An integrated system for soil energy collection and soil moisture detection

Abstract

The present invention discloses an integrated system that can realize soil energy collection and soil moisture content detection. On the one hand, through the electrode design of the double helix structure, the contact area between the electrode and the soil is increased, thereby improving the power collection efficiency of the soil energy collection module; on the other hand, the moisture content measurement module converts the soil moisture content into a voltage value through a sampling resistor based on the electric energy collected by the soil energy collection module, and the measurement module measures the soil moisture content based on the voltage value. The measurement method is simple, the measurement accuracy is high, and no external power supply is required. This technology realizes self-powered soil moisture content monitoring, and has application prospects in smart agricultural soil condition monitoring and landslide soil environment monitoring. At the same time, the detection module, moisture content measurement module and soil energy collection module of the entire system can be integrated into one, which is conducive to the miniaturization of the product.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental energy collection, and in particular relates to an integrated system capable of realizing soil energy collection and soil moisture content detection. Background Art

[0002] Soil is ubiquitous, renewable due to the natural metabolic reactions of microorganisms, and much cheaper than other energy sources. However, due to the different soil types and compositions, maximizing the extraction of electricity from soil and providing efficient power delivery still face major challenges. Existing soil energy harvesting technology mainly inserts two electrodes into the soil to collect electrical energy from the potential difference between the two electrodes under the principle of redox reaction. However, due to the low voltage and high internal resistance characteristics of the soil energy device itself, the energy harvesting efficiency is very low.

[0003] At the same time, soil moisture is an essential parameter in the agricultural production process and an important variable in geological disaster monitoring. However, due to long-term exposure to complex field environments, the maintenance cost of power supplies such as batteries and power cords of existing soil moisture measurement devices is high. How to solve the power supply problem is also one of the difficulties in current related research. Summary of the invention

[0004] The present invention aims to solve the problems of low soil energy collection efficiency and high maintenance cost of a power module of a soil moisture content measuring device, and proposes an integrated system for realizing soil energy collection and soil moisture content detection.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions: an integrated system capable of realizing soil energy collection and soil moisture content detection, comprising: a detection module, a moisture content measurement module and a soil energy collection module, wherein the detection module comprises a nylon rod, an electrode with a double helix structure and a double-throw switch, the electrode comprises an anode and a cathode arranged on the outer surface of the nylon rod in a double helix distribution manner, the output end of the anode is electrically connected to the fixed end of the double-throw switch, and the output end of the cathode is grounded; the moisture content measurement module comprises a sampling resistor and a measurement unit electrically connected in sequence, the input end of the sampling resistor is electrically connected to the first free end of the double-throw switch, and the measurement unit comprises The soil energy collection module comprises an energy collection unit and an electric energy storage unit which are electrically connected in sequence, the input end of the energy collection unit is electrically connected to the second free end of the double-throw switch, and the output end of the electric energy storage unit is electrically connected to the power interface of the measuring unit. When working, the electrode is in contact with the soil, when the second free end of the double-throw switch is turned on, the energy collection unit converts soil energy into electric energy, and the electric energy storage unit stores the electric energy. When the first free end of the double-throw switch is turned on, the electric energy storage unit supplies power to the measuring unit, the sampling resistor converts soil moisture content into a voltage value, and the measuring unit measures soil moisture content based on the voltage value.

[0006] The present invention proposes an integrated system that can realize soil energy collection and soil moisture content detection. On the one hand, the electrode design with a double helix structure increases the contact area between the electrode and the soil, thereby improving the power collection efficiency of the soil energy collection module; on the other hand, the moisture content measurement module converts the soil moisture content into a voltage value through a sampling resistor based on the electric energy collected by the soil energy collection module, and the soil moisture content is measured by the measurement unit based on the voltage value. The measurement method is simple, the measurement accuracy is high, and no external power supply is required. This technology realizes self-powered soil moisture content monitoring and has application prospects in smart agricultural soil condition monitoring and landslide soil environment monitoring. At the same time, the detection module, moisture content measurement module and soil energy collection module of the entire system can be integrated into one, which is conducive to the miniaturization of the product.

