JPS6282306A - Method and device for detecting breadthwise position of metallic ingot - Google Patents

Abstract

PURPOSE:To accurately detect breadthwise end positions without being affectddb disturbance by scanning a photodetecting element breadthwise, and comparing the voltage of a video signal of evey bitwith a threshold voltage and calculating the voltage difference of a video signal of every bit. CONSTITUTION:When a breadthwise position of a rolled material is detected, a voltage Vi+1 of the video signal A of the rolled material and the voltage Vi of a video signal which is stored in a shift register 14 and one address before are sent to a comparator 13 at intervals of one clock pulse C. The difference between the both is calculated by comparison and outputted to a comparator 15 and a shift register 16. The register 14 updates the value of the signal A at intervals of one pulse C. The voltage difference obtained by the comparator 13 and the last voltage difference which is stored in the register 16 are processed 15 by comparison and the sign of the resulting signal is discriminated 17. The voltage Vi+1 of the signal A, on the other hand, is compared with the threshold voltage VL momentarily and sent to a storage circuit 19. In this case, when the output of the comparator 15 becomes negative, a discrimination device 17 sends a clear pulse CE to a circuit 19 to discard its address and the address of the real breadthwise end position remains in the circuit 19.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of detecting the widthwise position of a high-temperature metal lump even when disturbances such as water or water vapor block the detection calculation field of view.
The present invention relates to a method and apparatus for detecting the widthwise position of a metal lump, which enables the width end position of the metal lump to be detected with good accuracy.

[Prior Art] In rolling or continuous processing, precise sheet width control is desired in order to improve product yield. Particularly in the case of hot rolling, when rolling n-'c horizontal reduction occurs, the width of the rolled material widens;
If rolling is repeated with this condition left as is, the width of the product sheet will be much larger than the set value, and the portion to be cut off during side trimming or the like in the subsequent process will increase, leading to a decrease in yield.

On the other hand, meandering tends to occur during reverse rolling in a jingle stand and in tensionless rolling when passing the leading and trailing ends in a continuous stand.
It is necessary to adjust the left and right roll gaps. However, with the conventional method of detecting and controlling meandering based on the rolling load difference, the difference in rolling load that occurs during rolling of irregularly shaped parts at the leading and trailing ends of the rolled material due to the bending of the two ends is detected and controlled. There were fatal flaws such as a tax error, which disrupted the rolling reduction level adjustment and even caused the rolling operation to be interrupted.

Therefore, in recent years, it has become desirable to control the plate width or meandering of heated fL metal ingots such as hot-rolled materials and continuous cast materials with high precision. A target width direction position detector has been developed. This device u is based on the principle shown in FIG.

That is, the rolled material 1 is illuminated by the floodlight 2 from below the rolled material 1.
The light receiver 3 provided above, that is, in the surface direction of the rolled material 1, measures the received light ω in a portion not shielded by the rolled material 1, thereby detecting the sheet width. The light receiver 3 includes one that uses a photodiode, one that uses a television camera type image pickup tube, etc., but one that uses a charging element will be described below. The principle remains the same even when a television camera angle tube is used. A plurality of photoelectric elements 4 are arranged in a straight line parallel to the projector 2 (
"bit" is generally used as a unit of quantity), lens 5
It emits an electrical signal 6 proportional to the received light value of the elephant focused through the lens. This received light is thresholded at a partial level by a predetermined converter, thereby converting the electrical signal into two types of Domei signals 1: on and off. The focusing distance per bit is determined by the focusing angle 2α (or focusing range L) of the lens 5 and the distance l! between the rolled material 1 as the object to be measured and the lens 5! !
! Since it is determined by iH, if the total number of photoelectric elements is N bits, the plate width W can be determined by the following equation.

w-L, x (N-(Nl +N2))/N=2H
CanαX (N (Nl +N2 > )/N
-□□C:) Therefore, it is possible to apply such a strip width detection means to detect meandering of rolled materials, etc., and this has already been done in some cases. is 80
Since the temperature is around 0° C., it is effective to eliminate the floodlight 2 shown in FIG. 4 and detect the light from the rolled material itself. The principle in this case will be explained with reference to FIG.
to detect light. At the time of detection, the light receiving element 10
．． Light is focused for each of the 11 bits, and a voltage proportional to the intensity of the focused light is generated for each bit. For example, the relationship between the voltage detected by the light-receiving grating 10F and each bit of the light-receiving element 10 is shown in FIG. Detected. Note that FIG. 6 is referred to as a video signal. In FIG. 6, ts represents each light receiving element 10.1
The scanning voltage required to scan all bits of 1 is the voltage representing the optical difference at the width edge of the rolled material.

