JP2010120047A - Method and device for controlling tension between rolling mills - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling tension between rolling mills for stably continuing rolling operation by preventing the deterioration of control characteristics due to the state change of process during the rolling operation and the change of the characteristics of the material to be passed, as regards the tension control of a material to be passed between the rolling mills in a hot rolling process provided with a looper between a plurality of finishing mills. <P>SOLUTION: A model parameter in the characteristic model of the tension generating system of the material is estimated during rolling operation by a looper tension generating system model identifying part and the tension between the rolling mills and the optimum control gain of a looper angle controller are calculated on the basis of the estimated parameter and the control gain is changed hourly. In the estimation of the characteristic model, after previously stipulating a representative reference model about the generating system of the tension between the rolling mills of the material, the characteristic model is calculated hourly from the reference model during the actual rolling operation, the phase relationship and amplification factor relationship of the input and output in actual rolling equipment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to tension control of a plate material passed between rolling mills in a rolling process having a looper between a plurality of rolling mills, and particularly prevents deterioration of control characteristics due to process state changes and characteristic changes of sheet passing material. In addition, the present invention relates to a rolling mill tension control method and apparatus for stably continuing the rolling operation.

  For example, in the hot rolling process of the steel industry, a looper is arranged between finish rolling mills, and in a system that controls the tension and thickness of the sheet material between rolling mills by controlling the looper angle and rolling mill speed, It is widely known that the control of the looper angle interferes with each other, and there arises a problem that the dimensional accuracy of the sheet passing material deteriorates due to the influence of these mutual interferences.

  As a method for solving these problems due to mutual interference, as disclosed in Patent Document 1, a control method is known in which adjacent rolling mills and a looper system installed therebetween are configured as an optimal regulator problem. . The control model for solving this optimal regulator problem is configured under the assumption that the operating state such as the rolling speed is constant. For this reason, when operating conditions such as rolling speed are changed, the assumed performance cannot be obtained, and in some cases, the control becomes unstable.

  For this problem, as disclosed in Patent Document 2, feedback gains at a plurality of rolling speeds assumed at the time of rolling are obtained in advance by solving the optimal regulator problem, and a plurality of these obtained at the time of rolling are obtained. There is also a control method that selects and uses a feedback gain according to the actual rolling speed. However, in this control method, there is a problem that the control performance deteriorates when a change in operation state other than the rolling speed (change in process characteristics) or a change in the characteristics of the sheet passing material occurs.

  Further, as disclosed in Patent Document 3, as a method corresponding to the change in the characteristics of the sheet material, control is performed by changing the characteristic by operating the control target value by learning using the neural network method. Although there is a technique that does not reduce the performance, it takes a certain amount of time to increase the accuracy of this learning, and there is a problem that it cannot cope with a sudden change such as disturbance.

Japanese Patent Laid-Open No. 2-21906 JP 2001-71010 A JP-A-5-208207

  In view of the problems of the prior art as described above, the present invention provides a process characteristic change in the tension control of the sheet passing material between rolling mills in a rolling process in which a looper is disposed between a plurality of rolling mills. It is an object of the present invention to provide a method and an apparatus for preventing deterioration of control characteristics due to a change in material characteristics and stably continuing a rolling operation.

