System and method for measuring position change of object in soil

Abstract

The invention provides a system and a method for measuring the position change of an object in soil, and relates to the technical field of geotechnical engineering testing. Comprising the steps that a model box is prepared, a soil body needed by an experiment is loaded in the model box, and a magnetic object is placed in the soil body; the magnetic field induction device is arranged around the model box and is used for respectively detecting the magnetic field of the magnetic object at the current position at each set measurement time point so as to obtain magnetic field data corresponding to each measurement time point; and the displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtains the position change information of the magnetic object through each position coordinate. According to the invention, the measurement precision is higher, the real-time monitoring can be realized, and the fine position change of the object can be sensitively captured. Meanwhile, the magnetic field induction is less affected by the complex soil environment, the stability and reliability of the system are improved, and a more accurate and effective measurement means is provided for related engineering and scientific research.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of geotechnical engineering testing, and particularly relates to a system and method for measuring the position change of an object in soil. Background Art

[0002] In many fields such as geotechnical engineering research, underground engineering construction, and geological disaster monitoring, accurately measuring the position change of an object in soil is extremely crucial. For example, in foundation engineering, the displacement condition of pile foundations in soil is of great significance for evaluating the engineering stability; in the early warning work of soil landslides, mastering the position changes of key objects inside potential sliding soil masses can detect dangers in advance and thus effectively prevent disasters from occurring.

[0003] However, the current measurement technologies have significant defects. The Particle Image Velocimetry (PIV) technology performs well in fluid flow field measurement, but when used for measurement in soil, soil particles will interfere with it. On the one hand, it can only reflect some situations from the side and cannot comprehensively present the position change of an object in soil; on the other hand, factors such as the friction between soil particles and the measurement object will seriously interfere with the measurement results, making it difficult to accurately obtain the position change information of an object in soil.

[0004] In addition, the traditional measurement method of burying sensors in soil also faces many problems. The complex soil environment, such as corrosive substances and large extrusion forces, will damage the sensors, resulting in corrosion, extrusion deformation, etc. of the sensors, thereby greatly reducing the measurement accuracy and even directly causing failure and being unable to complete the measurement work normally. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a system and method for measuring the position change of an object in soil in view of the deficiencies of the prior art.

[0006] The technical solution of the present invention to solve the above technical problem is as follows: A system for measuring the position change of an object in soil includes a model box, a magnetic field induction device, and a displacement analysis device:

[0007] The model box is used to load the soil required for the experiment and place a magnetic object in the soil;

[0008] The magnetic field induction device is arranged around the model box and is used to detect the magnetic field of the magnetic object at its current position at each set measurement time point to obtain the magnetic field data corresponding to each measurement time point;

[0009] The displacement analysis device is used to calculate the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtain the position change information of the magnetic object through each of the position coordinates.

[0010] Another technical solution for the present invention to solve the above technical problems is as follows: A method for measuring the position change of an object in soil, comprising:

[0011] Prepare a model box, load the soil required for the experiment in the model box, and place a magnetic object in the soil;

[0012] Arrange a magnetic field induction device around the model box. At each set measurement time point, detect the magnetic field of the magnetic object at its current position respectively to obtain the magnetic field data corresponding to each measurement time point;

[0013] A displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtains the position change information of the magnetic object through each of the position coordinates.

[0014] The beneficial effects of the present invention are as follows: The present invention innovatively uses magnetic field data to measure the movement change of an object in soil. The magnetic field induction device can stably collect the magnetic field data of the magnetic object at multiple measurement time points. These data are not affected by soil particles and have high accuracy. The displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data, and then obtains its position change information. The present invention not only has higher measurement accuracy, but also can realize real-time monitoring, and can sensitively capture the subtle position changes of the object. At the same time, the magnetic field induction is less affected by the complex soil environment, improving the stability and reliability of the system, and providing a more accurate and effective measurement means for related engineering and scientific research. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a connection schematic diagram of a system for measuring the position change of an object in soil provided by an embodiment of the present invention;

[0016] Figure 2 It is a flow schematic diagram of a method for measuring the position change of an object in soil provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] The object of the present invention is to provide a system and method for measuring the position change of an object in soil. To solve the problem in the prior art that the position change in soil cannot be effectively measured, achieve high-precision, real-time and reliable measurement of the position change of an object in soil, provide accurate position data support for various related applications, and ensure the engineering safety and scientific research accuracy. The following is a detailed description through multiple specific embodiments.

