A tunnel settlement monitoring device and method for extracting target feature points

Abstract

The application belongs to the technical field of civil engineering monitoring, and discloses a tunnel settlement monitoring device and method for extracting target feature points, which comprises a long-span flexible support, the long-span flexible support is arranged along the tunnel direction, the long-span flexible support is supported by a long-span shaft, the long-span shaft is arranged in parallel along the tunnel axial direction, a swing rod is rotatably connected to the long-span shaft, and a driving element for driving the swing rod to rotate is arranged on the long-span flexible support; a visual controller is installed on the swing rod of the long-span flexible support, and is used for collecting images of targets at measuring points on the two sides of the tunnel cross-section vault in the circumferential direction at multiple set angles; a microcomputer terminal is used for controlling the rotation direction of the swing rod and collecting the rotation angle information of the swing rod, controlling the visual controller to collect image data of the targets at the measuring points at the set angles, and calculating the convergence deformation and vault settlement of each cross-section according to the collected images; the device and method can automatically detect the target at the preset position, and are convenient to use.

Description

Technical Field

[0001] This invention relates to the field of civil engineering monitoring technology, specifically to a tunnel settlement monitoring device and method for extracting target feature points. Background Technology

[0002] Current methods for monitoring tunnel settlement can be divided into two main categories: traditional manual monitoring and automated monitoring.

[0003] Traditional manual monitoring methods rely on staff using tools such as dial indicators and convergence meters to sequentially inspect each monitoring section along the route, or on setting up deformation observation stations in tunnels and using precision measuring equipment such as theodolites, levels, and distance measuring instruments to measure and perform data processing to understand tunnel deformation. These methods are highly dependent on manual labor, inefficient, and cannot avoid human error.

[0004] While 3D laser scanning and measurement robots are common automated methods for monitoring tunnel deformation, they are expensive and require significant financial investment to achieve full-line inspection of subway systems.

[0005] Therefore, there is an urgent need to design a tunnel settlement monitoring device and method that can automatically detect targets at preset locations. Summary of the Invention

[0006] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a tunnel settlement monitoring device and method for extracting target feature points, which can automatically detect targets at preset positions and is easy to use, thereby solving the technical problems of low efficiency and high cost of existing devices and methods.

[0007] To achieve the above objectives, according to one aspect of the present invention, a tunnel settlement monitoring device for extracting target feature points is provided, comprising: A long-span flexible support is provided, which is arranged along the tunnel direction. The long-span flexible support supports a long-span shaft, which is arranged parallel to the tunnel axis. A swing arm is rotatably connected to the shaft, and a driving component for driving the swing arm to rotate is provided on the long-span flexible support. The long-span flexible support includes two side columns and a central cable located between the two side columns; the driving component includes a transmission component and a drive motor, the transmission component includes a rotating arm, the rotation center of the rotating arm is coaxially arranged with the center of the long-span shaft; the drive shaft of the drive motor is connected to the rotating arm, driving the rotating arm to swing back and forth in the circumferential direction; a rotating cable is connected between the two rotating arms, and the swing arm is arranged between the long-span shaft and the rotating cable; the inner end of the swing arm is rotatably connected to the long-span shaft, and the outer end of the swing arm is snapped and fixed to the rotating cable; A vision controller, mounted on the swing arm of the long-span flexible support, is used to acquire images of targets at measuring points on the tunnel cross-section arch and both sides at multiple set angles in the circumferential direction. The microcomputer terminal is used to control the rotation direction of the pendulum and collect the rotation angle information of the pendulum, control the vision controller to collect image data of the target at the measurement point at the set angle, and calculate the convergence deformation of each section and the settlement of the arch based on the collected images.

[0008] Preferably, a crossbeam is fixedly installed in the middle of the two side columns, and the two side columns are respectively fixedly connected to both ends of a long span shaft; the long span shaft is located directly above the central cable, and several support rods that support the long span shaft along the height direction are locked to the central cable.

[0009] Preferably, the upper and lower ends of the support rod are respectively provided with slots, the long span shaft is engaged in the slots at the upper ends of multiple support rods, and the slots at the lower ends of multiple support rods are respectively engaged in the central cable.

