Crop spectrum and photosynthesis monitoring device

Abstract

The invention relates to the technical field of crop spectrum, and discloses a crop spectrum and photosynthesis monitoring device, which comprises a main control unit, a sensing unit and a spectrograph unit, and the main control unit comprises a microcontroller and is used for realizing acquisition, calculation, storage and transmission of spectrum and temperature data of the sensing unit and further controlling the temperature control unit to adjust the temperature of the equipment, and a framework of an embedded core board and a bottom board is adopted as a whole. By integrating a single wide-spectrum and high-resolution optical fiber spectrometer, crop spectrum information of 400-900 nm can be obtained, high-resolution detection smaller than or equal to 1 nm is achieved, wavelength, irradiance, radiance, reflectivity and light intensity information within the wide-spectrum range of crops are output, and the spectrum information of the crops can be obtained through an algorithm library integrated in the main control unit. And inversion output of indication parameters such as sunlight-induced chlorophyll fluorescence, a novel leaf chlorophyll index, a normalized vegetation index, an enhanced vegetation index, a normalized red edge index and a photochemical vegetation index of crops is completed.

Description

Technical Field

[0001] The present invention relates to the field of crop spectrum technology, and in particular to a crop spectrum and photosynthesis monitoring device. Background Art

[0002] In the complex growth process of crops, their physical and chemical parameters are closely related to the growth process. They are affected by factors such as plant leaf color, leaf structure and water status, leaf physiological and biochemical properties, plant morphology, canopy structure, growth and growth period. Different crops, different growth periods of the same crop and different health conditions of the same crop have different spectral reflectance characteristics. The main difference between the spectra of different plants lies in the size of the reflectivity. Therefore, crop spectra and reflectivity can directly or indirectly reflect information such as crop growth, quality, and pests and diseases. In addition, the spectrum of farmland crops is actually a mixed spectrum. In addition to the condition of the crop itself, it is also affected by many factors such as soil background conditions, leaf and canopy structure. Therefore, the spectral characteristics of the crop itself must be accurately extracted, and the interference of background and structure must be compressed and eliminated to correctly understand the true growth status of the crop. Based on the spectral reflectance characteristics of farmland crops that reflect their own characteristics, remote sensing methods are used to monitor, diagnose and estimate the yield of crops, and the real-time, rapid and non-destructive measurement of the physical and chemical parameters of crops is the basis for scientific farmland management.

[0003] In the application of agricultural remote sensing in my country, especially for specific planting application scenarios at the plot level, there are high requirements for the real-time remote sensing monitoring of crops, which needs to meet the needs of timely monitoring of rapid crop growth changes. In recent years, sunlight-induced chlorophyll fluorescence remote sensing has become one of the most groundbreaking research frontiers in the field of vegetation remote sensing based on its advantage of being able to directly detect vegetation photosynthesis.

[0004] However, most of the existing monitoring methods and instruments are in the scientific research stage, and few of them can actually be implemented and guide agricultural production operations. They cannot meet the business application requirements of multiple scenarios and complex environments. In addition, the existing portable devices have limited spectral detection range and cannot obtain spectral information of crop blue edge (blue transition to green), green peak, and yellow edge (green transition to red). They are limited in all-round applications such as crop identification, crop yield estimation, crop nutrition diagnosis, and crop production management.

[0005] To this end, the present invention provides a crop spectrum and photosynthesis monitoring device. Summary of the invention

[0006] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a crop spectrum and photosynthesis monitoring device, so as to obtain the spectral information of the blue edge, green peak and yellow edge areas of the crop, so as to realize the multi-faceted applications of crop identification, crop yield estimation, crop nutrition diagnosis and crop production management.

[0007] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a crop spectrum and photosynthesis monitoring device, comprising a main control unit, a sensing unit and a spectrometer unit; The main control unit includes a microcontroller, which is used to collect, calculate, store and transmit the spectrum and temperature data of the sensing unit, and further control the temperature control unit to adjust the temperature of the device. The overall architecture adopts an embedded core board and baseboard. The baseboard subsystem and the core board subsystem are connected through two B2B connectors: The sensing unit uses optical fiber to collect crop upward radiation and solar downward radiation, and is connected to a cosine corrector to observe the solar downward irradiance, correct the photocurrent response error of the detection device at different light incident angles, and perform hemispherical radiation measurement; The spectrometer unit comprises a miniature spectrometer and a temperature control module. The miniature spectrometer adopts a CT optical structure, and the temperature control module adopts a cavity heat preservation structure combined with TEC temperature control to perform constant temperature control on the spectrometer.

