阅读说明：本技术 一种以板形控制为目标的弯辊补偿方法及系统 (Method and system for compensating bending roller by taking shape control as target ) 是由 白振华 顾清 张亚震 申立涛 张文军 于 2020-11-26 设计创作，主要内容包括：本发明公开了一种以板形控制为目标的弯辊补偿方法及系统。该方法包括：将轧制带材升降速过程分为多段；对于每一段,基于冷连轧机组中设备的工艺参数以及冷连轧机组生产带钢升降速段的工艺参数,计算油膜厚度、摩擦系数和轧制力；对于每一段,基于补偿系数初始值计算工作辊弯辊力补偿值、中间辊弯辊力补偿值以及补偿后的前张力；根据补偿后的前张力构建目标函数,并通过目标函数优化补偿后的前张力；根据优化后的补偿前张力确定优化后的工作辊弯辊力补偿值以及优化后的中间辊弯辊力补偿值；基于优化后的工作辊弯辊力补偿值以及优化后的中间辊弯辊力补偿值对1-4机架的工作辊弯辊力和中间辊弯辊力进行补偿。(The invention discloses a method and a system for compensating a bending roll by taking plate shape control as a target. The method comprises the following steps: dividing the process of increasing and decreasing the speed of a rolled strip into a plurality of sections; for each section, calculating the thickness of an oil film, the friction coefficient and the rolling force based on the technological parameters of equipment in the cold continuous rolling mill and the technological parameters of the strip steel production acceleration and deceleration section of the cold continuous rolling mill; for each section, calculating a working roll bending force compensation value, a middle roll bending force compensation value and a compensated front tension based on the compensation coefficient initial value; constructing an objective function according to the compensated front tension, and optimizing the compensated front tension through the objective function; determining an optimized working roll bending force compensation value and an optimized intermediate roll bending force compensation value according to the optimized tension before compensation; and compensating the working roll bending force and the intermediate roll bending force of the 1-4 frames based on the optimized working roll bending force compensation value and the optimized intermediate roll bending force compensation value.)

1. A roll bending compensation method targeting profile control, comprising:

setting initial values of compensation coefficients and optimized step lengths of the bending forces of the working rolls and the intermediate rolls of the 1-4 frames;

dividing the process of increasing and decreasing the speed of a rolled strip into a plurality of sections;

for each section, calculating the oil film thickness, the friction coefficient and the rolling force corresponding to the speed of the 1-4 stand based on the collected technological parameters of the equipment in the cold continuous rolling unit and the collected technological parameters of the strip steel production acceleration and deceleration section of the cold continuous rolling unit;

for each section, calculating a working roll bending force compensation value, a middle roll bending force compensation value and a compensated front tension corresponding to the speed of the 1-4 frame based on the initial value of the compensation coefficient;

constructing an objective function according to the compensated front tension, and optimizing the compensated front tension through the objective function;

determining an optimized working roll bending force compensation value and an optimized intermediate roll bending force compensation value according to the optimized tension before compensation;

compensating the working roll bending force of the 1-4 frames based on the optimized working roll bending force compensation value, and compensating the intermediate roll bending force of the 1-4 frames based on the optimized intermediate roll bending force compensation value;

judging whether the roll bending force of the working roll after the compensation of the 1-4 frames and the roll bending force of the middle roll after the compensation are within a constraint range;

if so, determining the optimal compensation coefficient of the bending force of the working roll and the middle roll;

if not, the roll bending force compensation coefficients of the working roll and the intermediate roll of the 1-4 frames are reset.

2. Method for roll bending compensation targeting strip shape control according to claim 1, characterized in that the process parameters of the equipment in the cold continuous rolling mill train comprise 1-5 stand work roll diameter D_jwDiameter D of intermediate roll_jmDiameter D of the support roller_jkLength L of working roll body of 1-5 frames_jwLength L of intermediate roll body_jmLength L of the roll body of the supporting roll_jb1-5 pitch in screw down of machine frame_jwMiddle distance l between the middle rollers and the screw_jmThe interval l between the support roller and the screw_jb1-5 frame work roll minimum roll bending force (S)_w)_jminAnd maximum roll bending force (S)_w)_jmaxMaximum bending force of the intermediate roll (S)_m)_jmin and minimum roll bending force (S)_m)_jmaxWorking roll elastic modulus E, working roll Poisson ratio v, and rolling oil dynamic viscosity eta₀The influence coefficient kc of the emulsion concentration, the viscosity compression coefficient theta of the lubricant, and the influence zeta of the roll roughness on the thickness of the lubricating film₀Liquid lubrication friction influence coefficient a, dry friction influence coefficient B and friction coefficient attenuation index B_ξ。

3. The roll bending compensation method aiming at the shape control as claimed in claim 2, wherein the process parameters of the cold continuous rolling mill group for producing the strip steel acceleration and deceleration section comprise: transverse thickness distribution H of incoming material_ikWidth B of the strip, strength σ of the strip_s1-5 entry deformation resistance k of strip of frame_0jAnd resistance to outlet deformation k_1j1-5 frame entrance and exit thicknesses (h)₀)_jk、(h₁)_jkJ is the number of stands, k is the longitudinal kth section of the rolled strip, and the rolling reduction set value epsilon of 1-5 stands_jAnd the actual value ε_jk1-5 frame unit front tension (σ)₀)_jAnd unit back tension (σ)₁)_j1-5 set value S of working roll bending force of machine frame_wjMiddle roll bending force setting S_mjSet value chi of roll inclination amount_jSet value of roll shifting amount1-5 frame emulsion flow w_jConcentration C_jTemperature T of the emulsion_jk1-5 set value V of rolling speed of stand_j ^*And the actual value V_jkRolling pressure set value P_jAnd the actual value P_jk。

4. Roll bending compensation method for controlling roll profiles according to claim 3, characterised in that the oil film thickness ζ_jkThe coefficient of friction mu_jkAnd said rolling force P_jkThe calculation formula of (a) is as follows:

K_mj＝k_0j+k_1j/2；

in the formula, xi_j＝0.3σ_j0+0.7σ_j1，Δh_jk＝(h₁)_jk-(h₀)_jk，K_mjThe j rack average deformation resistance is Mpa; xi_jkEqual tension of the kth section of the jth rack, Mpa; r'_jkThe k section of the jth rack is rolled to a flat radius of mm; c₀Is a constant; Δ h_jkIs the relative thickness of the kth section of the jth rack in mm.