[0019] Example 1: As Figure 1As shown in the figure, an embodiment of the present invention provides a system for measuring the position change of an object in soil, including a model box 1, a magnetic field induction device 3, and a displacement analysis device 4:

[0020] The model box 1 is used to load the soil required for the experiment and place a magnetic object in the soil;

[0021] The magnetic field induction device 3 is arranged around the model box and is used to detect the magnetic field of the magnetic object at its current position at each set measurement time point, so as to obtain the magnetic field data corresponding to each measurement time point;

[0022] The displacement analysis device 4 is used to calculate the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtain the position change information of the magnetic object through each of the position coordinates.

[0023] It should be understood that each measurement time point includes an initial time point and a plurality of set time nodes.

[0024] Specifically, a suitable magnetically perceptible object is selected, such as an iron block with precise counterweight, to ensure that its weight will neither undergo irregular displacement under soil disturbance due to being too light nor affect the original soil structure due to being too heavy. The iron block is carefully buried at a specific position in the soil model box to be measured. The model box is made of a magnetic-permeable material to avoid shielding interference with the magnetic field.

[0025] Around the key positions on the periphery of the model box, sensing coils that can sensitively sense magnetic field changes are evenly and symmetrically arranged. These sensing coils work based on the principle of electromagnetic induction and can capture the changes in magnetic field strength and direction caused by the movement of the iron block in real time.

[0026] The sensing coils (i.e., magnetic field sensors) of the magnetic field induction device are connected to collect magnetic field change signals at an extremely high sampling frequency, and quickly convert these analog signals into digital signals and transmit them to the displacement analysis device for analysis and processing.

[0027] In order to verify the conclusion in the embodiment that the position change of the magnetic object is determined based on the magnetic field data, an image acquisition device is also set up in this embodiment. The image acquisition device is arranged around the model box, acquires images of the magnetic object at each measurement time point, obtains the position information of the magnetic object from the images through an image analysis model, and establishes a coordinate system based on the position information to obtain the coordinates of the magnetic object corresponding to each measurement time point, so as to assist in judging the accuracy of the conclusion that the position change of the magnetic object is determined based on the magnetic field data.

[0028] In traditional measurement techniques, the particle image velocimetry technology is interfered by soil particles and it is difficult to accurately obtain the position change of an object in soil. Moreover, burying sensors is easily affected by the soil environment, resulting in reduced accuracy or even failure.

[0029] In this embodiment, by means of magnetic field induction technology, magnetic field data analysis is innovatively used for measurement. The magnetic field induction device can stably collect the magnetic field data of the magnetic object at multiple measurement time points. These data are not affected by soil particles and have high accuracy. The displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data, and then obtains its position change information. Not only is the measurement accuracy higher, but real-time monitoring can also be achieved, and subtle position changes of the object can be keenly captured. At the same time, magnetic field induction is less affected by the complex soil environment, improving the stability and reliability of the system, and providing a more accurate and effective measurement means for related engineering and scientific research.

[0030] Preferably, the magnetic field induction device includes a signal conditioning circuit, an analog-to-digital converter, and multiple magnetic field sensors;

[0031] In the magnetic field induction device, at each set measurement time point, the magnetic field of the magnetic object at the current position is respectively detected to obtain the magnetic field data corresponding to each measurement time point, including:

[0032] The multiple magnetic field sensors are arranged around and at intervals around the model box, and are used to respectively sense the magnetic field of the magnetic object at the current position at each set measurement time point to obtain the magnetic field signals corresponding to each measurement time point;

[0033] The signal conditioning circuit is connected to each magnetic field sensor and is used to condition each magnetic field signal respectively;

[0034] The analog-to-digital converter is connected to the signal conditioning circuit and is used to convert each conditioned magnetic field signal from an analog signal to a digital signal to obtain the magnetic field data corresponding to each measurement time point.

[0035] Magnetic field sensors of high sensitivity and low temperature drift are selected to reduce the influence of ambient temperature changes on the measurement results. The signal conditioning circuit adds a targeted filtering circuit according to the on-site electromagnetic interference situation, such as using a band-pass filter to filter interference signals of specific frequencies. The analog-to-digital converter selects a high-precision and high-sampling-rate chip to ensure the accuracy and real-time performance of the magnetic field signal conversion. In terms of data transmission, an optical fiber transmission method is adopted to avoid signal attenuation and interference during long-distance transmission.

