A wireless communication method applied to a three-dimensional displacement measuring device

Abstract

The application discloses a wireless communication method applied to a three-dimensional displacement measuring device for underground displacement. The device comprises a three-dimensional displacement measuring sensor array for underground displacement formed by multiple sensor units and a ground management terminal. The ground management terminal is connected with the uppermost sensor unit by wire, and the rest of the sensor units are connected by wireless communication. After initial power-on, each sensor unit is in standby mode and communicates with the upper adjacent sensor unit. The ground management terminal sends a command to the Nth sensor unit, and then continuously communicates between the adjacent sensor units from top to bottom to wake up each sensor unit in turn. After being woken up, each sensor unit is set as a slave of the lower sensor unit. Until the 1st sensor unit is automatically woken up by timing, each sensor unit is woken up in turn to perform data measurement and transmission by continuously communicating between the adjacent sensor units from bottom to top. The application can effectively solve the problems caused by the use of wired communication, so that the system can be applied to various complex field working environments.

Description

Technical Field

[0001] This invention relates to a communication control method in the field of geological disaster monitoring, specifically a wireless communication method for an underground displacement measuring device. Background Technology

[0002] To monitor landslides in real time and issue early warnings before they occur, the applicant previously proposed a three-dimensional underground displacement measurement sensor based on dual-mutual-inductance equivalent voltage. This sensor array uses power lines and an RS485 bus to connect sensors in series, measuring the relative displacement between adjacent sensor units to reflect the displacement of the soil and rock mass from the surface to deeper underground within the measurement area. However, because four wires (power line and RS485 bus) are used to connect the sensor units in series, problems such as incomplete soldering and incorrect soldering are inevitable during sensor welding. During the overall transportation of the device, wire breaks can easily cause system failures. Furthermore, the installation process requires a large number of personnel. Therefore, using four wires to connect the sensor units in series significantly increases the difficulty of welding, transporting, and installing the entire system. Summary of the Invention

[0003] Based on the above background, in order to solve the problems caused by using RS485 bus to connect underground displacement three-dimensional measurement sensors, this invention proposes a wireless communication method for underground displacement three-dimensional measurement devices, thus solving the problem of wired communication in the system.

[0004] To achieve the objectives of this invention, the following technical solution is proposed:

[0005] The present invention includes a sensor control board for a three-dimensional underground displacement measurement sensor, a ground management terminal, and a wireless communication method for the three-dimensional underground displacement measurement sensor array.

[0006] The method employs a three-dimensional underground displacement measurement device comprising a three-dimensional underground displacement measurement sensor array and a ground management terminal. The three-dimensional underground displacement measurement sensor array is formed by using a three-dimensional underground displacement measurement sensor as a sensor unit, transmitting data between multiple three-dimensional underground displacement measurement sensors via wireless communication, and connecting them in series using a power bus. The ground management terminal is connected to only one sensor unit of the three-dimensional underground displacement measurement sensor array via a power cable and an RS485 communication cable.

[0007] In the aforementioned three-dimensional underground displacement measurement sensor array, each sensor unit is arranged at intervals along the depth direction underground, and the ground management terminal is connected to the Nth sensor unit closest to the ground in the three-dimensional underground displacement measurement sensor array.

[0008] The underground displacement three-dimensional measurement sensor array is arranged underground, with its bottom end extending to the bedrock of the mountain. The ground management terminal is arranged on the surface of the mountain and is connected to the user's computer and the Internet of Things platform.

[0009] The aforementioned three-dimensional underground displacement measurement sensor includes an iron core coil, a sensor control board, a base plate, a hollow coil, and a PVC sleeve. The hollow coil is installed inside the PVC sleeve, and the iron core coil, sensor control board, and base plate are installed inside the hollow coil. The hollow coil and the iron core coil are arranged coaxially, and both the hollow coil and the iron core coil are electrically connected to the sensor control board. The sensor control board is connected to an external power source via two power lines.

[0010] Both ends of the PVC sleeve are sealed with glue.

[0011] The hollow coil and iron core coil are used to excite the hollow coil inside the underground displacement three-dimensional measurement sensor above the underground displacement three-dimensional measurement sensor where they are located, so that it generates a sinusoidal signal;

[0012] The sensor control board 303 is used to output a sinusoidal excitation signal, read the sinusoidal signal generated by the hollow coil 305 of the underground displacement three-dimensional measurement sensor located at its own location, read the attitude data, and exchange data with the underground displacement three-dimensional measurement sensor above or below through wireless communication.

[0013] The base plate 304 is used to fix the position of the magnetic core coil and the sensor control board inside the hollow coil.

[0014] The sensor control board includes a microprocessor, a signal selection module, a signal processing module, an attitude measurement module, a wireless communication module, a power supply module, and coils. The coils are divided into air-core coils and iron-core coils, which are connected via the signal selection module and the signal processing module. The microprocessor is connected to the signal processing module, the attitude measurement module, the wireless communication module, and the power supply module. The microcontroller controls whether the signal selection module is connected to the air-core coil or the iron-core coil, and selects whether to send or receive an excitation signal.

