An online calculation method for dynamic coupling roll profile of hot rolling

Abstract

The present invention provides an online calculation method for the dynamic coupling roll shape of hot rolling, which relates to the field of metallurgical equipment automation, including the forward setting and reverse real-time iteration of the coupled roll shape of each frame, obtaining the deviation curve between the optimal target roll shape and the online predicted roll shape, and using the elastic roll shape and the shifting roll shape to quickly adjust the load roll gap shape on the basis of identifying the original roll shape and the worn roll shape as short-term static factors, while considering the time lag conditions to avoid the previous experience control mode of the roll gap shape of a single factor or a single frame. Therefore, based on complex rolling conditions or rolling rhythms, it is very necessary to perform weighted optimization of each roll shape according to this strategy, which can not only deeply study the coupling degree of the static roll shape, but also facilitate the coupling setting of dynamic factors, so that the associated roll shape parameters can be adjusted in real time according to the actual target requirements, and finally obtain high-quality hot-rolled strip products that meet the shape and size index requirements.

Description

Technical Field

[0001] The invention relates to the field of automation of plastic processing equipment, and in particular to an online calculation method for a dynamic coupling roll profile of hot rolling. Background Art

[0002] Hot-rolled strip is the raw material of many industrial products or the incoming material of downstream cold-rolled products. Its transverse thickness difference or plate crown and edge drop are always the key indicators of hot-rolled strip quality, which directly determine the plate shape, warping degree and deviation range of the rolled strip. In the process of multi-pass continuous rolling, the rolls of each stand are affected by different loads, temperatures and wear, resulting in the dynamic change of the actual load roll gap shape with the rolling rhythm or variable specifications, which will affect the forming quality or shape size of the rolled piece to a certain extent. Based on the actual situation, the traditional roll gap adjustment methods mainly include two types: one is the offline design of the original roll shape and the grinding roll, and the other is the online adjustment of the roll gap shape by using the shifting roll, bending roll and tilting roll. On the basis of these two basic roll shapes, semi-empirical and semi-theoretical hot roll shapes and wear roll shapes are established based on actual experience and mathematical models. In the production process, the appropriate hot roll shape is first obtained through the hot roll, and the wear amount is estimated according to the amount of steel passing, and the load roll gap shape is fine-tuned.

[0003] However, in the actual control process, due to the lack of working conditions and measurement methods, the actual transverse roll gap shape cannot be measured, which depends to a large extent on the feedback of the mill force and energy parameters and the measurement of the post-rolling shape indicators. The previous thickness control was the thickness AGC control at the center of the bandwidth, which is a relatively mature technology at present. With the increasing requirements for the performance and shape and size accuracy of hot-rolled strip, the control of the rolling process has become increasingly demanding, especially the precise control of the transverse distribution of the roll gap, or the accurate control of the transverse thickness difference of the strip to achieve good plate shape, plate convexity, and accurate control of edge drop, deviation, and warping. Up to now, on the one hand, the calculation accuracy and efficiency of the rolling model are improved, and on the other hand, the data regression and empirical trial and error of the rolling process are carried out by combining online big data and offline measured indicators. This method will cause fluctuations in rolling parameters, a long multi-parameter nonlinear control cycle, and more reliance on field experience, resulting in inaccurate results. Summary of the invention

[0004] In view of this, the purpose of the present invention is to propose an online calculation method for the dynamic coupling roll shape of hot rolling, split different roll shape curves according to the online roll gap shape, and perform online setting of the dynamic coupling roll shape of each frame of hot rolling by weighted coupling. Using this method, on the one hand, it is convenient to deeply analyze the influence mechanism of single factors on the lateral distribution law of load roll gap, and on the other hand, it can accurately calculate the cascade characteristics of the coupling characteristics of various factors on the online load roll shape. The online setting of roll shape using different operating parameters is conducive to the dynamic regulation of the complex roll gaps of each frame of hot rolling, replacing the traditional manual mode that relies too much on experience. At the same time, it can be set in advance according to the rolling plan to minimize the roll shape deviation caused by operating condition fluctuations. Solve the problem of rolling parameter fluctuations in the prior art and ultimately improve the accuracy of plate shape and plate convexity.

