A method and system for monitoring three-dimensional deformation of a slope

Abstract

The present application relates to a kind of side slope three-dimensional deformation monitoring method and system, belong to side slope monitoring technical field, wherein, the method includes: the reflection spectrum data collected by the optical fiber sensitive unit embedded in side slope is acquired, and the optical fiber sensitive unit includes cylinder and the optical fiber grating around the cylinder;Based on reflection spectrum data, the bending direction and curvature data of optical fiber sensitive unit are determined;Based on bending direction and curvature data, three-dimensional reconstruction is carried out to side slope deformation curve, and the three-dimensional side slope deformation curve is obtained.The present application is by the optical fiber grating on the cylinder, so that the reflection spectrum data of optical fiber sensitive unit with different bending direction, different bending rate is anisotropic after being extruded and deformed, the characteristics of the anisotropy of reflection spectrum data are used, the bending direction and curvature data of optical fiber sensitive unit are obtained, and then three-dimensional reconstruction is carried out, effectively solve the technical problem that ordinary optical fiber grating sensor cannot distinguish direction in prior art.

Description

Technical Field

[0001] This invention relates to the field of slope monitoring technology, and in particular to a method and system for monitoring three-dimensional deformation of slopes. Background Technology

[0002] Slope monitoring refers to the long-term monitoring of slopes to understand their deformation and displacement patterns, analyze slope stability, and provide a reliable basis for slope management and protection.

[0003] In existing technologies, traditional methods for monitoring three-dimensional deformation of slopes use fiber optic grating sensors. Ordinary flexible fiber optic grating sensors calculate the strain by utilizing the drift of the center wavelength of the reflection spectrum caused by the change in grating spacing after the fiber is subjected to force along its axial direction.

[0004] However, ordinary fiber optic flexible sensors are isotropic strain sensors. When the fiber is subjected to lateral force, the direction of the force cannot be determined based on the spectral information. Therefore, their application range is relatively narrow and it is difficult to meet the requirements of dynamic three-dimensional deformation monitoring in complex slope environments. Summary of the Invention

[0005] In view of this, it is necessary to provide a method and system for monitoring three-dimensional deformation of slopes to solve the technical problem that ordinary fiber optic flexible sensors in the prior art cannot determine the direction of force and are difficult to meet the requirements for dynamic three-dimensional deformation monitoring of slopes in complex environments.

[0006] To address the aforementioned problems, this invention provides a method for monitoring three-dimensional deformation of slopes, comprising:

[0007] The reflectance spectrum data collected by the fiber optic sensing unit embedded in the slope is obtained. The fiber optic sensing unit includes a cylinder and a fiber optic grating wound around the cylinder.

[0008] Based on the reflected spectrum data, the bending direction and curvature data of the fiber optic sensing element are determined;

[0009] Based on the bending direction and curvature data, the slope deformation curve is reconstructed in three dimensions to obtain a three-dimensional slope deformation curve.

[0010] In one possible implementation, at least two fiber optic sensing units are provided, with the cylinders of adjacent fiber optic sensing units connected by flanges and the fiber gratings of adjacent fiber optic sensing units connected by optical fibers.

[0011] In one possible implementation, a protective tube is also fitted around the optical fiber sensing element.

[0012] In one possible implementation, determining the bending direction and curvature data of the fiber optic sensing element based on the reflection spectral data includes:

[0013] The reflection spectrum data is input into a fully trained deep learning model to obtain the bending direction and curvature data of the fiber optic sensing unit. The deep learning model includes an input layer, a shared convolutional layer, and a dual-head output layer connected in sequence. The input layer is used to input the reflection spectrum data. The shared convolutional layer includes several sets of convolutional layers and a pooling layer whose input end is connected to the output end of the convolutional layer. The dual-head output layer includes two output heads. The first output head is used to fit the bending direction data of the output fiber optic sensing unit, and the second output head is used to fit the curvature data of the output fiber optic sensing unit.

[0014] In one possible implementation, based on the bending direction and curvature data, the slope deformation curve is reconstructed in three dimensions to obtain a three-dimensional slope deformation curve, including:

[0015] Based on the geometric relationship of the fiber optic sensing element, as well as the bending direction and curvature data, the slope deformation curve is reconstructed in two dimensions to obtain a two-dimensional slope deformation curve.

[0016] Based on the bending direction data of each fiber optic sensing element, the two-dimensional slope deformation curve is reconstructed into a three-dimensional slope deformation curve.

[0017] In one possible implementation, at least two optical fiber sensing elements are provided, with adjacent optical fiber sensing elements connected end to end.

