CN104785543B - A kind of hot-strip crown feedback control method based on moving average filter - Google Patents

Abstract

The present invention relates to a kind of hot-strip crown feedback control method based on moving average filter, the method carries out moving average filter process by convexity actual value finish rolling F7 rack outlet being detected, front 4 frames F1～F4 in 7 frame hot continuous rolling finish rolling, actual convexity after processing according to moving average filter and the deviation of target convexity, extract the tendency change of convexity, dynamically F1 F4 bending roller force is adjusted, control to eliminate the trend of convexity change by crown feedback, and cyclic fluctuation is compensated by roll-force and eliminates.Avoid control overshoot and unstability that the large time delay of convexity fluctuation that temperature fluctuation causes and crown feedback causes, improve length direction entirety Crown control precision.Solve tradition convex degree control method and be susceptible to mistuning or overshoot, the problem that whole Crown control precision is low.

Description

A kind of hot-strip crown feedback control method based on moving average filter

Technical field

The present invention relates to hot-strip production technical field, be specifically related to a kind of hot-strip based on moving average filter Crown feedback control method.

Background technology

Plate shape is to weigh one of most important index of strip product quality, and weighing the plate shape common two indices of quality is plate Convexity and glacing flatness.Strip crown, also known as band steel lateral thickness difference, refers to Strip thickness difference in the width direction.Different hot-rolled strips Product made from steel, the requirement to strip crown is the most different, and hot-tandem unit is to ensure that finish rolling goes out to the requirement of the control of strip crown Under conditions of mouth band steel is straight, by Crown control to desired value.

In hot continuous rolling production process, affecting the principal element of strip profile has a roll machinery convexity, roller heat convex degree learning, rolls The convexity change that roller mill damage convexity and band steel lateral flow cause.The factor affecting roll machinery convexity mainly has roll original The bending of roll that convexity, roll-force cause and elastic flattening and the traversing position of Strip Shape Control mechanism such as CVC, the set amount at PC angle And the convexity change that the body of roll change in shape that causes of bending roller force set-point is brought.Wherein, roll-force is that to affect band steel total length convex The principal element of degree change, rolls' deformation changes along with the change of roll-force, so that strip profile changes, and affects The principal element of roll-force is exactly temperature, and temperature change directly results in roll-force and changes, thus affects band steel exports convexity. The convexity that roller heat convex degree learning, roll wear convexity and band steel lateral flow cause is physical process, and general device condition is constant, In same steel mill process, these values keep constant.

The Crown control of hot-strip major control means in early days are setup controls, and its principle is to calculate according to finishing stand setup Rolling data (roll-force of each frame, contact arc length, each rack outlet thickness of the current band steel that program (FSU) calculates Deng), PDI data (target width, thickness, target convexity, glacing flatness), and roller management application program provide roll data (working roll and the support diameter of roller, convexity, barrel length etc.), each road sub-band steel roll thermal crown of roll thermal crown computing module calculating, The abrasion convexity data of each road sub-band steel that roll wear computing module provides, the current PC angle transmitted from L1 and roller force value, Calculate the rolls' deformation of each frame and each rack outlet convexity with a series of models, thus calculate the Strip Shape Control machine of each frame The setting value (optimizing bending roller force, PC angle or the traversing position of CVC) of structure, it is ensured that band steel reaches Target Board convexity and flatness requirements. But, hot continuous rolling Strip Shape Control is a multivariable, time-varying, close coupling and nonlinear complex process, various in the operation of rolling Plate shape influence factor, as roll-force, bending roller force, roll wear, roll thermal crown etc. all can process become with locus over time Change, and interact, couple.According to formed bits for mill roller and band steel theory of plastic strain in matrix, various plate shape factors and final roller Mathematical relationship between seam is considerably complicated, therefore at present the Mathematical Modeling in plat control system be all built upon simplifying in a large number and Assuming on basis, result of calculation tends not to meet user's request and Product Precision.Although introducing adaptation mechanism, but It is that follow-up band steel is only worked by self adaptation, once sets and deviation occurs, would not in the whole operation of rolling of current strip profile There is any correction, cause strip profile entirety overproof.

Use setup control convexity to have disadvantages mentioned above due to simple, dynamically control in the last few years to be introduced in hot continuous rolling In Crown control, to reduce the convexity deviation that model specification is forbidden to bring, improve hot-strip total length convexity and lead to plate difference precision.Mesh Front dynamic control method mainly has two kinds: one is that roll-force compensates, and the most first one roll-force of locking, then in the operation of rolling According to the actual roll-force detected and the deviation of locking roll-force, dynamically adjust the bending roller force output of each frame, make each frame The convexity of outlet keeps fixed value.Another kind is crown feedback, is according to being arranged on the multi-functional instrument inspection below of finish rolling end frame The convexity actual value measured and desired value compare, and convexity deviation are converted into the correction value of each frame bending roller force, to convexity Carry out FEEDBACK CONTROL, because afer bay band steel flakiness ratio is the biggest, it is necessary to keep the rolling of equal proportion convexity, the most easily produce Raw shape wave defect, so the bending roller force of forebay is normally only worked by general crown feedback.

