JP6770811B2 - Bundling steel pipe inspection equipment and binding steel pipe inspection method - Google Patents

Description

The present invention relates to a bound steel pipe inspection device and a bound steel pipe inspection method for counting the number of steel pipes contained in a bundled steel pipe in which a plurality of steel pipes having the same diameter standard are bundled in the longitudinal direction.

It is common for the operator to visually count the number of bound steel pipes in the shipping work. However, as the number of steel pipes increases, human error occurs more often, and when erroneous shipment occurs, the work process is reviewed at the shipping destination (accepting side), and the bundled steel pipe is reshipped and erroneously shipped at the shipping source. There is a problem that work for collecting the bound steel pipe is required. Therefore, it has been proposed to automatically count steel pipes (long objects) without human intervention (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-21842

The technique described in Patent Document 1 counts the number of steel pipes using an image of the end face of the bound steel pipe, and prepares an image in which the end face of each steel pipe forming the bound steel pipe is clearly displayed. There is a need to. Here, if the end faces of the bound steel pipes are imaged from the front with a single camera, it is not possible to obtain an image in which the end faces of each steel pipe of the bound steel pipes are clearly displayed. Therefore, a plurality of steel pipes forming the bound steel pipes are formed. By imaging the end faces of the bound steel pipes at a plurality of positions and superimposing the obtained images to create a composite image so that at least a part of the above is included in common, the end faces of the bound steel pipes are created. Is getting a clearly displayed image. However, since it is necessary to perform a plurality of operations to obtain a composite image, there is a problem that the number of steel pipes cannot be confirmed immediately in response to the shipment of the bound steel pipes.

The present invention has been made in view of such circumstances, and it is possible to count the number of steel pipes contained in a bundled steel pipe in which a plurality of steel pipes having the same diameter standard are bundled in the longitudinal direction in accordance with shipment. It is an object of the present invention to provide a steel pipe inspection apparatus and a bound steel pipe inspection method.

The bound steel pipe inspection device according to the first invention according to the above object is a bound steel pipe inspection device for counting the number of steel pipes contained in a bundled steel pipe in which a plurality of steel pipes having the same diameter standard are bundled in the longitudinal direction.
An imaging means for creating an image of the end face of the bound steel pipe by photographing the end face of the bound steel pipe from the longitudinal direction of the bound steel pipe.
A contour line extraction means for extracting a contour line from the bound steel pipe end face image to form a contour line image, and
A circle that extracts the arc included in the contour image and obtains the center position of the arc-corresponding circle having the arc as a part of the circumference on the contour image and the total number of the arc-corresponding circles in the contour image. Detection means and
Using the center position of each arc-corresponding circle, a proximity center-to-center distance setting means for obtaining a proximity center-to-center distance to an arc-corresponding circle adjacent to each arc-corresponding circle.
Since the diameter standards of the steel pipes are the same, the distribution range of the distance between the adjacent steel pipe centers of the bound steel pipe is set, the distance between the proximity centers and the distribution range are compared for each arc-corresponding circle, and the proximity is said. An arc-corresponding circle whose center-to-center distance is outside the distribution range is specified, and the remaining number obtained by subtracting the number of the identified arc-corresponding circles from the total number is defined as the number of steel pipes of the bound steel pipe. Have and
The circle detecting means is provided with a function of obtaining the radius of each arc-corresponding circle.
Compare the data acquisition means for acquiring the bound steel pipe information of the bound steel pipe with the radius of the arc-corresponding circle obtained by the circle detecting means and the radius distribution range of the steel pipe set from the diameter standard in the bound steel pipe information. If the arc-corresponding circle with a radius outside the radius distribution range exists, it is determined that there is a different-diameter steel pipe, and if the arc-corresponding circle with a radius outside the radius distribution range does not exist, it is determined that there is no different-diameter steel pipe. It has a steel pipe detecting means .

The bound steel pipe inspection method according to the second invention according to the above object is a bound steel pipe inspection method for counting the number of steel pipes contained in a bundled steel pipe in which a plurality of steel pipes having the same diameter standard are bundled in the longitudinal direction.
The first step of photographing the end face of the bound steel pipe from the longitudinal direction of the bound steel pipe to create an image of the end face of the bound steel pipe.
The second step of extracting the contour line from the bound steel pipe end face image to form the contour line image, and
A third step of extracting an arc included in the contour line image and obtaining the center position of the arc-corresponding circle having the arc as a part of the circumference on the contour line image and the total number of the arc-corresponding circles.
The fourth step of obtaining the distance between the proximity centers to the adjacent arc-corresponding circles for each arc-corresponding circle using the center position of each arc-corresponding circle.
Since the diameter standards of the steel pipes are the same, the distribution range of the distance between the adjacent steel pipe centers of the bound steel pipe is set, the distance between the proximity centers and the distribution range are compared for each arc-corresponding circle, and the proximity is said. There is a fifth step in which the arc-corresponding circle whose center-to-center distance is outside the distribution range is specified, and the remaining number obtained by subtracting the number of the specified arc-corresponding circles from the total number is defined as the number of steel pipes of the bound steel pipe. And
In the first step, the bound steel pipe information of the bound steel pipe is acquired, in the third step, the diameter of each arc-corresponding circle is obtained, and further, the radius of the arc-corresponding circle and the bound steel pipe obtained in the third step. Comparing the radius distribution range of the steel pipe set from the diameter standard in the information, if there is the arc corresponding circle with a radius outside the radius distribution range, there is a different diameter steel pipe, and the radius deviating from the radius distribution range If the circular arc corresponding circle does not exist to have a sixth step of determining that no different-diameter steel pipe.

