JP2001012913A - Coil position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coil position detector in which the coil position can be operated accurately even for a coil having mirror surface by projecting the three-dimensional cross-section data of the coil in the radial and widthwise directions thereof and calculating the width and radius of the coil along with respective central positions thereof. SOLUTION: A slit light scanner 12 performs scanning by projecting laser slit light 12a to cut a coil 3 and transmits a signal of light projection angle θwhereas a TV camera 10 transmits the pickup image of light cutting line as an image signal. Based on the image signal and the light projection angle signal, an image synthesizer 14 generates a binarized image processing signal and a projection angle image signals and a regular reflected light noise removing unit 17 varies the light projection angle θ when regular reflected light is inputted. Based on both image signals, a profile operating unit 16 operates three- dimensional cross-section data and a coil operating unit 18 projects the cross-sectional data in the radial and widthwise directions of the coil and calculates the width and radius of the coil along with respective central positions thereof. According to the arrangement, influence of regular reflected light can be eliminated even when the coil 3 has mirror surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for non-contact measurement of a three-dimensional shape (position) such as the position and height of an object, and more particularly to an overhead crane which is operated unmanned in a coil yard of a steelworks. And a coil position detecting device for detecting a center position of the coil and the like.

[0002]

2. Description of the Related Art As a method for easily measuring three-dimensional information such as the position and height of an object, a light cutting method has been well known. In this light cutting method, the object to be measured is irradiated with laser slit light, and the shape pattern (light cutting line) of the laser slit light projected on the surface of the object to be measured is changed from a direction different from the irradiation direction of the laser slit light. Take an image with a TV camera. At this time, if the measured object has irregularities, the light cutting line is deformed on the captured image according to the irregularities of the measured object. Therefore, the shape of the object to be measured is calculated based on the principle of triangulation from the position of the light cutting line (deformation amount) when the image is taken by the television camera and the projection angle of the laser slit light. A coil position measuring apparatus is applied to the measurement of the width, the center of the diameter, and the like of the coil in the coil yard using the object to be measured as a coil.

Next, a case where this method is applied to a coil position measuring device will be described. Take an image with a TV camera,
In the processed image, the portion of the light section line is usually bright (that is, the brightness is high). Therefore, a high-luminance portion and a low-luminance portion are divided by a binarization process, and only the high-luminance portion is extracted. Then, the three-dimensional shape of the coil is calculated based on the principle of triangulation from the extracted portion and the projection angle of the laser slit light.

[0004]

As described above, the coil position detecting device irradiates a slit-shaped laser beam onto the coil surface and images a light cutting line appearing on the coil surface to create three-dimensional shape data. Then, the center position and the like of the coil are calculated based on the shape data. Then, the crane is controlled using the calculation result to carry the coil or the like. Here, if the surface property of the coil to be detected is a diffuse property of diffusely reflecting the irradiation light, the laser light irradiated on the coil surface is diffusely reflected over a wide angle. Therefore, regardless of the shape of the coil, the intensity of light input to the television camera is always stable.

However, when the properties of the coil surface to be irradiated with laser light are close to mirror-like, the irradiated laser light is not diffusely reflected but specularly reflected (= specularly reflected). Therefore, the intensity of light input to the television camera greatly changes depending on the position of the coil surface on which the laser light is irradiated.

FIG. 11 is a diagram showing a positional relationship between a coil for irradiating a laser beam and a television camera. For example, when the irradiated laser light is diffused due to the properties of the coil surface, the intensity of the light input to the television camera is substantially constant regardless of whether the laser light is applied to point A or B. On the other hand, when the irradiated laser light is regularly reflected due to the properties of the coil surface, the light that is regularly reflected is not input to the TV camera when the laser light is applied to the point A, so that the light input to the TV camera is not strong. However, when the light is applied to the point B, the light that is regularly reflected enters the television camera, so that the light at this time is very strong. Here, since the shape of the coil is usually cylindrical, the irradiation position of the laser beam when the specularly reflected light is input to the TV camera in this way depends on the arrangement of the laser light source and the TV camera and the inclination of the coil surface. Determined, and its location is limited to a specific portion of the coil surface.

FIG. 12 is a diagram showing a screen subjected to an image pickup process. If position detection is performed by a conventional method using a coil having a surface texture that causes specular reflection, regular reflection light is input to the television camera depending on the laser light source, the shape of the coil, and the positional relationship between the television camera as described above. May be done.
When extremely strong light such as specular reflection light enters the television camera, the lens and imaging surface of the television camera (for example, CC)
In the optical system composed of D), the input light is reflected,
Causes scattering and the like. Therefore, the light focused on the imaging surface has a wider range than the actual laser light. In some cases, a phenomenon such as a ghost image generated between the lens and the imaging surface may be reflected. For this reason, on the screen, a portion having a high luminance is generated even in a portion other than the irradiation portion to be actually obtained, and it is not possible to accurately detect a light cutting line due to laser light irradiation.

