KR20080057425A - The surface flaw detection apparatus and the method tereof - Google Patents

Abstract

A surface flaw detection apparatus and a method thereof are provided to detect a surface flaw by radiating white light with RGB(Red, Green, and Blue) light and determining a spot as the surface flaw where the white light is turned into a different color. A surface flaw detection apparatus includes a light source(30), a camera(1), an image processor(21), a main controller(22), and a power supply(23). The light source radiates white light made of RGB lights on an optical area(4) on a surface of a steel plate. The camera photographs the optical area. The image processor controls the operation of the camera and converts an image obtained by the camera to an RGB or YUV type signal to output. The main controller displays signals and determines as a surface flaw when the RGB or YUV value of the signal is different from the RGB or YUV value of the white light. The power supply supplies the components with power.

Description

Plate surface flaw detection apparatus and its method {The surface flaw detection apparatus and the method tereof}

1 is a schematic view of a plate surface defect inspection apparatus of the prior art,

Figure 2 is a schematic block diagram of a plate surface defect inspection apparatus according to an embodiment of the present invention,

Figure 3 is a flow chart showing the process of the surface defect inspection method using a tricolor light source according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: Plate surface defect inspection apparatus of the prior art

20: Plate surface defect inspection device of the present invention

1: camera

3: plate 4: light irradiation area

5: Defect 6: Operator

11: image processor 12: main PC

21: surface image processing unit 22: main control unit

23: power supply

30: light source

31: light source

31a: red light source 31b: green light source

31c: blue light source

32: light source control unit 33: light source movement control unit

The present invention relates to surface defect inspection of non-transparent plates, and more particularly, to a plate surface defect inspection apparatus and method for enabling inspection of surface defects of a scarfed steel sleeve after playing.

Scarping the surface of the steel plate after the refining process creates voids generated by the gas that has not escaped the steelmaking process and forms concave defects on the plate surface when the gas is cooled or discharged. These defects are the decisive cause for the surface defects of the hot rolled material in the later process. Therefore, various methods have been attempted to detect defects occurring on the surface of the plate in order to prevent the occurrence of surface defects of the hot rolled material in the subsequent process due to the plate surface defects as described above.

1 is a view showing a schematic configuration of a surface defect inspection apparatus 10 of a plate of the prior art.

As shown in FIG. 1, the surface defect inspection apparatus 10 (hereinafter, referred to as a 'prior art inspection apparatus') of a plate of the prior art includes a camera capable of acquiring an image of the scarfed surface of the plate 3. 1) and the main PC 12 which outputs the image signal processed by the image processor 11 and the image processor 11 as an image signal to process signals such as pixel information on the image obtained by the camera 1. It is configured to include.

The plate table and defect inspection process in the inspection apparatus 10 according to the related art having the above-described configuration will be described below.

In the inspection apparatus 10 of FIG. 1, when the image processing unit 11 converts an image obtained by the camera 1 into an image signal and transmits the image signal to the main PC 12, the main PC 12 receives the received image. When the video signal is output to the screen on the monitor, the operator 6 checks the screen image to determine whether there is a defect. In this case, there are also defects detected on the screen, but they do not appear on the screen, but there are also a lot of defects caused by the naked eye, and the present method cannot omit the naked eye. Therefore, when the operator 6 is inadequate in defect inspection by the surface image output on the screen, the operator 6 directly visits the site and visually reconfirms the defect.

That is, the inspection apparatus 10 of the prior art as described above is a waste of time, manpower and cost to inspect the defects on the plate surface because the operator must perform a double inspection to search through the screen and check again with the naked eye in the field This makes it difficult to detect defects quickly.

Accordingly, the present invention is to solve the above-mentioned problems of the prior art, and when the cameras are irradiated with a constant area of the surface of the plate using red, green, and blue light sources of homogeneous size so as to be white light when combined, By taking this picture and detecting whether the color of the corresponding part is changed to a color other than white, and when the color is changed to a color other than white, the plate is judged as a surface defect of the plate so that defects on the surface of the plate can be inspected. An object thereof is to provide a surface defect inspection apparatus and a method thereof.