By the way, since the temperature generally varies depending on the type of rolled material, a temperature difference occurs in the amount of light entering the light receiver 8.9 shown in FIG. 5. In other words, when the distance ts between scanning ports is increased in a rolled material having a high temperature, the time for light to enter the light receiving element 10. As a result, as shown in FIG. 7A, the voltage V suddenly rises at a position away from the rolled material 1, and the detection accuracy at the width end portion deteriorates. If the scanning time ts is too short for correspondence, the time for light to enter each bit of the light receiving element 10.11 will be shortened.
As a result of insufficient light being received by the light-receiving elements 10 and 11, the level of the voltage V decreases as shown at the bottom of FIG. There is a risk that detection will not be possible.

Therefore, the scanning time ts is automatically controlled, and the amount of light received by the light receiving element 1oyti is always kept constant.
It is necessary to adjust the voltage V as shown in 8 of FIG.

Therefore, the inventor of the present application, for example, in Japanese Patent Application No. 59-77214
As shown in No. 1iJ, when detecting the width end position of a metal lump using a detector composed of a light receiving element group and a lens that receive light emitted from a heated metal lump, the light receiving element is placed at the center of the metal lump. The scanning period is determined from the amount of light received by a light-receiving element near the light-receiving element that generates a voltage at a preset level in the video signal obtained by the scanning, and the detection calculation is performed. The light-receiving element is scanned from the center side of the metal mass in the width direction at a determined scanning period, and the address of the light-receiving element that generates a voltage at a preset level is determined to accurately locate the widthwise position of the metal mass. We proposed a detection method and device.

[Problems to be Solved by the Invention] However, in the method and device for detecting the position in the width direction of a metal lump described above, water vapor, water,
There is a problem in that if it is blocked by disturbances such as oxide scale, it is not possible to accurately detect the width end position of the metal lump.

In view of the above-mentioned circumstances, the present invention has been made with the object of making it possible to accurately detect the width end position of a metal lump without being affected by disturbance.

"Means for Solving the Problems" The present invention provides a method for detecting the width end position of a metal lump using a detector consisting of a group of light receiving elements and a lens that receives light emitted from a heated metal lump. The voltage difference of the video signal for each bit obtained by scanning the element in the width direction of the metal block is calculated, and the video g! Compare the signal with a predetermined threshold voltage, memorize the address at the time when the sign change occurs in the difference, and compare the voltage difference between the current video signal and the voltage difference between the video signals one point before. If there is a change in the positive or negative sign of the difference between the voltage differences of the 9 signals displayed at that point and the voltage difference of the video signal one point before within several points after the performance, the above-mentioned memorized Discard the address of the light receiving element,
If there is no change in the positive or negative sign of the difference between the voltage difference between the video signals at that point in time and the voltage difference between the video signals at a point before, the video signal voltage becomes lower than a predetermined threshold voltage. The address of the light-receiving element stored at the time when the address of the light-receiving element is recognized as the width end position of the metal lump is provided.

[Function] Therefore, in the present invention, the light-receiving element is scanned in the width direction of the metal base, and the voltage of the video signal for each bit is compared with the threshold voltage. When the signal voltage difference is calculated and the sign of 10 changes between the current video signal voltage difference and the video signal voltage difference one point before, the address at that point is at the width end of the metal block. If the sign of the voltage difference does not change, the address where the voltage of the video signal at that point is lower than the preset threshold voltage is the width end position of the metal block. It is said that

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

First, the principle of the present invention will be explained with reference to FIGS. 2 and 3. The video signal shown in FIG. 2 is not affected by disturbances such as water vapor, water, and oxide scale, and the video signal shown in FIG. are affected by external disturbances, and all of them are obtained by scanning a charging element using, for example, a photodiode in the width direction of the rolled material 1 at a predetermined scanning period. The method of scanning and how to adjust the scanning period is described in the patent application filed in 1973.
Is it indicated in the specification λ of No. 8-238540 and the specification of Japanese Patent Application No. 59-77214? 1'' Explanation will be omitted.

