JPH02274355A - Method and instrument for detecting cutting separation of continuously cast material - Google Patents

Abstract

PURPOSE:To enable stable detection only with adjustment of visual field in a camera and change of decision area in an image memory even when surrounding conditions are bad by picking up a picture of a continuously cast material with an industrial telecamera from diagonal upper part at position apart from an apparatus and analyzing the photographed picture images. CONSTITUTION:The industrial telecamera 1 is set on a truck providing a gas torch for cutting the continuously cast material 10 and picture area 4 containing a first area 7 at upstream side and a second area 8 at downstream side in the continuously cast material 10 as centering the line 5 cut with the gas torch, is picked up while directing the telecamera toward the diagonal lower part, and stored to the image memory 2 as electric signal corresponding to the contrast of the image 6. At first, average value of intensities of electric signals of the whole picture element in the first decision area 7 is obtd. Successively, each electric signal of each picture element in the second decision area 8 is binarized with the average value in the first area 7 and converted into signal 0 and signal 1. Therefore, when number of picture elements of signal 1 to the whole number of the picture elements, is more than the preset deciding value, it is decided that the casting material is cut and separated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for detecting separation of a continuous cast material that is cut to a predetermined length.

(Prior art) In the steel industry, it is common for continuous casting machines to produce semi-finished products such as slabs and blooms, and these semi-finished products are processed by means such as gas torches in the final process of the continuous casting machine. It is cut to a predetermined length.

Conventionally, confirmation of cutting and separation using a gas torch has been carried out using a light emitting/receiving type detector 9 (for example, trade name: Laser Master, Hokuyo Electric Co., Ltd.) shown in FIGS. 6a and 6b.

The light emitting/receiving type detector 9 is composed of a pair of light emitting and light receiving detectors 9a and 9b installed on the left and right sides of the cutting line 5 of the continuous casting material 10 using a gas torch, and the light emitting/receiving type detector 9 is configured to receive light as shown in FIG. 6a. When the device 9b does not receive the laser beam projected from the light projector 9a, it is determined that the continuous casting material 10 is continuous.

As shown in FIG. 6b, when the light receiver 9b receives the laser beam projected from the light projector 9a, it is determined that the continuous casting material IO has been cut and separated.

In addition, as a prior art related to the present invention, Japanese Patent Application Laid-Open No. 59-104
No. 260 discloses a slab cutting speed control method, and JP-A-61-75227 and JP-A-61-
Japanese Patent No. 2093 discloses a temperature measuring device for a moving object using an imaging device.

[Problem to be solved by the invention]

Since the detector 9 is of a light emitting/receiving type, it is easily affected by the surrounding atmosphere, and in particular, when cutting free-cutting steel or stainless steel with gas, there is a lot of dust, which often causes false detection. Furthermore, since the detector 9 needs to be installed in the immediate vicinity of the conveyance line, there is thermal damage caused by heat radiation from the continuous casting material IO. Furthermore, recently, one continuous casting machine is often used to manufacture slabs, blooms, and billets of significantly different sizes, so it is recommended to install the detector 9 on the machine side to detect cutting of small billets. A difficult situation has arisen.

Further, the above-mentioned Japanese Patent Application Laid-Open No. 59-104260 discloses a method of controlling the movement of the torch based on the cutting sound of the fusing torch to facilitate cutting. Since the publication relates to a device that measures the temperature from the maximum brightness level of a video signal captured from the vertical direction of a moving object, it is difficult to detect separation by gas cutting of continuous casting material, which is the object of the present invention. Not applicable.

[Means and effects for solving the problem] The present invention has been made in view of such problems, and involves photographing a continuous cast material from diagonally above at a position away from the machine side using an industrial television camera. The present invention relates to a method and apparatus for detecting cutting and separation of a continuous cast material by analyzing this captured image.

When a continuous casting material is cut into a predetermined length with a gas torch, the cut surface is at a higher temperature than the other surfaces, so when photographed with an industrial television camera, the contrast of one side is different. Therefore, the present invention utilizes this difference in contrast to detect cutting and separation of continuous cast material.

Hereinafter, the content of the present invention will be explained in detail using the drawings.

FIG. 1 shows a detection device to which the present invention is applied. This detection device consists of an industrial television camera that photographs continuous casting material IO and converts it into an electrical signal. Image memory for storing electrical signals from an industrial television camera 2. and a signal processing bag W that calculates the stored electrical signals and determines whether to cut or separate the continuous casting material IO.
Consists of 3.

The industrial television camera 1 is installed on a trolley (not shown) equipped with a gas torch for cutting the continuous casting material 10, and faces diagonally downward to observe the line of the continuous casting material 10 to be cut by the gas torch. A predetermined area 4 including the upstream and downstream areas around point 5 is photographed.

Since the cart (not shown) travels in synchronization with the casting speed of the continuous casting material 1o, the photographing area 4 always photographs the same position of the continuous casting material 10.

As shown in FIG. 1, the industrial television camera 1 photographs the top surface of the continuous casting material 10 when the continuous casting material 10 is not being cut by the gas torch.

As shown in FIG. 2, when the continuous casting material 1o is cut with a gas torch, the upper surface on the upstream side of the cutting line 5 of the continuous casting material 10, and a portion of the cut surface and the upper surface on the downstream side are photographed.

The image of the area 4 photographed by the industrial television camera 1 is divided into 512×512 pixels and stored in the image memory 2 as an electrical signal corresponding to the contrast of the image.

FIGS. 3 and 4 show the cutting, separating and detecting method of the present invention.

This will be explained with reference to FIGS. 5a and 5b.

As shown in FIG. 3, after setting determination areas 7 and 8 of predetermined sizes on the upstream and downstream sides of the cutting line 5 of the continuous casting material image 6 stored in the 1-image memory 2, first The average value V7a of the electric signal magnitude of all pixels in the determination area 7 is determined. That is, as shown by the first-order equation (1), the cumulative value S7 of the magnitude of the electric signals of all pixels in the determination area 7 is obtained, and the total number of pixels is divided by N7.

V7 a = S7 / N7...
・(1) Also, this average value v7a is calculated from the peak value when a histogram of the number of pixels as shown in FIG. Almost match.

Next, each pixel (8t
t, 8t2..., 8mn) electrical signals (V 1
t +V 12 +””Vlln) Nitsuite No. (1)
Equation 4: Binarize with the average value v7a of the signal obtained by,
A signal smaller than V7a is converted to a 0 signal, and a signal of v7a7a is converted to a 1 signal. In other words, ■11~vIIInkuv7a: “0”V 11~V
When n≧V7a(7), “l” −・−(2).

As shown in FIG. 5a, when the continuous casting material 10 is not cut, the average value of the electric signal in the judgment area 8 set on the downstream side of the cutting line 5 almost matches V7a, which is the same as on the upstream side. Therefore, the number of pixels of the O signal and the number of pixels of the 1 signal are approximately equal.

On the other hand, as shown in FIG. 5b, the continuous casting material 10
When the continuous casting material 10 is cut, the cut surface of the continuous casting material 10 is photographed, so the electric signal level in the first judgment area 8 becomes significantly higher than the value in the judgment area 7.

Therefore, when the number of pixels N81 of signal 1 reaches a predetermined determination value or more with respect to the total number of pixels NB in determination area 8,
It is determined that the continuous cast material 10 has been cut and separated.

According to tests, the standard for this judgment may be set to about 90%.

By performing such calculations in the signal processing device 3 shown in FIG. 1, it is possible to detect the cutting and separation of the continuous casting material IO by the gas torch.

〔Effect of the invention〕

The present invention detects cutting separation by relative comparison of the contrast between the side surface of the continuous casting material and the cut surface, so stable detection is possible even under poor surrounding environmental conditions.

In addition, even when the sizes of slabs, blooms, and billets are significantly different, or when multiple blooms and billets are simultaneously cast instead of one, only the field of view of the industrial television camera and the judgment area of the image memory can be changed. It can be detected by

Furthermore, since the measurements are taken from a position away from the continuous casting machine, there are no problems such as heat damage to the detection device.

As described above, the present invention is industrially extremely excellent.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the overall configuration of a detection device implementing the present invention as an example, Fig. 2 is an explanatory diagram showing a photographed view of a continuous cast material in a cut state, and Fig. 3 is an explanatory diagram showing the setting of an image judgment area. FIG. 4 is an explanatory diagram showing the method for setting the determination level. FIGS. 5a and 5b are explanatory diagrams showing the method for determining cutting separation of continuous cast material. FIGS. 6a and 6b are FIG. 2 is an explanatory diagram showing a conventional detection method. Industrial TV camera (Industrial TV camera) Image memory (Image memory) Signal processing device (Signal processing means) Photographing area of the industrial TV camera Cutting line of continuous casting material with a gas torch Judgment area on the upstream side of the image of continuous casting material ( 1st judgment area) Downstream judgment area (2nd judgment area) Light emitting/receiving type detector
10: Continuous casting material pixel door 1 figure voice 3 figure voice 2 figure voice 4 figure mu, 4 (bald five) voice 5a cause voice 5b section J6a figure figure 6b

Claims (2)

[Claims] (1) A continuous cast material is photographed diagonally from above using an industrial television camera, and the image is stored as an electrical signal in an image memory. Set a first judgment area and a second judgment area downstream, calculate the average value of the electrical signals in the first judgment area, and calculate the average value and the value of each pixel in the second judgment area. Binarizing each pixel in the second determination area by comparison with an electric signal, and detecting whether or not the continuous casting material is cut and separated based on the number of pixels having one of the values resulting from the binarization. A cutting separation detection method for continuous casting material, characterized by: (2) An industrial television camera that photographs continuous casting material and converts it into electrical signals in pixel sections; An image memory that stores the electrical signals; Of the electrical signals stored in the image memory, the upstream side of the cutting position of the continuous casting material The average value of the electrical signals in the first determination area set at binarize each pixel in the second determination area,
A signal processing means for detecting whether or not the continuous casting material is cut and separated based on the number of pixels having one value obtained by the binarization.