JPH07136707A - Method for controlling tension and looper between stands in continuous rolling mill - Google Patents

Abstract

PURPOSE:To satisfactorily attain control without being affected by the tension of a material to be rolled and the interference of a looper, and to facilitate an adjustment with a simple structure in a continuous rolling mill with a looper arranged between rolling stands. CONSTITUTION:When two control variables of the tension of a material to be rolled and a looper are controlled to be target values, in addition to a feedback loop controlling the tension by the rotational speed of a roll and a feedback loop controlling a looper angle by looper torque or a looper speed, two disturbance compensators 34 and 44 are provided. Interference between the two feedback loops are compensated and the two loops can be independently designed of each other by using disturbance compensation signals from those loops and compensators.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous rolling mill in which a looper is arranged between rolling stands, and relates to a method for controlling the tension and looper of a material to be rolled, and more particularly to a hot rolling finishing mill. Good control can be performed without being affected by the tension of the material to be rolled and the interference of the looper.
The present invention also relates to a method of controlling tension between stands and a looper, which has a simple structure and is easy to adjust.

[0002]

2. Description of the Related Art In a hot-rolling finishing mill, a mechanism called a looper is installed in order to maintain an appropriate loop amount between stands and a stable tension of a material to be rolled.

In this looper, it is important to stably control the tension which directly influences the size and shape of the material to be rolled and to suppress the variation of the looper angle from the viewpoint of stable operation. In order to control the two amounts of tension and looper angle, two manipulated variables of roll rotation speed and looper torque of a rolling stand have been conventionally used.

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

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

Therefore, as described in Japanese Patent Laid-Open No. 59-110410, the tension is measured by a load cell or the like installed in the looper, and the tension is controlled by using the roll rotation speed of the rolling stand as an operation amount. The looper angle is controlled using the looper speed as the operation amount. 2
A method using two feedback loops has been put to practical use.

Further, in order to cancel the influence of the interference between the tension and the looper angle, as shown in FIG. 2, a front compensator C called a cross controller is also used in front of the block G showing the looper characteristic. It is also considered to be non-interference due to the synergistic effect of the compensator C and the looper characteristic block G.

In addition, JP-A-59-118213 and JP-A-5-118213.
As described in 9-118214, a main controller that applies speed control to a looper drive motor, performs state feedback using observable amounts of tension, looper angle, and looper motor speed, and performs integration in the preceding stage. There is also proposed an integral type optimum regulator which combines the above and, and at that time, optimizes the evaluation functions of the P and I gains in the time domain.

In this optimum regulator, in order to obtain a desired control response, the weighting matrix of the quadratic evaluation function must be set by trial and error to determine the optimum control gain, which is improved. , H∞ control has also been proposed which facilitates design by defining a closed loop response in the frequency domain.

[0010]

However, in the non-interference control, since the inverse model of the controlled object is set in the cross controller, it is weak against the characteristic fluctuation of the controlled object, and the rolling speed fluctuation or the like occurs. There is a problem that there is no effect of decoupling against disturbance.

Further, in the integral type optimum regulator and the H ∞ control, not only the control system becomes complicated, but also the evaluation function is set and the parameters of the control system are designed so as to be optimum. Had a problem that it was difficult to adjust.

The present invention has been made to solve the above-mentioned conventional problems. In a continuous rolling mill in which a looper is arranged between rolling stands, the continuous rolling mill is affected by the tension of the material to be rolled and the interference of the looper. It is a first object of the present invention to provide a method for controlling the tension and looper of a material to be rolled, which can be controlled satisfactorily, has a simple structure, and can be easily adjusted.

A second object of the present invention is to provide a method for controlling inter-stand tension and looper in a continuous rolling mill capable of improving tension and looper stability while leaving a little interference between tension and looper. The purpose of.

