Title of the invention: Bending angle calculation method and calculation device
Technical field
[0001]
　The present invention relates to a method and an apparatus for calculating a bending angle at a joint of pipes.
Background technology
[0002]
　At the joints between the pipes, it is necessary to join them so that the bending angle is within the allowable range. As an example of the bending angle calculation method, the calculation method disclosed in Non-Patent Document 1 can be mentioned. In the calculation method, the distance between the white line drawn on the peripheral surface of one pipe and the end surface of the other pipe is measured at a plurality of points in the circumferential direction of the pipe, and the maximum and minimum values ​​of the distance are measured. The bending angle is calculated from the difference between the above and the nominal diameter of the pipe.
Prior art literature
Non-patent literature
[0003]
Non-Patent Document 1: Japan Ductile Iron Pipe Association, "T-shaped Ductile Iron Pipe Joining Procedure", p.21-22
Outline of the invention
Problems to be solved by the invention
[0004]
　However, the above-mentioned conventional technique has a problem that it takes time and effort because the operator needs to measure the distance between the above-mentioned white line and the end face a plurality of times for each joint of the pipes.
[0005]
　One aspect of the present invention is to realize a method for calculating a bending angle that can reduce the labor of an operator.
Means to solve problems
[0006]
　In order to solve the above problems, the method of calculating the bending angle according to one aspect of the present invention includes an imaging step of capturing an image of a tube in which a first tube and a second tube are joined by a joint, and the above-mentioned. From the image, the intersection angle of the derivation step for deriving the laying direction straight line corresponding to the laying direction of the pipe and the laying direction straight line of the first pipe and the laying direction straight line of the second pipe is the bending angle in the joint. Includes a calculation step to calculate as.
[0007]
　According to the above configuration, based on the images of the first pipe and the second pipe joined by the joint, the laying direction straight line corresponding to the laying direction of those pipes is derived, and the intersection angle of the laying direction straight line is derived. Is calculated as the bending angle. Therefore, it is possible to reduce the labor of the operator as compared with the conventional calculation method.
[0008]
　Further, the method for calculating the bending angle according to one aspect of the present invention includes a contour extraction step for extracting the contour of the first tube and the contour of the second tube in the image, and the derivation step includes the image. The laying direction straight line is derived based on the contour extracted from.
[0009]
　According to the above configuration, the contour of the pipe is extracted from the image, and the laying direction straight line is derived based on the contour. Therefore, the laying direction straight line on the image can be appropriately derived.
[0010]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, in the derivation step, a straight line indicating the side surface of the pipe is derived as a straight line in the laying direction of the pipe based on the contour of the pipe.
[0011]
　According to the above configuration, the bending angle can be calculated based on a straight line indicating the side surface of the pipe, that is, a straight line parallel to the laying direction of the pipe.
[0012]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, in the derivation step, a straight line orthogonal to the laying direction of the second pipe is formed on the second pipe based on the contour of the second pipe. It is derived as a straight line in the laying direction of.
[0013]
　According to the above configuration, the bending angle can be calculated based on a straight line orthogonal to the laying direction of the second pipe.
[0014]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, in the derivation step, the center line of the pipe is derived as the laying direction straight line based on the contour of the pipe.
[0015]
　According to the above configuration, the bending angle can be calculated based on the center line of the pipe, that is, a straight line parallel to the laying direction of the pipe.
[0016]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, in the derivation step, a plurality of straight lines intersecting the contour of the side surface of the pipe at two points among the contours of the pipe are defined, and the plurality of straight lines are defined. For each of the straight lines, the intermediate points of two points that intersect the contour of the side surface of the pipe are derived, and the approximate intermediate line, which is a straight line that approximates the set of the intermediate points, is derived, and within a predetermined distance from the approximate intermediate line. A straight line that approximates the set of the intermediate points existing in is derived as the laying direction straight line.
[0017]
　According to the above configuration, an approximate intermediate line that approximates a set of intermediate points of the two points of a plurality of straight lines that intersect the contour of the side surface of the pipe at the two points is derived. Further, a straight line that approximates a set of intermediate points existing within a predetermined distance from the approximate intermediate line is derived as a laying direction straight line. Therefore, it is possible to exclude points significantly far from the approximate intermediate line due to the influence of noise and the like, and improve the accuracy of the laying direction straight line.
[0018]
　Further, the method for calculating the bending angle according to one aspect of the present invention further includes an image generation step of generating a first component image showing the first component of the image and a second component image showing the second component, and the contour. In the extraction step, the contour of the first tube and the contour of the second tube in each of the first component image and the second component image are extracted, and in the derivation step, the first component image and the first component image are extracted. The approximate intermediate line is derived based on the contour of the tube in each of the two component images, and the intermediate point of the first component image and the second component image existing within a predetermined distance from the approximate intermediate line. The laying direction straight line is derived based on the contour of the pipe extracted from the image having the most.
[0019]
　According to the above configuration, an approximate intermediate line is derived for each of the first component image and the second component image, and the image having more intermediate points existing within a predetermined distance from the approximate intermediate line, that is, noise or the like. A straight line in the laying direction is derived based on the contour of the pipe extracted from the image with the smaller influence. Therefore, the accuracy of the laying direction straight line can be improved.
[0020]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, in the derivation step, a straight line indicating the laying direction of the pipe is derived as the laying direction straight line based on the shape of the pipe stored in advance.
[0021]
　According to the above configuration, it is possible to derive a laying direction straight line corresponding to the pattern based on the pattern of the shape of the pipe.
[0022]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, on the surface of at least one of the first tube and the second tube, two straight lines parallel to each other along the circumferential direction Is drawn, and in the derivation step, the laying direction straight line of the first pipe or the laying direction straight line of the second pipe is derived based on the distance between the two lines in the image.
[0023]
　According to the above configuration, a laying direction straight line is derived based on the distance in the image of two straight lines parallel to each other along the circumferential direction of the pipe. The distance in the image of two parallel straight lines along the circumferential direction of the tube changes for each position in the image according to the relationship between the imaging position and the laying angle. Therefore, the three-dimensional bending angle can be calculated based on the image.
