Apparatus and method for monitoring three-dimensional displacement structures with group microwave radar

Abstract

The application discloses a kind of group microwave radar monitoring three-dimensional displacement structure method and device, the device includes: microwave radar A, microwave radar B and microwave radar C installed on adjustable three radar positioning frame, power supply, controller, router and cloud server, reflective target installed in monitoring point;Microwave radar A, microwave radar B and microwave radar C are connected with power supply and controller respectively, and the microwave radar A, microwave radar B and microwave radar C are used to measure the distance of itself and reflective target and send to controller, and controller calculates the space coordinates of reflective target according to distance and sends to router, and reflective target is used to reflect radar signal, and router is used to transmit the space coordinates of reflective target to cloud server, and the cloud server is used to calculate deflection angle according to the space coordinates of reflective target, and deflection angle is greater than a certain threshold value to give early warning.The application can realize the monitoring and early warning of three-dimensional displacement structure.

Description

Technical Field

[0001] This invention relates to the field of monitoring three-dimensional displacement structures, and in particular to a device and method for monitoring three-dimensional displacement structures using a group microwave radar. Background Technology

[0002] Three-dimensional displacement structure monitoring mainly relies on sensors based on the principle of connecting pipes, reflective photoelectric sensors, and tilt sensors. However, these sensors are susceptible to problems such as liquid expansion, evaporation, leakage, and interference from passing vehicles. Furthermore, some sensors have narrow applicability, low monitoring coverage, and are greatly affected by natural environmental factors. Traditional manual monitoring methods are inaccurate and slow, failing to meet the needs of accurate monitoring. Existing AI-based measurement methods rely on visual sensors that are easily affected by changes in ambient light and background interference, leading to unstable measurement results. Traditional image processing methods are slow to dynamically update the background model and are easily affected by environmental changes. For slope monitoring, traditional methods rely heavily on manual inspections and simple tools, resulting in low efficiency and difficulty in achieving real-time monitoring and early warning. Although systems with multiple monitoring and early warning modules exist, they still have shortcomings, such as limited monitoring points, single monitoring methods, and independent monitoring methods that make it difficult to integrate data for comprehensive analysis. They also fail to fully consider factors such as deep slope microseismic monitoring and blasting vibration monitoring, resulting in high investment but low returns, making them unsuitable for complex scenarios and comprehensive monitoring needs. Summary of the Invention

[0003] The purpose of this invention is to provide a device and method for monitoring three-dimensional displacement structures using group microwave radar, aiming to solve the problem of monitoring three-dimensional displacement structures.

[0004] This invention provides a device for monitoring three-dimensional displacement structures using group microwave radar, comprising:

[0005] Microwave radar A, microwave radar B, and microwave radar C are installed on a three-radar positioning frame; power supply, controller, router, and cloud server; and reflective target is installed at the monitoring point.

[0006] Microwave radar A, microwave radar B, and microwave radar C are connected to the power supply and controller, respectively. The controller is connected to the router, and the router is connected to the cloud server.

[0007] The microwave radars A, B, and C are used to measure their distance from the reflective target and send the result to the controller. The controller calculates the spatial coordinates of the reflective target based on the distance and sends them to the router. The reflective target reflects the radar signal. The router transmits the spatial coordinates of the reflective target to the cloud server. The cloud server calculates the deflection angle based on the spatial coordinates of the reflective target. If the deflection angle is greater than a certain threshold, an early warning is issued.

[0008] The present invention also provides a method for monitoring three-dimensional displacement structures using group microwave radar, comprising:

[0009] n reflective targets are installed at the monitored point, where n is greater than 2. A group microwave radar device is installed within the reflection range of the n reflective targets. The group microwave radar device includes a controller, an adjustable three-radar positioning frame, microwave radar A, microwave radar B, and microwave radar C.