5. Method for roll bending compensation targeting at profile control according to claim 1, characterized in that the work roll bending force compensation value Δ (S)_w)_jkMiddle roll bending force compensation value delta (S)_w)_jkAnd compensated front tension (sigma)_1i)_jkThe calculation formula of (a) is as follows:

wherein, γ_1j＝{0.26,0.26,0.26,0.26}，γ_2j＝{0.12,0.12,0.12,0.12}；

In the formula: gamma ray_1jThe influence degree of the jth frame speed on the bending force of the working roll is shown; gamma ray_2jFor the influence of jth frame speed on the bending force of the intermediate rollsDegree; (lambda_w)_jkThe influence coefficient of the jth frame speed on the bending force of the working roll is shown; (lambda_m)_jkThe influence coefficient of the jth frame speed on the bending force of the intermediate roll is shown;

in the formula: (S)_w)′_jk、(S_m)′_jkThe roll bending force, KN, of the main working roll and the intermediate roll after compensation is carried out on the kth section of the jth frame strip; kappa_1jThe flattening coefficient between the working roll and the rolled piece of the jth frame can be calculated by iteration; kappa_2jThe flattening coefficient between the intermediate roll and the rolled piece of the jth stand can be calculated by iteration.

6. The roll bending compensation method aiming at plate shape control according to claim 5, wherein the objective function F (X) is:

in the formula: alpha is a transverse plate shape weighting coefficient; beta is a longitudinal plate shape weighting coefficient; phi is a weighting coefficient of the transverse plate shape and the longitudinal plate shape; (sigma)_1i)_kThe transverse distribution value of front tension corresponding to the kth section speed of the single frame is Mpa; g (X) is a single-frame plate shape fluctuation control function; g (X)'₁Subtracting the minimum value from the maximum value in the average value array of the longitudinal N sections of plate shapes; g (X) ", a₁Sequentially subtracting the average value of the transverse plate shape of the ith section of the N sections of the strip materials from the average value array of the longitudinal N sections of the plate shapes, and then calculating the average value; g (X)₁Is a dynamic plate-shaped transverse objective function; g (X)'₂Respectively subtracting the average value of the longitudinal N sections of plate shapes from the transverse array of each section of plate shape in the longitudinal directionThe array is obtained, and then the average value of N arrays in the N-segment subtraction values is obtained; g (X) ", a₂Subtracting the maximum value and the minimum value in the average value array average values of the longitudinal N-section plate shapes from the transverse array of each j section of each longitudinal N-section; g (X)₂Is a dynamic plate-shaped longitudinal objective function.

7. A roll bending compensation system targeted at strip shape control, comprising:

the setting module is used for setting the initial values of the compensation coefficients of the roll bending forces of the 1-4 frame working rolls and the middle roll and the optimized step length;

the dividing module is used for dividing the speed increasing and decreasing process of the rolled strip into a plurality of sections;

the first calculation module is used for calculating the oil film thickness, the friction coefficient and the rolling force corresponding to the speed of the 1-4 stand for each section based on the collected technological parameters of the equipment in the cold continuous rolling unit and the collected technological parameters of the strip steel production acceleration and deceleration section of the cold continuous rolling unit;

the second calculation module is used for calculating a working roll bending force compensation value, a middle roll bending force compensation value and a compensated front tension corresponding to the speed of the 1-4 machine frame based on the initial value of the compensation coefficient for each section;

the optimization module is used for constructing an objective function according to the compensated front tension and optimizing the compensated front tension through the objective function;

the determining module is used for determining an optimized working roll bending force compensation value and an optimized intermediate roll bending force compensation value according to the optimized tension before compensation;

the compensation module is used for compensating the working roll bending force of the 1-4 frames based on the optimized working roll bending force compensation value and compensating the middle roll bending force of the 1-4 frames based on the optimized middle roll bending force compensation value;

the judging module is used for judging whether the bending force of the working roll after the 1-4 machine frame compensation and the bending force of the middle roll after the compensation are in the constraint range;

the optimal compensation coefficient determining module is used for determining the optimal compensation coefficients of the bending force of the working roll and the bending force of the intermediate roll when the bending force of the working roll after the 1-4 machine frame compensation and the bending force of the intermediate roll after the compensation are in the constraint range;

and the resetting module is used for resetting the force compensation coefficients of the working roll and the intermediate roll of the 1-4 frames when the roll bending force of the working roll after the compensation of the 1-4 frames and the roll bending force of the intermediate roll after the compensation are not in the constraint range.

Technical Field

The invention relates to the technical field of cold rolling, in particular to a method and a system for compensating a bending roll by taking plate shape control as a target.

Background

In a cold continuous rolling unit, the head of a strip can be sequentially bitten into each rack at the initial rolling stage, before the speed is stable, the oil film thickness between the strip steel and a roller can be changed due to the change of the speed, and the change of the oil film thickness causes the change of the friction coefficient between the strip steel and the roller to be severe, so that the rolling pressure is changed, and the plate shape is unstable; at the tail part of the rolling, the strip is thrown out of each rack in sequence, the rolling speed is gradually reduced to 0, the tension is extremely unstable after the rolling, and the rolling force is also changed violently, so that the shape of the strip is not good; the rolling speed of each stand may not be increased to the maximum speed once during rolling, and may go through several acceleration processes, and in the short acceleration process, the plate shape is unstable due to the rapid change of the speed; finally, the finished plate shape has large fluctuation in the speed increasing and reducing section and is relatively poor, and the requirement of the site cannot be met. The influence of the speed on the plate shape in the speed increasing and reducing stage is divided into two conditions: (1) when the flow of the emulsion is sufficient, the rolling speed is increased, so that the thickness of an oil film is increased, the friction coefficient is reduced, the rolling force is reduced from large to small, and the plate shape develops towards the middle wave trend; (2) when the flow of the emulsion is insufficient, the rolling speed is increased, so that the deformation heat and the friction heat are increased, the viscosity of lubricating oil between a strip material and a roller is reduced, the thickness of an oil film is reduced, the friction coefficient is increased, the rolling force is increased from small to large, and the plate shape develops towards the edge wave trend. In the rolling process of the cold continuous rolling unit, the rolled strip is often in poor shape at the speed increasing and reducing stage due to the fact that the rolling force changes violently at the speed increasing and reducing stage and the rule that the rolling force changes along with the sufficiency of the flow of the emulsion is different, and production or use is affected.

