Disclosure of Invention
The invention aims to provide a dangerous rock collapse disaster deformation monitoring method and system based on ultra-bandwidth positioning, which utilize a mobile measurement base station to accurately acquire and calculate measurement tag displacement change data by searching and measuring the position of a tag optimal signal.
The technical scheme adopted by the invention is as follows:
dangerous rock collapse disaster deformation monitoring method based on ultra-bandwidth positioning, wherein at least one measurement tag is distributed on the surface of a disaster body, and the monitoring method comprises the following steps:
The signal pre-verification is that the mobile measurement base station flies to the preset positions of the corresponding measurement tags according to the preset tracks, and the mobile measurement base station searches the positions of the best signals between the mobile measurement base station and the measurement tags near the preset positions according to the signal intensity threshold;
And (3) positioning and measuring, namely carrying out data acquisition and displacement change measuring and calculating on the measurement tag at the position of the optimal signal by the mobile measurement base station.
In the preferred technical scheme, in the signal pre-verification, the specific steps for searching the position of the optimal signal according to the signal strength threshold value are as follows:
s1, a mobile measurement base station is preset with a signal strength threshold, when the signal strength received by the mobile measurement base station is lower than the threshold, the mobile measurement base station is poor in signal, and then the mobile measurement base station starts automatic optimizing near the preset position;
If the signal intensity received by the mobile measurement base station from the measurement tag is greater than or equal to the threshold value, the mobile measurement base station is an excellent signal, and hovers and carries out positioning measurement;
and S2, establishing a spherical mathematical model taking the preset position as a sphere center and taking the distance between the preset position and the measurement tag as a radius, and moving the measurement base station to search the position where the signal larger than or equal to the threshold value is located by taking the surface of the spherical mathematical model as a searching surface.
In the preferred technical scheme, the specific method for measuring the movement of the base station along the movement of the optimal signal found by the spherical data model in the step S2 is as follows:
s2a, taking four directions of the mobile measurement base station, namely the southeast, the northwest and the northwest as an initialization movement direction, starting to move in the southeast, the northwest and the northwest directions when the mobile measurement base station is at a preset position with poor signals, wherein the step length of each movement along a spherical mathematical model is X0<X-1 m;
S2b, when moving to the mobile measuring base station in four directions of southeast, southwest and northwest, respectively recording detection signals Peast, pwest, psouth and Pnorth, comparing the signal intensities in the four directions, wherein (Peast and Pwest) is a first group, (Psouth and Pnorth) is a second group, respectively taking out a larger value of one signal in the two groups to form a third group (Peast/Pwest and Psouth/Pnorth), taking the maximum value of the signal intensity in the third group, marking the maximum value as Pmax, respectively dividing two signal intensity values in the third group by the signal intensity maximum value Pmax to obtain weights in the two directions, and combining vectors by the weights to be used as the optimal direction D1 of the mobile measuring base station;
S2c, after the mobile measurement base station moves in the direction D1 by X step length, continuously searching the signal intensity in the four directions of southwest and northwest at the new position by X step length, and repeating the step S2b to obtain a new optimizing direction D2;
And S2d, repeating the step S2b and the step S2c after obtaining the new optimizing direction until the mobile measurement base station moves to a final position which is more than or equal to the signal intensity threshold value, stopping signal pre-verification, and performing positioning measurement.
In a preferred technical scheme, the specific method for positioning and measuring and calculating is as follows:
Monitoring whether signals of the mobile measurement base station and the measurement tag are time-synchronized, and calculating the distance between the mobile measurement base station and the measurement tag according to the signals received by the mobile measurement base station from the measurement tag when the monitoring result is synchronous;
When the monitoring result is asynchronous, one mobile measuring base station is selected as a reference base station by the mobile measuring base station, other mobile measuring base stations are time-synchronized by taking the time of the reference base station as a reference, the time difference of the signals transmitted by the measuring tag reaching different mobile measuring base stations is obtained, the distance between the measuring tag and the different mobile measuring base stations is calculated according to the time difference, the three-dimensional coordinates of the measuring tag are obtained through calculation, and then the displacement data of the measuring tag are calculated according to the obtained three-dimensional coordinates.
