Mounting position inspection device, mounting position inspection method, and mounting position inspection program
The mounting position inspection device uses 3D shape acquisition and normal vector extraction to enhance the accuracy of accessory detection on tubular objects by filtering out irrelevant data, addressing the limitations of existing CAD-based methods.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- NIPPON STEEL CORPORATION
- Filing Date
- 2024-11-19
- Publication Date
- 2026-05-29
Smart Images
Figure 2026088933000001_ABST
Abstract
Description
Technical Field
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[0001] The present invention relates to an attachment position inspection device, an attachment position inspection method, and an attachment position inspection program.
Background Art
[0002] Conventionally, in a method of detecting accessories such as suspension fittings using matching processing with CAD data, a technique for performing matching processing with high accuracy by including the surface of a steel pipe in addition to the accessories is known (for example, Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The technique described in Patent Document 1 above performs matching processing for accessories attached protruding in the normal direction of a steel pipe with another steel pipe, and does not consider detecting accessories that are difficult to process in the matching processing with CAD data.
[0005] The present invention has been made in view of the above circumstances, and provides an attachment position inspection device, an attachment position inspection method, and an attachment position inspection program capable of accurately specifying the position of an accessory of an inspection object.
Means for Solving the Problems
[0006] To achieve the above objective, the mounting position inspection device according to the first aspect of the present invention is a mounting position inspection device for an object to be inspected, comprising an elongated object body and an accessory attached to the object body, and for inspecting the mounting position of the accessory, comprising: a 3D shape acquisition unit that measures the surface shapes of the object body and the accessory and acquires point cloud data of the object body and the accessory; a central axis calculation unit that performs a fitting process to the point cloud data of the object body and the accessory using a model that mimics the external shape, and calculates the central axis in the point cloud data based on the central axis of the model of the object body obtained; and a distance perpendicular to the central axis, which is the distance from the central axis, for the point cloud data of the object body and the accessory, and when the distance is the maximum or minimum... The system includes: an identification unit that identifies the area around the position as an area that can be considered as the accessory; a normal vector calculation unit that calculates the normal vector of the point in question on a plane that includes the point in question and the point in question surrounding the point in question, with respect to the point cloud data included in the area that can be considered as the accessory; a normal vector extraction unit that extracts the normal vector of a point whose angle with respect to the central axis is greater than or equal to a preset threshold; a point cloud data deletion unit that deletes point cloud data from the point cloud data consisting of points corresponding to the normal vector extracted by the normal vector extraction unit, where the distance between adjacent point cloud data is greater than or equal to a predetermined distance; and a position determination unit that determines that the point closest to the end of the inspected object body among the point cloud data after deletion by the point cloud data deletion unit is the position of the end of the accessory.
[0007] According to the mounting position inspection device of the first aspect of the present invention, a 3D shape acquisition unit measures the surface shapes of the object to be inspected and the accessories, and acquires point cloud data of the object to be inspected and the accessories. A central axis calculation unit performs a fitting process to the point cloud data of the object to be inspected and the accessories using a model that mimics the external shape, and calculates the central axis in the point cloud data based on the central axis of the model of the object to be inspected obtained. An identification unit calculates the distance from the central axis to the point cloud data of the object to be inspected and the accessories, which is the distance perpendicular to the central axis, and identifies the area around the position where the distance is maximum or minimum as an area that can be considered as the accessories. A normal vector calculation unit calculates the normal vector of the point in the area that can be considered as the accessories, on a plane that includes the point in the area that can be considered as the accessories and the point in the area that can be considered as the accessories. The normal vector extraction unit extracts the normal vectors of points where the angle between the normal vector and the central axis is greater than or equal to a preset threshold. The point cloud data deletion unit deletes point cloud data from the point cloud data consisting of points corresponding to the normal vectors extracted by the normal vector extraction unit, where the distance between adjacent point cloud data is greater than or equal to a predetermined distance. The position determination unit determines that the point closest to the end of the main body of the object being inspected, among the point cloud data deleted by the point cloud data deletion unit, is the position of the end of the accessory. This allows for accurate identification of the position of the accessory of the object being inspected.
[0008] The mounting position inspection device according to the second aspect of the present invention is characterized in that, in the mounting position inspection device according to the first aspect, the threshold value is 42° to 48°.