Disclosure of Invention

The invention aims to provide a bending roll compensation method and a bending roll compensation system taking plate shape control as a target, which can reduce the maximum fluctuation of the plate shape and the whole plate shape fluctuation to the maximum extent in the process of accelerating and decelerating, mainly comprehensively considers the influence of emulsion flow on the plate shape in the process of accelerating and decelerating the cold continuous rolling mill set, ensures that the total bending roll force of a working roll and a middle roll of each rack does not exceed the allowable range of the mill set on the basis of determining the influence of the speed on rolling force and further influencing the plate shape, simultaneously considers that the reduction error of each rack is within the allowable range, realizes the minimum plate shape fluctuation, and provides effective technical guarantee for the control of the plate shape in the process of accelerating and decelerating the cold continuous rolling mill set.

In order to achieve the purpose, the invention provides the following scheme:

a roll bending compensation method targeting strip shape control, comprising:

setting initial values of compensation coefficients and optimized step lengths of the bending forces of the working rolls and the intermediate rolls of the 1-4 frames;

dividing the process of increasing and decreasing the speed of a rolled strip into a plurality of sections;

for each section, calculating the oil film thickness, the friction coefficient and the rolling force corresponding to the speed of the 1-4 stand based on the collected technological parameters of the equipment in the cold continuous rolling unit and the collected technological parameters of the strip steel production acceleration and deceleration section of the cold continuous rolling unit;

for each section, calculating a working roll bending force compensation value, a middle roll bending force compensation value and a compensated front tension corresponding to the speed of the 1-4 frame based on the initial value of the compensation coefficient;

constructing an objective function according to the compensated front tension, and optimizing the compensated front tension through the objective function;

determining an optimized working roll bending force compensation value and an optimized intermediate roll bending force compensation value according to the optimized tension before compensation;

compensating the working roll bending force of the 1-4 frames based on the optimized working roll bending force compensation value, and compensating the intermediate roll bending force of the 1-4 frames based on the optimized intermediate roll bending force compensation value;

judging whether the roll bending force of the working roll after the compensation of the 1-4 frames and the roll bending force of the middle roll after the compensation are within a constraint range;

if so, determining the optimal compensation coefficient of the bending force of the working roll and the middle roll;

if not, the roll bending force compensation coefficients of the working roll and the intermediate roll of the 1-4 frames are reset.

Further, the technological parameters of the equipment in the cold continuous rolling unit comprise 1-5 frames workingRoller diameter D_jwDiameter D of intermediate roll_jmDiameter D of the support roller_jkLength L of working roll body of 1-5 frames_jwLength L of intermediate roll body_jmLength L of the roll body of the supporting roll_jb1-5 pitch in screw down of machine frame_jwMiddle distance l between the middle rollers and the screw_jmThe interval l between the support roller and the screw_jb1-5 frame work roll minimum roll bending force (S)_w)_jminAnd maximum roll bending force (S)_w)_jmaxMaximum bending force of the intermediate roll (S)_m)_jmi_nWith minimum roll bending force (S)_m)_jmaxWorking roll elastic modulus E, working roll Poisson ratio v, and rolling oil dynamic viscosity eta₀The influence coefficient kc of the emulsion concentration, the viscosity compression coefficient theta of the lubricant, and the influence zeta of the roll roughness on the thickness of the lubricating film₀Liquid lubrication friction influence coefficient a, dry friction influence coefficient B and friction coefficient attenuation index B_ξ。

Further, the technological parameters of the strip steel acceleration and deceleration section produced by the cold continuous rolling unit comprise: transverse thickness distribution H of incoming material_ikWidth B of the strip, strength σ of the strip_s1-5 entry deformation resistance k of strip of frame_0jAnd resistance to outlet deformation k_1j1-5 frame entrance and exit thicknesses (h)₀)_jk、(h₁)_jkJ is the number of stands, k is the longitudinal kth section of the rolled strip, and the rolling reduction set value epsilon of 1-5 stands_jAnd the actual value ε_jk1-5 frame unit front tension (σ)₀)_jAnd unit back tension (σ)₁)_j1-5 set value S of working roll bending force of machine frame_wjMiddle roll bending force setting S_mjSet value chi of roll inclination amount_jSet value of roll shifting amount1-5 frame emulsion flow w_jConcentration C_jTemperature T of the emulsion_jk1-5 set value V of rolling speed of stand_j ^*And the actual value V_jkRolling pressure set value P_jAnd the actual value P_jk。

Further, the oil film thickness ζ_jkThe coefficient of friction mu_jkAnd said rolling force P_jkThe calculation formula of (a) is as follows:

K_mj＝k_0j+k_1j/2；

in the formula, xi_j＝0.3σ_j0+0.7σ_j1，Δh_jk＝(h₁)_jk-(h₀)_jk，K_mjThe j rack average deformation resistance is Mpa; xi_jkEqual tension of the kth section of the jth rack, Mpa; r'_jkThe k section of the jth rack is rolled to a flat radius of mm; c₀Is a constant; Δ h_jkIs the relative thickness of the kth section of the jth rack in mm.

Further, the work roll bending force compensation value delta (S)_w)_jkMiddle roll bending force compensation value delta (S)_w)_jkAnd compensated front tension (sigma)_1i)_jkThe calculation formula of (a) is as follows:

wherein, γ_1j＝{0.26,0.26,0.26,0.26}，γ_2j＝{0.12,0.12,0.12,0.12}；

In the formula: gamma ray_1jIs the jth machineThe degree of influence of the frame speed on the bending force of the working roll; gamma ray_2jThe influence degree of the jth frame speed on the bending force of the intermediate roll is shown; (lambda_w)_jkThe influence coefficient of the jth frame speed on the bending force of the working roll is shown; (lambda_m)_jkThe influence coefficient of the jth frame speed on the bending force of the intermediate roll is shown;

in the formula: (S)_w)′_jk、(S_m)′_jkThe roll bending force, KN, of the main working roll and the intermediate roll after compensation is carried out on the kth section of the jth frame strip; kappa_1jThe flattening coefficient between the working roll of the jth frame and a rolled piece is obtained; kappa_2jAnd the flattening coefficient between the intermediate roll of the jth stand and the rolled piece is shown.