[0005] The technical means adopted by the present invention are as follows:

[0006] An online calculation method for hot rolling dynamic coupling roll profile comprises the following steps:

[0007] The online load roll profile is divided into original roll profile, hot roll profile, worn roll profile, elastic roll profile and asymmetric roll profile caused by roll shifting;

[0008] The original roller shape, the hot roller shape, the worn roller shape, the elastic roller shape, and the asymmetric roller shape are respectively subjected to weighted processing to obtain a coupled roller shape;

[0009] The coupling roller profile is coupled and solved by using a roller system elastic deformation model and a metal plasticity model to obtain an online load roller gap shape;

[0010] Iterative optimization of the online load roll gap shape that meets the convergence conditions of each pass;

[0011] According to the optimized online load roll gap shape, the best setting parameters of rolling force, bending roll force, roll shifting displacement and rolling speed of each stand are obtained;

[0012] Online adjustment of the rolling force, bending roll force, shifting roll displacement and rolling speed of each stand to meet the optimal setting parameters and serve as verification parameters;

[0013] Obtain the current best online load roll gap shape;

[0014] Obtain measured data of plate shape and plate convexity after rolling;

[0015] According to the verification parameters and the measured data of the plate shape and plate convexity after rolling, the weighting factors of each roll type are obtained by reverse inference and adaptive adjustment;

[0016] An online roll profile target setting curve that meets different working conditions is obtained according to the roll profile weighting factor.

[0017] Furthermore, the formula of the coupling roller type is:

[0018] C z =ξ(λ o C o +λ T C T +λ a C a +λ d C d +λ s C s )+(1-ξ)C z0

[0019] Among them, C o Original roller type; C T It is hot roller type; C a For wear roller type; C d For elastic roller type; for C s Asymmetric roller profile; o is the original roll shape weighting factor; T is the heat roller type weighting factor; a is the weighting factor of the wear roller profile; d is the elastic roller weighting factor; s is the asymmetric roll weighting factor; C z0 is the set roller profile curve of the last similar working condition; ξ is the current adaptive adjustment factor.

[0020] Furthermore, the process of obtaining the coupling roller profile is as follows:

[0021] The elastic roll profile is solved according to the roll system elastic deformation model, the thermal roll profile curve is calculated using the roll temperature field, and the worn roll profile is calculated using a semi-empirical and semi-theoretical model;

[0022] The hot roll profile and the worn roll profile are weighted separately;

[0023] At the same time, the weighted original roll profile and the asymmetric roll profile are superimposed;

[0024] According to the reduction and rigidity of the operating side and the transmission side of the rolling mill, the online load roll gap shape is calculated to obtain the curve expression of the exit transverse thickness difference;

[0025] According to the curve expression of the transverse thickness difference, the pre-tension stress deviation used to represent the plate shape state is obtained based on the metal deformation model.

[0026] Furthermore, the outlet transverse thickness difference distribution curve expression is:

[0027] Δh(y)=ψ(C 0 ,λ,P,F w ,μ,k s ,v,T)

[0028] Among them, C 0 is the convexity of the incoming material; λ is the reduction rate; P is the rolling force; F w is the bending roller force; μ is the friction coefficient; k s is the deformation resistance; v is the rolling speed; T is the rolling temperature; y is the bandwidth direction.

[0029] Furthermore, when coupling and solving the coupling roller profile, a polynomial higher than sixth order is used to fit the roller gap shape.

[0030] Furthermore, the elastic roller type includes an elastic bending roller type and an elastic flattening roller type.

[0031] Furthermore, the application method of the online roll shape target setting curve comprises the following steps:

[0032] Automatically select the target roll profile curve that is closest to the current working condition from the sample database;

[0033] The predicted roll profile curve of the model is used as the current "soft measurement" measured value to obtain the deviation curve;

[0034] Set the roller shape according to the online target and adjust the transverse thickness difference of each pass online;

[0035] The rolling force, bending roll force, lateral displacement, cooling water volume and rolling rhythm are used to adjust the online load roll gap in real time.

