CN102366757B - Dynamic mean module and method thereof - Google Patents

Abstract

The invention provides a consecutive mean module and a method thereof for solving the mean value of monitoring thickness errors in a monitoring section. The consecutive mean module and method thereof are characterized in that shift registers are used for storing monitoring thickness error values and weights thereof; the thickness error value and weight thereof at the current time are stored in first positions of respective registers; along with the movement of an object corresponding to the error value, the error value and weight thereof move along in the registers; when the corresponding object moves for the whole monitoring section distance, the weight sum of the object on the monitoring section reaches 1.0, and by now, the monitoring thickness error values and weights thereof are multiplied and summarized to obtain the mean value of the monitoring thickness errors on the monitoring section. The consecutive mean module takes possible changes of transmission speed into account, and because the current transmission speed is input at each sampling instant, the mean value of the monitoring thickness errors on the monitoring section can be accurately solved while the speed changes randomly, so that the consecutive mean module can be widely used for solving the mean parameter of speed labile to change.

Description

Consecutive mean module and method thereof

Technical field

The present invention relates to a kind of be used to asking for the supervision thickness error in the consecutive mean module that monitors section mean value.

Background technology

In cold continuous rolling belt steel rolling process, in order to improve vertical tolerance of band steel, improve the product thickness hit rate, the tandem mill automatic thickness control system has been carried out a large amount of research both at home and abroad.The most frequently used in the past method for controlling thickness is by configuration calibrator after rolling-mill housing the actual (real) thickness of band steel to be measured, and then comes belt steel thickness is carried out FEEDBACK CONTROL by the hydraulic pressure roll gap of regulating milling train.This method for controlling thickness is called supervision AGC (Monitor Automatic Gauge Control).But because the restriction of rolling mill structure, calibrator generally is installed in the place apart from the mill roll-gap certain distance, and the actual like this fluctuation that shuts out thickness must just can obtain through one period lag time, and be totally unfavorable to the control system performance this lag time.

Might directly accurately measure strip speed because the release of laser velocimeter makes the nineties in last century, therefore not only can accurately obtain the advancing slip value of each frame, and can accurately calculate the deformed area exit thickness by the identical rule of deformed area second flow amount.The meaning of the constant rule of second flow amount is that the mass flow of metal is constant before and after the frame, again because the strip width basically identical before and after the frame then keeps strict proportionate relationship with speed and the thickness of steel before and after frame, that is:

V _en×h _en＝V _ex×h _ex

V in the formula _En-band steel entrance velocity; V _Ex-band steel exports speed; h _En-band steel inlet thickness; h _Ex-band steel exports thickness.If to band steel section h _EnThe actual measurement back is by postponing, as actual measurement h _EnBand steel section when entering the deformed area according to the V of actual measurement this moment _EnAnd V _ExCan accurately obtain the deformed area exit thickness of this band steel section.This technology has solved the problem of long-term puzzlement cold continuous rolling AGC system design, because the use of new pattern laser tachymeter can obtain the deformed area exit thickness accurately and can not carry out FEEDBACK CONTROL with lagging behind, thereby successfully thick control precision has been improved an order of magnitude.

Second, flow quantity AGC solved problem lag time that monitors AGC, had improved control performance greatly, but monitored that AGC still has necessity of its existence.Though at first export the calibrator measurement result hysteresis is arranged, its precision is very high, generally can reach 1um; Second flow amount accounting equation is difficult to the precision that reaches such, can utilize outlet calibrator measured value that second flow amount accounting equation is revised, and makes that the precision of second flow quantity AGC is higher; The second, a second flow quantity AGC can't overcome the error that the milling train operating point changes and causes, for example owing to long-term rolling roll wear, thermal expansion of rollers, the advancing slip coefficient of causing changes etc.The thick difference that these comparatively long-term processes cause needs still to monitor that AGC overcomes.

The best supervision AGC method of result of use has used Smith to estimate to overcome the lag time that the outlet calibrator is measured at present, if know the exact value of lag time, then Smith predictor method " prediction " band steel exports thickness well monitors that the performance of AGC is also relatively good.If but were with steel exports speed to change, would be a variable lag time that then exports the calibrator measurement, can have a strong impact on the performance of Smith predictor method if change greatly lag time.

The roll gap regulated quantity that original supervision AGC method calculates milling train usually realizes monitoring that AGC regulates, and mill roll-gap uses hydraulic press down system control, and hydraulic press down system precision height, response are fast, but its formula that calculates the roll gap regulated quantity is:

$\mathrm{\ΔS}=(1+\frac{C_m}{K_m})\mathrm{\Δh}$

In the formula, Δ S is for monitoring the roll gap regulated quantity of AGC; C _mFor-band steel plastic coefficient; K _mBe the mill stiffness coefficient; Δ h is band steel exports thickness error monitoring value; Wherein be with steel plastic coefficient C _mWith the mill stiffness COEFFICIENT K _mTest obtains in the test run stage for milling train, can't obtain exact value at present, and this has influenced the precision that monitors AGC.

Summary of the invention

The technical problem to be solved in the present invention is: provide a kind of be used to asking for the supervision thickness error in the consecutive mean module and the method thereof that monitor section mean value, can accurately ask for the mean value of thickness error on the supervision section under the situation that strip speed changes arbitrarily.