The tension control method between rolling mills of the present invention includes a plurality of rolling mills including a first rolling mill using a plate material as a rolling material and a second rolling mill downstream thereof, and two adjacent rolling mills among them. A rolling mill tension control method for controlling a tension between rolling mills using an optimum regulator for a rolling facility having a looper device disposed therebetween, wherein the first rolling mill is continuously inputted. Based on a plate speed difference actual value which is a difference between a rolling mill exit side plate speed of the second rolling mill and a rolling mill entry side plate speed of the second rolling mill, and the actual tension value between the first and second rolling mills, the rolling Calculating and estimating a Young's modulus and a tension feedback coefficient, which are model parameters for the rolled material during rolling, using a preset tension generating nominal model describing the tension generation mechanism of the material, and the estimation Yang Calculating an optimum feedback gain for controlling the tension between the first and second rolling mills and the angle of the looper device by an ILQ design method using a rate and a tension feedback coefficient, and The rolling is performed while adjusting the optimum feedback gain according to a change in characteristics of the rolled material and a change in process characteristics during rolling.
The tension control device between rolling mills of the present invention includes a plurality of rolling mills including a first rolling mill using a plate material as a rolling material and a second rolling mill downstream thereof, and two adjacent rolling mills among them. A rolling mill tension control device for controlling a tension between rolling mills using an optimum regulator for a rolling facility having a looper device disposed therebetween, wherein the first rolling mill is continuously input. Based on the actual plate speed difference value that is the difference between the rolling mill exit side plate speed of the second rolling mill and the rolling mill entry side plate speed of the second rolling mill, and the actual tension value between the first and second rolling mills, the rolling A Young's modulus E ′ and a tension feedback coefficient K ₁₀ ′, which are model parameters for the rolling material during rolling, are calculated and estimated using a preset tension generation nominal model that describes the tension generation mechanism of the material. Looper tension generation An optimum feedback gain for controlling the tension between the first and second rolling mills and the angle of the looper device is determined by an ILQ design method using a model identifier and the estimated Young's modulus and tension feedback coefficient. An optimum control gain calculating unit for calculating, and adjusting the optimum feedback gain in accordance with a change in characteristics of a rolled material and a change in process characteristics during rolling.
In the rolling mill tension control device according to the present invention, the looper tension generation system model identifier is continuously input, and the tension generation system nominal model is input with the sheet speed difference actual value as an input value. Is used to calculate the tension nominal value, and based on the phase difference between the tension nominal value and the actual tension value between the first and second rolling mills, the actual plate speed difference actual value. A corrected nominal model calculation unit that calculates a tension generation system time constant T ′ using the Young's modulus E _n and the tension feedback coefficient K _10n of the model, and a tension generation system time constant T ′ calculated by the correction nominal model calculation unit Using the tension generation system correction nominal model used, a tension correction nominal value is obtained from the plate speed difference actual value, and the maximum value and the minimum value of the tension correction nominal value in a preset period are obtained. The PP value which is the difference is calculated, and the PP value which is the difference between the maximum value and the minimum value in the preset period of the actual tension value between the first and second rolling mills is calculated and calculated. Based on the PP value of the tension correction nominal value and the PP value of the actual tension value, the generation of tension is estimated by calculating the Young's modulus E ′ and the tension feedback coefficient K ₁₀ ′, which are model parameters for the rolled material being rolled. And a system model parameter calculation unit.

  According to the tension control method and apparatus of the present invention, in the control method and control apparatus for the tension between rolling mills using the optimum regulator, the Young is applied to the rolling material during rolling based on the tension generation system nominal model and the actual tension value. Rate and tension feedback coefficient can be estimated and the optimum feedback gain can be switched following the change in the characteristics of the controlled object during the actual rolling operation, preventing deterioration of the control characteristics due to process characteristic changes and material characteristic changes. The rolling operation can be continued stably.

Hereinafter, an example of the rolling mill tension control device 25 will be described with reference to the drawings as an embodiment for carrying out the rolling mill tension control method and apparatus of the present invention.
FIG. 1 shows an example of a part of a hot rolling process composed of a plurality of rolling mills. As rolling equipment, i-th (i is a natural number) neighboring rolling mills ( _Fi rolling mills: 1 and i + 1-th rolling mill ( _{Fi + 1} rolling mill: second rolling mill) 2, the two rolling mills ( _Fi rolling mill, _{Fi + 1} rolling) machine) looper 3 installed in an intermediate position of the 1, 2, F _i mill (rotation) drive motor 4, F _{i + 1} rolling mill (rotation) drive motor 5, a looper to change the looper angle θ 3 is provided with a looper drive motor 6 for driving the motor 3 and ASR devices 7 to 9 for speed control of the drive motors 4 to 6.

