CN102513373B - Cold rolled plate shape residual eliminating method - Google Patents

Abstract

The invention relates to a cold rolled plate shape residual eliminating method, in particular to a method that each cooling sub region of a rolling roller including a work roller is firstly provided with a cooling liquid switch valve, and then, the switch valve is effectively controlled according to the proportional integral (PI) closed-loop control principle and the heat transfer principle between the rolling roller and the cooling liquid for eliminating the cold rolled plate shape residual on the corresponding cooling sub region. Compared with the prior art, the cold rolled plate shape residual eliminating method has following main beneficial effects that a key problem of a cold rolled plate shape control system can be solved, the equipment cost can be saved, the electric control system cost can be saved, the control effect of the sheet-shaped residual can be effectively ensured, and the service life of equipment can be prolonged.

Description

Cold rolled plate shape residual eliminating method

Technical field

The present invention relates to cold rolled strip steel production field, particularly relate to a kind of cold rolled plate shape residual eliminating method.

Background technology

Plate shape precision is a main quality index with steel and the key factor that determines its market competitiveness.Along with improving constantly that the industrial users such as automobile, light industry, household electrical appliances and Electric Manufacture require strip shape quality, plate shape control technology has become one of steel rolling field the most complicated most crucial technology, is the another hot issue of countries in the world developmental research after thickness of slab control.

Domestic main cold rolled strip steel production factory is all used plate shape control technology and control system on rolling mill production line, and the basic dependence on import of these plat control systems.At present only have in the world the famous trans-corporations of only a few such as German western mark, Sweden ABB can provide a complete set of industrial production required cold rolled sheet shape control technology and control system, expensive price has seriously limited cold rolled sheet shape control technology and control system in Chinese application.So plat control system also becomes one of important goal of domestic steel industry research and development breakthrough.

Plate shape refers to the warpage degree of sheet material, its essence is the distribution referring to steel internal residual stress.In cold rolling production, the implication of plate shape refers to the glacing flatness with steel, namely poor with the tensile stress in steel broad ways.In fact, the implication of plate shape also comprises the lateral thickness difference with steel, the just glacing flatness of plate shape of the plate shape representative that generally we mention, and do not consider lateral thickness difference.Conventional plate shape method for expressing has: " relative length difference representation ", " the poor representation of tensile stress ", " crown of strip representation ", " waveform representation " etc.

At present, it is the six-high cluster mill that intermediate calender rolls can move horizontally that conventional plate shape is controlled milling train, the major function of such Mill shape closed-loop control system is: first measure the actual plate shape under current state by plate shape measurement roller, then actual plate shape is compared with target flatness and obtain plate shape deviation signal, again dependent deviation signal is calculated to the controlled quentity controlled variable of press control, bend roller mechanism of battery and cooling fluid governor motion by certain control strategy, reach the object of closed-loop control plate shape.

As the feedback detecting unit of plate shape closed-loop control system, extensively adopt plate shape roller to reflect the plate shape with steel by the tension variation of measuring in strip width direction at plate shape control field at present.Although the measuring principle of various plate shape rollers and the mounting means of sensor are had nothing in common with each other, be all to reflect with the plate shape on steel cross section along the measurement data in each region in strip width direction.

Plate shape is controlled the control being actually roll gap shape, the namely control to roll forming.When rolling, only have and adjust at any time and the correct roll forming of controlling, could effectively compensate the variation of roll forming, obtain the good high-precision product of plate shape.

As shown in Figure 1, at present main plate shape closed-loop control means have: inclination control, intermediate calender rolls roller, work roll bending, intermediate calender rolls are traversing, cooling fluid is sprayed and controlled five kinds of regulating measures, in the six-high cluster mill that can move horizontally at intermediate calender rolls, the deviation of actual plate shape and target flatness is mainly revised by inclination, intermediate calender rolls roller, work roll bending, and remaining residual error is sprayed to control by cooling fluid and further revised.Concrete operations are as follows:

(1) support roller inclination press control: the one-sided swing of depressing by control, is actually the monolateral drafts of accommodation zone steel and eliminates the monolateral wave with steel.

(2) the roller control of working roll and intermediate calender rolls: by regulating the amount of deflection of working roll and intermediate calender rolls, can eliminate band steel middle wave and both sides wave defect.

(3) intermediate calender rolls is traversing: intermediate calender rolls is traversing is the outstanding advantages that six-high cluster mill plate shape is controlled, as shown in Figure 2, basic principle is to make it substantially to equate with the length with steel with the mediate contact length between backing roll by the traversing working roll that reduces of intermediate calender rolls, to eliminate the harmful contact portion between roller, thereby can expand the scope that roll forming is adjusted, the usefulness that increases roll-bending device, reaches belt plate shape control stability good, significantly improves the object of strip profile and flatness.

(4) cooling fluid is sprayed and is controlled: the measured plate shape deviation of plate shape measurement roller deducts roller, tilts to depress etc. after the deviation that can eliminate, obtains plate shape residual deviation, is sprayed to eliminate by cooling fluid.The sampling period that computer follow procedure is set is taken residual deviation, and determines corresponding with it coolant rate.

Summary of the invention

Technical problem to be solved by this invention is: provide a kind of and first for roll comprises each cooling subregion of working roll, a cooling fluid switch valve is set, according to the heat transfer theory between roll and cooling fluid and PI loop control theory, this switch valve is effectively controlled again, to eliminate the method for the cold rolled plate shape residual on corresponding cooling subregion.

The present invention solves its technical problem and adopts following technical scheme:

Cold rolled plate shape residual eliminating method provided by the invention, specifically a kind ofly first for roll comprises each cooling subregion of working roll, a cooling fluid switch valve is set, according to the heat transfer theory between roll and cooling fluid and PI loop control theory, this switch valve is effectively controlled again, to eliminate the method for the cold rolled plate shape residual on corresponding cooling subregion, the method comprises the following steps:

A. the plate shape deviation er[i detecting according to plate shape roller] call formula (1) and calculate the plate shape residual error er on each plate shape measurement district i _f[i]:

${\mathrm{er}}_f\left[i\right]=\mathrm{er}\left[i\right]-\underset{j=1}{\overset{k}{\mathrm{\Σ}}}{p}_j\left[i\right]*v_{\mathrm{aj}}$ (za_os≤i≤za_ds) (1)，

In formula: i is the numbering in plate shape measurement district; K is the quantity of mechanical profile regulation mechanism; Za_os is the numbering in the edge metering district of the actual use of OS side; Za_ds is the edge metering district numbering of the actual use of DS side; Er _f[i] is the plate shape residual error in i plate shape measurement district; v _ajfor the action regulated quantity of the mechanical profile regulation j of mechanism; p _j[i] is the efficiency factor of the mechanical profile regulation j of mechanism on plate shape measurement district i; Er[i] the i plate shape measurement district upper plate shape deviation that detects for plate shape roller;

B. the er calculating according to steps A _f[i], calls formula (2) and calculates the plate shape residual error er on the each cooling subregion j of roll _c[j];

er _c[j]＝convert(er _f[i])(za_os≤i≤za_ds，ca_os≤j≤ca_ds) (2)，

Formula (2) represents the plate shape residual error er corresponding with the cooling subregion of j in formula (1) _f[i] merges into the plate shape residual error of this cooling subregion by the method for averaging, in formula: the numbering that j is cooling subregion; Ca_os is the numbering of the cooling subregion corresponding with za_os; Ca_ds is the numbering of the cooling subregion corresponding with za_ds; Er _c[j] is the plate shape residual error on the cooling subregion of j;

C. the er calculating according to step B _c[j], calls formula (3) and calculates the nominal flow capacity value cool of the each cooling subregion j of roll in the time of the i time profile regulation _i[j];

${\mathrm{cool}}_i\left[j\right]=\left\{\begin{array}{cc}\mathrm{kp}*{\mathrm{er}}_c\left[j\right]+{\mathrm{cool}}_{i-1}\left[j\right]+\mathrm{ki}*{\mathrm{er}}_c\left[j\right]& (\mathrm{kp}>0,\mathrm{ki}>0)\\ \mathrm{kp}*{\mathrm{er}}_c\left[j\right]& (\mathrm{kp}>0,\mathrm{ki}\≤0)\\ 0& (\mathrm{kp}\≤0,\mathrm{ki}\≤0)\end{array}\right.---\left(3\right),$

In formula: i is the number of times that PI regulates; J is the numbering of cooling subregion, ca_os≤j≤ca_ds; Kp is the proportionality coefficient that PI regulates; Ki is the integral coefficient that PI regulates; Cool _i[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i time; Cool _i-1[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i-1 time;

D. the cool calculating according to step C _i[j], calls formula (4) and calculates nominal flow capacity value colim after the limit value of the each cooling subregion j of roll in the time of the i time profile regulation _i[j];