[0018] Based on the geometric relationship of the fiber optic sensing element, as well as the bending direction and curvature data, the slope deformation curve is reconstructed in two dimensions to obtain a two-dimensional slope deformation curve, including:

[0019] Each fiber optic sensing unit is divided into a straight segment at the beginning, an arc at the middle, and a straight segment at the end. The arc is considered to be uniformly curved, and the connection points between the straight segment at the beginning, the arc, and the straight segment at the end are all considered to be smoothly tangent, thus constructing a two-dimensional curve model of the fiber optic sensing unit.

[0020] Within the first preset range, the angle between the straight line segment at the beginning of the first fiber optic sensing unit and the coordinate axis is selected. Within the second preset range, the arc length of the arc of each fiber optic sensing unit is selected.

[0021] Based on the two-dimensional curve model, the measured coordinates of the first end of the first fiber sensing unit, the included angle, the arc length, and the bending direction and curvature data, starting from the first end of the first fiber sensing unit, the coordinates of the first and last ends of each fiber sensing unit are calculated sequentially, and finally the calculated coordinates of the last end of the last fiber sensing unit are obtained.

[0022] The deviation between the calculated coordinates of the tail end of the last fiber optic sensing unit and the measured coordinates of the tail end of the last fiber optic sensing unit is calculated. The included angle and arc length corresponding to the minimum deviation are selected, and the two-dimensional slope deformation curve is determined based on the included angle and arc length corresponding to the minimum deviation.

[0023] In one possible implementation, based on the two-dimensional curve model, the measured coordinates of the first end of the first fiber optic sensing unit, the included angle, the arc length, and the bending direction and curvature data, starting from the first end of the first fiber optic sensing unit, the coordinates of the first and last ends of each fiber optic sensing unit are calculated sequentially, and finally the calculated coordinates of the last end of the last fiber optic sensing unit are obtained, including:

[0024] S801. Select the first fiber optic sensing unit as the current fiber optic sensing unit, take the measured value of the first end coordinate of the first fiber optic sensing unit as the first end coordinate of the current fiber optic sensing unit, and determine the slope of the straight line segment at the first end of the current fiber optic sensing unit based on the included angle.

[0025] S802. Based on the coordinates of the first end of the current fiber optic sensitive unit, the slope and arc length of the straight line segment at the first end, calculate the coordinates of the connection point between the straight line segment and the arc at the first end.

[0026] S803. Based on the bending direction and curvature data of the current fiber optic sensitive unit, the coordinates of the connection point between the straight segment and the arc at the beginning, and the slope of the straight segment at the beginning, calculate the coordinates of the center of the curvature circle of the arc, and based on the coordinates of the center of the curvature circle, calculate the coordinates of the connection point between the arc and the straight segment at the end.

[0027] S804. Based on the geometric relationship between the straight line connecting the center of the curvature circle and the connection point between the arc and the tail line segment and the geometric line segment perpendicular to the tail line segment, the coordinates of the center of the curvature circle and the coordinates of the connection point between the arc and the tail line segment, calculate the tail coordinates of the current sensitive unit.

[0028] S805. Use the tail coordinate of the current sensitive unit as the head coordinate of the next sensitive unit, and use the slope of the straight line segment at the tail of the current sensitive unit as the slope of the straight line segment at the head of the next sensitive unit. Return to step S802 until the tail coordinate of the last sensitive unit is calculated.

[0029] In one possible implementation, at least two optical fiber sensing elements are provided, with adjacent optical fiber sensing elements connected end to end.

[0030] Based on the bending direction data of each fiber optic sensing element, the two-dimensional slope deformation curve is reconstructed into a three-dimensional slope deformation curve, including:

[0031] S901. Embed the two-dimensional slope deformation curve into the three-dimensional coordinate system to obtain the initial slope deformation curve, and use the first fiber optic sensing unit as the current fiber optic sensing unit.

[0032] S902. Determine the straight line parallel to the initial length direction of the fiber optic sensing unit and passing through the beginning of the current fiber optic sensing unit as the axis of rotation, and rotate the initial slope deformation curve around the axis of rotation to obtain the intermediate slope deformation curve.

[0033] S903. Retain the three-dimensional slope deformation curve corresponding to the current fiber optic sensitive unit in the intermediate slope deformation curve, and take the slope deformation curves corresponding to all fiber optic sensitive units in the intermediate slope deformation curve except for the current section as the initial slope deformation curve.

[0034] S904. Take the next fiber optic sensing unit as the current fiber optic sensing unit, return to step S902, until the target slope deformation curves corresponding to all fiber optic sensing units are obtained, and determine the final three-dimensional slope deformation curve based on the target slope deformation curves.

[0035] In one possible implementation, the method further includes an early warning module that issues an early warning signal when the curvature of the three-dimensional slope deformation curve is greater than a threshold.

[0036] On the other hand, the present invention also provides a three-dimensional deformation monitoring system for slopes, comprising:

[0037] A spectral acquisition module is used to acquire reflectance spectral data collected by an optical fiber sensing unit embedded in the slope. The optical fiber sensing unit includes a cylinder and a fiber grating wound around the cylinder.

[0038] The deformation prediction module is used to determine the bending direction and curvature data of the fiber optic sensing element based on the reflection spectrum data.

[0039] The three-dimensional reconstruction module is used to reconstruct the slope deformation curve in three dimensions based on the bending direction and curvature data, so as to obtain a three-dimensional slope deformation curve.

[0040] The beneficial effects of this invention are as follows: The three-dimensional deformation monitoring method for slopes provided by this invention, by winding a fiber optic grating around a cylinder to form a 360° full coverage of the bending direction, makes the reflection spectrum data of fiber optic sensitive units with different bending directions and curvatures anisotropic after being compressed and deformed. By utilizing the anisotropic characteristics of the reflection spectrum data, the bending direction and curvature data of the fiber optic sensitive units can be obtained, and then three-dimensional reconstruction can be performed. This effectively solves the technical problem that ordinary fiber optic grating sensors in the prior art cannot determine the direction, meets the requirements of dynamic three-dimensional deformation monitoring in complex slope environments, and has a wide range of applications. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of an embodiment of the slope three-dimensional deformation monitoring method provided by the present invention;

[0042] Figure 2 A schematic diagram of an embodiment of the fiber optic sensing unit provided by the present invention;

[0043] Figure 3 A schematic diagram illustrating the distribution of a reflectance spectrum according to an embodiment of the present invention;

[0044] Figure 4 A schematic diagram of the structure of an embodiment of the deep learning model provided by the present invention;

[0045] Figure 5 For the present invention Figure 1 A schematic flowchart of an embodiment of step S103;

[0046] Figure 6 For the present invention Figure 5 A schematic diagram of an embodiment of step S501;

[0047] Figure 7 A schematic diagram of an embodiment of the two-dimensional curve model provided by the present invention;

[0048] Figure 8 For the present invention Figure 6 A schematic flowchart of an embodiment of step S603;

[0049] Figure 9 For the present invention Figure 5 A schematic flowchart of an embodiment of step S502;

[0050] Figure 10 A schematic diagram of an embodiment of the initial slope deformation curve provided by the present invention;

[0051] Figure 11 A schematic diagram of an embodiment of the intermediate slope deformation curve provided by the present invention;

[0052] Figure 12 This is a schematic diagram of an embodiment of the slope monitoring system provided by the present invention;

[0053] Reference numerals: 10-cylinder; 110-threaded part; 1110-threaded groove; 120-connection part; 20-flange. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0055] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0056] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. "And / or" describes the relationship between related objects, indicating that three relationships may exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone.

[0057] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0058] This invention provides a method and system for monitoring three-dimensional deformation of slopes, which will be described below.

[0059] Figure 1 This is a schematic flowchart of an embodiment of the slope three-dimensional deformation monitoring method provided by the present invention, as shown below. Figure 1 As shown, the three-dimensional deformation monitoring method 1 for slopes includes:

[0060] S101. Acquire reflectance spectral data collected by an optical fiber sensing unit embedded in the slope. The optical fiber sensing unit includes a cylinder and a fiber optic grating wound around the cylinder.

[0061] It should be noted that, as Figure 2 As shown, the fiber optic sensing unit includes a cylinder 10 and a fiber optic grating (not shown). A threaded groove 1110 is formed on the side of the middle portion of the cylinder 10. Several fiber optic gratings are arranged in a ring, attached to the groove wall of the threaded groove 1110 at least once, forming a 360° full coverage in the bending direction. Therefore, after the fiber optic sensing unit is deformed by compression, the reflection spectrum exhibits irregular characteristics, and the reflection spectra of FBGs with different bending directions and curvatures are anisotropic. The reflection spectra are as follows: Figure 3 As shown.

[0062] Considering that a cylinder with a large outer diameter will affect sensitivity, while a cylinder with a small outer diameter is prone to damage, too few turns of the fiber Bragg grating around the cylinder will affect accuracy, and too many turns of the fiber Bragg grating around the cylinder will increase cost, in some embodiments of this invention, the final number of fiber Bragg gratings is set to three. It should be noted that the number of fiber Bragg gratings can be adjusted according to actual needs and is not limited to three, which will not be elaborated here.

[0063] To address practical monitoring needs, in some embodiments of the present invention, such as... Figure 2 As shown, at least two fiber optic sensing units are provided. The cylinders 10 of adjacent fiber optic sensing units are connected by flanges 20, and the fiber gratings of adjacent fiber optic sensing units are connected by optical fibers. Therefore, different numbers of fiber optic sensing units can be selected for splicing according to the detection depth to realize the extended use of multi-point networked monitoring. It has good scalability and strong practicality. In addition, a PVC protective sleeve (not shown in the figure) is also wrapped around the fiber optic sensing unit to protect the internal fiber optic sensing unit.

[0064] S102. Based on the reflection spectrum data, determine the bending direction and curvature data of the fiber optic sensing element;

[0065] Considering that most conventional methods use peak tracking to detect small shifts in Bragg wavelength when detecting reflectance spectral data, these methods mainly include direct methods, curve fitting methods, correlation-based methods, transformation-based methods, and optimization-based techniques. However, these methods share the characteristic that their detection accuracy is limited by the number of fiber grating spectral sample points. Essentially, the range of the analyzed grating spectrum is relatively small, resulting in low tolerance for spectral deformation of the fiber grating of this invention, making it difficult to apply to the complex situations described in this invention. Therefore, in some embodiments of this invention, step S102 includes: inputting the reflectance spectral data into a fully trained deep learning model to obtain the bending direction and curvature data of the fiber sensing element.

[0066] By using the aforementioned deep learning model to predict deformation from reflectance spectral data, the complex relationship between temperature and strain can be learned, enabling real-time temperature compensation. This avoids the information loss problem of conventional spectral signal detection methods, improves measurement accuracy, and allows for efficient and accurate three-dimensional slope deformation monitoring even in the absence of a clear physical model.

[0067] It should be noted that deep learning models, such as Figure 4 As shown, a CNN network is used, consisting of a sequentially connected input layer, a shared convolutional layer, and a dual-head output layer. The input layer is used to input reflectance spectral data. The shared convolutional layer includes four sets of convolutional layers and pooling layers connecting the input to the output of the convolutional layers. Specifically, the pooling layers are max pooling layers, and the ReLU activation function is used between the convolutional layers and the pooling layers. The dual-head output layer includes two output heads that perform fitting tasks. The first output head is responsible for fitting the bending direction of the output fiber optic sensing unit, and the second output head is responsible for fitting the curvature data of the output fiber optic sensing unit. Each output head includes multiple fully connected layers, and a dropout operation with a probability of 0.5 is used between the two fully connected layers. During model optimization, the mean squared error (MSE) loss function is used for optimization. It should be noted that the number of convolutional and pooling layers can be adjusted according to actual needs and is not limited to four, which will not be elaborated here.

[0068] By adopting the above structure, the hidden layer feature representations of the network can be shared by multiple output heads. This means that the network can learn shared feature representations between different fitting tasks, thereby reducing data redundancy, improving the efficiency and generalization ability of the model, and using operations such as multi-pooling and dropout helps to alleviate overfitting of the network.

[0069] S103. Based on the bending direction and curvature data, the slope deformation curve is reconstructed in three dimensions to obtain the three-dimensional slope deformation curve.

[0070] In summary, this invention, by winding a fiber optic grating around a cylinder to form a 360° full coverage along the bending direction, ensures that the reflection spectral data of fiber optic sensing units with different bending directions and curvatures exhibit anisotropy after being compressed and deformed. Utilizing the anisotropy of the reflection spectral data, the bending direction and curvature data of the fiber optic sensing units are obtained, and then three-dimensional reconstruction is performed. This effectively solves the technical problem that ordinary fiber optic grating sensors in the prior art cannot determine the direction, meets the requirements for dynamic three-dimensional deformation monitoring in complex slope environments, and has a wide range of applications.

[0071] In some embodiments of the present invention, such as Figure 5 As shown, step S103 includes:

[0072] S501. Based on the geometric relationship of the fiber optic sensing element, as well as the bending direction and curvature data, the slope deformation curve is reconstructed in two dimensions to obtain a two-dimensional slope deformation curve.

[0073] S502. Based on the bending direction data of each fiber optic sensing unit, the two-dimensional slope deformation curve is reconstructed into a three-dimensional slope deformation curve.

[0074] To better perform two-dimensional reconstruction, in some embodiments of the present invention, such as Figure 6 As shown, step S501 includes:

[0075] S601. Divide each fiber sensing unit into a straight line segment at the beginning, an arc segment at the middle, and a straight line segment at the end. Treat the arc segment as a uniform curve, and treat the connection points between the straight line segment at the beginning, the arc segment, and the straight line segment at the end as smooth tangents. Construct a two-dimensional curve model of the fiber sensing unit.

[0076] It should be noted that, as Figure 2 As shown, the cylinder 10 includes a threaded portion 110 in the middle and connecting portions 120 at both ends. Threaded grooves 1110 are formed on the threaded portion 110. The elastic modulus of the threaded portion 110 is less than that of the connecting portion 120. The elastic modulus of the protective sleeve is the same as that of the threaded portion 110. Therefore, when the cylinder deforms, the threaded portion 110 in the middle bends and deforms preferentially. Thus, the fiber optic sensing unit can be abstracted as follows: Figure 7 The two-dimensional curve model shown defines a two-dimensional coordinate system. The initial state of the fiber optic sensing element along The axis is a straight line, and The axis is perpendicular, defining the direction of bending towards The positive direction of the axis is 0°. The negative axis is 180°, and the first end of the first fiber optic sensing element. Fixed in Point; the fiber optic sensing element is equipped with indivual, Point is the The beginning of each fiber optic sensitive element, Point is the The tail end of each fiber optic sensing element, For the first The midpoint of each fiber optic sensing element, i.e., the bonding point of the fiber optic grating ( Point measurement of bending direction angle and curvature ), arc Length is cm, assuming the deformation at the arc is uniform curvature, and the curvature is equal to cm. curvature at ,definition for The center of the circle of curvature, central angle , radius of the circle of curvature ;neglect and The slight deformation can be regarded as a straight line segment, with smooth tangency at the connection point. The tail end of each fiber optic sensing element The next section is The beginning of each fiber optic sensing element Coincident; Define coordinates , , , , Given the measured coordinates of the first end of the first fiber optic sensing element. The coordinate measurement value of the tail end of the last fiber optic sensing element. The angle between the straight segment at the beginning of the first fiber optic sensing unit and the X-axis. and the Each fiber optic sensing unit arc arc length According to arc length and curvature The product result can be used to calculate the first... Each fiber optic sensing unit arc central angle .

[0077] S602. Within the first preset range, select the angle between the straight line segment at the beginning of the first fiber optic sensing unit and the coordinate axis, and within the second preset range, select the arc length of the arc of each fiber optic sensing unit.

[0078] It should be noted that the first preset range is {30°, 32°, 34°, ..., 150°}, and the second preset range is {10, 15, 20}.

[0079] S603. Based on the two-dimensional curve model, the measured coordinates of the first end of the first fiber sensing unit, the included angle, arc length, bending direction and curvature data, starting from the first end of the first fiber sensing unit, calculate the coordinates of the first and last ends of each fiber sensing unit in sequence, and finally obtain the calculated coordinates of the last end of the last fiber sensing unit.

[0080] It should be noted that, given the known coordinate measurements of the first and last fiber optic sensing elements, the calculated coordinates of the last fiber optic sensing element are determined based on the first coordinate measurement of the first fiber optic sensing element.

[0081] S604. Calculate the deviation between the calculated coordinates of the tail end of the last fiber optic sensing element and the measured coordinates of the tail end of the last fiber optic sensing element. Select the included angle and arc length corresponding to the minimum deviation, and determine the two-dimensional slope deformation curve based on the included angle and arc length corresponding to the minimum deviation.

[0082] It should be noted that the calculated coordinates of the tail end of the last fiber optic sensing element are as follows: The coordinate measurements of the tail end of the last fiber optic sensing element: The deviation is: traverse all and The value selection process ends, and the minimum deviation is determined. corresponding and value.

[0083] To better calculate the tail coordinates of the last fiber optic sensing element, in some embodiments of the present invention, such as... Figure 8 As shown, step S603 includes:

[0084] S801. Select the first fiber optic sensing unit as the current fiber optic sensing unit, take the measured coordinate value of the first end of the first fiber optic sensing unit as the first end coordinate of the current fiber optic sensing unit, and calculate the slope of the straight line segment at the first end of the current fiber optic sensing unit based on the included angle.

[0085] It should be noted that the coordinates of the first end of the first fiber optic sensing element are the measured values ​​of the first end of the first fiber optic sensing element. The coordinates of the first end of the remaining fiber optic sensing elements are the coordinates of the last end of the previous fiber optic sensing element. The slope of the straight line segment at the first end of the first fiber optic sensing element is... The slope of the straight line segment at the beginning of the remaining fiber optic sensing element is the slope of the straight line segment at the end of the previous fiber optic sensing element.

[0086] S802. Based on the coordinates of the first end of the current fiber optic sensitive unit, the slope and arc length of the straight line segment at the first end, calculate the coordinates of the connection point between the straight line segment and the arc at the first end.

[0087] It should be noted that, as Figure 5 As shown, The parametric equation is:

[0088]

[0089] In the formula, express The coordinates of a point on the [plane / space].

[0090] S803. Based on the bending direction and curvature data of the current fiber optic sensitive unit, the coordinates of the connection point between the straight segment and the arc at the beginning, and the slope of the straight segment at the beginning, calculate the coordinates of the center of the curvature circle of the arc. Based on the coordinates of the center of the curvature circle, calculate the coordinates of the connection point between the arc and the straight segment at the end.

[0091] It should be noted that, as Figure 5 As shown, The center of the circle of curvature coordinate( )for:

[0092]

[0093] In the formula, the first The bending direction angle of each fiber optic sensing element is ,when ,when ;

[0094] but The parametric equations are as follows:

[0095]

[0096]

[0097] In the formula, ( )express The coordinates of the upper point, For parameters, For point Corresponding parameters, For point The corresponding parameters are for the first fiber optic sensitive unit. .

[0098] S804. Based on the geometric relationship between the straight line connecting the center of the curvature circle and the connection point between the arc and the tail line segment, and the coordinates of the center of the curvature circle and the connection point between the arc and the tail line segment, calculate the tail coordinates of the current sensitive element.

[0099] It should be noted that, due to ⊥ ,point ( ) and points ( The point satisfies the following equation. ( The coordinates are:

[0100]

[0101] The parametric equation is: .

[0102] S805. Use the tail coordinate of the current sensitive unit as the head coordinate of the next sensitive unit, and use the slope of the straight line segment at the tail of the current sensitive unit as the slope of the straight line segment at the head of the next sensitive unit. Return to step S802 until the tail coordinate of the last sensitive unit is calculated.

[0103] To better perform 3D reconstruction, in some embodiments of the present invention, such as Figure 9 As shown, step S502 includes:

[0104] S901. Embed the two-dimensional slope deformation curve into the three-dimensional coordinate system to obtain the initial slope deformation curve, and use the first fiber optic sensing element as the current fiber optic sensing element.

[0105] It should be noted that constructing such Figure 10 As shown Three-dimensional coordinate system The origin is located in the aforementioned two-dimensional coordinate plane. Add to The axis is used to construct a three-dimensional coordinate system, and the initial state length direction of the fiber optic sensing element is... In the axial direction, the two-dimensional slope deformation curve is embedded into a three-dimensional coordinate system. The coordinates of the two-dimensional slope deformation curve in the spatial coordinate system are... ,in, These are the original two-dimensional coordinate values.

[0106] S902. Determine the straight line parallel to the initial length direction of the fiber sensing unit and passing through the beginning of the current fiber sensing unit as the axis of rotation, and rotate the initial slope deformation curve around the axis of rotation to obtain the intermediate slope deformation curve.

[0107] It should be noted that, in cases such as Figure 10 In the three-dimensional coordinate system shown, the axis of rotation is... Axis; Bending direction angle for Inclination direction and The angle between planes, i.e., the angle between three-dimensional curves. Projection curves on a plane and The included angle of the axis, along The positive direction of the axis is 0°, and the angle increases in the counterclockwise bending direction; define the rotation angle of the initial slope deformation curve. , Indicates counterclockwise rotation. Indicates clockwise rotation, when hour, ,when hour, , .

[0108] S903. Select the target slope deformation curve corresponding to the current fiber optic sensitive unit from the intermediate slope deformation curves, and take the slope deformation curves corresponding to all fiber optic sensitive units in the intermediate slope deformation curves except for the current section as the initial slope deformation curves.

[0109] It should be noted that the explanation uses a single fiber optic sensing element as an example, and will be as follows: Figure 10 The initial slope deformation curve ABCD shown is rotated. After adjusting the angle, we get the following: Figure 11 The deformation curve of the intermediate slope shown The three-dimensional slope deformation curve corresponding to the current fiber optic sensing element. exist Projection curves on a plane and The included angle of the axis is .

[0110] S904. Take the next fiber optic sensing unit as the current fiber optic sensing unit, return to step S902, until the target slope deformation curves corresponding to all fiber optic sensing units are obtained, and determine the final three-dimensional slope deformation curve based on the target slope deformation curves.

[0111] In some embodiments of the present invention, the method further includes comparing the three-dimensional slope deformation curve with the original state curve of the monitored slope, and issuing an early warning signal when the curvature of the three-dimensional slope deformation curve is greater than a threshold, specifically by displaying a "red" alarm symbol on the monitoring display interface.

[0112] To better implement the slope three-dimensional deformation monitoring method in this embodiment of the invention, based on a slope three-dimensional deformation monitoring method, correspondingly, as follows: Figure 12 As shown, this embodiment of the invention also provides a slope monitoring system 1200, comprising:

[0113] The spectral acquisition module 1201 is used to acquire reflectance spectral data collected by the fiber optic sensing unit buried in the slope. The fiber optic sensing unit includes a cylinder and a fiber optic grating wound around the cylinder.

[0114] It should be noted that, in terms of hardware, the spectrum acquisition module 1201 includes an optical fiber sensing unit and a demodulator. The demodulator is connected to the optical fiber sensing unit via an optical cable. There is only the transmission of optical signals between the demodulator and the optical fiber sensing unit. When in use, a broadband swept frequency light source is first input to the optical fiber sensing unit, and then the three non-overlapping and irregular reflection spectral optical information transmitted from the optical fiber sensing unit are acquired. The reflection spectral optical signals are then converted into reflection spectral data.

[0115] The deformation prediction module 1202 is used to determine the bending direction and curvature data of each fiber sensitive element based on the reflection spectrum data.

[0116] The 3D reconstruction module 1203 is used to perform 3D reconstruction of the slope deformation curve based on the bending direction and curvature data to obtain the 3D slope deformation curve.

[0117] It should be noted that, specifically in terms of hardware, the deformation prediction module 1202, the three-dimensional reconstruction module 1203, and the early warning function are integrated into the monitoring computer. The demodulator is also controlled by the monitoring software installed on the monitoring computer, which sends control commands to the sensor signal demodulator through the network interface. The sensor signal demodulator injects broadband scanning laser into the fiber optic sensing unit through the optical fiber.

[0118] The slope monitoring system 1200 provided in the above embodiments can realize the technical solutions described in the above embodiments of the three-dimensional slope deformation monitoring method. The specific implementation principles of each unit can be found in the corresponding content of the above embodiments of the three-dimensional slope deformation monitoring method, which will not be repeated here.

[0119] The above provides a detailed description of a three-dimensional deformation monitoring method for slopes provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0120] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for monitoring three-dimensional deformation of slopes, characterized in that, include: The reflectance spectrum data collected by the fiber optic sensing unit embedded in the slope is obtained. The fiber optic sensing unit includes a cylinder and a fiber optic grating wound around the cylinder. Based on the reflected spectrum data, the bending direction and curvature data of the fiber optic sensing element are determined; Based on the bending direction and curvature data, the slope deformation curve is reconstructed in three dimensions to obtain a three-dimensional slope deformation curve. This includes: reconstructing the slope deformation curve in two dimensions based on the geometric relationship of the fiber optic sensing element and the bending direction and curvature data to obtain a two-dimensional slope deformation curve; and reconstructing the two-dimensional slope deformation curve in three dimensions based on the bending direction data of each fiber optic sensing element to obtain a three-dimensional slope deformation curve. The optical fiber sensing element is provided in at least two, and adjacent optical fiber sensing elements are connected end to end. Based on the geometric relationship of the fiber optic sensing element, as well as the bending direction and curvature data, the slope deformation curve is reconstructed in two dimensions to obtain a two-dimensional slope deformation curve, including: Each fiber optic sensing unit is divided into a straight segment at the beginning, an arc at the middle, and a straight segment at the end. The arc is considered to be uniformly curved, and the connection points between the straight segment at the beginning, the arc, and the straight segment at the end are all considered to be smoothly tangent, thus constructing a two-dimensional curve model of the fiber optic sensing unit. Within the first preset range, the angle between the straight line segment at the beginning of the first fiber optic sensing unit and the coordinate axis is selected. Within the second preset range, the arc length of the arc of each fiber optic sensing unit is selected. Based on the two-dimensional curve model, the measured coordinates of the first end of the first fiber sensing unit, the included angle, the arc length, and the bending direction and curvature data, starting from the first end of the first fiber sensing unit, the coordinates of the first and last ends of each fiber sensing unit are calculated sequentially, and finally the calculated coordinates of the last end of the last fiber sensing unit are obtained. The deviation between the calculated coordinates of the tail end of the last fiber optic sensing unit and the measured coordinates of the tail end of the last fiber optic sensing unit is calculated. The included angle and arc length corresponding to the minimum deviation are selected, and the two-dimensional slope deformation curve is determined based on the included angle and arc length corresponding to the minimum deviation.

2. The method for monitoring three-dimensional deformation of slopes according to claim 1, characterized in that, At least two fiber optic sensing units are provided. The cylinders of adjacent fiber optic sensing units are connected by flanges, and the fiber gratings of adjacent fiber optic sensing units are connected by optical fibers.

3. The method for monitoring three-dimensional deformation of slopes according to claim 1, characterized in that, The fiber optic sensing unit is also covered by a protective tube.

4. The method for monitoring three-dimensional deformation of slopes according to claim 1, characterized in that, Based on the reflected spectral data, the bending direction and curvature data of the fiber optic sensing element are determined, including: The reflection spectrum data is input into a fully trained deep learning model to obtain the bending direction and curvature data of the fiber optic sensing unit. The deep learning model includes an input layer, a shared convolutional layer, and a dual-head output layer connected in sequence. The input layer is used to input the reflection spectrum data. The shared convolutional layer includes several sets of convolutional layers and a pooling layer whose input end is connected to the output end of the convolutional layer. The dual-head output layer includes two output heads. The first output head is used to fit the bending direction data of the output fiber optic sensing unit, and the second output head is used to fit the curvature data of the output fiber optic sensing unit.

5. The method for monitoring three-dimensional deformation of slopes according to claim 1, characterized in that, Based on the two-dimensional curve model, the measured coordinates of the first end of the first fiber optic sensing unit, the included angle, the arc length, and the bending direction and curvature data, starting from the first end of the first fiber optic sensing unit, the coordinates of the first and last ends of each fiber optic sensing unit are calculated sequentially, and finally the calculated coordinates of the last end of the last fiber optic sensing unit are obtained, including: S801. Select the first fiber optic sensing unit as the current fiber optic sensing unit, take the measured value of the first end coordinate of the first fiber optic sensing unit as the first end coordinate of the current fiber optic sensing unit, and determine the slope of the straight line segment at the first end of the current fiber optic sensing unit based on the included angle. S802. Based on the coordinates of the first end of the current fiber optic sensitive unit, the slope and arc length of the straight line segment at the first end, calculate the coordinates of the connection point between the straight line segment and the arc at the first end. S803. Based on the bending direction and curvature data of the current fiber optic sensitive unit, the coordinates of the connection point between the straight segment and the arc at the beginning, and the slope of the straight segment at the beginning, calculate the coordinates of the center of the curvature circle of the arc, and based on the coordinates of the center of the curvature circle, calculate the coordinates of the connection point between the arc and the straight segment at the end. S804. Based on the geometric relationship between the straight line connecting the center of the curvature circle and the connection point between the arc and the tail line segment and the geometric line segment perpendicular to the tail line segment, the coordinates of the center of the curvature circle and the coordinates of the connection point between the arc and the tail line segment, calculate the tail coordinates of the current sensitive unit. S805. Use the tail coordinate of the current sensitive unit as the head coordinate of the next sensitive unit, and use the slope of the straight line segment at the tail of the current sensitive unit as the slope of the straight line segment at the head of the next sensitive unit. Return to step S802 until the tail coordinate of the last sensitive unit is calculated.

6. The method for monitoring three-dimensional deformation of slopes according to claim 1, characterized in that, At least two fiber optic sensing elements are provided, and adjacent fiber optic sensing elements are connected end to end. Based on the bending direction data of each fiber optic sensing element, the two-dimensional slope deformation curve is reconstructed into a three-dimensional slope deformation curve, including: S901. Embed the two-dimensional slope deformation curve into the three-dimensional coordinate system to obtain the initial slope deformation curve, and use the first fiber optic sensing unit as the current fiber optic sensing unit. S902. Determine the straight line parallel to the initial length direction of the fiber optic sensing unit and passing through the beginning of the current fiber optic sensing unit as the axis of rotation, and rotate the initial slope deformation curve around the axis of rotation to obtain the intermediate slope deformation curve. S903. Retain the three-dimensional slope deformation curve corresponding to the current fiber optic sensitive unit in the intermediate slope deformation curve, and take the slope deformation curves corresponding to all fiber optic sensitive units in the intermediate slope deformation curve except for the current section as the initial slope deformation curve. S904. Take the next fiber optic sensing unit as the current fiber optic sensing unit, return to step S902, until the target slope deformation curves corresponding to all fiber optic sensing units are obtained, and determine the final three-dimensional slope deformation curve based on the target slope deformation curves.

7. The method for monitoring three-dimensional deformation of slopes according to claim 1, characterized in that, The method also includes an early warning module that issues an early warning signal when the curvature of the three-dimensional slope deformation curve is greater than a threshold.

8. A slope monitoring system for performing the three-dimensional deformation monitoring method for slopes as described in any one of claims 1-7, characterized in that, include: A spectral acquisition module is used to acquire reflectance spectral data collected by an optical fiber sensing unit embedded in the slope. The optical fiber sensing unit includes a cylinder and a fiber grating wound around the cylinder. The deformation prediction module is used to determine the bending direction and curvature data of the fiber optic sensing element based on the reflection spectrum data. The three-dimensional reconstruction module is used to reconstruct the slope deformation curve in three dimensions based on the bending direction and curvature data, so as to obtain a three-dimensional slope deformation curve.

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