  The angle of the looper 3 (looper angle θ) is measured by the looper angle detector 24, and the roll rotation speed of each of the rolling mills 1 and 2 is a speed detector (shown in the figure) attached to the motors 4 and 5 that drive the rolling mill. The rolling mill tension is estimated by the rolling mill tension calculator 23 using the current value of the looper motor 6 that drives the looper 3 under the control of the ASR device 8. In addition, about tension | tensile_strength between rolling mills, a tension | tensile_strength measuring device may be attached to the looper 3, and a track record value may be detected directly.

The speed command to the ASR devices 7 and 8 is output from the rolling mill tension and looper angle controller 10. More specifically, the ASR device 7 for controlling the F _i mill (rotation) drive motor 4 for driving the F _i rolling mill 1 includes a control output of the mill interstand tension and the looper angle controller 10, separately set I have been F _i rolling mill operation input value speed reference value and has been added is inputted. Further, F _{i + 1} rolling mill 2, separately set F _{i + 1} mill speed reference value is input to the ASR device 9 is controlled based on the F _{i + 1} mill speed reference value. On the other hand, in order to control the looper angle θ, the deviation between the separately set target looper angle value and the actual looper angle value measured by the looper angle detector 24 is input to the tension between the rolling mills and the looper angle controller 10. Then, the control output (looper angular velocity command) is input to the ASR device 8.

The tension between the rolling mills means a force in the pulling direction (rolling direction) acting on the steel plate between the i-th and i + 1-th rolling mills, and the looper angle θ is the arm of the looper 3. And the horizontal direction.
Further, FIG. 1 shows only between the i-th and i + 1-th rolling mills, but the tension control device 25 between rolling mills described below is also between other rolling mills not shown. You may apply similarly.

  Next, 12 is a looper tension generation system model identifier constituting the core part of the rolling mill tension control device of the present invention, and includes a corrected nominal model calculation unit 13 and a tension generation system model parameter calculation unit 14. It is configured. The optimal control gain calculation unit 11 uses the model parameter value estimated and calculated by the tension generation system model parameter calculation unit 14 to determine the optimal control gain (optimum feedback) of the rolling mill tension and looper angle controller 10. Gain).

(Description of looper tension generation system model identifier 12)
FIG. 2 shows an example of a block configuration inside the modified nominal model calculation unit 13 in the looper tension generation system model identifier 12. Here, the nominal model is a reference model that models an average behavior of a controlled object (rolling equipment in the present invention) used in a general control system design method. The parameter values used in the reference model (nominal model) are referred to as nominal values for each parameter. In the conventional looper control system, generally, the behavior of the tension between rolling mills is first defined as a tension generation system nominal model, and a control parameter is designed using that.

Tensioning system nominal model calculation unit 15 in FIG. 2, F _i rolling mill 1 (rotation) by the speed detector attached to the drive motor 4 is continuously measured, roll rotation speed results in F _i rolling mill 1 value to (F _i mill mill speed actual value), the rolling mill exit forward slip correction factor for calculating the side plate speed (1 + fi) and the value obtained by multiplying the similarly measured F _{i + 1} rolling mill The difference between the roll rotation speed actual value in Fig. 2 ( _{Fi + 1} rolling mill speed actual value) and the value obtained by multiplying the reverse rotation rate correction coefficient (1-bi) to calculate the rolling mill entry side plate speed Input as a speed difference actual value, and output a tension value (defined as nominal tension) generated by the action as an output value. The advance rate fi and the reverse rate bi are set as constants in advance based on the operation conditions.

