A method and system for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning

Abstract

The present invention belongs to the technical field of disaster monitoring, and discloses a deformation monitoring method for dangerous rock collapse disasters based on ultra-wideband positioning. At least one measurement tag is distributed on the surface of the disaster body, and the monitoring method includes: signal pre-verification: a mobile measurement base station flies to the preset positions of the corresponding measurement tags according to the preset trajectory, and the mobile measurement base station searches for the location of the best signal between it and the measurement tag according to the signal strength threshold near the preset position; positioning and calculation: the mobile measurement base station collects data and calculates displacement changes of the measurement tag at the location of the best signal; the present invention also discloses a deformation detection system for dangerous rock collapse disasters based on ultra-wideband positioning, including a measurement host, a mobile measurement base station and a measurement tag. The present invention can monitor polar disasters in a more complex environment, and can automatically find the best signal and collect and calculate data at the location of the best signal, so that the calculated data is more accurate.

Description

Technical Field

[0001] The present invention belongs to the technical field of disaster monitoring, and in particular relates to a method and system for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning. Background Art

[0002] At present, the monitoring of dangerous rock collapse bodies is still the weakest link in the monitoring of typical geological disasters such as collapse, landslide, and mud-rock flow; for safety reasons, the early manual inspection method has been discontinued; the widely used monitoring methods include GPS monitoring, geodetic measurement, photography, three-dimensional laser scanning, and related factor monitoring methods; the cost of using GPS monitoring is too high; and the geodetic measurement, photography, and three-dimensional laser scanning methods have high requirements for manual labor, and it is difficult to achieve automated measurement; the related factor monitoring method is difficult to summarize and accurately draw the corresponding relationship between the related factors and the deformation of the disaster body because the actual conditions of each disaster site vary greatly.

[0003] The development of ultra-wideband (UWB) technology provides an alternative to GPS for high-precision regional location measurement. However, UWB technology is currently mainly used for indoor positioning, and there are few technical cases of using UWB technology for outdoor positioning. It usually includes multiple micro base stations and multiple location tags; the location tags are distributed and deployed in potential dangerous rock areas, and receive instructions to transmit UWB positioning pulse signals. The location tags and micro base stations transmit information wirelessly. However, this method has the following defects:

[0004] First, the measurement accuracy of the sensor network composed of multiple micro base stations and location tags depends on the measurement of time, so the time between the base station and the tag is required to be completely synchronized. However, in actual measurements, it is difficult to achieve time synchronization between the base station and the tag. Each node (target / base station) has its own reference clock, which is generally provided by a crystal oscillator. Due to the influence of factors such as temperature and process, the crystal oscillator has frequency deviation and drift, and the phase-locked loop in the chip also has errors when multiplying the clock. These errors will cause errors in the final system clock. As time goes by, when the time asynchrony between the base station and the tag gradually increases, according to the actual measurement results, the measurement results will produce large errors.

[0005] Secondly, the outdoor environment is complex, and base stations are not suitable for building on dangerous rocks, which poses a major safety hazard. In addition, due to the presence of obstructions in the wild, the signal from the transmitter to the receiver is attenuated, resulting in the receiver not being able to receive the wireless pulse signal that arrives in a straight line. Summary of the invention

[0006] The present invention aims to provide a method and system for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning, which uses a mobile measurement base station to find the location of the excellent signal of the measurement tag to achieve accurate collection and measurement of the displacement change data of the measurement tag.

[0007] The technical solution adopted by the present invention is:

[0008] A method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning, wherein at least one measurement tag is distributed on the surface of the disaster body, and the monitoring method comprises:

[0009] Signal pre-verification: The mobile measurement base station flies to the preset positions of the corresponding measurement tags according to the preset trajectory. The mobile measurement base station searches for the position with the best signal between it and the measurement tag based on the signal strength threshold near the preset position.

[0010] Positioning and calculation: The mobile measurement base station collects data and calculates displacement changes of the measurement tag at the location of the best signal.

[0011] In the preferred technical solution, in the signal pre-verification, the specific steps of finding the location of the optimal signal according to the signal strength threshold are:

[0012] S1: The mobile measurement base station is preset with a signal strength threshold. When the signal strength received by the measurement tag is lower than the threshold, the signal is poor, and the mobile measurement base station automatically starts to optimize near the preset position;

[0013] If the signal strength received by the mobile measurement base station from the measurement tag is greater than or equal to the threshold, it is an excellent signal, and the mobile measurement base station keeps hovering and performs the positioning measurement; if the signal strength is less than the threshold, it goes to step S2;

[0014] S2: A spherical mathematical model is established with the preset position as the sphere center and the distance between the preset position and the measurement tag as the radius, and the mobile measurement base station uses the surface of the spherical mathematical model as a search surface to search for the location of the signal greater than or equal to the threshold.