[0024]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, a light source is arranged in a predetermined shape on the surface of at least one of the first tube and the second tube, and the derivation thereof is performed. In the step, the laying direction straight line of the first tube or the laying direction straight line of the second tube is derived based on the shape of the light source in the image.
[0025]
　According to the above configuration, a straight line in the laying direction is derived based on the shape in the image of the light source having a predetermined shape arranged on the surface of the tube. The shape of the light source having a predetermined shape arranged on the surface of the tube in the image changes depending on the relationship between the imaging position and the laying angle. Therefore, the three-dimensional bending angle can be calculated based on the image.
[0026]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, a straight line along the circumferential direction is drawn on the surface of at least one of the first pipe and the second pipe, and the derivation thereof is performed. In the step, the laying direction straight line of the first pipe or the laying direction straight line of the second pipe is derived based on the shape of the ellipse including the straight line in the image.
[0027]
　The straight line along the circumferential direction of the tube has the shape of a part of an ellipse according to the angle with respect to the imaging position in the image of the tube. According to the above configuration, a three-dimensional bending angle can be calculated by deriving a laying direction straight line based on the shape of the ellipse.
[0028]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, a predetermined pattern is displayed on the surface of at least one of the first pipe and the second pipe, and in the derivation step. , The laying direction straight line of the first pipe or the laying direction straight line of the second pipe is derived based on the shape of the pattern in the image.
[0029]
　According to the above configuration, a straight line in the laying direction is derived based on the shape in the image of the predetermined pattern displayed on the surface of the pipe. The shape of a predetermined pattern displayed on the surface of the tube in the image changes depending on the relationship between the imaging position and the laying angle. Therefore, the three-dimensional bending angle can be calculated based on the image.
[0030]
　Further, in the method for calculating the bending angle according to one aspect of the present invention, in the imaging step, an image is taken with the lead-out assisting tool attached to each of the first tube and the second tube, and in the lead-out step. , The laying direction straight line is derived based on the image of the derivation assisting tool.
[0031]
　According to the above configuration, the derivation unit can easily derive the laying direction straight line based on the image of the derivation assisting tool.
[0032]
　Further, the bending angle calculation device according to one aspect of the present invention includes an image acquisition unit that acquires an image of a pipe in which a first pipe and a second pipe are joined by a joint, and a pipe from the image. A derivation unit that derives a laying direction straight line corresponding to the laying direction, and a calculation unit that calculates the intersection angle of the laying direction straight line of the first pipe and the laying direction straight line of the second pipe as a bending angle in the joint. , Equipped with.
Effect of the invention
[0033]
　According to one aspect of the present invention, it is possible to realize a method of calculating a bending angle that can reduce the labor of an operator.
A brief description of the drawing
[0034]
FIG. 1 is a flowchart showing processing in the calculation system according to the first embodiment.
FIG. 2 is a block diagram showing a configuration of a main part of the calculation system according to the first embodiment.
FIG. 3 is a diagram showing the extraction of the contour of the first tube by the contour extraction unit.
FIG. 4 is a diagram showing the extraction of the contour of the second tube by the contour extraction unit.
FIG. 5 is a diagram showing a first example of a method for calculating a bending angle according to the first embodiment.
[Fig. 6] Fig. 6 is a diagram for explaining the derivation of a straight line in the laying direction of the first pipe by the derivation unit.
[Fig. 7] Fig. 7 is a diagram for explaining the derivation of a straight line in the laying direction of the second pipe by the derivation unit.
FIG. 8 is a diagram showing a second example of the bending angle calculation method according to the first embodiment.
FIG. 9 is a diagram showing a third example of the bending angle calculation method according to the first embodiment.
FIG. 10 is a diagram showing a fourth example of the bending angle calculation method according to the first embodiment.
FIG. 11 is a diagram showing a state in which a lead-out assisting tool is attached to the first pipe and the second pipe.
FIG. 12 is a diagram showing a state in which a lead-out assisting tool is attached to the first pipe and the second pipe.
FIG. 13 is a diagram showing a state in which a lead-out assisting tool is arranged as a background of the first pipe and the second pipe.
FIG. 14 is a block diagram showing a configuration of a main part of the calculation system according to the second embodiment.
FIG. 15 is a diagram showing an example of an image pickup method using a camera in the second embodiment.
FIG. 16 is a diagram showing a first example of the bending angle calculation method according to the second embodiment.
FIG. 17 is a diagram showing a second example of the bending angle calculation method according to the second embodiment.
FIG. 18 is a diagram showing a modified example of the second example of the bending angle calculation method according to the second embodiment.
FIG. 19 is a diagram showing a third example of the bending angle calculation method according to the second embodiment.
FIG. 20 is a diagram showing a fourth example of the bending angle calculation method according to the second embodiment.
FIG. 21 is a diagram showing a modified example of the fourth example of the bending angle calculation method according to the second embodiment.
FIG. 22 is a diagram showing a state in which the first tube is bent toward the front side of the image with respect to the second tube.
FIG. 23 is a diagram showing a state in which the first tube is bent toward the back of the image with respect to the second tube.
FIG. 24 is a diagram showing analysis results regarding the relationship between the vertical angle and θ3 and θ4 when θ0 is 0 °.
FIG. 25 is a diagram showing analysis results regarding the relationship between the vertical angle and θ3 and θ4 when θ0 is 4 °.
FIG. 26 is a diagram showing a table created by the calculation unit.
Embodiment for carrying out the invention
[0035]
　[Embodiment 1]
　Hereinafter, an embodiment of the present invention will be described in detail.
[0036]
　FIG. 2 is a block diagram showing a configuration of a main part of a bending angle calculation system 1 (hereinafter, simply referred to as a calculation system 1) according to the present embodiment. As shown in FIG. 2, the calculation system 1 includes an arithmetic unit 10 (bending angle calculation device), a camera 20, a display device 30, and a storage device 40.
[0037]
　The arithmetic unit 10 executes a process for calculating the bending angle at the joint portion of the pipes. The arithmetic unit 10 includes an image acquisition unit 11, a contour extraction unit 12, a derivation unit 13, a calculation unit 14, and a display processing unit 15.