[0015] The microcontroller is a single-chip microcontroller that samples and processes the signal returned by the signal processing module through its on-chip ADC, reads the attitude data of its own unit collected by the attitude measurement module, exchanges data with the sensor unit above or below via the serial port through the wireless communication module, controls the power supply module to work, and generates a sine wave. The waveform amplitude table of the sine wave is stored in the on-chip ROM. The microcontroller sets the internal DMA channel to output the single-cycle pulse of the sine wave to the on-chip DAC. The frequency of the sine wave is set by setting the speed of the sine wave. The output stable sine wave is used to excite the air coil in the sensor above by passing through the air coil or magnetic coil of its own unit.

[0016] The signal selection module includes an analog switch and its peripheral circuitry, used to output the sinusoidal signal generated by the microcontroller DAC to the air-core coil or to output the sinusoidal signal generated by the excitation of the air-core coil to the signal processing module.

[0017] The signal processing module includes an instrumentation amplifier and an RMS converter and their peripheral circuitry. The instrumentation amplifier is used to differentially amplify the output voltage of the air-core coil before inputting it to the RMS converter for processing. The RMS converter is used to convert the signal output from the instrumentation amplifier before inputting it to the microcontroller for ADC sampling.

[0018] The attitude measurement module is used to collect attitude data from the underground displacement three-dimensional measurement sensor where it is located and transmit it to the microcontroller via serial port;

[0019] The wireless communication module is used to wake up the microcontroller in the sensor control board of the underground displacement three-dimensional measurement sensor located at its location, exchange data with the microcontroller through the serial port, and form a master or slave unit with the above or below underground displacement three-dimensional measurement sensor. Only when configured as a master and slave unit can the two wireless communication modules exchange data and transmit signals.

[0020] The power module is used to generate a 3.3V voltage to power the microcontroller, attitude measurement module, and wireless communication module, and to generate a voltage controlled by the microcontroller to power the signal selection module and signal processing module. 5V voltage.

[0021] Adjacent sensor units establish a communication connection by issuing commands through their respective wireless communication modules; after establishing communication between adjacent sensor units, interactive control is performed as follows:

[0022] When the microcontroller of one sensor unit controls its connected signal selection module to send a sinusoidal excitation signal to the air-core / iron-core coil to generate a sinusoidal signal, the iron-core coil of another sensor unit receives the sinusoidal signal and sends it to the signal processing module through its connected signal selection module. The signal processing module identifies the sinusoidal signal, obtains the mutual inductance voltage, and sends it to the signal processing module for storage. At the same time, the microcontroller of the sensor unit controls its own attitude measurement module to measure and obtain attitude data, and saves it in the microcontroller.

[0023] The serial numbers of each sensor unit in the underground displacement three-dimensional measurement sensor array are set to natural numbers from 1 to N in order from the bottom to the closest to the ground. Only the bottommost sensor unit 1 has a fixed standby time preset after being woken up.

[0024] After the first power-on, each sensor unit in the underground displacement three-dimensional measurement sensor array is configured to wirelessly communicate with the sensor unit adjacent to it above. Then, each underground displacement three-dimensional measurement is performed in the following manner.

[0025] Phase One Process:

[0026] Initially, each sensor unit is in a disconnected or standby state. The ground management terminal issues a work command to initiate the first phase of the process, which is then sent to sensor unit N, waking it up and putting it into working mode. Then, each sensor unit is sequentially woken up by communicating between adjacent sensor units from top to bottom, ensuring that after waking up, each sensor unit is configured as a slave to the sensor unit directly below it:

[0027] Sensor unit i+1 is configured as the master of sensor unit i. It sends a wake-up command to sensor unit i to wake it up and start working. After receiving the wake-up command, sensor unit i is awakened and returns a wake-up command to sensor unit i+1, so that sensor unit i+1 and sensor unit i can successfully connect wirelessly. After receiving the wake-up command, sensor unit i+1 is configured as the slave of sensor unit i and enters standby mode.

[0028] After sensor unit 1 is awakened, it enters standby mode after a pre-set fixed wake-up time;

[0029] Second phase process:

[0030] After a pre-set fixed standby time, sensor unit 1 is automatically woken up and enters the working state. At this time, the wireless connection of each sensor unit is disconnected, and the process enters the next stage. Then, in the following manner, communication processing is continuously carried out between two adjacent sensor units from bottom to top to wake up each sensor unit in turn to carry out data measurement and data transmission.

[0031] In the second stage of the process, the communication between two adjacent sensor units is processed as follows:

[0032] S1, sensor unit i is configured as the host of sensor unit i+1. Sensor unit i sends wake-up commands to sensor unit i+1 in a loop to wake up sensor unit i+1 to start working. Sensor unit i+1 is woken up after receiving the wake-up command and then returns a wake-up command to sensor unit i.

[0033] S2. After receiving the wake-up command returned by sensor unit i+1, sensor unit i prepares for the excitation signal operation and cyclically sends the zeroth command F0 to sensor unit i+1. The preparation of the excitation signal includes the microprocessor control signal selection module switching to the air-core coil and generating a constant frequency sine wave signal to be transmitted to the air-core coil. After receiving the zeroth command F0, sensor unit i+1 prepares for signal processing and returns the zeroth command F0 to sensor unit i. The preparation of signal processing includes the microprocessor control signal selection module switching to the air-core coil and the air-core coil being connected to the signal processing module.

