A CVC roll control method and system for hot-rolled strip steel

Abstract

The present invention relates to the field of hot-rolled plate and strip rolling shape control, and discloses a CVC roller control method and system for hot-rolled plate and strip. Specifically, detailed grading calculations are performed based on the width and thickness of the strip to obtain a reasonably distributed CVC roller step length and bending roll force. Based on the collected disturbance factors, corresponding bending roll force compensation values and CVC roller step length compensation values are obtained, ultimately forming dynamic control of the CVC roller and bending roll. This method achieves a smooth transition of the CVC roller's channeling by optimizing the CVC roller step length limit. The system's control capability is improved by combining the linkage of the bending roll and the CVC roller. The deep coordination of static setting and dynamic adjustment improves the system's anti-disturbance capability, ensuring the stability of the roll gap and the strip shape quality.

Description

Technical Field

[0001] The present invention relates to the field of hot-rolled plate and strip steel rolling shape control, in particular to a CVC roller control method and system for hot-rolled plate and strip steel. Background Art

[0002] During the hot rolling process of strip steel, the control of CVC rolls (Continuous Variable Crown) and bending rolls is crucial to ensuring the crown and straightness of the strip steel. Existing bending rolls and CVC rolls are usually controlled separately on the hot rolling production line, and the bending rolls and CVC rolls are not effectively coordinated. When rolling thin-gauge strip steel, the control of the plate shape is more sensitive. Because the material is thinner, it is more likely to have problems such as edge waves and center waves. Traditional control methods often rely on fixed parameter settings and are difficult to adapt to various disturbances that occur during the rolling process of thin-gauge strip steel, resulting in uneven product thickness and low yield. Summary of the Invention

[0003] The purpose of the present invention is to provide a CVC roller control method and system for hot-rolled plate and strip steel in response to the problem that related technologies are difficult to adapt to the rolling of thin-gauge strip steel, which can effectively improve the adjustment ability of the roller gap and improve the plate shape, and is particularly beneficial to the rolling of thin-gauge strip steel and has good control stability.

[0004] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is a CVC roll control method for hot-rolled strip steel, comprising:

[0005] S1. Divide the thickness and width of the strip into multiple gears to form a data table of CVC roller step length limitation;

[0006] S2. Obtain the target thickness Hx and target width Bx of the strip, and obtain the correction value Sx of the CVC roller step limit of the stand in combination with the data table;

[0007] S3. Obtain the target roll gap crown C1, determine the CVC roll initial step length S0 and the actual CVC roll crown contribution C2 in combination with the correction value Sx, and obtain the initial roll bending force L to be compensated based on C1 and C2;

[0008] S4, based on the initial step length S0 of the CVC roll and the initial bending roll force L, the bending roll and the CVC roll are controlled to perform rolling, and multiple disturbance factors of the stand are collected in real time, each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roll step length compensation value required for each disturbance factor is calculated according to the threshold value;

[0009] S5. Obtaining a dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtaining a dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value;

[0010] S6. According to steps S2-S5, the CVC roller step length S0+ΔS and the bending roller force L+ΔLc corresponding to the rack Fi (i=1, 2, 3, 4, 5, 6, 7) are obtained, and the CVC roller and bending roller of the rack Fi are dynamically controlled.

[0011] In some optional embodiments, in step S4, the plurality of disturbance factors include rolling force fluctuation ΔP, strip transverse temperature gradient ΔT, and strip deviation ΔD, and are sequentially provided with corresponding first thresholds, second thresholds, and third thresholds;

[0012] When ΔP is greater than the first threshold, the bending roll force is adjusted first to obtain the bending roll force compensation value ΔLp; when ΔT is greater than the second threshold, the bending roll and CVC roll are adjusted synchronously to obtain the CVC roll step length compensation value ΔSt and the bending roll force compensation value ΔLt; when ΔD is greater than the third threshold, the CVC roll is adjusted first to obtain the CVC roll step length compensation value ΔSd.

[0013] In some optional embodiments, in step S5, obtaining the dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtaining the dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value, includes:

[0014] According to ΔLp, ΔSt, ΔLt, and ΔSd, the dynamic adjustment amount of the CVC roller step length ΔS=ΔSt+ΔSd is obtained, and |ΔS|≤0.4Sx is satisfied; the dynamic adjustment amount of the bending roller force ΔLc=ΔLp+ΔLt is satisfied, and |ΔLc|≤0.2L is satisfied.

[0015] In some optional embodiments, step S4 further includes: collecting the roll wear amount ΔW of the frame in real time, and when ΔW is greater than a fourth threshold, updating the CVC roll step limit to Sx', and the updated bending roll force compensation value Sx' satisfies |ΔS|≤0.4Sx'.

[0016] In some optional embodiments, after obtaining the bending roll force compensation value ΔLp in step S4, the step further includes updating the bending roll force compensation value ΔLp' in combination with the dynamic damping coefficient ζ, ΔLp'=ζ*ΔLp, wherein ζ=1 / (1+τ·|ΔP|), τ is the frame response time constant; and using the updated bending roll force compensation value ΔLp' to obtain the dynamic adjustment amount ΔLc of the bending roll force.

[0017] In some optional embodiments, the rolling force fluctuation ΔP, the strip transverse temperature gradient ΔT, and the strip deviation ΔD are set as disturbance compensation processing priorities from high to low, and ΔLp, ΔSt, ΔLt, and ΔSd are determined in sequence based on the limits of Sx and L.

