Direct insertion type soil nutrient detector

Abstract

The utility model relates to the technical field of soil detection, and discloses a direct insertion type soil nutrient detector which comprises an upper shell and a lower shell, the upper shell is fixedly connected with the lower shell, and the bottom of the lower shell is fixedly connected with a guide head; the display assembly is mounted on the upper shell; the detection probe is installed in the lower shell, a light emitting diode is fixed to the detection probe and used for emitting near-infrared light with the specific wavelength to soil, the photodiode is used for receiving the near-infrared light reflected by the soil and converting the near-infrared light into an electric signal, and the temperature sensor is used for monitoring the soil temperature in real time; the optical glass is fixedly connected with the detection probe, covers the outer sides of the light emitting diode, the photodiode and the temperature sensor, and is in direct contact with soil; and the mainboard is arranged in the clamping groove of the lower shell. The rapid and accurate detection of the contents of nitrogen, phosphorus, potassium and organic matters in the soil can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to soil detection technical field, more specifically, especially, it is a kind of straight insertion type soil nutrient detector. BACKGROUND

[0002] With the development of modern agriculture, the nitrogen, phosphorus, potassium and organic matter content of soil as the key index of measuring soil fertility, are concerned. Nitrogen promotes crop growth, phosphorus enhances stress resistance, potassium regulates nutrient metabolism, and organic matter improves soil structure and promotes fertility. Precise control of soil nutrient information is crucial for scientific fertilization and precision agricultural management, which helps to improve crop yield and quality and promote sustainable agricultural development.

[0003] Traditional soil nutrient detection methods (such as chemical analysis method) usually need complex sample processing, long analysis time, and the operation process is cumbersome, which is difficult to meet the demand of large-scale, rapid detection. In recent years, near infrared spectroscopy technology has been widely used in soil composition analysis due to its advantages of rapidity, no reagent consumption, etc. The technology analyzes the near infrared spectrum data reflected by soil and the physical and chemical properties of soil, and combines with multivariate regression model to realize rapid detection of soil nutrient content. Therefore, the soil nutrient detection instrument based on near infrared spectroscopy technology has the advantages of portability, real-time, precision and efficiency, and has important application value in precision agriculture.

[0004] However, the existing soil detection instrument depends on laboratory environment, which is difficult to meet the demand of in-situ detection. Therefore, it is of important scientific research and application value to develop a portable soil nutrient detection instrument, especially an instrument that can be directly inserted into soil for in-situ detection. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a kind of straight insertion type soil nutrient detector to solve the problems existing in prior art, can realize the rapid and accurate detection of soil nitrogen, phosphorus, potassium and organic matter content.

[0006] In order to achieve the above object, the utility model provides the following scheme: the utility model provides a straight insertion type soil nutrient detector, including upper casing and lower casing, the upper casing with lower casing fixed connection, the lower casing bottom fixedly connected with the guide head, display component, display component installs on the upper casing, detection probe, detection probe installs in the lower casing, fixedly installs the emitting diode on the detection probe, is used for emitting specific wavelength near infrared light to the soil, photodiode, is used for receiving the near infrared light of soil reflection and converts into electric signal, temperature sensor, is used for real time monitoring soil temperature, optical glass, the optical glass detection probe fixed connection, the optical glass covers the outside of emitting diode, photodiode and temperature sensor, and directly contacts with soil, mainboard, the mainboard installs in the lower casing top, the mainboard with detection probe signal connection, the mainboard is used for receiving the soil information of detection probe detection, and is fed back to display screen.

[0007] According to the straight insertion type soil nutrient detector provided by the utility model, the first fixed groove is arranged on the lower casing.

[0008] According to the straight insertion type soil nutrient detector provided by the utility model, the detection probe is connected with the optical glass through the second fixed screw.

[0009] According to the straight insertion type soil nutrient detector provided by the utility model, the positioning groove is arranged on the top of the lower casing, and the mainboard is installed in the positioning groove.

[0010] According to the straight insertion type soil nutrient detector provided by the utility model, the second fixed groove is arranged on the top of the lower casing, and the battery is installed in the second fixed groove, and the battery is electrically connected with the mainboard, the display and the detection probe.

