A UWB-based displacement monitoring system and method

Abstract

The present invention discloses a displacement monitoring system and method based on UWB, wherein the displacement monitoring system comprises: a service end and a device end connected by communication through a network; the service end comprises a server and a database; the device end comprises a central control station, multiple base stations and multiple monitoring points; the base stations and monitoring points are collectively referred to as devices, and each device has a unique ID number; each base station and all monitoring points, as well as each device and the central control station, perform data exchange through UWB signals. The present invention realizes displacement monitoring based on UWB. Since the present invention adopts UWB technology, compared with the simple use of GNSS, the displacement monitoring accuracy and real-time performance can be improved, and the device has the advantages of miniaturization and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of deformation monitoring, and in particular to a UWB-based displacement monitoring system and method. Background Art

[0002] Whether it is geological disasters such as collapse, landslide and collapse of natural slopes, or geological disasters caused by instability of artificial slopes due to human engineering activities such as water conservancy and hydropower development, mineral resource mining, and land transportation construction, they have caused huge losses to economic construction and people's property. Especially in the construction and operation of large-scale water conservancy projects, the stability of high slopes involves the safety of the project itself and the overall environment. Its instability and damage not only destroys the construction of the project, but also brings direct or indirect social disasters to civil foundation projects and people's living environment through force majeure environmental disasters. Therefore, it has become a major issue affecting the national economy and social sustainable development. It is of great significance to do a good job in real-time monitoring of slope safety, prevent disasters as soon as possible, or evacuate people in advance to reduce the impact of slope geological disasters on national economic construction.

[0003] The safety hazards of dams are mainly manifested in local settlement, displacement, cracks in the dam body, etc. The emergence of these safety hazards can be manifested as displacement of key positions of the project. The same is true for safety hazards of slopes and bridges. Therefore, by installing equipment with displacement detection function on dams, slopes or bridges, the displacement changes of key positions of the project can be well monitored. As an important indicator for evaluating the health status of these projects, early detection and early prevention and treatment of projects with these risks can greatly reduce the occurrence of major accidents and protect people’s lives and property safety to the greatest extent.

[0004] With the development of electronic technology, displacement monitoring technology has evolved from primitive manual measurement to current high-end instrument or equipment measurement. However, due to the large number of water conservancy projects in my country, various bridges, highways and slopes in river basins are widely distributed, and there are many projects that need to be monitored. On the other hand, there is a contradiction between limited maintenance costs. Due to the high price of existing high-end monitoring equipment, it is mainly used for monitoring key projects and dams, while a large number of small and medium-sized projects still remain in relatively backward or relatively single monitoring methods. Common external displacement monitoring technologies include: GNSS-based positioning monitoring system, total station, and slope radar.

[0005] (1) Problems with GNSS positioning include: When using GNSS positioning technology to monitor deformation, the accuracy of vertical displacement is generally not as good as that of horizontal displacement. For example, no obstacles with an elevation angle of more than 15° are allowed around the measuring station; the measuring station must be a certain distance (for example, 200 to 400 meters) away from signal interference objects and strong signal sources such as high-voltage lines, transformers, radio stations, television stations, and microwave relay stations; and signal reflectors such as houses, walls, billboards, hillsides, and large areas of water are not allowed around the measuring station to avoid multipath errors.

[0006] (2) Characteristics of slope radar system: high monitoring accuracy, capable of rapid and continuous scanning of a large area of ​​the monitoring area with sub-millimeter accuracy; wide monitoring range, measurement can cover the entire monitoring area. However, the cost of slope radar equipment is too high, and the operating expenses are high, which makes it difficult to meet the low-cost requirements and continuous real-time monitoring needs of a large number of small and medium-sized dams or slope monitoring.

[0007] (3) Characteristics of total station: Total station has high accuracy, but has the following problems: it is a high-precision optical instrument with complex operating procedures. It needs to be measured and maintained by a dedicated person. It is inconvenient to use and difficult to achieve real-time monitoring requirements. Moreover, total station is an optical monitoring device with certain weather conditions, making it difficult to achieve all-weather measurement requirements.

[0008] Therefore, there is an urgent need to develop a miniaturized and inexpensive displacement monitoring device to meet the needs of many small and medium-sized projects and slopes for real-time safety monitoring. Summary of the invention

[0009] The technical problem to be solved by the present invention is: to provide a UWB-based displacement monitoring system and method in view of the above-mentioned problems.

[0010] The present invention provides a UWB-based displacement monitoring system, comprising: a service end and a device end connected for communication via a network; the service end comprises a server and a database; the device end comprises a central control station, multiple base stations and multiple monitoring points; the base stations and monitoring points are collectively referred to as devices, each device having a unique ID number; data exchange is performed between each base station and all monitoring points, and between each device and the central control station, via UWB signals.

[0011] Furthermore, each of the devices includes a first UWB antenna, a first UWB chip and a first MCU connected in sequence, and a first power supply unit for supplying power.

[0012] Furthermore, each of the devices also includes a positioning module, which is connected to the first MCU and is used to monitor the positioning information of the device.

[0013] Furthermore, the central control station includes a UWB antenna, a UWB chip and an MCU connected in sequence, a power supply unit for powering, and a wireless communication module for communicating through a wireless network.

[0014] Furthermore, the central control station also includes a positioning module, which is connected to the second MCU and is used to monitor the positioning information of the central control station.

[0015] Furthermore, the central control station also includes a rainfall monitoring module and other environmental monitoring equipment connected to the second MCU, which are used to monitor rainfall information and other environmental information in the area where the central control station is located, and transmit the information to the server through the network.