[0036] Synchronously optimize the priorities of plate shape and plate convexity to ensure in real time that the edge drop, plate shape, plate convexity and temperature of the strip after rolling in the last stand meet the set targets respectively.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The present invention designs an online calculation method for the dynamic coupling roll shape of hot rolling, synchronously couples the original roll shape, hot roll shape, worn roll shape, deflected (including flattened) roll shape and antisymmetric shifting roll shape, and performs necessary weighted processing according to the actual working conditions to obtain the current load roll shape, and then accurately calculates the online roll gap shape according to the displacement and stiffness of the two sides of the rolling mill. On the one hand, according to the coupling calculation of the roll system elastic deformation model and the metal plastic deformation model, the target roll shape of each frame is set in reverse to improve the prediction accuracy of the plate shape and plate convexity of each frame; on the other hand, according to the current working conditions, the real-time lateral thickness difference change of each frame is forwardly calculated to accurately control the plate shape and plate convexity of each frame, and finally ensure the shape and size of the strip at the outlet of the finishing mill. This method is conducive to obtaining ideal control strategies using theoretical models, and is also convenient for timely feedback control of current rolling parameters in combination with actual working conditions. It can also conduct targeted theoretical research, experiments or measured analysis based on the weighting factors of various types of roll shapes, thereby maximizing the dynamic coupling roll shape accuracy of each working condition and each frame, and ultimately obtaining accurate quantitative control effects, replacing the previous qualitative control mode based on a large amount of manual experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 This is a diagram of the online setting process of the dynamic coupling roll type of hot rolling according to the present invention.

[0041] Figure 2 This is a diagram of the basic control method of the hot rolling dynamic coupling roll type of the present invention.

[0042] Figure 3 This is an online control diagram of the dynamic coupling roll type of hot rolling in the present invention.

[0043] Figure 4 This is an offline verification diagram of the hot rolling dynamic coupling roll type of the present invention. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] The present invention provides an online calculation method for a dynamic coupled roll profile of hot rolling. The online setting method divides the online load roll profile into an original roll profile, a hot roll profile, a worn roll profile, an elastic deflection (including flattening) roll profile and an asymmetric roll profile caused by roll shifting. After weighted processing is performed on these types of roll profiles, the roll system elastic deformation model and the metal plasticity model are coupled to solve the online load roll gap shape that meets the convergence conditions of each pass, and the online load roll gap shape that meets the convergence conditions of each pass is iteratively optimized. In addition, the rolling force, bending roll force, roll shifting displacement and rolling speed measured by each frame are used as verification parameters, and the roll profile parameters are reversely deduced in combination with the measured data of the plate shape and plate convexity after rolling, so as to finally form an online roll profile target setting curve that meets different working conditions. In the production process, the roll profile is set according to the online target, the lateral thickness difference of each pass is adjusted online, the priority of the plate shape and the plate convexity is optimized synchronously, and it is ensured in real time that the edge drop, plate shape, plate convexity and temperature of the strip after rolling in the last frame meet the set targets respectively.

[0047] First, set the room temperature original roll shape C o , hot roller type C T , Wear roller type C a , Elastic flexure (including flattening) roller type C d And the antisymmetric roller shape C caused by roller shifting s , weight the above roller profiles to obtain the coupling roller profile C z for

[0048] C z =ξ(λ o C o +λ T C T +λ a C a +λ d C d +λ s C s )+(1-ξ)C z0 (1)

[0049] where λ o ,λ T ,λ a ,λ d ,λ s are the adaptive weighting factors corresponding to the above roller types, which are converted based on the measured results and the current working conditions. z0 The set roll profile curve of the last similar working condition, ξ is the current adaptive adjustment factor, which is used to stabilize the current rolling conditions.