In the bound steel pipe inspection apparatus according to the first invention and the bound steel pipe inspection method according to the second invention, since the arc included in the contour line image of the bound steel pipe end face image is extracted to obtain the number of steel pipes, the end face of each steel pipe is obtained. A bound steel pipe end face image in which is clearly shown is not required. Therefore, it becomes easy to create an image of the end face of the bound steel pipe, and it is possible to count the number of steel pipes contained in the bound steel pipe in response to the shipment of the bound steel pipe.
Further, since the total number of arc-corresponding circles having a proximity center distance existing within the distribution range of the distance between adjacent steel pipe centers of the bound steel pipe is defined as the number of steel pipes, the arc is formed from the contour line not based on the steel pipe image in the contour line image. Even if it is extracted, the distance between the centers of the arc-corresponding circles that make this arc a part of the circumference greatly deviates from the distribution range of the distance between the centers of the adjacent steel pipes of the bound steel pipe, so it is included in the bound steel pipe from the end face image of the bound steel pipe. It becomes possible to accurately count the number of steel pipes.

It is a block diagram of the bound steel pipe inspection apparatus which concerns on one Embodiment of this invention. It is a flow chart of the bound steel pipe inspection method using the same bound steel pipe inspection apparatus. It is explanatory drawing of the 1st process of the bound steel pipe inspection method. It is explanatory drawing of the 3rd process of the bound steel pipe inspection method. (A) and (B) are explanatory views of the distance between the proximity centers set for the arc-corresponding circle existing in the bound steel pipe region in the fourth step of the bound steel pipe inspection method. It is the bundling steel pipe end face image used in Example 1. FIG. It is an image of the arc corresponding circle obtained from the bound steel pipe end face image of Example 1. It is the bundling steel pipe end face image used in Example 2. It is an image of the arc corresponding circle obtained from the bound steel pipe end face image of Example 2.

Subsequently, an embodiment embodying the present invention will be described with reference to the attached drawings, and the present invention will be understood.
As shown in FIGS. 1 and 3, in the bound steel pipe inspection device 10 according to the embodiment of the present invention, a plurality of steel pipes 11 having the same diameter standard (19 in FIG. 3) are bundled in the longitudinal direction. It is a device for counting the number of steel pipes contained in the bound steel pipe 12 formed in the above. Reference numeral 13 in FIG. 3 is a strip for binding the steel pipe 11.

The bound steel pipe inspection device 10 includes a CCD camera 14 which is an example of an imaging means for creating an image of the end face of the bound steel pipe 12 by photographing the end face of the bound steel pipe 12 illuminated by a lighting device (not shown) from the longitudinal direction of the bound steel pipe 12. Contour line extraction means 15 that extracts a contour line from the bound steel pipe end face image to form a contour line image, and an arc-corresponding circle that extracts an arc included in the contour line image and makes the extracted arc a part of the circumference. The total number M (M = 20 in FIG. 4) is obtained, and the center coordinates (in the two-dimensional coordinate system set on the contour line image) for each arc-corresponding circle C _i (i = 1, 2, ..., M) are obtained. It has a center position) and a circle detecting means 16 for obtaining the radius r.

Here, the contour line extracting means 15 performs differential processing on the obtained bound steel pipe end face image, and extracts points whose differential strength is larger than a predetermined threshold value (points extracted by binarization processing) as contour points. By mounting a program equipped with a function to perform this on a computer, the circle detecting means 16 uses the arc corresponding to the circle as a part of the circumference by Hough transforming the coordinates of the extracted contour points. Each can be configured by mounting a program having a function of obtaining the center coordinates and radii on the line image and the total number of circles corresponding to arcs on the computer.
Since the circle detecting means 16 detects the arc by mathematically processing the coordinates of the contour points on the contour line image, as shown in FIG. 4, the arc-corresponding circle obtained by the circle detecting means 16 is Arc-corresponding circles (C ₁ , C ₂ , ..., C _{19 in} FIG. 4) based on the arc extracted from the contour line of the bound steel pipe image in the bound steel pipe end face image and the bound steel pipe in the bound steel pipe end face image. composed of a circular arc corresponding circle (Fig. 4, C ₂₀₎ based on the arc extracted from the contour lines other than the picture.