${\mathrm{colim}}_i\left[j\right]=\left\{\begin{array}{cc}{\mathrm{cool}}_i\left[j\right]& (\mathrm{coll}<{\mathrm{cool}}_i[j]<\mathrm{colu})\\ \mathrm{colu}& \left({\mathrm{cool}}_i\right[j]\&GreaterEqual;\mathrm{colu})\\ \mathrm{coll}& \left({\mathrm{cool}}_i\right[j]\&le;\mathrm{coll})\end{array}\right.---\left(4\right),$

In formula: the numbering that j is cooling subregion, ca_os≤j≤ca_ds; Co lim _i[j] is nominal flow capacity value after the limit value of the cooling subregion of j in the time of the i time profile regulation; Coll is the lower limit of each cooling subregion name flow value; Colu is the higher limit of each cooling subregion name flow value, colu>=coll;

E. the colim calculating according to step D _i[j], calls formula (5) and calculates the each cooling subregion j of roll return 1 assumed name justice flow value coln in the time of the i time profile regulation _i[j],

${\mathrm{co}\ln }_i\left[j\right]=\left\{\begin{array}{cc}\mathrm{vll}+\frac{\mathrm{vlu}-\mathrm{vll}}{\mathrm{colu}-\mathrm{coll}}*\left({\mathrm{colim}}_i\right[j]-\mathrm{coll})& (\mathrm{ca}\_\mathrm{os}\&le;j\&le;\mathrm{ca}\_\mathrm{ds})\\ {\mathrm{co}\ln }_i[\mathrm{ca}\_\mathrm{os}]& (j=\mathrm{cas}\_\mathrm{os})\\ {\mathrm{co}\ln }_i[\mathrm{ca}\_\mathrm{ds}]& (j=\mathrm{cas}\_\mathrm{ds})\\ 0& (1\&le;j<\mathrm{cas}\_\mathrm{os})\\ 0& (\mathrm{cas}\_\mathrm{ds}<j\&le;\mathrm{cn})\end{array}\right.---\left(5\right),$

$\mathrm{cas}\_\mathrm{os}=\left\{\begin{array}{cc}1& (\mathrm{ca}\_\mathrm{os}=1)\\ \mathrm{ca}\_\mathrm{os}-1& (\mathrm{ca}\_\mathrm{os}>1)\end{array}\right.---\left(6\right),$

$\mathrm{cas}\_\mathrm{ds}=\left\{\begin{array}{cc}\mathrm{cn}& (\mathrm{ca}\_\mathrm{ds}=\mathrm{cn})\\ \mathrm{ca}\_\mathrm{ds}+1& (\mathrm{ca}\_\mathrm{ds}<\mathrm{cn})\end{array}\right.---\left(7\right),$

In formula: the maximum numbering that cn is cooling subregion; Cas_os is the numbering of the cooling zone, edge of the actual use of OS side; Cas_ds is the numbering of the cooling zone, edge of the actual use of DS side; Coln _i[j] is that the cooling subregion of j is returned 1 assumed name justice flow value in the time of the i time profile regulation; Vll is the lower limit that each cooling subregion is returned 1 assumed name's justice flow value, 0≤vll≤vlu; Vlu is the higher limit that each cooling subregion is returned 1 assumed name's justice flow value, vlu=1.0.

Carry out the each cooling subregion j of roll with switch valve and return 1 assumed name's justice flow value coln when the i time profile regulation _i[j], its step comprises:

(1), in CPU, a fixing valve control periodicity TB is set, for example TB=100; The minimum period that a permission valve opens is set counts TM, for example TM=2; The maximum number cn of cooling subregion is set, for example cn=40;

(2) for the arbitrary cooling subregion j of roll, a cycle counter CNT[j is set in CPU] and an aperture counter OPN[j];

(3) for the arbitrary cooling subregion j of roll, an information bit V[j is set in CPU], V[j]=1 represent the cooling fluid switch valve of the cooling subregion j of roll is opened, V[j]=0 represent the cooling fluid switch valve of the cooling subregion j of roll cuts out;

(4) in each execution cycle TA of the Interruption task of CPU, the each cooling subregion of the cooling subregion 1～cn of breaker roll, take arbitrary cooling subregion j as example, carries out following operation once: make CNT[j successively]=CNT[j]+1; If CNT[j] >=TB, make CNT[j]=0; Make OPN[j]=round (TB*coln _i[j]), that is, make OPN[j] equal TB*coln _ithe integer part of [j]; If CNT[j] < OPN[j] and OPN[j] > TM, make V[j]=1 to represent that the cooling fluid switch valve of the cooling subregion j of roll is opened, otherwise make V[j]=0 to represent that the cooling fluid switch valve of the cooling subregion j of roll cuts out.

Described nominal flow capacity value refers to the controlled quentity controlled variable that reaches control effect identical with flow-control, and it comprises actual flow value and the switch valve valve open period length that reaches control effect identical with actual flow control.

The present invention realizes the heat transfer between roll and cooling fluid according to following heat transfer equation, and this heat transfer equation is:

Q＝K _m*A _m*(T _r-T _l)*t

In formula: K _mfor the heat transfer coefficient between roll and cooling fluid, unit is W/m ²gK; A _mfor heat transfer area, i.e. the surface area of the each segmentation body of roll of roll, unit is m ²; T _r-T _lfor heat transfer temperature difference, i.e. heat transfer temperature difference between roll and cooling fluid, unit be K or ℃; Q is the heat output between roll and cooling fluid, and unit is J; T is the heat transfer time between roll and cooling fluid, and unit is s.

In above-mentioned steps B, can adopt following methods to carry out layout to cooling subregion, that is: in the layout of the cooling subregion of roll, make the overall width of cooling subregion equal the overall width of plate shape roller measurement zone, and make each cooling subregion corresponding one or more plate shape measurements district exactly in position.

The present invention compared with prior art has following main beneficial effect:

One. can solve a large key issue of cold rolled sheet shape control system.

Described key issue is, calculating after the action regulated quantity of the each mechanical profile regulation mechanism (as backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, intermediate calender rolls transverse-moving mechanism etc.) of corrected board shape deviation to greatest extent, calculate the coolant rate value on the each subregion of roll that can correct residue plate shape residual error, and adopt suitable mechanism and method to carry out these flow values.

For example, if certain 6 roller UCM milling train is at certain plate shape deviation state er[i] under, complete after backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, the calculating of intermediate calender rolls transverse-moving mechanism action regulated value, calculate the coolant rate value on the each cooling subregion of working roll that can correct residue plate shape residual error, and adopt suitable mechanism and method to carry out these flow values, the control method that uses so the present invention to propose, having reduced under the condition of equipment cost and electric control system cost, can effectively guarantee the control effect to plate shape residual error.

They are two years old. can save equipment cost.

Because switch valve only has standard-sized sheet, two states of complete shut-down, simple in structure, and proportioning valve can be realized any opening degree control between standard-sized sheet and complete shut-down, complex structure, therefore,, under same equal-specification condition, the unit price of proportioning valve is far above switch valve, control compared with flow with a proportioning valve with each cooling subregion, each cooling subregion is controlled and can be saved equipment cost plate shape residual error with a switch valve.

Control compared with flow with multiple switch valves with each cooling subregion, each cooling subregion is controlled and can be saved equipment cost plate shape residual error with a switch valve.

They are three years old. can save electric control system cost.

For electric control system, a switch valve only needs a switching point of amount of logic output module to control, and a proportioning valve needs a D/A ALT-CH alternate channel of analog output module to control, under Same Efficieney output condition, for example, with Siemens 16 switching point amount of logic output module SM 322, DO 16x DC 24V/0.5A (6ES7322-1BH01-0AA0) and Siemens 4 ALT-CH alternate channel analog output module SM 332, AO 4x 12 (6ES7332-5HD01-0AB0) is example, the price of a D/A ALT-CH alternate channel of analog output module is far above the price of a switching point of amount of logic output module, therefore, control compared with flow with a proportioning valve with each cooling subregion, each cooling subregion is controlled plate shape residual error with a switch valve, can save the cost of electric control system.

Control compared with flow with multiple switch valves with each cooling subregion, each cooling subregion controls to plate shape residual error the cost that can save electric control system with a switch valve.

They are four years old. can effectively guarantee the control effect to plate shape residual error.

Reducing under the condition of equipment cost and electric control system cost, its closed-loop control characteristic can be guaranteed the control effect to plate shape residual error effectively.

They are five years old. can extension device service life.

By suitable valve control periodicity TB and valve control interrupt task execution cycle time TA are set, can avoid switch valve frequently to open and close, extend its service life.

