A scalable distributed multileaf chamber open-path photosynthesis measurement system and method

Abstract

This invention discloses a scalable distributed multi-chamber open-path photosynthetic measurement system and method, relating to the field of plant physiological and ecological measurement technology. The system includes a main unit and at least two distributed chambers. The main unit centrally manages gas supply, concentration mixing, flow control, and high-precision concentration differential analysis. Each chamber is an independent unit, equipped with an adjustable LED light source, thermoelectric temperature control module, multiple types of sensors, independent power supply, and wireless communication module. An open path is formed through the gas supply pipeline and the return pipeline. The core of the method lies in the main unit polling and sampling the return gas from each chamber according to a preset program through a multi-channel automatic switching valve group. Combined with a "flushing stabilization" strategy, a single gas analysis unit is used to achieve high-precision, high-throughput parallel measurement of multiple chambers. This invention solves the problems of low throughput and high cost of traditional open-path instruments, achieving a balance between high precision and high throughput, and supports in-situ deployment in the field and remote monitoring.

Description

Technical Field

[0001] This invention relates to the field of plant physiological and ecological measurement technology, and in particular to a scalable distributed multi-leaf chamber open pathway photosynthesis measurement system and method. Background Technology

[0002] Photosynthesis is the core physiological process of plant matter production and energy conversion, and accurate measurement of its rate is an important foundation for plant physiological ecology research, crop genetic improvement, and precision agriculture management. Currently, leaf photosynthetic rate measurement techniques based on the principle of gas exchange are mainly divided into two categories: closed pathway methods and open pathway methods.

[0003] Closed-path methods typically employ a multi-channel design, connecting multiple independent chambers to a common gas analysis unit. This is achieved by sequentially closing each chamber and monitoring its internal components. The rate of decrease in concentration over time is used to calculate photosynthesis. This method allows for a degree of parallel measurement, but its inherent "non-steady-state" measurement mode results in slow response speed, long measurement cycles, and significantly increased errors under conditions of low photosynthetic rate or high stomatal conductance. Furthermore, microenvironmental changes caused by the closure of leaf chambers (such as increased temperature and humidity) can significantly interfere with the physiological state of leaves, affecting the accuracy of measurements and making it difficult to meet the needs for precise identification of in-situ, dynamic, and high-throughput physiological phenotypes in plants.

[0004] In contrast, the open-path method is considered the gold standard for photosynthesis measurement. Its working principle involves continuously introducing a gas of known and stable composition (such as a pre-set gas flow path) into the leaf chamber. (concentration of air), and to measure the concentration of inflow and outflow gases in real time with high precision. The net photosynthetic rate can be directly calculated by combining the concentration difference with precisely controlled flow. This method measures under steady-state conditions, has a fast response, is less affected by environmental disturbances, and provides high data accuracy. However, to achieve this high accuracy, traditional high-end open-pathway photosynthesis systems (such as the LI-6800 from LI-COR) must highly integrate a high-precision infrared gas analyzer, a precision gas mixing and flow control system, and a leaf chamber environment (light, temperature, and humidity) control module into a single main unit. This highly integrated design results in an exceptionally complex device structure, high manufacturing costs, and the ability to connect and measure only one leaf chamber at a time. Although sequential measurements can be achieved by manually changing leaf chambers, it is essentially still a serial operating mode with extremely low throughput, making it difficult to adapt to the high-throughput application scenarios of "multi-genotype, multi-environmental treatment, multi-biological replication, and long-term continuous monitoring" commonly required in modern plant phenomics research. While there are ideas for simply combining multiple traditional open-pathway instruments, the cost would increase exponentially, and it would be difficult to achieve synchronous measurement and centralized control, lacking engineering feasibility and economic viability.

