JPH07191702A - Control device, control method, rolling mill control device, and rolling mill control method - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a control device and a control method capable of stably realizing a control performance that requires a plurality of control amounts. [Structure] A sheet thickness response setting function for setting a desired sheet thickness response characteristic, a tension response setting function for setting a desired sheet tension response characteristic, a state feedback control means using a state quantity of a rolling mill, and a sheet thickness response. It is composed of a function feedback control means using the internal state quantities of the setting function and the tension response setting function, and a gain determining means for determining the control gain of each feedback control means. [Effect] Since the pressure reduction command and the speed command are calculated by using the internal state quantity of the response setting function in which the required characteristics of each controlled variable of the controlled object are set independently by the frequency characteristic, the robustness can be achieved by selecting the characteristic of the response setting function. It is possible to independently and optimally realize a plurality of control performance specifications such as stability and disturbance rejection characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a controlled object having at least one control amount and a control method therefor, and particularly, in a rolling mill, by changing commands of a reduction control device and a speed control device, a delivery side plate thickness. The present invention relates to a rolling mill control device and a rolling mill control method that control the rearward tension to be constant.

[0002]

2. Description of the Related Art Conventionally, as a plate thickness / tension control method for the inlet side plate thickness fluctuation which is a significant disturbance in control of a rolling mill, for example, JP-A-63-251804 and JP-A-64-44 are known.
As described in Japanese Patent No. 503 and Japanese Patent Application Laid-Open No. 4-361810, the current rolling state quantity such as the rolling position, the roll speed, the tension of the rolled material, and the plate thickness of the rolled material are multiplied by a feedback gain to reduce the rolling amount. The method of calculating the operation command to the control device and the speed control device and determining the gain is a method focusing on the time response characteristics such as the LQ optimal theory and the pole placement method.

However, when attention is paid to the time response characteristic, it is difficult to clearly introduce performances such as reduction of influence of disturbance and response speed of response into the design, and the control system which feeds back only the state quantity causes disturbance. There is a problem that sufficient control cannot be performed in order to reduce the influence.

[0004]

However, when attention is paid to the time response characteristic, it is difficult for any of the above-mentioned prior arts to introduce performance such as reduction of disturbance influence and quick response. there were. In other words, these are control methods that simply feed back only the measured state quantity, and there is a problem that the influence of disturbance cannot be reduced and sufficient control cannot be performed to obtain a response as instructed. It was

A first object of the present invention is to provide a control device which can reduce the influence of disturbance of the controlled object and can easily and stably control the characteristics requiring the controlled variable of the controlled object.

A second object of the present invention is to provide a control method capable of reducing the influence of disturbance of the controlled object and easily and stably controlling the characteristics requiring the controlled variable of the controlled object.

A third object of the present invention is to provide a rolling mill controller capable of reducing the influence of disturbance of the rolling mill and easily and stably controlling the characteristics required for the controlled amount of the rolling mill. .

A fourth object of the present invention is to provide a rolling mill control method capable of reducing the influence of disturbance of the rolling mill and easily and stably controlling the characteristics required of the controlled amount of the rolling mill. .

A fifth object of the present invention is to provide a rolling mill control device capable of reducing the influence of disturbance of the rolling mill and easily and stably controlling the plate thickness and tension of the rolled material to the required characteristics. Especially.

A sixth object of the present invention is to provide a rolling mill control method capable of reducing the influence of disturbance of the rolling mill and easily and stably controlling the thickness and tension of the rolled material to the required characteristics. Especially.

[0011]

SUMMARY OF THE INVENTION The present invention is intended to reduce the influence of disturbance on the controlled variable of a controlled object. The control performance of the controlled variable of the controlled object is expressed by a frequency characteristic to prevent the disturbance on the controlled variable. The effect and the inverse frequency characteristic are feedback-controlled to the controlled variable.

In other words, in order to achieve the object of the first aspect of the present invention, the present invention provides a control device for controlling an actuator that changes the state of a controlled object having at least one controlled variable. A first measuring unit that measures a control amount, a second measuring unit that measures an internal state of the actuator, and an operation amount of the actuator based on measured values of the first measuring unit and the second measuring unit. In a control device comprising state feedback control means for calculating, a control response specification function that sets a desired frequency response characteristic with respect to the controlled variable of the controlled object, the first measuring means and the second measurement. Response specification function feed bar for calculating the manipulated variable of the actuator from the internal state quantity of the control response specification function determined based on the measured value of the means It is obtained by including a click control means.

In order to achieve the second object of the present invention, the present invention provides a control method of a control device for controlling an actuator for changing the state of a controlled object having at least one controlled variable, wherein the controlled object In the control method of measuring the control amount of the actuator and the internal state of the actuator, and calculating the operation amount of the actuator based on these measurement values to control the control target, the control amount of the control target is A control response specification function with a desired frequency response characteristic is set, the measured value of the controlled variable of the controlled object is input to the control response specification function, and the inside of the control response specification function is determined based on the input value. The operation amount of the actuator is calculated from the state amount to control the controlled object.

In order to achieve the third object of the present invention, in the present invention, a rolling mill having at least one control amount, at least one actuator for changing the state of the rolling mill, and the actuator are controlled. A control device for a rolling mill, comprising: a control means; a first measuring means for measuring a control amount of the rolling mill; a second measuring means for measuring an internal state of the actuator; A rolling mill control apparatus comprising a measuring means and a state feedback control means for calculating an operation amount of the actuator based on a measurement result of the second measuring means, wherein a desired frequency response to the control amount of the rolling mill is provided. Control response specification function having a characteristic set, and the control response specification function defined based on the measurement values of the first measuring unit and the second measuring unit It is from the internal state quantity that includes a response specifications function feedback control means for calculating a manipulated variable of the actuator.

In order to achieve the fourth object of the present invention, in the present invention, a rolling mill having at least one controlled variable, an actuator for changing the state of the rolling mill,
A control device for a rolling mill having a control means for controlling the actuator, wherein the control amount of the rolling mill is measured and the internal state of the actuator is measured, and the operation amount of the actuator based on these measured values. In a control method for controlling the rolling mill by calculating the control response specification function that sets a desired frequency response characteristic with respect to the control amount of the rolling mill, the control response specification function in the control response specification function. Is input and the operation amount of the actuator is calculated from the internal state amount of the control response specification function determined based on the input value to control the rolling mill.

In order to achieve the fifth object of the present invention, in the present invention, a roll for rolling a rolled material, a reduction control device for controlling the reduction position of the roll, and a speed for controlling the rotation speed of the roll. A control device for a rolling mill including a control device, wherein a rolling position measuring means for measuring a rolling position of the roll set by the rolling control device, and rotation of the roll rotationally driven by the speed control device. A roll speed measuring means for measuring a speed, a tension measuring means for measuring a tension acting on the rolled material, and a plate thickness measuring means for measuring a plate thickness of the rolled material, and a measured value of the rolling position measuring means. A state feedback control for calculating an operation amount to the reduction control device and the speed control device based on the measured value of the roll speed measuring means, the measured value of the tension measuring means, and the measured value of the plate thickness measuring means. In a controller of a rolling mill comprising means, a plate thickness response specification function that sets a desired frequency response characteristic of the plate thickness deviation of the rolled material and a desired frequency response of the tension deviation that acts on the rolled material are set. The tension response specification function, the internal thickness of the plate thickness response specification function determined based on the measured value of the plate thickness measuring means and the target plate thickness of the rolled material, the measured value of the tension measuring means, and the rolled material. The specification function feedback control means for calculating the operation amount to the reduction control device and the speed control device from the internal state amount of the tension response specification function determined on the basis of the target tension.

In order to achieve the sixth object of the present invention, in the present invention, a roll for rolling a rolled material, a reduction control device for controlling the reduction position of the roll, and a speed for controlling the rotation speed of the roll. A method of controlling a rolling mill including a control device, wherein the rolling position of the roll set by the rolling control device, the rotation speed of the roll that is rotationally driven by the speed control device, and the rolling material. The working tension and the plate thickness of the rolled material are respectively measured, and the rolled position is controlled based on the measured rolling position of the roll, the tension acting on the rolled material, the plate thickness of the rolled material, and the rotation speed of the roll. In the control method of the rolling mill that calculates the operation amount to the apparatus and the speed control device, in the sheet thickness response specification function that sets a desired frequency response characteristic of the sheet thickness deviation of the rolled material and the tension deviation that acts on the rolled material. Desired lap A tension response specification function that sets a number response, the internal state quantity of the plate thickness response specification function determined based on the measured plate thickness of the rolled material and the target plate thickness of the rolled material, and the measured The operation amount to the reduction control device and the speed control device is calculated from the tension of the rolled material and the internal state amount of the tension response specification function determined based on the target tension of the rolled material. .