[0034] S3. After receiving the zeroth instruction F0 from sensor unit i+1, sensor unit i continuously sends the first instruction F1 to sensor unit i+1. Sensor unit i+1 receives the first instruction F1, completes the first signal acquisition, and then returns the first instruction F1 to sensor unit i.

[0035] S4. After receiving the first instruction F1 returned by sensor unit i+1, sensor unit i updates the excitation signal and cyclically sends the second instruction F2 to sensor unit i+1. The updated excitation signal includes the microprocessor control signal selection module switching to the magnetic core coil and generating the same sine wave signal to transmit to the magnetic core coil. Sensor unit i+1 receives the second instruction F2, completes the second signal acquisition, and then returns the second instruction F2 to sensor unit i.

[0036] Both the first and second signal acquisitions include the microprocessor turning on the signal processing module, processing the signal sent by the signal processing module to obtain mutual inductance voltage data and saving it, and then turning off the signal processing module.

[0037] After receiving the second instruction F2 from sensor unit i+1, sensor unit i shuts down the excitation signal and cyclically sends the third instruction F3 to sensor unit i+1. The shutdown of the excitation signal includes the microprocessor stopping the output of the sine wave signal to the magnetic core coil. Sensor unit i+1 receives the third instruction F3 and completes the third signal acquisition. The third signal acquisition includes turning on the attitude measurement module, having the attitude measurement module read the attitude data and store it in the microprocessor, and then turning off the attitude measurement module. Sensor unit i+1 combines the data obtained from the three signal acquisitions into underground three-dimensional data and then returns the third instruction F3 to sensor unit i.

[0038] S6. After receiving the third instruction F3 returned by sensor unit i+1, sensor unit i sequentially extracts the underground 3D data from sensor unit 1 to itself (sensor unit i) from the data stored in its own microprocessor, integrates it into the fourth instruction F4, and sends it sequentially. Sensor unit i+1 receives the fourth instruction F4, saves the data, and returns the fourth instruction F4 to sensor unit i. This process continues until sensor unit i receives the fourth instruction F4 returned by sensor unit i+1, which covers all the underground 3D data from sensor unit 1 to itself (sensor unit i). Then, sensor unit i sends the fifth instruction F5 to sensor unit i+1. After receiving the fifth instruction F5, sensor unit i+1 returns a work completion instruction and updates its configuration to become the master of sensor unit i+2. At the same time, sensor unit i receives the work completion instruction returned by sensor unit i+1, updates its configuration to become the slave of sensor unit i+1, and enters standby mode.

[0039] S7. Repeat steps S1 to S6 from bottom to top to complete data measurement and data transmission until sensor unit N receives the fifth instruction F5 from sensor unit N-1 and returns the work end instruction. Then, sensor unit N updates its configuration as a slave of the ground management terminal and transmits the data to the ground management terminal through the RS485 bus. After the data transmission is completed, sensor unit N enters standby mode.

[0040] Specifically, S6 is:

[0041] S61, Sensor unit i receives the third instruction F3 returned by sensor unit i+1;

[0042] S62, Sensor unit i integrates the underground three-dimensional data of sensor unit x into the fourth instruction F4 to form the fourth instruction F4x and sends it to sensor unit i+1. Sensor unit i+1 receives the fourth instruction F4x, saves the data, and returns the fourth instruction F4x to sensor unit i. Sensor unit i receives the fourth instruction F4x returned by sensor unit i+1.

[0043] S63. Repeat step S62 in the order of x from 1 to i until sensor unit i sends the fifth instruction F5 to sensor unit i+1 after receiving the fourth instruction F4i returned by sensor unit i+1.

[0044] After receiving the fifth instruction F5, sensor unit i+1 returns a work completion instruction and updates its configuration to become the master of sensor unit i+2. At the same time, sensor unit i receives the work completion instruction returned by sensor unit i+1, updates its configuration to become the slave of sensor unit i+1, and enters standby mode.

[0045] The aforementioned wake-up commands and F0 to F5 commands are all transmitted between the wireless communication modules of adjacent sensor units.

[0046] Thus, in this invention, the sensor units in the underground displacement three-dimensional measurement sensor array have five working states: slave standby, upper slave, lower master, lower slave, and upper master. When idle, the sensor unit is in slave standby state; after the ground management terminal issues a working command, the working state of the sensor unit changes sequentially from upper slave, lower master, slave standby, lower slave, upper master, and slave standby. Based on the change of working state, the sensor units automatically complete the measurement work.

[0047] The beneficial effects of this invention are:

[0048] The initial design of the underground displacement three-dimensional measurement sensor array of the present invention adopts a wired method, that is, four wires are connected in series. This method makes the overall welding, transportation and installation of the system more difficult.

[0049] The present invention utilizes a wireless communication method in a three-dimensional underground displacement measurement sensor array, which can effectively solve the problems caused by the use of wired communication in the system, making the system applicable to various complex field working environments. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall workflow of the underground displacement three-dimensional measurement system of the present invention.