In a word, in cold rolled strip steel production, the general hot Crown control system of a set of working roll body of roll for corrected board shape residual error has 20～40 cooling subregions, control compared with flow with a proportioning valve or multiple switch valve with each cooling subregion, provided by the inventionly realize the method that each cooling subregion uses a switch valve to control effectively to plate shape residual error and there is real technological value and economic implications.

Accompanying drawing explanation

Fig. 1 is the six-high cluster mill plate shape closed-loop control system principle that intermediate calender rolls can move horizontally.

Fig. 2 is the traversing schematic diagram of intermediate calender rolls.

Fig. 3 is the relative length difference schematic diagram of off-line glacing flatness.

Fig. 4 is the relative length difference schematic diagram of online glacing flatness.

Fig. 5 is margin plate shape measurement zone schematic diagram.

Fig. 6 is plate shape setting curve schematic diagram.

Fig. 7 is target flatness setting means schematic diagram.

Fig. 8 is definite method schematic diagram of plate shape bias vector.

Fig. 9 is profile regulation mechanism efficiency factor schematic diagram.

Figure 10 is plate shape measurement district and the cooling district location corresponding relation of roll schematic diagram.

Figure 11 uses switch valve to carry out nominal flow capacity value coln _ithe control method of [j].

The specific embodiment

Below in conjunction with embodiment and accompanying drawing, the invention will be further described.

Embodiment 1: the online test method of plate shape

Plate shape refers to the warpage degree of sheet material, its essence is the distribution referring to steel internal residual stress.In cold rolling production, the implication of plate shape refers to the glacing flatness with steel, namely poor with the tensile stress in steel broad ways.In fact, the implication of plate shape also comprises the lateral thickness difference with steel, the just glacing flatness of plate shape of the plate shape representative that generally we mention, and do not consider lateral thickness difference.Conventional plate shape method for expressing has: " relative length difference representation ", " the poor representation of tensile stress ", " crown of strip representation ", " waveform representation " etc.

The relative length difference representation of glacing flatness: as shown in Figure 3, if one section of tension-free band steel is cut from coil of strip, then this section strip steel is cut into slice.By measuring the length L (i) of i article of slice band steel, and the average length L (m) of L (i) and each slice band steel is done poor:

Δ L (i)=L (i)-L (m) (formula 1-1)

The relative length difference ε of this slice band steel ₀(i) be:

ε ₀(i)=Δ L (i)/L (m) (formula 1-2)

Due to ε ₀(i) numerical value is very little, and the unit of international expression strip profile and flatness is I, and the relative length difference of an I unit representation is 10 ^-5.Like this, the i article of glacing flatness f that slice band steel represents with relative length difference _a(i) be:

F _a(i)=10 ⁵* ε ₀(i) [I unit] (formula 1-3)

The poor representation of tensile stress of glacing flatness: as the feedback detecting unit of plate shape closed-loop control system, extensively adopt plate shape roller to reflect the plate shape with steel by the tensile stress variations of measuring in strip width direction at plate shape control field at present.Although the measuring principle of various plate shape rollers and the mounting means of sensor are had nothing in common with each other, be all to reflect with the plate shape on steel cross section along the measurement data in each region in strip width direction.As shown in Figure 4, in the time being with steel in as-rolled condition, band steel, under tension force effect, extends to L1 by the original length L (m), and the dominant plate shape of performance disappears, and is converted into potential plate shape.The strain stress (i) of the i measurement zone now being caused by the outer tensile stress that imposes on i plate shape measurement district is:

ε (i)=[Δ L (m)-Δ L (i)]/L (i) (formula 1-4)

Due to Δ L (i) < < L (m), so L (i) ≈ L (m), (formula 1-4) can be rewritten as:

ε (i)=[Δ L (m)-Δ L (i)]/L (m) (formula 1-5)

Order

ε (m)=Δ L (m)/L (m) (formula 1-6)

Obtained by (formula 1-2), (formula 1-5), (formula 1-6)

ε (i)=ε (m)-ε ₀(i) (formula 1-7)

The meaning that formula 1-7 shows is that mean strain equals detection strain and original relative length difference sum in i plate shape measurement district, i.e. these those length that disappear of the detection strain in i plate shape measurement district and glacing flatness to be checked.

Obtained by (formula 1-7), (formula 1-2):

$\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{\&epsiv;}\left(i\right)$

$=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}[\mathrm{\&epsiv;}\left(m\right)-{\mathrm{\&epsiv;}}_0\left(i\right)]$

$=n*\mathrm{\&epsiv;}\left(m\right)-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&epsiv;}}_0\left(i\right)$

(formula 1-8)

$=n*\mathrm{\&epsiv;}\left(m\right)-\frac{1}{L\left(m\right)}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;L}\left(i\right)$

Because $\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;L}\left(i\right)=0$

Obtained by (formula 1-8):

$\mathrm{\&epsiv;}\left(m\right)=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{\&epsiv;}\left(i\right)$ (formula 1-9)

Can be found out the mean value of ε (m) Shi Ge plate shape measurement district's strain stress (i) by (formula 1-9).

Obtained by (formula 1-3), (formula 1-7):

F _a(i)=10 ⁵* [ε (m)-ε (i)] [I unit] (formula 1-10)

The meaning that formula 1-10 shows is, if the detection strain in i plate shape measurement district is more less than mean strain, its original relative length difference is larger, glacing flatness is also larger, otherwise glacing flatness is less, i.e. these those length that disappear of the detection strain in i plate shape measurement district and glacing flatness to be checked, in formula:

F _a(i): the online glacing flatness in i plate shape measurement district,

ε (i): the detection strain in i plate shape measurement district,

ε (m): the mean value of strain stress (i) is detected in each plate shape measurement district,

Obtained by (formula 1-10):

F _a(i)=10 ⁵* [σ (m)-σ (i)]/E [I unit] (formula 1-11).

Formula 1-11 be rolling while carrying out in i plate shape measurement district with steel with the poor online glacing flatness representing of tensile stress, its meaning showing is, if the detection tensile stress in i plate shape measurement district is more less than average tensile stress, its original relative length difference is larger, glacing flatness is also larger, otherwise glacing flatness is less, i.e. these those length that disappear of the detection tensile stress in i plate shape measurement district and glacing flatness to be checked.

In formula 1-11: f _a(i) be the online glacing flatness in i plate shape measurement district; σ (i) is the detection tensile stress in i plate shape measurement district; σ (m) is the mean value that tensile stress σ (i) is detected in each plate shape measurement district; E is the elastic modelling quantity with steel.

The present invention is applied to cold rolled strip steel production field, require the online glacing flatness that detects, the present embodiment adopts plate shape roller by measuring the band steel tensile stress σ (i) in strip width direction Shang Ge plate shape measurement district, then calculates rolling by (formula 1-11) and carries out the online glacing flatness with steel in Shi Ge plate shape measurement district.

Embodiment 2: definite method of margin plate shape measurement zone and coverage rate thereof

As shown in Figure 5, if from OS side (fore side), to DS side (transmission side) finish, each measurement zone of plate shape measurement roller from z_1 open numbering, until will there are two measurement zone z_os and z_ds that contact with strip edge edge so in z_n.

The object of determining edge metering district is in order to determine that effective glacing flatness detects and control area.

As shown in Figure 5, OS side and DS side uncovering area length are calculated by following formula:

L_free_os=(w_zone_sum-w_strip) * 0.5-strip_shift+d_axial (formula 2-1),

L_free_ds=(w_zone_sum-w_strip)-l_free_os (formula 2-2),

In formula:

L_free_ds: DS side uncovering area length;

L_free_os: OS side uncovering area length;

W_zone_sum: plate shape roller measurement zone width sum;

W_strip: with the width of steel;

Strip_shift: Dai Gang center is with respect to the side-play amount of unit centre (deflection OS side for just);

D_axial: Ban Xinggun center is with respect to the side-play amount of unit centre (deflection OS side for just).

As shown in Figure 5, numbering and the coverage rate thereof of OS side and DS lateral edges measurement zone are calculated by following formula:

Z_os=round (l_free_os/z_w)+1 (formula 2-4),

Cf_z_os=1-[l_free_os/z_w-round (l_free_os/z_w)] (formula 2-5),

Z_ds=z_n-round (l_free_ds/z_w) (formula 2-6),

Cf_z_ds=1-[l_free_ds/z_w-round (l_free_ds/z_w)] (formula 2-7),

In formula:

Z_os: the numbering of OS lateral edges measurement zone,

Cf_z_os: the coverage rate (0.0～1.0) of OS lateral edges measurement zone,

L_free_os: OS side uncovering area length,

Z_ds: the numbering of DS lateral edges measurement zone,

Cf_z_ds: the coverage rate (0.0～1.0) of DS lateral edges measurement zone,

L_free_ds: DS side uncovering area length,

Z_w: the width of single measurement zone,

Z_n: total number of plate shape roller measurement zone,

Round (x): the integer part that x is got in representative.

