3D measurement system, measurement method, and measurement jig

Abstract

To acquire high-precision point cloud data or 3D data. [Solution] A measuring jig 400 is provided, which includes a first sphere 410, a second sphere 420, a connecting rod 430 as a sphere position maintaining means for maintaining the relative positions of the first sphere 410 and the second sphere 420, and a rod body 440 provided so as to be parallel to the central axis of a virtual line connecting the center of the first sphere 410 and the center of the second sphere 420. The 3D scanner 100 is used to perform measurements with the measuring jig 400 inserted into a hole 6 formed in the object to be measured, with the axial direction of the rod body 440 coinciding with the depth direction of the hole 6. The point cloud processing device 300' calculates the virtual line connecting the center of the first sphere 410 and the center of the second sphere 420 as the depth direction of the hole 6.

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 Art

[0002] In recent years, in the field of surveying, 3D measurement devices called laser 3D scanners have become widespread (see Patent Document 1). A laser 3D scanner measures distance by measuring the time it takes for a laser to travel back and forth between the measurement target object, and acquires point cloud data consisting of a large number of three-dimensional coordinates based on the direction in which the laser is irradiated. This point cloud data is transferred to a computer and, if necessary, converted into a 3D model and can be utilized in 3D CAD and other applications. In the fields of civil engineering and architecture, installation-type laser 3D scanners having tripods are often used.

[0003] However, surveying using an installation-type laser 3D scanner has the following problems in the measurement of existing structures. That is, in the measurement of existing structures, the measurement target often gets in the way of obstacles, so the installation location of the installation-type laser 3D scanner is limited, or a part of the structure cannot be measured. As one means of solving such problems, it is conceivable to temporarily install a scaffold around the existing structure, but such work requires a great deal of cost.

[0004] On the other hand, portable 3D scanners have emerged in recent years (see Patent Document 2). Portable 3D scanners are carried by the user or mounted on a means of transport 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 from each scan while moving. The principles for calculating point cloud data in portable 3D scanners include using the round-trip time of the laser, similar to the laser 3D scanners described above, calculating from stereo images acquired by a camera, and calculating from images acquired by a camera after projecting a predetermined pattern of striped images with a laser projector. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-045150 [Patent Document 2] Japanese Patent Publication No. 2022-074298 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, there is a problem with the accuracy of point cloud data acquired by portable 3D scanners. This is because portable 3D scanners recognize their own position and orientation using inertial measurement devices, but the accuracy of these devices is insufficient, and errors accumulate when combining point cloud data from multiple scans. As a result, a discrepancy occurs between the virtual space and the real space of the combined point cloud data, making it difficult to recognize which direction is appropriate as the reference axis direction (e.g., the vertical direction) for the point cloud data. For example, even if there is a perfectly vertical ridge in the real space, it may be tilted from the vertical axis in the virtual space.

[0007] Furthermore, generally speaking, in 3D scanning, accurately measuring the structure of a recessed area from the surface of a structure requires positioning the measuring device towards the bottom of the recess in a location where the entire recess can be observed. For example, in the field of bridges, numerous anchor holes are formed in concrete blocks for driving anchor bolts, and it is sometimes necessary to measure whether the depth direction (i.e., the axial direction) of these anchor holes is precisely in a predetermined direction (typically the vertical direction). Performing this measurement using a 3D scanner would require moving and setting up the measuring device for each anchor hole and performing the measurement work one by one, which is extremely inefficient and impractical.

[0008] The present invention has been made in view of the above circumstances, and its first objective is to provide a 3D measurement system capable of acquiring high-precision point cloud data or 3D data, a method for calculating the reference axis direction thereof, and a jig for calculating the reference axis direction. The second objective 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 jig. [Means for solving the problem]

[0009] Furthermore, in order to achieve the second objective described above, the present invention relates to a 3D measurement system comprising 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, wherein the method for measuring the depth direction of a hole formed in the measurement target into which a rod-shaped member is inserted is provided, comprising: a first sphere having a spherical surface of a certain radius from its center; a second sphere having a spherical surface of a certain radius from its center; a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere; and a virtual connection between the center of the first sphere and the center of the second sphere. The method is characterized by comprising: a first step of inserting the end of a rod, provided that the central axis of a jig is parallel to a line, into a hole formed in the object to be measured, such that the axial direction of the rod coincides with the depth direction of the hole; a second step of acquiring point cloud data including the jig placed in the real space by the 3D measuring 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 as the depth direction of the hole, based on the point cloud data or 3D data generated from the point cloud data.