[0018]

In the first aspect of the invention, in order to reduce the influence of the disturbance on the controlled variable of the controlled object, the control characteristics such as the response characteristic of the controlled object to the disturbance and the response characteristic to follow the target value are understood. A frequency response characteristic that can be expressed easily and directly is specified, and a control response specification function having the specified frequency characteristic is provided. That is, in addition to the state feedback control means for determining the operation amount of the actuator to be controlled, the response specification function feedback control means for feeding back the internal state amount of the control response specification function to determine the operation amount of the actuator to be controlled is also provided. With the provision, the control performance specified by the frequency response characteristic, which was difficult to be realized by the conventional state feedback means, can be stably realized.

In the second aspect of the present invention, in order to reduce the influence of the disturbance of the controlled variable of the controlled object, the control performance such as the response characteristic of the controlled object to the disturbance of the controlled variable and the response characteristic to follow the target value is known. A frequency response characteristic that can be expressed easily and directly is specified, and a control response specification function having the specified frequency characteristic is provided. That is, the control amount of the controlled object is measured and the internal state of the actuator that changes the state of the controlled object is measured, and the operation amount of the actuator is calculated based on these measured values to control the operation amount of the actuator. In addition, the operation amount of the actuator is calculated from the internal state amount of the control response specification function which is determined by inputting the measured value of the control amount of the control object to the control response specification function, and the actuator of the control object is calculated. By controlling, it is possible to stably realize the control performance designated by the frequency response characteristic, which was difficult to be realized by the conventional state feedback control.

In the third aspect of the invention, in order to reduce the influence of the disturbance on the control amount of the rolling mill, the control performance such as the response characteristic of the control amount to the disturbance of the rolling mill and the response characteristic to follow the target value are known. A frequency response characteristic that can be expressed easily and directly is specified, and a control response specification function having the specified frequency characteristic is provided. That is, in addition to state feedback control means for determining the operation amount of at least one actuator that changes the state of the rolling mill, response specification function feedback control means for calculating the operation amount of the actuator from the internal state amount of the control response specification function. By including the above, it is possible to stably realize the control performance specified by the frequency response characteristic, which was difficult to be realized by the conventional state feedback means.

In the fourth aspect of the invention, in order to reduce the influence of the disturbance of the controlled variable of the rolling mill, the control performance such as the response characteristic to the disturbance of the controlled variable in the rolling mill and the response characteristic to follow the target value are known. A frequency response characteristic that can be expressed easily and directly is specified, and a control response specification function having the specified frequency characteristic is provided. That is, the control amount of the rolling mill is measured and the internal state of the actuator that changes the state of the rolling mill is measured, and the operation amount of the actuator is calculated based on these measured values to control the operation amount of the actuator. In addition, by controlling the actuator by calculating the operation amount of the actuator from the internal state amount of the control response specification function which is determined by inputting the measured value of the control amount of the rolling mill to the control response specification function. The control performance specified by the frequency response characteristic, which was difficult to realize by the conventional state feedback, can be stably realized.

In the fifth aspect of the present invention, in order to reduce the influence of disturbance on the rolling reduction control device for controlling the rolling position of the roll of the rolling mill and the speed control device for controlling the rotation speed of the roll, these disturbances are reduced. A control response specification function having the designated frequency characteristic is provided by designating the control performance such as the response characteristic to the disturbance of the control amount and the response characteristic to follow the target value in an easily understandable and direct manner. That is, based on the measurement value of the reduction position measurement means, the measurement value of the roll speed measurement means, the measurement value of the tension measurement means, and the measurement value of the plate thickness measurement means, to the reduction control device and the speed control device. In addition to the state feedback control means for calculating the operation amount of, the plate thickness response specification function that sets the desired frequency response characteristic of the plate thickness deviation of the rolled material,
The tension response specification function that sets the desired frequency response of the tension deviation acting on the rolled material, and the inside of the plate thickness response specification function that is determined based on the measurement value of the plate thickness measurement means and the target plate thickness of the rolled material. A specification function for calculating an operation amount to the reduction control device and the speed control device from the state amount, the measurement value of the tension measuring means, and the internal state amount of the tension response specification function determined based on the target tension of the rolled material. By providing the feedback control means, it is possible to stably realize the control performance specified by the frequency response characteristic, which was difficult to be realized by the conventional state feedback.

In the sixth aspect of the present invention, in order to reduce the influence of disturbance on the control amount of the rolling control device for controlling the rolling position of the roll of the rolling mill and the speed control device for controlling the rotation speed of the roll, these are controlled. A control response specification function having the designated frequency characteristic is provided by designating the control performance such as the response characteristic to the disturbance of the control amount and the response characteristic to follow the target value in an easily understandable and direct manner. That is, the rolling position of the roll set by the rolling control device, the rotation speed of the roll rotationally driven by the speed control device, and the tension acting on the rolled material,
The plate thickness of the rolled material is measured, respectively, and the rolled position is measured based on the rolling position of the roll, the tension acting on the rolled material, the plate thickness of the rolled material, and the rotation speed of the roll. In addition to the state feedback control that calculates the manipulated variable to the control device, the desired thickness response specification function that sets the desired frequency response characteristics of the thickness deviation of the rolled material and the desired frequency response of the tension deviation that acts on the rolled material are set. With the set tension response specification function, the internal state quantity of the sheet thickness response specification function determined based on the measured sheet thickness of the rolled material and the target sheet thickness of the rolled material and the measured rolling. By calculating the operation amount to the reduction control device and the speed control device from the tension of the strip and the internal state amount of the tension response specification function determined based on the target tension of the rolled strip, the conventional state filter is calculated. In which can be stably realized control performance specified by a frequency response characteristic it is difficult to achieve in Dobakku.

[0024]

The control of the rolling mill, which is an embodiment of the present invention, will be described below. In this embodiment, a cold rolling mill will be described for convenience. In the control of the cold rolling mill, the controlled variables are the outlet side plate thickness and the backward tension, and consider the inlet side plate thickness fluctuation as a disturbance. FIG. 2 is a diagram showing an outline of the rolling mill which is the control target. In FIG. 2, the rolling mill 1 is provided with, as actuators, a speed control device 2-2 that rotates the roll 1-1 of the rolling mill 1 and a reduction control device 2-1 that drives the roll in the vertical direction. When the reduction control device 2-1 is operated, the load applied to the material to be rolled 1-2 changes, which affects the rolling phenomenon and affects the exit side plate thickness and the backward tension of the rolling mill 1. Further, when the speed control device 2-2 is operated, the rotation speed of the roll 1-1 changes. Then, the change in the rotation speed of the roll 1-1 changes the tension, which affects the rolling condition. To measure the changes in these phenomena,
The rolling position and the roll speed changed by the speed control device 2-2 and the rolling control device 2-1 are the rolling position measuring unit 3-
1 and the roll speed measuring unit 3-2. The strip thickness of the rolled material 1-2 flowing out from the rolling mill 1 is detected by the strip thickness measuring unit 3-4 on the delivery side of the rolling mill 1, and the tension acting on the rolled material 1-2 is measured by the tension measuring unit. 3-3 is detected.

FIG. 1 is a block diagram in which the present invention is applied to control of the outlet plate thickness and rear tension of a rolling mill. In FIG. 1, the rolling mill 1 to be controlled is operated by two actuators 2 of a speed control device 2-2 and a reduction control device 2-1. The rolling position, roll speed, backward tension, and delivery side plate thickness, which are the state quantities of the rolling mill 1, are measured by the state measuring unit 3 (the rolling position measuring unit 3-1, the roll speed measuring unit 3-2, the tension measuring unit 3).
-3, measured by the delivery side plate thickness measuring unit 3-4).

