JPH07253400A - Method for automatic discrimination of scrap containing copper from iron scrap group - Google Patents

Abstract

PURPOSE:To obtain the method in which a scrap containing copper is discriminated automatically from an iron scrap group after a crushing operation. CONSTITUTION:In a process, a scrap piece containing copper is discriminated and separated from an iron scrap group 1 after a crushing operation. In the process, one or a plurality of iron scraps are imaged by a color television camera 3, a chroma value 7 which is expressed by using an RGB signal value 5 for individual points inside an image is found regarding the parts, a hue angle value 8 which is expressed by using the RGB signal value 5 for the points is found, and whether the chroma value 7 for the points is at a preset prescribed value or higher or not is distinguished. When the chroma value 7 for the points is at the prescribed value or higher, whether points, on the scrap piece, which correspond to the points indicate copper or not is distinguished by whether the hue angle value 8 for the points is within a preset hue angle range for the copper or not. All points inside the image are processed in the above manner, and the scrap piece containing the copper is discriminated automatically from the iron scrap group 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically identifying scrap containing copper, which is an impurity element, from a group of iron scraps in iron scrap regenerative processing.

[0002]

2. Description of the Related Art In order to avoid deterioration of the quality of iron produced by scrap regeneration, it is necessary to prevent the inclusion of non-ferrous impurity elements such as copper, zinc and tin, which are generally called Trump elements. Zinc and tin are mainly present on the surface of the plated steel sheet, while copper is mainly present as copper wire in the motor core of automobiles and home appliances, so it is necessary to identify and separate at the crushing scrap stage to prevent contamination. Most effective. Conventionally, at the scrap regeneration site, identification of scraps, mainly motor cores containing copper, has been made visually by workers. In such manual identification work, it is difficult to expand the scrap processing amount, it is economically difficult to invest a large amount of labor costs, it is difficult to ensure uniform quality of scrap after copper removal, and it is difficult to improve the work environment. There is. As a means for automating this work, a method for performing automatic scrap identification by laser beam irradiation has also been proposed (Dr.
H.-P Sattler: VDI BERICHTE NR. 934, 1991: 'Scrap
sorting with Lazer-an automatic process for mixed
non-ferrous metals from automobile shredders').

[0003]

However, since the above method uses an expensive pulse laser irradiator, it is difficult to reduce the cost of the device, and the laser and the spectroscope must be used in a bad environment. Maintenance costs money and manpower. As a method for automatically identifying scrap containing copper, the present inventors have already applied for a patent for an automatic identification method based on hue angle (Japanese Patent Application No. 5-135119; identifying scrap containing copper from a group of iron scraps). how to). However, the method using only the hue angle showed that the hue angle became unstable in the area where the chroma value in the scrap was low, and the accuracy of discrimination between copper and iron was reduced. Therefore, it is an object of the present invention to improve the identification accuracy of a method for automatically identifying scrap containing copper using a hue angle.

[0004]

According to the present invention, in a process of identifying and separating scrap pieces containing copper from a crushed iron scrap group, one or more iron scraps are imaged by a color television camera; For each point, a saturation value represented by using the RGB signal value of the point is obtained; a hue angle value represented by using the RGB signal value of the point is obtained; It is determined whether it is equal to or greater than a preset specified value; if the saturation value of the point is equal to or larger than the specified value, is the hue angle value of the point within the preset hue angle range of copper? It is determined whether or not the point on the scrap corresponding to the point is copper; by performing the above processing on all the points in the image, copper is contained from the iron scrap group. This is a method for automatically identifying scrap.

[0005]

As shown in FIG. 1, the iron scrap group 1 is connected to the light source 2
The area of the iron scrap 1 requiring copper identification is imaged by the color television camera 3 in the state of being illuminated with. However, the light source is not always necessary if the image can be taken by the color television camera without the light source. Then, the presence or absence of copper is identified by performing the following process for all points on the image.

The image signal processing circuit 4 obtains an RGB signal 5 and a synchronizing signal 6 from the output of the color television camera.
The position information of all the points in the image is obtained from the synchronization signal 6. At all points in the image, the saturation value 7 and the hue angle value 8 are obtained from the RGB signal values at each point. For each point, it is checked whether the saturation value is equal to or more than the specified value required for copper identification 12. If the value is equal to or more than the specified value, the identification process is performed. If it is less than the specified value, the identification process is not performed and the integrated identification unit 13 determines that the copper is not copper. The hue angle value of each point is obtained, and the value is compared with the correspondence relationship between the material and the hue angle value range set in advance in the calculator 10 to see if the hue angle is within the range of copper. 11. If it is within the range, the integrated identification unit 13 determines that the point on the scrap corresponding to the point is copper. The position information 15 and the discrimination result 14 of all the points in the image are output.