[0010] The straight-line distance between microwave radar A and microwave radar B, the straight-line distance between microwave radar B and C, and the straight-line distance between microwave radar A and C are input to the controller; a spatial coordinate system is established, wherein the x-axis of the spatial coordinate system coincides with the line connecting microwave radar A and microwave radar B, the z-axis is perpendicular to the horizontal plane, and microwave radar A is the origin; the spatial coordinates of microwave radar A, microwave radar B, and microwave radar C are obtained based on the spatial coordinate system.

[0011] Within a certain time slice, three microwave radars run m times to measure the distances between microwave radar A, microwave radar B, and microwave radar C and n reflective targets. The controller obtains the distances between microwave radar A, microwave radar B, and microwave radar C and n reflective targets, and generates n lists containing 3 tuples, each tuple containing m elements.

[0012] The list is sent to the server via a router. The server takes a representative value from each of the m elements in the list to obtain the final list. Two sets of data are randomly selected from the n sets of data in the final list and combined to obtain multiple sets of dual-reflection target data. These multiple sets of dual-reflection target data are then combined into one set of data. F1 and F2 are the reflection targets. Let L be the distance between microwave radars A, B, and C and F1 and F2. AF1 L BF1 L CF1 L AF2 L BF2 L CF2 ;

[0013] Combine the spatial coordinates of the three with L AF1 L BF1 L CF1 L AF2 L BF2 L CF2 Input the spatial coordinate equation to calculate the spatial coordinates of F1 and F2. If F1 or F2 is higher than microwave radar A in the vertical direction, select a positive value; otherwise, select a negative value.

[0014] Using the spatial coordinates of F1 and F2 obtained from the first calculation as initial values, and the spatial coordinates of F1 and F2 obtained from real-time calculation as real-time values, the deflection angle occurring in the zy and xy planes is calculated based on the initial and real-time values ​​of F1 or F2.

[0015] Set warning values ​​for the zy and xy directions, and issue a warning when the deflection angle reaches the warning value.

[0016] The embodiments of the present invention utilize the principle of triangulation to achieve three-dimensional spatial positioning of the target, which can effectively overcome the limitations of single radar and dual radar. It can monitor the deformation of the monitored point and obtain the accurate spatial coordinates of the monitoring point in real time. It provides a high-precision and high-reliability solution for deformation monitoring and early warning of bridges, slopes and other structures, and has significant application prospects.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an adjustable three-radar positioning frame for a group microwave radar monitoring device for three-dimensional displacement structures according to an embodiment of the present invention;

[0020] Figure 2 This is a network workflow diagram of the device for monitoring three-dimensional displacement structures using group microwave radar according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the radar height and angle adjustment of the group microwave radar monitoring three-dimensional displacement structure according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the disassembly of the adjustable three-radar positioning frame of the group microwave radar monitoring three-dimensional displacement structure according to an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the overall structure of the displacement monitoring method for monitoring three-dimensional displacement structures using group microwave radar according to an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the workflow of the method for monitoring three-dimensional displacement structures using group microwave radar according to an embodiment of the present invention;

[0025] Figure 7This is a statistical diagram illustrating the absolute error of the reflected target when radar B produces a 1cm error, representing different radar arrangement methods according to an embodiment of the present invention. Figure 7 (a) represents the absolute error Δx of the reflective target F under different arrangement methods. Figure 7 (b) represents the absolute error Δy of the reflecting target F under different arrangement methods. Figure 7 (c) represents the absolute error Δz of the reflective target F under different arrangement methods.

[0026] Figure 8 This is a schematic diagram illustrating the statistical absolute error of the reflecting target under the condition of radar equidistant arrangement according to an embodiment of the present invention. Figure 8 (a) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the x-axis direction under the condition of equal-distance radar arrangement; Figure 8 (b) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the y-axis direction under the condition of equal-distance radar arrangement; Figure 8 (c) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the α=45° direction under the condition of equal-distance radar arrangement; Figure 8 (d) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the α = -45° direction under the condition of equal-distance radar arrangement.