[0008] In some embodiments, the microcontroller adopts a processing module of one of MCU, ARM, DSP or FPGA, and the whole adopts an embedded core board and baseboard architecture, and the baseboard subsystem and the core board subsystem are connected via two B2B connectors.

[0009] In some embodiments, the embedded core board is responsible for data access of the spectrometer, sensors and other hardware, and the algorithm chip has a built-in algorithm library that processes the data of the spectrometer into corresponding observation elements such as chlorophyll fluorescence and vegetation index, and uploads the results to the security management platform.

[0010] In some embodiments, the baseboard subsystem includes a power management circuit, an MCU processing circuit, an RTC clock module, a status monitoring module, a switch chip circuit, a serial port circuit, a network port circuit, etc. Among them, the status monitoring module is used to obtain the operating status and performance indicators of the device, receive relevant data collected in real time by various sensors installed on the device, and monitor the device self-test, the temperature / humidity status inside the device, and the voltage status of core components such as the mainboard.

[0011] In some embodiments, the RTC clock module uses the RV-4162-C7 high-precision I2C RTC clock chip, which can store time and date information in binary format, and has functions such as clock output, clock synchronization, and clock calibration. It can perform time calibration by responding to time calibration commands to ensure that the real-time clock timing error is no more than 1s / d. It has the characteristics of high precision, low power consumption, and strong anti-interference ability.

[0012] In some embodiments, in the automatic observation mode, an electronic TTL driven switch is used to sequentially collect the downward solar irradiance and the upward radiance of the vegetation canopy according to the single-beam sandwich method. The switching frequency is adjustable to adapt to changes in the external environment under different scenarios. The data is measured by introducing it into the same spectrometer through a Y-shaped bifurcated optical fiber assembly, which can reduce the inversion error of subsequent data products caused by the observation time difference.

[0013] In some embodiments, the micro-spectrometer adopts a 10μm slit, a blazed grating with a line pair number of 500g / mm, a collimator and a focusing lens are combined with the optical design simulation results, a lens with a focal length of 75mm or 100mm is selected, and a CCD uses a 2048×64 linear array detector, which can achieve wide spectrum detection of 400nm-900nm, full spectrum resolution ≤1nm, fluorescence spectrum resolution (650nm-800nm) can reach below 0.5nm, dynamic range ≥10000:1, signal-to-noise ratio: ≥600:1 (400nm~900nm), combined with the whole machine stray light elimination structure design, spectral stray light ≤0.1%.

[0014] In some embodiments, the spectrometer unit also includes a temperature control box, in which the micro-spectrometer and the temperature control module are placed. The temperature control box has a built-in TEC heating and cooling module, which includes a temperature control object, a temperature sensor, a PID controller, and a temperature control execution component. The entire loop uses TEC to cool using the Peltier effect of semiconductor materials, and bidirectional temperature control can be achieved through an H-bridge.

[0015] In some embodiments, the monitoring device further includes a power supply unit, which is powered by an external DC power supply, the external power supply voltage is 12V, and the power supply should have an anti-reverse connection function; the power supply unit can provide a stable 12 V or 5 V voltage for the devices in the sensing unit, the spectrometer unit and the main control unit.

[0016] In some embodiments, the monitoring device also includes an overall structure, which is a miniaturized box. The overall structure adopts three-dimensional packaging technology, and a sensing unit, a main control unit, a spectrometer unit, and a power supply unit are rationally arranged. By stacking chips and modules in the vertical direction and making full use of space, the overall structure is integrated into a miniaturized box.

[0017] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: Firstly, the present invention can obtain crop spectral information of 400nm-900nm by integrating a single wide-spectrum, high-resolution fiber spectrometer, realize high-resolution detection of ≤1nm, and output wavelength, irradiance, radiance, reflectivity and light intensity information within the wide spectrum range of crops. By using the algorithm library integrated in the main control unit, the inversion output of indicator parameters such as crop sunlight-induced chlorophyll fluorescence, new leaf chlorophyll index, normalized vegetation index, enhanced vegetation index, normalized red edge index and photochemical vegetation index is completed, providing effective and comprehensive data support for information management and application such as crop identification, crop yield estimation, and crop nutrition diagnosis.