[0005] Therefore, there is an urgent need in this field for an innovative technical solution that can inherit the core advantages of the open pathway method, such as high precision and fast response, while fundamentally breaking through its bottleneck of single-point serial measurement. This solution should achieve truly high-throughput, scalable, and automated parallel measurement at a reasonable cost, thereby providing effective tool support for large-scale plant physiological phenotypic identification. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned shortcomings in the existing technology and provide a scalable distributed multi-chamber open-path photosynthesis measurement system and method. Through the technical solution of "centralized gas control and analysis of the host, distributed environmental control of the chamber, and automatic polling switching of multiple hosts", it achieves true multi-chamber parallel, high-throughput, and continuous in-situ measurement at a reasonable system cost while maintaining the inherent advantages of the open-path method in terms of high precision and fast response. This provides a new, efficient, reliable, and scalable tool for modern plant phenomics research.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A scalable distributed multileaf chamber open-path photosynthesis measurement system includes: One host, and at least two leaf chambers; The main unit includes a gas supply and mixing unit configured to provide a reference gas source and pure gas. The gas source is used to mix the two in a preset ratio to create a product with a target... A mixture of gases of varying concentrations; The gas analysis unit is configured for high-precision measurement of the gas flow between the reference gas and the sample gas. Concentration difference; The multi-way automatic switching valve group is configured to selectively switch between multiple return air paths, with each return air path corresponding to one of the blade chambers; The main control and data processing unit is configured to control system operation, execute switching logic, collect data, and calculate photosynthetic physiological parameters. The leaf chamber is a distributed environmental control unit, and each leaf chamber independently includes: The leaf chamber and leaf clamping mechanism are used to accommodate and fix plant leaves; The distributed environmental control module includes at least an LED light source module with adjustable light intensity and a temperature control module with controllable temperature. The local sensing module includes at least sensors for monitoring the ambient temperature and humidity inside the leaf chamber; An independent power supply module is used to supply power to the various electrical components in the blade chamber; The main unit supplies the mixed gas to each blade chamber through the gas supply pipeline, and each blade chamber returns the gas exchanged by the blades to the main unit through its own return pipeline, forming an open passage structure.

[0008] Furthermore, the return pipeline between each leaf chamber and the multi-way automatic switching valve group has a substantially consistent physical length; and / or, the system further includes a negative pressure generating unit disposed in the return pipeline system to provide a stable driving pressure for gas return.

[0009] Furthermore, the multi-way automatic switching valve group is further connected to a bypass cleaning gas path. The bypass cleaning gas path is configured to, after switching to the target leaf chamber and before formal measurement, introduce the mixed gas supplied by the gas source and the mixing unit, or the clean gas obtained by diverting the mixed gas, into the flow path of the gas analysis unit for flushing.

[0010] Furthermore, the local sensing module of the blade chamber also includes a blade temperature measurement unit, which is configured to measure the temperature of the blade surface. This unit includes a contact temperature measuring component that uses a thermocouple or thermistor that directly contacts the lower surface of the blade, or a non-contact infrared temperature measuring component. In addition, the system also includes a wireless communication module, configured to realize bidirectional data communication and command transmission between the host, the blade chamber and a remote control terminal or cloud platform.

[0011] Secondly, the present invention provides a method for measuring photosynthesis in a multi-leaf chamber with an open pathway based on the above-mentioned system, characterized by comprising the following steps: (a) Gas supply and environmental setup procedures: The gas supply and mixing unit of the main unit generates and stably outputs a mixed gas of a set concentration, which is then synchronously delivered to all blade chambers through the gas supply pipeline. Meanwhile, each leaf chamber independently adjusts and maintains its internal light intensity and temperature through its distributed environmental control module according to the preset experimental plan; (b) Blade selection and gas path preparation steps: The main control and data processing unit controls the multi-channel automatic switching valve group to select and connect the i-th leaf chamber to be tested (i=1,2,…,N, where N is the total number of leaf chambers) according to the preset polling order. After the gas path switching is completed, a gas path flushing operation is performed. Clean gas from the gas supply and mixing unit is used to flush the common flow path from the valve group outlet to the gas analysis unit inlet for a duration of , in order to eliminate the residue from the previous measurement. (c) Differential measurement and parameter calculation steps: During the rinsing duration After completion, enter the effective measurement time window. ; exist Inside, the gas analysis unit synchronously or alternately measures the reference gas from the main unit and the return sample gas from the i-th leaf chamber, obtaining real-time data. Concentration difference ; Simultaneously, real-time environmental parameters monitored by the local sensing module of the i-th leaf chamber are collected, including at least the light intensity ( ), air temperature ( ) and relative humidity ( ); based on Given the known air supply flow rate (F) and the environmental parameters, the net photosynthetic rate of the leaf in the i-th leaf chamber is calculated in real time. ); (d) Data archiving and polling iteration steps: The i-th leaf chamber is in The average values ​​of physiological parameters and related environmental parameters calculated within the time window are stored together with the timestamp and leaf chamber identifier; After the measurement of the i-th leaf chamber is completed, the main control and data processing unit controls the multi-channel automatic switching valve group to switch to the next leaf chamber to be measured (i+1), and repeats steps (b) to (d) until a complete polling measurement of all N leaf chambers is completed, and then automatically starts the next cycle.