[0007] In a preferred embodiment, a display device is further included, and the measuring unit also includes a communication interface, and the display device is electrically connected to the communication interface. Since the electric energy for soil energy collection is limited, if the moisture content measurement module is also provided with a display module, the soil energy collection module needs to supply power to the measuring unit and the display module at the same time, and the power supply pressure is relatively large. Therefore, by providing a communication interface in the measuring unit, the moisture content measurement result is collected by means of an external display device.

[0008] In a preferred embodiment, the outer surface of the middle part of the nylon rod is provided with a spiral isolation groove, and the anode and the cathode are fixed by the isolation groove. Since the detection module needs to be inserted into the soil during operation to ensure that the electrode is in contact with the soil, the spiral groove for fixing the anode and the cathode is provided on the outer surface of the nylon rod to ensure that the detection module structure is stable during operation, and the anode and the cathode will not be offset or loosened.

[0009] Furthermore, the bottom of the nylon rod is arranged in a cone shape, and the cross-sectional area of ​​the cone gradually decreases from top to bottom. Such an arrangement enables the detection module to be conveniently and flexibly inserted into the soil.

[0010] Furthermore, an anode groove and a cathode groove are symmetrically arranged on both sides of the top of the nylon rod, and the anode groove and the cathode groove are arranged along the axial direction of the nylon rod. In this way, when working, the output ends of the anode and the cathode can be easily led out of the soil for connection with an external circuit.

[0011] Furthermore, the nylon rod is hollow or solid, and the cross section of the nylon rod is circular, square or polygonal.

[0012] In a preferred embodiment, the anode is selected from any of the following materials: zinc, iron, aluminum, and the cathode is selected from any of the following materials: carbon, silver, and copper. In the field of primary battery electrochemistry, a primary battery can be realized as long as the electron loss ability of the anode material is stronger than that of the cathode. Among them, zinc is the best material for the anode, and iron and aluminum can also be selected, and the cathode can be any of carbon, silver, and copper.

[0013] In a preferred embodiment, the energy harvesting unit includes an LTC3105 chip. In this configuration, the LTC3105 chip can boost the open circuit voltage output by the detection module to 3.3V, and its built-in MPPC technology can maximize the extraction of electrical energy from the low-voltage, high-impedance soil energy harvesting device.

[0014] In a preferred embodiment, the energy storage unit is a supercapacitor.

[0015] In a preferred embodiment, the measuring unit includes an MSP430 single-chip microcomputer. In this configuration, the MSP430 single-chip microcomputer has built-in ADC10, storage unit, processing unit, power interface and communication interface, wherein the ADC10 is used to convert the voltage signal into a digital signal, the storage unit is used to store the corresponding relationship between the soil moisture content and the voltage value obtained by the soil moisture content calibration method, and the processing unit is used to perform data segmentation fitting based on the above corresponding relationship and the digital signal converted from the voltage signal of the sampling resistor to obtain the soil moisture content.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] 1. In the present invention, when the volume of the detection module is the same, the double helix structure electrode design is conducive to increasing the contact area with the soil, thereby improving the soil energy collection efficiency;

[0018] 2. The present invention uses the corresponding relationship between voltage and soil moisture content to measure soil moisture content, and the measuring method is simple and has high measuring accuracy;

[0019] 3. The detection module, moisture content measurement module and soil energy collection module of the present invention can be integrated into one. The system can detect the change of soil moisture content while collecting soil energy, and no additional soil moisture sensor is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a system block diagram of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the detection module of the present invention;

[0022] Figure 3 A circuit diagram of an embodiment of the present invention;

[0023] Among them: 1: detection module; 11: nylon rod; 111: anode groove; 112: cathode groove; 12: electrode; 121: anode; 122: cathode; 123: isolation groove; 13: double-throw switch; 14: detection module equivalent circuit; 2: moisture content measurement module; 21: sampling resistor; 22: measurement unit; 221: power interface; 222: communication interface; 3: soil energy collection module; 31: energy collection unit; 32: electric energy storage unit; 4: display device. DETAILED DESCRIPTION

[0024] like Figure 1~Figure 3 As shown, an integrated system for realizing soil energy collection and soil moisture content detection includes: a detection module 1, a moisture content measurement module 2, a soil energy collection module 3 and a display device 4.

