JPH1119707A - Method for controlling tension of material to be rolled and looper angle in continuous rolling mill and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute the optimum control of a looper by dissolving the delay when tension flactuation is generated in a looper angle control system at the time of controlling the interstand tension and looper angle. SOLUTION: The tension of a strip 3 between stands 1, 2 is detected with a tension detector 11 and, based on the deviation between the detected value σand the target value σr of tension, the target correction value of looper angle, target correction value of looper angular velocity and target correction value of looper angular acceleration are calculated in accordance with a virtual impedance model with a looper target correction value arithmetic unit 17. Based on them, the target value θ0 of looper angle, target value v0 of looper angular velocity and target value q0 of looper torque are corrected and, by directly operating a looper angular velocity control system which is a minor loop to the looper angle control system and looper torque control system which is a minor loop to the looper angular velocity control system, the delay generated in the looper angle control system when the tension is fluctuated is dissolved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a tension and a looper angle of a material to be rolled in a continuous rolling mill in which a looper is provided between rolling stands, and more particularly to a hot rolling finishing mill. Preferably applied,
This makes it possible to suppress variations in the tension of the material to be rolled and the looper angle even with disturbances such as a rolling operation.

[0002]

2. Description of the Related Art In a finishing mill for hot rolling, a mechanism called a looper is provided between rolling stands in order to appropriately maintain a loop amount between rolling stands and to stably maintain a tension of a material to be rolled. I have.

[0003] In this looper, it is important to stably control the tension which directly affects the dimensional shape of the material to be rolled and to suppress the fluctuation of the looper angle from the viewpoint of stable operation. In order to control two amounts of tension and a looper angle, two operation amounts of a roll rotation speed of a rolling stand and a looper torque are conventionally used.

The most common control method is to set the looper angle θ to the upstream side (i) or the downstream side (i) as shown in FIG.
In this method, the tension σ is indirectly controlled to a target value by controlling the rotation speed of the rolling stand of +1) by correcting the roll rotation speed and adjusting the looper torque according to the variation of the looper angle θ.

[0005] However, this method has a problem that the tension control is poor because the tension is controlled by the open loop. In addition, the tension and the looper angle interfere with each other, and the fluctuation of the tension induces the fluctuation of the looper angle, and the fluctuation of the looper angle causes the fluctuation of the tension. However, in the conventional control, since this interference is not removed, the looper angle is not changed. There is also the problem of poor stability.

Therefore, as described in JP-A-59-110410, the tension is measured by using a load cell or the like installed on a looper, and the tension is controlled using the roll rotation speed of a rolling stand as an operation amount to control the tension. A method using two feedback loops for controlling a looper angle using a torque or a looper speed as an operation amount has been put to practical use.

Further, in order to cancel the interference effect between the tension and the looper angle, a pre-compensator called a cross controller C is used in front of a block G showing a looper characteristic as shown in FIG. Non-interference is also considered by the synergistic effect of C and the looper characteristic block G.

Further, as described in JP-A-59-118213 and JP-A-59-118214, speed control is applied to a looper drive motor, and tension, which is an observable amount, is controlled. The state feedback using the looper angle and the looper motor speed is combined with the main controller that performs integration in the preceding stage. At this time, the quadratic evaluation function related to the control performance and the magnitude of the operation amount is optimized in the time domain, and An integral type optimal regulator for obtaining a gain has also been proposed.

In this optimum regulator, to obtain a desired control response, the weight matrix of the secondary evaluation function must be set by trial and error to determine the optimum control gain. H∞ control for obtaining a gain by defining a closed loop response in a region has also been proposed.

In the non-interference control, the integral type optimal regulator, and the H∞ control, the controllability of the looper angle is remarkably improved as compared with the related art. In contrast to the indirect method of operating the looper angle, these controls are basically a direct method of driving the looper motor based on the looper angle deviation, and the response of the position servo system is This is because the controllability can be determined only by the above.
Therefore, the rigidity of the looper angle control becomes very high, the looper becomes almost fixed, and the looper angle becomes stable. However, on the other hand, the original function of the looper, in which the looper angle fluctuates when the tension changes and the tension fluctuation is absorbed, is lost.

