Measurement device

Abstract

Provided is a measurement device (10) that is inserted inside a pipeline (30) and generates point cloud data indicating the shape of the inner surface of the pipeline (30), the measurement device (10) including a laser scanner (12), a reflecting mirror (13), a support part (14), and a control unit (22). The laser scanner (12) is disposed so as to emit laser light in the longitudinal direction of the pipeline (30). The reflecting mirror (13) is positioned in the emission direction of the laser light of the laser scanner (12), reflects the laser light emitted from the laser scanner (12) in the direction of the inner surface (30a) of the pipeline (30), and reflects the reflected light of the laser light reflected by the inner surface (30a) in the direction of the laser scanner (12). The control unit (22) generates the point cloud data on the basis of the data about the reflected light detected by the laser scanner (12) and the shape of the reflecting mirror (13).

Description

Measurement device

[0001] The present disclosure relates to a measurement device.

[0002] In recent years, the decline in the working population and the aging of social infrastructure have been progressing, and as countermeasures thereto, DX (Digital Transformation) of the operation, maintenance and / or management of infrastructure facilities has been promoted. As part of this, attempts have been made to digitize social infrastructure facilities in three dimensions and utilize them for enhancing and streamlining maintenance and management as point cloud data.

[0003] Three-dimensional digitization using point clouds involves connecting point clouds intermittently acquired by photographing infrastructure facilities by overlapping them based on the positions (coordinates), orientations, and shape features between the point clouds at the time of photographing, thereby creating a continuous three-dimensional model of the object. Facilities visible from the ground can be efficiently three-dimensionally modeled using a mobile mapping system (MMS: mobile mapping system) that combines point clouds and satellite positioning, and drones, etc. On the other hand, it is difficult to obtain position information by satellite positioning for underground infrastructure facilities, and the shape of the facilities is also tunnel-shaped with few shape features. Therefore, three-dimensional modeling of underground infrastructure facilities has not advanced as much as that of above-ground facilities.

[0004] As an example, in Non-Patent Document 1, a method has been proposed in which point clouds acquired using three laser scanners for cross-section measurement, vertical measurement, and horizontal measurement are combined to create a continuous three-dimensional model of a relatively large-diameter (800 mm to 7000 mm) pipeline such as a water pipe.

[0005] Shoji Otsuki, "Development of a Point Cloud Measurement System for Underground Buried Pipes, etc.", Photogrammetry and Remote Sensing, Vol. 54, No. 6, pp. 275-279 (2015)

[0006] However, there are a vast number of narrow communication conduits underground, such as those with a diameter of about 8 cm. The total length of these conduits in Japan alone reaches approximately 600,000 km. It is physically difficult to install three laser scanners within these narrow conduits. Furthermore, even if installation were possible, laser scanners generally have a measurable distance of only a few tens of centimeters to a few meters, making it difficult to accurately acquire point cloud data and reconstruct the shape within these confined spaces.

[0007] Furthermore, when the diameter of the conduit is narrow, as shown in Figure 11, it is possible to measure the inner surface 100a of the conduit 100 with a single laser scanner 101 whose optical axis is directed in the longitudinal direction of the conduit 100. However, when the laser light L emitted from the laser scanner 101 is reflected off the inner surface 100a of the conduit 100, the angle of incidence is large (shallow), so most of it is reflected towards the back of the conduit 100 on the opposite side from the laser scanner 101. Therefore, since reflected light of sufficient intensity for measurement does not return to the laser scanner 101, it is difficult to obtain accurate shape data of the inner surface 100a of the conduit 100.

[0008] Therefore, the objective of the present invention, which has been made with these points in mind, is to improve the technique for measuring the inner surface of a pipeline.

[0009] A measuring device according to one embodiment is inserted inside a conduit and generates point cloud data showing the shape of the inner surface of the conduit, comprising: a laser scanner positioned to emit laser light in the longitudinal direction of the conduit; a reflector positioned in the direction of the laser light emission from the laser scanner, which reflects the laser light emitted from the laser scanner toward the inner surface of the conduit and reflects the reflected light from the inner surface toward the laser scanner; a support portion that supports the reflector relative to the laser scanner; and a control unit that generates the point cloud data based on the reflected light data detected by the laser scanner and the shape of the reflector.

