JPH08206719A - Device and method for controlling looper - Google Patents

Abstract

PURPOSE: To make high responses tension control and position control compatible with simple control systems by constituting a command value composite means so that tension control system and position control system are switched according to a deviation from a target looper angle. CONSTITUTION: A looper motor current command value following a detected looper angle to a target looper angle, is calculated by an ith looper position controller 113. The looper motor current command value following detected forward tension to target forward tension, is calculated by a tension controller 114. A parameter given from a parameter setting means 115 and a looper angle detected by a looper angle detector 110 are given from a target looper angle to the current controller 111 of an ith looper by an ith command value composite means 112, and either of a current command value from a looper position controller 113 or the current command value from a looper tension controller 114 is given to the current controller 111 of the ith looper. A command value making a looper motor current follow a looper motor current command value, is given to a looper arm drive device 109 by the current controller 111 of the looper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to tension control for continuous rolling mills and the like.

[0002]

2. Description of the Related Art In hot continuous rolling mills, etc., which are expected to perform various operations such as disturbances such as skid marks, biting, slipping out, acceleration, deceleration of rolling mills, and change of running strip thickness, etc. , Disturbance of tension cannot be ignored. Usually, in order to perform stable and highly efficient operation, a device called a looper is installed between rolling mill stands to control tension.

Conventional looper control methods can be roughly divided into two types, one that absorbs tension fluctuations by current control and one that absorbs tension fluctuations by position control.

(1) Current control p.306 of "Theory and practice of sheet rolling" issued by Japan Iron and Steel Institute
In the looper control described on page 307, current control, that is, tension control is performed by the looper, and position control of the looper is performed by main machine motor speed control.

[0005] looper current command value, the load torque applied to the looper from the looper angle θ and the tension t _f, can be calculated as the number 1.

[0006]

[Equation 1]

However, here, the angular velocity θ of the looper is zero,
That is, it is assumed that the looper is stationary. Therefore, the tension is controlled by giving the looper current command value according to the target tension and the looper angle. Further, the main machine motor speed command value ω _p can be calculated as in Expression 2, and the looper position is controlled by this.

[0008]

## EQU2 ## ω _p = K _p (Δθ) (Equation 2) (2) Position control The position control is performed passively as described in JP-A-5-293520 and JP-A-5-305322. Control and JP-A-5-337
There is active control as described in JP-A-529 and JP-A-6-7820.

In the passive control, the tension is controlled by the speed of the main motor, and the looper controls the position. That is, the looper does not actively control the tension, and is regarded as a damper that absorbs the tension fluctuation that cannot be followed by the tension control by the main motor speed.

Here, in the case of looperless rolling or when the rigidity of the position control of the looper is extremely high (the position of the looper does not change even if the tension changes), the looper cannot be used as a damper and the tension The control will be 100% dependent on the main motor speed control.

The active control positively controls the looper position in order to match the tension with the target value. If the material length is lifted by the looper and the material length becomes L ′, the change ΔL in material length becomes ΔL = L′−L, which directly affects the tension. Here, the tension is controlled by positively controlling the loop amount, that is, the looper position.
When the tension is higher than the target value, the looper position is lowered to reduce ΔL, and when the tension is lower than the target value, the looper position is raised and ΔL is increased to keep the tension constant. To control.

[0012]

In the looper current control,
Since the forcing current control system for starting the looper is indispensable, the control system becomes complicated, and it cannot coexist with the looperless rolling control system.

In the passive looper position control, the tension is controlled by the speed of the main motor, and the looper does not actively control the tension.
It is regarded as a damper that absorbs tension fluctuations that cannot be tracked by tension control based on the main motor speed. Since the responsiveness of the position control of the looper and the softness as a damper of the tension control are contradictory performances, it is difficult to tune the control gain.

In the active looper position control, the tension fluctuation absorbing effect does not appear unless the looper position control response is sufficiently faster than the main motor speed response. In general, the response of the position control system is slower than that of current control, so it is essential to devise measures such as lower inertia of the looper and higher response of the looper motor.
The problem is that the cost is high.