The delivery side plate thickness which is the controlled variable of the rolling mill 1 and the target plate thickness which is set corresponding to the output plate thickness are input to the plate thickness response setting function 7 and detected from another tension controlled unit 3-3 which is the controlled variable. The applied tension and the target tension set corresponding thereto are input to the tension response setting function 6. In the tension response setting function 6 and the plate thickness response setting function 7, the internal state quantities of the response setting functions 6 and 7 for the respective inputs are sent to the function feedback control unit 5.

In the function feedback control section 5, the function internal state quantities output from the tension response setting function 6 and the plate thickness response setting function 7 are input, and the operation to the reduction control device 2-1 and the speed control device 2-2 is performed. The amount of change is calculated to control the plate thickness and tension, which are the control amounts of the rolling mill 1.

Further, in the state feedback control section 4,
The reduction control device 2 receives as inputs the amount of reduction position change from the reduction position measurement unit 3-1, the amount of roll speed change from the roll speed measurement unit 3-2, and the amount of tension change from the tension measurement unit 3-3.
−1 and the operation change amount to the speed control device 2-2 are calculated to control the plate thickness and the tension which are the control amounts of the rolling mill 1.

The operation change amount of the state feedback control unit 4 and the function feedback control unit 5 is calculated by using the gain sent from the gain setting unit 8. At this time, the gain setting unit 8 calculates the control gain using the parameters for determining the plate thickness response setting function 7 and the tension response setting function 6 input from the input unit 9.

Next, the measurement of the outlet plate thickness, which is one of the controlled variables, will be described. An ordinary plate thickness gauge is installed at the exit of each stand away from directly under the roll. Therefore, a dead time is generated in detecting the exit side plate thickness just below the roll, which is a control amount. Therefore, a method for measuring the strip thickness just below the roll to eliminate this dead time will be described below.

In the case of a tandem rolling mill, the distance between the i-th stand and the i + 1-th stand is L, and the i-th stand and the i + th stand.
The tension between one stand is T _i , the Young's modulus of the rolled material is E, the plate thickness on the entrance side of the i-th stand is H _i , the exit plate speed of the i-th stand is V _oi , and the entrance plate speed of the i + 1-th stand is V i. _{ei + 1} , i th
The distance from directly below the roll of the stand to the plate speed meter is l _s , the velocity of the plate speed meter between the i-th stand and the (i + 1) th stand is V _si , and the plate speed immediately below the roll of the i-th stand to directly below the roll of the (i + 1) th stand. Assuming that the plate speed linearly changes, the plate thickness h _i immediately below the i-th stand roll is expressed by the following equation.

[0032]

[Equation 1]

Here, as the plate thickness H _{i on the} entrance side, the plate thickness measured with a plate thickness gauge between the front stand and the plate thickness H _i is used.

The output side plate thickness just below the roll can be estimated from the inlet side plate thickness, the plate speed, and the fluctuation of tension which can be measured by the above method.

Next, a method of setting the tension response setting function 6 and the plate thickness response setting function 7 in FIG. 1 which is an embodiment of the present invention will be described.

The tension response setting function 6 and the strip thickness response setting function 7 are constructed in accordance with the required control performance. In the following, however, there will be a main disturbance in the rolling mill for the inlet side plate thickness fluctuation and the outlet side plate thickness and tension fluctuation of the disturbance. Described below is the case of realizing control performance that reduces (reduces) the influence. In the present embodiment, it is considered to reduce (reduce) the influence of disturbance in the low frequency region, that is, to realize the control performance in which the control deviation does not occur in the steady state.

FIG. 3 is a diagram showing the frequency characteristics of the influence on the output side plate thickness and the tension change from the inlet side plate thickness change disturbance which is the main disturbance in the rolling mill when no control is performed. As can be seen from FIG. 3, in the case where no control is performed, the influence of the disturbance on the low frequency side cannot be reduced.

A plate thickness response setting function 7 and a tension response setting function 6 for correcting the characteristics of such an object are set. Therefore, the relationship between the plate thickness response setting function 7 and the tension response setting function 6 and the required transfer characteristics from the inlet side plate thickness fluctuation disturbance to the outlet side plate thickness and tension fluctuation will be described.

FIG. 4 is a diagram showing frequency characteristics of the plate thickness response setting function 7 and the tension response setting function 6 for reducing the influence of disturbance at low frequencies. Here, it is an object to reduce the influence of the low-frequency input side plate thickness disturbance on the output side plate thickness and the rear tension. That is, the purpose is to have a characteristic that the gain is lowered at low frequencies. In such a case, as shown in FIG. 4, when the input and output of the plate thickness response setting function 7 and the tension response setting function 6 are opposite, the transfer frequency characteristic may be set so that the gain decreases in the low frequency region. . For example, when it is desired to reduce the influence of the plate thickness disturbance on the output plate thickness at a low frequency, the inverse frequency characteristic in which the input and the output of the plate thickness response setting function 7 are reversed becomes the characteristic required at the low frequency. Set. Generally speaking,
The setting function related to the response characteristic of each control amount, that is, the inverse transfer characteristic in which the input and the output of the plate thickness response setting function 7 and the tension response setting function 6 are reversed, is from the disturbance to be actually realized to each control amount. The plate thickness response setting function 7 and the tension response setting function 6 are set so as to express the transfer characteristics.

The plate thickness response setting function 7 [W shown in FIG.
_s1 (s)] and the plate thickness response setting function 6 [W _s2 (s)] are expressed by a transfer function as in (Equation 2), and when expressed in a state space expression as in (Equation 3).

[0041]

[Equation 2]

However, s is a Laplace operator.

[0043]

[Equation 3]

However, x _si is the internal state quantity u of the plate thickness and tension response setting function, and u _wi is an input to the plate thickness and tension response setting function.

The required control performance is expressed by the transmission frequency characteristic from the plate thickness disturbance to the output side plate thickness and the tension, and the input to the plate thickness response setting function 7 and the tension response setting function 6 is the actual output. It is the deviation between the side plate thickness and the target plate thickness and the difference between the actual tension and the target tension.

Therefore, u _w1 and u in ( _Equation 3)
_w2 is the deviation of the outlet plate thickness from the target plate thickness and the tension deviation from the target tension, respectively.

Here, the parameters of the plate thickness response setting function 7 and the tension response setting function 6 are k _i and ω _i as expressed by (Equation 2) and (Equation 3), and these two types of parameter changes By doing so, it is possible to deal with changing the response speed of the disturbance removal. The parameters of the plate thickness response setting function 7 and the tension response setting function 6 can be set freely from the input unit 9. Further, the structures of the plate thickness response setting function 7 and the tension response setting function 6 can be freely set from the input unit 9. Considering the case where the influence of low frequency input side thickness disturbance on the output side thickness and backward tension is reduced,
As described above, the tension response setting function 6 and the thickness response setting function 7 are set so that the gain in the low frequency region of the inverse system in which the input and the output of the tension response setting function 6 and the thickness response setting function 7 are reversed is reduced. Just set it.

Therefore, in a more general expression, if each of the response setting functions 6 and 7 has an integrator, its inverse system has a low gain at low frequencies. Therefore, the structures of the plate thickness response setting function 7 and the tension response setting function 6 can be described by the following (Equation 4).

[0049]

[Equation 4]

FIG. 5 shows a case where the tension response setting function 6 and the plate thickness response setting function 7 have the configurations of (Equation 2) and (Equation 3), and the tension response setting in the embodiment of the present invention shown in FIG. It is the figure which showed the relationship between the function 6, the plate thickness response setting function 7, and the input part 9. To set the plate thickness response setting function 7 and the tension response setting function 6, the parameters (k ₁ , ω ₁ , k ₂ , ω ₂ ) of the plate thickness response setting function 7 and the tension response setting function 6 are input at the input unit 9. Then, the setting parameters k ₁ and ω ₁ are sent to the plate thickness response setting function 7, and the setting parameters k ₂ and ω ₂ are sent to the tension response setting function 6. As a result, the plate thickness response setting function 7 and the tension response setting function 6 realize functions having required characteristics based on the parameters k ₁ , ω ₁ and k ₂ , ω ₂ . For example, since k ₁ determines the maximum value of the inverse gain of the plate thickness response setting function 7 shown in FIG. 4, the magnitude of the transfer gain of disturbance in the high frequency region can be specified by the setting value of k ₁ . Further, since ω ₁ determines the frequency at which the gain is reduced in the inverse system of the plate thickness response setting function 7 shown in FIG. 4, up to which frequency the influence of the inlet side plate thickness disturbance on the output side plate thickness is reduced. It can be specified by ω ₁ . Practically, if it is desired to particularly reduce the influence of the entrance side plate thickness disturbance up to 10 (rad / sec), ω ₁ is set to be sufficiently larger than that and ω ₁ = 20 (rad / sec) is set. .