[0038]
　The image acquisition unit 11 acquires an image of a tube in which the first tube P1 and the second tube P2 (see FIG. 3 and the like) are joined by a joint. The material of the first tube P1 and the second tube P2 is not particularly limited, and may be metal or resin. In the following description, it is assumed that the first tube P1 and the second tube P2 are joined by inserting the insertion port of the first tube P1 into the receiving port of the second tube P2. In the present embodiment, the image acquisition unit 11 acquires an image captured by the camera 20. The contour extraction unit 12 extracts the contour of the first tube P1 and the contour of the second tube P2 in the image acquired by the image acquisition unit 11.
[0039]
　The derivation unit 13 derives a laying direction straight line corresponding to the laying direction of the pipe from the image acquired by the image acquisition unit 11. In the present embodiment, the derivation unit 13 derives the laying direction straight line based on the contour of the pipe extracted by the contour extraction unit 12. Specific processing in the derivation unit 13 will be described later. The calculation unit 14 calculates the intersection angle of the laying direction straight line of the first pipe P1 and the laying direction straight line of the second pipe P2 as the bending angle in the joint between the first pipe P1 and the second pipe P2.
[0040]
　The "laying direction straight line corresponding to the laying direction" is not limited to a straight line parallel to the laying direction, and may be, for example, a straight line orthogonal to the laying direction. When the laying direction straight line of either the first pipe P1 or the second pipe P2 is a straight line orthogonal to the laying direction, the angle obtained by subtracting the intersection angle of the laying direction straight line from 90 ° is the first. It is a bending angle in the joint between the pipe P1 and the second pipe P2. When the laying direction straight lines of both the first pipe P1 and the second pipe P2 are straight lines orthogonal to the laying direction, the intersection angle of the laying direction straight lines is the first pipe P1 and the second pipe P2. It is the bending angle in the joint.
[0041]
　The display processing unit 15 displays an image or the like showing the calculation result by the calculation unit 14 on the display device 30. The display processing unit 15 causes the display device 30 to display an image showing the bending angle at the joint portion between the first pipe P1 and the second pipe P2, for example, calculated by the calculation unit 14. Further, when the arithmetic unit 10 executes a determination process for determining whether or not the bending angle calculated by the calculation unit 14 is within the allowable range, the display processing unit 15 displays an image showing the result of the determination process. The process of displaying on the display device 30 may be performed.
[0042]
　The camera 20 is an image pickup device that captures an image of a joint portion between the first tube P1 and the second tube P2. The camera 20 may be, for example, a general-purpose camera attached to a smartphone or the like, but is not limited thereto. The display device 30 is a display device that displays an image. The storage device 40 is a storage device that stores information necessary for processing in the arithmetic unit 10. As for the camera 20, the display device 30, and the storage device 40, known devices can be used without particular limitation.
[0043]
　The calculation system 1 is used, for example, to calculate the bending angle of the pipe arranged in the groove. The usage conditions of the calculation system 1 are as follows, for example. The image pickup location of the tube may be outdoors, and the time zone may be day or night. The distance from the ground surface to the tube is 60 cm or more and 120 cm or less, and the distance from the camera 20 to the tube is adjusted so that the range from the end face of the second tube P2 to the left and right 400 mm is included in the image. The color of the tube is gray or black, and the surface of the tube is uneven. The diameter of the tube is in the range of 75 mm or more and 400 mm or less. However, the usage conditions of the calculation system 1 are not limited to this.
[0044]
　FIG. 1 is a flowchart showing processing in the calculation system 1. In the calculation system 1, first, the image acquisition unit 11 takes an image of a tube in which the first tube P1 and the second tube P2 are joined by a joint (S1, imaging step). Next, the contour extraction unit 12 extracts the contour of the first tube P1 and the contour of the second tube P2 in the image of the tube captured in step S1 (S2, contour extraction step).
[0045]
　The derivation unit 13 derives a laying direction straight line corresponding to the laying direction of the pipe based on the contour of the pipe extracted in step S2 (S3, derivation step). The calculation unit 14 calculates the intersection angle of the laying direction straight line of the first pipe P1 and the laying direction straight line of the second pipe P2 as the bending angle in the joint (S4, calculation step).
[0046]
　FIG. 3 is a diagram showing the extraction of the contour of the first tube P1 by the contour extraction unit 12. In FIG. 3, an example of an image captured by the camera 20 is indicated by reference numeral 3100. In the saturation image obtained by converting the captured image into HSV (Hue Saturation Value), the saturation is the image of the first tube P1 and the second tube P2 and the image of the soil as the background. Makes a big difference. The contour extraction unit 12 removes the highly saturated region, that is, the region of the image of the first tube P1 and the second tube P2 from the saturated image, so that the image indicated by reference numeral 3200 in FIG. 3 can be obtained. Generate.
[0047]
　Further, the contour extraction unit 12 generates an image in which an unnecessary background is removed, leaving only an image of the background in the vicinity of the first tube P1, which is indicated by reference numeral 3300 in FIG. Further, the contour extraction unit 12 generates an image in which only the region R1 of the first tube P1, which is indicated by reference numeral 3400 in FIG. 3, is extracted. The contour extraction unit 12 extracts the contour of the region R1 as the contour of the first tube P1.
[0048]
　FIG. 4 is a diagram showing the extraction of the contour of the second tube P2 by the contour extraction unit 12. Similar to the extraction of the contour of the first tube P1, the contour extraction unit 12 extracts the region of the image of the first tube P1 and the second tube P2 from the saturation image, which is indicated by reference numeral 4100 in FIG. Generate the removed image. Subsequently, the contour extraction unit 12 generates an image in which the unnecessary background is removed, leaving only the background image in the vicinity of the second tube P2, which is indicated by reference numeral 4200 in FIG. Further, the contour extraction unit 12 generates an image in which only the region R2 of the second tube P1, which is indicated by reference numeral 4300 in FIG. 4, is extracted. The contour extraction unit 12 extracts the contour of the region R2 as the contour of the second tube P2.