Here, the tension generation nominal model Pn (s) used in the tension generation nominal model calculation unit 15 takes the actual value of the plate speed difference as an input value, and inputs the tension between the rolling mills generated by the action as an output. As an output relational expression, it is defined by the following expression (1) in the form of a transfer function of a first-order lag system using the Laplace operator s. In the formula (1), the nominal value of the Young's modulus and tension FBK (Feedback) coefficient of the rolling material, respectively and E _n and K _10n, the distance between F _i rolling mill 1 and F _{i + 1} rolling mill 2 and L .

Here, T _n is the time constant of the tension generation nominal model Pn (s) in the rolling mill equipment.
The first input / output phase difference calculation unit 16 in FIG. 2 is output from the plate speed difference actual value that is an input value to the tension generation system nominal model Pn (s) and the tension generation system nominal model calculation unit 15. The phase difference (in this case, the time difference) from the nominal tension signal is calculated as the input / output phase difference tdn (defined as the nominal input / output phase difference) in the nominal model.

Further, the second input / output phase difference calculation unit 17 in FIG. 2 performs the above-described measurement of the actual plate speed difference actual value signal, the actual _Fi rolling mill 1 and the _{Fi + 1} rolling mill 2. The phase difference tdr (defined as the actual input / output phase difference) is calculated using the signal of the actual tension value of the steel plate between the two as an input signal.

In addition, the actual tension system Pr (s) of the tension generation system in the actual rolling mill equipment (hereinafter also referred to as the tension generation system actual system) Pr (s) is the true value of the Young's modulus and tension FBK coefficient of the rolled material, respectively. ₁₀ is defined by the following equation (2) in the form of a transfer function of a first-order lag system using the Laplace operator s.

  Here, T is the time constant of the actual tension generation system Pr (s) in the actual rolling mill equipment.

  The difference between the nominal input / output phase difference tdn and the actual input / output phase difference tdr is caused by the difference in the time constant in the first-order lag system described by the equations (1) and (2). The time constant T of the tension generating system at the time can be obtained as an estimated value T ′ using the following equation (3).

The tension generation system correction nominal model calculation unit 18 calculates and outputs an estimated value T ′ of the time constant T of the tension generation system in the actual rolling operation with a short period of about 10 msec, for example, using Equation (3). .
FIG. 3 shows an example of a block configuration of the tension generation system model parameter calculation unit 14 in the looper tension generation system model identifier 12.
The tension generation nominal value Pn ₂ (s) of the tension generation system correction nominal model used in the tension generation system correction nominal model calculation unit 19 in FIG. The transfer function of a first-order lag system having a time constant that matches the time constant of the tension generation system is defined by the following equation (4).

The tensioning system modified nominal model Pn ₂ (s) is, F _i roll rotation speed actual value of the rolling mill 1 in (F _i mill mill speed actual value), forward slip to calculate the plate velocity exiting the rolling mill To calculate the rolling mill entry side plate speed by multiplying the correction coefficient (1 + fi) and the actual roll rotation speed value of the Fi _{+ 1} rolling mill 2 (Fi _{+ 1} rolling mill speed actual value). The difference from the value multiplied by the reverse rate correction coefficient (1-bi) is input as the plate speed difference actual value, and the tension value between the rolling mills (defined as the corrected nominal tension value) generated by the action is calculated and output. To do.

The corrected nominal tension PP (Peak to Peak) value calculation unit 20 in the looper tension generation system model identifier 12 shown in FIG. 3 performs the correction nominal tension value signal continuously calculated as described above. calculating a difference between the maximum value and the minimum value between any period Tpp previously set as a correction nominal tension PP values pp _n. The other tension actual PP value calculation unit 21, as the actual tension actual value also tension actual PP value pp _r a difference between the maximum value and the minimum value of the signal between any period Tpp of (tension actual value rolling mill) Calculate. Dividing them by a divider, the tension PP value ratio α, which is the ratio of these, is calculated as in the following equation (5).

  Note that the arbitrary period Tpp is a value determined according to the fluctuation period of the plate speed difference actual value that is the input signal, for example, a value of about 1 to 2 times the period of the main cyclic fluctuation component of the input signal. And good.