[0018] Secondly, the present invention adopts a low-power temperature control design for the whole machine, which can achieve a constant operating temperature of the spectrometer at 25°C±1°C in an external environment of -20°C~+60°C, thereby ensuring the accuracy and stability of crop spectrum measurement. The average power consumption of the whole machine does not exceed 40W, and the structure is compact and easy to deploy. It can meet the power requirements of most field deployments that only rely on solar panels for power supply, and realize the commercial application of most domestic monitoring sites. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the system architecture of a crop spectrum and photosynthesis monitoring device of the present invention; Figure 2 The figure is a schematic diagram of the main control unit architecture of a crop spectrum and photosynthesis monitoring device of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0022] See also Figure 1 , the present invention provides a crop spectrum and photosynthesis monitoring device, including a main control unit, a sensing unit and a spectrometer unit; The main control unit includes a microcontroller, which can be specifically a processing module such as MCU, ARM, DSP, FPGA, etc., which is used to collect, calculate, store and transmit the spectrum and temperature data of the sensing unit, and further control the temperature control unit to adjust the temperature of the device. The overall architecture adopts an embedded core board and baseboard. The baseboard subsystem and the core board subsystem are connected through two B2B connectors (such as Figure 2 As shown). The embedded core board is responsible for data access of the spectrometer, sensors and other hardware. The algorithm chip has a built-in algorithm library that processes the spectrometer data into corresponding observation elements such as chlorophyll fluorescence and vegetation index, and uploads the results to the security management platform, which is implemented by the chip module. The design can be designed and connected according to the interface requirements of different scenarios.

[0023] The baseboard subsystem includes power management circuit, MCU processing circuit, RTC clock module, status monitoring module, switch chip circuit, serial port circuit, network port circuit, etc. Among them, the status monitoring module is used to obtain the operating status and performance indicators of the equipment, receive various sensors installed on the equipment to collect relevant data in real time, and monitor the equipment self-test, internal temperature / humidity status of the equipment, and voltage status of core components such as the motherboard; The RTC clock module uses the RV-4162-C7 high-precision I2C RTC clock chip, which can store time and date information in binary format, and has functions such as clock output, clock synchronization, and clock calibration. It can perform time calibration by responding to the time calibration command to ensure that the real-time clock running error is no more than 1s / d. It has the characteristics of high precision, low power consumption, and strong anti-interference ability. The memory adopts the Von Neumann structure, which can ensure that data will not be lost after power failure and meet the data storage requirements of 12 months. At the same time, the selection of multi-level decoders can effectively improve the complexity and reliability of the circuit.

[0024] The sensing unit uses two optical fibers with a core diameter of 1000 microns and a numerical aperture of 0.22 to collect crop upward radiation and solar downward radiation. The outer layer is a 304 stainless steel armored outer cladding, which is rainproof and dustproof. The length can be configured according to actual conditions. The upward optical fiber is connected to a cosine corrector to observe the solar downward irradiance and correct the photocurrent response error of the detection device at different light incident angles. Hemispherical radiation measurement can be performed with a field of view (FOV) of 180°.

[0025] In the automatic observation mode, an electronic TTL-driven switch is used to sequentially collect the downward irradiance of the sun and the upward radiance of the vegetation canopy according to the single-beam sandwich method. The switching frequency is adjustable to adapt to changes in the external environment in different scenarios. The data is measured by importing the same spectrometer through a Y-shaped bifurcated optical fiber assembly, which can reduce the inversion error of subsequent data products caused by the observation time difference. The automatic switching measurement mode using an electronic TTL-driven switch solves the problems of high system complexity and difficult calibration that previously required multiple spectrometers for wide-band observation data collection.

