KR20200087331A - Apparatus and method for inspecting steel products - Google Patents

Abstract

The present invention relates to a defect inspection apparatus and method for a steel product. The defect inspection apparatus for a steel product according to one aspect of the present invention includes: a first inspection means generating first image information by photographing the surface of a steel product; a second inspection means generating second image information by applying a magnetic field to the steel product and sensing a leakage magnetic flux; and a defect detection means detecting surface defects and internal defects of the steel product based on the first image information and the second image information. According to the present invention, inspection for the surface defects and the internal defects on the steel product can be integrally performed.

Description

Defect inspection device and method for steel products {Apparatus and method for inspecting steel products}

The present invention relates to a steel product defect inspection apparatus and method, and more particularly, to a steel product defect inspection apparatus and method for integrating and inspecting surface defects and internal defects occurring in a steel product.

Defects occurring in steel products can be divided into surface defects that appear on the surface and internal defects (including subsurface defects that exist directly under the surface) that exist inside the product.

In general, the surface defects occurring in the production process of steel products are detected by the human eye in the process in which the steel products are produced and transported, or detected through a surface inspection device equipped with a camera.

However, since internal defects cannot be seen by the camera or the human eye, in the case of the prior art, the inspection process of internal defects is omitted or, if necessary, a separate inspection process is performed while moving the sensing unit while the steel product is stopped. Internal defects were inspected.

However, the internal defect inspection is relatively complicated compared to the surface defect inspection, and when it is inspected in a separate inspection process, there is a problem in that it takes a lot of manpower, time, and cost, and the work efficiency is also poor.

In addition, since the data that can be analyzed is limited even through the internal defect inspection, although it is possible to detect the defect, there is a problem in that it is difficult to accurately detect the specific defect.

Korean Registered Patent Publication No. 10-1658700 Korean Registered Patent Publication No. 10-1745764

The present invention was devised to solve the above-described problems, and an object of the present invention is to provide a steel product defect inspection apparatus and method for integrating inspections of surface defects and internal defects on steel products.

Another object of the present invention is to photograph the surface of the steel product to generate the first image information, to sense the leakage flux of the steel product, to generate the second image information, and synchronize it in frame units to precisely inspect defects in the steel product. To provide a steel product defect inspection apparatus and method.

Another object of the present invention is to extract the defect feature information from the first image information generated by photographing the surface of the steel product and the second image information generated by sensing the leakage flux of the steel product, and based on a rule base (Rule-base) It is to provide a defect inspection apparatus and method for steel products capable of specifically classifying defect types using the defect classification method of.

Another object of the present invention uses a deep learning-based defect classification method for the first image information generated by photographing the surface of the steel product and the second image information generated by sensing the leakage flux of the steel product. Therefore, it is to provide a defect inspection apparatus and method for steel products capable of specifically classifying defect types.

For this purpose, the steel product defect inspection apparatus according to one embodiment of the present invention comprises: first inspection means for photographing a surface of a steel product and generating first image information; Second inspection means for generating a second image information by applying a magnetic field to the steel product and sensing a leakage magnetic flux; And defect detection means for detecting surface defects and internal defects of the steel product based on the first image information and the second image information.

Preferably, the second image information is generated in correspondence with the location and intensity of the leakage flux for a sensing area having the same size as the photographing area of the first inspection means.

Preferably, the defect detection means performs frame synchronization on at least one frame constituting the first image information and at least one frame constituting the second image information, and the frame of the synchronized first image information And a surface defect and an internal defect of the steel product based on the frame of the second image information.

Preferably, the defect detection means includes at least one of the shooting time information and the shooting area information for each frame constituting the first image information and the sensing time information for each frame constituting the second image information and The frame synchronization is performed based on at least one of sensing area information.

On the other hand, in the steel product defect inspection method according to one embodiment of the present invention, a first image information is generated by photographing a surface of a steel product, a magnetic field is applied to the steel product, and a leakage magnetic flux is sensed to generate second image information. To do; Performing frame synchronization on at least one frame constituting the first image information and at least one frame constituting the second image information; And detecting surface defects and internal defects of the steel product based on the synchronized frames of the first image information and the frames of the second image information.

Preferably, in the generating of the image information, the photographing area information for each frame constituting the first image information is generated, and the sensing region information for each frame constituting the second image information is generated. Including the process, the step of performing the synchronization comprises: synchronizing a frame of the first image information and a frame of the second image information corresponding to the same region based on the photographing region information and the sensing region information. Includes.