Several hot-continuous-rolling strip steel crown feedbacks control technology below currently mainly existing:

The patent of invention of the disclosed Patent No. 201010230419.8 of application in (1) 2010 year 07 month 20 days " connect by hot rolling The convexity of formula milling train and/or wedge shape autocontrol method and system ", this invention relates to the convexity of a kind of hot rolled in series type rolling machine And/or wedge shape autocontrol method and system (ASCC), by setting up in hot rolled in series type rolling machine from first to end platform finish rolling The working roller bending of frame and the FEEDBACK CONTROL of roll gap leveling, it is achieved that full-automatic band convexity (wedge shape) controls, and i.e. exists In the operation of rolling, ASCC model, after detecting band gad shape, relatively must deviate with target wedge ratio, utilizes the comprehensive fortune of system Calculate and control device is rectified a deviation, set up staged method of adjustment, so that the response of FEEDBACK CONTROL maximizes, to correct band steel Wedge shape and convexity, it is ensured that the glacing flatness that product is good, prevent the serpentine locomotion in each frame of the band steel, eliminate existing Crown control The drawback that means are single, the overall balance relation of convexity and glacing flatness.Wedge shape and convexity can comprehensively be controlled by this patent System, but do not carry out any process to along strip length direction convex value, and due to multi-functional instrument, apart from executing agency, (each frame is curved Roller power) distant, exist bigger delayed, when convexity fluctuation is bigger, overshoot can be caused or even reversely regulate, finish rolling can be strengthened The fluctuation of machine set outlet convexity.

(2) patent of invention " the STRIP PROFILE of Patent No. WO1995GB01354 filed in 06 month 09 day nineteen ninety-five CONTROL ", this patent is by measuring three frame tandem mill outlet convexity deviations, then according to this drift correction The water yield of frame cooling water thus control the outlet convexity of band steel and outlet convexity carried out feedback regulation.The method can improve band Steel Crown control precision.But this mode does not carries out any filtering process to convex measuring value equally, measured value directly applies to FEEDBACK CONTROL, it is difficult to the convexity fluctuation to the various upper frequencies occurred in the operation of rolling is controlled, due to measuring instruments The delayed large dead time with water-cool control convexity, is also easy to cause mistuning to save in some cases.

The above method mainly improves Crown control precision by FEEDBACK CONTROL, but due to the survey for FEEDBACK CONTROL Amount instrument is positioned at after finish rolling outlet frame, there is bigger time stickiness, can only be used for controlling the convexity of tendency change；And mesh Convex measuring value is all not handled by by front method, it is impossible to the convexity that elimination temperature or the fluctuation of supplied materials convexity cause periodically becomes Change, extracting the tendency change of convexity, so being susceptible to mistuning or overshoot in actual use, affecting whole Crown control Precision.

Summary of the invention

It is an object of the invention to provide a kind of hot-strip crown feedback control method based on moving average filter, the party Method utilizes the method for glide filter to filter off the convexity cyclic fluctuation caused due to temperature or roll-force fluctuation, only becomes convexity Gesture sexual deviation carries out FEEDBACK CONTROL, it is to avoid overshoot or reversely regulate, and improves the convexity precision of hot-strip product, in order to solve Tradition convex degree control method is susceptible to mistuning or overshoot, the problem that whole Crown control precision is low.

For achieving the above object, the solution of the present invention is: a kind of hot-strip crown feedback based on moving average filter Control method, the method is applied to 7 frame hot-rolling finishing mills, and Crown control equipment includes that multi-functional instrument, crown feedback control Device and process machine, described multi-functional instrument is arranged on finish rolling F7 rack outlet, and the signal of described multi-functional instrument and process machine is defeated Go out end to be connected with the signal input part of crown feedback controller, the control output end of described crown feedback controller and finish rolling F1 ～F4 frame connects, the method comprises the steps:

(1) according to the beam of water-cooling beam of heating furnace away from band steel threading speed, obtain the filter of finish rolling F7 rack outlet moving average The filtering cycle of ripple；

(2) process machine sets the convexity desired value of band steel, and sends crown feedback controller to；

(3) complete when band steel threading, and after the multi-functional instrument of head arrival finish rolling outlet, multi-functional instrument starts to measure band steel Convexity, and by measurement to strip profile measured value send crown feedback controller to；

(4) if crown feedback controller is less than moving average filter cycle, then finish rolling to the hits of convexity measured value The bending roller force of F1～F4 frame keeps constant；If the hits of convexity measured value is more than or equal to the moving average filter cycle, Then the convexity measured value of sampling is carried out moving average filter process；

(5) compare the convexity measured value after moving average filter processes and convexity desired value, obtain convexity deviation value, and will Convexity deviation value is assigned to finish rolling F1～F4 frame；

(6) the convexity deviation value of each rack outlet in finish rolling F1～F4 frame is converted into bending roller force correction value, by described The bending roller force correction value of each frame carry out PI regulation；

(7) the bending roller force correction value after being regulated by PI carries out amplitude limiting processing, it may be assumed that if the bending roller force correction value after PI regulation Beyond its limiting value, then bending roller force correction value is output as limiting value, without going beyond the limit of value, then exports step (6) and obtains Bending roller force correction value；

(8) bending roller force correction value step (7) obtained is overlapped with the current roller force value of F1～F4 frame, obtains New roller force value；

(9) export after new roller force value being carried out amplitude limit to finish rolling F1～F4 frame, the roller of regulation F1～F4 frame Power, completes the Crown control to one cycle of hot-strip, and starts the new cycle, until after tail part of band steel leaves F1 frame, Complete the crown feedback to whole band steel to control.