Further, as shown in FIG. 1, the binding steel pipe inspection device 10 uses the center coordinates of each arc-corresponding circle C _i (i = 1, 2, ..., M) to arc-corresponding circle C _i (i =. 1, 2, ..., M) A proximity center distance setting means 17 configured by mounting a program having a function of obtaining a proximity center distance to a circle corresponding to an arc adjacent to each other on a computer, and a steel pipe 11 since the diameter standards are identical, to set the distribution range of the adjacent steel center-to-center distance between the bundling steel pipe 12, by comparing the distribution range and the near-center distance for each arc corresponding circle C _i, the proximity distance between the centers (in FIG. 4, C ₂₀₎ arc corresponding circle is outside distribution range to identify the remaining number excluding the number S of the specified circular arc corresponding circle from the total number M (= M-S) the steel number of tie steel 12 It has a steel pipe number counting means 18.

As shown in FIG. 1, the bound steel pipe inspection device 10 further uses the bound steel pipe information (for example, the bound steel pipe 12) written on a recording medium 19 such as a two-dimensional bar code or an IC tag attached to the bound steel pipe 12. Data acquisition means 20 for acquiring (reading) the diameter standard, length, number of used pipes, etc. of the steel pipes 11 constituting the steel pipe 11 and the specified arc-corresponding circle (C ₁ , C ₂ , ..., C in FIG. 4). Compare the radius of ₁₉ ) with the radius distribution range of the steel pipe 11 set from the diameter standard in the bound steel pipe information, and if there is an arc-corresponding circle with a radius that deviates from the radius distribution range, there is a different diameter steel pipe and the radius distribution range. It has a different diameter steel pipe detecting means 21 configured by mounting a program having a function of determining that there is no different diameter steel pipe when there is no arc-corresponding circle having a radius deviating from the above.

Then, as shown in FIG. 1, the bound steel pipe inspection device 10 further compares the number of steel pipes obtained by the steel pipe number counting means 18 with the number of used steel pipes in the bound steel pipe information, and whether the number of steel pipes matches the number of used steel pipes. It is determined that the number of steel pipes matches the number of steel pipes used by the number matching means 22 and the number matching means 22 configured by mounting a program having a function of determining whether or not the pipe is mounted on the computer, and the different diameter steel pipe detecting means 21 is different. If it is determined that there is no diameter steel pipe, a pass judgment is made, and if it is determined that the number of steel pipes matches the number of used steel pipes and the different diameter steel pipe detecting means 21 determines that there is a different diameter steel pipe, a rejection judgment is made as an erroneous diameter. When it is determined that the number of steel pipes does not match the number of used pipes, the pass / fail judgment means 23 configured by mounting a program having a function of performing a fail judgment as an erroneous number on the computer and the judgment result of the pass / fail judgment means 23 For example, a display means 24 that displays using any one of characters, sound, and light, or a combination of two or more, a judgment result of the pass / fail judgment means 23, a bound steel pipe end face image of the bound steel pipe 12, and bound steel pipe information. It has a storage means 25 for storing the above.

Subsequently, a bound steel pipe inspection method using the bound steel pipe inspection device 10 according to the embodiment of the present invention will be described.
As shown in FIGS. 2, 3 and 4, a method of counting the number of steel pipes included in a bundled steel pipe 12 in which a plurality of steel pipes 11 having the same diameter standard are bundled in the same longitudinal direction, for example, the bound steel pipe 12 First, the bound steel pipe information of the bound steel pipe 12 written on the recording medium 19 attached to the above is acquired (read), and the end face of the bound steel pipe 12 is photographed from the longitudinal direction of the bound steel pipe 12 to create a bound steel pipe end face image. Corresponding to the process, the second step of extracting the contour line from the bound steel pipe end face image to form the contour line image, and the arc correspondence of extracting the arc included in the contour line image and making the extracted arc a part of the circumference. The total number M of the circles is calculated, and the center coordinates (center in the two-dimensional coordinate system set on the contour line image) of the arc-corresponding circles C _i (i = 1, 2, ..., M, M = 20 in FIG. 4) determining position) and a third step of determining the radius of the arc corresponding circle C _i, with the center coordinates of each arc corresponding circle C _i, the proximity distance between the centers to the arc corresponding circle in proximity to each arc the corresponding circle C _i It has a fourth step.