The present invention solves the problems of the technologies described above the technical scheme of taking to be: the consecutive mean module, it is characterized in that: the consecutive mean module comprises the 4th to the 6th shift register and judging treatmenting module, the monitoring segment length is divided into some sections, and hop count is determined that by strip speed every section length is L _S=V * T _S, L in the formula _SBe every section length, V is band steel transmission speed, T _SBe the sampling time;

The storage of the 4th shift register needs the sampled value of the input variable of dynamic calculation mean value, and is every through a sampling time T _SAll elements in the register is moved one successively backward, then the input sample value of current time is deposited in first position of this register;

The 5th shift register is used for storing the weights of input sample value, and weights determine that by strip speed the weights of each input sample value are W _X=V * T _S/ L _Mon, in the formula, L _MonFor monitoring the length of section; Every through a sampling time with backward mobile one successively of the weights of all storages in the register, then the weights of current time input variable are deposited in first position of this register;

The 6th shift register be used for storing the input sample value weights and, soon all the weights additions before the corresponding time obtain in the 5th shift register, each sampling instant is with the weights of all storages and move one backward successively, then the weights of current time input variable are stored in first position of this register, namely first element of the 6th shift register and the 5th shift register always equates; Three registers are corresponding one by one;

Judging treatmenting module judges that for each sampling time the element more than or equal to 1.0 appears in the 6th shift register at first, if i element more than or equal to 1.0 i-1 element less than 1.0, then i element of the 5th shift register deducted that i element surpasses 1.0 amount in the 6th shift register, with preceding i element guaranteeing the 5th shift register be 1.0 just in time; Then preceding i element of the 4th shift register be multiply by preceding i element value of corresponding the 5th shift register, and summation obtains monitoring that thickness error is at the mean value that monitors on the segment length.

The consecutive mean method is characterized in that: it may further comprise the steps:

The sampled value of the input variable of step 1, input strip speed V, supervision segment length L and need dynamic calculation mean value;

Step 2, the storage of the 4th shift register need the sampled value of the input variable of dynamic calculation mean value, and be every through a sampling time T _SAll elements in the register is moved one successively backward, then the input sample value of current time is deposited in first position of this register;

Step 3, the 5th shift register are used for storing the weights of input sample value, and weights determine that by strip speed the weights of each input variable are W _X=V * T _S/ L _Mon, in the formula, L _MonFor monitoring the length of section; Every through a sampling time with backward mobile one successively of the weights of all storages in the register, then the weights of current time input variable are deposited in first position of this register;

Step 4, the 6th shift register be used for storing the weights that monitor the thickness error sampled value and, soon all the weights additions before the corresponding time obtain in the 5th shift register, each sampling instant is with the weights of all storages and move one backward successively, then the weights of current time input variable are stored in first position of this register, namely first element of the 6th shift register and the 5th shift register always equates; Three registers are corresponding one by one;

Step 5, each sampling time are judged the element that occurs at first in the 6th shift register more than or equal to 1.0, if i element more than or equal to 1.0 i-1 element less than 1.0, then i element of the 5th shift register deducted that i element surpasses 1.0 amount in the 6th shift register, with preceding i element guaranteeing the 5th shift register be 1.0 just in time; Then preceding i element of the 4th shift register be multiply by preceding i element value of corresponding the 5th shift register, and summation obtains monitoring that thickness error is at the mean value that monitors on the segment length.

It also comprises step 6, the maximum memory space C of each shift register is set, and the weights W of current time is all judged in each sampling instant _XWhether more than or equal to minimum weights W _Min=1.0/C, and if less than minimum weights three shift register of this sampling instant all do not upgrade, and only with weights summations, judge weights and whether more than or equal to minimum weights in next sampling instant then; Just carry out the renewal of three shift registers more than or equal to minimum weights up to weights and value.

Operation principle of the present invention is: in the belt steel rolling process, enable simultaneously under the situation of second flow quantity AGC and supervision AGC, use exit thickness precomputation device to calculate band steel exports thickness, this one-tenth-value thickness 1/10 is to come out according to the band steel section THICKNESS CALCULATION at current time entrance calibrator place, for the detection thickness that uses the outlet calibrator is revised it, just must be with this calculated value synchronous transfer to exporting the calibrator place, compare with the detection thickness at outlet calibrator place then and just obtain second flow amount calculated thickness error, the supervision AGC compensating factor that multiply by the calculating of adaptive equalization device has just obtained supervision AGC error amount, consider that including one in this error amount monitors that AGC regulates the influence value that causes constantly, therefore this influence value must be deducted, the influence value that supervision AGC adjusting causes is by monitoring that AGC influences compensation arrangement and calculates.

Supervision AGC error is asked for it at the mean value that monitors on the section through the consecutive mean module, again by the ramp generator device, just obtains monitoring the average ramp value of AGC error.

Consider the speed regulating mechanism action delay, will monitor that the average ramp value of AGC error compensates the error correction values that action delay then obtains monitoring the second flow amount of AGC equation by the first first-order lag device.