[0018] In some optional embodiments, the data table for dividing the thickness and width of the strip into a plurality of gears to form the CVC roll step length limit includes:

[0019] According to the thickness of the strip, it is divided into multiple gears, each gear is provided with a thickness reference point H, each thickness reference point H corresponds to a preset CVC roller step limit basic value Si (i=1, 2, 3, 4, 5, 6, 7), and according to the width of the strip, it is divided into multiple gear intervals, each gear interval is provided with a width reference point B, and each gear interval corresponds to a preset CVC roller step influence coefficient b.

[0020] In some optional embodiments, obtaining the target thickness Hx and target width Bx of the steel strip and calculating the correction value Sx of the CVC roll step limit of the rack in combination with a data table includes:

[0021] According to the data table, select two thickness reference points H1 and H2 adjacent to the target thickness Hx, and the width interval corresponding to the target width Bx, determine the corresponding width reference point B and influence coefficient b, and obtain the correction value Sx based on the following formula: Sx=S1i+(S2i-S1i)(Hx-H1) / (H2-H1)+b(Bx-B), where S1i and S2i are the basic values of the CVC roller step corresponding to the thickness reference points H1 and H2 of the frame Fi (i=1, 2, 3, 4, 5, 6, 7).

[0022] In some optional embodiments, 1.5 mm, 3 mm, and 6 mm are used as three thickness reference points H to divide the strip thickness into three levels.

[0023] In some optional embodiments, the strip width is divided into three gear ranges according to less than 1000mm, 1000-1500mm and greater than 1500mm, the width reference point B of each gear range is set to 1000mm, 1000mm, 1500mm respectively, and the influence coefficients b corresponding to the three gear ranges are 12%, 15% and 18% respectively.

[0024] In some optional embodiments, the target roll gap convexity C1 is determined based on downstream customer usage requirements, control needs and / or equipment capabilities.

[0025] In some optional embodiments, the combination of the correction value Sx to determine the initial step length S0 of the CVC roller and the actual crown contribution C2 of the CVC roller also includes C2 / C1 being in the range of 60% to 80%.

[0026] A CVC roller control system for hot-rolled strip steel, comprising:

[0027] A data module is used to divide the thickness and width of the strip into multiple gears to form a data table for CVC roller step length limitation;

[0028] The step length correction module is used to obtain the target thickness Hx and target width Bx of the strip, and obtain the correction value Sx of the CVC roller step length limit of the stand in combination with the data table;

[0029] The initial value module is used to obtain the target roll gap crown C1, determine the initial step length S0 of the CVC roll and the actual crown contribution C2 of the CVC roll in combination with the correction value Sx, and obtain the initial bending roll force L to be compensated based on C1 and C2;

[0030] The compensation module controls the bending roll and CVC roll for rolling based on the initial step length S0 of the CVC roll and the initial bending roll force L, and collects multiple disturbance factors of the stand in real time. Each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roll step length compensation value required for each disturbance factor is calculated according to the threshold value;

[0031] A dynamic adjustment module, configured to obtain a dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtain a dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value;

[0032] The control module is used to obtain the CVC roller step length S0+ΔS and the bending roller force L+ΔLc corresponding to the frame Fi (i=1, 2, 3, 4, 5, 6, 7) according to steps S2-S5, and dynamically control the CVC roller and bending roller of the frame Fi.

[0033] The present invention provides a CVC roller control method and system for hot-rolled plate and strip steel. By optimizing the step limit of the CVC roller, detailed grading calculations can be performed according to the width and thickness of the strip steel. When producing strip steel of different specifications during the rolling process, a smooth transition of the CVC roller channeling amount is achieved, and the bending roller and the CVC roller are combined to control the roller gap convexity, thereby improving the control capability of the system. Through the deep coordination of static setting and dynamic adjustment, it can effectively cope with the influence of disturbances occurring during the rolling process, improve the anti-disturbance capability of the system, and ensure the stability of the roller gap and the plate shape quality of the strip steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 11 is a flow chart of a CVC roll control method for hot-rolled strip steel provided in this embodiment;

[0036] Figure 2 is a schematic diagram of a data table provided in this embodiment;

[0037] Figure 3 This is a schematic structural diagram of a CVC roller control system for hot-rolled strip steel provided in this embodiment. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] Currently, the stroke of the CVC roller on the hot rolling line is ±140mm. The secondary model control table only contains roll shifting strategies for all steel grades, and does not perform detailed grading and optimization based on actual conditions. When rolling thicker strips, greater convexity compensation is required because thick strips are more likely to have edge thinning or center bulge problems during the rolling process. For thinner strips, the requirements for plate shape may be higher, and the adjustment of the roll shifting amount may need to be more precise to avoid excessive shifting that causes unstable plate shape.

[0040] According to the current roller shifting step length control method, the roller shifting amount is often too large when rolling thin specifications, resulting in unstable roll gap and crown control, causing overshoot of the control of the last stand, and unable to ensure the stability of thickness when rolling thin specifications. At the same time, different width strips have different sensitive areas to the roll gap shape, and the concentration points of rolling force of wide strips and narrow strips are different. In order to ensure the stability of the roll gap, the CVC roller needs to be controlled in a targeted manner.

[0041] The present invention will be described below with reference to specific embodiments in conjunction with the accompanying drawings.