[0027] Figure 9 This is a statistical diagram illustrating the measured deflection error analysis of the method for determining the optimal installation position of three radars according to an embodiment of the present invention. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Device Examples

[0030] According to embodiments of the present invention, a device for monitoring three-dimensional displacement structures using group microwave radar is provided. Figure 1 This is a schematic diagram of a device for monitoring three-dimensional displacement structures using a group microwave radar according to an embodiment of the present invention, as shown below. Figure 1 As shown, it specifically includes:

[0031] Microwave radar A, microwave radar B, and microwave radar C are installed on a three-radar positioning frame; power supply, controller, router, and cloud server; and reflective target is installed at the monitoring point.

[0032] Microwave radar A, microwave radar B, and microwave radar C are connected to the power supply and controller, respectively. The controller is connected to the router, and the router is connected to the cloud server.

[0033] Microwave radars A, B, and C are used to measure their distance from the reflective target and transmit the data to the controller. The controller calculates the spatial coordinates of the reflective target based on the distance and sends the coordinates to the router. The reflective target is used to reflect radar signals, such as... Figure 2 As shown, the router is used to transmit the spatial coordinates of the reflective target to the cloud server, and the cloud server is used to calculate the deflection angle based on the spatial coordinates of the reflective target. If the deflection angle is greater than a certain threshold, an early warning is issued.

[0034] The three-radar positioning frame includes: a radar frame base, an adjustable support rod, an adjustable triangular base, a support rod, three retractable radar fixing rods, and three diagonal braces. The adjustable support rod is connected to the radar frame base and is used to adjust the vertical height and horizontal rotation angle. The adjustable triangular base is connected to the adjustable support rod and is used to adjust the vertical rotation angle. The support rod and the three retractable radar fixing rods are respectively connected to the adjustable triangular base. The angle between the three retractable radar fixing rods is 120° and their lengths are equal. The three retractable radar fixing rods are used to adjust the length of the three equal-length rods. The diagonal braces are fixed between the retractable radar fixing rods and the support rod.

[0035] like Figure 3 As shown, the device for monitoring three-dimensional displacement structures using group microwave radar employs an adjustable triangular base and an adjustable support rod to adjust the height and vertical rotation angle.

[0036] like Figure 4 As shown, the present invention can disassemble the three-radar positioning frame into three parts, which is convenient to store, easy to carry, simple to install, and highly applicable.

[0037] The first part consists of a radar mount base and an adjustable support rod; the second part consists of an adjustable triangular base, a support rod, three telescopic radar fixing rods, and the radar; and the third part consists of three diagonal braces.

[0038] The microwave radars A, B, and C are installed within the reflection range of the reflective target, that is, within the extension surface of the reflective target's reflector plate.

[0039] Method Implementation Examples

[0040] According to an embodiment of the present invention, a method for monitoring three-dimensional displacement structures using a group microwave radar is provided, specifically including:

[0041] n reflective targets are installed at the monitored point, where n is greater than 2. A group microwave radar device is installed within the reflection range of the n reflective targets. The group microwave radar device includes a controller, an adjustable three-radar positioning frame, microwave radar A, microwave radar B, and microwave radar C.

[0042] The straight-line distances between microwave radars A and B, B and C, and A and C are input to the controller; a spatial coordinate system is established, where the x-axis coincides with the line connecting microwave radars A and B, and the z-axis is perpendicular to the horizontal plane. With microwave radar A as the origin, the spatial coordinates of microwave radars A, B, and C are obtained based on the spatial coordinate system. (x...) a y a , z a ), (x b y b , z b ), (x c y c , z c );

[0043] Within a certain time slice, three microwave radars run m times to measure the distances between microwave radar A, microwave radar B, and microwave radar C and n reflective targets. The controller obtains the distances between microwave radar A, microwave radar B, and microwave radar C and n reflective targets, and generates n lists containing 3 tuples, each tuple containing m elements.

