JPH0423722B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for detecting the position in the width direction of a metal ingot in hot rolling equipment, continuous casting equipment, etc.

[Conventional technology]

In rolling or continuous casting processing, precise sheet width control is desired in order to improve product yield. In particular, in the case of hot rolling, the width of the rolled material widens due to the horizontal reduction in the rolling mill, but if rolling is repeated without this, the width of the product sheet will be much larger than the set value, and the later process The portion to be cut away due to side trimming, etc. increases, resulting in a decrease in yield.

On the other hand, meandering tends to occur in reverse rolling on a single stand and in tensionless rolling when passing the leading and trailing ends on a continuous stand, so it is necessary to detect the amount of meandering in the rolled material and adjust the left and right roll gaps. . However, with the conventional method of detecting and controlling meandering based on the difference in rolling load, it is possible to detect and control meandering based on the difference in rolling load that occurs when two pieces of the rolled material are bent due to end bending or when rolling irregularly shaped parts at the leading and trailing ends. It was determined that this was a phenomenon, and the reduction level adjustment was disrupted.
On the contrary, there were fatal flaws that caused the rolling industry to be disrupted.

Therefore, in recent years, it has become desirable to control the plate width or meandering of heated metal ingots such as hot-rolled materials and continuously cast materials with high precision, and optical methods are being used as a means of detecting the plate width or meandering, etc. A widthwise position detector has been developed. This device is based on the principle shown in FIG.

That is, the rolled material 1 is illuminated by a light emitter 2 from below the rolled material 1, and the amount of light received in the portion not shielded by the rolled material 1 is measured by the light receiver 3 provided above, that is, in the surface direction of the rolled material 1. This is to detect the board width. The light receiver 3 includes one using a photoelectric element (photodiode), one using a television camera type image pickup tube, etc., and the one using a photoelectric element will be explained below. The principle remains the same even when a television camera type image pickup tube is used. A plurality of photoelectric elements 5 are arranged in a straight line in parallel with the light projector 2 (a "bit" is generally used as a unit of number), and emit an electric signal 7 proportional to the amount of light received from an image focused through a lens 6. By thresholding the amount of received light at a constant level using a predetermined converter, the electric signal is converted into two types of synchronization signals 8: on and off. Since the focusing distance per 1 bit is determined by the focusing angle 2α (or focusing range L) of the lens 6 and the distance H between the rolled material 1 as the object to be measured and the lens 6, the total number of photoelectric elements is Assuming that W is N bits, the plate width W can be determined by the following formula.

W=L×{N-(N ₁ +N ₂ )}/N = 2Htanα×{N-(N ₁ +N ₂ )}/N
...() Therefore, it is possible to apply such a strip width detection means to detect meandering in rolled materials, etc., and this has already been done in some cases, but especially in hot rolling, when the rolled material itself Since the temperature is around .degree. C., it is effective to eliminate the light projector 2 shown in FIG. 1 and detect the light from the rolled material itself. The principle in this case will be explained with reference to FIG.
0 is provided, and the light from the rolled material 1 is detected by the light receivers 9 and 10. At the time of detection, the light receiving element 1
Light is focused for each of the 1st and 12th 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 element 11 and each bit of the light receiving element 11 is shown in FIG. Detected as . Note that FIG. 3 is referred to as a video signal. Third
In the figure, _ts is the scanning period required to scan all the bits of the respective light receiving elements 11 and 12, and V is the voltage representing the difference in light amount at the width end of the rolled material.

Incidentally, since the temperature generally varies depending on the type of rolled material, a difference occurs in the amount of light entering the light receivers 9 and 10 shown in FIG. 2 depending on the temperature. That is, when the scanning period t _s is increased for a hot rolled material, the time for light to enter the light receiving elements 11 and 12 becomes longer, and a large amount of weak light emitted from the rolled material and reflected on the roller table etc. is also transmitted to the light receiving elements 11 and 12. As a result, as shown in FIG. 4A, the voltage V suddenly rises at a position away from the rolled material 1, and the detection accuracy at the width end portion deteriorates. On the other hand, if the scanning period _ts is too short, the time for light to enter each bit of the light receiving elements 11 and 12 will be shortened, and as a result, the light will not be sufficiently received by the light receiving elements 11 and 12, resulting in the problem shown in FIG. The voltage V as shown
There is a possibility that the level of the plate width end detection signal will not reach the reference threshold level voltage _VL , and detection will become impossible. Therefore, it is necessary to automatically control the scanning period _ts , to keep the amount of light received by the light receiving elements 11 and 12 constant, and to adjust the voltage V as shown in Fig. 4C. .