[0025] The detection module 1 includes a nylon rod 11, an electrode 12 with a double helix structure and a double-throw switch 13. The nylon rod 11 consists of a top, a middle and a bottom. The two sides of the top are symmetrically provided with an anode groove 111 and a cathode groove 112, and the anode groove 111 and the cathode groove 112 are arranged along the axial direction of the nylon rod 11. The middle part is cylindrical, and a spiral isolation groove 123 is arranged on the outer surface. The bottom is arranged in a cone, and the cross-sectional area of ​​the cone gradually decreases from top to bottom.

[0026] The electrode 12 includes an anode 121 and a cathode 122 fixed to the isolation groove 123 in a double helix distribution manner. The anode 121 is a zinc wire, and the cathode 122 is a copper wire.

[0027] Preferably, the diameter of the middle part of the nylon rod 11 is 20 mm, the length is 160 mm, the bottom is conical, the spacing between the zinc wire and the copper wire is 1 mm, the pitch of a single spiral is 6 mm, and the total volume of the detection module 1 is 64.6 By designing the above parameters, the contact area between the electrode 12 and the soil is 10.575 Compared with the detection device in which the electrodes 12 are arranged in a linear shape, under the same volume condition, the contact area between the electrodes 12 and the soil is increased. At the same time, the 1mm spacing between the electrodes 12 not only improves the energy capture rate of the detection module 1, but also ensures that the two electrodes 12 do not short-circuit.

[0028] The moisture content measurement module 2 includes a sampling resistor 21 and a measuring unit 22 which are electrically connected in sequence, the input end of the sampling resistor 21 is electrically connected to the output end of the anode 121 through a double-throw switch 13, and the measuring unit 22 includes an MSP430 single-chip microcomputer, and the MSP430 single-chip microcomputer includes a power interface 221 and a communication interface 222;

[0029] The voltage signal obtained by the sampling resistor 21 comes from the amount of electricity output by the detection module 1. Based on the relationship between the sampling resistor 21 and the soil moisture content, the soil moisture content information is finally obtained through the MSP430 single chip microcomputer.

[0030] The soil energy collection module 3 includes an energy collection unit 31 and an electric energy storage unit 32 which are electrically connected in sequence, wherein the input end of the energy collection unit 31 is electrically connected to the output end of the anode 121 via a double-throw switch 13, and the output end of the electric energy storage unit 32 is electrically connected to the power supply interface 221 of the measuring unit 22;

[0031] The energy collection unit 31 includes an LTC3105 chip, which can boost the open circuit voltage output by the detection module 1 to 3.3V, and its built-in MPPC technology can maximize the extraction of electrical energy from the low-voltage, high-impedance detection module 1;

[0032] The electric energy storage unit 32 is a super capacitor, which stores the collected electric energy when the double-throw switch 13 turns on the detection module 1 and the soil energy collection module 3, and supplies power to the measurement unit 22 when the double-throw switch 13 turns on the detection module 1 and the moisture content measurement module 2.

[0033] The display device 4 is any one of a display screen, a desktop computer, a laptop computer or a tablet computer. The display device 4 is electrically connected to the MSP430 single chip microcomputer through the communication interface 222 .

[0034] The working principle is: the electrical model of the detection module 1 is equivalent to a voltage source , soil internal resistance In series, the detection module equivalent circuit 14 includes a voltage source , soil internal resistance .