[0011] According to the straight insertion type soil nutrient detector provided by the utility model, the display component includes a display screen and a key plate, the display screen is located at the top center of the casing, is used for displaying the soil nutrient content, temperature and battery capacity information in real time, and the key plate is installed below the display screen.

[0012] According to the straight insertion type soil nutrient detector provided by the utility model, the charging port is arranged on the upper casing, is used for charging and data transmission.

[0013] According to the straight insertion type soil nutrient detector provided by the utility model, the connecting port is arranged on the top of the upper casing, is used for connecting the display screen, the key plate, the charging port and the mainboard to the instrument.

[0014] The utility model provides a kind of direct insertion type soil nutrient detector, the handle is integrally formed with the top of lower shell.

[0015] According to the direct insertion type soil nutrient detector provided by the utility model, the photodiode cover is provided with a light blocking boss, and the light blocking boss is fixedly installed on the detection probe.

[0016] The utility model discloses the following technical effects:

[0017] The device is provided with an upper shell and a lower shell in a split type, so that the detection components can be replaced conveniently, and the device is inserted into soil for detection conveniently. The lower shell is provided with a guide head at the bottom, and the detection probe is installed in the lower shell. The light-emitting diode emits light to irradiate soil, the photodiode collects diffuse reflection spectrum data, and the temperature sensor reads the soil temperature. The influence of temperature on reflectivity is compensated by a preset algorithm, and then the detected soil information is fed back to the display screen through the mainboard, so that real-time and efficient detection is realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a whole structure schematic view of the utility model;

[0020] Figure 2 It is an explosion view of the whole utility model;

[0021] Figure 3 It is a structure schematic view of the lower shell in the utility model;

[0022] Figure 4 It is a top view of the lower shell in the utility model;

[0023] Figure 5 It is a structure schematic view of the lower shell from another angle in the utility model;

[0024] Figure 6 It is a structure schematic view of the detection probe in the utility model;

[0025] Figure 7 It is a side view of the detection probe in the utility model;

[0026] Figure 8 It is a structure schematic view of the upper shell in the utility model;

[0027] 1, upper shell; 2, lower shell; 3, guide head; 4, handle; 5, display screen; 6, key board; 601, calibration key; 602, detection key; 7, charging port; 8, connecting port; 9, first fixing screw; 10, positioning groove; 11, first fixing groove; 12, second fixing groove; 13, battery; 14, main board; 15, light emitting diode; 16, temperature sensor; 17, optical glass; 18, light blocking boss; 19, second fixing screw; 20, photodiode; 21, detection probe. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0029] In the following embodiments, near infrared spectroscopy technology is involved. The principle of near infrared spectroscopy technology in soil nutrient detection is mainly based on molecular vibration and spectral absorption characteristics. The near infrared spectral region usually refers to electromagnetic waves with a wavelength range of 780-2500 nm (wavenumber range of about 12800-4000 cm-1). When near infrared light irradiates the soil, the molecules (such as water, organic matter, nitrogen, phosphorus, potassium, etc.) in the soil will absorb light energy of specific wavelengths, causing the transition of molecular vibration energy levels. These vibrations mainly include C-H (carbon-hydrogen bond) O-H (hydroxyl group) N-H (amino group) and C=O (carbonyl group). Each type of chemical bond has a specific absorption wavelength corresponding to a specific vibration mode, so the absorption spectrum of different components in the soil is unique.

[0030] When near infrared light irradiates the soil surface, part of the light is absorbed and part of the light is reflected. By detecting the reflected near infrared spectrum of the soil, the spectral characteristics of the soil can be obtained. Different contents of nutrients (such as nitrogen, phosphorus, potassium) and organic matter in the soil will cause differences in the reflected spectrum. Specifically, soil with high nutrient content will absorb more light of specific wavelengths, resulting in a decrease in reflectivity; soil with low nutrient content has a higher reflectivity. By analyzing the changes in the reflected spectrum, the content of nutrients in the soil can be detected.

