CN103433295A - Method for controlling convexity of single-rack double-coiler aluminum hot mill - Google Patents

Abstract

The invention relates to a method for controlling convexity of a single-rack double-coiler aluminum hot mill. A convexity control strategy of the single-rack double-coiler aluminum hot mill is made according to the characteristics of the mill and field rolling experience; a convexity presetting model, a thermal expansion calculation model and convexity feed-forward and feedback control systems, which are suitable for a single rack, are established; excellent full-automatic control on convexity and flatness of an aluminium sheet strip in the rolling process of the mill is implemented; a corresponding convexity control strategy is made according to the alloy characteristics of the strip; roll bending force set values and head convexity guarantee values in a cooling spray mode in two rolling stages of rough rolling and finish rolling are given by the convexity presetting model and the thermal expansion model; feed-forward compensation on a roll bending force is carried out in the finishing pass so as to reduce influence of fluctuation of a rolling force on convexity; in the last third pass or the final pass in which convexity measurement is carried out, closed-loop control on the roll bending force is carried out according to the alloy characteristic condition so as to ensure full-length convexity and the sheet shape; and after rolling is finished, self-learning of the roll bending force and a cooling spray model is carried out so as to improve accuracy of the presetting model.

Description

The single-frame double-coiling aluminium hot-rolling mill convex degree control method

Technical field

The present invention relates to a kind of aluminothermy and roll the convex degree control method in production, particularly convexity and board-shape control method in the full belt length scope of a kind of single-frame double-coiling aluminium hot-rolling mill.

Background technology

Single-frame double-coiling aluminium hot-rolling mill becomes the first-selected type that numerous aluminium processing enterprise produces hot-rolled product.Different from iron and steel domain, because aluminium sheet band production scale is less, its technological level, the equipment automatization level is obviously on the low side, the phenomenon that the hot-rolling mill ubiquity unstable product quality that most enterprise is used, control device fall behind.Convexity is very important quality index of hot-rolled product, and along with improving constantly of customer requirement, more and more aluminium sheet band manufacturing enterprise starts to pay attention to the control of hot-rolled product convexity.

Convexity and glacing flatness have reflected respectively band shape of cross section and size extending longitudinally, and the two exists incidence relation.In aluminium sheet band production process, glacing flatness often becomes top-priority quality index, this is to be that experience by feat of the operative employee realizes fully because the aluminothermy of most rolls that convexity and plate shape control, adjust operation of rolling parameter according to the glacing flatness size of range estimation, until band is straight.By the artificial experience method, come control panel shape to there is following shortcoming: to be at first to take into account the control convexity in the situation that control glacing flatness; Next is to lack rational plate shape control strategy, and the profile regulation device can not have been given play to maximum effect, tend to occur the profile regulation device has reached limiting value can't the good phenomenon of control panel shape; The three products strip shape quality can fluctuate along with the experienced degree difference of operator, is unfavorable for obtaining stable product quality.

Deficiency for artificial experience method control panel shape, external relevant enterprise has developed complete Crown control system on aluminium sheet band hot continuous rolling, but its control method and strategy are not suitable for the single chassis hot-rolling mill, mainly be: be at first that continuous hot-rolling mill has multi-frame roller regulating power, the bending roller force of adjusting each frame according to outlet side actual measurement convexity distributes, and the bending roller force of single chassis hot-rolling mill is regulated and can only be completed in institute's mill train is inferior, this just calculates and has higher requirement the setting of bending roller force; Next is the band convexity that continuous hot-rolling mill can only be measured last frame exit, and for the single chassis hot-rolling mill, measure the band outlet convexity of two passages, therefore can utilize actual measurement convexity information to revise the target convex value of follow-up passage, and then improve setting accuracy; The 3rd, being responsible for one from each frame of continuous hot-rolling mill, to depress passage different, the single chassis hot-rolling mill will be responsible for all rolling passes, can cause like this heat expansion variation of working roll more frequent, and the real-time prediction work roll thermal crown is necessary for the raising of convexity setting accuracy.

Summary of the invention

The objective of the invention is to overcome the deficiency that prior art exists, a kind of single-frame double-coiling aluminium hot-rolling mill convex degree control method is provided, material volume convexity to be rolled is set and calculated and FEEDBACK CONTROL, guarantee to realize the uniformity of convexity in the band length range under the prerequisite good at the outlet strip flatness.

Purpose of the present invention is achieved through the following technical solutions:

The single-frame double-coiling aluminium hot-rolling mill convex degree control method comprises the following steps:

(1) overall Crown control policy development;

(2) determine the export goal convexity of each rolling pass band;

(3) the real-time hot convexity of working roll is calculated;

(4) calculate the setting value of each executing agency;

(5) the bending roller force feedforward gain is calculated;

(6) the crown feedback control strategy is formulated;

(7) improve the convexity setting accuracy by Model Self-Learning.

Further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, described overall Crown control policy development, press aluminium alloy kind, hardness, quality requirement and finished product thickness and divide the alloy feature of aluminum strip, and formulate corresponding Crown control strategy: the alloy species difference, its rolling strategy and finish to gauge require also different, alloy soft or hard degree difference, and its Crown control strategy is difference to some extent also; Finish to gauge thickness difference, its Crown control strategy of rolled plate or coiled material is also different;

1a) formulation of Crown control strategy need be considered the product quality emphasis of variety classes alloy, output, temperature, surface quality and plate shape are 4 important quality index of board rolling, when with output or temperature when paying the utmost attention to index, for the control of convexity, require to reduce; When with surface quality when paying the utmost attention to target, the convexity closed-loop control need to shift to an earlier date passage and carry out, and affects surface quality of strips to reduce extreme trace time convexity to regulate; When with plate shape when paying the utmost attention to index, need to optimize corresponding sharing of load to guarantee exit plate shape; Sometimes take several quality index during as common priority target, need to formulate corresponding Crown control strategy;

1b) at rough rolling step, each passage band outlet flakiness ratio is smaller, and the band lateral flow is larger, adopts the rolling of experience bending roller force; From the C4 passage, the inverse of the operation of rolling the 4th passage, implement different Crown control strategies according to alloy soft or hard degree and finished product thickness; For thin material, the passage that its operation of rolling camber instrument comes into operation has 2, and the passage of therefore implementing crown feedback control has at most two, depends on the soft or hard degree of alloy; Mild alloy has higher convexity regulating power than hard alloy, so 2 crown feedbacks control passage strategies of mild alloy enforcement, and hard alloy only carries out crown feedback control in the C3 passage; For the medium hardness alloy, adopt the Crown control strategy of hard alloy or mild alloy according to actual conditions in the operation of rolling; Therefore only for thick material, because the passage that profile gauge comes into operation only has 1, in the end a passage is carried out crown feedback control.