Therefore, depending on the position where the television camera receives the reflected light, the spread of the light generated by the regular reflection may reach outside the true coil edge. Therefore, even a portion where the coil does not actually exist is detected as if the coil exists. When the coil width and the center position are calculated by the conventional position detecting device, there is a problem that an accurate coil width or the like cannot be obtained because the coil width is detected as wide as the light is spread.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. Even if the surface of the coil is mirror-like,
It is an object of the present invention to obtain a coil position detecting device that can accurately calculate the position of a coil.

[0010]

A coil position detecting device according to the present invention is mounted on an overhead crane for transporting a coil, and irradiates a plurality of linear laser slit beams to the coil with a laser beam projecting means. Imaging means attached to the crane, for imaging an image with the coil as a subject,
An image processing unit that processes an image captured by the imaging unit to determine and extract a portion whose brightness has changed due to the irradiation of each laser slit light; and that the image captured by the imaging unit is regularly reflected by the laser slit light. It is determined whether or not light has been input, and when it is determined that the specularly reflected light has been input, specular reflection detecting means for instructing the laser light projecting means to change the irradiation position of the linear laser slit light and irradiate the light. When,
Based on the processed image, shape calculation means for calculating three-dimensional shape data of a portion where the brightness has changed, and, among the three-dimensional shape data calculated by the shape calculation means, extract three-dimensional shape data determined to be a coil portion. Projecting the extracted three-dimensional shape data in the radial direction of the coil to calculate at least the width of the coil and the center position of the width, and projecting the extracted three-dimensional shape data in the coil width direction to obtain at least the coil And a coil calculating means for calculating the diameter and the center position of the diameter. In the present invention, the laser light projecting means is attached to an overhead crane that carries the coil, and irradiates a plurality of linear laser slit lights so as to cut the coil. The image processing unit processes the image captured by the imaging unit, and determines and extracts a portion whose brightness has been changed by the irradiation of each laser slit light to create a processed image. The regular reflection light detection unit determines whether or not light that is regularly reflected by the laser slit light is input to the image captured by the imaging unit,
When it is determined that the specularly reflected light has been input, the laser light projecting unit is instructed to change the irradiation position of the linear laser slit light so that the light is irradiated. Is not detected. The shape calculation means creates three-dimensional shape data based on the processed image.
The coil calculating means determines and extracts the three-dimensional shape data of the coil portion from the three-dimensional shape data calculated by the shape calculating means, projects the extracted three-dimensional shape data in the radial direction of the coil, and outputs the width of the coil. And the center position of the width. Also, the extracted three-dimensional shape data is projected in the width direction of the coil to calculate the diameter of the coil and the center position of the diameter.

Further, in the coil position detecting device according to the present invention, a light projecting angle signal representing the light projecting angle of each laser slit light is output, and the specular reflection detecting means outputs the signal based on the processed image and the light projecting angle signal. The pixels in the extracted portion are counted for each laser slit light, and it is determined whether or not light that has been specularly reflected on the image captured by the imaging unit has been input based on the number of pixels for each laser slit light. In the present invention, the laser beam projecting means further outputs a beam projecting angle signal which is information obtained by irradiating the laser slit light. The regular reflection detecting means counts the pixels of the extracted portion for each laser slit light based on the processed image and the light projection angle signal, and abnormally has a large number of pixels based on the number of pixels for each laser slit light. Judge that specularly reflected light has been input.

Further, in the coil position detecting device according to the present invention, the laser beam projecting means irradiates a plurality of laser slit beams by scanning the laser spot two-dimensionally. In the present invention, when irradiating a plurality of laser slit lights, the laser light projecting means two-dimensionally scans and irradiates a laser spot which is a point of the laser light.

Further, in the coil position detecting device according to the present invention, when the laser light projecting means is instructed by the regular reflection detecting means to change the irradiation position of the linear laser slit light,
Irradiation is performed by shifting the interval of the linear laser slit light by a half cycle. In the present invention, when the laser light projecting unit is instructed to change the irradiation position of the linear laser slit light from the regular reflection detection unit, the laser light projecting unit changes the irradiation position for a half cycle of the interval of the laser slit light to reflect the light. Irradiate again at a position where no light is generated.

