Position measurement method

Abstract

To perform accurate position measurement using simple procedures.SOLUTION: The present disclosure relates to a position measurement method for measuring the position of a cylindrical measurement object placed on a wall. In this method, at least three measurement tools having target markers are installed at different positions on a measurement surface side of the measurement object, with the target markers facing the measurement surface. Then, image data is obtained by capturing the measurement object together with the reference surface of the measurement object and the at least three measurement tools.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a position measurement method and a measurement jig. [Background technology]

[0002] Embedded components such as pipes and metal fittings are often installed in the walls, floors, ceilings, etc. of buildings for various purposes. For example, when constructing a reinforced concrete building, these embedded components are installed in pre-designed positions before concrete is poured into the reinforcing bars that form the foundation and run along the flat surfaces of the walls, floors, ceilings, etc. Conventionally, the installation positions of embedded components have been confirmed and inspected by workers by measuring them manually, but the measurement results are easily affected by the skill of the workers, making it difficult to achieve good accuracy.

[0003] As a tool for improving measurement accuracy when such an embedded member is used as the measurement target, a device capable of measuring the position of the measurement target by photographing the measurement target with a camera and analyzing the image is known. For example, Patent Document 1 discloses a technology in which the measurement target is not an embedded member, but the position of a measurement point included in an image is measured based on an image photographed with a line camera from a different direction or position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-258486 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, the positions of measurement points included in an image are measured based on images taken from different directions or positions using a line camera. This requires a dedicated line camera to be prepared, and also requires taking images from different directions or positions, which increases the cost and effort required for the measurement work.

[0006] At least one embodiment of the present disclosure has been made in consideration of the above circumstances, and aims to provide a position measurement method and a measurement jig that enable accurate position measurement with a simple procedure. [Means for solving the problem]

[0007] In order to solve the above problem, a position measurement method according to at least one embodiment of the present disclosure includes: A position measurement method for measuring a position of a cylindrical measurement object placed on a wall portion, comprising: a step of placing at least three measurement jigs, each having a target marker, at different positions on a measurement surface side of the measurement object, with the target marker facing the measurement surface; acquiring imaging data by photographing the measurement object together with a reference surface of the measurement object and the at least three measurement jigs; Equipped with.

[0008] In order to solve the above problem, a measuring jig according to at least one embodiment of the present disclosure includes: A measurement jig used to measure the position of a cylindrical measurement object placed on a wall portion, a main body having a first surface on which a target marker is provided, and a second surface that faces the measurement object when the main body is placed on the measurement object so that the target marker faces the measurement surface; a flange portion extending from the main body along the measurement surface and forming a step portion between the main body and the second surface; a fixing portion for detachably fixing the main body to the measurement object; Equipped with. [Effects of the Invention]

[0009] According to at least one embodiment of the present disclosure, it is possible to provide a position measurement method and a measurement jig that enable accurate position measurement with a simple procedure. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a measurement target of a position measurement method according to an embodiment; [Figure 2] FIG. 1 is a perspective view showing a measuring jig according to an embodiment. [Figure 3] 1 is a flowchart illustrating a position measurement method according to an embodiment. [Figure 4] 10 is an example of setting a measurement jig to a measurement object having a substantially circular cross section. [Figure 5] 10 is an example of setting a measurement jig to a measurement object having a substantially rectangular cross section. [Figure 6] 4 is a schematic diagram showing a method for calculating a second center position in step S6 of FIG. 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the configurations described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0012] First, a measurement object 10 for a position measuring method according to at least one embodiment of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing a measurement object 10 for a position measuring method according to one embodiment.

[0013] The measurement object 10 is placed on a wall 12 that at least partially divides the adjacent first and second spaces V1 and V2. The wall 12 extends along the XY plane and has a thickness t1 along the Z direction. In the following description, the side of the wall 12 facing the first space V1 will be referred to as a first surface 12a, and the side facing the second space V2 will be referred to as a second surface 12b.

[0014] 1 shows an example of the wall portion 12, which partitions the first space V1 and the second space V2 adjacent to each other along the horizontal direction (Z direction), but the wall portion 12 may also be a floor surface that partitions the first space V1 and the second space V2 adjacent to each other in the vertical direction. At least one of the first space V1 and the second space V2 may be an indoor space or an outdoor space.