[0016] Furthermore, the second MCU is implemented by two connected MCUs.

[0017] The present invention also provides a UWB-based displacement monitoring method, which comprises the following steps:

[0018] Step 1: The displacement monitoring system is tested online. The central control station generates a status table for each device and sends it to the server. The status table marks the status information of each device in the displacement monitoring system, whether it is an online device or an abnormal device. The device with the status information of an online device is used to execute steps 3-5.

[0019] Step 2: The central control station determines the location information of itself and each device and sends it to the server;

[0020] Step 3: The server configures a displacement monitoring worksheet for the online device according to the status information in the status table, and sends it to the central control station;

[0021] Step 4: The central control station configures a pair of base stations and monitoring points in the displacement monitoring work table according to the displacement monitoring work table, so that the pair of base stations and monitoring points enter the working mode and then perform ranging; and after traversing the displacement monitoring work table and completing the ranging of each pair of base stations and monitoring points in the displacement monitoring work table, the ranging data is obtained;

[0022] Step 5: The central control station sends the ranging data to the server, and the server solves the three-dimensional coordinates of the monitoring point according to the positioning information and the ranging data;

[0023] Step 6: The server generates and displays a displacement change graph of the monitoring point based on the ranging data at different times in the database and the three-dimensional coordinates of the monitoring point.

[0024] Furthermore, step 1 includes the following sub-steps:

[0025] Step 101, the device is installed and powered on, and the initial device is in a receiving state;

[0026] Step 102, the central control station broadcasts a search UWB signal in the order of the device IDs, and each broadcast search UWB signal includes an ID number and a search instruction;

[0027] Step 103, the central control station enters a receiving state after each broadcast search for UWB signals, and presets a timeout period T1;

[0028] Step 104, after receiving the search UWB signal, all devices in the system compare the ID number therein with their own ID number. If the comparison result matches, they reply with a reception confirmation UWB signal and add their own ID number to the reception confirmation UWB signal;

[0029] Step 105, determine whether the central control station receives the reception confirmation UWB signal within the timeout period T1:

[0030] (1) If the central control station receives the reception confirmation UWB signal within the timeout period T1, it checks the ID number therein and records the device corresponding to the ID number as an online device;

[0031] (2) If the central control station does not receive the reception confirmation UWB signal within the timeout period T1, it returns to step 102 to broadcast the search UWB signal containing the ID number and then executes steps 103-105. If the central control station still does not receive the reception confirmation UWB signal after repeating the execution several times, it determines that the device corresponding to the ID number is an abnormal device;

[0032] Step 106: After searching all devices in steps 102-105, the central control station generates a status table and sends it to the server.

[0033] Furthermore, the method of step 2 is:

[0034] (1) If the central control station and the device are equipped with positioning modules, the central control station sends a positioning acquisition command UWB signal to the device; after receiving the positioning acquisition command UWB signal, the device obtains positioning information through its positioning module, and then broadcasts the positioning information UWB signal to the central control station; the central control station sends the received positioning information and the positioning information obtained by its positioning module to the server;

[0035] (2) If the central control station and the equipment are not equipped with a positioning module, the positioning information of the central control station and the equipment is determined by a total station or an external positioning device, and then the positioning information is manually input into the server.

[0036] Furthermore, step 4 includes the following sub-steps:

[0037] Step 401, the central control station broadcasts a measurement configuration UWB signal to a pair of base stations and monitoring points in the displacement monitoring work table;

[0038] Step 402, the central control station enters the receiving state after broadcasting and sets a waiting time T2;

[0039] Step 403, the base station and the monitoring point enter the working mode after receiving the measurement configuration UWB signal, and broadcast the measurement UWB signal at the same time;

[0040] Step 404, determine whether the central control station receives the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2:

[0041] (1) If the central control station receives the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2, it immediately enters the state of receiving ranging data; the current pair of base stations and monitoring points complete ranging in the working mode and transmit their ranging data to the central control station via the UWB signal;

[0042] (2) If the central control station does not receive the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2, it will re-broadcast the measurement configuration UWB signal to the pair of base stations and monitoring points, and then execute steps 402-404; if the central control station still does not receive the measurement UWB signal broadcast by the current pair of base stations and monitoring points after repeating the execution several times, it will skip the current pair of base stations and monitoring points and broadcast the measurement configuration UWB signal to the next pair of base stations and monitoring points, and then execute steps 402-404;

[0043] In step 405, a pair of base stations and monitoring points that have completed ranging will be removed from the displacement monitoring work table, while the skipped pair of base stations and monitoring points will remain in the displacement monitoring work table, and then steps 401-404 will be repeated until the displacement monitoring work table is empty, that is, the displacement monitoring work table is traversed, so that each pair of base stations and monitoring points in the displacement monitoring work table completes ranging and obtains ranging data.

[0044] In one embodiment, the method for measuring the distance between each pair of base stations and monitoring points comprises the following steps:

[0045] Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ;

[0046] Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ;

[0047] Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D bAfter a certain time, a third UWB measurement signal is broadcast to the base station;

[0048] Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ;

[0049] Step 415, calculate the distance between the base station and the monitoring point as:

[0050]

[0051] Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light, and the calculated distance between the base station and the monitoring point is the ranging data of the pair of base stations and monitoring points.

