Real-time monitoring method, device and system for tunnel section shape

Abstract

The invention relates to the technical field of tunnel monitoring, in particular to a tunnel section shape real-time monitoring method, device and system. The method comprises the following steps: a control device acquires chord length, arc height and inclination angle of a section to which a monitoring device belongs sent by each monitoring device in real time; for each monitoring section, acquiring a local monitoring curve of the monitoring section by adopting the chord length and the arc height of the monitoring section and the position information of the monitoring device in the monitoring section; and according to the inclination angle and the local monitoring curve of each monitoring section, acquiring a monitoring curve of the tunnel section under the overall coordinate system by adopting a numerical fitting mode. The beneficial effects are that each monitoring device monitors the chord length, the arc height and the inclination angle of the section to which the monitoring device belongs, and then the local monitoring curve of each monitoring area is determined based on the chord length and the arc height. Compared with the prior art, the local monitoring curve of each monitoring area better fits the radian structure of the tunnel section, so that the monitoring precision is improved.

Description

Technical Field

[0001] This application relates to the field of tunnel monitoring technology, and in particular to a method, apparatus and system for real-time monitoring of tunnel cross-sectional shape. Background Technology

[0002] Tunnels are buried in the ground, and under the pressure of the ground, the tunnel cross-section will deform. When the deformation is too large and intrudes into the clearance gauge, it will affect the normal passage of vehicles inside. The tunnel cross-section is the cross-sectional area of ​​the tunnel, and its deformation is one of the important indicators reflecting the structural safety status. For monitoring tunnel cross-section deformation, the industry usually uses the baseline method to calculate the convergence value to reflect the deformation status. However, this method requires good visibility inside the tunnel, and it cannot be implemented for tunnels with internal structures that obstruct the view.

[0003] To address the issue of tunnel cross-section monitoring being impossible due to potential obstructions from internal structures, related technologies propose setting up multiple interconnected measuring devices along the tunnel cross-section. Each device acquires the lengths of its two ends and its inclination angle to establish multiple polygonal segments along the tunnel cross-section. These polygonal segments are then fitted to obtain the monitored tunnel cross-section deformation. However, in this approach, the multiple polygonal lines exhibit linear characteristics and cannot accurately replicate the curvature of the tunnel cross-section. This results in a significant discrepancy between the fitted tunnel cross-section curve and the actual tunnel cross-section, leading to poor monitoring accuracy. Summary of the Invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, this application provides a method, device and system for real-time monitoring of tunnel cross-section shape, the main purpose of which is to improve the problem of poor monitoring accuracy in the current tunnel cross-section monitoring methods.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include:

[0006] In a first aspect, embodiments of this application provide a real-time monitoring method for the cross-sectional shape of a tunnel. The tunnel cross-section is divided into multiple segments according to its perimeter, and a monitoring device is fixed on the inner wall of each segment. All monitoring devices are communicatively connected to the control device of a designated tunnel. The method includes:

[0007] The control device acquires in real time the chord length, arc height, and tilt angle of the section to which each monitoring device belongs, sent by each monitoring device.

[0008] For each monitoring segment, the local monitoring curve of the monitoring segment is obtained by using the chord length, arc height and the location information of the monitoring device in the monitoring segment;

[0009] Based on the tilt angle and local monitoring curves of each monitoring section, the monitoring curves of the tunnel cross-section in the overall coordinate system are obtained by numerical fitting.

[0010] Optionally, for each monitoring segment, obtaining a local monitoring curve for the monitoring segment using the chord length, arc height, and position information of the monitoring device within the monitoring segment includes: establishing a local coordinate system corresponding to the monitoring segment using the position information of the monitoring device within the monitoring segment; determining three feature points in the corresponding local coordinate system based on the chord length and arc height of the monitoring segment; the three feature points include two vertices and an arc vertex of the monitoring segment; and obtaining the local monitoring curve using the two vertices and the arc vertex of the monitoring segment.

[0011] In this embodiment, direct physical measurement parameter values ​​are converted into local monitoring curves. Compared with the broken line method, the curves are more in line with the actual characteristics of the tunnel, providing a more accurate and reliable local shape data basis for subsequent fitting.

[0012] Optionally, determining three feature points in the corresponding local coordinate system based on the chord length and arc height of the monitoring segment includes: determining the midpoint of the chord length of the monitoring segment as the origin of the local coordinate system; determining two vertices of the three feature points based on the two endpoints of the chord length of the monitoring segment; and determining the arc vertex of the three feature points based on the arc height of the monitoring segment.

[0013] In this embodiment, by setting the origin of the coordinate system at the midpoint of the chord, the coordinate calculation formula for the three feature points is simplified, the complexity of data processing is reduced, and the calculation efficiency and real-time performance of the system are improved.

[0014] Optionally, the tunnel cross-section is divided into multiple continuous sections according to the cross-sectional perimeter, and the monitoring devices are arranged end to end along the inner wall of the tunnel cross-section.

[0015] In this embodiment, the end-to-end physical connection allows the data from adjacent monitoring devices to be geometrically connected, thereby improving monitoring accuracy.