On the other hand, in the invention described in Japanese Patent Application Laid-Open No. Hei 6-170425 previously proposed by the present applicant, as shown in FIG. 9, the roll rotation speed and the looper torque are used as operation amounts. In controlling both the tension of the material to be rolled and the looper angle to the target values, in a continuous rolling mill that calculates a correction value of the looper angle target value from the measured or estimated tension and controls the looper angle to the corrected looper angle target value. A method for controlling the tension of a material to be rolled and a looper angle is disclosed.

In this conventional example, when the tension changes due to disturbance, the looper control is coordinated to intentionally move the looper in a direction to absorb the tension fluctuation, thereby enabling the tension fluctuation to be quickly eliminated. .

In this conventional example, a method using a virtual mechanical impedance model of a looper system has been proposed as an example of a method of calculating the looper angle target correction value. When the tension increases, the looper angle decreases in accordance with the looper angle. Focusing on the fact that when the tension becomes low, the looper should follow and increase the angle, the virtual system is considered by considering a secondary system composed of a virtual mass, damper, and spring. This virtual impedance model is set as in the following equation.

K / {(s / ω) ² +2 {(s / ω) +1} where k is a gain, ω is a natural frequency, and ζ is an attenuation constant. The looper angle target correction value calculator is shown in FIG.
, And a virtual impedance model and an inverse model of the characteristics of the looper angle control loop are connected in series.

[0015]

SUMMARY OF THE INVENTION The above-mentioned conventional Japanese Patent Laid-Open No.
In the invention described in Japanese Patent No. 170425, a desired value of a looper angle when a tension variation occurs is calculated using a virtual impedance model, and the looper is positioned and controlled by the looper angle control system at the angle. Impedance control for controllably changing the mechanical impedance of the system is performed.

However, in this method, since the looper angle does not exactly match the desired value due to the influence of the delay of the looper angle control system, in order to compensate for the delay, the looper angle control system shown in FIG. The inverse model is used.

However, since this inverse model generally includes a higher-order derivative, the noise level of the looper angle target correction value increases, and it becomes necessary to limit the magnitude of the correction amount. There is a problem that cannot be performed. Also,
There is also a problem that the model of the looper angle control system included in the inverse model causes a mismatch with the characteristics of the actual looper angle control system, and the correction value becomes inappropriate.

Further, if the inverse model is not used, the follower of the looper angle is deteriorated due to the delay of the looper angle control system, and the looper system cannot be set as the virtual impedance. There is a problem that can not be performed.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the conventional example. In a continuous rolling mill in which a looper is provided between rolling stands, it is possible to prevent disturbance caused by a rolling operation or the like. It is an object of the present invention to provide a method and an apparatus for controlling the tension and the looper angle of a material to be rolled, which can suppress the fluctuation of the tension and the looper angle of the material to be rolled.

[0020]

In order to achieve the above object, a method for controlling the tension of a material to be rolled and a looper angle in a continuous rolling mill according to the present invention is a continuous rolling method in which a looper is provided between rolling stands. In the method for controlling the tension of the material to be rolled and the looper angle in a continuous rolling mill that controls both the tension and the looper angle of the material to be rolled to target values, the looper angle when receiving an external force due to the tension of the material to be rolled An optimal value and a looper-based virtual impedance model for calculating at least one optimal value of the looper angular velocity and the looper angular acceleration are set, and the tension of the material to be rolled between the rolling stands is measured or estimated, and the measurement or estimation is performed. The obtained tension is input to the virtual impedance model of the looper system to calculate the optimum value, and the looper angle is equal to the looper angle. Controlling the looper angle so that the looper angular velocity matches the optimum value of the looper angular velocity; and controlling the looper angular velocity so that the looper angular velocity matches the optimum value of the looper angular acceleration. It is characterized in that at least one of controlling the looper torque is performed so as to coincide with.

