Three-dimentional measuring system, reference axis direction calculation method therefor, reference axis direction calculation fixture, and measuring method and measuring fixture in 3D measuring system

Abstract

To acquire high-accuracy point group data or 3D data.SOLUTION: A correction processing fixture 200 including a first sphere 210, a second sphere 220 and sphere position maintaining means that maintains a relative position between the first sphere 210 and the second sphere 220 is arranged in a real space. Upon measurement by a 3D scanner 200, point group data including the correction processing fixture 200 is acquired. A point group processing device 300 corrects a virtual space coordinate system so that a virtual line connecting between the center of the first sphere 210 and the center of the second sphere 220 is parallel to a reference axis in the virtual space coordinate system of the point group data or 3D data.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a 3D measurement system that acquires point cloud data using a portable 3D measurement device and generates 3D data of a measurement target from the point cloud data. [Background technology]

[0002] In recent years, 3D measurement devices called laser 3D scanners have become popular in surveying sites (see Patent Document 1). Laser 3D scanners measure distances by measuring the time it takes for a laser to travel back and forth between the object and the scanner, and obtain point cloud data consisting of a large number of three-dimensional coordinates based on the direction of the laser irradiation. This point cloud data is transferred to a computer and converted into a 3D model as necessary, so that it can be used in 3D CAD and other applications. In the fields of civil engineering and architecture, stationary laser 3D scanners with tripods are often used.

[0003] However, surveying with a stationary laser 3D scanner has the following problems when measuring existing structures. When measuring existing structures, the measurement target is often in the way of obstacles, which limits where the stationary laser 3D scanner can be installed or makes it impossible to measure parts of the structure. One way to solve these problems would be to temporarily set up scaffolding around the existing structure, but this type of work requires a great deal of cost.

[0004] Meanwhile, portable 3D scanners have appeared in recent years (see Patent Document 2). Portable 3D scanners are carried by users or mounted on a means of transportation such as a small unmanned aerial vehicle (UAV) called a drone. Portable 3D scanners recognize their own position and orientation using an inertial measurement unit (IMU), and can acquire point cloud data over a wide measurement range by combining point cloud data obtained by scanning at any time while moving. The principle of calculating point cloud data in portable 3D scanners includes, as with the above-mentioned laser 3D scanner, a method based on the round-trip time of a laser, a method based on a stereo image acquired by a camera, a method based on a predetermined pattern of stripe images projected by a laser projector and calculated from the image acquired by a camera, and the like. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-045150 A [Patent Document 2] Patent Publication No. 2022-074298 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is a problem that the point cloud data acquired by a portable 3D scanner is not accurate enough. This is because a portable 3D scanner recognizes its own position and orientation using an inertial measurement unit, but the accuracy of this inertial measurement unit is not sufficient, and errors accumulate when combining point cloud data from multiple scans. This causes a misalignment between the virtual space and real space of the point cloud data obtained by combining, and there is a problem that it is not possible to recognize which direction is appropriate as the reference axis direction (e.g., vertical direction) for the point cloud data. For example, even if there is an accurately vertical ridgeline in real space, it may be tilted from the vertical axis in virtual space.

[0007] In general, in order to accurately measure the structure of a recess that is recessed from the surface of a structure, when using a 3D scanner, it is necessary to place a measuring device facing the bottom of the recess in a location where the entire recess can be observed. For example, in the field of bridges, many anchor holes are formed in concrete blocks to drive anchor bolts into them, and it is sometimes necessary to measure whether the depth direction (i.e., the axial direction) of these anchor holes is accurately aligned in a specified direction (typically vertical). To perform this measurement using a 3D scanner, it is necessary to move and install a measuring device for each anchor hole and perform the measurement work one by one, which is extremely inefficient and unrealistic.

[0008] The present invention has been made in view of the above circumstances, and its first object is to provide a 3D measurement system capable of acquiring highly accurate point cloud data or 3D data, a reference axis direction calculation method thereof, and a reference axis direction calculation tool. Also, its second object is to provide a 3D measurement system capable of measuring the depth direction of a hole into which a rod-shaped member is inserted, a measurement method thereof, and a measurement tool. [Means for solving the problem]

[0009] In order to achieve the above-mentioned first object, the present invention provides a method for calculating the direction of a reference axis in a virtual space in a 3D measurement system that scans a real space including a measurement target using a portable 3D measurement device to obtain point cloud data and generates 3D data of the measurement target from the point cloud data, the method including a first step of placing a jig in the real space, the jig including a first sphere having a spherical surface of a constant radius from the center, a second sphere having a spherical surface of a constant radius from the center, and a sphere position maintenance means for maintaining the relative positions of the first sphere and the second sphere; a second step of acquiring point cloud data including the jig placed in the real space by the 3D measurement device; and a third step of calculating the direction of a virtual line connecting the center of the first sphere and the center of the second sphere in the virtual space and setting the direction as the direction of the reference axis in the virtual space.

[0010] In addition, in order to achieve the above-mentioned first object, the present invention provides a 3D measurement system that scans a real space including a measurement target using a portable 3D measurement device to acquire point cloud data, and generates 3D data of the measurement target from the point cloud data, and is characterized in that the system includes a jig that includes a first sphere having a spherical surface of a constant radius from its center, a second sphere having a spherical surface of a constant radius from its center, and a sphere position maintenance means that maintains the relative positions of the first sphere and the second sphere, a point cloud data acquisition unit that acquires point cloud data including the jig placed in the real space by the 3D measurement device in a virtual space, and a reference axis direction calculation unit that calculates the direction of a virtual line connecting the center of the first sphere and the center of the second sphere, and sets the direction of the reference axis in the virtual space.