Further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, the described export goal convexity of determining each rolling pass band:

2a) determine each passage export goal convexity,, Cn means n passage reciprocal:

$C_{\mathrm{aim}1}=\left\{\begin{array}{c}{C}_{\mathrm{rn}}\\ C_{\mathrm{real}3}\·\frac{h_1}{h_3}\end{array}\right.,$ When C3 passage outlet convexity can be measured

$C_{\mathrm{aim}2}=\left\{\begin{array}{c}{C}_{\mathrm{real}3}\·\frac{h_2}{h_3}\\ C_{\mathrm{rn}}\·\frac{h_2}{h_1}\end{array}\right.,$ When C3 passage outlet convexity can be measured

$C_{\mathrm{aimi}}=C_{\mathrm{rn}}\·\frac{h_i}{h_1},$ When i=3 or i=4

C _aimithe export goal convexity that means i passage reciprocal, μ m, C _rnmean the finished product target convexity that enterprise requires, μ m, C _realimean Ci passage actual measurement outlet convexity, μ m, h _ithe exit thickness that means i passage reciprocal, mm;

2b) when finishing pass is greater than 4 passage, all uncertain to the target convexity of the 5th passage reciprocal from finish rolling the first passage.

Further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, the real-time hot convexity of described working roll is calculated:

3a) adopt the temperature field of two dimensional difference method evaluation work roller each point;

3b) according to the temperature field of working roll, obtain each hot convex value of working roll axial unit constantly;

3c) the comprehensive convexity of working roll is comprised of the initial grinding convexity of working roll and work roll thermal crown, and the former is that roll change is just determined before, in the operation of rolling, remains unchanged, according to the comprehensive convexity of the real-time evaluation work roller of the work roll thermal crown of real-time calculating.

Further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, the setting value of each executing agency of described calculating:

4a) for several passages before the finish rolling stage, have

C _out=E _p·P+E _B·BF+E _WR·C _WR

E _P=f _P(B)，E _B=f _B(B)

C _outmean band outlet convexity, μ m, E _pmean the roll-force influence coefficient, μ m/kN, P means roll-force, kN,

E _bmean the bending roller force influence coefficient, μ m/kN, BF means bending roller force, kN, E _wRmean the comprehensive convexity influence coefficient of working roll, C _wRmean the comprehensive convexity of working roll, μ m, B means rolled piece width, mm, f _p(B), f _b(B), E _wRmean roll-force and bending roller force influence coefficient calculating formula, by emulated data, return and obtain;

4b) for finish rolling several passages of stage Mo, have

C _out=E _p·P+E _C·C _in+E _B·BF+E _WR·C _WR

E _P=f _P(B,D _WR)，E _C=f _C(B,H,h,D _WR)，E _B=f _B(B,D _WR)

C _outmean band outlet convexity, μ m, E _pmean the roll-force influence coefficient, μ m/kN, P means roll-force, kN, E _cmean supplied materials convexity influence coefficient, C _inmean the supplied materials convexity, μ m, E _bmean the bending roller force influence coefficient, μ m/kN, BF means bending roller force, kN, E _wRmean the comprehensive convexity influence coefficient of working roll, C _wRmean the comprehensive convexity of working roll, μ m, B means rolled piece width, mm, D _wRmean work roll diameter, mm, H, h means rolled piece entrance and exit thickness, mm, E _p, E _c, E _bexpression formula and E _wRreturn and obtain by emulated data;

4c) single chassis aluminium hot-rolling mill entrance side and outlet side all are furnished with the cooling jet beam, and it is cooling that the cooling fluid of entrance side is mainly used in basis, and nozzle is distributed as and is uniformly distributed, and according to the difference of alloy rigidity, selects different cooling grades; The cooling grade classification of cooling fluid be strong, in, weak three kinds, the cooling grade that alloy of different hardness adopts is: the corresponding strong cooling grade of hard alloy, cooling grade, the weak cooling grade of mild alloy correspondence in the medium hardness correspondence;

4d) nozzle of outlet side is distributed as quadratic distribution, to adapt to the low characteristics in the middle high both sides of working roll heat expansion; Nozzle is opened number according to coming flitch wide fixed; In order to improve limit section regulating power, the cooling water inflow of limit section is set as 0, for ease of regulating, sprays grade, and the injection level setting of intermediate noxzzle is medium cooling grade, draws thus the injection grade of each nozzle:

$L_N=\mathrm{round}\left\{L_C\right[1-{\left(\frac{X_N}{X_E}\right)}^2]+E_{\mathrm{Lrn}}\}$

L _nthe nozzle ejection grade that expression is N from limit section, L _cthe injection grade that means intermediate noxzzle, X _nmean to be numbered the nozzle abscissa of N, X _ethe abscissa that means intermediate noxzzle, E _lrnmean chilling spray self study coefficient;

4e), for a batch of material of same specification, since the 2nd block of material, the injection grade of its each nozzle is:

$L_N^{\mathrm{SET}}=L_{N,\mathrm{Tail}}^{\mathrm{ACT}}$

the nozzle ejection grade that expression is N from limit section,

mean the nozzle afterbody actual ejection grade that last rolling off limit section is N.

Again further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, described bending roller force feedforward gain is calculated:

5a) the convexity of bending roller force quick adjustment roll gap, determine the regulated quantity of bending roller force according to the fluctuation size of actual measurement roll-force:

ΔBF=K _BF·ΔP

Δ BF means the bending roller force size that needs are regulated, kN, K _bFmean the bending roller force gain coefficient, Δ P means to survey the roll-force undulate quantity;

5b) when AGC comes into operation, the bending roller force gain is tried to achieve by following formula:

$\mathrm{\ΔBF}=K_F\·\frac{\mathrm{CR}}{h}\·\mathrm{\ΔS}+K_F(\frac{1}{C_P}\·\frac{\mathrm{CR}}{h}-\frac{1}{K_P})\mathrm{\ΔP}$

K _fmean that the bending roller force pair roller is the lateral stiffness of flexural deformation impact, kN/mm,

mean the export ratio convexity, Δ S means that roll gap is poor, mm, C _pmean the milling train longitudinal rigidity, kN/mm, K _pmean that the roll-force pair roller is the lateral stiffness of flexural deformation impact, kN/mm.

