JP2003014429A - Crop shape detector for strip coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the detection accuracy and detection efficiency in an image processing method for the crop shape of a strip coil. SOLUTION: In this device for radiating light ray to the crop of the strip coil on a cradle roll to project the crop on the coil circumferential surface and detecting the crop shape on the basis of the luminance difference between the image of the crop taken by a camera and its shadow, a light source 2 for radiating the light ray from the lower side of the strip coil 10 in the tangential direction thereof toward the crop 11 is movably arranged in a position corresponding to the winding diameter of the strip coil that is a subject of measurement. Instead of the structure for moving the light source 2, two or more light sources may be arranged in parallel in conformation to the winding diameter of the strip coil. The read of the crop shape by the luminance difference of the projected image is facilitated without being influenced by the warp shape of the crop 11, and the accuracy and efficiency of the detection is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip detecting device for a strip coil, and more particularly to a device capable of highly accurately and efficiently detecting and determining a crop shape by an image processing method.

[0002]

2. Description of the Related Art In a strip production, for example, a steel strip production line, it is necessary to appropriately set a cutting length when cutting and removing a crop of a steel strip. Insufficient cutting length (imperfect shape of crop left at the tip of the steel strip) causes trouble in the next process operation, and conversely setting an excessive cutting length leads to loss of product yield. In order to properly set the cutting length in order to avoid these problems, it is necessary to detect the crop shape with high accuracy, and an image processing method is used as a general detection technique.

Compared with the crop detection for a steel strip on a threading line, that of a steel strip wound around a coil is troublesome. Conventionally, the detection work is performed by the detection device configured as shown in FIG. In the figure, 1 is a cradle roll, 10 is a steel strip coil horizontally mounted on the roller, 2 is a light source, and 5 is an imaging camera. The light source (2) is
The camera (5) is installed diagonally below the strip coil (10) so as to irradiate the crop (11) from the front, and the camera (5) is oriented horizontally with respect to the circumferential surface of the coil (10).
It is installed at an appropriate position so that 1) and its shadow can be placed in the visual field.

In the above apparatus, when a light beam is emitted from the light source (2) toward the crop (11) of the steel strip coil (10), the crop (11) is formed on the coil peripheral surface (12) as shown in FIG. The crop (11) and its shadow (S) are projected and imaged by the camera (5). Then, the cropped shape is read by processing the image pickup data as a brightness difference between the crop surface (irradiation surface) and the shadow (S), and is output to the next step.

[0005]

In order to perform the crop detection with high accuracy by the above-mentioned detection device, the shadow (S) can be sufficiently differentiated based on the brightness difference between the crop and the shadow.
Need to be formed. However, the coil surface (1
The projection state of the crop to 2) depends on the warp of the crop (the size of the lift d from the coil circumferential surface). When the lift (d) is small, the shadow (S) is also small and discrimination based on the brightness difference. Recognition becomes difficult. Even if the steel strip coil (10) is rotated by the drive of the cradle roll (1) to adjust the direction of the crop (11) with respect to the light source (2), it is difficult to improve the detection accuracy by only that.

The present invention solves the above-mentioned problems relating to the detection of the crop of the strip coil, and can detect the crop shape based on the brightness difference accurately and efficiently without being affected by the rising form of the crop. It was done like this.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a light beam is projected toward a crop of a strip coil on a cradle roll to project the crop on the circumferential surface of the coil, and the crop captured by a camera and the shadow thereof. In the device that detects the crop shape based on the brightness difference, the light source for irradiating the coil from the lower side of the strip coil toward the crop portion in the tangential direction of the coil is provided at a plurality of locations corresponding to the winding diameter of the strip coil. It has a configuration arranged.

If desired, the detecting device of the present invention uses one light source (2) instead of the above-mentioned structure in which light sources are arranged in parallel at a plurality of places, and a crop (11) of strip plate coils having different winding diameter sizes. In order to irradiate the light source, the light source is mounted on a moving carriage and arranged so as to be capable of reciprocating in the horizontal direction, which is close to or away from the strip coil (10).

The projection of the crop in the present invention is carried out by irradiating light rays in the tangential direction by the light source (2) arranged below the strip coil (10), so that the crop (1
Even if the rise (d) of the crop is small without being affected by the warp shape of 1), it is easy to read the crop shape due to the difference in brightness between the imaged crop and its shadow. The degree of floating (d) of the crop depends on the cooling conditions (cooling speed, etc.) after winding the coil, the size of the winding diameter,
Although it depends on the thickness and width of the strip, the shape of the crop, and other conditions, the present invention enables accurate and efficient crop detection regardless of such conditions.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings showing embodiments. FIG. 1 shows an example of a detection device in which a plurality of light sources (2 ₁ ) (2 ₂ ) (2 ₃ ) are arranged in parallel to perform crop projection. The plurality of light sources (2 ₁ ) (2 ₂ ) (2 ₃ ) are located below the cradle roll (1) and are arranged at a plurality of horizontal positions orthogonal to the strip coil (10) at appropriate intervals. It is attached to the fixed base (3).

The number of light sources (2) to be installed and the number of installation positions are appropriately set so as to cover the winding diameter of the strip coil (10) to be measured (minimum winding diameter to maximum winding diameter). . In the illustrated example, the strip coil is divided into three classes of large-diameter coil, medium-diameter coil, and small-diameter coil, and three light sources (2 ₁ ), (2 ₂ ),
(2 ₃ ) They are installed in advance, and each of them is used properly based on the coil diameter information from the host.