The bundling steel pipe inspection method, since the diameter standard steel pipes 11 are identical, to set the distribution range of the adjacent steel center-to-center distance between the bundling steel pipe 12, the circular arc corresponding circle C _i distribution range and the near-center distance for each by comparing (in FIG. 4, C ₂₀₎ arc corresponding circle close center-to-center distance is outside distribution range to identify the remaining number excluding the number S of the specified circular arc corresponding circle from the total number M (= M Compare the radius of the arc-corresponding circle specified in the third step with the fifth step in which −S) is the number of steel pipes of the bound steel pipe 12, and the radius distribution range of the steel pipe 11 set from the diameter standard in the bound steel pipe information. If there is an arc-corresponding circle with a radius outside the radius distribution range, it is determined that there is a different-diameter steel pipe, and if there is no arc-corresponding circle with a radius outside the radius distribution range, it is determined that there is no different-diameter steel pipe. Compare the number of steel pipes obtained in the 5 steps with the number of used steel pipes in the bound steel pipe information, and if the number of steel pipes matches the number of used steel pipes and it is judged in the 6th step that there are no steel pipes of different diameters, a pass judgment is made and the number of steel pipes is passed. If it matches the number of used steel pipes and it is determined in the 6th step that there is a different diameter steel pipe, it is judged as a false diameter, and if the number of steel pipes does not match the number of used steel pipes, it is judged as a false circle. Has a process.

In the bound steel pipe inspection method of the present invention, for example, an image of the bound steel pipe end face of the bound steel pipe 12 can be easily created (first step) by photographing the bound steel pipe 12 with a CCD camera 14, and obtained. By applying a commercially available image analyzer to the bound steel pipe end face image, a contour line image of the bound steel pipe end face image can be easily formed (second step). Therefore, the first and second steps will be described. Omitted, the third to seventh steps will be described.

(Third step)
A two-dimensional coordinate system is provided on the contour line image, and three parameters (x coordinate of the center position of the circle) that display the contour points (x, y) on the contour line and all the circles passing through the contour points (x, y). It is transformed (Hough transform) into a curved surface in a three-dimensional space composed of P ₁ , the y coordinate P ₂ of the center position of the circle, and the radius r of the circle. As a result, there are curved surfaces corresponding to the number of contour points (x, y) in the three-dimensional space, and when there are common points on these curved surfaces, the contour points (x) corresponding to each curved surface are present. , Y) will exist on one circumference. Therefore, every time a shared point is detected while changing the position of the contour point (x, y), (x−P ₁ ) ² + (y−P ₂ ) for each contour point (x, y). By applying the relationship of ² = r ² , the center coordinates (P ₁ , P ₂ ) of the circle and the radius r can be determined, and the total number M of the shared points corresponds to the total number of circles. Numbers 1 to M are assigned to the detected arc-corresponding circles for identification.

When extracting a circle from a contour image, if the center coordinates (P ₁ , P ₂ ) and radius r of the circle are determined by performing a Hough transform on all contour points on the contour line, the calculation time becomes very long. Occurs. Therefore, using the model contour line image in which the center coordinates (P ₁ , P ₂ ), radius r, and total number of the circle are known, the circle detected while increasing the number of contour points set on the contour line. Find the changes in the center coordinates (P ₁ , P ₂ ), radius r, and total number of the detected circles, and set the detected center coordinates (P ₁ , P ₂ ), radius r, and total number to the known values. The calculation time was shortened by finding the number of contour points required for matching within a certain accuracy range. Therefore, an arc is extracted from the contour image, and the detected circle is an arc-corresponding circle having the extracted arc as a part of the circumference.

(4th step)
First, using the center coordinates of the circular arc corresponding circle C _i, determine the distance between centers of the circular arc corresponding circle. Next, for each arc-corresponding circle C _i (i = 1, ..., M), the arc-corresponding circle C _j (j = 1, ..., I-1, i + 1 existing around the arc-corresponding circle C _i ). , ・ ・ ・ M) The distance between centers _di1 , ・ ・ ・, _dii-1 , _{dii + 1} , ..., d _M are arranged in ascending order, and the kth from the beginning (from the smallest value) nearest neighbor set _N i with center distance of up to _{(= [d iλ1, d iλ2} , d iλ3, ···, d iλk]) the calculated recent average value of the elements beside the set _{N i} (= (d _{iλ1 + d iλ2 + d iλ3 +} ··· + d iλk)) / k) and the adjacent center-to-center distance _{L i.}

