Soil total nitrogen content detection device
Through the integrated soil total nitrogen content device of crushing, filtration and multi-spectral detection, the problems of soil particle size and dust interference are solved, and rapid and accurate soil total nitrogen content detection is achieved to meet the needs of modern agriculture.
Patent Information
- Application Number
- CN202510717709.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-08-15
AI Technical Summary
The existing soil total nitrogen content detection technology is disturbed by soil particle size and dust, resulting in large detection errors and making it difficult to achieve fast and accurate detection.
A device integrating soil crushing, filtration and multi-spectral detection was designed, and soil crushing was used by hydraulic presses, negative ion generators and carbon fiber brushes removed dust, and the soil nitrogen content was detected using LED lamps of specific wavelengths and high-sensitivity photodetectors, and the spectral data was corrected through soil particle size characteristic bands, and the total nitrogen content was calculated in combination with signal processing circuits and machine learning algorithms.
It realizes rapid and accurate detection of the total nitrogen content of soil, greatly reduces detection errors, improves detection efficiency, and provides a scientific basis for modern agriculture.
Smart Images
Figure CN120489983A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of soil detection, and in particular to a device for detecting total nitrogen content in soil. Background Art
[0002] Nitrogen is an important component of soil nutrients. For most crops, the nitrogen content level in the soil affects crop growth and development. Too little nitrogen will cause problems such as short crop plants and yellow leaves, while too much nitrogen will cause poor crop resistance and environmental pollution. Analyzing and measuring the total nitrogen content in the soil is of great significance for guiding fertilization.
[0003] Near-infrared spectroscopy is a detection technology used to analyze the composition and properties of substances. It can quickly detect and measure a variety of substances, but the soil spectral acquisition process is subject to interference from soil particle size and dust particles, resulting in significant errors.
[0004] Therefore, based on the characteristic band correction method of soil particle size, technicians in this field have designed a visible-near-infrared discrete wavelength soil total nitrogen content detection device, aiming to achieve rapid and accurate detection of soil nutrients and provide a scientific basis for agricultural production. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to overcome the above technical defects and provide a soil total nitrogen content detection device, which integrates soil crushing, filtration, and multi-spectral detection, and can realize rapid and accurate detection of soil total nitrogen content.
[0006] A soil total nitrogen content detection device, comprising:
[0007] The detection body includes a device housing, a feed port is provided at the top of the device housing, and a filter is provided at the feed port. A detection chamber is provided inside the device housing, and a soil collection box is provided below the detection chamber in a pull-out manner. A plurality of LED lights of different wavelengths and two photodetectors located in the center of the LED lights are also provided above the soil collection box.
[0008] A hydraulic press is arranged on the top of the device housing and is used for crushing the soil on the filter screen.
[0009] Furthermore, at least one negative ion generator is provided on the side wall of the detection chamber, and the negative ion generator extends into the detection chamber through a carbon fiber brush; a dust collection pipe is provided correspondingly below the carbon fiber brush and extends to the outside of the device casing.
[0010] Furthermore, the input end of the dust collection pipe opens toward the carbon fiber brush, the output end is closed by an openable and closable circular cover, and the angle between the input end and the output end is 135°.
[0011] Furthermore, the wavelength bands of the LED lamp include 490-500nm, 770-780nm, 800-805nm, 840-845nm, 1350nm, 1550nm, 1630nm and 1650nm, wherein 1350nm is a characteristic wavelength band of soil particle size.
[0012] Furthermore, the plurality of LED lamps are arranged in a ring, and a glass focusing lens with a diameter of 13 mm is provided on the upper surface of the LED lamp beads. The photodetectors arranged at the center of the LED lamp are respectively a silicon photodiode and an indium gallium arsenide diode, and the pins of the silicon photodiode and the indium gallium arsenide diode are connected to the signal processing circuit.
[0013] Furthermore, the signal processing circuit includes an ESP32 single-chip microcomputer and an H-bridge drive circuit. The H-bridge drive circuit is composed of four IGBTs as switching devices. The input end of the H-bridge is connected to a carbon fiber heating tube. The ESP32 single-chip microcomputer controls the working state of the carbon fiber heating tube by controlling the on and off of the IGBT in the H-bridge.
[0014] Furthermore, a temperature sensor DS18B20 is connected to the signal processing circuit for overheat protection.
[0015] Furthermore, a detection switch button and a USB slot are provided on the device housing, and a lithium battery pack is provided inside the detection chamber.