The present embodiment adopts (formula 2-4), (formula 2-5), (formula 2-6), (formula 2-7) to calculate numbering z_xs and the coverage rate cf_z_xs thereof of OS side and DS lateral edges measurement zone.

As shown in (formula 2-8)～(formula 2-11), the actual numbering za_xs in edge metering district and the Select Tactics of coverage rate fa_xs thereof using is: if the coverage rate cf_z_xs of marginal zone reaches minimum of a value cf_min (the present embodiment minimum of a value cf_min employing 1.0 of setting, take all standing district as marginal zone), so actual marginal zone za_xs and the coverage rate fa_xs using equals actual marginal zone z_xs and coverage rate cf_z_xs, otherwise, the marginal zone za_os=z_os+1 of the actual use of OS side, coverage rate fa_os=1.0, the marginal zone za_ds=z_ds-1 of the actual use of DS side, coverage rate fa_ds=1.0.Measured zone between za_os and za_ds is that effective glacing flatness detects and control area.

$\mathrm{za}\_\mathrm{os}=\left\{\begin{array}{cc}z\_\mathrm{os}& (\mathrm{cf}\_z\_\mathrm{os}\&GreaterEqual;\mathrm{cf}\_\min )\\ z\_\mathrm{os}+1& (\mathrm{cf}\_z\_\mathrm{os}<\mathrm{cf}\_\min )\end{array}\right.$ (formula 2-8),

$\mathrm{fa}\_\mathrm{os}=\left\{\begin{array}{cc}\mathrm{cf}\_z\_\mathrm{os}& (\mathrm{cf}\_z\_\mathrm{os}\&GreaterEqual;\mathrm{cf}\_\min )\\ 1.0& (\mathrm{cf}\_z\_\mathrm{os}<\mathrm{cf}\_\min )\end{array}\right.$ (formula 2-9),

$\mathrm{za}\_\mathrm{ds}=\left\{\begin{array}{cc}z\_\mathrm{ds}& (\mathrm{cf}\_z\_\mathrm{ds}\&GreaterEqual;\mathrm{cf}\_\min )\\ z\_\mathrm{ds}+1& (\mathrm{cf}\_z\_\mathrm{ds}<\mathrm{cf}\_\min )\end{array}\right.$ (formula 2-10),

$\mathrm{fa}\_\mathrm{ds}=\left\{\begin{array}{cc}\mathrm{cf}\_z\_\mathrm{ds}& (\mathrm{cf}\_z\_\mathrm{ds}\&GreaterEqual;\mathrm{cf}\_\min )\\ 1.0& (\mathrm{cf}\_z\_\mathrm{ds}<\mathrm{cf}\_\min )\end{array}\right.$ (formula 2-11),

In formula:

Za_os: the numbering in the edge metering district of the actual use of OS side;

Fa_os: the coverage rate (0.0～1.0) in the edge metering district of the actual use of OS side;

Za_ds: the numbering in the edge metering district of the actual use of DS side;

Fa_ds: the coverage rate (0.0～1.0) in the edge metering district of the actual use of DS side;

Cf_min: the minimum coverage rate (0.0～1.0) of setting.

Embodiment 3: the establishing method of target flatness

In cold rolling production, major part is rolled rear cold drawing also needs the further processing through later process, as the operation such as galvanizing, annealing unit, plate shape will affect the operation stability of these units, and in subsequent handling, plate shape also will change, therefore, in the time setting milling train flatness object curve, must consider the requirement of follow-up unit, conventionally by target flatness curve setting Cheng Weizhong wave or micro-limit wave.

In the present embodiment, plate shape setting curve adopts sectional curve as shown in Figure 6, and this curve handle is divided into middle part and limit portion two parts with the strip width that effective glacing flatness detects and control area is corresponding, and the expression formula of this curve is shown below:

$f_s\left(x\right)=\left\{\begin{array}{cc}B*[x/(0.5*W)]+\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000126628570000031.png,HDA0000126628570000032.png"\; state="\{\{state\}\}">C</figure-callout>}1*{[x/(0.5*W)]}^2& (-x_0<x<x_0)\\ B*[x/(0.5*W)]+\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000126628570000031.png,HDA0000126628570000032.png"\; state="\{\{state\}\}">C</figure-callout>}1*{[x/(0.5*W)]}^2+\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000126628570000032.png,HDA0000126628570000042.png"\; state="\{\{state\}\}">C</figure-callout>}2*{[x/(0.5*W)-{\mathrm{<figure-callout\; id="0"\; label="x"\; filenames="HDA0000126628570000042.png"\; state="\{\{state\}\}">x</figure-callout>}}_0/(0.5*W)]}^2& (x\&le;-{\mathrm{<figure-callout\; id="0"\; label="x"\; filenames="HDA0000126628570000042.png"\; state="\{\{state\}\}">x</figure-callout>}}_0,x\&GreaterEqual;x_0)\end{array}\right.$ (formula 3-1)

In formula:

F _s(x): the plate shape at x point place setting value in strip width direction, unit is I;

X: the coordinate figure that strip width direction Shang Yidaigang center is zero point;

W: glacing flatness effectively detects and control area, i.e. strip width between marginal zone za_os and za_ds,

(definite method of marginal zone za_os and za_ds is shown in formula 2-8～11);

X ₀: the separation defining between steel edge portion and middle part, the present embodiment is defined as x ₀=0.375*W;

B: the inclination amplitude in bandwidth W;

C1: the convexity amplitude in bandwidth W;

C2: with the amplitude of the additional convexity in wide width portion region.

As shown in Figure 7, in the present embodiment, target flatness be set with following two kinds of modes:

Mode 1: operating personnel set B, C1, C2 as target flatness on L1 level basic automation systems operation screen;

Mode 2: set B, C1, C2 on L2 level process automation system computer, send L1 level basic automation systems to as target flatness.

Embodiment 4: definite method of plate shape bias vector

As shown in Figure 8, in L1 level CPU, by target flatness curve discretization definite embodiment 3, then deduct the online plate shape that embodiment 1 determines, obtain the plate shape bias vector corresponding with plate shape measurement district, plate shape bias vector will be controlled the control deviation that function will regulate as plate shape.The expression formula that is obtained plate shape bias vector by (formula 3-1), (formula 1-11) is as follows:

Er[i]=f _s(x _i)-f _a(i) (za_os≤i≤za_ds) (formula 4-1)

In formula:

I: the numbering in plate shape measurement district,

Za_os: the numbering in the edge metering district of the actual use of OS side, see formula 2-8,

Za_ds: the numbering in the edge metering district of the actual use of DS side, see formula 2-10,

Er[i]: the plate shape deviation in i plate shape measurement district,

F _s(x _i): the target flatness in i plate shape measurement district, see formula 3-1,

F _a(i): the online plate shape in i plate shape measurement district, sees formula 1-11.

Embodiment 5: the definition of the profile regulation mechanism efficiency factor

As shown in Figure 1, at present main plate shape closed-loop control means have: inclination control, intermediate calender rolls roller, work roll bending, intermediate calender rolls are traversing, cooling fluid is sprayed and controlled five kinds of regulating measures, in the six-high cluster mill that can move horizontally at intermediate calender rolls, the deviation of actual plate shape and target flatness is mainly revised by inclination, intermediate calender rolls roller, work roll bending, and remaining residual error is sprayed to control by cooling fluid and further revised.

Profile regulation mechanism can be divided into mechanical profile regulation mechanism and non-mechanism profile regulation mechanism according to its class of establishment.As shown in Figure 2, mechanical profile regulation mechanism comprises: roller declination, intermediate calender rolls roller, work roll bending, intermediate calender rolls are traversing etc.Non-mechanism profile regulation mechanism comprises: working roll segmentation is cooling etc.

Before the removing method of explanation plate shape residual error, the definition of the profile regulation mechanism efficiency factor once is first described.

As shown in Figure 9, the efficiency factor of profile regulation mechanism in a certain plate shape measurement district is defined as: in the time that this profile regulation mechanism sends the action regulated quantity of a unit, and the plate shape variable quantity that it can cause in this plate shape measurement district.What efficiency factor reflected is profile regulation mechanism correction capability to plate shape deviation in each plate shape measurement district.To same profile regulation mechanism, the efficiency factor on each measurement zone will form the efficiency vector of this profile regulation mechanism.Therefore, the expression formula of profile regulation mechanism efficiency vector is as follows:

P _j[i]=-Δ f (x _i)/v _j(za_os≤i≤za_ds) (formula 5-1)

In formula:

I: the numbering in plate shape measurement district;

Za_os: the numbering in the edge metering district of the actual use of OS side, see formula 2-8;

Za_ds: the numbering in the edge metering district of the actual use of DS side, see formula 2-10;

P _j[i]: the efficiency factor of the j of profile regulation mechanism on plate shape measurement district i;

Δ f (x _i): the plate shape variable quantity in i plate shape measurement district;

V _j: the action regulated quantity of the j of profile regulation mechanism.