[0049]
　FIG. 5 is a diagram showing a first example of the bending angle calculation method according to the present embodiment. In the example shown in FIG. 5, the portion of the second tube P2 other than the receiving port is covered with the polyethylene sleeve S. The sleeve S is for protecting the second tube P2. In the example shown in FIG. 5, the lead-out unit 13 lays the center line of the first pipe P1 and the second pipe P2 based on the contours of the first pipe P1 and the second pipe P2. Derived as L2. The calculation unit 14 calculates the intersection angle θ1 of the laying direction straight lines L1 and L2 as the bending angle in the joint of the first pipe P1 and the second pipe P2.
[0050]
　FIG. 6 is a diagram for explaining the derivation of the laying direction straight line of the first pipe P1 by the derivation unit 13. First, the lead-out unit 13 defines a plurality of straight lines LA1 that intersect with the contour of the side surface of the first pipe P1 at two points. Next, as shown by reference numeral 6100 in FIG. 6, the derivation unit 13 derives two intermediate points intersecting the contour of the side surface of the first tube P1 for each of the plurality of straight lines LA1 and derives the intermediate points of the intermediate points. An approximate intermediate line C11 that approximates the set is derived. Further, as shown by reference numeral 6200 in FIG. 6, the derivation unit 13 derives a straight line C12 that approximates a set of the intermediate points existing within a predetermined distance from the approximate intermediate line C11 as a laying direction straight line L1.
[0051]
　Further, the derivation unit 13 may derive the laying direction straight line L1 after approximating the contour line of the side surface of the first pipe P1. In this case, the derivation unit 13 derives an approximate straight line by the least squares method for the set of points forming the contour line of the first tube P1, and again performs the least squares method for the set of points within a predetermined distance from the approximate straight line. By doing so, the contour line is approximated. After that, the derivation unit 13 derives the laying direction straight line L1 as described above using the approximated contour line. As a result, the laying direction straight line L1 can be derived with higher accuracy.
[0052]
　FIG. 7 is a diagram for explaining the derivation of the laying direction straight line of the second pipe P2 by the derivation unit 13. First, the lead-out unit 13 defines a plurality of straight lines LA2 that intersect with the contour of the side surface of the second pipe P2 at two points. Next, as shown by reference numeral 7100 in FIG. 7, the derivation unit 13 derives an intermediate point of two points intersecting the contour of the side surface of the second pipe P2 for each of the plurality of straight lines LA2, and derives the intermediate point of the intermediate point. An approximate intermediate line C21 that approximates the set is derived. Further, as shown by reference numeral 7200 in FIG. 7, the derivation unit 13 derives a straight line C22 that approximates a set of the intermediate points existing within a predetermined distance from the approximate intermediate line C21 as a laying direction straight line L2.
[0053]
　In the example shown in FIG. 7, the contour extraction unit 12 has the saturation (first component) of the image acquired by the image acquisition unit 11 before extracting the contours of the first tube P1 and the second tube P2. ) Saturation image (first component image) and lightness (second component) may be generated (second component image) (image generation step). In this case, the contour extraction unit 12 extracts the contours of the first tube P1 and the second tube P2 in the saturation image and the lightness image, respectively. The derivation unit 13 derives approximate intermediate lines C11 and C12 based on the contours of the first tube P1 and the second tube P2 in the saturation image and the lightness image, respectively. Further, the derivation unit 13 is a straight line in the laying direction based on the contour extracted from the saturation image and the lightness image, whichever has the most intermediate points and exists within a predetermined distance from the approximate intermediate lines C11 or C12. Is derived. In this case, the derivation unit 13 derives a straight line in the laying direction based on the contour of the tube extracted from the image having a small influence of noise or the like among the saturation image and the lightness image. Therefore, the accuracy of the laying direction straight line can be improved.
[0054]
　The contour extraction unit 12 indicates the hue of the image acquired by the image acquisition unit 11 in place of either the saturation image or the brightness image, or in addition to the saturation image and the brightness image, in the image generation step. A hue image may be generated. Further, in the image generation step, the contour extraction unit 12 replaces either one or both of the saturation image and the brightness image, and instead of the saturation image or the brightness image, the R component, the G component, the B component, or a component thereof of the image acquired by the image acquisition unit 11. An image of a component in which the components are combined may be generated.
[0055]
　FIG. 8 is a diagram showing a second example of the bending angle calculation method according to the present embodiment. In the example shown in FIG. 8, the lead-out unit 13 derives the laying direction straight lines L11 and L12 indicating the side surfaces of the first pipe P1 as the laying direction straight lines L1 of the first pipe P1. Further, the lead-out unit 13 derives a straight line orthogonal to the laying direction of the second pipe P2 as a laying direction straight line L2 of the second pipe P2 based on the contour P2 of the second pipe. For example, the out-licensing unit 13 derives the long axis of the ellipse appearing on the end face of the second pipe P2 as the laying direction straight line L2 of the second pipe P2. The calculation unit 14 sets one or both of the angle obtained by subtracting the intersection angle θ1 of the laying direction straight lines L11 and L2 from 90 ° and the angle obtained by subtracting the intersection angle θ2 of the laying direction straight lines L12 and L2 from 90 °. It is calculated as the bending angle in the joint of the pipe P1 and the second pipe P2.
[0056]
　When calculating both intersection angles, the two intersection angles may have different sizes due to the influence of noise and the like. In this case, the calculation unit 14 may output the larger crossing angle as the final bending angle in consideration of safety.
[0057]
　FIG. 9 is a diagram showing a third example of the bending angle calculation method according to the present embodiment. In the example shown in FIG. 9, the derivation unit 13 derives a straight line indicating the laying direction of the pipe as a laying direction straight line based on the shapes of the first pipe P1 and the second pipe P2 stored in advance. Specifically, in the example shown in FIG. 9, the pattern of the shapes of the first pipe P1 and the second pipe P2 and the laying direction of the pipe in the pattern are stored in the storage device 40 in advance in association with each other. ing. By matching the contours of the first pipe P1 and the second pipe P2 with the pattern, the lead-out unit 13 draws a straight line indicating the laying direction of the first pipe P1 and the second pipe P2 in the pattern. Derived as L1 and L2. The calculation unit 14 calculates the intersection angle θ1 of the laying direction straight lines L1 and L2 as the bending angle in the joint of the first pipe P1 and the second pipe P2.
