Subway monitoring dotting positioning method based on distributed optical fiber sensing

Abstract

The invention discloses a metro monitoring dotting positioning method based on distributed optical fiber sensing, which comprises the following steps: determining a space dotting point location in a tunnel according to an optical fiber laying route, knocking an optical fiber, determining the length of the optical fiber corresponding to the space dotting point location according to an optical fiber demodulation signal associated with knocking at the space dotting point location, and positioning the optical fiber according to the length of the optical fiber. Establishing a corresponding relation between the optical fiber length and the environmental position information in the tunnel; and according to the mapping relation between the underground tunnel and the ground position and the corresponding relation between the optical fiber length and the tunnel environment position information, establishing the corresponding relation between the optical fiber length and the ground position. According to the metro monitoring dotting positioning method based on distributed optical fiber sensing, the spatial position of the point location can be associated with the optical fiber demodulation signal, the calibration of the length of the optical fiber, the position in the tunnel and the ground building is facilitated, the generated spatial position can be found more accurately during the subsequent detection based on the distributed optical fiber sensing, and the detection accuracy is improved. Therefore, accurate positioning of sensing signals of the distributed optical fibers is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of subway inspection based on distributed optical fiber sensing, and in particular to a subway monitoring point positioning method based on distributed optical fiber sensing. Background Art

[0002] With the rapid growth of subway construction, the demand for underground construction is huge, and the importance of construction safety monitoring is even more prominent. In urban scenarios, illegal and irregular construction on the ground will seriously affect the normal operation of the subway. The existing monitoring method mainly conducts manual inspections in subway tunnels. This method is time-consuming and labor-intensive and cannot detect and prevent problems in a timely manner. At the same time, the inspection results in the tunnel cannot be associated with the ground construction location, and the inspection effect cannot be achieved. Distributed fiber optic sensing technology can use the existing communication optical fiber in the subway tunnel to conduct safety monitoring on the entire subway line, greatly improving the accuracy and timeliness of monitoring. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes a subway monitoring point positioning method based on distributed optical fiber sensing.

[0004] The present invention proposes a subway monitoring and positioning method based on distributed optical fiber sensing, which comprises the following steps:

[0005] Determine the spatial marking points in the tunnel according to the optical fiber laying route, tap the optical fiber at the spatial marking points, determine the optical fiber length corresponding to the spatial marking points according to the optical fiber demodulation signal associated with the tapping, and establish a corresponding relationship between the optical fiber length corresponding to the spatial marking points and the environmental position information in the tunnel;

[0006] A mapping relationship between the underground tunnel and the ground position is established according to the tunnel structure diagram and the ground map, and a corresponding relationship between the optical fiber length and the ground position is established according to the mapping relationship and the corresponding relationship between the optical fiber length and the tunnel environment position information.

[0007] Preferably, before determining the spatial marking points in the tunnel according to the optical fiber laying route, the optical fiber in the tunnel is tapped to determine the target optical fiber.

[0008] Preferably, the tunnel environment location information includes kilometer markers and / or tunnel rings.

[0009] Preferably, the spatial marking points include one or more of the starting point and the end point of the subway tunnel entrance, the location where the optical fiber enters and exits the machine room, the starting and ending points of the tunnel switch, and the starting and ending points of the subway platform.

[0010] Preferably, the mapping relationship between the underground tunnel and the ground position is established according to the tunnel structure and the ground map, and the corresponding relationship between the optical fiber length and the ground position is established according to the mapping relationship and the corresponding relationship between the optical fiber length and the tunnel environment position information, specifically including:

[0011] A mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and map, and then the optical fiber length is marked in the mapping diagram.

[0012] Preferably, the method further includes determining the longitude and latitude information corresponding to the optical fiber length according to the longitude and latitude information of the ground position.

[0013] Preferably, the mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and the map, specifically, the tunnel structure design drawing is converted into a vector diagram, and the vector diagram is projected onto a satellite map according to the longitude and latitude of the area.

[0014] Preferably, the mapping of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and the map, specifically, determining the area where the subway line is located in the satellite map, downloading a map image of the area, and superimposing the map image on the tunnel structure design drawing.