[0026] The spectrometer unit includes a micro-spectrometer and a temperature control module: The micro-spectrometer adopts CT optical structure, which is mainly divided into two types: "M" type and cross type. Based on the control requirements of stray light, the micro-spectrometer of this embodiment adopts "M" type. The size of the incident slit directly affects the spectral resolution of the spectrometer and the energy entering the spectrometer. In order to meet the requirements of high resolution and fluorescence measurement sensitivity, a 10μm slit is selected, and the grating selects a blazed grating with a line pair number of 500g / mm. The collimator and focusing lens are combined with the optical design simulation results. A lens with a focal length of 75mm or 100mm can be selected. The CCD uses a 2048×64 linear array detector. Through simulation and testing, the spectrometer can realize wide spectrum detection of 400nm-900nm and full spectrum. The segment resolution is ≤1nm, the fluorescence spectrum resolution (650nm-800nm) can reach below 0.5nm, the dynamic range is ≥10000:1, the signal-to-noise ratio is ≥600:1 (400nm~900nm), combined with the stray light elimination structure design of the whole machine, the spectral stray light is ≤0.1%, which meets the requirements of the input spectrum for the inversion calculation of the indicator parameters such as crop sunlight-induced chlorophyll fluorescence, new leaf chlorophyll index, normalized vegetation index, enhanced vegetation index, normalized red edge index and photochemical vegetation index; The temperature control module is based on the environmental use requirements of -20℃-+60℃, temperature control accuracy requirements and the application requirements of average power not exceeding 40W. It uses a cavity insulation structure combined with TEC temperature control to control the temperature of the spectrometer, ensuring that the working temperature of the spectrometer is constant at 25℃±1℃, avoiding the measurement deviation caused by temperature changes inside the spectrometer, resulting in resolution and wavelength temperature drift. The cavity insulation structure is made of polytetrafluoroethylene material, which fits the shape of the spectrometer and forms a good wrapping for it. It has insulation and heat insulation properties, can effectively ensure the temperature inside the cavity, block the heat exchange between the inside of the spectrometer and the environment, and reduce the power consumption of the temperature control system.

[0027] The spectrometer unit also includes a temperature control box, in which the micro-spectrometer and the temperature control module are placed. The temperature control box has a built-in TEC heating and cooling module, including a temperature control object, a temperature sensor, a PID controller, and a temperature control actuator. The entire loop uses TEC to utilize the Peltier effect of semiconductor materials for cooling, and bidirectional temperature control can be achieved through an H-bridge. The maximum current, maximum voltage, operating temperature range, maximum temperature difference and other parameters of TEC are obtained through thermal simulation, and a temperature control solution with a photoelectric separation structure and a single-stage TEC is adopted. NTC detection realizes feedback control, and through the PID algorithm, the accuracy can achieve stable and precise temperature control of ±1℃@25℃, which can effectively avoid the wavelength and resolution drift caused by the temperature fluctuation of the spectrometer operating environment, and ensure the accuracy of spectral data acquisition.

[0028] As a preferred embodiment, the monitoring device further includes a power supply unit, which is powered by an external DC power supply, the power supply voltage of the external power supply is 12V, and the power supply should have an anti-reverse connection function. The power supply unit can provide a stable 12 V or 5 V voltage for the components in the sensing unit, the spectrometer unit, and the main control unit.

[0029] At the same time, the monitoring device also includes the whole machine structure. The whole machine adopts three-dimensional packaging technology, and reasonably arranges the sensing unit, main control unit, spectrometer unit and power supply unit. By stacking chips and modules in the vertical direction, the space is fully utilized, and the whole machine is integrated into a miniaturized box; in addition, the main control unit adopts highly integrated circuit chips, which enables the equipment to achieve powerful computing and processing functions in a very small space, further improving the degree of integration and miniaturization, and can achieve the function, performance and miniaturization of the equipment without increasing the plane size of the equipment. The size of the whole machine does not exceed 600mm×400mm×300mm, which is convenient for deployment in multiple application scenarios such as field mobile monitoring, fixed installation, and pole suspension.

[0030] In general, the present invention aims to design a crop spectrum and photosynthesis monitoring device. With the emergence of remote sensing technology in recent years, its advantages such as rapid, non-destructive and large-area monitoring have made up for the shortcomings of traditional measurement methods. However, based on the needs of farmland crop monitoring, the existing methods still have room for improvement: In the blade monitoring scale, since the light inlet of the blade clip is small (1 cm in diameter), if the angle of inclination with the sun deviates slightly, the blade will be covered by the blade clip. Therefore, the radiant brightness of the incident light should be measured before and after each set of blades to ensure the stability of the incident light. This method requires manual operation, is highly complex, has large errors, lacks continuity, and the measurement results have poor regional representativeness; Compared with the leaf scale, the ground-based (mainly tower-based) SIF automatic observation system has the advantages of high frequency and continuity, which can effectively solve the problem of SIF time resolution and obtain SIF at the canopy scale. These tower-based canopy SIF observation systems usually have two modes: using a single spectrometer to obtain only 650nm-800nm ​​crop spectral information, lacking the blue edge (blue transition to green), green peak, and yellow edge spectral information necessary for vegetation index calculation, and having limitations in all-round applications such as crop identification, crop yield estimation, crop nutrition diagnosis, and crop production management; or using a full-spectrum SIF observation system, which usually requires the integration of multiple spectrometers, with a complex system, difficult calibration, poor applicability in multiple scenarios, high power consumption, and difficult deployment in farmland areas that cannot be connected to the mains in the wild, making it difficult to achieve nationwide business applications.