[0010] According to this disclosure, the technology for measuring the inner surface of a pipeline can be improved.

[0011] This figure schematically shows the appearance of a measuring device according to one embodiment, which is placed inside a pipeline. This is a block diagram illustrating the schematic configuration of the measuring device in Figure 2. This is a block diagram illustrating the schematic configuration of the laser scanner in Figure 1. This figure illustrates the coordinate transformation of the point cloud measured by the laser scanner. This figure illustrates an example of applying the measuring device of this disclosure to underground piping installed between manholes. This is a flowchart illustrating the procedure of the measurement method executed by the control unit of the measuring device. This figure shows an example of measurement using the measuring device in Figure 1. This figure shows an example of measurement using the measuring device in Figure 1. This is a side view of a measuring device according to another embodiment. This is a side view of a measuring device according to yet another embodiment. This figure illustrates measurement inside a pipeline according to the prior art.

[0012] Embodiments of this disclosure will be described below with reference to the drawings. The figures used in the following description are schematic. Dimensions and proportions shown in the drawings do not necessarily correspond to those of reality.

[0013] (Outline of the measuring device) A measuring device 10 according to one embodiment of the present disclosure is a device that is placed inside a small-diameter conduit 30, for example, with a diameter of several centimeters to several tens of centimeters or less, and acquires data on the shape of the inner surface 30a of the conduit 30. The conduit 30 is, for example, a conduit used for communication cables or power cables buried underground. The measuring device 10 includes a main body 11 that houses a laser scanner 12, a reflector 13, a support part 14, a plumb bob 15, and a rotating body 16.

[0014] In one embodiment, the measuring device 10 has a shape that is elongated in the longitudinal direction of the conduit 30. The measuring device 10 is movable in the longitudinal direction of the conduit 30. Since the length of the measuring device 10 in the longitudinal direction of the conduit 30 is longer than the inner diameter of the conduit 30, rotation of the measuring device 10 about an axis in a direction perpendicular to the longitudinal direction of the conduit 30 is restricted.

[0015] The main unit 11 incorporates electronic equipment for the measuring device 10 to perform measurements, in addition to the laser scanner 12. The electronic equipment includes an attitude measurement unit 19 and a position measurement unit 20 (both of which are described later in Figure 2). The main unit 11 may further incorporate a battery. The main unit 11 may not incorporate a battery and may receive power from an external battery via a power line. The main unit 11 may have a shape such as a cylindrical or rectangular prism.

[0016] The laser scanner 12 is positioned on the side of the main unit 11 facing the reflector 13, and scans pulsed laser light toward the reflective surface 13a of the reflector 13. The pulsed laser light will be referred to as "pulsed light" below.

[0017] The reflecting mirror 13 has a reflective surface 13a that is convex toward the laser scanner 12. The reflective surface 13a of the reflecting mirror 13 reflects the pulsed light emitted from the laser scanner 12 toward the inner surface 30a of the conduit 30. The reflective surface of the reflecting mirror 13 reflects the reflected light, which has been reflected off the inner surface 30a of the conduit 30 by the pulsed light emitted from the laser scanner 12, toward the laser scanner 12. The reflecting mirror 13 is, for example, a conical mirror, a spherical mirror, a hyperbolic mirror, and a parabolic mirror that are rotationally symmetric about the scanning central axis of the laser scanner 12, but is not limited to these. In the following description, the reflecting mirror 13 will be assumed to be a conical mirror.

[0018] The support portion 14 fixes the relative positional relationship between the laser scanner 12 and the reflector 13, and also supports the reflector 13. The support portion 14 may be, for example, a cylindrical member that is transparent to light of the wavelength of pulsed light emitted by the laser scanner 12. For example, the support portion 14 is fixed to the outer circumference of the main body portion 11 at one end and to the outer circumference of the reflector 13 at the other end.

[0019] The plumb bob 15 is constructed by attaching a weight to one end of a string. The other end of the string of the plumb bob 15 is attached to the apex of the reflective surface of the conical mirror 13. Therefore, the weight of the plumb bob 15 is positioned vertically below the apex of the conical mirror 13 due to gravity. The weight of the plumb bob 15 is located within the field of view of the laser scanner 12, and its position can be measured by the laser scanner 12.

[0020] The rotating body 16 is attached to an arm extending from the main body 11 and rotates while in contact with the inner surface 30a of the conduit 30 as the measuring device 10 moves in the longitudinal direction of the conduit 30. The rotating body 16 may be, for example, a small tire or a sphere. The rotating body 16 is used to measure the longitudinal position of the measuring device 10 within the conduit 30.

[0021] A more detailed configuration of the measuring device 10 will be described with reference to Figure 2. The measuring device 10 includes a data acquisition unit 17 that acquires measurement data and a data processing unit 18 that processes the acquired measurement data. The measurement data includes point cloud data measured by the laser scanner 12. The main body 11 of the measuring device 10 may include the entirety of the data acquisition unit 17 and the data processing unit 18, or it may include only the data acquisition unit 17. Alternatively, the main body 11 may include the data acquisition unit 17 and a part of the data processing unit 18. A part or all of the data processing unit 18 not included in the main body 11 may be implemented in an external information processing device. The information processing device may be a general-purpose device such as a PC (Personal Computer), or a dedicated device. The data acquisition unit 17 and the data processing unit 18 may be configured to send and receive data to and from each other by wired or wireless communication means.

[0022] (Configuration of the data acquisition unit) The data acquisition unit 17 is described below. The data acquisition unit 17 includes a laser scanner 12, an attitude measurement unit 19, and a position measurement unit 20.

[0023] The laser scanner 12 measures the object to be measured by scanning with pulsed light. The object to be measured is the inner surface 30a of the conduit 30. As shown in Figure 3, the laser scanner 12 includes a light emission unit 12a, a light detection unit 12b, a scanning unit 12c, a direction detection unit 12d, a distance calculation unit 12e, a coordinate calculation unit 12f, a storage unit 12g, and a control unit 12h.

[0024] The light emission unit 12a includes a light source that emits pulsed light repeatedly at high speed. The light source can be, for example, a semiconductor laser that emits infrared light.

[0025] The light detection unit 12b includes a light-receiving element that detects reflected light from the object being measured after pulsed light has been reflected. For example, a photodiode can be used as the light-receiving element.

[0026] The scanning unit 12c scans the pulsed light emitted from the light emission unit 12a in a predetermined pattern toward the area in front of the laser scanner 12. The scanning unit 12c may include two mirrors that rotate at high speed in the vertical and horizontal directions, respectively, and a motor that drives the mirrors. For example, a galvanometer scanner may be used for the scanning unit 12c. A piezo scanner or a MEMS (Micro Electro Mechanical Systems) scanner may also be used for the scanning unit 12c.

[0027] The direction detection unit 12d detects the direction from which the pulsed light is emitted by the scanning unit 12c. The direction detection unit 12d may be built into the scanning unit 12c and detect the scanning angle of the mirrors that constitute the scanning unit 12c.

[0028] The distance calculation unit 12e calculates the distance from the laser scanner 12 to the object to be measured, reflecting the pulsed light, using the Time of Flight (TOF) method, based on the time difference between the emission of the pulsed light by the light emission unit 12a and the reception of the reflected light by the light detection unit 12b for each pulse of light.

[0029] The coordinate calculation unit 12f calculates the three-dimensional coordinates of the object to be measured based on the direction from which the pulsed light is emitted, as detected by the direction detection unit 12d, and the distance to the object to be measured, as calculated by the distance calculation unit 12e. In this embodiment, the three-dimensional coordinates acquired by the coordinate calculation unit 12f are the apparent coordinates of the object to be measured as detected by the laser scanner 12, assuming that the reflector 13 is not attached.

[0030] The storage unit 12g may be configured to include, for example, one or more of semiconductor memory, magnetic memory, and optical memory. Semiconductor memory may include volatile memory and non-volatile memory. Magnetic memory may include, for example, a hard disk. Optical memory may include, for example, a CD (Compact Disc), DVD (Digital Versatile Disc), and BD (Blu-ray® Disc). The storage unit 12g sequentially stores the three-dimensional coordinates of the object to be measured calculated by the coordinate calculation unit 12f. The three-dimensional coordinates of the object to be measured are stored as first point cloud data, which is reflected light data.

[0031] The control unit 12h controls each part of the laser scanner 12. The control unit 12h may be configured to include one or more processors. In one embodiment, the "processor" is a general-purpose processor or a dedicated processor specialized for a specific process, but is not limited to these. The processor may be, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or an ASIC (Application Specific Integrated Circuit).

[0032] The control unit 12h controls the light emission timing of the light emission unit 12a and the scanning of pulsed light by the scanning unit 12c. The control unit 12h may acquire the reflected light reception signal from the light detection unit 12b. The control unit 12h may include the functions of a distance calculation unit 12e and a coordinate calculation unit 12f. For each pulse of light, the control unit 12h can detect the emission direction of the pulsed light, calculate the distance to the measurement target, and perform a process to identify the coordinates of the measurement target to which the pulsed light was reflected, assuming that the reflector 13 is not attached. The data of the coordinates to which the pulsed light was reflected is included in the reflected light data. The control unit 12h transmits the reflected light data stored in the storage unit 12g to the data processing unit 18 sequentially or in batches of a certain number.

[0033] The attitude measurement unit 19 in Figure 2 measures the rotation angle around at least one of the rotation axes of the laser scanner 12 as attitude data. In this embodiment, the attitude measurement unit 19 determines the vertically downward direction by measuring the position and orientation of the weight of the plumb bob 15. The position and orientation of the weight of the plumb bob 15 measured by the attitude measurement unit 19 correspond to the rotation angles around the roll axis and pitch axis of the main body 11. In this disclosure, the roll axis coincides with the scanning central axis of the laser scanner 12. The pitch axis is a horizontal axis perpendicular to the roll axis. The yaw axis is an axis perpendicular to the roll axis and the pitch axis. The rotation angles around the roll axis, pitch axis and yaw axis are called the roll angle, pitch angle and yaw angle, respectively. The attitude data measured by the attitude measurement unit 19 is used in the data processing unit 18 to correct at least one of the roll angle, pitch angle and yaw angle.

[0034] The position and orientation of the weight of the plumb bob 15 may be measured by the laser scanner 12. Therefore, the laser scanner 12 may at least partially also function as the attitude measurement unit 19. The data acquisition unit 17 may include a camera that images the plumb bob 15 as the attitude measurement unit 19, and the attitude measurement unit 19 may measure the position and orientation of the plumb bob 15 from the image captured by the camera. In addition, to detect the attitude data of the main body 11, the measuring device 10 may include a gyro sensor as the attitude measurement unit 19. In this case, the plumb bob 15 is not required. The gyro sensor may detect rotation around three axes, including the yaw axis.

[0035] The position measuring unit 20 measures the longitudinal position of the main body 11 inside the conduit 30. The position measuring unit 20 may include a rotary encoder that measures the amount of rotation of the rotating body 16 and converts this amount of rotation into an electrical signal to detect the distance traveled by the main body 11. The main body 11 may have multiple tires, one of which may be used as the rotating body 16 for detecting the distance traveled. The position measuring unit 20 may measure the position of the main body 11 by any other means.

[0036] (Configuration of the data processing unit) Next, the data processing unit 18 will be described. The data processing unit 18 includes an input unit 21, a control unit 22, a storage unit 23, and an output unit 24. The data processing unit 18 of this disclosure can also be implemented by a computer and a program. The program can be recorded on a recording medium or provided via a network.

[0037] The input unit 21 receives input to the data processing unit 18. If the data acquisition unit 17 and the data processing unit 18 are mounted on different hardware, the input unit 21 may include a communication interface for receiving input signals from the data acquisition unit 17. The data processing unit 18 can acquire point cloud data measured by the laser scanner 12, attitude data measured by the attitude measurement unit 19, and position data measured by the position measurement unit 20. The input unit 21 may further include a keyboard, mouse, touch panel, microphone, etc., for the user of the measuring device 10 to input instructions and information to the measuring device 10.

[0038] The control unit 22, like the control unit 12h of the laser scanner 12, includes one or more processors. The control unit 22 may manage the overall operation of the data processing unit 18. The control unit 22 may execute processing according to a program stored in the storage unit 23.

[0039] The control unit 22 acquires first point cloud data from the laser scanner 12. From the first point cloud data, the control unit 22 generates second point cloud data showing the shape of the inner surface 30a of the conduit 30. Based on the shape of the reflector 13 and the positional relationship between the reflector 13 and the laser scanner 12, the control unit 22 performs a coordinate transformation from the first point cloud data to the second point cloud data. For example, as shown in Figure 4, when the measuring device 10 is placed inside the conduit 30, due to reflection by the reflector 13, point P(x, y, z) on the inner surface 30a of the conduit 30 is measured as an apparent point P'(x', y', z') inside the conduit 30. For this reason, the control unit 22 transforms the coordinates (x', y', z') of point P' included in the first point cloud data measured by the laser scanner 12 to the coordinates (x, y, z) of point P in actual space included in the second point cloud data. The conversion formula from coordinates (x', y', z') to coordinates (x, y, z) can be determined by the surface shape of the reflecting mirror 13 and its positional relationship with the laser scanner 12.

[0040] More specifically, the control unit 22 calculates the intersection point Q of the line connecting the origin O and point P' with the reflective surface 13a of the mirror 13, based on the shape of the reflective surface 13a of the mirror 13 and the coordinates of point P', when the center of the lens is the origin O (0,0,0) and the vertex of the reflective surface 13a is (0,0,d). The control unit 22 calculates the orientation of the reflective surface 13a of the mirror at the intersection point Q and determines a point P such that the length of QP is equal to QP' in the direction in which a light ray incident on the reflective surface 13a from the origin O is specularly reflected by the reflective surface 13a. The storage unit 23 may store a conversion formula or conversion table for converting point P' to point P. The control unit 22 may use the conversion formula or conversion table stored in the storage unit 23 to convert the first point cloud data into a second point cloud data.

[0041] The control unit 22 can acquire attitude data measured by the attitude measurement unit 19 and correct the point cloud data acquired from the laser scanner. For example, when the attitude measurement unit 19 measures the position of the weight of the plumb bob 15, the control unit 22 rotates the second point cloud data so that the orientation of the plumb bob 15 acquired from the laser scanner 12 is parallel to the vertically downward axis of the coordinate system of the laser scanner 12. This allows the attitude data of the pitch angle and roll angle of the laser scanner 12 to be reflected in the second point cloud data.

[0042] As shown in Figure 1, the measuring device 10 can measure the measurement range 30b adjacent to the reflector 13 on the inner surface 30a of the conduit 30 at each measurement position. The control unit 22 can synthesize the measurement data of the inner surface 30a of the conduit 30 in the longitudinal direction based on the position data indicating the longitudinal position of the laser scanner 12 inside the conduit 30, which is acquired from the position measurement unit 20. By moving the measuring device 10 from one end of the conduit 30 to the other end, the measuring device 10 can acquire three-dimensional data of the shape of the inner surface 30a of the entire conduit 30.

[0043] The storage unit 23 may be configured to include one or more of the following: semiconductor memory, magnetic memory, and optical memory, similar to the storage unit 12g of the laser scanner 12. The storage unit 23 may function, for example, as a main memory, auxiliary memory, or cache memory. The storage unit 23 may store information acquired by the data processing unit 18, information processed by the data processing unit 18, and information for operating the data processing unit 18. The storage unit 23 may store a program for operating the control unit 22.

[0044] The output unit 24 outputs the measurement results of the measuring device 10. The output unit 24 may include a display for displaying the measurement results of the measuring device 10. The display may be, for example, a liquid crystal display (LCD), an organic EL (Electro-Luminescence) display, or an inorganic EL display. The output unit 24 may include a communication interface for transmitting the measurement results externally. The output unit 24 may output the measurement results to a portable storage medium. The portable storage medium includes a USB (Universal Serial Bus) memory, an SD (Secure Digital) memory card, and the like.

[0045] In addition to the components shown in FIG. 2, the measuring device 10 may have a moving mechanism for moving inside the pipeline 30. For example, the measuring device 10 may include a plurality of tires and a motor for rotating the tires as the moving mechanism. Further, the measuring device 10 may be configured such that a cable or a rope is connected to the main body 11 as the moving mechanism and is pulled from one end of the pipeline 30.

[0046] (Example of Measuring Underground Pipelines) An example of measuring a pipeline 30 buried underground using the measuring device 10 will be described with reference to FIG. 5. The measuring device 10 can be used to measure the pipeline 30 connecting a plurality of manholes 31A and 31B. The iron covers 32A and 32B located on the ground surface of the manholes 31A and 31B can obtain position information including latitude, longitude, and elevation using the signals of the Global Navigation Satellite System (GNSS). GNSS includes, for example, GPS (Global Positioning System), GLONASS, Galileo, Beidou, etc. The end portions 33A and 33B that are the starting and ending points of the pipeline 30 in the manholes 31A and 31B can be identified using their relative positional relationships with the iron covers 32A and 32B, respectively. Since the positions of the starting and ending points of the pipeline 30 are identified and the three-dimensional shape of the entire pipeline 30 is identified by the measuring device 10, it becomes possible to accurately identify the position of the pipeline 30 underground. As a result, it becomes possible to easily output the position of the pipeline 30 on any topographic map and drawing that can be plotted with latitude, longitude, and elevation.

[0047] Also, as shown in FIG. 5, there may be a case where a plurality of pipelines 30 are laid in multiple lines between the manholes 31A and 31B. In that case, since the positional relationships of the respective pipelines 30 are determined, if the coordinates of one pipeline 30 can be grasped, the positions of the other pipelines 30 laid in multiple lines on the same route can be calculated. As a result, it becomes unnecessary to measure all the pipelines 30, and it becomes possible to efficiently confirm the positions of the pipelines 30.

[0048] (Measuring Method) Next, the measuring method executed by the control unit 22 of the data processing unit 18 of the measuring device 10 will be described with reference to the flowchart of FIG. 6.

[0049] First, the measuring device 10 is arranged at one end of the pipeline 30, and the measurement is started according to the user's instruction. When the measurement by the measuring device 10 is started, the control unit 22 acquires the first point cloud data measured by the laser scanner 12 from the data acquisition unit 17 (step S101).

[0050] The control unit 22 converts the first point cloud data into second point cloud data representing the shape of the inner surface 30a of the conduit 30, based on the shape of the reflector 13 and the positional relationship between the reflector 13 and the laser scanner 12 (step S102).

[0051] The control unit 22 corrects the roll and pitch of the second point cloud data converted in step S102 based on the position and orientation of the plumb bob 15 (step S103). Note that the roll and pitch correction may be performed on the first point cloud data before step S102.

[0052] The measuring device 10 measures the inner surface 30a of the pipeline 30 while moving. The control unit 22 combines second point cloud data showing the shape of the inner surface 30a of the pipeline 30, which was corrected in step S103, based on the longitudinal position information of the pipeline 30 measured by the sequential position measuring unit 20 (step S104). The control unit 22 sequentially stores the point cloud data obtained as measurement results as measurement data in the sequential storage unit 23.

[0053] The control unit 22 repeats the processes from steps S101 to S104 until the measuring device 10 reaches the other end of the conduit 30 or until the user stops the measurement (step S105: No). When the measuring device 10 reaches the other end or the user stops the measurement (step S105: Yes), the measuring device 10 outputs three-dimensional information of the conduit 30 to the output unit 24 based on the measurement data accumulated in the storage unit 23 up to that point.

[0054] As described above, the measuring device 10 of this disclosure is equipped with a reflector 13 and reflects the pulsed light emitted from the laser scanner 12 toward the inner surface 30a of the conduit 30, thereby measuring the inner surface 30a. As a result, the pulsed light is incident on the inner surface 30a at a small angle of incidence, so the intensity of the reflected light that is reflected by the inner surface 30a and returned to the laser scanner 12 becomes stronger. Therefore, the measuring device 10 can acquire accurate shape data of the inner surface 30a even in a narrow conduit 30. In this way, the technology for measuring the inner surface 30a of the conduit 30 is improved.

[0055] For example, as shown in Figure 7, the measuring device 10 can measure the protrusion 34 located in the measuring range 30b in three dimensions. In this case, since pulsed light is irradiated onto the inner surface 30a where the protrusion 34 is located at a relatively near-right angle, it is unlikely that a part of the inner surface 30a will be hidden by the shadow of the protrusion 34, creating a blind spot.

[0056] Furthermore, even if the pipeline 30 has a pipeline connection 35, as shown in Figure 8, the measuring device 10 can more accurately measure the connection of the pipeline 30 from a direction that is nearly vertical. This makes it possible to more accurately evaluate the integrity of the pipeline 30 when inspecting it.

[0057] Furthermore, the measuring device 10 of this disclosure has, for example, a posture measurement unit 19 using a plumb bob 15, which can correct errors in the measurement data caused by the rotation of the laser scanner 12 inside the conduit 30. This makes it possible to measure the shape of the conduit 30 more accurately.

[0058] Furthermore, since the measuring device 10 of this disclosure can sequentially connect and synthesize three-dimensional measurement data in the longitudinal direction of the pipeline 30, it can accurately measure the three-dimensional shape of the entire pipeline 30 and its installation position underground.

[0059] (Other Embodiments) Figure 9 shows a measuring device 10A according to another embodiment of the present disclosure. In Figure 9, components that are the same as or similar to the components in Figure 1 are denoted by the same reference numerals and their descriptions are omitted. The measuring device 10A is provided with two laser scanners 12A and 12B on both sides of the longitudinal direction of the conduit 30 when placed inside the conduit 30. Reflecting mirrors 13A and 13B are positioned in the measurement direction of each of the laser scanners 12A and 12B in Figure 9, supported by support parts 14A and 14B, respectively, similar to the measuring device 10 in Figure 1. Plumb bobs 15A and 15B are connected to the vertices of the reflecting mirrors 13A and 13B. The laser scanners 12A and 12B, reflecting mirrors 13A and 13B, support parts 14A and 14B, and plumb bobs 15A and 15B are configured similarly to the laser scanner 12, reflecting mirror 13, support part 14, and plumb bob 15 of the measuring device 10 in Figure 1, respectively. The point cloud data measured by the laser scanners 12A and 12B is processed in the same manner as the measurement device 10 described above.

[0060] With this configuration, the measuring device 10A can simultaneously measure two measurement ranges 30b1 and 30b2 using the respective laser scanners 12A and 12B. By expanding the measurement range in a single measurement, the accuracy of the generated three-dimensional model of the conduit 30 can be improved. In particular, since the relative positions of the two laser scanners 12A and 12B are fixed, it is possible to combine the point cloud data measured by the two laser scanners 12A and 12B using known information. This improves the accuracy of the generated three-dimensional measurement data.

[0061] Figure 10 shows a measuring device 10B according to yet another embodiment of the present disclosure. In Figure 10, components that are the same as or similar to those in Figure 9 are denoted by the same reference numerals and their descriptions are omitted. The measuring device 10B is equipped with two laser scanners 12A and 12B on both sides of the longitudinal direction of the conduit 30 when placed inside the conduit 30. Unlike the measuring device 10A shown in Figure 9, the measuring device 10B does not have a support 14A, a reflector 13A, and a plumb bob 15A in front of the right-hand laser scanner 12A.

[0062] The laser scanner 12A on the right side of Figure 10 can acquire shape information, such as the bending state, within a measurement range 30b1 that extends relatively far along the longitudinal direction of the pipe 30. The laser scanner 12B on the left side of Figure 10 can acquire detailed shape information within a measurement range 30b2 of the inner surface 30a that is relatively close to the laser scanner 12B. Therefore, the measuring device 10B in Figure 10 can simultaneously acquire three-dimensional information of both the longitudinal bending information and the detailed shape information of the inner surface 30a. This allows for the measurement of shape information, such as the longitudinal bending state of the pipe 30, in addition to measuring the shape of the inner surface 30a of the pipe 30. This improves the accuracy of the measurement of the pipe 30.

[0063] Although the embodiments described above are representative examples, it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited by the embodiments and examples described above, and various modifications and / or changes are possible without departing from the scope of the claims. For example, it is possible to combine multiple component blocks described in the embodiments and examples into one, or to divide one component block.

[0064] The following additional information is disclosed regarding the embodiments described above.

[0065] (Note 1) A measuring device inserted inside a conduit and for generating point cloud data showing the shape of the inner surface of the conduit, comprising: a laser scanner positioned to emit laser light toward the longitudinal direction of the conduit; a reflector positioned in the direction of the laser light emission from the laser scanner and reflecting the laser light emitted from the laser scanner toward the inner surface of the conduit, and reflecting the reflected light from the inner surface toward the laser scanner; a support portion for supporting the reflector with respect to the laser scanner; and a control unit that generates the point cloud data based on the reflected light data detected by the laser scanner and the shape of the reflector. (Note 2) The measuring device according to Note 1, wherein the reflector is one of a cone, a spherical mirror, a hyperbolic mirror, and a parabolic mirror having a convex shape toward the laser scanner. (Note 3) The measuring device according to Note 1 or 2, further comprising a position measuring unit for measuring the longitudinal position of the laser scanner, wherein the control unit synthesizes the point cloud data in the longitudinal direction based on the longitudinal position of the laser scanner measured by the position measuring unit. (Note 4) The measuring device according to any one of Notes 1 to 3, further comprising an attitude measuring unit for measuring the rotation angle around at least one of the rotation axes of the laser scanner, wherein the control unit corrects the point cloud data based on the rotation angle measured by the attitude measuring unit.

[0066] 10, 10A, 10B Measuring device 11 Main body 12, 12A, 12B Laser scanner 12a Light emission unit 12b Light detection unit 12c Scanning unit 12d Direction detection unit 12e Distance calculation unit 12f Coordinate calculation unit 12g Storage unit 12h Control unit 13, 13A, 13B Reflector 13a Reflecting surface 14, 14A, 14B Support unit 15, 15A, 15B Plumb bob 16 Rotating body 17 Data acquisition unit 18 Data processing unit 19 Attitude measurement unit 20 Position measurement unit 21 Input unit 22 Control unit 23 Storage unit 24 Output unit 30 Pipe 30a Inner surface 30b, 30b1, 30b2 Measurement range 31A, 31B Manhole 32A, 32B Iron cover 33A, 33B End portion 34 Projection 35 Pipe connection

Claims

1. A measuring device inserted inside a conduit and for generating point cloud data showing the shape of the inner surface of the conduit, comprising: a laser scanner positioned to emit laser light in the longitudinal direction of the conduit; a reflector positioned in the direction of the laser light emission from the laser scanner and reflecting the laser light emitted from the laser scanner toward the inner surface of the conduit, and reflecting the reflected light from the inner surface toward the laser scanner; a support portion for supporting the reflector relative to the laser scanner; and a control unit that generates the point cloud data based on the reflected light data detected by the laser scanner and the shape of the reflector.

2. The measuring device according to claim 1, wherein the reflecting mirror is one of a conical mirror, a spherical mirror, a hyperbolic mirror, and a parabolic mirror having a convex shape toward the laser scanner.

3. The measuring device according to claim 1 or 2, further comprising a position measuring unit for measuring the longitudinal position of the laser scanner, wherein the control unit synthesizes the point cloud data in the longitudinal direction based on the longitudinal position of the laser scanner measured by the position measuring unit.

4. The measuring device according to any one of claims 1 to 3, further comprising an attitude measurement unit for measuring the rotation angle around at least one of the rotation axes of the laser scanner, wherein the control unit corrects the point cloud data based on the rotation angle measured by the attitude measurement unit.

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