Next, the tension generation system model parameter estimation unit 22 uses the tension PP value ratio α as described below, and the estimated value K ₁₀ ′ of the tension FBK coefficient of the rolling material, which is a model parameter, and the rolling material The estimated Young's modulus E ′ is calculated and output. That is, with respect to the tension PP value ratio α obtained using the equations (2), (4), and (5), the relationship of the following equation (6) is established.

Therefore, the tension generation system model parameter estimation unit 22 can calculate the estimated value K ₁₀ ′ of the tension FBK coefficient of the rolled material by the following equation (7).

Further, the tension generation system model parameter estimation unit 22 calculates the estimated value E ′ of the Young's modulus of the rolled material by the following formula (8) from the estimated value K ₁₀ ′ of the tension FBK coefficient of the rolled material and formula (3). Is possible.

(Explanation of optimal control gain calculation unit 11)
1 uses the estimated value K ₁₀ ′ of the tension FBK coefficient of the rolled material and the estimated value E ′ of the Young's modulus calculated by the above method by the looper tension generation system model identifying unit. By using the ILQ (Inverse Linear Quadratic) design method, which is a widely known optimum control gain design method, the optimal control gain for these model parameters is calculated from time to time, for example, at a cycle of about 10 msec. According to the change of the above, the tension between rolling mills and the control gain of the looper angle controller 10 are tuned during the rolling operation.

As described above, when a control system is conventionally designed by the rolling mill tension control device 25 including the looper tension generation system model identification unit 12 and the optimum control gain calculation unit 11, a fixed value is set during rolling operation. The tension FBK coefficient K ₁₀ and Young's modulus E (tension generation system model parameters during rolling operation) in the tension generation system, which have been handled in a simplified manner, are estimated and calculated momentarily in the looper tension system model identification unit 12 to obtain the optimum. The control gain calculation unit 11 calculates and tunes the optimum control gain in the state of the rolling operation from moment to moment, so that actual rolling that cannot be handled by conventional methods such as hardness variation and temperature change of the material to be rolled, etc. Even if the characteristics of the controlled object change during operation, a stable rolling mill control method is implemented without degrading the control performance, and the apparatus is implemented. It is possible to become.

The rolling mill tension control device 25 including the above-described units and devices can be configured using, for example, an FA computer or a PLC. At that time, and F _i mill (rotation) drive motor 4, F _{i + 1} rolling mill (rotation) Actual value of measured velocity at a rate detector attached to the drive motor 5, the looper angle detector 24 The actual value of the looper angle θ measured in step 1 is input, the I / O board for outputting a control signal to each of the ASR devices 7-9, and the respective setting values for control are input. The rolling mill tension control device 25 is provided with an input means such as a keyboard for display and a display means such as a display for presenting the control state to the operator. Then, a computer program for executing signal processing and data processing in each of the above-described units and devices is created, loaded into the FA computer, and executed.

  In the description of the present embodiment, the control technology of the present invention is applied when controlling the two regulators of the tension between the rolling mills and the looper angle by applying the optimal regulator control in the tension control between the rolling mills. The example has been described in detail. However, even outside the field, for example, in a manufacturing process in which a workpiece is continuously processed and manufacturing conditions fluctuate, the characteristics of the process are first order lag and gain (when the input is a constant amount). The control technique of the present invention is implemented by constructing a nominal model of the manufacturing process for a control device that applies optimal regulator control for two control variables when expressed by the ratio of output to input of Is possible.

An experiment was conducted to estimate the change in characteristics of the material to be rolled during the rolling operation by the above-described tension control method between rolling mills.
FIG. 4 shows the tension FBK coefficient K in the tension generation system by actually applying the method of the present invention to the tension between the fifth and sixth rolling mills during the rolling operation in the actual hot rolling line. ₁₀ and the experimental results of estimating Young's modulus E every moment are shown. The main operating conditions were a strip thickness of 2.2 mm for the fourth rolling mill of the material to be rolled, a plate feed speed of about 400 mpm, and an estimation calculation period of 25 ms. In this estimation example, only the looper tension system model identification unit 12 which is an example of the method of the present invention is applied, and tuning during the rolling operation of the control gain is not performed. The dotted lines in the figure are nominal values of Young's modulus and tension FBK coefficient under the rolling conditions, and are 1500 and 25, respectively.