An object of the present invention is to realize a looper control system which has low tension and high tension control performance and high position control performance in a tension control system of a continuous rolling mill without using a complicated control system. .

[0016]

To achieve the above object, according to the present invention, in a looper control device for a continuous rolling mill having a looper between rolling mill stands, the angle of the looper follows a looper angle command value. Looper position control means for calculating the command of the looper drive machine, tension control means for calculating the command of the looper drive machine for causing the tension of the steel material between rolling mill stands to follow the tension command value, and the detected state quantity of the rolling plant Based on the above, there is provided a loop control device characterized by having command value synthesizing means for determining a command for the looper drive machine from a command from the looper position control means and a command from the tension control means. In the loop control device, the command value synthesizing means preferably drives the looper from a command from the looper position control means and a command from the tension control means based on a result of comparison between the state quantity and a parameter given in advance. Determine the machine command. Further, according to the present invention, according to the present invention, in a looper control device of a continuous rolling mill having a looper between rolling mill stands, a looper position for calculating a command of a looper driving machine that causes the angle of the looper to follow a looper angle command value. Based on the control means, the tension control means for calculating the command of the looper driving machine that causes the tension of the steel material between the rolling mill stands to follow the tension command value, the detected state quantity of the rolling plant and the parameters given by the parameter setting means. And a command value synthesizing unit that determines a command for the looper driving machine from a command from the looper position control unit and a command from the tension control unit.

In the loop control device, the command value synthesizing means is preferably a gain computing means for computing a position control gain and a tension control gain from the state quantity of the plant and the parameters, the position control gain and the tension control gain. And a command value calculation means for calculating a command of the looper drive machine from a command from the looper position control means and a command from the tension control means.

In the above loop control device, the state quantity of the plant is preferably the looper angle, the looper angular velocity, the looper drive motor current and the tension, and the parameters are preferably the looper angle and / or the looper angular velocity. And / or looper drive motor current and / or said tension.

In the above loop control device, preferably, the parameter setting means changes the parameter according to the state quantity of the plant.

In the above loop control device, preferably, the parameter setting means has a hysteresis characteristic in changing the parameter.

In the above loop controller, the command value synthesizing means is preferably a fuzzy rule base for describing the relationship between each state quantity of the plant, the position control gain and the tension control gain by a fuzzy rule, and the plant. Fuzzy rule interpreting means for calculating the fitness of each fuzzy rule of the fuzzy rule base from each state quantity, and determining the position control gain and the tension control gain according to the fitness, the position control gain and the tension control gain And a command value calculation means for calculating a command of the looper drive machine from a command from the looper position control means and a command from the tension control means.

Further, according to the present invention, the first object is to calculate a command of a looper driving machine that causes the tension of a steel material between rolling mill stands of a continuous rolling mill having a looper between rolling mill stands to follow a tension command value. In the looper control device having the tension control means, the second tension control means for causing the tension to follow the target tension of the main machine motor speed, and the tension fluctuation from the tension command value of the tension to the low frequency of the tension fluctuation. And a high-frequency component of the tension fluctuation, the low-frequency component of the tension fluctuation is given to the second tension control means, and the high-frequency component of the tension fluctuation is given to the first tension control means. There is provided a looper control device characterized by the above.

Further, according to the present invention, there is provided a looper for calculating a current command of a looper drive electric motor for making the tension of a steel material between rolling mill stands of a continuous rolling mill having a looper between rolling mill stands follow a tension command value. In the control device, a positive current command is calculated when the tension is smaller than the tension command value, and a negative current command is calculated when the tension is larger than the tension command value, and the positive current command is calculated. There is provided a looper control device comprising switching means for switching the negative current command at high speed.

Further, according to the present invention, there is provided a looper between rolling mill stands of a continuous rolling mill and a looper control device for making the angle of the looper follow a looper angle command value. There is provided a looper control device comprising command value synthesizing means for synthesizing a new looper angle command value by multiplying the difference between the tension and the tension command value and the looper angle command value by a frequency weighting function.

