JPH0617779B2 - Rolling material meandering amount detection device - Google Patents

Description

The present invention relates to a meandering amount detection device for rolled material of a rolling mill.

<Prior art> In rolling mills, the phenomenon that the strip width center of the rolled material deviates from the center of the work roll and the sheet material flows laterally (meandering) is caused by poor leveling of the left-right rolling reduction device, uneven left-right strip thickness,
This is caused by uneven left and right hardness of the plate material. This meandering must be prevented in order to improve the yield of the rolled material and prevent damage to the work rolls, but in order to prevent this, it is first necessary to accurately detect the meandering amount of the plate material. In other words, simulations and model experiments have revealed that it is effective to feed back the amount of meandering of the plate material detected with high precision and control left and right leveling and roll bending force. Therefore, the point of the meandering control depends on the highly accurate detection of the meandering amount.

FIG. 2 shows an example of a meandering detection device which has been conventionally used in hot rolling. Here, 1 is a rolled material, 2 is a work roll, 3 is along the axial direction of the work roll 2 of the rolling mill CC
A camera 4 in which D elements are arranged is an arithmetic unit. In this apparatus, one camera 3 is arranged above the center of the work roll 2 and the entire strip width of the rolled material 1 is placed within the field of view 2D of the camera 3, and this camera obtains an output waveform as shown by 3w. . That is, in the camera 3, charges are accumulated in the CCD element corresponding to the portion of the rolled material 1, and other CCD elements are stored.
There is no charge accumulation in the device, and the output waveform 3 of the CCD camera 3
get w. In the calculation unit 4 arranged in the latter stage of the camera 3, the boundary portion (the portion of the output waveform 3w) between the portion where the electric charge is accumulated and the portion where the electric charge is not accumulated is determined as the plate width, and the center of the plate material is determined as the average value of both ends. Find the position. That is, in the arithmetic unit 4, the central position Ask for.

However, in order to cover the entire width with the field of view of one optical camera as shown in FIG. 2, the optical path length (distance between the plate and the camera) must be increased. Therefore, the measurement accuracy is lowered, and the influence of steam or cooling water between the optical paths is large, which makes detection extremely difficult.

As a countermeasure against this, as shown in FIG. 3, a method may be considered in which two optical cameras are used and the drive mechanism 5 is adjusted so that each of them has a plate width end within the field of view. In this case, although it is necessary to adjust the drive mechanism according to the plate width, the optical path length can be shortened, the accuracy is improved, and the influence of steam or the like can be relatively easily removed. The meandering amount y _c of the plate in this case is given by the following equation according to FIG.

<Problems to be Solved by the Invention> When the meandering detection is performed using the two optical cameras as described above, a camera normally used is a CCD (Charg).
e Coupled DeVice) or MOS
(Metal Oxide Semiconductor
It is a one-dimensional camera that uses a solid-state image sensor called r type. However, since this type of one-dimensional camera is in low demand, it is expensive and generally has a large shape, which makes it difficult to dispose the one-dimensional camera close to the plate as shown in FIG.

On the other hand, a camera using a solid-state image pickup device is generally used for a two-dimensional camera, and since there is a great demand for it, various devised devices are commercially available. Further, an extremely small shape (for example, a thumb-sized one) has been put into practical use so that it can be used for robots and various sensors. Therefore, if a two-dimensional camera using these solid-state image pickup devices can be used, it will be very effective in terms of space.

However, in the above-mentioned two-dimensional camera, the 1/2 screen imaged by the camera is scanned, and the scanning time is 1
It is set to / 60 seconds, but when the rolling speed increases, this value becomes larger than the required measurement interval, and it becomes impossible to control the meandering of the plate using the output value of this detector. As a countermeasure, the above scanning time may be shortened, but this modification is generally difficult.

Therefore, the present invention provides a meandering amount detection device for a rolled material in which a required measurement interval is shortened by using a small and popular two-dimensional camera.

<Means for Solving the Problems> The present invention that achieves the above-mentioned object is achieved by using two optical cameras that respectively accommodate both ends of the strip width of the rolled material within the visual field. In an apparatus for detecting the meandering amount of the rolled material with respect to a work roll center by detecting the end position, means for synchronizing the vertical scanning and horizontal scanning timings of the two optical cameras, and the two optical cameras. Means for counting any one of the horizontal synchronizing signals, means for setting and taking out the number of horizontal scanning lines in the two optical cameras by this count value, and a plate width end position from the number of horizontal scanning lines taken out. And a calculator for calculating the meandering amount.

<Working> Multiple required lines are taken out from one screen, and the taking-out positions of the left and right cameras are set to be the same position, and the meandering amount is output at short time intervals. That is, in the two-dimensional camera having the scanning condition shown in FIG. 4 (a), the signal specification is determined by the NTSC standard, and normally about 250 lines are required for the jumping operation (FIG. 4 (a)).
One field is composed of 1 to n horizontal scanning lines, and the scanning time is 1/60 seconds. And Fig. 4 (b)
As shown in, the scan A of one field is controlled by the vertical synchronizing signal, and the horizontal scan B is controlled by the horizontal synchronizing signal. Then, these two types of synchronization signals are combined with the video signal and output. Then, in order to synchronize the scanning of the left and right two cameras, as shown in FIG. 5, the horizontal and vertical synchronizing signals are simultaneously supplied from the signal generator 10 to the two cameras 3.
a and 3b to synchronize the scanning, or as shown in FIG. 6, the output of the synchronization signal generator already held inside one camera 3a is taken out and input to the other camera 3b to synchronize the scanning. Shows how to take.

