JP2010029889A - Device and method for controlling tension and looper angle in continuous rolling mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the mutual interference between the variation of the tension between rolling stands and the variation of a looper angle and to suppress the variation of the tension and the looper angle of a material to be rolled to the variation of tension in portions of the material to be rolled, which are generated caused by the variation of the mechanical property or the like of the material to be rolled. <P>SOLUTION: When controlling the tension F and the looper angle θof the material 3 to be rolled between the stand 1 of the preceding stage and the stand 2 of the succeeding stage by using the deviation T<SB>e</SB>between the detected value T<SB>m</SB>of " the tension F of the material 3 to be rolled between the stand 1 of the preceding stage and the stand 2 of the succeeding stage" which is detected with a tension detector 12 and a tension command value T<SB>ref</SB>and the deviation θ<SB>e</SB>between the detected value θ<SB>m</SB>of the looper angle θ detected with a looper angle detector 11 and a looper angle command value θ<SB>ref</SB>, the hardness (the amount K<SB>10</SB>of elongation of the material 3 to be rolled) of the material 3 to be rolled is estimated with an estimator 16 by using the deviation V<SB>e</SB>between the rotational speed V<SB>r1</SB>of a mill motor 4 of the preceding stage and the rotational speed V<SB>r2</SB>of a mill motor 5 of the succeeding stage, and the gain K<SB>f011</SB>of a looper controller 14 is changed by using that estimated value d<SB>s1</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention addresses fluctuations in the mechanical properties of a metal plate by adjusting the tension and looper angle of the material to be rolled during rolling by a continuous rolling mill in which a looper is installed between rolling stands in a metal plate manufacturing plant. The present invention relates to an apparatus and a method for stable and stable control.

  For example, a continuous rolling mill for finishing and rolling a steel plate that is a material to be rolled in a hot continuous rolling process of a steel plate that is one of plate materials such as metal materials includes a plurality of rolling stands. Further, in order to maintain the loop amount L of the material to be rolled between the rolling stands and to keep the tension F of the material to be rolled stable, an apparatus called a looper is often arranged between the rolling stands.

FIG. 9 is a diagram illustrating an example of a configuration of a continuous rolling mill.
In FIG. 9, 1 is a front stage stand, 2 is a rear stage stand, 3 is a material to be rolled, 4 is a front stage mill motor, 5 is a rear stage mill motor, 6 is a looper, and 7 is a looper motor. The tension F of the material to be rolled 3 is a force acting in the plane of the material to be rolled 3, but in the following description of the present application, the force F exerted from the material to be rolled 3 on the looper 6 is applied to the material to be rolled 3. The tension is F.

  In FIG. 9, the tip of the material 3 to be rolled moves from left to right and is sandwiched between the upper roll 1a and the lower roll 1b of the front stand 1 and then the upper roll 2a and the lower roll of the rear stand 2 2b. When the material to be rolled 3 is sandwiched between the front stand 1 and the rear stand 2, the looper 6 is rotated and raised by the looper motor 7 to press the material to be rolled 3. In the control of the looper 6, the “tension F between the front stand 1 and the rear stand 2” that directly influences the sheet width and thickness after finish rolling of the material 3 to be rolled is stably controlled, and is controlled with respect to a certain reference direction. It is important from the viewpoint of the stability of continuous rolling operation to suppress the fluctuation of the looper angle θ which is the rotation angle of the looper 6.

  As a phenomenon in which the tension F and the looper angle θ between the front stage stand 1 and the rear stage stand 2 cannot be stably controlled, for example, there are the following phenomena. That is, the mechanical properties such as hardness and deformation resistance of the material 3 to be rolled in the plate pass fluctuate depending on the part during rolling, the load applied to the rear stand 2 changes suddenly, and the hardness of the material 3 to be rolled is small. Then, the width of the upper roll 2a and the lower roll 2b of the rear stage stand 2 is narrowed, and the material 3 to be rolled cannot pass through the rear stage stand 2. For this reason, the tension F varies, and the looper angle θ also varies.

  Due to such a change in tension F caused by a sudden change in the hardness of the material 3 to be rolled, the thickness and width of the material 3 to be rolled may deviate from the target set values, or in the worst case There was a plate breakage in which the material to be rolled 3 was cut in the plate, and as a result, the productivity of the steel plate was sometimes deteriorated.

FIG. 10 is a block diagram showing a first example of a conventional tension / looper angle control device used for looper control of a continuous rolling mill.
In FIG. 10, the tension / looper angle control device controls the deviation (θ _ref) between the measured value θ _m of the looper angle detected by the looper angle detector 38 and the looper angle command value θ _ref when controlling the looper angle θ. −θ _m ) is obtained by the subtractor 42 and output to the PI controller 39. The output of the PI controller 39 becomes a speed correction value of the speed command value V _ref1 of the front mill motor 4 and is added to the speed command value V _ref1 of the front mill motor 4 by the adder 43. The added value of the output of the PI controller 39 and the speed command value V _ref1 of the pre-mill motor 4 is output to the pre-mill motor speed controller 37 which is a PI controller. In this way, the tension / looper angle control device controls the looper angle θ.

Further, when controlling the tensile force F is converted into a current command value I _ref by entering the tension command value T _ref to current conversion logic 41, the deviation between the current command value I _ref and Rupamota current value I _d ( A tension control system for controlling the tension F between the front stand 1 and the rear stand 2 is obtained by obtaining I _ref −I _d ) by the subtractor 44 and outputting it to the looper motor current controller 40.

However, this conventional tension / looper angle control device has a problem that the tension control performance is poor because the above-described tension control system is an open loop control in which the tension command value T _ref is a set value. Further, the tension F and the looper angle θ physically interfere with each other. That is, a change in tension induces a change in looper angle, and a change in looper angle induces a change in tension. In this conventional looper angle control device, since suppression of interference between the tension F and the looper angle θ is not considered, it is difficult to stably control the tension F and the looper angle θ with high accuracy. was there.