[0052] In one embodiment, the method for measuring the distance between each pair of base stations and monitoring points includes:

[0053] Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ;

[0054] Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ;

[0055] Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station;

[0056] Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ;

[0057] Step 415, calculate the distance between the base station and the monitoring point as:

[0058]

[0059] Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light;

[0060] Step 416, repeat the process of steps 411-415 n times to obtain the distances between n base stations and the monitoring point, and take the average value of the distances between the n base stations and the monitoring point as the distance measurement data of the pair of base stations and the monitoring point:

[0061]

[0062] in, represents the average value of the distance between n base stations and the monitoring point, represents the distance between the base station and the monitoring point obtained by the i-th measurement, i=1, 2, ..., n.

[0063] In one embodiment, the method for measuring the distance between each pair of base stations and monitoring points includes:

[0064] Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ;

[0065] Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ;

[0066] Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station;

[0067] Step 414, the base station records the time Td after receiving the third UWB measurement signal;

[0068] Step 415, calculate the distance between the base station and the monitoring point as:

[0069]

[0070] Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light;

[0071] Step 416, repeating steps 411-415 n times: wherein the distances between the m base stations and the monitoring points obtained m times are taken and sorted from small to large, the median value is taken as the reference value, and a boundary size is set as y, then when repeating the following nm times, the distances between the nm base stations and the monitoring points obtained must meet the following judgment conditions:

[0072]

[0073] Among them, abs represents absolute value operation, As the reference value, the distances between the base station and the monitoring point obtained by repeating the operation for the next nm times that do not meet the judgment condition are judged as abnormal values ​​and discarded; the average value of the distances between the base station and the monitoring point obtained after discarding the abnormal values ​​is taken as the ranging data of the pair of base stations and the monitoring points.

[0074] Furthermore, in step 4, the server can change the displacement monitoring worksheet at any time, and the changed displacement monitoring worksheet is sent to the central control station; after receiving the new displacement monitoring worksheet, the central control station will first complete the existing displacement monitoring worksheet, and then work according to the new displacement monitoring worksheet.

[0075] Furthermore, the method of step 5 is: after the server receives the ranging data of each pair of online devices in the displacement monitoring worksheet, the ranging data is stored in the database, and the ranging data is sent to the Kalman filter at the same time; the Kalman filter calculates the three-dimensional coordinates of the monitoring point according to the positioning information and measurement data of the base station; the three-dimensional coordinates of the monitoring point, as well as the positioning information of the central control station and each device are also stored in the database.

[0076] In one embodiment, the displacement monitoring method further includes a process of sudden displacement monitoring; the sudden displacement monitoring method includes the following steps:

[0077] Step 701: When the server detects that the displacement of a monitoring point exceeds a set displacement threshold or the displacement speed exceeds a set displacement speed threshold, a burst displacement monitoring work table is configured and sent to the central control station;

[0078] Step 702: After receiving the sudden displacement monitoring worksheet, the central control station calculates an i value according to the following formula:

[0079]

[0080] Among them, round represents rounding operation, X represents the measurement period in the original displacement monitoring worksheet, and Y represents the measurement period in the burst displacement monitoring worksheet;

[0081] Step 703, after the central control station has cycled through i rounds according to the method of step 4, it then cycles through i rounds according to the original displacement monitoring work table; this process repeats until the server sends an empty burst displacement monitoring work table to the central control station; then the central control station returns to the working state of the original displacement monitoring work table.

[0082] In one embodiment, the displacement monitoring method further includes a node operation process; the node operation method includes the following steps:

[0083] Step 801, the base station and the monitoring point monitor the battery power information through their power monitoring modules, and send the battery power information together with the ranging data to the central control station through the UWB signal;

[0084] Step 802, the central control station monitors the battery power information through its power monitoring module, and sends its battery power information, as well as the battery power information of the base station and the monitoring point to the service end through the network;

[0085] Step 803: The server receives the battery power information of the central control station, base station and monitoring point in real time, and compares the battery power information with the preset power threshold:

[0086] When the battery power information is lower than the preset power threshold, the server reduces the corresponding measurement cycle in the displacement monitoring work table, so that the corresponding central control station, base station or monitoring point is in energy-saving working mode to ensure that the equipment can still work under a certain power state;

[0087] When the solar panels of the central control station, base station or monitoring point in energy-saving working mode charge the battery back to a specific value, the server automatically adjusts the corresponding measurement cycle in the displacement monitoring work table back to the original measurement cycle, so that the displacement monitoring system works normally.

[0088] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0089] The present invention realizes displacement monitoring based on UWB. Since the present invention adopts UWB technology, compared with the technology adopting GNSS, the displacement monitoring accuracy and real-time performance can be improved, and the device has the advantages of miniaturization and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0091] Figure 1 This is a schematic diagram of a UWB-based displacement monitoring system according to Embodiment 1 of the present invention.

[0092] Figure 2 This is a schematic diagram of the structure of a base station and a monitoring point in Example 1 of the present invention.

[0093] Figure 3 This is a schematic diagram of the structure of the central control station of Example 1 of the present invention.

[0094] Figure 4 This is a flowchart of a UWB-based displacement monitoring method according to Embodiment 1 of the present invention.

[0095] Figure 5 This is a flowchart of a UWB-based displacement monitoring method according to Embodiment 4 of the present invention.

[0096] Figure 6 This is a schematic diagram of the structure of the base station and monitoring points of Example 5 of the present invention.

[0097] Figure 7 This is a schematic diagram of the structure of the central control station of Example 5 of the present invention.

[0098] Figure 8 This is a schematic diagram of the structure of the central control station of Example 6 of the present invention.