[0015] In the preferred technical solution, the specific method of moving the mobile measurement base station when searching for the optimal signal along the spherical data model in step S2 is:

[0016] S2a: The four directions of the mobile measurement base station are used as the initial movement directions. When the mobile measurement base station is at a preset position with poor signal, it starts to move in the four directions of southeast, northwest, and northeast. The step length of each movement along the spherical mathematical model is X, 0<X≤1 meter;

[0017] S2b: When moving toward the mobile measurement base station in the four directions of southeast, northwest, and northeast, the detection signals Peast, Pwest, Psouth, and Pnorth are recorded respectively, and the signal strengths in the four directions are compared, where (Peast, Pwest) is the first group, and (Psouth, Pnorth) is the second group. A larger signal value is taken from each of the two groups to form a third group (Peast / Pwest, Psouth / Pnorth), and the maximum signal strength in the third group is taken, recorded as Pmax, and then the two signal strength values ​​in the third group are divided by the maximum signal strength Pmax to obtain the weights of the two directions, and the weighted vector is synthesized as the optimal direction D1 of the mobile measurement base station;

[0018] S2c: After the mobile measurement base station moves X steps in the direction of D1, it continues to search for signal strength in the four directions of southeast, northwest and northeast at the new position with X steps, repeats step S2b, and obtains a new optimal direction D2;

[0019] S2d: After obtaining a new optimization direction, repeat steps S2b and S2c until the mobile measurement base station moves to a final position greater than or equal to the signal strength threshold, stop signal pre-verification, and perform positioning calculation.

[0020] In the preferred technical solution, the specific method of positioning and calculating is:

[0021] Monitor whether the signals of the mobile measurement base station and the measurement tag are time synchronized. When the monitoring result is synchronization, calculate the distance between the two based on the signal received by the mobile measurement base station from the measurement tag;

[0022] When the monitoring results are not synchronized, the mobile measurement base station selects one of the mobile measurement base stations as the reference base station, and synchronizes the other mobile measurement base stations with the time of the reference base station as a reference, obtains the time difference between the signal emitted by the measurement tag and reaching different mobile measurement base stations, calculates the distance between the measurement tag and different mobile measurement base stations based on the time difference, obtains the three-dimensional coordinates of the measurement tag through calculation, and then calculates the displacement data of the measurement tag based on the obtained three-dimensional coordinates.

[0023] In the preferred technical solution, the specific method for calculating the three-dimensional coordinates of the measurement tag is:

[0024] Sa: Select any three mobile measurement base stations, namely mobile measurement base station AP1, mobile measurement base station AP2, and mobile measurement base station AP3, and calculate the distance between the mobile measurement base station AP1, mobile measurement base station AP2, and mobile measurement base station AP3 and the measurement tag P1 to be measured respectively through formula (1), and then calculate the distance data obtained

[0025] (1);

[0026] In formula (1), c is the signal propagation speed, It is obtained by measuring the time it takes for the signal to reach each measurement base station, where is the time difference between the signal arriving at the mobile measurement base station AP2 and arriving at the mobile measurement base station AP1, is the time difference between the signal arriving at the mobile measurement base station AP3 and arriving at the mobile measurement base station AP1, is the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d 21 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d 31 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, d 23 The distance is calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3;

[0027] Sb: distance obtained according to formula (1) , calculate the three-dimensional coordinates of the measurement tag P1 to be measured.

[0028] In the preferred technical solution, the specific method for calculating the three-dimensional coordinates of the measurement tag P1 to be measured in step Sb is:

[0029] Set the three-dimensional coordinates of the selected three mobile measurement base stations as , , , the three-dimensional measurement label to be measured is set as ,Then the three-dimensional coordinates of the measurement tag to be measured are calculated by formula (2);

[0030] (2)

[0031] In a preferred technical solution, before the signal pre-verification, the monitoring method further includes:

[0032] Synchronous time correction: perform time correction on each mobile measurement base station.

[0033] In a preferred technical solution, the mobile measurement base station and the measurement tag are connected via an ultra-wideband pulse signal.

[0034] The present invention also provides a dangerous rock collapse disaster deformation detection system based on ultra-wideband positioning, including a measurement host, a mobile measurement base station and a measurement tag; wherein,

[0035] The measurement tags are provided in plurality and distributed on the surface of the disaster body; the measurement tags are communicatively connected with the mobile measurement base station and serve as monitoring targets of the mobile measurement base station;

[0036] There are multiple mobile measurement base stations, each corresponding to a measurement tag; the mobile measurement base station is connected to the measurement host for communication, and is used to find the location of the best signal between the mobile measurement base station and the measurement tag under the remote control of the measurement host, and collect relevant parameters of the measurement tag at the location of the best signal;

[0037] The measurement host is respectively connected to the mobile measurement base stations in communication; the measurement host is used to remotely control each mobile measurement base station and calculate the displacement change data of the measurement tag according to the relevant parameters obtained from the mobile measurement base station.

[0038] In a preferred technical solution, the measurement host includes:

[0039] Mathematical model and solution module, used to establish mathematical model and data calculation for finding optimal signals;

[0040] A flight control module, used for controlling the movement of each mobile measurement base station, wherein a plurality of mobile measurement base station position arrays are preset, and each mobile measurement base station position array includes a flight track of each mobile measurement base station in the array;

[0041] The pre-verification module is used to find the location of the optimal signal according to the signal strength threshold and mathematical model, and send a search and movement instruction to the flight control module;

[0042] The data collection and transmission module is used to receive the data information collected by the mobile measurement base station and send a command signal to the mobile measurement base station;

[0043] The first main control module is connected to the mathematical model and solution module, the flight control module, the pre-verification module and the data acquisition and transmission module respectively, and is used to receive and process data information from each module connected thereto and send relevant execution instructions to each module; the mobile measurement base station includes:

[0044] The flight driving module is used to drive the mobile measurement base station to fly and receive flight instructions from the flight control module;

[0045] An information transmission module is used to send relevant data information and transmit relevant instructions to the measurement host and measurement tags;

[0046] A second main control module, which is connected to the flight drive module and the information transmission module respectively, and is used to receive and process data information from each module connected thereto and send relevant execution instructions to each module;

[0047] The measurement tag comprises a first signal transceiver module, and the first signal transceiver module is used to send a signal to a mobile measurement base station.