To deal with such a problem, another conventional technique is a tension / looper angle control device as shown in FIG. FIG. 11 is a block diagram showing a second example of a conventional tension / looper angle control device used for looper control of a continuous rolling mill.
In the tension / looper angle control device shown in FIG. 11, a tension detector 90 is installed in the looper 6, and the deviation between the tension value T _m detected by the tension detector 90 and the tension command value T _ref is input to the tension controller 55. and it controls the tension F to set the speed of the preceding mill motor 4 at a tension controller 55, to a looper angle controller 56 with the looper angle measurements theta _m detected by the looper angle detector 11 looper angle theta Use two feedback loops to control.

  In the tension / looper angle control device shown in FIG. 11, a non-interacting controller (hereinafter also referred to as a cross controller) is used in combination to suppress interference between the tension F and the looper angle θ. One cross controller 57 suppresses interference with the tension fluctuation that affects the looper angle θ, and the other cross controller 58 suppresses interference with the looper angle fluctuation that affects the tension F. However, even the tension / looper control device shown in FIG. 11 sometimes cannot sufficiently suppress the interference between the tension F and the looper angle θ.

  Patent Document 1 discloses another invention relating to the tension between the stands and the looper control method in the continuous rolling mill. In the control method described in Patent Document 1, a tension control system including a first feedback loop for inputting a deviation between a tension measurement value and a tension command value to a tension controller, a looper angle measurement value, and a looper angle command value. The tension F and the looper angle θ are controlled using a looper angle control system including a second feedback loop that inputs a deviation from the looper angle controller. Further, the disturbance applied to each of the first feedback loop and the second feedback loop is estimated by a disturbance compensator using a predetermined model, and the estimated value is obtained in each of the tension control system and the looper angle control system. Is used to offset the disturbance.

  In the control method described in Patent Document 1, disturbances applied to the first and second feedback loops are estimated by predetermined models, respectively, and the signals of the first and second feedback loops are compensated, respectively. Since the phase delay occurs, there is a problem that the fluctuation of the tension F and the fluctuation of the looper angle θ cannot be sufficiently suppressed. There is also a problem that it is impossible to cope with the fluctuation of the tension F due to the fluctuation of the hardness of the material to be rolled. For this reason, the plate thickness and the plate width of the material to be rolled may deviate from the target set values, and the productivity may deteriorate due to plate breakage or the like.

JP 7-136707 A Generalization of ILQ optimal servo system design method: Takao Fujii, Takashi Shimomura, Transactions of the Institute of System Control Information, 1988 Vol. 1, no. 6, pp. 194-203

  In view of the problems of the conventional technology for controlling the tension and the looper angle between the stands of the continuous rolling mill in which the looper is installed between the rolling stands as described above, the present invention provides a variation in tension between the rolling stands and the looper. The tension of the material to be rolled and the looper angle with respect to the tension fluctuation in the part of the material to be rolled, which is caused by fluctuations in the mechanical properties of the material to be rolled and the mutual interference with the fluctuation of the angle being suppressed to a low level. The purpose is to suppress as much as possible the fluctuation of.

The gist of the present invention is as follows.
The tension and looper angle control device of the continuous rolling mill according to the present invention includes a front stand and a rear stand provided with a mill motor, and a looper provided with a looper motor disposed between the front stand and the rear stand. A continuous rolling mill using a metal plate as a material to be rolled, wherein a tension F of the material to be rolled and a looper angle θ of the looper between the front stand and the rear stand are set to target values T _ref and θ _ref , respectively. Is a tension and looper angle control device for a continuous rolling mill that follows the above, and inputs a deviation between the measured value of the tension F and the target value _Tref, and a deviation between the measured value of the looper angle θ and the target value _θref. A looper controller that calculates and outputs a control amount of the rotational speed of the front mill motor and a control amount of the angular speed of the looper using an adjustable gain K as values, and the front stand includes A subtractor that calculates and outputs a rotation speed deviation (V _r2 −V _r1 ) between the rotation speed V _r1 of the mill motor and the rotation speed V _{r2 of the} mill motor provided in the rear stage stand, and the rotation speed deviation (V _r2 − V _r1 ) as an input value, an estimator for estimating the elongation K _{10 of the} material to be rolled based on the mechanical characteristics of the material to be rolled by a disturbance observer of the continuous rolling mill, and the adjustable gain K , comprising a gain adjuster to set based on the estimated amount of elongation the material to be rolled which is estimated by the device K _10, the looper controller, adjusts to follow the variation of the mechanical properties of the material to be rolled The control amount is calculated on the basis of the gain K.
The tension and looper angle control device of another continuous rolling mill according to the present invention includes a front stand and a rear stand provided with a mill motor, and a looper provided with a looper motor disposed between the front stand and the rear stand. And a tension and looper angle control device of a continuous rolling mill provided with a continuous rolling mill using a metal plate as a material to be rolled, wherein the rotational speed of the mill motor provided in the front stand and the rotational speed of the mill motor provided in the rear stand The elongation amount of the material to be rolled is calculated on the basis of the first derivation means for deriving the rotation speed deviation with respect to the rotation speed deviation calculated by the first derivation means and the mechanical properties of the material to be rolled. Estimation means for estimating, and second derivation means for deriving a control amount of the rotational speed of the former mill motor and an angular speed of the looper, and the second derivation calculation Stage, depending on the elongation amount of the rolled material which has been estimated by the estimating means, and adjusts the control amount.
Further, the tension and looper angle control method of the continuous rolling mill of the present invention includes a front stand and a rear stand provided with a mill motor, and a looper provided with a looper motor disposed between the front stand and the rear stand. A continuous rolling mill control method using a metal plate as a material to be rolled, wherein the tension F of the material to be rolled and the looper angle θ of the looper between the front stand and the rear stand are target values, respectively. A tension and looper angle control method for a continuous rolling mill that follows T _ref and θ _ref , the deviation between the measured value of the tension F and the target value T _ref , and the measured value and the target value θ _{ref of the} looper angle θ. A looper control step for calculating and outputting the control amount of the rotational speed of the former mill motor and the control amount of the angular speed of the looper using an adjustable gain K, with the deviation from A subtraction step for calculating and outputting a rotational speed deviation (V _r2 −V _r1 ) between the rotational speed V _{r1 of the} mill motor provided in the front stage stand and the rotational speed V _{r2 of the} mill motor provided in the rear stage stand, and the rotational speed deviation ( V _r2 −V _r1 ) as an input value, the estimation step of estimating the elongation K _{10 of the} material to be rolled by the disturbance observer of the continuous rolling mill based on the mechanical characteristics of the material to be rolled, and the adjustable the gain K, and and a gain adjustment step of setting, based on the elongation amount K ₁₀ of the rolled material which has been estimated by the estimation process, the looper control step, follow the fluctuation of the mechanical properties of the material to be rolled The control amount is calculated based on the gain K adjusted in this way.

