Segment assembly system
The segment assembly system uses a stereo camera and laser irradiators for three-dimensional imaging to enhance positional accuracy and safety in shield tunneling, addressing the inefficiencies of conventional methods by enabling remote and precise segment piece alignment.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TAISEI CORP
- Filing Date
- 2022-10-06
- Publication Date
- 2026-07-22
AI Technical Summary
Existing segment assembly methods in shield tunneling require manual, time-consuming, and costly processes for positioning segment pieces, especially in confined spaces, with single-eye cameras limiting depth perception and requiring repetitive adjustments, complicating the assembly process.
A segment assembly system using a stereo camera and laser irradiators to provide three-dimensional imaging and positional data, allowing for efficient and accurate alignment of segment pieces through a head-mounted display, enabling remote operation of the erector.
Enables efficient and safe segment assembly by providing three-dimensional positional awareness, reducing manual effort and construction time, and eliminating the need for repetitive adjustments, thus improving overall construction efficiency.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a segment assembly system used for assembling segments in the shield method.
Background Art
[0002] In the shield method, at the rear of the shield tunneling machine, a plurality of segment pieces are assembled circumferentially to form a segment ring, and the segment ring is axially connected to an existing segment ring to form a cylindrical segment (tunnel lining). When assembling segments, it is generally performed by operating an erector that grips the segment piece. Usually, the work is carried out while visually checking the assembly position of the segment piece. However, inside the shield tunneling machine where various devices and equipment are arranged, in order to visually check the assembly position, it is necessary for the operator to change the body posture or move in a narrow space, which places a burden on the operator. In addition, the movement of people at the rear of the shield machine where multiple devices are operating needs to be carried out carefully to ensure safety. Furthermore, in the case of a large cross-section tunnel, it is necessary to install a gondola called a swing scaffold, which is time-consuming and costly. On the other hand, when a gondola cannot be installed, it takes time for long-distance movement. Therefore, a method for checking the assembly position of segment pieces using a captured image of a camera has been developed. For example, Patent Document 1 discloses a segment assembly method in which a camera attached to an erector captures a segment piece gripped by the erector and an existing segment piece that is the attachment destination of the segment piece, and the erector is operated while checking the captured image on a monitor to assemble the segment piece at a predetermined position. However, in the segment assembly method of Patent Document 1, since a single-eye camera is used, only a planar image can be captured, and the positional relationship in the planar depth direction cannot be grasped. Furthermore, Patent Document 2 discloses a segment assembly method in which a slit light is shone on the boundary between a segment piece and an existing segment piece to which the segment piece is assembled, and a correction amount is calculated from an image of this slit light to adjust the position of the segment piece relative to the existing segment piece. In the segment assembly method described in Patent Document 2, the segment pieces are finely adjusted by operating the erector according to the correction amount. Therefore, positioning the segment pieces requires repeating the calculation of the correction amount and the fine adjustment of the segment pieces multiple times, making the process complex. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-235998 [Patent Document 2] Japanese Patent Publication No. 2000-213294 [Overview of the project] [Problems that the invention aims to solve]
[0004] From this perspective, the present invention aims to propose a segment assembly system that enables efficient construction by appropriately understanding the positional relationship between newly installed segment pieces and existing segment pieces when assembling segment rings by remotely operating an erector. [Means for solving the problem]
[0005] The present invention, for solving the aforementioned problems, is a segment assembly system for assembling a segment ring at the rear of a shield tunneling machine, comprising: an erector for gripping a segment piece and moving it to a predetermined position; a stereo camera attached to the erector; and an image display unit for displaying an image captured by the stereo camera. In order to determine the relative positional relationship between the segment piece and the existing segment piece to which the segment piece is assembled, a laser irradiator is used to irradiate a line laser spanning the segment piece and the existing segment piece. The stereo camera comprises the segment piece and The aforementionedThe positional relationship between the joint surfaces of the existing segment pieces is positioned to allow for photography. Furthermore, based on the image information acquired by the line laser and the stereo camera, the three-dimensional relative positional relationship between the segment piece and the existing segment piece can be determined. Yes, they are. This segment assembly system utilizes image data from a stereo camera, allowing for accurate determination of the positional relationships between segment pieces, resulting in efficient construction. Specifically, the images captured by the stereo camera enable three-dimensional stereoscopic viewing, allowing for the determination of not only the position on a plane but also the relative position in the plane's depth direction. Therefore, the positioning of segment pieces can be performed easily and accurately.