During control of the realized thickness response setting function 7 and tension response setting function 6, the deviation between the thickness value output by the thickness measuring unit 3-4 and the target thickness, and the tension measuring unit 3-3. The deviation between the tension value output by and the target tension is input to the plate thickness response setting function 7 and the tension response setting function 6, respectively. At this time, the plate thickness response setting function 7 and the tension response setting function 6 output state quantities (x _s1 , x _s2 ) representing the states inside the functions. The state quantities (x _s1 , x _s2 ) of these response setting functions are sent to the function feedback control unit 5 to calculate the operation amount of the actuator 2. Then, the operation amount of the actuator 2 is also calculated by the state amounts of the rolling mill 1 and the actuator 2 sent to the state feedback control unit 4, and the actuator 2 is operated together with the operation amount of the function feedback control unit 5.

Next, the operation of the state feedback control section 4 will be described. FIG. 6 is a diagram showing details of the state feedback control unit 4. State feedback control unit 4
The state measuring unit 3, that is, the rolling position measuring unit 3-1.
The rolling position, the roll speed, and the internal state quantity of tension detected by the roll speed measuring unit 3-2 and the tension measuring unit 3-3 are input. Inside the state feedback control unit 4, a rolling-down command is performed by a product-sum calculation of the rolling-down command control gains (k ₁₁ , k ₁₂ , k ₁₃ ) designed by the gain setting unit 8 and the input rolling-down position, roll speed, and tension. Is calculated and the speed command control gain (k
_21, k _22, k ₂₃₎ and the input pressing position, roll speed,
The speed command is calculated by the product of tensions.

Next, the operation of the function feedback control section 5 will be described. FIG. 7 is a diagram showing details of the function feedback control unit 5. Function feedback control unit 5
The internal state quantity calculated by the plate thickness response setting function 7 and the tension response setting function 6 is input to. Inside the specification feedback control unit 5, the internal state quantities of the tension response setting function 6 and the plate thickness response setting function 7 which are input with the control gains (k ₁₄ , k ₁₅ ) for the reduction command set by the gain setting unit 8 are input. The reduction command is calculated by the sum of products calculation, and the speed command control gain (k ₂₄ ,
The velocity command is calculated by the sum of products of the internal state quantities of the tension response setting function 6 and the plate thickness response setting function 7 input with k ₂₅ ). Here, the control gain is not necessarily a constant gain having no dynamic characteristic, and may be expressed in the form of a transfer function having a dynamic characteristic.

Next, a method of setting the control gain sent from the gain setting unit 8 to the state feedback control unit 4 and the function feedback control unit 5 will be described.

FIG. 8 shows a flowchart of the control gain setting method. The control gain setting method first determines the frequency characteristic of the target to be requested. For this, for example, there is a requirement of specifications to reduce the gain in the low frequency region in the frequency characteristic from the input side plate thickness fluctuation disturbance to the output side plate thickness which is a control amount. Next, a plate thickness response setting function and a tension response setting function that realize the required frequency characteristics are set (S1 in the flowchart). For example, in FIG.
The tension response setting function 6 and the plate thickness response setting function 7 are set as displayed. Next, each set response setting function is modeled as a state equation as shown in (Equation 2) and (Equation 4) (S2 in the flowchart). In parallel with this, a control model of the rolling mill to be controlled is created (G1 in the flowchart). Then, a new control model (generalized plant) is created by combining each response setting function and the created rolling mill control model of the controlled object (S3 in the flowchart). Next, the Riccati equation is derived using the parameters of the created generalized plant and the condition parameters (G2 in the flowchart) set so that the Riccati equation has a solution (S4 in the flowchart). A solution is obtained from the derived Riccati equation. If no solution exists, return to the condition parameter setting (G2 in the flowchart) of the Riccati equation and change the parameter, or
Returning to the setting of the tension response setting function and the plate thickness response setting function (S1 in the flowchart), each response setting function is changed (J1 in the flowchart). Here, when a solution of the Riccati equation exists and a solution is obtained, the solution of the Riccati equation is converted into a control gain (S in the flowchart.
5). Evaluate the control performance by simulation etc. using the control gain obtained here, and confirm that the required control performance is obtained, and if higher control performance is obtained, the tension response setting function and Return to the setting of the plate thickness response setting function (S1 in the flowchart) (J2 in the flowchart). The flow of the control gain setting method has been described above, but an example of a detailed setting method will be described below.

Here, it is assumed that the influence of the input side plate thickness fluctuation disturbance, which has already been described as the required frequency characteristic, on the output side plate thickness and the tension is reduced on the low frequency side. The model of the plate thickness response setting function and the tension response setting function at this time is (Equation 3)
Since it can be expressed by, the models of the thickness response setting function and the tension response setting function are expressed by the following (Equation 5) and (Equation 6).

[0057]

[Equation 5]

Here, x _s1 is the internal state quantity of the plate thickness response setting function, and z ₁ is the output of the plate thickness response setting function.

[0059]

[Equation 6]

However, x _s2 is the internal state quantity of the tension response setting function, z ₂ is the output of the tension response setting function.
The model of is shown below. The control of the cold rolling mill 1 is usually
A non-linear rolling equation that describes rolling phenomenon by a feed-forward control calculation called a setup system,
In consideration of various factors such as electric motor capacity, rolling speed, load sharing, etc., the initial setting speed of the reduction control device for controlling the roll gap and the initial setting speed of the speed drive device for controlling the roll peripheral speed are determined. The setup system merely determines the operating point of the rolling mill, and the feedback control operates so that the control deviation becomes zero with the operating point determined by the setup system as the center. Therefore, the model of the cold rolling mill 1 is
For example, the gauge meter type, the mass flow type, the rolling load type, the advanced rate type, the strip speed, which expresses the rolling phenomenon as described in the design of the control system by the numerical analysis method (Ando et al. A state space model can be created from the following (Equation 7) to (Equation 14) in which equations, tension equations, etc. are linearized in the vicinity of the set values determined by the setup system.

[0061]

[Equation 7]

However, Δh _i : deviation of the outlet plate thickness from the setup set value ΔS _i : deviation of the rolling position from the setup set value ΔP _i : deviation of rolling load from the setup set value K _i : mill constant ΔS _Ri : roll eccentricity

[0063]

[Equation 8]

However, h _i : Outer side plate thickness setup set value H _i : Outer side plate thickness setup set value f _i : Advanced rate setup set value V _Ri : Roll speed setup set value ΔV _Ri : Roll speed deviation from the set set value Δh _i : Outgoing plate thickness deviation from setup setting value ΔH _i : Incoming plate thickness deviation from setup setting value Δf _i : _Advance rate deviation from setup setting value ΔV _ei : Incoming plate speed deviation from setup setting value

[0065]

[Equation 9]

Where ΔP _{i is} the rolling load deviation from the setup set value Δh _{i is} the exit side plate thickness deviation from the setup set value ΔH _{i is} the entrance side plate thickness deviation from the setup set value Δτ _{fi is} the forward tension from the setup set value Deviation Δτ _bi : Deviation of backward tension from the setup set value

[0067]

[Equation 10]

Where Δf _{i is the} deviation of the advance rate from the setup set value Δh _{i is the} deviation of the outgoing side plate thickness from the setup set value ΔH _{i is the} deviation of the incoming plate thickness from the setup set value Δτ _{fi is} the forward tension from the setup set value Deviation Δτ _bi : Deviation of backward tension from the setup set value

[0069]

[Formula 11] Plate speed formula: ΔV _oi = (1 + f _i ) ΔV _Ri + V _Ri Δf _i (Equation 11) where f _i : advanced rate setup set value V _Ri : roll speed setup set value ΔV _Ri : setup setting Roll speed deviation from value Δf _i : _Advance rate deviation from setup setting value ΔV _oi : Exit side plate speed deviation from setup setting value

[0070]

[Equation 12]

However, L _i : distance between stands E _i : Young's modulus ΔV _oi : deviation of outgoing side plate speed from setup set value ΔV _ei : deviation of incoming side plate speed from setup set value Δτ _bi : backward tension from setup set value deviation

[0072]

[Equation 13]

However, T _si : time constant ΔS _i : deviation of the rolling position from the setup set value ΔS _pi : amount of rolling command change

[0074]

[Equation 14]

However, T _vi : time constant ΔV _Ri : roll speed deviation from set-up set value ΔV _pi : speed command change amount Using the above equation, the state quantity of each stand is x _i = [ΔS
_i ΔV _Ri-1 Δτ _bi ] T, controlled variable y _i = [Δh _i Δτ _bi ]
With T and the disturbance d _i = ΔH _i , the state equation of each stand is as shown in (Equation 15) and (Equation 16) (where i represents the number of the stand).

