JP2003211256A - Apparatus for oscillating mold in continuous casting facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for oscillating a mold in a continuous casting facilities with which control corresponding to each movement characteristic of a controlled object can be performed by estimating the state quantity of the control object without detecting the state quantity of the mold. <P>SOLUTION: This apparatus contains: a hydraulic cylinder 27 for displacing a mold 28 in a reciprocating manner; a servo-valve 26 for controlling the supply of hydraulic oil into a hydraulic cylinder; a compensator 24 for giving the servo- valve a servo command value vc; a stroke sensor 29 for detecting the displacement xs of the hydraulic cylinder; and a state observing instrument 25 for giving an estimated state quantity xc by estimating the state quantity showing the states of the mold and the hydraulic cylinder on the basis of the displacement xs of the hydraulic cylinder and the servo command value vc. In this way, a desired oscillation can be given to the mold while eliminating the effect of a characteristic frequency by performing optimum control on the basis of the estimated state quantity xc without detecting the state quantity of the mold. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold vibrating device for vibrating a mold of a continuous casting facility in which molten metal is poured into a mold to continuously cast a profile.

[0002]

2. Description of the Related Art In continuous casting equipment in which molten metal is poured into a mold to continuously cast a profile, it is necessary to prevent seizure between the mold and the slab during continuous casting. As a method for preventing such seizure between the mold and the slab, there is a method of vibrating the mold to form a gap between the mold and the slab and pouring a lubricant into the gap.

FIG. 11 is a block diagram showing a continuous casting machine 0 using the mold oscillation method in the continuous casting machine disclosed in Japanese Patent Laid-Open No. 63-63562. This continuous casting machine 0 has a mold 1, four side links 2,
Beam 3, swing cylinder 4, mold acceleration detector 5,
It is composed of a position detector 6, pressure detectors 7 and 8, a servo amplifier 9, a servo valve 10 and a control circuit 11. The mold 1 is supported by the four-sided links 2 and the beam 3, and is vertically vibrated by a swing cylinder 4 which is an actuator connected to the beam 3. The control circuit 11 is
It is composed of a mold position estimating circuit 12, a compensator 13, an unbalance gain 14, and arithmetic circuits 15 and 16.

When the mold 1 is swung at a high frequency,
Resonance occurs in conformity with the natural frequency of the system including the mold 1, the four-sided link 2 and the beam 3, and the mold 1 cannot be made to vibrate as desired.

Therefore, the control circuit 11 determines the mold position based on the rod position of the rocking cylinder 4 detected by the position detector 6 and the cylinder pressure of the rocking cylinder 4 detected by the pressure detectors 7 and 8. The servo amplifier 9 is controlled by state feedback control based on the position of the mold 1 estimated by the estimation circuit 12 and the acceleration of the mold 1 detected by the mold acceleration detector 5. Thus, when the mold 1 is oscillated at a high frequency, resonance is prevented from occurring in accordance with the natural frequency of the system including the mold 1, the four-sided links 2 and the beam 3, and the desired vibration of the mold 1 is prevented. You can

[0006]

However, in the above continuous casting machine 0, the rod position and cylinder pressure of the rocking cylinder 4 and the acceleration of the mold 1 are detected, and the position detector 6 for detecting these is detected. The pressure detector 7 and the mold acceleration detector 5 are required, and a place for installing these detectors is also required. In particular, the place where the mold acceleration detector 5 is installed is not only in a high temperature atmosphere due to the molten metal of 1000 ° C. or higher poured into the mold 1, but also in order to cool the high temperature slab that has come out of the mold 1. The cooling water poured on the pieces evaporates, resulting in a very humid atmosphere. In such a hot and humid environment, the detector may malfunction or be damaged, and the place where the detector is installed is limited.

Further, in the continuous casting machine 0, as shown in FIG. 11, the rocking cylinder 4 is a double-sided rod type double-acting cylinder, and the dynamic characteristics in the operation of displacing the mold 1 of the rocking cylinder 4 in one direction. Since the dynamic characteristics in the operation of displacing in the other direction, which is the opposite direction to the one direction, are the same, the unbalance gain 14 used for correction in these two operations may be one. But swing cylinder 4
Is a one-sided rod double-acting cylinder, the dynamic characteristics in the first operation of displacing the mold 1 of the rocking cylinder in one of the one direction and the other direction and the other one of the one direction and the other direction. Unlike the dynamic characteristics in the second operation of displacing the rocking cylinder 4, the rocking cylinder 4 cannot be controlled by the state feedback control in the continuous casting machine 0 described above. In order to control such an oscillating cylinder, it is necessary to make the two characteristics the same. For the oscillating cylinder, the first control gain used for correction during the first operation and the correction during the second operation are required. It is necessary to set each second control gain to be used.

Further, due to some factors, the rocking cylinder 4 is overloaded due to an abnormal load being applied to the mold 1, and the position of the mold 1 estimated by the mold position estimating circuit 12 is greatly different from the actual position. In this case, if an abnormality occurs, such as when the control circuit 11 oscillates due to a change in the parameters of the system of the continuous casting machine 0, or when the position detector 6 that detects the rod position of the rocking cylinder 4 fails, continuous casting is performed. It may be necessary to stop the operation of the rocking cylinder 4 so as not to damage the machine 0.

When the input signal to the control circuit 11 is a sinusoidal wave which is a distorted sine wave and a signal is generated,
It is often performed by a method of synthesizing a high-order sine wave as shown in Expression (a). g (ωt) = A1sin (ωt) + A2sin (2ωt) + A3sin (3ωt) + ... (a)

In the above formula (a), A1, A2, A3, ...
The value of depends on the non-sine rate, which is the degree of distortion of the sine wave, and is calculated and calculated each time the ratio sine rate is changed.
Alternatively, it is necessary to select from a large amount of data collected in advance, and it is difficult to continuously change the non-sign ratio by such a method.

Therefore, an object of the present invention is to estimate the state quantity of the controlled object without detecting the state quantity of the mold, eliminate the influence of each dynamic characteristic of the controlled object, and perform the optimum control for the command value. It is an object of the present invention to provide a mold vibrating device for continuous casting equipment that can detect an abnormality when it occurs.

