JPH05249051A - Detecting apparatus of imperfection of solvent of ingot bloom - Google Patents

Abstract

PURPOSE:To detect a place of imperfection of a solvent accurately by a method wherein image information from CCD cameras disposed immediately behind hot scarfer installations is subjected to an image processing and the quality of the solvent is determined from a change in luminance of an ingot bloom. CONSTITUTION:Using picked-up image signals from CCD cameras 1a to 1d, an image processing device 2 subjects data obtained from each pixel of CCD to luminance conversion and then to a binary-coding processing. In the device 2, besides, a luminance change rate distribution is computed from luminance distribution data obtained from a luminance change rate and then it is binary- coded. An area wherein the luminance or the luminance change rate is high and an area wherein it is low are discriminated from each other by the device 2 and the result is sent to a personal computer 3. Receiving the signals subjected to the image processing and sent from the device 2 and manufacture information being necessary for detection of imperfection of a solvent and obtained from CPU 5, the personal computer 3 analyzes the signals from the device 2 and determines whether or not the imperfection of the solvent exists on the four sides of an ingot bloom W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a smelting process that occurs on the surface of a slab of a slab when the slab is hot-scraped by a hot scarf equipment installed behind the slab. The present invention relates to an apparatus for detecting defective welding of a slab of rolled material, which can automatically detect defects by image processing using a CCD (charge coupled device) camera.

[0002]

2. Description of the Prior Art A slab made of steel is heated and then
The slab is rolled by a slab mill. Since many surface flaws are present on the surface of the steel material immediately after the slabbing, the surface layer is ablated by a hot scarfer immediately after the slabbing to remove the surface flaws.

However, defective cutting may occur due to material factors such as the shape of the material, deposits on the surface of the material, material temperature and the like, and equipment factors of the main body of the hot scarf. If a defect occurs, it will cause a surface flaw defect in the subsequent process, and therefore appropriate measures are required.

Conventionally, in order to know the state of defective cutting of the slab of the slab by hot scarf, the operator has visually observed the ablated surface of the slab of the slab. However, the operator must observe it while operating the hot scarf and related equipment, and there is not enough visual observation between the operator's room where the operator is present and the slab to be rolled immediately after shaving. Since they are distant from each other and it is impossible to observe all four surfaces, it was not possible to sufficiently monitor the state of fusing.

[0005]

As has been described above, it is difficult to completely detect a defective welding by visual observation by an operator as in the prior art. Further, if the defective cutting by welding is overlooked, a surface flaw defective material will be produced in the subsequent process. It is an object of the present invention to provide a device for defectively cutting a slab of rolled slab, which can automatically monitor the state of welding without depending on the operator's visual inspection.

[0006]

Means for Solving the Problems The melt cutting defect detecting device for a slab of rolled steel of the present invention developed to solve the above problems is attached to a hot scarf equipment installed behind a slab. CC which is arranged immediately after the hot scarf equipment and is arranged around the conveyed slab to be opposed to the slab.
A D camera, an image processing device that receives image information from the CCD camera, performs image processing, and obtains a luminance distribution or a luminance change rate distribution of the slab, and a luminance distribution or luminance obtained by the image processing device. A personal computer that determines the presence or absence of melt cutting defects based on the change rate distribution and slab rolling manufacturing information, and the slab rolling manufacturing information that is necessary for the detection of melt cutting defects are accumulated and sent to the personal computer. Cutting situation statistics,
It is characterized in that it is provided with a high-order CPU that performs management.

That is, the inventors of the present invention have found that the brightness of the defective scraped part of the slab of rolled slab is lower than that of the normal scraped part, and that the brightness changes sharply at the boundary between the normal scraped part and the defective scraped part. In stead of the conventional method of detecting defective welding by visual inspection by a worker, a book that can clearly detect a defective welded portion by a method of image processing using a CCD camera. It is an invention.

The defective abraded portion can be detected by both the difference in luminance and the rate of change in luminance. However, in the vicinity of the corner of the slab, there is a tendency for the temperature to be slightly lower than in the other parts, and the difference in brightness causes a difference in brightness. Instead, it may be mistakenly detected as a defect.
In order to eliminate such erroneous detection, it is possible to accurately detect the presence or absence of a defect by determining the luminance change rate instead of the difference in luminance.

The reason for this is that the temperature in the vicinity of the corner changes gently from the high temperature part, and the resulting change in brightness is also moderate, while at the boundary between the defective and normal abraded parts. This is because a sudden change in brightness appears. Therefore, when it is expected that the brightness of the corner portion is low, it may be detected by the brightness change rate.

According to the present invention, scale is formed on the surface of the slab of the slab immediately after the shaving by the hot scarf.
Considering that defects can be detected only for a short time immediately after the fusing, CCD cameras are provided to face the four faces of the slab of rolled material at the position immediately after the fusing, and each side just before the scale is generated is imaged. Then, during image pickup, the designated camera is switched at regular intervals, the image pickup signal of each camera is subjected to image processing, the luminance or the luminance change rate of each surface is obtained, and a signal indicating the result is sent to the personal computer.

In the personal computer, manufacturing information such as the size of the slab and rolled material, the number of rollings, and the feed rate is obtained from a higher-level CPU, which will be described later, and the presence or absence of defective welding is determined based on the signal sent from the image processing apparatus. When a defect occurs, the position and size of the defect are calculated, and a signal for issuing an alarm is sent to the alarm device if necessary. Also, an output signal indicating the state of fusing is always sent to the upper CPU.

The alarm device can be installed in the vicinity of the operation room where the hot scarf is operated to observe the welding and cutting situation as required. For example, a buzzer or a warning light notifies the operator of the occurrence of the welding or welding failure. To do. By notifying the operator, it is possible to prevent a large amount of defective materials for fusing.

The upper CPU receives the data indicating the fusing state including the result of the presence or absence of the fusing defect from the personal computer and analyzes the fusing state and manages the statistics. With this, the degree of defective welding of slabs is ranked and expressed quantitatively, and by analyzing the results, the combustion control of the hot scarf and the feed rate of the slabs during scarf optimization can be optimized. It can also be set. In addition, the contents of the rolling schedule are stored in advance, and as described above, the manufacturing information of the slabbing rolling necessary for the determination of defective welding is sent to the personal computer.

[0014]

EXAMPLE An example of the present invention will be described below. FIG. 1 is a diagram showing the entire configuration of the apparatus of the present invention. W is a slab of rolled material immediately after smelting to which the apparatus of the present invention is applied, and 1a to 1d are CCD cameras for imaging the slab of rolled material W. .. The CCD
The cameras 1a to 1d are arranged so as to face the four faces of the slabbing material W, as shown in FIG. The image processing device 2 receives the image pickup signals from the CCD cameras 1a to 1d,
Image processing is performed and signals are output to the personal computer 3.

The image processing apparatus 2 performs image processing by switching the image pickup signals from the four CCD cameras 1a to 1d every 1/30 seconds by a camera switching unit inside thereof. That is, the four faces of the slab of rolled lump W are image-processed continuously by the CCD cameras 1a to 1d while the slab of the slab of rolled slab is being lapped in a cycle of 4/30 seconds.

In the image processing device 2, the image pickup signal obtained by the camera is used, and the data obtained for each pixel of the CCD is subjected to luminance conversion and binarized. Further, when the ablation state is detected by the brightness change rate, the brightness change rate distribution is calculated by the differential filter from the brightness distribution data obtained by the brightness conversion, and then binarized. The threshold value for the binarization process is preset based on experience. According to the above procedure, the image processing apparatus 2 distinguishes a region having a high luminance or a low luminance change rate from a region having a low luminance change rate, and sends the result to the personal computer 3.

The personal computer 3 accepts the image-processed signal from the image processing device 2 and the manufacturing information necessary for the defective cutting, which is obtained from the upper CPU 5, and analyzes the signal from the image processing device 2. It is determined whether or not the four faces of the slab of rolled slab W have defective cutting. In this embodiment, the material (lumped rolled material W) is displayed on the imaging screen when the signal is analyzed.
The dead zone processing is performed in accordance with the conveyance speed of to improve the determination accuracy.

When the defective cutting by welding occurs, the surface (region), the degree, and the degree of defective cutting by welding are displayed on the display (CRT) of the personal computer 3 and are recorded in a video and stored. Then, the personal computer 3 sends an alarm signal to the alarm device 7 via the relay circuit 6. The personal computer 3 also sends a signal indicating the state of fusing to the upper CPU 5.

The upper CPU 5 records the data such as the defective cutting obtained from the personal computer 3 and prints out the result to make it useful for production management of the cutting work by the hot scarf. In addition, data such as manufacturing conditions necessary for detecting defective welding are given to the personal computer 3. The interface 4 is located between the personal computer 3 and the host CPU 5 and the relay circuit 6 and serves to send and receive signals.

The alarm device 7 includes an interface 4 and a relay circuit 6 from the personal computer 3 when a defective cutting is generated.
It is composed of a buzzer and a warning light which are operated by receiving a signal via the above. In this embodiment, the buzzer is installed in the vicinity of the operation room to notify the operator that the defective cutting has occurred.

The slab-rolled material detector 8 is a sensor for activating the apparatus of the present invention, which is installed immediately after the hot scarf and slab-rolled immediately after the slab-rolled material passes through the hot scarf. Detects the tip of the material. In this embodiment, an opposed type phototube type is used. The operation of the device of the present invention is stopped by receiving a signal for the completion of the fusing work from the control circuit of the hot scarf.

Next, a case in which the use of the rate of change in brightness is appropriate for the determination of defective cutting by melting will be described by way of examples. Figure 3
(a) and (b) are examples of luminance distribution measurement in the direction perpendicular to the rolling direction having a defective welded portion, and FIG. 3 (c) is a graph in which the luminance change rate distribution is obtained from the data in FIG. 3 (b). In FIGS. 3 (a) and 3 (b), A and C indicate the end portions of the material, and B and D indicate defective welded portions. As is apparent from this figure, in the defective scraped portion, the brightness is lower than that in the normal scraped portion around the defective scraped portion, and a sharp change is observed at the boundary.

FIG. 3 (a) shows an example of a case where the decrease in brightness near the edge is small, and in this case, the defective cutting can be detected by the brightness distribution. On the other hand, in Fig. 3 (b),
There is a decrease in the brightness near the edges, and if judged from the brightness distribution, it will be erroneously detected as a defective area near the edges.
However, even if the luminance distribution shown in FIG. 3 (b) is measured, if the luminance change rate distribution is obtained, as shown in FIG. 3 (c), F _{1 at} the boundary between the normal and defective welded portions, Since a portion showing a high luminance change rate can be detected as shown in F ₂ ,
The position and size of the defective welded portion can be easily obtained. Note that E indicates the end of the material. As described above, by detecting from the luminance change rate, it is possible to make a determination without erroneous detection.

[0024]

EFFECTS OF THE INVENTION The apparatus for detecting defective cutting of a slab of rolled slabs according to the present invention is a slab for rolling a slab of rolled slab when the slab is rolled by a hot scarf equipment installed behind the slab. The defective cutting due to the cutting on the surface of the material can be detected automatically by the image processing using the CCD camera without the operator's visual inspection, so that the defective cutting point can be accurately found. Therefore, there is no concern that defective materials will be generated due to defective welding, and stable operation is possible, which greatly contributes to the industry.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of a defective welding cutting device for a slab of rolled material, which is an embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship between a hot scarfer, a slab of rolled material to be ablated, a CCD camera and the like in an embodiment of the apparatus of the present invention.

FIG. 3 is a graph showing an example of measurement of luminance distribution and luminance change rate distribution in the direction perpendicular to rolling.

[Explanation of symbols]

 1a to 1d CCD camera 2 Image processing device 3 Personal computer 4 Interface 5 Upper CPU 6 Relay circuit 7 Alarm device 8 Agglomerated rolled material detector W Agglomerated rolled material

Claims (1)

[Claims] 1. A slabbing material detection apparatus attached to a hot scarf equipment installed behind a slab mill, the slabbing material being placed immediately after the hot scarf equipment and being conveyed. An image for obtaining a luminance distribution or a luminance change rate distribution of the slab and rolled material by performing CCD image processing on the periphery of the slab and a CCD camera arranged at a position facing the slab and rolled material, and performing image processing by receiving image information from the CCD camera A processing device, a personal computer that determines the presence or absence of defective welding by using the luminance distribution or luminance change rate distribution obtained by the image processing device and manufacturing information for slab rolling, and the production of slab rolling necessary for detecting defective welding. Accumulate information,
An apparatus for detecting defective cutting of a slab of rolled slab, which is provided with a host CPU that sends the information to the personal computer and performs statistics and management of the cutting status.