JPH0585256B2 - - Google Patents

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.

[Conventional technology]

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 cut into predetermined lengths using a gas torch or other means in the final process of the continuous casting machine. be done.

Conventionally, confirmation of cutting and separation using a gas torch has been performed using a light emitting/receiving type detector 9 shown in FIGS. 6a and 6b.
(For example, the product name is Laser Master, manufactured by Hokuyo Electric Co., Ltd.).

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. 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 10 has been cut and separated.

In addition, as a prior art related to the present invention, Japanese Patent Application Laid-open No. 59-
104260 discloses a slab cutting speed control method, and JP-A-61-75227 and JP-A-Sho.
61-2093 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, thermal damage may occur due to heat radiation from the continuous casting material 10. moreover,
Recently, a single continuous casting machine is often used to manufacture slabs, blooms, and billets of significantly different sizes, making it difficult to install the detector 9 on the machine side to detect cutting of small billets. A situation is occurring.

Further, the above-mentioned Japanese Patent Application Laid-Open No. 59-104260 discloses a method of controlling the movement of a fusing torch based on the cutting sound of a cutting 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 actions for solving the problem]

The present invention was made in view of these problems, and it is possible to continuously cast materials by photographing them with an industrial television camera from diagonally above at a position away from the machine side, and by analyzing the photographed images. The present invention relates to a method and apparatus for detecting cutting and separation of materials. 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 on both sides will be 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 includes an industrial television camera 1 that photographs a continuous casting material 10 and converts it into an electric signal, an image memory 2 that stores the electric signal of the industrial television camera 1, and an image memory 2 that calculates the stored electric signal and performs continuous casting material 10
It consists of a signal processing device 3 that determines whether to cut or separate the signals.

The industrial television camera 1 is installed on a truck (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 10, 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 cut by the gas torch.
As shown in FIG. 2, when the continuous casting material 10 is cut with a gas torch, the upper surface of the continuous casting material 10 on the upstream side of the cutting line 5 and a portion of the cut surface and the upper surface on the downstream side are photographed.

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

The cutting separation detection method of the present invention is shown in FIGS. 3 and 4.
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 image memory 2, respectively, first, The average value V _7a of the magnitude of the electric signals of all pixels in the determination area 7 is determined. In other words, as shown in the following equation (1), the cumulative value of the magnitude of the electrical signals of all pixels in the determination area 7
Find S ₇ and divide it by the total number of pixels by N ₇ .

V _7a = S ₇ /N ₇ ...(1) Also, this average value V _7a is determined by the histogram of the number of pixels as shown in FIG. almost matches the peak value when created.

Next _, each electric signal _{( V 11} ,
V ₁₂ , . . . V _no ) are binarized using the average value V _7a of the signal determined by equation (1), and signals smaller than V _7a are converted to 0 signals and signals larger than V _7a are converted to 1 signal.
That is, when V ₁₁ to _{V no} <V _7a , it is “0” and when V ₁₁ to V _no ≧V _7a , it is “1” (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 V _7a , which is the same as on the upstream side. Therefore, the number of pixels for the 0 signal and the number of pixels for the 1 signal are approximately equal.

On the other hand, as shown in FIG. 5b, 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 determination area 8 is lower than the value in the determination area 7. significantly higher.

Therefore, when the number of pixels N ₈₁ of the signal 1 reaches a predetermined determination value or more with respect to the total number of pixels N ₈ in the determination area 8, it is determined that the continuous casting material 10 has been cut and separated.

According to tests, the standard for this judgment should be set at around 90%.

The signal processing device 3 shown in FIG.
By doing this, it is possible to detect the cutting and separation of the continuous casting material 10 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 if the sizes of slabs, blooms, billets, etc. are significantly different, or if multiple blooms or billets are cast simultaneously instead of one,
It can be detected simply by adjusting the field of view of an industrial television camera and changing the determination area of the image memory.

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 the drawing]

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. 1: Industrial television camera (industrial television camera), 2: Image memory (image memory), 3: Signal processing device (signal processing means), 4: Photographing area of industrial television camera, 5: Gas torch of continuous casting material cutting line, 6: image of continuous casting material, 7: upstream judgment area (first judgment area), 8: downstream judgment area (second judgment area), 9: light emitting/receiving type detector, 10: Continuous casting material, 11: Pixel.

Claims (1)

[Claims] 1. A continuous cast material is photographed diagonally from above with an industrial television camera, and this is stored as an electrical signal in an image memory, and among the information stored in the image memory, the cutting position of the continuous cast material is captured. A first judgment area is set on the upstream side and a second judgment area is set on the downstream side, the average value of the electrical signals in the first judgment area is calculated, and the average value and the second judgment area are calculated. Binarize each pixel in the second determination area by comparing it with the electric signal of each pixel, and determine whether or not the continuous casting material is to be 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 detecting. 2. An industrial television camera that photographs the continuous casting material and converts it into electrical signals in pixel divisions; An image memory that stores the electrical signals; Of the electrical signals stored in the image memory, the electrical signals are set upstream of the cutting position of the continuous casting material. The average value of the electrical signals in the first determination area is calculated, and the electrical signal of each pixel in the second determination area set downstream of the cutting position is compared with the average value. Continuous casting comprising: a signal processing means for binarizing each pixel in the second determination area and detecting whether or not the continuous casting material is cut and separated based on the number of pixels having one value resulting from the binarization; Material cutting separation detection device.