[0036] In this embodiment, the process of the magnetic field induction device obtaining accurate magnetic field data is described in detail. High-sensitivity and low-temperature-drift magnetic field sensors, targeted signal conditioning circuits, high-precision and high-sampling-rate analog-to-digital converters, and reliable optical fiber transmission methods jointly ensure the accuracy and real-time performance of the data, and improve the reliability of the measurement system.

[0037] Preferably, in the displacement analysis device, the position coordinates of the magnetic object are calculated based on the magnetic field data corresponding to each measurement time point, and the position change information of the magnetic object is obtained through each of the position coordinates, including:

[0038] Based on the magnetic field induction signal formula Derive the distance expression of the magnetic object to each magnetic field sensor Based on the distance expression, construct a magnetic field strength - distance relationship model, and substitute the magnetic field data corresponding to each measurement time point into the magnetic field strength - distance relationship model respectively to obtain the distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point. The magnetic field strength - distance relationship model is:

[0039]

[0040] Where, B (r) is the magnetic field strength vector, r i is the distance from the magnetic object to each magnetic field sensor, m is the magnetic moment vector of the magnetic object, k is the proportionality constant, μ 0 is the magnetic permeability of vacuum, and 1 / 3 represents the cube root operation;

[0041] Calculate the distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point according to the least - squares method respectively to obtain the position coordinates of the magnetic object corresponding to each measurement time point;

[0042] Use a visualization graph display tool to draw the magnetic object graph based on the position coordinates of the magnetic object corresponding to each measurement time point, and obtain the movement trajectory of the magnetic object based on the drawn magnetic object graphs corresponding to each measurement time point.

[0043] In this embodiment, the process of the displacement analysis device calculating the position coordinates of the magnetic object and obtaining the position change information is elaborated in detail. Considering the model correction of the complex geological environment, the iterative optimization of the least - squares method calculation, and the professional visualization graph display, it improves the measurement accuracy and intuitiveness, and provides strong support for engineering decision - making.

[0044] Preferably, in the displacement analysis device, calculating the position coordinates of the magnetic object corresponding to each measurement time point according to the least - squares method respectively, including:

[0045] Let the coordinates of the magnetic object be (x, y, z), and the coordinates of the magnetic field sensor be (x i , y i , z i ), and define the distance from the magnetic object to the magnetic field sensor as Define the error function as Let Obtain the linear equation Ax = b, and calculate the coordinate vector x = [x, y, z] of the magnetic object based on the linear equation T , and calculate the coordinate x of the magnetic object through the coordinate vector x=(A T A) -1 A T b, where b is the magnetic field strength vector

[0046] In this embodiment, the coordinates and the error function are set: To calculate the position coordinates of the magnetic object, first set the coordinates of the magnetic object as (x, y, z), and the coordinates of the magnetic field sensor as (x i , y i , z i ), and define the distance from the magnetic object to the magnetic field sensor as. On this basis, define the error function to establish a quantization relationship between the magnetic object and the magnetic field sensor, preparing for subsequent calculations

[0047] Construct a linear equation to solve: Let the relevant calculation results of the error function obtain the linear equation Ax = b. In this equation, b is the magnetic field strength vector. By solving this linear equation, the coordinate vector x = [x, y, z] of the magnetic object is obtained T . In this way, the complex problem of calculating position coordinates is transformed into a problem of solving a linear equation. With the help of mature linear algebra solving methods, the coordinates of the magnetic object can be accurately calculated, laying a foundation for determining its position change

[0048] Preferably, the system further includes a display and storage device for displaying and storing the position change information of the magnetic object. The added display and storage device facilitates the display and management of data. The combination of cloud storage and local storage ensures the secure storage and convenient access of data, and the interactive display interface improves the utilization efficiency of data, facilitating engineers to perform data analysis and decision-making

[0049] Preferably, the model box is made of a magnetic permeable material, and a rubber pad is pasted on the inner wall of the model box

[0050] The soil body required for the experiment loaded in the model box is sand and clay, and the sand and clay are filled into the model box in a predetermined layered structure

[0051] In actual application scenarios such as geological disaster monitoring, the model box simulates the soil environment under different geological conditions, and can be filled with sand and clay mixed in various proportions to simulate the soil structure in landslide and debris flow prone areas. The magnetic object is a specially made magnetic ball, and its surface is treated with anti-corrosion to avoid being corroded in a complex soil environment and affecting the magnetic field characteristics

[0052] The implementation process of this device will be introduced through a specific example below.