Further, the objective function f (x) is:

in the formula: alpha is a transverse plate shape weighting coefficient; beta is a longitudinal plate shape weighting coefficient; phi is a weighting coefficient of the transverse plate shape and the longitudinal plate shape; (sigma)_1i)_kThe transverse distribution value of front tension corresponding to the kth section speed of the single frame is Mpa; g (X) is a single-frame plate shape fluctuation control function; g (X)'₁Subtracting the minimum value from the maximum value in the average value array of the longitudinal N sections of plate shapes; g (X) ", a₁Sequentially subtracting the average value of the transverse plate shape of the ith section of the N sections of the strip materials from the average value array of the longitudinal N sections of the plate shapes, and then calculating the average value; g (X)₁Is a dynamic plate-shaped transverse objective function; g (X)'₂Respectively subtracting the average value array of the longitudinal N sections of plate shapes from the transverse array of each section of plate shape in the longitudinal direction, and then calculating the average value of N arrays in the N sections of subtraction values; g (X) ", a₂For every longitudinal direction N sections and every j sectionsSubtracting the maximum value and the minimum value in the average value array average values of the longitudinal N-section plate shapes from the array respectively; g (X)₂Is a dynamic plate-shaped longitudinal objective function.

The invention also provides a roll bending compensation system taking plate shape control as a target, which comprises the following components:

the setting module is used for setting the initial values of the compensation coefficients of the roll bending forces of the 1-4 frame working rolls and the middle roll and the optimized step length;

the dividing module is used for dividing the speed increasing and decreasing process of the rolled strip into a plurality of sections;

the first calculation module is used for calculating the oil film thickness, the friction coefficient and the rolling force corresponding to the speed of the 1-4 stand for each section based on the collected technological parameters of the equipment in the cold continuous rolling unit and the collected technological parameters of the strip steel production acceleration and deceleration section of the cold continuous rolling unit;

the second calculation module is used for calculating a working roll bending force compensation value, a middle roll bending force compensation value and a compensated front tension corresponding to the speed of the 1-4 machine frame based on the initial value of the compensation coefficient for each section;

the optimization module is used for constructing an objective function according to the compensated front tension and optimizing the compensated front tension through the objective function;

the determining module is used for determining an optimized working roll bending force compensation value and an optimized intermediate roll bending force compensation value according to the optimized tension before compensation;

the compensation module is used for compensating the working roll bending force of the 1-4 frames based on the optimized working roll bending force compensation value and compensating the middle roll bending force of the 1-4 frames based on the optimized middle roll bending force compensation value;

the judging module is used for judging whether the bending force of the working roll after the 1-4 machine frame compensation and the bending force of the middle roll after the compensation are in the constraint range;

the optimal compensation coefficient determining module is used for determining the optimal compensation coefficients of the bending force of the working roll and the bending force of the intermediate roll when the bending force of the working roll after the 1-4 machine frame compensation and the bending force of the intermediate roll after the compensation are in the constraint range;

and the resetting module is used for resetting the force compensation coefficients of the working roll and the intermediate roll of the 1-4 frames when the roll bending force of the working roll after the compensation of the 1-4 frames and the roll bending force of the intermediate roll after the compensation are not in the constraint range.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

according to the invention, by reasonably setting the roll bending force compensation coefficients of the working rolls and the intermediate rolls, the minimum fluctuation of the plate shape of the acceleration and deceleration section is realized by taking the plate shape as a control target on the basis of ensuring that the total roll bending force of the working rolls and the intermediate rolls of each rack does not exceed the allowable range of the unit and simultaneously considering that the reduction error is within the allowable range, and the method has important significance for reducing the production cost of a cold continuous rolling unit and improving the plate shape of the whole strip.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a flow chart of a roll bending compensation method of the present invention targeting strip shape control;

FIG. 2 is a general flow chart of the roll bending compensation method of the present invention targeting strip shape control;

FIG. 3 is a graph showing a change in rolling speed of the 4 th stand in example 1 of the present invention;

FIG. 4 is a three-dimensional graph of the profile of the ramp-up and ramp-down section after the invention has been used in example 1;

FIG. 5 is a graph showing a change in rolling speed of the 4 th stand in example 2;

FIG. 6 is a three-dimensional graph of the profile of the ramp-up and ramp-down section after the invention has been used in example 2;

FIG. 7 is a block diagram of the roll bending compensation system of the present invention targeting strip shape control.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a bending roll compensation method and a bending roll compensation system taking plate shape control as a target, which can reduce the maximum fluctuation of the plate shape and the whole plate shape fluctuation to the maximum extent in the process of accelerating and decelerating, mainly comprehensively considers the influence of emulsion flow on the plate shape in the process of accelerating and decelerating the cold continuous rolling mill set, ensures that the total bending roll force of a working roll and a middle roll of each rack does not exceed the allowable range of the mill set on the basis of determining the influence of the speed on rolling force and further influencing the plate shape, simultaneously considers that the reduction error of each rack is within the allowable range, realizes the minimum plate shape fluctuation, and provides effective technical guarantee for the control of the plate shape in the process of accelerating and decelerating the cold continuous rolling mill set.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, a roll bending compensation method targeting plate shape control includes:

step 101: setting the initial value eta of the bending force compensation coefficient of the working roll and the intermediate roll of the 1-4 frames_1j，η_2j，ξ_1j，ξ_2jLet the optimization step i equal to 1. Eta_1j、η_2jThe compensation coefficient between the roll bending force compensation value and the rolling speed of the working roll of the jth frame is obtained; xi_1j、ξ_2jAnd the compensation coefficient between the bending force compensation value and the rolling speed of the intermediate roll of the jth stand is shown. Eta_1j、η_2j、ξ_1j、ξ_2jIs an introduced calculation coefficient, η, without a specific meaning_1j、η_2jIs to obtain (lambda)_w)_jkExpression of (1), xi_1j、ξ_2jIs to obtain (lambda)_m)_jkWatch (A)And (4) expression.

Step 102: the process of increasing and decreasing the speed of the rolled strip is divided into a plurality of sections.

Step 103: and for each section, calculating the oil film thickness, the friction coefficient and the rolling force corresponding to the speed of the 1-4 stand based on the collected process parameters of the equipment in the cold continuous rolling unit and the collected process parameters of the strip steel production acceleration and deceleration section of the cold continuous rolling unit.