[0099] Fig. 9 This is a schematic diagram of the structure of the central control station of Example 7 of the present invention. DETAILED DESCRIPTION

[0100] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0101] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0102] Example 1

[0103] like Figure 1 The present embodiment shown provides a UWB-based displacement monitoring system, comprising: a service end and a device end connected for communication via a network; the service end comprises a server and a database; the device end comprises a central control station (CS), multiple base stations (BS) and multiple monitoring points (MS); the base stations and monitoring points are collectively referred to as devices, and each device has a unique ID number (for example, each device is numbered as 1, 2, ..., N); data exchange is performed between each base station and all monitoring points, and between each device and the central control station via UWB signals.

[0104] like Figure 2 As shown, each of the devices includes a first UWB antenna, a first UWB chip and a first MCU connected in sequence, and a first power supply unit for power supply. The first UWB antenna, the first UWB chip and the first MCU are used to enable each device to send and receive UWB signals.

[0105] like Figure 3 As shown, the central control station includes a second UWB antenna, a second UWB chip and a second MCU connected in sequence, a second power supply unit for power supply, and a wireless communication module for communication connection via a wireless network. The second UWB antenna, the second UWB chip and the second MCU are used to enable the central control station to send and receive UWB signals.

[0106] The central control station and each of the devices further include an optional positioning module, which is connected to the MCU and is used to monitor the positioning information of the central control station or the device. That is to say, among all the devices, each device may be equipped with a positioning module, each device may not be equipped with a positioning module, or some devices may be equipped with a positioning module.

[0107] Using the above-mentioned UWB-based displacement monitoring system, this embodiment also provides a UWB-based displacement monitoring method, such as Figure 4 As shown, the displacement monitoring method comprises the following steps:

[0108] Step 1: The displacement monitoring system is tested online. The central control station generates a status table for each device and sends it to the server. The status table marks the status information of each device in the displacement monitoring system, whether it is an online device or an abnormal device. The device with the status information of an online device is used to execute steps 3-5.

[0109] Specifically, step 1 includes the following sub-steps:

[0110] Step 101, the equipment is installed and powered on, and the initial equipment (base station and monitoring point) is in the receiving state;

[0111] Step 102, the central control station broadcasts a search UWB signal in the order of the device IDs, and each broadcast search UWB signal includes an ID number and a search instruction;

[0112] Step 103, the central control station enters a receiving state after each broadcast search for UWB signals, and presets a timeout period T1;

[0113] Step 104, after receiving the search UWB signal, all devices in the system compare the ID number therein with their own ID number. If the comparison result matches (i.e., the ID number in the received search UWB signal is consistent with their own ID number), they reply with a reception confirmation UWB signal and add their own ID number to the reception confirmation UWB signal;

[0114] Step 105, determine whether the central control station receives the reception confirmation UWB signal within the timeout period T1:

[0115] (1) If the central control station receives the reception confirmation UWB signal within the timeout period T1, it checks the ID number therein and records the device corresponding to the ID number as an online device;

[0116] (2) If the central control station does not receive the reception confirmation UWB signal within the timeout period T1, it returns to step 102 to broadcast the search UWB signal containing the ID number and then executes steps 103-105. If the central control station still does not receive the reception confirmation UWB signal after repeating the execution several times (generally 3 times), it determines that the device corresponding to the ID number is an abnormal device;

[0117] Step 106: After searching all devices in steps 102-105, the central control station generates a status table and sends it to the server. That is, the status table generated in step 1 marks the status information of each device in the displacement monitoring system, whether it is an online device or an abnormal device, and sends the status table to the server through the network, so that the server can remotely monitor the system status.

[0118] Step 2: The central control station determines the location information of itself and each device and sends it to the server;

[0119] Specifically, the method of step 2 is:

[0120] (1) If the central control station and the device are equipped with positioning modules, the central control station sends a positioning acquisition command UWB signal to the device; after receiving the positioning acquisition command UWB signal, the device obtains positioning information through its positioning module, and then broadcasts the positioning information UWB signal to the central control station; the central control station sends the received positioning information and the positioning information obtained by its positioning module to the server;

[0121] (2) If the central control station and the equipment are not equipped with a positioning module, the positioning information of the central control station and the equipment is determined by a total station or an external positioning device, and then the positioning information is manually input into the server.

[0122] Step 3: The server configures a displacement monitoring worksheet for the online device according to the status information in the status table, and sends it to the central control station;

[0123] In this embodiment, each row of the displacement monitoring work table represents a pair of base stations and monitoring points for distance measurement, as shown in Table 1.

[0124] Table 1, Displacement Monitoring Worksheet:

[0125]

[0126]

[0127] As can be seen from the table, one base station can correspond to multiple monitoring points, and one monitoring point can also correspond to multiple base stations. It should be noted that the base station ID and the monitoring point ID cannot be the same in the same row, that is, they cannot measure themselves.

