Method for monitoring deformation of pipe joint seam of immersed tunnel

Abstract

The invention discloses a deformation monitoring method for a pipe joint seam of an immersed tunnel, and the method employs a suspension rail type mobile inspection platform which is provided with a mechanical arm, a two-dimensional code positioning sensor, and a binocular vision detection unit. A two-dimensional code positioning auxiliary mark system and a binocular measurement auxiliary mark system which are used in cooperation with the mobile inspection platform are further designed, and the two-dimensional code positioning auxiliary mark system is used for being used in cooperation with a two-dimensional code positioning sensor and providing accurate position information and label information of pipe joint seams for the mobile inspection platform; the binocular measurement auxiliary marking system is used for being matched with the binocular vision detection unit for use and comprises marker groups mounted at joints of all pipe joints of the immersed tunnel, and when the mobile inspection platform works, the binocular vision detection unit on a mechanical arm photographs the marker groups by adjusting the mechanical arm of the mobile inspection platform so as to detect the pipe joints of the immersed tunnel. And analyzing whether the pipe joint seam of the immersed tunnel is deformed or not according to the acquired image.

Description

Technical Field

[0001] The invention belongs to the technical field of immersed tube tunnel monitoring, and in particular relates to a method for monitoring deformation at pipe joints of an immersed tube tunnel. Background Art

[0002] Due to the particularity of the environment, underwater immersed tube tunnels are extremely susceptible to factors such as topography, geology and water environment, as well as various processes of construction and operation; these factors can cause a series of problems in immersed tube tunnels, such as tunnel cracks, water leakage, and deformation and displacement of pipe segments.

[0003] Most immersed tube tunnels are thin-walled box-type structures. After the tunnel is built and put into operation, due to the repeated effects of external variable loads such as water scouring, overburden accumulation, foundation settlement, and traffic, the immersed tube section is in a complex bending, twisting, pulling, and compressing state for a long time, and the stress condition is very complex. Concrete pipe sections may be dislocated, shear keys may break, and prestressed cables may fail due to the influence of temperature, concrete shrinkage, earthquakes, etc. Under the action of water pressure, it will not only cause water erosion and variation of structural concrete and rust of steel bars, but also cause water seepage inside the tunnel. The top of the immersed tube in the water may be affected by water flow and sediment, which may cause scouring or silting of the overburden, affecting the safety of the tunnel. Researching the health monitoring technology of immersed tube tunnels and developing related monitoring technologies and analysis methods will help extend the service life of tunnels, reduce maintenance costs, and ensure traffic safety and the safety of life and property.

[0004] Traditionally, inspections of immersed tube tunnels are mainly carried out by manual inspections or vehicle inspections. Manual inspections require road closures, which is not only inefficient but also seriously hinders normal traffic operations. Vehicle inspections are mainly used for periodic inspections and are difficult to meet the needs of daily inspections and regular inspections.

[0005] At present, there are intelligent inspection mobile platforms to solve the above problems. For example, patent CN202111009819.0 discloses a suspended inspection mobile inspection platform, including a guide rail support, a power supply busbar and a mobile inspection platform design. However, the existing inspection mobile platform for deformation detection of pipe joints in immersed tube tunnels needs to be improved. How to quickly and accurately realize deformation detection of pipe joints in immersed tube tunnels is a technical problem that needs to be solved. Summary of the invention

[0006] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a method for monitoring deformation of pipe joints in an immersed tube tunnel.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for monitoring deformation of pipe joints of an immersed tube tunnel, comprising a track structure, a mobile inspection platform and an auxiliary marking system for the mobile inspection platform;

[0009] The track structure is arranged on the top of the immersed tube tunnel to be monitored;

[0010] The mobile inspection platform includes a walking mechanism, a function box, a mechanical arm, a two-dimensional code positioning sensor and a binocular vision detection unit; the walking mechanism is suspended and installed on the track of the track structure in a movable manner, the function box is fixed at the bottom of the walking mechanism, the mechanical arm is installed at the lower end of the function box, the two-dimensional code positioning sensor is arranged on the function box, and the binocular vision detection unit is arranged on the mechanical arm;

[0011] The auxiliary marking system of the mobile inspection platform includes a two-dimensional code positioning auxiliary marking system and a binocular measurement auxiliary marking system; the two-dimensional code positioning auxiliary marking system is used in conjunction with the two-dimensional code positioning sensor of the mobile inspection platform to provide the mobile inspection platform with accurate location information and label information of each pipe joint; the binocular measurement auxiliary marking system is used in conjunction with the binocular vision detection unit of the mobile inspection platform, and the binocular measurement auxiliary marking system includes a marker group installed at each pipe joint of the immersed tube tunnel, each marker group includes two marker units, and the two marker units are respectively fixedly installed on the pipe joints on both sides of the pipe joint, each marker unit includes at least one circular reflector, and multiple marker groups are arranged along each pipe joint in the cross-sectional direction of the immersed tube tunnel;

[0012] The method for monitoring deformation of pipe joints of an immersed tube tunnel comprises the following steps:

[0013] Step 1: When the mobile inspection platform reaches the inspection point at the pipe joint of the immersed tube tunnel, the robot arm is automatically adjusted according to a predetermined program so that the binocular vision detection unit on the robot arm takes pictures of each group of markers at the pipe joint in sequence, and the stroboscope of the binocular vision detection unit is activated for fill light when taking pictures, thereby obtaining images of each group of markers;

[0014] Step 2, performing image preprocessing on the collected images;

[0015] Step 3: After image preprocessing is completed, Huogh circle detection algorithm is used to identify the image coordinates of the center of each reflector in the image;

[0016] Step 4, calculating the spatial coordinates of the center of each reflector through a binocular 3D reconstruction algorithm;

[0017] Step 5: By comparing the historical spatial coordinate data of the center of each reflective sheet at the detection point, it can be determined whether the pipe joints of the immersed tube tunnel are deformed.

[0018] In the above technical solution, the track structure includes an aluminum profile track and a steel track hanger, wherein the groove of the track faces upward, the track hanger is installed in the groove, one end of the track hanger is installed at the top of the immersed tube tunnel and the other end is embedded in the groove, so that the track is suspended on the top of the immersed tube tunnel.

[0019] In the above technical solution, the functional box is a rectangular aluminum box, and the interior of the functional box is used to arrange the power supply and control system of the mobile inspection platform.

[0020] In the above technical solution, the robotic arm includes a base, a middle arm, and a terminal arm. The base is installed on the lower end of the function box through a vertically arranged first rotating shaft, the tail end of the middle arm is installed on the base through a horizontally arranged second rotating shaft, and the front end of the middle arm is connected to the tail end of the terminal arm through a horizontally arranged third rotating shaft.

[0021] In the above technical solution, the binocular vision detection unit includes two visual cameras, a stroboscope, an IMU sensor and an aluminum binocular bracket; wherein the aluminum binocular bracket is a T-shaped structure, the rear end of which is installed at the front end of the end arm of the robotic arm, the stroboscope is installed in the middle of the front end of the aluminum binocular bracket, the IMU sensor is installed close to the lower side of the stroboscope, and the two visual cameras are installed on both sides of the front end of the aluminum binocular bracket.

[0022] In the above technical solution, the QR code positioning auxiliary marking system includes a QR code label, which is affixed to the bottom surface of the track. The pipe joints of the immersed tube tunnel are used as detection points, and a QR code label is arranged on the bottom surface of the track corresponding to each detection point; each QR code label corresponds to a number, and the detection points are numbered in sequence along the inspection route of the mobile inspection platform, and each QR code label represents an absolute position information.

[0023] In the above technical solution, three groups of markers are set at each pipe joint in the cross-sectional direction of the immersed tube tunnel, wherein one group is set at the top of the immersed tube tunnel and one group is set on the left and right sides of the immersed tube tunnel respectively. When the mobile inspection platform is working, the binocular vision detection unit on the robotic arm is adjusted to take pictures of the three groups of markers respectively to obtain images.

[0024] In the above technical solution, in step 5, indicators such as differential displacement and tension on both sides of the pipe joint are calculated.

[0025] The advantages and beneficial effects of the present invention are:

[0026] The present invention adopts a suspended rail mobile inspection platform, on which a mechanical arm, a two-dimensional code positioning sensor and a binocular vision detection unit are arranged, and the present invention also designs a two-dimensional code positioning auxiliary marking system and a binocular measurement auxiliary marking system for use with the mobile inspection platform. Among them, the two-dimensional code positioning auxiliary marking system is used to cooperate with the two-dimensional code positioning sensor of the mobile inspection platform to provide the mobile inspection platform with accurate location information and label information of each pipe joint; the binocular measurement auxiliary marking system is used to cooperate with the binocular vision detection unit of the mobile inspection platform, and the binocular measurement auxiliary marking system includes a marker group installed at each pipe joint of the immersed tube tunnel, and each marker group includes two marker units, and the two marker units are respectively fixedly installed on the pipe joints on both sides of the pipe joint, and each marker unit At least one circular reflective sheet is included, and three groups of markers are arranged along each pipe joint in the cross-sectional direction of the immersed tube tunnel. When the mobile inspection platform is working, by adjusting its mechanical arm, the binocular vision detection unit on the mechanical arm can take pictures of the three groups of markers respectively to obtain images, and then identify the image coordinates of the center of each reflective sheet in the image, and calculate the spatial coordinates of the center of each reflective sheet through a binocular three-dimensional reconstruction algorithm. By comparing the historical spatial coordinate data of the center of each reflective sheet at the detection point, it can be obtained whether the pipe joint of the immersed tube tunnel is deformed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the installation structure of the track structure and the mobile inspection platform.

[0028] Figure 2 It is a schematic diagram of the deformation monitoring method at the pipe joint of the immersed tube tunnel of the present invention (the detection state of the binocular vision detection unit aligned with the top marker group).

[0029] Figure 3 It is a schematic diagram of the layout of the marker units at the joints of pipe sections.

[0030] Figure 4 It is a schematic diagram of the deformation monitoring method at the pipe joint of the immersed tube tunnel of the present invention (the detection state of the binocular vision detection unit aimed at the left marker group).

[0031] Figure 5 It is a schematic diagram of the deformation monitoring method at the pipe joint of the immersed tube tunnel of the present invention (the detection state of the binocular vision detection unit aimed at the right marker group).

[0032] Figure 6 It is a flow chart of the deformation monitoring steps at the pipe joints of the immersed tube tunnel of the present invention.

[0033] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments.

[0035] A method for monitoring deformation of pipe joints of an immersed tube tunnel comprises a track structure 1, a mobile inspection platform 2 and an auxiliary marking system of the mobile inspection platform.

[0036] The track structure 1 is arranged at the top of the immersed tube tunnel to be monitored, and includes an aluminum profile track and a steel track hanger, wherein the notch of the track faces upward, the track hanger is installed in the notch, one end of the track hanger is installed at the top of the immersed tube tunnel and the other end is embedded in the notch, so that the track is suspended at the top of the immersed tube tunnel.

[0037] The mobile inspection platform 2 is used to travel along the track to inspect the joints of each pipe section of the immersed tube tunnel. Figure 1 The mobile inspection platform 2 includes a walking mechanism 21, a function box 22, a mechanical arm 23, a two-dimensional code positioning sensor 24 and a binocular vision detection unit 25.

[0038] The walking mechanism 21 is suspended and installed on the track of the track structure in a movable manner, so as to enable the entire mobile inspection platform 2 to move along the track.

[0039] The function box 22 is fixed at the bottom of the walking mechanism 21 and is a rectangular aluminum box. The inside of the function box 22 is used to arrange the power supply and control system of the mobile inspection platform.

[0040] The mechanical arm 23 is installed at the lower end of the function box 22. The mechanical arm 23 includes a base 231, a middle arm 232, and an end arm 233. The base 231 is installed at the lower end of the function box 22 through a vertically arranged first rotating shaft, the tail end of the middle arm 232 is installed on the base 231 through a horizontally arranged second rotating shaft, and the front end of the middle arm 232 is connected to the tail end of the end arm 233 through a horizontally arranged third rotating shaft.

[0041] The two-dimensional code positioning sensor 24 is arranged on the function box 22, and is used to scan the two-dimensional code label on the track, and then obtain the absolute position information represented by the two-dimensional code label and the label information of the pipe joint (the label represents the pipe joint number of the immersed tube tunnel).