The technological parameters of the equipment in the cold continuous rolling unit comprise 1-5 frame working roll diameters D_jwDiameter D of intermediate roll_jmDiameter D of the support roller_jkLength L of working roll body of 1-5 frames_jwLength L of intermediate roll body_jmLength L of the roll body of the supporting roll_jb1-5 pitch in screw down of machine frame_jwMiddle distance l between the middle rollers and the screw_jmThe interval l between the support roller and the screw_jb1-5 frame work roll minimum roll bending force (S)_w)_jminAnd maximum roll bending force (S)_w)_jmaxMaximum bending force of the intermediate roll (S)_m)_jminWith minimum roll bending force (S)_m)_jmaxWorking roll elastic modulus E, working roll Poisson ratio v, and rolling oil dynamic viscosity eta₀The influence coefficient kc of the emulsion concentration, the viscosity compression coefficient theta of the lubricant, and the influence zeta of the roll roughness on the thickness of the lubricating film₀Liquid lubrication friction influence coefficient a, dry friction influence coefficient B and friction coefficient attenuation index B_ξ。

The technological parameters of the strip steel acceleration and deceleration section produced by the cold continuous rolling unit comprise: transverse thickness distribution H of incoming material_ikWidth B of the strip, strength σ of the strip_s1-5 entry deformation resistance k of strip of frame_0jAnd resistance to outlet deformation k_1j1-5 frame entrance and exit thicknesses (h)₀)_jk、(h₁)_jkJ is the number of stands, k is the longitudinal kth section of the rolled strip, and the rolling reduction set value epsilon of 1-5 stands_jAnd the actual value ε_jk1-5 frame unit front tension (σ)₀)_jAnd unit back tension (σ)₁)_j1-5 set value S of working roll bending force of machine frame_wjMiddle roll bending rollForce setting S_mjSet value chi of roll inclination amount_jSet value of roll shifting amount1-5 frame emulsion flow w_jConcentration C_jTemperature T of the emulsion_jk1-5 set value V of rolling speed of stand_j ^*And the actual value V_jkRolling pressure set value P_jAnd the actual value P_jk。

The oil film thickness ζ_jkThe coefficient of friction mu_jkAnd said rolling force P_jkThe calculation formula of (a) is as follows:

K_mj＝k_0j+k_1j/2；

in the formula, xi_j＝0.3σ_j0+0.7σ_j1，Δh_jk＝(h₁)_jk-(h₀)_jk，K_mjThe j rack average deformation resistance is Mpa; xi_jkEqual tension of the kth section of the jth rack, Mpa; r'_jkThe k section of the jth rack is rolled to a flat radius of mm; c₀Is a constant; Δ h_jkIs the relative thickness of the kth section of the jth rack in mm.

Step 104: and for each section, calculating a working roll bending force compensation value, a middle roll bending force compensation value and a compensated front tension corresponding to the speed of the 1-4 machine frame based on the initial value of the compensation coefficient.

Wherein, γ_1j＝{0.26,0.26,0.26,0.26}，γ_2j＝{0.12,0.12,0.12,0.12}。

In the formula: gamma ray_1jThe influence degree of the jth frame speed on the bending force of the working roll is shown; gamma ray_2jThe influence degree of the jth frame speed on the bending force of the intermediate roll is shown; (lambda_w)_jkThe influence coefficient of the jth frame speed on the bending force of the working roll is shown; (lambda_m)_jkThe influence coefficient of the jth frame speed on the bending force of the intermediate roll is shown;

in the formula: (S)_w)′_jk、(S_m)′_jkThe roll bending force, KN, of the main working roll and the intermediate roll after compensation is carried out on the kth section of the jth frame strip; kappa_1jThe flattening coefficient between the working roll and the rolled piece of the jth frame can be calculated by iteration; kappa_2jThe flattening coefficient between the intermediate roll and the rolled piece of the jth stand can be calculated by iteration.

Step 105: and constructing an objective function according to the compensated front tension, and optimizing the compensated front tension through the objective function.

The objective function F (X) is:

in the formula: alpha is a transverse plate shape weighting coefficient; beta is a longitudinal plate shape weighting coefficient; phi is a weighting coefficient of the transverse plate shape and the longitudinal plate shape; (sigma)_1i)_kIs a sheetThe transverse distribution value of front tension, Mpa, corresponding to the speed of the kth section of the frame; g (X) is a single-frame plate shape fluctuation control function; g (X)'₁Subtracting the minimum value from the maximum value in the average value array of the longitudinal N sections of plate shapes; g (X) ", a₁Sequentially subtracting the average value of the transverse plate shape of the ith section of the N sections of the strip materials from the average value array of the longitudinal N sections of the plate shapes, and then calculating the average value; g (X)₁Is a dynamic plate-shaped transverse objective function; g (X)'₂Respectively subtracting the average value array of the longitudinal N sections of plate shapes from the transverse array of each section of plate shape in the longitudinal direction, and then calculating the average value of N arrays in the N sections of subtraction values; g (X) ", a₂Subtracting the maximum value and the minimum value in the average value array average values of the longitudinal N-section plate shapes from the transverse array of each j section of each longitudinal N-section; g (X)₂Is a dynamic plate-shaped longitudinal objective function.

Step 106: and determining the optimized work roll bending force compensation value and the optimized intermediate roll bending force compensation value according to the optimized tension before compensation.

Step 107: and compensating the working roll bending force of the 1-4 frames based on the optimized working roll bending force compensation value, and compensating the intermediate roll bending force of the 1-4 frames based on the optimized intermediate roll bending force compensation value.

Step 108: and judging whether the roll bending force of the working roll after the compensation of the 1-4 frames and the roll bending force of the middle roll after the compensation are in the constraint range.

Step 109: if yes, determining the optimal compensation coefficient of the bending force of the working roll and the middle roll.

Step 1010: if not, the roll bending force compensation coefficients of the working roll and the intermediate roll of the 1-4 frames are reset.

Next, a bending roll compensation technique aiming at plate shape control in the acceleration and deceleration process of a cold continuous rolling mill set according to the present invention will be described in detail with reference to fig. 2 by taking an 1800 cold continuous rolling mill set of a steel mill as an example.

Example 1: the steel grade is DV8210A1, and the specification is 1.805 x 1118 mm.