[0010] Furthermore, in order to achieve the second objective described above, the present invention provides a 3D measurement system equipped with a 3D measurement device that scans a real space including a measurement target to acquire point cloud data, comprising: a first sphere having a spherical surface of a certain radius from its center; a second sphere having a spherical surface of a certain radius from its 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 a virtual line connecting the center of the first sphere and the center of the second sphere; and the measurement within the real space The invention is characterized by comprising: a point cloud data acquisition unit that acquires point cloud data from the 3D measuring device, which includes the jig, while the end of the rod of the jig is inserted into a hole formed in the object into which a rod-shaped member is inserted, with the axial direction of the rod coinciding with the depth direction of the hole; 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.

[0011] Furthermore, in order to achieve the second objective described above, the present invention relates to a 3D measurement system comprising 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, wherein the jig is used to measure the depth direction of a hole formed in the measurement target into which a rod-shaped member is inserted, and is characterized by comprising: a first sphere having a spherical surface of a certain radius from its center; a second sphere having a spherical surface of a certain radius from its center; a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere; a rod provided such 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 a position fixing means provided at the end of the rod, which contacts the inner wall of the hole when the end of the rod is inserted into the hole, and fixes the position of the rod in the hole such that the axial direction of the rod is parallel to the depth direction of the hole. [Effects of the Invention]

[0012] According to the present invention, the depth of the hole can be measured by inserting the end of the rod of a measuring jig into a hole formed in the object to be measured into which a rod-shaped member is inserted, and then performing a measurement using a 3D measuring device in this state. [Brief explanation of the drawing]

[0013] [Figure 1] Configuration diagram of the 3D measurement system according to the first embodiment [Figure 2] 3D scanner functional block diagram [Figure 3] Side view of the jig for calculating the reference axis direction. [Figure 4] Functional block diagram of the point cloud processing unit. [Figure 5] Conceptual diagram illustrating the calculation process of the reference axis direction in a point cloud processing system. [Figure 6] A flowchart illustrating the measurement process flow in a 3D measurement system. [Figure 7] Side view of the jig for calculating the reference axis direction according to the second embodiment. [Figure 8]Configuration diagram of the 3D measurement system according to the third embodiment [Figure 9] Side view of the measurement jig [Figure 10] A-A cross-sectional view of FIG. 9 for explaining the rod [Figure 11] Functional block diagram of the point cloud processing device according to the third embodiment [Figure 12] Figure for explaining a modification of the arrangement method of the reference axis direction calculation jig

Mode for Carrying Out the Invention

[0014] (First Embodiment) The 3D measurement system according to the 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 the 3D scanner, FIG. 3 is a side view of the reference axis direction calculation jig, FIG. 4 is a functional block diagram of the point cloud processing device, FIG. 5 is a conceptual diagram for explaining the reference axis direction calculation process in the point cloud processing device, and FIG. 6 is a flowchart for explaining the flow of the measurement process in the 3D measurement system.

[0015] <​​​​​​​​The 3D scanner 100 repeatedly performs a process to generate point cloud data of a measurement area by scanning a relative measurement area based on its own position and orientation during the period from the start to the end of measurement. During or after the measurement period, the 3D scanner 100 performs a matching process to match (align) multiple point cloud data. The 3D scanner 100 uses the matched point cloud data as the measurement result. The 3D scanner 100 stores the measurement result in a predetermined storage medium or outputs it to an external device.

[0018] The measurement principle of the 3D scanner 100 is not specified. In this embodiment, a 3D measurement device using a stripe light source projection method with a laser light source was used. Specifically, as shown in Figure 2, the 3D scanner 100 includes a laser irradiation unit 101, a camera 102, a point cloud generation unit 103, a point cloud merging unit 104, a point cloud data storage unit 110, an inertial measurement device 120, a communication interface unit 131, and a storage medium reader / writer unit 132.