[0051] Figure 2 This is a schematic diagram of the ground management terminal structure of the present invention.

[0052] Figure 3 This is a schematic diagram of the underground displacement three-dimensional measurement sensor structure of the present invention.

[0053] Figure 4 This is a schematic diagram of the working module of the underground displacement three-dimensional measurement sensor of the present invention.

[0054] Figure 5This is a schematic diagram of the idle working state of the underground displacement three-dimensional measurement sensor array of the present invention.

[0055] Figure 6 This is a schematic diagram of the working state of the underground displacement three-dimensional measurement sensor array of the present invention from top to bottom.

[0056] Figure 7 This is a schematic diagram of the working state of the underground displacement three-dimensional measurement sensor array of the present invention from bottom to top.

[0057] Table 1 shows the wireless communication function code settings of the present invention.

[0058] Wherein: 101—User computer, 102—Internet of Things platform, 103—Mountain surface, 104—Ground management terminal, 105—Underground displacement three-dimensional measurement sensor array, 106—Mountain bedrock;

[0059] 202—Two power cables and two RS485 communication cables;

[0060] 301—Iron core coil, 302—Two power lines, 303—Sensor control board, 304—Base plate, 305—Air core coil, 306—PVC sleeve. Detailed Implementation

[0061] The following is in conjunction with the appendix Figures 1-6 The present invention will be described in further detail below.

[0062] This invention discloses a wireless communication method for a three-dimensional underground displacement measurement device, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, it includes the overall system workflow, the ground management terminal structure, the underground displacement three-dimensional measurement sensor structure, the sensor power-on workflow, the sensor wake-up workflow from top to bottom, and the sensor wake-up workflow from bottom to top.

[0063] like Figure 1 As shown, the underground displacement three-dimensional measurement device used in the method includes an underground displacement three-dimensional measurement sensor array 105 and a ground management terminal 104. The underground displacement three-dimensional measurement sensor array 105 is formed by using an underground displacement three-dimensional measurement sensor as a sensor unit, transmitting data between multiple underground displacement three-dimensional measurement sensors via wireless communication, and connecting them in series using a power bus. The ground management terminal 104 is connected to only one sensor unit of the underground displacement three-dimensional measurement sensor array via a power line and an RS485 communication line 202.

[0064] Reference Figure 2In the underground displacement three-dimensional measurement sensor array 105, each sensor unit is arranged at intervals along the depth direction underground, and the ground management terminal 104 is connected to the Nth sensor unit closest to the ground in the underground displacement three-dimensional measurement sensor array.

[0065] The ground management terminal 104 is mainly used to receive, store and display three-dimensional underground displacement data, process remote commands from users, and activate the three-dimensional underground displacement measurement sensor array 105 to perform its work.

[0066] The underground displacement three-dimensional measurement sensor array 105 is arranged underground, and its bottom end extends to the bedrock 106 of the mountain. The ground management terminal 104 is arranged on the mountain surface 103. The ground management terminal 104 is connected to the user computer 101 and the Internet of Things platform 102 respectively.

[0067] The ground management terminal 104 is placed on the mountain surface 103. A borehole is drilled to the bedrock 106 to bury the underground displacement three-dimensional measurement sensor array 105 within the mountain, ensuring that sensor number 1 is positioned on the bedrock 106. The ground management terminal 104 controls the underground displacement three-dimensional measurement sensor array 105 to acquire underground displacement three-dimensional data. Users can use their computers 101 to view the underground displacement three-dimensional data transmitted by the ground management terminal 104 via the Internet of Things (IoT) platform 102, and can also control the operation of the ground management terminal 104 through the IoT platform 102, enabling remote monitoring of underground displacement three-dimensional information.

[0068] like Figure 3 As shown, the underground displacement three-dimensional measurement sensor includes an iron core coil 301, a sensor control board 303, a base plate 304, a hollow coil 305, and a PVC sleeve 306. The hollow coil 305 is installed inside the PVC sleeve 306. The iron core coil 301, the sensor control board 303, and the base plate 304 are installed inside the hollow coil 305. The hollow coil 305 and the iron core coil 301 are arranged coaxially. Both the hollow coil 305 and the iron core coil 301 are electrically connected to the sensor control board 303. The sensor control board 303 is connected to an external power source on the ground via two power lines 302.

[0069] In practice, the iron core coil 301 and the sensor control board 303 are mounted on the base plate 304. The base plate 304 is fixed inside the hollow coil 305 so that the iron core coil 301 and the hollow coil 305 are concentric. The hollow coil 305 is placed inside the PVC sleeve 306 and filled with sealant. Two power lines 302 are used to connect each sensor unit in series to form a three-dimensional underground displacement measurement sensor array, ensuring the power supply needs of each sensor.

[0070] like Figure 4As shown, the sensor control board 303 includes a microprocessor, a signal selection module, a signal processing module, an attitude measurement module, a wireless communication module, a power supply module, and coils. The coils are divided into air-core coils 305 and iron-core coils 301. The air-core coils 305 and iron-core coils 301 are connected to the signal selection module and the signal processing module. The microprocessor is connected to the signal processing module, the attitude measurement module, the wireless communication module, and the power supply module respectively. The microcontroller controls whether the signal selection module is connected to the air-core coil 305 or the iron-core coil 301, and selects whether to send or receive an excitation signal.