[0076]

[Equation 15]

However, A _ii is a 3 × 3 constant matrix _{showing the} influence of each state quantity on the variation of each state quantity B _ii is the 3 × 3 constant matrix _{showing the} influence of each operation quantity on the variation of each state quantity 3
× 2 constant matrix E _ii represents the influence of the entrance side plate thickness disturbance on the fluctuation of each state quantity 3 × 1 constant matrix A _ii-1 represents the effect of each state quantity of the previous stand 3
× 3 constant matrix A _{ii + 1} represents the influence of each state quantity of the subsequent stand 3
× 3 constant matrix E _ii-1 is a 3 × 1 constant matrix representing the effect of the entrance side plate thickness disturbance of the previous stand

[0078]

[Equation 16]

However, C _ii1 is a 1 × 3 constant matrix _{showing the} influence of each state quantity on the plate thickness C _ii2 is a 1 × 3 constant matrix _{showing the} influence of each state quantity on the tension F _ii1 is the entrance side plate thickness disturbance 1 × 1 representing the effect on thickness
The constant matrix F _ii2 is the 1 × 1 that represents the effect of the thickness disturbance on the entrance side on the tension.
The constant matrix C _{ii-1 1} represents the effect of each state quantity of the previous stand on the plate thickness 1 × 3. The constant matrix C _{ii-1 2} represents the effect of each state quantity of the previous stand on the tension 1 ×. 3-constant matrix Furthermore, the tandem rolling mill, which is a large-scale system composed of multiple stands, has developed a block-type non-interfering optimal control method for mill control
87-11, p. 101, Showa 62-11, Katayama et al.) Can be used to deinteract each stand. This decoupling is a control that cancels the influence from other stands by the rolling operation or the roll speed operation so that each stand is not affected by the other stands.

As shown in (Equation 16), the influence of the front and rear stands in each stand is represented by A _ii-1 , x _{i -1} ,
It is represented by A _{ii + 1} · x _{i + 1} . In order to cancel this influence, the state quantities (x _i−1 , x _{i + 1} ) of the front and rear stands are detected, and this value is used to cancel the non-interference control manipulated variable (−B _ii-1・ A _i-1・ x _i-1 , -B _ii-1・ A
_{i + 1} · x _{i + 1} ) is calculated and controlled.

More specifically, it is the rear tension and the plate thickness that receive interference from other stands. In addition, it is the rolling position and the roll speed that can be directly operated. Therefore, in order to cancel the interference with the plate thickness and the rearward tension, the method is to directly change the rolling position or the roll speed and cancel the interference via the rolling position or the roll speed. Therefore, interference with the plate thickness is canceled by changing the rolling position, and interference with the rear tension is canceled by changing the roll speed. As for the interference from the other stands with respect to the plate thickness, the change in the tension of the rear stand directly affects the plate thickness. Therefore, this effect is estimated from the rolling record (tension change) of the rear stand and the rolling mill model (A _{i + 1} · x _{i + 1} ). A reduction command is output according to the estimated interference amount to cancel the interference (-
B _ii-1 , A _i-1 , x _i-1 ). Similarly, interference from other stands with respect to tension is due to the tension, reduction position,
The change in roll speed affects the amount of change in tension. Therefore, this effect is estimated from the front and rear stand rolling results (changes in tension, rolling position, roll speed) and the rolling mill model (A _i−1 · x _i−1 , A _{i + 1} · x _{i + 1} ). Then, the roll speed command is output according to the estimated interference amount to cancel the interference (-B _ii-1 · A _i-1 · x _{i -1} , -B _ii-1 · A).
_{i + 1} · x _{i + 1} ).

By the above decoupling control, (A _i-1.
there is no _{x i-1, A i +} 1 · x i + 1) portion of the control model of the mill for each stand as follows (Equation 17) can be described by equation (18).

[0083]

[Equation 17]

[0084]

[Equation 18]

However, A _ii represents a 3 × 3 constant matrix representing the influence of each state quantity on the fluctuation of each state quantity B _ii represents the influence of each manipulated quantity on the fluctuation of each state quantity 3
× 2 constant matrix E _ii 1 × 3 constant matrix C _ii2 representing the influence 3 × 1 constant matrix C _ii1 representing the influence of entry side thickness disturbance has on the variation of each state quantity is the amount of each state has on the thickness Each The 1 × 3 constant matrix F _ii1 representing the effect of the state quantity on the tension is 1 × 1 representing the effect of the entrance-side thickness disturbance on the plate thickness.
The constant matrix F _ii2 is the 1 × 1 that represents the effect of the thickness disturbance on the entrance side on the tension.
Constant matrix The generalized plant in which the response setting functions of (Equation 5), (Equation 6), (Equation 17), and (Equation 18) are combined with the rolling mill model is as follows (Equation 19) to (Equation 22). ) Can be described.

[0086]

[Formula 19]

[0087]

[Equation 20]

[0088]

[Equation 21]

[0089]

[Equation 22]

The Riccati equation for the generalized plant in which the response setting function model and the rolling mill model such as (Equation 21) and (Equation 22) are fused is, for example, "Solution of H∞ control by state space theory" (measurement and Control <Journal of Japan Society for Measuring and Controlling>, Vol.29, No.2, 1990, p.129-p.1
35 Sanpei et al.), The following (Equation 23)
Described in.

[0091]

[Equation 23]

[0092] R, .XI _F is U, is uniquely determined regardless of the choice of sigma.

Here, ε and γ are parameters that determine the existence condition of the solution in the derived Riccati equation, and the solution is obtained by adjusting these.

Regarding the solution of the derived Riccati equation, for example, "Modern control series controller CAD"
A Hamiltonian matrix as shown in the following (Equation 24) shown in (Corona Publishing Co., Ltd., Kajiwara et al., P. 86 to p. 99) is created.

[0095]

[Equation 24]

Then, the eigenvector corresponding to the asymptotically stable eigenvalue of the Hamiltonian matrix (H) of (Equation 24) is calculated (Equation 25).

[0097]

[Equation 25]

If the condition is not good at this point, there may be no asymptotically stable eigenvalues. In this case, the parameters (ν, ε) are reset.

When the eigenvector is obtained, the solution (P) of the Riccati equation is calculated from the eigenvector as shown in (Equation 26).

[0100]

P = [ξ ₁ ξ ₂ ... ξ _n ] [η ₁ η ₂ ... η _n ] ^-1 (Equation 26) Further, the control gain of the solution of the Riccati equation obtained in (Equation 26) is "Solution of H∞ control by state space theory" (Measurement and control <Journal of Japan Society for Measurement and Control), Vol.2
9, No. 2, 1990, p.129-p.135 Sanpei et al.)
It is obtained by the calculation of (Equation 27) as described in.

[0101]

[Equation 27]

The control gain of the present invention can be set by the above procedure.

FIG. 9 is a diagram showing the results of frequency response simulation. FIG. 9 (a) shows the variation of the inlet side plate thickness variation to the output side plate thickness when the control gain set by the above-mentioned control gain setting method is used. FIG. 4B is a diagram showing the frequency characteristics of the inverse system of the plate thickness response setting function given as the required specifications up to the transmission frequency characteristic up to and including the case where the control gain set by the control gain setting method described above is used. FIG. 5 is a diagram showing a transfer frequency characteristic from an inlet side plate thickness fluctuation disturbance to an outlet side tension and an inverse frequency characteristic of a tension response setting function given as a required specification. As described above, the frequency characteristic of the inverse system of the plate thickness and tension response setting function specifies the transfer characteristic from the required disturbance to the plate thickness and tension, and the transfer frequency characteristic from the disturbance to the plate thickness and tension. Is a specification required to be equal to or less than the frequency characteristic of the inverse system of the plate thickness and tension response setting function. As shown in FIG. 9, it can be seen that the obtained transfer characteristics from the disturbance to the plate thickness and the tension satisfy the requirements, and the transmission gain of the disturbance on the low frequency side can be greatly reduced.