[0012]

The present invention according to claim 1 is an apparatus for vibrating a mold of a continuous casting facility for pouring molten metal into a mold to continuously cast a profile, wherein the mold is unidirectional. An actuator for reciprocating in the other direction and vice versa, valve means for controlling the supply of working fluid to the actuator, valve driving means for giving an operation command to the valve means, and position detection for detecting the operating position of the actuator. Unit, the state quantity representing the state of the mold and the actuator is estimated based on the operation position by the position detection means and the operation command by the valve driving means, and a correction command for correcting the operation command is given based on the estimated state quantity. A mold vibrating device for continuous casting equipment, comprising a correction commanding means.

According to the present invention, the correction command means represents the states of the mold and the actuator estimated based on the operating position of the actuator detected by the position detecting means and the operation command given to the valve means by the valve driving means. Based on the state quantity, give a correction command to correct the operation command,
The valve driving means gives an operation command corrected based on the correction command to the valve means, and the valve means controls the supply of the working fluid of the actuator to reciprocally move the mold.

As a result of this, for example the displacement of the mold,
The mold and actuator are based on the operation command and the operation position of the actuator by the correction command means without detecting the state quantities such as the speed and the acceleration, and the state quantities of the actuator, such as the operation speed, the operation acceleration, and the pressure. Of the natural frequency of the controlled object including the mold and the actuator by estimating the state quantity equal to the actual state quantity of the, and performing the optimum control of correcting the operation command given to the valve means based on the estimated state quantity. It is possible to eliminate the influence of the natural frequency and to cause the mold to generate a desired vibration without giving a command having a correction waveform that reduces the influence.

Further, since it is not necessary to detect state quantities such as mold displacement, velocity and acceleration, it is necessary to detect the state quantities of the mold in the vicinity of the mold, which is a severe environment for the detector such as high temperature and high humidity. There is no need to install a detector or a mechanism for installing a detector. Further, regarding the actuator, it is not necessary to provide a detector for detecting a state quantity other than the operating position, for example, the operating speed and the operating acceleration of the actuator, and it is not necessary to provide means for reducing the influence of noise on the detection by such a detector. The device can have a simple structure.

According to a second aspect of the present invention, the valve driving means comprises:
A linearized first state equation of the controlled object including the mold and the actuator is constructed based on the dynamic characteristics of the actuator in the first operation of displacing the mold in one direction or the other direction, and Based on the dynamic characteristics of the actuator in the second motion of displacing in one of the direction and the other direction, a linearized second state equation of the controlled object is constructed, and based on the first state equation, The first control gain used for the correction is determined, and used for the correction during the second operation so that the pole arrangement of the control system configured by the control target and the valve driving means during the first and second operations becomes the same. Second
It is characterized in that the control gain is determined.

According to the present invention, the valve driving means displaces the mold in one of the one direction and the other direction.
A linearized first state equation of the controlled object including the mold and the actuator is constructed based on the dynamic characteristics of the actuator in the operation, and the actuator in the second operation for displacing the mold in one of the one direction and the other direction. A second state equation of the controlled object is constructed on the basis of the dynamic characteristics of the first control equation, and the first control gain used for the correction during the first operation is determined on the basis of the first state equation. Since the second control gain used for the correction during the second operation is determined so that the pole arrangement of the control system configured by the control target and the valve driving means during operation is the same, the dynamic characteristics of the actuator are ,
Even if the first operation and the second operation are different, by controlling using the control gains according to the respective dynamic characteristics, the vibration of the mold with respect to the waveform of the mold position command caused by the dynamic characteristics of the actuator is generated. The distortion of the waveform can be reduced as much as possible to allow the mold to vibrate as desired.

According to the third aspect of the present invention, the control gain is automatically adjusted by adjusting each physical quantity without directly adjusting the control gain from the relationship between the physical quantity representing the characteristic of the control system and the control gain. It is characterized by being decided.

According to the present invention, the control gain is automatically determined by adjusting each physical quantity without directly adjusting the control gain from the relationship between the physical quantity representing the characteristic of the control system and the control gain. Therefore, the control gain can be easily determined by independently adjusting an arbitrary physical quantity of the plurality of physical quantities, without the plurality of physical quantities affecting each other.

According to a fourth aspect of the present invention, the correction command means estimates the mold displacement, and the valve drive means monitors the difference between the estimated mold displacement and the actuator displacement,
It is characterized by detecting an abnormality of the device.

According to the present invention, the correction command means estimates the mold displacement, which is one of the state quantities of the mold, and the valve driving means calculates the estimated mold displacement and the actuator displacement, which is the operating position of the actuator. Since the difference is monitored to detect the abnormality of the device, the difference in the estimated mold displacement and the detected actuator displacement is monitored to detect the abnormality in the mold vibrating device early and highly accurately. be able to. Thus, for example, when an abnormality is detected, by performing control such that the mold vibrating device is not damaged, for example, stopping the actuator, it is possible to prevent the mold vibrating device from being damaged due to the abnormality.

According to a fifth aspect of the present invention, there is provided a command generating means for giving a mold position command with a non-sinusoidal waveform in which sine waves having different frequencies depending on the phase are continuously provided, and the valve driving means includes the position command by the command generating means. It is characterized by giving an operation command based on.

According to the present invention, the valve driving means includes a command generating means for giving a mold position command with a non-sinusoidal waveform in which sine waves having different frequencies are continuous according to the phase, and the valve driving means operates based on the position command by the command generating means. Give a command, so
In order to generate a desired non-sinusoidal waveform, it can be generated with an extremely small amount of calculation as compared with a method of generating a non-sinusoidal wave by superposing a plurality of sine waves. Further, by estimating the state quantity, it is possible to easily change the frequency and the degree of distortion of the non-sinusoidal sine wave continuously while giving the position command.

[0024]

1 is a control block diagram showing a mold vibrating apparatus 20 for continuous casting equipment according to a first embodiment of the present invention, and FIG. 2 shows a configuration of a mold vibrating apparatus 20 for continuous casting equipment. It is a figure which shows typically. FIG. 3 is a sectional view schematically showing the continuous casting facility 80.

The mold vibrating device 20 vibrates the mold 28 in a continuous casting facility 80 for continuously casting molten metal in order to prevent seizure between the mold 28 and the unsolidified slab. It is a device for.