[0044] In embodiments of the present invention, such as Figure 6 As shown, time slice allocation and signal scheduling are implemented through a controller. Time slices are allocated to each radar in a fixed order. The radar uses time-division multiplexing technology, and at the receiving end, the multiplexed signals are demultiplexed according to the time slice order to recover the original signals. Digital signal processing technology is used to encode, decode, and maintain synchronization of the signals. A high-precision synchronous clock is shared to ensure that their time divisions are consistent and do not interfere with each other.

[0045] Microwave radars A, B, and C run sequentially for one cycle, generating n lists of 3 tuples each, with each tuple containing m elements:

[0046] [(L AF11 ,L AF12 ,L AF13 ,…,L AF1m ),(L BF11 ,L BF12 ,L BF13 ,…,L BF1m ),(L CF11 ,L CF12 ,L CF13,…,L CF1m )];

[0047] [(L AF21 ,L AF22 ,L AF23 ,…,L AF2m ),(L BF21 ,L BF22 ,L BF23 ,…,L BF2m ),(L CF21 ,L CF22 ,L CF23 ,…,L CF2m )];

[0048] ...

[0049] [(L AFn1 ,L AFn2 ,L AFn3 ,…,L AFnm ),(L BFn1 ,L BFn2 ,L BFn3 ,…,L BFnm ),(L CFn1 ,L CFn2 ,L CFn3 ,…,L CFnm )];

[0050] Where n depends on the number of reflective targets deployed, and m depends on the product of the time slice size allocated to each radar and the acquisition frequency, that is, the number of times a radar runs within a loop. The data list is remotely transmitted to the server via a router. The corresponding program on the server receives the data list and performs data cleaning and coordinate calculation on each tuple in each list using an algorithm within the program, obtaining a representative value, thus obtaining the final set of lists.

[0051] [L AF1 ,L BF1 ,L CF1 ];

[0052] [L AF2 ,L BF2 ,L CF2 ];

[0053] ...

[0054] [L AFn ,L BFn ,L CFn ];

[0055] This list of values ​​is combined with the spatial coordinate equation and the deflection angle. and The formula is used to calculate the real-time spatial coordinates (x, y) of the reflecting target F. Fn y Fn , z Fn and the deflection angles occurring in the zy and xy planes. and A three-dimensional dynamic graph of the deflection angle is drawn, and warning values ​​are set for different directions. When the deformation value of the monitored point reaches the warning value, an early warning is issued.

[0056] The list is sent to the server via a router. The server takes a representative value from each of the m elements in the list to obtain the final list. Two sets of data are randomly selected from the n sets of data in the final list and combined to obtain multiple sets of dual-reflection target data. These multiple sets of dual-reflection target data are then combined into one set of data. F1 and F2 are the reflection targets. Let L be the distance between microwave radars A, B, and C and F1 and F2. AF1 L BF1 L CF1 L AF2 L BF2 L CF2 ;

[0057] Combine the spatial coordinates of the three with L AF1 L BF1 L CF1 L AF2 L BF2 L CF2 Input the spatial coordinate equation to calculate the spatial coordinates of F1 and F2. If F1 or F2 is higher than microwave radar A in the vertical direction, select a positive value; otherwise, select a negative value.

[0058] In embodiments of the present invention, such as Figure 5 As shown, taking the reflective target F1 as an example, the spatial coordinates F1(x, y, z) of the reflective target F1 are obtained by solving the following spatial coordinate equation. The specific coordinates are represented by (x...). F1 y F1 , z F1 )express:

[0059] ;

[0060] ;

[0061] ;

[0062] The (x) F1 y F1 , z F1 Two solutions (x) are obtained by solving the simultaneous equations. F1 y F1 +z F1 ) and (xF1 y F1 -z F1 If the reflective target F1 is higher than the microwave radar A in the vertical direction, a positive value is selected; otherwise, a negative value is selected.