  According to the present invention, the amount of elongation due to fluctuations due to the location of the mechanical properties of the material to be rolled is sequentially estimated, and the adjustable gain of the looper controller is set based on the amount of elongation. Therefore, during high-speed and high-precision rolling of the material to be rolled, the mutual interference between fluctuations in tension between the stands and fluctuations in the looper angle is suppressed to a lower level than before, and fluctuations in the mechanical properties of the material to be rolled. Thus, it is possible to suppress the fluctuation of the tension and the looper angle of the material to be rolled as much as possible.

Taking a steel plate as an example of a rolled material of a metal plate, as an embodiment for carrying out the present invention, details of an example of a tension and looper angle control device and control method of a continuous rolling machine for steel plate using drawings and mathematical formulas Explained.
FIG. 1 is a block diagram illustrating an example of a schematic configuration of a tension and looper angle control device of a continuous rolling mill according to the present embodiment.
The main body of the continuous rolling mill includes the front stage stand 1, the rear stage stand 2, the front stage mill motor 4, the rear stage mill motor 5, the looper 6, and the looper motor 7, similarly to FIG. 9 described in the background art.

In each drawing, parts and devices having the same function are denoted by the same reference numerals to clarify the correspondence between the parts in the drawings. Further, in FIG. 1 and the like, the pre-mill motor speed controller 18 is a PI controller based on a proportional / integral control method (the transfer function is (K _p1 · s + K _i1 ) / s, where K _p1 and K _{i1 are} constants). The looper speed controller 9 is also a PI controller (the transfer function is (K _p2 · s + K _i2 ) / s, where K _p2 and K _{i2 are} constants). To do. Note that these mill motor speed controller 18 and looper speed controller 9 may be known controllers of the type commonly used in rolling mills, such as a PID controller, in addition to the PI controller.

In FIG. 1, with respect to the tension F applied to the material 3 to be rolled, a tension deviation (T _e = T) between a tension command value T _ref preset by the operator and a measured tension value T _m detected by the tension detector 12. _ref− T _m ) is calculated by the subtracter (B) 20. Further, the subtractor (C) 21 calculates a looper angle deviation (θ _e = θ _ref −θ _m ) between the preset looper angle command value θ _ref and the looper angle θ _m detected by the looper angle detector 11. . The tension deviation T _e and the looper angle deviation theta _e is input to the looper controller 14. Looper controller 14, and these tension deviation T _e and the looper angle deviation theta _e to zero, perform operations such as described in detail below, the front mill motor speed command value V _ref, looper angular velocity command The value ω _ref1 is calculated.

And front mill motor speed command value V _ref that is calculated by the looper controller 14, the front stage mill motor speed deviation between the rotational speed V _r1 of the preceding mill motor 4 detected in the previous paragraph the mill motor speed detector 8 (V _ref1 -V _r1) subtractor ( E) Calculate at 23 and output to the pre-mill motor speed controller 18. As described above, the pre-mill motor speed controller 18 performs the PI control calculation and drives the pre-mill motor 4 according to the control output based on the calculation result. By the above control loop, the tension F between the front stand 1 and the rear stand 2 (between stands) is controlled to be kept constant.

The subtractor (A) 19 calculates an angular velocity deviation (ω _ref1 −ω _m ) between the looper angular velocity command value ω _ref1 calculated by the looper controller 14 and the looper angular velocity ω _m detected by the looper velocity detector 10. To the looper speed controller 9. As described above, the looper speed controller 9 performs the PI control calculation, drives the looper motor 7 according to the control output based on the calculation result, and sets the looper angle θ to the set angle (looper angle command value θ _ref ). Control to keep. As will be described in detail below, the estimator 16 has a longitudinal speed deviation (V) between the rotational speed V _r1 of the front mill motor 4 and the rotational speed V _r2 of the rear mill motor 5 detected by the rear mill motor speed detector 13. _e = V _r2 −V _r1 ), the fluctuation of the hardness of the material 3 to be rolled is estimated by a disturbance observer, and the gain change of the looper controller 14 during rolling is estimated using the estimated value. 17 is instructed.

