Land soil moisture content monitoring device and system

Abstract

The invention relates to the technical field of land moisture content monitoring, in particular to a land moisture content monitoring device and system, and the device comprises a monitoring rod and a monitoring case disposed at the top of the monitoring rod. The monitoring rod comprises a transition section, a monitoring section and a bottom section in a length ratio of 2: 5: 1; a main control processing assembly is arranged in the monitoring case, and a reference sound wave emitter is arranged at the bottom of the monitoring case; the transition section of the monitoring rod is provided with a plurality of monitoring sensors which are arranged at certain vertical intervals, and the tail end of a monitoring probe of each monitoring sensor is provided with a sound wave transducer; when the main control processing assembly receives a soil moisture content monitoring instruction, first soil data and sound wave flight time corresponding to each monitoring sensor are obtained so as to calculate a corresponding position deviation value, and all the first soil data and the position deviation value are sent to a cloud platform so that the cloud platform can monitor the soil moisture content. The system has the beneficial effects that the real-time performance and the accuracy of monitoring data are ensured, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of soil moisture monitoring, and particularly to a land moisture monitoring device and system. Background Art

[0002] Land moisture is an important indicator for preventing debris flows and landslides, as well as for soil and water conservation. Land moisture monitoring devices are usually deployed in places such as farmland, forest land or greenhouses, and are mainly devices for measuring and recording the soil moisture content and its changes, capable of realizing functions such as automatic data collection, analysis and early warning, and are of great significance for fields such as agriculture, forestry, and environmental protection.

[0003] Although the current land moisture monitoring devices can be set in soils with different geologies in places such as farmland, forest land, and greenhouses, their sensors are usually fixedly installed at a preset depth, and parameters such as soil humidity and temperature are obtained through single-point measurement. However, the soil will shift due to reasons such as natural settlement, mechanical tillage or root growth, resulting in the actual position of the sensor probe deviating from the initial calibration position, and this position deviation will introduce new measurement errors. Therefore, the above-mentioned land moisture monitoring devices need to be frequently maintained on-site, but this on-site maintenance method has a certain lag, resulting in high costs for the current land moisture monitoring method, inaccurate monitoring results, and inability to correct position offsets in real time. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a land moisture monitoring device and system, which solves the technical problems that the existing land moisture monitoring devices need to be frequently maintained on-site, resulting in certain errors and lags in the monitored data, and further resulting in high maintenance costs, inaccurate monitoring results, and inability to correct position offsets in real time.

[0006] (II) Technical Solutions

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, an embodiment of the present invention provides a land moisture monitoring device, including: a monitoring chassis and a monitoring rod, the monitoring chassis is arranged at the top of the monitoring rod; the monitoring rod includes a transition section, a monitoring section and a bottom section, and the length ratio of the transition section, the monitoring section and the bottom section is 2:5:1;

[0009] A main control processing component and a communication component are arranged inside the monitoring chassis, and a reference sound wave transmitter is arranged at the bottom of the monitoring chassis;

[0010] A sensor array and epoxy resin for weighting are arranged inside the monitoring rod;

[0011] The sensor array includes at least one set of monitoring sensors, and each monitoring sensor is arranged on the monitoring section of the monitoring rod at a certain vertical interval; an acoustic transducer is arranged at the end of the monitoring probe of each monitoring sensor;

[0012] Among them, the communication component, the reference acoustic wave transmitter, all the monitoring sensors and all the acoustic transducers are electrically connected to the main control processing component;

[0013] The main control processing component is configured to, when receiving a soil moisture monitoring instruction, send a sampling instruction to each monitoring sensor to obtain first soil data collected by each monitoring sensor, and send a calibration instruction to the reference acoustic wave transmitter to obtain the acoustic wave flight time corresponding to each monitoring sensor according to the feedback signal of each acoustic transducer received by the reference acoustic wave transmitter;

[0014] And, according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, obtain the position deviation value corresponding to each monitoring sensor, and send the first soil data and the position deviation value corresponding to each monitoring sensor to the remote cloud platform, so that the cloud platform performs compensation and correction based on the first soil data corresponding to each position deviation value, and then performs land soil moisture monitoring.

[0015] Optionally, the communication component, the reference acoustic wave transmitter, any monitoring sensor or any acoustic transducer communicate with the main control processing component through the Modbus RTU protocol;

[0016] The acoustic wave pulses emitted by the reference acoustic wave transmitter and any acoustic transducer are both 40 kHz.

[0017] Optionally, the first soil data includes soil temperature and soil humidity;

[0018] Then, the main control processing component obtains the position deviation value corresponding to each monitoring sensor according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, including:

[0019] Obtain the temperature compensation parameter corresponding to each monitoring sensor according to the soil temperature corresponding to each monitoring sensor and the preset reference temperature; obtain the humidity compensation parameter corresponding to each monitoring sensor according to the soil humidity corresponding to each monitoring sensor;

[0020] Compensate the preset reference sound speed according to the temperature compensation parameter and the humidity compensation parameter corresponding to each monitoring sensor to obtain the dynamic sound speed corresponding to each monitoring sensor; obtain the position deviation value corresponding to each monitoring sensor according to the dynamic sound speed and the acoustic wave flight time corresponding to each monitoring sensor, and the preset formula two;

[0021] Δd = vt - d;

[0022] Wherein, Δd is the position deviation value corresponding to any monitoring sensor, t is the acoustic wave flight time corresponding to the monitoring sensor, and d is the preset initial position corresponding to the monitoring sensor.

[0023] Optionally, the first soil data includes soil temperature and soil humidity;

[0024] The main control processing component obtains the position deviation value corresponding to each monitoring sensor according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, including:

[0025] Obtain the soil parameter corresponding to each monitoring sensor according to the first soil data corresponding to each monitoring sensor and the preset formula three; The formula three is:

[0026] H = w1T + w2S;

[0027] Wherein, H is the soil parameter corresponding to any monitoring sensor, T is the soil temperature corresponding to the monitoring sensor, S is the soil humidity corresponding to the monitoring sensor, and w1 and w2 are both preset weight coefficients;

[0028] Judge whether the soil parameter corresponding to each monitoring sensor exceeds the preset soil parameter threshold;

[0029] Obtain the temperature compensation parameter corresponding to each monitoring sensor according to the soil temperature corresponding to each monitoring sensor and the preset reference temperature; Obtain the humidity compensation parameter corresponding to each monitoring sensor according to the soil humidity corresponding to each monitoring sensor;

[0030] Compensate the preset reference sound speed according to the temperature compensation parameter and humidity compensation parameter corresponding to each monitoring sensor to obtain the dynamic sound speed corresponding to each monitoring sensor;

[0031] When it does not exceed, then obtain the dynamic sound speed corresponding to each monitoring sensor according to the first soil data corresponding to each monitoring sensor and the preset formula four; The formula four is:

[0032] v = 1440 + 4.6T - 0.055T 2 + 1.3S;

[0033] Obtain the position deviation value corresponding to each monitoring sensor according to the dynamic sound speed, acoustic wave flight time corresponding to each monitoring sensor, and the preset formula two;

[0034] Δd = vt - d;

[0035] Among them, Δd is the position deviation value corresponding to any monitoring sensor, t is the acoustic wave flight time corresponding to this monitoring sensor, and d is the preset initial position corresponding to this monitoring sensor.