[0010] Preferably, the support rod is a plastic rod or a metal rod.

[0011] Preferably, the long-span flexible support also includes two load-bearing cables located between the two side columns, and a number of tripods arranged along the height direction are provided between the central cable and the two load-bearing cables along their length direction.

[0012] Preferably, a bushing is provided between the swing arm and the long-span shaft. The bushing is movably fitted outside the long-span shaft and can rotate relative to it. The bushing is fixedly connected to one end of the swing arm, and the other end of the swing arm is provided with a locking hole. One side of the locking hole is provided with an opening for the rotating cable to be pressed into the locking hole. Each swing arm has an arc-shaped part extending outward. A vision controller and a light intensity sensor are provided at intervals on the outer end face of the arc-shaped part. The vision controller is a monocular camera.

[0013] Preferably, the system also includes a middle column located between the two side columns, with a central cable passing through the middle column and two load-bearing cables locked and fixed to both sides of the crossbeam on the middle column to divide the long tunnel with a large span into sections. The middle column is equipped with the drive motor and the rotating arm.

[0014] Preferably, the two ends of the load-bearing cable extend outward and connect to the ground to form a stay cable.

[0015] To achieve the above objectives, according to another aspect of the present invention, a method for monitoring tunnel settlement by extracting target feature points is provided, comprising the following steps: S1: The tunnel settlement monitoring device described above is installed inside the tunnel. Targets are pre-set at measuring points A, B and C in the middle of the tunnel cross-section arch and the two side walls. The targets include a black metal plate for assisting in the identification of the structure and a reflective sheet for reflecting light. S2: The targets mentioned in step S1 are distributed along a circumferential direction perpendicular to the ground on the inner wall of the tunnel to form a settlement monitoring unit. Multiple settlement monitoring units are distributed at intervals along the tunnel axis, and vision controllers on several swing arms correspond one-to-one with the settlement monitoring units for monitoring. S3: Based on the settlement monitoring unit in step S2, by setting the angle and position of the vision controller, several vision controllers are aimed at the target location to be measured and take pictures. By reciprocating the swing arm, images of the target at the tunnel cross-section arch and the two sides of measuring point A, measuring point B and measuring point C are collected, and the automatic monitoring program is run.

[0016] The target uses a 4cm rhomboid diamond reflector, which is attached to a black metal plate. The image is analyzed by recognizing the changes in pixel position and length of the reflector's outline. The reflector is square; initially, the pixel coordinates of the two corner points along one diagonal of the reflector are designated as (x1, y1) and (x2, y2). After a period of time, the pixel coordinates of these two corner points are designated as (x...). 1’ y 1’ ), (x 2’ y 2’ Then, the settlement value at the target location during this period is:

[0017] in, This represents the settlement value.

[0018] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art: 1. The tunnel settlement monitoring device and method of the present invention are applicable to newly excavated highway tunnels or water conservancy tunnels where vehicle traffic is inconvenient. The central cable can fix a large span between the side columns, facilitating the installation of long-span shafts. The two ends of the long-span shaft are fixedly connected to the two side columns respectively. Several support rods are located below the side columns to enhance their rigidity. These support rods bear the weight of the central cable. The high rigidity and stability of the flexible support structure where the central cable is located give the long-span shaft a rigidity and stability far exceeding its own, enhancing the stability around the long-span shaft. Simultaneously, the long-span shaft is a rigid rod, further enhancing the stability of the swing arm rotation. The long-span flexible support structure exhibits excellent adaptability to the tunnel surface and internal space during its construction.

[0019] 2. This invention uses a servo motor to drive a rotating arm to reciprocate the swing arm, enabling the switching of multiple camera acquisition points in the circumferential direction. This facilitates long-distance use in tunnels, and the structure is simple and easy to use. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the structure assembled with several tripods, a central cable, and two load-bearing cables on a long-span flexible support in this embodiment.

[0021] Figure 2 This is a schematic diagram of the main view structure of this embodiment.

[0022] Figure 3 This is a schematic diagram of the assembly of the pendulum rod with the central cable and the rotating cable in this embodiment.

