Distributed soil moisture content monitoring system

Abstract

The invention discloses a distributed soil moisture content internet-of-things monitoring system which comprises a sensor unit, a main controller unit, an internet-of-things communication unit and an energy supply unit. The sensor unit comprises a plurality of groups of temperature and humidity sensors and supports independent or networking deployment. The main controller is responsible for data acquisition and dynamic frequency adjustment, the communication unit uploads data to a cloud platform through a wireless network, and the energy supply unit adopts solar energy and battery standby power to ensure long-term field operation. According to the invention, data aggregation and remote management are realized through the cloud platform and the client, the problems of few monitoring points, single parameter, inflexible deployment, difficult power supply and inconvenient data acquisition in the prior art are solved, and the system is suitable for precision agriculture and environment monitoring.

Description

Technical Field

[0001] This invention belongs to the field of agricultural environmental monitoring technology, and in particular relates to a distributed soil moisture monitoring system. Background Technology

[0002] Agricultural mulching technology is an important tool in modern field management. Accurately acquiring soil moisture (temperature and humidity) and environmental parameters (sunlight and rainfall) beneath the mulch is crucial for evaluating the moisture-retaining performance of the mulch, optimizing irrigation, and increasing crop yield. The hydrothermal dynamics of the microenvironment beneath the mulch, such as the condensate cycle and light-temperature-humidity coupling, exhibit rapid changes on a minute-by-minute scale.

[0003] Currently, traditional manual sampling methods are inefficient, and the actions of lifting or puncturing the film disrupt the sealed environment inside, making in-situ, continuous, and undisturbed real-time monitoring impossible. Existing monitoring equipment also has many limitations: some only support single-point, single-parameter measurements; some lack the ability to simultaneously monitor multi-dimensional environmental parameters such as light and rainfall; and some do not integrate IoT functionality, making it difficult to achieve remote real-time data transmission and network management. In particular, there is a lack of comprehensive monitoring solutions that can adapt to special scenarios such as mulched agriculture, support high-density, distributed, and flexible sensor deployment, and provide stable power for long-term operation in the field.

[0004] Therefore, there is an urgent need to develop a soil moisture monitoring device and system that can achieve synchronous acquisition of multiple parameters, support distributed and flexible networking, have remote real-time transmission capabilities, and meet the requirements for long-term stable operation in the field, so as to fill the technological gap in the acquisition of full-cycle, undisturbed, and high spatiotemporal resolution data in fields such as mulched agriculture. Summary of the Invention

[0005] This invention proposes a distributed soil moisture monitoring system to address the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides a distributed soil moisture monitoring system, comprising:

[0007] Several monitoring devices, each monitoring device including at least one set of sensors, a main controller, a communication unit and a power supply unit;

[0008] The sensor group is used to collect environmental parameters;

[0009] The main controller is connected to the sensor group and is used to acquire the data collected by the sensor group and process the data to obtain soil moisture data.

[0010] The communication unit is connected to the main controller and is used to send the soil moisture data to the Internet of Things cloud platform;

[0011] The power supply unit supplies power to the monitoring device;

[0012] The IoT cloud platform is connected to the communication unit and is used to receive and store soil moisture data from the monitoring device;

[0013] The client software connects to the IoT cloud platform and is used to acquire and display the soil moisture data.

[0014] Optionally, the sensor group includes several soil temperature sensors and several soil moisture sensors;

[0015] The main controller obtains the corresponding temperature data by identifying the unique address of each soil temperature sensor, and obtains the corresponding humidity data by identifying the pin connected to each soil moisture sensor.

[0016] Optionally, the main controller dynamically adjusts the data acquisition frequency of the sensor group based on changes in the soil temperature and soil moisture data.

[0017] Optionally, when the main controller determines that the sensor data changes gradually, it reduces the acquisition frequency; when it determines that the sensor data changes rapidly, it increases the acquisition frequency.