[0036] Optionally, the main control processing component is further configured to:

[0037] When receiving the soil moisture monitoring instruction, send wireless synchronization signals to each monitoring sensor respectively, so that each monitoring sensor obtains the corresponding transmission delay according to the received wireless synchronization signal, and then adjusts its own delay sampling window;

[0038] The delay sampling window is used for the monitoring sensor to perform data sampling within a specified time window when receiving the sampling instruction.

[0039] In a second aspect, an embodiment of the present invention provides a land soil moisture monitoring system, including a monitoring cloud platform and a land soil moisture monitoring device, where the land soil moisture monitoring device is the above-mentioned device; the land soil moisture monitoring device is communicatively connected to the monitoring cloud platform;

[0040] The land soil moisture monitoring device is configured to send the first soil data and the position deviation value corresponding to each monitoring sensor to the monitoring cloud platform at every preset time;

[0041] The monitoring cloud platform is configured to input the first soil data and the position deviation value corresponding to each monitoring sensor received into a preset dynamic compensation model for position compensation, and obtain the second soil data after position compensation corresponding to each monitoring sensor;

[0042] The dynamic compensation model is used to perform position compensation on the first soil data corresponding to each monitoring sensor according to the position deviation value corresponding to each monitoring sensor;

[0043] According to the second soil data corresponding to each monitoring sensor and a preset land soil moisture evaluation algorithm, obtain a land soil moisture evaluation index for assisting water resource management in the monitoring area.

[0044] Optionally, the land soil moisture monitoring device is further configured to: obtain the actual position corresponding to each monitoring sensor according to the position deviation value of each monitoring sensor and the preset initial position of each monitoring sensor, and send the actual position corresponding to each monitoring sensor to the monitoring cloud platform;

[0045] Then, the monitoring cloud platform inputs the first soil data and the position deviation value corresponding to each monitoring sensor received into a preset dynamic compensation model for position compensation, and obtains the second soil data after position compensation corresponding to each monitoring sensor, including:

[0046] Based on the position deviation value and the actual position corresponding to each monitoring sensor, and according to the preset Formula Five, perform position compensation on the first soil data corresponding to each monitoring sensor to obtain the second soil data after position compensation corresponding to each monitoring sensor; the Formula Five is:

[0047]

[0048] where C1 is the first soil data corresponding to any monitoring sensor, C2 is the second soil data corresponding to this monitoring sensor, Δd is the position deviation value corresponding to this monitoring sensor, a is the preset migration weight, is the fluctuation gradient corresponding to this first soil data, obtained from the actual positions and the first soil data corresponding to all monitoring sensors.

[0049] Optionally, both the first soil data and the second soil data include: soil temperature, soil humidity, soil nitrogen concentration, soil phosphorus concentration, and soil potassium concentration;

[0050] Then, the monitoring cloud platform, according to the second soil data corresponding to each monitoring sensor and the preset land moisture assessment algorithm, obtains a land moisture assessment index for assisting in water resource management within the monitoring area, including:

[0051] Subtract the compensated soil temperature corresponding to each monitoring sensor from the preset optimal temperature to obtain the corresponding temperature deviation, and use the ratio of the temperature deviation to the preset adaptive temperature as the temperature gain term corresponding to each monitoring sensor;

[0052] According to the compensated soil potassium concentration corresponding to each monitoring sensor and the critical threshold corresponding to the preset soil potassium concentration, obtain the soil potassium concentration gain corresponding to each monitoring sensor. According to the compensated soil phosphorus concentration corresponding to each monitoring sensor and the critical threshold corresponding to the preset soil phosphorus concentration, obtain the soil phosphorus concentration gain corresponding to each monitoring sensor. According to the compensated soil nitrogen concentration corresponding to each monitoring sensor and the critical threshold corresponding to the preset soil nitrogen concentration, obtain the soil nitrogen concentration gain corresponding to each monitoring sensor. Multiply the soil potassium concentration gain, soil phosphorus concentration gain, and nitrogen concentration gain corresponding to each monitoring sensor to obtain the nutrient gain term corresponding to each monitoring sensor;

[0053] According to the soil humidity and actual positions corresponding to all monitoring sensors, obtain the soil humidity gradient; obtain the corresponding gradient penalty term according to the soil humidity gradient;

[0054] Multiply the soil humidity corresponding to each monitoring sensor by the preset humidity weight, and multiply the temperature gain term and nutrient gain term corresponding to each monitoring sensor, then sum them up, and subtract the gradient penalty term to obtain the land moisture assessment index for assisting water resource management in the monitoring area.

[0055] Optionally, the monitoring cloud platform is further configured to:

[0056] Based on the received position deviation value corresponding to each monitoring sensor and the preset deviation threshold, determine whether the land moisture monitoring device needs to be adjusted in position;

[0057] If the position deviation value corresponding to any monitoring sensor is greater than the preset deviation threshold, that is, position adjustment is required, the monitoring cloud platform will give an alarm.

[0058] Optionally, the land moisture monitoring device is further configured to:

[0059] Before sending the first soil data to the monitoring cloud platform, preprocess the first soil data; the preprocessing includes data cleaning, standardization processing, outlier screening, and outlier replacement.

[0060] (III) Beneficial Effects

[0061] The beneficial effects of the present invention are as follows: For a land moisture monitoring device of the present invention, by arranging a reference acoustic wave transmitter at the bottom of the monitoring chassis and arranging an acoustic wave transducer at the end of the monitoring probe of each monitoring sensor, compared with the prior art, it can transmit an acoustic wave pulse from the reference acoustic wave transmitter to the acoustic wave transducer arranged for each monitoring sensor, and receive the feedback pulse returned by the acoustic wave transducer, thereby obtaining the acoustic wave flight time corresponding to each monitoring sensor, so as to infer whether each monitoring sensor has shifted, and feedback the position deviation value and the first soil data to the cloud platform for land moisture monitoring, which ensures the real-time and accuracy of the monitoring data while reducing the maintenance cost. Description of the Drawings

[0062] Figure 1 It is a schematic diagram of the internal structure connection of a land moisture monitoring device provided by an embodiment of the present invention;

[0063] Figure 2 It is a schematic diagram of the external structure of a land moisture monitoring device provided by an embodiment of the present invention;

[0064] Figure 3 It is a schematic diagram of the structure of a land moisture monitoring system provided by an embodiment of the present invention.

[0065]

Description of the Reference Numerals

[0066] 1: Monitoring chassis; 2: Monitoring rod; 21: Transition section; 22: Monitoring section; 23: Bottom section. Detailed implementation manner

[0067] To better explain the present invention for easier understanding, the present invention will be described in detail below in conjunction with the accompanying drawings through specific implementation manners.