[0042] like Figure 1 As shown, a CVC roller control method for hot-rolled strip steel of the present invention comprises:

[0043] S1. Divide the thickness and width of the strip into multiple gears to form a data table of CVC roller step length limitation;

[0044] S2. Obtain the target thickness Hx and target width Bx of the strip, and obtain the correction value Sx of the CVC roller step limit of the stand in combination with the data table;

[0045] S3. Obtain the target roll gap crown C1, determine the CVC roll initial step length S0 and the actual CVC roll crown contribution C2 in combination with the correction value Sx, and obtain the initial roll bending force L to be compensated based on C1 and C2;

[0046] S4, based on the initial step length S0 of the CVC roll and the initial bending roll force L, the bending roll and the CVC roll are controlled to perform rolling, and multiple disturbance factors of the stand are collected in real time, each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roll step length compensation value required for each disturbance factor is calculated according to the threshold value;

[0047] S5. Obtaining a dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtaining a dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value;

[0048] S6. According to steps S2-S5, the CVC roller step length S0+ΔS and the bending roller force L+ΔLc corresponding to the rack Fi (i=1, 2, 3, 4, 5, 6, 7) are obtained, and the CVC roller and bending roller of the rack Fi are dynamically controlled.

[0049] In some optional embodiments, in step S4, the multiple disturbance factors include rolling force fluctuation ΔP, strip transverse temperature gradient ΔT and strip deviation ΔD, and corresponding first threshold, second threshold and third threshold are set in sequence.

[0050] When ΔP is greater than the first threshold, the bending roll force is adjusted first to obtain the bending roll force compensation value ΔLp.

[0051] Since the rolling force fluctuation ΔP directly reflects the instantaneous change of the deformation resistance of the rolled piece, it is transmitted to the roll gap through the rolling mill stiffness, which will cause rapid fluctuations in the roll gap convexity and rolling torque. By setting the adjustment priority of the bending roll and CVC roll, the rapid response characteristics of the bending roll can be used to stabilize the roll gap convexity and avoid imbalance in the second flow rate due to lag (such as thickness fluctuation or increased deviation). At the same time, the priority adjustment of the bending roll force can avoid mechanical wear caused by frequent adjustment of the CVC roll. In addition, if the compensation of the bending roll force exceeds its own adjustment range, the step size of the CVC roll can be coordinated to compensate.

[0052] When ΔT is greater than the second threshold, the bending roller and the CVC roller are adjusted synchronously to obtain the CVC roller step length compensation value ΔSt and the bending roller force compensation value ΔLt.

[0053] Since the transverse temperature gradient of the strip will cause thermal expansion differences and lead to thermal crown effect and thermal stress effect, the synchronous control of the bending roll and the CVC roll can achieve coordinated control of crown and flatness. That is, the bending deformation of the bending roll is used to offset the internal bending moment of the strip caused by thermal stress, thereby suppressing flatness defects. At the same time, the CVC roll is used to change the superposition amount of the CVC roll curve to directly correct the equivalent crown deviation caused by the temperature gradient, thereby reducing the quality risk of insufficient correction in single control.

[0054] When ΔD is greater than the third threshold, the CVC roller is preferentially adjusted to obtain the CVC roller step length compensation value ΔSd.

[0055] Since the strip deviation ΔD is essentially the lateral displacement of the strip caused by the asymmetric force on the rolling line (such as uneven tension distribution and tilted roll gap), CVC roll adjustment is preferred. By axially moving the working roll, the lateral equivalent convexity distribution of the roll gap (such as the difference in convexity of the left / right roll gap) can be changed to generate a lateral torque to offset the deviation force. At the same time, by limiting the compensation amplitude, stress concentration in the contact area of the roll ends can be effectively avoided. Compared with bending roll adjustment, CVC rolls can directly generate lateral torque to correct deviation and avoid deterioration of the roll system force.

[0056] In some optional embodiments, in step S5, obtaining the dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtaining the dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value, includes:

[0057] According to ΔLp, ΔSt, ΔLt, and ΔSd, the dynamic adjustment amount of the CVC roller step length ΔS=ΔSt+ΔSd is obtained, and |ΔS|≤0.4Sx is satisfied; the dynamic adjustment amount of the bending roller force ΔLc=ΔLp+ΔLt is satisfied, and |ΔLc|≤0.2L is satisfied.

[0058] The total dynamic adjustment amount of the CVC roller and the bending roller is determined according to different disturbance factors, and a technical solution to prevent overshoot is further set up, that is, the adjustment amount ΔS of the CVC roller step size within a single sensor acquisition cycle does not exceed 40% of the step size limit Sx' of the dynamic update of the CVC roller, which can balance mechanical safety, control stability and multi-disturbance response capability, avoid the vicious cycle of "over-correction-oscillation", prevent the adjustment amount of the axial movement of the CVC roller from being too large, and reduce the risk of the local stress peak of the CVC roller exceeding the fatigue limit of the material and then cracking. It can be seen from actual measurements that the phenomenon of cumulative overshoot can be significantly reduced, and sufficient adjustment margin can be reserved for subsequent compensation; at the same time, the dynamic adjustment amount ΔLc of the bending roller force within a single sensor acquisition cycle does not exceed 20% of the compensation bending roller force L, which can match the hydraulic dynamic characteristics and the second flow balance, realize the closed-loop control of "fast response-precise convergence", effectively ensure the stability of the oil film, and reduce the risk of pressure oscillation caused by valve core response lag.