[0019] During the measurement period, the 3D scanner 100 projects a predetermined pattern (e.g., a striped pattern) onto the object to be measured 5 using the laser irradiation unit 101, and acquires a pattern image by capturing the projected pattern on the object to be measured 5 with the camera 102. The point cloud generation unit 103 generates point cloud data using the Structure from Motion (SfM) method from at least two pattern images taken from different positions during or after the measurement period. The point cloud merging unit 104 performs a matching process to match (align) multiple point cloud data during or after the measurement period. 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 needed.

[0020] In such a portable 3D scanner 100, as described above, a matching process is performed to match (align) multiple point cloud data measured at different measurement positions and directions during the measurement period. In this matching process, feature points of the measurement target 5 included in the point cloud data are extracted, and the coordinate transformation of the point cloud data is performed so that the coordinates of these feature points match. However, the accuracy of position and direction detection by the inertial measurement device 120 is not always sufficiently high, so detection errors in position and direction accumulate during the measurement period. As a result, 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 two columns that are precisely erected vertically in the real space which is the measurement area. If the portable 3D scanner 100 is used to measure while moving so that both columns are included in the measurement area in a single measurement, then in the point cloud data after the matching process, one column may be vertical in the virtual space while the other column is slightly tilted, or both columns may be tilted in the virtual space.

[0021] The present invention aims to eliminate the aforementioned discrepancies by calculating an appropriate reference axis in virtual space, i.e., one that matches the real space, and applying it to the virtual space. (1) As shown in Figure 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 together with the measurement object 5 is acquired by the 3D scanner 100 during the measurement period, and (2) the reference axis in virtual space is calculated in the point cloud processing device 300, thereby eliminating the aforementioned discrepancies in the virtual space.

[0022] As shown in Figure 3, the reference axis direction calculation jig 200 comprises a first sphere 210, a second sphere 220, a first suspension thread 230 connecting the first sphere 210 to the second sphere 220 and suspending the second sphere 220 from the first sphere 210, a second suspension thread 240 suspending the first sphere 210 to any location in real space, a weight 250, and a third suspension thread 260 connecting the second sphere 220 to the weight 250 and suspending the weight 250 from the second sphere 220. Each component of the reference axis direction calculation jig 200 can be arbitrarily made detachable.

[0023] The first sphere 210 and the second sphere 220 are each spheres 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 specified. For example, they can be formed from resin, wood, or metal.

[0024] The connection point of the second suspension thread 240 on the first sphere 210 is the pole of the first sphere 210 (referred to here as the North Pole). The connection point of the first suspension thread 230 on the first sphere 210 is the pole of the first sphere 210 opposite to the North Pole (referred to here as the South Pole). The center of gravity of the first sphere 210 is preferably on the axis connecting the North Pole and the South Pole, and more preferably at the center of the first sphere 210.

[0025] The connection point of the first suspension thread 230 on the second sphere 220 is the pole of the second sphere 220 (referred to here as the North Pole). The connection point of the third suspension thread 260 on the second sphere 220 is the pole of the second sphere 220 opposite to the North Pole (referred to here as the South Pole). The center of gravity of the second sphere 220 is preferably on the axis connecting the North Pole and the South Pole, and more preferably at the center of the second sphere 220.

[0026] The diameters of the first sphere 210 and the second sphere may be the same or different. Also, the weights of the first sphere 210 and the second sphere may be the same or different.

[0027] The first suspension thread 230, the second suspension thread 240, and the third suspension thread 260 are preferably lightweight, and in particular, they are preferably sufficiently lighter than the total weight of the first sphere 210, the second sphere 220, and the weight 250, and even more preferably sufficiently lighter than the weight of the weight 250. The material of the first suspension thread 230, the second suspension thread 240, and the third suspension thread 260 is not specified. For example, they can be made of synthetic fibers, metal, etc. The end of the second suspension thread 240 opposite to the side connected to the first sphere 210 is fitted with a hook or other attachment (not shown) for attaching to any structure. Alternatively, instead of the attachment, the end of the second suspension thread 240 may be processed into a loop and hooked onto any structure. Figure 1 shows the jig 200 for calculating the reference axis direction attached to the mounting base 2.