[0011] In addition, in order to achieve the above-mentioned first object, the present invention provides a 3D measurement system that scans a real space including a measurement object using a portable 3D measurement device to obtain point cloud data and generates 3D data of the measurement object from the point cloud data, the jig being used in a process of calculating the direction of a reference axis in a virtual space, the jig comprising: a first sphere having a spherical surface with a constant radius from the center; a second sphere having a spherical surface with a constant radius from the center; and a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere.

[0012] In order to achieve the second object, the present invention provides a 3D measurement system including a 3D measurement device that scans a real space including a measurement object to obtain point cloud data, and a point cloud processing device that processes the point cloud data, and a method for measuring a depth direction of a hole that is formed in the measurement object and into which a rod-shaped member is inserted, the method including: a first sphere having a spherical surface with a constant radius from the center; a second sphere having a spherical surface with a constant radius from the center; sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere; The method includes a first step of inserting an end of a rod of a jig, the rod being arranged so that its central axis is parallel to a virtual line connecting the centers of the first and second spheres, into a hole formed in the object to be measured; a second step of acquiring point cloud data including the jig arranged in the real space by the 3D measuring device; and a third step of calculating the direction of a virtual line connecting the centers of the first and second spheres as the depth direction of the hole based on the point cloud data or 3D data generated from the point cloud data.

[0013] In order to achieve the second object, the present invention provides a 3D measurement system including a 3D measurement device that scans a real space including a measurement target to acquire point cloud data, the system including a jig including a first sphere having a spherical surface of a constant radius from a center, a second sphere having a spherical surface of a constant radius from a center, a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere, and a rod body arranged so that its central axis is parallel to a virtual line connecting the center of the first sphere and the center of the second sphere, a point cloud data acquisition unit that acquires point cloud data including the jig by the 3D measurement device while an end of the rod body of the jig is inserted into a hole formed in the measurement target in the real space and into which a rod-shaped member is inserted, and a depth direction calculation unit that calculates the direction of a virtual line connecting the center of the first sphere and the center of the second sphere as the depth direction of the hole based on the point cloud data or 3D data generated from the point cloud data.

[0014] In addition, in order to achieve the second object, the present invention provides a 3D measurement system comprising a 3D measurement device that scans a real space including a measurement object to obtain point cloud data, and a point cloud processing device that processes the point cloud data, comprising a jig used to measure the depth direction of a hole formed in the measurement object and into which a rod-shaped member is inserted, the jig comprising a first sphere having a spherical surface of a constant radius from the center, a second sphere having a spherical surface of a constant radius from the center, a sphere position maintenance means that maintains the relative positions of the first sphere and the second sphere, and a rod body arranged so that its central axis is parallel to a virtual line connecting the center of the first sphere and the center of the second sphere, and the end of the rod body is inserted into the hole formed in the measurement object and into which a rod-shaped member is inserted. Effect of the Invention

[0015] According to the present invention, by arranging the virtual line connecting the center of the first sphere and the center of the second sphere so as to be parallel to a predetermined reference axis in the real space, the reference axis direction in the real space can be made parallel to the reference axis direction in the virtual space coordinate system of the point cloud data or 3D data. In other words, the deviation between the real space and the virtual space can be eliminated. Therefore, the point cloud data or 3D data has high accuracy.

[0016] Furthermore, according to the present invention, the end of the rod body of the measuring jig is inserted into a hole formed in the measurement object into which a rod-shaped member is inserted, and measurement is then performed in this state using a 3D measuring device, thereby making it possible to measure the depth direction of the hole. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a configuration diagram of a 3D measurement system according to a first embodiment. [Diagram 2] 3D scanner function block diagram [Diagram 3] Side view of the reference axis direction calculation jig [Figure 4] Functional block diagram of point cloud processing device [Diagram 5] FIG. 13 is a conceptual diagram illustrating a reference axis direction calculation process in a point cloud processing device. [Figure 6] Flowchart explaining the measurement process in the 3D measurement system [Figure 7] 13 is a side view of a reference axis direction calculation jig according to a second embodiment. [Figure 8] FIG. 13 is a configuration diagram of a 3D measurement system according to a third embodiment. [Figure 9] Side view of the measurement jig [Figure 10] AA cross-sectional view of FIG. 9 illustrating the rod body. [Figure 11] Functional block diagram of a point cloud processing device according to a third embodiment [Figure 12] FIG. 13 is a diagram for explaining a modified example of a method for arranging a reference axis direction calculation jig; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] (First embodiment) A 3D measurement system according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a configuration diagram of the 3D measurement system, Fig. 2 is a functional block diagram of a 3D scanner, Fig. 3 is a side view of a reference axis direction calculation jig, Fig. 4 is a functional block diagram of a point cloud processing device, Fig. 5 is a conceptual diagram explaining the reference axis direction calculation process in the point cloud processing device, and Fig. 6 is a flowchart explaining the flow of measurement process in the 3D measurement system.

[0019] The 3D measurement system according to this embodiment includes a 3D scanner 100 carried by a measurer 1, a reference axis direction calculation jig 200, and a point cloud processing device 300, as shown in FIG.

[0020] The 3D scanner 100 is a portable, non-contact 3D measuring device. The 3D scanner 100 is equipped with an inertial measurement device and a 3D measurement mechanism, and acquires and outputs point cloud data over a wide range by having a measurer 1 perform measurements while changing the measurement position and direction. Here, since the 3D scanner 100 is equipped with an inertial measurement device, the virtual space coordinate system of the point cloud data coincides with the real world space coordinate system with at least the Z axis, i.e., the vertical direction, with a predetermined accuracy. In addition, the directions of the virtual space coordinate system and the real world space coordinate system can also be matched with a predetermined accuracy with respect to the X axis and Y axis by initial settings before measurement.