Embodiment 6: the calculating of each cooling subregion cooling fluid nominal flow capacity regulated value

Before introducing embodiment 6, first illustrate of the present invention and nominal flow capacity value, so-called nominal flow capacity value, refer in the present invention the controlled quentity controlled variable that can reach control effect identical with flow-control, it comprises actual flow value and the valve open period length that can reach control effect identical with actual flow control.

As shown in Figure 1, after adjusting by the mechanical profile regulation such as roller declination, roller control and roll shifting mechanism, still may there is plate shape residual error, the present embodiment adopts breaker roll, below take working roll as example, carry out subregion cooling, to change the hot convexity of its body of roll, thereby reach the object of eliminating plate shape residual error.

As shown in Figure 1, by the plate shape deviation in L1 controller, after the plate shape deviation that deduction can be eliminated by the mechanical profile regulation such as roller declination, roller control and roll shifting mechanism, obtain plate shape residual error.

Plate shape residual vector can represent with (formula 6-1):

${\mathrm{er}}_f\left[i\right]=\mathrm{er}\left[i\right]-\underset{j=1}{\overset{k}{\mathrm{\&Sigma;}}}{p}_j\left[i\right]*v_{\mathrm{aj}}$ (za_os≤i≤za_ds) (formula 6-1)

In formula: i is the numbering in plate shape measurement district; K is the quantity of mechanical profile regulation mechanism; Za_os is the numbering in the edge metering district of the actual use of OS side, sees formula 2-8; Za_ds is the numbering in the edge metering district of the actual use of DS side, sees formula 2-10; Er _f[i] is the plate shape residual error in i plate shape measurement district; v _ajfor the action regulated quantity of the mechanical profile regulation j of mechanism; Pj[i] be the efficiency factor of the mechanical profile regulation j of mechanism on plate shape measurement district i, see formula 5-1; Er[i] the i plate shape measurement district upper plate shape deviation that detects for plate shape roller, see formula 4-1.

As shown in figure 10, in the present embodiment, in the layout of the cooling subregion of working roll, make the overall width of cooling subregion equal the overall width of plate shape roller measurement zone, and make each cooling subregion corresponding one or more plate shape measurements district exactly in position.Due to each cooling subregion corresponding one or more plate shape measurements district exactly in position, therefore plate shape residual error corresponding with same cooling subregion in formula 6-1 can be merged into the plate shape residual error of this cooling subregion by the method for averaging, shown in 6-2, like this, the new plate shape residual vector being made up of the plate shape residual error of each cooling subregion after merging is the plate shape residual error that subregion refrigerating function will regulate.

Er _c[j]=convert (er _f[i]) (za_os≤i≤za_ds, ca_os≤j≤ca_ds) (formula 6-2)

Formula 6-2 represents the plate shape residual error er corresponding with the cooling subregion of j in wushu 6-1 _f[i] merges into the plate shape residual error of this cooling subregion by the method for averaging, in formula: i is the numbering in plate shape measurement district; J is the numbering of cooling subregion; Za_os is the numbering in the edge metering district of the actual use of OS side, sees formula 2-8; Za_ds is the numbering in the edge metering district of the actual use of DS side, sees formula 2-10; Ca_os is the numbering of the cooling subregion corresponding with za_os; Ca_ds is the numbering of the cooling subregion corresponding with za_ds; Er _f[i] is the plate shape residual error in i plate shape measurement district, sees formula 6-1; Er _c[j] is the plate shape residual error on the cooling subregion of j.

In the present embodiment, determining by formula 6-2 after the plate shape residual error that subregion refrigerating function will regulate, will be according to plate shape residual error, and utilize PI Principles of Regulation to calculate the each subregion cooling fluid nominal flow capacity value for eliminating each subregion plate shape residual error.The nominal flow capacity value of the each cooling subregion j of working roll in the time of the i time profile regulation calculated by formula 6-3.

${\mathrm{cool}}_i\left[j\right]=\left\{\begin{array}{cc}\mathrm{kp}*{\mathrm{er}}_c\left[j\right]+{\mathrm{cool}}_{i-1}\left[j\right]+\mathrm{ki}*{\mathrm{er}}_c\left[j\right]& (\mathrm{kp}>0,\mathrm{ki}>0)\\ \mathrm{kp}*{\mathrm{er}}_c\left[j\right]& (\mathrm{kp}>0,\mathrm{ki}\&le;0)\\ 0& (\mathrm{kp}\&le;0,\mathrm{ki}\&le;0)\end{array}\right.$ (formula 6-3)

In formula: i is the number of times that PI regulates; J is the numbering of cooling subregion, ca_os≤j≤ca_ds; Kp is the proportionality coefficient that PI regulates; Ki is the integral coefficient that PI regulates; Er _c[j] is the plate shape residual error on the cooling subregion of j, sees formula 6-2; Cool _i[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i time; Cool _i-1[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i-1 time.

In actual cold-reduced sheet production process, the nominal flow capacity value calculating by formula 6-3 likely can exceed the minimum or maximum nominal flow capacity value of permission, therefore the nominal flow capacity value that formula 6-3 is calculated is carried out to limit value processing, shown in formula 6-4.

${\mathrm{colim}}_i\left[j\right]=\left\{\begin{array}{cc}{\mathrm{cool}}_i\left[j\right]& (\mathrm{coll}<{\mathrm{cool}}_i[j]<\mathrm{colu})\\ \mathrm{colu}& \left({\mathrm{cool}}_i\right[j]\&GreaterEqual;\mathrm{colu})\\ \mathrm{coll}& \left({\mathrm{cool}}_i\right[j]\&le;\mathrm{coll})\end{array}\right.$ (formula 6-4)

In formula: i is the number of times that PI regulates; J is the numbering of cooling subregion, ca_os≤j≤ca_ds; Co lim _i[j] is nominal flow capacity value after the limit value of the cooling subregion of j in the time of the i time profile regulation; Cool _i[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i time, sees formula 6-3; The lower limit of the each cooling subregion name flow value of coll; Colu is the higher limit of each cooling subregion name flow value, colu>=coll.

Carry out in order to facilitate plate shape residual error conditioning equipment, formula 6-4 is carried out to naturalization 1 to be processed, simultaneously, for all band steel liquid that is cooled is covered, make the flow value of cooling zone cas_os, cas_ds equate with the flow value of cooling zone ca_os, ca_ds respectively, shown in formula 6-5.

${\mathrm{co}\ln }_i\left[j\right]=\left\{\begin{array}{cc}\mathrm{vll}+\frac{\mathrm{vlu}-\mathrm{vll}}{\mathrm{colu}-\mathrm{coll}}*\left({\mathrm{colim}}_i\right[j]-\mathrm{coll})& (\mathrm{ca}\_\mathrm{os}\&le;j\&le;\mathrm{ca}\_\mathrm{ds})\\ {\mathrm{co}\ln }_i[\mathrm{ca}\_\mathrm{os}]& (j=\mathrm{cas}\_\mathrm{os})\\ {\mathrm{co}\ln }_i[\mathrm{ca}\_\mathrm{ds}]& (j=\mathrm{cas}\_\mathrm{ds})\\ 0& (1\&le;j<\mathrm{cas}\_\mathrm{os})\\ 0& (\mathrm{cas}\_\mathrm{ds}<j\&le;\mathrm{cn})\end{array}\right.$ (formula 6-5)

$\mathrm{cas}\_\mathrm{os}=\left\{\begin{array}{cc}1& (\mathrm{ca}\_\mathrm{os}=1)\\ \mathrm{ca}\_\mathrm{os}-1& (\mathrm{ca}\_\mathrm{os}>1)\end{array}\right.$ (formula 6-6)

$\mathrm{cas}\_\mathrm{ds}=\left\{\begin{array}{cc}\mathrm{cn}& (\mathrm{ca}\_\mathrm{ds}=\mathrm{cn})\\ \mathrm{ca}\_\mathrm{ds}+1& (\mathrm{ca}\_\mathrm{ds}<\mathrm{cn})\end{array}\right.$ (formula 6-7)

In formula: i is the number of times that PI regulates; J is the numbering of cooling subregion; Cn is the maximum numbering of cooling subregion; Ca_os is the numbering of the cooling subregion corresponding with za_os, and za_os is shown in formula 2-8; Ca_ds is the numbering of the cooling subregion corresponding with za_ds, and za_ds is shown in formula 2-10; Cas_os is the numbering of the cooling zone, edge of the actual use of OS side; Cas_ds is the numbering of the cooling zone, edge of the actual use of DS side; Colim _i[j] is nominal flow capacity value after the limit value of the cooling subregion of j in the time of the i time profile regulation, sees formula 6-4; Coln _i[j] is that the cooling subregion of j is returned 1 assumed name justice flow value in the time of the i time profile regulation; Vll is the lower limit that each cooling subregion is returned 1 assumed name's justice flow value, 0≤vll≤vlu; Vlu is the higher limit that each cooling subregion is returned 1 assumed name's justice flow value, vlu=1.0.