Preferably, in the generating of the image information, generating shooting time information for each frame constituting the first image information and generating sensing time information for each frame constituting the second image information are generated. Comprising a step of performing the synchronization, the difference between the shooting time and the sensing time based on the shooting time information and the sensing time information, the frame of the first image information corresponding to the inspection delay time and the second And synchronizing frames of video information.

According to the present invention, since the first image information is generated by photographing the surface of the steel product and the second magnetic flux information is generated by sensing the leakage flux of the steel product, the defects of the steel product are inspected by synchronizing them in frame units. It has the effect of integrating surface defect inspection and internal defect inspection on steel products.

Particularly, according to the present invention, the first area corresponding to the same area of the steel product is generated after the first area is generated for the steel product being transported to generate the first image information and the second area is sensed to generate the second image information. Since the surface defect inspection and internal defect inspection are performed in real time by matching the frame of the image information and the frame of the second image information, a separate internal defect inspection process is not required, thereby significantly reducing manpower, time, and cost. , Accordingly, has an effect of increasing the working efficiency.

In addition, according to the present invention, the rule-based defect classification method is primarily applied based on the first image information generated by photographing the surface of the steel product and the second image information generated by sensing the leakage flux of the steel product. And by applying the deep learning-based defect classification method secondary, it has the effect of more accurately detecting defects in steel products.

1 is a configuration diagram of a steel product defect inspection apparatus according to an embodiment of the present invention.
2 is a configuration diagram of a first inspection means according to an embodiment of the present invention.
3 is a configuration diagram of a second inspection means according to an embodiment of the present invention.
4 is a view showing a method of generating image information for a steel product being transported by a first inspection means and a second inspection means according to an embodiment of the present invention.
5 is a configuration diagram of a defect detection means according to an embodiment of the present invention.
6 is a configuration diagram of a defect classification means according to an embodiment of the present invention.
7 is a configuration diagram of a test setting means according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, in the following description, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted.

1 is a configuration diagram of a steel product defect inspection apparatus according to an embodiment of the present invention.

1, the steel product defect inspection apparatus 100 according to an embodiment of the present invention includes a first inspection means 110, a second inspection means 120, a defect detection means 130, a defect classification means ( 140), inspection setting means 150, defect display means 160, and the like.

The first inspection means 110 is provided in a path through which the steel product is transferred, and performs a function of inspecting the surface defect of the steel product.

In this regard, FIG. 2 shows the configuration of the first inspection means 110 according to an embodiment of the present invention.

Referring to FIG. 2, the first inspection means 110 according to an embodiment of the present invention includes an illumination unit 111, an image capturing unit 112, a first control unit 113, and the like.

The lighting unit 111 is equipped with one or more lights to emit light to the surface of the steel product, and the image capturing unit 112 is equipped with one or more cameras to photograph the surface of the steel product to generate first image information (data). do. In addition, the first control unit 113 is the lighting unit to generate the first image information with a predetermined frame standard (eg, resolution, frame rate) for a predetermined position (area) at a preset time with respect to the surface of the steel product. (111), the image capture unit 112 and the like are controlled. To this end, the first control unit 113 receives a synchronization signal (eg, a trigger pulse of an encoder), and other components of the steel product defect inspection apparatus 100 (in particular, the second inspection means ( 120) of the second controller 124).

The second inspection means 120 is provided in a path through which the steel product is transferred, and is preferably provided adjacent to the first inspection means 110 to perform a function of inspecting surface defects and internal defects of the steel product.

In this regard, FIG. 3 shows the configuration of the second inspection means 120 according to an embodiment of the present invention.

Referring to FIG. 3, the second inspection means 120 according to an embodiment of the present invention includes a magnetic field generating unit 121, a sensor unit 122, an imaging processing unit 123, a second control unit 124, etc. do.

The magnetic field generating unit 121 generates a magnetic field of a steel product, and the sensor unit 122 is provided with one or more magnetic sensors to detect a magnetic flux leakage of the steel product. Then, the imaging processing unit 123 generates second image information (data) imaged according to the position of each magnetic sensor of the sensor unit 122 and the intensity of the detected leakage magnetic flux, and the second control unit 124 The magnetic field generating unit 121, the sensor unit 122, and the imaging processing unit 123 are controlled so that the second image information can be generated in a predetermined frame standard for a preset position at a preset time for a steel product. To this end, the second control unit 124 similarly receives a synchronization signal (eg, an encoder trigger pulse), and other components of the steel product defect inspection apparatus 100 (in particular, the first control unit of the first inspection means 110) (113)).

Hereinafter, a method of generating image information and synchronizing the steel products being transported by the first inspection means and the second inspection means according to an embodiment of the present invention will be described with reference to FIG. 4.