[0058]
　FIG. 10 is a diagram showing a fourth example of the bending angle calculation method according to the present embodiment. In the example shown in FIG. 10, the sleeve S (see FIG. 5 and the like) of the second tube P2 is removed, and the cylindrical region opposite to the first tube P1 is exposed with respect to the receiving port. .. The lead-out unit 13 derives the laying direction straight lines L21 and L22 indicating the side surfaces of the region as the laying direction straight lines L2 of the second pipe P2. Further, the out-licensing unit 13 derives the laying direction straight line L1 of the first pipe P1 in the same manner as in the example shown in FIG. The calculation unit 14 may use a single predetermined combination of crossing angles of the laying direction straight line (for example, the crossing angle θ1 of the laying direction straight lines L11 and L21 or the crossing angle θ2 of the laying direction straight lines L12 and L22), or a plurality of crossing angles. The crossing angle of the combination is calculated as the bending angle in the joint of the first pipe P1 and the second pipe P2. When calculating the crossing angles of a plurality of combinations, the calculation unit 14 may set the largest of the plurality of crossing angles as the bending angle in the joint of the first pipe P1 and the second pipe P2.
[0059]
　Also in the example shown in FIGS. 8 to 10, the bending angle in the joint between the first pipe P1 and the second pipe P2 can be calculated in the same manner as in the example shown in FIG. In the examples shown in FIGS. 5 and 8 to 10, the first pipe P1 and the second pipe P2 were both straight pipes. However, the first pipe P1 and the second pipe P2 may be, for example, a T-shaped pipe, a deformed pipe such as a curved pipe, a valve, or the like.
[0060]
　When calculating the bending angle by the method described above, it is preferable to take an image in a state where the lead-out assisting tool is attached to the first tube P1 and the second tube P2 in the imaging step. In this case, in the derivation step, the derivation unit 13 derives the laying direction straight line based on the image of the derivation assisting tool. An example of the derivation aid will be described below.
[0061]
　FIG. 11 is a diagram showing a state in which the lead-out assisting tool 51 is attached to the first pipe P1 and the second pipe P2. The lead-out assisting tool 51 has a shape in which a cylinder that can be attached to the outside of each of the first pipe P1 and the second pipe P2 is cut along a surface passing through the central axis. The material of the extraction assisting tool 51 is not particularly limited, and is, for example, metal or resin. Further, the lead-out assisting tool 51 is colored in a color different from that of the first tube P1 and the second tube P2.
[0062]
　When the contrast between the color of the first tube P1 and the second tube P2 and the color of the background is small, the image is taken with the extraction assisting tool 51 attached to the first tube P1 and the second tube P2. Is preferable. In this case, since the contrast between the derivation assisting tool 51 and the background becomes large, the contour of the image of the derivation assisting tool 51 can be easily extracted from the captured image. Therefore, the derivation unit 13 can easily derive the laying direction straight line based on the extracted contour.
[0063]
　FIG. 12 is a diagram showing a state in which the lead-out assisting tool 52 is attached to the first pipe P1 and the second pipe P2. The lead-out assisting tool 52 has the shape of a part of a cylinder that can be attached to the outside of each of the first tube P1 and the second tube P2. Further, on the surface of the derivation assisting tool 52, a light source 52a having a shape in which a line segment perpendicular to the axial direction of the tube to be mounted and a line segment parallel to the axial direction intersect is provided. The light source 52a has, for example, a plurality of LEDs (Light Emitting Diodes) arranged in the shape thereof.
[0064]
　In the imaging step, by taking an image with the lead-out assisting tool 52 attached to the first tube P1 and the second tube P2, the lead-out unit 13 easily derives a straight line in the laying direction based on the shape of the light source 52a. be able to. Further, the derivation unit 13 may derive a straight line in the laying direction based on the contour of the derivation assisting tool 52, as in the case of using the derivation assisting tool 51.
[0065]
　FIG. 13 is a diagram showing a state in which the lead-out assisting tool 53 is arranged as the background of the first pipe P1 and the second pipe P2. The extraction assisting tool is not necessarily limited to the one attached to each of the first tube P1 and the second tube P2. The extraction assisting tool 53 is, for example, a paper or a flat plate colored in a color different from that of the first tube P1 and the second tube P2 (for example, red), or a backlight that emits surface light. By imaging the first tube P1 and the second tube P2 with the derivation assisting tool 53 arranged, the boundary between the first tube P1 and the second tube P2 and the background in the image becomes clear, and the contour is defined. It becomes easy to extract and derive the laying direction straight line.
[0066]
　As described above, according to the arithmetic unit 10, the bending angle in the joint of the first tube P1 and the second tube P2 is determined based on the images of the first tube P1 and the second tube P2 captured by the camera 20. Can be calculated. Therefore, the labor of the operator for calculating the bending angle is reduced.
[0067]
　[Embodiment 2]
　Other embodiments of the present invention will be described below. For convenience of explanation, the same reference numerals are given to the members having the same functions as the members described in the above-described embodiment, and the description thereof will not be repeated.
[0068]
　FIG. 14 is a block diagram showing a configuration of a main part of the bending angle calculation system 2 (hereinafter, simply referred to as the calculation system 2) according to the present embodiment. The calculation system 2 differs from the calculation system 1 in that the calculation device 60 (the bending angle calculation device) is provided instead of the calculation device 10. The arithmetic unit 60 is different from the arithmetic unit 10 in that the image area specifying unit 16 is provided instead of the contour extraction unit 12.
[0069]
　The image area specifying unit 16 specifies an area on the image used for deriving the laying direction straight line by the deriving unit 13. The image region specifying unit 16 identifies the region by matching with, for example, a tube shape pattern stored in advance in the storage device 40. The derivation unit 13 derives the laying direction straight line in the three-dimensional space based on the area of ​​the image specified by the image area specifying unit 16.
[0070]
　FIG. 15 is a diagram showing an example of an image pickup method by the camera 20 in the present embodiment. In the example shown in FIG. 15, a support column 71 is erected on the second pipe P2 in a direction horizontal to the axis of the second pipe P2. Further, the horizontal arm 72 extends from the support column 71 in a direction horizontal to the axis of the second pipe P2. The camera 20 is installed at a portion of the horizontal arm 72 facing the joint portion between the first tube P1 and the second tube P2.