[Problem that the invention seeks to solve]

According to the present invention, when detecting the widthwise position of a hot metal lump, the scanning period is set to an optimal time corresponding to the temperature of the metal lump, and the widthwise position of the metal lump is accurately detected. This was done to solve the problem.

[Means for solving problems]

In the present invention, the light receiving element is composed of a group of light receiving elements that receive light emitted from a heated metal lump and a lens, and the light receiving element is configured to scan in the width direction of the metal lump, and the detection means detects the light emitted by the detection means. a comparison means for comparing the video signal voltage of the metal block and a voltage at a preset level and outputting a signal when the video signal voltage exceeds the voltage at the set level; and a comparison means for receiving the signal from the comparison means. storage means for storing the address of the light-receiving element of the detection means at that time, the address sent from the storage means and an address near the address of the light-receiving element where the voltage of the set level is generated; A subtraction means for calculating the difference compares the difference between the address of the light receiving element obtained by the subtraction means and the count number of clock pulses counted at the start of scanning, and the count number of clock pulses is determined by the received light sent from the subtraction means. Comparing means gives a command to close a predetermined switch when the difference in address of the element becomes larger than the difference, and when the switch is closed, the metal block is scanned in the width direction at a speed corresponding to the video signal voltage held. Means for calculating the difference in signal voltage for each bit is provided.

Therefore, the metal block is scanned in the width direction by the detector, and 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 approximately at the intermediate level of the video signal obtained by the scanning. , the metal block is scanned in the width direction according to the determined scanning period, the voltage difference is calculated for each bit of the video signal, the position where the maximum voltage difference is obtained is found, and the width end of the metal block at that position is calculated. It can be the location.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, how to determine the scanning time (scanning period) will be explained with reference to Fig. 5 A and B and Fig. 6 A and B.
An element from which a signal of threshold level voltage V _L is obtained when the widthwise position of the rolled material is detected by scanning in the width direction of the rolled material for a predetermined scanning time with a detector having N bits of elements. If the address is N _C address, detect the voltage V _T at N _T address before it,
The scanning time is determined from the magnitude of this voltage V _T .
For example, in the case of a video signal with a small amount of light as shown in Figure 5 (a), the signal at the edge of the plate is attenuated, and as shown in Figure 5 (b), the voltage V _T before address N _T becomes low, so the scanning time is lengthened. However, in the case of a video signal with a large amount of light as shown in Figure 6A, the rise of the signal at the edge of the board is steep, and as shown in Figure 6B, the voltage V _T before the N _T address increases.
is high, so shorten the scanning time.

Next, the case where the calculation timing of the width direction position of the rolled material is scanned from the center of the metal mass toward the width end direction will be explained with reference to FIG. In the first scanning cycle from detection development point A, the threshold level voltage
The obtained N _C address of V _L is detected, and in the second scanning period, from the N _C address of the first scanning period, N _T
At the same time as sampling and holding the voltage V _T before the address, the N _C address obtained from the threshold level voltage V _L in the second scanning period is stored again, and in the third scanning period, the N _T address obtained in the second scanning period is stored. The detector is controlled to correspond to the voltage V _T of the rolled material, the width end position of the rolled material is calculated, and the result B is output. In the 4th scanning cycle, the position is N _T before the N _C address in the 2nd scanning cycle. At the same time, sample and hold the voltage V _T of _{N C}
The address is memorized again, and in the 5th scanning cycle, the detector is controlled to correspond to the voltage V _T at address N _T obtained in the 4th scanning cycle, and the width end position of the rolled material is calculated, and the result B is Similarly, at even-numbered addresses, the voltage V _T at the N _T address before the N _C address in the previous scanning cycle is sampled and held, and the threshold level voltage V _L in the corresponding scanning cycle is obtained. The N _C address is memorized again, and in the odd scanning cycle, the detector is controlled so as to correspond to the voltage V _T at the N _T address obtained in the previous scanning cycle, and the width end position of the rolled material is calculated. The result will be output. When scanning from the end direction of the metal lump plate to the center, N _C and V _T can be obtained simultaneously in the first scanning period, so the calculation result B is output in the second scanning period.