Further, according to the present invention, the above object is a continuous rolling mill having a looper between rolling mill stands, and in the looper control method for controlling the looper by current control or position control, the angle of the looper is adjusted. Calculate the command of the looper drive machine to follow the looper angle command value, calculate the command of the looper drive machine to follow the tension command value of the steel material tension between rolling mill stands, and based on the detected state quantity of the rolling plant There is provided a looper control method characterized by synthesizing a command of the looper drive machine from a command from the looper position control means and a command from the tension control means.

[0026]

In the loop control device of the present invention, the looper position control means for calculating the command of the looper driving machine for causing the angle of the looper to follow the looper angle command value, and the tension of the steel material between the stands of the rolling mill follow the tension command value. A tension control means for calculating a command for the looper drive machine, and a command for the looper drive machine is determined from the command from the looper position control means and the command from the tension control means based on the detected state quantity of the rolling plant. By having the command value synthesizing means, it is possible to achieve both highly responsive tension control and position control with a simple control system.

In addition, the tension control is performed because the command of the looper drive machine is determined from the command from the looper position control means and the command from the tension control means based on the result of comparison between the state quantity and the parameter given in advance. The state and the state in which the position control is performed can be freely determined.

Further, in the loop control device of the present invention,
State of the rolling plant detected by computing the command of the looper drive that causes the looper angle to follow the looper angle command value, and the command of the looper drive that causes the tension between the rolling mill stands to follow the tension command value. And the command of the looper drive machine is determined from the command from the looper position control means and the command from the tension control means based on the parameter given by the parameter setting means, so that the tension control and the position control with high response by a simple control system are performed. It is possible to achieve both of the above, and it is possible to freely determine the state in which tension control is performed and the state in which position control is performed.

Further, the position control gain and the tension control gain are calculated from the plant state quantity and parameters, and the position control gain, the tension control gain, the command from the looper position control means and the command from the tension control means are supplied to the looper drive machine. By calculating, it is possible to achieve both highly responsive tension control and position control.

Further, by providing the hysteresis characteristic to the parameter change, both the asymptoticity of the looper position control to the target looper angle and the expansion of the looper tension control range can be achieved. Also, the fuzzy rule base that describes the relationship between each state quantity of the plant, the position control gain, and the tension control gain by fuzzy rules, and the fitness of each fuzzy rule of the fuzzy rule base are calculated from each state quantity of the plant, and the goodness of fit is calculated. By determining the position control gain and the tension control gain according to the above, by calculating the command of the looper drive machine from the position control gain, the tension control gain, the command from the looper position control means, and the command from the tension control means. A high degree of control that incorporates the knowledge of the operator can be performed.

Also, the second tension control means for making the tension follow the target tension by the speed of the main machine, and the tension fluctuation from the tension command value of the tension to the low frequency component of the tension fluctuation and the tension fluctuation. A low-frequency component of the tension fluctuation is given to the second tension control means, and a high-frequency component of the tension fluctuation is given to the first tension control means, thereby controlling the motor speed. The tension control system can be operated only at high frequencies that cannot be absorbed by the tension control system.

Further, when the tension is smaller than the tension command value, a positive current command is calculated, and when the tension is larger than the tension command value, a negative current command is calculated to calculate the positive current command and the positive current command. By providing the switching means for switching the negative current command at high speed, the tension control having a higher response than the looper variable position control can be configured.

Further, by providing a command value synthesizing means for synthesizing a new looper angle command value by multiplying the difference between the tension of the steel material between the stands of the rolling mill and the tension command value and the looper angle command value by a frequency weighting function, looper control can be performed. It is possible to suppress sudden changes and perform control that does not adversely affect changes in tension and looper position.

[0034]

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows an i-th rolling mill, an i + 1-th rolling mill, an i-th looper and a tension controller in a continuous rolling mill.