[0006] Furthermore, if the image display unit is a head-mounted display, the wearer can change their orientation to view images in any direction. Furthermore, in order to determine the relative positional relationship between the segment piece and the existing segment piece, a laser irradiator is used to irradiate a line laser that spans both the segment piece and the existing segment piece. Equipped with Etei Therefore By calculating three-dimensional coordinates using the stereo method, the relative positions of the segment pieces are calculated, and information about the inter-segment distance (the distance between segment pieces) is obtained. Therefore, the operator can appropriately position the segment pieces by operating the system while viewing the image data, so that the inter-segment distance remains constant (the joint surfaces of the segments are parallel). Thus, this method is more efficient than conventional construction methods that involve repeating the operation of the erector and coordinate calculation multiple times. Furthermore, if a second laser irradiator is provided to emit a line laser to determine the positional relationship between the segment pieces and the outer periphery of the existing segment pieces, more detailed data regarding the positional relationship between the segment pieces can be obtained. [Effects of the Invention]
[0007] According to the segment assembly system of the present invention, when assembling segment rings by remotely operating the erector, it is possible to properly understand the positional relationship between newly installed segment pieces and existing segment pieces, thereby enabling efficient construction. [Brief explanation of the drawing]
[0008] [Figure 1] This is a cross-sectional view showing an overview of the segment assembly status using the segment assembly system according to an embodiment of the present invention. [Figure 2] This is a block diagram illustrating the overview of the segment assembly system. [Figure 3] This diagram shows a stereo camera, where (a) is a top view and (b) is a side view. [Figure 4] This is a front view showing the installation of the stereo camera. [Figure 5] This is a perspective view showing the irradiation position of the line laser at the boundary between segment pieces. [Modes for carrying out the invention]
[0009] This embodiment describes a case in which segment assembly in the shield tunneling method is performed remotely to reduce the effort required during assembly and improve construction efficiency. Figure 1 shows the segment assembly status. As shown in Figure 1, the segment ring 2 is formed at the rear of the shield tunneling machine 1 by combining multiple segment pieces 21. By pressing the shield jack against the assembled segment ring 2 and advancing the shield tunneling machine 1, a cylindrical tunnel lining made up of connected segment rings 2 is formed.
[0010] The segment pieces 21 are transported through the existing tunnel lining (existing segment rings 2) to the rear of the shield tunneling machine 1 from the tunnel entrance. The transported segment pieces 21 are assembled using the segment assembly system 3. Figure 2 shows an overview of the segment assembly system 3. As shown in Figure 2, the segment assembly system 3 comprises an erector 4, a stereo camera 5, an image display unit 6, a first laser irradiator 71, a second laser irradiator 72, and an image analysis means 8.
[0011] The erector 4 is located at the rear of the shield tunneling machine 1. The erector 4 is a device that grips the segment piece 21 and moves it to a predetermined position. As shown in Figure 1, it comprises a gripping part 41 for gripping the segment piece 21, a rotating frame 42 to which the gripping part 41 is attached, and a support part 43 that supports the rotating frame 42. The rotating frame 42 is supported by the support part 43 so as to be rotatable in the circumferential direction of the tunnel. The gripping part 41 is also movable forward and backward in the radial direction of the tunnel relative to the rotating frame 42. That is, the erector 4 grips the segment piece 21 with the gripping part 41, rotates the rotating frame 42, and then extends the gripping part 41 to position the segment piece 21 in the predetermined position.