[0048] In a preferred technical solution, the measurement host further includes:

[0049] A first time synchronization module, which is connected to the first main control module and is used to synchronize the time of the mobile measurement base station;

[0050] A positioning module, which is connected to the first main control module and is used to obtain the location information of each mobile measurement base station; the mobile measurement base station also includes:

[0051] A synchronization monitoring control module is connected to the second main control module and is used to monitor whether the measurement tag is synchronized with the mobile measurement base station, and collect the distance data between the mobile measurement base station and the measurement tag and the time difference parameter data of the signal received between the mobile measurement base station and the measurement tag according to the time synchronization situation. The second main control module processes the distance data and the time parameter data and sends the two data to the measurement host through the information transmission module;

[0052] A second time synchronization module, which is connected to the second main control module and is used to correct the time of the mobile measurement base station according to the timing of the first time synchronization module;

[0053] A navigation and positioning module, which is connected to the second main control module and is used for navigation and positioning;

[0054] The second signal transceiver module is connected to the second main control module and is used to send and receive relevant signals from the measurement tag and the measurement host respectively; the measurement tag also includes:

[0055] The GPS time synchronization module is connected to the first signal transceiver module and is used to send time information and positioning information to the mobile measurement base station.

[0056] In a preferred technical solution, the signals received and transmitted by the first signal transceiver module and the second signal transceiver module are ultra-wideband pulse signals.

[0057] The beneficial effects of the present invention are:

[0058] (1) The present invention pre-checks the signal received by the mobile measurement base station. The mobile measurement base station can move to the location of the best signal to collect and measure data according to the signal strength of the received measurement tag, thereby solving the technical problem that the signal from the transmitting end to the receiving end is attenuated by obstructions, resulting in the receiving end not receiving the wireless pulse signal that arrives in a straight line. The data parameters collected and measured are more accurate and have higher precision.

[0059] (2) The present invention calculates the distance and three-dimensional coordinates between the mobile measurement base station and the measurement tag according to the time synchronization between the two and combines the time difference positioning method, thereby greatly reducing the error of time synchronization, thereby making the displacement change data of the measurement tag more accurate and better for disaster situation analysis.

[0060] (3) The present invention realizes the installation of a base station by equipping a UWB chip on a drone group with a pre-stored array of multiple drones, thereby combining the drone and the base station. This solves the technical problems of complex outdoor environments, base stations being difficult to build on dangerous rocks, and major safety hazards. In addition, communication is carried out through ultra-wideband pulse signals, which makes the measurement accuracy higher.

[0061] (4) The detection system provided by the present invention is very suitable for monitoring dangerous rock collapse. Compared with the existing detection systems, it has the characteristics of low cost, high measurement accuracy and high degree of automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is an overall schematic diagram of the present invention;

[0063] Figure 2 It is a schematic diagram of the optimization principle of the mobile measurement base station of the present invention;

[0064] Figure 3 It is a module principle diagram of the monitoring system of the present invention. DETAILED DESCRIPTION

[0065] The following is combined with Figure 1-3 The present invention is further explained with reference to the following specific embodiments.

[0066] A method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning, wherein at least one measurement tag is distributed on the surface of the disaster body, and the monitoring method comprises:

[0067] Signal pre-verification: The mobile measurement base station flies to the preset positions of the corresponding measurement tags according to the preset trajectory. The mobile measurement base station searches for the position with the best signal between it and the measurement tag based on the signal strength threshold near the preset position.

[0068] Among them, there are multiple measurement tags and mobile measurement base stations and they correspond to each other; the mobile measurement base station includes a base station and a drone, and the drone carries the base station to form a mobile measurement base station; the mobile measurement base station flies to a preset position according to a preset flight trajectory, and the preset position corresponds to the initial position of the measurement tag; due to the presence of obstructions in the wild, the obstructions attenuate the signal from the transmitter to the receiver, resulting in the receiver not receiving the wireless pulse signal that arrives in a straight line, so the signal is pre-checked before positioning and calculating at the mobile measurement base station to avoid positioning and calculating at a location with poor signal, making it more accurate; specifically, the signal strength threshold is pre-set, and the signal strength threshold is used for judgment during the search, and when a signal strength greater than or equal to the signal strength threshold is found, it is the location of the excellent signal.

[0069] Positioning and calculation: The mobile measurement base station collects data and calculates displacement changes of the measurement tag at the location of the best signal.

[0070] The data information collected by the mobile measurement base station from the measurement tag at the location of the best signal includes time information and positioning information, and the displacement change data of the measurement tag is calculated based on this information.

[0071] In a preferred embodiment, in the signal pre-verification, the specific steps of finding the location of the best signal according to the signal strength threshold are:

[0072] S1: The mobile measurement base station is preset with a signal strength threshold. When the signal strength received by the measurement tag is lower than the threshold, the signal is poor, and the mobile measurement base station automatically starts to optimize near the preset position;

[0073] If the signal strength received by the mobile measurement base station from the measurement tag is greater than or equal to the threshold, it is an excellent signal, and the mobile measurement base station keeps hovering and performs the positioning measurement; if the signal strength is less than the threshold, it goes to step S2;

[0074] S2: A spherical mathematical model is established with the preset position as the sphere center and the distance between the preset position and the measurement tag as the radius, and the mobile measurement base station uses the surface of the spherical mathematical model as a search surface to search for the location of the signal greater than or equal to the threshold.