In a preferred technical scheme, the specific method for calculating the three-dimensional coordinates of the measurement tag is as follows:
Sa, selecting any three mobile measuring base stations, namely a mobile measuring base station AP1, a mobile measuring base station AP2 and a mobile measuring base station AP3, calculating the distances between the mobile measuring base station AP1, the mobile measuring base station AP2 and the mobile measuring base station AP3 and a to-be-measured measuring tag P1 through a formula (1), and then measuring by using the obtained distance data
(1);
In the formula (1), c is the signal propagation speed,Obtained from time measurements of arrival of signals at respective measuring base stations, whereinFor the time difference between the arrival of the signal at the mobile measuring base station AP2 and the arrival at the mobile measuring base station AP1,For the time difference between the arrival of the signal at the mobile measuring base station AP3 and the arrival at the mobile measuring base station AP1,For the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d21 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d31 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, and d23 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP 3;
Sb, distance obtained according to formula (1)And calculating the three-dimensional coordinates of the to-be-measured measurement tag P1.
In the preferred technical scheme, the specific method for calculating the three-dimensional coordinates of the to-be-measured measurement tag P1 in step Sb is as follows:
Setting three-dimensional coordinates of the selected three mobile measurement base stations as,,The three-dimensional of the measurement tag to be measured is set asThen calculating the three-dimensional coordinates of the measurement tag to be measured through a formula (2);
(2)
In a preferred embodiment, before the signal pre-verification, the monitoring method further includes:
And (3) synchronizing time correction, namely performing time correction on each mobile measurement base station.
In the preferred technical scheme, the mobile measurement base station is connected with the measurement tag through ultra-wideband pulse signals.
The invention also provides a dangerous rock collapse disaster deformation detection system based on ultra-bandwidth positioning, which comprises a measurement host, a mobile measurement base station and a measurement tag, wherein,
The system comprises a plurality of measuring labels, a mobile measuring base station, a plurality of monitoring targets and a plurality of monitoring targets, wherein the measuring labels are distributed on the surface of a disaster body;
The mobile measurement base station is in communication connection with the measurement host, and is used for searching the position of the optimal signal between the mobile measurement base station and the measurement label under the remote control of the measurement host, and collecting the related parameters of the measurement label at the position of the optimal signal;
the measuring host is used for remotely controlling each mobile measuring base station and calculating displacement change data of the measuring tag according to related parameters obtained from the mobile measuring base stations.
In a preferred technical solution, the measurement host includes:
The mathematical model and the resolving module are used for establishing a mathematical model for searching the optimal signal and calculating data;
The flight control module is used for controlling the movement of each mobile measurement base station, wherein a plurality of groups of position arrays of the mobile measurement base stations are preset, and each group of position arrays of the mobile measurement base stations comprises the flight track of each mobile measurement base station in the array;
the pre-checking module is used for searching the position of the optimal signal according to the signal intensity threshold value and the mathematical model and sending a searching movement instruction to the flight control module;
The data acquisition and transmission module is used for receiving the data information acquired by the mobile measurement base station and sending an instruction signal to the mobile measurement base station;
The first main control module is respectively connected with the mathematical model and the resolving module, the flight control module, the pre-checking module and the data acquisition and transmission module, and is used for receiving and processing data information from each module connected with the first main control module and sending related execution instructions to each module; the mobile measurement base station includes:
the flight driving module is used for driving the mobile measurement base station to fly and receiving a flight command of the flight control module;
the information transmission module is used for transmitting related data information and related transmission instructions to the measurement host and the measurement tag;
the second main control module is respectively connected with the flight driving module and the information transmission module and is used for receiving and processing data information from each module connected with the second main control module and sending related execution instructions to each module;
the measurement tag includes a first signal transceiver module for transmitting signals to a mobile measurement base station.
In a preferred technical solution, the measurement host further includes:
the first time synchronization module is connected with the first main control module and is used for timing the mobile measurement base station time;
The positioning module is connected with the first main control module and is used for acquiring the position information of each mobile measurement base station, and the mobile measurement base station further comprises:
the synchronous monitoring control module is connected with the second main control module and is used for monitoring whether the time between the measuring tag and the mobile measuring base station is synchronous or not, acquiring distance data between the mobile measuring base station and the measuring tag and time difference parameter data received by signals between the mobile measuring base station and the measuring tag according to the time synchronization condition, processing the distance data and the time parameter data by the second main control module and then transmitting the distance data and the time parameter data to the measuring host through the information transmission module;
The second time synchronization module is connected with the second main control module and is used for correcting the time of the mobile measurement base station according to the time service of the first time synchronization module;
the navigation positioning module is connected with the second main control module and used for navigation and positioning;
The second signal receiving and transmitting module is connected with the second main control module and is used for sending and receiving related signals from the measuring tag and the measuring host respectively, and the measuring tag further comprises:
And the GPS time synchronization module is connected with the first signal receiving and transmitting module and is used for transmitting time information and positioning information to the mobile measurement base station.