Firstly, collecting main equipment process parameters of a cold continuous rolling unit, and mainly comprising the following steps: 1-5 frame work roll diameter D_jw455mm, intermediate roll diameter D_jm430mm, support roll diameter D_jb1370mm, length L of working roll body of 1-5 machine frames_jw1850mm, length L of intermediate roll body_jm1850mm long and supporting roller body length L_jb1850mm, 1-5 rack screw down pitch l_jw4050mm, screw pitch l between intermediate rollers_jm4050mm, support roller screw down pitch l_jbWork roll minimum bending force (S) of 4070mm, 1-5 stands_w)_jmin-800KN and maximum roll bending force (S)_w)_jmaxMaximum bending force (S) of the intermediate roll (800 KN)_m)_jmin-800KN and minimum roll bending force (S)_m)_jmax800KN, 210Gpa of working roll elastic modulus E, 0.3 of working roll Poisson ratio v, and eta of dynamic viscosity of rolling oil₀0.02 pas, an emulsion concentration influence coefficient kc of 1.836, and a viscosity compression coefficient theta of 0.01Mpa^-1Zeta, influence of roll roughness on lubricating film thickness₀0.178, 0.0114 for liquid lubrication friction influence coefficient a, 0.1158 for dry friction influence coefficient B, and B for friction coefficient attenuation index_ξ＝-5.823。

b. Collecting technological parameters of a strip steel acceleration and deceleration section produced by a cold continuous rolling unit, and mainly comprising the following steps: transverse thickness distribution H of incoming material_ikTaking the 1 st segment of the speed increasing and decreasing process as an example:

H_i1the strip steel has the width B of 1118mm and the strength sigma of the strip steel is 3.401,3.412,3.423,3.451,3.478,3.501,3.545,3.585,3.574,3.541,3.521,3.498,3.472,3.455 and 3.421_s600Mpa, deformation resistance k₁₀＝602Mpa，k₂₀＝k₁₁＝655Mpa，k₃₀＝k₂₁＝745Mpa，k₄₀＝k₃₁＝802Mpa，k₅₀＝k₄₁＝851Mpa，k₅₁862Mpa, 1-5 rack inlet and outlet thickness, 1 st stage of the speed increasing and decreasing process as an example (h)₀)₁₁＝3.507mm，(h₁)₁₁＝(h₀)₂₁＝2.986mm，(h₁)₂₁＝(h₀)₃₁＝2.483mm，(h₁)₃₁＝(h₀)₄₁＝2.060mm，(h₁)₄₁＝(h₀)₅₁＝1.813mm，(h₁)₅₁1.805mm, a set value epsilon of the reduction ratio of 1-5 frames_j14.86%, 16.85%, 17.02%, 12.01%, 0.41% } and the actual value epsilon_jkTaking section 1 of the speed-up and speed-down process as an example, epsilon_j11-5 frame unit front-to-back tension (σ), 14.56%, 16.81%, 16.82%, 12.21%, 0.40% }₀)₁＝59.4Mpa，(σ₁)₁＝(σ₀)₂＝196.5Mpa，(σ₁)₂＝(σ₀)₃＝185.6Mpa，(σ₁)₃＝(σ₀)₄＝197.3Mpa，(σ₁)₄＝(σ₀)₅＝187.9Mpa，(σ₁)₅Working roll bending force set value S of 1-5 frames under 52.1Mpa_wj{259KN,256KN,260KN,253KN,80KN }, intermediate roll bending force setting S_mj267KN,254KN,250KN,245KN,140KN }, roll inclination setting χ_jSet value of roll shifting amount is 01-5 frame emulsion flow w_j(3100L/min, 3612L/min,3920L/min,3530L/min, 2103L/min), concentration C_j10% of emulsion temperature T_jkSet value V of rolling speed of 1-5 stands at 55 DEG C_j ^*{620m/min,715m/min,830m/min,940m/min,945m/min }, rolling pressure setpoint P_j＝{1400t,1350t,1356t,1210t,770t}。

c. Setting the initial value eta of the roll bending force compensation coefficient of the working roll and the intermediate roll of the 1-4 machine set_1j＝{0.1,0.1,0.1,0.1}，η_2j＝{0.001,0.001,0.001,0.001}，ξ_1j＝{0.1,0.1,0.1,0.1}，ξ_2jLet the optimization step i equal to 1,0.001,0.001,0.001 }.

d. Dividing the process of accelerating and decelerating the rolled strip into k sections, and initializing k to 1.

e. Calculating 1-4 gantry speedsDegree per section v_jkCorresponding oil film thickness ζ_jkCoefficient of friction mu_jkRolling force P_jk：

K_mj＝k_0j+k_1j/2；

In the formula, xi_j＝0.3σ_j0+0.7σ_j1，Δh_jk＝(h₁)_jk-(h₀)_jk；

Taking the 1 st section of the speed increasing and decreasing process as an example, calculating the oil film thickness, the friction coefficient and the rolling force of 1-4 frames:

ζ_j1＝{0.223um,0.214um,0.185um,0.173um}，

μj₁＝{0.1322,0.1315,0.1581,0.1576}，

P_j1＝{965t,931t,942t,910t,412t}。

f. calculating v_jkCorresponding delta (S)_w)_jk，Δ(S_w)_jk，(σ_1i)_jk：

Wherein the content of the first and second substances,γ_1j＝{0.26,0.26,0.26,0.26}，γ_2j0.12,0.12,0.12,0.12 }; taking the 1 st segment in the speed increasing and decreasing process as an example, the roll bending force compensation value of the 1-4 frames is as follows:

Δ(S_w)_j1＝{-45.21KN,-47.14KN,-50.21KN,-55.42KN}，

Δ(S_m)_j1＝{-20.86KN,-21.73KN,-23.21KN,-25.42KN}；

1-4 the calculated compensated front tension for the frame is:

(σ_1i)₁₁＝{48.9,52.6,56.4,60.2,63.9,67.8,71.5,75.3,71.4,68.0,63.7,60.2,56.3,52.5,48.8}；

(σ_1i)₂₁＝{184.9,188.4,192.3,196.6,200.4,204.9,208.6,212.5,208.4,204.1,200.7,196.5,192.3,188.6,184.5}；

(σ_1i)₃₁＝{176.4,179.8,182.5,185.7,188.4,191.5,194.7,197.6,194.2,191.3,188.6,185.7,182.4,179.6,176.1}；