In the continuous casting facility 80 shown in FIG. 3, the molten metal 91 produced in the melting furnace (not shown) is conveyed to the continuous casting facility 80 by the ladle 81 and temporarily stores the molten metal 91. It is poured into 82. Then, the molten metal 91 is added to the tundish 8.
It is poured into the mold 28 at a predetermined flow rate by the sliding nozzle 83 provided in the No. 2.

Molten metal 91 poured into the mold 28
Is cooled by the mold 28 and becomes an unsolidified slab 92 in which the metal on the outer periphery is solidified. The unsolidified slab 92 is
It is discharged to the guide roll group 84 provided below the mold 28 by the gravity and corrective drawing device 86. The unsolidified slab 92 is guided by the guide rolls 85 provided in the guide roll group 84, and the straightening / drawing device 86.
While being pulled out in the pulling direction A by, the slab is cooled by cooling water while passing through the guide roll group 84 to form a slab.

Mold 28 made of high temperature unsolidified slab 92
A lubricant is poured into the mold 28 in order to prevent the seizure of the mold 28. By vibrating the mold 28 by the mold vibrating device 20, a gap is formed between the mold 28 and the unsolidified cast piece 92, and the gap is formed in the gap. The lubricant enters, the lubrication between the mold 28 and the unsolidified slab 92 is improved, and seizure of the mold 28 can be prevented.

The mold vibrating device 20 is generally constituted by including a control device 21 and a controlled object 22. The controller 21 includes a signal generator 23, a compensator 24, and a state observer 25. The controlled object 22 includes a servo valve 26, a hydraulic cylinder 27, a mold 28, and a stroke sensor 29.

The signal generator 23, which is a command generating means, generates a signal having a target command value xref, which is a position command for the mold 28, and gives it to the compensator 24. The compensator 24, which is a valve driving means, corrects the target command value xref based on the estimated state quantity xc of the controlled object 22 from the state observer 25, and the servo command value vc which is an operation command to the servo valve 26.
To the servo valve 26 and the state observer 25.

The state observer 25, which is a correction command means, estimates the state quantity of the controlled object 22 based on the servo command value vc from the compensator 24 and the cylinder displacement xs of the hydraulic cylinder 27 from the stroke sensor 29. An estimated state quantity xc which is a correction command is given to the compensator 24.

The hydraulic unit 30 is composed of a hydraulic pump for supplying hydraulic oil, not shown, which is a high-pressure hydraulic fluid, and a tank for storing the hydraulic oil. The hydraulic cylinder 27, which is an actuator, is configured to include a cylinder tube 27a, a piston 27b, and a rod 27c, and a rod 27c is erected on one end surface of a substantially cylindrical piston 27b contained in the substantially cylindrical cylinder tube 27a. It is a single-sided rod type double acting cylinder. Servo valve 26 as valve means
Is connected to the hydraulic unit 30 and the hydraulic cylinder 27 and controls the direction and flow rate of the hydraulic oil.

The servo valve 26 opens and closes based on the servo command value vc from the compensator 24, and the hydraulic pump and the piston 2 of the cylinder tube 27a of the hydraulic cylinder 27 are opened.
7b is connected to either the space facing one end surface or the space facing the other end surface. In this way, the hydraulic oil is supplied to the hydraulic cylinder 27 and the opening and closing of the valve is switched to extend and retract the rod 27c. A stroke sensor 29, which is a position detecting means, is provided in the hydraulic cylinder 27, detects an actuator displacement which is an operating position of the hydraulic cylinder 27, that is, a cylinder displacement xs which is a displacement of the rod 27c, and outputs a signal having the cylinder displacement xs. It is given to the state observer 25.

The four-bar linkage 31 includes a mold 28, a drive arm 32, an auxiliary arm 33, and a column 34 installed substantially vertically. The mold 28 is supported by a column 34 so as to be vertically displaceable via a drive arm 32 and an auxiliary arm 33.

The drive arm 32 has one end 36 rotatably connected to the mold 28 and is connected to the mold 28.
The other end 37 is rotatably connected to the rod 27c of the hydraulic cylinder 27 and is connected to the rod 27c.
The central portion 35 between the other end portion 37 and the other end portion 37 is rotatably connected to the support column 34 and is connected to the support column 34. Drive arm 32
Is angularly displaceable around the central portion 35. The length from the other end portion 37 of the drive arm 32 to the central portion 35 is first
The arm length is a, and the length from the central portion 35 to the one end portion 36 is a second arm length b. a and b are positive real numbers.

The auxiliary arm 33 has one end 38 rotatably connected to the mold 28 and is connected to the mold 28.
The other end portion 39 is rotatable with respect to the support column 34 and the support column 3
4 is connected. The auxiliary arm 33 is always parallel to at least one end portion 36 to the central portion 35 of the drive arm 32 and is angularly displaceable about the other end portion 39. As a result, when the rod 27c of the hydraulic cylinder 27 extends, the mold 28 is displaced downward and the rod 27c
Is contracted, the mold 28 is displaced upward.

FIG. 4 is a block diagram showing the compensator 24 in the mold vibration device 20. The compensator 24 includes a gain device 40, a control gain device 41, and a calculator 42.

The gain unit 40 multiplies the target command value xref from the signal generator 23 by the gain Ka, and the value Ka
The xref is given to the calculator 42. The control gain device 41 is
Estimated state quantity xc of the controlled object 22 from the state observer 25
Is multiplied by the control gain Fd, and the value Fd xc is given to the calculator 42. The calculator 42 uses the value Ka xref from the gain unit 40 to calculate the value Fd x from the control gain unit 41.
The deviation obtained by subtracting c is output as the servo command value vc.

The hydraulic cylinder 27 is a cylinder tube 2
7a includes a rod 27 on one end face of a piston 27b.
Since c is a single-sided rod-type double-acting cylinder standing upright, the pressure receiving area of one end face of the piston 27b is different from the pressure receiving area of the other end face. Therefore, even if the same amount of hydraulic oil is supplied to the inner space facing one end surface of the piston 27b of the cylinder tube 27a and the inner space facing the other end surface thereof, the rod 27c
The expansion speed and the degeneration speed are different.