The i-th rolling mill is a rolling mill roll 10
1, a roll driving device 1 for rotating a rolling mill roll 101
02, rolling mill roll driving device speed detector 103 for detecting the rotation speed of the roll driving device 102, forward tension detection for detecting the tension applied to the steel material between the i-th rolling mill stand and the (i + 1) th rolling mill stand It is composed of a container 107.

The tension controller 105 of the i-th rolling mill is
The speed command value of the main motor that causes the front tension detected by the front tension detector 107 to follow the target front tension is calculated,
It is applied to the speed controller 104 of the second rolling mill. The rolling mill speed controller 104 gives the roll drive device 102 a command value that causes the main machine motor speed detected by the main machine motor speed detector 103 to follow the main machine motor speed command value.

The same applies to the (i + 1) th rolling mill stand.

The i-th looper is the looper arm 10.
8, a looper arm drive device 109 for rotating the looper arm 108, and a looper angle detector 110 for detecting the rotation angle of the looper arm 108.

The i-th looper position controller 113 calculates a looper motor current command value for causing the looper angle detected by the looper angle detector 110 to follow the target looper angle,
It is given to the i-th command value synthesis means 112.

The tension controller 114 of the i-th looper is
A looper motor current command value that causes the front tension detected by the front tension detector 107 to follow the target front tension is calculated,
The second command value synthesizing means 112 is given.

The i-th command value synthesizing means 112 uses the parameter η given from the parameter setting means 115, the looper angle detected by the looper angle detector 110, and the target looper angle to output a current command from the looper position controller 113. Either the value or the current command value from the looper tension controller 114 is given to the i-th looper current controller 111. The looper current controller 111 gives a command value for causing the looper motor current to follow the looper motor current command value to the looper arm drive device 109.

FIG. 2 is a block diagram showing details of the tension generation process.

The tension per unit area applied to the steel material between the stands of the rolling mill can be expressed by Equation 3.

[0044]

(Equation 3)

The tension when there is a looper between the stands is shown below. First, as shown in FIG. 3, the coordinate system, the looper arm fulcrum P ₀ (x ₀ , y ₀ ), the looper arm length Bar, the intersection point P (x, y) between the looper and the plate, the looper angle θ, the stand-to-stand length L.
Define ₀ , α, and β. The intersection P between the looper and the board is
From x ₀ , y ₀ , Bar and θ, they are shown as in Equation 4 and Equation 5.

[0046]

X = x ₀ + Bar cos θ (Equation 4)

[0047]

Y = y ₀ + Bar sin θ (Equation 5) The material length between the i stand and the i + 1 stand at the moment when the material is bitten into the i + 1 stand is equal to L ₀ . After that, the material length L after the lapse of t seconds is given by the equation 6. This is the original (no tension) material length.

[0048]

(Equation 6)

Assuming that the material is elastically deformed, the actual material length L ′ lifted by the looper is given by

[0050]

(Equation 7)

This is differentiated with respect to time, and the time change rate dL / dt of the material length L due to the vertical movement of the looper is given by

[0052]

(Equation 8)

However,

[0054]

[Equation 9]

[0055]

[Equation 10]

Here, the superscript is an index indicating each rolling mill stand, Δ is a minute change amount from the value at the operating point, and ω is a looper angular velocity.

A block 205 calculates the time change rate (Z) of the material length L due to the vertical movement of the looper, and the integrator 204 integrates the sum of dL / dt, v _e and -v _0. Further, block 203 Calculates the forward tension t _f per unit area by multiplying the integration result of the integrator 204 by the Young's modulus E and dividing by the material length L.

In block 202, the full load torque G applied to the looper is calculated. Here, the full load torque G applied to the looper is given by the following equation 11. However, the inertia of the material is ignored.