The application of the removing method of embodiment 7. plate shape residual errors

Provide the application process that uses switch valve to realize Flow-rate adjustment below:

As shown in Figure 1, one of plat control system large key issue is the action regulated quantity that the plate shape deviation that detects according to plate shape roller is calculated the each mechanical profile regulation mechanism (as backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, intermediate calender rolls transverse-moving mechanism etc.) that can correct to greatest extent these deviations.

Due to the restriction of the mechanical property of each mechanical profile regulation mechanism own, for example backing roll leaning device is suitable for correcting 1 power plate shape deviation, and intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, intermediate calender rolls transverse-moving mechanism are suitable for correcting 2 powers and part 4 power plate shape deviations etc.But in fact, the actual plate shape deviation detecting according to plate shape roller is complicated high power function, it has more than and is limited to 1 power, 2 powers and 4 power components.Therefore, mechanical profile regulation mechanism can not eliminate all plate shape deviations completely,,, after the adjusting of the mechanical profile regulation such as backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, intermediate calender rolls transverse-moving mechanism mechanism, still can there is plate shape residual error.

In the time of rolling, roll, especially working roll, the heat producing during due to rolling, its body of roll can produce certain hot convexity, on controlling, conventionally by breaker roll, for example working roll, carries out distinguishing subregion cooling, to change the hot convexity in the each segmentation of its body of roll, thereby reach the object of corrected board shape residual error.

Therefore, another large key issue of plat control system is, calculating after the action regulated quantity of the each mechanical profile regulation mechanism (as backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, intermediate calender rolls transverse-moving mechanism etc.) of corrected board shape deviation to greatest extent, calculate the coolant rate value on the each subregion of roll that can correct residue plate shape residual error, and adopt suitable mechanism and method to carry out these flow values.

For example, if certain 6 roller UCM milling train is at certain plate shape deviation state er[i] under, complete after backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, the calculating of intermediate calender rolls transverse-moving mechanism action regulated value, calculate the coolant rate value on the each cooling subregion of working roll that can correct residue plate shape residual error, and adopt suitable mechanism and method to carry out these flow values, have so two kinds of methods to use:

To above-mentioned two kinds of methods, can adopt identical algorithm to calculate the coolant rate value on the each cooling subregion of working roll for correcting residue plate shape residual error below.Suppose in the time of the i time profile regulation, the backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, the intermediate calender rolls transverse-moving mechanism action regulated value that have calculated are respectively v _a1, v _a2, v _a3, v _a4, so ensuing calculation process is:

(1) according to plate shape deviation er[i] and the action regulated value v of backing roll leaning device, intermediate calender rolls bend roller mechanism of battery, work roll bending mechanism, intermediate calender rolls transverse-moving mechanism _a1, v _a2, v _a3, v _a4, for k=4, j=1～k, the formula 6-1 of calling calculates the plate shape residual error er on each plate shape measurement district i _f[i];

(2) er calculating according to step (1) _f[i], the formula 6-2 of calling calculates the plate shape residual error er on the each cooling subregion j of working roll _c[j];

(3) er calculating according to step (2) _c[j], the formula 6-3 of calling calculates the nominal flow capacity value cool of the cooling subregion j of working roll in the time of the i time profile regulation _i[j];

(4) cool calculating according to step (3) _i[j], the formula 6-4 of calling calculates nominal flow capacity value colim after the limit value of the cooling subregion j of working roll in the time of the i time profile regulation _i[j];

(5) colim calculating according to step (4) _i[j], the formula 6-5 of calling calculates the cooling subregion j of working roll and return 1 assumed name justice flow value coln in the time of the i time profile regulation _i[j].

Complete above (1)～(5) calculate the cooling subregion j of working roll at the i time profile regulation time return 1 assumed name justice flow value coln _iafter [j], can adopt suitable mechanism and method to carry out these nominal flow capacity values.

For traditional control method, have two schemes to use: (1) can arrange a ratio adjusting valve on a cooling subregion, now, only need to be in the time of the i time profile regulation, the regulation of the ratio adjusting valve on cooling subregion j to coln _i[j]; (2) can on a cooling subregion, multiple switch valves be set, now, only need to be in the time of the i time profile regulation, according to coln _ithe switch valve that [j] opens corresponding number discharges different flows, for example, suppose to be provided with 5 switch valves to each cooling subregion, and the quantity of the switch valve that so cooling subregion j is opened in the time of the i time profile regulation can be set to round (5*coln _i[j]), that is, make the quantity of the switch valve that cooling subregion j is opened in the time of the i time profile regulation equal 5*coln _ithe integer part of [j].

The control method proposing for the present invention, it carrys out the cooling subregion j of execution work roller with single switch valve and returns the adopted flow value coln of 1 assumed name when the i time profile regulation _i[j].Now, as shown in figure 11, the control method of switch valve is as follows:

(1), in CPU, a fixing valve control periodicity TB is set, for example TB=100; The minimum period that a permission valve opens is set counts TM, for example TM=2; The maximum number cn of cooling subregion is set, for example cn=40;

(2) for the arbitrary cooling subregion j of working roll, a cycle counter CNT[j is set in CPU] and an aperture counter OPN[j];

(3) for the arbitrary cooling subregion j of working roll, an information bit V[j is set in CPU], V[j]=1 represent the cooling fluid switch valve of the cooling subregion j of working roll is opened, V[j]=0 represent the cooling fluid switch valve of the cooling subregion j of working roll cuts out;

(4) in each execution cycle TA of the Interruption task of CPU, for example within each execution cycle of the T3 task of the execution cycle Siemens TDC CPU551 that is TA=50ms (now, the duration in each valve control cycle is TA*TB, if for example TA=50ms, TB=100, the duration that represents each valve control cycle is TA*TB=50ms*100=5000ms), for the each cooling subregion of the cooling subregion 1～cn of working roll, take arbitrary cooling subregion j as example, carry out successively following operation once: make CNT[j]=CNT[j]+1; If CNT[j] >=TB, make CNT[j]=0; Make OPN[j]=round (TB*coln _i[j]), that is, make OPN[j] equal TB*coln _ithe integer part of [j] (OPN[j] meaning that represents is, makes the switch valve of cooling subregion j in each valve control cycle duration T A*TB, maintaining the time that valve leaves is TA*TB*coln _i[j], if for example TA*TB=50ms*100=5000ms, TA*TB*coln _i[j]=50ms*100*0.6=3000ms, the switch valve that represents cooling subregion j is within valve control cycle that is 5000ms each duration, maintaining the time that valve leaves is 3000ms); If CNT[j] < OPN[j] and OPN[j] > TM, make V[j]=1 to represent that the cooling fluid switch valve of the cooling subregion j of working roll is opened, otherwise make V[j]=0 to represent that the cooling fluid switch valve of the cooling subregion j of working roll cuts out.

The control principle of above two kinds of control methods and control effect analysis:

In the time of rolling, roll, especially working roll, the heat producing during due to rolling, its body of roll can produce certain hot convexity, on controlling, conventionally by breaker roll, for example working roll, carries out distinguishing subregion cooling, to change the hot convexity in the each segmentation of its body of roll, thereby reach the object of corrected board shape residual error.

By cooling fluid make in the each segmentation of the working roll body of roll the mutagenic process of hot convexity be one by working roll the process to cooling fluid transferring heat.

Formula 7-1 is heat transfer basic equation formula:

Q=K _m* A _m* (T _r-T _l) (formula 7-1)

According to formula 7-1, have:

Q=K _m* A _m* (T _r-T _l) * t (formula 7-2)

In formula 7-1～7-2, q is rate of heat transfer, and unit is W or J/s; K _mfor heat transfer coefficient, unit is W/m ²gK; A _mfor heat transfer area, unit is m ²; T _r-T _lfor heat transfer temperature difference, unit be K or ℃; Q is heat output, and unit is J; T is the heat transfer time, and unit is s.

From formula 7-2, by changing Coefficient K _m, heat transfer area A _m, heat transfer temperature difference T _r-T _l, conduct heat time t all can change heat output.For the diabatic process between working roll and cooling fluid, be by changing the Coefficient K between working roll and cooling fluid _m, the each segmentation body of roll of working roll heat transfer area A _m, heat transfer temperature difference T between working roll and cooling fluid _r-T _l, heat transfer time t between working roll and cooling fluid can change the heat output between working roll and cooling fluid.