[0018] Optionally, when the main controller fails to acquire sensor data, it replaces the failed sensor data with a preset value and generates abnormal information containing the identifier of the faulty sensor.

[0019] Optionally, the communication unit checks the communication connection status before sending data to the IoT cloud platform; if the connection fails, it performs a network reset operation.

[0020] When the communication unit fails to send data, the data is stored in the local memory; when the network is detected to be back to normal, the stored data is resent.

[0021] Optionally, the power supply unit includes a solar panel and an energy storage battery;

[0022] The solar panel converts light energy into electrical energy and charges the energy storage battery, which in turn powers the monitoring device.

[0023] Optionally, the power supply unit further includes a charging management circuit for controlling the charging process of the solar panel to the energy storage battery, and automatically switching to backup battery power supply when the voltage of the current power supply battery is detected to be insufficient.

[0024] Compared with the prior art, the present invention has the following advantages and technical effects:

[0025] This invention integrates multi-channel temperature and humidity sensors, high-performance microcontrollers, 4G communication modules, IoT cloud platforms, and computer software technologies to achieve high-frequency, remote, real-time unattended monitoring of soil moisture. It supports multi-node networking and synchronous acquisition of multi-dimensional environmental parameters, effectively solving key technical bottlenecks such as long-term power supply difficulties in the field, inflexible deployment, and weak real-time data transmission capabilities. It provides an efficient and reliable solution for precision agriculture, environmental research, and ecological monitoring. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1 This is a schematic diagram of the system structure according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of a temperature sensor according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of a humidity sensor according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram illustrating the use of a single unit in an embodiment of the present invention. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment provides a distributed soil moisture monitoring system, including:

[0035] Several monitoring devices, each monitoring device including at least one set of sensors, a main controller, a communication unit and a power supply unit;

[0036] The sensor array is used to collect environmental parameters.

[0037] The main controller is connected to the sensor group to acquire the data collected by the sensor group and process the data to obtain soil moisture data.

[0038] The communication unit is connected to the main controller and is used to send soil moisture data to the Internet of Things cloud platform;

[0039] The power supply unit supplies power to the monitoring device;

[0040] The Internet of Things (IoT) cloud platform connects to the communication unit and is used to receive and store soil moisture data from monitoring devices.

[0041] The client software connects to an IoT cloud platform to acquire and display soil moisture data.

[0042] Furthermore, the sensor group includes several soil temperature sensors and several soil moisture sensors, such as... Figures 2-3 As shown;

[0043] Specifically, the setup can be configured as follows: It includes at least two independently configured sensor groups; each sensor group includes at least four soil temperature sensors and four soil moisture sensors (which can be added as needed), and optionally one light intensity sensor and one raindrop detection sensor; the sensor groups support independent distributed operation or collaborative network operation modes; each device connects its respective sensor group to the ESP32 main control module via a wired connection. The devices access the OneNet IoT platform via a 4G network and upload data using the MQTT protocol. For multiple devices deployed in a distributed manner, the networking logic can be flexibly configured through OneNet cloud and PC software. Figure 4 A diagram illustrating the use of a single group is shown.

[0044] Among them, temperature sensors and humidity sensors can be deployed in layers according to soil depth or distributed according to soil points. Each group of sensors monitors soil profiles at different depths or surface points of different treatments.

[0045] Furthermore, the main controller obtains the corresponding temperature data by identifying the unique address of each soil temperature sensor, and obtains the corresponding humidity data by identifying the pin connected to each soil moisture sensor.

[0046] Specifically, the temperature sensor is identified and distinguished by its unique ROM address, while the soil moisture sensor is distinguished by the pin number connected to the ESP32. Data acquisition is achieved through a packaged temperature reading program, a soil moisture analog-to-digital conversion reading function formula (1) and program, a light intensity reading program, and a raindrop detection program.

[0047] SM = Ht / (H0-Hi) (1)

[0048] Where SM (%) represents soil moisture, Ht represents the actual analog-to-digital conversion value measured by the sensor at time t, H0 represents the analog-to-digital conversion value of the sensor in dry soil, and Hi represents the analog-to-digital conversion value of the sensor in water-saturated soil.