Referring to FIG. 4, the image capturing unit 112 of the first inspection means 110 and the sensor unit 122 of the second inspection means 120 are provided at a predetermined distance apart on a path through which steel products are transferred, Image information is generated for the same steel product.

Specifically, the image photographing unit 112 of the first inspection means 110 is provided on a path through which steel products are transported, and photographs a preset first area (shooting area) in units of a predetermined time, and is formed of one or more frames. 1 Generate (acquire) image information. In addition, when the first control unit 113 of the first inspection means 110 generates the first image information by the image capturing unit 112, the shooting time information and/or the shooting area information for each frame of the first image information Produces

Similarly, the sensor unit 122 of the second inspection means 120 is provided on the path through which the steel product is conveyed, detects the intensity of the leakage magnetic flux with respect to the preset second area (sensing area), and the second inspection means ( The imaging processing unit 123 of 120) generates second image information (consisting of one or more frames) corresponding to the location and intensity of the leakage magnetic flux. Then, the second control unit 124 of the second inspection means 120 generates sensing time information and/or sensing area information for each frame of the second image information when the second image information is generated by the imaging processing unit 123. To create.

For reference, the image information (frame) corresponding to the location and intensity of the leakage magnetic flux, and the position of each magnetic sensor when the sensor unit 122 is provided with a plurality of magnetic sensors in a two-dimensional sensing structure (planar sensing structure) Based on the intensity of the leakage flux detected at the corresponding location (which is expressed in color in the image), it may be generated using a two-dimensional interpolation method, etc., and the sensor unit 122 may sense one or more magnetic sensors in one dimension. In the case of having a structure (linear sensing structure), one-dimensional linear sensing data for a moving steel product can be generated continuously or at very short intervals corresponding to a distance corresponding to the second area, and then similarly generated using a two-dimensional interpolation method. have.

Meanwhile, the first area image of the first inspection means 110 and the second area image of the second inspection means 120 generated in this way are spaced apart by a predetermined distance in the longitudinal direction (transfer direction) of the steel product (area). In this regard, the steel product defect inspection apparatus 100 according to an embodiment of the present invention frames the first image information of the first inspection means 110 and the second image information of the second inspection means 120. Synchronize.

Specifically, when the first inspection means 110 generates the image information (first image information) of the first area, the first image information (consisting of one or more frames) in a predetermined frame standard (eg, resolution, frame rate) ). At this time, photographing time information and/or photographing area information for each frame of the first image information are generated together. Then, the first inspection means 110 transmits the first image information composed of one or more frames and the shooting time information and/or the shooting area information matching each frame of the first image information to the defect detection means 130 do.

Likewise, when the second inspection means 120 generates image information (second image information) in the second area, the second image information has the same frame standard (eg, resolution, frame rate) as the first inspection means 110. (Consisting of one or more frames), and at this time, sensing time information and/or sensing area information for each frame of the second image information is generated together. In addition, the second inspection means 120 transmits the second image information composed of one or more frames and sensing time information and/or sensing area information matching each frame of the second image information to the defect detection means 130. do.

Then, the defect detection means 130 uses the shooting time information and the sensing time information and/or the shooting area information and the sensing area information to frame and second image of the first image information corresponding to the same location (area) of the steel product. Frame synchronization is performed by matching frames of information.

For reference, the shooting time information and the sensing time information are synchronized with each other. When frame synchronization is performed using the shooting time information and the sensing time information, the first area (the shooting area of the first image information) and the second area (the second 2 Calculate the inspection delay time (difference between the shooting time and the sensing time for the same area of the steel product) based on the separation distance between the sensing area of the image information) and the transfer speed of the steel product, and perform frame synchronization based on this. Can. In addition, the photographing area information and the sensing area information can be obtained by calculating the relative distance by calculating the conveying distance based on the conveying speed and the conveying time based on the highest end (starting position) of the steel product. When using frame synchronization, frame synchronization may be performed by matching a frame of the first image information and a frame of the second image information corresponding to the same area (location).

Referring back to FIG. 1, the defect detection means 130 receives the first image information, the shooting time information, the shooting area information, etc. from the first inspection means 110 and the second image from the second inspection means 120. Information, sensing time information, sensing area information, and the like are received to detect surface defects and internal defects in steel products.

In this regard, FIG. 5 shows the configuration of the defect detection means 130 according to an embodiment of the present invention.

5, the defect detection means 130 according to an embodiment of the present invention includes a frame synchronization unit 131, a defect detection unit 132, a defect analysis unit 133, a defect image storage unit 134, etc. Includes.