[0035] Insert the detection module 1 into the soil, and the spiral copper wire and spiral zinc wire wrapped on the nylon rod 11 come into contact with the soil and produce an oxidation-reduction reaction, wherein the spiral zinc wire loses electrons and the spiral copper wire gains electrons. When it is necessary to obtain electrical energy, the detection module 1 and the soil energy collection module 3 are turned on through the double-throw switch 13, and the copper wire and zinc wire use the oxidation-reduction reaction to convert chemical energy into electrical energy. The low-voltage direct current output by the detection module 1 is boosted to 3.3V by the BOOST boost topology structure through the LTC3105 chip, and the MPPC maximum power point control technology is used to efficiently extract soil energy, and finally stored in the super capacitor;

[0036] When it is necessary to obtain soil moisture information, the detection module 1 and the moisture content measurement module 2 are turned on by the double-throw switch 13. The sampling resistor 21 divides the soil internal resistance The voltage signal is converted into a voltage value, and then the voltage signal is converted into a digital signal through the built-in ADC10 of the MSP430 microcontroller. At the same time, the MSP430 microcontroller obtains the soil moisture content according to the pre-stored functional relationship between the soil moisture content and the voltage value obtained by the soil moisture content calibration method. The soil moisture content is sent to the display device 4 through the communication interface 222 and displayed by the MSP430 microcontroller.

[0037] Specific circuit connection method: the detection module equivalent circuit 14 includes a voltage source , soil internal resistance , the voltage source The positive terminal and the soil internal resistance Electrical connection, soil internal resistance The other end is electrically connected to the output end of the anode 121, and the output end of the anode 121 is electrically connected to the fixed end of the double-throw switch 13. The negative terminal of the cathode 122 is electrically connected to the output terminal of the cathode 122, and the output terminal of the cathode 122 is grounded.

[0038] The soil energy harvesting module 3 includes a feedback voltage divider resistor , Feedback voltage divider resistor , Input decoupling capacitor , output filter capacitor 、Supercapacitor , feedforward capacitor 、Filter capacitor 、LTC3105 chip 、Filter capacitor 、MPPC feedback resistor ,inductance .

[0039] The input decoupling capacitor The upper end is electrically connected to the second free end of the double throw switch 13 and is also electrically connected to the LTC3105 chip One end of the electrical connection, input decoupling capacitor The lower end is grounded; the MPPC feedback resistor The upper end and LTC3105 chip The 2-terminal electrical connection of the MPPC feedback resistor The lower end is grounded;

[0040] The filter capacitor The upper end and LTC3105 chip The 3-terminal electrical connection of the filter capacitor The lower end is grounded; the filter capacitor The upper end and LTC3105 chip The 8-terminal electrical connection, at the same time, this port can output a 2.2V regulated voltage value, the filter capacitor The lower end is grounded;

[0041] The inductor One end is connected to the LTC3105 chip 1 end of the inductor is electrically connected to The other end is connected to the LTC3105 chip The 5-terminal electrical connection;

[0042] The feedforward capacitor The upper end and LTC3105 chip The 6-terminal electrical connection, feedforward capacitor The lower end and LTC3105 chip 7-terminal electrical connection;

[0043] The feedback voltage divider resistor The upper end passes through the feed-forward capacitor The upper end of the LTC3105 chip The 6-terminal electrical connection, feedback voltage divider resistor The lower end passes through the feed-forward capacitor The lower end of the LTC3105 chip 7-terminal electrical connection;

[0044] The feedback voltage divider resistor The upper end and the feedback voltage divider resistor The lower end of the feedback voltage divider resistor The lower end is grounded;

[0045] The output filter capacitor The upper end is fed back through the voltage divider resistor Upper side, feedforward capacitor The upper end of the LTC3105 chip The 6-terminal electrical connection of the output filter capacitor The lower end is grounded;

[0046] Supercapacitor The upper end is fed back through the voltage divider resistor Upper side, feedforward capacitor Upper side, output filter capacitor The upper end and LTC3105 chip The 6-terminal electrical connection of the supercapacitor The lower end is grounded.

[0047] Moisture content measurement module 2 includes Sampling resistor 21, MSP430 microcontroller 、Crystal Oscillator .

[0048] One end of the sampling resistor 21 is electrically connected to the first free end of the double-throw switch 13. The other end is connected to the MSP430 microcontroller The 0 terminal is electrically connected;

[0049] The crystal oscillator One end is connected to MSP430 microcontroller 1 terminal is electrically connected to the crystal oscillator The other end is connected to the MSP430 microcontroller The two ends are electrically connected;

[0050] The MSP430 microcontroller Terminals 3 and 4 are the microcontroller programming interfaces, which are electrically connected to the external programmer.