For traditional plate shape residual eliminating method, its essence of implementing PI control is to control the coolant rate size on respective partition according to the plate shape residual error size on each cooling subregion, controls formula 7-2 Coefficient K according to the plate shape residual error size on each cooling subregion _msize, draw different total amount of heats thereby realize from each cooling subregion, reach the hot convexity changing on working roll each cooling subregion, eliminate the object of the plate shape residual error on each cooling subregion.PI now regulates flow process to be: the plate shape deviation detecting according to plate shape roller is called formula 6-1～6-2 and calculate the plate shape residual error er of each cooling subregion _c[j]-> is according to plate shape residual error er _c[j] calls formula 6-3～6-5 and calculates the Coefficient K that can change each cooling subregion _mcoolant rate coln _i[j]-> uses a ratio adjusting valve or multiple switch valve and above-mentioned corresponding traditional control method to each cooling subregion, makes each cooling subregion with different coolant rate coln _i[j], each cooling subregion is with different Coefficient K _mcarry out cooling to the working roll body of roll on respective partition, to draw the working roll body of roll on the each cooling subregion of different heat-> due to thermal loss difference, cause temperature contrast, and then the generation hot convexity contrary with plate shape residual error, thereby eliminate the plate shape residual error on each cooling subregion.Can find out from above-mentioned adjusting flow process, the PI control making now of calling of formula 6-3 has closed-loop control characteristic, be that formula 6-3 makes changes in flow rate amount produce with plate shape residual generation, disappear with plate shape residual error, and the control result of changes in flow rate volume production life is total contrary (with the plate shape residual error of detection computations, when plate shape residual error be on the occasion of, it represents that the band steel extension on corresponding cooling subregion is excessive, it is large that the flow value now calculating by formula 6-3 becomes, it represents that the flow on corresponding cooling subregion becomes large, Coefficient K _mbecome large, by formula 7-2, it is large that the heat that cooling fluid is drawn from corresponding cooling subregion becomes, and work roll thermal crown diminishes, and band steel extends and diminishes thereupon; When plate shape residual error is negative value, it represents that the band steel on corresponding cooling subregion extends deficiency, and the flow value now calculating by formula 6-3 diminishes, and it represents that the flow on corresponding cooling subregion diminishes, Coefficient K _mdiminish, by formula 7-2, the heat that cooling fluid is drawn from corresponding cooling subregion diminishes, and it is large that work roll thermal crown becomes, and band steel extends and becomes large thereupon).To sum up state, for traditional plate shape residual eliminating method based on PI Principles of Regulation, in the time that each cooling subregion is controlled flow with the switch valve of a ratio adjusting valve or sufficient amount, its closed-loop control characteristic can be guaranteed the control effect to plate shape residual error effectively.

The plate shape residual eliminating method proposing for the present invention, its essence of implementing PI control is to control the cooling fluid injecting time length on respective partition according to the plate shape residual error size on each cooling subregion, control the length of formula 7-2 heat transfer time t according to the plate shape residual error size on each cooling subregion, thereby realize and draw different total amount of heats from each cooling subregion, reach the hot convexity changing on the each cooling subregion of working roll, eliminate the object of the plate shape residual error on each cooling subregion.PI now regulates flow process to be: the plate shape deviation detecting according to plate shape roller is called formula 6-1～6-2 and calculate the plate shape residual error er of each cooling subregion _c[j]-> is according to plate shape residual error er _c[j] calls formula 6-3～6-5 and calculates the nominal coolant rate coln of the heat transfer time t that can change each cooling subregion _ithe control method that [j]-> uses a switch valve and the present invention to propose to each cooling subregion, makes each cooling subregion in each valve control TB*TA cycle time, and the time that valve leaves equals TB*TA*coln _i[j], each cooling subregion is in each valve control TB*TA cycle time, with different heat transfer time t=TB*TA*coln _i[j] carries out cooling to the working roll body of roll on respective partition, to draw the working roll body of roll on the each cooling subregion of different heat-> due to thermal loss difference, cause temperature contrast, and then the generation hot convexity contrary with plate shape residual error, thereby eliminate the plate shape residual error on each cooling subregion.Can find out from above-mentioned adjusting flow process, the PI control making now of calling of formula 6-3 has closed-loop control characteristic, be that the formula 6-3 time variation amount that makes to conduct heat produces with plate shape residual generation, disappear with plate shape residual error, and the control result that heat transfer time variation amount produces is total contrary (with the plate shape residual error of detection computations, when plate shape residual error be on the occasion of, it represents that the band steel extension on corresponding cooling subregion is excessive, the heat transfer time of now calculating by formula 6-3 becomes large, it represents that the heat transfer time t on corresponding cooling subregion becomes large, by formula 7-2, it is large that the heat that cooling fluid is drawn from corresponding cooling subregion becomes, work roll thermal crown diminishes, band steel extends and diminishes thereupon, when plate shape residual error is negative value, it represents that the band steel on corresponding cooling subregion extends not enough, the heat transfer time of now calculating by formula 6-3 diminishes, it represents that the heat transfer time t on corresponding cooling subregion diminishes, by formula 7-2, the heat that cooling fluid is drawn from corresponding cooling subregion diminishes, and it is large that work roll thermal crown becomes, and band steel extends and becomes large thereupon).To sum up state, the plate shape residual eliminating method based on PI Principles of Regulation proposing for the present invention, as the valve control periodicity TB arranging and enough hour of valve control interrupt task execution cycle time TA, its closed-loop control characteristic can be guaranteed the control effect to plate shape residual error effectively; For the diabatic process of roll and cooling fluid, frequently open and close for fear of switch valve, TA*TB is set to 5000～7000ms, and while TA is set to 50～100ms and is advisable.

From embodiment 7, the present invention has following advantage compared with traditional control method:

1. can save equipment cost.

Because switch valve only has standard-sized sheet, two states of complete shut-down, simple in structure, and proportioning valve can be realized any opening degree control between standard-sized sheet and complete shut-down, complex structure, therefore,, under same equal-specification condition, the unit price of proportioning valve is far above switch valve, control compared with flow with a proportioning valve with each cooling subregion, each cooling subregion is controlled and can be saved equipment cost plate shape residual error with a switch valve.

Control compared with flow with multiple switch valves with each cooling subregion, each cooling subregion is controlled and can be saved equipment cost plate shape residual error with a switch valve.

2. can save electric control system cost.

For electric control system, a switch valve only needs a switching point of amount of logic output module to control, and a proportioning valve needs a D/A ALT-CH alternate channel of analog output module to control, under Same Efficieney output condition, for example, with Siemens 16 switching point amount of logic output module SM 322, DO 16x DC 24V/0.5A (6ES7322-1BH01-0AA0) and Siemens 4 ALT-CH alternate channel analog output module SM 332, AO 4x 12 (6ES7332-5HD01-0AB0) is example, the price of a D/A ALT-CH alternate channel of analog output module is far above the price of a switching point of amount of logic output module, therefore, control compared with flow with a proportioning valve with each cooling subregion, each cooling subregion is controlled plate shape residual error with a switch valve, can save the cost of electric control system.

Control compared with flow with multiple switch valves with each cooling subregion, each cooling subregion controls to plate shape residual error the cost that can save electric control system with a switch valve.

3. can effectively guarantee the control effect to plate shape residual error.

Reducing under the condition of equipment cost and electric control system cost, its closed-loop control characteristic can be guaranteed the control effect to plate shape residual error effectively.

4. can extension device service life.

By suitable valve control periodicity TB and valve control interrupt task execution cycle time TA are set, can avoid switch valve frequently to open and close, extend its service life.

In a word, in cold rolled strip steel production, the general hot Crown control system of a set of working roll body of roll for corrected board shape residual error has 20～40 cooling subregions, control compared with flow with a proportioning valve or multiple switch valve with each cooling subregion, realize the method that each cooling subregion uses a switch valve to control effectively to plate shape residual error and there is real technological value and economic implications.

