JPS6297712A - Plate turn controlling method for rolling mill - Google Patents

Abstract

PURPOSE:To automate the turning control of a plate by horizontally scanning a TV camera on a roll and by detecting the turning angle of the plate from the minimum scanning time from the scanning start of the plate and from the end of the plate until the scanning completion and number of scanning line. CONSTITUTION:A TV camera 5 starts the scanning from the upper left and generates a plate detecting signal when the scanning reaches to the uppermost degree point S of a plate 3. The plate signal is obtd. on (e) pieces of scanning line until no plate signal is detected by performing the scanning each pitch DELTAN. The scanning time is detected in order while from the scanning start detected in order on each scanning line until the plate signal is detected. The minimum one is identified from the detected scanning time T and it is taken as the minimum scanning time Tm and the scanning number thereof is taken as Nm=Ns+mDELTAN. The turning angle theta of the plate is found by using the scanning line number Ns at point S detected previously and scanning time Ts and the value at point M of Nm+mDELTAN, Tm.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a plate turning angle control method applied to, for example, a plate turning device of a thick plate rolling mill.

<Prior art> In a plate rolling mill, the plate is rolled at 90” in the intermediate pass.
It has a step of turning. A conceptual diagram of this turning device is shown in Fig. 7. Roll 1 is a roll with a large diameter on the operation side, and roll 2 is a roll with a large diameter on the drive side. By arranging these two types of rolls alternately and rotating them in opposite directions, the plate 3 rolled by the rolling mill 4 is rotated. In the conventional method, an operator monitors the rotation of the plate 3 and controls the rotation of the rolls 1, 2 so as to stop when the plate has rotated exactly 90 degrees.

<Problems to be developed by the invention> However, the conventional method shown in FIG. 7 has the following drawbacks.

(1) Since the board 3 must be visually monitored by the operator, labor savings cannot be achieved.

(2) Since the timing at which rolls 1 and 2 are stopped differs depending on the operator, if there is a malfunction, the plate 3 may turn too much or not enough, and the rolls 1 and 2 may be stopped again.
It becomes necessary to rotate 2 and make minor corrections.

That is, the biggest factor preventing unmanned rolling operations in thick plate rolling mills is the plate turning operation, which has the above-mentioned problem, and the present invention was developed to automate this process.

That is, an object of the present invention is to provide a turning control method that enables accurate turning of a plate without monitoring the plate so as to automatically turn the plate.

<Means for Solving the Problems> The present invention achieves the above-mentioned object by alternately arranging rolls having a large diameter on the operation side and rolls having a large diameter on the drive side.
In a plate turning device that turns the board by rotating seed rolls in opposite directions, a television camera that detects infrared rays emitted from the board is used to horizontally scan the roll at regular intervals, and horizontal scanning begins. The scanning time required from the edge of the plate to the end of the horizontal scan is detected, and the horizontal scanning line number is sequentially detected. It is characterized in that the turning angle of the plate is detected from each of the minimum scanning times up to and the scanning line number, and the first and last scanning times and scanning line numbers at which the plate signal is detected.

Embodiments FIG. 1 shows an example of an automatic plate rotation angle detection device according to the present invention. In this figure, 1 and 2 are rolls that rotate in opposite directions, 3 is a plate to be rotated, 4 is a rolling mill, and 5 is a television camera for detecting the rotation angle of the plate. This television camera 5 is configured to detect infrared rays emitted from the plate 3, and the scanning direction is made to match the rolling direction. Assume that the board is in the state shown in FIG. 1 at a certain moment, and at this time the television camera 5 receives an image as shown in FIG.

Now, the information we want to obtain is the turning angle θ (5th
In the figure, it is θ, ), but the method for finding this θ is described below. The television camera 5 starts scanning from the upper left of FIG. 2, and when the scanning reaches the upper vertex S of the board 3, it generates a board detection signal as shown in FIG. The horizontal scanning time until this detection signal is obtained is assumed to be Ts scanning line number Ns.

Next, the Ns+ΔNth line below the Nsth scanning line, N
The plate signal shown in FIG. 4 is obtained for each of a plurality of scanning lines with a pitch of ΔN: s+2ΔNth, Ns+3ΔNth, . . .

In FIG. 4, the portion where the camera output signal is observed indicates a time width corresponding to the board width on the screen. In this way, scanning is performed at intervals of ΔN, and a plate signal is obtained for every 0 scanning lines until no plate signal is detected. Here, the number of pitches ΔN may be any value as long as it is one or more and less than or equal to the total number of scanning lines on the screen (usually 250 to 520), and may be determined depending on the time required for calculations and memory capacity, which will be described later.

The scanning time T from the start of scanning until the plate signal is detected as shown in FIG.
T is sequentially detected until the plate signal is no longer detected.

As can be seen from FIG. 2, the time T from the start of horizontal scanning to plate signal detection gradually decreases from Ts, reaches a minimum at or near point M in the figure, and then increases again. Then, from among the scanning times T detected as described above, the smallest one is identified, and this is set as the minimum scanning time Tm, and its scanning line number is set as Nm=N5+mΔN. This scanning line number Nm means that point M on the board or its very vicinity has been detected for the reason described above: Here, the degree of proximity is determined by the scanning line interval ΔN, and the narrower the line, the greater the degree of proximity. .

Therefore, the scanning line number Ns and scanning time Ts of the eight points detected previously and the value Nm+mΔN,T at or near point M
Using m, the turning angle θ of the plate can be found as follows.

Here, the scanning time difference is Td (and, Td=Ts-Tm.

Therefore, equation (2) is obtained.