[0051] The MSP430 microcontroller The 5th, 6th, 7th and 8th terminals of the sensor are used together as a communication interface 222, which is electrically connected to an external desktop computer through a UART serial port communication to send the measured soil moisture information to the desktop computer for display;

[0052] The MSP430 microcontroller The 6 terminals are also connected to the super capacitor The upper end is electrically connected to obtain electrical energy for work.

[0053] It should be noted that the above-mentioned technical features are continuously combined with each other to form various embodiments not listed above, which are all regarded as the scope of the present invention;

[0054] Furthermore, it is apparent to those skilled in the art that improvements or changes may be made based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. An integrated system for soil energy collection and soil moisture content detection, characterized in that: include: A detection module (1), a moisture content measurement module (2) and a soil energy collection module (3), wherein: The detection module (1) comprises a nylon rod (11), an electrode (12) with a double helix structure and a double-throw switch (13); the electrode (12) comprises an anode (121) and a cathode (122) arranged on the outer surface of the nylon rod (11) in a double helix distribution manner; the output end of the anode (121) is electrically connected to the fixed end of the double-throw switch (13); the output end of the cathode (122) is grounded; the anode (121) is selected from any one of the following materials: zinc, iron, aluminum; the cathode (122) is selected from any one of the following materials: carbon, silver, copper; The moisture content measurement module (2) comprises a sampling resistor (21) and a measuring unit (22) which are electrically connected in sequence, the input end of the sampling resistor (21) is electrically connected to the first free end of the double-throw switch (13), and the measuring unit (22) comprises a power supply interface (221); The soil energy collection module (3) comprises an energy collection unit (31) and an electric energy storage unit (32) which are electrically connected in sequence, the input end of the energy collection unit (31) being electrically connected to the second free end of the double-throw switch (13), and the output end of the electric energy storage unit (32) being electrically connected to the power supply interface (221); When in operation, the electrode (12) contacts the soil; when the second free end of the double-throw switch (13) is turned on, the energy collection unit (31) converts soil energy into electrical energy; the electrical energy storage unit (32) stores the electrical energy; when the first free end of the double-throw switch (13) is turned on, the electrical energy storage unit (32) supplies power to the measuring unit (22); the sampling resistor (21) converts soil moisture content into a voltage value; and the measuring unit (22) measures soil moisture content based on the voltage value.

2. The integrated system for soil energy collection and soil moisture content detection according to claim 1 is characterized in that: It also includes a display device (4), and the measuring unit (22) also includes a communication interface (222), and the display device (4) is electrically connected to the communication interface (222).

3. The integrated system for soil energy collection and soil moisture content detection according to claim 1 is characterized in that: The outer surface of the nylon rod (11) is provided with a spiral separation groove (123), and the anode (121) and the cathode (122) are fixed through the separation groove (123).

4. The integrated system for soil energy collection and soil moisture content detection according to claim 3 is characterized in that: The bottom of the nylon rod (11) is configured as a cone, and the cross-sectional area of ​​the cone gradually decreases from top to bottom.

5. The integrated system for soil energy collection and soil moisture content detection according to claim 3 is characterized in that: An anode groove (111) and a cathode groove (112) are symmetrically provided on both sides of the top of the nylon rod (11), and the anode groove (111) and the cathode groove (112) are arranged axially along the nylon rod (11).

6. The integrated system for soil energy collection and soil moisture content detection according to claim 3 is characterized in that: The nylon rod (11) is hollow or solid, and the cross section of the nylon rod (11) is circular, square or polygonal.

7. The integrated system for soil energy collection and soil moisture content detection according to claim 1 is characterized in that: The energy collection unit (31) comprises an LTC3105 chip.

8. The integrated system for soil energy collection and soil moisture content detection according to claim 1 is characterized in that: The electric energy storage unit (32) is a super capacitor.

9. The integrated system for soil energy collection and soil moisture content detection according to claim 1 is characterized in that: The measuring unit (22) comprises an MSP430 single chip microcomputer.

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