[0071] Reference Figure 4 A schematic diagram of the working module of the underground displacement three-dimensional measurement sensor array 105 is shown. The sensor unit is divided into 7 working modules. Each module is controlled by a microprocessor and the status control of the upper or lower sensor unit is realized through data transmission of the wireless communication module.

[0072] Adjacent sensor units establish a communication connection through their respective wireless communication modules by issuing commands, thereby enabling interactive control. For example, the master sensor unit sends a wake-up signal from its own wireless communication module to search for slave signals, and the slave sensor unit's wireless communication module receives the wake-up signal, waking up the slave sensor unit. Alternatively, the master sensor unit sends a fixed command to the slave sensor unit from its own wireless communication module, and the slave sensor unit receives and executes the command.

[0073] After establishing communication between adjacent sensor units, interactive control is performed as follows:

[0074] When the microcontroller of one sensor unit controls the signal selection module connected to it to send a sinusoidal excitation signal to the air core coil 305 / iron core coil 301 to generate a sinusoidal signal, the iron core coil 301 of another sensor unit receives the sinusoidal signal and then sends it to the signal processing module connected to it through the signal selection module connected to it. The signal processing module recognizes the sinusoidal signal, obtains the mutual inductance voltage, and sends it to the signal processing module connected to it for storage.

[0075] When the air-core coil 305 and the iron-core coil 301 of one sensor unit generate sinusoidal signals in sequence, the iron-core coil 301 of another sensor unit receives two different sinusoidal signals, thereby obtaining two different mutual inductance voltages.

[0076] Meanwhile, the microcontroller of the sensor unit controls its own attitude measurement module to measure and obtain attitude data, and then saves it in the microcontroller.

[0077] Finally, the two different mutual inductance voltage and attitude data stored in the microcontroller of one sensor unit are sent to the microcontroller of another sensor unit through communication control and interactive control, and are then transmitted between the various sensor units in sequence, and finally sent to the ground management terminal 104.

[0078] The serial numbers of each sensor unit in the underground displacement three-dimensional measurement sensor array 105 are set to natural numbers from 1 to N in order from the bottom to the closest to the ground. The ground management terminal 104 and the closest sensor unit N are connected via an RS485 bus. Only the bottom sensor unit 1 has a fixed standby time preset after being woken up, that is, after the bottom sensor unit is woken up, it will automatically wake up after the fixed standby time.

[0079] Reference Figure 5 The power-on process diagram of the underground displacement three-dimensional measurement sensor array is as follows: After the sensor unit is powered on for the first time, the sensor unit is configured to communicate wirelessly with the sensor unit adjacent to it above. The wireless connection of each sensor unit is disconnected. Then the underground displacement three-dimensional measurement sensor array 105) enters standby mode and waits for the working instructions issued by the ground management terminal 104 to carry out the first stage process.

[0080] Reference Figure 6 The underground displacement three-dimensional measurement sensor array wake-up process diagram from top to bottom: The ground management terminal 104 sends a working command to sensor unit N, waking up sensor unit N and putting it into normal working mode. At this time, sensor unit N is configured as the master of sensor unit N-1 and sends a wake-up command to sensor unit N-1 to wake it up and start working. After receiving the wake-up command, sensor unit N-1 returns a wake-up command to sensor unit N, so that sensor unit N and sensor unit N-1 can successfully connect wirelessly. After receiving the wake-up command, sensor unit N is configured as the slave of sensor unit N-1 and enters standby mode. Sensor unit N-1 then configures itself as the master of sensor unit N-2.

[0081] Following this pattern, sensor unit i+1 is configured as the master of sensor unit i. After waking up sensor unit i, sensor unit i+1 is configured as the slave of sensor unit i and enters standby mode. Sensor unit i is then configured as the master of sensor unit i-1. This process is repeated from top to bottom, waking up the sensor string sequentially, with each sensor unit being configured as both the master and slave of the sensor unit immediately below it.

[0082] After sensor unit 1 completes its current workflow, it enters a standby state that will be woken up periodically after a fixed standby time. At this time, the wireless connection of each sensor unit is disconnected, and the sensor array enters the next stage of the process.

[0083] go through Figure 6 The workflow is as follows: Sensor unit 1 is woken up after a preset fixed standby time and its configuration is updated to match that of sensor unit 2. The underground displacement three-dimensional measurement sensor array (105) then begins the wake-up and data measurement and transmission work from bottom to top. Sensor unit i and sensor unit i+1 are randomly selected, such as... Figure 7 As shown, its working process is as follows:

[0084] 1. After sensor unit i, acting as the master of sensor unit i+1, and sensor unit i+1, acting as the slave of sensor unit i, successfully establish a wireless connection, sensor unit i+1 is awakened. Sensor unit i sends wake-up commands cyclically, and sensor unit i+1 returns a wake-up command to sensor unit i after receiving the command.