[0012] Furthermore, prior to performing the polling measurement, a system calibration and standardization step is included, which at least includes: Zero-point calibration: With the blade chamber unloaded and the system gas circulation stable, adjust the gas analysis unit to align the reference channel with the sample channel. The concentration reading difference is zero; Concentration span calibration: At least two known concentrations of different gas are generated through the gas supply and mixing unit. A standard gas is introduced into the gas analysis unit to establish and verify the linear relationship between the measured value and the true value; Leaf chamber environmental parameter calibration: Using external standard measuring instruments, the light intensity of the light sensor in each leaf chamber is calibrated, the temperature sensor is calibrated, and a mapping relationship table between the driving signal of the LED light source in each leaf chamber and the actual light intensity is established.

[0013] Furthermore, in the differential measurement and parameter calculation step, the gas analysis unit simultaneously measures the water vapor concentration difference between the reference gas and the sample gas. and combined Calculate the transpiration rate of the blade based on the air supply flow rate F and the water vapor pressure difference between the inside and outside of the blade chamber. ) and porosity ( ).

[0014] Furthermore, it also includes remote monitoring and management steps: The wireless communication module continuously uploads the environmental data and status information of each leaf chamber monitored in real time, as well as the physiological parameter data calculated by the host, to the cloud server or remote terminal. Control commands are sent to the host and / or designated leaf chamber via the cloud server or remote terminal to control the measurement program and target. Remote configuration, modification, or batch management of concentration, light intensity, and temperature settings for each leaf chamber.

[0015] Furthermore, the data storage in the data archiving and polling iteration steps adopts a dual-channel synchronous or asynchronous backup mode of local storage and cloud storage; wherein, local storage is used to cope with network interruptions, and cloud storage is used to support multi-terminal data sharing and long-term traceability.

[0016] Furthermore, the rinsing duration and effective measurement time window The length of the return pipeline is dynamically calculated or selected from a preset program by the main control and data processing unit based on one or more factors, including the physical length of the return pipeline, the system gas flow rate, and the required measurement accuracy.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: First, it achieves a balance between high precision and high throughput in the open-path method, resolving a long-standing technical contradiction. Traditional open-path photosynthesis measurement instruments, while highly accurate, suffer from extremely low throughput due to their single-channel serial measurement mode, failing to meet the high-throughput demands of modern phenomics. Existing high-throughput solutions (such as multi-chamber closed-path methods) often sacrifice measurement accuracy and response speed. This invention fundamentally resolves this contradiction through an innovative architecture of "centralized main unit gas control and analysis + distributed chamber environmental control + multi-channel automatic polling switching." The core high-precision gas analysis unit (such as...) The infrared analyzer is centralized in the main unit, ensuring the baseline accuracy of the measurements. Through a sophisticated multi-channel valve group and optimized timing control strategy, a single analyzer can perform stable and reliable polling measurements on multiple leaf chambers (such as 6, 8 or more). This allows the system to increase the measurement throughput by several to tens of times while maintaining the inherent advantages of high precision and fast response of the open-path method, providing a feasible technical tool for large-scale, multi-repetition physiological phenotypic studies.