[0016] Furthermore, the hydraulic press includes lifting rods relatively arranged on both sides of the top feed port of the outer shell, and the upper parts of the lifting rods on both sides are connected by an upper steel plate. A free steel plate is slidingly provided on the lifting rod, and the lower end of the free steel plate is provided with a pressure foot corresponding to the top feed port of the outer shell. The upper end surface of the free steel plate is connected to the bottom of the upper steel plate with a spring through an L-shaped connecting iron sheet. The free steel plate is also provided with a hydraulic jack located between the springs on both sides, and the plunger of the hydraulic jack can be pushed under the upper steel plate.
[0017] The advantages of the present invention compared with the existing technology are: the soil total nitrogen content detection device integrates soil crushing, filtration, and multi-spectral detection, achieves efficient soil crushing through a hydraulic press, uses a negative ion generator and a carbon fiber brush to effectively remove dust, and uses a carbon fiber heating tube to remove soil moisture to ensure detection accuracy; uses multiple LED lights with specific wavelengths arranged in a ring, combined with a central high-sensitivity, wide-spectral response range silicon photodiode and indium gallium arsenide diode, based on the absorption characteristics of nitrogen in the soil for specific wavelengths of light, can quickly and accurately detect the total nitrogen content in the soil; in addition, the characteristic band of soil particle size is used to correct the collected spectral data, which greatly reduces the error caused by soil particle size, provides a scientific basis for agricultural production, and greatly improves detection efficiency compared to traditional chemical analysis methods, meeting the needs of modern agriculture for rapid and real-time detection of soil nutrients. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is an overall schematic diagram of an embodiment of the present application;
[0019] Figure 2 is a cross-sectional view of the interior of the device in an embodiment of the present application;
[0020] Figure 3 This is the signal processing circuit diagram of this application.
[0021] As shown in the figure: 1. Lifting rod; 2. Device housing; 3. Temperature sensor DS18B20; 4. Carbon fiber heating tube; 5. Hydraulic jack; 6. Spring; 7. L-shaped connecting iron plate; 8. Presser foot; 9. Filter; 10. Dust collection tube; 11. Soil collection box; 12. Detection switch button; 13. USB slot; 14. Upper steel plate; 15. Free steel plate; 16. Lithium battery pack; 17. Negative ion generator; 18. Photodiode; 19. Imitation lumen LED light; 20. Carbon fiber brush; DETAILED DESCRIPTION
[0022] The present invention will be described in further detail below with reference to the accompanying drawings.
[0023] The specific embodiments of the present invention are further described below with reference to the accompanying drawings, wherein the same parts are represented by the same reference numerals.
[0024] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the accompanying drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.
[0025] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
[0026] Reference Attachment Figure 1 -Attached Figure 3 The present application provides a soil total nitrogen content detection device, comprising:
[0027] The detection body includes a device housing 2, a feed port is provided at the top of the device housing 2, and an 80-mesh filter screen 9 is provided at the feed port. A detection chamber is provided inside the device housing 2, and a soil collection box 11 is provided below the detection chamber in a pull-out manner for collecting filtered soil samples. A plurality of LED lights 19 of different wavelengths and two photodetectors 18 located in the center of the LED lights 19 are also provided above the soil collection box 11; and the signal processing circuit where the ESP32 microcontroller is located constitutes the detection system
[0028] The hydraulic press is arranged on the top of the device housing 2 and is used to crush the soil on the filter screen 9.
[0029] In one embodiment, at least one negative ion generator 17 is provided on the side wall of the detection chamber, and the negative ion generator 17 extends into the detection chamber through a carbon fiber brush 20; a dust collection pipe 10 is provided below the carbon fiber brush 20 and extends to the outside of the device housing 2, which is used to collect dust generated during the filtration process.
[0030] In one embodiment, the input end of the dust collection pipe 10 opens toward the carbon fiber brush 19, and the output end is closed by an openable and closable circular cover, with the angle between the input and output ends being 135 degrees. This design facilitates efficient dust collection and discharge.
[0031] In one embodiment, the wavelengths of LED light 19 include 490-500 nm, 770-780 nm, 800-805 nm, 840-845 nm, 1350 nm, 1550 nm, 1630 nm, and 1650 nm, with 1350 nm being a wavelength characteristic of soil particle size. These wavelengths were selected based on the absorption characteristics of nitrogen in soil at specific wavelengths of light. 1350 nm is also a wavelength characteristic of soil particle size and can be used for soil particle size correction.