In described step (1), the filtering cycle of moving average filter is:

$S_e=\frac{t_e}{T_c}$

Wherein, S_eFor the glide filter cycle；

t_eFor slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel；

T_cSampling period for crown feedback.

Described slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel be:

$t_e=\frac{l_e}{v_e\·(1+f_e)}\·G_v;$

Wherein, t_eFor slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel；

l_eFor slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel；

v_eThreading speed is exported for finish rolling；

f_eAdvancing slip value is exported for finish rolling；

G_vFor speed regulation coefficient.

Described slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel be:

$l_e=\frac{H_s\·W_s\·L_r}{h_e\·w_e}$

Wherein, l_eFor slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel；

H_sFor the slab thickness in heating furnace；

W_sFor the width of plate slab in heating furnace；

L_rWater-cooling beam of heating furnace beam away from；

h_eBelt steel thickness is exported for finish rolling；

w_eFinish rolling outlet strip width.

In described step (4), the method that the convexity measured value sampled carries out moving average filter process is: continuously The S of sampling_eIndividual convexity measured value regards a queue as, and the length of queue is fixed as S_e, sample a new convexity actual measurement every time Value puts into tail of the queue, and throws away a convexity measured value of original head of the queue, the S in queue_eIndividual convexity measured value carries out arithmetic puts down All computings, so that it may obtain new filter result.

In described step (5), the convexity measured value after moving average filter processes is:

${\mathrm{Cf}}_k=\frac{{\mathrm{\Σ}}_{j=k-S_e}^k{C}_j}{S_e}$

Wherein, Cf_kFor kth cycle convexity measured value after glide filter processes；

Cj: jth cycle original convexity measured value；

S_eFor the glide filter cycle.

In described step (5), the method that convexity deviation is assigned to finish rolling F1～F4 frame is:

First, convexity deviation being assigned to each frame of F1～F4, described convexity deviation is:

Δcm_i=ccm_i·(cf_j-c₀)

Wherein, Δ cm_iFor being assigned to the convexity deviation of the i-th frame, i=1,2,3,4；ccm_iIt it is the convexity distribution of the i-th frame Coefficient, is a constant relevant with description；Cfj is jth cycle convexity measured value after glide filter processes；C₀For Convexity desired value；

Then, according to the ratio convexity principle of correspondence, the convexity of finish rolling F7 rack outlet is converted into finish rolling F1-F4 frame and goes out The convexity correction value of mouth, it may be assumed that

$\mathrm{\Δ}{\mathrm{cs}}_i={\mathrm{Gcm}}_i\·\mathrm{\Δ}{\mathrm{cm}}_i\·\frac{h_i}{h_7}$

Wherein, Δ CS_iIt is the i-th rack outlet convexity correction value, i=1,2,3,4；Gcm_iIt it is the i-th frame convexity correction value Gain coefficient, for each frame, is a fixed value, i=1,2,3,4；h_iIt is the i-th rack outlet thickness, i=1,2,3,4； h₇It is the 7th rack outlet thickness.

In described step (6), bending roller force correction value is:

$\mathrm{\Δ}{\mathrm{fbc}}_i=\frac{\mathrm{\Δ}{\mathrm{cs}}_i}{{\mathrm{Gef}}_i}$

Wherein, Δ fbc_iIt it is total correction of the i-th frame bending roller force；

Gef_iIt it is the i-th frame bending roller force gain coefficient to convexity；

ΔCs_iIt it is the i-th rack outlet convexity correction value；

i=1,2,3,4。

In described step (6), the method that bending roller force correction value carries out PI regulation is:

ΔFbp_(i,j)=Δfbc_i·Gp_i

ΔFbI_(i,j)=Δfbc_i·GI_i·T_c+ΔFbI_(i,j-1)

Δfb_(i,j)=ΔFbp_(i,j)+ΔFbI_(i,j)

Wherein, Δ Fbp_(i,j)It it is the ratio correction part of the i-th frame jth cycle bending roller force correction value；

ΔFbI_(i,j)It it is the integration correction part of the i-th frame jth cycle bending roller force correction value；

(i j) is the i-th frame jth cycle total correction of bending roller force to Δ fb；

Gp_iIt it is the proportional control gain of the i-th frame；

GI_iIt it is the integration control gain of the i-th frame；

Δfbc_iIt it is total correction of the i-th frame bending roller force；

Tc is the control cycle of Crown control；

i=1,2,3,4。

In described step (8), new roller force value is:

fb_(i,j)=fb_s+Δfb_(i,j)

Wherein, fb_(i,j)For new roller force value；

fb_sInitial value for bending roller force；

Δfb_(i,j)It it is the i-th frame jth cycle total correction value of bending roller force；

i=1,2,3,4；J=1～S_e。

The beneficial effect that the present invention reaches: the convex degree control method of the present invention compensates roll-force and crown feedback closes The reason division of labor, carries out moving average filter process by convexity actual value finish rolling end rack outlet being detected, in seven frame heat Front four frames of tandem rolling finish rolling, the actual convexity after processing according to moving average filter and the deviation of target convexity, extract The tendency change of convexity, is dynamically adjusted F1-F4 bending roller force, controls to eliminate becoming of convexity change by crown feedback Gesture, and cyclic fluctuation is compensated by roll-force and eliminates.Avoid the big of convexity fluctuation that temperature fluctuation causes and crown feedback The delayed control overshoot caused and unstability, improve length direction entirety Crown control precision.