[0009] In the mounting position inspection device according to the third aspect of the present invention, the mounting position inspection device according to the first or second aspect is characterized in that the body of the object to be inspected is a tubular body.
[0010] A mounting position inspection method according to a fourth aspect of the present invention is a mounting position inspection method for an object to be inspected, comprising an elongated object body and an accessory attached to the object body, wherein the mounting position of the accessory is inspected, and the method involves measuring the surface shapes of the object body and the accessory, acquiring point cloud data of the object body and the accessory, fitting the point cloud data of the object body and the accessory to the point cloud data using a model that mimics the external shape of the object to be inspected, calculating the central axis in the point cloud data based on the central axis of the model of the object to be inspected, and calculating the distance from the central axis to the point cloud data of the object body and the accessory, which is perpendicular to the central axis. The computer identifies the area around the position where the distance is maximum or minimum as an area that can be considered as the accessory, calculates the normal vector of the point of interest on the plane containing the point of interest and the point of interest surrounding the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest among the point of interest, extracts the normal vector of the point where the angle between the normal vector and the central axis is greater than or equal to a predetermined threshold, deletes point of interest from the point of interest consisting of points corresponding to the extracted normal vectors where the distance between adjacent point of interest is greater than a predetermined distance, and determines that the point closest to the end of the main body of the inspected object among the point of interest after deletion is the position of the end of the accessory.
[0011] A fifth aspect of the present invention is an installation position inspection program for inspecting the installation position of an accessory attached to an object to be inspected, comprising a long-shaped object body and an accessory attached to the object body, wherein the program measures the surface shapes of the object body and the accessory, acquires point cloud data of the object body and the accessory, performs a fitting process to the point cloud data of the object body and the accessory using a model that mimics the external shape of the object to be inspected, calculates the central axis in the point cloud data based on the central axis of the model of the object to be inspected, calculates the distance perpendicular to the central axis for the point cloud data of the object body and the accessory, and the distance This is an installation position inspection program that causes a computer to perform the following actions: identify the area around the position where the distance is maximum or minimum as an area that can be considered as the accessory; calculate the normal vector of the point of interest on the plane containing the point of interest and the point of interest surrounding the point of interest among the point cloud data included in the area that can be considered as the accessory; extract the normal vector of the point where the angle between the normal vector and the central axis is greater than or equal to a preset threshold; delete point cloud data from the point cloud data consisting of points corresponding to the extracted normal vectors where the distance between adjacent point cloud data is greater than or equal to a predetermined distance; and determine that the point closest to the end of the inspected object body among the point cloud data after deletion is the position of the end of the accessory. [Effects of the Invention]
[0012] According to the present invention, the position of the accessories of the object being inspected can be accurately identified. [Brief explanation of the drawing]
[0013] [Figure 1] This is a diagram showing the schematic configuration of a position measuring device. [Figure 2] This is a diagram showing the configuration of the computing unit. [Figure 3] This figure shows the measurement data obtained when measuring the spinning top. [Figure 4] This figure shows cross-sectional data at a specific location in the circumferential direction. [Figure 5] This is a flowchart for the location inspection process. [Modes for carrying out the invention]
[0014] The following description of one embodiment of the present invention will be given with reference to the attached drawings as appropriate, using as an example the case in which the object to be inspected is a tubular spiral steel pipe and the accessory is a chuck. Here, "chuck" refers to a chuck for a pliers. A pliers is a temporary pile used to drive the pile head of a pre-fabricated pile, such as a driven pile or a trench pile, into the ground or water, and steel pipes are sometimes used for this purpose. In other words, a chuck for a pliers is attached to the inside or outside of a steel pipe in order to chuck it with heavy machinery during construction such as driving in or pulling out the steel pipe (pliers).
[0015] <Summary of this embodiment> Spiral steel pipes are fitted with accessories such as hanging brackets. These accessories are welded on by workers based on drawings, but another worker verifies that the mounting position and orientation of the accessories are within the tolerance range specified in the drawings. Currently, measurements are taken using a measuring tape and the results are entered into the system, but there can be variations in measurements depending on the worker, and incorrect results may be entered due to misreading, etc.