[0085] 2. After receiving the wake-up command from sensor unit i+1, sensor unit i prepares for the excitation signal (including the microprocessor-controlled power supply module of sensor unit i generating...). A 5V voltage supplies power to the signal selection module, controlling it to switch between connections to the air-core coil. Specifically, the signal selection module is connected to one end of the air-core coil, while the other end is grounded. The microprocessor generates a constant-frequency sine wave signal and transmits it to the air-core coil. It cyclically sends the zeroth instruction F0 to sensor unit i+1. Upon receiving the zeroth instruction F0, sensor unit i+1 prepares for signal processing (including the microprocessor controlling the power supply module of sensor unit i+1 to generate...). The 5V voltage supplies power to the signal selection module, which controls the switching connection to the air coil. The two ends of the air coil are then transmitted to the signal processing module as a differential signal. Then, the zero instruction F0 is returned to the i-th sensor unit.

[0086] 3. After receiving the zeroth instruction F0 returned by sensor unit i+1, sensor unit i sends the first instruction F1 to sensor unit i+1 in a loop. Sensor unit i+1 receives the first instruction F1 and completes the first signal acquisition work (including the microprocessor turning on the signal processing module, sampling and processing the signal sent by the signal processing module through its own internal analog-to-digital converter ADC to obtain mutual inductance voltage data and save the data, and then turning off the signal processing module). Then it returns the first instruction F1 to sensor unit i.

[0087] 4. After receiving the first instruction F1 returned by sensor unit i+1, sensor unit i updates the excitation signal (including the microprocessor controlling the signal selection module to switch the connection to the magnetic core coil, i.e., the signal selection module is connected to one end of the magnetic core coil, and the other end of the magnetic core coil is grounded; the microprocessor stops outputting the sine wave signal to the air core coil, generates a sine wave signal that is the same as before, and transmits the sine wave signal to the magnetic core coil), and cyclically sends the second instruction F2 to sensor unit i+1. Sensor unit i+1 receives the second instruction F2 and completes the second signal acquisition work (including the microprocessor turning on the signal processing module, sampling and processing the signal sent by the signal processing module through its own internal analog-to-digital converter ADC to obtain mutual inductance voltage data and save the data, and then turning off the signal processing module), and then returns the second instruction F2 to sensor unit i.

[0088] 5. After receiving the second instruction F2 from sensor unit i+1, sensor unit i shuts down the excitation signal (including the microprocessor stopping the output of the sine wave signal to the magnetic core coil). It then sends the third instruction F3 to sensor unit i+1 in a loop. Sensor unit i+1 receives the third instruction F3 and completes the third signal acquisition (including turning on its internal attitude measurement module, which reads the attitude data and stores it in the microprocessor before turning off the attitude measurement module). Then it returns the third instruction F3 to sensor unit i.

[0089] At this point, sensor unit i+1 combines the data obtained from the three signal acquisition operations into underground three-dimensional data, that is, the mutual inductance voltage from the first two acquisitions and the attitude data from the third acquisition are combined to form underground three-dimensional data.

[0090] 6. After receiving the third instruction F3 returned by sensor unit i+1, sensor unit i extracts the underground three-dimensional data from sensor unit 1 to itself i from the data stored in its own microprocessor, integrates it into the fourth instruction F4, and sends it sequentially. Sensor unit i+1 receives the fourth instruction F4, saves the data, and returns the fourth instruction F4 to sensor unit i.

[0091] Specifically, in the order of x from 1 to i, sensor unit i integrates the underground three-dimensional data of sensor unit x into the fourth instruction F4 to form the fourth instruction F4x and sends it to sensor unit i+1. After receiving the fourth instruction F4x, sensor unit i+1 saves the data and returns the fourth instruction F4x, indicating that the underground three-dimensional data of sensor unit x has been received.

[0092] When x=i, it means that sensor unit i+1 has completed receiving the underground three-dimensional data collected by sensor unit i and returns the fourth instruction F4i. At this time, it indicates that sensor unit i+1 has stored all the underground three-dimensional data from sensor unit 1 to sensor unit i.

[0093] 7. After receiving all the fourth instructions F4 returned by sensor unit i+1, sensor unit i sends the fifth instruction F5 to sensor unit i+1. After receiving the fifth instruction F5, sensor unit i+1 returns a work completion instruction and updates its configuration to become the master of sensor unit i+2. At the same time, sensor unit i receives the work completion instruction returned by sensor unit i+1, updates its configuration to become the slave of sensor unit i+1, and enters standby mode.

[0094] Specifically, after receiving the fourth instruction F4i returned by sensor unit i+1, sensor unit i sends the fifth instruction F5 to sensor unit i+1. After receiving the fifth instruction F5, sensor unit i+1 returns a work completion instruction and updates its configuration to become the master of sensor unit i+2. At the same time, sensor unit i receives the work completion instruction returned by sensor unit i+1, updates its configuration to become the slave of sensor unit i+1, and enters standby mode.

[0095] Following this pattern, the sensor array completes a measurement and data transmission from bottom to top. Once sensor unit N receives the fifth instruction F5 from sensor unit N-1 and returns a work completion instruction, sensor unit N finishes its work, updates its configuration to become a slave of the ground management terminal (104), and returns the data to the ground management terminal (104) via the RS485 bus. After the data transmission is completed, sensor unit N enters standby mode. The ground management terminal (104) saves, displays, and transmits the data to the Internet of Things platform for users to view remotely.

