JPH05172762A - Judging method for cleanliness of surface of steel material - Google Patents

Abstract

PURPOSE:To accurately judge the cleanliness of the surface of a steel material on the basis of a definite judging standard before painting or surface treatment. CONSTITUTION:The perfectly derusted surface of a steel material is subjected to binary-coded image processing to obtain image data which is, in turn, preliminarily stored in an image recognizing device 3 as a judging standard. The image data of the surface of the steel material 1 is detected by a television camera 2 and subjected to binary-coded image processing by the image recognizing device 3 using the preliminarily stored binary-coded image processing data for the judging standard to discriminate between a clean part and an unclean part and the result is formed into an image by a monitor television 4. At the same time, the area ratio of the clean part and the unclean part is operated by the image recognizing device 3 to be displayed on the monitor television 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the cleanliness of a steel surface before painting or surface treatment.

[0002]

2. Description of the Related Art ASTM is a conventional determination method of this type.
(Stainless Steel Structural Coatings Council) and SSPC (Stainless Steel Structural Coatings Council) have created the "Pre-painting Steel Surface Treatment Standards" standard (J
IS). According to this standard, the base material quality grades of steel materials classified into four rust grades are Sal, Sa2, Sa21 / 2,
The cleanliness is judged by visually or taking a photograph of the photograph sample clearly defined by the color print classified into four kinds of Sa3 as the criterion, and comparing it with the steel material surface.

[0003]

However, since this judgment method is to be compared with a photographic sample that is patterned to some extent, the judgment result largely depends on the subjectivity of the judge, and judgment is made for steel surfaces with the same cleanliness. There is a problem that the judgment result varies from person to person, and the judgment result varies depending on environmental conditions such as weather and the health condition of the judge.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned conventional problems, and the image data of the steel surface detected by the television camera is stored in advance in the image recognition device by the image recognition device. By comparing with the stored judgment reference image data, binarized image processing is performed, the clean part of the steel surface is differentiated from the other part, and the area ratio of the clean part is calculated. The cleanliness of the can be accurately determined.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is a steel material, and in this embodiment, the surface is blasted or rust removed to some extent by a power tool. Reference numeral 2 is a television camera arranged opposite to 1, reference numeral 3 is an image recognition device connected to 2, and the image data detected in 2 is subjected to binarized image processing, and based on that, judgment criteria and calculation to be described later. I do. Reference numeral 4 denotes a monitor television connected to 3, which displays the image of the binarized image processed in 3 and the calculation result. Although not shown, the image recognition device 3 has image data obtained by performing binary image processing on the steel surface completely rust-removed in advance by the same method as that of the steel 1.
It is stored as a criterion for the cleanliness.

In this structure, first, the television camera 2
Displays an image of the steel surface of the steel material 1 to be measured, which is not binarized by the image recognition device 3, on the monitor television 4, and adjusts the focus and brightness. The image data for the judgment standard obtained by binarizing the steel surface completely rust removed in advance by the image recognition device 3 adjusted to the same focus and brightness is stored, and the image data for the judgment standard is used. Then, the steel surface to be measured is binarized and image-processed, and the result is visualized on the monitor TV 4, and the area ratio of remaining rust or the area ratio of rust removed is calculated and displayed on the monitor TV. To do. In the above embodiment, the focus and brightness must be adjusted each time the judgment is made, but the lighting and the TV camera are integrated, and the jig and the steel material surface are kept at a constant distance by a jig so that the shooting conditions are constant. It is preferable to keep it at.

An example of such an embodiment is shown in FIG. FIG. 2 shows only a portion for detecting image data, 2 is a television camera arranged facing the steel material surface, and 5 is an illumination attached around the lens of the television camera 2 so as to obtain a uniform illuminance. Ring fluorescent lamp, 6 is a power source for stabilizing the voltage connected to 5 for lighting the ring fluorescent lamp 5, and 7 is a conical or pyramidal shape in which the television camera 2 and the ring fluorescent lamp 5 are integrated. It is a hood. With such a configuration, the distance between the TV camera 2 and the steel surface to be measured can be kept constant, and the hood 7 can illuminate with a constant illuminance, so that the TV camera can be focused on the measurement surface and the illuminance can be adjusted. It can be done easily and the shooting conditions can be kept constant. If it is desired to leave the measurement results in the above two embodiments, a video printer may be connected to the image recognition device 3 and recorded.

[0008]

As described above, according to the present invention, the image data of the steel surface detected by the television camera facing the steel surface is compared with the judgment standard stored in the image recognition device in advance. By doing so, the image recognition device performs binary image processing to differentiate the clean part and the non-clean part of the steel surface, and by calculating the area ratio of the clean part, the cleanliness of the steel surface can be changed depending on the measurer and environmental conditions. Instead, it can be accurately determined based on a fixed determination criterion.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention,

FIG. 2 is a diagram showing an image data detection unit in which an illumination and a television camera are integrated, and a jig is used so that the television camera and the steel material surface are always at a constant distance.

[Explanation of symbols]

 1 Steel 2 TV camera 3 Image recognition device 4 Monitor TV 5 Ring fluorescent lamp 6 Power supply 7 Hood

Claims (1)

[Claims] 1. A television camera arranged opposite to a steel surface, an image recognition device connected to the television camera for processing image data from the television camera, and an image recognition device connected to the image recognition device. Using a monitor TV that visualizes the processed data, and comparing the image data of the steel surface detected by the TV camera with the image data for the judgment standard stored in the image recognition device in advance by the image recognition device. By the binarized image processing, the distinction between the washed portion and the non-washed portion of the steel material surface is performed, and at the same time, the area ratio of the clean portion or the unclean portion is calculated by the image recognition device. Method.