[0028] 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 even more preferably heavier than the combined weight of the first sphere 210 and the second sphere 220.

[0029] The first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 function as a sphere position maintenance means that maintain the relative positions of the first sphere 210 and the second sphere 220 in real space. More specifically, the first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 function as a sphere position maintenance means that utilize gravity to maintain the spheres in a state where a virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is parallel to the vertical axis, which is one of the reference axes in real space.

[0030] In this embodiment, the first sphere 210 is suspended from the mounting fixture attached to the second suspension thread 240 by fixing it to any location in real space, and the second sphere 220 is suspended from the mounting fixture. Since the weight 250 is suspended from the second sphere 220, the position of the second sphere 220 is stably maintained. As a result, in real space, the positions of the first sphere 210 and the second sphere 220 are stably maintained with the direction connecting their center positions being vertical.

[0031] Preferably, the lengths of the first suspension thread 230, the second suspension thread 240, and the third suspension thread 260 are adjusted so that the positional relationship between the first sphere 210 and the second sphere 220 is stable, as described above. Furthermore, the length of the first suspension thread 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 appropriately performed according to the size of the measurement area, the measurable range of the 3D scanner 100, etc. In the striped projection type portable 3D scanner 100 used in this embodiment, if the projection target is lost during scanning, the scanner may lose its own position and be unable to perform accurate measurements. For this reason, it is preferable to appropriately adjust the length of the first suspension thread 230. In addition, the lengths of the first suspension thread 230, the second suspension thread 240, and the third suspension thread 260 can each be configured to be variable as needed.

[0032] In the reference axis direction calculation process in the point cloud processing device 300 described later, point cloud data measured from the first sphere 210 and the second sphere 220 are used. For this reason, it is preferable that the surfaces of the first sphere 210 and the second sphere 220 are plain so that this calculation process can be performed stably. It is also preferable that the surfaces of the first sphere 210 and the second sphere 220 are white or have a stable reflectivity. The color of the surfaces of the first sphere 210 and the second sphere 220 is not a requirement.

[0033] On the other hand, the point cloud data obtained by measuring the first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 are not used in the calculation process for the reference axis direction. Therefore, it is preferable that the thickness of the first suspension thread 230, the second suspension thread 240, and the third suspension thread 260, and the size of the weight 250, are sufficiently smaller than the first sphere 210 and the second sphere 220. Furthermore, it is preferable that the thickness of the first suspension thread 230, the second suspension thread 240, and the third suspension thread 260 is so thin that they cannot be sufficiently recognized by the 3D scanner 100 due to resolution limitations. Alternatively, it is preferable that the first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 have colors that cannot be sufficiently recognized by the 3D scanner 100. For example, it is preferable that they be formed from a transparent material. Alternatively, it is preferable that the colors of the first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 have a lower density than the first sphere 210 and the second sphere 220. On the other hand, from the viewpoint of data loss during scanning as described above, it is preferable that the first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 be set to a size and color such that they can be reliably recognized by the 3D scanner 100, in order to prevent data loss during scanning. For example, it is preferable to apply a pattern with many feature points, such as a camouflage pattern. From these multiple viewpoints, the size and color of the first suspension thread 230, the second suspension thread 240, the third suspension thread 260, and the weight 250 should be set appropriately according to the measurement environment and the specifications of the 3D scanner 100.

[0034] Next, the point cloud processing unit 300 will be described. The point cloud processing unit 300 can be configured using a conventionally known computer equipped with a main processing unit, main memory, auxiliary memory, input devices, output devices, communication devices, etc. The point cloud processing unit 300 can be implemented by installing a program on a computer. Alternatively, the point cloud processing unit 300 can be implemented as dedicated hardware. The point cloud processing unit 300 can be distributed and implemented across multiple computers.

[0035] As shown in Figure 4, 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.

[0036] 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 unit 300 and the 3D scanner 100 to receive point cloud data from the 3D scanner 100. Alternatively, for example, the 3D scanner 100 can store point cloud data in a portable storage medium, and this storage medium can be attached to the interface (not shown) of the point cloud processing unit 300 to acquire point cloud data from the storage medium.