[0096] The master-slave configuration in the above process of this invention can establish a fixed communication relationship between sensor units in the next communication, and cannot be interfered with or affected by other sensor units. For example, configuring sensor unit i as the slave of sensor unit i+1 enables sensor unit i to communicate only with sensor unit i+1 and can only be woken up by sensor unit i+1. This ensures that the sensors communicate sequentially, resulting in the characteristic that when a single sensor fails to work properly, the sensors above and below it can re-network and communicate, achieving the advantage that when a single sensor fails, the other sensors can still work normally.

Claims

1. A wireless communication method for a three-dimensional underground displacement measurement device, characterized in that: The method uses a three-dimensional underground displacement measurement device comprising a three-dimensional underground displacement measurement sensor array (105) and a ground management terminal (104). The three-dimensional underground displacement measurement sensor array (105) is formed by using a three-dimensional underground displacement measurement sensor as a sensor unit, transmitting data between multiple three-dimensional underground displacement measurement sensors via wireless communication, and connecting them in series using a power bus. The ground management terminal (104) is connected to only one sensor unit of the three-dimensional underground displacement measurement sensor array via a power line and an RS485 communication line (202). The aforementioned three-dimensional underground displacement measurement sensor includes an iron core coil (301), a sensor control board (303), a base plate (304), a hollow coil (305), and a PVC sleeve (306); the hollow coil (305) is installed inside the PVC sleeve (306), and the iron core coil (301), the sensor control board (303), and the base plate (304) are installed inside the hollow coil (305). The hollow coil (305) and the iron core coil (301) are arranged coaxially. Both the hollow coil (305) and the iron core coil (301) are electrically connected to the sensor control board (303), and the sensor control board (303) is connected to an external power source via two power lines (302). The sensor control board (303) includes a microprocessor, a signal selection module, a signal processing module, an attitude measurement module, a wireless communication module, a power supply module, and coils. The coils are divided into air-core coils (305) and iron-core coils (301). The air-core coils (305) and iron-core coils (301) are connected via the signal selection module and the signal processing module. The microprocessor is connected to the signal processing module, the attitude measurement module, the wireless communication module, and the power supply module, respectively. The microprocessor controls whether the signal selection module is connected to the air-core coil (305) or the iron-core coil (301), and selects whether to send or receive an excitation signal. Adjacent sensor units establish communication connections by issuing commands through their respective wireless communication modules; after establishing communication between adjacent sensor units, interactive control is performed as follows: When the microprocessor of one sensor unit controls its connected signal selection module to send a sinusoidal excitation signal to the air-core coil (305) / iron-core coil (301) to generate a sinusoidal signal, the iron-core coil (301) of another sensor unit receives the sinusoidal signal and sends it to the signal processing module through its connected signal selection module. The signal processing module recognizes the sinusoidal signal, obtains the mutual inductance voltage, and sends it to the signal processing module for storage. At the same time, the microprocessor of the sensor unit controls its own attitude measurement module to measure and obtain attitude data, and saves it in the microprocessor.

2. The wireless communication method for a three-dimensional underground displacement measurement device according to claim 1, characterized in that: In the underground displacement three-dimensional measurement sensor array (105), each sensor unit is arranged at intervals along the depth direction underground, and the ground management terminal (104) is connected to the Nth sensor unit closest to the ground in the underground displacement three-dimensional measurement sensor array.

3. The wireless communication method for a three-dimensional underground displacement measurement device according to claim 1, characterized in that: The underground displacement three-dimensional measurement sensor array (105) is arranged underground and its bottom end extends to the bedrock of the mountain (106). The ground management terminal (104) is arranged on the surface of the mountain (103). The ground management terminal (104) is connected to the user computer (101) and the Internet of Things platform (102) respectively.

4. The wireless communication method for a three-dimensional underground displacement measurement device according to claim 1, characterized in that: The serial numbers of each sensor unit in the underground displacement three-dimensional measurement sensor array (105) are set to natural numbers from 1 to N in order from the bottom to the closest to the ground. Only the bottommost sensor unit 1 has a fixed standby time preset after being woken up. After the first power-on, each sensor unit in the underground displacement three-dimensional measurement sensor array (105) is configured to wirelessly communicate with the sensor unit adjacent to it above. Then, each underground displacement three-dimensional measurement is performed in the following manner. Phase One Process: Initially, each sensor unit is in standby mode. The ground management terminal (104) issues a working command to sensor unit N, waking it up. Then, each sensor unit is woken up sequentially by communicating between adjacent sensor units from top to bottom, so that after being woken up, each sensor unit is configured as a slave of the sensor unit below it: Sensor unit i+1 is configured as the master of sensor unit i. It sends a wake-up command to sensor unit i to wake it up and start working. After receiving the wake-up command, sensor unit i is awakened and returns a wake-up command to sensor unit i+1, so that sensor unit i+1 and sensor unit i can successfully connect wirelessly. After receiving the wake-up command, sensor unit i+1 is configured as the slave of sensor unit i and enters standby mode. It will enter standby mode after sensor unit 1 is woken up; Second phase process: Sensor unit 1 is automatically woken up after a pre-set fixed standby time. Then, it continuously communicates and processes data between adjacent sensor units from bottom to top, thereby waking up each sensor unit in turn to perform data measurement and data transmission.