[0031] Multivariate regression models and quantitative analysis: To convert reflectance spectroscopy data into quantitative information of soil nutrients, multivariate regression models (such as partial least squares regression, PLSR) are usually used for analysis. The specific steps are as follows: Model establishment: By collecting a large number of soil samples with known nutrient content, measuring their near-infrared spectra, and establishing a mathematical relationship model between spectral data and nutrient content. Prediction of unknown samples: Input the reflectance spectrum of unknown soil samples into the model to calculate their nitrogen, phosphorus, potassium and organic matter content.

[0032] Temperature compensation and spectral correction: Since soil temperature can affect the reflectance characteristics of near-infrared spectra, a temperature compensation algorithm needs to be introduced during detection to eliminate the interference of temperature on the detection results. The specific method includes: Real-time monitoring of temperature sensor: Integrate temperature sensor in the detection probe to measure soil temperature in real time. Pre-set algorithm correction: Dynamically correct the reflectance spectrum data according to temperature changes to improve detection accuracy.

[0033] In the portable soil nutrient detector, near-infrared spectroscopy technology is realized through the following components: Light source: Use multi-band near-infrared LED light source to emit light of specific wavelength. Photoelectric detector: Receive soil reflected light and convert it into electrical signal. Optical glass: Protect the probe and directly contact with soil to ensure smooth light path. Mainboard module: Integrate spectral analysis algorithm and temperature compensation algorithm to calculate soil nutrient content in real time.

[0034] The principle of near-infrared spectroscopy technology in soil nutrient detection is to analyze the near-infrared spectrum reflected by soil, combined with multivariate regression model and temperature compensation algorithm, to quickly and non-destructively determine the content of nitrogen, phosphorus, potassium and organic matter in soil. This technology has the advantages of fast, portable, no reagent consumption, etc., and is suitable for in-situ detection needs in precision agriculture.

[0035] In the following examples, the mainboard function module is involved, mechanical connection: The mainboard module is integrated in the upper shell of the split shell, and is fixed by screws to realize detachable connection with the conical lower shell. The upper shell and the lower shell are precisely aligned by positioning pins and screw holes to ensure the stability of the overall structure. Function integration: The internal layout of the upper shell includes display screen (such as 1.47 inch OLED screen), key board and charging interface (Type-C interface), the mainboard is electrically connected with these components through internal wiring or flexible circuit board (FPC), realizing human-computer interaction and data display. Maintenance convenience: Split design allows the upper shell to be disassembled separately, facilitating the maintenance or upgrade of the mainboard module, while not affecting the core components such as detection probe in the lower shell.

[0036] Photoelectric signal processing: the photodiode in the detection probe converts the near-infrared light reflected by the soil into an electrical signal after receiving the near-infrared light reflected by the soil, and is connected to the mainboard through a shielded cable or PCB trace. The mainboard (such as an STM32F407 chip) has an AD conversion module built-in to amplify and digitize the signal. Temperature compensation mechanism: the temperature sensor is in close contact with the inside of the optical glass, and monitors the soil temperature in real time through a thermistor or DS18B20 chip. The signal is directly input into the temperature compensation algorithm module of the mainboard to correct the error of the reflected spectrum data.

[0037] Type-C interface design: the mainboard realizes dual functions (charging and data transmission) through a Type-C interface, the interface is integrated on the side of the upper shell, supports fast charging (such as PD protocol) and data interaction with external devices (such as mobile phones and tablets), and is connected to the detection end data line through a USB to RS485 serial port line. Calibration function: the mainboard has a built-in calibration algorithm, which calibrates the detector through a standard white board to eliminate environmental interference. The user can trigger the calibration program through the key board, and the calibration data is stored in the mainboard flash memory.

[0038] In order to make the above-mentioned purposes, characteristics and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail below in combination with the drawings and specific embodiments.

[0039] As shown in Figures 1-6 The utility model provides a straight insertion type soil nutrient detector, it includes: upper shell 1 and lower shell 2, upper shell 1 is fixedly connected with lower shell 2, and the bottom of lower shell 2 is fixedly connected with guide head 3;Display assembly, the display assembly is installed on upper shell 1;Detection probe 21, the detection probe 21 is installed in lower shell 2, and the light emitting diode 15 is fixedly installed on the detection probe 21, which is used to emit specific wavelength near-infrared light to the soil, the photodiode 20 is used to receive the near-infrared light reflected by the soil and convert it into an electrical signal, and the temperature sensor 16 is used to monitor the soil temperature in real time;Optical glass 17, the optical glass 17 is fixedly connected with the detection probe 21, and the optical glass 17 covers the outside of the light emitting diode 15, the photodiode 20 and the temperature sensor 16 and directly contacts the soil;Mainboard 14, the mainboard 14 is installed at the top of lower shell 2, and the mainboard 14 is signal connected with the detection probe 21, and the mainboard 14 is used to receive the soil information detected by the detection probe 21 and feedback to the display screen 5.