[0059] In some optional embodiments, step S4 further includes: collecting the roll wear amount ΔW of the frame in real time, and when ΔW is greater than a fourth threshold, updating the CVC roll step limit to Sx', and the updated bending roll force compensation value Sx' satisfies |ΔS|≤0.4Sx'.

[0060] Coupling the roll wear ΔW to the CVC roll step limit calculation can achieve online adaptive compensation of the wear amount, avoid model mismatch caused by roll shape changes, such as systematic deviation between the crown set value and the actual value, and extend the service life of the roll.

[0061] In some optional embodiments, after obtaining the bending roll force compensation value ΔLp in step S4, the step further includes updating the bending roll force compensation value ΔLp' in combination with the dynamic damping coefficient ζ, ΔLp'=ζ*ΔLp, wherein ζ=1 / (1+τ·|ΔP|), τ is the frame response time constant; and using the updated bending roll force compensation value ΔLp' to obtain the dynamic adjustment amount ΔLc of the bending roll force.

[0062] By introducing the dynamic damping coefficient ζ to calculate the bending roll force compensation value of the rolling force fluctuation, the system oscillation caused by the sudden change of the rolling force can be effectively suppressed. Together with the limiting of the bending roll force, it can form a double protection of "feedforward suppression + feedback truncation", that is, the dynamic damping coefficient is used to reduce the oscillation energy from the source, and the dynamic adjustment amount of the bending roll force is limited to prevent loss of control under extreme working conditions.

[0063] In some optional embodiments, the rolling force fluctuation ΔP, the strip transverse temperature gradient ΔT, and the strip deviation ΔD are set as disturbance compensation processing priorities from high to low, and ΔLp, ΔSt, ΔLt, and ΔSd are determined in sequence based on the limits of Sx and L.

[0064] Targeted design of more effective adjustment priorities based on different disturbance factors can effectively optimize the control effect, avoid calculation confusion in multiple disturbance overlapping scenarios, and improve the ability to handle unforeseen disturbance factors.

[0065] In some optional embodiments, the thickness and width of the strip are divided into multiple gears to form a data table for CVC roll step length limitation, including:

[0066] According to the thickness of the strip, it is divided into multiple gears, each gear is provided with a thickness reference point H, each thickness reference point H corresponds to a preset CVC roller step limit basic value Si (i=1, 2, 3, 4, 5, 6, 7), and according to the width of the strip, it is divided into multiple gear intervals, each gear interval is provided with a width reference point B, and each gear interval corresponds to a preset CVC roller step influence coefficient b.

[0067] It can be divided into detailed grades according to the width and thickness of the strip, so that a smoother initial value can be obtained in subsequent calculations.

[0068] In some optional embodiments, obtaining the target thickness Hx and target width Bx of the steel strip and calculating the correction value Sx of the CVC roll step limit of the rack in combination with the data table include:

[0069] According to the data table, select two thickness reference points H1 and H2 adjacent to the target thickness Hx, and the width interval corresponding to the target width Bx, determine the corresponding width reference point B and influence coefficient b, and obtain the correction value Sx based on the following formula: Sx=S1i+(S2i-S1i)(Hx-H1) / (H2-H1)+b(Bx-B), where S1i and S2i are the basic values of the CVC roller step corresponding to the thickness reference points H1 and H2 of the frame Fi (i=1, 2, 3, 4, 5, 6, 7).

[0070] This formula can achieve a smooth transition of CVC roll step length when producing strips of different specifications during the rolling process.

[0071] In some optional embodiments, 1.5 mm, 3 mm, and 6 mm are used as three thickness reference points H to divide the strip thickness into three levels.

[0072] Since thin-gauge strip steel is sensitive to roll gap fluctuations, the fixed step length of traditional CVC rolls will cause roll gap adjustment lag or excessive adjustment. Therefore, gear division is specially carried out for strip steel with a thickness of 1.5mm-6mm. This can effectively refine thin-gauge strip steel and obtain more precise control parameters, thereby improving the control stability and forming quality of rolled thin-gauge strip steel.

[0073] In some optional embodiments, the strip width is divided into three gear ranges according to less than 1000mm, 1000-1500mm and greater than 1500mm, the width reference point B of each gear range is set to 1000mm, 1000mm, 1500mm respectively, and the influence coefficients b corresponding to the three gear ranges are 12%, 15% and 18% respectively.

[0074] Since wide strip has higher requirements for the uniformity of the roll gap convexity, a larger amount of movement is usually required to compensate for the roll system deflection caused by the rolling force. In narrow strip, excessive movement will lead to excessive local convexity of the roll gap, causing "cat ear" defects. Therefore, the width is divided into three gear ranges, and the preset influence coefficient can be used to calculate the step limit of the CVC roller. On the basis of ensuring a smooth transition of the movement, the stability of the rolled wide strip is effectively improved. The setting of the influence coefficient can make the step limit of the CVC roller accurately adjusted according to the strip width, especially during the rolling process, when the strip width changes, it can respond synchronously to obtain the optimal control parameters. In addition, when establishing the corresponding basic value Si according to the strip thickness gear, the strip width of 1000mm can be selected as the default specification to obtain the optimal basic value Si based on experience.

[0075] In some optional embodiments, the target roll gap crown C1 is determined according to downstream customer usage requirements, control needs and / or equipment capabilities.