[0037] Figure 5 shows a conceptual diagram illustrating the processing performed by the reference axis direction calculation unit 320. For simplicity of explanation, Figure 5 shows the point cloud data with the camera oriented in the Y-axis direction. Figure 5(a) shows the point cloud data acquired from the 3D scanner 100, and Figure 5(b) shows the point cloud data rotated based on the calculated reference axis direction. In the figure, reference numeral 11 denotes the point cloud corresponding to the first sphere 210, reference numeral 12 denotes the point cloud corresponding to the second sphere 220, reference numeral 21 denotes the point cloud corresponding to the measurement target 5, and reference numeral 31 denotes a hypothetical line connecting the center of the first sphere 210 and the center of the second sphere 220.

[0038] The reference axis direction calculation unit 320 calculates the direction of the reference axis in virtual space from the point cloud data, which includes the reference axis direction calculation jig 200, so as to eliminate the shift in virtual space related to the point cloud data. Specifically, the reference axis direction calculation unit 320 first detects 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 spherical objects 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.

[0039] 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 the virtual space coordinate system relating to the point cloud data, as the 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 shift in the virtual space relating to the point cloud data. To perform this processing, the reference axis direction 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 as metadata indicating the vertical axis direction of the virtual space for the point cloud data.

[0040] The 3D data generation unit 330 converts the point cloud data processed by the reference axis direction calculation unit 320 into 3D model data in a predetermined format. The format of the 3D model data is not restricted.

[0041] The point cloud data acquired by the point cloud data acquisition unit 310 (raw point cloud data), the point cloud data processed by the reference axis direction calculation unit 320 (processed point cloud data), 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 each be stored in a storage device (not shown) or output to an external computer as needed. The point cloud processing device 300 may also include a display control unit that displays the raw point cloud data, processed point cloud data, and 3D model data on a two-dimensional display unit (not shown).

[0042] The 3D measurement processing method in the 3D measurement system according to this embodiment will now 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 a measurement so that the reference axis direction calculation jig 200 is included together with the measurement target 5, thereby acquiring point cloud data that includes the reference axis direction calculation jig 200 (step S2). Then, the point cloud processing device 300 performs calculation processing for the reference axis direction in virtual space (step S3). In this calculation processing, a virtual line is calculated connecting the center of the first sphere 210 and the center of the second sphere 220, 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.

[0043] Thus, according to this embodiment of the 3D measurement system, by arranging the reference axis direction calculation jig 200 so that a 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 discrepancy between real space and virtual space can be eliminated. Therefore, the point cloud data and 3D model data will be highly accurate.

[0044] (Second Embodiment) A 3D measurement system according to a second embodiment of the present invention will be described with reference to the drawings. Figure 7 is a side view of a jig for calculating the reference axis direction. The difference between this embodiment and the first embodiment lies in the structure of the jig for calculating the reference axis direction and the reference axis direction calculation process associated therewith. The other configurations and operations are the same as in the first embodiment, so only the differences will be described here.

[0045] The difference between the reference axis direction calculation jig 200' according to this embodiment and the reference axis direction calculation jig 200 according to the first embodiment lies in the 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 positions of the first sphere 210 and the second sphere 220 were maintained by suspending the second sphere 220 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 while maintaining their relative positional relationship. The structure of the reference axis direction calculation jig 200 will be described in detail below.

[0046] As shown in Figure 7, the reference axis direction calculation jig 200' comprises a first sphere 210, a second sphere 220, a connecting rod 270 connecting the first sphere 210 and the second sphere 220, and a fixing device 280 for fixing the reference axis direction calculation jig 200' at any location in the measurement area space. The first sphere 210 and the second sphere 220 are the same as in the first embodiment.

[0047] The connecting rod 270 functions as a sphere position maintaining means that maintains the relative positions of the first sphere 210 and the second sphere 220. The connecting rod 270 consists of a rod-shaped member whose axis passes through the centers of the first sphere 210 and the second sphere 220.