Notice that calculating is to use the thickness data at outlet calibrator place to calculate when monitoring the AGC error amount, therefore when influencing of causing controlled in the supervision of calculating current time, need be with the second flow amount error correction values synchronous transfer at roll gap place to exporting the calibrator place, re-use the sampling time-delay that the compensation of the second first-order lag device drops out mouthful calibrator, just obtain current time and monitor that AGC control is to next influence value that causes constantly.

Be with the steel exports speed adjusting device to calculate band steel exports speed regulated quantity according to monitoring that the average ramp value of AGC error is used at last, because rolling mill speed is controlled by transmission device, therefore the roller of having considered advancing slip and live-roller and working roll directly than situation under, calculate milling train live-roller linear velocity regulated quantity by the live-roller speed adjusting device.This regulated quantity is outputed to the milling train transmission device go just to have realized this high-precision supervision AGC control.

Beneficial effect of the present invention is:

1, because the consecutive mean module will obtain weights according to the band steel transmission speed of current time in each sampling time, therefore can monitor mean value on the section accurately asking for thickness error under the situation that strip speed changes arbitrarily, for the calculating of whole AGC control system provides the foundation.

2, overflow fault can not take place in order to ensure register, the weights W of current time is all judged in each sampling instant _XWhether more than or equal to minimum weights W _Min=1.0/C, and if less than minimum weights three shift register of this sampling instant all do not upgrade, and only with weights summations, judge weights and whether more than or equal to minimum weights in next sampling instant then; Just carry out the renewal of three shift registers more than or equal to minimum weights up to weights and value.

Description of drawings

Fig. 1 is five frame cold continuous rollings and main detecting element schematic diagram.

Fig. 2 is the program flow diagram of synchronous transfer model.

Fig. 3 is program flow diagram of the present invention.

Fig. 4 monitors the schematic diagram of automatic thickness control system for the high accuracy belt steel rolling.

The specific embodiment

Present embodiment is the application of consecutive mean module in high accuracy belt steel rolling supervision automatic thickness control system.

Fig. 1 is five frame cold continuous rollings and main detecting element schematic diagram, and five frames of five frame cold continuous rollings are six-high cluster mill all, and the numeral 1～5 above the frame represents frame respectively 1～No. 5, and rolling direction from left to right.Because the plant equipment of each frame is the same, form with the equipment that No. 3 frames are example explanation five frame connection rolling machine: No. 3 frames by upper support roller 6, go up intermediate calender rolls 7, top working roll 8, bottom working roll 9, following intermediate calender rolls 10, lower support roller 11 and form.In addition, jockey pulley 12 is equipped with in the tandem mill porch, coiling machine 13 is equipped with in the exit; Rolling mill transmission system is the intermediate calender rolls transmission, intermediate calender rolls uses frequency control motor 14,15 to carry out speed governing up and down, motor is driven by frequency converter 16, and programmable logic controller (PLC) (PLC) 17 is issued frequency converter with the speed regulated quantity, and frequency converter is regulated motor speed makes the live-roller linear velocity reach setting value; Milling train uses press down system 18 control roll gap; The control principle is that THICKNESS CONTROL (AGC) is finished by regulating the milling train transmission speed, and tension force is then finished by regulating roll gap between frame.Instrumentation comprises 4 cover X-ray thickness gauges, 3 cover laser velocimeters, some cover pulse coders (pulse coder all is housed) altogether on all bunchers.Wherein 4 cover X-ray thickness gauges are respectively No. 1 frame entrance calibrator 19,1 frame outlet calibrator 20,5 frame entrance calibrators, 21,5 frames and export calibrator 22; 3 cover laser velocimeters are respectively 1 frame outlet tachymeter 23,4 frames outlet tachymeter 24,5 frames outlet tachymeter 25; Because entrance jockey pulley place does not exist advancing sliply, at the entrance jockey pulley pulse coder 26 is installed and namely can be accurately obtained 1 frame strip steel at entry linear velocity in addition, such 1 frame porch does not need to dispose laser velocimeter.According to such instrument configuration, No. 1 and No. 5 frames can be used second flow quantity AGC and monitor the AGC control of AGC coupling, but because two frames in tandem mill end have three kinds of control models according to the specification difference of rolled band steel, be respectively Mode A, B and C, correspond respectively to thicker softer band steel, the band steel of intermediate gauge, thinner harder band steel, monitor that the implementation method of AGC has some differences.For example following No. 5 frames of C pattern are as smooth frame, and the exit thickness of 5 frames is not controlled, and need finish in preceding 4 frames the adjusting of band steel exports thickness, and the calculating of controlled quentity controlled variable and objective for implementation are with different under other pattern like this; The control method of tension force also has certain difference under A pattern and the B pattern.Because the supervision AGC method after diversity 5 frames of pattern is not suitable for illustrating the thought of this method, therefore present embodiment is that example is done an explanation with the supervision AGC method of No. 1 frame, supervision AGC control thought after 5 frames is the same, and just implementation method has some differences.