[0128] Step 4: The central control station configures a pair of base stations and monitoring points in the displacement monitoring work table according to the displacement monitoring work table, so that the pair of base stations and monitoring points enter the working mode and then perform ranging; and after traversing the displacement monitoring work table and completing the ranging of each pair of base stations and monitoring points in the displacement monitoring work table, the ranging data is obtained;

[0129] Due to the interference of UWB signals, when the central control station broadcasts the UWB measurement configuration signal, the corresponding device may not be able to receive the UWB measurement configuration signal, resulting in failure to enter the working mode. Therefore, this embodiment sets a retransmission mechanism to ensure stable communication. Specifically, step 4 includes the following sub-steps:

[0130] Step 401, the central control station broadcasts a measurement configuration UWB signal to a pair of base stations and monitoring points in the displacement monitoring work table;

[0131] Step 402, the central control station enters the receiving state after the broadcast, and sets a waiting time T2 (the waiting time is generally set to the measurement cycle in the displacement monitoring work table);

[0132] Step 403, the base station and the monitoring point enter the working mode after receiving the measurement configuration UWB signal, and broadcast the measurement UWB signal at the same time;

[0133] Step 404, determine whether the central control station receives the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2:

[0134] (1) If the central control station receives the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2, it immediately enters the state of receiving ranging data; the current pair of base stations and monitoring points complete ranging in the working mode and transmit their ranging data to the central control station via the UWB signal;

[0135] (2) If the central control station does not receive the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2, it will re-broadcast the measurement configuration UWB signal to the pair of base stations and monitoring points, and then execute steps 402-404; if the central control station still does not receive the measurement UWB signal broadcast by the current pair of base stations and monitoring points after repeating the execution several times (generally 3 times), it will skip the current pair of base stations and monitoring points and broadcast the measurement configuration UWB signal to the next pair of base stations and monitoring points, and then execute steps 402-404;

[0136] In step 405, a pair of base stations and monitoring points that have completed ranging will be removed from the displacement monitoring work table, while the skipped pair of base stations and monitoring points will remain in the displacement monitoring work table, and then steps 401-404 will be repeated until the displacement monitoring work table is empty, that is, the displacement monitoring work table is traversed, so that each pair of base stations and monitoring points in the displacement monitoring work table completes ranging and obtains ranging data.

[0137] The distance measurement data obtained through steps 401-405 is the distance measurement data of each pair of online devices in the displacement monitoring worksheet. Specifically, the method for measuring the distance of each pair of base stations and monitoring points includes the following steps:

[0138] Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ;

[0139] Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ;

[0140] Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station;

[0141] Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ;

[0142] Step 415, calculate the distance between the base station and the monitoring point as:

[0143]

[0144] Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light, and the calculated distance between the base station and the monitoring point is the ranging data of the pair of base stations and monitoring points.

[0145] Furthermore, in step 4, the server can change the displacement monitoring worksheet at any time, and the changed displacement monitoring worksheet is sent to the central control station; after receiving the new displacement monitoring worksheet, the central control station will first complete the existing displacement monitoring worksheet, and then work according to the new displacement monitoring worksheet.

[0146] Step 5: The central control station sends the ranging data to the server, and the server solves the three-dimensional coordinates of the monitoring point according to the positioning information and the ranging data.

[0147] Specifically, after receiving the ranging data of each pair of online devices in the displacement monitoring worksheet, the server stores the ranging data in the database and sends the ranging data to the Kalman filter at the same time; the Kalman filter calculates the three-dimensional coordinates of the monitoring point based on the positioning information and measurement data of the base station; the three-dimensional coordinates of the monitoring point, as well as the positioning information of the central control station and each device are also stored in the database; wherein, the server can quickly know the location of the central control station and each device through the positioning information, which is convenient for maintaining and monitoring the safety of the equipment.

[0148] Step 6: The server generates and displays the displacement change graph of the monitoring point based on the distance measurement data and the three-dimensional coordinates of the monitoring point at different times in the database. That is, as the monitoring time goes by, the distance measurement data and the three-dimensional coordinates of the monitoring point will change, and the displacement change graph generated thereby can intuitively observe the displacement of the monitoring point.

[0149] After the above steps 1-6, this embodiment realizes displacement monitoring based on UWB. Since the present invention adopts UWB technology, compared with the use of GNSS, the displacement monitoring accuracy and real-time performance can be improved, and it has the advantages of miniaturization and low cost.

[0150] Example 2

[0151] In Example 1, when each pair of base stations and monitoring points are measured, only one measurement result is used. However, a single measurement result may contain a large amount of noise, so this embodiment improves this. That is, in this embodiment, the method for measuring the distance between each pair of base stations and monitoring points includes:

[0152] Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ;

[0153] Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ;

[0154] Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station;

[0155] Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ;

[0156] Step 415, calculate the distance between the base station and the monitoring point as:

[0157]

[0158] Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light;

[0159] Step 416, repeat the process of steps 411-415 n times to obtain the distances between n base stations and the monitoring point, and take the average value of the distances between the n base stations and the monitoring point as the distance measurement data of the pair of base stations and the monitoring point:

[0160]

[0161] in, represents the average value of the distance between n base stations and the monitoring point, represents the distance between the base station and the monitoring point obtained by the i-th measurement, i=1, 2, ..., n.

[0162] Example 3

[0163] In Example 2, each pair of base stations and monitoring points is measured n times. However, due to the interference of UWB signals, abnormal values ​​may still appear in the measurement, which will seriously interfere with the measurement results. Therefore, this embodiment makes improvements on this. That is, in this embodiment, the method for measuring the distance between each pair of base stations and monitoring points includes:

[0164] Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ;

[0165] Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ;

[0166] Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station;

[0167] Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ;

[0168] Step 415, calculate the distance between the base station and the monitoring point as:

[0169]

[0170] Among them, DBS-MS is the distance between the base station and the monitoring point, C is the speed of light;

[0171] Step 416, repeat steps 411-415 n times: take the distances between the m base stations and the monitoring points obtained m times and sort them from small to large, and take the median value (i.e. the first distance after sorting). values, round is rounding operation) as the reference value, and set a boundary size as y, then when repeating the following nm times, the distances between the obtained nm base stations and the monitoring points must meet the following judgment conditions:

[0172]

[0173] Among them, abs represents absolute value operation, As the reference value, the distances between the base station and the monitoring point obtained by repeating the operation for the next nm times that do not meet the judgment condition are judged as abnormal values ​​and discarded; the average value of the distances between the base station and the monitoring point obtained after discarding the abnormal values ​​is taken as the ranging data of the pair of base stations and the monitoring points.