[0048] The length of the connecting rod 270, 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 appropriately performed according to the size of the measurement area, the measurable range of the 3D scanner 100, etc. Furthermore, the length of each connecting rod 270 can be made variable as needed. In addition, it is preferable that the connecting rod 270 has sufficient strength so as not to bend under the weight of the first sphere 210 and the second sphere 220.

[0049] The fixing device 280 is a jig for positioning and fixing the first sphere 210 and the second sphere 220 so that the virtual line connecting their centers is in a predetermined direction in real space, while maintaining the relative positional relationship between the first sphere 210 and the second sphere 220 by the connecting rod 270. Here, the predetermined direction can be arbitrary, but from the viewpoint of certainty and ease of positioning in real space, and ease of calculation of the reference axis direction calculation process, it is preferable that it be in the horizontal or vertical direction. In this embodiment, the fixing device 280 is a jig for positioning and fixing the first sphere 210 and the second sphere 220 so that the virtual line connecting their centers is in the horizontal direction in real space.

[0050] It is preferable that the fixing device 280 is connected to the connecting rod 270 without being connected to the first sphere 210 and the second sphere 220. This is because, from the viewpoint of improving the recognition accuracy of the first sphere 210 and the second sphere 220 in the subsequent reference axis direction calculation process, it is preferable that the fixing device 280 is not located near each sphere. In this embodiment, the fixing device 280 comprises a column 281 that is rotatably connected at the center of the connecting rod 270, and a support base 282 provided at the lower end of the column 281.

[0051] Similar to the first embodiment, the point cloud processing device 300 uses point cloud data obtained by measuring the first sphere 210 and the second sphere 220 in the calculation process of the reference axis direction. On the other hand, point cloud data obtained by measuring the connecting rod 270 and the fixing device 280 are not used in the calculation process. Therefore, the thickness of the connecting rod 270 is preferably as thin as possible while maintaining strength, from the viewpoint of improving the recognition accuracy of the first sphere 210 and the second sphere 220 in the subsequent calculation process. The connecting rod 270 and the fixing device 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 material. Alternatively, the color of the connecting rod 270 and the fixing device 280 is preferably of a lower density than that of the first sphere 210 and the second sphere 220. On the other hand, from the perspective of preventing data loss during scanning, it is preferable to set the size and color of the connecting rod 270 and the fixing device 280 so as to prevent data loss during scanning, that is, so as to ensure that the 3D scanner 100 can reliably recognize them. For example, it is preferable to apply a pattern with many feature points, such as a camouflage pattern. From these various perspectives, the size and color of the connecting rod 270 and the fixing device 280 should be set appropriately.

[0052] The 3D measurement processing method in the 3D measurement system according to this embodiment is similar to the first embodiment in that, first, the reference axis direction calculation jig 200 is placed in the measurement area. Specifically, the reference axis direction calculation jig 200 is placed on a substantially horizontal surface, such as the top surface of a structure, within the measurement area. Then, the connection angle between the connecting rod 270 and the fixing device 280 is adjusted so that the imaginary line connecting the centers of the first sphere 210 and the second sphere 220 is horizontal, that is, so that the connecting rod 270 is horizontal. A conventionally known spirit level can be used in this adjustment process.

[0053] Next, the 3D scanner 100 is used to take measurements so that the reference axis direction calculation jig 200 is included along with the object to be measured 5, thereby obtaining point cloud data that includes the reference axis direction calculation jig 200. Then, the point cloud processing device 300 performs calculation processing for the reference axis direction in virtual space. In this calculation process, a virtual line is calculated connecting the center of the first sphere 210 and the center of the second sphere 220, 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.

[0054] In this embodiment, the fixing device 280 supports the connecting rod 270 such that a virtual line connecting the center of the first sphere 210 and the center of the second sphere 220 is parallel to it. However, it may also be fixed in a vertical direction or a predetermined direction.

[0055] Thus, according to this embodiment of the 3D measurement system, by arranging the reference axis direction calculation jig 200' so that a 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 discrepancy between real space and virtual space can be eliminated. Therefore, the point cloud data and 3D model data will be highly accurate.

[0056] (Third embodiment) A 3D measurement system according to a third embodiment of the present invention will be described with reference to the drawings. Figure 8 is a configuration diagram of the 3D measurement system, Figure 9 is a side view of the measurement jig, Figure 10 is a cross-sectional view AA of Figure 9 illustrating the rod body, and Figure 11 is a functional block diagram of the point cloud processing device.

[0057] The difference between this embodiment and the first and second embodiments is that the measurement is performed using a measuring jig whose main parts are common to the reference axis direction calculation jig of the first and second embodiments.

[0058] As shown in Figure 8, the 3D measurement system according to this embodiment comprises a 3D scanner 100 carried by the measurer 1, a measurement jig 400, and a point cloud processing device 300'. The 3D scanner is the same as in the first and second embodiments.

[0059] The 3D measurement system according to this embodiment measures the depth direction of a hole formed in the object to be measured into which a rod-shaped member is inserted. More specifically, the 3D measurement system measures the depth direction, that is, the axial direction of the anchor hole 6, which is a hole formed in the object to be measured 5 such as a concrete member into which an anchor bolt, a rod-shaped member, is inserted.

[0060] As shown in Figure 9, the measuring jig 400 comprises 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 body 440 attached to the second sphere 420. The first sphere 410, the second sphere 420, and the connecting rod 430 are the same as in the second embodiment.

[0061] The rod 440 is provided coaxially with the connecting rod 430 on the side opposite to the connection side of the second sphere 420 with the connecting rod 430. That is, 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.

[0062] An elastic member 441 is provided at the end of the rod 440 as a position fixing means for fixing the position of the rod 440 in the anchor hole 6 by contacting the inner wall of the anchor hole 6. As shown in Figure 10(a), the elastic member 441 consists of a plurality of elastic wing members that are erected radially from the circumferential surface of the rod 440. The elastic force of each wing member is the same. In such a rod 440, the end of the rod 440 is inserted into the anchor hole 6 with the elastic member 441 elastically deformed to make its overall size smaller than the cross-section of the anchor hole 6. After insertion, when the deforming force on the elastic member 441 is released, as shown in Figure 10(b), an elastic force acting between the circumferential surface of the rod 440 and the inner wall surface of the anchor hole 6 acts as the elastic member 441 attempts to return to its original position. As a result, the center of the rod 440 is maintained at the center of the anchor hole 6. That is, the central axis of the rod 440 and the depth direction of the anchor hole 6 coincide. As mentioned 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.

[0063] As shown in Figure 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 the same as in the first and second embodiments.

[0064] 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, based on the point cloud data acquired by the point cloud data acquisition unit 310. Specifically, the depth direction calculation unit 340 first detects 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 spherical objects 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.

[0065] As described above, with the 3D measurement system according to this embodiment, the end of the rod 440 of the measurement jig 400 is inserted into the anchor hole 6, which is a hole formed in the object to be measured 5 into which a rod-shaped member is inserted, and by performing a measurement using the 3D scanner 100 in this state, the depth direction of the anchor hole 6 can be measured.

[0066] Furthermore, the point cloud processing device 300' may also have a function to calculate the difference between the depth direction of the anchor hole 6 and a predetermined direction (for example, the vertical direction). This difference can be expressed, for example, as an angle. The point cloud processing device 300' may also have a quality determination function to determine whether the difference is within a predetermined tolerance range.

[0067] 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 embodiments, and various improvements and modifications may be made without departing from the spirit of the present invention.

[0068] For example, in the first embodiment, the first sphere 210 was suspended from any structure in the measurement area by the second suspension string 240, but the first sphere 210 may be placed in the measurement area by other means. For example, as shown in Figure 12, the first sphere 210 can be fitted from above into a hole 501 formed in the structure 500, which has a smaller diameter than the first sphere 210.

[0069] Furthermore, in the first and second embodiments described above, the reference axis direction calculation process was performed on the point cloud data, but the reference axis direction calculation process may also be performed on the 3D model data generated from the point cloud data. Similarly, in the third embodiment described above, the depth direction of the hole was calculated based on the point cloud data, but the depth direction of the hole may also be calculated based on the 3D model data generated from the point cloud data.

[0070] Furthermore, in each of the above embodiments, the 3D scanner 100 was carried and used by the measurer 1, but it may also be mounted on a means of transport such as an unmanned aerial vehicle or a vehicle.

[0071] Furthermore, in the third embodiment described above, a portable 3D scanner 100 was used as the 3D measurement device, but other 3D measurement devices such as a stationary laser 3D scanner may also be used.

[0072] Furthermore, in the third embodiment described above, an elastic member 441 consisting of a plurality of wings extending radially from the rod body was used as a position fixing means for fixing the position of the rod body 440 in the anchor hole 6, but it may be fixed by other methods. For example, a cylindrical elastic member may be provided at the end of the rod body 440.

[0073] Furthermore, by marking the end of the rod 440 in the third embodiment described above, that is, the portion into which the anchor hole 6 is inserted, the depth direction of the anchor hole 6 can be easily confirmed by visual inspection. [Explanation of Symbols]

[0074] 1…Measurer 5...Object to be measured 6… Anchor hole 100...3D scanner 101...Laser irradiation area 102... Camera 103...Point cloud generation section 104...Point group connection part 110... Point cloud data storage unit 120...Inertial measuring device 131...Communication Interface Section 132...Storage medium reader / writer section 200,200′…Jig for calculating the reference axis direction 210... The first sphere 220... The second sphere 230...First suspension thread 240...Second suspension thread 250...weight 260... Third suspension thread 270…Connecting rod 280…Fixing tool 281... Pillar 282…Support stand 300,300'... Point cloud processing device 310...Point cloud data acquisition unit 320...Reference axis direction calculation unit 330...3D data generation unit 340... Depth direction calculation unit 400... Measuring fixtures 410... The first sphere 420... The second sphere 430…Connecting rod 440… Rod body 441...Elastic member

Claims

1. A 3D measurement system comprising 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, wherein a method for measuring the depth direction of a hole formed in the measurement target into which a rod-shaped member is inserted, A first step of inserting the end of the rod of a jig, which comprises a first sphere having a spherical surface of a certain radius from its center, a second sphere having a spherical surface of a certain radius from its center, a sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere, and a rod provided so as to be parallel to the central axis of a virtual line connecting the center of the first sphere and the center of the second sphere, into a hole formed in the object to be measured, such that the axial direction of the rod coincides with the depth direction of the hole, A second step is to acquire point cloud data including the jig placed in the real space using the 3D measuring device, Based on the point cloud data or 3D data generated from the point cloud data, the direction of a virtual line connecting the center of the first sphere and the center of the second sphere is calculated as the depth direction of the hole. The third step includes A measurement method in a 3D measurement system characterized by the following features.

2. The aforementioned hole is an anchor hole. A measurement method in the 3D measurement system according to claim 1, characterized in that it is a 3D measurement system.

3. A 3D measurement system comprising a 3D measurement device that scans the real space including the object to be measured and acquires point cloud data, A jig comprising: a first sphere having a spherical surface of a certain radius from its center; a second sphere having a spherical surface of a certain radius from its 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 a virtual line connecting the center of the first sphere and the center of the second sphere. A point cloud data acquisition unit acquires point cloud data from the 3D measuring device, which scans the 3D measuring device to include the jig, with the end of the rod of the jig inserted into a hole formed in the object to be measured in the real space into which a rod-shaped member is inserted, such that the axial direction of the rod coincides with the depth direction of the hole. The system includes 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. A 3D measurement system characterized by the following features.

4. A 3D measurement system comprising 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, wherein a jig is used to measure the depth direction of a hole formed in the measurement target into which a rod-shaped member is inserted, A first sphere having a spherical surface with a constant radius from its center, A second sphere having a spherical surface with a certain radius from its center, A sphere position maintaining means for maintaining the relative positions of the first sphere and the second sphere, A rod is provided such that its central axis is parallel to a hypothetical line connecting the center of the first sphere and the center of the second sphere, The rod body is provided with a position fixing means at its end, which contacts the inner wall of the hole when the end of the rod body is inserted into the hole, and fixes the position of the rod body in the hole so that the axial direction of the rod body is parallel to the depth direction of the hole. A measuring jig for a 3D measurement system, characterized by the following features.

Images