The plate surface inspection apparatus of the present invention for achieving the above object comprises a light source unit for irradiating the plate surface with a light source of red, green and blue so as to be white light when combined; A camera for photographing a plate surface area irradiated with white light by the light source unit; An image processor which controls the movement of the camera and outputs an image signal captured by the camera to a main controller; And a main control unit for outputting an image by the output signal of the image processing unit to the screen and comparing the intensity value of the tricolor light source with the value set for the white light source from the image signal and determining it as a defect in other cases. It is done.

The light source unit may include: a light source including a red light source, a green light source, and a blue light source for emitting red, green, and blue light, respectively; A light source control unit controlling the light intensity of the light source; And a light source movement control unit for controlling the movement of the light source.

The image processing unit may include a camera movement control unit for controlling the movement of the camera to photograph the plate surface area illuminated by the light source in conjunction with the light source movement control unit.

The image processing unit may convert the intensity of the red, green, and blue light sources in the image photographed by the camera into an RGB or YUV color signal and output the converted signal.

The plate surface inspection method of the present invention for achieving the above object comprises a light source irradiation process of shining a red, green, blue light source to form white light in the inspection area of the play; A photographing process of photographing a region to which the light source is irradiated by the light source irradiation process; An image processing step of converting an image obtained in the photographing process into an image signal having a tricolor light source value and outputting the converted image signal; And a defect detection process of comparing the image signal output in the image processing process with a tricolor light source value of white light and determining it as a defect in other cases.

In the above-described present invention, the tricolor light is characterized by being represented by either RGB or YUV values.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Figure 2 is a schematic block diagram of a plate surface defect inspection apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the defect inspection apparatus 20 of the plate surface according to the present invention, the light source unit 30 for irradiating the light irradiation region 4 of the plate surface by adjusting the red, green, blue to white light Wow; An image processing unit which controls the movement of the camera 1 and the camera 1 photographing the plate surface area irradiated by the light source unit 30, and outputs the processed image signal of the camera 1 by RGB or YUV signal processing. 21); A main main PC which outputs an output video signal of the image processor 22 to a display device such as a monitor, compares RGB or YUV color values of the image signal with RGB or YUV color values forming white light, and judges a defect in different cases. And a main control section 22 implemented with the power supply section 23 for supplying power to the above components.

The light source unit 30 described above includes a light source 31 composed of a red light source 31a, a green light source 31b, and a blue light source 31c as a light irradiator for irradiating red, green, and blue light, respectively. The light source controller 32 controls the intensity of each color of the light source 31, and each of the red light source 31a, the green light source 31b, and the blue light source 31c constituting the light source 31. It is configured to include a light source movement control unit 33 to control the setting the irradiation area.

The light source unit 30 configured as described above is a plate surface region irradiated by irradiating the light irradiation region 4 as a surface to be subjected to defect inspection on the surface of the red, green, and blue light plate 3 having a uniform intensity. Allow white light to be produced at

Although the image processing unit 21 is not shown in the drawing, the camera 1 controls the movement of the camera to capture an image of the light irradiation area 4 on the surface of the plate 3 irradiated by the light source unit 30. It is configured to include a motion control unit.

At this time, the camera movement controller receives the control value for the light source 30 from the light source movement controller 33 and photographs the plate surface light irradiation area 4 to which white light is irradiated using a preset coordinate axis. By controlling the movement or detecting the intensity of light in the image photographed by the camera 1, the camera 1 causes the camera 1 to photograph an area to which white light is automatically irradiated. The movement of the camera 1 is controlled to automatically photograph (4).