[0075] Among them, Figure 2 As shown, by establishing the spherical mathematical model with the preset position as the center and the distance between the preset position and the measurement tag as the radius, the mobile measurement base station can have a wider search range when looking for the location of the optimal signal, and will not deviate from the actual position of the measurement tag during the search, so that the location of the optimal signal can be found to the greatest extent.

[0076] In a preferred embodiment, the specific method of moving the mobile measurement base station when searching for the optimal signal along the spherical data model in step S2 is:

[0077] S2a: The four directions of the mobile measurement base station are used as the initial movement directions. When the mobile measurement base station is at a preset position with poor signal, it starts to move in the four directions of southeast, northwest, and northeast. The step length of each movement along the spherical mathematical model is X, 0<X≤1 meter;

[0078] S2b: When moving toward the mobile measurement base station in the four directions of southeast, northwest, and northeast, the detection signals Peast, Pwest, Psouth, and Pnorth are recorded respectively, and the signal strengths in the four directions are compared, where (Peast, Pwest) is the first group, and (Psouth, Pnorth) is the second group. A larger signal value is taken from each of the two groups to form a third group (Peast / Pwest, Psouth / Pnorth), and the maximum signal strength in the third group is taken, recorded as Pmax, and then the two signal strength values ​​in the third group are divided by the maximum signal strength Pmax to obtain the weights of the two directions, and the weighted vector is synthesized as the optimal direction D1 of the mobile measurement base station;

[0079] S2c: After the mobile measurement base station moves X steps in the direction of D1, it continues to search for signal strength in the four directions of southeast, northwest and northeast at the new position with X steps, repeats step S2b, and obtains a new optimal direction D2;

[0080] S2d: After obtaining a new optimization direction, repeat steps S2b and S2c until the mobile measurement base station moves to a final position greater than or equal to the signal strength threshold, stop signal pre-verification, and perform positioning calculation.

[0081] The mobile measurement base station searches from the east, west, south, and north directions at a preset position and searches for the location of the best signal according to the above method, which can search for the location of the best signal more efficiently and accurately, greatly improving the measurement efficiency and measurement accuracy. Specifically, the X step length is preferably 0.1 meters.

[0082] In a preferred embodiment, the specific method of positioning and calculating is:

[0083] Monitor whether the signals of the mobile measurement base station and the measurement tag are time synchronized. When the monitoring result is synchronization, calculate the distance between the two based on the signal received by the mobile measurement base station from the measurement tag;

[0084] When the monitoring results are not synchronized, the mobile measurement base station selects one of the mobile measurement base stations as the reference base station, and synchronizes the other mobile measurement base stations with the time of the reference base station as a reference, obtains the time difference between the signal emitted by the measurement tag and reaching different mobile measurement base stations, calculates the distance between the measurement tag and different mobile measurement base stations based on the time difference, obtains the three-dimensional coordinates of the measurement tag through calculation, and then calculates the displacement data of the measurement tag based on the obtained three-dimensional coordinates.

[0085] Among them, when the mobile measurement base station enters the tag positioning and measurement step, although each measurement tag has its time corrected, due to the geographical location and environmental limitations of the dangerous rock, when the GPS signal is weak, the time correction cannot be completed and the accuracy of the measurement tag time cannot be guaranteed, so there is a time asynchrony. Therefore, when the monitoring results are not synchronized, the displacement data of the measurement tag can be calculated by calculating the displacement data through the time difference.

[0086] In a preferred embodiment, the specific method for calculating the three-dimensional coordinates of the measurement tag is:

[0087] Sa: Select any three mobile measurement base stations, namely mobile measurement base station AP1, mobile measurement base station AP2, and mobile measurement base station AP3, and calculate the distance between the mobile measurement base station AP1, mobile measurement base station AP2, and mobile measurement base station AP3 and the measurement tag P1 to be measured respectively through formula (1), and then calculate the distance data obtained

[0088] (1);

[0089] In formula (1), c is the signal propagation speed, It is obtained by measuring the time it takes for the signal to reach each measurement base station, where is the time difference between the signal arriving at the mobile measurement base station AP2 and arriving at the mobile measurement base station AP1, is the time difference between the signal arriving at the mobile measurement base station AP3 and arriving at the mobile measurement base station AP1, is the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d 21 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d 31 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, d 23 The distance is calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3;

[0090] Sb: distance obtained according to formula (1) , calculate the three-dimensional coordinates of the measurement tag P1 to be measured.

[0091] In a preferred embodiment, the specific method for calculating the three-dimensional coordinates of the measurement tag P1 to be measured in step Sb is:

[0092] Set the three-dimensional coordinates of the selected three mobile measurement base stations as , , , the three-dimensional measurement label to be measured is set as ,Then the three-dimensional coordinates of the measurement tag to be measured are calculated by formula (2);

[0093] (2)

[0094] In a preferred embodiment, before the signal pre-verification, the monitoring method further includes:

[0095] Synchronous time correction: perform time correction on each mobile measurement base station.

[0096] Among them, since each node (target / base station) has its own reference clock, the clock source is generally provided by a crystal oscillator. Due to the influence of factors such as temperature and process, the crystal oscillator has frequency deviation and drift, and the phase-locked loop in the second UWB chip also has errors when multiplying the clock. These errors will cause errors in the final system clock. As time increases, the final time error becomes larger and larger; these factors will eventually affect the accuracy of capturing the sending and receiving timestamps of radio messages, and frequency drift will cause the center frequency of the ultra-wideband wireless pulse wave to shift. Therefore, by performing time correction before signal pre-verification, the error of time synchronization can be greatly reduced, and the time difference calculation method in the positioning measurement step can make the measured data more accurate. Specifically, the time correction performed by the measurement host on each mobile measurement base station, the mobile measurement base station and the measurement tag can be based on the time of the measurement host, so that the measurement data is more accurate.