Scanning synchronization of the left and right cameras can be obtained by using either method. Further, since the horizontal synchronizing signal is usually generated inside the camera based on the vertical synchronizing signal, the vertical synchronizing signal may be the only external signal required. Then, by appropriately cutting out this horizontal synchronization signal, horizontal line detection at short intervals can be performed in synchronization with the left and right cameras.

<Example> An example of the present invention will now be described with reference to FIG.
In FIG. 1, 3a and 3b are cameras arranged corresponding to the end portions of the rolled material. In this case, the cameras 3a and 3b are arranged so that the traveling direction of the rolled plate material and the horizontal scanning direction are orthogonal to each other. An external sync signal generator 10 generates a vertical sync signal, and the cameras 3a and 3b are synchronously scanned by the output of the sync signal generator 10. 11a, 11b
Is the output signal of the driven cameras 3a and 3b.
a is a signal processing circuit for detecting l _{w in} the signal indicated by 3aW shown in FIG. 3 and the value of l _{d in} the signal indicated by 3bW in the camera 3b, and 14a and 14b are the detected l _This is an addition and averaging circuit for extracting and averaging the output values of _w and l _d for a certain arbitrary number of scanning lines.

12 is a circuit for separating the horizontal synchronizing signal from the output signal of either one of the cameras (3a in FIG. 1),
Reference numeral 13 is a control circuit that counts and sets the number of the horizontal synchronizing signals and controls the timings of both addition and averaging circuits 14a and 14b. Of course, the number of this averaging can be arbitrarily set from the outside.

Reference _numeral 15 is a circuit that calculates and outputs the meandering amount based on the averaged detection signals l _w and l _d . The meandering control can be performed based on this output value.

By doing so, the conventional one field or one frame one data detection can be freely selected by setting the averaged number (horizontal scanning line number).

For example, if the averaged number is 25, the horizontal scanning line 1
.., 25, 26 to 50, 51 to 75, ..
In the case of 0 lines, it is possible to detect 110 data in 1 field from 250/25 = 10. Therefore, the detection interval is 1/10 of the conventional one, that is, 1/600 seconds, which is a sufficient interval for meandering control.

Of course, when the above detection is performed, strictly speaking, the position where the meandering is detected changes, so that correction is necessary, but this is determined by the number of horizontal scanning lines. It becomes possible by referring to the signal of the circuit 13.

Although the external circuit is used as the sync signal generator 10 in the above-described example, the same applies when the sync signal of one camera is used.

Further, it is possible to omit the horizontal synchronizing signal inside the camera directly by the synchronizing signal separating circuit instead of the external circuit.

Further, in the above description, all the scanning lines for one field or two fields and one frame are detected and a part of them is taken out, but only one intermittent line is detected if necessary. It is also possible. In that case, since the plurality of lines are not collectively detected, the averaging circuit 14 becomes unnecessary, and the output value of the detection circuit 11 at that time may be input to the output circuit 15 at each detection timing generated by the control circuit 13. .

<Effects of the Invention> As described above, the present invention uses the two-dimensional optical camera that can be downsized, and conventionally detects one field one data, and is sufficient for the meandering control when the rolling speed is fast. By allowing the detection intervals to be set almost freely for those that could not be handled, the meandering control of all rolling mills can be applied.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2, and FIG.
The figure shows the principle of two examples for detecting the width edge of rolled material. Fig. 4 (a) is an explanatory diagram of scanning lines. Fig. 4 (b) is a waveform diagram of vertical and horizontal synchronizing signals. The figure is an explanatory diagram when synchronization is taken. In the figure, 3a and 3b are cameras, 10 is a sync signal generator, 11a and 11b are signal processing circuits, 12 is a sync separation circuit, 13 is a control circuit, and 14a and 14b are averaging circuits.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-17465 (JP, A) JP-A-59-18413 (JP, A) JP-A-48-90549 (JP, A) Actual development Sho-62- 14310 (JP, U)

Claims (1)

[Claims] 1. A rolled material with respect to a work roll center by detecting the plate width end position of the rolled material within the field of view with two optical cameras that respectively accommodate both ends of the rolled material within the field of view. In the device for detecting the amount of meandering, the means for synchronizing the vertical scanning and horizontal scanning timings of the two optical cameras, the means for counting the horizontal synchronizing signal of one of the two optical cameras, A means for setting and taking out the number of horizontal scanning lines in the two optical cameras by the count value and an arithmetic unit for detecting the plate width end position from the taken out number of horizontal scanning lines and calculating the meandering amount are provided. A meandering amount detection device for rolled material.