This AGC method may further comprise the steps:

1. calculate the band steel exports thickness h at current time outlet calibrator place _{Exc, ethg}:

In the operation of rolling, enabled second flow quantity AGC simultaneously and monitored that precomputation obtains being with the steel exports one-tenth-value thickness 1/10 according to second flow amount equation under the situation of AGC, should value transfer to outlet calibrator place from the entrance calibrator by two synchronous transfer models, be specially:

(1) according to second flow amount equation precomputation band steel exports one-tenth-value thickness 1/10:

No. 1 the milling train porch is equipped with calibrator can record band steel inlet thickness, be equipped with pulse coder on the entrance jockey pulley, owing to do not exist advancing slip at the jockey pulley place, therefore can be with the jockey pulley linear velocity as band steel entrance velocity, 1 frame exit is equipped with laser velocimeter can obtain being with steel exports speed, according to the measured value that these instrumentations obtain, use exit thickness precomputation device 27 to calculate band steel exports thickness h with following formula _{Ex, calc}:

$h_{\mathrm{ex},\mathrm{calc}}=\frac{V_{\mathrm{en}}\×h_{\mathrm{en}}}{V_{\mathrm{ex}}}$

In the formula, h _{Ex, calc}Exit thickness for the calculating of second flow amount equation; V _EnFor band steel entrance velocity actual value, measured by pulse coder on the entrance jockey pulley; V _ExFor band steel exports speed actual value, measured by the outlet laser velocimeter; h _EnFor band steel inlet thickness actual value, measured by the entrance calibrator.

(2) use the first synchronous transfer model to obtain being transferred to the exit thickness value h at roll gap place _{Exc, gap}:

Use the first synchronous transfer model, with the h that calculates _{Ex, calc}From entrance calibrator synchronous transfer to 1 frame roll gap place, obtain the exit thickness value h at current time roll gap place with band steel entrance velocity _{Exc, gap}, that is:

h _exc，gap＝TPM1(h _ex，calc)

(3) use the second synchronous transfer model to obtain being transferred to the exit thickness value h at outlet calibrator place _{Exc, ethg}:

Use the second synchronous transfer model, with the exit thickness value h at roll gap place _{Exc, gap}With band steel exports speed from the roll gap synchronous transfer to exporting the calibrator place, obtain the exit thickness value h at current time outlet calibrator place _{Exc, ethg}, that is:

h _exc，ethg＝TPM2(h _exc，gap)。

The present invention adopts unique synchronous transfer model, the program flow diagram of synchronous transfer model TPM as shown in Figure 2, each synchronous transfer model structure is identical.Present embodiment is that example describes with the first synchronous transfer model, and the first synchronous transfer model is made up of first to the 3rd shift register and judge module, and each shift register can store several real variable.At first transmission range is divided into several sections, notices that the segmentation number do not fix, but determine that by strip speed the length of each section is: L _S=V * T _S, L in the formula _SBe every section length, V is transmission speed, T _SBe the sampling time; T _sBe fixed value, decide T in the present embodiment on the setting of PLC controller _s=4ms.

The belt steel thickness sampled value of first shift register storage input, every through a sampling time T _sThe data of all storages are moved one, first position of then the belt steel thickness sampled value of current time being deposited this register successively backward;

The length of the second shift register memory segment, every through a sampling time with backward mobile one successively of the data of all storages, then the section length of current time is stored in first position of this register;

The 3rd shift register is stored the distance that corresponding belt steel thickness sampled value is passed by, and is about to all the section length additions before the corresponding time of second shift register and obtains, and for example k element of the 3rd shift register is:

$B3\left[k\right]=\underset{m=1}{\overset{k}{\mathrm{\Σ}}}B2\left[m\right],$

In the formula, B2 and B3 represent the second and the 3rd shift register respectively.

Every through a sampling instant with backward mobile one successively of the distance value of all storages, then the section length of current time is stored in first position of this register, namely first element of the second and the 3rd shift register always equates; Three registers are corresponding one by one;

Judge module judges for each sampling time whether an order three shift registers have the element more than or equal to transmission range L, if i element value more than or equal to transmission range i-1 element value less than transmission range, represent that i element in first shift register transmitted the given transmission distance, then with i element value output in first shift register;

Note needing to arrange in advance the maximum memory space N of register here, if strip speed is very slow, the length of each segmentation is especially little, and the register overflow fault will take place for N section length and also do not reach the transmission range L of setting.Therefore in this mode, memory space N=500 is set, each sampling instant can be judged section length L _SWhether less than minimum section length L _Min=L/500, and if less than minimum section length three register of this sampling instant do not upgrade, and only with section length summation, judge section length in next sampling instant then with value whether more than or equal to minimum section length; Just carry out the renewal of three shift registers up to section length more than or equal to minimum section length with value.So just guaranteed that shift register overflow fault can not take place.

2. obtain and monitor AGC adaptive equalization factor F _Comp:

According to band steel exports speed, export thick poor, whether be in the adaptively selected supervision of this Several Factors of acceleration and deceleration stage AGC compensating factor, be specially:

(1) according to 1 frame muzzle velocity actual value access speed factor F _V, the more big then velocity factor of muzzle velocity is more little, and the velocity factor value is between 0.7～1.0.

(2) choose thickness factor F according to the exit thickness difference _h, it is more big to export the more big then thickness of the thick difference factor, and thickness factor value is between 0.6～1.0.