[0050] In theoretical calculation, the elastic (deflection and flattening) roll profile is solved according to the roll system elastic deformation model, the hot roll profile curve is calculated using the roll temperature field, and the wear roll profile is calculated using a semi-empirical and semi-theoretical model. On the basis of the above roll profiles, after superimposing the original roll profile at room temperature and the anti-symmetric roll profile caused by roll shifting, the load roll gap shape is accurately calculated according to the reduction and stiffness on the operating side and the transmission side of the rolling mill, and the outlet transverse thickness difference Δh(y) distribution curve is obtained, which is expressed as the incoming material convexity C 0 , reduction rate λ, rolling force P, bending roll force F w , friction coefficient μ, deformation resistance k s , rolling speed v, rolling temperature T, let y be the transverse coordinate (bandwidth direction), then

[0051] Δh(y)=ψ(C 0 ,λ,P,F w ,μ,k s ,v,T) (2)

[0052] According to the transverse thickness difference expression, the pre-tension stress deviation Δσ can be obtained based on the metal deformation model. 1 Or converted into the flatness I distribution, both can be used to represent the plate shape. When performing the coupled calculation of the roll system elastic deformation model and the metal model, in order to improve the calculation efficiency and consider the roll gap changes caused by roll shifting (or lateral movement), a polynomial higher than 6th order is needed to fit the roll gap shape.

[0053] In order to simultaneously consider the genetic effect brought about by the change of the transverse thickness difference of each frame, the transverse thickness difference of the front frame is used as the initial value of the entrance of the lower frame. First, the small cycle iterative calculation of each frame is performed, and then the progressive large cycle iterative calculation of each frame is performed, and finally the convexity and shape of the export plate meet the set convergence conditions. In the previous calculation process, the convexity deviation caused by the heredity of this parameter between frames is often ignored, which will lead to the accumulated error of each frame, and finally affect the inconsistency between the calculated value and the actual value of the convexity of the export plate shape. In the new method, not only the transverse thickness difference is used as a genetic condition, but also the key parameters such as speed, temperature, and tension of the rolling process and between frames will change due to changes in working conditions, so they all need to be added to the coupling model of the lower frame as initial conditions.

[0054] Secondly, in actual application, the rolling process often faces periodic changes, and the rolling conditions are randomly changed according to the rolling plan, which will cause obvious changes in the roll shape, resulting in mismatch with the strip cross-section formation. Therefore, in the calculation process, it is necessary to use the metal coupling model to pre-set the calculation according to the furnace discharge temperature, the rough rolling intermediate billet temperature and cross-sectional shape, and the finishing mill inlet temperature, and set the target roll shape curve of each frame according to the original roll shape, hot roll shape, and worn roll shape of each frame; on this basis, the deflection (including flattening) roll shape caused by the deformation of the roll system and the antisymmetric roll shape are used to adjust the load roll shape online to meet the lateral thickness difference requirements of each frame, and finally meet the export plate shape and plate convexity in line with the current target requirements.

[0055] During the control process, in order to better match the requirements of the outlet lateral thickness difference and minimize stubborn problems such as running, warping, and edge drop, the outlet lateral thickness difference (or plate shape and plate convexity) is used as the feedback control target. Considering the inheritance, the single-stand calculation of the above-mentioned roller shape is performed in reverse for each stand, so that it can better meet the preset roller shape curve of the same model, ensuring that the mean square deviation between the target set roller shape and the real-time calculated roller shape is as small as possible.

[0056] In addition to fine-tuning the transverse thickness difference, it is also necessary to adjust the contradictory relationship between the plate convexity and the plate shape, which requires the classification of working conditions according to the rolling requirements. Under normal circumstances, the plate convexity is adjusted intensively in the previous pass, and the transverse thickness difference deviation at the entrance and exit is greatly changed to obtain a cross-sectional shape as close to the ideal rectangle as possible; in the subsequent stands, the transverse thickness difference deviation at the entrance and exit is gradually reduced to improve the control effect of the plate shape. However, in the actual process, the plate convexity control amount is often insufficient due to the problem of the load roller shape in the previous pass, and it may cause obvious edge drop or local high points, which greatly affects the plate shape control effect of the subsequent stands, and it is impossible to obtain a good plate convexity or a good plate shape.