[0059]

[Number 11] _{G = G T + G L +} G W ... ( number 11) G _T: torque applied to the looper by the tension

[0060]

(Equation 12)

G _L : Torque applied to the looper by the weight of the material

[0062]

(Equation 13)

Ρ: Material density (kg / m ³ ) G _W : Torque applied to the looper by the weight of the looper

[0064]

[Equation 14]

W _L : Weight of looper (kg) l _r : Length to the center of gravity of the looper (m) FIG. 4 shows a tension generating process 201, a looper arm 108 and a looper arm driving device in the rolled material 106 between the rolling mill stands. It is a block diagram which modeled 109.

The looper arm 108 is connected to the looper arm driving device 109, and the angular velocity ω _L of the looper arm driving device 109 is multiplied by 1 / G _r via the gear 402, and further integrated by the integrator 401 to calculate the looper arm angle θ. Also, the looper load torque G from the tension generation process 201
Is applied to the looper arm driving device 109 via the gear 402 by a load torque of the looper arm driving device multiplied by 1 / G _r .

In this embodiment, the looper arm drive device 10 is used.
9 is an electric motor. A block 406 is a model of an electric motor, a block 404 is a current torque conversion coefficient, a block 405 is a back electromotive force coefficient, and a block 403 divides the generated torque by an inertia moment J _L and further integrates to calculate an angular velocity ω _L.

FIG. 5 is a block diagram showing an example of details of the looper current controller 111, the command value synthesizing means 112, the looper position controller 113, and the looper tension controller 114.

The current controller 111 uses the PI controller 502 to calculate the looper motor voltage command V _LP that causes the detected looper current I _L filtered by the filter 501 to follow the current command value I _LP passed through the current limiter 503.

The looper position controller 113 multiplies the difference between the looper angle θ detected by the looper angle detector 110 and the looper angle command value θ _ref by K _PP by the P controller 505 to calculate the looper angular velocity command value ω _LP . . The PI controller 504 calculates a looper current command value I _LP obtained by proportionally integrating the difference between the looper angular velocity ω and the looper angular velocity command value ω _LP .

When the tension t _f becomes higher than the target value t _{f ref} , the looper tension controller 114 outputs a negative torque.
(Looper current −KI _max ) is generated, and when the tension t _f becomes lower than the target value t _{f ref} , a positive torque (looper current KI _max ) is generated and the generated torque (looper current) Switch at high speed.

Compared with the position control system, the current control system, that is, the control of the torque generated by the looper, can be made highly responsive. Therefore,
In this embodiment of the looper tension controller, when the tension is higher than the target value, negative torque is generated, and when the tension is lower than the target value, positive torque is generated,
By switching the generated torque (looper current) at high speed, a tension control system having a higher response than the looper variable position control can be configured.

The command value synthesizing means 112 controls the looper tension only when the deviation from the target looper angle θ _ref is smaller than the parameter η given from the parameter setting means 115, and otherwise controls the looper position. Switch the current command value.

FIG. 6 shows an example of the processing flow of the command value synthesizing means 112. In processing 601, η, θ, I _LP1 and I _LP2 are set to the parameter setting means 115 and the looper angle detector 1, respectively.
10, looper position controller 113, looper tension controller 1
Read from 14. Next, in process 602, the target looper angle θ
_It is determined whether the deviation from _ref is larger than η. In the former case, the current command value I _{LP is set} to I _{LP1 in} processing 603, and in the latter case, the current command value I _{LP is set} to I _{LP2 in} processing 604.

In this embodiment, the looper tension control is performed only when the deviation from the target looper angle is very small, and the looper position control is performed at other times, and the command value synthesizing means having a simple structure is provided, so that it is simple. The control system can achieve both highly responsive tension control and position control.

FIG. 7 shows a processing flow of another embodiment of the command value synthesizing means 112. In process 701, η, θ, I _LP1 , I
_LP2 is read from the parameter setting means 115, the looper angle detector 110, the looper position controller 113, and the looper tension controller 114, respectively. Next, in step 702, the position control gain g ₁ and the tension control gain g ₂ are calculated in accordance with the looper angle θ, and in step 703 the current command value I _LP is calculated by the formula 15
Ask according to.

By having such a command value synthesizing means, the output of the looper position controller and the output of the looper tension controller can be synthesized in the form of an arbitrary function.

