change in the gap between the two sides of the rollers under different load pressures and the rotational speed of the support roller to obtain the mathematical relationship between the thickness of the oil film on both sides and the load pressure and the rotational speed of the support roller. S4. Before the strip enters the rolling mill, the change in oil film thickness on both sides is obtained according to the mathematical relationship, and the pre-compensation value of the roll gap deviation is calculated for pre-compensation. S5. After the strip enters the rolling mill, the real-time change in the thickness of the oil film on both sides and the marked value of the change in the thickness of the oil film on both sides at the moment of steel biting are obtained according to the mathematical relationship, so as to calculate the real-time compensation value for the roll gap deviation and perform real-time compensation. S6. After the strip leaves the rolling mill, the roll gap deviation compensation of the rolling mill is cancelled.

2. The method for compensating for the thickness deviation of the oil film on both sides of a support roller according to claim 1, characterized in that: In step S1, the preferred value range for the number of boundary points n is 3 to 8, and the value of the nth boundary point is denoted as Fr. n The speed regulation range is 70%-90% of the maximum rotational speed of the support roller.

3. The method for compensating for the thickness deviation of the oil film on both sides of a support roller according to claim 2, characterized in that: In step S2, the specific method for storing the change in the support roll speed and the roll gap on both sides of the mill, using n dividing points as values ​​for each pressure load range, is as follows: First, the load pressure is controlled to remain constant at Fr1, and the pressure on both sides of the rolling mill is equal. The guaranteed pressure value on one side is Fr1 / 2, in kN. Secondly, the rotational speed of the support roller is controlled to increase from zero speed to 80% of its maximum rotational speed using a uniform acceleration acc. The changes in the roller gap on both sides, the rotational speed of the support roller, and the load pressure data during this acceleration process are stored in the computer database. The preferred value range for acc is 0.1-0.4 m / s. 2 ; Finally, repeat the above process until the load pressure Fr1 is reduced to Fr. n The corresponding data storage is complete.

4. The method for compensating for the thickness deviation of the oil film on both sides of a support roller according to claim 2, characterized in that, The specific process of step S3 includes: S31. Under different load pressures, the change in the gap between the two sides of the rollers and the rotational speed of the support roller are fitted using a cubic equation as the correspondence. The fitting relationship is as follows: Morgoil_Ds_Fr n = a 3_Ds ·x³ + a 2_Ds ·x² + a 1_Ds ·x + a0_ Ds , Morgoil_Ws_Fr n = a 3_Ws ·x³ + a 2_Ws ·x² + a 1_Ws ·x + a 0_Ws , Among them, Morgoil_Ds_Fr n Indicated at the load pressure Fr n Under these conditions, the thickness of the oil film on the drive side varies with the rotational speed of the support roller, in mm; x represents the rotational speed of the support roller, in r / min; a0_ Ds - a 3_Ds Indicated at the load pressure Fr n Under certain conditions, the relationship coefficient between the thickness of the oil film on the transmission side and the rotational speed of the support roller; Morgoil_Ws_Fr n Indicated at the load pressure Fr n Under these conditions, the change in oil film thickness on the operating side following the rotational speed of the support roller is expressed in mm; a 0_Ws -a 3_Ws Indicated at the load pressure Fr n Under the given conditions, the relationship coefficient between the oil film thickness on the operating side and the rotational speed of the support roller; S32. After obtaining the relationship between the thickness of the oil film on both sides and the rotational speed of the support roller under different load pressure conditions, the n boundary points are added to the data fitting to obtain the following correspondence between the thickness of the oil film on both sides, the rotational speed of the support roller, and the load pressure: Morgoil_DsComp = P 00_Ds + P 10_Ds ·x + P 01_Ds ·y + P 20_Ds ·x² + P 11_Ds · x·y +P 02_Ds ·y², Morgoil_WsComp = P 00_Ws + P 10_Ws ·x + P 01_Ws ·y + P 20_Ws ·x² + P 11_Ws ·x·y +P 02_Ws ·y², Wherein, Morgoil_DsComp represents the change in oil film thickness on the drive side under different load pressures, following the rotational speed of the support roller and the load pressure; Morgoil_WsComp represents the change in oil film thickness on the operating side under different load pressures, following the rotational speed of the support roller and the load pressure; both units are mm. mn_Ds P represents the polynomial fitting coefficients on the transmission side. mn_Ws The coefficients are the polynomial fitting coefficients on the operating side; x represents the rotational speed of the support roller, in r / min; y represents the load pressure, in kN. S33. Implement data range protection for the load pressure input mentioned in the formula, wherein the protection range is Fr1-Fr n If the input load pressure is not within this range, the critical point protection value is taken.

5. The method for compensating for the thickness deviation of the oil film on both sides of a support roller according to claim 1, characterized in that, The formula for calculating the pre-compensation value of the roll gap deviation is: GapDevComp_MorEmp = (Morgoil_DsCompEmp - Morgoil_WsCompEmp) / 2, Wherein, Morgoil_DsCompEmp represents the change in oil film thickness on the drive side before the steel bite, and Morgoil_WsCompEmp represents the change in oil film thickness on the operating side before the steel bite, both in mm.

6. The method for compensating for the thickness deviation of the oil film on both sides of a support roller according to claim 1, characterized in that, The formula for calculating the real-time compensation value of the roll gap deviation is as follows: GapDevComp_MorLr = ((Morgoil_DsComp - Morgoil_DsCompLr) (Morgoil_WsComp -Morgoil_WsCompLr)) / 2, Wherein, Morgoil_DsCompLr is the marked value of the change in oil film thickness on the drive side at the moment of steel biting, Morgoil_DsComp is the real-time change in oil film thickness on the drive side, Morgoil_WsCompLr is the marked value of the change in oil film thickness on the operating side at the moment of steel biting, and Morgoil_WsComp is the real-time change in oil film thickness on the operating side of the mill, all in mm.

7. The method for compensating for the thickness deviation of the oil film on both sides of a support roller according to claim 1, characterized in that, Step S6 specifically involves: The steel bite signal of the rolling mill is monitored in real time. When a steel throwing signal is detected in the current stand, the roll gap deviation compensation amount is immediately set to 0.

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