[0032] In one embodiment, multiple LED lights 19 are arranged in a ring. Each LED 19 is fitted with a 13mm diameter glass focusing lens on its upper surface. The photodetectors 18 located in the center of the LEDs 19 are silicon photodiodes and indium gallium arsenide diodes, respectively. The pins of both the silicon photodiodes and indium gallium arsenide diodes are connected to a signal processing circuit. The silicon photodiodes have a response wavelength of 400-1100nm, while the indium gallium arsenide photodiodes have a response wavelength of 900-1700nm, fully covering the wavelength bands of the aforementioned LED lights.
[0033] In one embodiment, the signal processing circuit includes an ESP32 microcontroller and an H-bridge driver circuit. The H-bridge driver circuit is composed of four IGBTs as switching devices. The input end of the H-bridge is connected to a carbon fiber heating pipe 4. The ESP32 microcontroller controls the operating state of the carbon fiber heating pipe 4 by turning the IGBTs in the H-bridge on and off. The carbon fiber heating pipe 4 is used to dry soil and remove moisture.
[0034] In one embodiment, a temperature sensor DS18B203 is connected to the signal processing circuit for overheat protection.
[0035] In one embodiment, the device housing 2 is further provided with a detection switch button 12 and a USB slot 13, and a lithium battery pack is further provided inside the detection chamber.
[0036] In one embodiment, the hydraulic press includes a lifting rod 1 relatively arranged on both sides of the top feed port of the outer shell 2, and the upper parts of the lifting rods 1 on both sides are connected by an upper steel plate 14. A free steel plate 15 is slidably provided on the lifting rod 1, and the lower end of the free steel plate 15 is provided with a pressure foot 8 corresponding to the top feed port of the outer shell 2. The upper end surface of the free steel plate 15 is connected to the bottom of the upper steel plate 14 by an L-shaped connecting iron sheet 7 with a spring 6. The free steel plate 15 is also provided with a hydraulic jack 5 located between the springs 6 on both sides, and the plunger of the hydraulic jack 5 can be pushed under the upper steel plate 14. At the initial moment, the free steel plate 15 remains in a suspended and stationary state under the elastic force of the spring 6. When the soil needs to be crushed, the soil to be tested is placed in the filter screen 9 at the feed port, and is lifted upward by pressing the plunger of the hydraulic jack 7 until it touches the upper steel plate 18. Because the resistance of the upper steel plate 18 is greater than the elastic force of the spring 6, the free steel plate 15 and the hydraulic jack 7 both move downward under the action of the resistance of the upper steel plate 18 until they approach the soil at the feed inlet. The pressure foot 8 fixed under the free steel plate 15 collides and squeezes the soil to be tested, pushing it into the filter chamber inside the outer shell 2 of the filter device, completing the soil crushing operation.
[0037] The working principle is as follows: At the initial moment, the free steel plate 15 remains suspended and stationary under the action of the elastic force of the spring 6. The soil to be tested is placed in the filter screen 9 at the feed inlet, and the plunger is pushed upward by pressing the hydraulic jack 7 until it touches the upper steel plate 14 at the upper end. Under the action of the resistance of the upper steel plate 14, the free steel plate 15 and the hydraulic jack 7 both move downward, and the soil to be tested is collided and squeezed by the pressure foot 8 fixed under the free steel plate, and pushed into the filter chamber inside the outer shell 2 of the filter device. After the soil is crushed, it enters the filter chamber of the outer shell 2 through the mesh of the filter screen 9 and falls vertically into the soil collection box 11. During this period, the carbon fiber brush 20 at the end of the negative ion generator 17 releases electrons, which combine with oxygen molecules in the air to generate negative ions, promote the sedimentation of floating dust and fall into the dust collection pipe 10 below.
[0038] Then press the detection switch button 12, and the eight LED lights of different wavelengths inside the detection body 2 will start to work alternately, releasing light of different wavelengths to illuminate the soil to be tested. It is generally believed that smaller soil particle size can minimize the impact of soil particle size on soil spectrum detection. The spectrum data measured by soil with a particle size of 0.2mm through an 80-mesh filter can be used as the reference spectrum. The wavelength of 1350nm is also the characteristic band of soil particle size. Therefore, the reflectivity of 0.2mm soil at 1350nm is used as the reference value P, and the soil particle size correction coefficient k is introduced. c
[0039]
[0040] Where R 1350 To correct the reflectance of the soil at 1350nm, the soil spectral reflectance after correction by the correction coefficient is
[0041] R c =R×k c
[0042] Where R is the soil reflectance before correction.