(σ_1i)₄₁＝{190.8,192.4,194.7,196.9,199.5,201.3,203.4,205.3,202.5,200.1,198.6,196.3,194.7,192.1,190.4}。

g. determine if k is ≦ N? If not, making k equal to k +1, and going to step e, otherwise, h.

h. Determine if the objective function f (x) is minimal? If yes, otherwise, searching the step length again, and resetting the roll bending compensation coefficient eta_1j，η_2j，ξ_1j，ξ_2jTo step f, the objective function f (x) is:

the minimum value of the objective function is calculated to be f (x) 2.19, and the process proceeds to step i.

i. Judging the constraint condition, the total bending of the compensated working roll and the intermediate rollThe roll force is within the allowed roll bending force range,is there any? And (5) calculating to meet constraint conditions, and turning to the step j.

j. Output 1-4 optimum compensation coefficient X ═ eta (eta) for bending force of working roll and intermediate roll of machine frame_1j,η_2j,ξ_1j,ξ2j)，

η₁j＝{-1.12，-1.23，-0.98，-1.51}，η₂j＝{-0.0050，-0.0048，-0.0051，-0.0043}；ξ_1j＝{-0.98，-0.92，-0.101，-0.86}，ξ_2j＝{0.0041，0.0058，0.0047，0.0051}。

The change rule of the speed of the 4 th rack in the speed increasing and decreasing process is shown in the attached figure 3, and a three-dimensional graph of the plate shape after the compensation by the roller bending compensation technology taking the plate shape control as the target in the speed increasing and decreasing process of the cold continuous rolling unit is shown in the attached figure 4.

Example 2: the steel grade is DP0161D1, and the specification is 1.621 × 1170 mm.

Firstly, collecting main equipment process parameters of a cold continuous rolling unit, and mainly comprising the following steps: 1-5 frame work roll diameter D_jw455mm, intermediate roll diameter D_jm430mm, support roll diameter D_jb1370mm, length L of working roll body of 1-5 machine frames_jw1850mm, length L of intermediate roll body_jm1850mm long and supporting roller body length L_jb1850mm, 1-5 rack screw down pitch l_jw4050mm, screw pitch l between intermediate rollers_jm4050mm, support roller screw down pitch l_jbWork roll minimum bending force (S) of 4070mm, 1-5 stands_w)_jmin-800KN and maximum roll bending force (S)_w)_jmaxMaximum bending force (S) of the intermediate roll (800 KN)_m)_jmin-800KN and minimum roll bending force (S)_m)_jmax800KN, 210Gpa of working roll elastic modulus E, 0.3 of working roll Poisson ratio v, and eta of dynamic viscosity of rolling oil₀0.02 pas, an emulsion concentration influence coefficient kc of 1.836, and a viscosity compression coefficient theta of 0.01Mpa^-1Roll roughness versus lubricant film thicknessInfluence quantity ζ₀0.178, 0.0114 for liquid lubrication friction influence coefficient a, 0.1158 for dry friction influence coefficient B, and B for friction coefficient attenuation index_ξ＝-5.823。

b. Collecting technological parameters of a strip steel acceleration and deceleration section produced by a cold continuous rolling unit, and mainly comprising the following steps: transverse thickness distribution H of incoming material_ikTaking the 1 st segment of the speed increasing and decreasing process as an example:

H_i1-2.652, 2.683,2.711,2.726,2.742,2.751,2.769,2.781,2.772,2.756,2.745,2.723,2.710,2.691,2.663}, width B of strip steel 1170mm, strength σ of strip_s550MPa, deformation resistance k₁₀＝560Mpa，k₂₀＝k₁₁＝612Mpa，k₃₀＝k₂₁＝696Mpa，k₄₀＝k₃₁＝751Mpa，k₅₀＝k₄₁＝795Mpa，k₅₁824Mpa, 1-5 rack inlet and outlet thicknesses, section 1 of the ramp process as an example (h)₀)₁₁＝2.7mm，(h₁)₁₁＝(h₀)₂₁＝2.41mm，(h₁)₂₁＝(h₀)₃₁＝2.12mm，(h₁)₃₁＝(h₀)₄₁＝1.86mm，(h₁)₄₁＝(h₀)₅₁＝1.68mm，(h₁)₅₁1.62mm, a set value epsilon of the reduction ratio of 1-5 frames_j10.78%, 12.04%, 12.03%, 10.01%, 0.41% } and the actual value ε_jkTaking section 1 of the speed-up and speed-down process as an example, epsilon_j11-5 frame unit front-to-back tension (σ), 14.56%, 16.81%, 16.82%, 12.21%, 4.0% }₀)₁＝78.3Mpa，(σ₁)₁＝(σ₀)₂＝201.8Mpa，(σ₁)₂＝(σ₀)₃＝196.5Mpa，(σ₁)₃＝(σ₀)₄＝185.3Mpa，(σ₁)₄＝(σ₀)₅＝181.7Mpa，(σ₁)₅Working roll bending force set value S of 1-5 frames under 69.5Mpa_wj300KN,290KN,310KN,290KN,406KN, and intermediate roll bending force setting S_mj{320KN,300KN,300KN,300KN,440KN }, roll inclination set value χ_jSet value of roll shifting amount is 01-5 frame emulsion flow w_j3450L/min, 4609L/min,4801L/min,4109L/min,2450L/min, concentration C_j10% of emulsion temperature T_jkSet value V of rolling speed of 1-5 stands at 50 DEG C_j ^*(300 m/min,352m/min,405m/min,428m/min,445 m/min), rolling pressure setpoint P_j＝{1430t,1360t,1330t,1240t,1105t}。

c. Setting the initial value eta of the roll bending force compensation coefficient of the working roll and the intermediate roll of the 1-4 machine set_1j＝{0.1,0.1,0.1,0.1}，η_2j＝{0.001,0.001,0.001,0.001}，ξ_1j＝{0.1,0.1,0.1,0.1}，ξ_2jLet the optimization step i equal to 1,0.001,0.001,0.001 }.

d. Dividing the process of accelerating and decelerating the rolled strip into k sections, and initializing k to 1.

e. Calculating 1-4 frame speed per section v_jkCorresponding oil film thickness ζ_jkCoefficient of friction mu_jkRolling force P_jk：

K_mj＝k_0j+k_1j/2；

In the formula, xi_j＝0.3σ_j0+0.7σ_j1，Δh_jk＝(h₁)_jk-(h₀)_jk。

Taking the 1 st section of the speed increasing and decreasing process as an example, calculating the oil film thickness, the friction coefficient and the rolling force of 1-4 frames:

ζ_j1＝{0.314um,0.345um,0.296um,0.298um}，

μj₁＝{0.1128,0.1005,0.0981,0.0876},

P_j1＝{1550t,1495t,1472t,1340t,1256t}。

f. calculating v_jkCorresponding delta (S)_w)_jk，Δ(S_m)_jk，(σ_1i)_jk：

Wherein, γ_1j＝{0.26,0.26,0.26,0.26}，γ_2j0.12,0.12,0.12,0.12 }; taking the 1 st segment in the speed increasing and decreasing process as an example, the roll bending force compensation value of the 1-4 frames is as follows:

Δ(S_w)_j1＝{53.14KN,51.36KN,41.23KN,47.42KN}；

Δ(S_m)_j1＝{24.52KN,23.7KN,19.03KN,21.89KN}；

1-4 the calculated compensated front tension for the frame is:

(σ_1i)₁₁＝{189.4,193.7,197.2,201.6,205.8,209.4,213.7,217.5,213.8,209.4,205.9,201.6,197.4,193.6,189.1}；

(σ_1i)₂₁＝{182.7,186.4,190.1,193.4,197.3,200.6,204.2,207.5,204.1,200.7,197.1,193.5,189.8,186.1,182.8}；

(σ_1i)₃₁＝{176.3,197.5,182.6,185.4,188.3,191.7,194.1,197.3,194.4,191.6,188.7,185.6,182.9,179.4,176.1}；

(σ_1i)₄₁＝{175.3,177.6,179.8,181.1,182.4,183.1,189.7,187.5,185.4,183.2,181.5,179.6,177.4,175.2}。

g. determine if k is ≦ N? If not, making k equal to k +1, and going to step e, otherwise, h.

h. Determining an objective functionF (x) is minimal? If yes, otherwise, searching the step length again, and resetting the roll bending compensation coefficient eta_1j，η_2j，ξ_1j，ξ_2jTo step f, the objective function f (x) is:

the minimum value of the objective function is calculated to be f (x) 5.12, and the process proceeds to step i.

i. Judging the constraint condition, the total roll bending force of the compensated working roll and the intermediate roll is in the allowed roll bending force range,is there any? And (5) calculating to meet constraint conditions, and turning to the step j.

j. Output 1-4 optimum compensation coefficient X ═ eta (eta) for bending force of working roll and intermediate roll of machine frame_1j,η_2j,ξ_1j,ξ_2j)，

η₁j＝{1.32，1.11，1.24，0.96}，η₂j＝{0.0065，-0.0052，-0.0047，0.0061}；

ξ_1j＝{0.81，1.12，0.41，1.22}，ξ_2j＝{-0.0039，-0.0052，0.0031，-0.0072}。

The change rule of the speed of the 4 th rack in the speed increasing and decreasing process is shown in the attached figure 5, and the three-dimensional graph of the plate shape after the compensation by the roller bending compensation technology taking the plate shape control as the target in the speed increasing and decreasing process of the cold continuous rolling unit is shown in the attached figure 6.

In the cold continuous rolling mill set, the on-line adjustment of the plate shape by the bending roll force has the characteristic of flexibility and changeability, and the increase of the bending roll force is equivalent to the reduction of the rolling force, so that the edge wave defect of the plate shape is improved; on the contrary, reducing the roll bending force is equivalent to increasing the rolling force, so that the defect of the plate shape middle wave is improved. During rolling, the roll bending force of 1-4 stands is generally set in a high-speed state, and the roll bending force of the 5 th stand can be automatically adjusted. The roll bending force changes the shape of the loaded roll gap to realize the online control of the shape, so that the roll bending force compensation is adopted by the 1-4 frames to control the shape in the speed increasing and reducing stage. In the past, the plate shape regulation and control in the acceleration and deceleration process of the cold continuous rolling unit generally adopts tension compensation rolling force or roller bending force to compensate rolling force, and the final plate shape fluctuation size is not considered. According to the invention, the minimum plate shape fluctuation in the speed increasing and reducing stage in the rolling process of the cold continuous rolling mill set is realized by comprehensively optimizing the roll bending force of the working roll and the middle roll, the field production cost of the cold continuous rolling mill set is reduced, and the plate shape in the speed increasing and reducing stage is improved.

As shown in fig. 7, the present invention also provides a roll bending compensation system targeting the strip shape control, comprising:

and the setting module 701 is used for setting the initial values of the compensation coefficients of the bending forces of the working rolls and the intermediate rolls of the 1-4 frames and optimizing the step length.

The dividing module 702 is used for dividing the rolling strip material speed increasing and decreasing process into a plurality of sections.

The first calculating module 703 is configured to calculate, for each section, an oil film thickness, a friction coefficient, and a rolling force corresponding to the speed of the 1-4 stand based on the collected process parameters of the equipment in the cold continuous rolling mill and the collected process parameters of the strip steel production acceleration/deceleration section of the cold continuous rolling mill.

A second calculating module 704, configured to calculate, for each segment, a working roll bending force compensation value, an intermediate roll bending force compensation value, and a compensated front tension corresponding to the 1-4 frame speed based on the initial compensation coefficient value;

an optimizing module 705, configured to construct an objective function according to the compensated front tension, and optimize the compensated front tension through the objective function.

And a determining module 706, configured to determine an optimized work roll bending force compensation value and an optimized intermediate roll bending force compensation value according to the optimized pre-compensation tension.

And the compensation module 707 is configured to compensate the working roll bending force of the 1-4 rack based on the optimized working roll bending force compensation value, and compensate the intermediate roll bending force of the 1-4 rack based on the optimized intermediate roll bending force compensation value.

And the judging module 708 is used for judging whether the work roll bending force after the compensation of the 1-4 frames and the middle roll bending force after the compensation are in the constraint range.

And an optimal compensation coefficient determining module 709, configured to determine optimal compensation coefficients for the work roll bending force and the intermediate roll bending force when the compensated work roll bending force and the compensated intermediate roll bending force of the 1-4 frames are within the constraint range.

And the resetting module 7010 is used for resetting the 1-4 machine frame working roll and intermediate roll bending force compensation coefficients when the 1-4 machine frame compensated working roll bending force and the compensated intermediate roll bending force are not in the constraint range.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.