[0068] A soil moisture monitoring device proposed in an embodiment of the present invention, by setting a reference acoustic wave transmitter at the bottom of the monitoring chassis 1 and setting an acoustic wave transducer at the end of the monitoring probe of each monitoring sensor. Compared with the prior art, it can transmit an acoustic wave pulse from the reference acoustic wave transmitter to the acoustic wave transducers set for each monitoring sensor, and receive the feedback pulse returned by the acoustic wave transducer, so as to obtain the acoustic wave flight time corresponding to each monitoring sensor, infer whether each monitoring sensor has shifted, and feedback the position deviation value and the first soil data to the cloud platform for soil moisture monitoring, while ensuring the real-time and accuracy of the monitoring data and reducing the maintenance cost.

[0069] To better understand the above technical solution, the exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more clear and thorough understanding of the present invention and to be able to convey the scope of the present invention completely to those skilled in the art.

[0070] Embodiment 1

[0071] A soil moisture monitoring device, as Figure 1 shown, includes: a monitoring chassis 1 and a monitoring rod 2, the monitoring chassis 1 is fixedly connected to the top of the monitoring rod 2; the monitoring rod 2 includes a transition section 21, a monitoring section 22 and a bottom section 23, and the length ratio of the transition section 21, the monitoring section 22 and the bottom section 23 is 2:5:1;

[0072] A main control processing component and a communication component are arranged inside the monitoring chassis 1, and a reference acoustic wave transmitter is arranged at the bottom of the monitoring chassis 1;

[0073] A sensor array and epoxy resin for weighting are arranged inside the monitoring rod 2;

[0074] The sensor array includes at least one group of monitoring sensors, and each monitoring sensor is arranged at a certain vertical interval in the monitoring section 22 of the monitoring rod 2; an acoustic wave transducer is arranged at the end of the monitoring probe of each monitoring sensor;

[0075] Among them, the communication component, the reference acoustic wave transmitter, all the monitoring sensors and all the acoustic wave transducers are electrically connected to the main control processing component;

[0076] The main control processing component is configured to, when receiving a soil moisture monitoring instruction, send a sampling instruction to each monitoring sensor to obtain first soil data collected by each monitoring sensor, and send a calibration instruction to the reference acoustic wave transmitter to obtain the acoustic wave flight time corresponding to each monitoring sensor according to the feedback signal of each acoustic wave transducer received by the reference acoustic wave transmitter;

[0077] Moreover, according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, obtain the position deviation value corresponding to each monitoring sensor, and send the first soil data and the position deviation value corresponding to each monitoring sensor to the remote cloud platform, so that the cloud platform compensates and corrects the corresponding first soil data based on each position deviation value, and then conducts land soil moisture monitoring.

[0078] For a land soil moisture monitoring device proposed in this embodiment, by arranging a reference acoustic wave transmitter at the bottom of the monitoring chassis 1 and arranging an acoustic wave transducer at the end of the monitoring probe of each monitoring sensor, compared with the prior art, it can emit an acoustic wave pulse from the reference acoustic wave transmitter to the acoustic wave transducer arranged on each monitoring sensor, and receive the feedback pulse returned by the acoustic wave transducer, so as to obtain the acoustic wave flight time corresponding to each monitoring sensor, infer whether each monitoring sensor has shifted, and feedback the position deviation value and the first soil data to the cloud platform for land soil moisture monitoring, which ensures the real-time and accuracy of the monitoring data while reducing the maintenance cost.

[0079] Embodiment 2

[0080] This embodiment provides a land soil moisture monitoring device, as Figure 2 shown, including: a monitoring chassis 1 and a monitoring rod 2, and the monitoring chassis 1 is fixedly connected to the top of the monitoring rod 2;

[0081] The monitoring rod 2 includes a transition section 21, a monitoring section 22 and a bottom section 23, and the length ratio of the transition section 21, the monitoring section 22 and the bottom section 23 is 2:5:1; wherein, the monitoring section 22 and the bottom section 23 are usually buried inside the soil, and the transition section 21 is exposed outside the soil. The overall length of the monitoring rod 2 can be specifically adjusted according to different soil environments. For example:

[0082] When the monitoring device is applied to the farmland environment, since the plough layer of farmland is generally 0 - 50 cm (suitable for the root distribution of main crops such as wheat and corn), the length of the monitoring section 22 needs to be more than 50 cm, that is, the overall length of the monitoring rod 2 needs to be more than 80 cm; when the farmland soil is soft, to ensure that the bottom section 23 reaches the hard soil layer to enhance the anti-settlement ability, the overall length of the monitoring rod 2 can be set to 160 cm, that is, the bottom section 23 is 20 cm, the transition section 21 is 40 cm, and the monitoring section 22 is 100 cm; when the farmland soil is sandy, the bottom section 23 can be shortened to 10 cm to avoid tipping.

[0083] When the monitoring device is applied to wetlands and riparian zones, the length of the monitoring section 22 is adapted to the thickness of the peat layer (usually 20 - 80 cm), that is, the overall length can be set to 32 - 128 cm; in a silt environment, the overall length can be shortened to 80 cm, that is, the bottom section 23 is 10 cm, the transition section 21 is 20 cm, the monitoring section 22 is 50 cm, and the device shell can use lightweight materials to reduce sinking; in a high water level area, the bottom section 23 can use anti-corrosion metal piles.

[0084] When the monitoring device is applied to mountains and hills, to ensure that the sensor array fits the slope, the transition section 21 can be designed as a bendable structure, and to ensure that the bottom section 23 is anchored to the bedrock, the overall length can be set to 240 cm, that is, the bottom section 23 is 30 cm, the transition section 21 is 60 cm, the monitoring section 22 is 150 cm, and its transition section 21 can use hinge connections to adjust the angle; on a gravel slope, the monitoring section 22 can be shortened to 80 cm to avoid damage to the probe due to gravel movement.

[0085] When the monitoring device is applied to deserts and arid regions, the bottom section 23 is thickened and extended to more than 40 cm, and the monitoring section 22 is set to more than 100 cm, and it is fixed by screw piles, so that the device is buried below the sand layer to be effectively fixed against wind pulling.

[0086] When the monitoring device is applied to urban green spaces and construction sites, the bottom section 23 is strengthened into a conical structure, penetrating the compacted layer to the loose soil layer, and the overall can be set to 80 cm, that is, the bottom section 23 is 10 cm, the transition section 21 is 20 cm, the monitoring section 22 is 50 cm, and it is installed with an impact drill.

[0087] The above designs can achieve high-precision and high-stability soil moisture monitoring in multiple scenarios such as farmland, wetlands, mountains, and deserts.

[0088] Further, a main control component and a communication component are arranged inside the monitoring chassis 1, and a reference acoustic wave transmitter is arranged at the bottom of the monitoring chassis 1; a sensor array is arranged inside the monitoring rod 2; wherein, the sensor array includes at least one group of monitoring sensors, and each monitoring sensor is arranged at a certain vertical interval on the monitoring section 22 of the monitoring rod 2. For example, if the length of the monitoring section 22 is 50 cm, a group of monitoring sensors can be arranged every 10 cm; an acoustic wave transducer is arranged at the end of the monitoring probe of each monitoring sensor. The frequencies of the acoustic wave pulse emitted by the reference acoustic wave transmitter and the feedback pulse emitted by the acoustic wave transducer are generally 40 kHz, and the reference acoustic wave transmitter also serves as the coordinate origin of the space.