<Looper controller 14>
Next, the configuration of the control block of the looper controller 14 that controls the tension F and the looper angle θ constant, and the flow of signal processing in the looper controller 14 will be described. FIG. 2 is a block diagram showing an example of the configuration of the looper controller 14.
The looper controller 14 can be realized by combining the adders 71 to 74, the subtractors 75 and 76, the amplifiers 60 and 65 to 70, and the integrators 61 to 64 as shown in FIG.
The signals input to the looper controller 14 are the above-described tension deviation T _e , looper angle deviation θ _e , measured tension value T _m , and measured looper angle value θ _m , and the signal output from the looper controller 14 is The former mill motor speed command value V _ref1 and the looper angular speed command value ω _ref1 . The function and configuration of each block of the looper controller 14 will be described below.

(Cross controller)
The non- _interacting controller (cross controllers 57 and 58) shown in FIG. 11 and the non- _interacting controller (integrator 62 (K _i021 / s: gain K _i021 ) and integrator 63 shown in FIG. (K _i012 / s: gain K _i012 )) has the same role of canceling the interference between the tension F and the looper angle θ. However, in general, the conventional cross controllers 57 and 58 are expressed by a reverse transfer function of a tension model or a looper model, whereas the non-interacting controller (integrator 62 and integrator) of the present embodiment shown in FIG. The integrator 63) is expressed by a mathematical expression including a variable to be controlled and a variable of a designated response. For this reason, the non-interacting controller of the present embodiment has a feature that interference between the tension F and the looper angle θ can be reduced only by changing (adjusting) the variable of the designated response. On the other hand, the conventional non-interacting cross controllers (cross controllers 57 and 58) are expressed by the inverse transfer function of the tension model or the looper model, and therefore, when trying to reduce the interference between the tension F and the looper angle θ. Has the problem that the cross controllers 57 and 58 have to be redesigned.

(Calculation process for deriving the former mill motor speed command value V _ref1 and the looper angular speed command value ω _ref1 )
In FIG. 2, the pre-mill motor speed command value V _ref1 and the looper angular velocity command value ω _ref1 , which are output signals from the looper controller 14, are expressed by the following formulas (1) and (2), respectively.

Here, _Te is a tension deviation, θ _e is a looper angle deviation, T _m is a measured tension value, and θ _m is a measured value of the looper angle. The derivation of equations (1) and (2) and each coefficient K (gain) will be described below.

(Gain K derivation guideline and method by ILQ optimal servo design method)
The optimal servo system of the looper controller 14 can be designed by using an ILQ (Inverse Linear Quadratic) design method that utilizes a known inverse problem of the optimal regulator. The ILQ design method is described in detail in Non-Patent Document 1, for example.

  First, the ILQ design method will be briefly described. In a controllable and observable linear time-invariant system, such as a plant model (looper model and tension model) that is the subject of the present invention, the linearized mathematical model is in the form of the following equation (3): expressed.

  Here, x is a state quantity (n-dimension), u is an operation quantity (m-dimension), y is an output (control quantity: m-dimension), and A, B, and C have appropriate sizes specific to the mathematical model. It is a matrix, and rank B = rank C = m (n and m are natural numbers). Further, in the expression (3), “·” attached to x indicates that it is time differentiation.

The optimal servo solution that minimizes the predetermined evaluation function is obtained by examining the optimal servo design problem for the mathematical model described by equation (3). On the other hand, in the ILQ design method, the optimum control gain K is obtained by solving the inverse problem of the optimum servo. FIG. 3 is a block diagram showing an example of the configuration of the ILQ optimum servo system.
Specifically, when the optimum control gain K is used, the optimum control law is expressed by equation (4).

The optimum control gain K can be separated into a feedback gain K _f and an integral gain K _i, and the derivation equations thereof are the following equations (5) and (6).

  Here, I is a unit matrix. Further, F in the equation (6) is obtained as follows (a) to (d).

(A) Specify the position of the pole, that is, the response of the control system (see the following equation (7)).

(B) G = [g ₁ g ₂ ... G _n ] is calculated by the following equation (8).

However, W (S) is a transfer function matrix.
(C) T = [t ₁ t ₂ ... T _n ] is calculated by the following equation (9).

(D) Find T ⁻¹ (transposition matrix of T) in equation (9), and calculate F by the following equation (10).

以上の（ａ）〜（ｄ）の手順により、（６）式内のＦが求められる。
又、本実施の形態において各状態量ｘ、制御量ｙ、操作量ｕは、ぞれぞれ以下の（１１）式、（１２）式、（１３）式で与えられる。

F in the equation (6) is obtained by the above procedures (a) to (d).
In the present embodiment, the state quantity x, the control quantity y, and the operation quantity u are given by the following expressions (11), (12), and (13), respectively.

ここで、Δｔ_fは張力、Δω_Lはルーパモータ７の角速度、Δθはルーパ６の角度、ΔＶ_Rは前段ミルモータ４の回転速度、Δｘ_Hはルーパ速度制御器９の積分器の出力、ΔＶ_RREFは前段ミルモータ４の速度指令値、Δω_LREFはルーパモータ７の角速度の指令値である。
また、プラントモデル（ルーパモデルと前段ミルモデル）の状態方程式を求めると、（３）式のＡ、Ｂ、Ｃは、それぞれ以下の（１４）式、（１５）式、（１６）式のように表わされる。

Here, Δt _f is the tension, Δω _L is the angular speed of the looper motor 7, Δθ is the angle of the looper 6, ΔV _R is the rotational speed of the former mill motor 4, Δx _H is the output of the integrator of the looper speed controller 9, and ΔV _RREF is A speed command value for the former mill motor 4, Δω _LREF, is a command value for the angular speed of the looper motor 7.
Further, when the state equations of the plant model (looper model and previous mill model) are obtained, A, B, and C in the equation (3) are as shown in the following equations (14), (15), and (16), respectively. It is expressed in