[0057] Based on the above problems, on the basis of optimizing the roll gap shape of each frame load, the actual transverse thickness difference of the strip is adjusted in a progressive way, so as to change the contradictory relationship between the plate shape and the plate convexity. After each frame iteration converges, its outlet transverse thickness difference, plate shape and plate convexity are used as initial conditions, and the positive iteration of the next frame is carried out to make it meet the corresponding preset control target. Finally, the transverse thickness difference, plate shape and plate convexity at the outlet of the finishing mill are used as evaluation indicators, and the corresponding deviation curve is obtained after comparison with the set target of the last frame. The degree of deviation determines whether it is completely converged. If it converges, the stable working condition is maintained, and the deviation caused by the fluctuation of the rolling parameters is calculated and monitored in real time to see if it exceeds the limit. If it does not converge, it will be re-iterated from the entrance of the first frame of the finishing mill, and the core parameters of each frame are quickly adjusted to approach the convergence condition or meet the deviation downward trend.

[0058] The purpose of the present invention is to provide an online setting method for dynamic coupling roll profile of hot rolling, which determines that the lateral shape of the online load roll gap is the effect of the coupling roll profile, wherein the coupling roll profile is divided into original roll profile, hot roll profile, elastic roll profile, worn roll profile and shifted roll profile, which is completely different from the traditional single setting of roll profile curve, avoiding the randomness of a single roll profile curve, and facilitating the synchronization of the coupling of different roll profile curves; in addition, in the regulation process, according to the weighting factors of different roll profiles, the roll profile parameters with small weight coefficients are set to be approximately short-term static, which is convenient for a certain Fine control of the roll shape, using the existing rolling conditions (rolling parameters, rolling mill stiffness, and reduction system) to set the optimal target for the coupled roll shape of each stand, adjust the rolling parameters, and use the roll system model and metal model to predict the current coupled roll shape or load roll gap shape in real time, so that it is as close to the optimal target setting as possible, thereby obtaining the minimum deviation; this method is convenient to reversely calculate the lateral thickness difference changes of different stands based on the dynamic change law of a single roll shape and the coupled roll shape relationship, thereby realizing the process of forward target setting and reverse feedback control of each stand.

[0059] The method for setting the dynamic coupling roll shape of hot rolling described in the present invention comprises the following steps: first, based on the temperature field model, the roll system elastic deformation model and the metal deformation model, the changes of the hot roll shape, the elastic roll shape, the worn roll shape and the shifted roll shape under the fixed original roll shape are calculated, and after obtaining the weighted factors, an ideal coupling roll shape curve under the conditions of a specific rolling mill model is formed; on the basis of the theoretical model, according to the actual online working conditions and the offline measured data, the temperature, the lateral thickness difference (plate shape and plate convexity) and the worn roll shape are calibrated to verify the accuracy of the ideal coupling roll shape, and the weighted factors are used to calculate the ideal coupling roll shape curve under the conditions of a specific rolling mill model .... Through the self-adaptation and self-learning of the sub-module, a coupled roll profile curve that is closer to the actual working condition is obtained; in actual application, the target roll profile curve that is closest to the current working condition is automatically selected from the sample database, and then the predicted roll profile curve of the model is used as the current "soft measurement" measured value. After obtaining the deviation curve, the rolling force, bending roll force, lateral displacement, cooling water volume and rolling rhythm are used to perform real-time regulation of the online load roll gap, and finally meet the preset lateral thickness difference (plate shape and plate convexity), minimizing the problems of warping, edge drop, edge protrusion, wedge and deviation.