In the invention according to the first aspect, by measuring or estimating the tension of the material to be rolled, when the tension fluctuation is caused by the external force, the tension fluctuation can be absorbed by the looper according to the virtual impedance model of the looper system. The optimum value of the looper angle and the optimum value of at least one of the looper angular velocity and the looper angular acceleration are calculated, and the looper angle is controlled so that the looper angle matches the optimum value of the looper angle, and the looper angular velocity is adjusted. By performing at least one of controlling the looper angular velocity so as to match the optimum value of the looper angular velocity and controlling the looper torque so that the looper angular acceleration matches the optimum value of the looper angular acceleration, Without using the inverse model of the looper angle control system, By eliminating the delay in supermarkets angular velocity control system, approximate the characteristics of the looper by the characteristics of the virtual impedance model.

Further, in the continuous rolling mill according to the second aspect of the present invention, the tension and looper angle control device for the rolled material includes a continuous rolling mill in which a looper is provided between the rolling stands, and a tension and looper angle of the rolled material. A tension control device for controlling the tension of the material to be rolled and a looper angle in a continuous rolling mill, wherein the tension control device controls the angle of the looper to a looper angle target value. A looper angle control device that calculates an angular speed, a looper angular speed control device that calculates a looper torque target value for controlling the angular speed of the looper to the looper angular speed target value, and a looper that controls the looper torque target value. Looper torque control device, tension detecting means for measuring or estimating the tension of the material to be rolled, and the tension detecting means A correction value of the looper angle target value, a correction value of the looper angular velocity target value, and a correction value of the looper angular acceleration target value are calculated and calculated in accordance with a looper system virtual impedance model based on a deviation between the detected tension and the target tension. Correction means for correcting the looper angle target value, the looper angular velocity target value, and the looper torque target value based on the looper angle target correction value, the looper angular velocity target correction value, and the looper angular acceleration target correction value. I have.

In the invention according to the second aspect, the looper angle target correction value, the looper angular velocity target correction value, and the looper angle are determined based on the deviation between the tension of the material to be rolled and the target tension detected by the tension detection means by the correction means. By calculating the acceleration target correction values and correcting the looper angle target value of the looper angle control device, the looper angular speed target value of the looper angular speed control device, and the looper torque target value of the looper torque control device based on these, the looper angle control is performed. A command value can be directly given to the looper angular velocity control system that has a quicker response than the system and the looper torque control system that has a faster response to the control, and tension fluctuation can be performed without using an inverse model of the looper angle control system. The delay which sometimes occurs in the looper angle control system is eliminated.

Further, the apparatus for controlling the tension of the material to be rolled and the looper angle according to the third aspect of the present invention provides a continuous rolling mill in which a looper is provided between the rolling stands, and the tension of the material to be rolled and the looper angle both set to target values. A tension control device for controlling a tension of a material to be rolled and a looper angle in a continuous rolling mill having a control device for controlling the looper angle to a looper angle target value. Looper angle control device, a looper angular speed control device that calculates a looper torque target value for controlling the looper angular speed to a looper angular speed target value, and a looper torque control that controls the looper to generate the looper torque target value An apparatus, a tension detecting means for measuring or estimating the tension of the material to be rolled, and a tension detected by the tension detecting means. Based on the deviation from the target tension, a correction value of the looper angle target value and a correction value of the looper angular velocity target value are calculated according to a looper system virtual impedance model, and based on the calculated looper angle target correction value and looper angular velocity target correction value. Correction means for correcting the looper angle target value and the looper angular velocity target value.

Also in the invention according to the third aspect, a command value can be directly given to the looper angular velocity control system which has a faster response than the looper angle control system, and the tension can be obtained without using an inverse model of the looper angle control system. Eliminates delays in the looper angular velocity control system during fluctuations.

Further, the tension and looper angle control device for a material to be rolled according to the present invention is preferably a continuous rolling mill in which a looper is provided between rolling stands, and both the tension and the looper angle of the material to be rolled are set to target values. In a continuous rolling mill having a control device and a tension and looper angle control device of the rolled material, the tension control device sets a looper torque target value for controlling the looper angle to a looper angle target value. A looper angle control device for calculating, a looper torque control device for controlling the looper torque target value so that the looper generates, a tension detecting device for measuring or estimating the tension of the material to be rolled, and the tension detecting device for detecting the tension. A correction value and a loop for the looper angle target value according to a looper system virtual impedance model based on a deviation between the tension and the target tension. Correction means for calculating a correction value of the angular acceleration target value, and correcting the looper angle target value and the looper torque target value based on the calculated looper angle target correction value and looper angular acceleration target correction value. Features.

