Pipeline embedded type fertilizer liquid on-line detection sensor based on near-infrared principle

Abstract

The utility model relates to a near-infrared principle-based pipeline embedded type fertilizer liquid online detection sensor, which comprises joints and a multi-channel detection unit, the two ends of the multi-channel detection unit are connected with the joints, the multi-channel detection unit is communicated with a pipeline through the joints, and the multi-channel detection unit is of a multi-layer structure and comprises a light source chamber, a detection chamber and a photoelectric receiving chamber, the detection chamber is a middle layer, upper and lower layers of the detection chamber are provided with cavities, the cavities are communicated with the detection chamber, and the light source chamber and the photoelectric receiving chamber are embedded in the cavities and are of closed structures. Seamless connection between the sensor and an original pipeline does not influence the flow velocity of original fertilizer liquid, does not cause interference on nutrient ions in the to-be-detected fertilizer liquid and does not cause secondary pollution to the fertilizer liquid, near-infrared detection equipment is miniaturized, and the near-infrared detection equipment is applied to detection of liquid fertilizer components and plays an instructive role in accurate fertilization, so that the detection accuracy is improved. And a foundation is laid for precise fertilization and integration of water and fertilizer.

Description

Technical Field

[0001] This application relates to the technical field of irrigation and fertilization, and particularly to an in-pipe embedded fertilizer solution on-line detection sensor based on the near-infrared principle. Background Art

[0002] In the process of realizing precise irrigation and fertilization, the on-line rapid detection of the multi-nutrient components and their contents of the fertilizer solution is a research difficulty in this field and also a key link restricting its intellectualization. Only by accurately knowing the information of each fertilizer component and its content and feeding it back to the device to provide a decision-making basis for automatic water and fertilizer mixing can the goal of precise irrigation and fertilization according to the preset water and fertilizer ratio be achieved.

[0003] It is the development need of contemporary society to realize the detection in the agricultural field using non-destructive, rapid, environmentally friendly and high-throughput detection methods. At present, the detection of fertilizer solution component information mainly includes EC / pH detection method, ion selective electrode detection method and dielectric property detection method. These methods cannot be used for on-site operation, and some have high requirements for the experimental environment. They cannot achieve real-time on-line detection, have hysteresis, and can only detect the overall concentration of the fertilizer solution, and cannot identify the specific nutrient elements and their concentrations in the fertilizer solution. Traditional detection and analysis methods have the disadvantages of time-consuming and laborious, the detected samples cannot be sold again, and there are phenomena such as defective products being missed in detection. Utility Model Content

[0004] To solve or partially solve the problems existing in the related technologies, this application provides an in-pipe embedded fertilizer solution on-line detection sensor based on the near-infrared principle. By detecting the voltage value of the fertilizer solution at a specific wavelength and performing photoelectric conversion to obtain the corresponding absorbance, the types and specific concentrations of N, P, and K in the fertilizer solution component information can be detected on-line and rapidly.

[0005] The first aspect of this application provides an in-pipe embedded fertilizer solution on-line detection sensor based on the near-infrared principle, including: a joint, a multi-channel detection unit. The two ends of the multi-channel detection unit are connected to the joint and communicated with the pipeline through the joint. The multi-channel detection unit is a multi-layer structure, including a light source chamber, a detection chamber and a photoelectric receiving chamber. The detection chamber is the middle layer, and the upper and lower layers are provided with cavities. The cavities are communicated with the detection chamber, and the light source chamber and the photoelectric receiving chamber are embedded and installed in the cavities. The light source chamber and the photoelectric receiving chamber are airtight structures.

[0006] Further, the photoelectric receiving chamber includes a photoelectric receiving port base for receiving the near-infrared light emitted by the light source chamber.

[0007] Further, the light source chamber includes an LED light source, a photodetector, a photoelectric receiving port base, a fixing bracket, and a quartz glass sheet. The LED light source is installed at the upper end of the light source chamber based on the fixing bracket. The lower end of the light source chamber is installed with a photoelectric receiving port base through the fixing bracket, and the photoelectric receiving port base is located within the irradiation range of the LED light source. A photodetector is installed on the photoelectric receiving port base, and an installation hole for installing the quartz glass sheet is also provided on the fixing bracket.

