Field soil texture rapid judgment device and method based on mechanical properties

Abstract

The invention discloses a field soil texture rapid judgment device and method based on mechanical characteristics, and the device comprises a waterproof box body which is internally provided with a sample treatment cabin, and the sample treatment cabin is internally provided with a heating and spraying assembly; the mechanical detection unit is used for carrying out mechanical detection on the sample in the sample treatment cabin; the control unit is used for processing and displaying mechanical detection data; and the energy unit is used for supplying power to the mechanical detection unit and the control unit. According to the method, the field soil texture can be quickly, objectively and repeatedly judged, the limitation of a detection scene on operation is reduced, and the detection convenience and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of soil quality detection, and in particular to a device and method for quickly determining field soil texture based on mechanical properties. Background Art

[0002] At present, in my country's third national soil survey and routine soil surveys, field soil texture assessment mainly relies on empirical physical testing methods. Typical methods include:

[0003] (1) Ribbon Test

[0004] Procedure: Take a small amount of soil sample and gradually add water until it is plastic. Use your palms to repeatedly rub the soil into thin strips approximately 3mm in diameter. Observe the strips to see if they break and their length. Infer the texture type based on the stickiness (e.g., sandy soil will not form strips, while clay will form long, continuous strips). Dependency: According to the USDA Soil Texture Classification Guidelines, sandy soils, loamy soils, and clays have increasing strip-forming abilities.

[0005] Disadvantages: Environmental sensitivity: In low temperature environments (such as below 0°C), finger flexibility decreases, making it difficult to accurately control the wetness and rubbing strength; Observational error: Different operators have inconsistent understandings of qualitative descriptions such as "plastic state" and "viscosity", resulting in deviations in classification results; Inability to quantify: There is a lack of ability to quantify mechanical indicators of adhesion (such as soil compressive strength).

[0006] (2) Visual Estimation

[0007] Operation steps: Take dry soil and crush it and spread it flat on the palm of your hand or a piece of white paper; observe the particle composition with the naked eye (for example, sand particles reflect light clearly, powder particles are flour-like, and clay particles are clumping); roughly judge the texture based on the roughness of the hand (for example, sandy soil has a strong granular feel, while clay soil is fine).

[0008] Disadvantages: Low resolution: It is difficult to distinguish between similar types such as silt loam and sandy clay loam; Moisture interference: Wet soil tends to clump together, obscuring the true particle distribution characteristics; High experience threshold: Only operators who have undergone long-term training can ensure accuracy.

[0009] To compensate for the shortcomings of field methods, laboratories often use the following precise analytical methods, but they have significant limitations:

[0010] (1) Hydrometer Method

[0011] Principle and steps: Soil samples are dispersed in water and Stokes' Law is used to calculate the particle settling rate. The density of the suspension is measured at different time points using a hydrometer to estimate the mass percentages of sand (>0.05mm), silt (0.002-0.05mm), and clay (<0.002mm). The soil type is determined using a texture triangle diagram.

[0012] Disadvantages: Time-consuming: A single test needs to be left to stand for more than 24 hours, which cannot meet real-time needs in the field; Equipment limitations: It is necessary to carry fragile equipment such as glassware and constant temperature water baths, and the risk of field transportation is high; Pretreatment is complex: Interfering components such as organic matter and carbonates need to be removed, and the operation process is cumbersome.

[0013] (2) Laser Diffraction Analyzer

[0014] Principle: Invert soil particle size distribution through laser scattering model.

[0015] Disadvantages: High cost: The price of a single device exceeds 500,000 yuan, making it difficult for grassroots survey units to popularize it; Poor environmental adaptability: The instrument is sensitive to temperature and vibration, and it is difficult to power it in the field; High sample requirements: Thoroughly dispersed and dry soil powder is required, and wet samples cannot be directly tested.

[0016] Traditional methods can only qualitatively judge the viscosity of sand, but cannot simultaneously quantify its persistence (such as firmness and plasticity index). Low temperatures lead to uneven soil moisture (such as freezing or local overwetting), affecting the accuracy of the strip rubbing method. In addition, it is difficult to ensure the stability of field electricity and equipment, which limits the use of precision instruments. Although laboratory methods are accurate, they cannot achieve the integration of "on-site sampling-analysis-decision-making", and the laboratory testing cycle is as long as several days, delaying the census progress. Manual records and data integration are prone to errors and cannot meet the needs of large-scale censuses.

[0017] At the same time, some automated soil testing equipment relies on optical imaging technology, but is affected by field lighting conditions and soil color differences, resulting in an error rate of over 30%; indirect detection methods based on conductivity or pH values ​​cannot distinguish between the mechanical properties of sand particles and silt particles, and are significantly affected by soil salt content.