[0089] After the reference acoustic wave transmitter receives the calibration instruction sent by the main control processing component, it sequentially sends acoustic wave pulses to the acoustic wave transducers corresponding to the monitoring sensors at all levels, and the acoustic wave transducers at all levels record the acoustic wave arrival time, which is the acoustic wave flight time corresponding to the corresponding monitoring sensor. Optionally, after the acoustic wave transducers at all levels receive the acoustic wave pulse, they send a feedback acoustic wave to the reference acoustic wave transmitter. At this time, the reference acoustic wave transmitter can obtain the acoustic wave flight time based on the time of sending the acoustic wave pulse to each monitoring sensor and the time of receiving the corresponding feedback pulse.

[0090] Before / when the main control processing component sends the calibration instruction, it sends an acquisition instruction to the monitoring sensors at all levels to control the monitoring sensors at all levels to acquire the first soil data in the corresponding area. The first soil data includes but is not limited to soil temperature, soil humidity, soil potassium concentration, soil phosphorus concentration, soil nitrogen concentration, etc.; and in this embodiment, soil temperature and soil humidity are used to calculate the dynamic sound speed.

[0091] Further, the main control processing component obtains the soil parameter corresponding to each monitoring sensor according to the first soil data collected by the monitoring sensors at all levels and the preset formula three; the formula three is:

[0092] H = w1T + w2S;

[0093] Wherein, H is the soil parameter corresponding to any monitoring sensor, T is the soil temperature corresponding to the monitoring sensor, S is the soil humidity corresponding to the monitoring sensor, and w1 and w2 are both preset weight coefficients;

[0094] The main control processing component judges whether the soil parameter corresponding to each monitoring sensor exceeds the preset soil parameter threshold;

[0095] When it exceeds, the dynamic sound speed corresponding to each monitoring sensor is obtained according to the first soil data corresponding to each monitoring sensor and the preset formula one; the formula one is:

[0096]

[0097] Among them, v1 is the dynamic sound speed corresponding to any monitoring sensor, v0 is the preset reference sound speed, and α, β, γ, and δ are all preset empirical coefficients, and T ref is the preset reference temperature; usually, α = 0.012, β = 5, γ = 0.02, δ = 0.15. The humidity influence of this formula is described by γSe -δT which reflects the positive effect of humidity on the sound speed. However, this effect decays due to the evaporation of soil pore water at high temperatures. When the temperature rises, e -δT decreases, and the contribution of humidity to the sound speed decreases, which is consistent with the phenomenon that high temperatures accelerate water evaporation in actual soil. In this embodiment, through Formula 1, logarithmic temperature correction and exponential coupling humidity terms are used to significantly improve the sound speed prediction accuracy in complex environments while retaining the functions of the original formula.

[0098] When it does not exceed, the dynamic sound speed corresponding to each monitoring sensor is obtained according to the first soil data corresponding to each monitoring sensor and the preset Formula 4; (the soil temperature and soil humidity used here only provide numerical values without units for optimizing the attenuation of the speed) The Formula 4 is:

[0099] v = 1440 + 4.6T - 0.055T 2 + 1.3S;

[0100] According to the dynamic sound speed and acoustic wave flight time corresponding to each monitoring sensor, and the preset Formula 2, the position deviation value corresponding to each monitoring sensor is obtained;

[0101] Δd = vt - d;

[0102] Among them, Δd is the position deviation value corresponding to any monitoring sensor, t is the acoustic wave flight time corresponding to this monitoring sensor, and d is the preset initial position corresponding to this monitoring sensor.

[0103] The main control component selects the method for calculating the dynamic sound speed according to the first soil data collected by each monitoring sensor to ensure the accuracy of the result. Under the conditions of high temperature T > 50°C or high humidity S > 30%, the prediction ability of Formula 1 is better than that of Formula 4, while Formula 4 is simple to calculate and fast.

[0104] For example, assume T = 30°C, S = 25%;

[0105] Then, the calculation method through Formula 4 is:

[0106] v = 1440 + 4.6 * 30 - 0.055 * 900 + 1.3 * 15 = 1575.5 m / s;

[0107] Then, the calculation method of formula 1 is:

[0108]

[0109] At this time, the measured value is 1580m / s, the error of formula one is 0.8%, and the error of formula four is 0.3%; under extreme conditions, when T=60℃ and S=5%, formula four predicts v=1648m / s, formula one predicts v=1582m / s, and the actual measured value is 1565m / s; that is, under high temperature T>50℃ or high humidity S>30%, the prediction ability of formula one is better than that of formula four.

[0110] The main control processing component sends the first soil data and position deviation value corresponding to each monitoring sensor to the remote cloud platform, so that the cloud platform compensates and corrects the corresponding first soil data based on each position deviation value, and then monitors the soil moisture condition.

[0111] Furthermore, the master-slave clock synchronization is performed between the main control processing component and the monitoring sensors at all levels to ensure the corresponding acquisition window. The main control processing component sends a wireless synchronization signal (such as a LoRa timestamp packet) every 10 minutes, with GPS or network time attached. After receiving the synchronization signal, the monitoring sensor nodes at all levels calculate the transmission delay (based on the signal flight time) and adjust the local clock deviation. The main control processing component and the monitoring sensors at all levels use a two-way message exchange (such as a simplified version of the NTP protocol) to eliminate unidirectional transmission errors through multiple round-trip time (RTT) measurements. After the main control processing component issues a unified sampling instruction, the monitoring sensors at all levels complete data collection within the specified time window, and the deviation is controlled within ±1ms.

[0112] Furthermore, when the reference acoustic wave transmitter sends acoustic wave pulses to each level of monitoring sensors in turn, cross-ranging is also performed between adjacent monitoring sensors, such as Level 1→Level 2, Level 2→Level 3, etc., to verify and compensate the acoustic wave flight time / position deviation value / dynamic sound speed corresponding to each level of monitoring sensors.

[0113] Furthermore, filters are used on the reference sound wave transmitter and each level of sound wave transducers to extract sound wave pulses and suppress environmental noise (such as mechanical vibration, animal activities, etc.); the reference sound wave transmitter and each level of sound wave transducers use Barker codes to modulate sound wave signals to improve anti-interference capabilities in multipath environments.

[0114] Furthermore, the main control processing component adds a probe offset over-limit alarm mechanism to determine whether the position deviation value corresponding to each monitoring sensor is greater than a preset deviation threshold, and then determine whether to trigger an alarm signal to control the magnetically controlled switch of the control device to control the maintenance mode.

[0115] Furthermore, the position deviation value can be further processed. After the master control component issues a calibration instruction, the reference acoustic wave transmitter and each level of acoustic wave transducer perform acoustic wave ranging multiple times to obtain N sets of ranging data, which are sent to the main control component. The main control component then obtains multiple sets of position deviation values corresponding to each monitoring sensor based on this.