[0071]
　By installing the camera 20 in this way, the straight line in the laying direction of the second pipe P2 with respect to the camera 20 is always constant. Therefore, since the derivation unit 13 needs to derive only the laying direction straight line of the first pipe P1, the processing amount of the arithmetic unit 60 is reduced. The support column 71 may be installed in the first pipe P1. In that case, the horizontal arm 72 extends in a direction horizontal to the axis of the first pipe P1, and the straight line in the laying direction of the first pipe P1 with respect to the camera 20 is always constant.
[0072]
　FIG. 16 is a diagram showing a first example of the bending angle calculation method according to the present embodiment. In the example shown in FIG. 16, two straight lines L31 and L32 parallel to each other along the circumferential direction are displayed on the first tube P1. The straight lines L31 and L32 may be drawn directly on the first tube P1 with a light emitting paint or the like, or the light emitting tape may be attached in a straight line.
[0073]
　The image region specifying unit 16 identifies regions in the images of the first tube P1 and the second tube that include the images of the straight lines L31 and L32 including P2. The derivation unit 13 derives the laying direction straight line of the first pipe P1 based on the distance between the straight lines L31 and L32 in the image. However, when the straight lines L31 and L32 are displayed on the second pipe P2, the lead-out unit 13 derives the laying direction straight line of the second pipe P2.
[0074]
　Specifically, the derivation unit 13 calculates the distances at a plurality of points between the straight lines L31 and L32. The distances at the plurality of locations are, for example, the distances d1 and d2 at both ends of the first pipe P1 in the width direction. The relative relationship of the distances at the plurality of locations depends on the laying direction of the first tube P1 and the positional relationship between the camera 20 and the first tube P1. Therefore, the derivation unit 13 derives the laying direction straight line of the first tube P1 based on the relative relationship of the distances between the straight lines L31 and L32 at the plurality of locations and the positional relationship between the camera 20 and the first tube P1. be able to.
[0075]
　FIG. 17 is a diagram showing a second example of the bending angle calculation method according to the present embodiment. In the example shown in FIG. 17, the calculation jig 81 is arranged on the first pipe P1. The calculation jig 81 has a shape along the surface of the first pipe P1. A light source 81a having a predetermined shape is arranged on the surface of the calculation jig 81. In FIG. 17, the shape of the light source 81a is not limited to two line segments orthogonal to each other. The light source 81a is, for example, a plurality of LEDs arranged in the shape.
[0076]
　The image region specifying unit 16 identifies a region including an image of the light source 81a in the images of the first tube P1 and the second tube. The derivation unit 13 derives the laying direction straight line of the first tube P1 or the laying direction straight line of the second tube P2 based on the shape of the light source 81a in the image. However, when the calculation jig 81 is arranged in the second pipe P2, the lead-out unit 13 derives a straight line in the laying direction of the second pipe P2.
[0077]
　The shape of the light source 81a in the image depends on the laying direction of the first tube P1 and the positional relationship between the camera 20 and the first tube P1. Therefore, the derivation unit 13 can derive the laying direction straight line of the first tube P1 depending on the shape of the light source 81a and the positional relationship between the camera 20 and the first tube P1.
[0078]
　Instead of the light source 81a, a mark having a predetermined shape that does not emit light may be drawn on the surface of the calculation jig 81. However, by using the self-luminous light source 81a, the influence of noise in the image is reduced.
[0079]
　FIG. 18 is a diagram showing a modified example of the second example of the bending angle calculation method according to the present embodiment. When calculating the bending angle using the calculation jig 81, it is not always necessary to install the camera 20 as shown in FIG. For example, as shown in FIG. 18, by arranging the calculation jig 81 not only in the first pipe P1 but also in the second pipe P2, the lead-out unit 13 can use the first pipe P1 and the second pipe. A straight line in the laying direction can be derived for each of P2.
[0080] [0080]
　FIG. 19 is a diagram showing a third example of the method of calculating the bending angle in the present embodiment. In the example shown in FIG. 19, a straight line L41 along the circumferential direction is displayed on the first tube P1. The straight line L41 may be represented by a light emitting paint or a light emitting tape in the same manner as the straight lines L31 and L32. In FIG. 19, for the sake of simplicity, the image of the straight line L41 is shown as a straight line. However, the image of the straight line L41 in the image actually captured by the first tube P1 becomes a curve that is a part of the ellipse L42 according to the positional relationship between the camera 20 and the straight line L41.
[0081]
　The image region specifying unit 16 identifies a region including an image of the straight line L41 in the images of the first tube P1 and the second tube. The derivation unit 13 derives a straight line in the laying direction of the first pipe P1 based on the shape of the ellipse L42 including the straight line L41 in the image. However, when the straight line L41 is displayed on the second pipe P2, the lead-out unit 13 derives the laying direction straight line of the second pipe P2.
[0082]
　The derivation unit 13 identifies the ellipse L42 by a total of three points, one point at both ends of the image of the straight line L41 and one point between them. The length of the minor axis of the ellipse L42 depends on the laying direction of the first tube P1 in the direction perpendicular to the plane of the image and the positional relationship between the camera 20 and the first tube P1. Further, the direction of the long axis of the ellipse L42 depends on the laying direction of the first tube P1 in the direction parallel to the plane of the image and the positional relationship between the camera 20 and the first tube P1. Therefore, the derivation unit 13 derives a straight line including the long axis of the ellipse L42 as a laying direction straight line orthogonal to the laying direction of the first pipe P1 on the plane parallel to the image. Further, the derivation unit 13 can derive a laying direction straight line parallel to the laying direction of the first pipe P1 on the plane perpendicular to the image from the ratio of the lengths of the short axis and the long axis of the ellipse L42. In this case, the calculation unit 14 calculates the bending angle for each of the plane parallel to the image and the plane perpendicular to the image.