[0076] In some optional embodiments, the initial step length S0 of the CVC roller and the actual crown contribution C2 of the CVC roller are determined in combination with the correction value Sx, and C2 / C1 is also included in the range of 60% to 80%.

[0077] The step length of the CVC roller can cover 60%~80% of the crown requirements. Combined with the bending roller force to compensate for the remaining 20%~40% of the crown requirements, the weight ratio of the bending roller and the CVC roller can be reasonably allocated, which is conducive to sufficient compensation margin for subsequent dynamic adjustments.

[0078] Based on the requirements of specific working conditions, a certain selection and combination is made among various optional implementation methods. A CVC roll control method for hot-rolled strip steel specifically includes the following steps:

[0079] S1. Divide the thickness and width of the strip into multiple gears to form a data table for CVC roller step length limitation.

[0080] Specifically, the CVC roller step limit of frames F1-F7 is divided into three gears according to the thickness of the strip. The thickness reference points H of the three gears correspond to strip thicknesses of 1.5mm, 3mm and 6mm respectively. At the same time, the CVC roller step limit of frames F1-F7 is divided into three gear intervals according to the width of the strip. The strip widths corresponding to the three gear intervals are less than 1000mm, 1000-1500mm and above 1500mm, and the corresponding width reference points B are 1000mm, 1000mm and 1500mm respectively.

[0081] It should be noted that the width reference point B for widths less than 1000mm and 1000-1500mm is both 1000mm. This is because when the basic value Si is determined based on experience, a width of 1000mm is used as the default specification. That is, when the width of the rolled strip is greater than 1000mm, a larger amount of movement is required to compensate for the roller deflection caused by the rolling force. Accordingly, a certain CVC roller step limit is added to the basic value Si to meet the process requirements. When the width of the rolled strip is less than 1000mm, the CVC roller step limit can be reduced on the basic value Si to fully improve the rolling stability.

[0082] Specifically, the following can be established according to the thickness of the strip: Figure 2 The data table of basic values of CVC roller step limit for the stands shown in the figure shows that the preset CVC roller step influence coefficient b=12% corresponds to the gear range of strip width less than 1000mm, which is applicable to all seven stands F1-F7; the preset CVC roller step influence coefficient b=15% corresponds to the gear range of strip width 1000-1500mm, which is applicable to all seven stands F1-F7; the preset CVC roller step influence coefficient b=18% corresponds to the gear range of strip width greater than 1500mm, which is applicable to all seven stands F1-F7.

[0083] S2. Obtain the target thickness Hx and target width Bx of the strip steel, and obtain the correction value Sx of the CVC roller step limit of the stand in combination with the data table.

[0084] Specifically, it includes executing for each frame separately: selecting two thickness reference points H1 and H2 adjacent to the target thickness Hx, and the width interval corresponding to the target width Bx in the data table, determining the corresponding width reference point B and influence coefficient b, and then obtaining the correction value Sx based on the following formula, Sx=S1i+(S2i-S1i)(Hx-H1) / (H2-H1)+b(Bx-B), where S1i and S2i are the basic values of the CVC roller step corresponding to the thickness reference points H1 and H2 of the frame Fi (i=1, 2, 3, 4, 5, 6, 7).

[0085] For example, when the target thickness of the strip is 2mm and the target width is 1200mm, for frame F1, two adjacent reference points H1=1.5mm and H2=3mm are selected in the data table. Figure 1It can be seen that the preset CVC roller step length limit basic value S11 = 35μm at the reference point H1 = 1.5mm for frame F1, and the preset CVC roller step length limit basic value S21 = 80μm at the reference point H2 = 3mm. The target thickness of the strip belongs to the width range of 1000-1500m, so the corresponding CVC roller step length influence coefficient b is 15%, and the reference point B = 1000mm. Therefore, according to the formula, the CVC roller step length limit correction value Sx of frame F1 can be obtained as follows: 35 + (80-35) * (2-1.5) / (3-1.5) + 15% * (1200-1000) = 80 μm. Similarly, the preset CVC roller step length limit basic value S12 = 30 μm for rack F2 at the reference point H1 = 1.5 mm, and the preset CVC roller step length limit basic value S22 = 60 μm for rack F2 at the reference point H2 = 3 mm. The corresponding CVC roller step length influence coefficient b is also 15%. Therefore, according to the formula, the CVC roller step length limit correction value Sx = 30 + (60-30) * (2-1.5) / (3-1.5) + 15% * (1200-1000) = 70 μm for rack F2 can be obtained. The calculation principle for racks F3-F7 is the same and will not be repeated here.

[0086] For example, when the target thickness of the strip is 3mm and the target width is 900mm, the target thickness just corresponds to the thickness reference point, and the target width reference point B = 1000mm. Similarly, the CVC roller step limit correction value Sx of stand F1 is Sx = 80 + 12% * (900-1000) = 68μm. The calculation principle involving stands F2-F7 is the same and will not be repeated here.

[0087] S3. Obtain the target roll gap crown C1, determine the initial step length S0 of the CVC roll and the actual crown contribution C2 of the CVC roll in combination with the correction value Sx, and obtain the initial bending roll force L to be compensated based on C1 and C2.