[0174] Example 4

[0175] like Figure 5 As shown, the UWB-based displacement monitoring system of this embodiment also includes a function of sudden displacement monitoring; the sudden displacement monitoring method includes the following steps:

[0176] Step 701: When the server detects that the displacement of a monitoring point exceeds a set displacement threshold or the displacement speed (the displacement speed refers to the result obtained by dividing the distance measurement data of two times by the time difference between the two measurements) exceeds the set displacement speed threshold, a burst displacement monitoring work table (initially empty) is configured and sent to the central control station;

[0177] In this embodiment, the sudden displacement monitoring work table is shown in Table 2.

[0178]

[0179] It can be seen from Table 2 that the burst displacement monitoring work table includes monitoring points where displacement or displacement speed exceeding the corresponding threshold has been detected, as well as measurement combinations related to these monitoring points (i.e., base stations corresponding to ranging data), and also includes a measurement period, which is smaller than the measurement period in the original displacement monitoring work table.

[0180] Step 702: After receiving the sudden displacement monitoring worksheet, the central control station calculates an i value according to the following formula:

[0181]

[0182] Among them, round represents rounding operation, X represents the measurement period in the original displacement monitoring worksheet, and Y represents the measurement period in the burst displacement monitoring worksheet;

[0183] Step 703, after the central control station works i rounds according to the method of step 4, it then works once according to the original displacement monitoring work table, and then works i rounds according to the burst displacement monitoring work table; this process repeats until the server sends an empty burst displacement monitoring work table to the central control station; then the central control station returns to the working state of the original displacement monitoring work table. This method can be used to increase the monitoring density of important monitoring points.

[0184] Example 5

[0185] Since the central control station, base station and monitoring point are often located in the wild, most of them are in areas without mains electricity, in this embodiment, Figure 6 , 7 As shown, the first power supply unit and the second power supply unit both include a solar panel, a battery and a power monitoring module; wherein the solar panel and the battery are connected to power the central control station or the device; the power monitoring module is connected to the MCU of the central control station or the device to monitor the battery power information of the central control station or the device.

[0186] Based on the above configuration, the UWB-based displacement monitoring system of this embodiment also has a power-saving function; the power-saving method includes the following steps:

[0187] Step 801, the base station and the monitoring point monitor the battery power information through their power monitoring modules, and send the battery power information together with the ranging data to the central control station through the UWB signal;

[0188] Step 802, the central control station monitors the battery power information through its power monitoring module, and sends its battery power information, as well as the battery power information of the base station and the monitoring point to the service end through the network;

[0189] Wherein, the server displays the battery power information while displaying the displacement change graph;

[0190] Step 803: The server receives the battery power information of the central control station, base station and monitoring point in real time, and compares the battery power information with the preset power threshold:

[0191] When the battery power information is lower than the preset power threshold, the server reduces the corresponding measurement cycle in the displacement monitoring work table, so that the corresponding central control station, base station or monitoring point is in energy-saving working mode to ensure that the equipment can still work under a certain power state;

[0192] When the solar panels of the central control station, base station or monitoring point in energy-saving working mode charge the battery back to a specific value, the server automatically adjusts the corresponding measurement cycle in the displacement monitoring work table back to the original measurement cycle, so that the displacement monitoring system works normally.

[0193] By setting the above energy-saving working function, the displacement monitoring system can continue to work for a long time without interruption.

[0194] Example 6

[0195] like Figure 8 As shown, the central control station also includes a rainfall monitoring module and other environmental monitoring equipment (such as temperature sensors, humidity sensors, etc.) connected to the second MCU, which are used to monitor the rainfall information and other environmental information in the area where the central control station is located, and transmit them to the server through the network; the server also displays the rainfall information and other environmental information while displaying the displacement change graph. By collecting rainfall information and other environmental information from the monitoring point, it can be used to assist users in judging displacement changes. For example, when a user finds that the displacement speed of a monitoring point has accelerated in a certain time period, and observes its rainfall information and environmental information and finds that there is obvious rainfall in this time period, the user can determine that the monitoring point needs to be waterproofed and reinforced.

[0196] Example 7

[0197] like Fig. 9 As shown, in the actual application of the above embodiment, in order to ensure the continuity and stability of the ranging process, the second MCU can be implemented by two connected MCUs, one MCU is used to connect the UWB chip and the UWB antenna in sequence to realize the reception and transmission of UWB signals, and the other MCU is used to connect the power monitoring module, the positioning module, the network communication module, the rainfall monitoring module and other environmental monitoring equipment to realize the control and data processing of the corresponding functions.