5. The wireless communication method for a three-dimensional underground displacement measurement device according to claim 4, characterized in that: In the second stage of the process, the communication between two adjacent sensor units is processed as follows: S1, sensor unit i is configured as the host of sensor unit i+1. Sensor unit i sends wake-up commands to sensor unit i+1 in a loop. Sensor unit i+1 is woken up after receiving the wake-up command and then returns a wake-up command to sensor unit i. After receiving the wake-up command returned by sensor unit i+1, sensor unit i prepares an excitation signal and cyclically sends the zeroth command F0 to sensor unit i+1. The preparation of the excitation signal includes the microprocessor control signal selection module switching to the air-core coil and generating a constant frequency sine wave signal to be transmitted to the air-core coil. After receiving the zeroth command F0, sensor unit i+1 prepares signal processing and returns the zeroth command F0 to sensor unit i. The preparation of signal processing includes the microprocessor control signal selection module switching to the air-core coil and the air-core coil being connected to the signal processing module. S3. After receiving the zeroth instruction F0 from sensor unit i+1, sensor unit i continuously sends the first instruction F1 to sensor unit i+1. Sensor unit i+1 receives the first instruction F1, completes the first signal acquisition, and then returns the first instruction F1 to sensor unit i. S4. After receiving the first instruction F1 returned by sensor unit i+1, sensor unit i updates the excitation signal and cyclically sends the second instruction F2 to sensor unit i+1. The updated excitation signal includes the microprocessor control signal selection module switching the connection to the iron core coil (301) and generating a sine wave signal to transmit to the iron core coil (301). Sensor unit i+1 receives the second instruction F2, completes the second signal acquisition, and then returns the second instruction F2 to sensor unit i. Both the first and second signal acquisitions include the microprocessor turning on the signal processing module, processing the signal sent by the signal processing module to obtain mutual inductance voltage data and saving it, and then turning off the signal processing module. After receiving the second instruction F2 returned by sensor unit i+1, sensor unit i shuts down the excitation signal and cyclically sends the third instruction F3 to sensor unit i+1. The shutdown of the excitation signal includes the microprocessor stopping the output of the sine wave signal to the iron core coil (301). Sensor unit i+1 receives the third instruction F3 and completes the third signal acquisition. The third signal acquisition includes turning on the attitude measurement module, having the attitude measurement module read the attitude data and store it in the microprocessor, and then turning off the attitude measurement module. Sensor unit i+1 combines the data obtained from the three signal acquisitions into underground three-dimensional data and then returns the third instruction F3 to sensor unit i. S6. After receiving the third instruction F3 returned by sensor unit i+1, sensor unit i sequentially extracts the underground 3D data from sensor unit 1 to itself i from the data stored in its own microprocessor, integrates it into the fourth instruction F4, and sends it sequentially. Sensor unit i+1 receives the fourth instruction F4, saves the data, and returns the fourth instruction F4 to sensor unit i. This continues until sensor unit i receives all the fourth instructions F4 returned by sensor unit i+1, at which point it sends the fifth instruction F5 to sensor unit i+1. Sensor unit i+1 receives the fifth instruction F5, returns a work completion instruction, and updates its configuration to become the master of sensor unit i+2. At the same time, sensor unit i receives the work completion instruction returned by sensor unit i+1, updates its configuration to become the slave of sensor unit i+1, and enters standby mode. S7. Repeat steps S1 to S6 from bottom to top to complete data measurement and data transmission until sensor unit N receives the fifth instruction F5 from sensor unit N-1 and returns the work end instruction. Then, sensor unit N updates its configuration as a slave of ground management terminal (104) and transmits data to ground management terminal (104) via RS485 bus. After the data transmission is completed, sensor unit N enters standby mode.

6. The wireless communication method for a three-dimensional underground displacement measurement device according to claim 5, characterized in that: Specifically, S6 is: S61, Sensor unit i receives the third instruction F3 returned by sensor unit i+1; S62, Sensor unit i integrates the underground three-dimensional data of sensor unit x into the fourth instruction F4 to form the fourth instruction F4x and sends it to sensor unit i+1. Sensor unit i+1 receives the fourth instruction F4x, saves the data, and returns the fourth instruction F4x to sensor unit i. Sensor unit i receives the fourth instruction F4x returned by sensor unit i+1. S63. Repeat step S62 in the order of x from 1 to i until sensor unit i sends the fifth instruction F5 to sensor unit i+1 after receiving the fourth instruction F4i returned by sensor unit i+1. After receiving the fifth instruction F5, sensor unit i+1 returns a work completion instruction and updates its configuration to become the master of sensor unit i+2. At the same time, sensor unit i receives the work completion instruction returned by sensor unit i+1, updates its configuration to become the slave of sensor unit i+1, and enters standby mode.

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