  From FIG. 4, the Young's modulus and the tension FBK coefficient, which were conventionally assumed as constant values during the rolling operation, have changed over time, and occurred during the rolling operation by using an example of the method of the present invention. It turns out that the characteristic change of material can be estimated. It should be noted that the tension FBK coefficient has changed abruptly since the time of 33 seconds, and has finally changed to a value that is at least twice the nominal value of 25. However, during actual operation, the Young Since the control was carried out by the conventional control system designed assuming that the rate and tension FBK coefficient were fixed values, the rolling mill tension fluctuated greatly, which led to a threading trouble.

FIG. 5 shows a case where the same conditions as the rolling operation state in FIG. 4 are reproduced by a computer simulator, and the material properties of the steel plate between the fifth rolling mill and the sixth rolling mill change greatly. Simulation of tension controllability in the conventional method, that is, when the control gain is fixed during rolling operation, and when the parameter fluctuation is estimated using the method of the present invention and the control gain is adjusted every moment accordingly. Results of comparison are shown. In the simulation, the simulated in the rolled material are model parameters takes the tension generating systems tension FBK coefficient K ₁₀ and Young's modulus E, chronologically changing with the value estimated by the experiment shown in FIG. 4 It was. In confirming the effect of the method of the present invention, assuming that the change of the parameter is unknown, the parameter change is estimated by the method of the present invention, the optimal control gain is calculated at a 25 msec period, and the control gain is actually tuned. I let them. From FIG. 5, from around 30 seconds when the tension FBK coefficient starts to change suddenly, the fluctuation of the tension between the rolling mills becomes very large in the conventional control method, and the tension between the looper 3 and the steel sheet, where the tension is 0 or less at the maximum fluctuation. A non-contact state has occurred and the operation is unstable. In contrast, by using the method of the present invention, the tension fluctuation range under such circumstances is suppressed, which is more stable than the case where the conventional method controlled without considering the change in material properties is applied. It can be seen that simple control can be realized.

The embodiment of the present invention described above can be realized by a computer executing a program. Further, a means for supplying the program to the computer, for example, a computer-readable recording medium such as a CD-ROM recording such a program, or a transmission medium for transmitting such a program may be applied as an embodiment of the present invention. it can. A program product such as a computer-readable recording medium that records the program can also be applied as an embodiment of the present invention. The programs, computer-readable recording media, transmission media, and program products are included in the scope of the present invention.
In addition, the embodiments of the present invention described above are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. Is. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

It is a figure which shows the rolling mill tension control apparatus and rolling equipment which concern on this invention. It is a block diagram which shows the structure of the correction nominal model calculating part in the tension control apparatus between rolling mills shown in FIG. It is a block diagram which shows the structure of the tension generation system model parameter calculating part in the tension control apparatus between rolling mills shown in FIG. It is a figure which shows the result of having implemented parameter identification during the actual rolling operation in the looper tension generation system model identification part which concerns on this invention. It is a figure which shows the result of having simulated the controllability of embodiment of this invention and the example of a prior art method.