[0014]

The first invention of the present invention is as follows:
In a continuous rolling mill in which a looper is arranged between rolling stands, the tension of the material to be rolled between the stands is measured or estimated, and the roll rotation speed of the rolling stand is based on the difference between the target tension and the actual tension estimated or estimated. The first feedback loop for correcting the roll rotation speed and the angle of the looper are measured, and the command value of the torque generated by the looper or the speed of the looper is calculated based on the difference between the looper angle and the target looper angle. And a second feedback loop for correcting the command value of the looper torque or the looper speed, and a model in which the command value of the roll rotation speed of the rolling stand is input and the tension of the material to be rolled between the stands is output. Estimated tension obtained by inputting the actual roll rotation speed command value to A first disturbance compensator that estimates the disturbance applied to the first feedback loop from the difference with the tension and calculates a correction value of the roll rotation speed that cancels the disturbance, and the command value of the looper torque or the looper speed are From the difference between the looper angle estimated value obtained by inputting the actual looper torque command value or the looper speed command value to the model that takes the input and the looper angle as the output, and the looper angle measurement value, the second feedback loop is calculated. A second disturbance compensator for estimating a disturbance applied to the first feedback loop and calculating a correction value of the looper torque or the looper speed for canceling the disturbance, and the roll rotation speed command value of the first feedback loop is set to the first rotation speed command value. The roll rotation speed is controlled based on the value obtained by adding the correction values calculated by the disturbance compensator, and the roll speed of the second feedback loop is controlled. The first object is achieved by controlling the looper torque or the looper speed based on the value obtained by adding the correction value calculated by the second disturbance compensator to the command value of the looper torque or the looper speed. Is.

A second aspect of the present invention is a continuous rolling mill in which a looper is similarly arranged between rolling stands, and the tension of the material to be rolled between the stands is measured or estimated, and the difference between the target tension and the measured or estimated actual tension is measured. A first feedback loop that calculates a roll rotation speed command value of the rolling stand based on the above, and corrects the roll rotation speed;
A second feedback loop for measuring the angle of the looper, calculating a command value of the torque generated by the looper or the speed of the looper based on the difference from the target looper angle, and correcting the command value of the looper torque or the looper speed. With the roll rotation speed command value of the rolling stand as an input, the tension estimated value obtained by inputting the actual roll rotation speed command value into a model that outputs the tension of the material to be rolled between the stands, and the measurement Alternatively, a disturbance applied to the first feedback loop is estimated from a difference from the estimated actual tension, and a first disturbance compensator that calculates a correction value of the roll rotation speed that cancels the disturbance and the looper torque command value or A model that uses the looper speed command value as input and the looper speed as output outputs the actual looper torque command value or looper A disturbance value applied to the second feedback loop is estimated from the difference between the looper speed estimated value obtained by inputting the speed command value and the looper speed measured value, and a correction value of the looper torque or the looper speed that cancels the disturbance is estimated. And a second disturbance compensator for calculating the roll rotation speed based on a value obtained by adding a correction value calculated by the first disturbance compensator to the roll rotation speed command value of the first feedback loop. The looper torque or the looper speed is controlled based on a value obtained by adding a correction value calculated by the second disturbance compensator to the command value of the looper torque or the looper speed of the second feedback loop. In the same manner, the first object is achieved.

In a third aspect of the present invention, similarly, in a continuous rolling mill in which a looper is arranged between rolling stands, the tension of the material to be rolled between the stands is measured or estimated, and the target tension and the measured or estimated actual tension are set. A command value of the roll rotation speed of the rolling stand is calculated based on the difference, the first feedback loop that corrects the roll rotation speed, and the angle of the looper are measured, and the looper angle of the looper is measured based on the difference between the target looper angle. A second feedback loop that calculates a generated torque or a command value of the speed of the looper and corrects the command value of the looper torque or the looper speed, and inputs the command value of the roll rotation speed of the rolling stand and the looper speed, In the model that outputs the tension of the rolled material between the stands, the actual roll rotation speed command value and A tension estimates obtained by entering the over speed from the difference between the actual tension and the measured or estimated,
A first disturbance compensator that estimates a disturbance applied to the first feedback loop and calculates a correction value of the roll rotation speed that cancels the disturbance and the looper torque or the looper speed command value are input, and the looper angle is output. The looper angle estimated value obtained by inputting the actual looper torque command value or looper speed command value into the model, and
A second disturbance compensator that estimates a disturbance applied to the second feedback loop from the difference from the looper angle measurement value and calculates a correction value of a looper torque or a looper speed that cancels the disturbance is provided. The roll rotation speed is controlled based on a value obtained by adding the correction value calculated by the first disturbance compensator to the roll rotation speed command value of the first feedback loop, and the looper torque or the looper speed of the second feedback loop is controlled. The second object is achieved by controlling the looper torque or the looper speed based on the value obtained by adding the correction value calculated by the second disturbance compensator to the command value of.