8 and 9 show examples of g ₁ (θ) and g ₂ (θ) which are functions of θ.

The embodiment of FIG. 8 is a simple embodiment of FIG.
It is reproduced in the embodiment of FIG. In comparison,
In the embodiment, the output of the looper position controller and the output of the looper tension controller are continuously and smoothly changed, and in the vicinity of the target looper angle θ _ref , the looper tension control is focused, and the looper position is separated from the target looper angle θ _ref. According to the above, the looper position control is intensively performed, abrupt changes in the looper control are suppressed, and it is possible to perform control that does not adversely affect changes in the tension and the looper position.

[0080]

I _LP = g ₁ I _LP1 + g ₂ I _LP2 ( _Equation 15) FIG. 10 shows another embodiment of the command value synthesizing means 112. The command value synthesizing means 112 has a fuzzy rule base 1001 that describes the relationship between each state quantity and the parameter of the plant as the antecedent part and a fuzzy rule that determines the position control gain and the tension control gain as the consequent part, and the fuzzy rule base 1001 of the plant. A fuzzy rule interpreting means that calculates the fitness of each fuzzy rule in the fuzzy rule base from each state quantity and parameter, and synthesizes the consequent part according to the fitness of each fuzzy rule to determine the position control gain and tension control gain. 1002
The command value calculation means 1003 is included. The fuzzy rule base 1001 is represented by a fuzzy rule as shown in FIG. 10, for example, and the fuzzy rule interpretation means 1002 is shown in FIG.
Evaluate the suitability of the antecedent part with a membership function like 0,
The position control gain g ₁ and the tension control gain g ₂ are calculated by synthesizing the membership functions of the consequent part. The command value calculation means 1003 calculates the current command value I _LP from the calculated position control gain g _1, tension control gain g ₂ , I _LP1 and I _LP2 .

In this embodiment, by determining the position control gain and the tension control gain by the fuzzy rule, it is possible to perform high-level command value synthesis incorporating the operator's knowledge.

The command value synthesizing means 112 may be composed of a neural network which inputs the respective state quantities of the plant and the parameters and outputs the position control gain and the tension control gain. According to this embodiment, an excellent command value synthesizing means can be constructed only by learning the relationship between the favorable position control gain and tension control gain obtained from actual data or the like in the neural network.

FIG. 11 shows a processing flow of an embodiment of the parameter setting means 115. In processing 1101, η ₁ and η ₂ are set manually or automatically, and the value of the internal state status is set to 1.

Process 1102 is the looper angle detector 110.
Read the looper angle θ from. Internal state in process 1103
The status value is determined, and if the value is 1, processing 1104
If 2, then the process proceeds to step 1108. Process 1104 determines the looper angle deviation | Δθ |, and if | Δθ | is larger than η ₁ , η is set to η _{1 in} process 1105, and if smaller, the value of the internal state status is set to 2 in process 1106, and process 1107 is executed. Let η be η ₂ . Process 1108 determines the looper angle deviation | Δθ |, and if | Δθ | is smaller than η ₂ , η is set to η _{2 in} process 1111. If larger, process 1108 is performed.
At 109, the value of the internal state status is set to 1, and at step 1110, η is set to η ₁ . Process 1105, Process 1107, Process 111
0, the process 1111 merges, η is set in the command value synthesizing means 112 in the process 1112, and the process returns to the process 1102. By this processing, it is possible to give a hysteresis characteristic to the parameter change as shown in FIG. An example of executing this processing is shown in FIG.

By simply switching the looper position control and the looper tension control with the threshold value η, the looper position control cannot approach the target looper angle θ _ref beyond the threshold value η. Priority is given to the looper position control, and the threshold value η
When is smaller, the looper tension control range is narrowed. According to this embodiment, the target looper angle θ _{ref for the} looper position control is
It is possible to achieve both the asymptotic property to and the expansion of the looper tension control range.