[0018] The above analysis shows that there is an urgent need for a field soil texture detection solution that is rapid, objective, and environmentally robust to address the core defects of traditional methods and laboratory techniques. Summary of the Invention

[0019] The purpose of the present invention is to provide a device and method for quickly judging the texture of field soil based on mechanical properties. The device and method can realize rapid, objective and repeatable judgment of the texture of field soil, reduce the restrictions of the detection scene on the operation, and improve the convenience and efficiency of detection.

[0020] The technical solution adopted by the present invention to solve the above problems is:

[0021] A device for quickly judging soil texture in the field based on mechanical properties, comprising:

[0022] A waterproof box body, which contains a sample processing cabin, and a heating spray component is provided in the sample processing cabin;

[0023] A mechanical testing unit, which is used to perform mechanical testing on samples in the sample processing chamber;

[0024] A control unit, which is used for processing and displaying mechanical detection data;

[0025] The energy unit is used to supply power to the mechanical detection unit and the control unit respectively.

[0026] Furthermore, a sample inlet that can be opened and closed is provided on the top of the sample processing chamber, and a tray for placing samples is detachably installed on the bottom of the sample processing chamber, and the surface of the tray is coated with an anti-stick coating.

[0027] Furthermore, the heating spray assembly includes a micro water pump, a water storage tank and an atomizing nozzle. The water inlet and outlet of the micro water pump are connected to the water storage tank and the atomizing nozzle through a water pipe. The water pipe between the micro water pump and the atomizing nozzle is provided with a heating resistance wire for heating the water flow.

[0028] Furthermore, a humidity sensor for detecting moisture content is provided in the sample processing chamber.

[0029] Furthermore, the water temperature output by the atomizing nozzle is 5-40°C.

[0030] Furthermore, the mechanical detection unit includes a pressure sensor and a torque sensor, and the sample processing chamber is provided with a telescopic arm for applying standard pressure to the sample surface and a conical probe for drilling into the sample.

[0031] Furthermore, the pressure sensor has a measuring range of 0-50N and a resolution of 01N, the torque sensor has a measuring range of 0-5N·m, and the rotation speed of the conical probe is 10r / min.

[0032] Furthermore, the control unit includes a main control chip and a touch screen. The pressure sensor, torque sensor and touch screen are all electrically connected to the main control chip. The main control chip has a built-in sand viscosity-sustainability judgment algorithm, and the touch screen is provided with physical buttons for inputting the initial humidity of the sample and selecting the detection mode.

[0033] Furthermore, the energy unit includes a 12V lithium battery, and the pressure sensor, torque sensor, touch screen and main control chip are all electrically connected to the 12V lithium battery.

[0034] The present invention also provides a method for quickly determining soil texture in the field based on the mechanical properties of any one of the above technical solutions, comprising the following steps:

[0035] Step 1: Sample pretreatment: 50-100g of undisturbed soil sample collected in the field is placed in the processing chamber. The initial state of the soil is then input through the control module, and the amount of water replenishment is automatically calculated;

[0036] Step 2: Standardized humidification: The water temperature is adjusted according to the ambient temperature through the heated spray component. At the same time, the moisture content is monitored in real time through the humidity sensor. The spraying is stopped after the atomized spray reaches the target humidity.

[0037] Step 3: Mechanical property test: Use the telescopic arm to press down to the soil surface and apply pressure to 10N / cm at a rate of 2mm / s 2 ,At the same time, the pressure-displacement curve is recorded by the control module, and the elastic modulus is calculated. Then, the cone probe is cut into the soil at a constant speed to a depth of 5mm to collect the maximum torque value;

[0038] Step 4: Intelligent judgment: The elastic modulus and torque values ​​are substituted into the pre-stored database through the algorithm built into the main control chip, and matched with the USDA / China texture classification standard. The "texture type + durability level" is then output synchronously through the touch screen, and an encrypted data package is generated for later import into the census platform.

[0039] Compared with the prior art, the present invention has the following advantages and effects:

[0040] (1) The present invention solves the problems of uneven manual water addition and low-temperature freezing in traditional methods through a heated spray system, ensuring the standardization of the wetting process. In addition, the pressure and shear probes work together to simultaneously quantify the cohesiveness (compressive strength) and sand viscosity (cohesion), overcoming the limitations of a single sensor indicator.

[0041] (2) The present invention dynamically adjusts the water spray volume through a humidity sensor to avoid detection deviation caused by over-humidification / under-humidification, and can be operated with one button through a control unit, integrating the preheating, humidification, and detection processes. The entire process takes ≤3 minutes, which is more than 95% more efficient than laboratory methods.

[0042] (3) The waterproof box of the present invention adopts IP67 protection grade, can operate in a wide temperature range of -10℃ to 50℃, and the whole machine power is ≤60W, which can adapt to outdoor scenarios without power supply.