Next, the main controller 22 controls the driving of the image processor 21 and the light source unit 30, and compares the color value of the image signal input from the image processor 21 with the color value of white light. (3) It is judged whether the defect 5 generate | occur | produced on the surface.

At this time, when the light irradiation area 4 of the plate surface includes the defect 5, the intensity of each of the three colors of light reflected from the defect 5 is changed by the difference in the reflection angle of the light in the defect 5, the white light The color is converted into a color value signal by the image processor 21, and the main controller 22 compares the color value signal with a color value signal that forms white light and determines that the surface is defective. Done.

That is, the main controller 22 applies the value output from the image processor 21 to the basic defect detection algorithm, outputs the degree of the defect on the screen, and performs a subsequent procedure such as outputting a warning signal according to the occurrence of the defect.

Figure 3 is a flow chart showing the process of the surface defect inspection method using a tricolor light source according to an embodiment of the present invention.

Next, the plate surface defect inspection method according to the present invention with reference to Figures 2 and 3 will be described in detail.

The light irradiation area 4 is formed on the plate 3 on which the defect 5 on the surface is to be detected by applying tricolor light to the irradiation area by using the light source unit 30 (S1).

Thereafter, the image processor 21 receives the light source control signal of the light source movement control unit 33 of the light source unit 30 or controls the camera 1 to face the light irradiation area 4 by detecting the white light region. The light irradiation area 4 is photographed (S2).

The image of the light irradiation area 4 photographed by the camera 1 in step S2 is converted into color signal information having three color values by the image signal processing 210 and then output to the main control unit 22. It can be expressed in the manner of RGB or YUV (S3).

The main controller 22, which receives the video signal converted into the color signal information having the tricolor value by the image processor 21 by the process S3, outputs a resolution image to a screen such as a display unit, and forms a light irradiation area 4. When the three-color value of each pixel on the image screen is different from the three-color value of the white light by comparing the three-color value of the white light, it is determined as a defect. Then, by outputting a warning signal informing of the occurrence of a defect, it is possible to carry out a follow-up action to solve the problem of the subsequent work.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

The present invention as described above is able to automatically detect the porosity defects present on the surface of the plate (slab) at the front end of the rolling, thereby significantly reducing the defects of the hot rolled and cold rolled steel sheet in the future, thereby manufacturing costs To reduce costs and improve productivity.

Claims (6)

A light source unit emitting red, green, and blue light sources onto a surface of a plate so as to be white light when combined; A camera for photographing a plate surface area irradiated with white light by the light source unit; An image processor which controls the movement of the camera and outputs an image signal captured by the camera to a main controller; And a main control unit for outputting an image by the output signal of the image processing unit to the screen and comparing the intensity value of the tricolor light source with the value set for the white light source from the image signal and determining it as a defect in other cases. Plate surface defect inspection apparatus. The method according to claim 1, wherein the light source unit, A light source having a red light source, a green light source, and a blue light source for emitting red, green, and blue light, respectively; A light source controller for controlling the light intensity of the light source; Plate surface defect inspection apparatus comprising a; light source movement control unit for controlling the movement of the light source. The method of claim 2, wherein the image processing unit, And a camera movement control unit for controlling the movement of the camera so as to photograph the plate surface area illuminated by the light source in association with the light source movement control unit. The method according to any one of claims 1 to 3, wherein the image processing unit, The plate surface defect inspection apparatus, characterized in that for converting the intensity of the red, green, blue light source in the image taken by the camera to the RGB or YUV color signal output. A light source irradiation process of illuminating red, green, and blue light sources to form white light in the inspection area of the play; A photographing process of photographing a region to which the light source is irradiated by the light source irradiation process; An image processing step of converting an image obtained in the photographing process into an image signal having a tricolor light source value and outputting the converted image signal; And a defect detection process of comparing the image signal output in the image processing process with a three-color light source value of white light and determining it as a defect in other cases. The method of claim 5, wherein the tricolor light is represented by either RGB or YUV values.

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