[0008] Further, a photoelectric receiving port base is provided inside the photoelectric receiving chamber, and the photoelectric receiving port base is installed directly below the quartz glass sheet.

[0009] Further, a quartz glass layer is provided on the outer sides of the light source chamber and the photoelectric receiving chamber, and a sealed structure is formed based on the quartz glass layer.

[0010] Further, internal threads are provided inside the connector, external threads are provided at both ends of the multi-channel detection unit, and the connector is threadedly connected to the multi-channel detection unit.

[0011] Further, the multi-channel detection unit is a four-channel detection unit, and four LED light sources and eight photoelectric receiving port bases are correspondingly provided. The four channels are respectively used to detect whether the fertilizer solution to be measured contains HPO2-4, NH+4, H2PO-4, and K. + 。

[0012] Further, it further includes a sensor housing, the sensor housing is sleeved on the outer side of the multi-channel detection unit, and a wire lead-out port is provided on the sensor housing.

[0013] The technical solution provided by this application may include the following beneficial effects:

[0014] This application provides a pipeline-embedded fertilizer solution on-line detection sensor based on the near-infrared principle. The sensor is designed to be plug-in type, which can realize the detection of fertilizer solution in various occasions. The sensor is seamlessly connected to the original pipeline without affecting the flow rate of the original fertilizer solution, and can realize detection at different flow rates of the fertilizer solution. The detection speed is fast and the operation is convenient and fast. The sensor only uses near-infrared light as the external excitation source, which will not interfere with the nutrient ions in the fertilizer solution to be measured, nor cause secondary pollution to the fertilizer solution. It miniaturizes the near-infrared detection equipment and applies it to the detection of liquid fertilizer components, which plays a guiding role in precise fertilization. It solves the problem that the existing fertilizer solution detection device can only detect the overall concentration of the fertilizer solution and cannot identify the specific nutrient elements and their concentrations in the fertilizer solution, greatly facilitating the acquisition of fertilizer solution component information in practical engineering applications and laying a foundation for precise fertilization and water-fertilizer integration.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. Description of the Drawings

[0016] The above and other objects, features, and advantages of the present application will become more apparent by describing the exemplary embodiments of the present application in more detail with reference to the accompanying drawings, where, in the exemplary embodiments of the present application, the same reference numerals generally represent the same components.

[0017] Figure 1 is a schematic structural diagram of the sensor shown in the embodiments of the present application;

[0018] Figure 2 is a schematic structural diagram of the multi-channel detection unit shown in the embodiments of the present application;

[0019] Figure 3 is a three-dimensional structural diagram of the multi-channel detection unit shown in the embodiments of the present application;

[0020] Figure 4 is a schematic structural diagram of the joint shown in the embodiments of the present application;

[0021] Figure 5 is a schematic structural diagram of the sensor housing shown in the embodiments of the present application;

[0022] Reference numerals:

[0023] In the figure, 1 - joint, 2 - sensor housing, 3 - multi-channel detection unit, 4 - light source chamber, 5 - detection chamber, 6 - photoelectric reception chamber, 7 - LED light source mounting groove, 8 - photoelectric reception port base, 9 - fixing bracket, 10 - quartz glass sheet, 11 - wire lead-out port, 12 - window. Detailed implementation manners

[0024] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0025] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0026] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0027] Unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0028] The technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings.

[0029] The near-infrared spectrum of organic substances is mainly composed of the overtone and combination absorption bands of hydrogen-containing groups such as C-H, N-H, O-H, S-H, and P-H, and the C-H, N-H, and O-H groups are the constituent groups of the main active ingredients in the fertilizer solution. When the fertilizer solution is irradiated by near-infrared light starting from the light source, the bonds in the infrared-active molecules in the fertilizer solution will interact with the near-infrared photons, generating near-infrared spectrum absorption. These hydrogen-containing groups have strong absorption frequency characteristics, are less affected by the internal and external environments of the molecules, and the sample spectral characteristics in the near-infrared spectral region are more stable than those in the mid-infrared spectral region. Therefore, different types of fertilizer solutions can be identified by near-infrared spectroscopy.