FIG. 10 is a simulation result diagram of the time response to the disturbance, and FIG. 10A is a diagram showing the time response characteristic of the output side sheet thickness to the disturbance on the inlet side plate thickness variation.
FIG. 9B is a diagram showing a time response characteristic of the tension on the outlet side with respect to the disturbance on the variation of the plate thickness on the inlet side. Here, the time response characteristics of the outgoing side plate thickness and the tension to the external disturbance when the incoming side plate thickness becomes 0.02 mm thick stepwise as the incoming side plate thickness disturbance are shown. As can be seen from FIG. 10, even if the entrance side plate thickness fluctuates on the step, the exit side plate thickness and the tension settle to zero deviation, and the steady deviation can be removed.

FIG. 11 is a frequency response simulation result diagram, and (a) to (d) show the case where the setting parameters ω ₁ and ω ₂ of the plate thickness response setting function 7 and the tension response setting function 6 are changed, respectively. FIG. 6 is a diagram showing a transmission frequency characteristic from an inlet side plate thickness fluctuation disturbance to an outlet side plate thickness and tension.

(A) shows setting parameters of the plate thickness response setting function 7 and the tension response setting function 6 as ω ₂ = 20, k ₁ = 2.
The figure which shows the transfer frequency characteristic from the entrance side plate thickness fluctuation disturbance to the tension when k ₂ = 0.04 is fixed and only the setting parameter ω ₁ of the plate thickness response setting function 7 is changed to 5,50,500. Is.

In (b), the setting parameters of the plate thickness response setting function 7 and the tension response setting function 6 are ω ₂ = 20, k ₁ = 2.
It shows the transfer frequency characteristics from the input side thickness fluctuation disturbance to the output side plate thickness when k ₂ = 0.04 is fixed and only the setting parameter ω ₁ of the plate thickness response setting function 7 is changed to 5,50,500. It is a figure.

As can be seen from these (a) and (b),
Only by changing the setting parameter ω ₁ of the plate thickness response setting function of (Equation 5), it is possible to change the transfer frequency characteristic of the outgoing side plate thickness variation from the incoming side plate thickness fluctuation disturbance, and to change the quick response of the disturbance removal. Then, at this time, the transmission frequency characteristic of the tension is hardly affected by the disturbance on the inlet side plate thickness variation.

Similarly, in (c), the setting parameters of the plate thickness response setting function 7 and the tension response setting function 6 are ω ₁ = 20,
Transfer frequency characteristic from the inlet side plate thickness fluctuation disturbance to the tension when k ₁ = 2, k ₂ = 0.04 is fixed and only the setting parameter ω ₂ of the tension response setting function 6 is changed to 5,50,500 It is the figure which showed.

(D) shows setting parameters of the plate thickness response setting function 7 and the tension response setting function 6 as ω ₁ = 20, k ₁ = 2.
The transfer frequency characteristic from the inlet side plate thickness fluctuation disturbance to the output side plate thickness is shown when only the setting parameter ω ₂ of the tension response setting function 6 is changed to 5,50,500 while fixing k ₂ = 0.04. It is a figure.

As can be seen from these (c) and (d),
Only by changing the setting parameter ω ₂ of the tension response setting function of (Equation 6), there is almost no influence on the transmission frequency characteristic of the outgoing side plate thickness fluctuation disturbance to the outgoing side plate thickness fluctuation, and the tension transmission from the incoming side plate thickness fluctuation disturbance. It can be seen that the frequency characteristic can be changed and the quick response of the disturbance removal can be changed. That is, the effect that the response characteristics of a plurality of controlled variables can be independently set freely is obtained.

FIG. 12 is a frequency response simulation result diagram, and (a) to (d) show complementary sensitivity functions concerning plate thickness response and tension response when the control method of the present invention is used and the input at that time. It is the figure which showed the frequency response from the side plate thickness fluctuation disturbance to the outgoing side plate thickness and tension.

(B) is a frequency response diagram expressing the target value followability from the target output side plate thickness to the output side plate thickness as a complementary sensitivity function regarding the plate thickness response, and (a) is the variation of the input side plate thickness at that time. It is a frequency response diagram from a disturbance to an exit side plate thickness.

Further, (d) is a frequency response diagram expressing the target value followability from target tension to tension as a complementary sensitivity function relating to tension response, and (c) is the tension from the input side thickness fluctuation disturbance at that time. It is a frequency response diagram up to.

The complementary sensitivity function referred to here is "system control theory for advanced control" (Asakura Shoten, p.2).
~ P.3, Maeda et al.), It has the role of an evaluation function that defines the modeling error for the stability of the closed loop system. As an example, the stability is guaranteed when the inverse system of the multiplicative modeling variation of the controlled object, which will be described in detail later, is less than or equal to this complementary sensitivity function.

Therefore, the frequency characteristic of tracking the target value is used for the determination as one method for determining the stability of the closed loop system against the model error.

FIG. 13 is a diagram showing the relationship between the controlled object model and its multiplicative model error. In general, the control model cannot completely describe the controlled object. Therefore, the behavior of the model and the behavior of the actual controlled object are different. If there is such an error between the actual object and the model, the controller set for the model may operate stably with respect to the model but may become unstable with the actual object. A robust stable control, which is a design method that considers the model error by evaluating the error between the actual object and the model, is being considered to solve such a problem. The model error is used to represent the part that does not match the actual behavior, but it cannot be described accurately because there are many unknown parts. As a method of expressing the model error, there is an additive model error in addition to the multiplicative model error shown in FIG. The multiplicative model error is
The model error described as (Equation 28) is shown.

[0118]

(Equation 28) P _r = P (I + ΔP _m ) (Equation 28) where P _r : actual object P: model ΔP _m : multiplicative model error Further, the additive model error is as shown in (Equation 29). Shows the model error described.

[0119]

P _r = P + ΔP _a (Equation 29) where P _r : actual object P: model ΔP _a : additive model error Here, the complementary sensitivity function described above and this multiplicative model error and stability When the relation is shown, the stability condition can be expressed by the following (Equation 30).

[0120]

‖ΔP _m (s) ‖∞ <G _yr (s) -1 (Equation 30) where ΔP _m (s): Multiplicative model error G _yr (s): Complementary sensitivity function It is a frequency response simulation result diagram,
11A to 11D are diagrams showing the relationship between the complementary sensitivity function shown in FIG. 11 and the parameters ω ₁ and ω ₂ of each response setting function.

In FIG. 14B, the parameters of each response setting function are fixed as k ₁ = 2, k ₂ = 0.04, ω ₂ = 20, and the parameter ω ₁ of the plate thickness response setting function 7 is set. 5,50,
The complementary sensitivity function (target thickness tracking frequency characteristic) regarding the plate thickness response when changed to 500 is shown, and (a) shows the complementary sensitivity function (target tension following frequency characteristic) regarding the tension response at that time. . From this result, the complementary sensitivity function relating to the thickness response can be changed only by changing the setting parameter ω ₁ of the thickness response setting function 7 of (Equation 5), and the stability degree to the model error of the closed loop system regarding the thickness response can be determined. Can be changed. At this time, the complementary sensitivity function concerning the response of tension is hardly affected.

In FIG. 13 (d), the parameters of each response setting function are fixed as k ₁ = 2, k ₂ = 0.04, ω ₁ = 20, and the parameter ω ₂ of the tension response setting function 6 is set to 5 , 50,
The complementary sensitivity function (target thickness tracking frequency characteristic) regarding the plate thickness response when changed to 500 is shown, and (c) shows the complementary sensitivity function (target tension following frequency characteristic) regarding the tension response at that time. . From this result, the complementary sensitivity function relating to the tension response can be changed only by changing the setting parameter ω ₂ of the tension response setting function 6 of (Equation 5), and the degree of stability of the closed loop system relating to the tension response to the model error can be changed. At this time, the complementary sensitivity function concerning the thickness response is hardly affected. From this result, the response setting functions 6 and 7 are also obtained for the complementary sensitivity function.
It can be changed independently by changing the parameters ω ₁ and ω ₂ . However, when the model variation on the high frequency side, which is said to have a large actual model error, the complementary sensitivity function is reduced on the high frequency side in order to increase the allowable range of the model error variation for the system to be stable ( ω ₁ = 5, ω ₂ =
5) As can be seen from the result of FIG. 11, the gain of the disturbance removal characteristic cannot be lowered, resulting in the sacrifice of the disturbance response characteristic and the target tracking characteristic. However,
The setting parameters ω ₁ and ω ₂ of each response setting function can clarify the trade-off between the disturbance rejection characteristics (target value tracking characteristics) and the stability against model error. And
Furthermore, there is an effect that the trade-off between the response regarding the plate thickness and the response regarding the tension can be set independently.