[0012] Figure 3 shows the stereo camera 5. As shown in Figure 3(a), the stereo camera 5 is a device equipped with two lenses 51, 51 that enables three-dimensional imaging and is attached to the erector 4. The lenses 51, 51 are arranged so that their optical axes are parallel. In this embodiment, a wide-angle stereo camera capable of 180° or 360° VR imaging is used as the stereo camera 5. Figure 4 shows the installation of the stereo camera on the erector 4. As shown in Figure 4, the stereo camera 5 is attached to the rotating frame 42. The stereo camera 5 is capable of capturing the positional relationship between the joint surfaces of the segment piece 21 gripped by the gripping part 41 and the existing segment piece 21a to which the segment piece 21 is assembled. The images captured by the stereo camera 5 are transmitted to the image display unit 6. As shown in Figures 3(a) and (b), the stereo camera 5 of this embodiment includes a housing 52 that holds (houses) the camera and a mounting part 53 fixed to the back surface of the housing 52. The mounting part 53 protrudes laterally from the housing 52 at the corner of the housing 52. As an example, a magnet 54 is fixed to the tip of the mounting part 53 as a means of fixing it to the erector 4. The stereo camera 5 is connected via Ethernet with PoE, and each camera supports RTSP (Realtime Transfer Streaming Protocol). As shown in FIG. 2, the captured images of the stereo camera 5 are aggregated at the PoE hub 31 installed on the erector 4 and connected to the in-tunnel Wi-Fi infrastructure through the Wi-Fi repeaters 32 and 33. In this embodiment, high-speed communication such as optical fiber or local 5G is used for data transfer in the tunnel pit. Note that the stereo camera 5 is not limited to PoE power supply, and for example, it may be equipped with a battery.
[0013] The image display unit 6 displays the images captured by the stereo camera 5. The image display unit 6 of this embodiment is a head-mounted display worn by the operator (see FIG. 2). While looking at the images displayed on the head-mounted display, the operator can operate the erector 4 to confirm and move the position of the segment piece 21 in real time during segment assembly. Here, since the arc length of the key segment 21k is shorter than the arc lengths of the other segment pieces 21, in this embodiment, as shown in FIG. 4, a stereo camera 5b for the key segment 21k and a stereo camera 5a for the other segment pieces 21 are respectively arranged on the erector 4. The operator performs the work while switching the images displayed on the image display unit 6 during the construction of the key segment 21k and during the construction of the other segment pieces 21.
[0014] The first laser irradiator 71 irradiates a line laser L1 for grasping the relative positional relationship between the segment piece 21 and the existing segment piece 21a. An irradiation example of the line laser is shown in FIG. 5. As shown in FIG. 5, the line laser L1 irradiates the boundary portion on the inner surface side of the segment piece 21 and the existing segment piece 21a so as to straddle the segment piece 21 and the existing segment piece 21a. The first laser irradiator 71 is equipped on the stereo camera 5 and irradiates in the shooting direction of the stereo camera 5. In the present embodiment, three line lasers L1 straddling the segment piece 21 and the existing segment piece 21a are irradiated in the tunnel circumferential direction, and by recognizing the intersection points of the ridge line on the inner surface side of the segment piece 21 and the line laser L1 by image analysis, the separation distance, inclination, and operation speed of the segment piece 21 with respect to the existing segment piece 21a can be confirmed in real time while performing the operation. Note that the number of line lasers L1 to be irradiated is not limited to three and may be determined as appropriate. For example, two or more may be used for a straight line, and three or more may be used for a curve.
[0015] As shown in FIG. 5, the second laser irradiator 72 irradiates a line laser L2 on the outer peripheral side boundary portion between the segment piece 21 and the existing segment piece 21a. The positional relationship on the outer peripheral side of the segment piece 21 and the existing segment piece 21a can be grasped by the line laser L2 (the intersection point between the end face 21e of each segment piece 21 and the line laser L2) irradiated from the second laser irradiator 72. In the present embodiment, three line lasers L2 straddling the segment piece 21 and the existing segment piece 21a are irradiated in the tunnel circumferential direction, and by recognizing the intersection points of the ridge line on the outer surface side of the segment piece 21 and the line laser L2 by image analysis, the separation distance, inclination, and operation speed of the segment piece 21 with respect to the existing segment piece 21a are confirmed in real time. The second laser irradiator 72 is disposed at a position where the line laser L2 can be irradiated to the outer peripheral side of the segment piece 21 by a holding means (not shown) extended from the erector 4 or the like as needed. Also, the number of line lasers L2 to be irradiated is not limited to three and may be determined as appropriate.