[0016] To address this problem, point cloud data is acquired using a three-dimensional shape meter (laser scanner), and the mounting position of the accessories is measured by processing the point cloud data.
[0017] Regarding the detection of the position of accessories, when the shape is clearly different from the surface of the steel pipe like a hanging bracket, it is possible to detect by using a method (matching process) of extracting feature quantities from the acquired point cloud data and CAD data respectively and making a comparison. However, for accessories whose shape is similar to the surface of the steel pipe such as a plate, when using the matching process, the CAD data may match the surface of the steel pipe, or the matching position may shift due to the welding beads on the side surface of the accessory, and thus it may not be possible to accurately detect the accessory. In the present embodiment, a method capable of accurately detecting is used for accessories that cannot be detected by using the matching process.
[0018] <System Configuration> FIG. 1 is a diagram schematically showing a schematic configuration of a position measuring device according to an embodiment of the present invention.
[0019] As shown in FIG. 1, the position measuring device 100 according to the present embodiment is a device for inspecting the attachment position of an accessory (hanging bracket) S2 with respect to a test object (spiral steel pipe) S including a test object main body (spiral steel pipe) S1 and an accessory (hanging bracket) S2 attached so as to protrude in the normal direction on the outer surface of the test object main body S1. Generally, the outer diameter of the spiral steel pipe is about 2500 mm at maximum, and the length is about 70 m at maximum. Also, generally, a pair of hanging brackets are attached facing each other in the radial direction at a position about 1 to 2 m away from the end face of the spiral steel pipe.
[0020] The position measuring device 100 according to the present embodiment includes an optical three-dimensional shape measuring device 1 and an arithmetic device 2.
[0021] The three-dimensional shape measurement device 1 is a device that measures the surface shape of the inspection object S by emitting and receiving light to and from the inspection object S. Specifically, the three-dimensional shape measurement device 1 of the present embodiment measures the distance to the surface of the inspection object S based on the phase difference between the emitted light (such as laser light) and the light received after the emitted light is reflected by the inspection object S, and scans the light projection direction to measure the surface shape of the inspection object S. It is a phase-shift method three-dimensional shape measurement device. Since the phase-shift method three-dimensional shape measurement device has a wide measurement range, even for a large-sized inspection object S such as when the inspection object main body S1 is a spiral steel pipe, three-dimensional point cloud data can be obtained relatively easily. Since the specific configuration of the phase-shift method three-dimensional shape measurement device is well-known, a detailed description thereof is omitted here. As the phase-shift method three-dimensional shape measurement device 1, for example, the laser scanner "Scan Station" manufactured by Leica Geosystems or the laser scanner "Focus Laser Scanner" manufactured by FARO can be preferably used.
[0022] However, the three-dimensional shape measurement device 1 used in the present invention is not necessarily limited to the phase-shift method three-dimensional shape measurement device, and as long as the measurement environment permits, a three-dimensional shape measurement device using the TOF (Time Of Flight) method, the stereo camera method, or the pattern projection method can also be applied.
[0023] In this embodiment, as shown in Figure 1, a single 3D shape measuring device 1 is moved to a total of four positions: a position where the end face SE of the object to be inspected S is approximately at the center of the measurement range (positions indicated by reference numerals 1a and 1b), and a position where the accessory S2 of the object to be inspected S is approximately at the center of the measurement range (positions indicated by reference numerals 1c and 1d). The surface shape of the object to be inspected S is measured at each of these positions. At least the measurement ranges of the 3D shape measuring device 1 at adjacent positions in the longitudinal direction (left-right direction in Figure 1) of the object to be inspected S overlap. That is, the measurement range of the 3D shape measuring device 1 at position 1a and the measurement range of the 3D shape measuring device 1 at position 1c overlap. Also, the measurement range of the 3D shape measuring device 1 at position 1b and the measurement range of the 3D shape measuring device 1 at position 1d overlap. Then, before measuring the surface shape of the object S under inspection, a calibration piece (for example, a reference sphere) is placed in the overlapping portion, and the position of the calibration piece is measured by the 3D shape measuring device 1 at each of the positions 1a to 1d.