[0198] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A displacement monitoring method based on UWB, characterized in that: The displacement monitoring method is implemented by a UWB-based displacement monitoring system, which includes: a service end and a device end connected by communication through a network; the service end includes a server and a database; the device end includes a central control station, multiple base stations and multiple monitoring points; the base stations and monitoring points are collectively referred to as devices, and each device has a unique ID number; each base station and all monitoring points, as well as each device and the central control station, exchange data through UWB signals; The displacement monitoring method comprises the following steps: Step 1: The displacement monitoring system is tested online. The central control station generates a status table for each device and sends it to the server. The status table marks the status information of each device in the displacement monitoring system, whether it is an online device or an abnormal device. The device with the status information of an online device is used to execute steps 3-5. Step 2: The central control station determines the location information of itself and each device and sends it to the server; Step 3: The server configures a displacement monitoring worksheet for the online device according to the status information in the status table, and sends it to the central control station; Step 4: The central control station configures a pair of base stations and monitoring points in the displacement monitoring work table according to the displacement monitoring work table, so that the pair of base stations and monitoring points enter the working mode and then perform ranging; and after traversing the displacement monitoring work table and completing the ranging of each pair of base stations and monitoring points in the displacement monitoring work table, the ranging data is obtained; Step 5: The central control station sends the ranging data to the server, and the server solves the three-dimensional coordinates of the monitoring point according to the positioning information and the ranging data; Step 6: The server generates and displays a displacement change graph of the monitoring point based on the ranging data at different times in the database and the three-dimensional coordinates of the monitoring point.

2. The UWB-based displacement monitoring method according to claim 1, characterized in that: Step 1 includes the following sub-steps: Step 101, the device is installed and powered on, and the initial device is in a receiving state; Step 102, the central control station broadcasts a search UWB signal in the order of the device IDs, and each broadcast search UWB signal includes an ID number and a search instruction; Step 103, the central control station enters a receiving state after each broadcast search for UWB signals, and presets a timeout period T1; Step 104, after receiving the search UWB signal, all devices in the system compare the ID number therein with their own ID number. If the comparison result matches, they reply with a reception confirmation UWB signal and add their own ID number to the reception confirmation UWB signal; Step 105, determine whether the central control station receives the reception confirmation UWB signal within the timeout period T1: (1) If the central control station receives the reception confirmation UWB signal within the timeout period T1, it checks the ID number therein and records the device corresponding to the ID number as an online device; (2) If the central control station does not receive the reception confirmation UWB signal within the timeout period T1, it returns to step 102 to broadcast the search UWB signal containing the ID number and then executes steps 103-105. If the central control station still does not receive the reception confirmation UWB signal after repeating the execution several times, it determines that the device corresponding to the ID number is an abnormal device; Step 106: After searching all devices in steps 102-105, the central control station generates a status table and sends it to the server.

3. The UWB-based displacement monitoring method according to claim 1, characterized in that: The method for step 2 is: (1) If the central control station and the device are equipped with positioning modules, the central control station sends a positioning acquisition command UWB signal to the device; after receiving the positioning acquisition command UWB signal, the device obtains positioning information through its positioning module, and then broadcasts the positioning information UWB signal to the central control station; the central control station sends the received positioning information and the positioning information obtained by its positioning module to the server; (2) If the central control station and the equipment are not equipped with a positioning module, the positioning information of the central control station and the equipment is determined by a total station or an external positioning device, and then the positioning information is manually input into the server.

4. The UWB-based displacement monitoring method according to claim 1, characterized in that: Step 4 includes the following sub-steps: Step 401, the central control station broadcasts a measurement configuration UWB signal to a pair of base stations and monitoring points in the displacement monitoring work table; Step 402, the central control station enters the receiving state after broadcasting and sets a waiting time T2; Step 403, the base station and the monitoring point enter the working mode after receiving the measurement configuration UWB signal, and broadcast the measurement UWB signal at the same time; Step 404, determine whether the central control station receives the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2: (1) If the central control station receives the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2, it immediately enters the state of receiving ranging data; the current pair of base stations and monitoring points complete ranging in the working mode and transmit their ranging data to the central control station via the UWB signal; (2) If the central control station does not receive the measurement UWB signal broadcast by the current pair of base stations and monitoring points within the waiting time T2, it will re-broadcast the measurement configuration UWB signal to the pair of base stations and monitoring points, and then execute steps 402-404; if the central control station still does not receive the measurement UWB signal broadcast by the current pair of base stations and monitoring points after repeating the execution several times, it will skip the current pair of base stations and monitoring points and broadcast the measurement configuration UWB signal to the next pair of base stations and monitoring points, and then execute steps 402-404; In step 405, a pair of base stations and monitoring points that have completed ranging will be removed from the displacement monitoring work table, while the skipped pair of base stations and monitoring points will remain in the displacement monitoring work table, and then steps 401-404 will be repeated until the displacement monitoring work table is empty, that is, the displacement monitoring work table is traversed, so that each pair of base stations and monitoring points in the displacement monitoring work table completes ranging and obtains ranging data.

5. The UWB-based displacement monitoring method according to claim 1, characterized in that: Each method for measuring the distance between a base station and a monitoring point includes the following steps: Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ; Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ; Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station; Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ; Step 415, calculate the distance between the base station and the monitoring point as: Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light, and the calculated distance between the base station and the monitoring point is the ranging data of the pair of base stations and monitoring points.

6. The UWB-based displacement monitoring method according to claim 1, characterized in that: The distance measurement method for each pair of base stations and monitoring points includes: Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ; Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ; Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station; Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ; Step 415, calculate the distance between the base station and the monitoring point as: Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light; Step 416, repeat the process of steps 411-415 n times to obtain the distances between n base stations and the monitoring point, and take the average value of the distances between the n base stations and the monitoring point as the distance measurement data of the pair of base stations and the monitoring point: in, represents the average value of the distance between n base stations and the monitoring point, Represents the distance between the base station and the monitoring point obtained by the i-th measurement, i = 1, 2, …, n.