[0015] The measurement object 10 is an embedded member arranged so that at least a portion of it is embedded in the wall portion 12. In this embodiment, the measurement object 10 is a tubular member having a cylindrical shape, and is arranged with respect to the wall member 12 so that its central axis C is in the Z direction. The measurement object 10 has an axial length L and a thickness t2, and by setting the axial length L to be sufficiently larger than the thickness t2 of the wall portion 12, the measurement object 10 is arranged so that a first end 10A is exposed on the first space V1 side, and a second end 10B is exposed on the second space V2 side.

[0016] The measurement object 10 has a cylindrical shape that includes an internal space 14. This cylindrical shape may have a bottom, but in this embodiment, the measurement object 10 is configured as a so-called through sleeve so that the first space V1 and the second space V2 penetrate through the internal space 14. Although not shown in FIG. 1, wiring including a power cable, a communication cable, etc. can be laid in the internal space 14 between the first space V1 and the second space V2.

[0017] The first end 10A and the second end 10B of the measurement object 10 both have end faces that are approximately perpendicular to the axial direction of the cylindrical shape. That is, as shown in Fig. 1, when the measurement object 10 is arranged on the wall portion 12 so that the axial direction of the measurement object 10 is the Z direction, the end faces of the first end 10A and the second end 10B extend along the XY plane and are perpendicular to the Z direction.

[0018] Next, a description will be given of the measuring jig 20 used when measuring the measurement object 10 having the above configuration. Fig. 2 is a perspective view showing the measuring jig 20 according to one embodiment.

[0019] The measuring jig 20 includes a main body 22 on which a target marker 24 is provided. The target marker 24 is provided on a first surface 26 of the main body 22 that faces the measurement surface when the measuring jig 20 is attached to the measurement object 10, as described below. The target marker 24 is provided as a mark that can be distinguished from its surroundings when photographed, for example, by having at least one of a predetermined color, shape, reflectance, etc. In this embodiment, an example of the target marker 24 is a sticker-like mark that is attached to the main body 2 as a substantially circular symbol mark, but the form is not limited to this.

[0020] The main body 22 has a second surface 28 that is approximately perpendicular to the first surface 26 on which the target marker 24 is provided. The second surface 28 is provided at a position that contacts the measurement object 10 when the measurement jig 20 is attached to the measurement object 10 so that the target marker 24 faces the measurement surface. The main body 22 is provided with a fixing portion 38 for detachably fixing the measurement jig 20 to the measurement object 10. The measurement object 10 is made of a magnetic material such as metal, and the fixing portion 38 is configured as a magnet (e.g., a neodymium magnet) embedded in the main body 22. As a result, when the second surface 28 is attached so as to contact the measurement object 10, the measurement jig 20 can be detachably fixed to the measurement object 10 by the fixing portion 38.

[0021] The main body 22 also has a first extension portion 34 and a second extension portion 36 that extend from the center where the target marker 24 is provided along a first direction a and a second direction b that intersect with each other. In this embodiment, the first extension portion 34 and the second extension portion 36 intersect at an angle of approximately 90 degrees, but this intersecting angle may be any angle.

[0022] The body 22 has a flange 30 extending from the first surface 26 on the outer side (i.e., on the obtuse angle side of the intersection angle between the first extension portion 34 and the second extension portion 36). The flange 30 extends along a plane defined by the first direction a and the second direction b, similar to the first surface 26, and forms a step 32 together with a second surface 28 that is perpendicular to the plane. When the measuring jig 20 is attached to the measurement object 10 so that the second surface 28 is in contact with the measurement object 10, the step 32 engages with the end of the measurement object 10, thereby stabilizing the posture of the measuring jig 20.

[0023] It should be noted that the above-mentioned fixing portions 38 are provided in plurality so as to be embedded in the first extending portion 34 and the second extending portion 36 of the main body 22, but the layout of the fixing portions 38 is not limited thereto.

[0024] Next, a description will be given of a position measurement method for measuring the position of the measurement object 20 using such a measurement jig 20. Fig. 3 is a flowchart showing a position measurement method according to one embodiment. In the following description, a case where position measurement is performed from the first space V1 side will be exemplified, but unless otherwise specified, the same applies to a case where position measurement is performed from the second space V2 side.