[0088] Specifically, the target roll gap crown can be calculated by combining the target strip cross-section (such as parabolic crown and edge thinning) with a rolling force prediction model. The CVC roll step length S0 for each stand is determined based on actual operating conditions within the constraints of the corresponding Sx. The actual CVC roll crown contribution C2 is determined from S0 using the CVC characteristic curve (axial displacement-crown mapping). Finally, the formula L = k*(C2-C1) is used, where k is the elastic deformation coefficient of the corresponding stand. Furthermore, L, C1, and C2 can also be calculated using other existing technologies and are not limited here.

[0089] S4. Based on the initial step length S0 of the CVC roller and the initial bending roll force L, the bending roll and the CVC roller are controlled to perform rolling, and multiple disturbance factors of the frame are collected in real time. Each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roller step length compensation value required for each disturbance factor is calculated according to the threshold value.

[0090] That is, during rolling, each stand has a corresponding CVC roll with an initial step length of S0 and an initial bending roll force of L, which completes the early static setting stage and then enters the dynamic adjustment stage.

[0091] Specifically, during the rolling process, the sensor group collects the disturbance factors of each stand in real time, including the rolling force fluctuation ΔP, the strip transverse temperature gradient ΔT, the strip deviation ΔD and the roll wear ΔW. Among them, the rolling force fluctuation ΔP can be detected and obtained by a combination of a piezoelectric pressure gauge and a strain gauge pressure sensor; the strip transverse temperature gradient ΔT can be detected and obtained by a combination of an infrared thermal imager and a multi-channel line scanning thermometer; the strip deviation ΔD can be detected and obtained by a combination of a laser displacement sensor and a CCD visual sensor; and the roll wear ΔW can be detected and obtained by a combination of a laser profiler and a vibration acceleration sensor.

[0092] When the rolling force fluctuation ΔP is greater than the first threshold, the bending roll force is adjusted first to obtain the bending roll force compensation value ΔLp for compensation, specifically according to the bending roll force compensation value ΔLp=c·ΔP, where c is the rolling force-bending roll force coupling coefficient.

[0093] In addition, the dynamic damping coefficient ζ can be further combined to update the bending roll force compensation value to obtain the updated bending roll force compensation value ΔLp', specifically according to ΔLp'=ζ*ΔLp, where ζ=1 / (1+τ·|ΔP|), and τ is the frame response time constant.

[0094] When the transverse temperature gradient ΔT of the strip is greater than the second threshold, the bending roll and CVC roll are adjusted synchronously to obtain the CVC roll step compensation value ΔSt and the bending roll force compensation value ΔLt for compensation; specifically, according to the CVC roll step compensation value ΔSt=d·ΔT, the bending roll force compensation value ΔLt=e·ΔT, where d is the temperature-CVC roll correlation factor, and e is the temperature-bending roll correlation factor.

[0095] When the strip deviation ΔD is greater than the third threshold, the CVC roller step length is adjusted first to obtain the CVC roller step length compensation value ΔSd for compensation; specifically, according to the CVC roller step length compensation value ΔSd=f·ΔD, f is the deviation correction coefficient, and ΔSd can be further limited to 0.3Sx.

[0096] When the roller wear ΔW is greater than the fourth threshold, the CVC roller step limit is updated to obtain the CVC roller step limit Sx'; specifically, according to Sx'=Sx·(1-ΔW / Wmax), where Wmax is the maximum allowable roller wear.

[0097] At the same time, the rolling force fluctuation ΔP, the strip transverse temperature gradient ΔT, and the strip deviation ΔD are set as the disturbance compensation processing priorities from high to low, and ΔLp, ΔSt, ΔLt, and ΔSd are determined in sequence based on the limits of Sx' and L. In this way, more matching adjustment objects and more effective adjustment priorities are designed based on different disturbance factors, which can improve the optimization control effect and the ability to handle unforeseen disturbance factors.

[0098] S5. Obtain a dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtain a dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value.

[0099] Specifically, according to ΔLp', ΔSt, ΔLt, ΔSd, and ΔW, the following is obtained: the dynamic adjustment amount of the CVC roller step ΔS=ΔSt+ΔSd, and satisfies |ΔS|≤0.4Sx'; the dynamic adjustment amount of the bending roller force ΔLc=ΔLp'+ΔLt, and satisfies |ΔLc|≤0.2L.

[0100] S6. According to steps S2-S5, the CVC roller step length S0+ΔS and the bending roller force L+ΔLc corresponding to the rack Fi (i=1, 2, 3, 4, 5, 6, 7) are obtained, and the CVC roller and bending roller of the rack Fi are dynamically controlled.

[0101] Specifically, all seven stands will go through the static setting stage and the dynamic adjustment stage. After calculating the initial step length and initial bending roll force of each stand respectively, they will enter the rolling stage. Then the sensor can collect the disturbance factors of each stand respectively, and then determine the CVC roll step length and bending roll force of each stand dynamically adjusted in turn. Of course, based on the data processing capability, it is also possible to evaluate the risk of disturbance severity caused by different disturbance factors for stands in different positions, and then selectively collect different disturbance factors for different stands, thereby realizing personalized dynamic control of each stand.

[0102] The present invention provides a CVC roller control method for hot-rolled plate and strip steel. By optimizing the step length limit of the CVC roller, the method can perform detailed grading calculations according to the width and thickness of the strip steel. When rolling strip steel of different specifications, the method can achieve a smooth transition of the CVC roller's channeling, effectively avoiding abnormal roll gap convexity when the specifications of the strip steel on the rolling line are changed. The method further combines the bending roll force to perform convexity compensation, and fully utilizes the control weights of the CVC roller and the bending roll to achieve the required roll gap convexity requirements. On the basis of ensuring the plate shape quality of the strip steel, the stability of the roll gap is effectively guaranteed.