As described above, the hydraulic cylinder 27, which is a single-sided rod double-acting cylinder, has different dynamic characteristics when the rod 27c extends and when the rod 27c retracts. That is, the rod 27c of the hydraulic cylinder 27 extends and the mold 2
8 is a one-way unidirectional displacement, and rod 2
The dynamic characteristic of the controlled object 22 is different from the second motion in which the mold 28 is contracted and the mold 28 is displaced upward in the other direction.

The procedure for determining the control gain Fd of the control gain unit 41 in the compensator 24 for controlling the controlled object 22 having different dynamic characteristics by such an operation will be described below.

First, first and second state equations of the controlled object 22 in the first operation and the second operation are constructed. The state quantity of the controlled object 22 is xc, the command value to the servo valve 26 output from the compensator 24 is vc, the drive arm 32 is modeled as an elastic body, and the elasticity of the auxiliary arm 33 is modeled to simplify the calculation. Ignore, that is, the auxiliary arm 33 is modeled as a rigid body, and the controlled object 2 in the first motion is
The first state equation of No. 2 is represented by equation (1), and the second state equation of the controlled object 22 in the second operation is represented by equation (2).

[0043]

[Equation 1]

In the above equation (1), Ac1 is the system matrix of the controlled object 22 in the first operation, and Bc1 is the control matrix. In the above equation (2), Ac2 is the system matrix of the controlled object 22 in the second operation, and Bc2 is the control matrix. D / on the right side of equations (1) and (2)
dt is a differential operator with respect to time t.

Next, the control gain Fd, which is the first control gain used for the correction during the first operation, is determined based on the first state equation (1). Here, the evaluation function Jc is represented by the following expression (3).

[0046]

[Equation 2]

In the above equation (3), Qc is a non-negative definite target matrix, rc is a positive definite target matrix, and these matrices Qc and rc are weighting matrices of the evaluation function Jc. The superscript T represents the transpose of the matrix.

The optimum gain that minimizes the evaluation function Jc represented by the above equation (3) is obtained. This optimum gain is the control gain Fd in the first operation. At this time, the Riccati equation is expressed by the following equation (4). Ac1 ^T P + P Ac1 + Qc-P Bc1 rc- ¹ Bc1 ^T P = 0 (4)

The control gain Fd is represented by the following equation (5) using the solution P of the above equation (4). Fd = −r ⁻¹ Bc1 ^T P (5)

When the control device 21 is a digital control device, the first and second control targets 22 are controlled.
The control gain Fd is determined by discretizing the state equation (1) and the equation (2) and obtaining the optimum gain in the first operation of the discretized controlled object 22. Specifically, when the state quantity of the controlled object 22 is xd, the command value to the servo valve 26 output from the compensator 24 is vd, and the hold method is discretized as the 0th-order hold, the discretized first object of the controlled object 22 is The first and second equations of state are represented by the following equations (6) and (7). xd [i + 1] = Ad1 xd [i] + Bd1 vd [i] (6) xd [i + 1] = Ad2 xd [i] + Bd2 vd [i] (7)

In the above equation (6), Ad1 is the system matrix of the controlled object 22 in the first operation, and Bd1 is the control matrix. In the above equation (7), Ad2 is the system matrix of the controlled object 22 in the second operation, and Bd2 is the control matrix. Further, i is an integer of 0 or more. These matrices Ad1, Bd1, Ad2, Bd2 are obtained by the following equations (8) to (11).

[0052]

[Equation 3]

In the above equations (8) to (11), Td
Is the cycle of digital operation. Next, based on the first state equation (6), the first control gain used for the correction during the first operation is determined. Here, the evaluation function Jd is expressed by the following equation (12).
It is represented by.

[0054]

[Equation 4]

In the above equation (12), Q is a non-negative definite target matrix, r is a positive definite target matrix, and these matrices Q and r are weighting matrices of the evaluation function Jd.

The optimum gain that minimizes the evaluation function Jd represented by the above equation (12) is obtained. This optimum gain is
It is the control gain Fd in the operation. At this time, the Riccati equation is expressed by the following equation (13). P = Q + Ad ^T P Ad-Ad ^T P Bd (r + Bd ^T P Bd) ^-1 Bd ^T P Ad (13)

The control gain Fd is expressed by the following equation (14) using the solution P of the above equation (13). Fd =-(r + Bd ^T P Bd) ^-1 Bd ^T P Ad (14)

Weighting matrix Q of the above-mentioned evaluation functions Jc and Jd
Regarding c and Q, in order to control the position of the mold 28, the diagonal elements of the weight matrices Qc and Q with respect to the mold displacement xm are set to 1 and the other elements are set to 0. Hereinafter, the weighting matrices Qc and Q are collectively referred to as Q. It is assumed that the state quantity xc of the controlled object 22 is expressed by the following equation (15).

[0059]

[Equation 5]

In the above equation (15), as is the servo valve 2
6 is the valve opening degree which is the opening degree of the valve of No. 6. In this case, the weight matrix Q is expressed by the following equation (16).

[0061]

[Equation 6]

In the above equation (16), the mold speed dx
By adjusting the diagonal element β regarding m / dt while observing the response, unnecessary vibration of the mold 28 can be suppressed. Further, the state quantity of the controlled object 22 is calculated by the following equation (1
Let xch represented by 7).

[0063]

[Equation 7]

In the above equation (17), xh is the amount of strain. Assuming that the drive arm 32 is a rigid body that does not bend, when the rod 27c of the hydraulic cylinder 27 is displaced by xs, the mold 28 is displaced by xm. Therefore, the relationship between the cylinder displacement xs and the mold displacement xm is The ratio of xs to the mold displacement xm is equal to the ratio of the first length a and the second length b of the drive arm 32, and is expressed by the following equation (18). a xm = -b xs (18)

In the above equation (18), the cylinder displacement xs
Is positive in the direction in which the rod 27c extends, and the mold displacement xm is positive in the direction in which the mold 28 is directed upward.

Since the drive arm 32 is an elastic body, it may bend, and the bend may not satisfy the equal sign of the equation (18). Therefore, the arm ratio Ga based on the ratio of the first and second arm lengths a and b expressed by the following equation (19)
The strain amount xh is defined by the following equation (20) using Ga = -b / a (19) xh = xm-Ga xs (20)

Further, the state quantity of the controlled object 22 is calculated by the equation (17)
When the state quantity xch represented by
The state quantity xc represented by the equation (15) is converted by the equation (1) and the first and second state equations (1) and (2) of the controlled object 22 are transformed by similarity.