Next, to explain how to calculate the width end position of the rolled material using Fig. 8, the voltage difference of the video signal is calculated for each bit of the light receiving element, and the address where the maximum voltage difference is obtained is calculated. Assume that there is a width end of the rolled material at . That is, if the voltage of the video signal obtained by the light-receiving element before address 1 is V _i and the voltage of the video signal obtained by the light-receiving element at the current address is V _{i +1} , then
The voltage difference ΔV _i+1 =V _i+1 −V _i is calculated in sequence, and the address N _E of the light-receiving element with the largest voltage difference ΔV _i+1 is set as the width end. The scanning direction in this case may be from the center side to the width end side of the rolled material, or may be from the width end side to the center side.

Next, a specific example of determining the scanning period of the width end portion of a rolled material in the present invention will be explained with reference to FIG.

In the figure, 21 is a comparator that compares the rolled material video signal voltage V detected by a detector (not shown) with a set threshold level voltage V _L and outputs a signal when V≧V _L ; is the clock pulse count number N _C (N _C
23 is a memory circuit for storing the clock pulse count N _C stored in the memory circuit 22 by the enable signal V _I from the detector, and 24 is a memory circuit for storing the clock pulse count from the memory circuit 23. Count number N _C and setting device 2
A subtraction circuit 26 subtracts the count number N _T set in step 5, and a subtraction circuit 26 subtracts the count number N C −N _T before the N _{T address from the N C address} sent from the subtraction circuit 24 and the count number N _C −NT sent from the counter 27. The count number at counter 27 is compared with the count number N _C − N _T
A comparator capable of outputting a signal when the signal becomes larger, 28 is a switch that closes in response to a command signal from the comparator 26, and 29 holds the voltage V _T of the rolled material video signal at that time when the switch 28 is closed. sample hold circuit, 30 is gain,
31 is a V/F conversion circuit that converts a voltage signal into a pulse of a corresponding frequency; 32 is a counter that counts the output pulses of 31; and 33 is a start pulse generation circuit.

All counters 27 and 3 are activated by the start pulse.
2 is cleared, and at the same time the count of clock pulses with a frequency corresponding to the initial voltage V _O is counted by counter 3.
Started by 2. Further, the video signal voltage V generated in the light receiving element of the detector by the light emitted by the rolled material is outputted to the comparator 21 for each bit, and the comparator
V′−V _L is compared and calculated. When V≧V _L , a signal is output from the comparator 21 to the memory circuit 22, and the count number N _C of clock pulses at that time is stored in the memory circuit 22.

When an enable signal is generated from the detector, the count number N _C is transferred to the storage circuit 23, and at the same time, N _C -N _T is calculated in the subtraction circuit 24, and the sample and hold circuit 29 goes into a standby state.

When the clock pulse has finished counting the number of light-receiving elements of the detector, a start pulse is generated again, and the comparator 26 compares the clock pulse count with N _{C -NT} , and the clock pulse count becomes N _C -.
When it becomes larger than N _T , the output signal from the comparator 26 closes the switch 28, and the voltage V _T of the video signal at that time is at the address N _T before the address N _C of the light receiving element corresponding to the threshold level voltage V _L. It is held in the sample hold circuit 29 as a video signal. At the same time, the threshold level voltage in this scanning period
The count number N _C corresponding to V _L is obtained in the same manner as described above and stored in the storage circuit 22.

Furthermore, an enable signal V _I is generated from the detector,
The assert pulse is generated again, the selector switch 40 is switched, and counting of clock pulses at a frequency corresponding to the voltage V _T is started.

Thereafter, the above sequence is repeated and the scanning period is controlled to be optimal in accordance with the brightness of the rolled material. Note that it goes without saying that the value of V _L can be changed as appropriate by adjustment.

Next, a specific example of detecting the width end portion of a rolled material will be described with reference to FIG.

In the figure, 34 indicates the voltage V _i+1 of the video signal obtained from the light receiving element at the current address and the signal sent from the shift register 35 for each pulse of the clock pulse C when determining the width end of the rolled material. A comparator 39 compares and calculates the voltage V _i of the video signal obtained from the light-receiving element in front of address 1, the voltage difference ΔV _i+1 = V _i-1 − V _i sent from the comparator 35. and the voltage difference _{ΔV i} sent from the shift register 37 at a point before,
The comparator 38 for calculation is a storage circuit that stores the number of clock pulses N _E (address N _E of the light receiving element) counted by the counter 39 up to that time when ΔV _i+1 >ΔV _i .