Again further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, described crown feedback control strategy is formulated:

6a) according to the deviation of profile gauge measured value and convexity desired value, formulate the crown feedback control strategy; Bending roller force and chilling spray are two kinds of means of Crown control, and bending roller force is regulated and is swift in motion, and are applicable to the on-line control convexity; Because single-frame double-coiling aluminium hot-rolling mill is equipped with the bikini profile gauge, by the mode presetted, control convexity;

6b) with target convexity deviation, in the convexity fluctuation range of permission the time, do not need plate shape is regulated when outlet convexity that profile gauge is measured; When deviate is greater than the convexity fluctuation range of permission and while being less than bending roller force regulation and control high-low limit, use bending roller force to regulate the convexity deviation; Guarantee glacing flatness well and the strategy adjustment bending roller force of sacrifice convexity otherwise use;

6c) crown feedback of single chassis hot-rolling mill is only controlled and is carried out in current pass, can only regulate the bending roller force of current pass, adjusts the chilling spray flow and adjusts convexity, to improve the bending roller force regulation and control effect of next piece material;

6d) use the single chassis hot-rolling mill to be rolled, have at most 2 passages to carry out crown feedback control;

6e) the influence coefficient value of crown feedback in controlling is given according to alloy, thickness, width interval by the convexity setting model.

Again further, above-mentioned single-frame double-coiling aluminium hot-rolling mill convex degree control method, describedly improve the convexity setting accuracy by Model Self-Learning:

7a) before carrying out self study, carry out self adaptation according to measured value, just start self study after the self adaptation through certain number of times, bending roller force model coefficient self adaptation formula is:

$K_{\mathrm{BF}\_\mathrm{new}}=K_{\mathrm{BF}\_\mathrm{old}}+(\frac{{\mathrm{BF}}_m}{{\mathrm{BF}}_c}-K_{\mathrm{BF}\_\mathrm{old}})\×\mathrm{VAD}$

K _{bF_new}for new bending roller force model coefficient, K _{bF_old}for old bending roller force model coefficient, BF _mfor bending roller force measured value, BF _cfor the bending roller force value calculated with measured value, VAD is total gain amplifier;

7b), through after 15～20 self adaptations, carrying out self study, the bending roller force self learning model is

L _{BF_new}=L _{BF_old}+(K _{BF_new}-L _{BF_old})×VP

L _{bF_new}for new bending roller force self study coefficient, L _{bF_old}for old adaptive bending roller force self study coefficient, the K of not yet passing through _{bF_new}for the adaptive model coefficient of process, VP is the self study amplification coefficient;

7c) chilling spray pattern self study computational methods and bending roller force self study coefficient are similar, and concrete calculating formula is:

$E_{\mathrm{LrnN}}^{\mathrm{Cur}}=L_N^{\mathrm{ACT}}-L_N^{\mathrm{SET}}$

$E_{\mathrm{LrnN}}^{\mathrm{New}}=E_{\mathrm{LrnN}}^{\mathrm{Old}}+(E_{\mathrm{LrnN}}^{\mathrm{Cur}}-E_{\mathrm{LrnN}}^{\mathrm{Old}})\·\mathrm{\β}$

mean N the self study coefficient that nozzle is current; the actual spray flow that means N nozzle,

the initial setting flow that means N nozzle,

the new self study coefficient that means N nozzle,

mean the old self study coefficient of N nozzle, β means the self study gain coefficient.

The substantive distinguishing features that technical solution of the present invention is outstanding and significant progressive being mainly reflected in:

1. single-frame double-coiling aluminium hot-rolling mill Crown control system can be rolled the passage convexity and automatically presets and FEEDBACK CONTROL, has made up the deficiency by artificial experience control panel shape; Also reduced the dependence to operative employee's experience, can, when improving the product strip shape quality, guarantee the stability of strip shape quality simultaneously;

2. adopt head to preset the uniformity that the strategy of controlling with band middle part crown feedback can realize under the prerequisite good in the outlet glacing flatness guaranteeing full belt length outlet convexity;

3. according to theoretical derivation of plate shape, obtain in the setting computing formula of good glacing flatness and convexity, taken into full account the impact of chilling spray for Gap crown, the size of nozzle distribution, spray flow and cooling water inflow by setting cooling fluid is controlled roll crown, thereby alleviated the adjusting burden of bending roller force, each control measures that occurred while having avoided by the artificial experience rolling all reach the unfavorable condition of production of the limit, have extended the service life of equipment when improving the quality of products.

The accompanying drawing explanation

Below in conjunction with accompanying drawing, technical solution of the present invention is described further:

Fig. 1 is the overall Crown control policy map (illustrate: C1～C4 passage means that respectively rolling passage last is to the fourth from the last passage) by different qualified kinds and specification institution;

The two-dimensional grid division figure that Fig. 2 is evaluation work roller heat expansion;

Fig. 3 is the crown feedback control block diagram.

The specific embodiment

The present invention sets and calculates and FEEDBACK CONTROL material volume convexity to be rolled, guarantees to realize the uniformity of convexity in the band length range under the prerequisite good at the outlet strip flatness, thereby overcomes the shortcoming of artificial experience control panel shape.The main method step is as follows:

(1) overall Crown control policy development.

Overall Crown control strategy is under the prerequisite of existing plate shape control device, thereby solve maximum effect how to bring into play these control devices, avoids bending roller force and chilling spray to use irrational problem, thereby reaches purpose of the present invention.

Because Crown control of the present invention is to carry out under the good prerequisite of outlet glacing flatness guaranteeing, so the crown feedback passage that comes into operation is subject to the restriction of the factors such as product thickness, product material.

1a) alloy soft or hard degree difference, its Crown control strategy also can be distinguished to some extent.In the present invention, 5xxx is associated to gold and is defined as hard alloy, 1xxx be, 8xxx system, and part 3xxx be associated gold and be defined as mild alloy, all the other 3xxx are associated to gold and are defined as the medium hardness alloy.

1b) finish to gauge thickness difference, its Crown control strategy also can be different.In the present invention, in rules, containing 3 material volumes that batch passage, being defined as thin material, and in rules, containing 1 or 2 material volume that batches passage, being defined as thick material.

1c) the overall Crown control strategy of single-frame double-coiling aluminium hot-rolling mill as shown in Figure 1.At rough rolling step, each passage band outlet flakiness ratio is smaller, and the band lateral flow is larger, can not produce plate shape problem, therefore can adopt experience bending roller force (general balance bending roller force) to carry out rolling.Different from hot continuous rolling, the single chassis aluminium hot-rolling mill still has less flakiness ratio at front several passage outlet bands of finish rolling, and the method for employing experience bending roller force is rolled and does not there will be plate shape problem.

1d) from C4 passage (inverse of the operation of rolling the 4th passage, lower same), start, according to alloy soft or hard degree and finished product thickness, implement different Crown control strategies.For thin material, the passage that its operation of rolling camber instrument comes into operation has 2, and the passage of therefore implementing crown feedback control has at most two, and this depends on the soft or hard degree of alloy.In general, mild alloy has higher convexity adjustability than hard alloy, so 2 crown feedbacks control passage strategies of mild alloy enforcement, and hard alloy only carries out crown feedback control in the C3 passage.For the medium hardness alloy, in the operation of rolling, can adopt according to actual conditions the Crown control strategy of hard alloy or mild alloy.Therefore only for thick material, because the passage that profile gauge comes into operation only has 1, in the end a passage is carried out crown feedback control.