As a disturbance, a skid mark (25 ° C., 1 Hz) in which tension fluctuation is likely to occur is assumed, and a simulation is performed to compare the tension fluctuation absorption effects of the conventional looper current control system, looper position control system, and this control system. The results of carrying out are shown in FIGS. 14 to 16.

FIG. 14 is a looper position control system, and FIG. 15 is a simulation result of this control system. These show the time response of the forward tension fluctuation when the skid mark is given as a disturbance. FIG. 16 is a result of comparing the tension fluctuations from the first stand to the fourth stand for each control method. From this result, it can be seen that the tension fluctuation of this control system is significantly smaller than that of other control systems.

FIG. 17 shows another embodiment. The command value synthesizing means 1701 is obtained by multiplying the difference Δt _f between the tension of the steel material between the stands of the rolling mill and the tension command value by the gain K1702, the looper angle command value Δθ _ref, and the new looper angle command value Δθ _p.
In this example, the sum of the difference between and is integrated by an integrator 1703 having a time constant T is used as a new looper angle command value Δθ _p .
In this case, the new looper angle command value Δθ _p becomes a function of Δt _f and Δθ _{ref as shown in} the equation 16, and Δt _f becomes Δ
As shown in FIG. 18, the gains from θ _p and Δθ _ref to Δθ _p are the looper angle command value Δθ on the low frequency side with the time constant T as a boundary.
_Ref is prioritized, and Δt _f is prioritized on the high frequency side.

According to this embodiment, the tension control system can be operated only at a high frequency that cannot be absorbed by the tension control system by the main machine motor speed control, and the adverse effect of the extremely slow tension fluctuation on the looper position control can be reduced. .

[0090]

[Equation 16]

[0091]

As compared with the position control system, the response of the current control system, that is, the control of the torque generated by the looper can be improved, and when the tension becomes higher than the target value,
If a negative torque is generated and the tension becomes lower than the target value, a tension control system that generates a positive torque can be considered. By switching the generated torque (looper current) at high speed, a tension control system having a higher response than the looper position control can be configured. In addition, it has a command value synthesizing means, and the variable current control is performed only when the deviation from the target looper angle is small (threshold value η or less), and in other cases, the looper position control is performed. The control system can achieve both highly responsive tension control and position control.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of the present invention.

FIG. 2 Tension generation process.

FIG. 3 Definition of a looper coordinate system and the like.

FIG. 4 is an example of a block diagram of a looper arm and a looper arm drive device.

FIG. 5 shows an example of tension and position control means.

FIG. 6 shows an example of processing of command value synthesizing means.

FIG. 7 shows an example of processing of command value synthesizing means.

FIG. 8 is an example of processing of command value combining means.

FIG. 9 shows an example of tension and position control gain.

FIG. 10 shows another embodiment of the command value synthesizing means.

FIG. 11 shows an example of execution of fuzzy rule interpretation means.

FIG. 12 shows an example of processing of parameter setting means.

FIG. 13 shows an example of execution of parameter setting means.

FIG. 14 is a simulation result of the looper position control method.

FIG. 15 is a simulation result of this control method.

FIG. 16 is a comparison result of control methods.

FIG. 17 is another embodiment of the looper control device.

FIG. 18 shows frequency characteristics of command value synthesizing means 1701.

[Explanation of symbols]

101 ... Rolling mill roll, 102 ... Rolling mill roll drive device, 103 ... Speed detector, 104 ... Speed controller, 105
... tension controller, 106 ... rolled material, 107 ... front tension detector, 108 ... looper arm, 109 ... looper arm drive device, 110 ... looper angle detector, 111 ... current controller, 112 ... command value synthesizing means, 113 ... looper Position controller, 114 ... Tension controller, 115 ... Parameter setting means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Morooka 7-1, 1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory

Claims (13)