[0043] (4) The present invention achieves rapid, objective, and repeatable determination of soil texture in the field through structural integration (spraying + detection integration), dual-dimensional data (pressure + shear mechanics index), and automated operation (intelligent humidity control), providing a reliable technical tool for the third national soil census. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention is a schematic structural diagram of a field soil texture rapid judgment device based on mechanical properties.

[0045] Figure 2 This is a diagram of the steps for using a device for quickly determining soil texture in the field based on mechanical properties according to the present invention.

[0046] Among them, there are a waterproof box 100, a sample processing chamber 110, an inlet 111, a tray 112, a heating spray assembly 113, a micro water pump 113a, an atomizing nozzle 113b, a heating resistor 113c, a water pipe 113d, a water storage tank 114, a humidity sensor 115, a mechanical detection unit 120, a pressure sensor 121a, a telescopic arm 121b, a torque sensor 122a, a conical probe 122b, a control unit 130, a main control chip 131, a touch screen 132a, a physical button 132b, an energy unit 140, and a 12V lithium battery 141. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0048] See also Figure 1 The present embodiment provides a field soil texture rapid judgment device based on mechanical properties, comprising: a waterproof housing 100, in which a sample processing chamber 110 is provided, and a heating spray assembly 113 is provided in the sample processing chamber 110; a mechanical detection unit 120, which is used to perform mechanical detection on the sample in the sample processing chamber 110; a control unit 130, which is used to process and display mechanical detection data; and an energy unit 140, which is used to supply power to the mechanical detection unit 120 and the control unit 130 respectively.

[0049] See also Figure 1 The top of the sample processing chamber 110 is provided with an openable and closable sample inlet 111, and the bottom of the sample processing chamber 110 is detachably provided with a tray 112 for placing samples, and the surface of the tray 112 is coated with an anti-stick coating.

[0050] See also Figure 1 The heating spray assembly 113 includes a micro water pump, a water storage tank 114 and an atomizing nozzle. The water inlet and outlet of the micro water pump are connected to the water storage tank 114 and the atomizing nozzle through a water pipe. A heating resistance wire for heating the water flow is provided on the water pipe between the micro water pump and the atomizing nozzle.

[0051] In this embodiment, a humidity sensor 115 for detecting the moisture content is provided in the sample processing chamber 110, and the temperature of the water output by the atomizing nozzle is 5-40°C.

[0052] See also Figure 1 The mechanical detection unit 120 includes a pressure sensor and a torque sensor. The sample processing chamber 110 is provided with a telescopic arm for applying a standard pressure to the sample surface and a conical probe for drilling into the sample.

[0053] The pressure sensor has a measuring range of 0-50N and a resolution of 0.1N, the torque sensor has a measuring range of 0-5N·m, and the rotation speed of the conical probe is 10r / min.

[0054] In this embodiment, the telescopic arm is slidably disposed in the sample processing chamber 110 via a linear drive device, and the conical probe is rotated by a motor and disposed in the sample processing chamber 110 .

[0055] See also Figure 1 The control unit 130 includes a main control chip 131 and a touch screen. The pressure sensor, torque sensor and touch screen are all electrically connected to the main control chip 131. The main control chip 131 has a built-in sand viscosity-sustainability judgment algorithm. The touch screen is provided with physical buttons for inputting the initial humidity of the sample and selecting the detection mode.

[0056] See also Figure 1 The energy unit 140 includes a 12V lithium battery 141, and the pressure sensor, torque sensor, touch screen and main control chip 131 are all electrically connected to the 12V lithium battery 141.

[0057] In this embodiment, in addition to using built-in batteries for power supply, external 220V AC power can also be used for power supply.

[0058] When using the above-mentioned field soil texture rapid judgment device based on mechanical properties to judge the texture of a sample soil, the following steps are included:

[0059] Step 1: Sample pretreatment: Place 50-100g of undisturbed soil sample collected in the field into the processing chamber 110, close the sampling port 111, and then input the initial state of the soil (dry / wet / saturated) through the touch screen, and the water replenishment amount is automatically calculated (for example, dry soil requires 15% to 25% water replenishment);

[0060] Step 2: Standardized humidification: The water temperature is adjusted by the heating spray component 113 according to the ambient temperature (e.g., heating to 25°C at -5°C). At the same time, the moisture content is monitored in real time by the humidity sensor 115. The spraying is stopped after the target humidity is reached (error ±2%).

[0061] Step 3: Mechanical property test: Use the telescopic arm to press down to the soil surface and apply pressure to 10N / cm at a rate of 2mm / s 2 At the same time, the control module records the pressure-displacement curve and calculates the elastic modulus (sustainability index). Then, the cone probe cuts into the soil at a constant speed to a depth of 5mm and collects the maximum torque value (viscosity index).