(2) determine the export goal convexity of each rolling pass band.

Its final goal of the work that the present invention does is to guarantee under the good prerequisite of glacing flatness, makes final pass band outlet convexity hit value in length range.For the single chassis aluminium hot-rolling mill, the overall process that is worked into finished product aluminium volume from the supplied materials aluminium ingot all completes at this milling train, therefore the whole operation of rolling is divided into to roughing and two stages of finish rolling, and it is line of demarcation that heavy pruning shearing stub bar material tail passage is take in roughing and finish rolling.Because rough rolling step does not relate to the Crown control problem, so a convex degree control method of the present invention passage for the finish rolling stage.

Convexity and glacing flatness are two indexs of plate shape, relevant between the two, and Crown control need carry out under the prerequisite good in the assurance glacing flatness.In general, good in order to guarantee to export glacing flatness, need to meet band entrance cross-section shape and the similar condition of outlet shape of cross section, be also that entrance ratio convexity equates with the export ratio convexity.But roll for aluminothermy, because several passages before finish rolling have less flakiness ratio, metal can produce certain lateral flow on width, even if there are certain difference in band entrance ratio convexity and export ratio convexity, as long as this difference, in the scope of special formula regulation that continues, just can not produce flatness defects.Can make accordingly the target convexity of each passage.

2a) determine the method for each passage (Cn means n passage reciprocal) export goal convexity:

$C_{\mathrm{aim}1}=\left\{\begin{array}{c}{C}_{\mathrm{rn}}\\ C_{\mathrm{real}3}\·\frac{h_1}{h_3}\end{array}\right.,$ When C3 passage outlet convexity can be measured.

$C_{\mathrm{aim}2}=\left\{\begin{array}{c}{C}_{\mathrm{real}3}\·\frac{h_2}{h_3}\\ C_{\mathrm{rn}}\·\frac{h_2}{h_1}\end{array}\right.,$ When C3 passage outlet convexity can be measured.

$C_{\mathrm{aimi}}=C_{\mathrm{rn}}\·\frac{h_i}{h_1},$ When i=3 or i=4.

C _aimithe export goal convexity that means i passage reciprocal, μ m, C _rnmean the finished product target convexity that enterprise requires, μ m, C _realimean Ci passage actual measurement outlet convexity, μ m, h _ithe exit thickness that means i passage reciprocal, mm.

2b) when finishing pass is greater than 4 passage, the target convexity from finish rolling the first passage to the 5th passage reciprocal does not all need to determine.

(3) the real-time hot convexity of working roll is calculated.

The working roll heat expansion for the impact of Gap crown and bending roller force for the impact of Gap crown with the order of magnitude, and because the single chassis hot-rolling mill needs all passages of rolling from the aluminium ingot to the finished product, its working roll heat expansion changes frequent, and can not obtain working roll heat expansion value by measurement means, therefore can only obtain the real-time hot convexity of working roll by the method for calculating.

Therefore 3a) set up the parted pattern of working roll in circular cylindrical coordinate, because roll often circles, circumferentially the boundary condition of each unit is the same, can be the working roll model simplification only to consider axially and the two dimensional model of unit radially, as shown in Figure 2.Adopt the two dimensional difference method to come the temperature field of evaluation work roller each point, can also improve computational speed like this when guaranteeing precision, be adapted at line computation.

3b) according to the temperature field of working roll, can obtain each hot convex value of working roll axial unit constantly.

3c) the comprehensive convexity of working roll is comprised of the initial grinding convexity of working roll and work roll thermal crown, the former is that roll change is just determined before, in the operation of rolling, remain unchanged, the work roll thermal crown that therefore basis is calculated in real time just can the real-time comprehensive convexity of evaluation work roller.

(4) calculate the setting value of each executing agency.

Start to drop in a period of time of FEEDBACK CONTROL (head) to profile gauge from threading, can only lean on the setting value of each executing agency to guarantee the convexity of this section band.Setting value accurately whether directly affect head convexity precision, therefore need to carry out analog simulation to the operation of rolling, obtain Gap crown and affect the relational expression between the Gap crown factor.

4a) for several passages before the finish rolling stage, have

C _out=E _p·P+E _B·BF+E _WR·C _WR ⑴

E _P=f _P(B)，E _B=f _B(B)

C _outmean band outlet convexity, μ m, E _pmean the roll-force influence coefficient, μ m/kN, P means roll-force, kN,

E _bmean the bending roller force influence coefficient, μ m/kN, BF means bending roller force, kN, E _wRmean the comprehensive convexity influence coefficient of working roll, C _wRmean the comprehensive convexity of working roll, μ m, B means rolled piece width, mm, f _p(B), f _b(B), E _wRmean roll-force and bending roller force influence coefficient calculating formula, by emulated data, return and obtain.

4b) for finish rolling several passages of stage Mo, have

C _out=E _p·P+E _C·C _in+E _B·BF+E _WR·C _WR ⑵

E _P=f _P(B,D _WR)，E _C=f _C(B,H,h,D _WR)，E _B=f _B(B,D _WR)

C _outmean band outlet convexity, μ m, E _pmean the roll-force influence coefficient, μ m/kN, P means roll-force, kN, E _cmean supplied materials convexity influence coefficient, C _inmean the supplied materials convexity, μ m, E _bmean the bending roller force influence coefficient, μ m/kN, BF means bending roller force, kN, E _wRmean the comprehensive convexity influence coefficient of working roll, C _wRmean the comprehensive convexity of working roll, μ m, B means rolled piece width, mm, D _wRmean work roll diameter, mm, H, h means rolled piece entrance and exit thickness, mm, E _p, E _c, E _bexpression formula and E _wRreturn and obtain by emulated data.

After each passage target convexity is determined, just can utilize (1) and bending roller force that (2) formula is determined each passage sets value.(1), (2) the roll-force in formula with rolling force model calculate, the supplied materials convexity before the outlet convexity of a time.

4c) single chassis aluminium hot-rolling mill entrance side and outlet side all are furnished with the cooling jet beam, and it is cooling that the cooling fluid of entrance side is mainly used in basis, and nozzle is distributed as and is uniformly distributed, and according to the difference of alloy rigidity, selects different cooling grades.The cooling grade classification of cooling fluid be strong, in, weak three kinds, the cooling grade that alloy of different hardness adopts is: the corresponding strong cooling grade of hard alloy, cooling grade, the weak cooling grade of mild alloy correspondence in the medium hardness correspondence.