Further, in the coil position detecting device according to the present invention, when projecting the three-dimensional shape data in the radial direction of the coil, the coil calculating means sets the diameter of the coil to a perpendicular line and a line segment perpendicular to the overhead crane. Projected onto a plane parallel to. In the present invention, when projecting the three-dimensional shape data in the radial direction of the coil, the coil calculating means sets the diameter of the coil as a perpendicular,
Also, project onto a plane parallel to the vertical line segment on the overhead crane so that the highest part of the coil is always included.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. FIG. 1 is a configuration diagram for explaining the measurement principle of the coil measurement device of the present invention.
In the figure, a coil 3 is placed on a reference plane (floor surface) 1. A television camera 10 serving as an imaging unit is arranged so that its center axis is orthogonal to the reference plane 1, converts a captured image into a video signal, and transmits the video signal. The slit light scanning device 12 serving as a laser light projecting unit is arranged at a position different from the television camera 10. The slit light scanning device 12 generates the laser slit light 12 a from the laser spot light, scans the laser slit light 12 a, and irradiates the laser so as to cut the coil 3. Further, a light projection angle signal representing the light projection angle θ based on the scanning is transmitted. The image synthesizing device 14 serving as an image synthesizing unit converts the binary processed image signal and the light projection angle image signal based on the video signal transmitted from the television camera 10 and the light projection angle signal transmitted from the slit light scanning device 12. Generate processing. Shape calculation device 16 serving as shape calculation means
Calculates three-dimensional cross-sectional shape data based on the binary processed image signal and the projection angle image signal generated and processed by the image synthesis device 14. The specular reflection light noise elimination device 17 serving as the specular reflection detection unit determines whether or not the spread of the laser light has occurred by using the spread of the laser light in the captured image when the specular reflection light is input, If it is determined that a laser beam has occurred, the laser beam irradiation position is changed. A coil operation device 18 serving as a coil operation means obtains a diameter, a width, and the like of the coil 3 based on the three-dimensional cross-sectional shape data obtained by the shape operation device 16. At this time, components generated by the spread of the laser spot light based on the regular reflection are removed. The configuration of the coil position detecting device is as described above. Before describing the overall operation of the coil position detecting device of FIG. 1, the measuring method, the image synthesizing method, the relationship and the shape between the position of the laser slit light and the projection angle θ are described. The operation of each related device will be described from the viewpoint of the operation principle.

(A) Measuring Method FIG. 2 is a diagram showing a configuration of the slit light scanning device 12. The measurement method according to the present embodiment will be described with reference to FIG. As a measuring method, a method generally called a light section method is used. In the figure, a semiconductor laser 20 emits a laser spot light. The drive motor 22a controls the rotation of the first scanning mirror 22. The first scanning mirror 22 is
The laser spot light emitted from the semiconductor laser 20 is reflected while rotating. Thereby, the laser spot light scans, and laser slit light is generated. Here, the direction of the generated laser slit light is controlled by the drive motor 22a as shown in FIG.
The rotation of the first scanning mirror 22 is controlled so as to be in the y-axis direction. Further, the drive motor 24a controls the rotation of the second scanning mirror 24, and controls the irradiation position of the generated laser slit light in the x-axis direction in FIG. Thereby, the generated laser slit light is scanned in the x-axis direction, and a plurality of laser slit lights are irradiated. At the same time, the projection angle θ determined by the second scanning mirror 24
Is transmitted to the image synthesizing device 14 as a projection angle signal.
The television camera 10 outputs the captured image to the image synthesizing device 14 as a video signal.

Then, the second scanning mirror 24 is moved from θ to Δ
Rotate by θ and execute again. Such an operation is repeated an appropriate number of times. Here, in order to measure the coil position and the like, the value of the projection angle θ is necessary. If a proper number of laser slit lights can be irradiated on the coil, and the value of θ can be determined, the value of Δθ to be rotated is changed each time. It does not matter if they are not the same.

The image synthesizing device 14 processes the video signal of the television camera 10 while synthesizing the video signal by each light cutting line. Then, a binary processed image signal and a projection angle image signal are generated from the video signal and the projection angle signal. The shape calculation device 16 performs the image processing by the image synthesis device 14.
A plurality of three-dimensional cross-sectional shape data is calculated using the value-processed image signal and the projection angle image signal. Based on these calculation results, the overall shape of the coil 3 is obtained.

Here, in order to improve the measurement accuracy, a light cutting line (laser slit light having a projection angle θ) and a light cutting line (projection angle θ) are used.
It is necessary not to irradiate the laser light unnecessarily with the laser slit light of + Δθ. Therefore, the slit light scanning device 12 shown in FIG. This is controlled in synchronization with the drive motor 24a, and until the projection angle θ of the laser slit light changes to θ + Δθ,
The laser slit light is not irradiated on the coil 3. This is because the projection angle θ of the laser slit light is θ + Δθ
The laser spot light may not be generated in the semiconductor laser 20 until it changes to. The smaller the rotation pitch Δθ of the second scanning mirror 24 is, the more the shape resolution of the coil 3 is improved. However, on the other hand, the arithmetic processing increases, and the measurement time increases.

The coil calculating device 18 calculates the center position, the width and the like of the coil based on the respective shape data and the projection angle θ.

(B) Image Synthesizing Method FIG. 3 is a block diagram showing the configuration of the image synthesizing device 14. The video signal transmitted from the television camera 10 is A /
The signal is converted into a digital signal by the D converter 30 and input to the maximum luminance image calculation unit 31. Maximum brightness image calculation unit 31
Is composed of a comparator 31a, a selector 31b and a maximum luminance image memory 32. The maximum luminance image calculation unit 31 obtains the video signal of the maximum luminance level of each pixel area by the comparator 31a and the selector 31b, and stores the video signal in the corresponding pixel area in the maximum luminance image memory 32.