Also in the invention according to the fourth aspect, a command value can be directly given to the looper torque control system which has a faster response than the looper angle control system, and the tension can be obtained without using an inverse model of the looper angle control system. Eliminates delays in the looper angular velocity control system during fluctuations.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to a hot rolling mill. In this embodiment, a looper angular velocity is called a looper velocity, and a looper angular acceleration is called a looper acceleration.

In the drawing, reference numerals 1 and 2 are provided at predetermined intervals.
Mill stands 1 and 2
Are a pair of rolling strips 3 each as a material to be rolled.
Work roll WR₁And WR_TwoAnd placed outside these
Backup roll BR ₁And BR_TwoAnd composed of
Work roll WR in the mill stand 1 on the upstream side
₁And WR_TwoIs rotationally driven by the drive motor 4.

A looper 6 is provided between the mill stands 1 and 2 to contact and support the strip 3. The looper 6 includes a rotation arm 8 attached to a rotation shaft of a drive motor 7 and a looper roll 9 rolled from below onto the strip 3 attached to the tip thereof.

Then, the tension of the strip 3 and the angle of the looper 6 are controlled by the tension controller 12 and the looper angle controller 32, respectively. That is, the tension of the strip 3 is detected by the tension detector 11 as a reaction force received by the looper 6 from the strip 3 by, for example, a load cell installed on the looper 6, and the detected tension value σ of the tension detector 11 is transmitted to the tension controller 12. input.

The tension controller 12 receives a target tension value σr from a host computer 13 that controls the hot rolling line, and performs a roll based on the deviation between the target tension value σr and the detected tension value σ. calculates the rotational speed command value V _R, by inputting the roll rotation speed command value V _R to the speed controller 14, the drive motor 4 of the work roll WR ₁ and WR ₂ of strip 3 at this speed control device 14 Control is performed so that the tension matches the tension target value σr.

On the other hand, the detected tension value σ of the tension detector 11 is
The data is input to the subtractor 16, and the subtracter 16
The tension detection value σ is subtracted from the tension target value σr from 3 to calculate a tension deviation Δσ, which is input to the looper target correction value calculation device 17.

The looper target correction value calculating device 17
A looper-based virtual impedance model, which is based on the tension deviation Δσ input from the subtractor 16, is based on the looper angle target correction value Δθr and the looper speed target correction value Δv.
r and the looper acceleration target correction value Δαr are calculated and output.

Here, the looper angle target correction value Δθr,
In the virtual impedance model for calculating the looper speed target correction value Δsθr and the looper acceleration target correction value Δαr, when the tension of the strip 3 increases, the looper angle should decrease accordingly, and the tension decreases. In such a case, the looper angle should be increased correspondingly, and is determined by modeling them.

That is, a virtual impedance is considered as a model, and this is set as a secondary system represented by the following equation (1) composed of a virtual mass, a damper, and a spring. , The output is a looper angle target correction value.

K / {(s / ω) ² +2 {(s / ω) +1} (1) where k is a gain, ω is a natural frequency, and ζ is an attenuation constant. This virtual impedance model is represented by a block diagram as shown in FIG. 2, in which the tension deviation Δσ is supplied to a proportional element 21 having a transfer function set to a gain k, and the output thereof is input to a subtracter 22, The subtraction output of the subtracter 22 is supplied to a proportional element 23 whose transfer function is set to ω ² ,
A value obtained by integrating the output of the proportional element 23 with the integrating element 24 is input to a proportional element 25 having a transfer function set to 2ζ / ω, the output of which is input to an adder 26, and the integrated output of the integrating element 24 is output. Further, integration is performed by an integration element 27, and the integrated output is supplied to a proportional element 28 whose transfer function is set to "1". The output is input to the adder 26, and the added output of the adder 26 is subtracted. The integrated output of the integration element 27 is output as a looper angle target correction value Δθr.