[0016] The image analysis means 8 analyzes the images captured by the stereo camera 5 to calculate the positional relationship between the segment pieces 21. Specifically, the image analysis means 8 uses line lasers L1 and L2 to calculate the distance and angle of the segment piece 21 to the existing segment piece 21a using three-dimensional coordinate calculation based on the stereo method. The analysis results from the image analysis means 8 are displayed on the head-mounted display (image display unit 6). Specifically, the image analysis means 8 calculates the coordinates of the intersection points P1 and P2 between the line lasers L1 and L2 and the edges (edges of the end faces 21e) of the segment piece 21, and the intersection points P1a and P2a between the line lasers L1 and L2 and the edges (edges of the end faces) of the existing segment piece 21a, and uses these coordinates to calculate the positional relationship between the segment piece 21 and the existing segment piece 21a. The operator assembles the segment piece 21 into a predetermined position by operating the erector 4 while checking the images captured by the stereo camera 5 and the analysis results of the image analysis means 8.
[0017] Next, we will explain how to assemble the segment ring 2 using the segment assembly system 3. The segment ring 2 is assembled at the rear of the shield tunneling machine 1 and is positioned within the ground G as the shield tunneling machine 1 excavates. The assembly of the segment ring 2 begins with transporting the segment pieces 21 from the tunnel entrance to the rear of the shield tunneling machine 1 (see Figure 1). The segment pieces 21 are transported using a transport means 11 provided inside the existing segment ring 2 formed at the rear of the shield tunneling machine 1. The segment piece 21, transported to the rear of the shield tunneling machine 1, is held by the gripping part 41 of the erector 4, and the rotating frame 42 is rotated to position it inside the installation site.
[0018] Next, the gripping portion 41 is pushed outward (towards the ground) to position the segment piece 21 in a predetermined location and to join it with other adjacent segment pieces 21 (existing segment pieces 21a). When joining the segment piece 21 to the existing segment piece 21a, the erector 4 is operated while confirming the positional relationship (distance, tilt, etc.) between the segment piece 21 and the existing segment piece 21a using image data from the stereo camera 5 displayed on the head-mounted display (image display unit 6).
[0019] According to the segment assembly system 3 of this embodiment, since image data from the stereo camera 5 is used, the positional relationship between the segment pieces 21 can be appropriately understood, and as a result, efficient construction becomes possible. In other words, because the images captured by the stereo camera 5 can be viewed in three dimensions, in addition to understanding the position on a plane, the relative position in the plane depth direction can also be understood. Furthermore, because the operator is viewing the image in three dimensions using a head-mounted display, they can view images from any direction by changing the orientation of their head. Therefore, they can also see parts of the erector that are in shadow (parts that are difficult to see with the naked eye). In addition to the positional awareness on a plane that is possible with a monocular camera, they can also grasp the relative position in the plane depth direction. In other words, in this implementation, the system using a 180° VR camera and VR goggles (head-mounted display) enables stereoscopic viewing, thereby simulating the situation as seen from erector 4 and facilitating positional alignment.
[0020] Because the Erector 4 can be remotely controlled, the time required to move through the tunnel to the segment assembly position is eliminated, making construction more efficient. Furthermore, by transmitting images from the stereo camera 5 with low latency, the segment ring 2 can be assembled by operating the erector 4 even from a position where the operating status cannot be visually observed. Therefore, there is no need to station personnel to visually confirm the position of the segment pieces 21, which reduces the effort (such as the effort required for personnel to move and safety management) and costs of construction.