[0116] Furthermore, an equation corresponding to the ranging data is constructed:

[0117]

[0118] That is, when expanded, it is:

[0119]

[0120] Among them, (x0, y0, z0) is the initial processing preset for any monitoring sensor, (Δx, Δy, Δz) is the offset of this monitoring sensor, and d q is the actual position of this monitoring sensor, and (x q , y q , z q ) is the reference position preset for this monitoring sensor;

[0121] Assume that the offsets Δx, Δy, Δz are small, and the above equation is expanded using Taylor series, retaining the first-order terms:

[0122]

[0123] Let, Then the equation is simplified to a linear form:

[0124] (x0 - x q )Δx + (y0 - y q )Δy + (z0 - z q )Δz = B q ;

[0125] Furthermore, a matrix equation is constructed, and all ranging points of each monitoring sensor are substituted into it to form an overdetermined system of equations: A·△ = B;

[0126] Among them:

[0127]

[0128] where q = 1, 2,..., N;

[0129] By minimizing the sum of squared residuals ||A△ - B|| 2 , the solution is obtained:

[0130] △ = (A T A) -1 A T WB;

[0131] Let \(W\) be a pre-set weight matrix, and calculate \(A\). T \(A\) results in a \(3\times3\) symmetric matrix, and calculate \(A\). T \(B\) results in a \(3\times1\) vector. Take the inverse and multiply through matrix operations to obtain the offsets \(\Delta x\), \(\Delta y\), \(\Delta z\), which are the final position deviation values sent by the monitoring sensor to the cloud platform.

[0132] Through the above process, decompose the position deviation values corresponding to each level of monitoring sensor into direction vectors to obtain the deviation values in each direction, thereby ensuring more accurate soil moisture monitoring by the subsequent cloud platform.

[0133] Furthermore, ensure that \(A\) T is invertible to avoid collinearity problems. Subsequently, robust algorithms such as RANSAC can be used to filter out noise data.

[0134] A soil moisture monitoring device proposed in this embodiment, by setting a reference acoustic wave transmitter at the bottom of the monitoring chassis 1 and a acoustic wave transducer at the end of the monitoring probe of each monitoring sensor. Compared with the prior art, it can transmit acoustic wave pulses from the reference acoustic wave transmitter to the acoustic wave transducers set for each monitoring sensor, and receive the feedback pulses returned by the acoustic wave transducers, thereby obtaining the acoustic wave flight time corresponding to each monitoring sensor, to infer whether each monitoring sensor has shifted, and feedback the position deviation value and the first soil data to the cloud platform for soil moisture monitoring. While ensuring the real-time and accuracy of the monitoring data, the maintenance cost is reduced.

[0135] Embodiment 3

[0136] This embodiment provides a soil moisture monitoring device, which can implement all the functions of the device provided in Embodiment 1 or Embodiment 2. The device adopts a high-precision chip, advanced algorithms and Internet of Things technology, can measure soil parameters at multiple depths, and outputs through RS485 or uploads to the cloud platform via 4G network.

[0137] This device can be widely used in the real-time monitoring of soil temperature and humidity in farmland, forest areas, grasslands, and irrigation areas, and can also be used in the water conservancy and geological disaster industries to provide data support for monitoring natural disasters such as landslides and mudslides.

[0138] This device can measure the temperature and humidity of the soil at any depth between 10 and 50 cm (generally 10 cm per level) through the monitoring rod 2. By default, it is 4 layers, 5 layers, 8 layers of standard tubes, and customization is supported.

[0139] The device box part (i.e., the monitoring chassis 1) has components such as sensing, transmission, and power supply inside. The monitoring chassis 1 and the monitoring rod 2 are integrally designed, which is convenient for installation. External acquisition devices can be expanded. The transmission device inside the monitoring chassis 1 is connected to the mobile phone via Bluetooth through a small program, and the device can be remotely monitored on any mobile terminal equipped with an APP, realizing in-depth interaction, configuration, and remote sending between the mobile terminal and the device.

[0140] The monitoring sensor is built-in with a high-efficiency lithium battery, and the RTU adopts a low-power design. It can work for more than 180 days under continuous rainy days when fully charged. It can be externally connected to solar power supply to provide a high-frequency transmission mode.

[0141] The device has an integrated potting structure. The monitoring rod 2 part is designed with potting using insulating waterproof materials such as epoxy resin. The internal structure of the equipment is stable and the equipment counterweight is not easily affected by soil movement; it meets the requirements for long-term outdoor applications and waterlogged environments.

[0142] The device adopts a magnetic control switch design (built-in 4G model), and the device can be turned on and off by using the randomly attached magnet to prevent situations such as accidental shutdown by humans in the wild at the site.

[0143] Cloud platform storage technology is adopted. Each time the data sent can be saved to the independent cloud platform or a third-party platform that meets the "Hydrological Monitoring Data Communication Specification SL651-2014". It supports MQTT service docking with third-party platforms, supports protocol customization, and has a default API interface for docking. An external solar power supply system can be expanded, with a supporting bracket of 150 cm to 400 cm, the default is 200 cm. Supporting the monitoring sensor is convenient for expanding other parameters, and configuring accessories such as cross arms and embedded parts as needed, and supports customized brackets.

[0144] Measuring parameters:

[0145] Volumetric water content / volume water content / soil moisture, unit % (m 3 / m 3 ), or %Vol, humidity range 0 - 100%Vol, resolution: 0.01%Vol; accuracy: error ≤ 3%Vol within the effective range; measurement area: 90% of the influence is within a cylindrical measurement carrier with a diameter of 10 cm around the monitoring sensor; no precision drift; sensor linear discrete deviation rate 1%; soil moisture monitoring principle: FDR (Frequency Domain Reflectometry) humidity, measuring volumetric water content, calibrated by comparing with the oven drying method of the ring knife pattern in the laboratory.

[0146] Soil temperature, unit ℃, temperature range: -40~+60℃; resolution: 0.01℃; accuracy: ±0.5℃; stabilization time: about 1s after power on; soil temperature monitoring principle: high-precision NTC chip; response time: the response enters a stable state within 1s; sensor operating voltage: 5~24V DC (internal 5V for built-in 4G model); sensor operating current: static current 4mA, collection current 35mA; sensor waterproof level IP68; operating temperature: -40~+80℃; built-in RTU power consumption: standby 10μAh, transmission 100mAh; transmission 4G output to the platform, RS485 and other outputs, optional third-party docking. RS485 output power supply: DC5~24V, current less than 25mA.

[0147] Nitrogen, phosphorus and potassium, N / P / K content measurement range: 0-2000mg / kg, N / P / K content resolution: 1mg / kg; Measurement principle: Monitoring of nitrogen, phosphorus and potassium content based on soil EC to meet the consistency of saturated underwater data.

[0148] Solar power supply components: external 50W solar panel, 12V20Ah (240Wh) lithium battery, monitoring chassis 1 is an integrated bracket waterproof box.