[0018] Second, it significantly reduces the cost of single-point measurement and improves the system's economy and scalability. Traditional high-precision photosynthesis systems highly integrate all functions (gas path, analysis, and environmental control), resulting in high overall costs and requiring a complete set of expensive equipment for each measurement point. This invention centralizes the most expensive core analytical components in a reusable main unit, while delegating the relatively independent and mass-producible environmental control functions to distributed leaf chambers. Users can flexibly configure the number of leaf chambers according to the scale of the experiment (e.g., expanding from 2 to dozens), with the main unit serving as a shared resource, significantly reducing the average measurement cost per leaf or treatment. This "one-to-many" expansion model gives this system significant cost advantages and application potential in research institutions with limited funding or breeding projects requiring large-scale deployment.

[0019] Third, it enhances the adaptability and reliability of in-situ field measurements. In response to the complex environment of the field, this invention incorporates several specialized designs: (1) Each leaf chamber is powered independently (by a battery combined with a solar panel), eliminating reliance on a fixed power source and supporting long-term unattended measurement; (2) The leaf chambers are fixed by tripods or robotic arms, enabling in-situ, non-destructive clamping of the plants, minimizing interference with the physiological state of the leaves, and ensuring that the measurement data better reflects the true growth status; (3) The system has protection mechanisms such as temperature and humidity over-limit alarms, enhancing operational reliability under extreme weather conditions; (4) 5G and other wireless communication technologies are used to support remote monitoring and parameter setting, reducing the hardship of researchers traveling back and forth to the field. These designs enable the system to be stably and reliably applied to real farmland, greenhouses, or field ecological stations, obtaining continuous, in-situ first-hand data.

[0020] Fourth, it improves the automation, intelligence, and data management efficiency of the measurement process. This invention achieves fully automated and intelligent management of the entire process through a combination of hardware and software: (1) The measurement process is completely programmed, automatically polling each chamber according to a set cycle to complete the entire process of rinsing, measurement, calculation, and storage; (2) It supports remote batch setting or modification of experimental parameters such as light and temperature of each chamber through a cloud platform, which greatly improves the efficiency of experimental setup and adjustment; (3) Measurement data is synchronously stored locally (SD card) and backed up in the cloud, which not only ensures that data is not lost when the network is poor, but also facilitates remote sharing, real-time viewing and analysis by project team members; (4) The system has a complete built-in calibration process (zero point, span, environmental parameter calibration), which simplifies operation and ensures the long-term comparability of data. These features enable researchers to efficiently design and manage complex multi-process, long-cycle experiments and focus more on data analysis and scientific discovery.

[0021] Fifth, the stability of engineering design and measurement was optimized, ensuring the comparability of multi-channel data. To achieve stable comparability of data from multiple distributed leaf chambers, this invention proposes a series of key engineering constraints and control strategies: (1) an "equal-length return pipeline" design to ensure that the gas returning to the main unit from each leaf chamber experiences the same transmission delay; (2) a "negative pressure return" mechanism to provide stable power for gas return flow and reduce switching disturbances and pressure fluctuations; and (3) a valve control strategy of "flushing stable time window + effective measurement time window" to effectively suppress gas crosstalk and residual errors during multi-channel switching. These designs ensure that even when multiple leaf chambers are operating in parallel, the measurement conditions of each channel remain highly consistent, and the measurement of core parameters such as ΔCO2 is stable and reliable, enabling direct comparability of multi-leaf chamber data and laying a solid foundation for statistical analysis. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an application scenario of the system of the present invention; Figure 2 This is a schematic diagram of the internal core modules of the host computer of the present invention; Figure 3 This is a schematic diagram of a complete polling measurement process according to the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0024] Example 1 This embodiment provides a scalable distributed multi-leaf chamber open-path photosynthesis measurement system, including: One host, and at least two leaf chambers; The host includes: The gas supply and mixing unit is configured to provide a reference gas source and pure gas. The gas source is used to mix the two in a preset ratio to create a product with a target... A mixture of gases of varying concentrations; The gas analysis unit is configured for high-precision measurement of the gas flow between the reference gas and the sample gas. Concentration difference; The multi-way automatic switching valve group is configured to selectively switch between multiple return air paths, with each return air path corresponding to one of the blade chambers; The main control and data processing unit is configured to control system operation, execute switching logic, collect data, and calculate photosynthetic physiological parameters. The leaf chamber is a distributed environmental control unit, and each leaf chamber independently includes: The leaf chamber and leaf clamping mechanism are used to accommodate and fix plant leaves; The distributed environmental control module includes at least an LED light source module with adjustable light intensity and a temperature control module with controllable temperature. The local sensing module includes at least sensors for monitoring the ambient temperature and humidity inside the leaf chamber; An independent power supply module is used to supply power to the various electrical components in the blade chamber; The main unit supplies the mixed gas to each blade chamber through the gas supply pipeline, and each blade chamber returns the gas exchanged by the blades to the main unit through its own return pipeline, forming an open passage structure.