However, since the time and scanning pitch are obtained for Td and ΔN which are actually measured, it is necessary to convert these into length. Now, returning to Figure 2, when the horizontal viewing length of the screen is lH1 and the vertical viewing length is 4V, in a normal TV camera, the -scanning line time is 56μSee, and the vertical scanning line Since the number is approximately 260, it can be converted as follows.

Te (length conversion Td) -1l, X-1211156
μSee Therefore, this length TI, ΔNN is Td, Δ
By using it instead of N, the actual turning angle θ can be determined.

The angle θ mentioned above is the angle that the side MS of the plate 3 makes with the vertical direction of the screen in FIG. Find θ ) in the figure. Using the same method as above to find the angle θ, plate 3 is
When scanning is performed at a pitch of ΔN sequentially from the scanning line number Ns where the upper vertex S is first detected, the horizontal scanning ends from the point where the detection signal of the plate 3 ends (the end along the scanning direction of the plate 3). The time T' (see T' in FIG. 4) until the scanning line Ns is detected for each horizontal scan.
It gradually decreases until it reaches the N point, which is To-Ts, reaches the minimum time Tn at the N point, and then increases until it reaches the E point. Here, TO is the horizontal scanning time on the screen. In this way, by identifying the minimum time Tn and the scanning line number Nn=N5+n, ΔN from among the plurality of detected times T', the angle θ' in FIG. 2 becomes the following equation (3).

Since To-Ts-Tn and ΔN are time, scanning line Bi, and Sochi, it is natural that they need to be converted to distance in the same way as when calculating angle θ, but as mentioned in the explanation of angle θ, Omitted.

In this way, the scanning times To, Ts, Tm, T
n, Te.

Scanning line Ns, Nm=N5+m, △N5Nn==Nsten
Obtain △N, Ne=Ns+e, ΔN1. Therefore, the fifth
The angle of each corner of the plate 3 shown in the figure with respect to the television screen, that is, the rotation angle 01 to θ4, is determined by the following equation.

In the end, the rotation angle θ is determined by the following equation as the average value of the values of the above four equations.

The rotation angle θ of the plate can originally be found using one of the above equations (4), but the advantages of using the average value of the four values as shown in equation (4) are as follows: be.

(No. 11 plates are not necessarily perfectly rectangular. In that case, by using the average value of the turning angles measured using each corner, the influence of the shape of the plate can be further reduced.

(2) Depending on the size of the sampling interval ΔN, it is not necessarily the case that the corner of the board is always detected, but strictly speaking, it will be detected in the vicinity thereof. In that case, try to minimize the error by using the average value.

(3) The rectangular ratio (aspect ratio) can be detected and used to determine the completion of a turn.

That is, when θ is 90″ or near θ″, the following approximation holds true.

Horizontal length W=TOTl1-Tn Vertical length L #N e -N s= (e -s
) ΔN rectangular ratio #L/W (For the actual length, use the one converted to Te and ΔN described above instead of Td and ΔN.) The turning angle θ determined in this direction is shown in Figure 6. 9 according to the turn
Monotonically increases up to 0°.

When the angle exceeds 90°, the side of the plate to be measured, θ1, changes from the 3M side in Figure 2 to the ME side, so θ rapidly drops to zero or a value close to it, and then repeats the same process as above. It will increase monotonically.

Therefore, for example, the timing to end plate rotation is as follows.
Take advantage of the sudden change from 90° to Oo.

However, in this case, θ is slightly negative (90°
If it is set to a state of 90 degrees (slightly less), a change from 90 degrees to 09 degrees will occur at the same time as the start, causing a problem. It is possible to complete the rotation by detecting the next change from 90° to 0@, or to utilize the change in the rectangular ratio φ before and after the rotation (for example, φ×1−φ〉1). is necessary.

In addition, if it takes time to brake the rotation of the plate, for example, θ=
Control such as starting braking at 70° is also possible.

<Effects of the Invention> (1) Since the turning angle of the plate can be automatically detected, automation of the plate turning device can be achieved by using this method.

(2) By using a television camera, the turning angle can be detected from a distance and with high accuracy.

[Brief explanation of drawings]

Figures 1 to 6 are shown to explain a method of an embodiment of the present invention, and Figure 1 (al is a side view of the plate rotary table, Figure 1 (bl is a plan view of Figure 1 Tal) , FIG. 2 is an explanatory diagram showing the image receiving screen and its scanning, FIG. 3 is a waveform diagram of the output signal of the vertex P, and FIG. 4 is a waveform diagram of the plate width signal due to scanning.
Fig. 5 is an explanatory diagram of the position of the rotation angle to be measured, Fig. 6 is a waveform diagram showing the degree of rotation and the rotation angle, Fig. 7 (al is a side view of a conventional plate rotary table, Fig. 7 (plane of bl) In the figure, 1.2 is a roll, 3 is a board, and 5 is a television camera.

Claims (1)

[Claims] In a plate turning device that rotates a plate by alternating rolls with a large diameter on the operating side and rolls with a large diameter on the drive side and rotating these two types of rolls in opposite directions, the amount of energy emitted from the plate is A television camera that detects ultraviolet rays is used to horizontally scan the above roll at regular intervals, and the scanning time required from the start of the horizontal scan to the detection of the plate, the scanning time from the detected edge of the plate to the end of the horizontal scan, and the horizontal The scanning line number and each minimum scanning time from the start of horizontal scanning to the board and from the end of the board to the end of horizontal scanning, and the scanning line number,
and a plate turning angle control method for a rolling mill, characterized in that the turning angle of the plate is detected from the first and last scanning times and scanning line numbers at which the plate signal is detected.