Here, E is the Young's modulus of the material to be rolled 3, K ₁₀ is the amount of elongation of the material to be rolled 3, L is the distance between the stands, J _L is the inertia of the looper motor 7, φ is the torque constant of the looper motor 7, and g _L is The gear ratio of the looper motor 7, α ₂ is a conversion coefficient from the rotational speed of the mill motor to the loop amount, T _v is a time constant of the speed control system of the pre-stage mill motor 4, and K ₂₁ is a PI control system (looper) for controlling the speed of the looper motor 7 proportional gain of the speed controller 9), the transfer function of the T ₂₁ is an integral gain of PI control system controlling the speed of Rupamota 7, F ₁ is the load torque generation function, F ₂ from the angle θ of the looper 6 to the loop amount, F ₃ is a conversion coefficient from tension F to load torque, and Z is a looper damping coefficient.
The optimum control gain K of ILQ control (hereinafter abbreviated as gain K) is derived from the equations (3) to (16).

(Each gain setting)
With the ILQ design method described above, each gain K shown in FIG. 2 can be derived as follows.
_{Expressions of} the gains K _f011 , K _f012 , K _f021 , and K _f022 are shown in the following expressions (17), (18), (19), and (20), respectively.

Here, ω _TC is a tension control response, and ω _HC is a looper angle control response.
Ω _HC and ω _TC , which are designated response variables of the tension control system and looper angle control system, are parameters that can be set freely. By changing these parameters, it is possible to obtain an arbitrary tension control response and looper angle control response. Therefore, the gain K is easy to adjust on site.
The gains K _i011 , K _i012 , K _i021 , and K _i022 can also be set by calculating the equations (5) to (16).

<Estimator 16>
As shown in the equation (17), the calculation formula of the gain K _f011 of the looper controller 14 includes the parameters of the material 3 to be rolled such as the Young's modulus E of the material 3 to be rolled and the elongation K _{10 of the} material to be rolled. It is out. However, the steel sheet that is the material to be rolled 3 generally varies in temperature, hardness, and the like depending on the part during passing. This fluctuation adversely affects the control of the continuous rolling mill as a disturbance. In the present embodiment, in order to reduce the influence of the fluctuation on the control system, the gain K _f011 of the looper controller 14 is changed by using the estimator 16 and the gain adjuster 17, thereby The gain K _f011 suitable for the material to be rolled 3 is adjusted and set.

In the present embodiment, a disturbance observer as described below is constructed in the estimator 16 in order to evaluate how much the hardness variation between the front stage stand 1 and the rear stage stand 2 affects the rolling. Using the tension measurement value T _m detected by the detector 12 and the estimated tension value, the elongation amount K ₁₀ of the material to be rolled 3 is estimated as follows.

First, the rotational speed V _r1 , which is the rotational speed per unit time of the front-stage mill motor 4 measured by the front-stage mill motor speed detector 8, and the rotational speed per unit time of the rear-stage mill motor 5 measured by the rear-stage mill motor speed detector 13. Using the rotational speed deviation V _e (= V _r2 −V _r1 ) with the rotational speed V _r2 , the elongation K ₁₀ of the material to be rolled 3 between the front stage stand 1 and the rear stage stand 2 is measured using a disturbance observer. Estimation is performed by the estimator 16. Here, the rotational speed deviation V _e is calculated by the subtractor 22.

The disturbance observer uses a rotational speed deviation (V _e = V _r2 −V _r1 ) as an input value, and estimates a parameter representing the elongation of the material 3 to be rolled, which is affected by the hardness variation of the material 3 to be rolled. The equation of state of this disturbance observer is shown in equation (21).

Here, x _s1 is an estimated tension value, d _s1 is an estimated value of the elongation amount K ₁₀ of the material to be rolled 3 between the front stage stand 1 and the rear stage stand 2 (that is, by the front stage stand 1), and V _e is a rotational speed difference. , T _m represents the measured tension of the actual machine, and K ₁ and K ₂ represent the observer gain.

As described above, the state equation (model) of the disturbance observer described by the equation (21) is a model that reproduces the actual tension value of the actual machine, and uses the difference between the actual tension value of the model and the measured tension value of the actual machine. Thus, the error between the model and the actual machine (plate elongation) is estimated.
FIG. 4 is a block diagram showing an example of the configuration of the disturbance observer represented by the equation (21). As shown in FIG. 4, the disturbance observer can be realized by combining an adder 85, subtracters 84 and 86, amplifiers (observer gain) 81 and 82, and integrators 80 (tension generation model) and 83. .

The estimated value d _s1 of the elongation amount of the material to be rolled 3 estimated by the disturbance observer based on the measured tension value T _{m of the} actual machine and the estimated tension value x _s1 is adopted as the elongation amount K ₁₀ of the material to be rolled 3 described above. . Estimator 16 uses the elongation amount K _10, for example (17) sequentially changed in real time preset cycle elongation of K ₁₀ of the rolled material 3 which is used in the formula. The gain adjuster 17 calculates the gain K _f011 each time the elongation amount K _{10 of the} material to be rolled 3 is changed in this way, and outputs it to the looper controller 14.

By the way, as described above, the gain adjuster 17 changes the gain K _f011 of the looper controller 14 to realize suppression of “variation in tension F and variation in looper angle θ” due to variation in hardness of the material 3 to be rolled. However, when the gain K is changed in this way, the gain K of the looper controller 14 changes abruptly. For this reason, the tension F may become unstable when the gain K is changed. Therefore, in the present embodiment, the gain K of the looper controller 14 is subjected to a moving average to prevent a steep change in the gain K. As a method for this, as shown in the following equation (23), 50 pieces of data (data for a preset period) of the gain K of the looper controller 14 calculated by the gain adjuster 17 are averaged, and looper control is performed. The gain K of the device 14 is changed gently. In Equation (23), K ₁₀ , which is the elongation amount of the material to be rolled 3 included in the gain K _f011 of the looper controller 14 shown in Equation (17), is estimated by the disturbance observer. change with elongation amount K _10, an example of executing the moving average of the gain K _f011 of the looper controller 14.