[0063] Using the spatial coordinates of F1 and F2 obtained from the first calculation as initial values, and the spatial coordinates of F1 and F2 obtained from real-time calculation as real-time values, the deflection angle occurring in the zy and xy planes is calculated based on the initial and real-time values ​​of F1 or F2.

[0064] In this embodiment of the invention, calculating the deflection angle specifically includes:

[0065] When there are two monitoring points, reflective targets F1 and F2 are installed. The spatial coordinates (x, y, y) of the two reflective targets F1 and F2 are calculated according to the spatial coordinate equation. F1 y F1 , z F1 ) and (x F2 y F2 , z F2 ), will be the first detected (x) F1 y F1 , z F1 ) and (x F2 y F2 , z F2 ) as the initial value (x) F10 y F10 , z F10 ) and (x F20 y F20 , z F20 ), through real-time detection (x) F1 y F1 , z F1 ) and (x F2 y F2 , z F2 Subtract the initial value (x) from the coordinates respectively F10 y F10 , z F10 ) and (x F20 y F20 , z F20 ), can obtain and The deflection angles occurring in the zy and xy planes are calculated using the following formulas. and :

[0066] , , ;

[0067] , , ;

[0068] ;

[0069] ;

[0070] Set warning values ​​for the zy and xy directions, and issue a warning when the deflection angle reaches the warning value.

[0071] Installing a group microwave radar device within the reflection range of n reflecting targets specifically includes:

[0072] Adjust the adjustable three-radar positioning frame so that the distance between the reflective target furthest from the total distance of all radars and microwave radars A, B, and C is equal. Install the reflective target F and microwave radars A, B, and C according to the site conditions. The initial arrangement is based on the triangle formed by the lines connecting microwave radars A, B, and C, with side length L. AB L AC L BC With a distance of not less than 2m, take the position of microwave radar A as the origin of the spatial coordinate system, and measure the spatial coordinates of microwave radar B and microwave radar C.

[0073] Three microwave radars are activated to obtain the distances from the three radars to the reflective target F and send them to the controller. The reflective target F is the reflective target with the farthest total distance from all radars. The controller calculates the spatial coordinates of the reflective target F based on the spatial coordinates of microwave radar A, microwave radar B and microwave radar C and the distances from the three radars to the reflective target F.

[0074] The controller uses the spatial coordinates of microwave radar A, microwave radar C and reflective target F as initial values, and modifies the spatial coordinates of microwave radar B to produce an error compared to the initial position of microwave radar B.

[0075] In this embodiment of the invention, the coordinates of microwave radars A and C and the reflective target F are used as initial values. It is assumed that microwave radar B has errors of ±1cm, ±2cm, ±3cm, ±4cm, ±5cm, ±6cm, ±7cm, ±8cm, ±9cm, and ±10cm in the x-axis, y-axis, α=±45°, and ±135° directions (where α refers to the angle between the microwave radar B and the positive x-axis in the xy plane), respectively. The spatial coordinates of radar B after the microwave radar B has generated errors are calculated.

[0076] The initial values ​​and modified spatial coordinates are input into the spatial coordinate equation to obtain the distance between the reflective target F and the microwave radar B;

[0077] Based on the coordinates of microwave radar A, microwave radar B, and microwave radar C before the error occurred, and the distance between the reflecting target F and microwave radar B after the error occurred, calculate the coordinates of the reflecting target F after the error occurred.

[0078] Calculate the absolute errors Δx, Δy, and Δz between the coordinates of the reflecting target before and after the error occurs;

[0079] Figure 7 (a) represents the absolute error Δx of the reflective target F under different arrangement methods. Figure 7 (b) represents the absolute error Δy of the reflecting target F under different arrangement methods. Figure 7 (c) represents the absolute error Δz of the reflective target F under different arrangement methods.

[0080] When the three radars and the reflective target are installed with the normal to the center of the surface formed by the three radars, the error is minimized. Therefore, the radars and the reflective target should be aligned as much as possible to reduce the error.