Here, the arc corresponding circle _{C i (i = 1, ···} , M) an arc corresponding circle _{C j (j = 1, ···} , M, where i ≠ j) and center-to-center distance _{d ij} between Using the center coordinates of the arc-corresponding circle C _i (P ₁ ⁱ , P ₂ ⁱ ) and the center coordinates of the arc-corresponding circle C _j (P ₁ ^j , P ₂ ^j ), _dij = {(P ₁ ⁱ −P) It can be ^calculated as ₁ ^j ) ² + (P ₂ ⁱ −P ₂ ^j ) ² } ^1/2 . In addition, in FIG. 5A, the distances between the centers d ₁₂ and d with the arc-corresponding circle C _j (j = 2, ..., 20) existing around the arc-corresponding circle C _{1 in} FIG. ₁₃ , d ₁₄ , ..., d ₁₁₇ , d ₁₁₈ , d ₁₁₉ , d ₁₂₀ , and in FIG. 5 (B), the arc-corresponding circle C _j (j) existing around the arc-corresponding circle C _{20 in} FIG. = 1, 2, 3, ..., 19) and the center-to-center distances d ₂₀₁ , d ₂₀₂ , d ₂₀₃ , ..., d ₂₀₁₇ , d ₂₀₁₈ , d ₂₀₁₉ , respectively.

When the bound steel pipe 12 is formed using steel pipes 11 having the same diameter standard, the steel pipes existing inside the bound steel pipe 12 have 6 steel pipes, and the steel pipes existing at the outer peripheral corners of the bound steel pipe 12 have 6 steel pipes. Three steel pipes are present in the outer peripheral portion of the bound steel pipe 12, and four steel pipes are adjacent to each other. Therefore, the maximum number of arc-corresponding circles that are in close contact with each other is 6, and even if the position of the arc-corresponding circle for which the distance between the proximity centers is obtained changes in the bound steel pipe 12, the distance between the proximity centers shows a constant value. The value of can be set in the range of 1 to 6. The bundling since arc corresponding circle at a position away from the bundle of tie steel of the steel pipe end face image probability of multiple detected is very small, around the arc corresponding circle C _i detected at a position away from the bundle of tie steel When the center-to-center distance _dij with the arc-corresponding circle C _j existing in is arranged in ascending order, the nearest neighbor set N _j is formed using the center-to-center distance from the first to the second, and the second smallest value. set elements of the probability indicating the center distance between the arc corresponding circle C _j in the bundling steel arcs corresponding circle C _i and bundling steel pipe end face image is high. Therefore, by setting the value of k to at least 2, the proximity center distance _Li is set to the location of the arc-corresponding circle (inside the binding steel pipe 12 or away from the bundle of the binding steel pipe 12) for obtaining the proximity center distance. It is a value that reflects the position).

(Fifth step)
First, since the diameter standards of the steel pipes 11 are the same, the distribution range of the distance between the centers of the adjacent steel pipes of the bound steel pipes 12 is set. Then, the arc corresponding circle _{C i (i = 1, ···} , M) by comparing the near-center distance L _i and distribution range for each, near center distance L _i is the arc corresponding circle is outside distribution range ( for example, detected at a position away from the bundle of tie steel unity steel edge image the arc corresponding circle, to identify C ₂₀₎ in Figure 4, the number S of the specified circular arc corresponding circle from the total number M of the circular arc corresponding circle The remaining number (= MS) excluded is the number of steel pipes of the bound steel pipe 12.
Here, the distribution range between adjacent steel center distance is, for example, a circular arc corresponding circle _{C i (i = 1, ···} , M) average _L A proximity center distance _{L i} of _{(= (L} 1 + L ₂ + ... ₊ a L M) / M), and unbiased standard deviation u obtained from the unbiased variance ^{u 2} proximity center distance _{L i,} numerical coefficients alpha _1, with alpha _2, the upper limit _{L a} + alpha ₁ u, the lower limit can be set as _L a _{-α 2} u. Incidentally, unbiased variance ^{u 2} is calculated as ^{_{{(L 1 -L A) 2}} + (L 2 -L A) 2 + ··· + (L M -L A) 2} / (M-1)) ..

Then, the diameter standard steel pipe 11 in the bundling steel information bundling steel pipe 12 obtained in the first step, the diameter of the steel pipe image in bundled steel edge image (number of pixels) is known, L A ₊ alpha _{1 u} is steel image to be greater than the diameter, to set the alpha ₁ according to the value of L _a and u. Thus, for example, the proximity distance between the centers of the detected arc corresponding circle at a position apart from the bundle of tie steel unity steel edge image (C ₂₀ in FIG. ₄₎ is eliminated in the counting of the steel pipe number to exceed the upper limit The remaining number 19 obtained by subtracting the number 1 of the specified arc-corresponding circles C 20 from the total number ₂₀ is defined as the number of steel pipes of the bound steel pipe 12.
_{Further, L} A-.alpha. ₂ u is to be smaller than the diameter of the steel pipe image, sets the alpha ₂ in accordance with the value of _{L A} and u. As a result, for example, when arc-corresponding circles are detected to overlap, the distance between the proximity centers of these arc-corresponding circles is less than the lower limit, so the overlapping arc-corresponding circles are excluded in counting the number of steel pipes. .. Here, when comparing between the respective adjacent centers of arcs corresponding circles overlap distance and L _A -α _{2 u} sequentially arc corresponding circle close center-to-center distance corresponding smaller than L _A -α _{2 u} each time it is eliminated in the counting of the steel pipe number, the value of re-calculating the mean value L _a proximity distance between the centers of each arc corresponding circle with the center coordinates of the remaining arcs corresponding circle L _{a-.alpha. 2 u} Do it while updating. As a result, in counting the number of steel pipes, one of the overlapping arc-corresponding circles can be left and the other arc-corresponding circles can be excluded.