In a fourth aspect of the present invention, similarly, in a continuous rolling mill in which a looper is arranged between rolling stands, the tension of the material to be rolled between the stands is measured or estimated, and the target tension and the measured or estimated actual tension are set. A command value of the roll rotation speed of the rolling stand is calculated based on the difference, the first feedback loop that corrects the roll rotation speed, and the angle of the looper are measured, and the looper angle of the looper is measured based on the difference between the target looper angle. A second feedback loop that calculates a generated torque or a command value of the speed of the looper and corrects the command value of the looper torque or the looper speed, and inputs the command value of the roll rotation speed of the rolling stand and the looper speed, In the model that outputs the tension of the rolled material between the stands, the actual roll rotation speed command value and A tension estimates obtained by entering the over speed from the difference between the actual tension and the measured or estimated,
A first disturbance compensator that estimates a disturbance applied to the first feedback loop and calculates a correction value of the roll rotation speed that cancels the disturbance, and the looper torque command value or the looper speed command value as inputs, and the looper speed. The disturbance applied to the second feedback loop is estimated from the difference between the looper speed estimated value obtained by inputting the actual looper torque command value or the looper speed command value into the model that outputs And a second disturbance compensator that calculates a correction value of the looper torque or the looper speed that cancels it out, and the first disturbance compensator calculates the roll rotation speed command value of the second feedback loop. The roll rotation speed of the second feedback loop is controlled based on the value obtained by adding the correction value Rui is the command value of the looper speed,
The second object is also achieved by controlling the looper torque or the looper speed based on the value obtained by adding the correction values calculated by the second disturbance compensator.

[0018]

With the method for controlling the tension between the stands and the looper in the continuous rolling mill according to the present invention, as shown in FIGS. 3 and 4, as in the case of non-interference control, which is one of the conventional techniques, the material to be rolled between the stands is rolled. Measuring or estimating the tension of
Based on the difference between the target tension and the measured or estimated actual tension, a command value of the roll rotation speed of the rolling stand is calculated, and a first feedback loop for correcting the roll rotation speed and the angle of the looper are measured. Then, a second feedback loop is provided for calculating a command value of the torque generated by the looper or the speed of the looper based on the difference from the target looper angle, and correcting the command value of the looper torque or the looper speed.

The difference from the conventional non-interference control is that in the present invention, the disturbance applied to the two feedback loops is
As shown in FIGS. 3 and 4, two disturbance compensators are used for estimation, and a signal for canceling the estimation is added to the signal calculated by the feedback control system. The disturbance referred to here is the influence of interference from other feedback loops, the rolling speed fluctuation due to the plate thickness of the material to be rolled, plate temperature fluctuation, etc., as well as the control target due to parameter fluctuations such as Young's modulus fluctuation of the material to be rolled. The characteristic fluctuation of is also included as an equivalent disturbance.

Thus, in the control method according to the present invention,
The disturbance compensation signals from the two disturbance compensators compensate for the interference between the two feedback loops so that the two loops can be designed independently, so that not only an easy and clear design is possible, but also rolling is possible. A control system that is strong against disturbances such as speed fluctuations and characteristic fluctuations of the control system can be realized.

In the first invention shown in FIG. 3, in the second disturbance compensator, in order to estimate the disturbance applied to the second feedback loop, the looper torque command value or the looper speed command value is input. , A looper angle estimated value obtained by inputting an actual looper torque command value or a looper speed command value to a model that outputs a looper angle, and the looper angle measured value are used.

On the other hand, in the second invention shown in FIG.
The looper velocity estimate and the looper velocity measurement are used to estimate the disturbance applied to the second feedback loop. That is, the model of the looper system and the disturbance compensator in the first aspect of the invention are modified by using the relationship θ = (1 / s) ω ... (1) between the looper angle θ and the looper speed ω. Therefore, although the first invention and the second invention have the same meaning of the control system, according to the second invention, the looper model and the filter in the first invention are reduced in dimension, and the control system is simplified. To be done.

Further, in the first and second inventions, the input to the model that outputs the tension of the material to be rolled between the stands is only the command value of the roll rotation speed of the rolling stand. In the fourth invention, in addition to the command value of the roll rotation speed of the rolling stand, the looper speed is also input to the model that outputs the tension of the material to be rolled between the stands.