4d) nozzle of outlet side is distributed as quadratic distribution, to adapt to the low characteristics in the middle high both sides of working roll heat expansion.Nozzle is opened number, and according to coming, flitch is wide to be determined.In order to improve limit section regulating power, the cooling water inflow of limit section is set as 0, for the ease of regulating, sprays grade, and the injection grade of intermediate noxzzle can be set as medium cooling grade, can draw thus the injection grade of each nozzle:

$L_N=\mathrm{round}\left\{L_C\right[1-{\left(\frac{X_N}{X_E}\right)}^2]+E_{\mathrm{Lrn}}\}---\left(3\right)$

L _nthe nozzle ejection grade that expression is N from limit section, L _cthe injection grade that means intermediate noxzzle, X _nmean to be numbered the nozzle abscissa of N, X _ethe abscissa that means intermediate noxzzle, E _lrnmean chilling spray self study coefficient.

4e), for a batch of material of same specification, since the 2nd block of material, the injection grade of its each nozzle is:

$L_N^{\mathrm{SET}}=L_{N,\mathrm{Tail}}^{\mathrm{ACT}}$

the nozzle ejection grade that expression is N from limit section,

mean the nozzle afterbody actual ejection grade that last rolling off limit section is N.

(5) the bending roller force feedforward gain is calculated.

Can guarantee the plate shape of band head by setting value, but the Crown control in full belt length also needs to feedover and control to realize with crown feedback by bending roller force.

In the operation of rolling, because the supplied materials temperature difference, alloying component skewness etc. can cause the fluctuation of roll-force, especially after AGC comes into operation, if the fluctuation of roll-force is not done to any processing, will make Gap crown constantly fluctuation along with the fluctuation of roll-force, thereby cause the continuous variation of outlet convexity.Can adopt bending roller force to feedover to compensate the impact of roll-force fluctuation for Gap crown.

The convexity that 5a) bending roller force can the quick adjustment roll gap, therefore can determine according to the fluctuation size of actual measurement roll-force the regulated quantity of bending roller force:

ΔBF=K _BF·ΔP ⑷

Δ BF means the bending roller force size that needs are regulated, kN, K _bFmean the bending roller force gain coefficient, Δ P means to survey the roll-force undulate quantity.

5b) when AGC comes into operation, the bending roller force gain can be tried to achieve by following formula:

$\mathrm{\ΔBF}=K_F\·\frac{\mathrm{CR}}{h}\·\mathrm{\ΔS}+K_F(\frac{1}{C_P}\·\frac{\mathrm{CR}}{h}-\frac{1}{K_P})\mathrm{\ΔP}---\left(5\right)$

K _fmean that the bending roller force pair roller is the lateral stiffness of flexural deformation impact, kN/mm,

mean the export ratio convexity, Δ S means that roll gap is poor, mm, C _pmean the milling train longitudinal rigidity, kN/mm, K _pmean that the roll-force pair roller is the lateral stiffness of flexural deformation impact, kN/mm.

(6) the crown feedback control strategy is formulated.

Formulate the crown feedback control strategy according to the deviation of profile gauge measured value and convexity desired value.Bending roller force and chilling spray are two kinds of means of Crown control, and bending roller force is regulated and is swift in motion, and are applicable to the on-line control convexity.What because single-frame double-coiling aluminium hot-rolling mill is general, be equipped with is the bikini profile gauge, therefore can't carry out FEEDBACK CONTROL by chilling spray, can only control convexity by the mode presetted.

6a) convexity bias adjustment strategy, when outlet convexity that profile gauge is measured, does not need plate shape is regulated in the convexity fluctuation range of permission the time with target convexity deviation; When deviate is greater than the convexity fluctuation range of permission and while being less than bending roller force regulation and control high-low limit, with bending roller force, regulate the convexity deviation; Otherwise well sacrifice the strategy of convexity and regulate bending roller force with guaranteeing glacing flatness.

6b) with bending roller force, carry out the crown feedback control strategy as shown in Figure 3.From continuous hot-rolling mill use bending roller force carry out Crown control different be, the crown feedback of single chassis hot-rolling mill is controlled and can only be carried out in current pass, can only regulate the bending roller force of current pass, likely do not compensate the convexity error of upstream passage accumulation, adjust convexity thereby need to adjust the chilling spray flow, to improve the bending roller force regulation and control effect of next piece material; Use in addition the single chassis hot-rolling mill to be rolled, can have at most 2 passages to carry out crown feedback control, this is that continuous hot-rolling mill is not available.

6c) the influence coefficient value of crown feedback in controlling is given according to alloy, thickness, width interval by the convexity setting model.

(7) improve the convexity setting accuracy by Model Self-Learning.

Because each coefficient of convexity equation returns and obtains by emulated data, therefore when model is applied to certain a time, calculate setting value and there will be deviation, in order to eliminate the adverse effect of this deviation for Crown control, need to carry out according to measured data the self study coefficient of adjustment model, thereby improve the Crown control precision of follow-up material volume.

7a) before carrying out self study, first according to measured value, to carry out self adaptation, just start self study after the self adaptation through certain number of times, bending roller force model coefficient self adaptation formula is:

$K_{\mathrm{BF}\_\mathrm{new}}=K_{\mathrm{BF}\_\mathrm{old}}+(\frac{{\mathrm{BF}}_m}{{\mathrm{BF}}_c}-K_{\mathrm{BF}\_\mathrm{old}})\×\mathrm{VAD}---\left(6\right)$

K _{bF_new}for new bending roller force model coefficient, K _{bF_old}for old bending roller force model coefficient, BF _mfor bending roller force measured value, BF _cfor the bending roller force value calculated with measured value, VAD is total gain amplifier.

7b), through after 15～20 self adaptations, carrying out self study, the bending roller force self learning model is

L _{BF_new}=L _{BF_old}+(K _{BF_new}-L _{BF_old})×VP ⑺

L _{bF_new}for new bending roller force self study coefficient, L _{bF_old}for old adaptive bending roller force self study coefficient, the K of not yet passing through _{bF_new}for the adaptive model coefficient of process, VP is the self study amplification coefficient.

7c) chilling spray pattern self study computational methods and bending roller force self study coefficient are similar, and concrete calculating formula is:

$E_{\mathrm{LrnN}}^{\mathrm{Cur}}=L_N^{\mathrm{ACT}}-L_N^{\mathrm{SET}}$

$E_{\mathrm{LrnN}}^{\mathrm{New}}=E_{\mathrm{LrnN}}^{\mathrm{Old}}+(E_{\mathrm{LrnN}}^{\mathrm{Cur}}-E_{\mathrm{LrnN}}^{\mathrm{Old}})\·\mathrm{\β}$

mean N the self study coefficient that nozzle is current;

the actual spray flow that means N nozzle,

the initial setting flow that means N nozzle,

the new self study coefficient that means N nozzle,

mean the old self study coefficient of N nozzle, β means the self study gain coefficient.