The frame synchronization unit 131 synchronizes the first image information transmitted from the first inspection means 110 and the second image information transmitted from the second inspection means 120 on a frame-by-frame basis. As described above with reference to FIG. 4, the frame synchronization unit 131 uses shooting time information matched with each frame of the first image information and sensing time information matched with each frame of the second image information, and/or Alternatively, by using the shooting area information matched with each frame of the first image information and the sensing area information matched with each frame of the second image information, the frame of the first image information corresponding to the same location (area) of the steel product and Frame synchronization is performed by matching frames of the second image information.

The defect detection unit 132 applies the respective defect detection criteria (defect determination criteria) to the frame of the first image information and the frame of the second image information synchronized by the frame synchronization unit 131 on a frame-by-frame basis. Detects. For example, the defect detection unit 132 applies the first defect detection criterion to the frame of the first image information to determine whether it is in a normal state or a defective state, and applies a second defect detection criterion to the frame of the second image information. After determining whether it is in a normal state or a defective state, if any one of the frames of the synchronized first image information and the second image information is defective, it is determined that there is a defect and a defect of the steel product is detected.

The defect analysis unit 133 analyzes defects of the steel products detected by the defect detection unit 132 to extract defect feature information. For example, the defect analysis unit 133 analyzes the frame of the first image information and the frame of the second image information that are determined to be defective by the defect detection unit 132 to analyze the location, size, shape of the defect, Defect characteristic information such as a shadow value, a distribution degree, and a shadow ratio is extracted.

Then, the defect image storage unit 134 stores the frames of the first image information and the frames of the second image information, which are determined to be defective, by the defect detection unit 132.

Referring to FIG. 1 again, the defect classification means 140 precisely determines which defect is specifically using at least one defect classification method for defects of the steel product detected by the defect detection means 130.

In this regard, FIG. 6 shows the configuration of the defect classification means 140 according to an embodiment of the present invention.

6, the defect classification means 140 according to an embodiment of the present invention includes a first defect classification unit 141, a second defect classification unit 142, a post-processing unit 143, a defect result storage unit ( 144).

The first defect classification unit 141 uses a rule-based defect classification method based on defect characteristic information extracted from the defect analysis unit 133 of the defect detection means 130 to determine defects in steel products. Classify. For example, the first defect classification unit 141 applies defect classification criteria for the location, size, shape, shading value, distribution ratio, and shading ratio of defects to defect characteristic information to determine which defects of steel products fall into defects. .

The second defect classification unit 142 is based on deep learning on the frames of the first image information and the frames of the second image information that are determined to be defective by the defect detection unit of the defect detection unit 130. Classify defects in steel products using the defect classification method of For example, the second defect classifying unit 142 refers to the defect learning data learned through defect classification learning for the frames of the first image information and the frames of the second image information that are mutually synchronized, so that the defects of the steel products are related to any defects. Determine if applicable.

According to a preferred embodiment of the present invention, the first defect classification unit 141 firstly determines the defect type of the steel product based on the defect characteristic information, and the second defect classification unit 141 provides deep learning learning data. By referring to the secondary defect type of the steel product, it is possible to more accurately determine the defect of the steel product.

The post-processing unit 143 is separate from or added to the rule-based defect classification method of the first defect classification unit 141 and the deep learning-based defect classification method of the second defect classification unit 142. By applying the defect classification method set by the company, it is determined what kind of defect is a defect in the steel product.

In addition, the defect result storage unit 144 stores defect results of steel products specifically determined through the first defect classification unit 141, the second defect classification unit 142, and the post-processing unit 143.

Referring back to FIG. 1, the inspection setting means 150 provides a user interface for a user to directly set a defect detection function, a defect classification function, a post-processing function, etc., and the defect detection means 130 according to the user's setting Defect detection function details and defect classification function details of the defect classification means 140 and post-processing function details are adjusted.

In this regard, Figure 7 shows the configuration of the inspection setting means 150 according to an embodiment of the present invention.

Referring to FIG. 7, the inspection setting means 150 according to an embodiment of the present invention includes a defect detection setting unit 151, a defect classification setting unit 152, a post-processing setting unit 153, and the like.

The defect detection setting unit 151 provides a user interface for directly setting a defect detection function to a user, and detects details of a frame synchronization method, a defect detection criterion, and a defect feature information extraction method according to a user's setting. Transfer to (130) to set the defect detection function of the defect detection means (130).

The defect classification setting unit 152 provides a user interface for directly setting a defect classification function to a user, and details defects of a rule base-based defect classification method, a deep learning-based defect classification method according to a user's setting, and the like. The defect classification function of the defect classification means 140 is set by transmitting to the classification means 140.