The processing procedure until the maximum luminance image calculation section 31 stores the maximum luminance image signal will be described in detail. A
If / D converter 30 the video signal a _c of the pixel region that is through is input, the comparator 31a from the maximum brightness image memory 32, reads the signal a _m of the pixel area corresponding to the video signal a _c. Then, comparing the luminance level of the signal a _m brightness level and a maximum brightness image memory 32 of the video signal a _c. Here, in the case of a _c> a _m transmits the selector signal to the selector 34a of the selector 31b and the coded image calculation unit 34. When the selector 31b selector signal is input, the signal a _m of the maximum brightness image memory 32
To the video signal a _c (that is, a _c = a
_m ). In the case of a _c ≦ a _m, not rewrite (i.e., a _m = a _m). Such processing is performed by the TV camera 1
Sequentially performed for the video signal a _c inputted from 0.
Therefore, the maximum brightness image level of each pixel region is stored in the maximum brightness image memory 32 as a maximum brightness image signal.

The projection angle signal of the laser slit light transmitted from the slit light scanning device 12 is converted into a digital signal by the A / D converter 33 and input to the coded image calculation unit 34. The coded image calculation unit 34 includes a selector 34a and a projection angle image memory 35. In the coded image calculation unit 34, the projection angle signal at the time when the maximum luminance image level is obtained for each pixel area is projected to the pixel area of the projection angle image memory 35 corresponding to the maximum luminance image memory 32. It is coded and stored as a projection angle image signal representing the angle θ.

The processing procedure in which the coded image calculation section 34 stores the light projection angle signal will be described in detail. Comparator 31a of the maximum brightness image calculation unit 31 compares the luminance level of the signal a _m brightness level and a maximum brightness image memory 32 of the video signal a _c, when it is determined that satisfies the a _c> a _m, a selector signal Is output. When the selector 33a receives the selector signal, the signal b of the projection angle image memory 34 corresponding to the pixel area whose luminance level is compared
The _m, rewrites the projection angle image signals b _c obtained by coding the projection angle θ represented by the projection angle signal transmitted at that time.
Such processing is sequentially performed based on the video signal a _c input from the television camera 10 and the light projection angle signal b _c input from the slit light scanning device 12. Therefore, the angle signal image memory 35, projection angle θ when the maximum brightness image level in each pixel area is stored as the projection angle image signal b _m.

Further, the video signal transmitted from the television camera 10 is converted into a digital signal by the A / D converter 36 and input to the minimum luminance image calculation unit 37. The minimum brightness image calculation unit 37 includes a comparator 37a, a selector 37
b and a minimum brightness image memory 38. The minimum luminance image calculation unit 37 obtains the video signal of the minimum luminance level of each pixel region by the comparator 37a and the selector 37b, and stores the video signal in the corresponding pixel region in the minimum luminance image memory 38.

The minimum luminance image calculation section 37 outputs the minimum luminance image
The processing procedure up to storing the image signal will be described in detail. Ko
The comparator 37a is connected to an image via the A / D converter 36.
Video signal a of the elementary area_c Is input, the minimum brightness image
From the moly 38, the video signal a_c Of the pixel area corresponding to
Signal a_miIs read. Then, the video signal a_c Brightness
Level and signal a of minimum brightness image memory 38_miBrightness level
Compare with Where a_c <A_miIn the case of
And the selector 34 of the coded image calculation unit 34
Transmit the selector signal to a. Selector 31b is select
When the data signal is input, the signal of the minimum brightness image memory 38 is output.
a_miIs the video signal a_c (That is, a_c =
a_mi). a_c ≧ a_miIs not rewritten (that is,
a_mi= A _mi). Such processing is performed by the TV camera 10
Video signal a input from_c Are performed sequentially. did
Therefore, the minimum brightness image memory 38 stores the minimum pixel area.
The luminance image level is stored as the minimum luminance image signal.

FIG. 4 is an explanatory diagram conceptually showing the arithmetic processing of the image synthesizing device 14. FIG. 4A is a diagram illustrating the maximum luminance image level between AA ′. FIG. 4 (b)
It is a figure showing the minimum luminance image level between BB '. FIG. 4C is a diagram showing the light projection angle θ when the maximum luminance image level is obtained between CC ′ (AA ′). In FIG. 4B, the minimum luminance image level of the coil portion is higher than the luminance of the reference plane because the reflected light (background light) of the light other than the laser spot light is affected.
The image synthesizing device 14 is, as described above, the TV camera 10
Real-time processing of the video signal imaged at the step (a), the maximum luminance image level and the minimum luminance image level of each pixel area are detected, and the maximum luminance image memory 32 and the minimum luminance image memory 3
8 is maintained. Further, the projection angle signal at the timing when the image reaches the maximum luminance image level (normally, at the position irradiated with the laser spot light, when a corresponding point in the visual field is hit) is stored in the projection angle image memory 35 at the maximum. Brightness image memory 3
2 is recorded in the pixel area corresponding to 2. Therefore, it is possible to simultaneously obtain a maximum or minimum luminance image signal obtained by combining a plurality of laser slit lights and a projection angle image signal.