[0031] A variety of global satellite SIF products have been produced based on different satellite platforms. The original satellite SIF inversion products have problems such as spatial discontinuity or low spatiotemporal resolution. Several studies have used machine learning, deep learning and other methods based on the original SIF inversion products combined with auxiliary data such as MODIS reflectivity to obtain spatially continuous SIF datasets with improved spatiotemporal resolution. However, these reconstructed SIF products may be affected by the uncertainty of auxiliary datasets and machine learning methods, and may not necessarily reflect the SIF signals actually emitted by plants. In addition, due to the limitations of the satellite's own physical performance, spatial resolution and temporal resolution restrict each other. There are still many problems in the relationship between SIF and GPP mechanisms, satellite SIF remote sensing data assimilation, vegetation phenology and stress monitoring, etc., which need further research.

[0032] In view of the above problems and difficulties, the demand for the commercial application of portable crop spectrum and photosynthesis monitoring devices based on characteristic bands is becoming more and more urgent. This device can obtain crop spectrum information of 400nm-900nm by integrating a single wide-band, high-resolution micro-fiber spectrometer, and obtain indicator parameters such as blue edge (blue transition to green), green peak, yellow edge (green transition to red), and red edge (near infrared region), so as to realize all-round applications such as crop identification, crop yield estimation, crop nutrition diagnosis, and crop production management. It has a compact structure and is easy to deploy. Its core component, the spectrometer, is a precision instrument with high requirements for ambient temperature. In order to ensure the accuracy of physical and chemical parameters, the working temperature of the spectrometer needs to be constant at 25℃±1℃. This device can realize the constant temperature operation of the spectrometer in an external environment of -20℃~+60℃ through the low-power temperature control design of the whole machine, and the power consumption of the whole machine does not exceed 40W, which can meet the power requirements of field deployment in most cases where it only relies on solar panels for power supply, and realize the commercial application of most domestic monitoring sites.

[0033] Specifically, under natural light conditions, the crop spectrum and photosynthesis monitoring device obtains the irradiance spectrum and solar radiation spectrum reflected by the vegetation through the sensing unit, and according to the idea of ​​filling dark lines by SIF in the Fraunhofer Line Discriminator (FLD), the electronic TTL drive switch is used to realize the sequential switching between the two input optical paths of the solar incident spectrum and the canopy reflectance spectrum. The two optical paths are measured in an orderly manner through a spectrometer, and the wavelength, irradiance, radiance, reflectivity and light intensity information within the wide spectrum range of the crop are output and transmitted to the main control unit. The algorithm library integrated in the main control unit is used to complete the inversion output of indicator parameters such as crop sunlight-induced chlorophyll fluorescence, new leaf chlorophyll index, normalized vegetation index, enhanced vegetation index, normalized red edge index and photochemical vegetation index, so as to realize information management and application such as crop identification, crop yield estimation and crop nutrition diagnosis.

[0034] The embodiments disclosed in the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. The embodiments disclosed in the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part, and / or installed from a removable medium. When the computer program is executed by the central processing unit, the above functions defined in the method of the present application are executed. It should be noted that the computer-readable medium mentioned above in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of an electrical, magnetic, optical, electromagnetic, infrared segment, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wire segments, a portable computer disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless segments, wire segments, optical cables, RF, etc., or any suitable combination of the above.

[0035] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0036] Those skilled in the art should understand that the above description is only a specific implementation mode of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A crop spectrum and photosynthesis monitoring device, characterized in that: It includes a main control unit, a sensing unit and a spectrometer unit; The main control unit includes a microcontroller, which is used to collect, calculate, store and transmit the spectrum and temperature data of the sensing unit, and further control the temperature control unit to adjust the temperature of the device. The overall architecture adopts an embedded core board and baseboard. The baseboard subsystem and the core board subsystem are connected through two B2B connectors: The sensing unit uses optical fiber to collect crop upward radiation and solar downward radiation, and is connected to a cosine corrector to observe the solar downward irradiance, correct the photocurrent response error of the detection device at different light incident angles, and perform hemispherical radiation measurement; The spectrometer unit comprises a miniature spectrometer and a temperature control module. The miniature spectrometer adopts a CT optical structure, and the temperature control module adopts a cavity heat preservation structure combined with TEC temperature control to perform constant temperature control on the spectrometer.