[0024] <Configuration of the arithmetic unit> Next, we will describe the configuration of the arithmetic unit. Figure 2 shows the functional configuration of the arithmetic unit 2.
[0025] As shown in Figure 2, the computing unit 2 includes a 3D shape acquisition unit 110, a central axis calculation unit 112, an identification unit 114, a normal vector calculation unit 116, a normal vector extraction unit 118, a point cloud data deletion unit 120, and a position determination unit 122.
[0026] The 3D shape acquisition unit 110 acquires 3D point cloud data of the object to be inspected, obtained by measuring the surface shape of the object to be inspected.
[0027] Specifically, the arithmetic unit 2 receives input of the surface shape of the object under inspection S measured by the 3D shape measuring device 1 at each position 1a to 1d, and the position of the calibration piece measured by the 3D shape measuring device 1 at each position 1a to 1d. The 3D shape acquisition unit 110 then synthesizes the surface shape of the object under inspection S measured by the 3D shape measuring device 1 at position 1a and the surface shape of the object under inspection S measured by the 3D shape measuring device 1 at position 1c, based on the position of the calibration piece measured by the 3D shape measuring device 1 at position 1a and the position of the calibration piece measured by the 3D shape measuring device 1 at position 1c, so that the positions of these calibration pieces match. This synthesizes the surface shape of the object under inspection S, including the range from the end face SE of the object under inspection S to the accessory S2 (the upper accessory S2 in Figure 1), and generates (acquires) 3D point cloud data of the surface of the object under inspection S. Similarly, the 3D shape acquisition unit 110, based on the position of the calibration piece measured by the 3D shape measuring device 1 at position 1b and the position of the calibration piece measured by the 3D shape measuring device 1 at position 1d adjacent to position 1b, synthesizes the surface shape of the object under inspection S measured by the 3D shape measuring device 1 at position 1b and the surface shape of the object under inspection S measured by the 3D shape measuring device 1 at position 1d, so that the positions of these calibration pieces match, and generates (acquires) 3D point cloud data of the surface of the object under inspection S, including the range from the end face SE of the object under inspection S to the accessory S2 (the lower accessory S2 in Figure 1).
[0028] The central axis calculation unit 112 processes the 3D point cloud data acquired by the 3D shape acquisition unit 110 to fit the point cloud data using a model that mimics the external shape of the object under inspection, and calculates the direction of the central axis in the 3D point cloud data based on the central axis of the obtained model. In other words, the central axis calculation unit 112 uses a model that mimics the external shape of the object under inspection, enlarges or reduces it in the length and diameter directions to match it with the 3D point cloud data, and calculates the direction of the central axis in the 3D point cloud data based on the central axis of the obtained model. Here, the central axis refers to the axis passing through the center of a cross-section perpendicular to the longitudinal direction of the object under inspection or the model.
[0029] Here, the computing device 2 has a model pre-configured that mimics the external shape of the object under inspection S. Specifically, the model that mimics the external shape is a model that replicates a shape similar to the general external shape of the object under inspection, such as a cylinder or a rectangular prism. In other words, in this embodiment, a cylindrical model that mimics the external shape of a spiral steel pipe is used, so the axis perpendicular to the circular cross-section is set as the central axis of the model.
[0030] In this embodiment, the central axis calculation unit 112 moves the 3D point cloud data acquired by the 3D shape acquisition unit 110 so that its central axis aligns with one of the orthogonal coordinate axes, such as the X-axis. More specifically, the central axis calculation unit 112 performs a fitting process to fit the 3D point cloud data using a cylinder, which is a model that mimics the outer shape of the object S under inspection. Then, the central axis calculation unit 112 calculates the central axis of the fitted cylinder and The cylinder and 3D point cloud data are translated and rotated so that they align with one of the orthogonal coordinate axes, such as the X-axis. Then, the central axis of the cylinder is calculated as the direction of the central axis in the 3D point cloud data.