There is a mutual interference between the tension and the looper angle as described above. This mutual interference means that when a tension fluctuation occurs, the looper moves so as to absorb the tension fluctuation. Therefore, when the mutual interference is appropriate, the tension fluctuation becomes smaller than when the mutual interference is completely canceled by the control, and as a result, the looper angle fluctuation becomes smaller. That is, it is possible to improve the stability of the tension and the looper by appropriately leaving the mutual interference between the tension and the looper angle, rather than completely removing them. Therefore, in the third and fourth inventions, the looper speed is incorporated as an input to the model that outputs the tension of the material to be rolled between the stands, thereby adjusting the portion of the mutual interference that is estimated and canceled as a disturbance. ing.

[0025]

Embodiments of the present invention applied to control of inter-stand tension and looper in a hot rolling mill will be described below in detail with reference to the drawings.

FIG. 5 is an overall configuration diagram of a first embodiment in which the first invention is applied to two adjacent stands in a hot rolling mill. 10 is a material to be rolled, 12 and 13 are adjacent 2
One stand, 12a, 12b, 13a, 13b
Indicates a work roll.

The work rolls 12a and 12b are driven by a motor 20 and controlled by a speed controller 22 to rotate at a speed target value.

The looper 16 supports from below the rolled material 10 to be rolled while being transferred from the left to the right in the figure, and is equipped with a looper roll 16a at its tip, and the looper arm 16b has a looper at the base thereof. A motor 24 for applying a driving torque to 16 is controlled by a looper torque control device 26 so as to generate a target torque.

First, the tension control system will be described.

Reference numeral 30 is a tension detector for detecting the reaction force received by the looper 16 from the material 10 to be rolled by a load cell (not shown) installed in the looper 16 and calculating the tension of the material 10 to be rolled. The roll speed command value u _b is calculated by the tension feedback (F / B) control device 32 based on the difference between the tension measurement value σ output from the detector 30 and the tension target value transmitted from the host computer 50. It

The tension system disturbance compensator 34 according to the present invention estimates the disturbance applied to the tension control system and calculates a roll rotation speed correction value u _f that cancels the disturbance. Value u _b and roll rotation speed correction value u _f
Is added by the adder 36 to obtain the final speed command value u to the speed control device 22.

The tension system disturbance compensator 34 has a model inside, and a tension estimated value obtained by inputting the speed command value u into the model and a tension measurement value input from the tension detector 30. The difference is considered to be due to the disturbance applied to the tension system, its amount is estimated, and the roll rotation speed correction value u _f necessary to cancel it is calculated.

Next, the looper control system will be described.

In FIG. 5, reference numeral 40 denotes a looper angle detector, and the looper angle control device 42 has a looper angle θ measured by the looper angle detector 40 and the host computer 5.
Based on the difference from the motor angle target value transmitted from 0,
Calculate the looper torque command value g _b .

The looper system disturbance compensator 44 according to the first invention.
Is to estimate a disturbance applied to the looper control system and calculate a looper torque correction value g _f that cancels the disturbance. The looper torque command value g _b and the looper torque correction value g _f are added by the adder 46. Then, the final torque command value g to the looper torque control device 26 is obtained.

The looper system disturbance compensator 44 has a model inside, and a looper angle estimated value obtained by inputting the torque command value g into the model and a looper angle measurement sent from the looper angle detector 40. The looper torque correction value necessary to cancel the difference by considering the difference from the value as the disturbance applied to the looper system and estimating the amount.
Calculate g _f .

In the first embodiment, the looper angle is controlled by the looper torque control device 26 by adjusting the looper torque. However, as in the second embodiment shown in FIG. 6, looper speed detection is performed. It is also possible to install a device 52, feed back the detected looper speed, and configure a looper speed control loop by the looper speed control device 54.

Details of models and filters of the tension system disturbance compensator 34 and the looper system disturbance compensator 44 in the case of the second embodiment will be described.

The tension between the stands and the characteristics of the looper in the target hot rolling mill are as shown in FIG. 7, for example. Kg σ and Kg θ in the figure are influence coefficients indicating interference between the tension and the looper angle. When creating a model of tension and looper, use the following equation that does not have these interferences and that reduces the order of the transfer function and is simplified.

Tension system model: Gσ = e Kv / {(s + e Kv σ) (1 + Tvs)} (2) Looper system model: Gθ = 1 / {s (1 + T _ASR s)} (3)

In these model formulas, the interference existing in the actual controlled object and the disturbance applied from the outside are neglected. Therefore, the estimated values of the tension and the looper angle output by these are free from the interference and the disturbance. Further, it can be considered as a tension value and a looper angle when the characteristics are ideal. Therefore,
The difference between the estimated value output from the model and the value in the actual controlled object reflects interference, disturbance, and the difference in the characteristics between the model and the actual controlled object.