[0149] Overall power consumption of the device: ≤3W in high-frequency acquisition mode with external DC12V power supply.

[0150] Sensor interface: Aviation plug connection, convenient for expansion and replacement. Monitoring sensor: optional built-in acquisition, expandable external collector to provide high-frequency acquisition, data processing, and stronger scalability. It has the functions of collecting data, processing data, transmitting and forwarding platform through 4G, and supports remote OTA upgrade configuration, with good scalability. The hardware and platform interact with configuration information and perception information. The maximum transmission rate is 100Mbps.

[0151] Default monitoring parameters: four-layer soil temperature (10 cm per layer), four-layer soil moisture (volume moisture content, 10 cm per layer), soil nitrogen, phosphorus and potassium and other parameters, which can be expanded to other soil or auxiliary meteorological parameters.

[0152] The selection of representative plots for soil moisture monitoring should consider their geomorphology, soil, meteorological, and hydrogeological conditions, as well as the representativeness of the planted crops. The collection scope can be based on the county level, and several representative areas should be selected within the county-level unit (the reference basis for representativeness can refer to the categories of geomorphology and the regional scope of key crops). If in a hilly area, the monitoring points should be set in plots with a smaller slope gradient and a larger area, and collection should not be carried out in the bottom of the ditch or plots with a large slope. Representative plots in the plain area should be collected in flat plots that are not prone to waterlogging. The detailed collection plots should be in plots that are more than 10 m away from the edge of the representative plot and the roadside and are flat, avoiding low-lying areas prone to waterlogging, and keeping a distance of more than 20 m from the trenches and water supply channels to avoid the influence of ditch seepage on soil moisture content. For collection in plots within a hydrological station, it is strictly prohibited to be in the middle of the vegetable fields in the station to avoid the influence of watering on the collection accuracy. It is recommended to select the collection points in a relatively open location, not close to houses or walls.

[0153] In this embodiment, the communication component, the reference acoustic wave transmitter, any monitoring sensor, or any acoustic transducer communicate with the main control processing component through the Modbus RTU protocol; the baud rate of this communication protocol is 9600; the data bits are 8; the stop bits are 1; and there is no parity bit.

[0154] The regulations for returning error codes are as follows: For the sensor's reception of incorrect commands (including CRC16 checksum errors), the method of not returning error codes is implemented. The host computer can consider the issued command to have failed when it does not receive the return data 100 ms after the command is issued and can resend the command.

[0155] Explanation of standard MODBUS registers: Special attention: In the MODBUS command, the number or length of the registers is in units of two bytes (16 bits), with the high byte first and the low byte second, rather than in units of single bytes (8 bits).

[0156] Internal registers: Read with function code 03; write with function code 06.

[0157] The installation steps of the soil moisture monitoring device provided in this embodiment are as follows:

[0158] Select a relatively flat installation location and directly use an earth drill to open holes in the ground: Remove the blue pipe cap at the bottom of the tubular earth drill to take out the handle, and screw the two handles into both ends of the screw in the clockwise direction respectively; Insert the tubular earth drill vertically along the central hole of the flange, press down with appropriate force while rotating the hands horizontally back and forth in parallel until the required depth is reached (during this process, you can feel whether there are stones in the soil. If there are too many stones, you need to reselect the location). During the drilling process, every 10 cm of the maximum depth, the earth drill needs to be lifted out and shaken forcefully to shake out the soil in the pipe. You can also use a long screwdriver handle or a hammer handle (do not use the hammer head to strike the pipe body to avoid deforming the pipe body) to strike the lower pipe body of the earth drill to shake out the soil or dig the soil from the bottom with a screwdriver until all the soil falls. Use a ruler to measure that the drilling depth should be 7 - 8 cm deeper than the measurement depth of the sensor; Sieve the soil taken out from the drilled hole and mix it into mud; Pour the mud into the drilled hole in the ground, and the pouring amount should reach at least the depth; Insert the sensor into the ground hole filled with backfilled mud, and the position of the sensor marked with the horizon should be flush with the ground.

[0159] Precautions during installation: Observe the data through the platform to confirm that the data is normal; Prepare the tools for installation (basin, water, shovel or earth drill, sieve with 2 - 4 mm pores); The drilling should be vertically downward; Drill to an appropriate depth and pay attention to whether there are many stones. If there are many stones, it is recommended to reselect the location; Backfill the mud and vertically insert the monitoring rod 2; Confirm the installation depth of the sensor.

[0160] The soil moisture monitoring device provided in this embodiment effectively realizes the real - time monitoring of soil data at different depths, providing a structural basis for the accuracy of subsequent soil moisture monitoring.

[0161] Embodiment 4

[0162] This embodiment provides a soil moisture monitoring system, as Figure 3 shown, including a monitoring cloud platform and a soil moisture monitoring device. The soil moisture monitoring device is the device described in any one of Embodiments 1 to 3; The soil moisture monitoring device is communicatively connected to the monitoring cloud platform;

[0163] Among them, the soil moisture monitoring device is used to send the first soil data and position deviation value corresponding to each monitoring sensor to the monitoring cloud platform at preset time intervals;

[0164] The monitoring cloud platform is used to input the first soil data and position deviation value corresponding to each monitoring sensor received into a pre - set dynamic compensation model for position compensation to obtain the second soil data after position compensation corresponding to each monitoring sensor;

[0165] The dynamic compensation model is used to perform position compensation on the first soil data corresponding to each monitoring sensor according to the position deviation value corresponding to each monitoring sensor;

[0166] According to the second soil data corresponding to each monitoring sensor and a preset soil moisture assessment algorithm, a soil moisture assessment index for assisting water resource management in the monitoring area is obtained.

[0167] Furthermore, the soil moisture monitoring device is also used to: obtain the actual position corresponding to each monitoring sensor according to the position deviation value of each monitoring sensor and the preset initial position of each monitoring sensor, and send the actual position corresponding to each monitoring sensor to the monitoring cloud platform;

[0168] Then, the monitoring cloud platform inputs the first soil data and the position deviation value corresponding to each received monitoring sensor into a preset dynamic compensation model for position compensation, and obtains the second soil data after position compensation corresponding to each monitoring sensor, including:

[0169] Perform position compensation on the first soil data corresponding to each monitoring sensor according to the position deviation value and the actual position corresponding to each monitoring sensor, and the preset formula five, to obtain the second soil data after position compensation corresponding to each monitoring sensor; The formula five is:

[0170]

[0171] Among them, C1 is the first soil data corresponding to any monitoring sensor, C2 is the second soil data corresponding to this monitoring sensor, Δd is the position deviation value corresponding to this monitoring sensor, a is a preset migration weight, is the fluctuation gradient corresponding to this first soil data, and is obtained through the actual positions and the first soil data corresponding to all monitoring sensors.

[0172] Furthermore, the soil temperature and soil humidity can use the following compensation formula:

[0173] C corrected =C measured +Δz·(o·p+r·X measured );

[0174] C corrected is the soil temperature / soil humidity after compensation, C mensured is the soil temperature / soil humidity, o, p, and r are all preset empirical coefficients, X neasured is the soil humidity / soil temperature corresponding to C mensured , when C mensured is the soil temperature, X neasured is the soil humidity, when C mensuredWhen it is soil humidity, X neasured is the soil temperature.