[0053] As Figure 1 shown, specifically, this system includes a cube-shaped model box 1, an iron block 5 (i.e., a magnetic object), a magnetic field induction device 3, and a displacement analysis device 4; the magnetic field induction device 3 includes a sensing coil array 2 (i.e., a magnetic field sensor), a signal conditioning circuit, and an NI CompactDAQ module. An iron block 5 with a mass of 50 g is accurately buried at a depth of 10 cm at the center of the soil model box 1, and the initial coordinates are recorded. When the measuring device is started, the sensing coil array 2 starts to work in real time. It continuously captures the magnetic field change signals caused by the movement of the iron block 5. Since the magnetic field change signals captured by the sensing coil array 2 are relatively weak and may be subject to noise interference, these signals need to be conditioned. A signal conditioning circuit of model LM358 is used in the magnetic field induction device 3. The signal conditioning process includes operations such as amplifying and filtering the signals to improve the quality and stability of the signals. The conditioned signals are transmitted to the NI CompactDAQ module. After receiving the conditioned signals, the NI CompactDAQ module converts them into digital signals. This digital signal has higher precision and stronger anti-interference ability, facilitating subsequent processing and analysis. The measurement data converted into digital signals is uploaded to the displacement analysis device 4. After receiving the digital signals from the magnetic field induction device 3, the displacement analysis device 4 starts to process the data in real time, calculates the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtains the position change information of the magnetic object through each of the position coordinates.

[0054] Example 2: As Figure 2 shown, an embodiment of the present invention also provides a method for measuring the position change of an object in soil, including:

[0055] Prepare a model box, load the soil required for the experiment in the model box, and place the magnetic object in the soil;

[0056] Arrange the magnetic field induction device around the model box, and at each set measurement time point, detect the magnetic field of the magnetic object at the current position respectively to obtain the magnetic field data corresponding to each measurement time point;

[0057] The displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtains the position change information of the magnetic object through each of the position coordinates.

[0058] In this embodiment, by means of magnetic field induction technology, magnetic field data analysis is innovatively used for measurement. The magnetic field induction device can stably collect the magnetic field data of the magnetic object at multiple measurement time points. These data are not affected by soil particles and have high accuracy. The displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data, and then obtains the position change information thereof. Not only is the measurement accuracy higher, but real-time monitoring can also be achieved, and the subtle position changes of the object can be keenly captured. At the same time, the magnetic field induction is less affected by the complex soil environment, improving the stability and reliability of the system, and providing a more accurate and effective measurement means for related engineering and scientific research.

[0059] Preferably, the magnetic field induction device includes a signal conditioning circuit, an analog-to-digital converter, and multiple magnetic field sensors;

[0060] At each set measurement time point, the magnetic field of the magnetic object at the current position is respectively detected to obtain the magnetic field data corresponding to each measurement time point, including:

[0061] The multiple magnetic field sensors are arranged around and at intervals of the model box. At each set measurement time point, the magnetic field of the magnetic object at the current position is respectively sensed to obtain the magnetic field signals corresponding to each measurement time point;

[0062] The signal conditioning circuit respectively conditions each magnetic field signal;

[0063] The analog-to-digital converter respectively converts each conditioned magnetic field signal from an analog signal to a digital signal to obtain the magnetic field data corresponding to each measurement time point.