[0068]

[Equation 8]

When the state quantity is xch, the weight matrix Q
Is expressed by the following equation (22).

[Equation 9]

In the above equation (22), the strain rate dx
By adjusting the diagonal element γ regarding h / dt while observing the response, it is possible to suppress unnecessary vibration of the mold 28 due to the bending of the drive arm 32 due to the elasticity.

Further, the weighting matrix rc of the evaluation functions Jc and Jd,
For r, the weighting matrices rc, r are adjusted so that the response has the desired responsiveness.

When the control gain Fd in the first operation is determined in this way, subsequently, the pole in the closed loop control system including the control device 21 and the controlled object 22 is obtained. In the closed loop control system including the control device 21 and the controlled object 22 in the first operation, the control gain unit 41 multiplies the estimated state quantity xc by the control gain Fd to obtain the target command value x.
State feedback in which ref is 0, that is, the servo command value vc = -Fd calculated by the calculator 42
Since it is considered that xc is input to the controlled object 22 to perform control, the state equation of the closed loop control system including the control device 21 and the controlled object 22 in the first operation is represented by the following expression (23).

[0073]

[Equation 10]

The matrix (Ac1-Bc) in the above equation (23)
The eigenvalue of 1 Fd) is the pole of the closed loop control system including the control device 21 and the controlled object 22 in the first operation to be obtained.

Subsequently, the pole of the closed loop control system including the control device 21 and the controlled object 22 in the second operation is the closed loop control system including the control device 21 and the controlled object 22 in the first operation obtained as described above. The control gain Fd of the compensator 24 of the control device 21 in the second operation is determined so that the pole arrangement is the same as the pole arrangement of the.

The compensator 24 controls the control target 22 during the first operation.
Control is performed using the control gain Fd in the first operation, and the control target 22 in the second operation is controlled using the control gain Fd in the second operation.

According to the mold vibrating device 20 of the present embodiment, the state quantities of the mold 28 such as displacement, speed and acceleration, and the state quantities of the hydraulic cylinder 27 such as operating speed, operating acceleration and pressure are calculated. The state observer 25 estimates the state quantity equal to the actual state quantity of the mold 28 and the hydraulic cylinder 27 based on the servo command value vc and the cylinder displacement xs of the hydraulic cylinder 27 without detecting, and estimates the state quantity. A correction waveform that reduces the influence of the natural frequency of the controlled object 22 including the mold 28 and the hydraulic cylinder 27 by performing the optimum control of correcting the servo command value vc given to the servo valve 26 based on the state quantity xc. , The influence of the natural frequency is eliminated, and the mold 28
Can be made to vibrate as desired.

Further, since it is not necessary to detect state quantities such as displacement, speed and acceleration of the mold 28, the mold 2 which is a severe environment for the detector, such as high temperature and high humidity.
It is not necessary to install a detector for detecting the state quantity of the mold 28 or a mechanism for installing the detector in the vicinity of 8. Further, regarding the hydraulic cylinder 27, a detector for detecting a state quantity other than the cylinder displacement xs, for example, the operating speed and the operating acceleration of the hydraulic cylinder 27 is not required, and means for reducing the influence of noise on the detection by such a detector. Therefore, the mold vibration device 20 can have a simple structure.

The mold vibrating device 20 of this embodiment is also used.
According to the above, even if the dynamic characteristics of the hydraulic cylinder 27 differ between the first operation and the second operation, the dynamic characteristics of the hydraulic cylinder 27 are controlled by controlling using the control gain Fd according to the respective dynamic characteristics. Target command value x caused by
The distortion of the waveform of the mold displacement xm with respect to the waveform of ref can be reduced as much as possible, and the mold 28 can be made to vibrate as desired.

In the mold vibration device 20 of the present embodiment, the estimated state quantity xc is the state quantity shown in the equation (15), but the state quantity is not limited to this, and various state quantities in the controlled object 22 may be used. .

Further, the mold vibrating device 20 of the present embodiment.
At the compensator 24 of the controller 21 in the first operation
Although the control gain Fd in the second operation is determined after determining the control gain Fd in (1), even if the control gain Fd in the second operation is determined first and then the control gain Fd in the first operation is determined. Good.

FIG. 5 is a block diagram showing a compensator 24A of the mold vibration device 20A according to the second embodiment of the present invention. The mold vibrating device 20A according to the present embodiment is shown in FIG.
Further, except for the compensator 24 of the mold vibration device 20 of the first embodiment shown in FIG. 2 and the mold vibration device 20 of the first embodiment, the configuration is the same as that of the mold vibration device 20 of the first embodiment. For the mold vibration device 20A, the compensator 2
Descriptions other than 4A are omitted. The compensator 24A of the mold vibration device 20A of the present embodiment is configured to include a gain device 40A, a control gain device 41A, a calculator 42A, and a conversion calculator 43.

The gain device 40A multiplies the target command value xref from the signal generator 23 by the gain Ka, and outputs the value Ka.
xref is given to the calculator 42A. Conversion calculator 43
Is the estimated state quantity x of the controlled object 22 from the state observer 25.
A predetermined calculation is performed on c, and a feedback state quantity xct obtained by performing a similarity transformation on the estimated state quantity xc is given to the calculator 42. The control gain unit 41A multiplies the feedback state quantity xct from the conversion computing unit 43 by the control gain Fd,
The value Fd xct is given to the calculator 42. Calculator 42
A outputs a deviation obtained by subtracting the feedback state quantity xc from the control gain unit 41 from the value Ka xref from the gain unit 40A as a servo command value vc.

The conversion calculator 43 calculates the estimated state quantity xc from the state observer 25 on the basis of the mold displacement xm and the cylinder displacement xs contained in the estimated state quantity xc. The strain amount xh represented by the same equation (24) is obtained, conversion is further performed to differentiate the strain amount xh with respect to time, and the feedback state amount xct represented by the equation (25) is given to the calculator 42. xh =
xm-Ga xs
…(twenty four)

[0085]

[Equation 11]

In the present embodiment, the control gain device 41
The control gain Fd of A is expressed by the following equation (26). Fd = [f1 f2 f3] (26)

At this time, the transfer function from the target command value xref to the mold displacement xm, that is, the transfer function Xm / Xref of the system including the control device 21 and the controlled object 22 is set to 3
If it is a transfer function of a second-delay system, it is expressed by the following equation (27).