[0083]
　Further, when the method shown in FIG. 19 is used, it is not always necessary to install the camera 20 as shown in FIG. When the camera 20 is not installed as shown in FIG. 15, for example, a light emitting paint or a light emitting tape is applied to the end face or the end portion of the second tube P2, and the camera 20 is placed on the second tube P2 with respect to the end face. An image is taken in a state where the tube 1 is arranged on the P1 side. In this case, the image captured by the camera 20 includes an image of the end face or the end portion of the second tube P2. The lead-out unit 13 can derive the laying direction straight line of the second pipe P2 on each of the plane parallel to the image and the plane perpendicular to the image, based on the shape of the end face or the ellipse L43 including the end face.
[0084]
　FIG. 20 is a diagram showing a fourth example of the method of calculating the bending angle in the present embodiment. In the example shown in FIG. 20, a sheet 82 on which a predetermined pattern is drawn is arranged on the first tube P1. The material of the sheet is not particularly limited, and is, for example, paper or resin. In the example shown in FIG. 20, the pattern drawn on the sheet 82 is a grid pattern, but the pattern is not limited to this. Further, the pattern may be drawn directly on the first tube P1.
[0085]
　The image region specifying unit 16 identifies a region including an image of the sheet 82 in the images of the first tube P1 and the second tube. The lead-out unit 13 derives a straight line in the laying direction of the first pipe P1 based on the shape of the pattern in the image. However, when the sheet 82 is arranged in the second pipe P2, the lead-out unit 13 derives a straight line in the laying direction of the second pipe P2.
[0086]
　The shape of the pattern drawn on the sheet 82 in the image depends on the laying direction of the first tube P1 and the positional relationship between the camera 20 and the first tube P1. Therefore, the lead-out unit 13 can derive the laying direction straight line of the first tube P1 by the shape of the pattern drawn on the sheet 82 and the positional relationship between the camera 20 and the first tube P1.
[0087]
　The sheet 82 may be a translucent sheet on which a three-dimensional lattice is drawn. In this case, the derivation unit 13 easily derives the laying direction straight line of the first tube P1 based on the shape of the three-dimensional grid in the image, particularly the grid spacing in the direction perpendicular to the surface of the first tube P1. can do.
[0088]
　FIG. 21 is a diagram showing a modified example of the fourth example of the method for calculating the bending angle according to the second embodiment. When calculating the bending angle using the sheet 82, it is not always necessary to install the camera 20 as shown in FIG. For example, as shown in FIG. 21, by arranging the sheet 82 not only in the first pipe P1 but also in the second pipe P2, the lead-out unit 13 can use the first pipe P1 and the second pipe P2, respectively. Can be derived from the laying direction straight line in the three-dimensional space. As a result, even when the position of the camera 20 is not fixed, the calculation unit 14 can calculate the bending angle based on the respective laying direction straight lines of the first pipe P1 and the second pipe P2. can.
[0089]
　As described above, according to the arithmetic unit 60, the bending angle can be calculated three-dimensionally for the first pipe P1 and the second pipe P2. Therefore, the labor of the operator can be further reduced.
[0090]
　[Embodiment 3]
　Still another embodiment of the present invention will be described below. In the present embodiment, the calculation unit 14 has an angle calculated from the images of the first tube P1 and the second tube P2, and an angle formed by the first tube P1 and the second tube P2 in the depth direction of the image. Create a table showing the relationship with (hereinafter, simply referred to as vertical angle), and calculate the vertical angle with reference to the table.
[0091]
　FIG. 22 is a diagram showing a state in which the first tube P1 is bent toward the front side of the image with respect to the second tube P2. FIG. 23 is a diagram showing a state in which the first tube P1 is bent toward the back side of the image with respect to the second tube P2. The calculation unit 14 calculates the angle θ0 formed by the center line of the first tube P1 and the center line of the second tube P2 by the method described above with reference to FIG. 5 and the like. Further, the calculation unit 14 calculates the angles θ1 and θ2 (θ1 ≦ θ2) formed by each of the side surfaces of the first pipe P1 and the end faces of the second pipe P2. Further, the calculation unit 14 calculates the angles θ3 and θ4 formed by the center line of the first pipe P1 and the contour lines of both side surfaces of the first pipe P1. In creating the table, the calculation unit 14 calculates θ1 to θ4 for an image in which the vertical angles are varied in a plurality of ways. Then, the relationship between the vertical angle and θ3 + θ4 is analyzed for each value of θ0.
[0092]
　FIG. 24 is a diagram showing an analysis result regarding the relationship between the vertical angle and θ3 + θ4 when θ0 is 0 °. FIG. 25 is a diagram showing an analysis result regarding the relationship between the vertical angle and θ3 + θ4 when θ0 is 4 °. In FIGS. 24 and 25, the horizontal axis is a vertical angle and the vertical axis is θ3 + θ4. In the analysis, the calculation unit 14 calculates the value of θ3 + θ4 10 times for each vertical angle. In each of FIGS. 24 and 25, the values ​​of θ3 + θ4 when the vertical angles are -4 °, −2 °, 0 °, + 2 °, and + 4 ° are plotted at a total of 50 points.
[0093]
　Based on these points, the calculation unit 14 analyzes the relationship between the vertical angle formed by the first tube P1 and the second tube P2 and θ3 + θ4. In the examples shown in FIGS. 24 and 25, the relationship between the vertical angle and θ3 + θ4 is expressed by the following equations (1) and (2), respectively.
y = 0.4124x + 0.0971 (1)
y = 0.4189x + 0.0138 (2) In
equations (1) and (2), x is a vertical angle and y is θ3 + θ4. The calculation unit 14 performs the same analysis even when θ0 is other than 0 ° and 4 °, and derives a relational expression similar to the equation (1) or (2).
[0094]
　FIG. 26 is a diagram showing a table created by the calculation unit 14. Based on the analysis results shown in FIGS. 24 and 25, the calculation unit 14 is three-dimensionally calculated from the relationship between the values ​​of θ0 to θ4 and the vertical angle, as well as the value of θ0 and the vertical angle, as shown in FIG. Create a table showing the relationship with the typical bending angle (three-dimensional angle). The above-mentioned analysis and table creation are performed for each diameter of the first pipe P1 and the second pipe P2.
[0095]
　After creating the above table, when calculating the bending angle of the joint portion of the pipe at another construction site or the like, the calculation unit 14 calculates θ0 to θ4 for the image of the joint portion, and then basically θ0. The vertical angle is calculated using the relational expression corresponding to the value of and the value of θ3 + θ4. After that, the calculation unit 14 calculates the three-dimensional angle by the vertical angle and θ0. In this method, the processing takes time, but the three-dimensional angle can be calculated with high accuracy.
[0096]
　As another method for calculating the bending angle, the calculation unit 14 may calculate the bending angle with reference to the table shown in FIG. 26. In this case, the calculation unit 14 selects the combination of the values ​​of θ0 and θ3 + θ4 in the table that is closest to the values ​​of θ0 and θ3 + θ4 calculated from the image, and uses the three-dimensional angle corresponding to the combination as the bending angle. calculate. In this case, the processing can be simplified at the cost of lower accuracy as compared with the method using the relational expression.
[0097]
　[Example of realization by software]
　The control blocks (particularly the image acquisition unit 11, the derivation unit 13 and the calculation unit 14) of the arithmetic units 10 and 60 are realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like. It may be realized by software.
[0098]
　In the latter case, the arithmetic units 10 and 60 include a computer that executes instructions of a program that is software that realizes each function. The computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a "non-temporary tangible medium", for example, a ROM (Read Only Memory) or the like, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.
[0099]
　The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.
Code description
[0100]
　10, 60 Arithmetic logic unit (Bending angle calculation device)
　11 Image acquisition unit
　13 Derivation unit
　14 Calculation unit
The scope of the claims
[Claim 1]
　An imaging step of capturing an image of a pipe in which a first pipe and a second pipe are joined by a joint,
　a derivation step of deriving a laying direction straight line corresponding to the laying direction of the pipe from the image, and the
　first step. A method for calculating a bending angle, which comprises a calculation step of calculating an intersection angle of a straight line in the laying direction of one pipe and a straight line in the laying direction of the second pipe as a bending angle in the joint.
[Claim 2]
　A contour extraction step for extracting the contour of the first pipe and the contour of the second pipe in the image is included, and in the
　derivation step, the laying direction straight line is derived based on the contour extracted from the image. The method for calculating a bending angle according to claim 1, wherein the bending angle is calculated.
[Claim 3]
　The method for calculating a bending angle according to claim 2, wherein in the derivation step, a straight line indicating the side surface of the pipe is derived as a straight line in the laying direction of the pipe based on the contour of the pipe.
[Claim 4]
　The second aspect of the present invention is characterized in that, in the derivation step, a straight line orthogonal to the laying direction of the second pipe is derived as a laying direction straight line of the second pipe based on the contour of the second pipe. The method of calculating the bending angle described.
[Claim 5]
　The method for calculating a bending angle according to claim 2, wherein in the derivation step, the center line of the pipe is derived as the laying direction straight line based on the contour of the pipe.
[Claim 6]
　In the derivation step,
　　among the contours of the pipe, a plurality of straight lines that intersect the contour of the side surface of the pipe at two points are defined, and
　　for each of the plurality of straight lines, two points that intersect the contour of the side surface of the pipe. An
　　approximate intermediate line, which is a straight line that approximates the set of intermediate points, is derived, and a straight line
　　that approximates the set of intermediate points existing within a predetermined distance from the approximate intermediate line is drawn in the laying direction. The method for calculating a bending angle according to claim 5, wherein the method is derived as a straight line.
[Claim 7]
　Further including an image generation step of generating a first component image showing the first component of the image and a second component image showing the second component, the
　contour extraction step includes the first component image and the second component image. The contour of the first tube and the contour of the second tube in each are extracted, and in the
　derivation step, the approximate intermediate is based on the contour of the tube in each of the first component image and the second component image. A line is derived, and the line is derived based on the contour of the tube extracted from the image having the most intermediate points existing within a predetermined distance from the approximate intermediate line among the first component image and the second component image. The method for calculating a bending angle according to claim 6, wherein the laying direction straight line is derived.
[Claim 8]
　The method for calculating a bending angle according to claim 2, wherein in the derivation step, a straight line indicating the laying direction of the pipe is derived as the laying direction straight line based on the shape of the pipe stored in advance.
[Claim 9]
　Two straight lines parallel to each other along the circumferential direction are drawn on the surface of at least one of the first tube and the second tube, and in the
　derivation step, the two straight lines in the image are drawn. The method for calculating a bending angle according to claim 1, wherein a straight line in the laying direction of the first pipe or a straight line in the laying direction of the second pipe is derived based on the distance between the straight lines.
[Claim 10]
　A light source is arranged in a predetermined shape on the surface of at least one of the first tube and the second tube, and in the
　derivation step, the first tube is based on the shape of the light source in the image. The method for calculating a bending angle according to claim 1, wherein the straight line in the laying direction of the pipe or the straight line in the laying direction of the second pipe is derived.
[Claim 11]
　A straight line along the circumferential direction is drawn on the surface of at least one of the first tube and the second tube, and in the
　derivation step, the shape of the ellipse including the straight line in the image is used. The method for calculating a bending angle according to claim 1, wherein the straight line in the laying direction of the first pipe or the straight line in the laying direction of the second pipe is derived.
[Claim 12]
　A predetermined pattern is displayed on the surface of at least one of the first tube and the second tube, and in the
　derivation step, the first tube is based on the shape of the pattern in the image. The method for calculating a bending angle according to claim 1, wherein the straight line in the laying direction or the straight line in the laying direction of the second pipe is derived.
[Claim 13]
　In the imaging step, an image is taken with the derivation assisting tool attached to each of the first tube and the second tube, and in the
　derivation step, the laying direction straight line is derived based on the image of the derivation assisting tool. The method for calculating a bending angle according to any one of claims 1 to 12, wherein the bending angle is calculated.
[Claim 14]
　An image acquisition unit that acquires an image of a pipe in which a first pipe and a second pipe are joined by a joint,
　a derivation unit that derives a laying direction straight line corresponding to the laying direction of the pipe from the image, and the above-
　mentioned A bending angle calculation device comprising: a calculation unit for calculating an intersection angle of a straight line in the laying direction of a first pipe and a straight line in a laying direction of the second pipe as a bending angle in the joint.