[0049] The main controller dynamically adjusts the data acquisition frequency of the sensor group based on changes in soil temperature and moisture data. When the main controller determines that the sensor data changes are gradual, it reduces the acquisition frequency; when it determines that the sensor data changes rapidly, it increases the acquisition frequency. This embodiment's adaptive sampling mechanism determines the environmental change state by calculating the variance or gradient of the sensor data in real time. When the calculated value is below a preset threshold, the system determines it as "gradual change" and reduces the sampling frequency to save energy; when rainfall, sudden changes in light intensity, or drastic fluctuations in temperature and humidity are detected, causing the variance or gradient value to exceed the threshold, the system determines it as "rapid change" and immediately switches to a high-frequency acquisition mode. This strategy, based on dynamic adjustment of data statistical characteristics, significantly reduces power consumption and data traffic under normal conditions while ensuring that key change events are fully captured. When the main controller fails to acquire sensor data, it replaces the failed sensor data with a preset value and generates anomaly information containing the faulty sensor identifier.

[0050] Specifically, the main controller (ESP32) incorporates a dynamic sampling algorithm, allowing the system to calculate the variance or gradient of sensor data in real time. When temperature and humidity changes are gradual, the sampling frequency is automatically reduced (e.g., once every 10 minutes) to save power and bandwidth. When rainfall begins, light intensity changes abruptly, or temperature and humidity fluctuate rapidly, the system automatically switches to a high-frequency acquisition mode (e.g., once every 1 minute) and uploads data to the OneNet cloud server at a frequency of 0-30 minutes. This significantly reduces data volume and energy consumption, extending battery life while ensuring no critical information is lost. If a sensor fails to read data, the system automatically replaces it with the preset value corresponding to that sensor number, preventing data array misalignment or loss. Simultaneously, it triggers a data anomaly alarm on the computer and uploads device fault codes (power failure, sensor failure, etc.) for timely data verification or sensor repair / replacement.

[0051] Furthermore, before sending data to the IoT cloud platform, the communication unit checks the communication connection status; if the connection fails, a network reset operation is performed. When the communication unit fails to send data, the data is stored in local memory; when the network is detected to be back to normal, the stored data is retransmitted.

[0052] Specifically, the communication unit transmits the processed data to the IoT cloud platform via a 4G or 5G wireless network. The device uses the MQTT protocol for data transmission and employs TLS encryption to ensure security during the transmission process. Before each transmission, the system automatically checks the MQTT connection status; if the connection fails, a network reset process is automatically triggered to attempt to restore communication. After transmission is complete, the system determines whether the data was sent successfully based on the return value; if transmission fails, the data at that point in time is automatically saved to the Flash memory and retransmitted after the network returns to normal. When the device goes offline, the monitoring platform will trigger an alarm in real time and upload communication fault codes (signal failure, service interruption due to unpaid fees, etc.), prompting maintenance personnel to promptly inspect the equipment and ensure stable system operation.

[0053] In this embodiment, the IoT wireless 4G communication unit is connected to the China Mobile OneNet cloud platform via an A7670C module.

[0054] Furthermore, the power supply unit includes a solar panel and an energy storage battery; the solar panel converts light energy into electrical energy and charges the energy storage battery, which in turn powers the monitoring device. This unit includes a solar panel, an MPPT high-efficiency charging controller, an energy storage battery (such as a lithium battery), and a power management circuit that includes overcharge / over-discharge protection, UPS switching, and voltage conversion (to 5V). The charging management circuit controls the charging process of the solar panel to the energy storage battery and automatically switches to backup battery power when the current power supply battery voltage is detected to be insufficient.