[0175] Furthermore, both the first soil data and the second soil data include: soil temperature, soil humidity, soil nitrogen concentration, soil phosphorus concentration, and soil potassium concentration;

[0176] Then, the monitoring cloud platform obtains a land moisture evaluation index for assisting in water resource management within the monitoring area according to the second soil data corresponding to each monitoring sensor and a pre-set land moisture evaluation algorithm, including:

[0177] Obtain a land moisture evaluation index for assisting in water resource management within the monitoring area according to the second soil data corresponding to each monitoring sensor, a pre-set land moisture evaluation algorithm, and a pre-set formula six; the formula six is:

[0178]

[0179] where L is the land moisture evaluation index, i is the index of the monitoring sensor, j is the index of soil nitrogen concentration, soil phosphorus concentration, or soil potassium concentration, w i is the humidity weight corresponding to the monitoring sensor with index i, S i is the compensated soil humidity corresponding to the monitoring sensor with index i, T i is the compensated soil temperature corresponding to the monitoring sensor with index i, D i,j is the compensated soil nitrogen concentration, soil phosphorus concentration, or soil potassium concentration corresponding to the monitoring sensor with index i, b is a pre-set temperature sensitivity coefficient, T opt is a pre-set optimal temperature, T range is a pre-set suitable temperature range, c j is the nutrient gain coefficient corresponding to the pre-set soil nitrogen concentration, soil phosphorus concentration, or soil potassium concentration, D j,crit is the critical threshold corresponding to the pre-set soil nitrogen concentration, soil phosphorus concentration, or soil potassium concentration, is the soil humidity gradient, obtained from the actual positions and soil humidity of all monitoring sensors. Among them, for the temperature gain term, when T i > T opt the temperature rise accelerates evaporation and reduces the effective moisture weight. When T i < T opt low temperature inhibits transpiration and improves water use efficiency; for example, if T i = 30°C, T opt = 25°C, T range = 20°C, then the temperature correction term is 1+(30 - 25) / 20*0.2 = 1.05. For the nutrient gain term, when D i,j > Dj,crit When the nutrient is sufficient, it promotes the crop to absorb water and the land moisture assessment index increases. When D i,j <D j,crit When the nutrient is insufficient, it restricts water utilization, the gain approaches 1, and there is no contribution. It is necessary to avoid the toxic effects caused by excessive single nutrient, such as D i,j >>D j,crit When the gain is saturated. For the gradient penalty term, when the vertical humidity gradient is too large (such as the surface is dry and the deep layer is wet), the root water absorption is blocked, and it is necessary to reduce the land moisture assessment index.

[0180] Furthermore, the monitoring cloud platform is also used for:

[0181] Judging whether the land moisture monitoring device needs to be adjusted in position according to the position deviation value corresponding to each monitoring sensor received and the preset deviation threshold;

[0182] If the position deviation value corresponding to any monitoring sensor is greater than the preset deviation threshold, that is, position adjustment is required, the monitoring cloud platform will give an alarm.

[0183] Furthermore, the land moisture monitoring device is also used for:

[0184] Before sending the first soil data to the monitoring cloud platform, preprocess the first soil data; the preprocessing includes data cleaning, standardization processing, outlier screening and outlier replacement.

[0185] The land moisture monitoring system provided by this embodiment is based on the land moisture monitoring device, and compensates the first soil data in real time through the position deviation value corresponding to each monitoring sensor, and then obtains more accurate second soil data for land moisture monitoring. While ensuring the real-time performance and accuracy of moisture monitoring, the maintenance cost is reduced.

[0186] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0187] In the present invention, unless otherwise clearly specified or limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium; it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0188] In the present invention, unless otherwise clearly specified or limited, when a first feature is "on" or "under" a second feature, it may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, when a first feature is "above", "over" and "on top of" a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it merely means that the horizontal height of the first feature is higher than that of the second feature. When a first feature is "under", "below" and "beneath" a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it merely means that the horizontal height of the first feature is lower than that of the second feature.

[0189] In the description of this specification, the descriptions of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0190] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A soil moisture monitoring device, characterized in that, Including: A monitoring chassis and a monitoring pole, the monitoring chassis is arranged at the top of the monitoring pole; the monitoring pole includes a transition section, a monitoring section and a bottom section, and the length ratio of the transition section, the monitoring section and the bottom section is 2:5:1; A main control processing component and a communication component are arranged inside the monitoring chassis, and a reference acoustic wave transmitter is arranged at the bottom of the monitoring chassis; A sensor array and epoxy resin for weight balancing are arranged inside the monitoring pole; The sensor array includes at least one group of monitoring sensors, and each monitoring sensor is arranged at a certain vertical interval in the monitoring section of the monitoring pole; an acoustic wave transducer is arranged at the end of the monitoring probe of each monitoring sensor; Wherein, the communication component, the reference acoustic wave transmitter, all the monitoring sensors and all the acoustic wave transducers are electrically connected to the main control processing component; The main control processing component is configured to, when receiving a soil moisture monitoring instruction, send a sampling instruction to each monitoring sensor to obtain first soil data collected by each monitoring sensor, and send a calibration instruction to the reference acoustic wave transmitter to obtain the acoustic wave flight time corresponding to each monitoring sensor according to the feedback signal of each acoustic wave transducer received by the reference acoustic wave transmitter; And, according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, obtain the position deviation value corresponding to each monitoring sensor, and send the first soil data and the position deviation value corresponding to each monitoring sensor to the remote cloud platform, so that the cloud platform performs compensation and correction based on the first soil data corresponding to each position deviation value, and then performs land soil moisture monitoring.

2. The soil moisture monitoring device according to claim 1, characterized in that The communication component, the reference acoustic wave transmitter, any monitoring sensor or any acoustic wave transducer communicate with the main control processing component through the Modbus RTU protocol; The acoustic wave pulses emitted by the reference acoustic wave transmitter and any acoustic wave transducer are both 40 kHz.

3. The soil moisture monitoring device according to claim 1, characterized in that, The first soil data includes soil temperature and soil humidity; Then, the main control processing component obtains the position deviation value corresponding to each monitoring sensor according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, including: Obtaining the temperature compensation parameter corresponding to each monitoring sensor according to the soil temperature corresponding to each monitoring sensor and the preset reference temperature; obtaining the humidity compensation parameter corresponding to each monitoring sensor according to the soil humidity corresponding to each monitoring sensor; Compensating the preset reference sound speed according to the temperature compensation parameter and the humidity compensation parameter corresponding to each monitoring sensor to obtain the dynamic sound speed corresponding to each monitoring sensor; obtaining the position deviation value corresponding to each monitoring sensor according to the dynamic sound speed and the acoustic wave flight time corresponding to each monitoring sensor and the preset formula two; Δd = vt - d; Wherein, Δd is the position deviation value corresponding to any monitoring sensor, t is the acoustic wave flight time corresponding to the monitoring sensor, and d is the preset initial position corresponding to the monitoring sensor.