[0060] like Figure 1The sequence and control strategy of several roller profiles of the above-mentioned single stand are shown. For a single stand, firstly, the original roll shape at room temperature is ground according to the grinding roll curve, which is the initial condition for roll shape optimization; after the new roll is put into the machine, the geometric roll shape after the roll shifting is calculated according to the rolling mill characteristics, and the basic coupled roll shape of the original roll shape and the shifted roll shape is obtained; during the rolling process, it is necessary to calculate the elastic deflection (including flattening) roll shape under the current rolling parameters according to the roll system elastic deformation model and the metal deformation model, so as to realize the transient coupled roll shape that meets the rolling conditions, which can meet the rolling requirements to a certain extent and predict the actual roll gap lateral distribution law under specific rolling parameters; however, in the actual rolling process, on the one hand, due to the heat transfer of the high-temperature strip steel, on the other hand, due to the periodic or random changes in the rolling rhythm, it will bring about obvious dynamic thermal roll shape changes, which is the key factor causing the frequent fluctuations of the load roll gap, and the parameter fluctuations of a single stand will also directly affect the roll shape changes of other stands. Therefore, in the above model, the thermal roll shape is the key factor to be considered, and it needs to be calculated periodically, considering the time lag or thermal conductivity of the temperature, and using the transient thermal equilibrium temperature field to calculate the current thermal roll shape change characteristics.

[0061] Figure 2 The basic process of setting the coupling roll profile in multiple passes of hot rolling is shown. According to the incoming material convexity (or intermediate billet convexity) and the F1 (first stand of the finishing mill) coupling roll profile conditions set by the rolling mill, the outlet convexity of F1 is calculated using the roll system elastic deformation model and the metal deformation model, and compared with the set F1 target convexity to obtain the convexity deviation of F1. After the convergence condition is met, the deviation calculation of the next pass is carried out based on the basic conditions. After the cycle calculation is completed, observe whether the convexity deviation of the last stand (such as F5) meets the requirements, or whether it corresponds to the actual post-rolling convexity and plate shape, so as to judge the reliability and accuracy of the set target. If the deviation exceeds the convergence condition, it is repeated from F1. During the forward setting process, if the rolling conditions change, a new coupling roll profile setting is performed based on the new rolling parameters to meet the actual working conditions.

[0062] Figure 3The adjustment strategy after the above working conditions change is shown. Under the current working conditions, the coupled roll profile is used to obtain a stable rolling state and a relatively stable thermal balance condition. At this time, the benchmark is set according to the target hot roll profile in the standard sample library to compensate for the roll gap deviation of the original roll profile, and with the assistance of the elastic roll profile, the wear roll profile and the shifting roll profile, a fixed load roll gap shape and the lateral thickness difference of the exit strip are formed. Among them, the elastic roll profile and the shifting roll profile are used to adjust the load roll gap shape in real time, and the hot roll profile is used to adjust the local wear roll profile or local strip thickness difference (such as edge drop or edge protrusion) caused by local roll profile problems. After offline actual measurement of the hot roll profile and the wear roll profile, the prediction accuracy of the theoretical model is reversely verified, and the grinding roll profile (i.e., the original roll profile) is redesigned or optimized on this basis. This can greatly reduce the load roll gap shape deviation caused by other roll profile fluctuations.