In the case of a tension system, this will be described by mathematical expressions.

Assuming that the transmission coefficient of the tension system in the actual controlled object is Pσ and the roll rotation speed command value that is an input to the tension control system is u, the difference Δσ between the model output and the actual tension is expressed by the following equation. .

Δσ = (Pσ−Gσ) u + Pσd (4)

Here, d is the above disturbance.

A filter Fσ is placed, and its characteristic is given by the following equation.

Fσ = -1 / Gσ (5)

When the output of the filter Fσ with respect to Δσ is the roll rotation speed correction value u _f , u _f is expressed by the following equation by a simple calculation.

U _f = -d (6)

This is the sign of the disturbance d being inverted. Therefore, _if the roll rotation speed command value is corrected based on u _f , the disturbance can be canceled out completely. However, in this case, the noise contained in the measured tension value is a great influence, and it cannot be realized due to a problem of stability or the like. Therefore, the characteristic Fσ of the filter is set as the following equation.

Fσ = −L / Gσ (7)

Here, L is a low-pass filter, and the disturbance suppression characteristic can be determined by its characteristic.

In this way, the tension system disturbance compensator 34 can be constituted by the tension system model, the subtractor for computing the difference Δσ between the tension estimation value and the tension measurement value calculated by the model, and the filter.

The same applies to the looper system. The model of the looper system, the subtracter for calculating the difference between the looper angle estimated value calculated by the model and the looper angle measured value, and the looper system disturbance compensator 44 are constructed by a filter. Can be configured.

In the above, the tension F / B control device 32 and the looper angle control device 42 respectively determine the followability of the tension and the looper angle with respect to the target values.

Next, the embodiment of the second invention will be described in detail.

The looper system disturbance compensator 60 used in the third embodiment shown in FIG. 8 estimates the disturbance applied to the looper control system, and cancels it by the looper torque correction value g.
_f is calculated, and the looper torque command value g _b and the looper torque correction value g _f are added by the adder 62,
The final torque command value g to the looper torque control device 26 is obtained.

The looper system disturbance compensator 60 has a model inside, and a looper speed estimation value obtained by inputting the torque command value g into the model and a looper speed sent from the looper speed detector 52. The difference from the measured value,
It is assumed that the disturbance is due to the disturbance applied to the looper system, the amount is estimated, and the looper torque correction value g _f necessary to cancel it is calculated.

In the third embodiment, the looper angle is controlled by adjusting the looper torque by the looper torque control device 26, but as in the fourth embodiment shown in FIG. 9, looper speed detection is performed. It is also possible to install a device 52, feed back the detected looper speed, and configure a looper speed control loop by the looper speed control device 54.

In the case of the fourth embodiment, the model of the looper system uses Gθ (s) = 1 / (using the relational expression (1) between the looper angle and the looper speed in the model expression (3) in the second embodiment. 1 + T _ASR s) (8), which is lower in order than the model of the second embodiment. Model Gθ (s) for the filter
Since the model is reduced due to the inclusion of, the filter is also reduced in dimension.

The effects of the first and second inventions confirmed by simulation are shown in FIGS. Considering the rolling speed fluctuation due to the rolling operation of 10 μm as the disturbance, the non-interference control and the control methods according to the first and second inventions were compared. In the conventional non-interference control shown in FIGS. 10 and 11, both the tension (FIG. 10) and the looper angle (FIG. 11) greatly fluctuate, and the steady state is not easily restored. On the other hand, in the first and second inventions shown in FIGS. 12 and 13, the fluctuations in the tension (FIG. 12) and the looper angle (FIG. 13) are suppressed to a very small level.

Next, an embodiment of the third invention will be described in detail.

In the fifth embodiment shown in FIG. 14, the output from the looper speed detector 52 is input to the tension system disturbance compensator 34 through the interference adjustment gain 70, and the signal input to the tension system disturbance compensator 34 is , Is input to the model inside the tension system disturbance compensator 34. The part of the looper speed that is input to the tension system disturbance compensator 34 can be adjusted by the interference adjustment gain 70, and since it is input to the model, it is not canceled as estimated disturbance.

In the fifth embodiment, the looper angle is controlled by adjusting the looper torque by the looper torque control device 26, but as in the sixth embodiment shown in FIG. 15, looper speed detection is performed. It is also possible to feed back the looper speed detected by the device 52 and use a looper speed control device 54 to form a looper speed control loop.