(3) whether basis is in acceleration and deceleration stage selection acceleration factor F _aIf, be not in the acceleration and deceleration stage, then acceleration factor is taken as 1.0; If be in the acceleration and deceleration stage, then need improve acceleration factor, can be taken as 1.2;

(4) calculate supervision AGC adaptive equalization factor F with following formula _Comp:

F _comp＝F _V×F _h×F _a

3. obtain and monitor the average ramp value of AGC exit thickness error

At first try to achieve the supervision thickness error E of exit thickness _Mon, ask for this error then at the mean value that monitors on the section, step appears in order to prevent controlled quentity controlled variable, at last also in addition the slope handle and obtain monitoring the average ramp value of AGC exit thickness error

Be specially:

(1) calculates current time with following formula and monitor thickness error E _Mon:

E _mon(n)＝(h _ex，thg-h _exc，ethg)×F _comp-E _tpm(n-1) n＞1；

E _mon(n)＝(h _ex，thg-h _exc，ethg)×F _comp n＝1；

In the formula, h _{Ex, thg}Be outlet calibrator measured value; E _Tpm(n-1) monitor the exit thickness influence value that the AGC controlled quentity controlled variable causes current time constantly for last one; N represents current time; Because last one constantly monitors after AGC regulates and can the exit thickness in this moment be impacted, therefore moment of the supervision AGC controlled quentity controlled variable of calculating current time must be earlier with on one control the influence value that causes constantly and deduct.If current time is initial time, the supervision AGC controlled quentity controlled variable that goes up a moment so is 0, so its influence value also is 0.

(2) use the consecutive mean module to ask for E _MonAt the mean value that monitors on the section

Flow chart is as shown in Figure 3:

Monitor that AGC is the trend (thin partially or thick partially) that changes the thick difference of outlet that causes for the comparatively long-term process of compensation, therefore need ask for E to whole supervision section (namely from the frame roll gap to exporting this segment distance of calibrator) _MonMean value, the error that interference more at random causes can be cancelled out each other.

Use consecutive mean module MAV to ask for E _MonAt the mean value that monitors on the section

That is:

$\stackrel{\‾}{E_{\mathrm{mon}}}=\mathrm{MAV}\left(E_{\mathrm{mon}}\right).$

The consecutive mean module is made up of the 4th to the 6th shift register and judging treatmenting module, will the section of monitoring (namely from the frame roll gap to exporting this segment distance of calibrator) be divided into some sections, segments is determined that by strip speed every section length is L _S=V * T _S, L in the formula _SBe every section length, V is band steel transmission speed, T _SBe the sampling time;

The 4th shift register storage input variable E _MonSampled value, every through a sampling time T _SThe value of all storages in the register is moved one successively backward, then the sampled value of current time input variable is deposited in first position of this register;

The 5th shift register is used for storing the weights of input variable sampled value, and weights determine that by strip speed the weights of each input variable are W _X=V * T _S/ L _Mon, in the formula, L _MonFor monitoring the length of section; Every through a sampling time with backward mobile one successively of the weights of all storages in the register, then the weights of current time input variable are deposited in first position of this register;

The 6th shift register be used for storing the input variable sampled value weights and, be about to that all the weights additions before the corresponding time obtain in the 5th shift register, for example k element in the 6th shift register is:

$B6\left[k\right]=\underset{m=1}{\overset{k}{\mathrm{\Σ}}}B5\left[m\right],$

In the formula, B5 and B6 represent the 5th and the 6th shift register respectively.

Each sampling instant is with the weights of all storages and move one backward successively, then the weights of current time input variable is stored in first position of this register, and namely first element of the 6th shift register and the 5th shift register always equates.Three registers are corresponding one by one;

Judging treatmenting module judges that for each sampling time the element more than or equal to 1.0 appears in the 6th shift register at first, if i element more than or equal to 1.0 i-1 element less than 1.0, then i element of the 5th shift register deducted that i element surpasses 1.0 amount in the 6th shift register, with preceding i element guaranteeing the 5th shift register be 1.0 just in time; Then preceding i element of the 4th shift register be multiply by preceding i element value of corresponding the 5th shift register, i.e. each input variable E constantly _MonMultiply by its corresponding weights and sue for peace and just obtained input variable E _MonAt the mean value that monitors on the segment length That is:

$\stackrel{\‾}{E_{\mathrm{mon}}}=\underset{j=1}{\overset{i}{\mathrm{\Σ}}}\left(B4\right[j]\×B5[j\left]\right),$

In the formula, B4 and B5 represent the 4th and the 5th shift register respectively.

Note needing to arrange in advance the maximum memory space C of register here, if strip speed is very slow, the weights of each segmentation are especially little, and the register overflow fault will take place for C weights and also do not reach 1.0.Therefore in this consecutive mean module, memory space C=100 is set, each sampling instant can be judged current time weights W _XWhether more than or equal to minimum weights W _Min=1.0/C, and if less than minimum weights three shift register of this sampling instant all do not upgrade, and only with weights summations, judge weights and whether more than or equal to minimum weights in next sampling instant then; Just carry out the renewal of three shift registers more than or equal to minimum weights up to weights and value.