Explanation of symbols

1 F _i rolling mill (i-th)
2 F _{i + 1} rolling mill (i + 1)
3 Looper 4 F _i rolling mill drive motor 5 F _{i + 1} rolling mill drive motor 6 Looper driving motor 7 F _i rolling mill drive motor ASR device 8 Looper driving motor ASR device 9 F _{i + 1} rolling mill drive motor ASR apparatus 10 Tension and looper angle controller 11 Optimal control gain calculation unit 12 Looper tension generation system model identification unit 13 Corrected nominal model calculation unit 14 Tension generation system model parameter calculation unit 15 Tension generation system nominal model calculation unit 16 First input / output phase difference calculation unit 17 Second input / output phase difference calculation unit 18 Tension generation system correction nominal model calculation unit 19 Tension generation system correction nominal model 20 Correction nominal tension PP value calculation unit 21 Actual tension PP value calculation unit 22 Tension Generation system model parameter estimation unit 23 Tension calculator between rolling mills 24 Looper angle detector 25 Tension controller between rolling mills

Claims (3)

A rolling machine having a plurality of rolling mills including a first rolling mill using a plate material as a rolling material and a second rolling mill downstream from the first rolling mill, and a looper device disposed between two adjacent rolling mills. About equipment, it is a tension control method between rolling mills to control the tension between rolling mills using an optimal regulator,
The sheet speed difference actual value which is a difference between the rolling mill exit side plate speed of the first rolling mill and the rolling mill entry side plate speed of the second rolling mill, and the first and second continuously input. Based on the actual tension value between the rolling mills, using the preset tension generation system nominal model describing the tension generation mechanism of the rolling material, the Young's modulus and tension are model parameters for the rolling material during rolling. Calculating and estimating a feedback coefficient;
Calculating an optimum feedback gain when controlling the tension between the first and second rolling mills and the angle of the looper device by an ILQ design method using the estimated Young's modulus and tension feedback coefficient; Have
A rolling mill tension control method, wherein rolling is performed while adjusting the optimum feedback gain in accordance with a change in characteristics of a rolling material and a change in process characteristics during the rolling. A rolling machine having a plurality of rolling mills including a first rolling mill using a plate material as a rolling material and a second rolling mill downstream from the first rolling mill, and a looper device disposed between two adjacent rolling mills. About equipment, it is a tension control device between rolling mills that controls the tension between rolling mills using an optimum regulator,
Continuously input sheet speed difference actual value which is a difference between the rolling mill exit side plate speed of the first rolling mill and the rolling mill entry side plate speed of the second rolling mill, and the first and second Based on the actual tension value between the rolling mills, a Young's modulus E ′, which is a model parameter for the rolling material during rolling, using a preset tension generation system nominal model that describes the tension generation mechanism of the rolling material. And a looper tension generation system model identifier for calculating and estimating a tension feedback coefficient K ₁₀ ′,
The optimum control gain for calculating the optimum feedback gain when controlling the tension between the first and second rolling mills and the angle of the looper device by the ILQ design method using the estimated Young's modulus and the tension feedback coefficient. An arithmetic unit,
A tension control device between rolling mills, wherein the optimum feedback gain is adjusted in accordance with a change in characteristics of a rolled material and a change in process characteristics during rolling. The looper tension generation system model identifier is:
Continuously input, the plate speed difference actual value as an input value, using the tension generation system nominal model to calculate a tension nominal value,
The tension nominal value, and based on the phase difference between the plate speed difference actual value of the respective tension actual value between the first and second rolling mill, the Young's modulus E _n and tension feedback coefficient of the tensioning system nominal model A modified nominal model calculation unit for calculating a tension generation system time constant T ′ using K _10n ;
Using the tension generation system correction nominal model using the tension generation system time constant T ′ calculated by the correction nominal model calculation unit, a tension correction nominal value is obtained from the plate speed difference actual value, and the tension correction nominal The PP value which is the difference between the maximum value and the minimum value in a preset period of the value is calculated, and the maximum and minimum values in the preset period of the actual tension value between the first and second rolling mills The PP value that is the difference between
Based on the calculated PP value of the tension correction nominal value and the PP value of the actual tension value, the Young's modulus E ′ and the tension feedback coefficient K ₁₀ ′, which are model parameters for the rolled material being rolled, are calculated and estimated. The tension control device between rolling mills according to claim 2, further comprising: a tension generation system model parameter calculation unit that performs the operation.

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