Claims (4)

1. a cold rolled plate shape residual eliminating method, it is characterized in that a kind ofly first for roll comprises each cooling subregion of working roll, a cooling fluid switch valve being set, according to the heat transfer theory between roll and cooling fluid and PI loop control theory, this switch valve is effectively controlled again, to eliminate the method for the cold rolled plate shape residual on corresponding cooling subregion, the method comprises the following steps:

A. the plate shape deviation er[i detecting according to plate shape roller] call formula (1) and calculate the plate shape residual error er on each plate shape measurement district i _f[i]:

${\mathrm{er}}_f\left[i\right]=\mathrm{er}\left[i\right]-\underset{j=1}{\overset{k}{\mathrm{\&Sigma;}}}{p}_j{\left[i\right]}^{*}{v}_{\mathrm{aj}}(\mathrm{za}\_\mathrm{os}\&le;i\&le;\mathrm{za}\_\mathrm{ds})---\left(1\right),$

In formula: i is the numbering in plate shape measurement district; K is the quantity of mechanical profile regulation mechanism; Za_os is the numbering in the edge metering district of the actual use of fore side; Za_ds is the edge metering district numbering of the actual use of transmission side; Er _f[i] is the plate shape residual error in i plate shape measurement district; v _ajfor the action regulated quantity of the mechanical profile regulation j of mechanism; p _j[i] is the efficiency factor of the mechanical profile regulation j of mechanism on plate shape measurement district i; Er[i] the i plate shape measurement district upper plate shape deviation that detects for plate shape roller;

B. the er calculating according to steps A _f[i], calls formula (2) and calculates the plate shape residual error er on the each cooling subregion j of roll _c[j];

er _c[j]＝convert(er _f[i])(za_os≤i≤za_ds,ca_os≤j≤ca_ds) （2），

Formula (2) represents the plate shape residual error er corresponding with the cooling subregion of j in formula (1) _f[i] merges into the plate shape residual error of this cooling subregion by the method for averaging, in formula: the numbering that j is cooling subregion; Ca_os is the numbering of the cooling subregion corresponding with za_os; Ca_ds is the numbering of the cooling subregion corresponding with za_ds; Er _c[j] is the plate shape residual error on the cooling subregion of j;

C. the er calculating according to step B _c[j], calls formula (3) and calculates the nominal flow capacity value cool of the each cooling subregion j of roll in the time of the i time profile regulation _i[j], nominal flow capacity value refers to the controlled quentity controlled variable that reaches control effect identical with flow-control, it comprises actual flow value and the switch valve valve open period length that reaches control effect identical with actual flow control;

${\mathrm{cool}}_i\left[j\right]=\left\{\begin{array}{cc}{\mathrm{kp}}^{*}{\mathrm{er}}_c\left[j\right]+{\mathrm{cool}}_{i-1}\left[j\right]+{\mathrm{ki}}^{*}{\mathrm{er}}_c\left[j\right]& (\mathrm{kp}>0,\mathrm{ki}>0)\\ {\mathrm{kp}}^{*}{\mathrm{er}}_{c}p\left[j\right]& (\mathrm{kp}>0,\mathrm{ki}\&le;0)\\ 0& (\mathrm{kp}\&le;0,\mathrm{ki}\&le;0)\end{array}\right.---\left(3\right),$

In formula: i is the number of times that PI regulates; J is the numbering of cooling subregion, ca_os≤j≤ca_ds; Kp is the proportionality coefficient that PI regulates; Ki is the integral coefficient that PI regulates; Cool _i[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i time; Cool _i-1[j] is the nominal flow capacity value of the cooling subregion of j in the time regulating for the i-1 time;

D. the cool calculating according to step C _i[j], calls formula (4) and calculates nominal flow capacity value colim after the limit value of the each cooling subregion j of roll in the time of the i time profile regulation _i[j];

${\mathrm{colim}}_i\left[j\right]=\left\{\begin{array}{cc}{\mathrm{cool}}_i\left[j\right]& (\mathrm{coll}<{\mathrm{cool}}_i[j]<\mathrm{colu})\\ \mathrm{colu}& \left({\mathrm{cool}}_i\right[j]\&GreaterEqual;\mathrm{colu})\\ \mathrm{coll}& \left({\mathrm{cool}}_i\right[j]\&le;\mathrm{coll})\end{array}\right.---\left(4\right),$

In formula: the numbering that j is cooling subregion, ca_os≤j≤ca_ds; Colim _i[j] is nominal flow capacity value after the limit value of the cooling subregion of j in the time of the i time profile regulation; Coll is the lower limit of each cooling subregion name flow value; Colu is the higher limit of each cooling subregion name flow value, colu>=coll;

E. the colim calculating according to step D _i[j], calls formula (5) and calculates the each cooling subregion j of roll return 1 assumed name justice flow value coln in the time of the i time profile regulation _i[j],

${\mathrm{co}\ln }_i\left[j\right]=\left\{\begin{array}{cc}\mathrm{vll}+\frac{\mathrm{vlu}-\mathrm{vll}}{\mathrm{volu}-\mathrm{coll}}*\left({\mathrm{colim}}_i\right[j]-\mathrm{coll})& (\mathrm{ca}\_\mathrm{os}\&le;j\&le;\mathrm{ca}\_\mathrm{ds})\\ {\mathrm{co}\ln }_i[\mathrm{ca}\_\mathrm{os}]& (j=\cos \_\mathrm{os})\\ {\mathrm{co}\ln }_i[\mathrm{ca}\_\mathrm{ds}]& (j=\mathrm{cas}\_\mathrm{ds})\\ 0& (1\&le;j<\mathrm{cas}\_\mathrm{os})\\ 0& (\mathrm{cas}\_\mathrm{ds}<\_j\&le;\mathrm{cn})\end{array}\right.---\left(5\right),$

$\mathrm{cas}\_\mathrm{os}=\left\{\begin{array}{cc}1& (\mathrm{ca}\_\mathrm{os}=1)\\ \mathrm{ca}\_\mathrm{os}-1& (\mathrm{ca}\_\mathrm{os}>1)\end{array}\right.---\left(6\right),$

$\mathrm{cas}\_\mathrm{ds}=\left\{\begin{array}{cc}\mathrm{cn}& (\mathrm{ca}\_\mathrm{ds}=\mathrm{cn})\\ \mathrm{ca}\_\mathrm{ds}+1& (\mathrm{ca}\_\mathrm{ds}<\mathrm{cn})\end{array}\right.---\left(7\right),$

In formula: the maximum numbering that cn is cooling subregion; Cas_os is the numbering of the cooling zone, edge of the actual use of fore side; Cas_ds is the numbering of the cooling zone, edge of the actual use of transmission side; Coln _i[j] is that the cooling subregion of j is returned 1 assumed name justice flow value in the time of the i time profile regulation; Vll is the lower limit that each cooling subregion is returned 1 assumed name's justice flow value, 0≤vll≤vlu; Vlu is the higher limit that each cooling subregion is returned 1 assumed name's justice flow value, vlu=1.0.

2. cold rolled plate shape residual eliminating method according to claim 1, is characterized in that carrying out the each cooling subregion j of roll with switch valve returns 1 assumed name's justice flow value coln when the i time profile regulation _i[j], its step comprises:

(1), in CPU, a fixing valve control periodicity TB is set; The minimum period that a permission valve opens is set counts TM; The maximum number cn of cooling subregion is set;

(2) for the arbitrary cooling subregion j of roll, a cycle counter CNT[j is set in CPU] and an aperture counter OPN[j];

(3) for the arbitrary cooling subregion j of roll, an information bit V[j is set in CPU], V[j]=1 represent the cooling fluid switch valve of the cooling subregion j of roll is opened, V[j]=0 represent the cooling fluid switch valve of the cooling subregion j of roll cuts out;

(4) in each execution cycle TA of the Interruption task of CPU, the each cooling subregion of the cooling subregion 1～cn of breaker roll, take arbitrary cooling subregion j as example, carries out following operation once: make CNT[j successively]=CNT[j]+1; If CNT[j] >=TB, make CNT[j]=0; Make OPN[j]=round (TB*coln _i[j]), that is, make OPN[j] equal TB*coln _ithe integer part of [j]; If CNT[j] <OPN[j] and OPN[j] >TM, make V[j]=1 to represent that the cooling fluid switch valve of the cooling subregion j of roll is opened, otherwise make V[j]=0 to represent that the cooling fluid switch valve of the cooling subregion j of roll cuts out.

3. cold rolled plate shape residual eliminating method according to claim 1, is characterized in that realizing the heat transfer between roll and cooling fluid according to following heat transfer equation, and this heat transfer equation is:

Q＝K _m*A _m*(T _r-T _l)*t

In formula: K _mfor the heat transfer coefficient between roll and cooling fluid, unit is W/m ²k; A _mfor heat transfer area, i.e. the surface area of the each segmentation body of roll of roll, unit is m ²; T _r-T _lfor heat transfer temperature difference, i.e. heat transfer temperature difference between roll and cooling fluid, unit be K or ℃; Q is the heat output between roll and cooling fluid, and unit is J; T is the heat transfer time between roll and cooling fluid, and unit is s.

4. cold rolled plate shape residual eliminating method according to claim 1, it is characterized in that in step B, adopt following methods to carry out layout to cooling subregion, that is: in the layout of the cooling subregion of roll, make the overall width of cooling subregion equal the overall width of plate shape roller measurement zone, and make each cooling subregion corresponding one or more plate shape measurements district exactly in position.

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