[0062] Step 4: Intelligent judgment: The elastic modulus (E) and torque (T) are substituted into the pre-stored database (e.g., sandy soil E < 0.5 MPa, T < 0.3 N·m; clay soil E > 2 MPa, T > 1.2 N·m) through the algorithm built into the main control chip 131, and matched with the USDA / China texture classification standard. The "texture type + consistency level" (e.g., "clay loam - solid consistency") is then synchronously output through the touch screen, and an encrypted data package is generated for later import into the survey platform.

[0063] The above contents described in this specification are merely examples of the present invention. Those skilled in the art may make various modifications, additions, or substitutions to the described embodiments, without departing from the contents of this specification or exceeding the scope defined by the claims, and such modifications, additions, or substitutions may be made to the described embodiments. Such modifications, additions, or substitutions may be made by persons skilled in the art. Such modifications, additions, or substitutions may be made to the described embodiments without departing from the contents of this specification or exceeding the scope defined by the claims, and such modifications shall fall within the scope of protection of the present invention.

Claims

1. A device for quickly judging soil texture in the field based on mechanical properties, characterized in that: include: A waterproof box body, which contains a sample processing cabin, and a heating spray component is provided in the sample processing cabin; A mechanical testing unit, which is used to perform mechanical testing on samples in the sample processing chamber; A control unit, which is used for processing and displaying mechanical detection data; The energy unit is used to supply power to the mechanical detection unit and the control unit respectively.

2. The field soil texture rapid determination device based on mechanical properties according to claim 1, characterized in that: The top of the sample processing chamber is provided with an openable and closable sample inlet, and the bottom of the sample processing chamber is detachably provided with a tray for placing samples, and the surface of the tray is coated with an anti-stick coating.

3. The field soil texture rapid determination device based on mechanical properties according to claim 1, characterized in that: The heating spray assembly includes a micro water pump, a water storage tank and an atomizing nozzle. The water inlet and outlet of the micro water pump are connected to the water storage tank and the atomizing nozzle through a water pipe. A heating resistance wire is provided on the water pipe between the micro water pump and the atomizing nozzle to heat the water flow.

4. The field soil texture rapid determination device based on mechanical properties according to claim 3, characterized in that: A humidity sensor for detecting moisture content is provided in the sample processing chamber.

5. The field soil texture rapid determination device based on mechanical properties according to claim 3 is characterized by: The water temperature output by the atomizing nozzle is 5-40°C.

6. The field soil texture rapid determination device based on mechanical properties according to claim 1, characterized in that: The mechanical detection unit includes a pressure sensor and a torque sensor. A telescopic arm for applying standard pressure to the sample surface and a conical probe for drilling into the sample are provided in the sample processing chamber.

7. The field soil texture rapid determination device based on mechanical properties according to claim 5, characterized in that: The pressure sensor has a measuring range of 0-50N and a resolution of 0.1N. The torque sensor has a measuring range of 0-5N·m. The rotation speed of the conical probe is 10r / min.

8. The field soil texture rapid determination device based on mechanical properties according to claim 6, characterized in that: The control unit includes a main control chip and a touch screen. The pressure sensor, torque sensor and touch screen are all electrically connected to the main control chip. The main control chip has a built-in sand viscosity and adhesion determination algorithm. The touch screen is provided with physical buttons for inputting the initial humidity of the sample and selecting the detection mode.

9. The field soil texture rapid determination device based on mechanical properties according to claim 1, characterized in that: The energy unit includes a 12V lithium battery, and the pressure sensor, torque sensor, touch screen and main control chip are all electrically connected to the 12V lithium battery.

10. A method for quickly judging soil texture in the field based on the mechanical properties according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: Sample pretreatment: 50-100g of undisturbed soil sample collected in the field is placed in the processing chamber. The initial state of the soil is then input through the control module, and the amount of water replenishment is automatically calculated; Step 2: Standardized wetting: adjust the water temperature according to the ambient temperature through the heated spray component, and monitor the moisture content in real time. Stop spraying after the atomized spray reaches the target humidity; Step 3: Mechanical properties test, by applying pressure to the soil surface at a rate of 2 mm / s to 10 N / cm 2 ,At the same time, the pressure-displacement curve is recorded by the control module, and the elastic modulus is calculated.,Then the soil is cut into 5mm depth at a constant speed to collect the maximum torque value; Step 4: Intelligent judgment: by substituting the elastic modulus and torque values ​​into the pre-stored database and matching them with the USDA / China texture classification standards, the "texture type + durability level" is then output synchronously, and an encrypted data package is generated for later import into the census platform.

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