[0025] First, at least three measuring jigs 20 are placed on the measurement object 10 (step S1). These measuring jigs 20 are placed with respect to the edge of the first end 10A of the cylindrical measurement object 10 on the first space V1 side so that the target marker 24 faces the measurement surface (i.e., the measuring jigs shown in FIG. 2 are placed so that the first surface 26, which is a plane defined by the first direction a and the second direction b, is parallel to the XY plane in FIG. 1). Each measuring jigs 20 has the configuration described above with reference to FIG. 2, and is placed so that the stepped portion 32 engages with the edge of the first end 10A, so that the target marker 24 faces the first space V1 side.

[0026] 4 and 5, several examples of installation of the measuring jig 20 in step S1 of Fig. 3 will be specifically described. Fig. 4 shows an example of installation of the measuring jig 20 for the measurement object 10 having a substantially circular cross section, and Fig. 5 shows an example of installation of the measuring jig 20 for the measurement object 10 having a substantially rectangular cross section.

[0027] 4, four measuring jigs 20 are installed relative to a first end 10A having a substantially circular end face. In particular, each measuring jig 20 is fixed to the inner circumferential surface of the first end 10A of the measurement object 10 by a magnet embedded in the main body 22 as a fixing portion 38, in an orientation in which the outer sides of the first extending portion 34 and the second extending portion 36 (i.e., the obtuse angle side of the intersection angle) face the inner circumferential surface of the measurement object 10. At this time, each measuring jig 20 is installed so that the step portion 32 engages with the end face of the first end 10A, thereby stabilizing its orientation.

[0028] 4 illustrates a case where the measuring jigs 20 are arranged at equal intervals from each other along the circumferential direction at the first end 10A of the measurement object 10, but at least some of them may be arranged at different intervals (preferably, the measuring jigs 20 are arranged evenly to the extent that there is no extreme deviation in the positions of the measuring jigs 20 in the circumferential direction). Also, while FIG. 4 illustrates a case where multiple measuring jigs 20 are installed along the inner circumferential edge on the first end 10A side of the measurement object 10, at least some of these measuring jigs 20 may be arranged along the outer circumferential edge.

[0029] In FIG. 5, four measuring jigs 20 are installed on a first end 10A having a substantially rectangular end face. In particular, each measuring jig 20 is fixed to the inner peripheral surface of the first end 10A of the measurement object 10 by a magnet embedded in the main body 22 as a fixing portion 38, in an orientation in which the outer sides of the first extension portion 34 and the second extension portion 36 (i.e., the obtuse angle side of the intersection angle) face the inner peripheral surface of the measurement object 10. At this time, the first extension portion 34 and the second extension portion 36 of the measuring jig 10 are arranged so as to be in contact along two adjacent sides that form corners of the substantially rectangular end face. At this time, each measuring jig 20 has a step portion 32 that engages with the end face of the first end 10A. The position is stabilized by being installed so that the two components fit together.

[0030] 3, the measurement object 10 on which the measuring jig 20 is placed is then photographed from one side together with the reference surface of the measurement object 10 (step S2). In this embodiment, the reference surface of the measurement object 10 is the first surface 12a of the wall portion 12 on which the measurement object 10 is placed, and the measurement object 10 is photographed so that the photographing range includes the measurement object 10 and at least a part of the reference surface (first surface 12a) from the side of the first space V1 on which the measuring jig 20 is placed. The photographed image includes the measurement object 10 as well as at least three position measuring jigs 20 placed on the measurement object 10.

[0031] In step S2, an imaging device such as a three-dimensional camera is used that can obtain image data that allows three-dimensional coordinates to be specified for each pixel of the captured image.

[0032] Next, imaging data is acquired for the image captured in step S2 (step S3), and the imaging data is subjected to image analysis (step S4). In step S4, the imaging data is analyzed to identify three-dimensional coordinates for the target markers 24 of each measuring jig 20 included in the image. These three-dimensional coordinates are identified as coordinates corresponding to a first coordinate system corresponding to the imaging data.

[0033] Next, the positions of the characteristic parts of the measurement object 10 are measured based on the position coordinates of each target marker 24 identified by the image analysis in step S4 (step S5). In step S5, the positions of the characteristic parts are geometrically calculated based on the position coordinates of each target marker 24 identified by the image analysis. The geometric calculation method used in step S5 is not limited.

[0034] The feature to be calculated in step S5 may be a first center position O1 at the first end. Here, with reference to FIGS. 4 and 5, several specific examples of the geometric calculation method in step S5 will be described. For example, FIG. 4 shows the target markers 24 of four measuring jigs 20 arranged at the first end 10A having a circular end face, as described above, and schematically illustrates how the first center position O1 is determined as the center of an approximate circle that is uniquely identified based on these target markers 24. Furthermore, FIG. 5 also shows the measuring jigs 20 arranged at the four corners of the rectangular end face, as described above, and schematically illustrates how the first center position O1 is identified as the point where two straight lines connecting two pairs of opposing target markers 24 intersect.

[0035] 5, similarly to FIG. 4, the first center position O1 may be identified based on an approximate circle that passes through each target marker 24.

[0036] Furthermore, the characteristic portion to be calculated in step S5 may be the second center position O2 of the second end portion 10B. In this case, the second center position O2 can be calculated using the above-mentioned first center position O1.

[0037] Fig. 6 is a schematic diagram showing a method for calculating the second center position O2 in step S5 of Fig. 3. The end face at the first end 10A can be identified based on at least three target markers 24 of the measurement jig 20. This end face can be identified based on three target markers 24, but by identifying it based on four target markers 24 as in this embodiment, the torsional component of the end face can also be evaluated, enabling more accurate measurement.

[0038] Next, a second center position C2 at the second end 10B is identified based on the end face at the first end 10A and the length L of the measurement object 10. Specifically, a position on a line L0 that is perpendicular to the end face at the first end 10A and passes through the first center position O1, and that is separated from the first center position O1 by the length L, is identified as the second center position O2.

[0039] Furthermore, the characteristic portion to be calculated in step S5 may be the inclination θ with respect to the measurement surface (first surface 12a) of the measurement object 10. For example, in FIG. 6, this inclination θ can be specified as the angle between the measurement surface (first surface 12a) and a straight line L0 connecting the first center position O1 and the second center position O2.

[0040] Next, the three-dimensional coordinates of the feature portion measured in step S5 in the first coordinate system are converted into the second coordinate system (step S6). The second coordinate system is the XYZ coordinate system shown in FIG.

[0041] Next, evaluation is performed by comparing the position coordinates of the characteristic parts transformed in step S6 with an allowable range (step S7). The mounting layout of the measurement object 10 relative to the wall 12 is specified in advance by design information, etc. In step S7, the position coordinates of the characteristic parts transformed in step S6 are compared with the allowable error specified based on such design information, etc., to evaluate whether the measurement object is properly mounted to the wall 12 based on the design information.

[0042] Next, the various evaluation results are output (step S8). The evaluation results output in step S8 may include, in addition to the evaluation results in step S7, various information such as the position coordinates of the characteristic parts of the measurement object that have been coordinate-transformed in step S6.

[0043] As described above, according to each of the above embodiments, the measurement object 10 placed on the wall portion 12 has a cylindrical shape, and at least three measuring jigs 20 are respectively installed so that the target markers 24 face the measurement surface. These measuring jigs 20 are photographed together with the reference surface (first surface 12a) of the measurement object 10 and the measurement object 10, thereby acquiring imaging data. The imaging data acquired in this manner includes the target markers 24 of the at least three measuring jigs 20 placed on the measurement object 10, and by analyzing the imaging data, it is possible to suitably measure any position of the measurement object 10 placed on the wall portion based on the positions of these target markers 24.

[0044] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0045] The contents described in each of the above embodiments can be understood, for example, as follows.

[0046] (1) A position measurement method according to one aspect includes: A position measurement method for measuring a position of a cylindrical measurement object placed on a wall portion, comprising: a step of placing at least three measurement jigs, each having a target marker, at different positions on a measurement surface side of the measurement object, with the target marker facing the measurement surface; acquiring imaging data by photographing the measurement object together with a reference surface of the measurement object and the at least three measurement jigs; Equipped with.

[0047] According to the above aspect (1), the measurement object placed on the wall has a cylindrical shape, and at least three measurement jigs are installed so that their target markers face the measurement surface. These measurement jigs are photographed together with the reference surface of the measurement object and the measurement object, thereby acquiring imaging data. The imaging data acquired in this manner includes the target markers of the at least three measurement jigs installed on the measurement object, and by analyzing the imaging data, it is possible to suitably measure any position on the measurement object installed on the wall based on the positions of these target markers.