[0103] At the same time, during the rolling process, a dynamic adjustment strategy was designed based on the disturbance factors obtained by the sensors, that is, on the basis of static settings, it can perform real-time optimization control according to the working conditions, including: through the disturbance graded compensation mechanism, differentiated compensation strategies are designed for the four types of disturbances, namely rolling force, strip transverse temperature, strip deviation, and roll wear, breaking through the limitations of a single compensation model; dynamic priority logic is adopted to give priority to the bending roll response speed when the rolling force suddenly changes, and the CVC roll and the bending roll are adjusted synchronously when the temperature is abnormal to achieve optimal configuration of control resources; a multi-constraint anti-overshoot algorithm is introduced to ensure system stability through triple protection of the amplitude limit of the single adjustment of the CVC roll step size, the amplitude limit of the single-cycle adjustment of the bending roll force, and the dynamic damping coefficient.

[0104] This application achieves significant improvement in the system's anti-disturbance capability while ensuring the accuracy of convexity control through deep coordination of static setting and dynamic adjustment. In particular, when rolling wide, thin-gauge strip steel, it can avoid excessive adjustment of the convexity that causes the strip edge to be too thin, or overshoot of the downstream frame and steel accumulation due to plate shape fluctuations, thereby comprehensively improving the control performance of thin-gauge strip rolling. After actual measurement on the company's production line of rolling thin-gauge strip steel with a thickness of 2mm and a width of 1600mm, the thickness stability of the strip steel has been effectively improved, the thickness tolerance has been reduced from ±15μm to ±7μm, the plate shape has been improved, the occurrence rate of edge waves and middle waves has been reduced by about 30%, and the yield rate has been increased by 5%. It has good application prospects.

[0105] The following describes a CVC roller control system for hot-rolled steel strip provided by the present application. The system described below and the method described above can be referenced to each other. Based on the above embodiment, Figure 3 This is a schematic diagram of the structure of a CVC roller control system for hot-rolled strip steel provided by this application. Figure 3As shown, the system includes: a data module 10, which is used to divide the thickness and width of the strip into multiple gears to form a data table of CVC roll step limit; a step correction module 20, which is used to obtain the target thickness Hx and target width Bx of the strip, and obtain the correction value Sx of the CVC roll step limit of the stand in combination with the data table; an initial value module 30, which is used to obtain the target roll gap crown C1, and determine the initial step length S0 of the CVC roll and the actual crown contribution C2 of the CVC roll in combination with the correction value Sx, and obtain the initial bending roll force L to be compensated based on C1 and C2; a compensation module 40, which controls the bending roll and the CVC roll based on the initial step length S0 of the CVC roll and the initial bending roll force L Rolling, and real-time collection of multiple disturbance factors of the frame, each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roll step length compensation value required for each disturbance factor are calculated according to the threshold value; a dynamic adjustment module 50 is used to obtain the dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or to obtain the dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value; a control module 60 is used to obtain the CVC roll step length S0+ΔS and the bending roll force L+ΔLc corresponding to the frame Fi (i=1, 2, 3, 4, 5, 6, 7) according to steps S2-S5, and dynamically control the CVC roll and bending roll of the frame Fi.

[0106] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0107] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A CVC roller control method for hot-rolled strip steel, characterized in that: include: S1. Divide the thickness and width of the strip into multiple gears to form a data table of CVC roller step length limitation; S2. Obtain the target thickness Hx and target width Bx of the strip, and obtain the correction value Sx of the CVC roller step limit of the stand in combination with the data table; S3, obtaining the target roll gap crown C1, combining the correction value Sx to determine the CVC roll initial step S0 and the actual CVC roll crown contribution C2, and obtaining the initial roll bending force L to be compensated based on C1 and C2; S4, based on the initial step length S0 of the CVC roll and the initial bending roll force L, the bending roll and the CVC roll are controlled to perform rolling, and multiple disturbance factors of the stand are collected in real time, each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roll step length compensation value required for each disturbance factor is calculated according to the threshold value; Among them, the multiple disturbance factors include rolling force fluctuation ΔP, strip transverse temperature gradient ΔT and strip deviation ΔD, and are sequentially provided with corresponding first threshold, second threshold and third threshold; When ΔP is greater than the first threshold, the bending roll force is adjusted first to obtain the bending roll force compensation value ΔLp; when ΔT is greater than the second threshold, the bending roll and CVC roll are adjusted synchronously to obtain the CVC roll step length compensation value ΔSt and the bending roll force compensation value ΔLt; when ΔD is greater than the third threshold, the CVC roll is adjusted first to obtain the CVC roll step length compensation value ΔSd; S5. Obtaining a dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtaining a dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value; S6. According to steps S2-S5, the CVC roller step length S0+ΔS and the bending roller force L+ΔLc corresponding to the rack Fi (i=1, 2, 3, 4, 5, 6, 7) are obtained, and the CVC roller and bending roller of the rack Fi are dynamically controlled.