[0025] The overall system architecture of this embodiment is referenced. Figure 1 .

[0026] Figure 1 This is a schematic diagram illustrating an application scenario of the system of the present invention. The system includes a main unit and six leaf chambers (numbered AF). The main unit is placed in the field experimental area and connected to each leaf chamber via a main air supply pipe and a main air return pipe. Each leaf chamber is fixed near the corresponding plant being tested using a tripod, holding its functional leaves. Data communication between the main unit and the leaf chambers also occurs via a wireless network (such as 5G / 4G). The leaf chambers can be powered by built-in batteries in conjunction with solar panels to achieve long-term in-situ measurements.

[0027] like Figure 2 The diagram shown is a schematic representation of the internal core modules of the main unit of this invention. The main unit includes a gas supply and mixing unit, a gas analysis unit, a multi-channel automatic switching valve group, and a main control and data processing unit.

[0028] Gas supply and mixing unit: including a unit equipped with... air (or low) A steel cylinder containing air and a cylinder containing pure The gas cylinders. The two gas streams, after passing through pressure reducing and regulating valves, are mixed proportionally by two high-precision mass flow controllers (MFCs). For example, the target concentration is set to 400 ppm. At that time, the main control unit controls the flow ratio of the two MFCs, and the mixed gas is output through the buffer chamber.

[0029] Gas analysis unit 120: Employs non-dispersive infrared (NDIR) The analyzer has two gas inlets: a reference gas inlet connected to the mixed gas from the buffer chamber (i.e., reference gas), and a sample gas inlet connected to the gas from a multi-channel automatic switching valve assembly (i.e., sample gas). The analyzer outputs real-time data. and Signal.

[0030] Multi-channel automatic switching valve assembly: Consists of a set of solenoid valves. The common terminal connects to the sample gas inlet of the analyzer, and each branch is connected to the outlet of the corresponding leaf chamber via a return line. The inlet of the bypass purging valve is also connected to the reference gas, and its outlet merges into the common terminal.

[0031] Main control and data processing unit: Based on a microprocessor, it executes control logic, data acquisition, and parameter calculation.

[0032] The specific structure of each leaf chamber includes: Leaf chamber and clamping mechanism: The chamber has a transparent window and a blade clamping groove made of flexible pads inside, which can firmly clamp the blade without damaging the leaf vein.

[0033] Distributed environmental control module: includes an LED light source board (integrated with red and blue LED chips in a ratio of approximately 3:1, with light intensity adjusted via PWM) and a thermoelectric cooler (TEC) and its heat sink, used to control light intensity and cavity temperature, respectively.

[0034] Local sensing module: includes sensors for measuring the temperature and humidity of the air inside the cavity, and a miniature thermocouple that extends into the cavity and can make good contact with the lower surface of the blade for measuring the blade temperature.

[0035] Independent power supply module: includes lithium battery pack and power management circuit, and can be connected to external solar panels.

[0036] The gas supply lines deliver the mixed gas generated by the main unit to the inlets of all blade chambers. The outlet of each blade chamber is connected to the valve assembly of the main unit via an independent return line. This forms a complete open-circuit system: the gas flows out of the main unit, passes through the blade chambers, and a portion returns to the main unit for analysis, forming a measurement loop.

[0037] Example 2 Furthermore, the return pipeline between each leaf chamber and the multi-way automatic switching valve group has a substantially consistent physical length; and / or, the system further includes a negative pressure generating unit disposed in the return pipeline system to provide a stable driving pressure for gas return.