[0064] Preferably, calculating the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtaining the position change information of the magnetic object through each of the position coordinates, including:

[0065] Based on the magnetic field induction signal formula Derive the distance expression of the magnetic object to each magnetic field sensor Based on the distance expression, construct a magnetic field intensity-distance relationship model, and substitute the magnetic field data corresponding to each measurement time point into the magnetic field intensity-distance relationship model respectively to obtain the distance of the magnetic object to each magnetic field sensor corresponding to each measurement time point. The magnetic field intensity-distance relationship model is:

[0066]

[0067] Among them, B (r) is the magnetic field intensity vector, r i is the distance of the magnetic object to each magnetic field sensor, m is the magnetic moment vector of the magnetic object, k is the proportionality constant, μ0 is the vacuum permeability;

[0068] According to the least squares method, calculate the distances from the magnetic object to each magnetic field sensor corresponding to each measurement time point, and obtain the position coordinates of the magnetic object corresponding to each measurement time point;

[0069] Use a visualization graph display tool to draw a magnetic object graph based on the position coordinates of the magnetic object corresponding to each measurement time point, and obtain the movement trajectory of the magnetic object based on the drawn magnetic object graphs corresponding to each measurement time point.

[0070] Preferably, it further includes the step of displaying and storing the position change information of the magnetic object.

[0071] The advantages of the present invention are:

[0072] 1. High-precision measurement and real-time monitoring: Through magnetic field induction technology and the least squares method optimization algorithm, high-precision and real-time measurement of the position change of objects in soil can be achieved.

[0073] 2. High system integration: The model box, magnetic field induction device, displacement analysis device, and display and storage device are organically combined to form a complete measurement system, which is convenient for operation and management.

[0074] 3. High signal stability and data accuracy: The introduction of a signal conditioning circuit and an analog-to-digital converter improves the quality of the signal and the accuracy of the data.

[0075] 4. Good visualization effect: Use a visualization graph display tool to draw the movement trajectory of the magnetic object, intuitively display the position change situation, and facilitate analysis and research.

[0076] 5. Strong model adaptability: The magnetic field strength and distance relationship model can adapt to magnetic field changes under different experimental conditions and has good versatility.

[0077] 6. Complete data storage: The storage device can save complete measurement data and processing results, which is convenient for subsequent further analysis and research.

[0078] 7. Small magnetic field interference: The model box made of a magnetic-permeable material will not interfere with the magnetic field, ensuring the measurement accuracy of the magnetic field induction device.

[0079] 8. High structural stability: The rubber pads on the inner wall can effectively buffer external impacts and protect the soil and magnetic objects inside the model box.

[0080] 9. Realistic simulation environment: The sand and clay filled in layers can simulate the actual soil environment, improving the reliability and practicality of the experimental results.

[0081] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0082] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0083] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present invention.

[0084] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for measuring the change in position of an object in soil, characterized in that: Including model box, magnetic field sensing device and displacement analysis device: The model box is used to load the soil required for the experiment and place the magnetic object in the soil; The magnetic field sensing device is arranged around the model box, and is used to detect the magnetic field of the magnetic object at the current position at each set measurement time point, and obtain the magnetic field data corresponding to each measurement time point; The displacement analysis device is used to calculate the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtain the position change information of the magnetic object through each position coordinate.

2. The system for measuring position changes of an object in soil according to claim 1, characterized in that: The magnetic field sensing device includes a signal conditioning circuit, an analog-to-digital converter and a plurality of magnetic field sensors; In the magnetic field sensing device, at each set measurement time point, the magnetic field of the magnetic object at the current position is detected respectively to obtain magnetic field data corresponding to each measurement time point, including: The plurality of magnetic field sensors are arranged around the model box at intervals, and are used to sense the magnetic field of the magnetic object at the current position at each set measurement time point, and obtain magnetic field signals corresponding to each measurement time point; The signal conditioning circuit is connected to each magnetic field sensor and is used to condition each magnetic field signal respectively; The analog-to-digital converter is connected to the signal conditioning circuit and is used to convert each conditioned magnetic field signal from an analog signal to a digital signal to obtain magnetic field data corresponding to each measurement time point.

3. The system for measuring position change of an object in soil according to claim 2, characterized in that: In the displacement analysis device, the position coordinates of the magnetic object are calculated based on the magnetic field data corresponding to each measurement time point, and the position change information of the magnetic object is obtained through each of the position coordinates, including: Based on the magnetic field induction signal formula Derive the distance expression from the magnetic object to each magnetic field sensor A magnetic field strength and distance relationship model is constructed based on the distance expression. The magnetic field data corresponding to each measurement time point is respectively substituted into the magnetic field strength and distance relationship model to obtain the distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point. The magnetic field strength and distance relationship model is: Among them, B (r) is the magnetic field intensity vector, r i is the distance from the magnetic object to each magnetic field sensor, m is the magnetic moment vector of the magnetic object, k is the proportional constant, μ0 is the magnetic permeability of vacuum; The distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point is calculated according to the least square method to obtain the position coordinates of the magnetic object corresponding to each measurement time point; A visual graphic display tool is used to draw a magnetic object graphic for the position coordinates of the magnetic object corresponding to each measurement time point, and a moving trajectory of the magnetic object is obtained based on the drawn magnetic object graphic corresponding to each measurement time point.