Now, in FIG. 2, assuming that the video signal is scanned from the center of the rolled material 1 in the width direction, the preset threshold voltage VL and the voltage at each address are sequentially compared, and VL
Address NE of the light receiving element that provides the smaller voltage VE
is determined to be the board width end.

By the way, as shown in FIG. 3, for example, when a scale 12 is placed on the rolled material 1 and the amount of light entering the light receiving element from that part decreases, the voltage of the video signal of the corresponding light receiving element drops. In this state, if the width end position of the rolled material 1 is determined by the method explained in FIG. 2, the width end position will be determined as the part on which the scale 12 is placed, resulting in a large error in detection.

In the present invention, in order to prevent this, the voltage difference between the video signal at each address and the one before it, that is, AV1+□=i
Sequentially find VLya, check the sign change at each point in time of the obtained "i+1", and if a sign change occurs, set the address that gives a voltage smaller than the threshold in the video signal obtained at that point. , i.e., the third
In the figure, when i = +1, AVk+, -Vk-■ +, >0 are obtained, and since Vk+ and <V are set, address Nk+□ is determined to be the width end position. However, at the next i= +2nd time point r t, t, ``k+2- vk+1'' +2
<O, and the sign changes from positive to negative. As can be seen from FIG. 3, such a sign change never occurs at the width end position.

Therefore, when this sign change is detected and occurs, the address Nk+ which is Vk+1<VL which has been obtained up to that point
□ is rejected. By doing so, it is possible to accurately determine the address corresponding to the end position of the rolled material on the light receiving element without being affected by disturbances such as scale. Figures 2 and 3
Although the figure shows a case in which the scanning direction is scanned from the center of the rolled material 1 toward the width end, the same applies to the case where the scanning direction is scanned from the width end toward the center. In this case, the sign of the voltage difference changes from negative to positive, and the address at which the voltage difference first becomes larger than the threshold voltage VL is the width end position. Therefore, no matter which direction you scan, the video signal and threshold voltage are compared,
It is sufficient to find the address of the video signal at the time when the sign change occurs.

Next, with reference to FIG. 1, a specific example of the present invention will be described regarding scanning from the center side to the width end direction.

In the figure, A is a video signal obtained by scanning the detection calculation photoelectric element in the width direction of the rolled material as disclosed in the above-mentioned specification, and 13 is the image signal of the address currently being scanned for each pulse of the clock pulse C. Voltage V of the video signal obtained by the light receiving element
A comparator 15 compares and crushes the voltage Vi of the video signal obtained at the light receiving element in front of address 1 sent from the shift register 14, and the voltage difference A sent from the comparator 13. Vi or □-vi+1 'i and the ゛+-11 difference A sent from the shift register 16 at the previous point.
Vi = vi -Vi-1 and wo comparison Ll 'I comparator, 17t, i sign discrimination circuit for determining the sign of the output signal of comparator 15, 18 is voltage to video Ci, and threshold. A comparator that compares the hold voltage LL V L,
19 stores the address of the video signal that gives a voltage smaller than the threshold voltage VL compared by the comparator 18, and when the clear pulse CE from the code discrimination circuit 17 is input, the stored address is changed to East 7J]. A memory circuit 20 is a counter that counts the number of clock pulses C and sends it to the memory circuit 19 as an address.

When detecting the rolled H width end position, the video signal △ of the rolled material is
The voltages V and + of the video signal stored in the shift register 14 before the first address are sent to the comparator 13 every pulse C, and the difference between the two is A.
V, = V, -V,, 1+1 1 and the voltage difference AV is input to the comparator 131+
1 to the comparator 15 and shift register 16.

Further, in the shift register 14, the value of the video signal is updated every pulse of the clock pulse C.

