Wearable magnetic grid type three-dimensional deformation monitoring method and system

Abstract

The application provides a kind of wearing magnetic grid type three-dimensional deformation monitoring method and system, i.e. the surface of the engineering structure to be monitored is buried with several nodes, each node is at least connected with three nodes around it to form a monitoring branch, and a magnetic grid range ruler for measuring the distance change between two nodes is arranged on each monitoring branch.Each node, each magnetic grid range ruler and each monitoring branch form a three-dimensional deformation monitoring network on the outside of the monitored object;GNSS receivers are arranged at the positions of each node to monitor the absolute deformation of each node.Each magnetic grid range ruler and GNSS receiver transmits the measurement results to the data acquisition system and cloud server, the cloud server processes the received data, calculates the displacement of each node and the coordinates after displacement, and generates the overall deformation result of the monitored object;The processed deformation data is input into the numerical model for simulation calculation, and the stability and reliability of the monitored object are evaluated according to the simulation results.

Description

Technical Field

[0001] This invention relates to a monitoring method and system for monitoring the deformation of engineering structures, specifically, to a wearable magnetic grating-based three-dimensional deformation monitoring method and system. This invention can be widely applied in the fields of engineering projects such as buildings, bridges, tunnels, earth-rock dams, and geological disaster monitoring. Background Technology

[0002] In the construction of buildings, bridges, tunnels, dams, and other engineering projects, monitoring the deformation of the structure is a crucial step. Traditional deformation monitoring methods primarily involve embedding various sensors or measuring instruments within the structure during construction to monitor its deformation. However, this approach has several drawbacks: 1. Inaccurate monitoring results. Because the sensors or instruments are embedded inside the structure, their representation of overall external deformation is inaccurate. 2. High requirements for sensor or instrument deployment, time-consuming and labor-intensive, resulting in long construction periods and high costs. 3. If a sensor or instrument at a particular location malfunctions and cannot be repaired during the monitoring period, data for that location may be missing, leading to incomplete monitoring results. Summary of the Invention

[0003] For the reasons stated above, the purpose of this invention is to provide a wearable magnetic grating-based three-dimensional deformation monitoring method and system. This monitoring method and system can accurately and realistically reflect the deformation of engineering structures.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a wearable magnetic grating-type three-dimensional deformation monitoring method, which includes the following:

[0005] S1. Establish a deformation monitoring system;

[0006] Several nodes are embedded on the surface of the monitored engineering structure. Each node is connected to at least three surrounding nodes to establish a monitoring branch. A magnetic grating rangefinder is installed on each monitoring branch.

[0007] S2. Based on the measurement results of each magnetic grating distance measuring ruler, calculate the displacement of each node, i.e., each monitoring point;

[0008] S3. Use a GNSS receiver to monitor the absolute coordinates of each monitoring point;

[0009] Install a GNSS receiver on the monitoring point described in step S1, receive satellite signals, record the absolute coordinates and absolute elevation of each monitoring point, and calculate the displacement of each monitoring point.

[0010] S4. Determine the coordinates of each monitoring point after deformation and draw the outline of the monitored engineering structure after deformation.

[0011] The displacement of each monitoring point on the surface of the monitored engineering structure calculated in step S2 is weighted and averaged with the displacement of each monitoring point obtained by the GNSS receiver in step S3 to obtain the coordinates of each monitoring point after deformation, and the outline of the monitored engineering structure after deformation is drawn.

[0012] Furthermore, the method for calculating the displacement of each node in step S2 is to calculate the displacement of each node (Δx). k ,Δy k ,Δz k The method is as follows:

[0013] S2.1. Read the measurement results of all magnetic grating distance measuring rods at time t, and calculate the length change Δl of all magnetic grating distance measuring rods connected to the k-th node. i , where the subscript i represents the i-th section of the magnetic grating distance measuring ruler connected to node k (i = 1, 2, 3, 4);

[0014] Assuming that node k and node (k+1) are adjacent, and the i-th section of the magnetic grating distance measuring ruler measures the length between node k and node (k+1), then the length of the i-th section of the magnetic grating distance measuring ruler at time t-1 is... Expressed as formula (1), the length of the i-th magnetic grating rangefinder at time t. Represented as formula (2):

[0015]

[0016]

[0017] Section i: The length change Δl measured by the distance measuring ruler during a measurement time period. i for:

[0018]

[0019] S2.2. Based on step S2.1, the length change Δl of all magnetic grating distance measuring scales adjacent to the k-th node can be calculated. i (i = 1, 2, 3, 4), the displacement (Δx) of the k-th node k ,Δy k ,Δz k The length change Δl of all magnetic grating distance measuring scales adjacent to the k-th node i The relationship is:

[0020]

[0021] In the formula, Δl i This represents the length change Δl of the magnetic grating distance measuring scale adjacent to the k-th node. i , where i = 1, 2, 3, 4; [Ki ] represents the coefficient matrix, and {Δ} is the displacement matrix of the k-th node;

[0022] S2.3. According to step S2.2, accumulate the changes in the length of all distance measuring rods adjacent to the k-th node, i.e., formula (5):

[0023]

[0024] The cumulative change in the length of the rangefinder adjacent to the k-th node is denoted by {d}. k The displacement {Δ} of each node can be calculated.

[0025]

[0026] S2.4 Repeat steps S2.1-S2.3 to calculate the deformation of each node in three directions;

[0027] When each node is connected to at least 3 members, and the length variation of all members is known {Δl} k When}, equation (6) can be solved to obtain the displacement {Δ} of each node (measuring point); after the displacement is generated, the coordinates of each node are given by equation (7):

[0028]

[0029] S2.5. Periodically read the readings of each distance measuring rod. Assume that N readings have been taken up to time t. Then the cumulative displacement of each measuring point is:

[0030]

[0031] In the formula: ΔK(t) is the cumulative displacement of the k-th node at time t. ΔK i Let be the displacement in the i-th time period.

[0032] Furthermore, the deformation monitoring method also includes embedding several series-connected flexible inclinometers within the monitored engineering structure, measuring the changes in horizontal displacement at different depths within the monitored engineering structure using the flexible inclinometers to determine the deep deformation of the monitored engineering structure; and comparing the deformation of the engineering structure monitored in step S4 with the deformation of the monitored engineering structure to evaluate the deformation trend and stability of the monitored engineering structure.

[0033] A wearable magnetic grating three-dimensional deformation monitoring system is provided, in which several nodes are embedded on the surface of the monitored engineering structure; each node establishes a connection with at least three nodes around it, and a monitoring branch is formed between two nodes. A magnetic grating distance measuring ruler for measuring the change in distance between two nodes is installed on each monitoring branch.

[0034] The nodes, magnetic grating rangefinders, and monitoring branches form a magnetic grating three-dimensional deformation monitoring network that is fitted onto the surface of the monitored engineering structure.

[0035] Furthermore, it also includes a GNSS receiver, which monitors the absolute coordinates and absolute elevation of each node; each magnetic grating rangefinder and GNSS receiver transmits the measurement results to the data acquisition system wirelessly; after receiving the measurement data, the data acquisition system transmits the data to the cloud server, which processes the received data, calculates the change in distance between each node, and then calculates the displacement of each node and its coordinates after displacement.

[0036] Furthermore, the node is an anchor, metal rod, or concrete column embedded in the surface of the monitored engineering structure, and the magnetic grating rangefinder is connected to the node.

[0037] Furthermore, the wearable magnetic grating three-dimensional deformation monitoring system also includes several flexible inclinometers; the flexible inclinometers are buried at different depths in the monitored engineering structure to measure its deformation at different depths, and their data output ends are connected to the data acquisition system via wired or wireless means to transmit data.

[0038] Compared with traditional deformation monitoring systems and methods, the present invention has the following advantages:

[0039] 1. It can achieve all-round, three-dimensional monitoring of engineering structures, with no blind spots.

[0040] 2. The three-dimensional deformation monitoring system of this invention is like a garment covering the outside of the engineering structure, eliminating the need for wiring inside the structure. It is simple to construct, highly efficient, and low in cost. Furthermore, the distance measuring instruments deployed on the outer surface of the engineering structure have a low failure rate and are easy to repair and replace.

[0041] 3. High deformation monitoring accuracy and strong anti-interference ability.

[0042] Since the magnetic grating rangefinder constituting the three-dimensional deformation monitoring system of the present invention can achieve sub-millimeter level deformation monitoring and has strong anti-interference ability, the deformation monitoring accuracy of the present invention is high and the anti-interference ability is strong.

[0043] 4. Good real-time performance.

[0044] This invention can monitor the deformation of engineering structures in real time, and the data acquisition system can process and analyze data in real time, with good real-time performance.

[0045] 5. After the deformation monitoring system of this invention is dismantled, the magnetic grating rangefinder can be reused. Attached Figure Description

[0046] Figure 1This is a schematic diagram of the wearable magnetic grating three-dimensional deformation monitoring system of the present invention;

[0047] Figure 2 This is a schematic diagram of data transmission in the wearable magnetic grating three-dimensional deformation monitoring system of the present invention;

[0048] Figure 3 This is a schematic diagram of the deformation distribution of an engineering structure after time t, monitored using the deformation monitoring system and method of the present invention. Detailed Implementation

[0049] The structure and features of the present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that various modifications can be made to the embodiments disclosed herein; therefore, the embodiments disclosed in this specification should not be considered as limitations on the present invention, but merely as examples to make the features of the present invention readily apparent.

[0050] like Figure 1 , Figure 2 As shown, the wearable magnetic grating-type three-dimensional deformation monitoring system disclosed in this invention employs magnetic grating sensor technology. Several nodes 1 are embedded on the surface of the monitored engineering structure. Each node establishes a connection with at least three surrounding nodes, and a magnetic grating-type distance measuring ruler 2 is installed between them to measure the distance change between two nodes. Each magnetic grating-type distance measuring ruler transmits the measurement results to a data acquisition system 3 wirelessly. After receiving the data measured by each distance measuring ruler, the data acquisition system processes the data, calculates the distance change between each node, and then calculates the displacement of each node. Based on the displacement of each node, it then draws the contour line 4 of the engineering structure after the change (e.g., ...). Figure 3 (As shown).

[0051] The magnetic grating distance measuring scales deployed on the surface of the monitored engineering structure and between the nodes form a three-dimensional deformation monitoring system, which is like a piece of clothing worn on the outside of the monitored engineering structure.

[0052] In a preferred embodiment of the present invention, the node can be an anchor, metal rod, or concrete column embedded in the surface of the monitored engineering structure, as long as its outermost end can be fixed to the magnetic grating rangefinder.

[0053] Each node must establish connections with at least three of its surrounding nodes, such as Figure 1 Node A is Y-shaped, connecting with three surrounding nodes to form three monitoring branches; Node B is cross-shaped, connecting with four surrounding nodes to form four monitoring branches; and Node C connects with five surrounding nodes to form five monitoring branches. This invention utilizes the monitoring branches of each node on the surface of the monitored engineering structure to form a three-dimensional wearable magnetic grating deformation monitoring system.

[0054] In a preferred embodiment of the present invention, the distance measuring ruler is a magnetic grating distance measuring ruler (also called a pull-string encoder), which uses the principle of a magnetic grating sensor to measure the distance between two points. It has high measurement accuracy and strong anti-interference ability, and the measurement results can be transmitted to a data acquisition system, such as an industrial control computer, wirelessly. Of course, a distance measuring ruler, a laser rangefinder, or other types of instruments for measuring distance can also be used.

[0055] To further monitor the deformation of engineering structures in real time, the monitoring system of this invention also includes a GNSS receiver, which monitors the overall deformation of the exterior of the engineering structure in real time.

[0056] The data acquisition system 3 reads the deformation values ​​of each node of the engineering structure monitored by the GNSS receiver, as well as the distance change values ​​between each node measured by each magnetic grating distance measuring ruler. The data is then uploaded to the cloud server via wireless transmission. The cloud server calculates the deformation value and the coordinates of each node of the monitored engineering structure by weighted averaging the deformation values ​​of each node obtained by the two monitoring methods, and draws the outer contour line 4 of the monitored engineering structure after the change.

[0057] The monitoring system of this invention also includes several flexible inclinometers connected in series. These inclinometers are embedded within the monitored engineering structure. The inclinometers measure the changes in horizontal displacement at different heights within the monitored engineering structure to determine its internal deformation. This deformation is then compared with the external deformation monitored by a magnetic grating rangefinder and a GNSS receiver to evaluate the deformation trend and stability of the monitored engineering structure.

[0058] The method for monitoring the deformation of engineering structures using the wearable magnetic grating three-dimensional deformation monitoring system of the present invention is as follows:

[0059] S1. Establish a deformation monitoring system;

[0060] Based on the scale and importance of the monitored engineering structure, several nodes are buried on the surface of the monitored engineering structure. Each node establishes a monitoring branch with at least three surrounding nodes. Each monitoring branch is equipped with a magnetic grating rangefinder, forming a wearable magnetic grating three-dimensional deformation monitoring network deployed on the surface of the monitored engineering structure.

[0061] S2. Based on the measurement results of each magnetic grating distance measuring ruler, calculate the displacement (Δx) of each node, i.e., each monitoring point. k ,Δy k ,z k );

[0062] S2.1. Read the measurement results of all magnetic grating distance measuring rods at time t, and calculate the length change Δl of all magnetic grating distance measuring rods connected to the k-th node. i, where the subscript i represents the i-th section of the magnetic grating distance measuring ruler connected to node k (i = 1, 2, 3, 4);

[0063] Assuming that node k and node (k+1) are adjacent, and the i-th section of the magnetic grating distance measuring ruler measures the length between node k and node (k+1), then the length of the i-th section of the magnetic grating distance measuring ruler at time t-1 is... Expressed as formula (1), the length of the i-th magnetic grating rangefinder at time t. Represented as formula (2):

[0064]

[0065]

[0066] Section i: The length change Δl measured by the distance measuring ruler during a measurement time period. i For formula (3)

[0067]

[0068] S2.2. Based on step S2.1, the length change Δl of all magnetic grating distance measuring scales adjacent to the k-th node can be calculated. i (i = 1, 2, 3, 4), the displacement (Δx) of the k-th node k ,Δy k ,Δz k The length change Δl of all magnetic grating distance measuring scales adjacent to the k-th node i This can be expressed as formula (4):

[0069]

[0070] In the formula, Δl i This represents the length change Δl of the magnetic grating distance measuring scale adjacent to the k-th node. i , where i = 1, 2, 3, 4; [K i ] represents the coefficient matrix, and {Δ} is the displacement matrix of the k-th node.

[0071] S2.3. According to step S2.2, accumulate the changes in the length of all distance measuring rods adjacent to the k-th node, i.e., formula (5):

[0072]

[0073] That is, the cumulative change in the length of the measuring rod adjacent to the k-th node is known {d}. k The displacement {Δ} of each node can be calculated.

[0074]

[0075] S2.4 Repeat steps S2.1-S2.3 to calculate the deformation of each node in three directions;

[0076] When each node is connected to at least 3 members, and the length variation of all members is known {Δl} k When}, equation (6) can be solved to obtain the displacement {Δ} of each node (measuring point). After the displacement is generated, the coordinates of each node are given by equation (7):

[0077]

[0078] S2.5. Periodically read the readings of each distance measuring rod. Assume that N readings have been taken up to time t, then the cumulative displacement of each measuring point is given by equation (8):

[0079]

[0080] In the formula: ΔK(t) is the cumulative displacement of the k-th node at time t. ΔK i Let be the displacement increment in the i-th time period. The displacement process line at point k can be drawn using equation (8).

[0081] For time t, once the displacements of all nodes are known, the deformation distribution after time t can be plotted.

[0082] S3. Use a GNSS receiver to monitor the absolute coordinates of each monitoring point;

[0083] Install a GNSS receiver on each monitoring point (i.e., each node) as described in step S1, receive satellite signals, record the absolute coordinates and absolute elevation of each monitoring point, and calculate the displacement of each monitoring point.

[0084] The measuring scales and GNSS receivers constituting the three-dimensional deformation monitoring system of this invention wirelessly transmit data from each monitoring point at different time periods to the data acquisition system. The data acquisition system connects to a cloud server via a wireless network and uploads the received data to the cloud server. The cloud server processes the data, calculates the deformation increment and cumulative deformation at each time point, and further analyzes the safety of the monitored engineering structure. When an abnormality occurs, the system issues an alarm signal so that corresponding measures can be taken.

[0085] Since each monitoring point / node is connected to at least three surrounding monitoring points, forming a closed polygon, the cloud server processes the data received from the GNSS receiver as follows:

[0086] S3.1. Perform noise reduction and adjustment processing on the acquired monitoring data;

[0087] S3.2 Based on the monitoring data after denoising and adjustment, calculate the closed loop difference for each closed polygon; perform weighted adjustment on the closed loop difference results to correct the coordinates of each monitoring point within each closed polygon;

[0088] S3.3. Perform averaging and data storage on the corrected coordinates.

[0089] S4. Determine the coordinates of each monitoring point after deformation and draw the outline of the monitored engineering structure after deformation.

[0090] The displacement of each monitoring point on the surface of the monitored engineering structure calculated in step S2 is weighted and averaged with the displacement of each monitoring point obtained by the GNSS receiver in step S3 to obtain the coordinates of each monitoring point after deformation. The outline of the monitored engineering structure after deformation is then drawn, as shown below. Figure 3 As shown.

[0091] This invention involves embedding several series-connected flexible inclinometers within the monitored engineering structure. These inclinometers measure the deformation at different depths within the structure (e.g., a slope). The changes in horizontal displacement at different heights within the structure are measured using the flexible inclinometers to determine the deformation at different depths. Then, computer simulation software is used to compare the internal depth deformation measured by the flexible inclinometers with the deformation monitored by a magnetic grating rangefinder and a GNSS receiver, thereby evaluating the deformation trend and stability of the monitored structure.

[0092] When conducting a comprehensive analysis of the deformation trend and stability of the monitored engineering structure, firstly, all deformation monitoring data of the monitored engineering structure are collected, including the absolute coordinates of each monitoring point / node on the surface of the engineering structure monitored by the GNSS receiver, the relative deformation of the surface of the engineering structure monitored by the wearable magnetic grating three-dimensional deformation monitoring network, and the relative deformation of the deep interior of the engineering structure monitored by the flexible inclinometer. The collected data includes the horizontal and vertical displacements of the monitored engineering structure, and the collected data are processed as follows:

[0093] S5.1 Data Processing: Process the collected data, such as data cleaning, outlier identification and correction, etc.

[0094] S5.2 Establish a numerical model: Use numerical analysis software to establish a numerical model of the monitored engineering structure. This model takes into account factors such as the structural characteristics, material properties, and geological conditions of the engineering structure.

[0095] S5.3 Simulation Calculation: The processed deformation data is input into the numerical model for simulation calculation. The calculation process will simulate the overall deformation of the monitored engineering structure based on the model settings and the input deformation data.

[0096] S5.4 Result Analysis: The simulation results are analyzed in detail, including deformation trends and deformation amounts, and can be compared and verified with actual conditions.

[0097] S5.5 Safety Assessment and Measures: Based on the simulation results, conduct a safety assessment of the monitored engineering structure to evaluate its stability and reliability.

[0098] S5.6 Monitoring and Updating: During continuous monitoring, new monitoring data is updated into the numerical model. This helps to evaluate the effectiveness of the measures and can further optimize the design and operation of the monitored engineering structures.

[0099] This invention has the advantages of simple structure, convenient installation and low cost of use, and can be widely used in the field of deformation monitoring of various engineering structures.

[0100] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wearable magnetic grating-based three-dimensional deformation monitoring method, characterized in that: It includes the following: S1. Establish a deformation monitoring system; Several nodes are embedded on the surface of the monitored engineering structure. A monitoring branch is established between each node and four surrounding nodes. A magnetic grating rangefinder is installed on each monitoring branch. S2. Based on the measurement results of each magnetic grating distance measuring ruler, calculate the displacement of each node, i.e., each monitoring point; S3. Use a GNSS receiver to monitor the absolute coordinates of each monitoring point; S4. Determine the coordinates of each monitoring point after deformation and draw the outline of the monitored engineering structure after deformation. The displacement of each monitoring point calculated by S2 is weighted and averaged with the displacement of each monitoring point obtained by S3 to obtain the coordinates of each monitoring point after deformation. S2 calculates the displacement (Δx) of each node. k ,Δy k ,Δz k The method is as follows: S2.

1. Read the measurement results of all magnetic grating distance measuring rods at time t, and calculate the length change Δl of all magnetic grating distance measuring rods connected to the k-th node. i , where i represents the i-th section of the magnetic grating rangefinder connected to node k, i = 1, 2, 3, 4; Assuming that node k and node (k+1) are adjacent, and the i-th section of the magnetic grating distance measuring ruler measures the length between node k and node (k+1), then the change in length measured by the i-th section of the distance measuring ruler over a measurement time period is Δl. i for: ,in Let be the length of the i-th section of the distance measuring rod at time t-1. Let be the length of the i-th measuring rod at time t; S2.

2. Based on S2.1, calculate the length change Δl of all magnetic grating distance measuring scales adjacent to the k-th node. ki For i = 1, 2, 3, 4, the displacement (Δx) of the k-th node. ki ,Δy ki ,Δz ki The length change Δl of all magnetic grating distance measuring scales adjacent to the k-th node ki The relationship is: （4） In the formula, Δl ki This represents the change in length of the magnetic grating rangefinder adjacent to the k-th node, where i = 1, 2, 3, 4; [K ki ] represents the coefficient matrix, [Δ ki [] is the displacement matrix of the k-th node; S2.

3. Based on S2.2, accumulate the changes in the lengths of all distance measuring rods adjacent to the k-th node, i.e., formula (5): {d k}={ }= （5） The cumulative change in the length of the rangefinder adjacent to the k-th node is denoted by {d}. k }, calculate the displacement [Δ] of each node. k ], （6） S2.4 Repeat steps S2.1-S2.3 to calculate the deformation of each node in three directions; When each node connects to four members, and the length changes of all members are known, {Δl} k When solving equation (6), the displacements [Δ] of each node are obtained. k After displacement, the coordinates of each node are given by equation (7): （7） S2.

5. Periodically read the readings of each distance measuring rod. Assume that N readings have been taken up to time t. Then the cumulative displacement of each measuring point is: （8） In the formula: Let be the cumulative displacement of the k-th node at time t. , Let be the displacement during the j-th time period.

2. The wearable magnetic grating-type three-dimensional deformation monitoring method according to claim 1, characterized in that: The deformation monitoring method also includes embedding several series of flexible inclinometers in the monitored engineering structure, measuring the changes in horizontal displacement at different depths inside the monitored engineering structure through the flexible inclinometers, and determining the deep deformation of the monitored engineering structure. The deformation of the monitored engineering structure is compared with that monitored in step S4 to evaluate the deformation trend and stability of the monitored engineering structure.

3. The wearable magnetic grating-type three-dimensional deformation monitoring method according to claim 1, characterized in that: A GNSS receiver is installed at the monitoring point. By receiving satellite signals, the absolute coordinates and absolute elevation of each monitoring point are recorded, and the displacement of each monitoring point is calculated.

4. The wearable magnetic grating-type three-dimensional deformation monitoring method according to claim 1, characterized in that: The length of the i-th section of the magnetic grating distance measuring scale at time t-1 Expressed as formula (1), the length of the i-th magnetic grating rangefinder at time t. Represented as formula (2): 。

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