In the equation (23), K _f011 [k−1] represents data one time before the gain K _f011 of the looper controller 14.
By using these methods (21) to (23), the gain K _f011 of the looper controller 14 can be changed so as to follow the fluctuation of the hardness of the material 3 to be rolled. It becomes possible to suppress the fluctuation of the tension F and the fluctuation of the looper angle θ due to the fluctuation of the hardness.

FIG. 5 is a block diagram showing an example of the configuration of the gain adjuster 17 for calculating the gain K _f011 of the looper controller 14. That is, the gain adjuster 17 is a block diagram showing the processing performed by the aforementioned equations (17) and (23).
As shown in FIG. 5, a configuration for calculating gain K _f011 by combining multipliers 100 to 102, dividers 103 and 104, amplifiers 105 to 107, first-order lag element 106, subtractor 108, and adder 109. Is obtained in the gain adjuster 17.

The gain adjuster 17 inputs the elongation d _s1 (K ₁₀ ) of the material to be rolled 3 calculated by the estimator 16 by the equation (21), and calculates the gain K _f011 . The gain K _f011 is averaged using the data obtained up to 50 _hours before the calculated gain K _f011 , and the output value is set as the gain K _f011 of the amplifier 66 shown in FIG. The block for calculating the moving average shown in FIG.
As described above, in the present embodiment, the first derivation unit is realized by the subtractor 22, the estimation unit is realized by the estimator 16, and the second derivation unit is realized by the looper controller 14 and the gain adjuster 17. The
It should be noted that the gain adjuster 17 can be incorporated in the estimator 16 or the looper controller 14 in addition to the above-described aspects.

Further, by setting the moving average value of the gain K _f011 looper controller 14, although preferably it is possible to prevent the change of the steep gain K, set looper controller 14 a gain K _f011 itself rather than the moving average value May be.
Further, for example, a threshold value for determining whether or not to change the gain K _f011 is set in the looper controller 14 in advance, and the “gain K _f011 itself or the movement of the gain K _f011 obtained by the gain adjuster 17 is obtained. average "is, whether more than the threshold value determined looper controller 14, if it exceeds the threshold value, the gain K _f011 obtained by the gain adjuster 17" gain K _f011 itself or gain K _f011 If not, the gain K _f011 may not be changed.

Further, the tension and looper control device of the continuous rolling mill of the present embodiment schematically shown in FIG. 1 can be configured by a personal computer, PLC (Programmable Logic Controller) or the like. When the control device is incorporated in the master control device, the longitudinal deviation (V _e = V _r2 −V _r1 ) between the rotational speed V _r1 of the front mill motor 4 and the rotational speed V _r2 of the rear mill motor 5 is used. An estimator that estimates the elongation K ₁₀ of the rolled material 3 and a mathematical expression that averages the gain K of the looper controller 14 as shown in equation (23) are discretized so as to operate at a predetermined clock time. Constitute. When the master control device is constituted by a personal computer or PLC, a semiconductor memory or hard disk drive, a keyboard and mouse as input means, a computer display as output means, and a digital or analog input / output board may be used. Further, the master control device may be provided with a LAN board for connecting to a factory network. Then, a computer program for executing signal processing and data processing such as each calculation for control described above may be created and installed in a built-in memory or the like of the master control device. Further, the tension and looper control device of the continuous rolling mill according to the present embodiment has been described in detail above, but a series of calculation / control executed in each block shown in FIG. 1, FIG. 2, FIG. 4, and FIG. The tension and looper control method of the continuous rolling mill configured by the above processing procedure is also included in the present invention.

<Simulation results>
In order to confirm the fluctuation of the tension F due to the fluctuation of the hardness of the material to be rolled 3 between the front stage stand 1 and the rear stage stand 2, a continuous rolling mill was simulated. Calculating Specifically, by using an actual tension measurements T _m, the equation (21), the estimated value d _s1 elongation amount (the rolled material 3 to estimate the elongation amount K ₁₀ of material to be rolled 3 A simulation was performed.
FIG. 6 is a diagram illustrating an example of a result of estimating the elongation amount K ₁₀ of the material to be rolled 3 by performing simulation of the continuous rolling mill.
FIG. 6 shows Young's modulus E = 1500 [kgf / mm ² ], distance between stands L = 5846 [mm], ω _HC = 10 [rad / s], ω _TC = 20 [rad / s], disturbance observer gain K _This is a result of simulation assuming that ₁ = 20, K ₂ = 365, and steel material having a plate thickness of 2 mm is formed as rolling conditions.

As shown in FIG. 6, when the fluctuation of the tension F occurs due to the fluctuation of the hardness of the material 3 to be rolled, the estimated value d _s1 of the elongation K ₁₀ of the material 3 to be rolled changes greatly. Here, FIG. 6 shows the result of estimation using data such as the measured tension value T _m of the actual machine and the longitudinal speed deviation V _e (rotational speed of the mill motor). At this time, the “elongation amount K _{10 of the} material 3 to be rolled” shown in the equation (17) is constant, and between the actual elongation amount of the material 3 to be rolled and the set value of the elongation amount of the material 3 to be rolled. There is a possibility that a large divergence occurs and the tension F fluctuates.

Therefore, in order to confirm this, a variation in the hardness of the material to be rolled 3 was simulated by simulation. Specifically, it was decided to change the parameter indicative of the elongation of K ₁₀ of the rolled material 3, after 10 seconds from the start of the simulation steps. FIG. 7 is a diagram illustrating an example of a result of simulating the tension F _BK generated in the material to be rolled 3 when the plate elongation parameter of the material to be rolled 3 is changed in a step shape.