4. The system for measuring position change of an object in soil according to claim 3, characterized in that: In the displacement analysis device, the distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point is calculated according to the least square method to obtain the position coordinates of the magnetic object corresponding to each measurement time point, including: Assume the coordinates of the magnetic object are (x, y, z) and the coordinates of the magnetic field sensor are (x i ,y i ,z i ), the distance from the magnetic object to the magnetic field sensor is defined as The error function is defined as make Get the linear equation Ax = b, and calculate the coordinate vector x = [x, y, z] of the magnetic object based on the linear equation T , calculate the coordinate x of the magnetic object through the coordinate vector T A) -1 A T b, where b is the magnetic field strength vector.

5. The system for measuring position change of an object in soil according to any one of claims 1 to 4, characterized in that: The system also includes a display and storage device for displaying and storing the position change information of the magnetic object.

6. The system for measuring position change of an object in soil according to any one of claims 1 to 4, characterized in that: The model box is made of magnetically permeable material, and a rubber pad is pasted on the inner wall of the model box; The soil required for the experiment in the model box is sand and clay, and the sand and clay are filled into the model box in layers according to a predetermined layered structure.

7. A method for measuring the change in position of an object in soil, characterized in that: include: A model box is prepared, the soil required for the experiment is loaded into the model box, and a magnetic object is placed in the soil; The magnetic field sensing device is arranged around the model box, and at each set measurement time point, the magnetic field of the magnetic object at the current position is detected to obtain magnetic field data corresponding to each measurement time point; The displacement analysis device calculates the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtains the position change information of the magnetic object through each position coordinate.

8. The method for measuring the position change of an object in soil according to claim 7, characterized in that: The magnetic field sensing device includes a signal conditioning circuit, an analog-to-digital converter and a plurality of magnetic field sensors; At each set measurement time point, the magnetic field of the magnetic object at the current position is detected respectively to obtain magnetic field data corresponding to each measurement time point, including: The plurality of magnetic field sensors are arranged around the model box at intervals, and at each set measurement time point, respectively sense the magnetic field of the magnetic object at the current position to obtain a magnetic field signal corresponding to each measurement time point; The signal conditioning circuit conditions each magnetic field signal respectively; The analog-to-digital converter converts each conditioned magnetic field signal from an analog signal to a digital signal to obtain magnetic field data corresponding to each measurement time point.

9. The method for measuring the position change of an object in soil according to claim 8, characterized in that: The calculating the position coordinates of the magnetic object based on the magnetic field data corresponding to each measurement time point, and obtaining the position change information of the magnetic object through each position coordinate, includes: Based on the magnetic field induction signal formula Derive the distance expression from the magnetic object to each magnetic field sensor A magnetic field strength and distance relationship model is constructed based on the distance expression. The magnetic field data corresponding to each measurement time point is respectively substituted into the magnetic field strength and distance relationship model to obtain the distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point. The magnetic field strength and distance relationship model is: Among them, B (r) is the magnetic field intensity vector, r i is the distance from the magnetic object to each magnetic field sensor, m is the magnetic moment vector of the magnetic object, k is the proportional constant, μ0 is the magnetic permeability of vacuum; The distance from the magnetic object to each magnetic field sensor corresponding to each measurement time point is calculated according to the least square method to obtain the position coordinates of the magnetic object corresponding to each measurement time point; A visual graphic display tool is used to draw a magnetic object graphic for the position coordinates of the magnetic object corresponding to each measurement time point, and a moving trajectory of the magnetic object is obtained based on the drawn magnetic object graphic corresponding to each measurement time point.

10. The method for measuring the position change of an object in soil according to any one of claims 7 to 9, characterized in that: The method also includes the steps of displaying and storing the position change information of the magnetic object.

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