7. The UWB-based displacement monitoring method according to claim 1, characterized in that: The distance measurement method for each pair of base stations and monitoring points includes: Step 411: The monitoring point broadcasts a first UWB measurement signal to the base station, and records the sending time of the first UWB measurement signal as T a ; Step 412: The base station receives the first UWB measurement signal and waits for D a After time, the second UWB measurement signal is broadcast to the monitoring point, and the sending time of the second UWB measurement signal is recorded as T b ; Step 413: After the monitoring point receives the second UWB measurement signal, it records the time T at that moment. c , and waiting for D b After a certain time, a third UWB measurement signal is broadcast to the base station; Step 414: After receiving the third UWB measurement signal, the base station records the time T at that moment. d ; Step 415, calculate the distance between the base station and the monitoring point as: Among them, D BS-MS is the distance between the base station and the monitoring point, C is the speed of light; Step 416, repeating steps 411-415 n times: wherein the distances between the m base stations and the monitoring points obtained m times are taken and sorted from small to large, the median value is taken as the reference value, and a boundary size is set as y, then when repeating the following nm times, the distances between the nm base stations and the monitoring points obtained must meet the following judgment conditions: Among them, abs represents absolute value operation, As the reference value, the distances between the base station and the monitoring point obtained by repeating the operation for the next nm times that do not meet the judgment condition are judged as abnormal values ​​and discarded; the average value of the distances between the base station and the monitoring point obtained after discarding the abnormal values ​​is taken as the ranging data of the pair of base stations and the monitoring points.

8. The UWB-based displacement monitoring method according to claim 1, characterized in that: In step 4, the server can change the displacement monitoring worksheet at any time, and the changed displacement monitoring worksheet is sent to the central control station; after receiving the new displacement monitoring worksheet, the central control station will first complete the existing displacement monitoring worksheet, and then work according to the new displacement monitoring worksheet.

9. The UWB-based displacement monitoring method according to claim 1, characterized in that: The method of step 5 is: after receiving the distance measurement data of each pair of online devices in the displacement monitoring work table, the server stores the distance measurement data in the database and simultaneously sends the distance measurement data to the Kalman filter; The Kalman filter calculates the three-dimensional coordinates of the monitoring point based on the positioning information and measurement data of the base station; the three-dimensional coordinates of the monitoring point, as well as the positioning information of the central control station and each device are also stored in the database.

10. The UWB-based displacement monitoring method according to claim 1, characterized in that: The displacement monitoring method also includes a process of sudden displacement monitoring; the sudden displacement monitoring method includes the following steps: Step 701: When the server detects that the displacement of a monitoring point exceeds a set displacement threshold or the displacement speed exceeds a set displacement speed threshold, a burst displacement monitoring work table is configured and sent to the central control station; Step 702: After receiving the sudden displacement monitoring worksheet, the central control station calculates an i value according to the following formula: Among them, round represents rounding operation, X represents the measurement period in the original displacement monitoring worksheet, and Y represents the measurement period in the burst displacement monitoring worksheet; Step 703, after the central control station has cycled through i rounds according to the method of step 4, it then cycles through i rounds according to the original displacement monitoring work table; this process repeats until the server sends an empty burst displacement monitoring work table to the central control station; then the central control station returns to the working state of the original displacement monitoring work table.

11. The UWB-based displacement monitoring method according to claim 1, characterized in that: The displacement monitoring method also includes a node working process; the node working method includes the following steps: Step 801, the base station and the monitoring point monitor the battery power information through their power monitoring modules, and send the battery power information together with the ranging data to the central control station through the UWB signal; Step 802, the central control station monitors the battery power information through its power monitoring module, and sends its battery power information, as well as the battery power information of the base station and the monitoring point to the service end through the network; Step 803: The server receives the battery power information of the central control station, base station and monitoring point in real time, and compares the battery power information with the preset power threshold: When the battery power information is lower than the preset power threshold, the server reduces the corresponding measurement cycle in the displacement monitoring work table, so that the corresponding central control station, base station or monitoring point is in energy-saving working mode to ensure that the equipment can still work under a certain power state; When the solar panels of the central control station, base station or monitoring point in energy-saving working mode charge the battery back to the set value, the server automatically adjusts the corresponding measurement cycle in the displacement monitoring work table back to the original measurement cycle, so that the displacement monitoring system works normally.

12. The UWB-based displacement monitoring method according to claim 1, characterized in that: Each of the devices includes a first UWB antenna, a first UWB chip and a first MCU connected in sequence, and a first power supply unit for supplying power.

13. The UWB-based displacement monitoring method according to claim 12, characterized in that: Each of the devices further includes a positioning module, which is connected to the first MCU and is used to monitor the positioning information of the device.

14. The UWB-based displacement monitoring method according to claim 11, characterized in that: The central control station includes a second UWB antenna, a second UWB chip, a second MCU, a second power supply unit for power supply, and a wireless communication module for communication connection via a wireless network, which are connected in sequence.

15. The UWB-based displacement monitoring method according to claim 14, characterized in that: The central control station further includes a positioning module, which is connected to the second MCU and is used to monitor the positioning information of the central control station.

16. The UWB-based displacement monitoring method according to claim 15, characterized in that: The central control station also includes a rainfall monitoring module and other environmental monitoring equipment connected to the second MCU, which are used to monitor rainfall information and other environmental information in the area where the central control station is located, and transmit the information to the server through the network.

17. The UWB-based displacement monitoring method according to any one of claims 14 to 16, characterized in that: The second MCU is implemented by two connected MCUs.

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