[0043] The photodiode 18 detects the reflected light intensity in each band, and the total nitrogen content in the soil is calculated using a machine learning algorithm. Finally, the data is transmitted to the host computer via serial communication, and the host computer displays the specific information of the total nitrogen content.
[0044] Table 1 Test results
[0045]
[0046] Table 1 above is a soil total nitrogen content detection table. The measured values of the soil total nitrogen content detection system are not much different from the actual physical and chemical values. The maximum absolute difference is 0.209, the minimum absolute difference is 0.047, the maximum relative difference is 11.2%, and the minimum relative difference is 3.1%. It can be seen that the detection device can basically meet the detection requirements of soil total nitrogen content and can be applied to actual production.
[0047] Through the detailed description of the above embodiments, it can be seen that the soil nutrient detection device is highly reasonable and practical in terms of structural design, working principle and operation process, providing strong support for the accurate detection of soil total nitrogen content.
[0048] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.
Claims
1. A soil total nitrogen content detection device, characterized in that: include: The detection body comprises a device housing (2), a feed port is provided at the top of the device housing (2), and a filter screen (9) is provided at the feed port; a detection chamber is provided inside the device housing (2); a soil collection box (11) is provided below the detection chamber in a retractable manner; and a plurality of LED lights (19) of different wavelengths and two photoelectric detectors (18) located in the center of the LED lights (19) are provided above the soil collection box (11); A hydraulic press is arranged on the top of the device housing (2) and is used to crush the soil on the filter screen (9).
2. A soil total nitrogen content detection device according to claim 1, characterized in that: At least one negative ion generator (17) is provided on the side wall of the detection chamber, and the negative ion generator (17) extends into the detection chamber through a carbon fiber brush (20); a dust collection pipe (10) is provided correspondingly below the carbon fiber brush (20) and extends to the outside of the device housing (2).
3. A soil total nitrogen content detection device according to claim 2, characterized in that: The input end of the dust collecting pipe (10) opens toward the carbon fiber brush (19), and the output end is closed by an openable and closable circular cover, and the angle between the input end and the output end is 135 degrees.
4. A soil total nitrogen content detection device according to claim 1, characterized in that: The wavelength bands of the LED lamp (19) include 490-500nm, 770-780nm, 800-805nm, 840-845nm, 1350nm, 1550nm, 1630nm and 1650nm, wherein 1350nm is a characteristic wavelength band of soil particle size.
5. A soil total nitrogen content detection device according to claim 4, characterized in that: The plurality of LED lamps (19) are arranged in a ring shape, and a glass focusing lens with a diameter of 13 mm is provided on the upper surface of each LED lamp bead. The photodetectors (18) arranged at the center of the LED lamp (19) are respectively a silicon photodiode and an indium gallium arsenide diode, and the pins of the silicon photodiode and the indium gallium arsenide diode are connected to a signal processing circuit.
6. A soil total nitrogen content detection device according to claim 5, characterized in that: The signal processing circuit includes an ESP32 single-chip microcomputer and an H-bridge drive circuit. The H-bridge drive circuit is composed of four IGBTs as switching devices. The input end of the H-bridge is connected to a carbon fiber heating tube (4). The ESP32 single-chip microcomputer controls the working state of the carbon fiber heating tube (4) by controlling the on and off of the IGBTs in the H-bridge.
7. A soil total nitrogen content detection device according to claim 6, characterized in that: A temperature sensor DS18B20 (3) is connected to the signal processing circuit for overheat protection.
8. A soil total nitrogen content detection device according to claim 1, characterized in that: The device housing (2) is also provided with a detection switch button (12) and a USB slot (13), and a lithium battery pack (16) is also provided inside the detection chamber.
9. A soil total nitrogen content detection device according to claim 1, characterized in that: The hydraulic press comprises lifting rods (1) relatively arranged on both sides of the top feed port of the outer shell (2), the upper parts of the lifting rods (1) on both sides are connected by an upper steel plate (14), a free steel plate (15) is slidingly provided on the lifting rod (1), the lower end of the free steel plate (15) is provided with a pressure foot (8) corresponding to the top feed port of the outer shell (2), the upper end surface of the free steel plate (15) is connected to the bottom of the upper steel plate (14) by an L-shaped connecting iron sheet (7) with a spring (6), and the free steel plate (15) is also provided with a hydraulic jack (5) located between the springs (6) on both sides, and the plunger of the hydraulic jack (5) can be pressed under the upper steel plate (14).