JP2000094020A - Device for controlling shape of rolling mill and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape controller for rolling mills with which the presence of abnormality in rolling conditions is judged and a sheet shape is controlled using appropriate influence coefficient and its control method. SOLUTION: In a rolling mill provided with actuators for controlling the shape and a shape detecting sensor, a 1st means 20 for detecting the control results Δx of the actuators, 2nd means 21 for detecting the change Δf in the shape based on the sensor, 3rd means 22 for determining the influence coefficient Δα=Δf/Δx using the control results Δx and influence coefficient Δf, 4th means 23 in which the normal influence coefficient Δαs is preserved, 5th means 24 by which the influence coefficient Δα in the 3rd means 22 and the influence coefficient Δαs in the 4th means 23 are compared, 6th means 25 for judging the presence of abnormality in the rolling conditions based on the result of the 5th means 24 and 7th means 26 for selecting the influence coefficient Δαa to be used for shape control based on the judgement in the 6th means 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for controlling the shape of a rolling mill.

[0002]

2. Description of the Related Art As this kind of shape control device and method,
For example, Japanese Patent Publication No. 7-106377 and Japanese Patent Publication No. 7-1
No. 06378 is known. This conventional device includes m plate shape control actuators and n plate shape detection sensors, and sets the operation amount of each actuator to Δx _j (j = 1 to an integer of m). When the detection amount of the sensor is Δf _i (i = 1 to an integer of n),

[0003]

(Equation 1)

[0004] The alpha _ij expressed as, as the influence coefficient of the Delta] f _i of [Delta] x _j, has been used in a plate shape control. That is, the plate shape control using the influence coefficient converts the relationship between the movement amount of one shape control actuator and the shape change amount (multipoint data in the rolled material width direction) based on the movement amount into a coefficient (influence coefficient). This is a control method that determines the amount of movement of the actuator for shape control so that the shape is optimized using (effect coefficient).

[0005] In the plate shape control using the above-mentioned influence coefficient, the rolling conditions are different depending on the rolled material, mill, speed, load, method of using a rolling mill, and the like. Should be controlled. However, it is actually impossible to collect the influence coefficient under each rolling condition, because the changes in the rolling conditions are various.

Therefore, in the case of rolling conditions that do not significantly change the tendency of the influence coefficient from the viewpoint of the influence coefficient, it is not determined that the rolling conditions are different, and the same influence coefficient is used to increase the magnitude of the influence coefficient. The gain is applied to make it correspond. In the case where there is a change in the rolling situation where the change in the influence coefficient is determined to be large, the actual control of various parameters uses an influence coefficient model arranged according to the rolling conditions inside the computer. Therefore, for the change of the rolling condition of the large change, know in advance what the current rolling conditions are,
It was necessary to use and control an influence coefficient suitable for the condition.

[0007]

However, in the case of rolling conditions, such as a roll kiss of a rolling roll, in which it is difficult to grasp the state, it is difficult to appropriately change the parameters. That is, in the state where the roll kiss is not generated, the rolling load is received by the rolled material, but in the state where the roll kiss is generated, the rolling load is partially received by the roll portion. There is a difference in load distribution. Therefore, the influence coefficient used for the control must be different between the two. Nevertheless, if control is performed using the same influence coefficient model without knowing this state, appropriate control cannot be performed.

Accordingly, the present invention provides a shape control device for a rolling mill and a control method therefor, in which the presence or absence of abnormal rolling conditions is determined and the plate shape is controlled using an appropriate influence coefficient. Aim.

[0009]

In order to achieve the above object, the present invention takes the following measures. That is, a feature of the present invention is that, in a shape control device of a rolling mill including a shape control actuator and a shape detection sensor, a first means for detecting a control result Δx of the actuator and a sensor based on the sensor A second means for detecting the shape change Δf, a third means for calculating the influence coefficient Δα = Δf / Δx using the control result Δx and the shape change Δf, and a fourth means for storing the reference influence coefficient Δα _s means a fifth means for comparing the influence coefficient [Delta] [alpha] _s of the influence coefficient [Delta] [alpha] and the fourth means of the third means, based on the results of the fifth means, sixth means for determining the presence or absence of roll Kiss, And _a seventh means for selecting an influence coefficient Δα _a to be used for shape control based on the judgment of the sixth means.

The reference influence coefficient Δα _s is an influence coefficient Δα _r when no roll kiss occurs and an influence coefficient Δα _k when a roll kiss occurs,
The fourth means stores either one or both. Eighth means for causing the first, second, and third means to be performed under special conditions may be provided.

A ninth means for judging whether or not to perform the operation of the fifth, sixth and seventh means can be provided. In the shape control method for a rolling mill including the shape control actuator of the present invention and a shape detection sensor, a control result Δx of the actuator is obtained, a shape change Δf based on the sensor is obtained, and the control result Δx and the shape are obtained. Using the change Δf, an influence coefficient Δα = Δf / Δx is obtained, and the obtained influence coefficient Δα is compared with an influence coefficient Δα _{s serving} as a preset reference to determine the presence or absence of a roll kiss. since selecting the influence coefficient [Delta] [alpha] _a to be used for shape control, can select the appropriate impact coefficient, it is appropriate flatness control.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 2 and 3 show an outline of a shape control device of a multi-high rolling mill. The rolling mill includes a pair of upper and lower work rolls 2 that are in contact with a rolled material 1, and a first roll disposed behind the work rolls. Intermediate roll 3 and the first roll
A second intermediate roll 4 disposed behind the intermediate roll 3,
This is a 20-high rolling mill having a backup roll 5 disposed behind the second intermediate roll 4.

The 20-high rolling mill is provided with m plate shape control actuators 6 to 13. That is, the backup roll 5 is divided in the axial direction, and each of the divided backup rolls 5 is provided with first to fourth crown actuators 6, 7, 8, 9 for giving a roll crown. Have been. The first intermediate roll 3 has a taper and is movable in the axial direction, and is provided with tapered roll moving actuators 10 and 11 for moving the first intermediate roll 3 in the axial direction. I have. Further, a work-side tilt pressure lowering actuator 12 and a drive-side tilt actuator 13 are provided for individually pressing the left and right roll housings. That is, in this embodiment, m = 8 actuators 6 to 13 are provided.

A plate detection sensor 14 for detecting the elongation (plate shape) of the rolled material 1 in the rolling direction is provided at a position slightly downstream from the 20-high rolling mill. The n sensors 14 are provided along the width direction of the rolled material 1. Upstream side of the 20-high rolling mill and the plate detection sensor
A thickness gauge that detects the thickness of the inlet side and the thickness of the outlet side downstream of 14.
15,16 are arranged.

On the basis of the detection results obtained by the thickness gauges 15 and 16, a thickness control device 17 for controlling the thickness of the rolled material 1 by outputting an operation amount as a control signal to the tilt-down actuators 12 and 13 is provided. Have been. Further, based on the detection result by the plate shape detection sensor 14, the crown actuators 6, 7, 8, 9
A plate shape control device 18 is provided which outputs the operation amounts to the actuators 10 and 11 and the tilt-down actuators 12 and 13 as control signals and controls the plate shape of the rolled material 1.

The sheet thickness control device 17 includes detection signals a and b from the thickness gauges 15 and 16 and a preset target output side sheet thickness signal c.
Based on the above, the operation amount is calculated by the normal feed-forward type thickness control or the feedback type thickness control, and the control amount d is output. This control signal d is transmitted to the plate shape control device.
The thickness change caused by changing the operation amount of the roll crown actuators 6, 7, 8, 9 and the taper roll movement actuators 10, 11 by adding the control signal which is the operation amount calculated by 18 Is taken into account. After such correction, the control signal is output to the tilt-down actuators 12 and 13 to control the thickness of the rolled material 1.

On the other hand, based on the signal e from the plate shape detection sensor 14 and the preset target plate shape signal f, the plate shape control device 18 controls the roll crown actuators 6, 7,.
Operation amount of 8, 9 and taper roll moving actuator 10, 11
And the operation amounts of the tilt pressure lowering actuators 12 and 13 are calculated and output as control signals g, h and i, respectively.
In each of the actuators 6 to 13, the position of each roll is operated by an operation amount designated in accordance with each of the control signals g to i, and the shape of the rolled material 1 is controlled.

As shown in FIG. 1, the plate shape control device 18 includes first means 20 for detecting the control results of the actuators 6 to 13. This first means 20
Is composed of a displacement meter, etc., and all actuators 6 to
Observe 13 movements. The amount of movement for an operation command of a certain actuator is defined as Δx _j . The subscript j indicates the position of the actuator, and in this embodiment, j = 1
Ｍm, and m = 8.

The plate shape control device 18 includes second means 21 for detecting a change in the shape of the rolled material 1 based on the plate shape detection sensor 14. The second means 21 detects the plate shape before and after the movement of an actuator by the plate shape detection sensor.
Was observed with 14, it is intended to determine the shape variation amount Delta] f _i on the basis of the observations are constituted by hardware and software of a computer. The suffix i indicates the position of the plate shape detection sensor, and in this embodiment, i = 1 to n (n is an integer greater than 1).

The plate shape control device 18 is provided with a third means 22 for obtaining an influence coefficient Δα = Δf / Δx using the control result Δx of the actuator and the shape change amount Δf of the rolled material 1. The third means 22 is constituted by an arithmetic function of a computer or the like. Note that the influence coefficient Δα for the actuator at a certain j position is represented as Δα ₁ to Δα _n = Δf ₁ / Δx _{j to} Δf _n / Δx _j .

The plate shape control device 18 is provided with a fourth means 23 for storing a reference influence coefficient Δα _s .
The fourth means 23 is constituted by a computer memory or the like. The reference influence coefficient Δα _s stored in the fourth means 23 is, for example, an influence coefficient Δα _r (= Δα _{r1 to} Δα _rn ) when a roll kiss does not occur, and a roll kiss occurs. Influence coefficient Δα _k (= Δα _k1 ~
Δα _kn ) or both.

The plate shape control device 18 includes the third means
Influence coefficient of 22 [Delta] [alpha] and the fifth means 24 for comparing the influence coefficient [Delta] [alpha] _s of the fourth means 23, based on the result of said fifth means 24,
Sixth means 25 for judging the presence or absence of abnormal rolling conditions;
And _a seventh means 26 for selecting an influence coefficient Δα _a to be used for shape control based on the judgment of the means 25. Each of these means is composed of computer hardware and software.

That is, the fifth step 24 is based on the influence coefficient Δα of the third means 22 obtained by the actual measurement and the influence when no roll kiss is generated, which is stored in the fourth means 23, for example. For the coefficient Δα _r , compare some values with the largest or largest difference. That is, Max (Δα ₁ −Δα _r1 , Δα ₂ −Δα _r2 ,... Δα _n
−Δα _rn )> N where Max (S): returns the maximum value of the set S. N is a constant.

Alternatively, _j satisfying Δα _j −Δα _rj > N is M
Output the comparison result such as the existence of Or, compare the integrals of the differences as follows:

[0025]

(Equation 2)

Alternatively, the square errors are compared as follows.

[0027]

(Equation 3)

Alternatively, higher order errors are compared as follows.

[0029]

(Equation 4)

The sixth means 25 determines whether there is an abnormality in the rolling conditions based on the comparison result of the fifth means 24. In this embodiment, the presence or absence of a roll kiss is determined. That is,
As a result of the comparison by the fifth means 24, when the influence coefficient Δα based on the actually measured value is similar to the stored reference value (the influence coefficient Δα _r when no roll kiss occurs),
It is determined that a roll kiss has not occurred, and if not similar, it is determined that a roll kiss has occurred.

Here, "in the case of dissimilarity" refers to the above equation: Max (Δα ₁ −Δα _r1 , Δα ₂ −Δα _r2 ,... Δα _n
-Δα _rn )> N shows a case where the inequality holds when the inequality is used as a comparison inequality. Or, for example, Δα _j · Δ
_{Here, it} is _assumed that j in which α _rj holds is a predetermined number M or more. Instead of the above, "Equation 2", "Equation 3"
Alternatively, it is also possible to use the formula shown in “Equation 4” as an inequality for comparison, and to make them satisfied. Note that the comparison method described here is an example, and the present invention is not limited to this.

In the seventh means 26, when it is determined by the sixth means 25 that there is no roll kiss, the roll kiss stored in the fourth means is used as the influence coefficient Δα _a used for actual control. Influence coefficient Δ when not occurring
Choose to use α _r . Conversely, if it is determined that there is a roll kiss, the influence coefficient Δα used for actual control is used.
_{As a} , it is selected to use the influence coefficient Δα _k stored in the fourth means when a roll kiss occurs.

According to the shape control device 18, it is possible to change the influence coefficient used for the control and perform more appropriate control. Note that the fifth means 24 calculates the influence coefficient Δα of the third means 22 obtained by the actual measurement, and the influence coefficient Δα _k stored in the fourth means 23 when a roll kiss occurs. May be compared. Or, the influence coefficient Δα of the third means 22 obtained by actual measurement,
You may compare both Δα _r and Δα _k . Then, in the sixth means 25, in the fifth means 24, if [Delta] [alpha] is determined to be more similar to [Delta] [alpha] _r, it is determined that no roll Kiss.
If the Δα is determined to be similar by Δα _k, it is determined that there is roll Kiss.

The influence coefficient Δ obtained by the third means 22 is
Since α is an experimental value, it includes experimental noise. As one of the conditions for further reducing this noise, consider that the operation of the input actuator is an ideal operation. Usually, when the actuator is operated, an inching operation, a simultaneous operation with another actuator, a simultaneous operation with a change in other rolling conditions such as a rolling speed, and the like are considered, and each of them becomes noise.

In view of this, an eighth means is provided for controlling the sampling of the experimental value during such a noise-free condition. That is, the eighth means causes the first to third means 20, 21, and 22 to be performed under special conditions of no noise. In this case, data collection with less noise is realized by automatic operation such as smooth movement, large movement with a high S / N ratio, operation of a single actuator, or operation when rolling conditions are stable or data is discarded when unstable. I do.

The data collection by the smooth movement means that data is collected under conditions that the actuator moves continuously without inching the actuator from the start to the end of the movement and causes no action other than the movement. You do it. The significance of collecting experimental values in a large operation with a high S / N ratio is as follows. That is, since the shape changes with respect to the movement amount, the smaller the movement amount, the smaller the shape change. When the shape change is small, the detection as a signal becomes small with respect to noise such as an unstable amount of the shape itself and a detection error coming from the rolling mill.

The reason for collecting data by the operation of a single actuator is that, when a plurality of actuators move, it is necessary to separate the influence on the shape between the actuators. In this separation, non-linear components cannot be separated, resulting in an error. This is for the purpose of moving alone and eliminating the need for separation. Or, to perform stable operation of rolling conditions, or to discard data when unstable, if there is a change in material at the time of data collection, or a change in rolling load due to operation, besides the shape change due to actuator movement which is the purpose of this experiment,
The shape changes due to changes in other rolling conditions. Since this becomes a disturbance of the collected data, the data in such a case is discarded.

Further, the shape control device 18 is provided with ninth means for determining whether or not to perform the operations of the fifth to seventh means 24, 25, 26. That is, if the rolling conditions under which the roll kiss occurs are known to some extent, the above determination need not be performed in all cases. Roll kiss is likely to occur when the material thickness is sufficiently small in the specifications of the rolling mill. In addition, it tends to occur to some extent when the material width is small. In addition, when a large rolling load is required for the material hardness, it is likely to occur when the rolling roll is bent. Since each condition can be converted into a constant, a rough value can be grasped as an experiment or an experimental value. The condition that the roll kiss can not clearly occur can be determined by this grasp, so that the condition in which the roll kiss cannot clearly occur can be determined by the ninth means, and the fifth, sixth, seventh means 24, 25 can be determined by the means. , 26 are not performed.

It should be noted that the present invention is not limited to the embodiment described above, and can be used for determining a state other than a roll kiss.

[0040]

According to the present invention, it is possible to determine that an abnormality such as a roll kiss has occurred, and the control constant can be automatically changed based on the result of the determination, so that appropriate control can be performed.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the procedure of the method of the present invention.

FIG. 2 is a side block diagram of a rolling mill used in the present invention.

FIG. 3 is a front block diagram of the same.

[Explanation of symbols]

 6 to 13 Plate shape control actuator 14 Shape detection sensor 20 First means 21 Second means 22 Third means 23 Fourth means 24 Fifth means 25 Sixth means 26 Seventh means

Claims (5)

[Claims] 1. A rolling mill provided with a shape control actuator and a shape detection sensor, wherein: first means for detecting a control result Δx of the actuator; and second means for detecting a shape change Δf based on the sensor. The influence coefficient Δα using the control result Δx and the shape change Δf.
= Δf / Δx, fourth means storing a reference effect coefficient Δα _s , influence coefficient Δα of the third means and influence coefficient Δα of the fourth means
_s , a sixth means for determining the presence or absence of abnormal rolling conditions based on the result of the fifth means, and an influence coefficient Δα _{a to} be used for shape control based on the determination of the sixth means. And a seventh means for selecting the shape of the rolling mill. 2. The influence coefficient Δα _{s serving as a} reference is an influence coefficient Δα _r when a roll kiss does not occur and an influence coefficient Δα _k when a roll kiss occurs. The shape control device for a rolling mill according to claim 1, wherein one or both of them are stored. 3. An apparatus according to claim 2, further comprising an eighth means for performing said first, second and third means under special conditions. 4. The apparatus according to claim 3, further comprising ninth means for determining whether or not to perform the operations of said fifth, sixth and seventh means. 5. A shape control method for a rolling mill comprising a shape control actuator and a shape detection sensor, wherein: a control result Δx of the actuator is obtained; a shape change Δf based on the sensor is obtained; Influence coefficient Δα using shape change Δf
= Δf / Δx, comparing the determined influence coefficient Δα with a predetermined reference influence coefficient Δα _s to determine whether there is an abnormal rolling condition, and based on the determination, an influence coefficient to be used for shape control. Δα _a
And a method for controlling the shape of a rolling mill.