FIG. 15 is a block diagram in which the present invention is applied to the control of a general multi-input / multi-output control object. In FIG. 15, the control target 1 is a plurality of control devices (2-
1, 2-2, ..., 2-n). The control amount of the controlled object 1 is the measurement unit 3 (3-
1, 3-2, ..., 3-n), and the internal state quantity of the controlled object 1 is measured by the measuring unit 3 (3-n1, 3-n2 ,.
3-nm).

The plurality of controlled variables of the controlled object 1 are input to the respective control response setting functions 6-1 to 6-n. The control response setting functions 6-1 to 6-n send the internal state quantities of the response setting functions 6-1 to 6-n to the respective inputs to the function feedback control unit 5.

The function feedback control unit 5 receives the respective function internal state quantities output from the respective control response setting functions 6-1 to 6-n as input, and changes the state of the controlled object 1 to the control devices 2-1 to 2-. The operation change amount to n is calculated to control the control amount of the controlled object 1.

Further, in the state feedback control section 4,
Measuring units 3-n1 to 3-n for measuring the internal state of the controlled object
The control device 2-1 receives the change amount of the state amount from m as an input.
The control amount of the controlled object 1 is controlled by calculating the operation change amount to ~ 2-n.

The operation change amount of the state feedback control unit 4 and the function feedback control unit 5 is calculated by using the gain sent from the gain determining unit 8. At this time, the gain setting unit 8 calculates the control gain using the parameters that determine the respective control response setting functions 6-1 to 6-n input from the input unit 9.

[0128]

As described above, according to the first aspect of the invention, in addition to the state feedback control means for determining the operation amount of the actuator to be controlled, the required characteristic of the control amount to be controlled is independent of the frequency characteristic. , And the response specification function feedback control means for calculating the manipulated variable of the actuator to be controlled from the internal state quantity of the control response specification function determined based on this frequency characteristic, the characteristics of the control response specification function By the selection, there is an effect that it is possible to provide a control device that can independently and optimally realize a plurality of control performance specifications such as robust stability and disturbance rejection characteristics.

According to the second aspect of the invention, in addition to the state feedback control for determining the manipulated variable of the controlled object actuator, the required characteristic of the controlled object controlled variable is independently set by the frequency characteristic, and based on this frequency characteristic. Since the manipulated variable of the actuator to be controlled is calculated from the internal state quantity of the control response specification function that is defined by the control response specification function, multiple control performance specifications such as robust stability and disturbance rejection characteristics can be made independent by selecting the characteristics of the control response specification function. There is an effect that it is possible to provide a control method that can be optimally realized by.

According to the third invention, in addition to the state feedback control means for determining the operation amount of the actuator for changing the state of the rolling mill, the required characteristic of the control amount of the rolling mill is independently set by the frequency characteristic, Since a response specification function feedback control means for calculating the operation amount of the rolling mill actuator from the internal state quantity of the control response specification function determined based on this frequency characteristic is provided, robust stability is achieved by selecting the characteristic of the control response specification function. There is an effect that it is possible to provide a control device for a rolling mill, which can independently and optimally realize a plurality of specifications of control performances such as performance and disturbance rejection characteristics.

According to the fourth aspect of the invention, in addition to the state feedback control for determining the operation amount of the actuator for changing the state of the rolling mill, the required characteristic of the control amount of the rolling mill is set independently by the frequency characteristic. Since the operating amount of the rolling mill actuator is calculated from the internal state quantity of the control response specification function that is determined based on the frequency characteristics, it is possible to select multiple characteristics such as robust stability and disturbance rejection characteristics by selecting the characteristics of the control response specification function. There is an effect that it is possible to provide a control method for a rolling mill that can independently and optimally realize the specifications of.

According to the fifth invention, in addition to the state feedback control means for determining the reduction amount of the rolling mill and the operation amount of the roll rotation speed, the required characteristic of the control amount of the rolling mill is set independently by the frequency characteristic. , The response specification function feedback control means for calculating the operation amount of the rolling reduction and the rolling speed of the rolling mill from the internal state quantity of the control response specification function determined based on this frequency characteristic is provided. There is an effect that it is possible to provide a control device for a rolling mill that can independently and optimally realize a plurality of specifications of control performance such as robust stability and disturbance rejection characteristics by selecting characteristics.

According to the sixth aspect of the invention, in addition to the state feedback control for determining the reduction amount of the rolling mill and the operation amount of the roll rotation speed, the required characteristic of the controlled amount of the rolling mill is set independently by the frequency characteristic, Since the amount of reduction of the rolling mill and the manipulated variable of the roll rotation speed are calculated from the internal state quantity of the control response specification function determined based on this frequency characteristic, robust stability and disturbance rejection characteristics can be selected by selecting the characteristic of the control response specification function. There is an effect that it is possible to provide a control method of a rolling mill that can independently and optimally realize a plurality of specifications of control performance.

[Brief description of drawings]

FIG. 1 is a block diagram applied to plate thickness / tension control in a rolling mill showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing an outline of a rolling mill to be controlled.

FIG. 3 is a diagram showing a frequency characteristic of an influence exerted on an outlet side plate thickness and a tension change from an inlet side plate thickness change disturbance which is a main disturbance in a rolling mill when no control is performed.

FIG. 4 is a diagram showing frequency characteristics of a plate thickness response setting function and a tension response setting function for reducing the influence of disturbance at low frequencies.

5 is a diagram showing a relationship between a tension response setting function, a plate thickness response setting function and an input section in the embodiment of the present invention shown in FIG.

FIG. 6 is a diagram showing details of a state feedback control unit.

FIG. 7 is a diagram showing details of a function feedback control unit.

FIG. 8 is a flowchart showing a control gain setting method.

FIG. 9 is a diagram showing a result of frequency response simulation, where (a) is a transfer frequency characteristic from an input side plate thickness fluctuation disturbance to an output side plate thickness when a set control gain is used and given as required specifications. It is a figure showing the frequency characteristic of the inverse system of the plate thickness response setting function, (b) is the transfer frequency characteristic from the input side plate thickness fluctuation disturbance to the output side tension when the set control gain is used, and the required specifications It is the figure which showed the frequency characteristic of the inverse system of the plate thickness response setting function given as.

FIG. 10 is a simulation result diagram of a time response to a disturbance, (a) is a diagram showing a time response characteristic of an outgoing side plate thickness with respect to an incoming side plate thickness fluctuation disturbance, and (b) is a diagram showing an output against an incoming side plate thickness fluctuation disturbance It is the figure which showed the time response characteristic of side tension.

FIG. 11 is a frequency response simulation result diagram,
(A)-(d) is the figure which showed the transfer frequency characteristic from the entrance side board thickness fluctuation disturbance to the exit side board thickness and tension when the setting parameter of a board thickness response setting function and a tension response setting function was each changed.

FIG. 12 is a frequency response simulation result diagram,
(A) to (d) show complementary sensitivity functions concerning plate thickness response and tension response when the control system of the present invention is used, and frequency response from the inlet side thickness fluctuation disturbance to the outlet side plate thickness and tension at that time. It is a figure.

FIG. 13 is a diagram showing a relationship between a controlled object model and its multiplicative model error.

FIG. 14 is a frequency response simulation result diagram,
(A)-(d) is a figure which showed the complementary sensitivity function shown in FIG. 11, and the relationship of the parameter of each response setting function.

FIG. 15 is a block diagram in which the present invention is applied to control of a general multi-input / multi-output control target.