(3) use ramp generator to produce and monitor the exit thickness AME

Ramp value

Owing to need to use Calculate the controlled quentity controlled variable that monitors AGC, in general, avoid AGC controlled quentity controlled variable generation step to change, can bring bigger impact to the executing agency of controller like this, therefore used ramp generator RGE (Ramp Generator) to produce the ramp value of the thick poor mean value of outlet here

When the variable generation step of input changed, step can not take place and change in the output valve of ramp generator like this, but the slope arrives the input variable value.

Ramp generator is calculated as follows ramp value:

$Y_{\mathrm{ramp}}\left(n\right)=Y_{\mathrm{ramp}}(n-1)+\frac{T_S}{T_A},$

In the formula, Y _Ramp(n) be current time ramp generator output valve, Y _Ramp(n-1) be a last moment ramp generator output valve, T _SBe the sampling time, T _ABe the slope time, by regulating T _AThe speed degree that the control slope changes, T _AMore big then slope changes more slowly, T _AMore little then slope changes more soon.

Use ramp generator to produce and monitor the average ramp value of exit thickness error

That is:

$\stackrel{\‾}{E_{R,\mathrm{mon}}}=\mathrm{RGE}\left(\stackrel{\‾}{E_{\mathrm{mon}}}\right)$

Work as like this

When changing,

Be not to become new value at once, but each sampling instant change

Up to Reach new value.

4. obtain second flow amount calculated thickness error correction values Δ h _MFCMonitor the influence value E that AGC controls with current time _Tpm(n):

At first with the average ramp value of thickness error Action delay by first first-order lag link compensation executing agency namely obtains a second flow quantity AGC thickness error correction value Δ h _MFCUse the 3rd synchronous transfer model and the second first-order lag link to ask for the influence value E that current time monitors AGC then _Tpm(n), be specially:

(1) compensate the action delay that AGC controls executing agency by the first first-order lag link:

Need compensate the action delay of AGC control executing agency in the time of error of calculation correction value, represent AGC control executing agency with the first first-order lag link PT1 here, the PT1 link algorithm of discretization is:

$Y_{\mathrm{pt}1}\left(n\right)=Y_{\mathrm{pt}1}(n-1)+\frac{T_S}{T_D}\×(X_n-X_{n-1})$

In the formula, Y _Pt1(n) be the output valve of PT1 link current time; Y _Pt1(n-1) be the output valve in a moment on the PT1 link; T _SBe the sampling time of PLC controller; T _DBeing PT1 link time constant, being taken as the rise time of AGC control executing agency here, because tandem mill AGC carries out by regulating transmission speed, is the rise time of speed regulating mechanism so here; X _nFor the current time input value, here be

The value of current time; X _N-1For

The value in a last moment.

Will

By the rise time of the first first-order lag link compensation speed governor motion, obtain the thickness error correction amount h of second flow quantity AGC _MFC, that is:

$\mathrm{\&Delta;}{h}_{\mathrm{MFC}}=\mathrm{<figure-callout\; id="1"\; label="PT"\; filenames="HDA0000091731980000012.png,HDA0000091731980000021.png"\; state="\{\{state\}\}">PT</figure-callout>}{1}_{\mathrm{SA}}\left(\stackrel{\&OverBar;}{E_{R,\mathrm{mon}}}\right),$

Subscript SA represents speed regulating mechanism in the formula.

Calculate the correction thickness error Δ h that monitors AGC second of flow quantity AGC _MFCAfter, with Δ h _MFCDirectly be added to the second flow amount and calculate outlet one-tenth-value thickness 1/10 h _{Ex, calc}Get on, just obtain exporting one-tenth-value thickness 1/10 through monitoring that the revised second flow amount of AGC is calculated, according to the controlled quentity controlled variable of revised exit thickness value calculating second flow quantity AGC, can further improve the control accuracy of second flow quantity AGC like this.

(2) use the 3rd synchronous transfer model with Δ h _MFCValue transfers to outlet calibrator place from roll gap, obtains Δ h _{MFC, ethg}, the 3rd synchronous transfer model is identical with the first synchronous transfer model structure.

Notice that calculating is to use the thickness data at outlet calibrator place to calculate when monitoring the AGC error amount, therefore when influencing of causing controlled in the supervision of calculating current time, need to use the 3rd synchronous transfer model 34 that the second flow amount error correction values at roll gap place is transferred to outlet calibrator place, this model is with the Δ h that calculates _MFCWith band steel exports speed from the roll gap synchronous transfer to exporting the calibrator place, that is:

Δh _MFC，ethg＝TPM3(Δh _MFC)

(3) delay time by the detection of second first-order lag link compensation outlet calibrator;

Feed the 3rd first-order lag link with transferring to flow quantity AGC thickness error correction value second that the outlet calibrator goes out, the detection time-delay of compensation outlet calibrator, the time constant of the 3rd first-order lag link detects delay time for the outlet calibrator.Finally obtain current time and monitor that the AGC controlled quentity controlled variable is to next influence value E that causes constantly _Tpm(n), that is:

E _tpm(n)＝PT1 _ethg(Δh _MFC，ethg)

In the formula, subscript ethg represents to export calibrator; The influence value E of current time _Tpm(n) use constantly for n+1 after calculating.