An embodiment can be similarly constructed for the fourth invention.

The effect of the third invention confirmed by simulation is shown in FIGS. 10μ as disturbance
The rolling speed fluctuation due to the reduction operation of m was considered. Comparing the non-interference control (FIG. 16) and the control method according to the third invention (FIG. 17), in the non-interference control, both the tension and the looper angle fluctuate greatly, and the steady state does not return easily. On the other hand, in the third invention, the fluctuations in the tension and the looper angle are suppressed to a very small level.

Further, comparing with FIGS. 12 and 13 which are simulation results of the first invention and the second invention for completely suppressing the interference between the tension and the looper, the tension variation is slightly different in the third invention. It is suppressed. Regarding the looper angle fluctuation, the first invention and the second invention are slightly smaller than the third invention, but the looper angle fluctuation in the case of the third invention is a range in which the rolled material can pass through the plate sufficiently stably, and actually, There is no problem at all. The above result is because the interference between the tension and the looper is appropriately left by the third invention, and the looper moves to absorb the tension fluctuation.

The same simulation result can be shown for the fourth invention.

In each of the above embodiments, the tension was detected by the tension detector 30, but instead, the looper torque is detected and the tension torque component of the material to be rolled is calculated from the looper torque. A method of obtaining the estimated tension value may be used.

Even when two feedback loops for controlling the tension by the looper torque or the looper speed and the looper angle by the roll rotation speed are used as in the conventional control, two disturbance compensators are used as in the present invention. Can be added to each feedback loop to enhance controllability. However, in that case, since the control becomes indirect through the interference term of the tension and the looper angle, the order of the controlled object becomes high and the order of the model becomes high, so that the control system becomes complicated, which is not preferable. .

Further, in the present invention, the tension system disturbance compensator 3
4 and the looper system disturbance compensator 44, 60 are combined into one,
It is also possible to use the model of the disturbance compensator which includes the interference term of the tension and the looper angle. However, in this case, conversely, the output from the disturbance compensator does not include a component for compensating for interference, so in order to deal with this, the portion corresponding to the predistorter is connected to the tension feedback control device 3
2 and the tension control device 42 must be provided separately, which complicates the configuration. When such pre-compensation is not performed, it is better to compensate the interference as one of the disturbances by the disturbance compensator without including the interference term in the model as in the above-described embodiment. can get.

In all of the embodiments described above, the tension F / B control device 32 for controlling the tension to the target value and the looper angle control device 42 for controlling the looper angle to the target value are independently configured. However, seeing the controlled object as a two-output controlled object of the tension and the looper angle including the interference between the tension and the looper, the tension F / B control device for controlling the tension to the target value and the looper angle to the target value. There is also a multivariable control method in which the looper angle control device for control is collectively configured. Third
Since the invention and the fourth invention can prevent the interference between the tension and the looper from being suppressed, the invention and the fourth invention can easily deal with the control target including the interference and can be combined with such multivariable control.

In the above embodiment, the tension system and looper system models are provided, and the difference between the output and the measured value of the tension and looper angle is passed through a filter to obtain a signal for compensating for the disturbance. In the tension system, the filter is configured as in equation (7) and uses the inverse model 1 / Gσ. That is,
The difference between the actual plant Pσ and the model Gσ is obtained, and the result is passed through the inverse model 1 / Gσ, and the configuration is as shown in FIG. As shown in FIG. 19, this may be configured so that the inverse model is passed from the beginning.

As shown in FIG. 20, the difference between the actual plant Pσ and the model Gσ is integrated, multiplied by the gain K and fed back to the model Gσ, and the feedback signal can be used as the disturbance compensation signal. In this case, the signs of the disturbance compensation signal u _f are reversed.

In addition, FIGS. 18 to 20 can be freely modified within a range equivalent to the block diagram.

The controlled object is not limited to hot rolling.

[0077]

As described above, according to the present invention, in the continuous rolling mill in which the looper is arranged between the rolling stands, the tension of the material to be rolled and the two control amounts of the looper are controlled to the target values. A feedback loop that controls the tension by the roll rotation speed and a feedback loop that controls the looper angle by the looper torque or the looper speed are provided, and the interference between the two feedback loops is compensated by the disturbance compensation signal from the two disturbance compensators. ,
Since the two loops can be designed independently, not only is it possible to design easily and with good visibility, but also a control system that is strong against disturbances such as rolling speed fluctuations and characteristic fluctuations of the control system can be provided. Therefore, there is an excellent effect that the dimension and shape of the material to be rolled can be kept good and stable operation can be ensured.