In a preferred technical scheme, the signals received and transmitted by the first signal receiving and transmitting module and the second signal receiving and transmitting module are ultra-wideband pulse signals.
The beneficial effects of the invention are as follows:
(1) According to the method and the device for detecting the wireless pulse signals, the pre-verification of the signals received by the mobile measurement base station is carried out, the mobile measurement base station can be moved to the position where the optimal signals are located according to the signal intensity of the received measurement tag to carry out data acquisition and calculation, the technical problem that the wireless pulse signals which arrive in a straight line cannot be received by the receiving end due to the fact that the signals from the transmitting end to the receiving end are attenuated by the shielding object is solved, and the acquired and calculated data parameters are more accurate and higher in accuracy.
(2) According to the invention, the distance and the three-position coordinates between the mobile measurement base station and the measurement tag are measured according to the time synchronization condition of the mobile measurement base station and the measurement tag by combining a time difference positioning method, so that the error of time synchronization is greatly reduced, and further, the displacement change data of the measurement tag is more accurate, and the disaster condition is better analyzed.
(3) According to the invention, the base station is carried by carrying the UWB chip on the unmanned aerial vehicle unit with the prestored multiple groups of unmanned aerial vehicle arrays, and the unmanned aerial vehicle is combined with the base station, so that the technical problems that the field environment is complex, the base station is not easy to build at dangerous rock positions and the potential safety hazard is large are solved, and the ultra-wideband pulse signal is used for communication, so that the measurement precision is higher.
(4) The detection system provided by the invention can be very suitable for monitoring dangerous rock collapse, and has the characteristics of low cost, high measurement precision and high degree of automation compared with the existing detection system.
Detailed Description
The invention is further illustrated with reference to figures 1-3 and the specific examples.
Dangerous rock collapse disaster deformation monitoring method based on ultra-bandwidth positioning, wherein at least one measurement tag is distributed on the surface of a disaster body, and the monitoring method comprises the following steps:
The signal pre-verification is that the mobile measurement base station flies to the preset positions of the corresponding measurement tags according to the preset tracks, and the mobile measurement base station searches the positions of the best signals between the mobile measurement base station and the measurement tags near the preset positions according to the signal intensity threshold;
The mobile measurement base station comprises a base station and an unmanned aerial vehicle, the unmanned aerial vehicle is used for carrying the base station to form the mobile measurement base station, the mobile measurement base station flies to a preset position corresponding to the initial position of the measurement tag according to a preset flight track, a shielding object attenuates signals from a transmitting end to a receiving end due to covering in the wild, the receiving end cannot receive a wireless pulse signal arriving in a straight line, therefore, the signal pre-verification is carried out before the mobile measurement base station carries out positioning measurement, the positioning measurement is avoided at a position with poor signals, the positioning measurement is more accurate, the specific signal strength threshold is preset, the judgment is carried out by the signal strength threshold when searching, and the position where the signal is located is the best signal when the signal strength threshold is found or more than the signal strength threshold.
And (3) positioning and measuring, namely carrying out data acquisition and displacement change measuring and calculating on the measurement tag at the position of the optimal signal by the mobile measurement base station.
The mobile measurement base station acquires data information of the measurement tag at the position of the optimal signal, wherein the data information comprises time information and positioning information, and displacement change data of the measurement tag is calculated according to the time information and the positioning information.