By constructing the virtual impedance model as shown in FIG. 2, the integral output of the integration element 24 becomes the looper speed target correction value Δvr, and the output of the proportional element 23 becomes the looper acceleration target correction value Δαr. Therefore, these can be obtained simultaneously with the looper angle target correction value Δθr.

The looper target correction value calculation device 17
Looper angle target correction value Δθr output from is input to the adder 31, the looper angle target value theta ₀ inputted from the host computer 13 adds the looper angle target correction value Δθr In this adder 31, is corrected The corrected looper angle target value θr is calculated, and this looper angle target value is input to the looper angle controller 32.

The looper angle control device 32 receives a looper angle detection value θ of a looper angle detector 33 composed of a rotary potentiometer or a rotary encoder for detecting the angle of the rotation axis of the drive motor 7 of the looper 6. cage, so the looper angle detection value θ coincides with the looper angle target value [theta] r, calculates the looper speed target value v _0.

The looper speed target value v ₀ is calculated by performing a proportional integral (PI) operation of the following equation (2) based on the input looper angle target value θr and the detected looper angle value θ. .

V ₀ = Ka ｛1 + 1 / (Ta · s)｝ · (θr-θ) (2) where Ka is a proportional gain, Ta is an integral gain, and s is a Labrath operator. And the looper angle control device 3
The looper speed target value v ₀ calculated in 2 is input to the adder 34. The adder 34 receives the looper target speed correction value Δvr output from the looper target correction value calculator 17 and corrects the looper target speed v ₀ with the looper speed correction value Δvr. vr is input to the looper speed controller 35.

The looper speed controller 35 receives a looper speed detection value v from a looper speed detector 36 including a tachometer or a pulse generator for detecting the rotation speed of the drive motor 7 of the looper 6. The looper torque target value q is set such that the looper speed detection value v matches the corrected looper speed target value vr.
Calculate ₀ .

The looper torque target value q ₀ is calculated based on the looper speed target value vr and the looper speed detection value v input in the same manner as the looper angle controller 32 described above, using the following proportional integral (3). PI) calculation.

Q ₀ = Kv ｛1 + 1 / (Tv · s)｝ · (vr−v) (3) where Kv is a proportional gain, Tv is an integral gain, and s is a Laplace operator. And the looper speed control device 3
The looper torque target value q ₀ calculated in step 5 is added to the adder 37.
Is input to The looper target correction value Δαr calculated by multiplying the looper target correction value Δαr output from the looper target correction value calculation device 17 by the gain G in the gain multiplier 38 is input to the adder 37. The corrected looper torque target value qr corrected by adding the looper torque target correction value Δqr to the looper torque target value q ₀ by the adder 37 is used as the looper torque control device 4.
Enter 0.

The looper torque control device 40 controls the drive of the drive motor 7 so that the input correction looper torque target value qr is generated by the drive motor 7 of the looper 6. Therefore, the looper torque control system forms a minor loop of the looper speed control system, and the looper speed control system forms a minor loop of the looper angle control system.

Next, the operation of the above embodiment will be described. The target tension value σr is sent from the host computer 13 to the subtractor 16 and the tension control device 12, and the looper angle target value θ ₀ is added to the adder 31.
Are output respectively.

When the detected tension value σ of the strip 3 detected by the tension detector 11 is input to the work roll tension control device 12, the tension control device 12 sets the target tension value σr and the detected tension value σ. The speed command value V is set so that the deviation from zero is zero, that is, the tension detection value σ matches the tension target value σr.
By calculating r and outputting this to the speed control device 14, the drive motor 4 of the entrance mill stand 1 is controlled,
The tension of the strip 3 is controlled.

At the same time, the looper target correction value calculation unit 17 calculates the looper angle target correction value Δθr based on the above-described equation (1) according to the virtual impedance model based on the tension detection value σ of the tension detector 11. ,
A looper speed target correction value Δvr and a looper acceleration target correction value Δαr are calculated.

With the calculated target correction values Δθr, Δvr and Δαr, the looper angle target value θ ₀ output from the host computer 13 and the looper angle controller 3
Since the looper target value v ₀ calculated in step 2 and the looper torque target value q ₀ calculated by the looper speed controller 35 are respectively corrected and the minor loop is directly operated, the characteristics of the looper system are changed to those of the virtual impedance model. Can be brought closer.