Accompanying drawing explanation

Fig. 1 is the theory diagram that the crown feedback that the present invention uses controls device；

Fig. 2 is the schematic flow sheet that crown feedback of the present invention controls；

Fig. 3 is the schematic diagram of moving average filter of the present invention；

Fig. 4 is that the crown feedback using glide filter in application example of the present invention controls effect schematic diagram；

Fig. 5 be in application example of the present invention through moving average filter process after convexity measured value；

Fig. 6 is that in application example of the present invention, each frame bending roller force controls output valve；

Fig. 7 is that in application example of the present invention, tradition crown feedback controls effect schematic diagram；

Fig. 8 is that in application example of the present invention, tradition crown feedback controls each frame bending roller force control output valve.

Detailed description of the invention

The present invention is further detailed explanation below in conjunction with the accompanying drawings.

Such as Fig. 1,1～7 is finishing stand F1～F7, and 8 is multi-functional instrument, and 10～15 is kink.The convexity that the present invention uses Controlling device and include multi-functional instrument, crown feedback controller and process machine, described multi-functional instrument is arranged on finish rolling F7 frame and goes out Mouthful, the signal output part of described multi-functional instrument and process machine is connected with the signal input part of crown feedback controller, described The control output end of crown feedback controller is connected with finish rolling F1～F4 frame.

The course of work of this control device is as follows: when band steel threading completes, after head arrives the multi-functional instrument after F7 frame, Multi-functional instrument measure band steel convexity measured value, multi-functional instrument by measurement to convexity measured value send crown feedback control to Device.After crown feedback controller receives convexity measured value, the convexity measured value received is carried out moving average filter process. Convexity measured value and the convexity desired value transmitted from process machine after process compare, and calculate a deviation, are then passed through one The calculating of series Mathematical Modeling, the gain etc. of convexity is counted by thickness and bending roller force in conjunction with each passage belonged to from process machine According to, calculate the correction value eliminating the F1-F4 each frame bending roller force needed for this convexity deviation.The correction value of this bending roller force is added to In current roller force value, give bending roller force executing agency i.e.: each frame of F1-F4, then start next control cycle, until band steel Till afterbody leaves F1 frame.

Such as Fig. 2, the crown feedback control method of the present invention comprises the steps:

(1) according to the beam of water-cooling beam of heating furnace away from band steel threading speed, obtain the filter of finish rolling F7 rack outlet moving average The filtering cycle of ripple；

(2) process machine sets the convexity desired value of band steel, and sends crown feedback controller to；

(3) complete when band steel threading, and after the multi-functional instrument of head arrival finish rolling outlet, multi-functional instrument starts to measure band steel Convexity, and by measurement to strip profile measured value send crown feedback controller to；

(4) if crown feedback controller is less than moving average filter cycle, then finish rolling to the hits of convexity measured value The bending roller force of F1～F4 frame keeps constant；If the hits of convexity measured value is more than or equal to the moving average filter cycle, Then the convexity measured value of sampling is carried out moving average filter process；

(5) compare the convexity measured value after moving average filter processes and convexity desired value, obtain convexity deviation value, and will Convexity deviation value is assigned to finish rolling F1～F4 frame；

(6) the convexity deviation value of each rack outlet in finish rolling F1～F4 frame is converted into bending roller force correction value, by described The bending roller force correction value of each frame carry out PI regulation；

(7) the bending roller force correction value after being regulated by PI carries out amplitude limiting processing, it may be assumed that if the bending roller force correction value after PI regulation Beyond its limiting value, then bending roller force correction value is output as limiting value, without going beyond the limit of value, then exports step (6) and obtains Bending roller force correction value；

(8) bending roller force correction value step (7) obtained is overlapped with the current roller force value of F1～F4 frame, obtains New roller force value；

(9) export after new roller force value being carried out amplitude limit to finish rolling F1～F4 frame, the roller of regulation F1～F4 frame Power, completes the Crown control to one cycle of hot-strip, and starts the new cycle, until after tail part of band steel leaves F1 frame, Complete the crown feedback to whole band steel to control.

Hot-continuous-rolling strip steel is afer bay F5-F7 when, and general thickness is the thinnest, if to curved in the operation of rolling Roller power is adjusted, and easily produces shape wave defect, so the crown feedback of hot continuous rolling typically comes with the bending roller force of forebay F1-F4 Regulation convexity.Owing to nearest frame distance convex measuring instrument is the most remote, exist bigger delayed, so this, there is cunning The advantage of the hot continuous rolling Crown control technology of dynamic filtering is that and is only controlled the overall offset trend of convexity, it is to avoid convex Overshoot or mistuning that degree fluctuation causes save.