2. The CVC roller control method for hot-rolled strip steel according to claim 1, characterized in that: In step S5, the dynamic adjustment amount ΔLc of the bending roll force is obtained according to the bending roll force compensation value, and / or the dynamic adjustment amount ΔS of the CVC roll step length is obtained according to the CVC roll step length compensation value, including: According to ΔLp, ΔSt, ΔLt, and ΔSd, the dynamic adjustment amount of the CVC roller step length ΔS=ΔSt+ΔSd is obtained, and |ΔS|≤0.4Sx is satisfied; the dynamic adjustment amount of the bending roller force ΔLc=ΔLp+ΔLt is satisfied, and |ΔLc|≤0.2L is satisfied.

3. The CVC roller control method for hot-rolled strip steel according to claim 2, characterized in that: Step S4 also includes: collecting the roll wear amount ΔW of the stand in real time, and when ΔW is greater than a fourth threshold, updating the CVC roll step limit to Sx', and the updated bending roll force compensation value Sx' satisfies |ΔS|≤0.4Sx'.

4. The CVC roller control method for hot-rolled strip steel according to claim 2, characterized in that: After obtaining the bending roll force compensation value ΔLp in step S4, the step also includes updating the bending roll force compensation value ΔLp' in combination with the dynamic damping coefficient ζ, ΔLp'=ζ*ΔLp, where ζ=1 / (1+τ·|ΔP|) and τ is the frame response time constant; and using the updated bending roll force compensation value ΔLp' to obtain the dynamic adjustment amount ΔLc of the bending roll force.

5. The CVC roller control method for hot-rolled strip steel according to claim 2, characterized in that: The rolling force fluctuation ΔP, the strip transverse temperature gradient ΔT, and the strip deviation ΔD are set as the disturbance compensation processing priorities from high to low, and ΔLp, ΔSt, ΔLt, and ΔSd are determined in sequence based on the limits of Sx and L.

6. The CVC roll control method for hot-rolled strip steel according to any one of claims 1 to 5, characterized in that: The data table for dividing the thickness and width of the strip into multiple gears to form the CVC roller step length limit includes: According to the thickness of the strip, it is divided into multiple gears, each gear is provided with a thickness reference point H, each thickness reference point H corresponds to a preset CVC roller step limit basic value Si (i=1, 2, 3, 4, 5, 6, 7), and according to the width of the strip, it is divided into multiple gear intervals, each gear interval is provided with a width reference point B, and each gear interval corresponds to a preset CVC roller step influence coefficient b.

7. The CVC roll control method for hot-rolled strip steel according to claim 6, characterized in that: The method of obtaining the target thickness Hx and target width Bx of the strip and calculating the correction value Sx of the CVC roller step limit of the rack in combination with the data table includes: According to the data table, select two thickness reference points H1 and H2 adjacent to the target thickness Hx, and the width interval corresponding to the target width Bx, determine the corresponding width reference point B and influence coefficient b, and obtain the correction value Sx based on the following formula: Sx=S1i+(S2i-S1i)(Hx-H1) / (H2-H1)+b(Bx-B), where S1i and S2i are the basic values of the CVC roller step corresponding to the thickness reference points H1 and H2 of the frame Fi (i=1, 2, 3, 4, 5, 6, 7).

8. The CVC roller control method for hot-rolled strip steel according to claim 6, characterized in that: The strip width is divided into three ranges according to less than 1000mm, 1000-1500mm and greater than 1500mm. The width reference point B of each range is set to 1000mm, 1000mm, 1500mm respectively, and the influence coefficients b corresponding to the three ranges are 12%, 15% and 18% respectively.

9. A CVC roller control system for hot-rolled strip steel, characterized in that: include: A data module is used to divide the thickness and width of the strip into multiple gears to form a data table for CVC roller step length limitation; The step length correction module is used to obtain the target thickness Hx and target width Bx of the strip, and obtain the correction value Sx of the CVC roller step length limit of the stand in combination with the data table; The initial value module is used to obtain the target roll gap crown C1, determine the initial step length S0 of the CVC roll and the actual crown contribution C2 of the CVC roll in combination with the correction value Sx, and obtain the initial bending roll force L to be compensated based on C1 and C2; The compensation module controls the bending roll and CVC roll for rolling based on the initial step length S0 of the CVC roll and the initial bending roll force L, and collects multiple disturbance factors of the stand in real time. Each disturbance factor is respectively provided with a corresponding threshold value, and the bending roll force compensation value and / or CVC roll step length compensation value required for each disturbance factor is calculated according to the threshold value; Among them, the multiple disturbance factors include rolling force fluctuation ΔP, strip transverse temperature gradient ΔT and strip deviation ΔD, and are sequentially provided with corresponding first threshold, second threshold and third threshold; When ΔP is greater than the first threshold, the bending roll force is adjusted first to obtain the bending roll force compensation value ΔLp; when ΔT is greater than the second threshold, the bending roll and CVC roll are adjusted synchronously to obtain the CVC roll step length compensation value ΔSt and the bending roll force compensation value ΔLt; when ΔD is greater than the third threshold, the CVC roll is adjusted first to obtain the CVC roll step length compensation value ΔSd; A dynamic adjustment module, configured to obtain a dynamic adjustment amount ΔLc of the bending roll force according to the bending roll force compensation value, and / or obtain a dynamic adjustment amount ΔS of the CVC roll step length according to the CVC roll step length compensation value; The control module is used to obtain the CVC roller step length S0+ΔS and the bending roller force L+ΔLc corresponding to the frame Fi (i=1, 2, 3, 4, 5, 6, 7) according to steps S2-S5, and dynamically control the CVC roller and bending roller of the frame Fi.

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