(C) Extraction of position and projection angle information of laser slit light In order to extract a light cutting line from the above-described maximum luminance image signal, minimum luminance image signal and projection angle image signal, the following equation (1) is used. ) Is performed, and the luminance level due to the influence of the background light (light generated by an influence other than the laser light) is subtracted. Luminance image level = maximum luminance image level−minimum luminance image level (1) A luminance image level from which the influence of the background light has been subtracted by the image calculation of equation (1) is calculated. To extract only a high-brightness portion (usually a light cutting line) above a threshold level as a binarized image signal. In the present embodiment,
As described above, the minimum luminance image calculation is performed at the same time, the difference between the maximum luminance level and the minimum luminance level is calculated, and then the binarization processing is performed by the comparing unit 39. Alternatively, the comparison unit 39 may perform a binarization process to extract a high luminance portion.

In the image synthesizing device 14, the luminance image memory 3
The binarized image signal stored in 9a is transmitted. In addition, the projection angle image signal is transmitted from the projection angle image memory 35.

(D) Principle of Shape Calculation Next, a binarized image signal and a projection angle image signal are used.
The calculation of three-dimensional cross-sectional shape data based on triangulation will be described. The shape calculation device 16 obtains the entire shape of the coil 3 by calculating the three-dimensional coordinates of each of the light cutting lines for the plurality of laser slit lights generated by the slit light scanning device 12. This shape calculation is based on a triangulation method. The slit light scanning device 12 emits the laser slit light 12 a onto the coil 3 at an emission angle θ. The height z of the point (x ', y') where the laser light extracted from the image obtained by capturing the state is applied
(X ', y') is expressed by the following equation (2) in consideration of the perspective effect of the captured image. z (x ′, y ′) = Z ₀ − {X ₀ − (1−z (x ′, y ′) / a) x} × tan θ (x ′, y ′) (2) x ′: Television The position of the image picked up by the camera on the reference plane (x-axis direction) y ': The position of the image picked up by the TV camera on the reference plane (y-axis direction) X ₀ : x of the laser light scanning rotation axis Coordinate Z ₀ : z coordinate of laser light scanning rotation axis a: distance between television camera and reference plane θ: laser slit light projection angle If the above equation (2) is modified, the height of the point hit by the laser slit light z (x ', y') is obtained by the following equation (3).

[0031]

(Equation 1)

The coordinates (x, y) on the three-dimensional coordinates of the point (x ', y') where the laser light is extracted on the image are given by the following equations (4) and (5). x = ｛1−z (x ′, y ′) / a｝ x ′ (4) y = ｛1−z (x ′, y ′) / a｝ y ′ (5)

As is clear from the above description, the three-dimensional coordinates (x, y) of the point where the laser slit light is detected at the projection angle θ at the coordinates (x ′, y ′) on the image of the television camera 10.
y, z) is obtained by the above equations (3), (4), and (5).
Here, the above equations (4) and (5) have been corrected for the perspective effect that the closer to the TV camera 10 the larger the closer to the TV camera 10 because the distance between the coil 3 and the TV camera 10 is finite. It is. It can be seen that accurate shape detection cannot be performed with a two-dimensional image obtained by simply processing a captured image, and it is necessary to perform correction.

FIGS. 5A, 5B and 5C show the optical system of FIG. 1 (TV camera 10, slit light scanning device 12).
FIG. 2 is a plan view, a front view, and an image in the field of view of the television camera 10 when the camera is placed on an overhead crane. As shown in FIG. 1A, the television camera 10 is moved clockwise in a direction
It is arranged in a direction rotated by 5 ° and its optical axis is positioned vertically downward. Further, the slit light scanning device 12 is located on the trolley 30 and the x of the television camera 10.
Installed on axis. Then, the direction of the generated laser slit light is adjusted so as to be parallel to the y-axis direction of the television camera 10. The coil 3 to be measured is placed parallel to the traversing direction or traveling direction of the overhead crane. Usually, in the yard, the coil 3 is arranged in either the traversing direction or the traveling direction of the overhead crane, and the arrangement direction is known by the system computer managing the yard.
It is possible to arrange. Therefore, in the present embodiment, the coil 3 captured by the television camera 10
Is inclined (rotated) by 45 ° in the visual field.

The slit light scanning device 12 generates laser slit light from the laser spot light, and scans the laser slit light in the field of view of the television camera 10 so as to cut the coil 3. The television camera 10 captures the state. The captured image is an image obtained by irradiating the coil 3 with the laser slit light at an angle of 45 degrees. The image synthesizing device 14 generates a synthesized image by the method described above. The shape calculation device 16 calculates the shape of the portion (light cutting line) hit by the laser slit light based on the composite image based on the above calculation formula. By performing calculations for each light cutting line, the TV camera 10
A plurality of cross-sectional shapes of the object within the measurement field of view can be obtained.

The specular reflected light noise elimination device 17 determines whether or not regular reflected light is input to the television camera 10 based on the binarized image and the projected angle image transmitted from the image synthesizing device 14. I do.