(6th step)
The steel pipe image in the bound steel pipe end face image is composed of an outer peripheral line and an inner peripheral line reflecting the wall thickness of the steel pipe 11, but when the bound steel pipe end face image is binarized, the outer peripheral line and the inner peripheral line are included. The contour line corresponding to the clearer (higher contrast) line is easily extracted.
For example, when the contour line image obtained by binarizing the end face image of the bound steel pipe includes the contour line corresponding to the inner peripheral line of the steel pipe 11, the radius of the arc-corresponding circle specified in the third step is the steel pipe. Corresponds to the inner radius of 11. On the other hand, the maximum inner radius and the minimum inner radius of the steel pipe 11 can be set by using the number of pixels, respectively, based on the diameter standard in the bound steel pipe information. Therefore, the inner radius distribution of the steel pipe 11 is compared with the inner diameter distribution range of the steel pipe 11 set by using the maximum inner diameter and the minimum inner diameter of the steel pipe 11 and the radius of each arc-corresponding circle specified in the third step. If there is an arc-corresponding circle with a radius outside the range, it means that the image of the different diameter steel pipe exists in the bound steel pipe end face image, and it can be determined that there is a different diameter steel pipe in the bound steel pipe 12, and the steel pipe 11 If there is no arc-corresponding circle with a radius outside the inner radius distribution range of, the image of the different diameter steel pipe does not exist in the bound steel pipe end face image, and it can be determined that there is no different diameter steel pipe in the bound steel pipe 12.

(7th step)
The pass / fail condition of the bound steel pipe is that the number of steel pipes counted using the bound steel pipe end face image matches the number used in the bound steel pipe information, and the size of the steel pipe obtained from the steel pipe image used for counting the number of steel pipes (for example). , Radius) is within the range of the diameter standard in the bound steel pipe information. Therefore, first, the number of steel pipes obtained in the fifth step is compared with the number of used steel pipes in the bound steel pipe information, and if the number of steel pipes does not match the number of used steel pipes, it is determined as an erroneous number and rejected. Next, when the number of steel pipes matches the number used, the size of the steel pipe image is within the range of the diameter standard in the bound steel pipe information for each steel pipe image of each steel pipe 11 constituting the bound steel pipe (different diameter steel pipe). Judge whether or not (with different diameter steel pipe). Then, if it is determined that there is a different diameter steel pipe, it is determined to be rejected as an erroneous diameter, and if it is determined that there is no different diameter steel pipe, it is determined to be acceptable.

(Example 1)
The present invention was applied to a bound steel pipe in which 19 25A steel pipes were bundled, and it was confirmed that the number of steel pipes in the bound steel pipe could be counted and the diameter of the steel pipe could be detected.
First, as shown in FIG. 6, the end face of the bound steel pipe was photographed from the longitudinal direction to create a bound steel pipe end face image (482 × 383 pixels). Next, a contour line image is formed from the bound steel pipe end face image, and each contour point of the contour line image is Hough-transformed to extract the arcs included in the contour line image and obtain the center coordinates and inner radius of the arc-corresponding circle. I asked. Then, the total number of arc-corresponding circles detected at the time when the extraction of the arcs included in the contour line image was completed was 19. The image of the detected arc-corresponding circle is shown in FIG. 7, and the center coordinates and inner radius of each detected arc-corresponding circle are shown in Table 1.

Next, for each arc-corresponding circle, the center-to-center distances between the arc-corresponding circles and other arc-corresponding circles are arranged in ascending order, and the nearest neighbor set is formed using the center-to-center distance from the first to the second. did. Then, the average value of the elements of the nearest neighbor set for the arc-corresponding circle was obtained, and the distance between the proximity centers with respect to the arc-corresponding circle was obtained. Here, the average value of the proximity center distance calculated using the proximity center distance obtained for each arc-corresponding circle is 70.08 (unit is pixel), and the unbiased standard deviation of the proximity center distance is 0.95 (unit). Was a pixel).