[Claims] 1. A looper control device for a continuous rolling mill having a looper between rolling mill stands, the looper position control means for calculating a command of a looper driving machine for causing the angle of the looper to follow a looper angle command value, and a rolling mill. From the tension control means for calculating the command of the looper driving machine that causes the tension of the steel material between stands to follow the tension command value, and the command from the looper position control means and the tension control means based on the detected state quantity of the rolling plant. 2. A looper control device comprising command value synthesizing means for determining the command of the looper drive machine from the command of 1. 2. The command value synthesizing means according to claim 1, based on a result of comparing the state quantity and a parameter given in advance, based on a command from the looper position control means and a command from the tension control means. A looper control device characterized by synthesizing commands of the looper driving machine. 3. A looper control device for a continuous rolling mill having a looper between rolling mill stands, the looper position control means for calculating a command of a looper driving machine for causing the angle of the looper to follow a looper angle command value, and a rolling mill. Tension control means for calculating the command of the looper driving machine that causes the tension of the steel material between stands to follow the tension command value, and the looper position control means based on the detected state quantity of the rolling plant and the parameters given by the parameter setting means. A looper control device comprising a command value synthesizing means for determining a command for the looper driving machine from a command from the above and a command from the tension control means. 4. The gain calculating means for calculating a position control gain and a tension control gain from the state quantity of the plant and the parameter, the position control gain and the tension control gain according to claim 3. And a command value computing means for computing a command for the looper driving machine from a command from the looper position control means and a command from the tension control means. 5. The looper control device according to claim 3, wherein the state quantities of the plant are the looper angle, the looper angular velocity, the looper drive motor current, and the tension. 6. The looper control device according to claim 3, wherein the parameter is the looper angle and / or the looper angular velocity and / or the looper drive motor current and / or the tension. 7. The looper control device according to claim 3, wherein the parameter setting unit makes the parameter variable according to the state quantity of the plant. 8. The looper control device according to claim 3, wherein the parameter setting unit has a hysteresis characteristic in changing the parameter. 9. The fuzzy rule base for describing a relationship between each state quantity of the plant, a position control gain, and a tension control gain by a fuzzy rule, and the respective states of the plant according to claim 3. A fuzzy rule interpreting means for calculating the fitness of each fuzzy rule of the fuzzy rule base from a quantity and determining the position control gain and the tension control gain according to the fitness, the position control gain, the tension control gain, and the A looper control device comprising command value calculation means for calculating a command for the looper drive machine from a command from the looper position control means and a command from the tension control means. 10. A looper control device having a first tension control means for calculating a command of a looper driving machine for causing a tension between steel stands between rolling mill stands having a looper between rolling mill stands to follow a tension command value. In the second tension control means for causing the tension to follow the target tension of the main motor speed, and the tension fluctuation from the tension command value of the tension into a low-frequency component of the tension fluctuation and a high-frequency component of the tension fluctuation. A looper control device comprising: separating means for dividing, wherein the low frequency component of the tension fluctuation is given to the second tension control means, and the high frequency component of the tension fluctuation is given to the first tension control means. 11. A looper control device for calculating a current command of a looper drive electric motor that causes a tension between steel stands between rolling mill stands of a continuous rolling mill having a looper between rolling mill stands to follow a tension command value. A positive current command is calculated when it is smaller than the command value, and a negative current command is calculated when the tension is larger than the tension command value, and the positive current command and the negative current command are switched at high speed. A looper control device having switching means for controlling the looper. 12. A looper control device having a looper between rolling mill stands of a continuous rolling mill, which makes the angle of the looper follow a looper angle command value, the difference between the tension of the steel material between the rolling mill stands and the tension command value. A looper control device comprising a command value synthesizing means for synthesizing a new looper angle command value by multiplying the looper angle command value by a frequency weighting function. 13. A continuous rolling mill having a looper between stands of a rolling mill, wherein a looper control method for controlling the looper by current control or position control comprises a looper drive for making the angle of the looper follow a looper angle command value. The command of the looper drive machine that calculates the command of the rolling mill and causes the tension of the steel material between the rolling mill stands to follow the tension command value is calculated, and the command from the looper position control means based on the detected state quantity of the rolling plant. And a command from the looper driving machine based on a command from the tension control means.