[0097] In a preferred embodiment, the mobile measurement base station and the measurement tag are connected via an ultra-wideband pulse signal.

[0098] The present invention also provides a dangerous rock collapse disaster deformation detection system based on ultra-wideband positioning, such as Figure 1 and Figure 3 As shown, it includes a measurement host, a mobile measurement base station and a measurement tag; wherein,

[0099] The measurement tags are provided in plurality and distributed on the surface of the disaster body; the measurement tags are communicatively connected with the mobile measurement base station and serve as monitoring targets of the mobile measurement base station;

[0100] There are multiple measurement tags, each corresponding to a mobile measurement base station; specifically, the measurement tag sends a pulse signal to the outside world, and the mobile measurement base station flies to a preset position corresponding to the measurement tag according to a preset trajectory, receives the pulse signal at the preset position and sends a related command signal to collect and calculate the displacement change data.

[0101] There are multiple mobile measurement base stations, each corresponding to a measurement tag; the mobile measurement base station is connected to the measurement host for communication, and is used to find the location of the best signal between the mobile measurement base station and the measurement tag under the remote control of the measurement host, and collect relevant parameters of the measurement tag at the location of the best signal;

[0102] Among them, the mobile measurement base station can be composed of a base station and a drone. The mobile measurement base station can be composed of a drone carrying a base station, or it can be a mobile device with both functions; the mobile measurement base station is remotely controlled by the measurement host and flies to a preset position according to a preset flight array; the above-mentioned related parameters include time synchronization information and distance information between the mobile measurement base station and the measurement tag.

[0103] The measurement host is respectively connected to the mobile measurement base stations in communication; the measurement host is used to remotely control each mobile measurement base station and calculate the displacement change data of the measurement tag according to the relevant parameters obtained from the mobile measurement base station.

[0104] In a preferred embodiment, the measurement host includes: a mathematical model and solution module, which is used to establish a mathematical model and data calculation for finding an optimal signal; a flight control module, which is used to control the movement of each mobile measurement base station, wherein a plurality of groups of mobile measurement base station position arrays are preset, and each group of mobile measurement base station position arrays includes the flight trajectory of each mobile measurement base station in the array; a pre-verification module, which is used to find the location of the optimal signal according to the signal strength threshold and the mathematical model, and send a search movement instruction to the flight control module; a data acquisition and transmission module, which is used to receive data information collected by the mobile measurement base station, and send a command signal to the mobile measurement base station; a first main control module, which is respectively connected to the mathematical model and solution module, the flight control module, the pre-verification module and the data acquisition and transmission module, and is used to receive and process data information from each module connected thereto and send relevant execution instructions to each module;

[0105] The mobile measurement base station includes: a flight driving module, which is used to drive the mobile measurement base station to fly and receive flight instructions from the flight control module; an information transmission module, which is used to send relevant data information and transmit relevant instructions to the measurement host and the measurement tag; a second main control module, which is connected to the flight driving module and the information transmission module respectively, and is used to receive and process data information from each module connected thereto and send relevant execution instructions to each module;

[0106] The measurement tag comprises a first signal transceiver module, and the first signal transceiver module is used to send a signal to a mobile measurement base station.

[0107] In this embodiment, at the beginning of monitoring, the flight control module of the measurement host controls the flight of the mobile measurement base station, and the mobile measurement base station flies to the preset position corresponding to the corresponding measurement tag according to the preset trajectory through the flight drive module, and then the mobile measurement base station receives the signal sent from the measurement tag, and processes and judges the received signal information through the second main control module to determine whether the signal is an excellent signal greater than or equal to the preset signal strength threshold; when the judgment result is an excellent signal, the second main control module sends a hovering instruction to the flight drive module, and at the same time sends the status information of the mobile measurement base to the measurement host through the information transmission module, the measurement host receives the status information through the data acquisition and transmission module, and the first main control module controls the mobile measurement base station to perform positioning and measurement; when the judgment result is that the signal is poor, the second control module transmits the information to the flight drive module to determine whether the signal is an excellent signal. The module sends the result to the measurement host, which receives and transmits it to the first main control module through the data acquisition and transmission module. The first main control module executes the signal optimization step. The mathematical model and solution engine module establishes a spherical mathematical model with the preset position as the center and the distance between the preset position and the measurement tag as the radius according to the positioning information of the measurement tag obtained from the mobile measurement base station. The first main control module sends a movement instruction to the flight control module. After receiving the instruction, the flight control module controls the mobile measurement base station to search for the optimal signal along the spherical mathematical model. At the same time, the mobile measurement base station feeds back the received signal strength information to the measurement host; the pre-verification module performs group comparison and analysis according to the signal strength values ​​of multiple groups of different directions obtained in the process of searching for the optimal signal, and obtains a new search direction. The mobile measurement base station is controlled by the flight control module to perform the following steps:

[0108] S2a: The four directions of the mobile measurement base station are used as the initial movement directions. When the mobile measurement base station is at a preset position with poor signal, it starts to move in the four directions of southeast, northwest, and northeast. The step length of each movement along the spherical mathematical model is X, 0<X≤1 meter;