FIG. 6 is a diagram showing a binarized image in which no regular reflection light input has occurred, and a histogram showing the number of pixels at each projection angle. TV camera 10 with specular reflection
, The number of pixels at each light projection angle becomes substantially uniform. This is because the size of the laser spot light to be imaged does not differ depending on each projection angle.

FIG. 7 is a diagram showing a binarized image in which regular reflection light input has occurred and a histogram representing the number of pixels at each light projection angle. When strong light such as specularly reflected light is input to the television camera 10, the light is largely imaged. Therefore, only the projection angle at that time increases the number of pixels (that is, the number of pixels at the projection angle at which the regular reflection light input occurs becomes the largest).

Therefore, the specular reflection light noise elimination device 17 is provided with a threshold value. Then, the regular reflection light noise removing means 17
It is determined that specularly reflected light is generated if there is a light projection angle with the number of pixels equal to or larger than the threshold value. When it is determined that the regular reflection light is generated, the regular reflection light noise removing unit 17
For example, it instructs the slit light scanning device 12 to re-irradiate the laser light after shifting the interval of the laser slit light by about half (half cycle).

FIG. 8 is a diagram showing before and after shifting the interval of the laser slit light. When the specularly reflected light is input to the television camera 10, the position is limited by the positional relationship between the camera mounted on the crane, the laser projection position, and the surface shape of the coil. Therefore, if the position is not irradiated with the laser light again, the input of the specularly reflected light to the television camera 10 can be eliminated, and the specularly reflected light is not input to the television camera 10.

Next, the coil calculating device 18 uses the cross-sectional shape data to identify the coil and the peripheral portion (the floor and the truck) from the difference in height because the coil is higher than the floor and the truck. Then, only the shape data of the portion determined to be a coil is extracted. Further, from the extracted data on the cross-sectional shape of the coil, data on the projected shape in the radial and width directions of the coil is obtained in order to detect the position of the coil. Here, it is assumed that the projection is made on a plane perpendicular to the reference plane 1 in the radial direction of the coil.

FIG. 9 is an explanatory diagram for obtaining data on the projected shape of the radial projection and the width projection of the coil. In FIG. 9, the number of laser slit lights and the light projection direction of the slit light scanning device 12 are different from those in FIG. 5 for simplicity of description. Here, the TV camera 1 which is a detection head
The shape of the coil 3 is projected in a direction rotated by an installation angle of 0 (45 °), that is, in a traversing direction and a traveling direction of the trolley 30. In the projection in the coil width direction, the average value of shape data in the coil width direction of each cross-sectional shape is obtained,
The value is used as data of the projection shape in the width direction. In the projection in the coil radial direction, the maximum value of the shape data in the coil radial direction of each cross-sectional shape is used as data of the radially projected shape.

FIG. 10 is a diagram showing the relationship between the projected shape of the coil width and the threshold level for width determination. Coil arithmetic unit 1
8 obtains a coil width direction position, a coil width, a coil radial direction center position, and a coil diameter from respective projection shape data obtained by projecting the cross-sectional shape in the coil width direction and the radial direction.
As for the radial direction of the coil, a certain threshold is set, and as shown in FIG. 9, from the projected shape data in the radial direction, points at the left and right ends of the portion equal to or larger than the threshold are detected, and the point is set to the right of the coil. Recognize as an edge and a left edge. The coil width and the width center position are obtained by the following equations (5) and (6), respectively. Coil width center position = (right edge + left edge) / 2 (5) Coil width = | right edge−left edge | (6)

Next, calculation of data of the projection shape in the width direction will be described. The laser slit light 41, 42, 43 of FIG.
In, for example, an average value at the illustrated point is obtained, and the average value is used as the coordinate value of the point in the projected shape in the coil width direction. Similarly, laser slit light 41, 42, 4
The average value of the other points 3 and 44 is also obtained, and the entire projected shape 45 in the coil width direction is obtained. Theoretically, the obtained projected shape in the width direction is a semicircle.

In the coil width direction, since the projected coil shape becomes a semicircle, the center position and the diameter of the coil can be obtained by substituting the shape data into the equation of the circle. (X−c _x ) ² + (z−z _x ) ² = r ² ... (7) x, z: semicircular shape data c _x of the coil obtained by the projection, z _x: coil radially central position r: radius of the coil

Specifically, if there is projection shape data at three or more points in the width direction of the coil, the above equation (7) can be solved to obtain the center position and the like. Here, in order to effectively use the projection shape data in the coil width direction and improve the reliability of position detection, a plurality of combinations of three points are set for the projection shape data in the coil width direction. Numerical values that do not satisfy the rules are removed from the plurality of center positions obtained by the respective calculations, and then statistical processing is performed to obtain highly accurate and reliable coil diameters and diameter center positions.

As a method for setting and removing the prescribed values, a method of obtaining a distribution of measured values and removing points separated from a predetermined range by majority rule, or an average of all center positions obtained by point calculation There is a method of deleting data of points set in advance in order of increasing distance from the value.
Such a process is naturally used also at the stage of obtaining the cross-sectional shape in the coil radial direction and for removing abnormal shape data from the obtained cross-sectional shape.