[0023] Figure 4 This is a cross-sectional view of the assembly structure of the support rod, central cable, and long-span shaft in this embodiment.

[0024] Figure 5 This is a schematic diagram of the initial position of the vision controller in this embodiment.

[0025] Figure 6 This is a schematic diagram of the end point position of the vision controller in this embodiment.

[0026] Figure 7 This is a schematic diagram of the structure in this embodiment where the rotating arm and servo motor are assembled on the side column.

[0027] Figure 8 This is a schematic diagram of the anchor points of the central cable and the load-bearing cable on the crossbeam in this embodiment.

[0028] Figure 9 This is a schematic diagram of the structure of the center cable and load-bearing cable anchor points on the side columns of this embodiment.

[0029] In the attached diagram: 1-Side column, 2-Central cable, 41-Rotating arm, 42-Drive motor, 5-Tripod, 6-Rotating cable, 7-Swing rod, 71-Single-lens camera, 72-Light intensity sensor, 73-Shaft sleeve, 74-Holding hole, 75-Opening, 8-Long span shaft, 9-Bearing cable, 91-Stay cable, 12-Crossbeam, 21-Support rod, 211-Slot, 100-Support base, 101-Coupling, 102-Bearing seat, 103-Rotating shaft. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Please see Figures 1-9 The present invention provides a tunnel settlement monitoring device for extracting target feature points, comprising: A long-span flexible support is provided, which is set along the tunnel direction. The long-span flexible support supports a long-span shaft 8, which is horizontal and suspended. The long-span shaft 8 is set parallel to the tunnel axis and a swing arm 7 is rotatably connected to it. The long-span flexible support is provided with a driving component to drive the swing arm 7 to rotate.

[0032] The long-span flexible support includes two side columns 1 and a central cable 2 located between the two side columns 1. The driving component includes a transmission component and a drive motor 42. The transmission component includes rotating arms 41, which are respectively installed on opposite sides of the two side columns 1. The rotation center of the rotating arms 41 is coaxially arranged with the center of the long-span shaft 8. The drive shaft of the drive motor 42 is connected to the rotating arms 41, driving the rotating arms 41 to swing back and forth in the circumferential direction. A rotating cable 6 is connected between the two rotating arms 41, and the swing rod 7 is arranged between the long-span shaft 8 and the rotating cable 6. The inner end of the swing rod 7 is rotatably connected to the long-span shaft, and the outer end of the swing rod 7 is snapped and fixed to the rotating cable 6.

[0033] A vision controller, mounted on the swing arm 7 of the long-span flexible support, is used to acquire images of targets at measuring points on the tunnel cross-section arch and both sides at multiple set angles in the circumferential direction; wherein the measuring points are measuring points A, B and C, which are pre-set at the middle positions of the tunnel cross-section arch and both side walls. The microcomputer terminal is used to control the rotation direction of the pendulum 7 and collect the rotation angle information of the pendulum 7, control the vision controller to collect image data of the target at the measurement point at the set angle, and calculate the convergence deformation of each section and the settlement of the arch based on the collected images.

[0034] A crossbeam 12 is fixedly installed in the middle of the two side columns 1, and the two side columns 1 are respectively fixedly connected to the two ends of a long-span axle 8. The long-span axle 8 is located directly above the central cable 2, and several support rods 21 that support the long-span axle 8 along the height direction are locked to the central cable 2. The central cable 2 can realize a large span range between the fixed side columns 1, which is convenient for the installation of the long-span axle 8 over a large span. The two ends of the long-span axle 8 are fixedly connected to the two side columns 1 respectively. Several support rods 21 are located below the side columns 1 to enhance their rigidity. The support rods 21 bear the weight on the central cable 2. The flexible support structure on which the central cable 2 is located has high rigidity and stability, which makes the long-span axle 8 have much higher rigidity and stability than itself, greatly enhancing the stability around the long-span axle 8. At the same time, the long-span axle 8 is a rigid rod, which further enhances the stability of the rotation of the swing arm 7. The long-span flexible support has good adaptability to the tunnel ground and internal space during the construction process and is easy to use.