In a preferred embodiment, in the signal pre-verification, the specific steps for searching the position of the best signal according to the signal strength threshold value are as follows:
s1, a mobile measurement base station is preset with a signal strength threshold, when the signal strength received by the mobile measurement base station is lower than the threshold, the mobile measurement base station is poor in signal, and then the mobile measurement base station starts automatic optimizing near the preset position;
If the signal intensity received by the mobile measurement base station from the measurement tag is greater than or equal to the threshold value, the mobile measurement base station is an excellent signal, and hovers and carries out positioning measurement;
and S2, establishing a spherical mathematical model taking the preset position as a sphere center and taking the distance between the preset position and the measurement tag as a radius, and moving the measurement base station to search the position where the signal larger than or equal to the threshold value is located by taking the surface of the spherical mathematical model as a searching surface.
As shown in fig. 2, 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 search a wider range when searching the position of the best signal, and can not deviate from the actual position of the measurement tag during searching, so that the position of the best signal can be searched to the greatest extent.
In a preferred embodiment, the specific method for measuring the movement of the base station in searching the optimal signal along the spherical data model in step S2 is as follows:
s2a, taking four directions of the mobile measurement base station, namely the southeast, the northwest and the northwest as an initialization movement direction, starting to move in the southeast, the northwest and the northwest directions when the mobile measurement base station is at a preset position with poor signals, wherein the step length of each movement along a spherical mathematical model is X0<X-1 m;
S2b, when moving to the mobile measuring base station in four directions of southeast, southwest and northwest, respectively recording detection signals Peast, pwest, psouth and Pnorth, comparing the signal intensities in the four directions, wherein (Peast and Pwest) is a first group, (Psouth and Pnorth) is a second group, respectively taking out a larger value of one signal in the two groups to form a third group (Peast/Pwest and Psouth/Pnorth), taking the maximum value of the signal intensity in the third group, marking the maximum value as Pmax, respectively dividing two signal intensity values in the third group by the signal intensity maximum value Pmax to obtain weights in the two directions, and combining vectors by the weights to be used as the optimal direction D1 of the mobile measuring base station;
S2c, after the mobile measurement base station moves in the direction D1 by X step length, continuously searching the signal intensity in the four directions of southwest and northwest at the new position by X step length, and repeating the step S2b to obtain a new optimizing direction D2;
And S2d, repeating the step S2b and the step S2c after obtaining the new optimizing direction until the mobile measurement base station moves to a final position which is more than or equal to the signal intensity threshold value, stopping signal pre-verification, and performing positioning measurement.
The mobile measurement base station searches the position of the excellent signal according to the method by searching the position of the excellent signal from the north-south direction of the east and west in the preset position, so that the position of the excellent signal can be searched more efficiently and more accurately, and the measuring efficiency and measuring precision are greatly improved. Specifically, the X step length is preferably 0.1 meter.
In a preferred embodiment, the specific method for positioning measurement is as follows:
Monitoring whether signals of the mobile measurement base station and the measurement tag are time-synchronized, and calculating the distance between the mobile measurement base station and the measurement tag according to the signals received by the mobile measurement base station from the measurement tag when the monitoring result is synchronous;
When the monitoring result is asynchronous, one mobile measuring base station is selected as a reference base station by the mobile measuring base station, other mobile measuring base stations are time-synchronized by taking the time of the reference base station as a reference, the time difference of the signals transmitted by the measuring tag reaching different mobile measuring base stations is obtained, the distance between the measuring tag and the different mobile measuring base stations is calculated according to the time difference, the three-dimensional coordinates of the measuring tag are obtained through calculation, and then the displacement data of the measuring tag are calculated according to the obtained three-dimensional coordinates.
When the mobile measurement base station enters the step of label positioning measurement, although each measurement label carries out time correction on the measurement label, because the geographical position and the environment where dangerous rock is located are limited, the time correction cannot be completed when the GPS signal is low and weak, and the accuracy of the time of the measurement label cannot be guaranteed, so that the situation that the time is not synchronous exists, and therefore, the displacement data of the measurement label can be calculated through calculating the displacement data through time difference under the situation that monitoring results are not synchronous.
In a preferred embodiment, the specific method for calculating the three-dimensional coordinates of the measurement tag is as follows:
Sa, selecting any three mobile measuring base stations, namely a mobile measuring base station AP1, a mobile measuring base station AP2 and a mobile measuring base station AP3, calculating the distances between the mobile measuring base station AP1, the mobile measuring base station AP2 and the mobile measuring base station AP3 and a to-be-measured measuring tag P1 through a formula (1), and then measuring by using the obtained distance data
(1);
In the formula (1), c is the signal propagation speed,Obtained from time measurements of arrival of signals at respective measuring base stations, whereinFor the time difference between the arrival of the signal at the mobile measuring base station AP2 and the arrival at the mobile measuring base station AP1,For the time difference between the arrival of the signal at the mobile measuring base station AP3 and the arrival at the mobile measuring base station AP1,For the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d21 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d31 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, and d23 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP 3;
Sb, distance obtained according to formula (1)And calculating the three-dimensional coordinates of the to-be-measured measurement tag P1.
