JPH0787934B2 - Rolled material shape control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rolled material shape control device, and determines a widthwise shape parameter of a rolled material by correcting a shape correcting operation force such as a roll bending force. It relates to a device for controlling.

[Conventional technology]

Conventionally, as a method of recognizing the shape of a rolled material, the distance from the center point in the width direction of the rolled material is defined as an independent variable X, and the distance to the center of the rolled material at the point where the distance from the center in the width direction of the rolled material is X. Let the difference in elongation be f (X), and the function that best fits this is f (X) = λ ₁ X ¹ + λ ₂ X ² + λ ₃ X ³ + λ ₄ X ⁴ + ... That is, the nth power series of X assumed, for determining the coefficients lambda ₁ to [lambda] _n in terms of X ¹ to X ⁿ in the least squares method, to as easily intuitively grasped more shape parameters, the width-direction coordinate
X (X _i ) i = _{1 to n} at each point (shape parameter recognition point) X ₁ , X ₂ , ..., X _n is a shape parameter expressing a shape pattern. As a known example of the prior art, Japanese Patent Application No.
There is 51-58794.

[Problems to be Solved by the Invention]

However, since the width-direction coordinates X _{1 to} X _n are fixed values (that is, the position of the shape parameter recognition point is fixed with respect to the center of the rolled material width direction), after the shape pattern as shown in FIG. The shape parameters are all zero, which causes a phenomenon that an accurate shape cannot be expressed.

An object of the present invention is to provide a shape control device capable of accurately recognizing the shape of a rolled material and performing good shape control.

[Means for Solving the Problems]

The above-mentioned object is to use the signal of the elongation rate in the width direction of the rolled material as an input, and to calculate the difference in the elongation rate with respect to the center of the rolled material at the point of the distance X from the center of the rolled material by the distance X by the method of least squares.
A power series conversion processing device (11) for obtaining an n-th power series coefficient representing a variable, and a shape parameter conversion processing device (11) for obtaining n shape parameters by inputting the n-th power series coefficient A control amount calculation device (1 that calculates the correction amount of the shape correction operation force based on the obtained shape parameter
2) In the shape control device for a rolled material provided with and, the recognition point of the shape parameter in the width direction of the rolled material is an extreme value of the shape distribution of the rolled material based on the power series coefficient from the power series conversion processing device. A shape parameter recognition point selection device (17) for selecting and setting at a position where there is a, and a conversion matrix calculating device (18) for linearly converting n power series coefficients based on the selected and set shape parameter recognition points. And a control model conversion device (19) for converting a prepared control model by the converted matrix and outputting the converted control model to the control amount calculation device.

[Action]

According to the above invention, the shape parameter recognition point selection device determines the recognition point of the shape parameter in the width direction of the rolled material based on the power series coefficient from the power series conversion processing device. (Value) is selected and set in the position where it exists, shape recognition corresponding to the shape defect that occurs in the rolled material can be performed, and based on this selected and set recognition point, the roll bending force, etc. Since the operating force is corrected, accurate shape control is possible.
In this case, the control model for displaying the operation end and the shape parameter changes with the change (position setting) of the recognition point, but the control model also changes to correspond to the change of the recognition point. , No problem.

Here, the transformation matrix of the shape parameters (linear transformation)
The necessity of changing the control model and the method of changing it are explained.

That is, as described above, the shape parameter is quantified by the n-th power series, and in order to intuitively grasp it, f (X _i ) i = at the width direction coordinates X ₁ ... X _n of the rolled material Although 1 ... n is used as a shape parameter (hereinafter expressed as f (X _i ) = Λ _i ), this power series coefficient λ _i and shape parameter Λ _i
The relation with and is expressed by the following equation. The letters on the right side of the equation indicate exponents of powers (the same applies below).

= ····················· (1) ′ The control end in the shape control is set as M ₁ , M ₂ …… M _n , and the relationship with the shape parameter is expressed by the following equation.

= ·········· (2) ′ Here, a _ij is called the influence coefficient and is defined by the following equation.

The width-direction coordinate point X of the strip _'1, X' _2, relationship between the coefficients of shape parameters and power series in ...... X _'n is given by the following formula, ′ ＝ ′ ··· (3) ′ At this time, the relationship between the shape parameter and the operating end is as follows.

′ ＝ ′ ··· (4) ′ As described above, when the shape parameter is changed, the control model also needs to be changed.

However, between and ', the relation of the following equation (5) can be derived from the above (3)' and (4). That is, from equations (3) and (3) ', == ... (3)' = '... (3)' Therefore, == ^-1. ' It becomes ^-1 . On the other hand, (4), (4) 'control model from the equation = - ......... (4)' a = '- ......... (4)', - as a ^'-1' = -, thus' = ′ ・ ′ ^-1・ ・ where ′ ・^-1・ ＝ 'because it is ′ ＝' ・^-1・ ………… (5) where ^-1 represents the inverse matrix.

Therefore, it can be seen that even if the recognition point of the shape parameter is changed based on the position of the extreme value of the n-th power series, the control model can be easily changed in accordance therewith.

Now, the selection setting of the shape recognition point of the above-mentioned shape parameter is
This is to monitor at which point on the X coordinate the extreme value of the shape distribution of the rolled material is located on the X coordinate (shape detection) during the rolling, and to select and set that point as the recognition point of the shape parameter.

The extreme value of its shape distribution is Is determined by finding a value of X (coordinates) that satisfies

For example, when the shape distribution is approximated by a quartic function and further separated into a symmetric component f _S (X) = λ ₂ X ² + λ ₄ X ⁴ and an asymmetric component f _N (X) = λ ₁ X + λ ₃ X ³ , The extreme value of the symmetric component is determined by the following equation.

However, λ ₂ · λ ₄ <0 [Example] An example of the present invention will be described with reference to FIG. 1. The shape detector 5 installed between the outlet side of the rolling mill 1 and the deflow 3 outputs elongation rate signals at several tens of points in the strip width direction.

This elongation rate signal is input to the power series conversion processing device 10 and the fourth-order power series coefficient λ ₁ , λ ₂ , λ is calculated using the method of least squares.
Outputs ₃ and λ ₄ . Various proposals have been made for the n-th order function approximation method, and therefore will not be described here.

The shape parameter recognition point selection device 17 receives the power series coefficient λi from the power series conversion processing device 10, and uses the formula (7) to recognize the shape recognition points X ₁ ′, X ₂ ′, X ₃ ′, X ₄ ′. Is selectively output. That is, the shape parameter recognition point selection device 17 obtains the coordinate values at which the extrema of the function f (X) having the obtained λ ₁ , λ ₂ , λ ₃ and λ ₄ as power series functions exist. The respective coordinate values are output as the coordinate values X ₁ ′, X ₂ ′, X ₃ ′, X ₄ ′ of the shape recognition point.

The conversion matrix calculation device 15 calculates a shape parameter conversion matrix 'from the X ₁ ' to X ₄ '.

The shape parameter conversion processing device 11 includes outputs λ _{1 to} λ ₄ from the power series conversion processing device 10 and a conversion matrix calculation device.
The shape parameters Λ ′ _{1 to} Λ ′ ₄ are calculated from ′ calculated in step 18 by using the equation (3).

The model conversion processing device 19 calculates the control model to be used this time 'from the formula calculated by the conversion matrix calculation device 18, the control model provided from the control model storage device 20, and the formula (5).

The control amount calculating device 12 calculates the correction amount of the following shape operation end, intermediate roll bending 16, and work roll bending 15 by using the deviation between the shape parameter target value and the actual value and the control model. This method has various proposals (for example, Japanese Patent Application No.
No. 53-114956), so it will not be explained here.

The means for controlling the shape is limited to roll bending, reduction leveling, coolant, etc., and it is not possible or necessary to control the shape in the plate width direction independently at several tens of points. Therefore, it is necessary to represent the shape distributed in the plate width direction using several parameters. In this embodiment, as described in Japanese Patent Publication No. 54-18301, 4
The case of recognizing a shape by the following power series is described. The rolling mill is exemplified by a 6-high rolling mill having work roll bending and intermediate roll bending effective for shape control.

Symmetrical components F _W and F _{I of} work roll bending force and intermediate roll bending force and symmetric components of shape parameters Λ ₂ and Λ
_It is known that ₄ has an almost linear relationship. FIG. 3 shows an example thereof. The inclination of this straight line changes depending on the size of the rolling mill and the rolling conditions.

Therefore, the influence coefficient a _{ij of the} equation (2) described above is
If the conditions such as plate width are constant, it can be expressed by a constant.

The asymmetrical components Λ ₁ and Λ _{3 of the} shape parameters and the asymmetrical components DF _W and DF _{I of the} bending force are also the symmetric components Λ ₂ and Λ _{4 of} the shape parameters and the symmetric components F _W and F _{I of the} intermediate roll bending force. It has the same relationship and can be expressed by the following equation.

Therefore, the following description will be made only for the symmetric component.

The shape parameters Λ ₂ and Λ ₄ are the fourth-order power series λ ₂ and λ ₄ ,
It is calculated using the coordinate X _i of the shape recognition point in which the plate width is normalized by ± 1. With X ₂ = 1 and X ₄ = 0.5, Λ ₂ and Λ ₄ are
Based on the equation (1), it is expressed as follows.

Now, when X ₂ = 0.9, X ₄ = 0.6 is obtained from the formula (7) as the position where the extreme value of the power series exists, the recognition point of the shape parameter is X ₂ = 0.9, X ₄ = 0.6. Change to. The shape parameter at the new shape recognition point is based on the equation (3),
It can be calculated by the following formula.

At this time, it is necessary to correct the relationship between the shape parameter and the shape operation end, but this is possible by performing the following calculation in the model conversion processing device (19).

here From the above, stable control is possible even if the shape recognition point is changed according to the shape distribution represented by a power series.

Therefore, unlike the case of FIG. 2, it becomes less likely that the defective shape can be recognized, and the accuracy of shape control can be improved.

The case where roll bending is adopted as the shape operation end has been described, but other operation ends (intermediate roll shift 14,
The same applies to the case of reduction leveling 13).

〔The invention's effect〕

As described above, according to the present invention, since the shape recognition point is selectively set to the extreme value of the shape distribution in the width direction during rolling,
The shape pattern can be converted into shape parameters accurately, and the shape of the rolled material can be controlled well.

[Brief description of drawings]

FIG. 1 is an outline view of a rolling mill and a block diagram of a shape control device, FIG. 2 is a distribution diagram of elongation ratio of rolled material in a width direction, and FIG. 3 is a diagram showing a relationship between roll bending force and elongation ratio. Is. 1 ... 6-high rolling mill, 2 ... rolling material, 3 ... deflector roll, 4 ... tension reel, 5 ... shape detector, 6
…… Intermediate roll, 7 …… Work roll, 9 …… Backup roll, 10 …… Power series conversion processing device, 11 …… Shape parameter conversion processing device, 12 …… Control amount calculation device, 13 ……
Reduction leveling, 14 …… Intermediate roll shifter, 15 ……
Work roll bending, 16 ... Intermediate roll bending, 17 ... Shape parameter recognition point selection device, 18 ... Transformation matrix calculation device, 19 ... Model transformation processing device, 20 ...
... Control model storage device.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B21B 37/00 BBK

Claims (1)

[Claims] 1. An elongation difference from the center of the rolled material at the point of a distance X from the center of the rolled material in the width direction is calculated by a least squares method using an elongation rate signal in the width direction of the rolled material as an input.
, Which is a variable, and a power series transformation processing device that obtains an nth power series coefficient, a shape parameter transformation processing device that obtains n shape parameters using the nth power series coefficient as an input, and a shape based on the obtained shape parameter. In a shape control device for a rolled material equipped with a control amount calculation device for calculating a correction amount of a correction operation force, a recognition point of a shape parameter in the width direction of the rolled material is converted into a power series coefficient from the power series conversion processing device. Based on the shape parameter recognition point selection device that selects and sets the extreme value of the shape distribution of the rolled material based on the above, and linearly transforms n power series coefficients based on the selected and set shape parameter recognition points A conversion matrix calculation device, and a control model prepared in advance is converted by the converted matrix, and the converted control model is controlled by the control. Rolled material of shape control apparatus and a control model conversion unit for outputting a calculation device, comprising the to.