[0040] The instrument is designed in a split type, and includes an upper shell 1 and a lower shell 2. The upper shell 1 is mainly responsible for installing a display screen 5, a key plate 6 and a charging port 7. The charging port 7 is connected with a mainboard 14 through an external Type-C. The lower shell 2 is installed with a power supply module, the mainboard 14 and a detection probe 21. The upper shell 1 and the lower shell 2 are connected through a first fixing screw 9. The upper shell 1 and the lower shell 2 are made of 304 stainless steel and are polished on the surface. The mainboard 14 is clamped on the lower shell 2 through a positioning groove 10 and is connected with a light-emitting diode 15, a photodiode 20 and a temperature sensor 16 of the detection probe 21 through a flexible printed circuit (FPC). The mainboard 14 is internally provided with a multivariate regression model, which is used to calculate the contents of nitrogen, phosphorus, potassium and organic matter in soil according to reflected spectrum data and a temperature compensation algorithm. The mainboard 14 module realizes charging and data transmission through a Type-C interface and integrates a calibration algorithm. The detection instrument can be calibrated through a standard white board to eliminate environmental interference.

[0041] The lower shell 2 is integrally connected with a handle 4 at the top. The handle 4 is used to improve the vertical downward force supporting point when the handle 4 is inserted into soil. The lower shell 2 is fixedly connected with a guide head 3 below. The guide head 3 is a conical soil insertion guide head 3. The guide head 3 is made of 304 stainless steel corrosion-resistant material and has a hydrophobic coating on the surface, which is suitable for wet, saline-alkali and other responsible soil environments. The gradually tapered angle design reduces the resistance in the soil insertion process.

[0042] The lower shell 2 is provided with a second fixing groove 12 at the top. A battery 13 is installed in the second fixing groove 12. In this embodiment, the battery 13 is a lithium battery 13, which provides power for the whole device and drives the light-emitting diode 15 to emit near-infrared light of a specific wavelength to excite the soil reflected spectrum. The photodiode 20 receives the reflected light signal and converts it into an electric signal. The mainboard 14 runs a multivariate regression model and a temperature compensation algorithm to calculate the nutrient content. The display screen 5 displays the detection results (nitrogen, phosphorus, potassium, organic matter content, temperature and power) in real time. The temperature sensor 16 monitors the soil temperature in real time and participates in data correction.

[0043] The lower shell 2 is provided with a first fixing groove 11 in the middle. The first fixing groove 11 fixes the detection probe 21 on the lower shell 2 through a second fixing screw 19.

[0044] The light-emitting diode 15, the photodiode 20 and the temperature sensor 16 are fixedly installed on the detection probe 21, the optical glass 17 is fixedly connected with the detection probe 21 through the second fixing screw 19, the optical glass 17 covers the outer side of the light-emitting diode 15, the photodiode 20 and the temperature sensor 16, the detection probe 21 is located in the first fixing groove 11 and is embedded in the lower shell 2, the optical glass 17 is directly contacted with the soil, the light transmittance is greater than or equal to 90%, and the optical glass 17 is wear-resistant and scratch-resistant. The light-emitting diode 15 is an LED light source, the LED light source is a 3535 packaging LED with three wave bands packaged together, two LEDs have six wavelengths, and the two LEDs are responsible for emitting specific near-infrared light. The photodiode 20 is responsible for receiving soil reflected light and converting the soil reflected light into an electrical signal, and the photodiode 20 is provided with a light-blocking boss 18. The temperature sensor 16 is closely attached to the inner side of the optical glass 17 and monitors the contact surface temperature. The included angle between the LED and the photodiode 20 is 45 degrees.