The voltage difference AVi+1 output from comparator 13 is
3, the signal is stored in the shift register 16 and compared and sieved by the voltage difference av, av, -7111v, before the iter point, and the signal is output to the sign discriminator 17. It is determined whether the output from the comparator 15 is positive or negative.

On the other hand, the voltage V,+ to the video signal is constantly compared with the threshold voltage VL by the comparator 18 and sent to the storage circuit 19, but since VL > V at the Nk address, at this point the Nk address The value +L remains in the storage circuit 19. If this continues, the Nk address will be mistakenly recognized as the width end of the rolled material, but if the output of the comparator 15 becomes negative, the sign determination circuit 17
A clear pulse CE is then sent to the memory circuit 19, and the address Nk is rejected. Through this operation, the address NE of the light receiving element representing the true width end position of the rolled material 1 is stored in the memory circuit 19.
remains in

Further, in the shift register 16, the value of the voltage difference is updated every pulse of the clock pulse C.

As described above, even if the detection calculation field of view is partially blocked by steam, water, etc., or if water, oxidized scale, etc. remain on the rolled material, the width end portion of the rolled material can be accurately determined.

J3. In the embodiments of the present invention, the case of detecting the position of the width end of a rolled material has been described, but the present invention is applicable not only to rolled materials but also to any metal as long as it is a high-temperature metal lump. It goes without saying that the device can be configured by a computer or by hardware such as an electronic circuit, and that various other changes can be made without departing from the gist of the present invention.

[Effects of the Invention] According to the method and device for detecting the position in the width direction of a metal lump of the present invention, water vapor, water, oxide scale, etc. can be avoided when measuring the end position of a heated metal lump with an optical detector. This has the excellent effect of eliminating the influence of disturbances that cannot be measured, making it possible to perform highly accurate measurements.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example embodying the method and device for detecting the position in the width direction of a metal lump according to the present invention, and FIGS. An explanatory diagram of the principle, Fig. 4 is an explanatory diagram of the principle of detecting the widthwise position of a material such as a metal lump, Fig. 5 is an explanatory diagram of the principle of detecting the widthwise position of a heated metal lump, Fig. 6 is not shown in Fig. 5, but is a graph showing the relationship between the scanning time and the signal representing the light m difference generated at the width edge in the case of width direction position detection, and Fig. 7 is a graph showing the relationship between the scanning time and the signal representing the light m difference generated at the width edge in the case of width direction position detection. FIG. 3 is an explanatory diagram showing changes in output signals due to changes in scanning time when scanning. In the figure, 13 is a comparator, 14 is a shift register, 15 is a comparator, 16 is a shift register, 17 is a sign discrimination circuit, 18
is a comparator, 19 is a storage circuit, and 20 is a counter. Ward\! Shocking Ward Ward Ln ■ Palpation ni (＊＼

Claims (1)

[Claims] 1) When detecting the width end position of a metal lump using a detector consisting of a light receiving element group and a lens that receive light emitted from a heated metal lump, the light receiving element is moved in the width direction of the metal lump. The video signal voltage for each bit obtained by scanning is compared with a predetermined threshold voltage, and the address of the video signal at the time when a sign change occurs is memorized. A position in the width direction of a metal block, characterized in that the voltage difference between the current video signal and the video signal one time before is calculated, and if a sign change occurs in the voltage difference, the stored address is discarded. Detection device. 2) A detector consisting of a light-receiving element group and a lens that receives the light emitted by the heated metal lump and is capable of scanning the metal lump in the width direction, and a detector that detects the video signal of the detected predetermined location and the nearest location. A comparator that compares and calculates the voltage difference between video signals, a comparator that compares and calculates the voltage difference between the current video signal sent from the comparator, and the voltage difference between the video signal at a point before, and the current video signal. A sign discrimination circuit that determines the positive or negative sign of the voltage difference between the signal and the voltage difference of the video signal at one point before and outputs a clear pulse when the sign changes; A comparator that compares and calculates the difference between the output of the comparator and a threshold voltage, and when a sign change occurs in the output of the comparator, the address of the light receiving element at that time is memorized and a clear pulse is sent from the sign discrimination circuit. A device for detecting a position in the width direction of a metal lump, further comprising a memory circuit for discarding the stored address of the light-receiving element.