2. A crop spectrum and photosynthesis monitoring device according to claim 1, characterized in that: The microcontroller adopts a processing module of one of MCU, ARM, DSP or FPGA, and the whole adopts an embedded core board and baseboard architecture, and the baseboard subsystem and the core board subsystem are connected through two B2B connectors.

3. A crop spectrum and photosynthesis monitoring device according to claim 2, characterized in that: The embedded core board is responsible for data access of the spectrometer, sensors and other hardware. The algorithm chip has a built-in algorithm library that processes the data of the spectrometer into corresponding observation elements such as chlorophyll fluorescence and vegetation index, and uploads the results to the security management platform.

4. A crop spectrum and photosynthesis monitoring device according to claim 2, characterized in that: The baseboard subsystem includes power management circuit, MCU processing circuit, RTC clock module, status monitoring module, switch chip circuit, serial port circuit, network port circuit, etc. Among them, the status monitoring module is used to obtain the operating status and performance indicators of the equipment, receive various sensors installed on the equipment to collect relevant data in real time, and monitor the equipment self-test, internal temperature / humidity status of the equipment, and voltage status of core components such as the mainboard.

5. A crop spectrum and photosynthesis monitoring device according to claim 4, characterized in that: The RTC clock module adopts the RV-4162-C7 high-precision I2C RTC clock chip, which can store time and date information in binary format, and has functions such as clock output, clock synchronization, and clock calibration. It can perform time calibration by responding to the time calibration command to ensure that the real-time clock running error is no more than 1s / d. It has the characteristics of high precision, low power consumption, and strong anti-interference ability.

6. A crop spectrum and photosynthesis monitoring device according to claim 1, characterized in that: In the automatic observation mode, an electronic TTL-driven switch is used to collect the downward solar irradiance and the upward radiance of the vegetation canopy in sequence according to the single-beam sandwich method. The switching frequency is adjustable to adapt to changes in the external environment in different scenarios. The data is measured by importing it into the same spectrometer through a Y-shaped bifurcated optical fiber assembly, which can reduce the inversion error of subsequent data products caused by the observation time difference.

7. A crop spectrum and photosynthesis monitoring device according to claim 1, characterized in that: The micro-spectrometer adopts a 10μm slit, a blazed grating with a line pair number of 500g / mm, a collimator and a focusing lens are combined with the optical design simulation results, a lens with a focal length of 75mm or 100mm is selected, and a CCD uses a 2048×64 linear array detector, which can achieve wide spectrum detection of 400nm-900nm, the full spectrum resolution is ≤1nm, the fluorescence spectrum resolution (650nm-800nm) can reach below 0.5nm, the dynamic range is ≥10000:1, the signal-to-noise ratio is: ≥600:1 (400nm~900nm), combined with the stray light elimination structure design of the whole machine, the spectral stray light is ≤0.1%.

8. The crop spectrum and photosynthesis monitoring device according to claim 1, characterized in that: The spectrometer unit also includes a temperature control box, in which the micro-spectrometer and the temperature control module are placed. The temperature control box has a built-in TEC heating and cooling module, which includes a temperature control object, a temperature sensor, a PID controller and a temperature control execution component. The entire loop uses TEC to cool using the Peltier effect of semiconductor materials, and bidirectional temperature control can be achieved through an H-bridge.

9. The crop spectrum and photosynthesis monitoring device according to claim 1, characterized in that: The monitoring device also includes a power supply unit, which is powered by an external DC power supply. The power supply voltage of the external power supply is 12V, and the power supply should have an anti-reverse connection function; the power supply unit can provide a stable 12 V or 5 V voltage for the devices in the sensing unit, spectrometer unit and main control unit.

10. A crop spectrum and photosynthesis monitoring device according to claim 9, characterized in that: The monitoring device also includes an overall structure, which is a miniaturized box. The overall structure adopts three-dimensional packaging technology, and rationally arranges the sensing unit, the main control unit, the spectrometer unit, and the power supply unit. By stacking chips and modules in the vertical direction and making full use of the space, the overall structure is integrated into the miniaturized box.

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