[0021] Furthermore, the relative positions of the segment pieces are calculated using stereometric 3D coordinate calculations from the line laser image spanning the segment piece 21 and the existing segment piece 21a, providing information about the inter-segment distance and tilt angle. Therefore, the operator can appropriately position the segment piece 21 by manipulating it while viewing the image data so that the inter-segment distance and tilt angle become zero. Furthermore, by using a line laser to determine the positional relationship on the outer periphery of the segment piece 21 and the existing segment piece 21a, the positional relationship on the outer periphery of the segment pieces 21 themselves can also be determined, allowing for more efficient operation of the erector 4. In addition, by determining the positional relationship (distance, etc.) between the segment piece 21 and the existing segment piece 21a on the inside and outside of the segment piece 21, the inclination of the segment piece 21 relative to the existing segment piece 21a can be calculated, making it easier to understand the positional relationship.
[0022] Thus, the construction method using the segment assembly system 3 of this embodiment is a sequential control method that determines the amount of deviation in relative position and angle between segment pieces and operates the erector 4 to bring the amount of deviation closer to zero. Therefore, it is more efficient than conventional construction methods that repeat coordinate calculation (the work of calculating the correction amount) and operation of the erector 4 (positioning work according to the correction amount) multiple times.
[0023] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and each of the above-mentioned components can be modified as appropriate without departing from the spirit of the present invention. The image display unit 6 is not limited to a head-mounted display, but may also be a surface-type display or a tablet device monitor, for example. The second laser irradiator 72 may be installed as needed and may be omitted. Similarly, the first laser irradiator may be installed as needed. Note that the first laser irradiator 71 does not necessarily need to be mounted on the stereo camera 5; it can be appropriately installed in a position where a line laser can be irradiated across the segment piece 21 and the existing segment piece 21a. In the above embodiment, the case in which a line laser is irradiated between the segment pieces 21 was described, but the line laser may be irradiated in a grid pattern. By irradiating with a line laser in a grid pattern, the displacement of the segment pieces 21 in the direction of the tunnel axis and the displacement of the segment pieces 21 in the direction of the tunnel circumferential direction can be checked simultaneously.
[0024] In the above embodiment, the operator remotely controls the erector 4 while checking the image on the head-mounted display. However, the erector 4 may be automatically controlled to assemble the segment pieces 21 to predetermined positions according to the analysis results of the image analysis means 8. The means for fixing the stereo camera 5 is not limited to the magnet 54, but may also be a gripping means, bolts and nuts, etc. By connecting the ground level to a remote location with a dedicated fiber optic cable, the Erector 4 can be operated remotely from a room located within Japan (away from the construction site). In this way, based on a schedule created by adjusting the scheduled segment assembly times, one operator can handle the segment assembly for multiple projects. [Explanation of symbols]
[0025] 1. Shield tunneling machine 2-segment ring 21 Segment Pieces 3-segment assembly system 4 Erector 5 Stereo Cameras 6. Image display section 71 First Laser Irradiator 72 Second laser irradiator 8. Image analysis means G Ground
Claims
1. A segment assembly system for assembling segment rings at the rear of a shield tunneling machine, An erector that grips a segment piece and moves it to a predetermined position, A stereo camera attached to the aforementioned erector, An image display unit that displays images captured by the stereo camera, The system includes a laser irradiator that emits a line laser spanning the segment piece and the existing segment piece in order to determine the relative positional relationship between the segment piece and the existing segment piece, The stereo camera is positioned to capture the positional relationship between the joint surfaces of the segment piece and the existing segment piece. A segment assembly system characterized in that it is possible to determine the three-dimensional relative positional relationship between the segment piece and the existing segment piece based on image information acquired by the line laser and the stereo camera.
2. The segment assembly system according to claim 1, characterized in that the image display unit is a head-mounted display.
3. The segment assembly system according to claim 1, further comprising a second laser irradiator for irradiating a line laser for determining the positional relationship between the segment piece and the outer periphery of the existing segment piece.