The detailed process implementing the inventive method is as follows:

(1) the filtering cycle of moving average filter is calculated

The convexity fluctuation of hot continuous rolling finish rolling outlet, produces due to roll-force fluctuation mostly, and the fluctuation of roll-force Being that temperature fluctuation causes, temperature fluctuation mostlys come from the watermark point that heating of plate blank process produces, and is the step due to heating furnace Enter what beam caused.Therefore, in order to extract convexity variation tendency, it is necessary to filter the convexity change that temperature causes, and temperature change The cycle of the convexity change caused is on all four with watermark point.We use the method for glide filter, therefore, first Must according to the beam of water-cooling beam of heating furnace away from, calculate F7 outlet glide filter the filtering cycle.

First, computational length is the distance that heating furnace beam exports away from slab to finish rolling:

$l_e=\frac{H_s\·W_s\·L_r}{h_e\·w_e}$

In above formula, l_eFor slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel；H_sFor heating furnace In slab thickness；W_sFor the width of plate slab in heating furnace；L_rWater-cooling beam of heating furnace beam away from；h_eBelt steel thickness is exported for finish rolling；w_e Strip width is exported for finish rolling.

Then, the rolling time that this length band steel exports is calculated in finish rolling:

$t_e=\frac{l_e}{v_e\·(1+f_e)}\·G_v;$

In above formula, t_eFor slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel；l_eFor plate Base a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel；v_eThreading speed is exported for finish rolling；f_eGo out for finish rolling The advancing slip value of mouth；G_vFor speed regulation coefficient.

Finally, the filtering cycle of moving average filter is obtained:

$S_e=\frac{t_e}{T_c}$

In above formula, S_eFor the glide filter cycle；t_eFor slab a length of water-cooling beam of heating furnace beam away from band steel finish rolling export Rolling time；T_cSampling period for crown feedback.

(2) the convexity measured value measured is carried out moving average filter process

Moving average filter is also referred to as recurrence average filter method, belongs to the one of low pass filter, and its advantage is to the cycle Property interference have a good inhibitory action, smoothness is high, it is adaptable to the system of the higher-order of oscillation；Shortcoming is that sensitivity is low, to accidentally going out The inhibitory action of existing pulse feature interference is poor, is difficult to eliminate the sampled value deviation caused by impulse disturbances, is not suitable for Impulse disturbances is than more serious occasion.

The convexity change of hot-continuous-rolling strip steel finish rolling outlet can be decomposed into two parts: a part is owing to temperature change produces The fluctuation of periodic convexity, be a kind of high-frequency signal；Another part is the tendency change of convexity, and convexity is overall higher or inclined Low, it is a kind of slowly varying low frequency signal.Seldom there is unexpected acute variation in convexity, so using moving average filter, Can filter the periodicity convexity fluctuation caused due to temperature fluctuation particularly watermark point, the trend extracting convexity change is carried out Control.

The implementation method of moving average filter is to regard a queue as taking N number of sampled value continuously, and the length of queue is fixed For N, sample a new data every time and put into tail of the queue, and throw away a secondary data of original head of the queue, the N number of data in queue are entered Row arithmetic average computing, so that it may obtain new filter result.Specific to the moving average filter of the convexity of finishing mill outlet actual measurement, Because as long as convexity uses the purpose of glide filter to filter the convexity cyclic fluctuation that the temperature fluctuation that watermark point causes causes, So filtering periodic quantity S that N is exactly previous step to be calculated_e。

As shown in Figure 3, it is assumed that the S calculated_eEqual to 6, when taking the lead multi-functional instrument position after finish rolling on earth, multi-functional instrument is surveyed After first convexity data, time delay a period of time convexity data needed for accumulation glide filter, delay duration must be big In equal to t_eValue.When strip profile hits is more than S_eAfter, start glide filter and calculate, first group of band after glide filter Steel convex value Cf₆It is equal to include current sample values C₆The mean value of the first six convexity data, it may be assumed that Next convexity measured value C₇After collecting, first data C of jettisoning sequence₁, then calculate current sample values C₇Before push away 6 numbers C₂～C₇Mean value,With post processing data by that analogy, concrete formula is as follows:

${\mathrm{Cf}}_k=\frac{{\mathrm{\Σ}}_{j=k-S_e}^k{C}_j}{S_e}$

Wherein, Cf_kFor kth cycle convexity measured value after glide filter processes；

Cj: jth cycle original convexity measured value；

S_eFor the glide filter cycle.

(3) convexity deviation is assigned to each frame

The deviation of convex measuring value and desired value after moving average filter processes is the deviation after F7, and crown feedback Executing agency is F1-F4 frame, thus must by measurement to convexity deviation be assigned to each frame.