[0063] Figure 4 The typical verification process of hot roll profile is given. In previous studies, the influence of rolling rhythm on hot roll profile is often ignored. Basically, the hot roll profile is measured under ideal continuous rolling conditions, which leads to a large deviation from the actual hot roll profile. In order to eliminate the influence of rolling rhythm on hot roll profile as much as possible, on the one hand, the rolling rhythm is stabilized, or the hot roll profile characteristics under a specific rolling rhythm are classified and formulated, and the equivalent hot roll profile of the mixed rolling rhythm is calculated, that is, necessary idealized assumptions are made and necessary temporary static processing is performed; on the other hand, the inheritance factors of different rolling rhythms are considered, from the beginning of rolling, intermittent slow rolling, faulty stop rolling, water volume changes, nozzle blockage, etc., according to the actual number of steel passing in the rolling rhythm, according to the changes in the working conditions in the time history, the online temperature field and hot roll profile are calculated in real time to ensure the continuity and real-time nature of the working conditions. After the rolls are off the mill, the actual measurement of the temperature field and even the hot roll profile is carried out within a fixed time (10-15 minutes), and the actual comparison is carried out with the prediction model to feedback the correctness of the online model. Finally, based on the application of hot roll type, and referring to the convexity, plate shape, edge drop and edge protrusion of the strip, and comprehensively considering the influence of other roll types, the original roll type is optimized and high-precision ground to better meet the setting conditions of the coupled roll types of each stand. At the same time, real-time online feedback control is performed in a reverse manner, ultimately ensuring the shape control accuracy of the outlet lateral thickness difference (plate shape and plate convexity) of the final rolling stand.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An online calculation method for hot rolling dynamic coupling roll profile, characterized in that: The steps include: The online load roll profile is divided into original roll profile, hot roll profile, worn roll profile, elastic roll profile and asymmetric roll profile caused by roll shifting; The original roller shape, the hot roller shape, the worn roller shape, the elastic roller shape, and the asymmetric roller shape are respectively subjected to weighted processing to obtain a coupled roller shape; The formula for the coupling roller type is: in, It is the original roller type; It is a hot roller type; It is a wear roller type; It is an elastic roller type; Asymmetric roller profile; is the original roll profile weighting factor; is the heat roller type weighting factor; is the weighting factor of the wear roller profile; is the elastic roller type weighting factor; is the asymmetric roll profile weighting factor; The set roller profile curve for the last similar working condition; is the current adaptive adjustment factor; The coupling roller profile is coupled and solved by using a roller system elastic deformation model and a metal plasticity model to obtain an online load roller gap shape; Iterative optimization of the online load roll gap shape that meets the convergence conditions of each pass; According to the optimized online load roll gap shape, the best setting parameters of rolling force, bending roll force, roll shifting displacement and rolling speed of each stand are obtained; Online adjustment of the rolling force, bending roll force, shifting roll displacement and rolling speed of each stand to meet the optimal setting parameters and serve as verification parameters; Obtain the current best online load roll gap shape; Obtain measured data of plate shape and plate convexity after rolling; According to the verification parameters and the measured data of the plate shape and plate convexity after rolling, the weighting factors of each roll type are obtained by reverse inference and adaptive adjustment; Obtaining an online roll profile target setting curve that meets different working conditions according to the roll profile weighting factor; The process of obtaining the coupling roller profile is as follows: The elastic roll shape is solved according to the roll system elastic deformation model, the thermal roll shape is calculated using the roll temperature field, and the worn roll shape is calculated using a semi-empirical and semi-theoretical model; Weight the hot roll profile and the worn roll profile separately; At the same time, the weighted original roll profile and the asymmetric roll profile are superimposed; According to the reduction and rigidity of the operating side and the transmission side of the rolling mill, the online load roll gap shape is calculated to obtain the curve expression of the exit transverse thickness difference; According to the curve expression of the transverse thickness difference, the pre-tension stress deviation used to represent the plate shape state is obtained based on the metal deformation model.

2. The online calculation method for hot rolling dynamic coupling roll profile according to claim 1 is characterized in that: The outlet transverse thickness difference distribution curve expression is: in, is the convexity of the incoming material; is the reduction rate; is the rolling force; is the bending roll force; is the friction coefficient; is the deformation resistance; is the rolling speed; is the rolling temperature; The bandwidth direction.

3. The online calculation method for hot rolling dynamic coupling roll profile according to claim 1 is characterized in that: When coupling and solving the coupling roller profile, a polynomial higher than sixth order is used to fit the roller gap shape.

4. The online calculation method for hot rolling dynamic coupling roll profile according to claim 1 is characterized in that: The elastic roller type includes an elastic flexing roller type and an elastic flattening roller type.

5. The online calculation method for hot rolling dynamic coupling roll profile according to claim 1 is characterized in that: The application method of the online roll profile target setting curve comprises the following steps: Automatically select the target roll profile curve that is closest to the current working condition from the sample database; The predicted roll profile curve of the model is used as the current "soft measurement" measured value to obtain the deviation curve; Set the roller shape according to the online target and adjust the transverse thickness difference of each pass online; The rolling force, bending roll force, lateral displacement, cooling water volume and rolling rhythm are used to adjust the online load roll gap in real time. Synchronously optimize the priorities of plate shape and plate convexity to ensure in real time that the edge drop, plate shape, plate convexity and temperature of the strip after rolling in the last stand meet the set targets respectively.

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