[Explanation of symbols]

1 ... Rolling mill, 2 ... Actuator, 3 ... State measuring unit, 4
State feedback control unit, 5 function feedback control unit, 6 tension response setting function, 7 plate thickness response setting function, 8 gain setting unit, 9 input unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G05B 11/32 A 7531-3H (72) Inventor Yutaka Saito 5-2 Omika-cho, Hitachi-shi, Ibaraki No. 1 Incorporated company Hitachi Ltd. Omika Plant (72) Inventor Satoshi Hattori 52-1 Omikacho, Hitachi City, Ibaraki Prefecture Incorporated Hitachi Ltd. Omika Plant (72) Inventor Toshiyuki Kashiwagi Omika Town, Hitachi City, Ibaraki Prefecture 5-2-1 HITACHI CORPORATION Mika Factory

Claims (22)

[Claims] 1. A control device for controlling an actuator for changing a state of a controlled object having at least one controlled variable, comprising: first measuring means for measuring the controlled variable of the controlled object; and an internal state of the actuator. Second to measure
And a state feedback control means for calculating the operation amount of the actuator based on the measurement values of the first measurement means and the second measurement means. Of the control response specification function that sets a desired frequency response characteristic with respect to the quantity, and the internal state quantity of the control response specification function that is determined based on the measurement values of the first measuring unit and the second measuring unit. A control device comprising a response specification function feedback control means for calculating a manipulated variable. 2. The control device according to claim 1, further comprising gain determining means for determining a control gain of the response specification function feedback control means. 3. The control device according to claim 1, wherein the control response specification function is determined from a transfer frequency characteristic of a disturbance affecting the controlled object. 4. The control device according to claim 1, wherein the control response specification function is determined from a transfer frequency characteristic of a disturbance affecting the controlled object and a modeling error of the controlled object. Control device. 5. A control method of a control device for controlling an actuator for changing a state of a controlled object having at least one controlled variable, comprising: measuring a controlled variable of the controlled object and measuring an internal state of the actuator. In the control method of controlling the controlled object by calculating the manipulated variable of the actuator based on these measured values, a control response specification function that sets a desired frequency response characteristic for the controlled variable of the controlled object is set. , The measured value of the control amount of the controlled object is input to the control response specification function, and the manipulated variable of the actuator is calculated from the internal state amount of the control response specification function determined based on the input value to control the controlled object. A control method characterized by controlling. 6. The control method according to claim 5, wherein the operation amount of the actuator calculated from the internal state amount of the response specification function uses a control gain determined based on the desired frequency response characteristic. A control method characterized by calculating. 7. The control method according to claim 5, wherein the control response specification function is determined from a transfer frequency characteristic of a disturbance affecting the controlled object. 8. The control method according to claim 5, wherein the control response specification function is determined from a transfer frequency characteristic of a disturbance that affects the controlled object and a modeling error of the controlled object. Control method. 9. A rolling mill control device comprising: a rolling mill having at least one controlled variable; at least one actuator for changing the state of the rolling mill; and control means for controlling the actuator, Based on the measurement results of the first measuring means for measuring the control amount of the rolling mill, the second measuring means for measuring the internal state of the actuator, the first measuring means and the second measuring means, A control device for a rolling mill comprising: a state feedback control means for calculating an operation amount of an actuator; and a control response specification function that sets a desired frequency response characteristic with respect to the control amount of the rolling mill, and the first measurement. Means and the operation amount of the actuator are calculated from the internal state quantity of the control response specification function determined based on the measurement values of the second measuring means. Rolling mill control apparatus characterized by comprising a response specifications function feedback control means. 10. The control device for a rolling mill according to claim 9, wherein the control amount is a strip thickness on the delivery side of the rolling mill or a tension of a rolled material on the delivery side of the rolling mill. Control device. 11. The control device for a rolling mill according to claim 9, wherein the actuator is a roll reduction device for rolling a rolled material or a drive device for the roll. 12. A controller for a rolling mill, comprising a roll for rolling a rolled material, a reduction control device for controlling a reduction position of the roll, and a speed control device for controlling a rotation speed of the roll. A rolling position measuring unit that measures the rolling position of the roll set by the rolling control unit, a roll speed measuring unit that measures the rotation speed of the roll that is rotationally driven by the speed control unit, and acts on the rolled material. A tension measuring unit for measuring tension and a plate thickness measuring unit for measuring the plate thickness of the rolled material are provided, and the measured value of the rolling position measuring unit, the measured value of the tension measuring unit, and the plate thickness measuring unit are measured. In a control device for a rolling mill comprising state feedback control means for calculating an operation amount to the reduction control device and the speed control device based on a value and a measurement value of the roll speed measurement device, A plate thickness response specification function that sets a desired frequency response characteristic of the plate thickness deviation of the rolled material, a tension response specification function that sets a desired frequency response of the tension deviation that acts on the rolled material, and a measurement of the plate thickness measuring means. Value and the internal state quantity of the plate thickness response specification function determined based on the target thickness of the rolled material, the measured value of the tension measuring means and the tension response specification function determined based on the target tension of the rolled material A control device for a rolling mill, comprising: a specification function feedback control means for calculating an operation amount to the reduction control device and the speed control device from an internal state amount. 13. The rolling mill control apparatus according to claim 9 or 12, further comprising gain determining means for determining a control gain of the response specification function feedback control means. apparatus. 14. The rolling mill control apparatus according to claim 9 or 12, wherein the control response specification function is determined from a transfer frequency characteristic of a disturbance affecting the controlled object. Machine control device. 15. The control device for a rolling mill according to claim 9 or 12, wherein the control response specification function is based on a transfer frequency characteristic of a disturbance affecting the controlled object and a modeling error of the controlled object. A control device for a rolling mill characterized by making a decision. 16. A rolling mill having at least one controlled variable, and an actuator for changing the state of the rolling mill,
A method of controlling a rolling mill comprising: a control means for controlling the actuator, wherein a control amount of the rolling mill is measured and an internal state of the actuator is measured, and an operation amount of the actuator is based on these measured values. In the control method of the rolling mill to control the rolling mill by calculating the, a control response specification function that sets a desired frequency response characteristic with respect to the control amount of the rolling mill is provided, and the control object is the control response specification function. Input the measured value of the control amount and the measured value of the internal state of the actuator, calculate the operation amount of the actuator from the internal state amount of the control response specification function determined based on the input value, A method for controlling a rolling mill, comprising controlling. 17. The rolling mill control method according to claim 16, wherein the controlled variable is a strip thickness on the delivery side of the rolling mill or a tension of a rolled material on the delivery side of the rolling mill. Control method. 18. The method for controlling a rolling mill according to claim 16, wherein the actuator is a roll reduction device for rolling a rolled material or a driving device for the roll. 19. A method for controlling a rolling mill, comprising: a roll for rolling a rolled material; a reduction control device for controlling a reduction position of the roll; and a speed control device for controlling a rotation speed of the roll. The rolling position of the roll set by the rolling control device, the rotation speed of the roll rotationally driven by the speed control device, the tension acting on the rolled material, and the plate thickness of the rolled material are measured. A rolling operation that calculates the operation amount to the reduction control device and the speed control device based on the measured rolling position of the roll, the tension acting on the rolled material, the plate thickness of the rolled material, and the rotation speed of the roll. In a machine control method, a strip thickness response specification function that sets a desired frequency response characteristic of the strip thickness deviation of the rolled material and a tension response specification function that sets a desired frequency response of the tension deviation acting on the rolled material are provided. , Previous The internal state quantity of the plate thickness response specification function determined based on the measured plate thickness of the rolled material and the target plate thickness of the rolled material, the measured tension of the rolled material, and the target tension of the rolled material. A method of controlling a rolling mill, wherein an operation amount to the reduction control device and the speed control device is calculated from an internal state amount of the tension response specification function determined based on the above. 20. The rolling mill control method according to claim 16 or 19, wherein the operation amount of the actuator calculated from the internal state amount of the response specification function is determined based on the desired frequency response characteristic. A control method characterized in that calculation is performed using the generated control gain. 21. The rolling mill control method according to claim 16 or 19, wherein the control response specification function is determined from a transfer frequency characteristic of a disturbance affecting the controlled object. Control method. 22. The rolling mill control method according to claim 16 or 19, wherein the control response specification function is based on a transfer frequency characteristic of a disturbance affecting the controlled object and a modeling error of the controlled object. A method for controlling a rolling mill, characterized by determining.