[0035] The support rod 21 is provided with slots 211 at its upper and lower ends. The long-span shaft 8 is engaged in the slots 211 at the upper ends of multiple support rods 21, and the slots 211 at the lower ends of multiple support rods 21 are engaged in the central cable 2. In this embodiment, the support rod 21 is a plastic rod with a hollow plastic body, which is easy to manufacture, lightweight, and has sufficient support strength. In addition to the above embodiment, the support rod 21 can also be a metal rod or other composite rod, as long as it can provide support in the height direction.

[0036] The long-span flexible support also includes two load-bearing cables 9 located between the two side columns 1, and a number of tripods 5 are provided between the central cable 2 and the two load-bearing cables 9 along their length direction and along their height direction.

[0037] A bushing 73, made of stainless steel, is provided between the swing arm 7 and the long-span shaft 8. The bushing 73 is movably fitted onto the long-span shaft 8 and can rotate relative to it. The bushing 73 is fixedly connected to one end of the swing arm 7, and the other end of the swing arm 7 has a locking hole 74. One side of the locking hole 74 has an opening 75 for the rotating cable 6 to be pressed into the locking hole 74. Each swing arm 7 has an outwardly extending arc portion 70, and a vision controller and a light intensity sensor 72 are spaced apart on the outer end face of the arc portion 70. The vision controller is a monocular camera 71. The function of the stainless steel bushing 73 is to improve the stability of the swing arm's rotation, reduce the rotational frictional resistance between the swing arm 7 and the long-span shaft 8, and has a simple structure, which is convenient for mass assembly and use.

[0038] The load-bearing cable 9 extends outward at both ends and connects to the ground to form a stay cable 91, which helps to enhance the stability of the entire device.

[0039] In this embodiment, the central cable 2, the rotating cable 6, and the load-bearing cable 9 are all flexible cables. The fixing structures of the central cable 2, the load-bearing cable 9, and the tripod 5 are existing technologies. The fixing structures of the rotating cable 6 and the rotating arm 41 are also existing technologies and will not be discussed in detail here.

[0040] like Figure 7 As shown, two horizontally extending support seats are provided on opposite sides of the two side columns 1, and the servo motor 42 is mounted on the support seats. The lower end of the rotating arm 41 is fixedly connected to the outside of the output shaft of the servo motor 42.

[0041] The servo motor 42 adopts a through-shaft design, and the servo motor shaft is designed as a hollow structure, allowing the external long-span shaft 8 to pass through it, so that the long-span shaft 8 and the servo motor 42 can be driven coaxially. The two ends of the long-span shaft 8 pass through the shaft holes on the two side columns 1 and extend outward. The extended ends are clamped by upper and lower clamps, and then the upper and lower clamps are locked with bolts and nuts.

[0042] Specifically, such as Figure 9As shown, a crossbeam 12 is fixedly installed in the middle of the two side columns 1. The anchor points of the central cable 2 and the load-bearing cable 9 are at different positions on the same horizontal plane of the crossbeam 12. The anchor points at both ends of the central cable 2 are at the middle position of the upper end of the crossbeam 12, and the anchor points at both ends of the two load-bearing cables 9 are on the left and right sides of the upper end of the crossbeam 12. The central cable 2 is set horizontally at the anchor point, and the load-bearing cable 9 is set inclined at the anchor point. The two ends of the central cable 2 are locked to the anchor points on the crossbeam 12 by clamp anchors.

[0043] In this embodiment, a light intensity sensor 72 and a monocular camera 71 are mounted on the same swing arm 7. The monocular camera 71 is a type of vision sensor. The light intensity sensor 72 is used to detect the light intensity inside the tunnel. When the light intensity is insufficient, the supplementary light mounted on the swing arm 7 can be turned on to complete the normal detection.

[0044] The main load-bearing component on the long-span shaft 8 is a plastic swing arm, which has a small load-bearing capacity and does not require a thick solid metal rod. In this embodiment, the long-span shaft 8 is composed of multiple hollow stainless steel tubes connected sequentially. Adjacent stainless steel tubes are connected by threads, that is, one end of a stainless steel tube has an internal thread and the other end has an external thread. The end with the external thread can be inserted into the end of another stainless steel tube with an internal thread. The overall structure is simple, convenient for construction and assembly in tunnels, and easy to use.