[0045] The upper shell 1 adopts a modular functional partition design and mainly integrates the following components: the display screen 5 is located at the top center of the shell and adopts a 1.47-inch OLED display screen 5, which is used for displaying soil organic matter content, temperature and battery 13 power information in real time; the calibration key 601 and the detection key 602 are arranged on the key plate 6, the detection key 602 is also a power-on / off key, and the calibration key 601 and the detection key 602 are symmetrically distributed on the two sides of the display screen 5. The rear part of the upper shell 1 is provided with a Type-C charging port 7, which is responsible for charging and data transmission. The electrical connection port 8 is arranged at the bottom center and is used for connecting the display screen 5, the key, the Type-C port and the mainboard 14 to the instrument.

[0046] The mainboard 14 functions are realized through the following steps: firstly, signal processing, the photodiode 20 output signal is amplified by AD8232, AD conversion is performed by an STM32F407 chip, then a temperature compensation algorithm is performed, then a mapping relationship between the corrected reflectivity data and soil nitrogen, phosphorus, potassium and organic matter content is established based on a PLSR algorithm, and model training data come from 500 laboratory calibration samples. The calculation result is displayed in real time on the OLED display screen 5, and the Type-C interface is also supported to export data to external equipment.

[0047] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0048] The above-described embodiments are merely preferred modes of the present application, and are not intended to limit the scope of the present application, and various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A direct insertion soil nutrient detector characterized by, Include: Upper shell (1) and lower shell (2), the upper shell (1) is fixedly connected with the lower shell (2), the bottom of the lower shell (2) is fixedly connected with the guide head (3); Display assembly, the display assembly is installed on the upper shell (1); Detection probe (21), the detection probe (21) is installed in the lower shell (2), the detection probe (21) is fixedly installed with light emitting diode (15), for emitting specific wavelength near infrared light to soil, photodiode (20), for receiving near infrared light reflected by soil and converting into electrical signal, temperature sensor (16), for real-time monitoring of soil temperature; Optical glass (17), the optical glass (17) is fixedly connected with the detection probe (21), the optical glass (17) covers the outside of the light emitting diode (15), photodiode (20) and temperature sensor (16), and is in direct contact with soil; Mainboard (14), the mainboard (14) is installed on the top of the lower shell (2), the mainboard (14) is signal connected with the detection probe (21), and the mainboard (14) is used for receiving soil information detected by the detection probe (21) and feeding back to the display screen (5).

2. The direct insertion soil nutrient detector according to claim 1, characterized in that: The first fixed groove (11) is formed in the lower shell (2), and the detection probe (21) is fixedly installed in the first fixed groove (11).

3. The direct insertion soil nutrient detector according to claim 2, characterized in that: The detection probe (21) and the optical glass (17) are connected through the second fixed screw (19).

4. The direct insertion soil nutrient detector according to claim 1, characterized in that: The positioning groove (10) is formed in the top of the lower shell (2), and the mainboard (14) is installed in the positioning groove (10).

5. The direct insertion soil nutrient detector according to claim 1, characterized in that: The second fixed groove (12) is formed in the top of the lower shell (2), the battery (13) is installed in the second fixed groove (12), and the battery (13) is electrically connected with the mainboard (14), the display assembly and the detection probe (21).

6. The direct insertion soil nutrient detector according to claim 5, characterized in that: The display assembly includes a display screen (5) and a key pad (6), the display screen (5) is located at the top center of the shell, for displaying soil nutrient content, temperature and battery (13) power information in real time, and the key pad (6) is installed below the display screen (5).

7. The direct insertion soil nutrient detector according to claim 6, characterized in that: The charging port (7) is formed in the upper shell (1), which is used for charging and data transmission.

8. The direct insertion soil nutrient detector according to claim 7, characterized in that: The connecting port (8) is formed in the top of the upper shell (1), which is used for connecting the display screen (5), the key pad (6), the charging port (7) and the mainboard (14) to the instrument.

9. The direct insertion soil nutrient detector according to claim 1, characterized in that: The handle (4) is integrally formed on the top of the lower shell (2).

10. The direct insertion soil nutrient detector according to claim 1, characterized in that: The light blocking boss (18) is arranged on the photodiode cover and is fixedly installed on the detection probe (21).

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