[0048] (2) In another embodiment, in the above embodiment (1), specifying position coordinates of a feature portion of the measurement object in a first coordinate system based on the imaging data; determining a measurement result by transforming the position coordinates into a second coordinate system defined by the reference plane and a normal axis relative to the reference plane; Further provided with:

[0049] According to the above aspect (2), the position coordinates of the characteristic portion of the measurement object in the first coordinate system are identified based on the imaging data. The identified position coordinates can be used to suitably determine the position of the measurement object relative to the reference plane by converting the first coordinate system in the imaging data into a second coordinate system defined by the reference plane and a perpendicular axis of the reference plane.

[0050] (3) In another embodiment, in the above embodiment (2), The method further includes the step of determining whether the measurement result is within an allowable range.

[0051] According to the above aspect (3), by comparing the measurement results obtained as described above with an allowable range obtained, for example, based on the design information of the measurement object, the positioning of the measurement object relative to the measurement object surface can be suitably evaluated.

[0052] (4) In another embodiment, in the above embodiment (2), The characteristic portion includes a first center position on a first end face of the measurement object on the measurement surface side.

[0053] According to the above aspect (4), the first center position of the first end face on the measurement surface side of the measurement object can be suitably measured.

[0054] (5) In another embodiment, in the above embodiment (4), the measurement object is disposed so as to penetrate the wall portion, The characteristic portion includes the first center position and, based on design information of the measurement object, a second center position on a second end face of the measurement object that is on the opposite side of the wall portion from the first end face.

[0055] According to the above aspect (5), it is possible to suitably measure the second center position of the measurement object disposed so as to penetrate the wall portion, based on the first center position and design information.

[0056] (6) In another embodiment, in the above embodiment (5), The characteristic portion includes an inclination of the measurement object relative to the wall portion, which is specified by the first center position and the second center position.

[0057] According to the above aspect (6), the inclination of the measurement object relative to the wall portion can be suitably measured based on the first center position and the second center position.

[0058] (7) In another embodiment, in any one of the above (1) to (6), The at least three measurement jigs include four or more measurement jigs.

[0059] According to the above aspect (7), by installing at least four or more measuring jigs on the object to be measured, when uniquely identifying the plane on which the measuring jigs are installed based on the target markers of these measuring jigs, it is possible to take into account the torsion element of the plane, thereby enabling more accurate position measurement.

[0060] (8) In another embodiment, in any one of the above (1) to (7), The at least three measurement jigs are arranged on at least one of the inner periphery and the outer periphery of the end face of the object to be measured on the side of the measurement surface.

[0061] According to the above aspect (8), at least three measurement jigs are arranged on the inner or outer periphery of the end face of the cylindrical measurement object on the measurement surface side. By positioning the target marker near the periphery of the end face on the measurement surface side, the end face can be accurately identified, thereby enabling accurate position measurement of the measurement object.

[0062] (9) In another embodiment, in any one of the above (1) to (8), the measurement object has a cylindrical shape, The at least three measurement jigs are arranged at different positions along the periphery of the measurement object on the measurement surface side.

[0063] According to the above aspect (9), by placing at least three measurement jigs at different positions along the circumference of the measurement surface side of a cylindrically shaped measurement object, it is possible to suitably measure a cylindrically shaped measurement object.

[0064] (10) In another embodiment, in any one of the above (1) to (8), The measurement object has a rectangular cylindrical shape, The at least three measurement jigs are disposed at at least some corners of an end face of the measurement object on the measurement surface side.

[0065] According to the above aspect (10), by placing the measuring jig at at least a corner of the end face of the object to be measured having a rectangular cylindrical shape, the object to be measured having a rectangular cylindrical shape can be suitably measured.

[0066] (11) A measuring jig according to one aspect includes: A measurement jig used to measure the position of a cylindrical measurement object placed on a wall portion, a main body having a first surface on which a target marker is provided, and a second surface that faces the measurement object when the main body is placed on the measurement object so that the target marker faces the measurement surface; a flange portion extending from the main body along the measurement surface and forming a step portion between the main body and the second surface; a fixing portion for detachably fixing the main body to the measurement object; Equipped with.

[0067] According to the above aspect (11), the main body of the measuring jig has a flange extending from the first surface on which the target marker is provided along the measurement surface, thereby forming a step between the first surface and the second surface facing the measurement object when the measuring jig is attached. As a result, by positioning the measuring jig so that the step engages with the periphery of the measurement surface side of the measurement object, it is possible to take an image while stably maintaining the posture of the measuring jig attached to the measurement object, and thereby it is possible to preferably acquire the above-mentioned image data.