The product of 2400 single reversing hot mill with coilers located on each side of the mill productions of certain aluminum fabrication plant of below take illustrates embodiments of the present invention as example.

The material volume information of choosing is: alloy designations 3003, and the wide 1290mm of plate, finish to gauge thickness 7mm, the total passage of rolling is 20,7 of finishing passes wherein batch 3 of passages.Finish rolling stage supplied materials thickness is 100mm.

Adopt artificial experience to set the bending roller force value of last several rolling passes, as shown in table 1.

Table 1

Table 2

Be 5.9 μ m from the total length measured value of the C1 passage shown in table 2 (passage last, lower same), be starkly lower than target convex value (35 μ m).From table 1, can see, the total length bending roller force measured value of C1 passage is-1831kN, extremely approaches the least limit (2200kN) of bending roller force, and this explanation is if improve the outlet convexity of C1 passage, the regulating measure of bending roller force is very limited, leans on the adjusting of bending roller force still not reach the target convexity.And the total length of C4 actual measurement bending roller force is 900kN, (exist relation between bending roller force and Gap crown: bending roller force is larger to also have very large roller regulating power, Gap crown is less, and rolling band convexity out is also just less), this illustrates that current convexity allocation strategy is also irrational.

During from the rolling of C1 passage, the distribution curve of milling train outlet actual measurement convexity can be seen, in length range, the uniformity of convexity is poor, and its fluctuation range is-50 μ m～30 μ m, and especially at head, its fluctuation range is larger.

A kind of single-frame double-coiling aluminium hot-rolling mill Crown control systems approach provided by the invention, its concrete implementation step is:

1) overall Crown control policy development.It is 3003 that material to be rolled intervolves gold, belongs to the mild alloy kind in strategy.The finish to gauge exit thickness is 7mm, in the operation of rolling, has 3 to batch passage, belongs to the category of thin material, so the Crown control strategy should be carried out the overall Crown control strategy of the thin material of mild alloy.

2) determine the target convexity of each passage.As can see from Figure 1, only have last 4 passages need to set calculating, therefore also only need to determine the target convexity of these 4 passages.Because the convexity of C3 passage can be measured, therefore the target convexity allocation result of last 4 passages is as shown in table 3.

Table 3

3) work roll thermal crown is calculated.The calculating of the real-time hot convexity of working roll is completed by the heat expansion program.Program read the variation of rolling state and working roll boundary condition every 2 seconds, calculate the real-time hot convexity of one action roller, and the hot convex value calculated each time is stored in work roll thermal crown and calculates in journal file.Therefore when carrying out convexity setting calculating, can from journal file, read required hot convexity data.

4) calculate the setting value of each executing agency.After obtaining the real-time hot convex value of working roll, just can according to (1) formula and (2) formula calculate bending roller force and set value, determine the injection rank of each nozzle according to (3) formula.

Therefore in C4 and C3 passage, flakiness ratio is respectively 46 and 76, all is less than 100, calculates bending roller force according to (1) formula, and the expression formula of bending roller force is

$\mathrm{BF}=\frac{C_{\mathrm{out}}-(E_p\·P+E_{\mathrm{WR}}\·C_{\mathrm{WR}})}{E_B}$

Therefore in C2 and C1 passage, flakiness ratio is respectively 112 and 184, all is greater than 100, calculates bending roller force according to (2) formula, and the expression formula of bending roller force is

$\mathrm{BF}=\frac{C_{\mathrm{out}}-(E_p\·P+E_C\·C_{\mathrm{in}}+E_{\mathrm{WR}}\·C_{\mathrm{WR}})}{E_B}$

If meet through the more stable bending roller force value formed after self study

BF>BF _max80% or BF<BF _min80%

BF _max, BF _minrepresent respectively the maximum bending roller force value of equipment and minimum bending roller force value.

Illustrate that now bending roller force is bigger than normal, because chilling spray is a slow process for the impact of convexity, therefore need to reduce by regulating work roll thermal crown the burden of follow-up material volume bending roller force.After the relation of having determined between the cooling jet regularity of distribution, cooling uninterrupted and cooling water inflow and work roll thermal crown, just can change the condition that these affect work roll thermal crown, reduce the bending roller force setting value, thereby control larger bending roller force regulated quantity is provided for crown feedback.

5) the bending roller force feedforward gain is calculated.In the operation of rolling, roll-force can be measured, thereby can be according to the poor bending roller force value of adjusting of actual measurement roll-force, and when AGC drops into and do not come into operation, bending roller force gain calculating formula is that institute is distinguishing.

After threading, just can be rolled force measurement, now the bending roller force setting value is also inoperative, therefore can adjust and set the bending roller force value according to the bending roller force deviation of calculating; After crown feedback control is come into operation, the purpose of FEEDFORWARD CONTROL is mainly to compensate the bending roller force deviate according to the roll-force undulating value, thereby keeps the stable of roll gap lateral stiffness, obtains good convexity and glacing flatness.

6) crown feedback is controlled and is realized.The passage that FEEDBACK CONTROL only satisfies condition just is performed, and in this example, in the C3 passage, carries out the crown feedback control strategy.In the C3 passage, according to the special formula that continues, the entrance and exit ratio convexity of this passage is poor to be met

$-0.0254\&le;\frac{C_{\mathrm{in}}}{H}-\frac{C_{\mathrm{out}}}{h}\&le;0.0127$

The adjustable range of bending roller force must guarantee that entrance and exit ratio convexity is poor within this scope, otherwise the situation that plate shape is bad may occur.

7) Model Self-Learning is realized.In the operation of rolling, the process datas such as bending roller force, roll-force, outlet convexity can be measured, and therefore can carry out self study to model according to actual measurement data, to improve the precision of model.

Head at rolled strip, (10 milliseconds) get a sampled point at regular intervals, gather 10 sampled points, and these 5 sampled points are averaged, sample data as this sampling, 10～15 groups of sample datas of continuous acquisition are as the sample of model adaptation, every group of sample calculates an adaptation value according to (6) formula, through after 10～15 self adaptations, calculate the self study coefficient of this volume by (7) formula, then upgrade the same specification alloy Constant in the self study table, during for follow-up same specification alloy rolling.

Along with the continuous increase of rolling material volume, the self study coefficient value in the self study table tends towards stability gradually, and rolling material volume head convexity and strip shape quality out also just can constantly improve.

By step as above, solved in current production the following problem existed:

1) lack according to the theoretical bending roller force computation model of deriving of plate shape.

2) can't the Accurate Prediction work roll thermal crown, the plate shape control ability of chilling spray can't be given full play of.

3), by manual adjustment plate shape, can't reach all good purposes of glacing flatness and convexity.