[0038] To ensure that the gas returning from different chambers experiences the same transmission delay and pressure loss, thereby guaranteeing the consistency of measurement timing and the comparability of data, all return lines 302 are cut to the exact same length during system deployment, for example, 2.5 meters each. All lines are laid to the same length.

[0039] In addition, such as Figure 2As shown, a miniature diaphragm pump is installed upstream of the multi-channel automatic switching valve assembly on the return gas main pipe as a negative pressure generating unit. This pump operates continuously, creating a stable negative pressure (e.g., -5 kPa) in the return pipeline, which is evenly applied to the return gas paths of all blade chambers. This design has two advantages: first, it provides a stable driving force for the gas to flow back from the blade chamber to the main unit, reducing flow fluctuations caused by blade chamber position or pipeline bends; second, the stable negative pressure can mitigate the instantaneous disturbance to the internal gas pressure of the blade chamber during valve switching, avoiding impact on the porosity of the blades. This combination of "equal-length pipeline + active negative pressure" is one of the key engineering guarantees for achieving stable and repeatable multi-channel polling measurements in this system.

[0040] Example 3 Furthermore, the multi-way automatic switching valve group is further connected to a bypass cleaning gas path. The bypass cleaning gas path is configured to, after switching to the target leaf chamber and before formal measurement, introduce the mixed gas supplied by the gas source and the mixing unit, or the clean gas obtained by diverting the mixed gas, into the flow path of the gas analysis unit for flushing.

[0041] Specifically, when the system needs to switch from measuring the current leaf chamber (e.g., leaf chamber A) to the next leaf chamber (e.g., leaf chamber B): Switching time (t0): The main control unit controls the valve group to close the solenoid valve (V1) leading to blade chamber A, and at the same time open the solenoid valve (V2) leading to blade chamber B.

[0042] Rinsing Phase (t0 to t1): At the same moment (or slightly delayed) as V2 is opened, the main control unit simultaneously opens the bypass rinsing valve 132. At this time, the gas flowing through the sample gas path of analyzer 121 has two sources: mostly return gas from the newly selected leaf chamber B, but also mixed with pure reference gas from the bypass valve (i.e., a mixed gas with known composition from the buffer chamber). This mixed rinsing process lasts for a preset time. (For example, 20 seconds). The purpose is to quickly "flush" and replace the residual gas from the previous leaf chamber A in the common sample line (from the common end of the valve assembly to the analyzer inlet) and the dead volume inside the valve body using a large amount of clean reference gas. This effectively prevents crosstalk between the gases in the two leaf chambers and ensures the independence of each measurement.

[0043] Measurement Phase (starting at t1): At time t1, the main control unit closes the bypass purging valve. At this point, the gas flowing through the analyzer's sample gas path originates entirely from chamber B. The system enters the effective measurement time window. (For example, 180 seconds), begin stable data collection. Data such as...

[0044] This "switch first, then rinse, then measure" valve control strategy is the core software and process innovation to ensure the measurement accuracy of multiple open paths.

[0045] Example 4 Furthermore, the local sensing module of the blade chamber also includes a blade temperature measurement unit, which is configured to measure the temperature of the blade surface. This unit includes a contact temperature measuring component that uses a thermocouple or thermistor that directly contacts the lower surface of the blade, or a non-contact infrared temperature measuring component. In addition, the system also includes a wireless communication module, configured to realize bidirectional data communication and command transmission between the host, the blade chamber and a remote control terminal or cloud platform.

[0046] Specifically, the leaf temperature measurement unit uses a 0.1mm diameter T-shaped thermocouple wire. Its measuring end is gently pressed against a specific location (avoiding the midrib) on the lower surface (far-axial surface) of the held leaf using a miniature, highly elastic insulating clip. The thermocouple signal, after signal conditioning, is read by the microcontroller in the leaf chamber and transmitted to the host computer via a wireless communication module. Direct contact measurement more accurately reflects the temperature of the leaf itself, rather than the temperature of the chamber air, which is crucial for accurately calculating biochemical parameters dependent on leaf temperature (such as dark respiration). Alternatively, in another experimental embodiment, the leaf temperature measurement unit can be a small infrared temperature sensor mounted on the inner wall of the chamber and aligned with the leaf, achieving non-contact measurement.