[0081] Figure 8 (a) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the x-axis direction under the condition of equal-distance radar arrangement; Figure 8 (b) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the y-axis direction under the condition of equal-distance radar arrangement; Figure 8 (c) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the α=45° direction under the condition of equal-distance radar arrangement; Figure 8 (d) represents the absolute errors Δx, Δy, and Δz of microwave radar B when it produces an error of 1 cm in the α = -45° direction under the condition of equal radar arrangement. In the event of an error, the side length distance between radars can be adjusted to reduce the error. Therefore, before the formal installation and measurement of radars, error analysis is performed to find the side length distance between radars corresponding to the smaller allowable error.

[0082] Adjust the side length L of the triangle formed by the lines connecting microwave radars A, B, and C. AB L AC and L BC Recalculate the spatial coordinates of microwave radar B and microwave radar C;

[0083] The absolute errors Δx, Δy, and Δz of the coordinates of the reflecting target F before and after the error occur are calculated for different side lengths of the triangle.

[0084] Based on the site conditions, the reflection angle of the reflective targets, and the radar's ability to identify the reflective targets, determine the maximum allowable distance between the radars on site. Then, based on the maximum allowable distance between the radars on site, find the side lengths between the three radars corresponding to the minimum absolute errors △x, △y, and △z. Use the side lengths between the three radars as the optimal radar installation side lengths, and adjust the horizontal and vertical rotation angles of the radar mounts so that the radars can identify all the reflective targets.

[0085] In this embodiment of the invention, the accuracy of the measured displacement is analyzed based on the optimal installation position.

[0086] like Figure 9 Based on the optimal installation position, an analysis of the accuracy of the measured displacement was conducted. The results are as follows: 1) The error caused by the displacement value measured when the radar is installed horizontally is much greater than the error caused by the displacement value measured when the three radars are installed vertically and along the normal line; 2) The error increases with the displacement. Since there are errors in both the theoretical coordinates and the measured coordinates before and after the displacement, the errors in the measured coordinates before and after the displacement are canceled out, so the displacement error value is very small. Taking the installation of radar and reflective target along their normals with a distance of 2m between the radars as an example, the coordinates (in meters) of the three radars and the reflective target are (0, 0, 0), (0.5, 0, 0), (0.25, 0.433, 0), and (0.25, 30, 5), respectively. When one of the radars (0.5, 0, 0) shifts by -10mm on the y-axis and the reflective target shifts by -10mm on the z-axis, the absolute errors between the theoretical and measured spatial coordinates of the reflective target after the shift are calculated to be (0mm, 0.02801mm, 0.00412mm). When the reflective target shifts by -20mm on the z-axis, the absolute errors between the theoretical and measured spatial coordinates of the reflective target after the shift are calculated to be (0mm, 0.05602mm, 0.00824mm).

[0087] The beneficial effects of this invention are as follows:

[0088] Compared to commonly used single-radar monitoring, single-radar monitoring has poor accuracy and reliability. When the monitoring point deforms, single-radar monitoring has a large number of blind spots. If the deformation occurs on the surface of a sphere with the location of the single radar as the center and the distance between the single radar and the reflecting target as the radius of the sphere, the deformation cannot be detected because the single radar's recognition distance remains unchanged. Therefore, in practical applications, single-radar monitoring of bridge deflection has extremely poor accuracy and reliability. Compared to dual-radar monitoring of bridge deflection, dual-radar also has monitoring blind spots, cannot detect three-dimensional deformation of the monitoring point, and will generate signal interference between the two radars, affecting its accuracy and reliability.