The voltage V _i+1 of the rolled material video signal and the voltage V _i of the video signal at the previous address stored in the shift register 35 are sent to the comparator 34, and the comparator 34 converts the voltage V i for each pulse of the clock _pulse C. The difference between ₊₁ and _Vi is compared and calculated, and the voltage difference ΔV _i+1 is output from the comparator 34. Further, the value of the video signal in the shift register 35 is updated every pulse of the clock pulse C.

The voltage difference ΔV _i+1 outputted from the comparator 34 is compared and calculated with the voltage difference ΔV _i one time before in the comparator 38, and when ΔV _i+1 > ΔV _i , the counter 39 counts by then. The number of clock pulses N _E obtained is stored in the memory circuit 38. This clock pulse number N _E becomes the width end position of the rolled material. Further, the value of the voltage difference in the shift register 37 is updated every pulse of the clock pulse C.

In the embodiments of the present invention, a case has been described in which the position of the width end of a rolled material is detected, but it is applicable not only to rolled materials but also to any high-temperature metal ingot. It goes without saying that it can be configured by software 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.

〔Effect of the invention〕

According to the method and device for detecting the widthwise position of a metal lump of the present invention, it is possible to obtain an appropriate video signal of the edge of a rolled material plate, and it is also possible to accurately detect the width end position of a metal lump. .

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the principle of detecting the widthwise position of a material such as a metal lump, Fig. 2 is an explanatory diagram of the principle of detecting the widthwise position of a heated metal lump, and Fig. 3 is an explanatory diagram of the principle of detecting the widthwise position of a material such as a metal lump.
The graph shown in the figure shows the relationship between the signal representing the difference in light amount that occurs at the width edge and the scanning time in the case of width direction position detection. 5A is an explanatory diagram showing the change in the output signal due to a change in the amount of light. FIG.
An explanatory diagram of the signal voltage at a predetermined address that is sampled and held in the case of the video signal in Figure A, Figure 6A is an explanatory diagram of the video signal in the present invention when the amount of light is large,
FIG. 6B is an explanatory diagram of the signal voltage at a predetermined address sampled and held in the case of the video signal of FIG. 6B,
Fig. 7 is an explanatory diagram of an example of calculation timing when scanning a metal lump according to the present invention, Fig. 8 is an explanatory diagram of the principle of detecting the width end position of a metal lump according to the present invention, and Fig. 9 is an explanatory diagram of the principle of detecting the width end position of a metal lump according to the present invention. FIG. 10 is an explanatory diagram of an embodiment embodying the means for determining the scanning period in the present invention, and FIG. FIG. In the figure, 21 is a comparator, 22 and 23 are storage circuits, and 2
4 is a subtraction circuit, 26 is a comparator, 27 is a counter,
28 is a switch, 29 is a sample hold circuit,
31 is a V/F conversion circuit, 32 is a counter, 33 is a start pulse generation circuit, 34 is a comparator, 35 is a shift register, 36 is a comparator, 37 is a shift register, 38 is a storage circuit, and 39 is a counter.

Claims (1)

[Claims] 1. 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 moved in the width direction 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 scanning period is determined by the determined scanning period. A method for detecting a position in the width direction of a metal lump, characterized by scanning the lump in the width direction, calculating a voltage difference for each bit of a video signal, and finding a position where the maximum voltage difference is obtained. 2. A detection means configured by a light-receiving element group and a lens that receive light emitted from a heated metal lump and capable of scanning the metal lump in the width direction, and a video signal voltage of the metal lump detected by the detection means. and a voltage at a preset level, comparing means for outputting a signal when the video signal voltage exceeds the voltage at the set level, and receiving a signal from the comparing means;
A storage means stores the address of the light receiving element of the detection means at that time, and the output of the storage means is compared with the count number of clock pulses counted at the start of scanning, and the count number of clock pulses is greater than the output of the storage means. a comparison means for giving a command to close a predetermined switch when the switch is closed; a means for changing the scanning period based on the video signal voltage held when the switch is closed; 1. A width direction position detection device for a metal lump, characterized in that it is provided with means for calculating the width direction position of a metal lump.