[0031] The identification unit 114 calculates the distance perpendicular to the central axis of the 3D point cloud data of the object under inspection S, including the accessory S2, and identifies the area around the position where this distance is maximum or minimum as an area that can be considered to be the accessory S2. Specifically, if the accessory S2 is attached to the outside of the object under inspection S, the distance of the point cloud data of the accessory S2 to the central axis will be greater than the distance of the point cloud data of the object under inspection S to the central axis. Also, if the object under inspection S is cylindrical and the accessory S2 is attached to the inside, the distance of the point cloud data of the accessory S2 to the central axis will be smaller than the distance of the point cloud data of the object under inspection S to the central axis. Therefore, the identification unit 114 can identify the area around the position where the distance to the central axis is maximum or minimum as an area where the accessory S2 is attached.
[0032] The normal vector calculation unit 116 calculates the normal vector of each point of interest among the point cloud data included in the region that can be considered as accessory S2, using the point of interest and the point cloud data surrounding the point of interest. Here, the normal vector of the point of interest is a vector indicating the normal direction at the point of interest on the surface where the point of interest and the point cloud data surrounding the point of interest exist. Here, the region targeted for calculation by the normal vector calculation unit 116 may be wider than the region that can be considered as accessory S2 and may include the object under inspection.
[0033] Here, Figure 3 shows the point cloud data obtained when measuring the spool. Figure 4 shows the circumferential cross-sectional data at the location of this point cloud data. The data for the part to which the spool is attached is outside the data for the object under inspection. It is necessary to detect the position of the outermost part of this spool. There is a welding bead on the side of the spool, and the side of the spool is not perpendicular to the central axis, so it is difficult to detect the position of the spool based on the side data. Therefore, in this embodiment, the position of the spool is detected based on the normal vector of the data around the spool. Note that the horizontal lines shown in Figure 3 and the vertical lines shown in Figure 4 are displayed according to the specifications of the actual device of the calculation unit 2 and are not related to the invention according to this embodiment.
[0034] Specifically, the normal vector extraction unit 118 extracts normal vectors from the normal vectors of each point in the point cloud data included in the region that can be considered as accessory S2, where the angle between the normal vector and the central axis is greater than or equal to a preset threshold. Here, the threshold is, for example, 42° to 48°. In other words, the normal vectors extracted using the normal vector extraction unit 118 are normal vectors at points located in a plane approximately parallel to the center line, and data on the sides of the frame can be deleted.
[0035] The point cloud data deletion unit 120 deletes point cloud data from the point cloud data consisting of points corresponding to the normal vectors extracted by the normal vector extraction unit 118, where the distance between adjacent point cloud data is greater than or equal to a predetermined distance, based on the region that can be considered as accessory S2. If the region targeted for calculation by the normal vector calculation unit 116 includes the object under inspection as a region that can be considered as accessory S2, the normal vector extraction unit 118 extracts the normal vectors of the plane portion of the object under inspection or the frame, which are the normal vectors of a plane approximately parallel to the center line. Therefore, by using the point cloud data deletion unit 120 to delete point cloud data where the distance in the direction of the central axis of adjacent point cloud data is greater than or equal to a predetermined distance, based on the position of the frame region, only the region that can be considered as the frame can be extracted.
[0036] The position determination unit 122 determines that the point closest to the end of the object being inspected S1 is the position of the end of the accessory among the point cloud data after deletion by the point cloud data deletion unit 120.
[0037] Specifically, the position determination unit 122 identifies the point closest to the end of the inspected object body S1 from the point cloud data remaining after deletion by the point cloud data deletion unit 120 in the area that can be considered as the accessory S2, and determines that the position of that point is the position of the end of the accessory.
[0038] The computing unit 2 consists of, for example, a computer on which programs or applications that perform the processing of each of the above parts are installed. Specifically, the computing unit 2 can be configured by implementing a known point cloud processing library on a computer, such as the open-source "PCL (Point Cloud Library)" or MVTec's "HALCON". The above point cloud processing libraries can handle not only point cloud data but also surface data (data composed of cylinders, planes, triangular meshes, etc.), and can perform various calculations related to point cloud data and surface data, such as preprocessing such as smoothing and thinning, extraction of point cloud data based on coordinates and distances, coordinate transformation, matching, fitting, dimensional measurement of point cloud data, and generation of three-dimensional surfaces.