The method of finding the true center position from the calculated many coil center positions is a method of finding the average value of many points, or dividing the distribution of many points into a mesh and taking the maximum value of the distribution. There is a method of obtaining the position, and the like.

The above description is an example in which the arrangement direction of the coil 3 is known in advance.
Can be processed in the same manner even when the direction of is not known in advance. In that case, the direction of the coil 3 is temporarily determined, and then data on the projected shape in the coil width direction and the radial direction is obtained. Since the arrangement direction of the coil 3 can be determined from the obtained shape data, it is compared with the provisionally determined arrangement direction of the coil.
Data on the above-described coil radial direction shape is obtained for the determined arrangement direction.

The overhead crane is controlled based on the coil width and the center position obtained by the coil position detecting device,
Carry the coil.

In the present embodiment, as is apparent from the above description, the slit light scanning device 12 irradiates the coil 3 with the laser slit light by scanning the laser spot light two-dimensionally. The illuminated light cutting line is imaged by the television camera 10, and the image synthesizing device 14 synthesizes the luminance image level and the projection angle at that time by irradiating each laser slit light, and binarizes the image signal and the projection. An angle image signal is generated, and the specular reflected light noise elimination device 17 counts the number of pixels for each projection angle, and if the number of pixels equal to or larger than the threshold value exists in a certain laser slit light, the specular reflected light is input. Judge
For example, by shifting the projection angle θ, the interval between the irradiation positions is reduced to about 1 /
Shift by 2 and measure again. Regular reflection light noise elimination device 1
If 7 does not determine that specularly reflected light has been input, the shape calculation device 16 calculates three-dimensional cross-sectional shape data based on the binarized image signal and the projection angle image signal light. This cross-sectional shape data represents the position coordinates of the light section line. The coil calculating device 18 projects the cross-sectional shape in the radial direction, and calculates the coil width and the center position of the width. At this time, in the projection in the coil radial direction, only the shape created at the same light projection angle is removed, and then the coil width and the center position of the width are calculated.
Further, the sectional shape data is projected in the coil width direction, and the center position of the diameter and the size of the diameter are calculated. Therefore, even if the surface property of the coil 3 is mirror-like, the influence of the specular reflection light can be eliminated, and the coil width can be calculated accurately, so that a highly accurate coil position detecting device can be obtained. Also,
The slit light scanning device 12 outputs a projection angle signal representing the projection angle θ of each laser slit light, which is simultaneously obtained based on the irradiation of the laser slit light, and the regular reflection light noise elimination device 17 outputs Since the calculation is performed based on θ, the accuracy can be more easily improved. When the slit light scanning device 12 irradiates a plurality of laser slit lights, the laser spot light, which is a point of the laser light, is two-dimensionally scanned and irradiated. Irradiation with slit light can also be performed. Further, according to the present invention, when projecting the three-dimensional cross-sectional shape data in the radial direction of the coil, the coil calculation means 18 projects the data on the surface perpendicular to the reference plane 1, so that the coil diameter is perpendicular to the reference plane. And projecting onto a plane parallel to a vertical line segment to the overhead crane, always including the part where the z-axis direction of the coil 3 is the largest (the part with the highest height). The accuracy of the calculation can be improved.

Embodiment 2 FIG. In the above-described embodiment, the description is limited to the coil position detecting device. However, the present invention is not limited to this, and can be applied to an object to be measured other than the coil.

Embodiment 3 FIG. In the above-described embodiment, the input of the regular reflection is determined based on the number of pixels of the laser slit light of the combined processed image. The processing may be performed on all of the captured image screens, and the input of specular reflection may be determined based on all of the captured images. Alternatively, a certain threshold may be determined, the intensity of light input to the television camera 10 may be constantly measured, and the input of specular reflection light may be determined based on the threshold.

Embodiment 4 FIG. In the above-described embodiment, processing such as shape calculation is performed after the images captured by the image synthesis apparatus 14 are once synthesized. However, the present invention is not limited to this. Processing such as shape calculation may be performed in parallel with image creation.

[0055]

As described above, according to the present invention, the regular reflection light detecting means determines whether or not the regularly reflected laser slit light has been input to the image captured by the imaging means, and determines that the laser slit light has been input. Since the laser light projecting means is instructed to change the irradiation position of the plurality of linear laser slit lights and irradiate the laser light again, when the regular reflection light is input, the position detection based on the image is not performed. By performing the calculation based on a captured image in which regular reflection light is not input without performing the calculation, the coil width can be accurately calculated, and a highly accurate coil position detection device can be obtained.

Further, according to the present invention, the laser light projecting means outputs a light projecting angle signal obtained by irradiating the laser slit light, and the specular reflection detecting means outputs the signal based on the processed image and the light projecting angle signal. The pixels in the extracted portion are counted for each laser slit light, and an abnormally large number of pixels is determined to be a regular reflection of the laser slit light. Obtainable.