[0030] As shown in the figure, a pipeline-embedded on-line detection sensor for fertilizer solution based on the near-infrared principle includes: a joint 1, a sensor housing 2, and a four-channel detection unit 3. The two ends of the four-channel detection unit 3 are connected to the joint 1. One end of the joint 1 is provided with an internal thread on the inner side and an external thread on the other end. The two ends of the four-channel detection unit 3 are provided with external threads. The internal thread end of the joint 1 is threadedly connected to the four-channel detection unit 3, and the external thread end is connected to the conveying pipeline. After the fertilizer solution enters the sensor from one end joint 1, it is output from the other end joint 1. Since the two ends of the sensor are embedded and connected in the circular pipeline and are seamlessly connected to the original pipeline, the fertilizer solution to be measured can flow freely in the pipeline.

[0031] A sensor housing 2 is sleeved outside the four-channel detection unit 3. An appropriate gap is provided between the sensor housing 2 and the detection unit, which not only facilitates the installation of the housing but also provides necessary protection and light-shielding functions to ensure the stability and reliability of the system. A wire outlet 11 is provided on the wall surface of the sensor housing 2, leaving a space of 2 mm to facilitate the connection wires of the internal components to be led out. At the same time, it covers the internal detection structure, effectively reducing the penetration of external light, minimizing external light interference, and ensuring the smooth operation of the system and the stable transmission of signals.

[0032] The four-channel detection unit 3 is a multi-layer cylindrical structure, including a light source chamber 4, a detection chamber 5, and a photoelectric receiving chamber 6, and is provided with four detection channels, four LED light-emitting diodes, four quartz glass sheets 10, four LED fixing supports, and eight photoelectric receiving port bases 8. The four-channel detection unit 3 is sequentially provided with a light source chamber 4, a detection chamber 5, and a photoelectric receiving chamber 6 from top to bottom. The detection chamber 5 is arranged in the middle layer, and the upper and lower layers are arranged as cavities. The detection chamber 5 communicates with the cavities of the upper and lower layers. The light source chamber 4 is embedded and installed in the upper cavity, and the photoelectric receiving chamber 6 is embedded and installed in the lower cavity. The side wall of the cavity forms a flow channel with the light source chamber 4 and the photoelectric receiving chamber 6. A window 12 is provided on the side wall of the cavity, and the window 12 is sealed with quartz glass.

[0033] A quartz glass layer is provided outside the light source chamber 4 and the photoelectric receiving chamber 6 to form a sealed structure based on the quartz glass layer. The fertilizer solution flows into the sensor through a connector 1 on one side, enters the detection chamber 5 through the flow channel formed by the upper cavity and the light source chamber 4, continuously flows into the detection area of the detection chamber 5 until it is full, and then passes through the flow channel formed by the lower cavity and the photoelectric receiving chamber 6, and finally flows out through the connector 1 on the other side. The fertilizer solution to be measured in the detection area is in a dynamic equilibrium state with the fertilizer solution in the pipeline, and the overall nutrient components of the fertilizer solution to be measured are consistent inside and outside the fertilizer solution chamber, enabling the sensor to realize real-time monitoring of the fertilizer solution to be measured.

[0034] The light source chamber 4 includes an LED light source, a photodetector, a photoelectric receiving port base 8, a fixing bracket 9, and a quartz glass sheet 10. In this embodiment, the LED light source is an LED light emitting diode that emits different light source wavelengths, and is respectively installed and fixed through the LED light source installation slots 7 opened on the fixing bracket 9. The photodetector is fixedly installed on the photoelectric receiving port base 8 through a photodetector washer, and allows the connection wire to be pulled out from the wire outlet, and is uniformly managed and pulled out from the sleeve wire outlet of the sensor housing 2. The LED light emitting diode with a specific wavelength is installed at the upper end of the light source chamber 4 through the fixing bracket 9 to ensure the emission of stable near-infrared light. At the lower end of the light source chamber 4, by calculating the light emitting angle of the LED light emitting diode, four photoelectric receiving port bases 8 corresponding to four LED light sources are set and fixed on the lower fixing bracket 9 so that they are within the irradiation range of the LED light emitting angle, so that the photodetector can receive the near-infrared light that has not been transmitted through the fertilizer solution to be measured. A round hole with a diameter of 20 mm is also opened on the fixing bracket 9 for installing a transparent quartz glass round sheet to ensure that the near-infrared light can smoothly pass through the fertilizer solution to be measured and will not absorb the near-infrared light.