Further, when a small amount of mutual interference between the tension and the looper is left, it has an excellent effect that the stability of the tension and the looper can be further enhanced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a conventional general looper control system.

FIG. 2 is a block diagram showing an example of a conventional non-interference looper control system.

FIG. 3 is a block diagram showing a basic configuration of a stand tension and looper control method according to the first invention.

FIG. 4 is a block diagram showing a basic configuration of a stand tension and looper control method according to a second invention.

FIG. 5 is a block diagram showing a configuration of a first embodiment according to the first invention applied to hot rolling.

FIG. 6 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 7 is a block diagram showing a model of a looper tension system used in the above embodiment.

FIG. 8 is a block diagram showing the configuration of a third embodiment according to the second invention applied to hot rolling.

FIG. 9 is a block diagram showing a structure of a fourth embodiment of the present invention.

FIG. 10 is a diagram showing an example of a response of tension in a conventional non-interference control system.

FIG. 11 is a diagram showing an example of the response of the looper angle.

FIG. 12 is a diagram showing an example of response of tension in the control system according to the first and second inventions.

FIG. 13 is a diagram showing an example of the response of the looper angle.

FIG. 14 is a block diagram showing a configuration of a fifth embodiment according to the third invention applied to hot rolling.

FIG. 15 is a block diagram showing a structure of a sixth embodiment of the present invention.

FIG. 16 is a diagram showing an example of rolling speed fluctuations in a conventional non-interference control system.

FIG. 17 is a diagram showing an example of rolling speed fluctuations in the control system according to the third invention.

FIG. 18 is a control system diagram of the embodiment.

FIG. 19 is a control system diagram of a modified example.

FIG. 20 is a control system diagram of another modified example.

[Explanation of symbols]

 10 ... Rolled material 12, 13 ... Stand 16 ... Looper 20, 24 ... Motor 22 ... Speed controller 26 ... Looper torque controller 30 ... Tension detector 32 ... Tension feedback controller 34 ... Tension system disturbance compensator 40 ... Looper Angle detector 42 ... Looper control device 44, 60 ... Looper system disturbance compensator 52 ... Looper speed detector 54 ... Looper speed control device 70 ... Interference adjustment gain

Claims (4)