[0088]

[Equation 12]

In the above equation (27), s is a Laplace operator, Xm is a Laplace transform of the mold displacement xm, Xref is a Laplace transform of the target command value xref, and c1 to c10 and Cb0. Is a coefficient.

A constant α, which is a unique physical quantity indicating the characteristics of the system including the control device 21 and the controlled object 22, and a natural frequency ω.
The transfer function of the third-order lag system based on n and the damping coefficient ζ is generally expressed by the following equation (28).

[0091]

[Equation 13]

The constant α is a real number pole s = −α existing on the real axis when the pole of the transfer function represented by the above equation (28) is represented on the complex plane, and the equation (28) It is the reciprocal of the time constant, which is one of the physical quantities peculiar to the transfer function system.

The elements f1, f2 and f3 of the control gain Fd obtained by comparing the coefficients of the equations (27) and (28) are shown in the following equations (29) to (31).

[0094]

[Equation 14] In Expressions (29) to (31), k1 to k13 are coefficients.

FIG. 6 is a pole arrangement diagram showing the arrangement of poles when only the constant α is changed, and FIG. 7 is a natural frequency ωn.
FIG. 9 is a pole arrangement diagram showing the arrangement of the poles when only the change is made, and FIG. 8 is a pole arrangement diagram showing the arrangement of the poles when only the damping coefficient ζ is changed. 6 to 8, the horizontal axis is the real axis representing the value of the real part of the pole, and the vertical axis is the imaginary axis representing the imaginary part of the pole.

From the relationship of the equation (28), when the natural frequency ωn and the damping coefficient ζ are fixed and the constant α is changed, the transfer function Xm of the system including the control device 21 and the controlled object 22 is changed.
/ Xref changes as shown in FIG. The constant α
When the damping coefficient ζ is fixed and the natural frequency ωn is changed, the transfer function Xm / Xref changes as shown in FIG. 7. Similarly, when the constant α and the natural frequency ωn are fixed and the damping coefficient ζ is changed, the transfer function Xm / Xre
f changes as shown in FIG.

As described above, one of the constant α, the natural frequency ωn, and the damping coefficient ζ is changed, and the other is fixed, and the pole, which is the characteristic of the system including the control device 21 and the controlled object 22, is set to the desired value. Arrange so that it has characteristics. When the arrangement of the poles is determined, the constant α, the natural frequency ωn, and the damping coefficient ζ at that time are substituted into the equations (29) to (30) to determine the elements f1, f2, and f3 of the control gain Fd. Then, the optimum control gain Fd for the system including the control device 21 and the controlled object 22 is determined by this.

According to the mold vibration device 20A of the present embodiment, the state quantities of the mold 28 such as displacement, speed and acceleration, and the state quantities of the hydraulic cylinder 27 such as operating speed, operating acceleration and pressure are determined. The state observer 25 estimates the state quantity equal to the actual state quantity of the mold 28 and the hydraulic cylinder 27 based on the servo command value vc and the cylinder displacement xs of the hydraulic cylinder 27 without detecting, and estimates the state quantity. By performing the optimum control of correcting the servo command value vc given to the servo valve 26 based on the state quantity xc, the mold 28
The effect of the natural frequency is eliminated without giving a command having a correction waveform for reducing the effect of the natural frequency of the controlled object 22 including the hydraulic cylinder 27 and the mold 2
8 can be made to vibrate as desired.

Further, since it is not necessary to detect the state quantities such as displacement, speed and acceleration of the mold 28, the mold 2 which is a severe environment for the detector such as high temperature and high humidity.
It is not necessary to install a detector for detecting the state quantity of the mold 28 or a mechanism for installing the detector in the vicinity of 8. Further, regarding the hydraulic cylinder 27, a detector for detecting a state quantity other than the cylinder displacement xs, for example, the operating speed and the operating acceleration of the hydraulic cylinder 27 is not required, and means for reducing the influence of noise on the detection by such a detector. Therefore, the mold vibration device 20 can have a simple structure.

Further, the mold vibrating device 20 of the present embodiment.
According to A, each physical quantity is adjusted without directly adjusting the control gain Fd from the relationship between the control gain Fd and the physical quantity representing the characteristics of the control system such as the constant α, the natural frequency ωn, and the damping coefficient ζ. As a result, the control gain Fd is automatically determined. Therefore, by independently adjusting an arbitrary physical quantity among the plurality of physical quantities, the plurality of physical quantities do not affect each other, and the control gain Fd does not affect each other.
Can be easily determined.

In the mold vibration device 20A of the present embodiment, the feedback state quantity xct is the state quantity shown in the equation (25), but the state quantity is not limited to this, and various state quantities in the controlled object 22 may be used. . Further, the conversion calculator 43 may perform a calculation to convert the estimated state quantity xc from the state observer 25 into an arbitrary feedback state quantity xct.

Further, the mold vibrating device 20 of the present embodiment.
In A, the transfer function Xm / Xref of the system including the control device 21 and the controlled object 22 is a third-order delay system as shown in Expression (27), but is not limited to the third-order delay system,
For example, a second-order lag system and a sixth-order lag system, such as a first-order or higher order, may be used.

FIG. 9 is a flow chart showing a procedure for detecting an abnormality and stopping the hydraulic cylinder 27 in the mold vibrating device 20, 20A. The procedure starts at step s0 and proceeds to step s1. In step s1, the state observer 25 estimates the state quantity of the control target 22 including the mold displacement xm and the cylinder displacement xs based on the cylinder displacement xs and the servo command value vc, and the step s
Go to 2.

At step s2, the compensators 24 and 24A are
Monitors the mold displacement xm and the cylinder displacement xs,
Go to step s3. In step s3, the compensator 24,
24A calculates the strain amount xh from the mold displacement xm and the cylinder displacement xs based on the equation (19), and proceeds to step s4.

At step s4, the compensators 24 and 24A are
Determines whether the strain amount xh calculated in step s3 is equal to or greater than a predetermined threshold value emax. In step s4, the strain amount xh is the threshold value e
is greater than or equal to max, that is, the mold vibration device 20, 2
When it is judged that some abnormality has occurred at 0A,
Go to step s5. In step s5, the compensator 24,
24A performs an emergency stop process for stopping the operation of the hydraulic cylinder 27, proceeds to step s6, and ends all the procedures. The threshold value emax is set based on the elastic range in which the drive arm 32 bends due to elasticity.

When it is determined in step s4 that the strain amount xh is less than the threshold value emax, that is, no abnormality has occurred in the mold vibrating devices 20 and 20A, the process returns to step s1.

Mold vibrating devices 20, 2 of the present embodiment
According to 0A, the mold cylinder 28 is overloaded due to an abnormal load on the mold 28 due to some factors, and the mold displacement x estimated by the state observing device 25 is estimated.
The mold vibrating device 20 such as when the compensator 24 or 24A oscillates due to a change in a parameter in the system including the control device 21 and the controlled object 22 or when the stroke sensor 29 fails, when m is actually different from the actual displacement. , 20A, the difference between the cylinder displacement xs and the estimated mold displacement xm is monitored to determine whether or not the strain amount xh based on these displacements xm and xs is equal to or greater than a predetermined threshold value emax. By doing so, it is possible to detect early and with high accuracy. Thus, for example, when an abnormality is detected, the mold vibration apparatuses 20 and 20A are controlled so as not to be damaged, for example, the hydraulic cylinder 27 is stopped, so that the mold vibration apparatuses 20 and 20A caused by the abnormality are controlled. It can prevent damage.

Mold vibrating devices 20, 2 of this embodiment
Regarding the threshold value emax at 0 A, for example, a strain amount when the mold vibration device 20 is normally operating is obtained, and this strain amount is set as a reference strain amount, and the reference strain amount is increased by 5% and 10%. It is assumed that the increased value is obtained as the threshold value emax, but it is not limited to this.

Further, the mold vibrating device 2 of the present embodiment
In 0 and 20A, when the abnormality is detected, the control for stopping the hydraulic cylinder 27 is performed. However, the control is not limited to this, for example, the control for preventing the damage of the mold vibration device 20, 20A, for example, without stopping the hydraulic cylinder 27. You may make it control to change the frequency which oscillates the mold 28, and control to prevent the compensator 24, 24A from transmitting.

FIG. 10 is a diagram showing the waveform f (t) of the signal having the target command value xref generated by the signal generator 23. The waveform f (t) is a non-sinusoidal waveform in which sine waves having different frequencies are continuous according to the phase θ. More specifically, when the phase θ is π / 2 or more and less than 3π / 2, the frequency is ω2, and in the other phases θ, the frequency is ω1.
And is represented by the following equation (32).

[0111]

[Equation 15]

When the control device 21 is a digital control device, when the mold vibrating device 20 is continuously operated for the time t, the phase θ = ωt exceeds the input range of the sine function. There is. Therefore, the following equation (3
As shown in 3), the phase θ in one cycle of digital operation
The addition values dθ ₁ and dθ ₂ are calculated, and the addition values dθ ₁ and dθ ₂
Is added for each calculation, and the value of the phase θ _n is reset every 2π, so that overflow exceeding the input range of the sine function can be avoided.

[0113]

[Equation 16]

Mold vibrating devices 20, 2 of the present embodiment
According to 0A, in order to generate a desired non-sinusoidal waveform, it suffices to change the frequencies ω1 and ω2 in the equation (32), which is compared with the method of superimposing a plurality of sine waves to generate a non-sinusoidal wave. Therefore, it can be generated with an extremely small amount of calculation.

In the control method in which the correction waveform is input in order to reduce the influence of the natural frequency of the controlled object, the equation (3
Although the signal of the waveform f (t) as shown in 2) and the equation (33) cannot be used, in the mold vibration device 20 or 20A of the present invention, the optimum control for estimating the state quantity of the control target 22 is performed. Since the influence of the natural frequency of the controlled object is reduced without inputting the correction waveform as described above, the waveform f as shown in the equations (32) and (33) is obtained.
The signal of (t) can be used.

In the mold vibrating devices 20 and 20A of the first and second embodiments described above, the hydraulic cylinder 27 is used.
Is a single-sided rod-type double-acting cylinder, but it may be a double-sided rod-type double-acting cylinder.

[0117]

According to the present invention as set forth in claim 1, state quantities such as displacement, velocity and acceleration of the mold,
And a state equal to the actual state quantity of the mold and the actuator based on the operation instruction and the operating position of the actuator by the correction instruction means without detecting the state quantity of the actuator such as the operating speed, the operating acceleration and the pressure. A correction waveform that reduces the influence of the natural frequency of the control target including the mold and the actuator by estimating the amount and performing the optimal control of correcting the operation command given to the valve means based on this estimated state amount. It is possible to eliminate the influence of the natural frequency and to cause the mold to perform a desired vibration without giving a command having “.

Further, since it is not necessary to detect state quantities such as mold displacement, velocity, and acceleration, it is possible to detect the state quantities of the mold in the vicinity of the mold, which is a severe environment for the detector, such as high temperature and high humidity. There is no need to install a detector or a mechanism for installing a detector. Further, regarding the actuator, it is not necessary to provide a detector for detecting a state quantity other than the operating position, for example, the operating speed and the operating acceleration of the actuator, and it is not necessary to provide means for reducing the influence of noise on the detection by such a detector. The device can have a simple structure.

According to the second aspect of the present invention, the valve driving means includes the mold and the actuator based on the dynamic characteristics of the actuator in the first operation for displacing the mold in one of the one direction and the other direction. The first linear equation of state of the controlled object is constructed, and
A linearized second equation of state of the controlled object is constructed based on the dynamic characteristics of the actuator in the second operation of displacing the mold in one direction and the other direction.
A first control gain used for correction during the first operation is determined based on the first state equation, and the pole arrangement of the control system configured by the controlled object and the valve driving means during the first and second operations is the same. Since the second control gain used for the correction during the second operation is determined so as to be as follows, even if the dynamic characteristics of the actuator are different between the first operation and the second operation, the second control gain is adjusted according to the respective dynamic characteristics. By controlling using the gain, the distortion of the mold vibration waveform with respect to the mold position command waveform caused by the actuator dynamic characteristics can be reduced as much as possible, and the mold can be made to vibrate as desired. it can.

According to the third aspect of the present invention, from the relationship between the physical quantity representing the characteristics of the control system and the control gain, the physical quantity is adjusted without directly adjusting the control gain, and the control is automatically performed. Since the gain is determined, the control gain can be easily determined by independently adjusting an arbitrary physical quantity of the plurality of physical quantities without the plurality of physical quantities affecting each other.

According to the fourth aspect of the present invention, by monitoring the difference between the estimated mold displacement and the detected actuator displacement, it is possible to detect an abnormality in the mold vibrating device early and with high accuracy. . Thus, for example, when an abnormality is detected, by performing control such that the mold vibrating device is not damaged, for example, stopping the actuator, it is possible to prevent the mold vibrating device from being damaged due to the abnormality.

According to the fifth aspect of the present invention, the valve driving means includes a command generating means for giving a mold position command with a non-sinusoidal waveform in which sinusoidal waves having different frequencies are continuous according to the phase. Since the operation command based on the position command is given, it can be generated with an extremely small amount of calculation compared with the method of generating a non-sinusoidal wave by superimposing a plurality of sinusoidal waves in order to generate a desired non-sinusoidal waveform. it can.

[Brief description of drawings]

FIG. 1 is a control block diagram showing a mold vibrating device 20 of a continuous casting facility according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically showing a configuration of a mold vibrating device 20 of a continuous casting facility.

FIG. 3 is a sectional view schematically showing a continuous casting facility 80.

FIG. 4 is a block diagram showing a compensator 24 in the mold vibration device 20.

FIG. 5 is a block diagram showing a compensator 24A of a mold vibrating device 20A according to a second embodiment of the present invention.

FIG. 6 is a pole arrangement diagram showing the arrangement of poles when only the constant α is changed.

FIG. 7 is a pole arrangement diagram showing the arrangement of poles when only the natural frequency ωn is changed.

FIG. 8 is a pole arrangement diagram showing the arrangement of poles when only the damping coefficient ζ is changed.

FIG. 9 is a flowchart showing a procedure of detecting an abnormality and stopping the hydraulic cylinder 27 in the mold vibration device 20, 20A.

FIG. 10 is a target command value xr generated by the signal generator 23.
It is a figure which shows the waveform f (t) of the signal which has ef.

FIG. 11 is a block diagram showing a continuous casting machine 0 using the mold oscillation method in the continuous casting machine, which is disclosed in JP-A-63-63562.

[Explanation of symbols]

20 Mold vibration device 21 Control device 22 Control target 23 signal generator 24 Compensator 25 State Observer 26 Servo valve 27 hydraulic cylinder 28 Mold 29 Stroke sensor 41 Control gain device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Setsuo Tachibana             59, 46 Nakahara, Tobata-ku, Kitakyushu, Fukuoka               Engineering Nippon Steel Co., Ltd.             Within the business headquarters (72) Hiromi Hara, Inventor             59, 46 Nakahara, Tobata-ku, Kitakyushu, Fukuoka               Engineering Nippon Steel Co., Ltd.             Within the business headquarters (72) Inventor Yasuaki Miura             59, 46 Nakahara, Tobata-ku, Kitakyushu, Fukuoka               Engineering Nippon Steel Co., Ltd.             Within the business headquarters (72) Inventor, Shoman Yonei             59, 46 Nakahara, Tobata-ku, Kitakyushu, Fukuoka               Nittetsu Plant Design Co., Ltd. (72) Inventor Hiroaki Fujimoto             1-1 Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries             Akashi Factory Co., Ltd. (72) Inventor Tomoyuki Uno             1-1 Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries             Akashi Factory Co., Ltd. (72) Inventor Takehisa Kato             234 Matsumoto, Higashi-cho, Nishi-ku, Kobe-shi, Hyogo             Saki Heavy Industry Co., Ltd. Nishi-Kobe factory (72) Inventor Keita Morikawa             234 Matsumoto, Higashi-cho, Nishi-ku, Kobe-shi, Hyogo             Saki Heavy Industry Co., Ltd. Nishi-Kobe factory (72) Inventor Koji Sato             234 Matsumoto, Higashi-cho, Nishi-ku, Kobe-shi, Hyogo             Saki Heavy Industry Co., Ltd. Nishi-Kobe factory F-term (reference) 4E004 AD05 MA02

Claims (5)

[Claims] 1. An apparatus for vibrating a mold of a continuous casting facility for pouring molten metal into a mold to continuously cast a profile, the actuator for reciprocally displacing the mold in one direction and the other direction. A valve means for controlling the supply of the working fluid to the actuator; a valve drive means for giving an operation command to the valve means; a position detection means for detecting the operation position of the actuator; and an operation position and a valve drive means by the position detection means. Based on the operation command by, the state quantity representing the state of the mold and the actuator is estimated, and based on this estimated state quantity,
A mold vibrating device for continuous casting equipment, comprising: a correction command means for giving a correction command for correcting an operation command. 2. The valve drive means is a linearized first state of a controlled object including the mold and the actuator, based on a dynamic characteristic of the actuator in a first operation for displacing the mold in one of the one direction and the other direction. The equation is constructed, and the linearized second state equation of the controlled object is constructed based on the dynamic characteristics of the actuator in the second operation for displacing the mold in one direction and the other direction, and the first state Based on the equation, the first control gain used for the correction in the first operation is determined, and the pole arrangement of the control system constituted by the controlled object and the valve driving means in the first and second operations is the same. The mold vibrating device for continuous casting equipment according to claim 1, wherein a second control gain used for correction during the second operation is determined. 3. The control gain is automatically determined by adjusting each physical quantity without directly adjusting the control gain from the relationship between the physical quantity representing the characteristic of the control system and the control gain. The mold vibrating device for continuous casting equipment according to claim 1. 4. The correction command means estimates the mold displacement, and the valve drive means monitors the difference between the estimated mold displacement and the actuator displacement to detect an abnormality of the apparatus. The mold vibrating device of the continuous casting equipment according to any one of 1 to 3. 5. The valve drive means includes a command generation means for giving a mold position command with a non-sinusoidal waveform in which sine waves having different frequencies depending on the phase are continuous, and the valve drive means gives an operation command based on the position command by the command generation means. The mold vibrating device for continuous casting equipment according to any one of claims 1 to 4.