In the present specification, the saturation value means that, as shown in FIG. 2, the RGB component of the color information is a color vector 1 in a three-dimensional space.
7 Color vector 17 and unit plane 16 (R = G = B =
Let P be the intersection of (1). As shown in FIG. 3, the color vector 17 is observed from the direction perpendicular to the unit surface 16 in the same space. At this time, as shown in FIG. 3, Aya what the length of the line segment O'P19 projected observed unit surface 16, normalized by the radius O'S ₁ circle S ₁ · S ₂ · S ₃ Degree.

In the present specification, the hue angle value is the color vector 17 in the three-dimensional space of the RGB components of the color information, as shown in FIG. Consider an observation plane when the color vector 17 is observed from a direction perpendicular to the unit surface 16 (FIG. 4). At this time, the angle θ20 formed by the observation axis O′R′21 and the line segment O′P of the R axis in the color space (FIG. 2) is defined as the hue angle (0 ° ≦ θ <360 °).

[0009]

EXAMPLE FIG. 5 shows an example of the apparatus configuration for carrying out the present invention.
In this example, in order to reduce the influence of light such as a fluorescent lamp in the room, a dark room 22 is provided and the measurement is performed in the dark room 22. A four-point light source 24 as a light source and a CCD camera 2 as a color television camera
3 was used. The four-point light source illuminates scrap from four directions. Compared to a light source that illuminates from one direction,
It has the effect of reducing the shadows that occur on the scrap and its installation table.

A four-point light source is not always required as long as it is possible to limit the generation of shadows to a range that does not interfere with the identification process. The identification processing device 29 includes a hue angle calculation unit 8, a saturation calculation unit 7, a material-hue angle range correspondence record holding unit 10, a copper determination unit 11, a saturation value appropriateness determination unit 12, and a hue angle value-color value integration. The identification unit 13, the identification result 14 and the position information 15 are output.

Further, in this embodiment, the CCD camera picked-up image is temporarily stored in the image taking-in device 27 in order to simplify the timing process of the identification processing device 29 picking up the iron scrap image picked up by the CCD camera 23. Identification processing device 2
9 collects RGB information at any time. This image capture device 27
It goes without saying that the identification device can be configured without the above.

In this embodiment, an attempt is made to automatically identify a copper portion of a motor core squeezing scrap made of iron and copper. Prior to the actual discrimination experiment, a preliminary experiment for determining the boundary value between the saturation value and the hue angle value for discrimination was carried out. Under the same optical conditions (identifying conditions as the light source 24, the operating condition of the CCD camera 23, the dark room 22, the distance between devices and the distance between target scraps, etc.), the scrap copper part, scrap iron part,
The distribution of hue angle values of each table on which scrap is placed was measured. Furthermore, under the same conditions, the saturation value distribution states of the scrap copper part, scrap iron part, and base part were measured.

From the results of these preliminary experiments, an appropriate range of saturation value (sat) for judging copper and a range of hue angle value (hue) of the copper part were found. As shown in FIG. 6 and FIG. 7, these are (0.3 ≦
sat ≦ 1.0) 30, and for the hue angle value (0 ° ≦ h
ue ≦ 52 ° and 329 ° ≦ hue <360 °) 31,
Is. In the discrimination experiments described below, the boundary values of the saturation value and the hue angle value for these discriminations were used.

The identification method procedure of this embodiment is shown as a flow chart in FIG. This is what is actually processed by the identification device. In the present embodiment, with respect to the point where the saturation value does not reach the specified value, it is determined that the point on the scrap corresponding to it is not copper without referring to the hue angle value.

In the present embodiment, the discrimination processing is performed on the points where the picked-up image is decomposed into 77440 pixels (320 × 242 pixels). For these points, the saturation value and the hue angle value are calculated by the identification processing device 29 based on the definitions shown in FIGS. 3 and 4, respectively. Then, the saturation value is (0.3 ≦ s
At a point where at ≦ 1.0) 30 is exceeded, the hue angle value is (0 ° ≦ hue ≦ 52.0 ° or 329 ° ≦ sat ≦
(360 °) 31 is determined.

For points where both the saturation value and the hue angle value are within the range, it is determined that copper is present, and the corresponding point in the result display window of the identification processing device 29 is, for example, a red point. Is displayed. For points where the saturation value or hue angle value is not within the range, it is determined that copper does not exist, and a blue point, for example, is displayed at the corresponding point in the result display window of the identification processing device 29. To do.