[0016] Optionally, based on the tilt angle and local monitoring curve of each monitoring section, a numerical fitting method is used to obtain the monitoring curve of the tunnel section in the overall coordinate system, including: determining the coordinate information of the origin of the local coordinate system of the first monitoring device in the overall coordinate system based on the installation position of the first monitoring device; determining the coordinate information of the three feature points corresponding to the first monitoring device in the overall coordinate system based on the tilt angle of the first monitoring device, and determining the position of the local monitoring curve corresponding to the first monitoring device in the overall coordinate system; for the nth monitoring device, determining the endpoint of the section to which the (n-1)th monitoring device belongs in the overall coordinate system. The coordinates are used as the starting coordinates of the nth monitoring device in the overall coordinate system; where n is an integer greater than 1, and the (n-1)th monitoring device and the nth monitoring device are arranged end to end; based on the starting coordinates, the chord length and tilt angle of the nth monitoring device, the coordinate information of the three feature points corresponding to the nth monitoring device in the overall coordinate system is determined, and the position of the local monitoring curve corresponding to the nth monitoring device in the overall coordinate system is determined; after determining the position of the local monitoring curve corresponding to each monitoring device in the overall coordinate system, all local monitoring curves are fitted to obtain the monitoring curve of the tunnel cross section.

[0017] In this embodiment, a high-precision data fusion method with low error accumulation is implemented. Each sensor only needs to measure its own segment, and this algorithm can "stitch together" multiple local measurement results into a high-precision overall profile.

[0018] Optionally, the tunnel cross-section is divided into multiple discontinuous sections based on the cross-sectional perimeter.

[0019] In this embodiment, the sections can be set as discontinuous, and can be selectively arranged in key sections according to the actual situation inside the tunnel, such as areas obscured by internal structures or equipment, or budget constraints. This achieves an optimal balance between cost and benefit.

[0020] Optionally, when the section is discontinuous, the monitoring curve of the tunnel cross-section in the global coordinate system is obtained by numerical fitting based on the tilt angle and local monitoring curve of each monitoring section. This includes: for sections equipped with the monitoring device, transforming the local monitoring curve of each monitoring section in the local coordinate system to the global coordinate system; for sections without the monitoring device, obtaining the tunnel shape data of the tunnel cross-section in the sections without the monitoring device; constructing an original shape curve for the sections without the monitoring device in the global coordinate system based on the tunnel shape data; and fitting the monitoring curve of the tunnel cross-section in the global coordinate system based on the local monitoring curve and the original shape curve.

[0021] In this embodiment, by selectively deploying equipment in key sections, the monitoring accuracy of key components is ensured with limited hardware deployment.

[0022] Optionally, the tunnel is constructed using the shield tunneling method for lining, and tunnel segments are installed on the tunnel cross section, with segment joints existing at the junction of two adjacent tunnel segments; during the arrangement of the monitoring device, the segments with joints are arranged across the joints.

[0023] In this embodiment, considering that a tunnel cross-section is typically assembled from multiple tunnel segments, and that there are segment joints at the junctions of adjacent segments, these joints are critical areas for structural stress and deformation. Therefore, when arranging monitoring devices, a cross-joint arrangement is adopted for locations with segment joints. This means that the monitoring section corresponding to one monitoring device spans the joint, thereby capturing the health status information of the weakest link in the structure and improving accuracy.

[0024] Secondly, embodiments of this application provide a real-time monitoring device for the cross-sectional shape of a tunnel, comprising:

[0025] The displacement monitoring component is configured to monitor the chord length of the section to which the monitoring device belongs at any given time;

[0026] A laser ranging component is configured to monitor the arc height of the segment to which the monitoring device belongs at any given time;

[0027] An angle monitoring component is configured to monitor the tilt angle of the section to which the monitoring device belongs at any given time.

[0028] Thirdly, embodiments of this application provide a real-time monitoring system for tunnel cross-sectional shape, including a real-time monitoring device and a control device for tunnel cross-sectional shape as described in the second aspect. The control device is electrically connected to multiple monitoring devices and executes any of the real-time monitoring methods for tunnel cross-sectional shape mentioned in the first aspect.

[0029] By employing the above technical solution, this application provides a method, apparatus, and system for real-time monitoring of tunnel cross-sectional shape. The tunnel cross-section is divided into multiple segments based on its perimeter. A monitoring device is fixed to the inner wall of each segment, and all monitoring devices are communicatively connected to a control device for the designated tunnel. The method includes: the control device acquiring in real-time the chord length, arc height, and tilt angle of the segment to which each monitoring device belongs; for each monitoring segment, using the chord length, arc height, and position information of the monitoring devices within the segment, acquiring a local monitoring curve for that segment; and based on the tilt angle and local monitoring curve of each monitoring segment, using numerical fitting to obtain the monitoring curve of the tunnel cross-section in the overall coordinate system. This application sets up corresponding monitoring devices for the divided segments, and the control device acquires in real-time the chord length, arc height, and tilt angle of the segment to which each monitoring device belongs. Due to the introduction of the arc height parameter, a corresponding local monitoring curve can be generated for each monitoring segment. Compared to existing technologies, the local monitoring curve better conforms to the curvature of the tunnel cross-section, thereby improving monitoring accuracy. Attached Figure Description