For example, a medium-diameter band plate coil (1
In the 0 ₂ ) crop detection, the medium size coil light source (2 ₂ ) installed at the position corresponding to the tip of the crop irradiates the crop. At this time, the light source for small diameter (2 ₁ ) and the light source for large diameter (2 ₃ ) are turned off. Similarly, the light source (2 ₁ ) is used for crop detection of the small-diameter band coil (10 ₁ ) and the light source (2 ₃ ) is used for the large-diameter band coil (10 ₃ ).
Crop projection is performed with other light sources turned off.
The light irradiation in the tangential direction to the strip coil (10) may be performed by directing the light source (2) substantially vertically upward as shown in FIG.

FIG. 4 shows the light beam irradiation and the projection state of the crop on the crop of the strip coil in the detection apparatus of FIG. As an effect of irradiation from the lower side of the strip coil (10) in the tangential direction, even if the lift (d) of the crop (11) is small, the crop is largely projected on the coil peripheral surface (12), The crop (11) and the shadow (S) are picked up by the camera (5) and image-processed.

FIG. 2 shows an example in which a light source moving device (4) is installed in place of the structure shown in FIG. 1 (a plurality of light sources are arranged in parallel) and the light source (2) is horizontally moved to adjust its position. Is shown. The light source moving device (4) comprises a carriage (4 ₁ ) equipped with a light source and a rail (4 ₂ ), and the rail (4 ₂ ) is arranged in a direction orthogonal to the axis of the strip coil (10). There is. Light source mounting carriage (4 ₁₎ performs horizontal movement close to or apart by being guided by the rail relative to the strip coil (10).

The horizontal movement of the light source carrier (2) is adjusted according to the winding diameter of the strip coil (10). For example, in detecting the crop of the strip coil (10 ₂ ), the light source (2) is moved to the position b by the traveling of the carriage (4 ₁ ), and the vertically upward light irradiation is performed on the crop (11). Further, the light source (2) is moved to the position a for crop detection of the strip coil (10 ₁ ), and to position c for the strip coil (10 ₃ ), respectively.
The light is applied to the crop (11) in the tangential direction of (0).

The movement (position adjustment) of the light source (3) is carried out by driving and controlling the light source mounted carriage (4 ₁ ) based on the coil diameter information from the upper layer, whereby one light source (2) As shown in FIG. 4B, it is possible to obtain a projected image with large shading for strip coil of various sizes having different winding diameters.

Under the above-mentioned light source selection (FIG. 1) or light source position movement control (FIG. 2), a camera (5) oriented horizontally with respect to the strip coil (10) captures a crop projection image. To do. In actual operation, cradle roll (1)
Since the strip coil coil (11) placed on (1) hardly faces the front of the camera (5) (the position of the crop is random), the cradle roll (1) is provided for each strip coil. Is rotated and imaged at an appropriate cycle, for example, a coil diameter × 1.3 turns at a 1-second pitch. In this way, it is possible to efficiently perform crop imaging and shape detection for a large number of strip plate coils having different crop orientations, and also to obtain multiple images even in the case of a long crop where the projected image does not fit within one visual field. The total shape can be efficiently determined by adding

The crop (11) to be detected according to the present invention refers to a tip portion having an irregular shape generated by rolling, and is usually called a fish tail, a tongue, a one-sided extension, etc. It doesn't matter.

[0019]

According to the present invention, the accuracy of crop detection of the strip coil by the image processing method can be improved and the detection work can be efficiently performed. By improving the detection accuracy, it is possible to eliminate the need for visual monitoring of workers and the staffing for that purpose. Also, by increasing the accuracy of crop shape determination, it is easy to set the optimum cutting position of the crop, and the excess and deficiency of crop cutting and the problems due to it, for example, the trouble in the next process operation due to the insufficient crop discard amount. Are alleviated, and the yield of products is improved by avoiding unnecessary cropping.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a detection device of the present invention.

FIG. 2 is a front view showing another embodiment of the detection device of the present invention.

FIG. 3 is an explanatory diagram of a light source position in the device of the present invention.

FIG. 4 is an explanatory diagram (FIG. 2 is a side view of FIG. 1) showing an irradiation / projection state of a fish tail in the detection apparatus of the present invention.

FIG. 5 is a front view showing a conventional detection device.

FIG. 6 is an explanatory diagram showing an irradiation / projection state of a fish tail in the detection device of FIG.

[Explanation of symbols]

1: Cradle roll 2, 2 ₁ , 2 ₂ , 2 ₃ : Light source 3: Light source fixing base 4: Light source moving device 4 ₁ : Light source mounting carriage 4 ₂ : Rail 5: Camera 10: Strip coil 11: Crop 12: Coil Perimeter S: Shadow

Claims (2)

[Claims] 1. A light beam is directed toward a crop of a strip coil on a cradle roll to project the crop on a coil peripheral surface, and a crop shape is determined based on a brightness difference between the crop captured by a camera and its shadow. In the detecting device, a light source for irradiating the coil from the lower side toward the crop portion in the tangential direction of the coil is arranged at a plurality of positions corresponding to the winding diameter of the coil. Crop shape detector. 2. A light beam is directed toward the crop of the strip coil on the cradle roll to project the crop on the coil peripheral surface, and the crop shape is determined based on the brightness difference between the crop captured by the camera and its shadow. In the device for detecting, a light source for irradiating the coil from the lower side of the strip coil toward the crop in the tangential direction of the coil is mounted on a light source moving device horizontally installed in a direction orthogonal to the axis of the strip coil, A crop shape detecting device for a strip coil, which is movably arranged at a position corresponding to a winding diameter of the plate coil.