The present invention formulates the Crown control strategy of single-frame double-coiling hot rolling according to characteristics and the on-the-spot rolling experience of this type milling train, foundation is applicable to the convexity preset model of single chassis, the heat expansion computation model, the feedforward of convexity and feedback control system, realize that Aluminum Plate and Strip well controls in full-automatic convexity and the glacing flatness of this kind of mill milling, , (press alloy species according to the alloy feature of band, hardness, the division such as quality requirement and finished product thickness) formulate corresponding Crown control strategy, by convexity preset model and the roughing of heat expansion model, bending roller force setting value and the chilling spray pattern of two rolling sequences of finish rolling guarantee the head convex value, carry out the feedforward compensation of bending roller force at finishing pass to reduce the impact of roll-force fluctuation on convexity, carry out the bending roller force closed-loop control to guarantee total length convexity and plate shape in the passage third from the bottom that can carry out convex measuring or extreme trace according to alloy feature situation, after finishing, rolling carries out the self study of bending roller force and chilling spray model, improve the preset model precision.The present invention can guarantee that Aluminum Plate and Strip reaches the target convex value in head and length range when the single reversing hot mill with coilers located on each side of the mill rolling, keeps good plate shape simultaneously, improves the economic benefit of enterprise.

Need to understand: the above is only the preferred embodiment of the present invention; for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (8)

1. single-frame double-coiling aluminium hot-rolling mill convex degree control method is characterized in that comprising the following steps:

(1) overall Crown control policy development;

(2) determine the export goal convexity of each rolling pass band;

(3) the real-time hot convexity of working roll is calculated;

(4) calculate the setting value of each executing agency;

(5) the bending roller force feedforward gain is calculated;

(6) the crown feedback control strategy is formulated;

(7) improve the convexity setting accuracy by Model Self-Learning.

2. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1, it is characterized in that: described overall Crown control policy development, press aluminium alloy kind, hardness, quality requirement and finished product thickness and divide the alloy feature of aluminum strip, and formulate corresponding Crown control strategy: the alloy species difference, its rolling strategy and finish to gauge require also different, alloy soft or hard degree difference, its Crown control strategy is difference to some extent also; Finish to gauge thickness difference, its Crown control strategy of rolled plate or coiled material is also different;

1a) formulation of Crown control strategy need be considered the product quality emphasis of variety classes alloy, output, temperature, surface quality and plate shape are 4 important quality index of board rolling, when with output or temperature when paying the utmost attention to index, for the control of convexity, require to reduce; When with surface quality when paying the utmost attention to target, the convexity closed-loop control need to shift to an earlier date passage and carry out, and affects surface quality of strips to reduce extreme trace time convexity to regulate; When with plate shape when paying the utmost attention to index, need to optimize corresponding sharing of load to guarantee exit plate shape; Sometimes take several quality index during as common priority target, need to formulate corresponding Crown control strategy;

1b) at rough rolling step, each passage band outlet flakiness ratio is smaller, and the band lateral flow is larger, adopts the rolling of experience bending roller force; From the C4 passage, the inverse of the operation of rolling the 4th passage, implement different Crown control strategies according to alloy soft or hard degree and finished product thickness; For thin material, the passage that its operation of rolling camber instrument comes into operation has 2, and the passage of therefore implementing crown feedback control has at most two, depends on the soft or hard degree of alloy; Mild alloy has higher convexity regulating power than hard alloy, so 2 crown feedbacks control passage strategies of mild alloy enforcement, and hard alloy only carries out crown feedback control in the C3 passage; For the medium hardness alloy, adopt the Crown control strategy of hard alloy or mild alloy according to actual conditions in the operation of rolling; Therefore only for thick material, because the passage that profile gauge comes into operation only has 1, in the end a passage is carried out crown feedback control.

3. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1 is characterized in that: the described export goal convexity of determining each rolling pass band:

2a) determine each passage export goal convexity,, Cn means n passage reciprocal:

$C_{\mathrm{aim}1}=\left\{\begin{array}{c}{C}_{\mathrm{rn}}\\ C_{\mathrm{real}3}\&CenterDot;\frac{h_1}{h_3}\end{array}\right.,$ When C3 passage outlet convexity can be measured

$C_{\mathrm{aim}2}=\left\{\begin{array}{c}{C}_{\mathrm{real}3}\&CenterDot;\frac{h_2}{h_3}\\ C_{\mathrm{rn}}\&CenterDot;\frac{h_2}{h_1}\end{array}\right.,$ When C3 passage outlet convexity can be measured

$C_{\mathrm{aimi}}=C_{\mathrm{rn}}\&CenterDot;\frac{h_i}{h_1},$ When i=3 or i=4

C _aimithe export goal convexity that means i passage reciprocal, μ m, C _rnmean the finished product target convexity that enterprise requires, μ m, C _realimean Ci passage actual measurement outlet convexity, μ m, h _ithe exit thickness that means i passage reciprocal, mm;

2b) when finishing pass is greater than 4 passage, all uncertain to the target convexity of the 5th passage reciprocal from finish rolling the first passage.

4. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1 is characterized in that: the real-time hot convexity of described working roll is calculated:

3a) adopt the temperature field of two dimensional difference method evaluation work roller each point;

3b) according to the temperature field of working roll, obtain each hot convex value of working roll axial unit constantly;

3c) the comprehensive convexity of working roll is comprised of the initial grinding convexity of working roll and work roll thermal crown, and the former is that roll change is just determined before, in the operation of rolling, remains unchanged, according to the comprehensive convexity of the real-time evaluation work roller of the work roll thermal crown of real-time calculating.

5. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1 is characterized in that: the setting value of each executing agency of described calculating:

4a) for several passages before the finish rolling stage, have

C _out=E _p·P+E _B·BF+E _WR·C _WR

E _P=f _P(B)，E _B=f _B(B)

C _outmean band outlet convexity, μ m, E _pmean the roll-force influence coefficient, μ m/kN, P means roll-force, kN,

E _bmean the bending roller force influence coefficient, μ m/kN, BF means bending roller force, kN, E _wRmean the comprehensive convexity influence coefficient of working roll, C _wRmean the comprehensive convexity of working roll, μ m, B means rolled piece width, mm, f _p(B), f _b(B), E _wRmean roll-force and bending roller force influence coefficient calculating formula, by emulated data, return and obtain;

4b) for finish rolling several passages of stage Mo, have

C _out=E _p·P+E _C·C _in+E _B·BF+E _WR·C _WR

E _P=f _P(B,D _WR)，E _C=f _C(B,H,h,D _WR)，E _B=f _B(B,D _WR)