[0109] S2b: When moving toward the mobile measurement base station in the four directions of southeast, northwest, and northeast, the detection signals Peast, Pwest, Psouth, and Pnorth are recorded respectively, and the signal strengths in the four directions are compared, where (Peast, Pwest) is the first group, and (Psouth, Pnorth) is the second group. A larger signal value is taken from each of the two groups to form a third group (Peast / Pwest, Psouth / Pnorth), and the maximum signal strength in the third group is taken, recorded as Pmax, and then the two signal strength values ​​in the third group are divided by the maximum signal strength Pmax to obtain the weights of the two directions, and the weighted vector is synthesized as the optimal direction D1 of the mobile measurement base station;

[0110] S2c: After the mobile measurement base station moves X steps in the direction of D1, it continues to search for signal strength in the four directions of southeast, northwest and northeast at the new position with X steps, repeats step S2b, and obtains a new optimal direction D2;

[0111] S2d: After obtaining a new optimization direction, repeat steps S2b and S2c until the mobile measurement base station moves to a final position greater than or equal to the signal strength threshold, stop signal pre-verification, and perform positioning calculation.

[0112] The radio message signal reaching the obstacle is affected in two ways. Part of the signal energy is reflected back from the obstacle, while the rest enters the obstacle. Of the signal that enters the obstacle, part is absorbed into the material (causing the material to heat up), the rest of the signal may be further reflected from the far edge of the obstacle, and the rest will come out of the obstacle to block the other side. The above solution can effectively solve this problem.

[0113] At the same time, the power amplifier at the front end of the RF transmitting part of the UWB chip can be adjusted to increase the transmission power of the signal, thereby increasing the signal's ability to penetrate walls. At the same time, the LNA of the RF receiving part of the second UWB chip on the drone can also be used to amplify the received signal strength and improve the receiving sensitivity.

[0114] In a preferred embodiment, the measurement host further includes: a first time synchronization module, which is connected to the first main control module and is used to synchronize the time of the mobile measurement base station; a positioning module, which is connected to the first main control module and is used to obtain the location information of each mobile measurement base station;

[0115] The mobile measurement base station also includes: a synchronization monitoring control module, which is connected to the second main control module and is used to monitor whether the measurement tag is synchronized with the mobile measurement base station, and collect the distance data between the mobile measurement base station and the measurement tag and the time difference parameter data of the signal received between the mobile measurement base station and the measurement tag according to the time synchronization situation, and the second main control module processes the distance data and the time parameter data and sends the two data to the measurement host through the information transmission module; a second time synchronization module, which is connected to the second main control module and is used to correct the time of the mobile measurement base station according to the timing of the first time synchronization module; a navigation and positioning module, which is connected to the second main control module and is used for navigation and positioning, that is, a GNSS module; a second signal transceiver module, which is connected to the second main control module and is used to send and receive relevant signals from the measurement tag and the measurement host respectively;

[0116] The measurement tag further includes: a GPS time synchronization module, which is connected to the first signal transceiver module and is used to send time information and positioning information to the mobile measurement base station.

[0117] Before the mobile measurement base station performs signal pre-verification, the atomic clock module inside the first time synchronization module of the measurement host synchronizes the time of the second time synchronization module of one of the mobile measurement base stations, and the second time synchronization module calibrates the crystal oscillator of the second signal transceiver module of the mobile measurement base station. At the same time, after the mobile measurement base station gives feedback to the measurement host each time, the measurement host queries the power of the mobile measurement base station and synchronizes the time of the drone. In this way, the problem that the accuracy of capturing the sending and receiving timestamps of radio messages is affected due to time difference, and the frequency drift causes the center frequency of the ultra-wideband wireless pulse wave to shift.

[0118] After the mobile measurement base station finds a good signal position, the second main control module sends an execution instruction to the synchronous monitoring control module. The synchronous monitoring control module monitors whether the signal between the measurement tag and the mobile measurement base station is synchronized. When the monitoring result is synchronized, the synchronous monitoring control module calculates the distance between the measurement tag and the mobile measurement base station based on the signal transmitted from the measurement tag to the mobile measurement base station, obtains the distance data, and then obtains the location information of the measurement tag; when the monitoring result is not synchronized, the synchronous monitoring control module uses the mobile measurement base station as a reference base station, and synchronizes the time of other mobile measurement base stations with the reference base station as a benchmark, and obtains the time difference of the measurement tag signal reaching different mobile measurement base stations, thereby obtaining the time difference data; the synchronous monitoring control module sends the obtained time difference information data and distance data to the measurement host through the information transmission module, and the mathematical model and solution module of the measurement host calculate the time difference data and distance data according to the following formula to obtain the three-dimensional coordinates and displacement data of the measurement tag.

[0119] Sa: Calculate the distances between the mobile measurement base station AP1, the mobile measurement base station AP2, the mobile measurement base station AP3 and the measurement tag P1 to be measured respectively by formula (1);

[0120] (1);

[0121] In formula (1), c is the signal propagation speed, It is obtained by measuring the time it takes for the signal to reach each measurement base station, where is the time difference between the signal arriving at the mobile measurement base station AP2 and arriving at the mobile measurement base station AP1, is the time difference between the signal arriving at the mobile measurement base station AP3 and arriving at the mobile measurement base station AP1, is the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d 21 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d 31 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, d 23 The distance is calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3;

[0122] Sb: distance obtained according to formula (1) , calculate the three-dimensional coordinates of the measurement tag P1 to be measured. Set the three-dimensional coordinates of the selected three mobile measurement base stations as , , , the three-dimensional measurement label to be measured is set as ,Then the three-dimensional coordinates of the measurement tag to be measured are calculated by formula (2), and the displacement data of the tag is measured.