As shown in FIG. 7, by changing the parameter representing the extension amount K ₁₀ of material to be rolled 3 stepwise variation of the tension F _BK is generated. From this, it can be seen that the fluctuation of the tension F _BK is caused by the fluctuation of the hardness of the material 3 to be rolled.
In this way, in order to suppress the fluctuation of the tension F _BK generated by the fluctuation of the hardness of the material 3 to be rolled, the elongation K ₁₀ of the material 3 estimated by the disturbance observer shown in the equation (21) The gain K of the looper controller 14 was changed using the estimated value d _s1 . 8, using the estimated value d _s1 elongation of the rolled material. 3 shows an example of a simulation result of the tensile force F _BK occurring material to be rolled 3 when changing the gain K _f011 of the looper controller 14 FIG. This simulation is a parameter indicating the extension amount K ₁₀ of the rolled material 3, after 10 seconds from the start of the simulation is changed stepwise.

As shown in FIG. 8, with respect to the fluctuation of the hardness of the material to be rolled 3, the elongation K ₁₀ of the material to be rolled 3 shown in the equations (21) to (23) is estimated by a disturbance observer, By changing the gain K of the looper controller 14 following the elongation K ₁₀ of the rolled material 3, the tension F due to the fluctuation of the hardness of the rolled material 3 between the front stand 1 and the rear stand 2 is changed. Variations can be suppressed. As a result, troubles such as deterioration of the plate thickness and width of the material to be rolled 3 and plate breakage can be prevented, leading to a large increase in production.

As described above, in the present embodiment, the detected value T _{m of the} “tension F of the material to be rolled 3 between the front stand 1 and the rear stand 2” detected by the tension detector 12 and the tension command value T _ref and the deviation T _e, with a deviation theta _e between the detection value theta _m and the looper angle command value theta _ref of the looper angle theta which is detected by the looper angle detector 11, the between front stand 1 and the rear stage stand 2 When controlling the tension F and the looper angle θ of the rolled material 3, the estimator 16 uses the deviation V _e between the rotational speed V _r1 of the front mill motor 4 and the rotational speed V _r2 of the rear mill motor 5 to estimate the material to be rolled. 3 (elongation K _{10 of the} material 3 to be rolled) is estimated, and the gain K _f011 of the looper controller 14 is changed using the estimated value d _s1 . That is, in the present embodiment, the elongation amount K ₁₀ due to the variation of the mechanical properties of the material 3 to be rolled 3 is sequentially estimated, and the looper controller 14 can be adjusted based on the estimated value d _s1 of the elongation amount K _10. The gain K _f011 was set. Therefore, during high-speed and high-precision rolling of the material 3 to be rolled, the mutual interference between the fluctuation of the tension F between the stands 1 and 2 and the fluctuation of the looper angle θ is suppressed to a lower level than before, and the material 3 to be rolled. It is possible to suppress the fluctuation of the tension F and the looper angle θ of the rolled material 3 as much as possible with respect to the fluctuation of the tension of the rolled material 3 caused by the fluctuation of the mechanical characteristics and the like.

Further, in the present embodiment, the tension deviation (T _e = T _ref −T _m ) between the measured value of the tension F and the target value T _ref of the material 3 to be rolled, and the measured value and the target value θ _{ref of the} looper angle θ. Deviation (θ _ref −θ _m ) as an input value, the interference between the tension F of the material 3 to be rolled and the looper angle θ is expressed by a mathematical formula including a variable to be controlled and a variable of a designated response. The non-interacting controller (cross controllers 62 and 63) cancels out. Therefore, the mutual interference between the fluctuation of the tension F between the rolling stands 1 and 2 and the fluctuation of the looper angle θ can be easily suppressed to a lower level than before.

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. It will not be. 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 block diagram which shows embodiment of this invention and shows an example of schematic structure of the tension | tensile_strength and looper angle control apparatus of a continuous rolling mill. It is a block diagram which shows embodiment of this invention and shows an example of a structure of a looper controller. It is a block diagram which shows embodiment of this invention and shows an example of a structure of an ILQ optimal servo system. It is a block diagram which shows embodiment of this invention and shows an example of a structure of a disturbance observer. FIG. 4 is a block diagram illustrating an example of a configuration of a gain adjuster for calculating a gain of a looper controller according to the embodiment of this invention. It is a figure which shows embodiment of this invention and shows an example of the result of having performed the simulation of the continuous rolling mill and estimating the elongation amount of a to-be-rolled material. It is a figure which shows embodiment of this invention and shows an example of the result of having simulated the tension | tensile_strength which arises in a to-be-rolled material when the plate elongation parameter of a to-be-rolled material is changed in step shape. It is a figure which shows embodiment of this invention and shows an example of the result of having simulated the tension | tensile_strength which arises in the to-be-rolled material 3 when the gain of a looper controller is changed using the estimated value of the elongation amount of to-be-rolled material. It is a figure which shows an example of a structure of a continuous rolling mill. It is a block diagram which shows the 1st example of the conventional tension | tensile_strength and looper angle control apparatus used for the looper control of a continuous rolling mill. It is a block diagram which shows the 2nd example of the conventional tension | tensile_strength and looper angle control apparatus used for the looper control of a continuous rolling mill.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pre-stage stand 2 Post-stage stand 3 Rolled material 4 Pre-stage mill motor 5 Rear-stage mill motor 6 Looper 7 Looper motor 8 Pre-stage mill motor speed detector 9 Looper speed controller 10 Looper speed detector 11 Looper angle detector 12 Tension detector 13 Rear stage mill motor speed detection 14 Looper controller 16 Estimator (disturbance observer)
17 Gain adjuster 18 Pre-stage mill motor speed controller 19-23 Subtractor