[0015] In the present invention, the proposed subway monitoring and marking positioning method based on distributed optical fiber sensing determines the spatial marking points in the tunnel according to the optical fiber laying route, taps the optical fiber, and determines the optical fiber length corresponding to the spatial marking points according to the optical fiber demodulation signal associated with the tapping at the spatial marking points, and establishes a corresponding relationship between the optical fiber length and the environmental position information in the tunnel; according to the mapping relationship between the underground tunnel and the ground position, and the corresponding relationship between the optical fiber length and the tunnel environmental position information, a corresponding relationship between the optical fiber length and the ground position is established. Through the above-mentioned optimized design of the subway monitoring and marking positioning method based on distributed optical fiber sensing, through the above-mentioned subway monitoring and marking positioning method based on distributed optical fiber sensing, the spatial position of the point can be associated with the optical fiber demodulation signal, which helps to calibrate the optical fiber length, the position in the tunnel and the ground building. In the subsequent distributed optical fiber sensing detection, the spatial position of the occurrence can be found more accurately, thereby facilitating the precise positioning of the sensing signal of the distributed optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a tunnel structure design diagram in an implementation of a subway monitoring and marking positioning method based on distributed optical fiber sensing proposed by the present invention.

[0017] Figure 2 A mapping diagram of the tunnel structure and surface buildings in an implementation of a subway monitoring and positioning method based on distributed optical fiber sensing proposed by the present invention.

[0018] Figure 3 A surface topographic map is provided in one implementation of a subway monitoring point positioning method based on distributed optical fiber sensing proposed by the present invention.

[0019] Figure 4 This is a topological flow chart of an implementation of a subway monitoring point positioning method based on distributed optical fiber sensing proposed by the present invention. DETAILED DESCRIPTION

[0020] like Figures 1 to 4 As shown, Figure 1 This is a tunnel structure design diagram in an implementation of a subway monitoring and positioning method based on distributed optical fiber sensing proposed by the present invention. Figure 2 A mapping diagram of the tunnel structure and the surface buildings in an implementation of a subway monitoring and positioning method based on distributed optical fiber sensing proposed by the present invention, Figure 3 A surface topographic map in one embodiment of a subway monitoring and positioning method based on distributed optical fiber sensing proposed by the present invention, Figure 4 This is a topological flow chart of an implementation of a subway monitoring point positioning method based on distributed optical fiber sensing proposed by the present invention.

[0021] The present invention proposes a subway monitoring and positioning method based on distributed optical fiber sensing, which comprises the following steps:

[0022] First, the spatial marking points in the tunnel are determined according to the optical fiber laying route, the optical fiber is tapped at the spatial marking points, the optical fiber length corresponding to the spatial marking points is determined according to the optical fiber demodulation signal associated with the tapping, and a corresponding relationship between the optical fiber length corresponding to the spatial marking points and the environmental position information in the tunnel is established. The environmental position information in the tunnel includes kilometer markers and / or tunnel rings.

[0023] Specifically, before determining the spatial marking points in the tunnel according to the optical fiber laying route, the optical fiber in the tunnel is struck to determine the target optical fiber.

[0024] Specifically, the space marking points include one or more of the starting point and the end point of the subway tunnel entrance, the location where the optical fiber enters and exits the machine room, the starting and ending points of the tunnel switch, and the starting and ending points of the subway platform.

[0025] Then, a mapping relationship between the underground tunnel and the ground position is established according to the tunnel structure diagram and the ground map, and a corresponding relationship between the optical fiber length and the ground position is established according to the mapping relationship and the corresponding relationship between the optical fiber length and the tunnel environment position information.

[0026] The step of establishing a mapping relationship between an underground tunnel and a ground position according to the tunnel structure and the ground map, and establishing a corresponding relationship between the optical fiber length and the ground position according to the mapping relationship and the corresponding relationship between the optical fiber length and the tunnel environment position information, specifically includes:

[0027] A mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and the map, and then the optical fiber length is marked in the mapping diagram. Specifically, the tunnel structure design drawing is converted into a vector diagram, and the vector diagram is projected onto the satellite map based on the longitude and latitude of the area. In addition, the longitude and latitude information corresponding to the optical fiber length can also be determined based on the longitude and latitude information of the ground location.

[0028] Furthermore, the mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and the map, specifically, the area where the subway line is located in the satellite map is determined, a map image of the area is downloaded, and the map image is superimposed on the tunnel structure design drawing.

[0029] In this embodiment, the proposed subway monitoring and marking positioning method based on distributed optical fiber sensing determines the spatial marking points in the tunnel according to the optical fiber laying route, taps the optical fiber, and determines the optical fiber length corresponding to the spatial marking points according to the optical fiber demodulation signal associated with the tapping at the spatial marking points, and establishes a corresponding relationship between the optical fiber length and the environmental position information in the tunnel; according to the mapping relationship between the underground tunnel and the ground position, and the corresponding relationship between the optical fiber length and the tunnel environmental position information, a corresponding relationship between the optical fiber length and the ground position is established. Through the above-mentioned optimized design of the subway monitoring and marking positioning method based on distributed optical fiber sensing, the communication optical fiber in the tunnel is matched with the ground position by projection, fixed point and other methods, providing a highly reliable marking positioning for subsequent distributed optical fiber sensing detection, and realizing the location of the event by determining the event along the length of the optical fiber.

[0030] Through the above-mentioned subway monitoring point positioning method based on distributed optical fiber sensing, the spatial position of the point and the optical fiber demodulation signal can be associated to help calibrate the optical fiber length, the position in the tunnel and the ground buildings. In the subsequent distributed optical fiber sensing detection, the spatial position of the occurrence can be found more accurately, thereby facilitating the precise positioning of the distributed optical fiber sensing signal.

[0031] The practical application of the subway monitoring point positioning method based on distributed optical fiber sensing of this embodiment is described in detail below through specific examples.

[0032] Based on distributed fiber optic sensing technology, the existing communication optical fiber in the subway tunnel is used to conduct safety monitoring of the entire subway line.

[0033] 1. Fiber optic positioning in underground subway tunnels, establishing the correspondence between fiber optic sensing signals and physical locations.

[0034] When working, the tunnel to be drilled is first determined. The machine room staff and tunnel staff maintain continuous communication to ensure the preparation and timeliness of information transmission.

[0035] The machine room staff is in the DAS equipment room, recording the corresponding track number of the knocking signal, optical fiber length, signal response and physical landmark information fed back by the tunnel staff in real time, and completing the organization of all information.

[0036] The tunnel staff enters the tunnel where the target optical cable is located (here the up and down lines or left and right lines of the tunnel need to be determined). First, the optical cable needs to be tapped at the beginning of the entry to determine whether the current tunnel is the tunnel where the target optical cable is located and which optical cable is the target optical cable. Then, the tunnel staff designates the tapping location and performs the optical fiber tapping work. At this time, the machine room staff determines the optical fiber length of the tapping point based on the signal response and feeds back the result to the tunnel staff. The tunnel staff records the kilometer mark, tunnel ring and other location information near the designated tapping location.

[0037] Then, repeat the above steps until the marking work of the area to be monitored is completed.

[0038] 2. Create a topographic map based on the results of optical fiber positioning in underground subway tunnels

[0039] First, according to Figure 1 The tunnel structure design drawing is completed and the surface building is mapped. Mapping can be achieved through map projection. Map projection can be achieved through two methods: direct map projection splicing and exported map overlay.

[0040] (I) Direct map projection stitching (suitable for simpler situations)

[0041] 1. If the subway provides a dwg file, export the file to dxf format first.

[0042] 2. Open the 91 satellite map, select "Vector Draw" → "Load Vector" → "Open DXF File" in the menu bar. Select the DXF file save path in the pop-up box, the coordinate projection is determined according to the coordinate projection system used, and select the projection zone method and central meridian of the region in the parameter setting.

[0043] 3. Click OK to project the vector map onto the ground. The software defaults to Tiandi Map, because Tiandi Map is prohibited from downloading, Baidu, Amap and Tencent will cause certain deviations.

[0044] 4. Take screenshots directly through Tiandi Map, and then put them into Photoshop software for splicing.

[0045] Reference Figure 1-3 , the following takes Hefei Metro Line 3 Station 4 as an example.

[0046] 1. The format provided by Hefei Metro is dwg. Open the dwg file with AutoCAD software and save it in DXF format.

[0047] 2. Open 91 Weitu software. Import the DXF image. Select "Vector Drawing" → "Load Vector" → "Open DXF File" from the menu bar.

[0048] Select the file path. The Hefei subway is projected in the WGS84 coordinate system. Select the projection parameters for Hefei. The zone method is 3 degrees and the central meridian is 117.