[0021] The 3D scanner 100 repeatedly performs a process of scanning a measurement area relative to its own position and direction during a period from the start of measurement to the end of measurement, and generating point cloud data of the measurement area. The 3D scanner 100 performs a matching process for matching (aligning) multiple point cloud data during the measurement period or after the end of measurement. The 3D scanner 100 regards the point cloud data that has been subjected to the matching process as the measurement result. The 3D scanner 100 stores the measurement result in a predetermined storage medium or outputs it to an external device.

[0022] There is no question about the measurement principle of the 3D scanner 100. In this embodiment, a 3D measurement device of a stripe light source projection method using a laser light source is used. Specifically, as shown in FIG. 2, the 3D scanner 100 includes a laser irradiation unit 101, a camera 102, a point cloud generation unit 103, a point cloud combination unit 104, a point cloud data storage unit 110, an inertial measurement unit 120, a communication interface unit 131, and a storage medium reader / writer unit 132.

[0023] During the measurement period, the 3D scanner 100 uses the laser irradiation unit 101 to project a predetermined pattern (e.g., a striped pattern) onto the measurement target 5, and captures the pattern projected onto the measurement target 5 with the camera 102 to obtain a pattern image. The point cloud generation unit 103 generates point cloud data from at least two pattern images captured from different positions during the measurement period or after the measurement is completed, using a structure from motion (SfM) method. In addition, the point cloud combination unit 104 performs a matching process for matching (aligning) multiple point cloud data during the measurement period or after the measurement is completed. The matched point cloud data is stored in the point cloud data storage unit 110, and can be output to an external device via the communication interface unit 131 or stored in a removable storage medium attached to the storage medium reader / writer unit 132, as necessary.

[0024] In such a portable 3D scanner 100, as described above, a matching process is performed to match (align) a plurality of point cloud data measured at different measurement positions and directions during a measurement period. In this matching process, feature points of the measurement target 5 included in the point cloud data are extracted, and the coordinate conversion of the point cloud data is performed so that the coordinates of the feature points match. However, since the detection accuracy of the position and direction by the inertial measurement unit 120 is not necessarily high enough, detection errors of the position and direction accumulate during the measurement period. For this reason, there is a problem that the point cloud data related to the measurement target 5 is shifted in the virtual space due to the matching process. For example, consider that there are two pillars that are accurately erected vertically in the real space that is the measurement area. If the portable 3D scanner 100 performs measurement while moving so that both pillars are included in the measurement area in one measurement, an event occurs in which one pillar is vertical in the virtual space but the other pillar is slightly tilted, or both pillars are tilted in the virtual space, in the point cloud data after the matching process.

[0025] The present invention aims to eliminate the above-mentioned deviation by calculating an appropriate reference axis in virtual space, i.e., a reference axis that coincides with real space, and applying this to the virtual space. (1) As shown in FIG. 1, a reference axis direction calculation jig 200 is placed in the measurement area, and point cloud data including the reference axis direction calculation jig 200 along with the measurement target 5 is obtained during the measurement period using the 3D scanner 100, and (2) a reference axis in the virtual space is calculated in a point cloud processing device 300, thereby eliminating the above-mentioned deviation in the virtual space.

[0026] 3, the reference axis direction calculation jig 200 includes a first sphere 210, a second sphere 220, a first hanging string 230 that connects the first sphere 210 to the second sphere 220 and suspends the second sphere 220 from the first sphere 210, a second hanging string 240 that suspends the first sphere 210 at an arbitrary location in real space, a weight 250, and a third hanging string 260 that connects the second sphere 220 to the weight 250 and suspends the weight 250 from the second sphere 220. Each component of the reference axis direction calculation jig 200 can be made detachable as desired.

[0027] The first sphere 210 and the second sphere 220 are each a sphere having a spherical surface with a certain radius from the center. The first sphere 210 and the second sphere 220 may be hollow or solid. The material of the first sphere 210 and the second sphere 220 is not important. For example, they can be made of resin, wood, or metal.

[0028] The connection position of second suspension string 240 in first sphere 210 is the pole (here referred to as the north pole) of first sphere 210. The connection position of first suspension string 230 in first sphere 210 is the pole (here referred to as the south pole) opposite the north pole of first sphere 210. The position of the center of gravity of first sphere 210 is preferably on an axis connecting at least the north pole and the south pole, and more preferably is the center of first sphere 210.

[0029] The connection position of first suspension string 230 in second sphere 220 is the pole (here referred to as the north pole) of second sphere 220. The connection position of third suspension string 260 in second sphere 220 is the pole (here referred to as the south pole) opposite the north pole of second sphere 220. The position of the center of gravity of second sphere 220 is preferably on an axis connecting at least the north pole and the south pole, and more preferably is the center of second sphere 220.

[0030] The diameters of the first sphere 210 and the second sphere may be the same or different, and the weights of the first sphere 210 and the second sphere may be the same or different.