First, convexity deviation being assigned to each frame of F1～F4, the convexity deviation being assigned to each frame is:

Δcm_i=ccm_i·(cf_j-c₀)

Wherein, Δ cm_iFor being assigned to the convexity deviation of the i-th frame, i=1,2,3,4；ccm_iIt it is the convexity distribution of the i-th frame Coefficient, is a constant relevant with description；Cfj is jth cycle convexity measured value after glide filter processes；C₀For Convexity desired value；

Then, according to the ratio convexity principle of correspondence, the convexity of finish rolling F7 rack outlet is converted into finish rolling F1-F4 frame and goes out The convexity correction value of mouth, it may be assumed that

$\mathrm{\Δ}{\mathrm{cs}}_i={\mathrm{Gcm}}_i\·\mathrm{\Δ}{\mathrm{cm}}_i\·\frac{h_i}{h_7}$

Wherein, Δ Csi is the i-th rack outlet convexity correction value, i=1,2,3,4；Gcmi is the i-th frame convexity correction value Gain coefficient, for each frame, is a fixed value, i=1,2,3,4；Hi is the i-th rack outlet thickness, i=1,2,3,4； h₇It is the 7th rack outlet thickness.

(4) regulated quantity that each rack outlet convexity deviation is converted into bending roller force is exported to executing agency F1～F4 frame

During hot rolling, the deviation of convexity can only be revised by the change of bending roller force, therefore, it is necessary to first will The convexity deviation of each rack outlet that previous step calculates is converted into the correction of bending roller force, it may be assumed that

$\mathrm{\Δ}{\mathrm{fbc}}_i=\frac{\mathrm{\Δ}{\mathrm{cs}}_i}{{\mathrm{Gef}}_i}$

Wherein, Δ fbc_iIt it is total correction of the i-th frame bending roller force；Gef_iIt it is the i-th frame bending roller force gain system to convexity Number；ΔCs_iIt it is the i-th rack outlet convexity correction value；i=1,2,3,4.

Directly giving executing agency by bending roller force correction value can cause system oscillation, causes convexity to fluctuate on the contrary, the most right Bending roller force correction value to carry out PI regulation by a PI controller, to reduce system fluctuation, improves control accuracy.PI regulation Process is:

ΔFbp_(i,j)=Δfbc_i·Gp_i

ΔFbI_(i,j)=Δfbc_i·GI_i·T_c+ΔFbI_(i,j-1)

Δfb_(i,j)=ΔFbp_(i,j)+ΔFbI_(i,j)

Wherein, Δ Fbp_(i,j)It it is the ratio correction part of the i-th frame jth cycle bending roller force correction value；ΔFbI_(i,j)It is The integration correction part of i frame jth cycle bending roller force correction value；(i is j) that the i-th frame jth cycle bending roller force is always revised to Δ fb Amount；Gp_iIt it is the proportional control gain of the i-th frame；GI_iIt it is the integration control gain of the i-th frame；Δfbc_iIt it is the i-th frame bending roller force Total correction；Tc is the control cycle of Crown control；i=1,2,3,4.

The correction value of each frame bending roller force of each control cycle and the total output valve of bending roller force are required for carrying out amplitude limit, if Current bending roller force correction value is more than the amplitude limit value upper limit, then bending roller force correction value is equal to the amplitude limit value upper limit；If if when antecurvature Roller power correction value is less than amplitude limit value lower limit, then bending roller force correction value is equal to amplitude limit value lower limit.Total bending roller force output is also required to Carrying out bound inspection, bound is respectively the bending roller force bound that each frame plant equipment allows, when total bending roller force is more than Higher limit, then total bending roller force is equal to higher limit.When total bending roller force is less than lower limit, then total bending roller force is equal to lower limit.

A concrete application example of the present invention be described below:

The present invention applies in certain factory 1580 course of hot rolling machine transformation project plat control system, uses in being embodied as Relevant parameter as follows:

Step rate beam is away from L_r=1.1m

Speed regulation coefficient G_v=1.2

F1～F4 each frame convexity distribution coefficient ccm_iValue is as shown in table 1:

Table 1

Frame	F1	F2	F3	F4
					ccmi	0.3	0.3	0.3	0.1

The gain coefficient Gcm of F1～F4 each frame convexity correction value_iValue is as shown in table 2:

Table 2

Frame	F1	F2	F3	F4
					Gcmi	0.15	0.15	0.15	0.1

The proportional control gain Gp of each frame of F1～F4_iValue is as shown in table 3:

Table 3

Frame	F1	F2	F3	F4
					Gpi	0.4	0.4	0.35	0.2

The integration control gain GI of each frame of F1～F4_iValue is as shown in table 4:

Table 4

Frame	F1	F2	F3	F4
					GIi	0.35	0.35	0.3	0.25

The control cycle T of Crown control_c=1.0s。

One-step control amplitude limit value is as shown in table 5:

Table 5

One-step control amplitude limit (KN)	F1	F2	F3	F4
					The upper limit	900	900	900	700
Lower limit	-400	-400	-400	-400

Total bending roller force amplitude limit value is as shown in table 6:

Table 6

Total bending roller force amplitude limit (KN)	F1	F2	F3	F4
					The upper limit	1200	1200	1200	900
Lower limit	-1200	100	100	100

The specification of rolled band steel: slab specification: thickness H_s=230mm width W_s=1150mm, hot-strip trimmed size finish rolling Exit thickness h_e=2.32mm, finish rolling exit width w_e=1050mm, target convexity C₀=40_μm.The bending roller force that process machine calculates is to convex The gain coefficient Gef of degree_iValue is such as table 7:

Table 7

Frame	F1	F2	F3	F4
					Gefi	-191643	-180439	-153281	-96651.4

Fig. 4～Fig. 6 is that the crown feedback using moving average filter controls effect, and Fig. 7, Fig. 8 are that same batch band steel is adopted The effect controlled with tradition crown feedback.Fig. 5 be through moving average filter process finish rolling outlet convexity measured value, Fig. 5 and Fig. 4 contrast understands: filtered convexity measured value medium-high frequency wave portion in Fig. 5, only remains the trend of convexity change.Right Than Fig. 7 and Fig. 4 it can be seen that crown feedback based on moving average filter controls more traditional crown feedback and controls more steady, Overshoot is little, and convexity fluctuating range significantly reduces.Fig. 6 and Fig. 8 is that crown feedback based on moving average filter controls and passes respectively The regulation output of the bending roller force of each frame that system crown feedback controls, contrast from figure is it can be seen that use moving average filter Crown feedback output steadily, and tradition Crown control output pulsation is big, and there is bigger overshoot.

From this application example it can be seen that use the crown feedback of moving average filter to control more traditional crown feedback and control Controlling smoother, overshoot is few, and convexity fluctuation is less.The present invention uses moving average filter to control after processing convexity measured value System, more traditional crown feedback technology can effectively reduce the delayed control hyperharmonic mistuning brought of system, controls more steady, essence Du Genggao, has promotional value widely in hot continuous rolling field.

The quality index that convexity Shi Ge hot continuous rolling factory is important.It is contemplated that utilize a kind of convexity based on glide filter anti- Feedback control method, the crown feedback that the convexity fluctuation that elimination causes due to temperature fluctuation causes controls overshoot and unstability, improves band The convexity precision of steel total length.Specifically in front four frames of seven frame hot continuous rolling finish rolling, detect according to end rack outlet Actual convexity and the deviation of target convexity, be dynamically adjusted F1-F4 bending roller force, and convexity deviation being eliminated is zero.Main special Point is the band steel obvious for band steel total length watermark point, temperature fluctuation is bigger, and the convexity arriving reality measurement uses filter of sliding The mode of ripple eliminates the convexity fluctuation that temperature fluctuation causes, and extracts the change of total length convexity tendency, only becomes convexity Gesture change carries out FEEDBACK CONTROL, and the cyclic fluctuation of convexity then solved by roll-force force compensating, it is to avoid temperature fluctuation Control overshoot that the convexity fluctuation caused and the large time delay of crown feedback cause and unstability.

Claims (10)

1. a hot-strip crown feedback control method based on moving average filter, the method is applied to 7 frame hot continuous rollings Finishing mill, Crown control equipment includes multi-functional instrument, crown feedback controller and process machine, and described multi-functional instrument is arranged on essence Rolling F7 rack outlet, the signal output part of described multi-functional instrument and process machine connects with the signal input part of crown feedback controller Connecing, the control output end of described crown feedback controller is connected with finish rolling F1～F4 frame, it is characterised in that: the method includes Following steps:

(1) according to the beam of water-cooling beam of heating furnace away from band steel threading speed, obtain finish rolling F7 rack outlet moving average filter The filtering cycle；

(2) process machine sets the convexity desired value of band steel, and sends crown feedback controller to；

(3) complete when band steel threading, and after the multi-functional instrument of head arrival finish rolling outlet, it is convex that multi-functional instrument starts to measure band steel Degree, and by measurement to strip profile measured value send crown feedback controller to；

(4) if crown feedback controller to the hits of convexity measured value less than the moving average filter cycle, then finish rolling F1～ The bending roller force of F4 frame keeps constant, continues the convexity measured value that sampling multi-functional instrument is measured；If the sampling of convexity measured value Number more than or equal to the moving average filter cycle, then carries out moving average filter process to the convexity measured value of sampling；

(5) compare the convexity measured value after moving average filter processes and convexity desired value, obtain convexity deviation value, and by convexity Deviation value is assigned to finish rolling F1～F4 frame；

(6) the convexity deviation value of each rack outlet in finish rolling F1～F4 frame is converted into bending roller force correction value, by described each The bending roller force correction value of frame carries out PI regulation；

(7) the bending roller force correction value after being regulated by PI carries out amplitude limit, it may be assumed that if the bending roller force correction value after PI regulation is beyond its pole Limit value, then bending roller force correction value is output as limiting value, without going beyond the limit of value, then exports the bending roller force that step (6) obtains Correction value；

(8) bending roller force correction value step (7) obtained is overlapped with the current roller force value of finish rolling F1～F4 frame, obtains New roller force value；

(9) export after new roller force value being carried out amplitude limit to finish rolling F1～F4 frame, regulation finish rolling F1～the roller of F4 frame Power, completes the Crown control to one cycle of hot-strip, and starts the new cycle, until tail part of band steel leaves finish rolling F1 frame After, complete the crown feedback to whole band steel and control.

Hot-strip crown feedback control method based on moving average filter the most according to claim 1, its feature exists In described step (1), the filtering cycle of moving average filter is:

$S_e=\frac{t_e}{T_c}$

Wherein, S_eFor the glide filter cycle；

t_eFor slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel；

T_cSampling period for crown feedback.