[0055] Specifically, the power supply unit can be either a 220V AC grid or a solar power unit. The 220V AC power unit includes a step-down converter and a voltage regulator. The solar power unit includes solar panels, a charging management circuit, and two energy storage batteries, one for backup and one for standby. A power detection function automatically switches the power supply battery based on battery voltage, providing a backup power source for the entire device. The solar panels use 60W / 18V monocrystalline silicon modules, installed at a low-cost fixed tilt angle of 36° facing due south to adapt to local sunlight conditions. The charging control section uses a solar charge controller with maximum power point tracking (MPPT) function, supporting a maximum charging and discharging current of 4A and featuring UPS uninterrupted charging and discharging capabilities. The energy storage section uses a 3.7V / 36000mAh lithium battery pack, which can support continuous operation of a single device for more than 5 days when fully charged. This power module has high reliability and can meet the long-term power supply needs of unattended outdoor environments.

[0056] In this embodiment, the soil moisture retention and temperature increase effects of different types of plastic film were evaluated in a maize mulching experimental field in an arid region of Northwest China. Deployment: A monitoring device was set up for each type of plastic film treatment. The sensor group of each device was arranged in a vertical layer, with four temperature and humidity sensor probes buried at a depth of 15cm in the soil to monitor water infiltration, evaporation dynamics, and heat transfer processes. Simultaneously, a light sensor and a rain sensor were installed on top of the device. Application: All equipment was deployed before sowing and mulching. Throughout the growing season, the equipment automatically collected data every 5 minutes and uploaded it to the OneNet cloud platform via a 4G network. Data Application: Researchers remotely acquired data in real time through client software, accurately grasping the spatiotemporal variation patterns of soil moisture at different depths and successfully capturing the daily cycle of condensation and evaporation within the film. By comparing data under different types of plastic film, the differences in soil moisture retention performance of various types of plastic film were clearly quantified. The minute-level data provided by the system provided a solid foundation for establishing a hydrothermal coupling model.

[0057] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A distributed soil moisture monitoring system, characterized in that, The system comprises: a plurality of monitoring devices, each comprising at least one sensor group, a main controller, a communication unit, and a power supply unit; wherein the sensor group is configured to collect environmental parameters; the main controller is connected to the sensor group and configured to obtain data collected by the sensor group and process the data to obtain soil condition data; the communication unit is connected to the main controller and configured to send the soil condition data to an Internet of Things cloud platform; the power supply unit supplies power to the monitoring device; the Internet of Things cloud platform is connected to the communication unit and configured to receive and store soil condition data from the monitoring device; a client software connected to the Internet of Things cloud platform and configured to obtain and display the soil condition data.

2. The system of claim 1, wherein: the sensor group comprises a plurality of soil temperature sensors and a plurality of soil humidity sensors; the main controller obtains temperature data by identifying the unique address of each soil temperature sensor and obtains humidity data by identifying the pin connected to each soil humidity sensor.

3. The system of claim 2, wherein: the main controller dynamically adjusts the data collection frequency of the sensor group based on the changes in soil temperature data and soil humidity data.

4. The system of claim 3, wherein: when the main controller determines that the sensor data changes slowly, it reduces the collection frequency; when it determines that the sensor data changes rapidly, it increases the collection frequency.

5. The system of claim 2, wherein: when the main controller fails to obtain sensor data, it uses a preset value to replace the failed sensor data and generates abnormal information containing the identification of the faulty sensor.

6. The system of claim 1, wherein: the communication unit detects the communication connection state before sending data to the Internet of Things cloud platform; if the connection fails, it performs a network reset operation. when the communication unit fails to send data, it stores the data in the local memory; when it detects that the network has returned to normal, it resends the stored data.

7. The system of claim 1, wherein: the power supply unit comprises a solar panel and an energy storage battery; the solar panel converts light energy into electrical energy and charges the energy storage battery, which supplies power to the monitoring device.

8. The system of claim 7, wherein: the power supply unit further comprises a charging management circuit for controlling the charging process of the energy storage battery by the solar panel and automatically switching to a backup battery for power supply when it detects that the current energy supply battery voltage is insufficient.

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