[0031] The first hanging string 230, the second hanging string 240, and the third hanging string 260 are preferably light in weight, and in particular, are preferably sufficiently lighter than the total weight of the first sphere 210, the second sphere 220, and the weight 250, and are further preferably sufficiently lighter than the weight of the weight 250. The first hanging string 230, the second hanging string 240, and the third hanging string 260 may be made of any material. For example, they may be made of synthetic fiber, metal, or the like. An attachment (not shown) such as a hook for attachment to an arbitrary structure is attached to the end of the second hanging string 240 on the side opposite to the connection side with the first sphere 210. Instead of the attachment, the end of the second hanging string 240 may be processed into a loop shape so that it can be hooked on an arbitrary structure. FIG. 1 shows a state in which the reference axis direction calculation jig 200 is attached to the mounting base 2.

[0032] The weight 250 is for stabilizing the posture of the first sphere 210 and the second sphere 220. The weight of the weight 250 is preferably heavier than the second sphere 220, and more preferably heavier than the total weight of the first sphere 210 and the second sphere 220.

[0033] The first hanging string 230, the second hanging string 240, the third hanging string 260, and the weight 250 function as a sphere position maintaining means for maintaining the relative positions of the first sphere 210 and the second sphere 220 in real space. More specifically, the first hanging string 230, the second hanging string 240, the third hanging string 260, and the weight 250 function as a sphere position maintaining means for utilizing gravity to maintain a state in which a virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is arranged parallel to the vertical axis, which is one of the reference axes in real space.

[0034] In this embodiment, the first sphere 210 is suspended from the fixture attached to the second hanging string 240 by fixing it to an arbitrary location in real space, and is suspended from the second sphere 220. Since the weight 250 is suspended from the second sphere 220, the position of the second sphere 220 is stably maintained. As a result, the positions of the first sphere 210 and the second sphere 220 are stably maintained in a state in which the direction connecting the centers of the first sphere 210 and the second sphere 220 is vertical in real space.

[0035] The lengths of the first hanging string 230, the second hanging string 240, and the third hanging string 260 are preferably adjusted so that the positional relationship between the first sphere 210 and the second sphere 220 is stable as described above. In addition, the length of the first hanging string 230, that is, the distance between the first sphere 210 and the second sphere 220, is preferably adjusted so that the reference axis direction calculation process described later can be properly performed according to the width of the measurement area, the measurable range of the 3D scanner 100, and the like. In the portable stripe pattern projection type 3D scanner 100 used in this embodiment, if the projection target is lost during scanning, the position of the scanner itself may be lost, and accurate measurement may not be possible. For this reason, it is preferable to appropriately adjust the length of the first hanging string 230 from this viewpoint. In addition, the first hanging string 230, the second hanging string 240, and the third hanging string 260 can be configured so that their lengths can be changed as necessary.

[0036] In the reference axis direction calculation process in the point cloud processing device 300 described later, point cloud data measured on the first sphere 210 and the second sphere 220 is used. For this reason, in order to stably perform the calculation process, it is preferable that the surfaces of the first sphere 210 and the second sphere 220 are plain. It is also preferable that the surfaces of the first sphere 210 and the second sphere 220 have a stable reflectance, such as white. The color of the surfaces of the first sphere 210 and the second sphere 220 does not matter.

[0037] On the other hand, the point cloud data obtained by measuring the first hanging thread 230, the second hanging thread 240, the third hanging thread 260, and the weight 250 is not used in the reference axis direction calculation process. Therefore, it is preferable that the thickness of the first hanging thread 230, the second hanging thread 240, and the third hanging thread 260 and the size of the weight 250 are sufficiently smaller than the first sphere 210 and the second sphere 220. In addition, it is preferable that the thickness of the first hanging thread 230, the second hanging thread 240, and the third hanging thread 260 is thin enough that they cannot be sufficiently recognized in the 3D scanner 100 due to the resolution. Alternatively, it is preferable that the first hanging thread 230, the second hanging thread 240, the third hanging thread 260, and the weight 250 are of a color that cannot be sufficiently recognized in the 3D scanner 100. For example, it is preferable that they are formed from a transparent member. Alternatively, it is preferable that the colors of the first hanging thread 230, the second hanging thread 240, the third hanging thread 260, and the weight 250 are lower in density than those of the first sphere 210 and the second sphere 220. On the other hand, from the viewpoint of loss during scanning as described above, it is preferable that the first hanging thread 230, the second hanging thread 240, the third hanging thread 260, and the weight 250 are set to a size, color, etc. that can be prevented from being lost during scanning, that is, that can be reliably recognized by the 3D scanner 100. For example, it is preferable to give a pattern with many characteristic points, such as a camouflage pattern. From the above multiple viewpoints, the size, color, etc. of the first hanging thread 230, the second hanging thread 240, the third hanging thread 260, and the weight 250 may be appropriately set according to the measurement environment, the specifications of the 3D scanner 100, etc.

[0038] Next, the point cloud processing device 300 will be described. The point cloud processing device 300 can be configured by a conventionally known computer equipped with a main processing unit, a main memory unit, an auxiliary memory unit, an input device, an output device, a communication device, and the like. The point cloud processing device 300 can be implemented by installing a program in the computer. The point cloud processing device 300 can also be implemented as dedicated hardware. The point cloud processing device 300 can be implemented in a distributed manner on multiple computers.

[0039] The point cloud processing device 300 includes a point cloud data acquisition unit 310, a reference axis direction calculation unit 320, and a 3D data generation unit 330, as shown in FIG.

[0040] The point cloud data acquisition unit 310 acquires point cloud data from the 3D scanner 100. The data acquisition method is not limited. For example, a communication path can be established between the point cloud processing device 300 and the 3D scanner 100, and the point cloud data can be received from the 3D scanner 100. Also, for example, the point cloud data can be stored in a portable storage medium in the 3D scanner 100, and the storage medium can be attached to an interface (not shown) of the point cloud processing device 300 to acquire the point cloud data from the storage medium.