Further, according to the present invention, when irradiating a plurality of laser slit lights, the laser light projecting means is configured to two-dimensionally scan and irradiate a laser spot which is a point of the laser light. It is also possible to irradiate laser slit light according to the size of the coil.

Further, according to the present invention, the laser beam projecting means changes the irradiation position by a half cycle of the interval of the laser slit light in response to the irradiation position change instruction from the regular reflection detection means, and irradiates the laser beam again. Therefore, utilizing the fact that the input of the specularly reflected light occurs only under certain conditions, it is possible to reliably obtain a coil position detecting device to which the specularly reflected light is not input.

According to the present invention, when the coil calculating means projects the three-dimensional shape data in the radial direction of the coil,
Since the diameter of the coil is perpendicular and projected onto a plane parallel to the vertical line segment on the overhead crane, the highest part of the coil is always included, so the accuracy of calculating the width of the coil and the center position in the width direction is improved. Can be enhanced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining a measurement principle of a coil measurement device of the present invention.

FIG. 2 is a diagram showing a configuration of a slit light scanning device 12.

FIG. 3 is a block diagram illustrating a configuration of the image composition device 14.

FIG. 4 is an explanatory diagram conceptually showing a calculation process of the image synthesizing device 14.

FIG. 5 is a plan view, a front view, and a view showing an image in the field of view of the television camera 10 when the optical system of FIG. 1 is arranged on an overhead crane.

FIG. 6 is a diagram showing a histogram of a binarized image in which no regular reflection light input occurs and a histogram of the number of pixels at each light projection angle.

FIG. 7 is a diagram showing a histogram of a binarized image in which regular reflection light input occurs and a histogram of the number of pixels at each projection angle.

FIG. 8 is a diagram showing before and after shifting the interval of laser slit light.

FIG. 9 is an explanatory diagram for obtaining projection shape data of a radial projection and a width projection of a coil.

FIG. 10 is a diagram illustrating a relationship between a projected shape of a coil width and a threshold level for width determination.

FIG. 11 is a diagram showing a positional relationship between a coil for irradiating a laser spot light and a television camera.

FIG. 12 is a diagram illustrating a screen on which an imaging process has been performed.

[Explanation of symbols]

 Reference Signs List 10 TV camera 12 Slit light scanning device 14 Image synthesizing device 16 Shape calculation device 17 Specular reflection light noise elimination device 18 Coil calculation device

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Mitsuaki Uesugi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. (reference) 2F065 AA04 AA12 AA17 AA26 AA52 AA53 BB08 CC00 DD12 EE00 FF01 FF02 FF09 FF42 FF65 GG04 HH04 HH05 HH12 HH14 HH16 HH18 JJ03 JJ09 JJ26 MM26 NN02 NN17 PP01 PP05 QQ02 QQ03 QQ05 QQ23 QQ24 QQ25 QQ29 QQ34 QQ41 QQ42 QQ43 QQ45

Claims (5)

[Claims] 1. A laser beam projecting means attached to an overhead crane for transporting a coil and irradiating the coil with a plurality of linear laser slit lights; and an image attached to the overhead crane and having the coil as a subject. An image processing unit that processes an image captured by the imaging unit, determines and extracts a portion whose brightness has been changed by the irradiation of the laser slit light, and an image captured by the imaging unit. It is determined whether or not light specularly reflected by the laser slit light is input to the image, and when it is determined that the specularly reflected light is input, the irradiation position of the linear laser slit light is determined by the laser light projecting means. A specular reflection detecting means for instructing to change and irradiate, and a shape for calculating three-dimensional shape data of the portion where the brightness has changed based on the processed image Calculating means, extracting the three-dimensional shape data determined as the coil portion from the three-dimensional shape data calculated by the shape calculating means, and projecting the extracted three-dimensional shape data in a radial direction of the coil. A coil calculation for calculating at least a width of the coil and a center position of the width, projecting the extracted three-dimensional shape data in a width direction of the coil, and calculating at least a diameter of the coil and a center position of the diameter. Means for detecting a coil position. 2. The laser beam projecting unit outputs a beam projecting angle signal representing a beam projecting angle of each of the laser slit lights, and the specular reflection detecting unit outputs based on the processed image and the projecting angle signal. Then, the pixels of the extracted portion are counted for each laser slit light, and it is determined whether or not the specularly reflected light has been input to the image captured by the imaging unit based on the number of pixels for each laser slit light. The coil position detecting device according to claim 1, wherein: 3. The coil position detecting device according to claim 1, wherein the laser beam projecting unit irradiates the plurality of laser slit beams by two-dimensionally scanning a laser spot beam. 4. The laser beam projecting means, when instructed to change the irradiation position of the linear laser slit light by the regular reflection detecting means, irradiates the laser beam with a half cycle of the interval of the linear laser slit light. The coil position detecting device according to claim 1, 2 or 3, wherein: 5. The coil calculating means, when projecting the three-dimensional shape data in a radial direction of the coil, sets the diameter of the coil to a perpendicular line and projects the surface on a plane parallel to a line perpendicular to the overhead crane. The coil position detecting device according to any one of claims 1 to 4, wherein: