Measurement device
The measuring device with a light-shielding cylinder and telescopic mechanism addresses the challenge of noise interference in narrow conduits, enabling accurate shape measurement by blocking unmeasurable regions and adjusting for varying diameters.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NT T INC
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-25
AI Technical Summary
Existing measuring devices face challenges in accurately measuring the shape of narrow underground conduits due to blind zones and noise interference from unmeasurable regions, which degrade measurement accuracy.
A measuring device with a light-shielding cylinder positioned along the central axis of the conduit to block reflected light from unmeasurable regions, combined with a TOF camera or laser scanner to measure the inner surface of pipelines, and a telescopic mechanism to adjust the light-shielding cylinder's length for precise measurements.
The device effectively eliminates noise and interference, ensuring accurate measurement of the inner surface of small-diameter pipelines by blocking unwanted reflected light, thereby improving measurement accuracy and adaptability to varying conduit diameters.
Smart Images
Figure JP2024044668_25062026_PF_FP_ABST
Abstract
Description
Measuring device
[0001] The present disclosure relates to a measuring 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 improving the sophistication and efficiency of maintenance and management as point cloud data.
[0003] Three-dimensional digitization using point clouds involves connecting point clouds obtained by intermittently photographing infrastructure facilities by superimposing them based on their positions (coordinates), orientations, and shape features between the point clouds at the time of photographing, and creating a continuous three-dimensional model of the object. Facilities that can be confirmed 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. On the other hand, it is difficult to obtain position information by satellite positioning for underground infrastructure facilities, and their shape is also tunnel-shaped with few shape features. Therefore, the three-dimensional modeling of underground infrastructure facilities has not advanced as much as that of above-ground facilities.
[0004] As an example of an attempt to measure underground infrastructure facilities, Non-Patent Document 1 proposes a measurement method for obtaining point clouds using a measurement robot equipped with three laser scanners for cross-section measurement, vertical measurement, and horizontal measurement. In this method, point clouds obtained from pipelines with a relatively large diameter (800 mm to 7000 mm) such as sewer pipes are combined to generate a continuous three-dimensional model.
[0005] To acquire three-dimensional point cloud data, Time of Flight (TOF) laser scanners and TOF cameras capable of measuring distance from the measuring device are used. In the TOF method, the distance to the object is measured using the time it takes for light, such as laser light emitted from a light-emitting unit, to be reflected by the object being measured and detected by a light-receiving unit. By performing this measurement simultaneously or at high speed on a large number of points (e.g., 300,000 points), the three-dimensional shape of the object can be measured.
[0006] Shoji Otsuki, "Development of a Point Cloud Measurement System for Underground Pipes and Other Structures," Photogrammetry and Remote Sensing, Vol. 54, No. 6, pp. 275-279 (2015).
[0007] Today, there are a vast number of narrow communication conduits underground, such as those with a diameter of about 8 cm. Their total length in Japan alone reaches approximately 600,000 km. Within these narrow conduits, it is physically difficult to introduce a relatively large measurement robot equipped with three laser scanners, as described in Non-Patent Document 1.
[0008] Furthermore, TOF (Time of Flight) measuring devices used to measure point cloud data have a blind zone or blind area near the device, which is a region where measurement is difficult. In this application, this region is referred to as the "unmeasurable region." When the object to be measured is in such a region, the light emitted by the measuring device is reflected by the object and returns to the measuring device in a very short time. However, because the measuring device has insufficient response speed to the returned light, it may not be able to process the reflected light even if it is detected. In such cases, the light reflected from the object in the unmeasurable region becomes noise, which can degrade the measurement accuracy of the region that is normally measurable (referred to as the "measurable region"). In particular, when used in narrow conduits, reflection from the inner surface of the conduit at a short distance from the measuring device can degrade the measurement accuracy of the device within the conduit.
[0009] Therefore, the object of the present invention, which has been made with these points in mind, is to provide a measuring device that can accurately measure the shape inside a pipeline.
[0010] A measuring device according to one embodiment is a measuring device inserted into a pipeline and measuring point cloud data indicating the shape of the inner surface of the pipeline, and includes a light-emitting unit and a light-receiving unit that receives reflected light from the light-emitting unit that is reflected off the inner surface, and comprises a main body whose central axis of measurement range is oriented in the longitudinal direction of the pipeline, and a light-shielding cylinder that extends from around the light-receiving unit of the main body along the central axis and blocks the incidence of reflected light from an unmeasurable region of the inner surface to the light-receiving unit.
[0011] The measuring device described herein can accurately measure the shape inside a pipeline.
[0012] This figure shows a measuring device according to one embodiment positioned inside a pipeline. This is a block diagram illustrating the schematic configuration of the measuring device shown in Figure 2. This figure illustrates the method for calculating the length of the light-shielding tube. This is a flowchart illustrating the procedure of the measurement method executed by the control unit of the measuring device. This figure illustrates the challenges of measuring the shape of the inner surface of a pipeline using a TOF (Time-of-Flight) measuring device.
[0013] Before describing the embodiments of this disclosure, an example will be described using a measuring device 101, which is a relatively compact conventional TOF camera, to measure the inside of a narrow conduit 100 with a diameter of several centimeters to about 30 centimeters, with reference to Figure 5. In this case, the measuring device 101 irradiates light from the light-emitting unit 102 onto the object to be measured, and the light reflected by the object to be measured is received by the light-receiving unit 103. The object to be measured is the inner surface 100a of the conduit 100.
[0014] The measuring device 101 has an unmeasurable area of, for example, about 30 cm in front of the light-receiving unit 103. Therefore, if the surface on which the light-emitting unit 102 and light-receiving unit 103 of the measuring device 101 are arranged faces the inner surface 100a of the conduit 100, the light-receiving unit 103 of the measuring device 101 and the inner surface 100a become too close together, making measurement impossible.
[0015] On the other hand, as shown in Figure 5, it is possible to orient the measuring device 101 with the central axis C of the measurement range in the longitudinal direction of the conduit 100 and measure the shape of the inner surface 100a of the conduit 100 within the measurable area 105, which is farther away from the unmeasurable area 104. However, some of the light emitted from the light-emitting part 102 of the measuring device 101 may be reflected by the unmeasurable area 104 of the inner surface 100a of the conduit 100, becoming reflected light 106 and entering the light-receiving part 103 of the measuring device 101. When reflected light 106 from the unmeasurable area 104 enters the light-receiving part 103, it may generate noise and / or interfere with reflected light 107 from the measurable area 105, making accurate measurement impossible.
[0016] If there is reflected light 106 from such an unmeasurable region 104, the measuring device 101 may measure the inner diameter of the pipe 100 as larger than it actually is, and the cross-sectional shape of the pipe 100 may not be measured as a perfect circle. In addition, the relatively high-intensity reflected light incident from the relatively close unmeasurable region 104 may significantly shorten the measurable area in the longitudinal direction of the pipe.
[0017] One embodiment of this disclosure prevents deterioration of measurement accuracy in a pipeline by suppressing the incidence of such noise-causing reflected light on the light-receiving section of the measuring device. The measuring device of one embodiment of this disclosure will be described below with reference to the drawings. The dimensional ratios and other details in the drawings do not necessarily correspond to those in reality.
[0018] (Configuration of the measuring device) As shown in Figure 1, the 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 30 centimeters or less, and acquires point cloud data showing 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.
[0019] As shown in Figure 1, the measuring device 10 includes a main body 11 and a light-shielding cylinder 12. In one embodiment, the main body 11 is a TOF camera equipped with a light-emitting unit 13 and a light-receiving unit 14 (see Figure 2). The TOF camera of the main body 11 may use either a direct TOF method or an indirect TOF method. In the direct TOF method, the distance is calculated by measuring the time it takes for pulsed light emitted from the light-emitting unit 13 to be received by the light-receiving unit 14. In the indirect TOF method, the distance is calculated by measuring the phase difference between the light emitted from the light-emitting unit 13 and the light detected by the light-receiving unit 14 using a continuous wave.
[0020] The measuring device 10 is not limited to a TOF camera; a laser scanner employing the TOF method can also be used. The laser scanner acquires the shape of the object to be measured by scanning it with laser light and measuring the reflected light. When the measuring device 10 is a laser scanner, the direction of the center of the area scanned by the laser light is the direction of the central axis C.
[0021] The main body 11 is installed inside the conduit 30 with the central axis C of the measurement range facing the longitudinal direction of the conduit 30. The light-shielding cylinder 12 is a cylindrical member that extends along the longitudinal direction of the conduit 30 from the surface of the main body 11 on which the light-receiving unit 14 (see Figure 2) is located, surrounding the light-receiving unit 14. The light-shielding cylinder 12 is positioned to block reflected light 33 from the unmeasurable region 31 on the inner surface 30a of the conduit 30 from entering the light-receiving unit 14, and to allow reflected light 34 from the measurable region 32 to enter the light-receiving unit 14.
[0022] In one embodiment, the main body 11 has a shape that is elongated in the longitudinal direction of the conduit 30. The main body 11 has, for example, a cylindrical shape. The shape of the main body 11 may be other shapes such as a rectangular prism or a hexagonal prism. 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. The main body 11 may have means of movement including wheels and a motor for moving in the longitudinal direction of the conduit 30. The main body 11 may also have a wire attached to it for pulling it from the outside along the longitudinal direction of the conduit 30.
[0023] The configuration of the measuring device 10 will be described in more detail with reference to Figure 2. The main body 11 includes a light-emitting unit 13, a light-receiving unit 14, and a signal processing unit 17. The light-receiving unit 14 includes a lens 15 and an image sensor 16. The main body 11 may further include an extension / retraction mechanism 18 for extending and retracting the light-shielding cylinder 12. The main body 11 may also have a built-in battery. The main body 11 may not have a built-in battery and may receive power from an external battery via a power line. Although not required, the main body 11 may be connected to an external information processing device 40 via wired or wireless communication.
[0024] The light-emitting unit 13 is a light source that emits pulsed light in response to a signal from the signal processing unit 17, for example, in a direct TOF (Time-of-Flight) method. The light-emitting unit 13 may also emit continuously wave modulated light in an indirect TOF method. Multiple light-emitting units 13 are arranged on the outside of the light-shielding cylinder 12, spaced apart from each other. In the illustrated embodiment, four light-emitting units 13 are arranged around the light-shielding cylinder 12 at positions offset by approximately 90 degrees each. The number of light-emitting units 13 is not limited to four. The light-emitting unit 13 may be any of the following: a laser diode (LD) including a vertical cavity surface-emitting laser (VCSEL) and an edge-emitting laser (EEL), and a light-emitting diode (LED).
[0025] The lens 15 forms an image of light from the object to be measured onto the light-receiving surface of the image sensor 16. The lens 15 is not limited to a single lens, but may include two or more lenses. The optical axis of the lens 15 may coincide with the central axis C of the measurement range. The lens 15 may be located in the center of the side of the main body 11 where the light-shielding cylinder 12 is provided. The image sensor 16 is an image sensor capable of measuring time for each pixel arranged in two dimensions. As the image sensor 16, a SPAD (Single Photon Avalanche Diode) sensor compatible with the direct TOF method, or an image sensor with a CMOS image sensor structure compatible with the indirect TOF method is used.
[0026] The signal processing unit 17 controls the emission of light from the light-emitting unit 13, acquires signals detected by the image sensor 16, and generates point cloud data. The signal processing unit 17 may also generate a depth image by imaging the point cloud data. In Figure 2, the signal processing unit 17 is included in the main unit 11, but it is also possible for a part of the signal processing unit 17 to be not included in the main unit 11 and to be implemented in an external information processing device 40. The information processing device 40 may be a general-purpose device such as a PC (Personal Computer) or a dedicated device. The main unit 11 and the external information processing device 40 may be configured to send and receive data to and from each other by wired or wireless communication means. The signal processing unit 17 includes an acquisition unit 21, a control unit 22, a storage unit 23, and a transmission / reception unit 24.
[0027] The acquisition unit 21 is an interface for acquiring input signals from the image sensor 16. The acquisition unit 21 acquires information about the charge accumulated in each pixel of the image sensor 16. The acquisition unit 21 also acquires information such as the time difference or phase difference between the light emitted from the light-emitting unit 13 and the light received by the light-receiving unit 14 for each pixel.
[0028] The control unit 22 controls each part of the main unit 11. The control unit 22 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). The control unit 22 may manage the overall operation of the main unit 11. The control unit 22 may execute processing according to a program stored in the storage unit 23.
[0029] If the measuring device 10 employs a direct TOF method, the control unit 22 may transmit a signal to the light-emitting unit 13 to control the timing of emitting pulsed light from the light-emitting unit 13. If the measuring device 10 employs an indirect TOF method, the control unit 22 may transmit a signal to the light-emitting unit 13 to modulate the continuous wave light emitted from the light-emitting unit 13.
[0030] The control unit 22 calculates the time of flight T of light incident on each pixel of the image sensor 16 based on the signal from each pixel acquired by the acquisition unit 21. Based on the time of flight T, the control unit 22 calculates the distance L to the inner surface 30a of the pipe 30 to be measured, as detected by each pixel. The distance L to the measurement target can be calculated using the following formula, where c is the speed of light: L = c × T / 2 From the coordinates of the pixels on the image sensor 16 and the distance L, the control unit 22 can calculate point cloud data in a three-dimensional coordinate system. This allows the control unit 22 to measure the shape of the inner surface 30a of the pipe 30.
[0031] When the measuring device 10 performs a measurement, the control unit 22 illuminates one of the multiple light-emitting units 13 at a time. The control unit 22 does not illuminate multiple light-emitting units 13 simultaneously. For example, if there are four light-emitting units 13, the control unit 22 illuminates the four light-emitting units 13 one by one in sequence, performing a total of four or more measurements. In this way, the measuring device 10 ensures that there are no blind spots on the inner surface 30a of the conduit 30 where light from the light-emitting units 13 is blocked by the light-shielding cylinder 12 and therefore cannot be measured.
[0032] The storage unit 23 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 23 can sequentially store the three-dimensional coordinates of the point cloud data calculated by the control unit 22.
[0033] The main unit 11 may have means for measuring its position inside the conduit 30. While the main unit 11 moves inside the conduit, the control unit 22 may sequentially acquire data from the image sensor 16 to calculate point cloud data of the inner surface 30a of the conduit 30 and store it in the storage unit 23 along with the position information of the main unit 11. After or during the measurement of the conduit 30, the control unit 22 may synthesize the point cloud data stored in the storage unit 23 to calculate the shape of the inner surface 30a of the entire conduit 30.
[0034] The transmitting / receiving unit 24 includes, for example, a communication interface that supports wired and / or wireless communication for transmitting and receiving information to and from an external information processing device 40. The transmitting / receiving unit 24 may transmit point cloud data measured by the measuring device 10 and stored in the storage unit 23 to the external information processing device 40. The measuring device 10 and the external information processing device 40 may constitute a measurement system. In one embodiment, the control unit 22 of the measuring device 10 may receive instructions from the information processing device 40, such as the start of measurement, via the transmitting / receiving unit 24. The control unit 22 of the measuring device 10 may sequentially transmit the point cloud data measured during measurement to the information processing device 40. The information processing device 40 may calculate the shape of the inner surface 30a of the conduit 30 on behalf of the control unit 22, store it in the memory of the information processing device, and display it on the display of the information processing device 40.
[0035] The telescopic mechanism 18 extends and retracts the light-shielding cylinder 12 in the direction of the central axis C. Before starting the measurement, the control unit 22 may operate the telescopic mechanism 18 to adjust the length of the light-shielding cylinder 12 so that good point cloud data can be acquired. For example, the light-receiving part 14 side of the light-shielding cylinder 12 may be configured to be housed inside the main body 11. The light-shielding cylinder 12 may be able to move forward or backward in the direction along the central axis C. The telescopic mechanism 18 may include a motor. The rotation of the motor may be converted into the movement of the light-shielding cylinder 12 to move forward or backward via any mechanical mechanism.
[0036] In addition to the above-mentioned components, the main body 11 may have means for measuring the displacement of the central axis C of the main body 11 with respect to the center of the conduit 30, and / or the horizontal and vertical inclination of the main body 11 with respect to the longitudinal direction of the conduit 30. The main body 11 may also have means for suppressing these displacements and inclinations to stabilize the position and orientation of the main body 11. The main body 11 may also have sensors such as acceleration sensors for detecting movement inside the conduit 30.
[0037] The light-shielding tube 12 may be a cylindrical member surrounding the light-receiving part 14 of the main body 11. The light-shielding tube 12 blocks the light emitted from the light-emitting part 13 and reflected off the inner surface 30a of the conduit 30 located in the non-measurable region 31, preventing it from reaching the light-receiving part 14. The light-shielding tube 12 is positioned so that the light emitted from the light-emitting part 13 and reflected off the inner surface 30a of the conduit 30 located in the measurable region 32 passes through the inside of the light-shielding tube 12 and reaches the light-receiving part 14. Preferably, the measuring device 10 is positioned so that its central axis C (i.e., the optical axis of the lens 15) coincides with the central axis of the conduit. The inner diameter and length of the light-shielding tube 12 may be determined to satisfy the above requirements. If the central axis C of the measuring device 10 is misaligned from the longitudinal direction of the conduit 30 during measurement, the inner diameter and length of the light-shielding tube 12 may be determined so that, even considering the misalignment, reflected light reflected in the unmeasurable region 31 does not enter the light-receiving unit 14.
[0038] As an example, consider the case shown in Figure 3, where the inner diameter of the conduit 30 is 83 mm (radius 41.5 mm), the inner diameter of the light-shielding tube 12 is 20 mm (radius 10 mm), and the boundary between the unmeasurable region 31 and the measurable region 32 of the measuring device 10 is 300 mm in front of the light-receiving unit 14. In this case, the following proportion holds from the relationship of the side lengths of similar triangles. Here, x is the length of the light-shielding tube 12. x:300 = 10:41.5 From the above equation, in the example shown in Figure 3, the length of the light-shielding tube 12 can be calculated to be 72.3 mm. In this way, when the inner diameter of the light-shielding tube 12 is given, the length of the light-shielding tube 12 for blocking the incidence of reflected light from the unmeasurable region 31 can be determined.
[0039] The light-shielding tube 12 is made of a material that easily absorbs the light emitted by the light-emitting part 13. For example, a sponge-like urethane foam can be used as the material for the light-shielding tube 12. In addition, the outer and inner surfaces of the light-shielding tube 12 have a color that easily absorbs the light emitted by the light-emitting part 13, such as black. This prevents reflected light from the unmeasurable area 31 from being reflected by the outer surface of the light-shielding tube 12 and then repeatedly reflected before entering the light-receiving part 14. Furthermore, it prevents reflected light from the measurable area 32 from hitting the inner surface of the light-shielding tube 12 and being reflected again (secondary reflection) before reaching the light-receiving part 14, which can cause noise and / or measurement errors.
[0040] (Measurement Method) Next, the measurement method performed by the control unit 22 of the measuring device 10 will be explained with reference to the flowchart in Figure 4. The flowchart in Figure 4 assumes that the measuring device 10 has a function to automatically adjust the length of the light-shielding tube 12. Before starting the measurement, the user of the measuring device 10 installs the measuring device 10 inside the conduit 30. In the initial state, the light-shielding tube 12 may be in its shortest state, housed to the maximum extent within the main body 11.
[0041] When the measuring device 10 is activated, the control unit 22 operates the light-emitting unit 13 and the image sensor 16 to start measuring the shape of the inner surface 30a of the conduit 30 (test measurement) (step S101).
[0042] In step S101, the control unit 22 calculates the inner diameter of the conduit 30 from the measurement results of the inner surface shape of the conduit 30 (step S102). The control unit 22 may further calculate the roundness of the conduit 30. The control unit 22 may calculate the inner diameter and roundness of the conduit 30 closest to the light receiving unit 14 of the measuring device 10.
[0043] The control unit 22 determines whether the inner diameter of the conduit 30 obtained in step S102 matches the predetermined inner diameter of the conduit 30 (step S103). The predetermined inner diameter of the conduit 30 is the inner diameter specified in the specifications of the conduit 30 to be measured. The control unit 22 can use not only the inner diameter of the conduit but also the degree of roundness of the conduit 30 as a criterion for determining whether the measurement result of the conduit 30 matches the dimensions of the conduit.
[0044] In step S103, when the length of the light-shielding cylinder 12 is short and the reflected light reflected by the non-measurable area 31 enters the light-receiving unit 14, the control unit 22 cannot accurately measure the inner diameter of the pipeline 30. When the dimension of the inner diameter of the pipeline 30 calculated as a result of measuring the pipeline 30 does not match the predetermined inner diameter of the pipeline 30 (step S103: No), the control unit 22 adjusts the length of the light-shielding cylinder 12 (step S104). Each time the control unit 22 executes step S104, the light-shielding cylinder 12 may be extended or advanced by a predetermined length in the longitudinal direction of the pipeline 30. After step S104, the control unit 22 returns to the process of step S101.
[0045] In step S103, when the dimension of the inner diameter of the pipeline 30 calculated as a result of measuring the pipeline 30 matches the predetermined inner diameter of the pipeline 30 (step S103: Yes), the control unit 22 determines the length of the light-shielding cylinder 12 to be the length at that time (step S105). At this time, the light-shielding cylinder 12 has a length that can block the incidence of the reflected light from the non-measurable area 31 to the light-receiving unit 14.
[0046] The control unit 22 fixes the length of the light-shielding cylinder 12 to the length determined in step S105 and starts the shape measurement (this measurement) of the pipeline 30 (step S106). The control unit 22 acquires the point cloud data of the inner surface 30a of the pipeline 30.
[0047] After measuring the inner surface 30a of the pipeline 30 in step S106, the measuring device 10 moves to the next measurement point (step S107). When the measuring device 10 has a moving means for moving inside the pipeline 30, the control unit 22 may control the moving means to move inside the pipeline 30. Further, the measuring device 10 may be pulled from the outside by a wire or the like. Until the measurement of the pipeline 30 is completed (step S108: No), the control unit 22 repeatedly executes steps S106 and S107 to perform the shape measurement inside the pipeline 30.
[0048] When the measuring device 10, for example, finishes moving from one end to the other end inside the pipeline 30 to be measured, it ends the measurement (step S108). The control unit 22 may synthesize the point cloud data of the inner surface 30a of the pipeline 30 stored in the storage unit 23 to calculate the shape of the entire pipeline 30. The process of synthesizing the shape data of the entire pipeline 30 may be performed by another device including an external information processing device 40.
[0049] As described above, according to the measuring device 10 according to the present embodiment, a light shielding cylinder 12 is provided to block the reflected light from the non-measurable area 31 of the inner surface 30a of the pipeline 30 from entering the light receiving unit 14. Thereby, the measuring device 10 can eliminate noise and / or interference that inhibits measurement inside the pipeline 30, and can accurately measure the detailed shape of the inner surface 30a of the small-diameter pipeline 30. In addition, since the light shielding cylinder 12 is made of a material that is easy to absorb the light emitted by the light emitting unit 13, the generation of noise light can be reduced, and the measurement accuracy of the inner surface 30a of the pipeline 30 can be further improved.
[0050] In the measuring device 10 of the present embodiment, a plurality of light emitting units 13 are arranged at positions separated from each other outside the light shielding cylinder 12. Thereby, it is possible to prevent a region where the irradiation of light from the light emitting unit 13 is blocked by the light shielding cylinder 12 and becomes a blind spot, resulting in an area where measurement cannot be performed.
[0051] Furthermore, when the measuring device 10 includes a telescopic mechanism 18 that expands and contracts the light shielding cylinder 12 along the central axis C, the length of the light shielding cylinder 12 can be adjusted so that the inner diameter of the pipeline 30 calculated from the point cloud data measured by the light receiving unit 14 approaches a predetermined value. Thereby, the measuring device 10 can automatically adjust the length of the light shielding cylinder 12 so as not to detect the reflected light from the non-measurable area 31 by the light receiving unit 14. In addition, since the length of the light shielding cylinder 12 is optimally adjusted according to the inner diameter of the pipeline 30 to be measured, the measuring device 10 of the present embodiment can accurately perform shape measurement on pipelines 30 with various inner diameters.
[0052] 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.
[0053] While the embodiments described herein have primarily focused on the apparatus, these embodiments can also be implemented as methods that include steps performed by each component of the apparatus. The signal processing unit of the embodiments described herein can also be implemented using a computer and a program, and the program can be recorded on a recording medium or provided via a network. These are also included within the scope of this disclosure.
[0054] The following additional information is disclosed regarding the embodiments described above.
[0055] (Note 1) A measuring device inserted into a conduit and measuring point cloud data indicating the shape of the inner surface of the conduit, comprising: a main body which includes a light-emitting unit and a light-receiving unit that receives reflected light from the light-emitting unit that has been reflected off the inner surface, and whose central axis of measurement range is oriented toward the longitudinal direction of the conduit; and a light-shielding cylinder which extends from around the light-receiving unit of the main body along the longitudinal direction and blocks the incidence of reflected light from an unmeasurable region of the inner surface to the light-receiving unit. (Note 2) The measuring device according to Note 1, wherein the main body includes a plurality of light-emitting units which are spaced apart from each other on the outside of the light-shielding cylinder. (Note 3) The measuring device according to Note 1, wherein the main body is a TOF camera or a laser scanner. (Appendix 4) The measuring device according to Appendix 1, further comprising: an extension / retraction mechanism for extending and retracting the light-shielding cylinder in the longitudinal direction; and a control unit for extending and retracting the light-shielding cylinder so that the inner diameter of the conduit calculated from the point cloud data approaches a predetermined value.
[0056] 10 Measuring device 11 Main body 12 Light-shielding tube 13 Light-emitting unit 14 Light-receiving unit 15 Lens 16 Image sensor 17 Signal processing unit 18 Telescopic mechanism 21 Acquisition unit 22 Control unit 23 Storage unit 24 Transmitting / receiving unit 30 Conduit 30a Inner surface 31 Non-measurable area 32 Measurable area 40 Information processing device C Central axis
Claims
1. A measuring device inserted into a conduit to measure point cloud data indicating the shape of the inner surface of the conduit, comprising: a main body which includes a light-emitting unit and a light-receiving unit which receives reflected light that has been reflected off the inner surface from the light-emitting unit, and whose central axis of measurement range is oriented in the longitudinal direction of the conduit; and a light-shielding cylinder which extends from around the light-receiving unit of the main body along the central axis and blocks the incidence of reflected light from an unmeasurable region of the inner surface to the light-receiving unit.
2. The measuring device according to claim 1, wherein the main body includes a plurality of light-emitting units arranged apart from each other on the outside of the light-shielding cylinder.
3. The measuring device according to claim 1, wherein the main body is a TOF camera or a laser scanner.
4. The measuring device according to claim 1, further comprising: an extension / retraction mechanism for extending and retracting the light-shielding cylinder in the longitudinal direction; and a control unit for extending and retracting the light-shielding cylinder so as to bring the inner diameter of the conduit calculated from the point cloud data closer to a predetermined value, or so as to bring the shape of the inner surface of the conduit calculated from the point cloud data closer to a perfect circle.