[0041] Fig. 5 shows a conceptual diagram for explaining the processing by the reference axis direction calculation unit 320. Fig. 5 shows the point cloud data with the camera facing the Y-axis direction for ease of explanation, Fig. 5(a) shows the point cloud data acquired from the 3D scanner 100, and Fig. 5(b) shows the point cloud data rotated based on the calculated reference axis direction. In the figure, reference numeral 11 denotes a point cloud corresponding to the first sphere 210, reference numeral 12 denotes a point cloud corresponding to the second sphere 220, reference numeral 21 denotes a point cloud corresponding to the measurement target 5, and reference numeral 31 denotes a virtual line connecting the center of the first sphere 210 and the center of the second sphere 220.

[0042] The reference axis direction calculation unit 320 calculates the direction of the reference axis in the virtual space from the point cloud data including the reference axis direction calculation jig 200 so that the deviation of the virtual space related to the point cloud data can be eliminated. Specifically, the reference axis direction calculation unit 320 first detects the locations corresponding to the first sphere 210 and the second sphere 220 from the point cloud data. That is, the reference axis direction calculation unit 320 detects a spherical object from the point cloud data. Next, the reference axis direction calculation unit 320 calculates the center points of the first sphere 210 and the second sphere 220.

[0043] Next, the reference axis direction calculation unit 320 calculates the direction of a virtual line 31 connecting the center of the first sphere 210 and the center of the second sphere 220 in a virtual space coordinate system related to the point cloud data as a vertical axis (Z axis) direction, which is one of the reference axes of the virtual space coordinate system. Thereafter, when processing the point cloud data, the reference axis direction is treated as the calculated reference axis direction, thereby eliminating the deviation of the virtual space related to the point cloud data. In order to perform such processing, the reference axis direction calculation unit 320 can perform a setting process so that the calculated reference axis direction becomes the reference axis direction of the virtual space coordinate system of the point cloud data. For example, the direction of the virtual line 31 can be set for the point cloud data as metadata indicating the vertical axis direction of the virtual space.

[0044] The 3D data generating unit 330 converts the point cloud data set and processed by the reference axis direction calculating unit 320 into 3D model data in a predetermined format. The format of the 3D model data is not important.

[0045] The point cloud data (raw point cloud data) acquired by the point cloud data acquisition unit 310, the point cloud data (processed point cloud data) set and processed by the reference axis direction calculation unit 320, the reference axis direction calculated by the reference axis direction calculation unit 320, and the 3D model data generated by the 3D data generation unit 330 can be stored in a storage device (not shown) or output to an external computer as necessary. Furthermore, the point cloud processing device 300 may include a display control unit that displays the raw point cloud data, the processed point cloud data, and the 3D model data on a two-dimensional display unit (not shown).

[0046] A 3D measurement processing method in the 3D measurement system according to the present embodiment will be described. First, the reference axis direction calculation jig 200 is placed in the measurement area (step S1). Next, the 3D scanner 100 is used to perform measurement so that the reference axis direction calculation jig 200 is included together with the measurement target 5, thereby acquiring point cloud data including the reference axis direction calculation jig 200 (step S2). Then, the point cloud processing device 300 performs a calculation process for the reference axis direction in the virtual space (step S3). In this calculation process, a virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is calculated, and the virtual space coordinate system is set so that the direction of this virtual line is parallel to the direction of the vertical axis in the virtual space coordinate system of the point cloud data.

[0047] In this way, according to the 3D measurement system of this embodiment, by arranging the reference axis direction calculation jig 200 so that the virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is parallel to a predetermined reference axis in real space, the direction of the reference axis in real space and the direction of the reference axis in the virtual space coordinate system of the point cloud data can be made parallel. In other words, the deviation between the real space and the virtual space can be eliminated. Therefore, the point cloud data and the 3D model data can be highly accurate.

[0048] (Second embodiment) A 3D measurement system according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 7 is a side view of a reference axis direction calculation jig. This embodiment differs from the first embodiment in the structure of the reference axis direction calculation jig and the associated reference axis direction calculation process. Other configurations and operations are the same as those of the first embodiment, so only the differences will be described here.

[0049] The reference axis direction calculating jig 200' according to this embodiment differs from the reference axis direction calculating jig 200 according to the first embodiment in the sphere position maintaining means for maintaining the relative positional relationship between the first sphere 210 and the second sphere 220. That is, in the first embodiment, the relative position between the first sphere 210 and the second sphere 220 is maintained by suspending them from the first sphere 210. On the other hand, in this embodiment, in order to maintain the relative positional relationship between the first sphere 210 and the second sphere 220, the two are connected and fixed in a state where the relative positional relationship between them is maintained. The structure of the reference axis direction calculating jig 200 will be described in detail below.

[0050] 7, the reference axis direction calculating jig 200' includes a first sphere 210, a second sphere 220, a connecting rod 270 connecting the first sphere 210 and the second sphere 220, and a fixture 280 for fixing the reference axis direction calculating jig 200' to an arbitrary position in the measurement region space. The first sphere 210 and the second sphere 220 are similar to those in the first embodiment.

[0051] The connecting rod 270 functions as a sphere position maintaining means for maintaining the relative positions of the first sphere 210 and the second sphere 220. The connecting rod 270 is made of a rod-shaped member whose axis passes through the centers of the first sphere 210 and the second sphere 220.

[0052] The length of the connecting rod 270, i.e., the distance between the first sphere 210 and the second sphere 220, is preferably adjusted so that the reference axis direction calculation process described later can be appropriately performed according to the size of the measurement area, the measurable range of the 3D scanner 100, etc. Furthermore, the connecting rods 270 can be configured so that their lengths can be changed as necessary. Furthermore, the connecting rods 270 preferably have a strength sufficient to prevent them from bending due to the weight of the first sphere 210 and the second sphere 220.

[0053] The fixture 280 is a jig for arranging and fixing the first sphere 210 and the second sphere 220 so that a virtual line connecting the centers of the first sphere 210 and the second sphere 220 is in a predetermined direction in real space while the relative positional relationship between the first sphere 210 and the second sphere 220 is maintained by the connecting rod 270. Here, the predetermined direction can be any direction, but it is preferably a horizontal direction or a vertical direction from the viewpoint of reliability and ease of arrangement in real space and ease of calculation of the reference axis direction calculation process. In this embodiment, the fixture 280 is a jig for arranging and fixing the first sphere 210 and the second sphere 220 so that a virtual line connecting the centers of the first sphere 210 and the second sphere 220 is in the horizontal direction in real space.

[0054] It is preferable that the fixture 280 is connected to the connecting rod 270 without being connected to the first sphere 210 and the second sphere 220. This is because it is preferable that the fixture 280 is not located near each sphere from the viewpoint of improving the recognition accuracy of the first sphere 210 and the second sphere 220 in the reference axis direction calculation process at a later stage. In this embodiment, the fixture 280 includes a pillar 281 rotatably connected to the center of the connecting rod 270, and a support base 282 provided at the lower end of the pillar 281.

[0055] As in the first embodiment, in the reference axis direction calculation process in the point cloud processing device 300, point cloud data obtained by measuring the first sphere 210 and the second sphere 220 is used. On the other hand, point cloud data obtained by measuring the connecting rod 270 and the fixture 280 is not used in the calculation process. Therefore, the thickness of the connecting rod 270 is preferably thin within a range in which strength can be maintained, from the viewpoint of improving the recognition accuracy of the first sphere 210 and the second sphere 220 in the calculation process at the later stage. The connecting rod 270 and the fixture 280 are preferably of a color that cannot be sufficiently recognized by the 3D scanner 100. For example, it is preferable to form them from a transparent member. Alternatively, it is preferable that the color of the connecting rod 270 and the fixture 280 is lower in density than that of the first sphere 210 and the second sphere 220. On the other hand, from the viewpoint of the above-mentioned loss during scanning, it is preferable to set the size, color, etc. of the connecting rod 270 and the fixing device 280 so as to prevent loss during scanning, that is, so that the 3D scanner 100 can reliably recognize them. For example, it is preferable to give them a pattern with many characteristic points, such as a camouflage pattern. The size, color, etc. of the connecting rod 270 and the fixing device 280 may be appropriately set from the above-mentioned multiple viewpoints.

[0056] In the 3D measurement processing method in the 3D measurement system according to this embodiment, first, the reference axis direction calculation jig 200 is placed in the measurement area, as in the first embodiment. Specifically, the reference axis direction calculation jig 200 is placed on a substantially horizontal location, such as the top surface of a structure in the measurement area. Then, the connection angle between the connection rod 270 and the fixture 280 is adjusted so that the virtual line connecting the centers of the first sphere 210 and the second sphere 220 is horizontal, that is, so that the connection rod 270 is horizontal. In this adjustment process, a conventionally known spirit level can be used.

[0057] Next, the 3D scanner 100 is used to perform measurement so that the reference axis direction calculation jig 200 is included together with the measurement target 5, thereby acquiring point cloud data including the reference axis direction calculation jig 200. Then, the point cloud processing device 300 performs a calculation process of the reference axis direction in the virtual space. In this calculation process, a virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is calculated, and the virtual space coordinate system is set so that the direction of this virtual line is parallel to the direction of the horizontal axis in the virtual space coordinate system of the point cloud data.

[0058] In this embodiment, the fixing device 280 supports the connecting rod 270 so that the imaginary line connecting the center of the first sphere 210 and the center of the second sphere 220 is parallel, but it may also be fixed so that it is vertical or in a specified direction.

[0059] In this way, according to the 3D measurement system of this embodiment, by arranging the reference axis direction calculation jig 200' so that the virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is parallel to a predetermined reference axis in real space, the direction of the reference axis in real space can be made parallel to the direction of the reference axis in the virtual space coordinate system of the point cloud data. In other words, the deviation between the real space and the virtual space can be eliminated. Therefore, the point cloud data and the 3D model data can be highly accurate.

[0060] (Third embodiment) A 3D measurement system according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 8 is a configuration diagram of the 3D measurement system, Fig. 9 is a side view of the measurement jig, Fig. 10 is a cross-sectional view taken along the line AA in Fig. 9 for explaining the rod body, and Fig. 11 is a functional block diagram of a point cloud processing device.

[0061] The present embodiment differs from the first and second embodiments in that measurements are performed using a measurement jig that has major parts in common with the reference axis direction calculation jig of the first and second embodiments.

[0062] The 3D measurement system according to this embodiment includes a 3D scanner 100 carried by a measurer 1, a measuring tool 400, and a point cloud processing device 300', as shown in Fig. 8. The 3D scanner is the same as in the first and second embodiments.

[0063] The 3D measurement system according to this embodiment measures the depth direction of a hole that is formed in a measurement object and into which a rod-shaped member is inserted. More specifically, the 3D measurement system measures the depth direction of an anchor hole 6 that is formed in a measurement object 5 such as a concrete member and into which an anchor bolt, which is a rod-shaped member, is inserted, that is, the axial direction of the anchor hole 6.

[0064] 9, the measurement jig 400 includes a first sphere 410, a second sphere 420, a connecting rod 430 connecting the first sphere 410 and the second sphere 420, and a rod 440 attached to the second sphere 420. The first sphere 410, the second sphere 420, and the connecting rod 430 are the same as those in the second embodiment.

[0065] Rod body 440 is provided coaxially with connecting rod 430 on the side opposite to the side of second sphere 420 connected to connecting rod 430. In other words, rod body 440 is parallel to and coaxial with an imaginary line connecting the center of first sphere 410 and second sphere 420.

[0066] An elastic member 441 is provided at the end of the rod body 440 as a position fixing means for fixing the position of the rod body 440 in the anchor hole 6 by contacting the inner wall of the anchor hole 6. The elastic member 441 is made of a plurality of elastic wing members arranged radially from the circumferential surface of the rod body 440 as shown in FIG. 10(a). The elastic force of each wing member is the same. In such a rod body 440, the end of the rod body 440 is inserted into the anchor hole 6 in a state in which the elastic member 441 is elastically deformed to make the overall size smaller than the cross section of the anchor hole 6. When the force of deformation on the elastic member 441 is released after insertion, the elastic force of the elastic member 441 to return acts between the circumferential surface of the rod body 440 and the inner wall surface of the anchor hole 6 as shown in FIG. 10(b). As a result, the center of the rod body 440 is maintained in a state of being located at the center of the anchor hole 6. In other words, the central axis of the rod body 440 and the depth direction of the anchor hole 6 coincide with each other. As described above, the rod 440 is parallel to and coaxial with the imaginary line connecting the center of the first sphere 410 and the second sphere 420. Therefore, the imaginary line connecting the center of the first sphere 410 and the second sphere 420 is parallel to and coincides with the depth direction of the anchor hole 6.

[0067] 10, the point cloud processing device 300' includes a point cloud data acquisition unit 310 and a depth direction calculation unit 340. The point cloud data acquisition unit 310 is similar to that in the first and second embodiments.

[0068] Based on the point cloud data acquired by the point cloud data acquisition unit 310, the depth direction calculation unit 340 calculates the direction of a virtual line connecting the center of the first sphere 410 and the center of the second sphere 420 as the depth direction of the anchor hole 6. Specifically, the depth direction calculation unit 340 first detects the locations corresponding to the first sphere 410 and the second sphere 420 from the point cloud data. That is, the depth direction calculation unit 340 detects a spherical object from the point cloud data. Next, the depth direction calculation unit 340 calculates the center points of the first sphere 410 and the second sphere 420. Then, the depth direction calculation unit 340 calculates the direction of a virtual line connecting the calculated center points of the first sphere 410 and the second sphere 420 as the depth direction of the anchor hole 6.

[0069] Thus, according to the 3D measurement system of this embodiment, the end of the rod body 440 of the measurement jig 400 is inserted into the anchor hole 6, which is a hole formed in the measurement object 5 and into which a rod-shaped member is inserted, and measurement is performed using the 3D scanner 100 in this state, thereby making it possible to measure the depth direction of the anchor hole 6.

[0070] The point cloud processing device 300' may further have a function of calculating the difference between the depth direction of the anchor hole 6 and a predetermined direction (e.g., vertical direction). The difference can be expressed, for example, by an angle. The point cloud processing device 300' may further have a pass / fail judgment function of judging whether the difference is within a predetermined allowable range.

[0071] Although the first to third embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications may be made without departing from the spirit and scope of the present invention.

[0072] For example, in the first embodiment, the first sphere 210 is suspended from an arbitrary structure in the measurement area by the second hanging string 240, but the first sphere 210 may be arranged in the measurement area by other methods. For example, as shown in Fig. 12, the first sphere 210 can be fitted from above into a hole 501 formed in a structure 500 and having a smaller diameter than the first sphere 210.

[0073] In the first and second embodiments, the reference axis direction calculation process is performed on the point cloud data, but the reference axis direction calculation process may be performed on the 3D model data generated from the point cloud data. Similarly, in the third embodiment, the hole depth direction is calculated based on the point cloud data, but the hole depth direction may be calculated based on the 3D model data generated from the point cloud data.

[0074] Furthermore, in each of the above embodiments, the 3D scanner 100 is carried by the person 1 for use, but it may also be mounted on a means of transportation such as an unmanned aerial vehicle or a vehicle for use.

[0075] Furthermore, in the third embodiment, the portable 3D scanner 100 is used as the 3D measurement device, but other 3D measurement devices such as a stationary laser 3D scanner may also be used.

[0076] In the third embodiment, the elastic member 441 consisting of a plurality of wings extending radially from the rod body is used as a position fixing means for fixing the position of the rod body 440 in the anchor hole 6, but other fixing methods may be used. For example, a cylindrical elastic member may be provided at the end of the rod body 440.