The above processing is performed for all points within the image pickup range of the CCD camera. As a result, the identification result display is made as a color graphic on the result display window of the identification processing device 29. That is, the portion corresponding to copper on the scrap is displayed in red, and the portion not corresponding to copper is displayed in blue. Below, the discrimination accuracy comparison results of the method of performing discrimination using only the hue angle value (Japanese Patent Application No. 5-135119) and the method of performing discrimination using both the hue angle value and the saturation value of the present invention are shown. .

FIG. 9 shows an outline of a captured image of the motor core scrap before the identification processing. As shown in the figure, the motor core scrap is a copper core 33 entwined with an iron core 32. FIG. 10 shows an outline of the result of copper identification using only the hue angle value. The original result is that the hue angle value is 0.0
The portions within the ranges of 5 ° to 52.0 ° and 329.0 ° to 360 ° (31 in FIG. 7) are displayed in red. In the figure, the portion displayed in red in the result is shown in black. FIG. 11 shows the result of copper identification using the saturation value and the hue angle value. This has a saturation value of 0.3 or more and a hue angle value of 0.0 ° to 52.0 ° and 329.0 °.
The part within the range of (1) to 360 ° (31 in FIG. 7) is shown in black.

As is clear from a comparison between FIG. 9 and FIG. 10, in FIG. 10, the iron portion on the scrap shown in FIG. here,
Comparing FIG. 10 and FIG. 11, there is a clear reduction in the portion of the original image that was erroneously identified as copper although it was iron. According to the output result of the identification processing device 29, FIG.
When the number is 0, the number of pixels in red is 17210.
11, the number of pixels in the portion displayed in red in FIG. 11 is 10
It is 259. The reduction rate of the red display portion is about 40%. Most of this decrease was due to the misidentification of the iron part as copper.

[0020]

By using the method for identifying copper in a scrap group using the method of the present invention, it is possible to automate and improve the accuracy of the identification work that has been conventionally performed by the visual inspection of workers, and as a result, scrap processing is possible. It is possible to solve the conventional problems such as easy expansion of the quantity, no need to invest a large amount of personnel, ensuring uniform quality of scrap after copper removal, and easy improvement of working environment.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an identification device configuration according to the present invention.

FIG. 2 is a conceptual diagram of a color space.

FIG. 3 is an explanatory diagram of a definition of a saturation value.

FIG. 4 is an explanatory diagram of the definition of a hue angle value.

FIG. 5 is a configuration diagram of an automatic identification device according to an embodiment.

FIG. 6 is an explanatory diagram of an appropriate saturation value range in the embodiment.

FIG. 7 is an explanatory diagram of a hue angle value range of copper in the example.

FIG. 8 is a processing flowchart of the embodiment.

FIG. 9 is a schematic diagram of an original image of a motor core squeezing scrap to be identified in the embodiment.

FIG. 10 is a schematic diagram of identification result 1 of the example.

FIG. 11 is a schematic diagram of identification result 2 of the example.

[Explanation of symbols]

 1 Iron Scrap 2 Light Source 3 Color TV Camera 4 Image Signal Processing Circuit 5 RGB Signal 6 Sync Signal 7 Saturation 8 Hue Angle 9 Position Information Detection Section 10 Material-Hue Angle Range Correspondence Record Storage Section 11 Copper Discrimination Section 12 Saturation Value Discrimination unit 13 Integrated discrimination unit 14 Discrimination result 15 Position information 16 Unit plane 17 Color vector 18 Intersection of unit plane and color vector 19 Line segment representing saturation 20 Hue angle 21 Hue angle definition reference axis 22 Dark room 23 CCD camera 24 4 points Light source 25 Monitor TV 26 Video signal 27 Image capture device 28 RGB information of each point on the image 29 Identification processing device 30 Appropriate saturation range for identification processing 31 Hue angle range of copper 32 Motor core scrap Iron core part 33 Motor core scrap Copper wire part

Claims (1)

[Claims] 1. In a process of identifying and separating scrap pieces containing copper from a group of iron scraps after crushing, one or more iron scraps are imaged by a color television camera; for each point in the image, the point Saturation value represented by using the RGB signal value possessed by ;; Hue angle value represented by using the RGB signal value possessed by that point; Saturation value at that point is equal to or greater than a preset specified value If the saturation value of the point is greater than or equal to the specified value, the point is determined by whether the hue angle value of the point is within the preset copper hue angle range. It is determined whether or not the point on the corresponding scrap is copper; the above processing is performed for all the points in the image, and the scrap containing copper is automatically identified from the iron scrap group. how to.