4. The soil moisture monitoring device according to claim 1, wherein The first soil data includes soil temperature and soil humidity; The main control processing component obtains the position deviation value corresponding to each monitoring sensor according to the acoustic wave flight time and the first soil data corresponding to each monitoring sensor, including: Based on the first soil data corresponding to each monitoring sensor and the preset Formula 3, obtain the soil parameters corresponding to each monitoring sensor; the Formula 3 is: H = w1T + w2S; where H is the soil parameter corresponding to any monitoring sensor, T is the soil temperature corresponding to this monitoring sensor, S is the soil humidity corresponding to this monitoring sensor, and both w1 and w2 are preset weight coefficients; Judge whether the soil parameters corresponding to each monitoring sensor exceed the preset soil parameter threshold; Based on the soil temperature corresponding to each monitoring sensor and the preset reference temperature, obtain the temperature compensation parameter corresponding to each monitoring sensor; based on the soil humidity corresponding to each monitoring sensor, obtain the humidity compensation parameter corresponding to each monitoring sensor; Based on the temperature compensation parameter and humidity compensation parameter corresponding to each monitoring sensor, compensate the preset reference sound speed to obtain the dynamic sound speed corresponding to each monitoring sensor; When it does not exceed, then based on the first soil data corresponding to each monitoring sensor and the preset Formula 4, obtain the dynamic sound speed corresponding to each monitoring sensor; the Formula 4 is: v = 1440 + 4.6T - 0.055T 2 + 1.3S; Based on the dynamic sound speed and acoustic wave flight time corresponding to each monitoring sensor and the preset Formula 2, obtain the position deviation value corresponding to each monitoring sensor; Δd = vt - d; where Δd is the position deviation value corresponding to any monitoring sensor, t is the acoustic wave flight time corresponding to this monitoring sensor, and d is the preset initial position corresponding to this monitoring sensor.

5. The soil moisture monitoring device according to claim 1, characterized in that The main control processing component is further configured to: When receiving the soil moisture monitoring instruction, send wireless synchronization signals to each monitoring sensor respectively, so that each monitoring sensor obtains the corresponding transmission delay according to the received wireless synchronization signal, and then adjusts its own delay sampling window; The delay sampling window is used for the monitoring sensor to perform data sampling within a specified time window when receiving the sampling instruction.

6. A soil moisture monitoring system, characterized in that, It includes a monitoring cloud platform and a land soil moisture monitoring device, and the land soil moisture monitoring device is the device described in any one of claims 1 to 5; the land soil moisture monitoring device is communicatively connected to the monitoring cloud platform; The land soil moisture monitoring device is configured to send the first soil data and the position deviation value corresponding to each monitoring sensor to the monitoring cloud platform every preset time; The monitoring cloud platform is configured to input the first soil data and the position deviation value corresponding to each monitoring sensor received into a preset dynamic compensation model for position compensation to obtain the second soil data after position compensation corresponding to each monitoring sensor; The dynamic compensation model is used to perform position compensation on the first soil data corresponding to the monitoring sensor according to the position deviation value corresponding to each monitoring sensor; Based on the second soil data corresponding to each monitoring sensor and the preset land soil moisture assessment algorithm, obtain the land soil moisture assessment index for assisting water resource management in the monitoring area.

7. The soil moisture monitoring system according to claim 6, characterized in that, The land moisture monitoring device is further configured to: obtain the actual position corresponding to each monitoring sensor according to the position deviation value of each monitoring sensor and the preset initial position of each monitoring sensor, and send the actual position corresponding to each monitoring sensor to the monitoring cloud platform; Then, the monitoring cloud platform inputs the first soil data and the position deviation value corresponding to each monitoring sensor received into a preset dynamic compensation model for position compensation to obtain the second soil data after position compensation corresponding to each monitoring sensor, including: Perform position compensation on the first soil data corresponding to each monitoring sensor according to the position deviation value and the actual position corresponding to each monitoring sensor, and a preset formula five, to obtain the second soil data after position compensation corresponding to each monitoring sensor; the formula five is: Among them, C1 is the first soil data corresponding to any monitoring sensor, C2 is the second soil data corresponding to the monitoring sensor, Δd is the position deviation value corresponding to the monitoring sensor, and a is the preset migration weight. It is the fluctuation gradient corresponding to the first soil data and is obtained from the actual positions and the first soil data corresponding to all monitoring sensors.

8. The soil moisture monitoring system according to claim 7, characterized in that, Both the first soil data and the second soil data include: soil temperature, soil humidity, soil nitrogen concentration, soil phosphorus concentration, and soil potassium concentration; Then, the monitoring cloud platform obtains a land moisture assessment index for assisting in water resource management within the monitoring area according to the second soil data corresponding to each monitoring sensor and a preset land moisture assessment algorithm, including: Subtract the preset optimal temperature from the compensated soil temperature corresponding to each monitoring sensor to obtain the corresponding temperature deviation, and use the ratio of the temperature deviation to the preset adaptive temperature as the temperature gain term corresponding to each monitoring sensor; Obtain the soil potassium concentration gain corresponding to each monitoring sensor according to the compensated soil potassium concentration corresponding to each monitoring sensor and the critical threshold corresponding to the preset soil potassium concentration, obtain the soil phosphorus concentration gain corresponding to each monitoring sensor according to the compensated soil phosphorus concentration corresponding to each monitoring sensor and the critical threshold corresponding to the preset soil phosphorus concentration, obtain the soil nitrogen concentration gain corresponding to each monitoring sensor according to the compensated soil nitrogen concentration corresponding to each monitoring sensor and the critical threshold corresponding to the preset soil nitrogen concentration, and multiply the soil potassium concentration gain, soil phosphorus concentration gain, and nitrogen concentration gain corresponding to each monitoring sensor to obtain the nutrient gain term corresponding to each monitoring sensor; Obtain a soil humidity gradient according to the soil humidity and the actual position corresponding to all monitoring sensors; obtain a corresponding gradient penalty term according to the soil humidity gradient; Multiply and sum the soil humidity corresponding to each monitoring sensor, the preset humidity weight, the temperature gain term, and the nutrient gain term corresponding to each monitoring sensor, and subtract the gradient penalty term to obtain a land moisture assessment index for assisting in water resource management within the monitoring area.

9. The soil moisture monitoring system according to claim 6, characterized in that, The monitoring cloud platform is further configured to: Judge whether the land moisture monitoring device needs to be adjusted in position according to the position deviation value corresponding to each monitoring sensor received and a preset deviation threshold; If the position deviation value corresponding to any monitoring sensor is greater than the preset deviation threshold, that is, position adjustment is required, the monitoring cloud platform will give an alarm.

10. The soil moisture monitoring system according to claim 6, wherein The land moisture monitoring device is further configured to: Before sending the first soil data to the monitoring cloud platform, preprocess the first soil data; the preprocessing includes data cleaning, standardization processing, outlier screening, and outlier replacement.

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