[0030] Figure 1a A schematic diagram illustrating a measurement performed using the baseline method, provided as an embodiment of this application;

[0031] Figure 1b A schematic diagram illustrating another measurement performed using the baseline method, provided as an embodiment of this application;

[0032] Figure 1c A schematic diagram illustrating another measurement performed using the baseline method, provided as an embodiment of this application;

[0033] Figure 1d A schematic diagram illustrating another measurement performed using the baseline method, provided as an embodiment of this application;

[0034] Figure 2 A schematic diagram illustrating tunnel cross-sectional shape detection using a laser profiler, provided as an embodiment of this application;

[0035] Figure 3 A schematic diagram of a tunnel with internal structural shielding provided for an embodiment of this application;

[0036] Figure 4 A flowchart illustrating a real-time monitoring method for tunnel cross-sectional shape provided in this application embodiment;

[0037] Figure 5 This is a schematic diagram of the module structure of a monitoring device provided in an embodiment of this application;

[0038] Figure 6 A schematic diagram of a local coordinate system for a monitoring device provided in an embodiment of this application;

[0039] Figure 7 A schematic diagram illustrating the establishment of an overall coordinate system based on a tunnel cross-section, provided for an embodiment of this application;

[0040] Figure 8 A schematic diagram illustrating the coordinate relationship of various feature points provided in an embodiment of this application;

[0041] Figure 9 This is a schematic diagram of a monitoring device installed on a tunnel cross section, provided as an embodiment of this application.

[0042] Figure 10 A schematic diagram of another tunnel cross-section monitoring device provided in this application embodiment;

[0043] Figure 11 This is a schematic diagram of a real-time monitoring device for the cross-sectional shape of a tunnel, provided in an embodiment of this application. Detailed Implementation

[0044] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application can be understood more clearly and thoroughly, and that the scope of this application can be fully conveyed to those skilled in the art.

[0045] As mentioned in the background, tunnel cross-sectional deformation is one of the important indicators reflecting the structural safety status. For monitoring tunnel cross-sectional deformation, the industry typically uses the baseline method to calculate convergence values ​​to reflect the deformation status. For example... Figure 1a , Figure 1b , Figure 1c and Figure 1d As shown, several examples of baseline methods are illustrated, demonstrating the monitoring of tunnel cross-sectional deformation using one, two, three, and multiple horizontal baselines, respectively. Based on the baseline method, a method for detecting tunnel cross-sectional shape using laser ranging is also proposed, such as... Figure 2 As shown, a laser profilometer emits a laser from the center point of the tunnel's horizontal plane to various points along the tunnel's perimeter, thereby quickly measuring distances and improving detection efficiency and accuracy.

[0046] However, the above methods require good visibility inside the tunnel. In practice, large-diameter tunnels often have various internal structures, including smoke exhaust ducts, escape routes, escape staircases, prefabricated components, lane pillars, and layered lane slabs, etc. Figure 3 As shown, a tunnel with an internal structure for shielding is illustrated, which is clearly beneficial for tunnels such as... Figure 3For tunnels like this, which are shielded by internal structures, none of the above methods can be implemented.

[0047] To address this issue, related technologies have proposed setting up multiple interconnected measuring devices. Each device acquires the lengths at both ends and the inclination angle of the current measuring device to establish multiple polygonal line segments along the tunnel cross-section. These polygonal line segments are then fitted to obtain the deformation of the monitored tunnel cross-section. However, polygonal lines exhibit straight-line characteristics and cannot accurately replicate the curvature of the tunnel cross-section. This results in a significant discrepancy between the fitted tunnel cross-section curve and the actual tunnel cross-section, leading to poor monitoring accuracy.

[0048] To address the issue of poor monitoring accuracy in current tunnel cross-section monitoring methods, this application proposes a real-time monitoring method for tunnel cross-section shape. This method can be applied to a real-time monitoring system for tunnel cross-section shape and can execute any of the real-time monitoring methods for tunnel cross-section shape mentioned below during operation. For example... Figure 4 As shown, the method includes:

[0049] S101, the control device acquires in real time the chord length, arc height and tilt angle of the section to which each monitoring device belongs, sent by each monitoring device.

[0050] First, in this embodiment, the tunnel cross-section is divided into multiple segments based on its perimeter. A monitoring device is fixed to the inner wall of each segment, and all monitoring devices are communicatively connected to the control device of the designated tunnel. That is, each monitoring device corresponds to a monitoring segment, which is determined by dividing the tunnel cross-section according to its perimeter. Further, the monitoring devices collect the chord length, arc height, and inclination angle of their respective segments. The control device obtains the chord length, arc height, and inclination angle collected by each monitoring device for subsequent processing. Furthermore, for monitoring the entire tunnel, multiple tunnel cross-sections can be selected for monitoring to obtain the overall deformation of the tunnel.

[0051] For example, a tunnel cross-section can be selected every 20 meters along the tunnel's length as the cross-section to be monitored. Further, if the tunnel in this embodiment is semi-circular with a diameter of 10 meters, the corresponding circumference is approximately 15.7 meters. Since the measurement length of a single monitoring device is 20 cm, a corresponding number of monitoring devices can be set according to their measurement range. Simultaneously, the control device can be installed on-site, for example, on one side of the tunnel; or it can be installed off-site, for example, by a computer terminal acquiring the chord length, arc height, and tilt angle via wireless communication and then processing the data. It should be noted that the tunnel mentioned here typically refers to a diameter greater than or equal to 10 meters; this is only used to illustrate that a tunnel can accommodate various internal structures and does not imply a requirement for a specific diameter. The specific arrangement can be flexibly selected based on the actual application.

[0052] As a feasible implementation method, the monitoring device is also called a circular arc segment shape monitoring sensor unit (or simply sensor unit), which can be composed of multiple sensor units with different functions. For example... Figure 5 As shown, the system includes a displacement monitoring module capable of measuring displacement along its axial direction to obtain the chord length Ln of the corresponding section. On' is the origin, which is also the midpoint of the chord length Ln. It also includes a laser ranging module, set perpendicular to the chord length at the origin On', measuring the distance to the tunnel edge to obtain the arc height Hn of the corresponding section. Finally, it includes an angle monitoring module used to measure the angle between the chord direction and the horizontal plane to obtain the tilt angle θn of the corresponding section.

[0053] In addition, the monitoring device may also include a communication device for transmitting the chord length, arc height, and tilt angle collected by the monitoring device to a control device via wired or wireless means. The monitoring device may also include an encapsulation module for encapsulating the displacement monitoring module, laser ranging module, and angle monitoring module; furthermore, it may include a fixing bracket for fixing to the tunnel wall and / or connecting to other monitoring devices. The monitoring device in this embodiment is small in size and easy to fix, although... Figure 5 A cuboid structure is shown, but it can actually be fixed and installed using various existing portable methods, which is beneficial for the stability of device installation and signal transmission.

[0054] It should be further clarified that commercially available monitoring sensors can be used for each monitoring module. For example, the angle monitoring module can use a commercially available bidirectional inclinometer, including X and Y axis inclinometers. The X-axis can be aligned with the axis of the displacement monitoring module, and the Y-axis can be perpendicular to the axis. The tilt angle is 0 when the positive X-axis coincides with the vertically downward direction, and the positive value is obtained by counterclockwise rotation. Angle values ​​are measured using the range of 0 to 2π. The displacement detection module can be a commercially available joint gauge, consisting of a fixed end and a movable end. The movable end of the sensor can move with the movement of the measured structure (such as deformation caused by tunnel compression), thereby measuring the displacement change along the axis of the joint gauge, i.e., the chord length change.

[0055] S102, for each monitoring section, the local monitoring curve of the monitoring section is obtained by using the chord length, arc height and location information of the monitoring device in the monitoring section.

[0056] Obtaining local monitoring curves for a monitoring section requires constructing a local coordinate system for that section. The origin of this local coordinate system can be determined based on the location information of the monitoring devices within the section. For example... Figure 6 As shown, without considering the tilt, a schematic diagram is shown of a monitoring curve for a given section determined by the chord length and arc height. The origin position in the diagram can be determined based on the position information of the monitoring device within the monitoring section. For example, based on the position of the monitoring device, the midpoint of the measured chord length can be used as the origin.

[0057] S103. Based on the tilt angle and local monitoring curve of each monitoring section, the monitoring curve of the tunnel section in the overall coordinate system is obtained by numerical fitting.

[0058] In this embodiment, monitoring devices are first set up for the divided sections. The control device acquires the chord length, arc height, and tilt angle of the section to which each monitoring device belongs in real time. Due to the introduction of the arc height parameter, a corresponding local monitoring curve can be generated for each monitoring section. Compared with the prior art, the local monitoring curve can better fit the curvature structure of the tunnel cross-section, thereby improving the monitoring accuracy.

[0059] Optionally, for each monitoring segment, the local monitoring curve of the monitoring segment is obtained using the chord length, arc height, and location information of the monitoring device within the monitoring segment. This includes: establishing a local coordinate system corresponding to the monitoring segment using the location information of the monitoring device within the monitoring segment; determining three feature points in the corresponding local coordinate system based on the chord length and arc height of the monitoring segment; the feature points include the two vertices and arc vertices of the monitoring segment; and obtaining the local monitoring curve using the two vertices and arc vertices of the monitoring segment.

[0060] In this embodiment, for each monitoring segment, a local monitoring curve is obtained using the chord length, arc height, and location information of the monitoring devices within the segment. Specifically, a local coordinate system is established for that monitoring segment using the location information of the monitoring devices. For example, the midpoint of the measured chord length is used as the origin, based on the location of the monitoring devices. Then, based on the measured chord length and arc height, the coordinates of three feature points are precisely determined in this local coordinate system. These three feature points include the two vertices of the monitoring segment, i.e., the two endpoints of the chord length, and the midpoint (arc vertex) of the arc of the segment, which is also the highest point determined by the arc height. Finally, using these three feature points, a local monitoring curve for the segment is obtained through mathematical fitting. The technical advantage of this step is that it transforms the measured parameter values ​​of chord length, arc height, and inclination angle into a local monitoring curve. Compared to a broken line method, the curve better reflects the actual characteristics of the tunnel, providing a more accurate and reliable local shape data foundation for subsequent fitting.

[0061] Optionally, based on the chord length and arc height of the monitoring section, three feature points are determined in the corresponding local coordinate system, including: determining the midpoint of the chord length of the monitoring section as the origin of the local coordinate system; determining two vertices of the three feature points based on the two endpoints of the chord length of the monitoring section; and determining the arc vertex of the three feature points based on the arc height of the monitoring section.

[0062] In this embodiment, the steps for determining three feature points in the corresponding local coordinate system based on the chord length and arc height of the monitoring segment are further explained. Specifically, the midpoint of the chord length of the monitoring segment is set as the origin of the local coordinate system; thus, the coordinates of the two vertices in the local coordinate system can be directly calculated based on the chord length and the tilt angle (e.g., if not horizontal). Simultaneously, the coordinates of the arc vertices can be determined based on the arc height measured perpendicular to the chord length direction. This can be combined with... Figure 6 As shown, by setting the origin of the coordinate system at the midpoint of the chord, the formula for calculating the coordinates of the three feature points is greatly simplified, the complexity of data processing is reduced, and the computational efficiency and real-time performance of the system are improved.

[0063] It should be noted that the relative positions of the various sub-modules of the monitoring device are fixed and can be used as fixed parameters. For example, to improve calculation efficiency, after measuring the chord length, the coordinates of the origin can be directly calculated based on the fixed parameters and the tilt angle (if there is tilt).

[0064] Optionally, the tunnel cross-section is divided into multiple continuous sections according to the cross-sectional perimeter, and the monitoring devices are arranged end to end along the inner wall of the tunnel cross-section.

[0065] In this embodiment, the tunnel cross-section is divided into multiple segments based on its perimeter. These segments can be continuous or discontinuous, allowing the monitoring devices to be arranged either end-to-end or spaced apart. In this embodiment, the end-to-end physical connection ensures a geometrical connection between the data from adjacent monitoring devices, thereby improving monitoring accuracy. It should be noted that the overlap of the fixing supports of two monitoring devices at the connecting feet does not affect monitoring accuracy.

[0066] Optionally, based on the tilt angle and local monitoring curve of each monitoring section, a numerical fitting method is used to obtain the monitoring curve of the tunnel cross-section in the overall coordinate system, including: determining the coordinate information of the origin of the local coordinate system of the first monitoring device in the overall coordinate system based on the installation position of the first monitoring device; determining the coordinate information of the three feature points corresponding to the first monitoring device in the overall coordinate system based on the tilt angle of the first monitoring device, and determining the position of the local monitoring curve corresponding to the first monitoring device in the overall coordinate system; for the nth monitoring device, determining the position of the section to which the (n-1)th monitoring device belongs in the overall coordinate system. The coordinates of the point are used as the starting coordinates of the nth monitoring device in the overall coordinate system; where n is an integer greater than 1, and the (n-1)th and nth monitoring devices are arranged end-to-end. Based on the starting coordinates, the chord length and tilt angle of the nth monitoring device, the coordinate information of the three feature points corresponding to the nth monitoring device in the overall coordinate system is determined, and the position of the local monitoring curve corresponding to the nth monitoring device in the overall coordinate system is determined. After determining the position of the local monitoring curve corresponding to each monitoring device in the overall coordinate system, all local monitoring curves are fitted to obtain the monitoring curve of the tunnel cross section.

[0067] In this embodiment, with the monitoring devices arranged end-to-end, the process of fitting local monitoring curves to obtain the monitoring curve of the tunnel cross-section is explained. For example... Figure 7 The diagram illustrates the arrangement of monitoring devices (sensor units) within an overall coordinate system. Due to supporting structures (such as corbels) on the tunnel walls, sensor units cannot be installed at these locations. Instead, sensor units are installed end-to-end in all locations except for the supporting structures, thus representing a connected arrangement. First, based on the installation position of the first monitoring device (sensor 1 in the diagram), the coordinates of its local coordinate system origin in the overall coordinate system XOY are determined. The origin of the overall coordinate system is typically set to the center of the tunnel, but this can be flexibly chosen based on the specific application. Then, based on its measured tilt angle, the coordinates of three feature points in the section belonging to sensor 1 are calculated in the overall coordinate system through coordinate rotation and translation, thereby determining the position of its local monitoring curve within the overall system. This end-to-end physical connection allows for a natural geometric connection of data from adjacent monitoring devices, thus improving monitoring accuracy.

[0068] Furthermore, for the nth monitoring device (such as sensor 2, sensor 3), its starting coordinates are directly inherited from the ending coordinates of the previous monitoring device (sensor 1, sensor 2), and its position in the global coordinate system is calculated by combining its own measured chord length and tilt angle. After all local monitoring curves are located, they are connected and fitted to obtain the complete tunnel cross-section monitoring curve.

[0069] As a feasible implementation method, the following will be combined with Figure 6 , Figure 7 and Figure 8 The specific fitting process will be explained. First, the tunnel cross-section is divided into several segments with smaller arc lengths based on its perimeter, such as... Figure 7 The sensor is arranged in a connected manner, where shorter segments result in higher measurement accuracy. A local coordinate system Xn'On'Yn' is then established for each segment, where n is the sensor number; for example, sensor 1 corresponds to the local coordinate system X1'O1'Y1'. Further, as... Figure 8 Based on the data measured by each module, such as chord length, arc height, and tilt angle, determine A. n B n C n The coordinates (xA, B are the two vertices of the chord, and C is the vertex of the arc) of three feature points in the local coordinate system. n ,yA n ), (xB n ,yB n (xC) n ,yC n Then, taking the center of the tunnel cross-section as the origin, a global coordinate system XOY is established for the tunnel cross-section area.

[0070] The process of fitting the tunnel cross-section shape curve is as follows:

[0071] ① The coordinates of points An, Bn, and Cn in the local coordinate system are (-Ln / 2, 0), (Ln / 2, 0), and (0, Hn), respectively; where Ln is the chord length and Hn is the arc height.

[0072] ②Based on the sensor arrangement scheme, we can obtain Figure 7 The coordinates (X) of the origin O1' of the first sensor in the lower left corner in the global coordinate system. o1 Y o1 );

[0073] ③ Based on the sensor measurement results, calculate the coordinates (X, Y, F, C) of points A1, B1, and C1 in the global coordinate system. A1 ,Y A1 ), (X) B1 Y B1), (X) C1 Y C1 ). Combination Figure 8 Where θ1 is the tilt angle of the first sensor, and according to geometric relationships, the coordinate values ​​have the following relationship:

[0074] (Formula 1)

[0075] (Formula 2)

[0076] (Formula 3)

[0077] Furthermore, according to the sensor installation plan, point A n With point B n-1 Coincidence means that the coordinates of the two sensors are the same (n>1). Therefore, referring to Formula 4, point A can be calculated based on the coordinates of the (n-1)th sensor. n The coordinates of point B (i.e., the coordinates of point B) n-1 Referring to Formula 5, and combining the chord length and inclination angle θ... n The coordinates of On' (Xo(n), Yo(n)) are calculated from the chord length Ln. Referring to formulas six and seven, and combining the arc height Hn, the coordinates of Cn (Xo(n), Yo(n)) are calculated. C(n) Y C(n) ) and the coordinates (X) of point Bn. B(n) Y B(n) Based on geometric relationships, the coordinate values ​​have the following relationship:

[0078] (Formula 4)

[0079] (Formula 5)

[0080] (Formula 6)

[0081] (Formula 7)

[0082] By combining formulas one through seven above, the feature points corresponding to each monitoring segment in the local coordinate system can be transformed into the global coordinate system, thereby obtaining the local monitoring curves of each monitoring area in the global coordinate system. This embodiment achieves a high-precision, low-error-accumulation data fusion method. Each sensor only needs to measure its own segment, and this algorithm can "stitch together" multiple local measurement results into a high-precision overall profile.

[0083] Optionally, the tunnel cross-section is divided into multiple discontinuous sections based on the cross-sectional perimeter.

[0084] In this embodiment, as Figure 7As shown, due to practical application scenarios or cost considerations, the sections can be set as discontinuous. Therefore, the monitoring devices do not necessarily have to be connected end to end. They can be selectively deployed in key sections based on the actual conditions inside the tunnel, such as areas obstructed by internal structures or equipment, or budget constraints. This achieves the best balance between cost and benefit.

[0085] Furthermore, when the sections are discontinuous, the monitoring curves of the tunnel cross-section in the global coordinate system are obtained by numerical fitting based on the tilt angle and local monitoring curves of each monitoring section. This includes: for sections equipped with monitoring devices, transforming the local monitoring curves of each monitoring section in the local coordinate system to the global coordinate system; for sections without monitoring devices, obtaining the tunnel shape data of the tunnel cross-section in the sections without monitoring devices; based on the tunnel shape data, constructing the original shape curves of the sections without monitoring devices in the global coordinate system; and fitting the monitoring curves of the tunnel cross-section in the global coordinate system based on the local monitoring curves and the original shape curves.

[0086] In this embodiment, a corresponding overall curve fitting method is provided for the aforementioned discontinuous section arrangement. Specifically, for sections with installed monitoring devices, their local monitoring curves are transformed into the overall coordinate system. For sections without installed monitoring devices, the original design data of the tunnel cross-section is retrieved to obtain its theoretical tunnel shape data, and the original shape curve of the section is constructed in the overall coordinate system. That is, for locations without installed sensors, the shape curve is assumed to be the arc corresponding to the tunnel's designed inner diameter. Finally, the measured local monitoring curves are fused and fitted with the theoretical original shape curves to obtain the complete tunnel cross-section monitoring curve. This ensures the monitoring accuracy of key components under limited hardware deployment.

[0087] Furthermore, even with a discontinuous setup, the coordinates of the nth sensor can be calculated from the endpoint coordinates of the (n-1)th sensor. Specifically, for installations where the beginning and end are not connected, the starting coordinates of the nth sensor can be calculated based on the endpoint coordinates of the (n-1)th and nth sensors, as well as the tunnel shape data of the corresponding section between the nth and nth sensors.

[0088] It should be noted that regardless of whether the monitoring devices are arranged end-to-end or spaced out, with the original design data of the tunnel used to replace the spaced sections, the fitted monitoring curves of the tunnel cross-section in the overall coordinate system are all connected, and there is no break in the middle.

[0089] Optionally, the tunnel is constructed using the shield tunneling method for lining, and tunnel segments are installed on the tunnel cross section. There are segment joints at the junction of two adjacent tunnel segments. During the arrangement of the monitoring device, the segments with joints are arranged across the joints.

[0090] In this embodiment, as Figure 9 and Figure 10 As shown, the tunnel segment is the part that comes into contact with the monitoring device (circular arc shape monitoring sensor unit). Figure 9 The monitoring device uses expansion bolts to fix the support to the tunnel segments and to connect it end-to-end with the support of another monitoring device. An overall diagram can be seen in conjunction with... Figure 10 As shown. Segment joints exist at the junctions of two adjacent tunnel segments. Considering that a tunnel cross-section is typically assembled from multiple tunnel segments, and that segment joints exist at the junctions of adjacent segments, these joints are critical parts for structural stress and deformation. Therefore, when arranging monitoring devices, a cross-joint arrangement is adopted for locations with segment joints. This means that the monitoring section corresponding to one monitoring device spans the joint, thereby capturing the health status information of the weakest link in the structure and improving accuracy. Furthermore, cross-joint arrangements can be implemented using either end-to-end connections or non-end-to-end connections, such as... Figure 10 The presence of corbels and flue plates prevents the monitoring devices from being connected end to end, but this does not affect the cross-joint arrangement of the monitoring devices.

[0091] The real-time monitoring method for tunnel cross-section shape provided by any of the above embodiments first collects the chord length, arc height, and tilt angle of the monitored area. Based on the chord length and arc height, three feature points—two endpoints and an arc vertex—are calculated in the local coordinate system corresponding to each segment. A local monitoring curve is then constructed based on these three feature points. Compared with related technologies, this method determines the arc vertex feature point based on the arc height parameter, enabling the construction of a local monitoring curve that better matches the actual shape of the tunnel cross-section, thus improving monitoring accuracy. Furthermore, the local monitoring curve is transformed into a global coordinate system to fit the monitoring curve of the tunnel cross-section, achieving higher-precision monitoring of the tunnel cross-section.

[0092] In addition, this application embodiment also provides a real-time monitoring device for the cross-sectional shape of a tunnel, including: a displacement monitoring component configured to monitor the chord length of the section to which the monitoring device belongs; a laser ranging component configured to monitor the arc height of the section to which the monitoring device belongs; and an angle monitoring component configured to monitor the tilt angle of the section to which the monitoring device belongs.

[0093] In this embodiment, as Figure 11The diagram illustrates a real-time monitoring device for the cross-sectional shape of a tunnel. A displacement monitoring component 1 is configured to monitor the chord length of the segment to which the monitoring device belongs; specifically, it measures the distance between the two endpoints of the displacement monitoring component to obtain the chord length of the segment. A laser ranging component 2, positioned on the displacement monitoring component 1 facing the tunnel, is configured to monitor the arc height of the segment to which the monitoring device belongs; that is, the laser ranging component emits a laser towards the tunnel wall of its segment and obtains the distance to the tunnel wall to obtain the arc height of the segment. An angle monitoring component 3, positioned on the displacement monitoring component 1, is configured to monitor the tilt angle of the segment to which the monitoring device belongs; that is, the angle between the axis of the monitoring device and the horizontal plane. Exemplarily, the device may further include a package 4 for encapsulating the displacement monitoring component 1, the laser ranging component 2, and the angle monitoring component 3; a wireless communication device 5; and a fixing bracket 6 for fixing the components to the tunnel wall. A fixing nut 7 is used to connect the displacement monitoring component 1 and the fixing bracket 6.

[0094] Furthermore, this application also provides a real-time monitoring system for tunnel cross-section shape, including a real-time monitoring device and a control device for tunnel cross-section shape as mentioned above. The control device is communicatively connected to multiple monitoring devices and executes the real-time monitoring method for tunnel cross-section shape mentioned in any of the above embodiments.

[0095] This embodiment proposes a complete real-time monitoring system for tunnel cross-section shape to facilitate practical application. Specifically, it includes a monitoring device for real-time acquisition of the chord length, arc height, and inclination angle of the corresponding section. Multiple monitoring devices can be installed, each corresponding to a monitoring section. A communication device is used to transmit the chord length, arc height, and inclination angle acquired by the monitoring devices in real time, i.e., to send the monitoring data to a control device for subsequent data processing. This can be done via wired or wireless communication. For ease of transmission, the communication device can be installed on or integrated with the monitoring devices. A control device is also included, configured to acquire the chord length, arc height, and inclination angle of the section to which each monitoring device belongs in real time. Furthermore, the control device uses numerical fitting to obtain the monitoring curve of the tunnel cross-section in the overall coordinate system based on the inclination angle and local monitoring curve of each monitoring section.

[0096] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0097] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0098] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0099] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0100] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for real-time monitoring of tunnel cross-sectional shape, characterized in that, The cross-section of a tunnel in use is divided into multiple sections according to its perimeter. A monitoring device is fixed to the inner wall of each section. All monitoring devices are communicatively connected to the control device of a designated tunnel. The method includes: The control device acquires in real time the chord length, arc height, and tilt angle of the section to which each monitoring device belongs, sent by each monitoring device. For each monitoring segment, the local monitoring curve of the monitoring segment is obtained by using the chord length, arc height and the location information of the monitoring device in the monitoring segment; Based on the tilt angle and local monitoring curves of each monitoring section, the monitoring curves of the tunnel cross-section in the overall coordinate system are obtained by numerical fitting.

2. The method according to claim 1, characterized in that, For each monitoring segment, the local monitoring curve of the monitoring segment is obtained using the chord length, arc height, and location information of the monitoring device within the monitoring segment, including: A local coordinate system corresponding to the monitoring section is established based on the location information of the monitoring devices within the monitoring section. Based on the chord length and arc height of the monitoring section, three feature points are determined in the corresponding local coordinate system; the three feature points include the two vertices and the arc vertex of the monitoring section; The local monitoring curve is obtained using the two vertices and the arc vertex of the monitoring section.

3. The method according to claim 2, characterized in that, The step involves determining three feature points in the corresponding local coordinate system based on the chord length and arc height of the monitoring section, including: The midpoint of the chord length of the monitoring section is determined as the origin of the local coordinate system; Two vertices of the three feature points are determined based on the two endpoints of the chord length of the monitoring section; The arc vertex among the three feature points is determined based on the arc height of the monitored section.

4. The method according to claim 3, characterized in that, The tunnel cross-section is divided into multiple continuous sections according to the cross-sectional perimeter, and the monitoring devices are arranged end to end along the inner wall of the tunnel cross-section.

5. The method according to claim 4, characterized in that, Based on the tilt angle and local monitoring curves of each monitoring section, the monitoring curves of the tunnel cross-section in the global coordinate system are obtained using numerical fitting, including: Based on the installation location of the first monitoring device, determine the coordinate information of the origin of the local coordinate system of the first monitoring device in the global coordinate system; Based on the tilt angle of the first monitoring device, the coordinate information of the three feature points corresponding to the first monitoring device in the overall coordinate system is determined, and the position of the local monitoring curve corresponding to the first monitoring device in the overall coordinate system is determined. For the nth monitoring device, the endpoint coordinates of the segment to which the (n-1)th monitoring device belongs in the overall coordinate system are taken as the starting coordinates of the nth monitoring device in the overall coordinate system; where n is an integer greater than 1, and the (n-1)th monitoring device and the nth monitoring device are arranged end to end; Based on the starting point coordinates, the chord length and tilt angle of the nth monitoring device, determine the coordinate information of the three feature points corresponding to the nth monitoring device in the overall coordinate system, and determine the position of the local monitoring curve corresponding to the nth monitoring device in the overall coordinate system; After determining the position of the local monitoring curve corresponding to each monitoring device in the overall coordinate system, all local monitoring curves are fitted to obtain the monitoring curve of the tunnel cross section.

6. The method according to claim 3, characterized in that, The tunnel cross-section is divided into multiple discontinuous sections based on its perimeter.

7. The method according to claim 6, characterized in that, When the section is discontinuous, based on the tilt angle and local monitoring curve of each monitoring section, a numerical fitting method is used to obtain the monitoring curve of the tunnel cross-section in the overall coordinate system, including: For the sections equipped with the monitoring devices, the local monitoring curves of each monitoring section in the local coordinate system are transformed to the global coordinate system; For sections where the monitoring device is not installed, obtain the tunnel shape data of the tunnel cross section in the section where the monitoring device is not installed; Based on the tunnel shape data, an original shape curve is constructed in the overall coordinate system for the section where the monitoring device is not installed; Based on the local monitoring curve and the original shape curve, a monitoring curve for the tunnel cross-section in the global coordinate system is fitted.

8. The method according to claim 3, characterized in that, The tunnel was constructed using the shield tunneling method for lining. Tunnel segments are installed on the tunnel cross section, and there are segment joints at the junction of two adjacent tunnel segments. During the arrangement of the monitoring device, the segments with joints are arranged across the joints.

9. A real-time monitoring device for tunnel cross-sectional shape, characterized in that, include: The displacement monitoring component is configured to monitor the chord length of the section to which the monitoring device belongs at any given time; A laser ranging component is configured to monitor the arc height of the segment to which the monitoring device belongs at any given time; An angle monitoring component is configured to monitor the tilt angle of the section to which the monitoring device belongs at any given time.

10. A real-time monitoring system for tunnel cross-sectional shape, characterized in that, It includes the monitoring device and control device as described in claim 9, wherein the control device is communicatively connected to multiple monitoring devices and performs the real-time monitoring method for the cross-sectional shape of any one of claims 1 to 8.

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