5. obtain the live-roller linear velocity regulated quantity Δ V that monitors AGC _{R, mon}:

According to monitoring the average ramp value of AGC exit thickness error Calculate needed muzzle velocity regulated quantity Δ V _Mon, obtain 1 frame live-roller linear velocity regulated quantity Δ V according to the advancing slip factor and roller footpath calculation of parameter again _{R, mon}, be specially:

(1) calculates needed 1 frame muzzle velocity regulated quantity Δ V with following formula _Mon:

$\mathrm{\&Delta;}{V}_{\mathrm{mon}}=-\frac{V_{\mathrm{ex}}\&times;\stackrel{\&OverBar;}{E_{R,\mathrm{mon}}}}{h_{\mathrm{ex},\mathrm{set}}},$

In the formula, h _{Ex, set}Be band steel exports thickness setting value, by process computer according to rolling procedure making.

(2) calculate the regulated quantity Δ V of 1 frame live-roller linear velocity with following formula _{R, mon}:

$\mathrm{\&Delta;}{V}_{r,\mathrm{mon}}=\frac{\mathrm{\&Delta;}{V}_{\mathrm{mon}}}{(1+F_{\mathrm{sl}})\&times;R_d}$

In the formula, F _SlBe the advancing slip factor of 1 frame, general value is between 0.03～0.5; R _dFor the roller of live-roller and working roll directly than, be the intermediate calender rolls transmission in this example, therefore be exactly that intermediate calender rolls is with the ratio in working roll roller footpath here.

Through above-mentioned steps, finally obtain second flow amount calculated thickness error correction values Δ h _MFCWith the transmission speed regulated quantity Δ V that monitors AGC _{R, mon}, the second flow amount error correction values of trying to achieve is delivered to a second flow quantity AGC program, and the transmission speed regulated quantity is delivered to frequency converter remove to regulate the frame driving motor, just finished this supervision AGC and regulated.

The high accuracy belt steel rolling monitors automatic thickness control system as shown in Figure 4, realizes that in the PLC programming it comprises with lower device:

Exit thickness precomputation device 27 is used for calculating band steel exports thickness in band steel porch according to second flow amount equation:

$h_{\mathrm{ex},\mathrm{calc}}=\frac{V_{\mathrm{en}}\&times;h_{\mathrm{en}}}{V_{\mathrm{ex}}},$

In the formula, h _{Ex, calc}Exit thickness for the calculating of second flow amount equation; V _EnFor band steel entrance velocity actual value, measured by pulse coder on the entrance jockey pulley; V _ExFor band steel exports speed actual value, measured by the outlet laser velocimeter; h _EnFor band steel inlet thickness actual value, measured by the entrance calibrator;

The first synchronous transfer model 28 is used for h _{Ex, calc}With the device of band steel entrance velocity synchronous transfer to the mill roll-gap place, obtain mill roll-gap place precomputation thickness h _{Exc, gap}

The second synchronous transfer model 29 is used for the precomputation thickness h with the roll gap place _{Exc, gap}To exporting the calibrator place, obtain exporting the precomputation exit thickness h at calibrator place with band steel exports speed synchronous transfer _{Exc, ethg}

Adaptive equalization device 30 is asked for supervision AGC adaptive equalization factor F for, gantry speed poor according to exit thickness, acceleration _Comp, this device utilizes following formula to calculate:

F _comp＝F _V×F _h×F _a

In the formula, F _VBe the muzzle velocity factor; F _hFor exporting the thick poor factor; F _aBe acceleration factor;

Be compensated factor F _CompAfter, calculate current time with following formula and monitor thickness error E _Mon:

E _mon(n)＝(h _ex，thg-h _exc，ethg)×F _comp-E _tpm(n-1) n＞1；

E _mon(n)＝(h _ex，thg-he _xc，ethg)×F _comp n＝1；

In the formula, h _{Ex, thg}Be outlet calibrator measured value; E _Tpm(n-1) monitor the exit thickness influence value that the AGC controlled quentity controlled variable causes current time constantly for last one; N represents current time; Because last one constantly monitors after AGC regulates and can the exit thickness in this moment be impacted, therefore moment of the supervision AGC controlled quentity controlled variable of calculating current time must be earlier with on one control the influence value that causes constantly and deduct.If current time is initial time, the supervision AGC controlled quentity controlled variable that goes up a moment so is 0, so its influence value also is 0.