[0042] The binocular vision detection unit 25 is arranged on the end arm 233 of the mechanical arm 23, and is used to obtain the image of the detection point. Specifically, the binocular vision detection unit 25 includes two visual cameras, a stroboscope, an IMU sensor and an aluminum binocular bracket; wherein the aluminum binocular bracket is a T-shaped structure, and its rear end is installed at the front end of the end arm 233 of the mechanical arm 23, the stroboscope is installed in the middle position of the front end of the aluminum binocular bracket, the IMU sensor is installed close to the lower side of the stroboscope, and the two visual cameras are installed on both sides of the front end of the aluminum binocular bracket. wherein the stroboscope is used to fill in the light of the detection point; the two visual cameras are used to take pictures of the detection point and obtain images; the IMU sensor is used to provide posture data for the two visual cameras.

[0043] The auxiliary marking system of the mobile inspection platform includes a two-dimensional code positioning auxiliary marking system and a binocular measurement auxiliary marking system.

[0044] 1. The two-dimensional code positioning auxiliary marking system is used in conjunction with the two-dimensional code positioning sensor 24 of the mobile inspection platform to provide the mobile inspection platform with accurate location information and label information of each pipe joint. The two-dimensional code positioning auxiliary marking system includes a two-dimensional code label, which is attached to the bottom surface of the track. The pipe joints of the immersed tube tunnel are used as detection points, and a two-dimensional code label is arranged on the bottom surface of the track for each detection point; each two-dimensional code label corresponds to a label, and the labels are arranged in sequence at each detection point along the inspection route of the mobile inspection platform, and each two-dimensional code label represents an absolute location information.

[0045] 2. The binocular measurement auxiliary marking system is used in conjunction with the binocular vision detection unit 25 of the mobile inspection platform. Figure 2 and attached Figure 3 The binocular measurement auxiliary marking system includes a marker group 6 installed at each pipe joint 7 of the immersed tube tunnel, each marker group 6 includes two marker units 61 and 62, which are fixedly installed on the pipe joints on both sides of the pipe joint 7, each marker unit includes at least one circular reflector. In this embodiment, each marker unit includes 3 circular reflectors; further, see the attached Figure 4 In the cross-sectional direction of the immersed tube tunnel, a plurality of marker groups 6 are arranged along each pipe joint 7. In this embodiment, three marker groups 6 are arranged at each pipe joint 7, wherein one group is arranged at the top of the immersed tube tunnel, and one group is arranged at the left and right sides of the immersed tube tunnel respectively. When the mobile inspection platform 2 is working, by adjusting its mechanical arm 23, the binocular vision detection unit 25 on the mechanical arm can take pictures of the three marker groups respectively (see the attached figure). Figure 2 , Attachment Figure 4 and attached Figure 5), obtain images, and then analyze whether deformation occurs at the joints of the immersed tube tunnel based on the images obtained.

[0046] See below for details. Figure 6 , specifically describes the process of deformation detection of pipe joints of immersed tube tunnels, including the following steps.

[0047] Step 1, when the mobile inspection platform 2 reaches the inspection point at the pipe joint of the immersed tube tunnel, the robot arm 23 is automatically adjusted according to a predetermined program, so that the binocular vision detection unit 25 on the robot arm 23 takes pictures of each group of markers at the pipe joint 7 in turn, and the stroboscope of the binocular vision detection unit is started for fill light when taking pictures, thereby obtaining images of each group of markers.

[0048] Step 2, preprocessing the captured image, including image denoising, threshold segmentation and edge detection, aiming to reduce the amount of image data and extract edge information of the circular reflector.

[0049] Step 3: After image preprocessing is completed, the Huogh circle detection algorithm is used to identify the image coordinates of the center of each reflective sheet in the image.

[0050] Step 4: Calculate the spatial coordinates of the center of each reflector through a binocular 3D reconstruction algorithm.

[0051] Step 5, by comparing the historical spatial coordinate data of the center of each reflective sheet at the detection point, it can be determined whether the pipe joint of the immersed tube tunnel has been deformed. For example, the differential displacement and tension on both sides of the pipe joint can be calculated.

[0052] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A method for monitoring deformation of pipe joints in an immersed tube tunnel, characterized in that: It includes track structure, mobile inspection platform and auxiliary marking system of mobile inspection platform; The track structure is arranged on the top of the immersed tube tunnel to be monitored; The mobile inspection platform includes a walking mechanism, a function box, a mechanical arm, a two-dimensional code positioning sensor and a binocular vision detection unit; the walking mechanism is suspended and installed on the track of the track structure in a movable manner, the function box is fixed at the bottom of the walking mechanism, the mechanical arm is installed at the lower end of the function box, the two-dimensional code positioning sensor is arranged on the function box, and the binocular vision detection unit is arranged on the mechanical arm; The auxiliary marking system of the mobile inspection platform includes a two-dimensional code positioning auxiliary marking system and a binocular measurement auxiliary marking system; the two-dimensional code positioning auxiliary marking system is used in conjunction with the two-dimensional code positioning sensor of the mobile inspection platform to provide the mobile inspection platform with accurate location information and label information of each pipe joint; the binocular measurement auxiliary marking system is used in conjunction with the binocular vision detection unit of the mobile inspection platform, and the binocular measurement auxiliary marking system includes a marker group installed at each pipe joint of the immersed tube tunnel, each marker group includes two marker units, and the two marker units are respectively fixedly installed on the pipe joints on both sides of the pipe joint, each marker unit includes at least one circular reflector, and multiple marker groups are arranged along each pipe joint in the cross-sectional direction of the immersed tube tunnel; The method for monitoring deformation of pipe joints of an immersed tube tunnel comprises the following steps: Step 1: When the mobile inspection platform reaches the inspection point at the pipe joint of the immersed tube tunnel, the robot arm is automatically adjusted according to a predetermined program so that the binocular vision detection unit on the robot arm takes pictures of each group of markers at the pipe joint in sequence, and the stroboscope of the binocular vision detection unit is activated for fill light when taking pictures, thereby obtaining images of each group of markers; Step 2, performing image preprocessing on the collected images; Step 3: After image preprocessing is completed, Huogh circle detection algorithm is used to identify the image coordinates of the center of each reflector in the image; Step 4, calculating the spatial coordinates of the center of each reflector through a binocular 3D reconstruction algorithm; Step 5: By comparing the historical spatial coordinate data of the center of each reflective sheet at the detection point, it can be determined whether the pipe joints of the immersed tube tunnel are deformed.

2. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 1, characterized in that: The track structure includes an aluminum profile track and a steel track hanger, wherein the track slot faces upward, the track hanger is installed in the slot, one end of the track hanger is installed at the top of the immersed tube tunnel and the other end is embedded in the slot, so that the track is suspended on the top of the immersed tube tunnel.

3. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 1, characterized in that: The functional box is a rectangular aluminum box, and the interior of the functional box is used to arrange the power supply and control system of the mobile inspection platform.

4. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 1, characterized in that: The robotic arm includes a base, a middle arm, and a terminal arm. The base is installed at the lower end of the function box through a vertically arranged first rotating shaft, the tail end of the middle arm is installed on the base through a horizontally arranged second rotating shaft, and the front end of the middle arm is connected to the tail end of the terminal arm through a horizontally arranged third rotating shaft.

5. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 4, characterized in that: The binocular vision detection unit includes two visual cameras, a stroboscope, an IMU sensor and an aluminum binocular bracket; wherein the aluminum binocular bracket is a T-shaped structure, the rear end of which is installed at the front end of the end arm of the robotic arm, the stroboscope is installed in the middle of the front end of the aluminum binocular bracket, the IMU sensor is installed close to the lower side of the stroboscope, and the two visual cameras are installed on both sides of the front end of the aluminum binocular bracket.

6. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 1, characterized in that: The two-dimensional code positioning auxiliary marking system includes a two-dimensional code label, which is affixed to the bottom surface of the track. The pipe joints of the immersed tube tunnel are used as detection points, and a two-dimensional code label is arranged on the bottom surface of the track corresponding to each detection point; each two-dimensional code label corresponds to a number, and the detection points are numbered in sequence along the inspection route of the mobile inspection platform, and each two-dimensional code label represents an absolute position information.

7. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 1, characterized in that: In the cross-sectional direction of the immersed tube tunnel, three groups of markers are set at each pipe joint, among which one group is set at the top of the immersed tube tunnel, and one group is set on the left and right sides of the immersed tube tunnel respectively. When the mobile inspection platform is working, the binocular vision detection unit on the robotic arm is adjusted to take pictures of the three groups of markers respectively to obtain images.

8. The method for monitoring deformation of pipe joints in an immersed tube tunnel according to claim 1, characterized in that: In step 5, the differential displacement and tension on both sides of the pipe joint are calculated.

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