Claims (8)

The tension and looper of a continuous rolling mill using a metal plate as a material to be rolled, comprising a front stand and a rear stand provided with a mill motor, and a looper provided with a looper motor disposed between the front stand and the rear stand. Tension of a continuous rolling mill, which is an angle control device and causes the tension F of the material to be rolled and the looper angle θ of the looper to follow the target values T _ref and θ _ref , respectively, between the front stand and the rear stand. And a looper angle control device,
Using the deviation between the measured value of the tension F and the target value T _ref and the difference between the measured value of the looper angle θ and the target value θ _ref as input values, the control amount of the rotational speed of the pre-mill motor and the angular speed of the looper A looper controller that calculates and outputs a control amount using an adjustable gain K;
A subtractor that calculates and outputs a rotational speed deviation (V _r2 −V _r1 ) between the rotational speed V _{r1 of the} mill motor provided in the front stage stand and the rotational speed V _{r2 of the} mill motor provided in the rear stage stand;
An estimator for estimating the amount of elongation K _{10 of the} material to be rolled by a disturbance observer of the continuous rolling mill based on the mechanical characteristics of the material to be rolled, using the rotational speed deviation (V _r2 −V _r1 ) as an input value; ,
Said adjustable gain K, and and a gain adjuster for setting based on the estimated amount of elongation the material to be rolled which is estimated by the device K _10,
The looper controller calculates the control amount based on the gain K adjusted in accordance with a change in mechanical properties of the material to be rolled, and a tension and looper angle control device for a continuous rolling mill . The gain regulator for elongation amount K ₁₀ of the rolled material which has been outputted from the estimator calculates a moving average value of the period set in advance, the moving average value of the elongation of K ₁₀ of the material to be rolled was the operational 2. The tension and looper angle control device for a continuous rolling mill according to claim 1, wherein the adjustable gain K is set by using the control device. The gain regulator, when setting the adjustable gain K, the estimated amount of elongation the material to be rolled which is output from the unit K _10, or moving average value of the elongation of K ₁₀ of the rolled material, The tension and looper angle of the continuous rolling mill according to claim 1 or 2, wherein it is determined whether or not a threshold value is exceeded, and the adjustable gain K is changed when the threshold value is exceeded. Control device. The looper controller uses the deviation between the measured value of the tension F of the material to be rolled and the target value _Tref and the deviation between the measured value of the looper angle θ and the target value _θref as input values. The tension and looper angle of the continuous rolling mill according to any one of claims 1 to 3, further comprising a cross controller that is a non-interacting controller that cancels interference between the tension F of the material and the looper angle θ. Control device. A control method for a continuous rolling mill using a metal plate as a material to be rolled, comprising a front stand and a rear stand provided with a mill motor, and a looper provided with a looper motor disposed between the front stand and the rear stand. Yes, tension and looper angle control of a continuous rolling mill for causing the tension F of the material to be rolled and the looper angle θ of the looper to follow the target values T _ref and θ _ref , respectively, between the front stage stand and the rear stage stand. A method,
Using the deviation between the measured value of the tension F and the target value T _ref and the difference between the measured value of the looper angle θ and the target value θ _ref as input values, the control amount of the rotational speed of the pre-mill motor and the angular speed of the looper A looper control step for calculating and outputting the control amount using an adjustable gain K;
A subtraction step of calculating and outputting a rotational speed deviation (V _r2 −V _r1 ) between the rotational speed V _{r1 of the} mill motor included in the front stand and the rotational speed V _{r2 of the} mill motor included in the rear stand;
An estimation step of estimating the elongation K _{10 of the} material to be rolled by a disturbance observer of the continuous rolling mill based on the mechanical characteristics of the material to be rolled, using the rotational speed deviation (V _r2 −V _r1 ) as an input value; ,
Said adjustable gain K, and and a gain adjustment step of setting, based on the elongation amount K ₁₀ of the rolled material which has been estimated by the estimating step,
In the looper control step, the control amount is calculated based on the gain K that is adjusted in accordance with a change in mechanical properties of the material to be rolled. A tension and looper angle control method for a continuous rolling mill, . Wherein the gain adjustment step, the elongation amount K ₁₀ of the rolled material obtained in the estimating step calculates the moving average of the period set in advance, the moving average value of the elongation of K ₁₀ of the rolled material obtained by the calculation The method of controlling the tension and looper angle of the continuous rolling mill according to claim 5, wherein the adjustable gain K is set by using the control. In the looper control step, the deviation between the measured value of the tension F of the material to be rolled and the target value _Tref and the deviation between the measured value of the looper angle θ and the target value _θref are input values, respectively. 7. The continuous rolling mill tension and looper angle control method according to claim 5, wherein the interference between the material tension F and the looper angle θ is canceled by a cross controller which is a non-interacting controller. A continuous rolling mill comprising a front stand and a rear stand provided with a mill motor, a looper provided with a looper motor disposed between the front stand and the rear stand, and a continuous rolling mill using a metal plate as a material to be rolled. Tension and looper angle control device,
First derivation means for deriving a rotational speed deviation between a rotational speed of the mill motor provided in the front stand and a rotational speed of the mill motor provided in the rear stand;
An estimation means for estimating an elongation amount of the material to be rolled based on the rotational speed deviation calculated by the first derivation means and the mechanical characteristics of the material to be rolled;
Second derivation means for deriving a control amount of the rotational speed of the front mill motor and a control amount of the angular speed of the looper;
The tension and looper angle control device for a continuous rolling mill, wherein the second derivation unit adjusts the control amount in accordance with the elongation amount of the material to be rolled estimated by the estimation unit.

Images