[0035] The photoelectric receiving chamber 6 is provided with four photoelectric receiving port bases 8 corresponding to four LED light sources. The photoelectric receiving port base 8 is located directly below the quartz glass round sheet. The near-infrared light emitted by the light source chamber 4 passes through the quartz glass sheet 10 and the fertilizer solution in the detection chamber 5 is received by the photodetector.

[0036] The four detection channels inside the sensor are consistent in the structure of the light source chamber 4, and the only difference lies in the light source wavelength emitted by the LED light emitting diode. This design not only ensures the stability and accuracy of the light source, but also can effectively isolate and transmit the fertilizer solution to be measured, so as to realize the accurate monitoring and concentration calculation of different nutrient ions.

[0037] The designed in-line sensor part is directly connected to the pipeline of the fertilizer solution to be measured. Quartz glass flakes are pasted on the placement chambers of each component of the sensor to ensure that the fertilizer solution to be measured does not flow into the interior of the sensor, avoiding problems such as water leakage and circuit short - circuit. Four different wavelength LED light sources of 980, 1450, 1550, and 1600 nm are selected for the sensor respectively. These light sources pass through the filter ports of their respective channels in sequence. The photodetectors on the filter ports receive the first near - infrared light and convert it into an electrical signal. When the near - infrared light of 980, 1450, 1550, and 1600 nm passes through their respective filter ports, the photodetectors on the light source receiving ports receive the second near - infrared light and also convert it into an electrical signal. These electrical signals enter the voltage - current detection module after passing through the signal conditioning circuit. The voltage - current detection module detects the two - time near - infrared light of the four channels and outputs the voltage - current values of a total of eight electrical signals to the ADS8860 analog - to - digital conversion module. The ADS8860 analog - to - digital conversion module converts the received analog signal into a digital representation and outputs the result to the single - chip microcomputer. The single - chip microcomputer calculates the type and concentration results of the fertilizer solution to be measured according to the pre - established mathematical model. The final results are displayed on the OLED screen, realizing an intuitive display of the type and concentration of the fertilizer solution to be measured.

[0038] According to the Lambert - Beer law, the relationship between absorbance and incident light and transmitted light is as follows:

[0039]

[0040] A—Absorbance of the measured solution;

[0041] I o —Intensity of incident monochromatic light;

[0042] I t —Intensity of transmitted light.

[0043] When the fertilizer solution detection device is embedded in the pipeline of the fertilizer solution to be measured for detection, the incident light is the light from the LED light source reaching the photodetector in the light source chamber 4, and the transmitted light is the light from the LED light source penetrating the fertilizer solution and reaching the photodetector in the photoelectric receiving chamber. The intensities of the incident light and the transmitted light in each detection channel are represented by the output voltages (Vi and Vt) of 2 photodetectors respectively. To eliminate the influence of the ambient light in the actual detection environment on the detection results of the device as much as possible, before each time the LED light source is turned on for detection, the photodetector detects and records the voltage Va corresponding to the ambient light once in advance. The absorbance calculation formula is as follows.

[0044]

[0045] This sensor adopts a detection strategy of "first species, then concentration" to achieve the detection of the component information of the fertilizer solution to be measured. The absorbance change ranges of the four nutrient ions at their respective characteristic wavelengths are also significantly different. Therefore, when identifying the type of the fertilizer solution to be measured, the fertilizer solution to be measured can be irradiated with four characteristic wavelength light sources of 980, 1450, 1550, and 1600 nm in sequence, and whether the fertilizer solution to be measured contains HPO2-4, NH+4, H2PO-4, and K can be judged according to the absorbance extreme values of each nutrient ion at these wavelengths. + To complete the identification of the type of fertilizer solution.