Hot-strip crown feedback control method based on moving average filter the most according to claim 2, its feature exists In described slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel be:

$t_e=\frac{l_e}{v_e\·(1+f_e)}\·G_v;$

Wherein, t_eFor slab a length of water-cooling beam of heating furnace beam away from the rolling time that exports in finish rolling of band steel；

l_eFor slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel；

v_eThreading speed is exported for finish rolling；

f_eAdvancing slip value is exported for finish rolling；

G_vFor speed regulation coefficient.

Hot-strip crown feedback control method based on moving average filter the most according to claim 3, its feature exists In described slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel be:

$l_e=\frac{H_s\·W_s\·L_r}{h_e\·w_e}$

Wherein, l_eFor slab a length of water-cooling beam of heating furnace beam away from the distance that exports to finish rolling of band steel；

H_sFor the slab thickness in heating furnace；

W_sFor the width of plate slab in heating furnace；

L_rFor water-cooling beam of heating furnace beam away from；

h_eBelt steel thickness is exported for finish rolling；

w_eStrip width is exported for finish rolling.

Hot-strip crown feedback control method based on moving average filter the most according to claim 2, its feature exists In described step (4), the method that the convexity measured value sampled carries out moving average filter process is: continuous sampling S_eIndividual convexity measured value regards a queue as, and the length of queue is fixed as S_e, sample a new convexity measured value every time and put into Tail of the queue, and throw away a convexity measured value of original head of the queue, the S in queue_eIndividual convexity measured value carries out arithmetic average computing, It is achieved with new filter result.

Hot-strip crown feedback control method based on moving average filter the most according to claim 5, its feature exists In described step (5), the convexity measured value after moving average filter processes is:

${\mathrm{Cf}}_k=\frac{{\mathrm{\Σ}}_{j=k-S_e}^k{C}_j}{S_e}$

Wherein, Cf_kFor kth cycle convexity measured value after glide filter processes；

C_j: jth cycle original convexity measured value；

S_eFor the glide filter cycle.

Hot-strip crown feedback control method based on moving average filter the most according to claim 1, its feature exists In described step (5), by the method that convexity deviation value is assigned to finish rolling F1～F4 frame it is:

First, convexity deviation value being assigned to each frame of F1～F4, described convexity deviation value is:

Δcm_i=ccm_i·(cf_j-c₀)

Wherein, Δ cm_iFor being assigned to the convexity deviation value of the i-th frame, i=1,2,3,4；ccm_iBe the i-th frame convexity distribution system Number, is a constant relevant with description；cf_jFor jth cycle convexity measured value after glide filter processes；c₀For convex Degree desired value；

Then, according to the ratio convexity principle of correspondence, the convexity of finish rolling F7 rack outlet is converted into finish rolling F1-F4 rack outlet Convexity correction value, it may be assumed that

${\mathrm{\Δcs}}_i={\mathrm{Gcm}}_i\·{\mathrm{\Δcm}}_i\·\frac{h_i}{h_7}$

Wherein, Δ cs_iIt is the i-th rack outlet convexity correction value, i=1,2,3,4；Gcm_iIt it is the gain of the i-th frame convexity correction value Coefficient, for each frame, is a fixed value, i=1,2,3,4；h_iIt is the i-th rack outlet thickness, i=1,2,3,4；h₇ It is the 7th rack outlet thickness.

Hot-strip crown feedback control method based on moving average filter the most according to claim 1, its feature exists In described step (6), bending roller force correction value is:

${\mathrm{\Δfbc}}_i=\frac{{\mathrm{\Δcs}}_i}{{\mathrm{Gef}}_i}$

Wherein, Δ fbc_iIt it is total correction of the i-th frame bending roller force；

Gef_iIt it is the i-th frame bending roller force gain coefficient to convexity；

Δcs_iIt it is the i-th rack outlet convexity correction value；

I=1,2,3,4.

Hot-strip crown feedback control method based on moving average filter the most according to claim 1, its feature exists In described step (6), the method that bending roller force correction value carries out PI regulation is:

ΔFbp_(i,j)=Δ fbc_i·Gp_i

ΔFbI_(i,j)=Δ fbc_i·GI_i·T_c+ΔFbI_(i,j-1)

Δfb_(i,j)=Δ Fbp_(i,j)+ΔFbI_(i,j)

Wherein, Δ Fbp_(i,j)It it is the ratio correction part of the i-th frame jth cycle bending roller force correction value；

ΔFbI_(i,j)It it is the integration correction part of the i-th frame jth cycle bending roller force correction value；

Δfb_(i,j)It it is the i-th frame jth cycle total correction of bending roller force；

Gp_iIt it is the proportional control gain of the i-th frame；

GI_iIt it is the integration control gain of the i-th frame；

Δfbc_iIt it is total correction of the i-th frame bending roller force；

T_cThe control cycle for Crown control；

I=1,2,3,4.

Hot-strip crown feedback control method based on moving average filter the most according to claim 1, its feature exists In described step (8), new roller force value is:

fb_(i,j)=fb_s+Δfb_(i,j)

Wherein, fb_(i,j)For new roller force value；

fb_sInitial value for bending roller force；

Δfb_(i,j)It it is the i-th frame jth cycle total correction value of bending roller force；

I=1,2,3,4；J=1～S_e。