[0089] This invention proposes a multi-microwave radar collaborative spatial displacement monitoring system, providing a radar deployment scheme and a method for calculating the spatial coordinates of monitoring points. It can monitor deformation in any direction at the monitoring point, acquire the spatial coordinates of the monitoring point in real time, and employs Time Division Multiplexing (TDM) technology to improve the accuracy and reliability of multi-microwave radar monitoring, preventing mutual interference between the three radar signals. Microwave radars A, B, and C share a high-precision synchronization clock, ensuring consistent time slice division. Signal multiplexing is achieved through a controller. The controller manages the allocation of time slices and signal scheduling. Signal scheduling and time slice allocation are implemented through software. The radar's working cycle is divided into multiple fixed-length time slices, each allocated to one radar. The length and allocation of time slices are dynamically adjusted according to the actual working requirements of the radar. Time slices are allocated to each radar sequentially in a fixed order.

[0090] Signals from multiple radars are multiplexed onto a single channel in time-slot order. At the receiving end, the multiplexed signals are demultiplexed in time-slot order to recover the original signals. Digital signal processing (TDM) techniques are used for signal encoding, decoding, and synchronization maintenance. The TDM function is ensured to be compatible with existing signal processing algorithms (such as pulse compression, coherent accumulation, and constant false alarm rate (CFAR) processing) to prevent interference between radars.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not 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; and these modifications or substitutions to the technical solutions of the embodiments of the present invention do not cause the essence of the corresponding technical solutions to deviate from the scope of the present solution.

Claims

1. A device for monitoring three-dimensional displacement structures using group microwave radar, characterized in that, include: Microwave radar A, microwave radar B, and microwave radar C are installed on an adjustable three-radar positioning frame; power supply, controller, router, and cloud server; and a reflective target is installed at the monitoring point. Microwave radar A, microwave radar B, and microwave radar C are connected to the power supply and controller, respectively. The controller is connected to the router, and the router is connected to the cloud server. The microwave radars A, B, and C are used to measure their distance from the reflective target and send the result to the controller. The controller calculates the spatial coordinates of the reflective target based on the distance and sends the result to the router. The reflective target reflects the radar signal. The router transmits the spatial coordinates of the reflective target to the cloud server. The cloud server calculates the deflection angle based on the spatial coordinates of the reflective target. If the deflection angle is greater than a certain threshold, an early warning is issued. The adjustable three-radar positioning frame includes: a radar frame base, an adjustable support rod, an adjustable triangular seat, a support rod, three retractable radar fixing rods, and three diagonal braces. The adjustable support rod is connected to the radar frame base and is used to adjust the vertical height and horizontal rotation angle. The adjustable triangular seat is connected to the adjustable support rod and is used to adjust the vertical rotation angle. The support rod and the three retractable radar fixing rods are respectively connected to the adjustable triangular seat. The angle between the three retractable radar fixing rods is 120° and their lengths are equal. The three retractable radar fixing rods are used to adjust the length of the three equal-length rods. The diagonal braces are fixed between the retractable radar fixing rods and the support rod. The microwave radars A, B, and C are installed within the reflection range of the reflective target, that is, within the extension surface of the reflective target's reflector plate.