C _outmean band outlet convexity, μ m, E _pmean the roll-force influence coefficient, μ m/kN, P means roll-force, kN, E _cmean supplied materials convexity influence coefficient, C _inmean the supplied materials convexity, μ m, E _bmean the bending roller force influence coefficient, μ m/kN, BF means bending roller force, kN, E _wRmean the comprehensive convexity influence coefficient of working roll, C _wRmean the comprehensive convexity of working roll, μ m, B means rolled piece width, mm, D _wRmean work roll diameter, mm, H, h means rolled piece entrance and exit thickness, mm, E _p, E _c, E _bexpression formula and E _wRreturn and obtain by emulated data;

4c) single chassis aluminium hot-rolling mill entrance side and outlet side all are furnished with the cooling jet beam, and it is cooling that the cooling fluid of entrance side is mainly used in basis, and nozzle is distributed as and is uniformly distributed, and according to the difference of alloy rigidity, selects different cooling grades; The cooling grade classification of cooling fluid be strong, in, weak three kinds, the cooling grade that alloy of different hardness adopts is: the corresponding strong cooling grade of hard alloy, cooling grade, the weak cooling grade of mild alloy correspondence in the medium hardness correspondence;

4d) nozzle of outlet side is distributed as quadratic distribution, to adapt to the low characteristics in the middle high both sides of working roll heat expansion; Nozzle is opened number according to coming flitch wide fixed; In order to improve limit section regulating power, the cooling water inflow of limit section is set as 0, for ease of regulating, sprays grade, and the injection level setting of intermediate noxzzle is medium cooling grade, draws thus the injection grade of each nozzle:

$L_N=\mathrm{round}\left\{L_C\right[1-{\left(\frac{X_N}{X_E}\right)}^2]+E_{\mathrm{Lrn}}\}$

L _nthe nozzle ejection grade that expression is N from limit section, L _cthe injection grade that means intermediate noxzzle, X _nmean to be numbered the nozzle abscissa of N, X _ethe abscissa that means intermediate noxzzle, E _lrnmean chilling spray self study coefficient;

4e), for a batch of material of same specification, since the 2nd block of material, the injection grade of its each nozzle is:

$L_N^{\mathrm{SET}}=L_{N,\mathrm{Tail}}^{\mathrm{ACT}}$

the nozzle ejection grade that expression is N from limit section,

mean the nozzle afterbody actual ejection grade that last rolling off limit section is N.

6. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1 is characterized in that: described bending roller force feedforward gain is calculated:

5a) the convexity of bending roller force quick adjustment roll gap, determine the regulated quantity of bending roller force according to the fluctuation size of actual measurement roll-force:

ΔBF=K _BF·ΔP

Δ BF means the bending roller force size that needs are regulated, kN, K _bFmean the bending roller force gain coefficient, Δ P means to survey the roll-force undulate quantity;

5b) when AGC comes into operation, the bending roller force gain is tried to achieve by following formula:

$\mathrm{\&Delta;BF}=K_F\&CenterDot;\frac{\mathrm{CR}}{h}\&CenterDot;\mathrm{\&Delta;S}+K_F(\frac{1}{C_P}\&CenterDot;\frac{\mathrm{CR}}{h}-\frac{1}{K_P})\mathrm{\&Delta;P}$

K _fmean that the bending roller force pair roller is the lateral stiffness of flexural deformation impact, kN/mm,

mean the export ratio convexity, Δ S means that roll gap is poor, mm, C _pmean the milling train longitudinal rigidity, kN/mm, K _pmean that the roll-force pair roller is the lateral stiffness of flexural deformation impact, kN/mm.

7. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1 is characterized in that: described crown feedback control strategy is formulated:

6a) according to the deviation of profile gauge measured value and convexity desired value, formulate the crown feedback control strategy; Bending roller force and chilling spray are two kinds of means of Crown control, and bending roller force is regulated and is swift in motion, and are applicable to the on-line control convexity; Because single-frame double-coiling aluminium hot-rolling mill is equipped with the bikini profile gauge, by the mode presetted, control convexity;

6b) with target convexity deviation, in the convexity fluctuation range of permission the time, do not need plate shape is regulated when outlet convexity that profile gauge is measured; When deviate is greater than the convexity fluctuation range of permission and while being less than bending roller force regulation and control high-low limit, use bending roller force to regulate the convexity deviation; Guarantee glacing flatness well and the strategy adjustment bending roller force of sacrifice convexity otherwise use;

6c) crown feedback of single chassis hot-rolling mill is only controlled and is carried out in current pass, can only regulate the bending roller force of current pass, adjusts the chilling spray flow and adjusts convexity, to improve the bending roller force regulation and control effect of next piece material;

6d) use the single chassis hot-rolling mill to be rolled, have at most 2 passages to carry out crown feedback control;

6e) the influence coefficient value of crown feedback in controlling is given according to alloy, thickness, width interval by the convexity setting model.

8. single-frame double-coiling aluminium hot-rolling mill convex degree control method according to claim 1 is characterized in that: describedly by Model Self-Learning, improve the convexity setting accuracy:

7a) before carrying out self study, carry out self adaptation according to measured value, just start self study after the self adaptation through certain number of times, bending roller force model coefficient self adaptation formula is:

$K_{\mathrm{BF}\_\mathrm{new}}=K_{\mathrm{BF}\_\mathrm{old}}+(\frac{{\mathrm{BF}}_m}{{\mathrm{BF}}_c}-K_{\mathrm{BF}\_\mathrm{old}})\&times;\mathrm{VAD}$

K _{bF_new}for new bending roller force model coefficient, K _{bF_old}for old bending roller force model coefficient, BF _mfor bending roller force measured value, BF _cfor the bending roller force value calculated with measured value, VAD is total gain amplifier;

7b), through after 15～20 self adaptations, carrying out self study, the bending roller force self learning model is

L _{BF_new}=L _{BF_old}+(K _{BF_new}-L _{BF_old})×VP

L _{bF_new}for new bending roller force self study coefficient, L _{bF_old}for old adaptive bending roller force self study coefficient, the K of not yet passing through _{bF_new}for the adaptive model coefficient of process, VP is the self study amplification coefficient;

7c) chilling spray pattern self study computational methods and bending roller force self study coefficient are similar, and calculating formula is:

$E_{\mathrm{LrnN}}^{\mathrm{Cur}}=L_N^{\mathrm{ACT}}-L_N^{\mathrm{SET}}$

$E_{\mathrm{LrnN}}^{\mathrm{New}}=E_{\mathrm{LrnN}}^{\mathrm{Old}}+(E_{\mathrm{LrnN}}^{\mathrm{Cur}}-E_{\mathrm{LrnN}}^{\mathrm{Old}})\&CenterDot;\mathrm{\&beta;}$

mean N the self study coefficient that nozzle is current;

the actual spray flow that means N nozzle,

the initial setting flow that means N nozzle,

the new self study coefficient that means N nozzle,

mean the old self study coefficient of N nozzle, β means the self study gain coefficient.

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