[0123] (2)

[0124] In a preferred embodiment, the signals received and transmitted by the first signal transceiver module and the second signal transceiver module are ultra-wideband pulse signals, wherein the first signal transceiver module and the second signal transceiver module are respectively the first UWB chip and the second UWB chip, and when time synchronization is performed, the crystal oscillator of the chip is also synchronized.

[0125] In this monitoring system, the measurement host also includes a system configuration function module, a data evaluation module, and a data display and analysis module respectively connected to the first main control module; the data evaluation module is used to evaluate the displacement change data of each measurement tag; the system configuration module is used to set relevant system parameters; the data display and analysis module is used to analyze and display the displacement change data after evaluation, which includes a PC terminal and a mobile terminal. The measurement host and the mobile measurement base station are also connected through an ultra-wideband pulse signal.

[0126] The present invention is not limited to the above optional implementations, and anyone can derive other various forms of products under the enlightenment of the present invention. The above specific implementations should not be understood as limiting the scope of protection of the present invention. The scope of protection of the present invention should be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning, wherein at least one measurement tag is distributed on the surface of the disaster body, and the method is characterized by: The monitoring method comprises: Signal pre-verification: The mobile measurement base station flies to the preset positions of the corresponding measurement tags according to the preset trajectory. The mobile measurement base station searches for the position with the best signal between it and the measurement tag based on the signal strength threshold near the preset position. Positioning and calculation: The mobile measurement base station collects data and calculates displacement changes of the measurement tag at the location of the best signal; In signal pre-verification, the specific steps for finding the location of the best signal based on the signal strength threshold are: S1: The mobile measurement base station is preset with a signal strength threshold. When the signal strength received by the measurement tag is lower than the threshold, the signal is poor, and the mobile measurement base station automatically starts to optimize near the preset position; If the signal strength received by the mobile measurement base station from the measurement tag is greater than or equal to the threshold, it is an excellent signal, and the mobile measurement base station keeps hovering and performs the positioning measurement; if the signal strength is less than the threshold, it goes to step S2; S2: establishing a spherical mathematical model with the preset position as the sphere center and the distance between the preset position and the measurement tag as the radius, and the mobile measurement base station searches for the position of the signal greater than or equal to the threshold value using the surface of the spherical mathematical model as the search surface; The specific method of moving the mobile measurement base station when searching for the optimal signal along the spherical data model in step S2 is: S2a: The four directions of the mobile measurement base station are used as the initial movement directions. When the mobile measurement base station is at a preset position with poor signal, it starts to move in the four directions of southeast, northwest, and northeast. The step length of each movement along the spherical mathematical model is X, 0<X≤1 meter; S2b: When moving toward the mobile measurement base station in the four directions of southeast, northwest, and northeast, the detection signals Peast, Pwest, Psouth, and Pnorth are recorded respectively, and the signal strengths in the four directions are compared, where Peast and Pwest are the first group, and Psouth and Pnorth are the second group. A signal with a larger value is taken from each of the two groups to form a third group, and the maximum signal strength in the third group is taken, recorded as Pmax, and then the two signal strength values ​​in the third group are divided by the maximum signal strength Pmax to obtain the weights of the two directions, and the weighted vector is synthesized as the optimal direction D1 for the mobile measurement base station; S2c: After the mobile measurement base station moves X steps in the direction of D1, it continues to search for signal strength in the four directions of southeast, northwest and northeast at the new position with X steps, repeats step S2b, and obtains a new optimal direction D2; S2d: After obtaining a new optimization direction, repeat steps S2b and S2c until the mobile measurement base station moves to a final position greater than or equal to the signal strength threshold, stop signal pre-verification, and perform positioning calculation.

2. The method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning according to claim 1 is characterized by: The specific method of positioning calculation is: Monitor whether the signals of the mobile measurement base station and the measurement tag are time synchronized. When the monitoring result is synchronization, calculate the distance between the two based on the signal received by the mobile measurement base station from the measurement tag; When the monitoring results are not synchronized, the mobile measurement base station selects one of the mobile measurement base stations as the reference base station, and synchronizes the other mobile measurement base stations with the time of the reference base station as a reference, obtains the time difference between the signal emitted by the measurement tag and reaching different mobile measurement base stations, calculates the distance between the measurement tag and different mobile measurement base stations based on the time difference, obtains the three-dimensional coordinates of the measurement tag through calculation, and then calculates the displacement data of the measurement tag based on the obtained three-dimensional coordinates.

3. The method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning according to claim 2 is characterized by: The specific method for calculating the three-dimensional coordinates of the measurement tag is: Sa: Select any three mobile measurement base stations, namely mobile measurement base station AP1, mobile measurement base station AP2, and mobile measurement base station AP3, and calculate the distances between the mobile measurement base station AP1, the mobile measurement base station AP2, and the mobile measurement base station AP3 and the measurement tag P1 to be measured respectively by formula (1); (1)； In formula (1), c is the signal propagation speed, It is obtained by measuring the time it takes for the signal to reach each measurement base station, where is the time difference between the signal arriving at the mobile measurement base station AP2 and arriving at the mobile measurement base station AP1, is the time difference between the signal arriving at the mobile measurement base station AP3 and arriving at the mobile measurement base station AP1, is the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d 21 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d 31 The distance calculated based on the time difference between the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, d 23 The distance is calculated based on the time difference between the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3; Sb: distance obtained according to formula (1) , calculate the three-dimensional coordinates of the measurement tag P1 to be measured.