2. A method for monitoring three-dimensional displacement structures using group microwave radar, characterized in that, The apparatus according to claim 1 includes: n reflective targets are installed at the monitored point, where n is greater than 2. A group microwave radar device is installed within the reflection range of the n reflective targets. The group microwave radar device includes a controller, an adjustable three-radar positioning frame, microwave radar A, microwave radar B, and microwave radar C. The straight-line distance between microwave radar A and microwave radar B, the straight-line distance between microwave radar B and C, and the straight-line distance between microwave radar A and C are input to the controller; a spatial coordinate system is established, wherein the x-axis of the spatial coordinate system coincides with the line connecting microwave radar A and microwave radar B, the z-axis is perpendicular to the horizontal plane, and microwave radar A is the origin; the spatial coordinates of microwave radar A, microwave radar B, and microwave radar C are obtained based on the spatial coordinate system. Within a certain time slice, three microwave radars run m times to measure the distances between microwave radar A, microwave radar B, and microwave radar C and n reflective targets. The controller obtains the distances between microwave radar A, microwave radar B, and microwave radar C and n reflective targets, and generates n lists containing 3 tuples, each tuple containing m elements. The list is sent to the server via a router. The server takes a representative value from each of the m elements of each tuple in the list to obtain the final list. Two sets of data are randomly selected from the n sets of data in the final list and arranged to obtain multiple sets of dual-reflection target data. One set of data from these multiple sets of dual-reflection target data is selected, where F1 and F2 are the reflecting targets. The distances L between microwave radars A, B, and C and F1 and F2 are denoted as L. AF1 L BF1 L CF1 L AF2 L BF2 L CF2 ; The spatial coordinates of microwave radar A, microwave radar B, and microwave radar C are combined with L. AF1 L BF1 L CF1 L AF2 L BF2 L CF2 Input the spatial coordinate equation to calculate the spatial coordinates of F1 and F2. If F1 or F2 is higher than microwave radar A in the vertical direction, select a positive value; otherwise, select a negative value. Using the spatial coordinates of F1 and F2 obtained from the first calculation as initial values, and the spatial coordinates of F1 and F2 obtained from real-time calculation as real-time values, the deflection angle occurring in the zy and xy planes is calculated based on the initial and real-time values ​​of F1 or F2. Set warning values ​​for the zy and xy directions, and issue a warning when the deflection angle reaches the warning value.

3. The method according to claim 2, characterized in that, Installing a group microwave radar device within the reflection range of n reflecting targets specifically includes: Adjust the adjustable three-radar positioning frame so that the distance between the reflective target furthest from the total distance of all microwave radars is equal to the distance between microwave radars A, B, and C. Install n reflective targets and microwave radars A, B, and C according to the site conditions. The initial arrangement of the triangle formed by the lines connecting microwave radars A, B, and C has a side length L. AB L AC L BC With a distance of not less than 2m, take the position of microwave radar A as the origin of the spatial coordinate system, and measure the spatial coordinates of microwave radar B and microwave radar C. Three microwave radars are activated to obtain the distances from the three microwave radars to the reflective target F and send them to the controller. The reflective target F is the reflective target with the farthest total distance from all microwave radars. The controller calculates the spatial coordinates of the reflective target F based on the spatial coordinates of microwave radar A, microwave radar B and microwave radar C and the distances from the three microwave radars to the reflective target F. The controller uses the spatial coordinates of microwave radar A, microwave radar C, and reflective target F as initial values, modifies the spatial coordinates of microwave radar B to produce an error compared to the initial position of microwave radar B, and inputs the initial values ​​and modified spatial coordinates into the spatial coordinate equation to obtain the distance between reflective target F and microwave radar B. Based on the coordinates of microwave radar A, microwave radar B, and microwave radar C before the error occurred, and the distance between the reflecting target F and microwave radar B after the error occurred, calculate the coordinates of the reflecting target F after the error occurred. Calculate the absolute errors Δx, Δy, and Δz between the coordinates of the reflecting target before and after the error occurs; Adjust the side length L of the triangle formed by the lines connecting microwave radars A, B, and C. AB L AC and L BC Recalculate the spatial coordinates of microwave radar B and microwave radar C; By statistically analyzing the absolute errors Δx, Δy, and Δz of the coordinates of the reflecting target F before and after the error occurs under different side lengths of the triangle, and based on the site conditions, the reflection angle of the reflecting target, and the microwave radar's ability to identify the reflecting target, the maximum allowable distance between the microwave radars on site is determined. Then, based on the maximum allowable distance between the microwave radars on site, the side lengths between the three microwave radars corresponding to the minimum absolute errors Δx, Δy, and Δz are found. The side lengths between the three microwave radars are taken as the optimal installation side lengths of the microwave radars. The horizontal and vertical rotation angles of the adjustable three-radar positioning frame are adjusted to enable the microwave radar to identify the reflecting target.

4. The method according to claim 3, characterized in that, The method also includes: drawing a three-dimensional dynamic graph of the deflection angle.

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