[0068] (12) In another embodiment, in the above embodiment (11), the main body has a first extension portion and a second extension portion extending from a central portion where the target marker is provided along a first direction and a second direction that intersect with each other, The flange portion is provided along an edge portion of the main body on the side where the intersection angle between the first extension portion and the second extension portion is obtuse.

[0069] According to the above aspect (12), the flange that forms the step portion together with the second surface is set so that the intersection angle between the first extending portion and the second extending portion of the main body is on the obtuse side. As a result, when the measuring jig is placed so that the step portion engages with the periphery of the measurement object, the flange is suitably fitted to the periphery of the measurement object, and the posture of the measuring jig can be stably maintained.

[0070] (13) In another embodiment, in the above embodiment (11) or (12), The fixed portion is at least one magnet embedded in the body portion.

[0071] According to the above aspect (13), by using a magnet embedded in the main body as the fixing part, the measurement jig can be detachably fixed to the measurement object. This makes it possible to easily detach the measurement jig from the measurement object, while stably fixing the position of the target marker during measurement, thereby enabling accurate position measurement. [Explanation of symbols]

[0072] 10 Measurement object 10A 1st end 10B 2nd end 12 Wall 12a 1st surface (measurement surface) 12b Side 2 14 Interior Space 20 Measuring fixture 22 Main Unit 24 Target Marker 26 Page 1 28 Side 2 30 Collar 32 Step 34 1st extension part 36 Second extension part 38 Fixed part V1 1st space V2 2nd space O1 1st center position O2 2nd center position

Claims

1. A position measurement method for measuring a position of a cylindrical measurement object placed on a wall portion, comprising: a step of placing at least three measurement jigs, each having a target marker, at different positions on a measurement surface side of the measurement object, with the target marker facing the measurement surface; acquiring imaging data by photographing the measurement object together with a reference surface of the measurement object and the at least three measurement jigs; A position measurement method comprising:

2. specifying position coordinates of a characteristic portion of the measurement object in a first coordinate system based on the imaging data; determining a measurement result by transforming the position coordinates into a second coordinate system defined by the reference plane and a normal axis relative to the reference plane; The position measurement method according to claim 1 , further comprising:

3. The position measurement method according to claim 2 , further comprising the step of determining whether the measurement result is within an allowable range.

4. The position measuring method according to claim 2 , wherein the characteristic portion includes a first center position of a first end face of the measurement object that is on the measurement surface side.

5. the measurement object is disposed so as to penetrate the wall portion, 5. The position measurement method according to claim 4, wherein the characteristic portion includes the first center position and a second center position on a second end face of the measurement object that is on the opposite side of the wall portion from the first end face based on design information of the measurement object.

6. The position measurement method according to claim 5 , wherein the characteristic portion includes an inclination of the measurement object with respect to the wall portion, the inclination being specified by the first center position and the second center position.

7. The position measuring method according to claim 1 , wherein the at least three measuring jigs include four or more measuring jigs.

8. 3. The position measuring method according to claim 1, wherein the at least three measuring jigs are arranged on at least one of an inner periphery and an outer periphery of an end face of the measurement object on the side of the measurement surface.

9. the measurement object has a cylindrical shape, The position measuring method according to claim 1 or 2, wherein the at least three measuring jigs are arranged at different positions along a periphery of the measurement object on the measurement surface side.

10. The measurement object has a rectangular cylindrical shape, The position measuring method according to claim 1 , wherein the at least three measuring jigs are arranged at at least some corners of an end face of the measurement object on the side of the measurement surface.

11. A measurement jig used to measure the position of a cylindrical measurement object placed on a wall portion, a main body having a first surface on which a target marker is provided, and a second surface that faces the measurement object when the main body is placed on the measurement object so that the target marker faces the measurement surface; a flange portion extending from the main body along the measurement surface and forming a step portion between the main body and the second surface; a fixing portion for detachably fixing the main body to the measurement object; A measurement jig comprising:

12. the main body has a first extending portion and a second extending portion extending from a central portion where the target marker is provided along a first direction and a second direction that intersect with each other, The measurement jig according to claim 11 , wherein the flange portion is provided along an edge portion of the main body on the side where the intersection angle between the first extension portion and the second extension portion is obtuse.

13. The measuring jig according to claim 11 or 12, wherein the fixing portion is at least one magnet embedded in the main body portion.

Images