[0046] Since the detection device cannot directly measure the absorbance of each nutrient ion, but indirectly measures it by detecting the voltage value. Therefore, when designing the sensor of the detection device, the voltage values recorded by the photodetectors on the LED optical paths corresponding to each wavelength of each fertilizer solution are respectively set as V1-V4 and Va-Vd, which represent the states before and after the light source passes through the fertilizer solution to be measured; substituting them into formula 2 respectively, the absorbances A1-A4 of the four nutrient ions of this fertilizer solution to be measured can be obtained, and the effective detection of the change in the concentration of the nutrient ions in the fertilizer solution can be achieved by substituting the established mathematical model.

[0047] Finally, it should also be noted that in this article, relationships such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to this process, method, article or device.

[0048] The unit described as a separation component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0049] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The choice of terms used in this article is intended to best explain the principles of the embodiments, practical applications or improvements to the technologies in the market, or to enable other ordinary technical personnel in the technical field to understand the embodiments disclosed in this article.

Claims

1. A pipeline embedded fertilizer liquid online detection sensor based on near infrared principle, characterized in that: include: A connector and a multi-channel detection unit, wherein both ends of the multi-channel detection unit are connected to the connector and the multi-channel detection unit is connected to the pipeline through the connector. The multi-channel detection unit is a multi-layer structure, including a light source chamber, a detection chamber and a photoelectric receiving chamber. The detection chamber is the middle layer and the upper and lower layers are set as cavities. The cavity is connected to the detection chamber. The light source chamber and the photoelectric receiving chamber are embedded and installed in the cavity. The light source chamber and the photoelectric receiving chamber are closed structures.

2. The pipeline embedded fertilizer liquid online detection sensor according to claim 1 is characterized in that: The photoelectric receiving chamber comprises a photoelectric receiving port base, and the photoelectric receiving port base is used to receive the near infrared light emitted by the light source chamber.

3. The pipeline embedded fertilizer liquid online detection sensor according to claim 1 is characterized in that: The light source chamber includes an LED light source, a photoelectric detector, a photoelectric receiving port base, a fixing bracket and a quartz glass sheet. The LED light source is installed at the upper end of the light source chamber based on the fixing bracket. The photoelectric receiving port base is installed at the lower end of the light source chamber through the fixing bracket and the photoelectric receiving port base is located within the irradiation range of the LED light source. The photoelectric detector is installed on the photoelectric receiving port base, and the fixing bracket is also provided with a mounting hole for mounting the quartz glass sheet.

4. The pipeline embedded fertilizer liquid online detection sensor according to claim 3 is characterized in that: A photoelectric receiving port base is arranged in the photoelectric receiving chamber, and the photoelectric receiving port base is installed directly below the quartz glass sheet.

5. The pipeline embedded fertilizer liquid online detection sensor according to claim 1 is characterized in that: A quartz glass layer is provided outside the light source chamber and the photoelectric receiving chamber, and a sealed structure is formed based on the quartz glass layer.

6. The pipeline embedded fertilizer liquid online detection sensor according to claim 1 is characterized in that: An internal thread is formed on the inner side of the joint, external threads are formed on both ends of the multi-channel detection unit, and the joint is threadably connected to the multi-channel detection unit.

7. The pipeline embedded fertilizer liquid online detection sensor according to claim 1 is characterized in that: The multi-channel detection unit is a four-channel detection unit, which is provided with four LED light sources and eight photoelectric receiving port bases. The four channels are respectively used to detect whether the fertilizer solution to be tested contains HPO2-4, NH+4, H2PO-4 and K + .

8. The pipeline embedded fertilizer liquid online detection sensor according to claim 1 is characterized in that: It also includes a sensor housing, which is sleeved on the outside of the multi-channel detection unit and has a wire lead-out port.

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