Consecutive mean module 31 is used for asking for supervision thickness error E _MonAt the mean value that monitors on the section

Second flow amount calculated thickness error correction device is used for calculating the exit thickness error correction values that the second flow amount is calculated, and comprises ramp generator 32 and the first first-order lag device 33; Ramp generator 32 is used for calculating

Ramp value

The rise time that the first first-order lag device 33 is used for the compensation speed governor motion obtains second flow amount calculated thickness round-off error Δ h _MFC

The 3rd synchronous transfer model 34 is used for Δ h _MFCObtain exporting the thickness round-off error Δ h at calibrator place to outlet calibrator place from the roll gap synchronous transfer _{MFC, ethg}

The second first-order lag device 35, the sampling time-delay that is used for compensation outlet calibrator obtains current time monitoring AGC controlled quentity controlled variable to next exit thickness influence value E that causes constantly _Tpm(n);

Monitor the AGC adjusting device, be used for calculating supervision AGC controlled quentity controlled variable, comprise band steel exports speed adjusting device 36 and live-roller speed adjusting device 37; Band steel exports speed adjusting device is used for basis

Calculate band steel exports speed regulated quantity Δ V _MonThe live-roller speed adjusting device is used for according to band steel exports speed regulated quantity Δ V _MonCalculate live-roller linear velocity regulated quantity Δ V _{R, mon}

The first synchronous transfer model 28, the second synchronous transfer model 29, consecutive mean module 31, the first first-order lag device 33, the 3rd synchronous transfer model 34, the second first-order lag device 35 monitor that with the high accuracy belt steel rolling the first synchronous transfer model, the second synchronous transfer model, consecutive mean module, the first first-order lag device, the 3rd synchronous transfer model, the second first-order lag device in the automatic thickness control method are corresponding respectively.

Below in conjunction with the embodiments the present invention has been done concrete description, but not as restriction of the present invention, all modifications and variations in claim scope of the present invention all drop on and are subjected within protection scope of the present invention.

Claims (3)

1. consecutive mean module, it is characterized in that: the consecutive mean module comprises the 4th to the 6th shift register and judging treatmenting module, and the monitoring segment length is divided into some sections, and hop count is determined that by strip speed every section length is L _S=V * T _S, L in the formula _SBe every section length, V is band steel transmission speed, T _SBe the sampling time;

The 4th shift register is used for the sampled value that storage needs the input variable of dynamic calculation mean value, and is every through a sampling time T _SAll elements in the register is moved one successively backward, then the input sample value of current time is deposited in first position of this register;

The 5th shift register is used for the weights of storage input sample value, and weights determine that by strip speed the weights of each input sample value are W _X=V * T _S/ L _Mon, in the formula, L _MonFor monitoring the length of section; Every through a sampling time with backward mobile one successively of the weights of all storages in the register, then the weights of current time input variable are deposited in first position of this register;

The 6th shift register be used for storage input sample value weights and, soon all the weights additions before the corresponding time obtain in the 5th shift register, each sampling instant is with the weights of all storages and move one backward successively, then the weights of current time input variable are stored in first position of this register, namely first element of the 6th shift register and the 5th shift register always equates; Three shift registers are corresponding one by one;

Judging treatmenting module judges that for each sampling time the element more than or equal to 1.0 appears in the 6th shift register at first, if i element more than or equal to 1.0 i-1 element less than 1.0, then i element of the 5th shift register deducted that i element surpasses 1.0 amount in the 6th shift register, with preceding i element guaranteeing the 5th shift register be 1.0 just in time; Then preceding i element of the 4th shift register be multiply by preceding i element value of corresponding the 5th shift register, and summation obtains monitoring that thickness error is at the mean value that monitors on the segment length.

2. consecutive mean method, it is characterized in that: it may further comprise the steps:

The sampled value of the input variable of step 1, input strip speed V, supervision segment length L and need dynamic calculation mean value;

Step 2, the storage of the 4th shift register need the sampled value of the input variable of dynamic calculation mean value, and be every through a sampling time T _SAll elements in the register is moved one successively backward, then the input sample value of current time is deposited in first position of this register;

Step 3, the 5th shift register are used for storing the weights of input sample value, and weights determine that by strip speed the weights of each input variable are W _X=V * T _S/ L _Mon, in the formula, L _MonFor monitoring the length of section; Every through a sampling time with backward mobile one successively of the weights of all storages in the register, then the weights of current time input variable are deposited in first position of this register;

Step 4, the 6th shift register be used for storing the weights that monitor the thickness error sampled value and, soon all the weights additions before the corresponding time obtain in the 5th shift register, each sampling instant is with the weights of all storages and move one backward successively, then the weights of current time input variable are stored in first position of this register, namely first element of the 6th shift register and the 5th shift register always equates; Three registers are corresponding one by one;

Step 5, judging treatmenting module judge that for each sampling time the element more than or equal to 1.0 appears in the 6th shift register at first, if i element more than or equal to 1.0 i-1 element less than 1.0, then i element of the 5th shift register deducted that i element surpasses 1.0 amount in the 6th shift register, with preceding i element guaranteeing the 5th shift register be 1.0 just in time; Then preceding i element of the 4th shift register be multiply by preceding i element value of corresponding the 5th shift register, and summation obtains monitoring that thickness error is at the mean value that monitors on the segment length.

3. consecutive mean method according to claim 2, it is characterized in that: it also comprises step 6, the maximum memory space C of each shift register is set, and the weights W of current time is all judged in each sampling instant _XWhether more than or equal to minimum weights W _Min=1.0/C, and if less than minimum weights three shift register of this sampling instant all do not upgrade, and only with weights summations, judge weights and whether more than or equal to minimum weights in next sampling instant then; Just carry out the renewal of three shift registers more than or equal to minimum weights up to weights and value.

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