4. The method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning according to claim 3 is characterized by: The specific method for calculating the three-dimensional coordinates of the measurement tag P1 to be measured in step Sb is: Set the three-dimensional coordinates of the selected three mobile measurement base stations as , , , the three-dimensional measurement label to be measured is set as ,Then the three-dimensional coordinates of the measurement tag to be measured are calculated by formula (2); （2）。 5. The method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning according to claim 1, characterized in that: Before the signal pre-verification, the monitoring method further includes: Synchronous time correction: perform time correction on each mobile measurement base station.

6. The method for monitoring deformation of dangerous rock collapse disasters based on ultra-wideband positioning according to claim 1, characterized in that: The mobile measurement base station is connected to the measurement tag via an ultra-wideband pulse signal.

7. A dangerous rock collapse disaster deformation detection system based on ultra-wideband positioning, characterized by: It includes a measurement host, a mobile measurement base station and a measurement tag; wherein, The measurement tags are provided in plurality and distributed on the surface of the disaster body; the measurement tags are communicatively connected with the mobile measurement base station and serve as monitoring targets of the mobile measurement base station; There are multiple mobile measurement base stations, each corresponding to a measurement tag; the mobile measurement base station is connected to the measurement host for communication, and is used to find the location of the best signal between the mobile measurement base station and the measurement tag under the remote control of the measurement host, and collect relevant parameters of the measurement tag at the location of the best signal; The measuring host is respectively connected to the mobile measuring base stations in communication; the measuring host is used to remotely control each mobile measuring base station and calculate the displacement change data of the measuring tag according to the relevant parameters obtained from the mobile measuring base station; The measurement host comprises: Mathematical model and solution module, used to establish mathematical model and data calculation for finding optimal signals; A flight control module, used for controlling the movement of each mobile measurement base station, wherein a plurality of mobile measurement base station position arrays are preset, and each mobile measurement base station position array includes a flight track of each mobile measurement base station in the array; The pre-verification module is used to find the location of the optimal signal according to the signal strength threshold and mathematical model, and send a search and movement instruction to the flight control module; The data collection and transmission module is used to receive the data information collected by the mobile measurement base station and send a command signal to the mobile measurement base station; The first main control module is connected to the mathematical model and solution module, the flight control module, the pre-verification module and the data acquisition and transmission module respectively, and is used to receive and process data information from each module connected thereto and send relevant execution instructions to each module; the mobile measurement base station includes: The flight driving module is used to drive the mobile measurement base station to fly and receive flight instructions from the flight control module; An information transmission module is used to send relevant data information and transmit relevant instructions to the measurement host and measurement tags; A second main control module, which is connected to the flight drive module and the information transmission module respectively, and is used to receive and process data information from each module connected thereto and send relevant execution instructions to each module; The measurement tag comprises a first signal transceiver module, and the first signal transceiver module is used to send a signal to a mobile measurement base station; The flight control module controls the mobile measurement base station to perform the following steps: S2a: The four directions of the mobile measurement base station are used as the initial movement directions. When the mobile measurement base station is at a preset position with poor signal, it starts to move in the four directions of southeast, northwest, and northeast. The step length of each movement along the spherical mathematical model is X, 0<X≤1 meter; S2b: When moving toward the mobile measurement base station in the four directions of southeast, northwest, and northeast, the detection signals Peast, Pwest, Psouth, and Pnorth are recorded respectively, and the signal strengths in the four directions are compared, where Peast and Pwest are the first group, and Psouth and Pnorth are the second group. A signal with a larger value is taken from each of the two groups to form a third group, and the maximum signal strength in the third group is taken, recorded as Pmax, and then the two signal strength values ​​in the third group are divided by the maximum signal strength Pmax to obtain the weights of the two directions, and the weighted vector is synthesized as the optimal direction D1 for the mobile measurement base station; S2c: After the mobile measurement base station moves X steps in the direction of D1, it continues to search for signal strength in the four directions of southeast, northwest and northeast at the new position with X steps, repeats step S2b, and obtains a new optimal direction D2; S2d: After obtaining a new optimization direction, repeat steps S2b and S2c until the mobile measurement base station moves to a final position greater than or equal to the signal strength threshold, stop signal pre-verification, and perform positioning calculation.

8. The system for detecting deformation of dangerous rock collapse disasters based on ultra-wideband positioning according to claim 7 is characterized by: The measurement host also includes: A first time synchronization module, which is connected to the first main control module and is used to synchronize the time of the mobile measurement base station; A positioning module, which is connected to the first main control module and is used to obtain the location information of each mobile measurement base station; the mobile measurement base station also includes: A synchronization monitoring control module is connected to the second main control module and is used to monitor whether the measurement tag is synchronized with the mobile measurement base station, and collect the distance data between the mobile measurement base station and the measurement tag and the time difference parameter data of the signal received between the mobile measurement base station and the measurement tag according to the time synchronization situation. The second main control module processes the distance data and the time parameter data and sends the two data to the measurement host through the information transmission module; A second time synchronization module, which is connected to the second main control module and is used to correct the time of the mobile measurement base station according to the timing of the first time synchronization module; A navigation and positioning module, which is connected to the second main control module and is used for navigation and positioning; The second signal transceiver module is connected to the second main control module and is used to send and receive relevant signals from the measurement tag and the measurement host respectively; the measurement tag also includes: The GPS time synchronization module is connected to the first signal transceiver module and is used to send time information and positioning information to the mobile measurement base station.

9. The ultra-wideband positioning-based dangerous rock collapse disaster deformation detection system according to claim 8, characterized in that: The signals received and transmitted by the first signal transceiver module and the second signal transceiver module are ultra-wideband pulse signals.

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