[0039] Next, the position inspection process performed by the computing device 2 will be explained with reference to the flowchart shown in Figure 5. Here, it is assumed that 3D point cloud data of the surface of the object S under inspection has been obtained by measuring the surface shape of the object S under inspection using the 3D shape measuring device 1. Specifically, the 3D shape measuring device 1 is moved to four positions 1a to 1d, and the surface shape of the object S under inspection and the surface shape of the calibration piece are measured at each position. These measurement results are input to and stored in the computing device 2 via a storage medium such as an SD card.
[0040] In step S100, the 3D shape acquisition unit 110 acquires 3D point cloud data of the object to be inspected S, which is obtained by measuring the surface shape of the object to be inspected S.
[0041] In step S102, the central axis calculation unit 112 performs a process to fit the 3D point cloud data acquired by the 3D shape acquisition unit 110 to the point cloud data using a model that mimics the outer shape of the object to be inspected, and calculates the direction of the central axis in the 3D point cloud data based on the central axis of the obtained model.
[0042] In step S104, the identification unit 114 calculates the distance perpendicular to the central axis from the three-dimensional point cloud data of the object S under inspection, including the accessory S2, and identifies the area around the position where the distance is maximum or minimum as an area that can be considered to be the accessory S2.
[0043] In step S106, the normal vector calculation unit 116 calculates the normal vector of each point of interest from the point cloud data included in the region that can be considered as accessory S2, using the point of interest and the point cloud data surrounding the point of interest.
[0044] In step S108, the normal vector extraction unit 118 extracts normal vectors whose angle with respect to the central axis is greater than or equal to a preset threshold.
[0045] In step S110, the point cloud data deletion unit 120 deletes point cloud data from the point cloud data corresponding to the normal vector extracted by the normal vector extraction unit 118, where the distance between adjacent point cloud data is greater than or equal to a predetermined distance, based on the region that can be considered as accessory S2.
[0046] In step S112, the position determination unit 122 determines that the point closest to the end of the object being inspected S1 among the point cloud data deleted by the point cloud data deletion unit 120 is the position of the end of the accessory S2.
[0047] In this embodiment, for each point of interest in the point cloud data included in the region that can be considered an accessory of the object under inspection, a normal vector is calculated. The normal vectors of points where the angle between the normal vector and the central axis is greater than or equal to a preset threshold are extracted. From the point cloud data consisting of points corresponding to the extracted normal vectors, point cloud data where the distance between adjacent point cloud data is greater than a predetermined distance is deleted. The point closest to the end of the object under inspection among the remaining point cloud data is determined to be the position of the end of the accessory. This allows for accurate identification of the position of the accessory of the object under inspection. In particular, the mounting position of an accessory (e.g., a spool) of a spiral steel pipe can be measured with high precision.
[0048] Although the explanation uses the example of a spiral steel pipe as the object under inspection, it is not limited to this. The object under inspection may be a tubular body other than a spiral steel pipe, or a columnar body such as a rectangular prism. Furthermore, the object under inspection may be a plate-shaped member. If the object under inspection is a plate-shaped member, it is sufficient to identify the area around the position where the distance is greatest as an area that can be considered an accessory.
[0049] The embodiments of the present invention described above can be realized by a computer executing a program. Furthermore, a computer-readable recording medium on which the program is recorded, and a computer program product such as the program itself, can also be applied as embodiments of the present invention. Examples of recording media that can be used include flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, magnetic tapes, non-volatile memory cards, ROMs, and the like. The present invention may also be applied to program products.
[0050] The following additional information is disclosed regarding the embodiments described above.