[0077] Furthermore, by marking the end of rod body 440 in the third embodiment, i.e., the portion into which anchor hole 6 is inserted, with a scale, it is possible to easily visually check the depth direction of anchor hole 6. [Explanation of symbols]

[0078] 1...Measurer 5…Measurement target 6…Anchor Hole 100…3D scanner 101...Laser irradiation unit 102...Camera 103...Point cloud generation section 104...Point group connection part 110...Point cloud data storage unit 120...Inertial measurement unit 131...Communication interface unit 132...Storage medium reader / writer unit 200,200'...Reference axis direction calculation jig 210…First Sphere 220…Second sphere 230…First hanging thread 240…Second hanging thread 250…weight 260…Third hanging string 270…Connecting rod 280…Fixing tool 281…Pillar 282…Support stand 300,300'...Point cloud processing device 310…Point cloud data acquisition section 320...Reference axis direction calculation unit 330…3D data generation section 340...Depth direction calculation unit 400…Measuring fixture 410…First Sphere 420…Second sphere 430…Connecting rod 440…Rod 441...Elastic member

Claims

1. 1. A method for calculating a direction of a reference axis in a virtual space in a 3D measurement system that scans a real space including a measurement target with a portable 3D measurement device to acquire point cloud data and generates 3D data of the measurement target from the point cloud data, comprising: a first step of placing a jig in the real space, the jig including a first sphere having a spherical surface with a constant radius from a center, a second sphere having a spherical surface with a constant radius from a center, and a sphere position maintaining means for maintaining a relative position between the first sphere and the second sphere; a second step of acquiring point cloud data including the jig arranged in the real space by the 3D measuring device; and a third step of calculating a direction of an imaginary line connecting the center of the first sphere and the center of the second sphere in the virtual space, and setting the direction of the imaginary line as a direction of a reference axis in the virtual space. A reference axis direction calculation method in a 3D measurement system.

2. the sphere position maintaining means includes a hanging string that suspends the second sphere from the first sphere; In the first step, the jig is placed in the real space so that a virtual line that coincides with the hanging string when the second sphere is suspended passes through the centers of the first sphere and the second sphere.

2. The method for calculating a reference axis direction in a 3D measurement system according to claim 1.

3. the sphere position maintaining means includes a rod-shaped member that connects the first sphere and the second sphere in a state where the relative positions of the first sphere and the second sphere are fixed and has an axis passing through the centers of the first sphere and the second sphere, In the first step, the jig is placed in the real space so that the rod-shaped member is oriented vertically or horizontally in the real space.

2. The method for calculating a reference axis direction in a 3D measurement system according to claim 1.

4. A 3D measurement system that scans a real space including a measurement target using a portable 3D measurement device to acquire point cloud data, and generates 3D data of the measurement target from the point cloud data, comprising: a jig including a first sphere having a spherical surface with a constant radius from the center, a second sphere having a spherical surface with a constant radius from the center, and a sphere position maintaining means for maintaining a relative position between the first sphere and the second sphere; a point cloud data acquisition unit that acquires point cloud data including the jig placed in the real space by the 3D measurement device; a reference axis direction calculation unit that calculates a direction of a virtual line connecting the center of the first sphere and the center of the second sphere in a virtual space and sets the direction of the reference axis in the virtual space. A 3D measurement system comprising:

5. 1. A 3D measurement system that scans a real space including a measurement target with a portable 3D measurement device to acquire point cloud data and generate 3D data of the measurement target from the point cloud data, comprising: A first sphere having a spherical surface with a constant radius from a center; a second sphere having a spherical surface of a constant radius from the center; and a sphere position maintaining means for maintaining the relative position of the first sphere and the second sphere. A reference axis direction calculation jig for a 3D measurement system.

6. 1. A method for measuring a depth direction of a hole formed in the measurement object and into which a rod-shaped member is inserted, in a 3D measurement system including a 3D measurement device that scans a real space including a measurement object to acquire point cloud data, and a point cloud processing device that processes the point cloud data, comprising: a first step of inserting an end of a rod of a jig including a first sphere having a spherical surface of a constant radius from the center, a second sphere having a spherical surface of a constant radius from the center, a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere, and a rod provided such that its central axis is parallel to an imaginary line connecting the center of the first sphere and the center of the second sphere, into a hole formed in the measurement object; a second step of acquiring point cloud data including the jig arranged in the real space by the 3D measuring device; and a third step of calculating, as a depth direction of the hole, a direction of a virtual line connecting a center of the first sphere and a center of the second sphere based on the point cloud data or 3D data generated from the point cloud data. A measurement method in a 3D measurement system.

7. A 3D measurement system including a 3D measurement device that scans a real space including a measurement target to acquire point cloud data, a jig including a first sphere having a spherical surface of a constant radius from the center, a second sphere having a spherical surface of a constant radius from the center, a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere, and a rod body arranged so that its central axis is parallel to an imaginary line connecting the center of the first sphere and the center of the second sphere; a point cloud data acquisition unit that acquires point cloud data including the jig by the 3D measurement device in a state in which an end of a rod body of the jig is inserted into a hole formed in the measurement target in the real space and into which a rod-shaped member is inserted; and a depth direction calculation unit that calculates a direction of a virtual line connecting a center of the first sphere and a center of the second sphere as a depth direction of the hole based on the point cloud data or 3D data generated from the point cloud data. A 3D measurement system comprising:

8. A 3D measurement system including a 3D measurement device that scans a real space including a measurement target to acquire point cloud data, and a point cloud processing device that processes the point cloud data, comprising: a jig used to measure a depth direction of a hole that is formed in the measurement target and into which a rod-shaped member is inserted, the jig comprising: A first sphere having a spherical surface with a constant radius from a center; a second sphere having a spherical surface of a constant radius from the center; a sphere position maintaining means for maintaining a relative position between the first sphere and the second sphere; a rod body provided so that a central axis is parallel to an imaginary line connecting the center of the first sphere and the center of the second sphere; The end of the rod is inserted into a hole formed in the measurement object into which a rod-shaped member is inserted. A measuring jig for use in a 3D measuring system.

9. The end of the rod is provided with a position fixing means for abutting against the inner wall of the hole to fix the position of the rod in the hole.

9. A measuring tool for use in a 3D measuring system according to claim 8.

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