[0045] In addition to the above embodiments, the long-span shaft 8 may also be made of rigid plastic, wood or other composite materials. The material of the long-span shaft 8 is not a limitation on the scope of protection of this application, but shall be a rigid material with sufficient rigidity.

[0046] In addition to the above embodiments, a middle column can be set between the two side columns 1 to divide the long tunnel with a large span into sections. In this case, servo motors and rotating arms are respectively set on both sides of the middle column, thereby dividing the long tunnel with a large span into two independent sections. The two sections share the central cable and the load-bearing cable, and each section has its own rotating cable. Each rotating cable works independently between the side columns and the middle column. At this time, the central cable 2 passes through the middle column, and the two load-bearing cables 9 are locked and fixed on both sides of the crossbeam on the middle column, thereby avoiding large swings due to the excessive length of the load-bearing cables.

[0047] The monitoring method based on the above-mentioned tunnel settlement monitoring device includes the following steps: S1: The tunnel settlement monitoring device is installed inside the tunnel. Targets are pre-set at measuring points A, B, and C on the tunnel cross-section arch and both sides. The targets include a black metal plate for auxiliary identification and a reflective sheet for reflection. That is, the target consists of two parts: one part is the auxiliary identification structure, including a black outer perimeter for auxiliary identification; the other part is the reflective sheet, which can reflect light. S2: The targets mentioned in step S1 are distributed along a circumferential direction perpendicular to the ground on the inner wall of the tunnel to form a settlement monitoring unit. Multiple settlement monitoring units are distributed at intervals along the tunnel axis, and vision controllers on several swing arms correspond one-to-one with the settlement monitoring units for monitoring. S3: Based on the settlement monitoring unit in step S2, by setting the angle and position of the vision controller, several vision controllers are aimed at the target location to be measured and take pictures. By reciprocating the swing arm, images of the target at the tunnel cross-section arch and the two sides of measuring point A, measuring point B and measuring point C are collected, and the automatic monitoring program is run.

[0048] The existing technology involves identifying target displacement using reflective targets and processing the acquired images with software algorithms to run an automatic monitoring program. Generally, the acquired images undergo grayscale processing, with Gaussian and median filtering applied to remove noise. After noise removal, the images are binarized. Contour detection is then performed on the filtered grayscale or binarized images, and the contours are filtered using area and roundness to obtain the reflective target feature points. The grayscale centroid method is then used to obtain the coordinates of these feature points in the image coordinate system, completing the identification of the reflective target feature points and their two-dimensional coordinate positioning in the image coordinate system. Combined with the initial calibration of the reflective film, calibration parameters are obtained, and the convergence deformation of the reflective target feature points and the settlement of the arch in the image coordinate system are calculated.

[0049] In this embodiment, the target uses a 4cm rhomboid diamond reflector, which is attached to a black metal plate. The image is analyzed by recognizing the changes in pixel position and length of the reflector's outline. The reflector is square; initially, the pixel coordinates of the two corner points along the diagonal of the reflector are designated as (x1, y1) and (x2, y2). After a period of time, the pixel coordinates of these two corner points along the diagonal are designated as (x...). 1’ y 1’ ), (x 2’ y 2’ Then, the settlement value at the target location during this period is:

[0050] 0≤ <a, Level I minor deformation, the surrounding rock is in a complete state of continuous elastic-plastic deformation, no support is required, or to prevent loose rock mass from falling due to tunneling disturbance, and also to optimize the tunnel cross-section and compensate for over- and under-excavation deficiencies, simple support can be provided by shotcrete; a≤ <b, Level 2, medium deformation, with single-crack shear fracture of the surrounding rock. To prevent further fracture, loosening, and collapse of the fractured rock mass under the influence of groundwater, artificial disturbance, or age-related deterioration of the surrounding rock strength, steel arch lining + shotcrete support is required, supplemented by random anchor bolts for local reinforcement of the fractured rock mass; b≤ <c, Level III severe large deformation, the surrounding rock undergoes X-type conjugate shear fracturing, and the fractured rock mass slides and dilates along the main shear zone. Lining + shotcrete + systematic anchor bolt / cable support is required. When the fracture range is shallow, systematic anchor bolt support can be used; when the fracture range is deep, anchor cable reinforcement can be used, and the anchoring end of the anchor bolt / cable should extend into the intact surrounding rock. At this level, the fractured blocks are large in size, and the anchor bolt / cable reinforcement effect is better, preventing large deformation of the fractured blocks along the main shear plane. x≥ The Class IV extremely severe deformation indicates that the weak surrounding rock has undergone pulverizing failure under high stress, making it difficult to form a clear main shear zone. The surrounding rock presents as fragmented blocks, resulting in a fragmentation and swelling effect. Therefore, grouting reinforcement is necessary to re-cement the fragmented blocks into a complete rock mass, enabling the surrounding rock itself to bear the load. This is supplemented by the aforementioned support measures, namely, implementing support measures mainly consisting of lining + shotcrete + systematic anchor bolts / cables + grouting reinforcement.

[0051] In this embodiment, a, b, c, and x are all preset parameters, and their actual values ​​can be adjusted.

[0052] In addition to the above-described implementation methods, such as Figure 8 In the second embodiment shown, the support base 100 is further provided with a bearing housing 102. A rotating shaft 103 is rotatably connected to the bearing housing 102 via a bearing. One end of the rotating shaft 103 is connected to the output shaft of the servo motor 42 via a coupling 101, and the other end of the rotating shaft 103 is integrally connected to the lower end of the rotating arm 41. The coupling 101 consists of a pair of connecting flanges, each integrally connected to the lower end of the rotating arm 41 and the output shaft of the servo motor 42, respectively. The two flanges are locked together with bolts and nuts.

[0053] The bearing housing 102 is used to bear weight, and the rotating arm 41 can withstand greater tensile strength, so that multiple rotating cables 6 can be used between a pair of rotating arms 41, which is beneficial to the stability of the device operation of the present invention.

[0054] There can be multiple rotating cables 6 between a pair of rotating arms 41. The multiple rotating cables 6 are arranged in parallel, and several swing rods 7 are respectively engaged with each of the rotating cables 6. The multiple rotating cables 6 are used to enhance the stability of the connection between the rotating cables 6 and the swing rods 7, and to ensure that the swing rods 7 rotate synchronously with the rotating arms 41.

[0055] The embodiments of the present invention are suitable for newly excavated highway tunnels or water conservancy tunnels with inconvenient vehicle access. During the construction of long-span flexible supports, they are highly adaptable to the tunnel surface and internal space, and are easy to use.

[0056] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tunnel settlement monitoring device for extracting target feature points, characterized in that, include: Long-span flexible support, the long-span flexible support is set along the tunnel direction, the long-span flexible support supports a long-span shaft (8), the long-span shaft (8) is set parallel to the tunnel axis, and a swing arm (7) is rotatably connected on it, and a driving component for driving the swing arm (7) to rotate is provided on the long-span flexible support; The long-span flexible support includes two side columns (1) and a central cable (2) located between the two side columns (1); the driving component includes a transmission component and a drive motor (42), the transmission component includes a rotating arm (41), the rotation center of the rotating arm (41) is coaxially arranged with the center of the long-span shaft (8); the drive shaft of the drive motor (42) is connected to the rotating arm (41), driving the rotating arm (41) to swing back and forth in the circumferential direction; a rotating cable (6) is connected between the two rotating arms (41), and the swing rod (7) is arranged between the long-span shaft (8) and the rotating cable (6); the inner end of the swing rod (7) is rotatably connected to the long-span shaft, and the outer end of the swing rod (7) is snapped and fixed to the rotating cable (6); A vision controller is installed on the swing arm (7) of the long-span flexible support and is used to acquire images of the target at the measuring points on the tunnel cross-section arch and both sides at multiple set angles in the circumferential direction. The microcomputer terminal is used to control the rotation direction of the pendulum (7) and collect the rotation angle information of the pendulum (7), control the vision controller to collect the image data of the target at the measurement point at the set angle, and calculate the convergence deformation of each section and the settlement of the arch based on the collected images.