[0051] [Note 1] An inspection device for inspecting the mounting position of an accessory attached to an object to be inspected, comprising an elongated main body of the object to be inspected and an accessory attached to the main body of the object to be inspected, A 3D shape acquisition unit measures the surface shape of the object to be inspected and the accessories, and acquires point cloud data of the object to be inspected and the accessories, A central axis calculation unit performs a fitting process on the point cloud data of the object to be inspected and the accessories using a model that mimics the external shape, and calculates the central axis in the point cloud data based on the central axis of the model of the object to be inspected obtained. An identification unit that, with respect to the point cloud data of the object to be inspected and the accessories, calculates the distance perpendicular to the central axis and the distance from the central axis, and identifies the area around the position where the distance is maximum or minimum as an area that can be considered to be the accessories, A normal vector calculation unit calculates the normal vector of a point of interest on a plane that includes the point of interest and the point of interest surrounding the point of interest, with respect to the point cloud data included in the region that can be considered as an accessory. A normal vector extraction unit extracts the normal vectors of points where the angle between the normal vector and the central axis is greater than or equal to a preset threshold, A point cloud data deletion unit deletes point cloud data from the point cloud data consisting of points corresponding to the normal vectors extracted by the normal vector extraction unit, where the distance between adjacent point cloud data is greater than a predetermined distance. A position determination unit determines that the point closest to the end of the main body of the object being inspected is the position of the end of the accessory, after the point cloud data has been deleted by the point cloud data deletion unit. A mounting position inspection device having the following features. [Note 2] The mounting position inspection device according to Appendix 1, characterized in that the threshold is 42° to 48°. [Note 3] The mounting position inspection device described in Appendix 1 or 2, wherein the object to be inspected is a tubular body. [Note 4] A mounting position inspection method for an object to be inspected, comprising an elongated object body and accessories attached to the object body, wherein the mounting position of the accessories is inspected, The surface shapes of the object to be inspected and the accessories are measured, and point cloud data of the object to be inspected and the accessories are acquired. The point cloud data of the object under inspection and its accessories are fitted to the point cloud data using a model that mimics the external shape of the object under inspection, and the central axis in the point cloud data is calculated based on the central axis of the model of the object under inspection obtained. With respect to the point cloud data of the object to be inspected and the accessories, the distance perpendicular to the central axis is calculated, and the area around the position where this distance is maximum or minimum is identified as an area that can be considered as the accessories. With respect to the point cloud data included in the region that can be considered as an accessory, calculate the normal vector of the point of interest on the plane that includes the point of interest and the point cloud data surrounding the point of interest within the point cloud data included in the region that can be considered as an accessory. The normal vectors of points where the angle between the aforementioned normal vector and the central axis exceeds a predetermined threshold are extracted. From the point cloud data consisting of points corresponding to the extracted normal vector, point cloud data where the distance between adjacent point cloud data is greater than a predetermined distance is deleted. Of the point cloud data after the aforementioned deletion, the point closest to the end of the object being inspected is determined to be the position of the end of the accessory. A method for inspecting mounting positions, performed by a computer. [Note 5] A mounting position inspection program for inspecting the mounting position of an accessory, comprising an elongated body to be inspected and an accessory attached to the body to be inspected, The surface shapes of the object to be inspected and the accessories are measured, and point cloud data of the object to be inspected and the accessories are acquired. The point cloud data of the object under inspection and its accessories are fitted to the point cloud data using a model that mimics the external shape of the object under inspection, and the central axis in the point cloud data is calculated based on the central axis of the model of the object under inspection obtained. With respect to the point cloud data of the object to be inspected and the accessories, the distance perpendicular to the central axis is calculated, and the area around the position where this distance is maximum or minimum is identified as an area that can be considered as the accessories. With respect to the point cloud data included in the region that can be considered as an accessory, calculate the normal vector of the point of interest on the plane that includes the point of interest and the point cloud data surrounding the point of interest within the point cloud data included in the region that can be considered as an accessory. The normal vectors of points where the angle between the aforementioned normal vector and the central axis exceeds a predetermined threshold are extracted. From the point cloud data consisting of points corresponding to the extracted normal vector, point cloud data where the distance between adjacent point cloud data is greater than a predetermined distance is deleted. Of the point cloud data after the aforementioned deletion, the point closest to the end of the object being inspected is determined to be the position of the end of the accessory. A mounting position inspection program that has a computer perform the following task. [Explanation of symbols]
[0052] 1 3D shape measuring device 2 Arithmetic unit 100 Position Measuring Device 110 3D shape acquisition section 112 Central axis calculation section 114 Identification Unit 116 Normal Vector Calculation Unit 118 Normal vector extraction unit 120-point cloud data deletion unit 122 Position judgment part S Subject under inspection S1 Main body of the object to be inspected S2 Accessories SE end face
Claims
1. An inspection device for inspecting the mounting position of an accessory attached to an object to be inspected, comprising an elongated main body of the object to be inspected and an accessory attached to the main body of the object to be inspected, A 3D shape acquisition unit measures the surface shape of the object to be inspected and the accessories, and acquires point cloud data of the object to be inspected and the accessories, A central axis calculation unit performs a fitting process on the point cloud data of the object under inspection and its accessories using a model that mimics the external shape of the object under inspection, and calculates the central axis in the point cloud data based on the central axis of the obtained model of the object under inspection, An identification unit that, with respect to the point cloud data of the object to be inspected and the accessories, calculates the distance perpendicular to the central axis and the distance from the central axis, and identifies the area around the position where the distance is maximum or minimum as an area that can be considered to be the accessories, A normal vector calculation unit calculates the normal vector of a point of interest on a plane that includes the point of interest and the point of interest surrounding the point of interest, with respect to the point cloud data included in the region that can be considered as an accessory. A normal vector extraction unit extracts the normal vector of a point where the angle between the normal vector and the central axis is greater than or equal to a preset threshold. A point cloud data deletion unit deletes point cloud data from the point cloud data consisting of points corresponding to the normal vectors extracted by the normal vector extraction unit, where the distance between adjacent point cloud data is greater than a predetermined distance. A position determination unit determines that the point closest to the end of the main body of the object being inspected is the position of the end of the accessory, after the point cloud data has been deleted by the point cloud data deletion unit. A mounting position inspection device having the following features.
2. The mounting position inspection device according to claim 1, characterized in that the threshold is 42° to 48°.
3. The mounting position inspection device according to claim 1, wherein the body of the object to be inspected is a tubular body.
4. A mounting position inspection method for an object to be inspected, comprising an elongated object body and accessories attached to the object body, wherein the mounting position of the accessories is inspected, The surface shapes of the object to be inspected and the accessories are measured, and point cloud data of the object to be inspected and the accessories are acquired. The point cloud data of the object under inspection and its accessories are fitted to the point cloud data using a model that mimics the external shape of the object under inspection, and the central axis in the point cloud data is calculated based on the central axis of the model of the object under inspection obtained. With respect to the point cloud data of the object to be inspected and the accessories, the distance perpendicular to the central axis is calculated, and the area around the position where this distance is maximum or minimum is identified as an area that can be considered to be the accessories. With respect to the point cloud data included in the region that can be considered as an accessory, calculate the normal vector of the point of interest on the plane that includes the point of interest and the point cloud data surrounding the point of interest within the point cloud data included in the region that can be considered as an accessory. The normal vectors of points where the angle between the aforementioned normal vector and the central axis exceeds a predetermined threshold are extracted. From the point cloud data consisting of points corresponding to the extracted normal vectors, point cloud data where the distance between adjacent point cloud data is greater than a predetermined distance is deleted. Of the point cloud data after the aforementioned deletion, the point closest to the end of the object being inspected is determined to be the position of the end of the accessory. A method for inspecting mounting positions, performed by a computer.
5. A mounting position inspection program for inspecting the mounting position of an accessory, comprising an elongated body to be inspected and an accessory attached to the body to be inspected, The surface shapes of the object to be inspected and the accessories are measured, and point cloud data of the object to be inspected and the accessories are acquired. The point cloud data of the object under inspection and its accessories are fitted to the point cloud data using a model that mimics the external shape of the object under inspection, and the central axis in the point cloud data is calculated based on the central axis of the model of the object under inspection obtained. With respect to the point cloud data of the object to be inspected and the accessories, the distance perpendicular to the central axis is calculated, and the area around the position where this distance is maximum or minimum is identified as an area that can be considered to be the accessories. With respect to the point cloud data included in the region that can be considered as an accessory, calculate the normal vector of the point of interest on the plane that includes the point of interest and the point cloud data surrounding the point of interest within the point cloud data included in the region that can be considered as an accessory. The normal vectors of points where the angle between the aforementioned normal vector and the central axis exceeds a predetermined threshold are extracted. From the point cloud data consisting of points corresponding to the extracted normal vectors, point cloud data where the distance between adjacent point cloud data is greater than a predetermined distance is deleted. Of the point cloud data after the aforementioned deletion, the point closest to the end of the object being inspected is determined to be the position of the end of the accessory. A mounting position inspection program that has a computer perform the following task.