[Claims] 1. A continuous rolling mill having loopers arranged between rolling stands, in which the tension of a material to be rolled between stands is measured or estimated, and rolling is performed based on a difference between a target tension and the measured or estimated actual tension. A first feedback loop that calculates a roll rotation speed command value for the stand and corrects the roll rotation speed and the angle of the looper are measured, and the torque generated by the looper or the looper is generated based on the difference between the looper angle and the target looper angle. Second feedback loop for calculating the command value of the looper torque or the looper speed and the command value of the roll rotation speed of the rolling stand as input, and the tension of the material to be rolled between the stands. The estimated tension value obtained by inputting the actual roll rotation speed command value to the model that outputs Or a first disturbance compensator that estimates the disturbance applied to the first feedback loop from the estimated difference from the actual tension and calculates a correction value of the roll rotation speed that cancels the disturbance, and the looper torque or the looper. With a speed command value as an input, a looper angle estimated value obtained by inputting an actual looper torque command value or a looper speed command value into a model that outputs a looper angle, and the difference between the looper angle measurement value, A second disturbance compensator that estimates a disturbance applied to the second feedback loop and calculates a correction value of the looper torque or the looper speed that cancels the disturbance is provided, and the roll rotation speed command value of the first feedback loop is set. , The roll rotation speed is controlled based on a value obtained by adding the correction values calculated by the first disturbance compensator, A continuous rolling mill characterized by controlling the looper torque or the looper speed based on a value obtained by adding a correction value calculated by the second disturbance compensator to a command value of the looper torque or looper speed of the back loop. Control of tension between stands and looper. 2. A continuous rolling mill in which a looper is arranged between rolling stands, in which the tension of a material to be rolled between stands is measured or estimated, and rolling is performed based on a difference between a target tension and the measured or estimated actual tension. A first feedback loop that calculates a roll rotation speed command value for the stand and corrects the roll rotation speed and the angle of the looper are measured, and the torque generated by the looper or the looper is generated based on the difference between the looper angle and the target looper angle. Second feedback loop for calculating the command value of the looper torque or the looper speed and the command value of the roll rotation speed of the rolling stand as input, and the tension of the material to be rolled between the stands. The estimated tension value obtained by inputting the actual roll rotation speed command value to the model that outputs Or a first disturbance compensator for estimating a disturbance applied to the first feedback loop from the difference between the estimated actual tension and a roll rotation speed compensation value for canceling the disturbance, and the looper torque command value. Or with the looper speed command value as an input, the looper speed estimated value obtained by inputting the actual looper torque command value or the looper speed command value to the model that outputs the looper speed, and the difference between the looper speed measurement value, A second disturbance compensator that estimates a disturbance applied to the second feedback loop and calculates a correction value of a looper torque or a looper speed that cancels the disturbance is provided, and a roll rotation speed command value of the first feedback loop is provided. The roll rotation speed is controlled based on a value obtained by adding the correction value calculated by the first disturbance compensator to A stand in a continuous rolling mill characterized in that the looper torque or the looper speed is controlled based on a value obtained by adding a correction value calculated by the second disturbance compensator to a command value of the looper torque or looper speed of the feedback loop. Control method of inter-tension and looper. 3. A continuous rolling mill having loopers arranged between rolling stands, in which the tension of a material to be rolled between stands is measured or estimated, and rolling is performed based on the difference between the target tension and the measured or estimated actual tension. A first feedback loop that calculates a roll rotation speed command value for the stand and corrects the roll rotation speed and the angle of the looper are measured, and the torque generated by the looper or the looper is generated based on the difference between the looper angle and the target looper angle. Second feedback loop for calculating the command value of the speed of the looper and correcting the command value of the looper torque or the looper speed, and using the command value of the roll rotation speed of the rolling stand and the looper speed as inputs, rolling between the stands is performed. Input the actual roll rotation speed command value and looper speed to the model that outputs the tension of the material. Disturbance compensator for estimating a disturbance applied to the first feedback loop from the difference between the estimated tension value and the measured or estimated actual tension, and calculating a roll rotation speed correction value for canceling the disturbance. And a looper angle estimated value obtained by inputting the actual looper torque command value or looper speed command value into a model that inputs the looper torque or looper speed command value and outputs the looper angle, and the looper angle measurement value. And a second disturbance compensator that estimates a disturbance applied to the second feedback loop from the difference between the first and second feedback loops and calculates a correction value of the looper torque or the looper speed that cancels the disturbance. The roll rotation speed is based on a value obtained by adding the correction value calculated by the first disturbance compensator to the roll rotation speed command value. The looper torque or the looper speed based on a value obtained by adding a correction value calculated by the second disturbance compensator to the command value of the looper torque or the looper speed of the second feedback loop. A method for controlling tension between stands and a looper in a continuous rolling mill, comprising: 4. A continuous rolling mill having loopers arranged between rolling stands, in which the tension of a material to be rolled between stands is measured or estimated, and rolling is performed based on the difference between the target tension and the measured or estimated actual tension. A first feedback loop that calculates a roll rotation speed command value for the stand and corrects the roll rotation speed and the angle of the looper are measured, and the torque generated by the looper or the looper is generated based on the difference between the looper angle and the target looper angle. Second feedback loop for calculating the command value of the speed of the looper and correcting the command value of the looper torque or the looper speed, and using the command value of the roll rotation speed of the rolling stand and the looper speed as inputs, rolling between the stands is performed. Input the actual roll rotation speed command value and looper speed to the model that outputs the tension of the material. Disturbance compensator for estimating a disturbance applied to the first feedback loop from the difference between the estimated tension value and the measured or estimated actual tension, and calculating a roll rotation speed correction value for canceling the disturbance. And a looper speed estimated value obtained by inputting the actual looper torque command value or looper speed command value to a model that inputs the looper torque command value or looper speed command value and outputs the looper speed, and the looper speed. A second disturbance compensator that estimates a disturbance applied to the second feedback loop from the difference from the measured value and calculates a correction value of the looper torque or the looper speed that cancels the disturbance is provided, and the second feedback is provided. Roll based on a value obtained by adding a correction value calculated by the first disturbance compensator to the roll rotation speed command value of the loop The rotation speed is controlled, and the looper torque or the looper speed is controlled based on a value obtained by adding a correction value calculated by the second disturbance compensator to the command value of the looper torque or the looper speed of the second feedback loop. A method for controlling the inter-stand tension and the looper in a continuous rolling mill, comprising: