JPS63171213A - Method for detecting meandering amount of rolled stock - Google Patents

Abstract

PURPOSE:To detect the meandering amt. in the plate width of a rolled stock adding the vertical movement of a plate with high accuracy by finding the height position of the rolled stock from the height of the rolled stock looper, finding the magnification of an optical camera system by a geometric operation based thereon and correcting a meandering amt. by the value thereof. CONSTITUTION:The whole plate width of a rolled stock 1 is placed in the visual field of a camera 3 by arranging the camera 3 at the upper part of the center of a work roll 2 to find plate end positions l1, l2 from the output waveform 3W thereof. A meandering amt. yc is found from these plate end positions l1, l2 to perform the correction. The rolled stock height Vx from the pass line level 30 of the meandering detection part now under rolling is found by a geometric calculation from the height V2 of a looper roller 6 part. The optical magnification at the rolled stock height Vx is found to find the absolute value Yc of the meandering amt. from the magnification thereof and meandering amt. yc. The meandering amt. of good accuracy without being affected by the vertical movement of the plate 1 can thus be found.

Description

[Detailed description of the invention] 〈Industrial use distribution〉 The present invention relates to a meandering amount detection device for a rolled material of a rolling mill.

<Prior art> In a rolling mill, the phenomenon in which the center of the width of the rolled material deviates from the center of the work roll and the material flows sideways (meandering) is caused by poor leveling of the left and right rolling devices, non-uniform left and right thickness of the entry side,
This occurs due to uneven hardness of the left and right sides of the board. This meandering must be prevented in order to improve the yield of rolled material and prevent damage to work rolls, but in order to prevent this, it is first necessary to accurately detect the amount of meandering of the plate material. In other words, it has been found through simulations and model experiments that it is effective to control the horizontal leveling and roll pending force by feeding back the accurately detected meandering amount of the plate material. Therefore, the point of meandering control depends on highly accurate detection of the amount of meandering.

FIG. 2 shows an example of a conventional meandering detection device for hot rolling. Here, 1 is a rolled material, 2 is a work roll, and 3 is a CO along the axial direction of the work roll 2 of the rolling mill.
A camera in which D elements are arranged, 4 is a calculation section. In this device, one camera 3 is placed above the center of the work roll 2, and the entire width of the rolled material 1 is placed within the arrow 2D of the camera 3, and this camera obtains an output waveform as shown in 3W. There is. That is, in the camera 3, charges are accumulated in the COD element corresponding to the rolled material 10 portion, and other COD elements are accumulated.
There is no charge accumulation in the element, and the output waveform 3 of the CCD camera 3
Get W. The arithmetic unit 4 placed after the camera 3 determines the boundary between the part where charge is accumulated and the part where no charge is accumulated (■, ■ part of the output waveform 3a) as the plate edge, and calculates the average value of both ends. Find the center position of the board. That is, in the calculation unit 4, the center position (problem to be solved by the invention) is detected.However, in the above-mentioned detection method, the vertical movement of the plate is not taken into account, and there is the following problem. In other words, although the vertical movement of the plate immediately after rolling is almost negligible, in such places the influence of cooling water and steam is large and detection with an optical camera is extremely difficult. In this case, the installation location is severely restricted and it is virtually impossible to install the camera, so the camera installation position must be 1 mm or more above the lowered position.

However, if the camera positions are separated in this way, the board will move up and down to some extent. This is caused not only by the running of the rolled material, but also by the movement of the louver, which moves up and down to control the tension of the rolled material. If it is caused by the movement of the louver, it can reach about 400+m+.

Therefore, with only information on the position of the edge of the rolled material within the field of view of the camera, it is difficult to detect the true amount of meandering because the image magnification of the optical system changes due to the vertical movement of the board, resulting in large errors.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, it is an object of the present invention to provide a method for detecting the amount of meandering of a rolled material with high accuracy, taking into account the vertical movement of the sheet.

Means for Solving the Problems> The present invention provides a method for detecting the meandering amount of a rolled material with respect to a work roll center by detecting the plate end position of the rolled material. The height position of the rolled material is determined from the height of the rolled material louver, and an optical camera,
The method is characterized in that the magnification of the optical camera system is calculated from the geometrical arrangement of the rolled material meandering amount measurement points and the rolled material louvers, and the absolute value of the meandering amount is determined from this magnification and the meandering amount detected by the optical camera. .

Function> By correcting the magnification of the optical system with the above configuration to the meandering measurement amount detected by the optical camera, it becomes possible to detect the true meandering amount to be determined.

Embodiments Here, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram for explaining meandering amount calculation, and FIG. 2 is a λ device using the method of the embodiment. First, Figure 1, Figure 2
In the figure, 1 is a rolled material during hot rolling, 2 is a pair of upper and lower work rolls, and 3 is a CCD installed on the top of the rolled material.
A camera, 4 a calculation unit, 5 a pair of upper and lower backup rolls, 6 a louver roll installed between the rolling mills, and 7 a drive motor for the louver roll 6. Further, 3W indicates the output waveform of the CCD camera 3.

The CCD camera 3 is installed in such a way that the center of the plate is at the center of the camera field of view when the rolling conditions are set and the rolled material is not meandering. The plate edge position of the rolled material within the field of view of the camera (lengths j and j2 in Figure 2) is located at the boundary between the COD elements where charges are accumulated and the COD elements where no charges are accumulated (■, in Figure 2). ■). and,
In this case, due to the output waveform 3W, I! 112 is a relative value determined from the scanning time of the CCD camera, and its absolute value changes depending on the size of the entire field of view 2D of the camera, that is, the magnification of the optical system. Here, if the vertical position of the board changes, the magnification will change, so you must take care of this.

Therefore, the procedure for calculating the magnification will be explained. In Figure 1, H
, distance between the work roll 2 and the louver roll 6, H
2 is the distance between the work roll 2 and the CCD camera 3, ■
Let be the height from the pass line level 30 to the CCD camera 3, v2 the height from the pass line level 30 to the rolled material of the louver roller 6 section, and ■ be the height of the rolled material from the pass line level 30 to the rolled material meandering detection part. . The optical system magnification m when the rolled material 1 is at the pass line level 30 can be known in advance from the mounting position and optical characteristics of the CCD camera 3.

When the magnification m1 at the height V of the rolled material of the meandering detection part currently being rolled is calculated using the magnification m, the following equation is obtained.

Furthermore, since the rolled material 1 is strongly pulled by the rolling mill and the louver roll 6, and is in a straight line between the louver roll 6 and the work roll 2, the height vx can be determined by geometric calculation using the following equation.

In this case, the upper end height V of the louver roll 6 can be determined by measuring the position of the louver roll 6 with a displacement meter or by using the louver motor 7.
It can be easily measured using the rotation angle calculation method.

Therefore, the following equation is obtained from the absolute value of the amount of meandering, Yc-ycXm.

As a result, even if the plate moves up and down, the effect is on the height v
2, it becomes possible to detect the true meandering amount.

<Effects of the Invention> As explained above, according to the present invention, in the method of detecting the meandering amount of a rolled material by detecting the plate end position with a COD camera, the height of the rolled material louver is detected, The image magnification of the camera system is determined by geometric calculations based on this, and the detected meandering amount is corrected using that value, thereby providing a highly accurate meandering detection method that is not affected by the vertical movement of the board. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining an embodiment method of the present invention,
FIG. 2 is a configuration diagram of a meandering amount detection device for rolled material. In the figure, 1 is the rolled material, 2 is the work roll, 3 is the COD camera, 3W is the output waveform, 4 is the amount of calculation, 6 is the louver roll, 30 is the pass line level, Hl, H, are the work roll, louver roll, and COD camera The distance v11v2pvx is the height from the pass line level to the COD camera, the upper end of the louver roller section, and the meandering detection section.

Claims (1)

[Claims] In a method for detecting the meandering amount of a rolled material relative to a work roll center by detecting the plate edge position of the rolled material, the height position of the rolled material is determined from the height of the rolled material louver, and an optical camera is used to detect the meandering amount of the rolled material with respect to the work roll center. The magnification of an optical camera system is calculated from the geometrical arrangement of the measurement points and the rolled material louvers, and the absolute value of the amount of meandering is determined from this magnification and the amount of meandering detected by the optical camera. Meandering amount detection method.