Subsequently, the diameter standard steel pipe, the upper limit of the proximity distance between the centers of the numerical coefficients alpha ₁ as 2 71.98 (in pixels), the numerical coefficient alpha ₂ as 2 the lower limit of the proximity distance between the centers 68. Set the distribution range of the distance between the centers of the adjacent steel pipes of the bound steel pipe to be 17 (unit is pixel), compare the distance between the proximity centers obtained for each arc-corresponding circle and the distribution range, and the distance between the proximity centers is out of the distribution range. When the arc-corresponding circle in was specified, the corresponding arc-corresponding circle did not exist. Therefore, the remaining number 19 obtained by subtracting the number 0 of the specified arc-corresponding circles from the total number 19 is the number of steel pipes of the bound steel pipe, which matches the number of used bound steel pipes.

Further, since the inner radius of the steel pipe of 25A has a length of about 28 pixels on the end face image of the bound steel pipe, the inner radius of the arc-corresponding circle specified as shown in Table 1 is 27 to 29 pixels. Therefore, the diameter of the steel pipe constituting the bound steel pipe can be confirmed through the image of the end face of the bound steel pipe.

(Example 2)
The present invention was applied to a bound steel pipe in which 18 25A steel pipes and one 20A steel pipe were bundled, and it was confirmed that the number of steel pipes in the bound steel pipe could be counted and different diameter steel pipes in the bound steel pipe could be detected.
As shown in FIG. 8, a bound steel pipe end face image (484 × 387 pixels) is created by the same method as in Example 1, a contour line image is formed from the bound steel pipe end face image, and each contour point of the contour line image is formed. By Hough transform, the center coordinates and inner radius of the arc-corresponding circle corresponding to the arc included in the contour image were obtained. Then, the total number of arc-corresponding circles detected at the time when the extraction of the arcs included in the contour line image was completed was 19. The image of the detected arc-corresponding circle is shown in FIG. 9, and the center coordinates and inner radius of each detected arc-corresponding circle are shown in Table 2.

Next, for each arc-corresponding circle, the center-to-center distances between the arc-corresponding circles and other arc-corresponding circles are arranged in ascending order, and the nearest neighbor set is formed using the center-to-center distance from the first to the second. did. Then, the average value of the elements of the nearest neighbor set for the arc-corresponding circle was obtained, and the distance between the proximity centers with respect to the arc-corresponding circle was obtained. Here, the average value of the proximity center distance calculated using the proximity center distance obtained for each arc-corresponding circle is 75.75 (unit is pixel), and the unbiased standard deviation of the proximity center distance is 2.30 (unit). Was a pixel).

Subsequently, the diameter standard steel pipe, the upper limit of the proximity distance between the centers of the numerical coefficients alpha ₁ as 3 82.64 (in pixels), as numerical coefficients alpha ₂ and 3 the lower limit of the proximity distance between the centers 68. Set the distribution range of the distance between the centers of the adjacent steel pipes of the bound steel pipe to 86 (unit is pixel), compare the distance between the proximity centers obtained for each arc-corresponding circle and the distribution range, and the distance between the proximity centers is out of the distribution range. When the arc-corresponding circle in was specified, the corresponding arc-corresponding circle did not exist. Therefore, the remaining number 19 obtained by subtracting the number 0 of the specified arc-corresponding circles from the total number 19 is the number of steel pipes of the bound steel pipe, which matches the number of used bound steel pipes.

Further, on the end face image of the bound steel pipe, the inner radius of the steel pipe of 25A has a length of 27 to 30 pixels, and the inner radius of the steel pipe of 20A has a length of 23 to 25 pixels. Therefore, as shown in Table 2, among the specified arc-corresponding circles, there are 18 arc-corresponding circles with an inner radius of 27 to 30 pixels and one arc-corresponding circle with an inner radius of 23 to 25 pixels. From this, it can be confirmed from the image of the end face of the bound steel pipe that the bound steel pipe is composed of 18 steel pipes of 25A and one steel pipe of 20A (the bound steel pipe includes a steel pipe having a different diameter).
Further, since the center coordinates of the arc-corresponding circle corresponding to the 20A steel pipe are known, for example, FIG. 9 can be used to indicate the location of the 20A steel pipe (different diameter steel pipe).

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the configuration described in the above-described embodiments, and the matters described in the claims. It also includes other embodiments and variations that may be considered within the scope.
Further, the present invention also includes a combination of the components included in the present embodiment and other embodiments and modifications.