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 as follows:
Setting three-dimensional coordinates of the selected three mobile measurement base stations as,,The three-dimensional of the measurement tag to be measured is set asThen calculating the three-dimensional coordinates of the measurement tag to be measured through a formula (2);
(2)
in a preferred embodiment, the monitoring method further comprises, prior to the signal pre-verification:
And (3) synchronizing time correction, namely performing time correction on each mobile measurement base station.
In which each node (target/base station) has its own reference clock, the clock source is typically provided by a crystal oscillator. Due to the influence of temperature process and other factors, the crystal oscillator has frequency deviation and drift, and the phase-locked loop and the like in the second UWB chip have errors when the clock is multiplied, and the errors can cause errors of a final system clock. With time, the time error is larger and larger, the accuracy of the time stamp is affected when the wireless message is captured, and the center frequency of the ultra-wideband wireless pulse wave is shifted due to frequency drift. Therefore, by carrying out time correction before signal pre-verification, the error of time synchronization can be greatly reduced, and the calculated data can be more accurate by a time difference calculation method in the step of positioning calculation. Specifically, the time correction is performed on each mobile measurement base station by the measurement host, and the mobile measurement base station and the measurement tag can take the time of the measurement host as the reference, so that the measurement and calculation data are more accurate.
In a preferred embodiment, the mobile measurement base station is connected with the measurement tag through an ultra-wideband pulse signal.
The invention also provides a dangerous rock collapse disaster deformation detection system based on ultra-bandwidth positioning, which is shown in figures 1 and 3 and comprises a measurement host, a mobile measurement base station and a measurement tag, wherein,
The system comprises a plurality of measuring labels, a mobile measuring base station, a plurality of monitoring targets and a plurality of monitoring targets, wherein the measuring labels are distributed on the surface of a disaster body;
the measuring label is provided with a plurality of mobile measuring base stations, and specifically, the measuring label sends pulse signals to the outside, the mobile measuring base stations fly to preset positions corresponding to the measuring label according to preset tracks, receive the pulse signals at the preset positions and send relevant instruction signals, and acquisition and calculation of displacement change data are carried out.
The mobile measurement base station is in communication connection with the measurement host, and is used for searching the position of the optimal signal between the mobile measurement base station and the measurement label under the remote control of the measurement host, and collecting the related parameters of the measurement label at the position of the optimal signal;
The mobile measurement base station is remotely controlled by a measurement host and flies to a preset position according to a preset flight array, and the related parameters comprise time synchronization information and distance information of the mobile measurement base station and a measurement tag.
The measuring host is used for remotely controlling each mobile measuring base station and calculating displacement change data of the measuring tag according to related parameters obtained from the mobile measuring base stations.
In a preferred embodiment, the measurement host comprises a mathematical model and a calculation module, wherein the mathematical model and the calculation module are used for establishing a mathematical model for searching for an optimal signal and calculating data; the system comprises a flight control module, a data acquisition and transmission module, a first main control module, a data acquisition and transmission module, a data transmission module and a data transmission module, wherein the flight control module is used for controlling the movement of each mobile measurement base station, the position arrays of a plurality of groups of mobile measurement base stations are preset, each group of mobile measurement base station position arrays comprise the flight track of each mobile measurement base station in the array, the pre-verification module is used for searching the position of an optimal signal according to a signal intensity threshold value and a mathematical model and sending a movement searching instruction to the flight control module;
The mobile measurement base station comprises a flight driving module, an information transmission module, a second main control module, a first control module and a second control module, wherein the flight driving module is used for driving the mobile measurement base station to fly and receiving flight instructions of a flight control module;
the measurement tag includes a first signal transceiver module for transmitting signals to a mobile measurement base station.