[0049] 3. Scale the ground with the vector image superimposed to the required size, cut it and use Photoshop to splice it.

[0050] (II) Exporting map overlay projections (suitable for more complex situations)

[0051] 1. Open the 91 Satellite Map software and find the location of the subway line on the satellite map.

[0052] 2. Download the satellite map of the map area in image format (.tif). Please note that Tiandi Map cannot be downloaded. You need to switch to Baidu, Amap or Tencent Map in the upper left corner and download it after the switch is completed.

[0053] 3. Open the cad file and drag the surface image to import it directly.

[0054] 1) Select the image, click the edge you want to view, then right-click and select "Drawing Order" → "Send to Back";

[0055] 2) Before importing, calculate the border length of the image in CAD according to the CAD file scale and screenshot range, and adjust the image scale so that the road width in the image corresponds to that in the CAD file;

[0056] 3) If there is no scale, you need to measure the width of the same road in the CAD lines, ground lines and surface pictures (CAD distance measurement function), and calculate the scale to be scaled after the measurement is completed;

[0057] 4) Left-click the edge of the image to select it, and then use the zoom tool to adjust the image. Since the satellite map is offset, it is recommended that the zoom origin should not be too far from the subway line.

[0058] 5) Select the base point to move the image to the corresponding position of the subway line. When selecting the base point, please note that the base point position must be determined in the image and CAD lines in advance.

[0059] 4. Export the required area as a pdf file.

[0060] The mapping result is as follows Figure 2 shown.

[0061] Then organize the fiber marking results into Figure 2 The results are as follows Figure 3 In addition, by determining the longitude and latitude of the ground position, the longitude and latitude information corresponding to a certain optical fiber length can be obtained. Figure 3 Determine the fiber length corresponding to the surface construction location.

[0062] The exact position of the target construction unit on the surface within the subway protection zone can be accurately located, and based on the fact that the optical fiber is in the underground subway tunnel, the mapping of the underground subway tunnel and the surface buildings can be completed.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A subway monitoring and positioning method based on distributed optical fiber sensing, characterized in that: The following steps are involved: Determine the spatial marking points in the tunnel according to the optical fiber laying route, tap the optical fiber at the spatial marking points, determine the optical fiber length corresponding to the spatial marking points according to the optical fiber demodulation signal associated with the tapping, and establish a corresponding relationship between the optical fiber length corresponding to the spatial marking points and the environmental position information in the tunnel; A mapping relationship between the underground tunnel and the ground position is established according to the tunnel structure diagram and the ground map, and a corresponding relationship between the optical fiber length and the ground position is established according to the mapping relationship and the corresponding relationship between the optical fiber length and the tunnel environment position information.

2. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 1 is characterized in that: Before determining the spatial marking points in the tunnel according to the optical fiber laying route, the optical fiber in the tunnel is tapped to determine the target optical fiber.

3. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 1 is characterized in that: The tunnel environment location information includes kilometer markers and / or tunnel rings.

4. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 1 is characterized in that: The spatial marking points include one or more of the starting point and the end point of the subway tunnel entrance, the position where the optical fiber enters and exits the machine room, the starting and ending points of the tunnel switch, and the starting and ending points of the subway platform.

5. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 1 is characterized in that: The method of establishing a mapping relationship between an underground tunnel and a ground position according to the tunnel structure and the ground map, and establishing a corresponding relationship between the optical fiber length and the ground position according to the mapping relationship and the corresponding relationship between the optical fiber length and the tunnel environment position information, specifically includes: A mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and map, and then the optical fiber length is marked in the mapping diagram.

6. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 5 is characterized in that: The method also includes determining the longitude and latitude information corresponding to the optical fiber length according to the longitude and latitude information of the ground position.

7. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 5 is characterized in that: The mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and the map. Specifically, the tunnel structure design drawing is converted into a vector diagram, and the vector diagram is projected onto a satellite map based on the longitude and latitude of the area.

8. The subway monitoring and positioning method based on distributed optical fiber sensing according to claim 5 is characterized in that: The mapping diagram of the tunnel structure and the surface buildings is established based on the tunnel structure design drawing and the map, specifically, the area where the subway line is located in the satellite map is determined, the map image of the area is downloaded, and the map image is superimposed on the tunnel structure design drawing.

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