10: Bundling steel pipe inspection device, 11: Steel pipe, 12: Bundling steel pipe, 13: Strip, 14: CCD camera, 15: Contour line extracting means, 16: Circle detecting means, 17: Proximity center distance setting means, 18: Steel pipe number counting means, 19: Recording medium, 20: Data acquisition means, 21: Different diameter steel pipe detecting means, 22: Number matching means, 23: Pass / fail determination means, 24: Display means, 25: Storage means

Claims (4)

In a bound steel pipe inspection device that counts the number of steel pipes contained in a bundled steel pipe in which a plurality of steel pipes having the same diameter standard are bundled in the longitudinal direction.
An imaging means for creating an image of the end face of the bound steel pipe by photographing the end face of the bound steel pipe from the longitudinal direction of the bound steel pipe.
A contour line extraction means for extracting a contour line from the bound steel pipe end face image to form a contour line image, and
A circle that extracts the arc included in the contour image and obtains the center position of the arc-corresponding circle having the arc as a part of the circumference on the contour image and the total number of the arc-corresponding circles in the contour image. Detection means and
Using the center position of each arc-corresponding circle, a proximity center-to-center distance setting means for obtaining a proximity center-to-center distance to an arc-corresponding circle adjacent to each arc-corresponding circle.
Since the diameter standards of the steel pipes are the same, the distribution range of the distance between the adjacent steel pipe centers of the bound steel pipe is set, the distance between the proximity centers and the distribution range are compared for each arc-corresponding circle, and the proximity is said. An arc-corresponding circle whose center-to-center distance is outside the distribution range is specified, and the remaining number obtained by subtracting the number of the identified arc-corresponding circles from the total number is defined as the number of steel pipes of the bound steel pipe. Yes, and
The circle detecting means is provided with a function of obtaining the radius of each arc-corresponding circle.
Compare the data acquisition means for acquiring the bound steel pipe information of the bound steel pipe with the radius of the arc-corresponding circle obtained by the circle detecting means and the radius distribution range of the steel pipe set from the diameter standard in the bound steel pipe information. If the arc-corresponding circle with a radius outside the radius distribution range exists, it is determined that there is a different-diameter steel pipe, and if the arc-corresponding circle with a radius outside the radius distribution range does not exist, it is determined that there is no different-diameter steel pipe. bundling steel pipe inspection apparatus characterized that you have and a steel tube detector. In the bound steel pipe inspection apparatus according to claim 1 , the number of steel pipes obtained by the steel pipe number counting means is compared with the number of used steel pipes in the bound steel pipe information, and whether or not the number of steel pipes matches the number of used steel pipes. If it is determined by the number matching means and the number matching means that the number of steel pipes matches the number of used steel pipes and the different diameter steel pipe detecting means determines that there is no different diameter steel pipe, a pass judgment is made. If it is determined that the number of steel pipes matches the number of used steel pipes and it is determined that there are steel pipes of different diameters, it is judged as an erroneous diameter. A bound steel pipe inspection device characterized by having a pass / fail judgment means for making a pass judgment. In a bound steel pipe inspection method that counts the number of steel pipes contained in a bundled steel pipe in which a plurality of steel pipes having the same diameter standard are bundled in the longitudinal direction.
The first step of photographing the end face of the bound steel pipe from the longitudinal direction of the bound steel pipe to create an image of the end face of the bound steel pipe.
The second step of extracting the contour line from the bound steel pipe end face image to form the contour line image, and
A third step of extracting an arc included in the contour line image and obtaining the center position of the arc-corresponding circle having the arc as a part of the circumference on the contour line image and the total number of the arc-corresponding circles.
The fourth step of obtaining the distance between the proximity centers to the adjacent arc-corresponding circles for each arc-corresponding circle using the center position of each arc-corresponding circle.
Since the diameter standards of the steel pipes are the same, the distribution range of the distance between the adjacent steel pipe centers of the bound steel pipe is set, the distance between the proximity centers and the distribution range are compared for each arc-corresponding circle, and the proximity is said. There is a fifth step in which the arc-corresponding circle whose center-to-center distance is outside the distribution range is specified, and the remaining number obtained by subtracting the number of the specified arc-corresponding circles from the total number is defined as the number of steel pipes of the bound steel pipe. And
In the first step, the bound steel pipe information of the bound steel pipe is acquired, in the third step, the diameter of each arc-corresponding circle is obtained, and further, the radius of the arc-corresponding circle and the bound steel pipe obtained in the third step. Comparing the radius distribution range of the steel pipe set from the diameter standard in the information, if there is the arc corresponding circle with a radius outside the radius distribution range, there is a different diameter steel pipe, and the radius deviating from the radius distribution range tying steel test method if the circular arc corresponding circle does not exist, characterized in that the chromatic sixth step of determining that no different-diameter steel pipe. In the bound steel pipe inspection method according to claim 3, the number of the steel pipes obtained in the fifth step is compared with the number of used pipes in the bound steel pipe information, and the number of the used steel pipes matches the number of used steel pipes and different diameter steel pipes. If it is determined that there is no steel pipe, the number of steel pipes matches the number of used steel pipes, and if it is determined that there is a steel pipe with a different diameter, it is judged as a false diameter and the number of steel pipes matches the number of used steel pipes. A method for inspecting bound steel pipes, which comprises a seventh step of determining a failure as an erroneous number if not.