In the embodiment, when monitoring starts, a flight control module of a measuring host controls a mobile measuring base station to fly to a preset position corresponding to a corresponding measuring tag through a flight driving module according to a preset track, then the mobile measuring base station receives signals sent by the measuring tag for processing and judging through a second main control module, judges whether the signals are optimal signals with the intensity greater than or equal to a preset signal intensity threshold value, when the judging result is the optimal signals, the second main control module sends a hover instruction to the flight driving module, meanwhile, the information transmission module sends state information of a mobile measuring base station to the measuring host, the measuring host receives the state information through a data acquisition and transmission module and controls the mobile measuring base station to perform positioning measurement through the first main control module, when the judging result is the signal which is not good, the second control module sends the result to the measuring host through the information transmission module, the measuring host receives and transmits the signal to the first main control module through the data acquisition and transmission module, the first main control module executes a signal optimizing step, the mathematical model and the mathematical model engine module establishes the preset position and the spherical surface measuring base station according to positioning information acquired by the mobile measuring base station, the preset position and sends the information to the spherical surface measuring base station, and the mathematical model is fed back to the spherical surface measuring base station receives the information to the spherical surface measuring base station, and the information is the spherical surface measuring base station is controlled by the mathematical model, and the spherical base station is controlled to move the spherical base station and the spherical station is measured by the spherical station, and the spherical station. And carrying out grouping comparison analysis according to a plurality of groups of signal intensity values in different directions obtained in the process of searching the excellent signal, obtaining a new searching direction, and controlling the mobile measuring base station to execute the following steps through the flight control module:
s2a, taking four directions of the mobile measurement base station, namely the southeast, the northwest and the northwest as an initialization movement direction, starting to move in the southeast, the northwest and the northwest directions when the mobile measurement base station is at a preset position with poor signals, wherein the step length of each movement along a spherical mathematical model is X0<X-1 m;
S2b, when moving to the mobile measuring base station in four directions of southeast, southwest and northwest, respectively recording detection signals Peast, pwest, psouth and Pnorth, comparing the signal intensities in the four directions, wherein (Peast and Pwest) is a first group, (Psouth and Pnorth) is a second group, respectively taking out a larger value of one signal in the two groups to form a third group (Peast/Pwest and Psouth/Pnorth), taking the maximum value of the signal intensity in the third group, marking the maximum value as Pmax, respectively dividing two signal intensity values in the third group by the signal intensity maximum value Pmax to obtain weights in the two directions, and combining vectors by the weights to be used as the optimal direction D1 of the mobile measuring base station;
S2c, after the mobile measurement base station moves in the direction D1 by X step length, continuously searching the signal intensity in the four directions of southwest and northwest at the new position by X step length, and repeating the step S2b to obtain a new optimizing direction D2;
And S2d, repeating the step S2b and the step S2c after obtaining the new optimizing direction until the mobile measurement base station moves to a final position which is more than or equal to the signal intensity threshold value, stopping signal pre-verification, and performing positioning measurement.
The radio message signal reaching the obstacle suffers from two effects. A portion of the energy of the signal is reflected back from the obstruction while the remainder is directed into the obstruction. In the signal entering the obstacle, a part of the signal is absorbed into the material (which can cause the material to heat), the rest of the signal can be further reflected from the far end edge of the obstacle, and the rest of the signal can be out of the obstacle to block the other side, so that the problem can be effectively solved by adopting the scheme.
Meanwhile, the power amplifier at the front end of the radio frequency transmitting part of the UWB chip can be adjusted to increase the transmitting power of the signal, so that the wall penetrating capacity of the signal is increased, meanwhile, the received signal strength can be amplified through the LNA at the radio frequency receiving part of the second UWB chip on the unmanned aerial vehicle, and the receiving sensitivity is improved.
In a preferred embodiment, the measurement host also comprises a first time synchronization module, a positioning module, a second time synchronization module, a first time synchronization module, a second time synchronization module and a second time synchronization module, wherein the first time synchronization module is connected with the first main control module and is used for time service of the mobile measurement base station;
the mobile measurement base station further comprises a synchronous monitoring control module, a navigation positioning module, a second signal receiving and transmitting module, a first signal transmitting and receiving module and a second signal receiving and transmitting module, wherein the synchronous monitoring control module is connected with the second main control module and is used for monitoring whether the time between the measurement tag and the mobile measurement base station is synchronous or not, collecting distance data between the mobile measurement base station and the measurement tag and time difference parameter data received by signals between the mobile measurement base station and the measurement tag according to the time synchronization condition, processing the distance data and the time parameter data by the second main control module and then transmitting the distance data and the time parameter data to the measurement host through the information transmission module;
the measurement tag further comprises a GPS time synchronization module which is connected with the first signal receiving and transmitting module and used for sending time information and positioning information to the mobile measurement base station.