The post-processing setting unit 153 provides a user interface for directly setting a post-processing function to the user, and transmits details of a defect classification method, etc. to the defect classification means 140 according to the user's settings, thereby defining the defect classification means ( 140).

Referring back to FIG. 1, the defect display means 160 notifies the user of the result of the defect of the steel product finally classified by the defect classification means 140 through a display, LED, alarm sound, etc. When a product defect is inquired, a defect result stored in the defect classification means 140 is fetched and displayed.

So far, the present invention has been described in detail with reference to preferred embodiments, but the person skilled in the art to which the present invention belongs can be implemented in other specific various forms without changing the technical spirit or essential features of the present invention. It should be understood that the embodiments described in the above are illustrative in all respects and not restrictive.

And, the scope of the present invention is specified by the claims, which will be described later, rather than by the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. It should be interpreted as.

Claims (14)

First inspection means for capturing the surface of the steel product and generating first image information;
Second inspection means for generating a second image information by applying a magnetic field to the steel product and sensing a leakage magnetic flux; And
And a defect detection means for detecting surface defects and internal defects of the steel product based on the first image information and the second image information. According to claim 1,
The second image information is a steel product defect inspection apparatus characterized in that it is generated in correspondence with the location and intensity of the leakage magnetic flux for the sensing area of the same size as the imaging area of the first inspection means. According to claim 2,
The defect detection means performs frame synchronization on at least one frame constituting the first image information and at least one frame constituting the second image information, and the second frame and the second frame of the synchronized first image information. Steel product defect inspection device, characterized in that for detecting the surface defects and internal defects of the steel product based on the frame of the image information. According to claim 3,
The defect detection means may include at least one of shooting time information and shooting area information for each frame constituting the first image information, and sensing time information and sensing area information for each frame constituting the second image information. Steel frame defect inspection apparatus characterized in that for performing the frame synchronization based on at least one piece of information. The method according to any one of claims 1 to 4,
The first inspection means,
An image photographing unit photographing the surface of the steel product to generate the first image information composed of one or more frames; And
And a first control unit generating at least one of shooting time information and shooting area information for each frame of the first image information. The method of claim 5,
The second inspection means,
A magnetic field generator for generating a magnetic field with the steel product;
A sensor unit that senses the leakage flux of the steel product;
An imaging processing unit generating the second image information composed of one or more frames corresponding to the location and intensity of the leaked magnetic flux sensed by the sensor unit; And
And a second control unit generating at least one of sensing time information and sensing area information for each frame of the second image information. The method of claim 6,
The defect detection means,
A frame synchronization unit performing synchronization on a frame-by-frame basis for the first image information and the second image information;
A defect detection unit detecting a defect of the steel product based on the synchronized frame of the first image information and the frame of the second image information; And
And a defect analysis unit configured to extract defect characteristic information by analyzing defects of the steel product detected by the defect detection unit. The method of claim 7,
And defect classification means for classifying defects in the steel product using a rule-based defect classification method based on the defect characteristic information. The method of claim 7,
Further comprising a defect classification means for classifying the defects of the steel product using a deep learning-based defect classification method for the synchronized frame of the first image information and the frame of the second image information Steel product defect inspection device. Generating first image information by photographing the surface of the steel product, generating a second image information by applying a magnetic field to the steel product and sensing a leakage magnetic flux;
Performing frame synchronization on at least one frame constituting the first image information and at least one frame constituting the second image information; And
And detecting surface defects and internal defects of the steel product based on the synchronized frame of the first image information and the frame of the second image information. The method of claim 10,
The generating of the image information includes a process of generating photographing area information for each frame constituting the first image information, and generating sensing region information for each frame constituting the second image information. ,
The step of performing the synchronization may include synchronizing a frame of the first image information and a frame of the second image information corresponding to the same region based on the photographing region information and the sensing region information. Steel product defect inspection method. The method of claim 11,
The photographing area information and the sensing area information are generated by calculating a conveying distance based on a conveying speed and a conveying time based on the highest end of the steel product. The method of claim 10,
The generating of the image information includes a process of generating shooting time information for each frame constituting the first image information, and generating sensing time information for each frame constituting the second image information. ,
In the performing of the synchronization, a frame of the first image information and a frame of the second image information corresponding to an inspection delay time in which a difference between a shooting time and a sensing time is based on the shooting time information and the sensing time information A method for inspecting defects in steel products, comprising a step of synchronizing. The method of claim 13,
The inspection delay time is calculated based on the separation distance between the photographing area of the first image information and the sensing area of the second image information, and the conveyance speed of the steel product.

Images