Here, in order to show the effectiveness of the present embodiment, the present embodiment is compared with the prior art of Japanese Patent Application Laid-Open No. 6-170425 by a simulation in which the rolling speed is reduced stepwise by 100 mm / sec. FIGS. 3 and 4 show such examples.

3 and 4 show the tension deviation and the looper angle deviation, respectively. The solid line shows the tension / looper control according to the present embodiment, and the dotted line shows the conventional example. Since both perform impedance control using the virtual impedance model, they perform an operation of reducing the looper angle with respect to the tension fluctuation to absorb the tension fluctuation. However, in the conventional example, the response of the looper angle is poor due to the delay of the looper angle control system, and a sufficient effect is not obtained because the looper angle does not decrease rapidly. On the other hand, according to the present embodiment, the looper angle can be rapidly reduced by about 3 degrees, and as a result, the peak value of the tension variation is reduced from 10 Mpa of the conventional example to 8 Mpa. As described above, according to the present embodiment, the behavior of the looper system when the tension fluctuation occurs can be assumed to be ideal. In other words, the looper angle can be quickly changed in response to the tension fluctuation within a range where the operation is not hindered, and the tension fluctuation can be absorbed. Therefore, the variation in tension can be reduced as compared with the related art.

In the above embodiment, the case where the looper target correction value calculation unit 17 calculates the looper angle target correction value Δθr, the looper speed target correction value Δvr, and the looper acceleration target correction value Δαr according to the virtual impedance model has been described. However, the present invention is not limited to this, and as shown in FIG.
7. The gain multiplier 38 is omitted, and the looper target correction value calculation device 17 calculates only the looper angle target correction value Δθr and the looper speed target correction value Δvr according to the virtual impedance model. Even if the set looper torque target value q ₀ is directly input to the looper torque control device 40, the looper speed system, which is a minor loop of the looper angle control system, can be directly operated. As a result, the response becomes faster, the response delay of the looper angle control system can be eliminated by this amount, and the follower of the looper angle can be improved as compared with the conventional example.

Similarly, as shown in FIG. 6, the adder 34, the looper speed control device 35, and the looper speed detector 36 in FIG. 1 are omitted, and the looper target correction value calculation device 17 uses the looper angle according to the virtual impedance model. Target correction value Δθr and looper acceleration target correction value Δ
Only αr is calculated, and the looper angle controller 32
Is the corrected looper angle target value θr
The looper torque target value q ₀ is calculated so that
Even when this is directly input to the adder 37, the looper torque control system, which is a minor loop of the looper angle control system, can be directly operated, so that the response is faster than when the looper angle control system is operated. The response delay of the looper angle control system can be eliminated by this amount, and the followability of the looper angle can be improved as compared with the conventional example.

In each of the above embodiments, the case where the tension of the strip 3 is directly detected by the tension detector 11 has been described. However, the present invention is not limited to this, and the tension of the strip 3 is estimated by a known method. And
The estimated value may be input to the tension controller 12 and the looper target correction value calculator 17.

Further, since the present invention does not depend on a method of controlling the tension and the looper angle to target values, both the tension and looper angle control by a multivariable control system such as non-interference control, an optimal regulator, and H∞ control are performed. Can be combined. In the present invention, since the target value of the looper control system is corrected, it is desirable that the target value is faithfully realized. In this regard, the multivariable control system has high positioning accuracy of the looper, and has a looper speed control system and a looper torque control system as its minor loop.
Only suitable in combination with the present invention. As described above, by combining the present invention and the multivariable control system, the looper, which is a problem of the above-described multivariable control system, is controllably fixed, and the original function of the looper, which absorbs the tension fluctuation, is lost. By coordinating the tension control and the looper angle control, it is possible to obtain good controllability even for disturbances caused by collapse of the mass flow balance due to the rolling-down operation.