2. The tunnel settlement monitoring device for extracting target feature points as described in claim 1, characterized in that, A crossbeam (12) is fixedly installed in the middle of the two side columns (1), and the two side columns (1) are respectively fixedly connected to the two ends of a long span shaft (8); the long span shaft (8) is located directly above the central cable (2), and several support rods (21) that support the long span shaft (8) along the height direction are locked to the central cable (2).

3. The tunnel settlement monitoring device for extracting target feature points as described in claim 2, characterized in that, The upper and lower ends of the support rod (21) are respectively provided with slots (211). The long span shaft (8) is engaged in the slots (211) at the upper end of the multiple support rods (21), and the slots (211) at the lower end of the multiple support rods (21) are respectively engaged in the center cable (2).

4. The tunnel settlement monitoring device for extracting target feature points as described in claim 3, characterized in that, The support rod (21) is a plastic rod or a metal rod.

5. The tunnel settlement monitoring device for extracting target feature points as described in claim 3, characterized in that, The long-span flexible support also includes two load-bearing cables (9) located between the two side columns (1), and a number of tripods (5) are provided between the central cable (2) and the two load-bearing cables (9) along their length direction and along their height direction.

6. The tunnel settlement monitoring device for extracting target feature points as described in claim 1, characterized in that, A bushing (73) is provided between the swing arm (7) and the long span shaft (8). The bushing (73) is movably fitted outside the long span shaft (8) and can rotate relative to it. The bushing (73) is fixedly connected to one end of the swing arm (7). The other end of the swing arm (7) is provided with a locking hole (74). One side of the locking hole (74) is provided with an opening (75) for the rotating cable (6) to be pressed into the locking hole (74). Each swing arm (7) has an arc part (70) extending outward. A vision controller and a light intensity sensor (72) are provided at intervals on the outer end face of the arc part (70). The vision controller is a monocular camera (71).

7. The tunnel settlement monitoring device for extracting target feature points as described in claim 6, characterized in that, It also includes a middle column set between two side columns (1), a central cable (2) passing through the middle column, and two load-bearing cables (9) locked and fixed on both sides of the crossbeam on the middle column to divide the long tunnel with a large span. The middle column is equipped with the drive motor (42) and the rotating arm (41).

8. The tunnel settlement monitoring device for extracting target feature points as described in claim 6, characterized in that, The load-bearing cable (9) extends outward at both ends and connects to the ground to form a stay cable (91).

9. A method for monitoring tunnel settlement by extracting target feature points, characterized in that, Includes the following steps: S1: A tunnel settlement monitoring device as described in any one of claims 1-8 is installed inside the tunnel. Targets are pre-set at measuring points A, B and C in the middle of the tunnel cross-section arch and the two side walls. The targets include a black metal plate for assisting in the identification of the structure and a reflective sheet for reflecting light. S2: The targets mentioned in step S1 are distributed along a circumferential direction perpendicular to the ground on the inner wall of the tunnel to form a settlement monitoring unit. Multiple settlement monitoring units are distributed at intervals along the tunnel axis, and vision controllers on several swing arms correspond one-to-one with the settlement monitoring units for monitoring. S3: Based on the settlement monitoring unit of step S2, by setting the angle position of the vision controller, several vision controllers are aligned with the target to be measured to take pictures. The pendulum rod (7) is swung back and forth to collect images of the target at the tunnel cross-section arch and the two sides of measuring points A, B and C, and the automatic monitoring program is run.

10. The tunnel settlement monitoring method for extracting target feature points as described in claim 9, characterized in that, The target uses a 4cm rhomboid diamond reflector, which is attached to a black metal plate. The image is analyzed by recognizing the changes in pixel position and length of the reflector's outline. The reflector is square; initially, the pixel coordinates of the two corner points along one diagonal of the reflector are designated as (x1, y1) and (x2, y2). After a period of time, the pixel coordinates of these two corner points are designated as (x...). 1’ y 1’ ), (x 2’ y 2’ Then, the settlement value at the target location during this period is: in, This represents the settlement value.

Images