Before a mobile measurement base station performs signal pre-verification, an atomic clock module in a first time synchronization module of a measurement host machine is used for carrying out time service on a second time synchronization module of one mobile measurement base station, the second time synchronization module is used for correcting crystal oscillator of a second signal receiving and transmitting module of the mobile measurement base station, and meanwhile, after each time of feedback to the measurement host machine, the mobile measurement base station is subjected to electric quantity inquiry and unmanned aerial vehicle time service by the measurement host machine, so that the problems that accuracy of capturing a radio message sending and receiving time stamp is affected due to time difference and frequency drift can cause ultra-wideband wireless pulse wave center frequency to deviate can be solved.
After the mobile measurement base station finds the good position of the optimal signal, the second main control module sends an execution instruction to the synchronous monitoring control module, the synchronous monitoring control module monitors whether signals between the measurement tag and the mobile measurement base station are synchronous, when the monitoring result is synchronous, the synchronous monitoring control module calculates the distance between the measurement tag and the mobile measurement base station according to the signals transmitted from the measurement tag to the mobile measurement base station to obtain distance data, and further position information of the measurement tag can be obtained, when the monitoring result is asynchronous, the synchronous monitoring control module takes the mobile measurement base station as a reference base station, performs time synchronization on other mobile measurement base stations by taking the reference base station as a reference base station to obtain time difference of the signals of the measurement tag reaching different mobile measurement base stations, so as to obtain time difference data, the synchronous monitoring control module sends the obtained time difference information data and the distance data to the measurement host through the information transmission module, and the mathematical model and the resolving module of the measurement host calculates the time difference data according to the following formula to obtain three-dimensional coordinates and displacement data of the measurement tag.
Calculating the distances between the mobile measurement base station AP1, the mobile measurement base station AP2 and the mobile measurement base station AP3 and the to-be-measured measurement tag P1 through a formula (1);
(1);
In the formula (1), c is the signal propagation speed,Obtained from time measurements of arrival of signals at respective measuring base stations, whereinFor the time difference between the arrival of the signal at the mobile measuring base station AP2 and the arrival at the mobile measuring base station AP1,For the time difference between the arrival of the signal at the mobile measuring base station AP3 and the arrival at the mobile measuring base station AP1,For the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP3, d21 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP1, d31 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP3 and the signal reaching the mobile measurement base station AP1, and d23 is the distance converted from the time difference of the signal reaching the mobile measurement base station AP2 and the signal reaching the mobile measurement base station AP 3;
Sb, distance obtained according to formula (1)And calculating the three-dimensional coordinates of the to-be-measured measurement tag P1. Setting three-dimensional coordinates of the selected three mobile measurement base stations as,,The three-dimensional of the measurement tag to be measured is set asThen, calculating the three-dimensional coordinates of the measurement tag to be measured through the formula (2), and further measuring the displacement data of the tag.
(2)
In a preferred embodiment, the signals received by the first signal receiving and transmitting module and the second signal receiving and transmitting module are ultra wideband pulse signals, wherein the first signal receiving and transmitting module and the second signal receiving and transmitting module are respectively a first UWB chip and a second UWB chip, and when time synchronization is performed, time synchronization is performed on crystal oscillators of the chips.
In the monitoring system, the measuring host also comprises a system configuration function module, a data evaluation module and a data display and analysis module which are respectively connected with the first main control module, wherein the data evaluation module is used for evaluating the displacement change data of each measured label, the system configuration module is used for setting related system parameters, and the data display and analysis module is used for analyzing and displaying the evaluated displacement change data and comprises a PC end and a mobile end. The measuring host is also connected with the mobile measuring base station through ultra-wideband pulse signals.
The invention is not limited to the alternative embodiments described above, but any person may derive other various forms of products in the light of the present invention. The above detailed description should not be construed as limiting the scope of the invention, which is defined in the claims and the description may be used to interpret the claims.