Furthermore, in each of the above embodiments,
A looper angle target correction value Δθr and a looper speed target correction value Δ based on a virtual impedance model of a looper system.
The case where at least one of vr and the looper acceleration target correction value Δαr is calculated has been described. However, the present invention is not limited to this. The optimum value of the looper angle when receiving an external force due to the tension of the material to be rolled by the virtual impedance model And the looper angular speed and the looper angular acceleration are directly calculated, and the looper angle is controlled so that the looper angle matches the optimum value of the looper angle, and the looper angular speed is matched with the optimum value of the looper angular speed. And / or controlling the looper torque so that the looper angular acceleration matches the optimum value of the looper angular acceleration.

In each of the above embodiments, the case where the present invention is applied to a hot rolling mill has been described. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to other rolling mills. No.

[0059]

As described above, according to the first aspect of the present invention, when the tension fluctuation is caused by the external force, the looper can absorb the tension fluctuation in accordance with the looper system virtual impedance model. And an optimum value of at least one of the looper angular velocity and the looper angular acceleration are calculated, the looper angle is controlled so that the looper angle matches the optimum value of the looper angle, and the looper angular velocity matches the optimum value of the looper angular velocity. Control the looper angular velocity so that the looper angular acceleration and the looper torque control so that the looper angular acceleration matches the optimum value of the looper angular acceleration. This eliminates the delay of the looper angular velocity control system during tension fluctuations without using The characteristics of the over only bets can be brought closer to the characteristics of the virtual impedance model, the effect is obtained that it is possible to perform ideal impedance control.

According to the present invention, the optimum values of the looper angle, the looper angular velocity and the looper angular acceleration are calculated according to the virtual impedance model based on the detected tension value, and the looper angle and the looper angular velocity are calculated according to these optimum values. And by controlling the looper torque, a command value is directly given to a looper angular velocity control system that has a faster response than the looper angle control system and a looper torque control system that has a faster response to this. Without using the inverse model of the looper angle control system,
By eliminating the delay of the looper angle control system, the characteristics of the looper can be made closer to the virtual impedance model, and an effect that ideal impedance control can be performed can be obtained.

According to the third aspect of the present invention, the optimum values of the looper angle and the looper angular velocity are calculated according to the virtual impedance model based on the detected tension value, and the looper angle and the looper angular velocity are controlled in accordance with these optimum values. As a result, since the command value is directly given to the looper angular velocity control system that has a faster response than the looper angle control system, the delay of the looper angle control system is eliminated without using an inverse model of the looper angle control system, The looper characteristic can be made closer to the virtual impedance model, and an effect that ideal impedance control can be performed is obtained.

Further, according to the present invention, the optimum values of the looper angle and the looper torque are calculated in accordance with the virtual impedance model based on the detected tension value, and the looper angle and the looper torque are controlled in accordance with these optimum values. As a result, the command value is directly given to the looper torque control system, which has a faster response than the looper angle control system, so that the delay of the looper angle control system can be eliminated without using an inverse model of the looper angle control system. The looper characteristic can be made closer to the virtual impedance model, and an effect that ideal impedance control can be performed is obtained.

Therefore, according to the present invention, even when a tension fluctuation occurs due to a disturbance such as a sheet thickness fluctuation, the movement of the looper can be coordinated, the tension fluctuation can be eliminated quickly, and the dimensional accuracy of the material to be rolled can be reduced. It can contribute to securing and stable rolling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a virtual impedance model of the looper target correction value calculation device of FIG. 1;

FIG. 3 is a characteristic diagram showing a simulation result representing a change in a tension deviation.

FIG. 4 is a characteristic diagram showing a simulation result representing a change in a looper angle deviation.

FIG. 5 is a block diagram showing a modification of the present invention.

FIG. 6 is a block diagram showing still another modified example of the present invention.

FIG. 7 is a block diagram showing a conventional general looper control system.

FIG. 8 is a block diagram showing a conventional non-interference looper control system.

FIG. 9 is a block diagram showing a conventional looper control system for changing a looper angle target value when a tension changes.

FIG. 10 is a block diagram showing a configuration of a looper angle target value used in a conventional looper control system that changes the looper angle target value when the tension changes.

[Explanation of symbols]

 Reference numerals 1 and 2 Mill stand 4 Drive motor 6 Looper 7 Drive motor 11 Tension detector 12 Work roll tension controller 13 Host computer 14 Speed controller 16 Subtractor 17 Looper target correction value calculator 31 Adder 32 Looper angle controller 33 Looper angle detector 34 Adder 35 Looper speed controller 36 Looper speed detector 37 Adder 38 Gain multiplier 40 Looper torque controller

Claims (4)

[Claims] 1. A method for controlling a tension and a looper angle of a material to be rolled in a continuous rolling mill in which a looper is provided between rolling stands and the tension and the looper angle of the material to be rolled are both controlled to target values. The optimal value of the looper angle when receiving an external force due to the tension of the material to be rolled,
A looper system virtual impedance model for calculating the looper angular velocity and at least one of the optimum values of the looper angular acceleration is set, and the tension of the material to be rolled between the rolling stands is measured or estimated. The optimum value is calculated by inputting to a virtual impedance model of a looper system, the looper angle is controlled so that the looper angle matches the optimum value of the looper angle, and the looper angular velocity is the optimum value of the looper angular velocity. Controlling the looper angular velocity so as to match the looper angular acceleration and controlling the looper torque so that the looper angular acceleration matches the optimum value of the looper angular acceleration. Method for controlling tension and looper angle of material to be rolled. 2. The tension of a material to be rolled in a continuous rolling mill having a continuous rolling mill having a looper disposed between rolling stands and a control device for controlling both the tension of the material to be rolled and the looper angle to target values. And a looper angle control device, wherein the tension control device calculates a target looper angular speed for controlling the angle of the looper to a looper angle target value, and the looper angular speed to the looper angular speed target value. A looper angular velocity control device for calculating a looper torque target value for controlling, a looper torque control device for controlling the looper torque target value so that the looper generates, and a tension detecting means for measuring or estimating the tension of the material to be rolled And a looper virtual impedance model based on the deviation between the tension detected by the tension detecting means and the target tension. A correction value of the looper angle target value, a correction value of the looper angular velocity target value, and a correction value of the looper angular acceleration target value are calculated according to the above, and the calculated looper angle target correction value, looper angular velocity target correction value, and looper angular acceleration target correction are calculated. Correction means for correcting the looper angle target value, the looper angular velocity target value, and the looper torque target value based on the values, and a method and apparatus for controlling the tension of the material to be rolled and the looper angle in a continuous rolling mill. 3. The tension of a material to be rolled in a continuous rolling mill having a continuous rolling machine having a looper disposed between rolling stands and a control device for controlling both the tension of the material to be rolled and the looper angle to target values. And a looper angle control device, wherein the tension control device calculates a looper angular speed target value for controlling the looper angle to a looper angle target value, and the looper angular speed to the looper angular speed target value. A looper angular velocity control device for calculating a looper torque target value for controlling, a looper torque control device for controlling the looper torque target value so that the looper generates, and a tension detecting means for measuring or estimating the tension of the material to be rolled And a looper virtual impedance model based on a deviation between the tension detected by the tension detecting means and the target tension. The correction value of the looper angle target value and the correction value of the looper angular velocity target value are calculated according to the following formula, and the looper angle target value and the looper angular velocity target value are corrected based on the calculated looper angle target correction value and looper angular velocity target correction value. An apparatus for controlling the tension of a material to be rolled and a looper angle in a continuous rolling mill, comprising a correction means. 4. The tension of a material to be rolled in a continuous rolling mill having a continuous rolling mill having a looper disposed between rolling stands and a control device for controlling both the tension of the material to be rolled and the looper angle to target values. And a looper angle control device, wherein the tension control device calculates a looper torque target value for controlling the looper angle to a looper angle target value, and the looper generates the looper torque target value. A looper torque control device, a tension detecting means for measuring or estimating the tension of the material to be rolled, and a looper system virtual impedance model based on a deviation between the tension detected by the tension detecting means and the target tension. A correction value of the looper angle target value and a correction value of the looper angular acceleration target value are calculated, and the calculated looper angle target correction value and the calculated looper angle target correction value are calculated. Correction means for correcting the looper angle target value and the looper torque target value based on the looper angular acceleration target correction value, and a tension and looper angle control device for a material to be rolled in a continuous rolling mill.