[0047] Simultaneously, both the main unit and each leaf chamber are equipped with a 5G communication module. This allows the main unit to transmit polled measurements... , , The data is uploaded to the cloud server in real time. Users can remotely view the real-time data curves of all foliage chambers via a mobile app or computer web browser. More importantly, users can issue commands from the cloud, for example, to uniformly adjust the light intensity of all foliage chambers to 500. Alternatively, the target temperature for three of the leaf chambers can be changed from 25°C to 30°C. These instructions are sent from the cloud to the host computer, which then distributes them to the microcontrollers in each leaf chamber via a wireless network, thus achieving true distributed remote cluster control.

[0048] Example 5 A method for measuring photosynthesis in an open pathway of a multi-leaf chamber based on the above-described system includes the following steps: (a) Gas supply and environmental setup procedures: The gas supply and mixing unit of the main unit generates and stably outputs a mixed gas of a set concentration, which is then synchronously delivered to all blade chambers through the gas supply pipeline. Meanwhile, each leaf chamber independently adjusts and maintains its internal light intensity and temperature through its distributed environmental control module according to the preset experimental plan; (b) Blade selection and gas path preparation steps: The main control and data processing unit controls the multi-channel automatic switching valve group to select and connect the i-th leaf chamber to be tested (i=1,2,…,N, where N is the total number of leaf chambers) according to the preset polling order. After the gas path switching is completed, a gas path flushing operation is performed. Clean gas from the gas supply and mixing unit is used to flush the common flow path from the valve group outlet to the gas analysis unit inlet for a duration of , in order to eliminate the residue from the previous measurement. (c) Differential measurement and parameter calculation steps: During the rinsing duration After completion, enter the effective measurement time window. ; exist Inside, the gas analysis unit synchronously or alternately measures the reference gas from the main unit and the return sample gas from the i-th leaf chamber, obtaining real-time data. Concentration difference ; Simultaneously, real-time environmental parameters monitored by the local sensing module of the i-th leaf chamber are collected, including at least the light intensity ( ), air temperature ( ) and relative humidity ( ); based on Given the known air supply flow rate (F) and the environmental parameters, the net photosynthetic rate of the leaf in the i-th leaf chamber is calculated in real time. ); (d) Data archiving and polling iteration steps: The i-th leaf chamber is in The average values ​​of physiological parameters and related environmental parameters calculated within the time window are stored together with the timestamp and leaf chamber identifier; After the measurement of the i-th leaf chamber is completed, the main control and data processing unit controls the multi-channel automatic switching valve group to switch to the next leaf chamber to be measured (i+1), and repeats steps (b) to (d) until a complete polling measurement of all N leaf chambers is completed, and then automatically starts the next cycle.

[0049] Specifically, this embodiment describes a complete polling measurement process, and the flowchart is as follows: Figure 3 As shown.

[0050] (a) Gas supply and environmental setup procedures: The user sets up an experimental program through the cloud platform: host supply Air concentration was kept constant at 400 ppm; light intensities in the six leaf chambers were set to 0, 100, 300, 500, 800, and 1000 ppm, respectively. ; The temperature is set to 25℃. After the program starts, the main unit's gas supply unit begins to work, stably outputting 400ppm of mixed gas, which is delivered to all blade chambers through the gas supply pipeline. At the same time, the microcontroller of each blade chamber receives the instruction, independently adjusts the drive current of its LED light source board to the corresponding level, and starts the TEC203 to control the temperature, so that the environment inside each chamber quickly reaches the set value.

[0051] (b) Blade selection and gas path preparation steps: The main control unit begins polling in the order A->B->C->D->E->F. First, the control valve group connects the return air path of blade chamber A and executes the flushing process corresponding to claim 3 (continuous). =20 seconds).

[0052] (c) Differential measurement and parameter calculation steps: After rinsing, proceed =180 seconds of effective measurement window. During this period, the analyzer measures at a frequency of 10Hz. and The host synchronously receives real-time data reported by leaf chamber A via the wireless network. , , as well as Data. The host computer calculates and updates the data every second in real time based on the open pathway photosynthesis calculation formula. , and The value of .

[0053] (d) Data archiving and polling iteration steps: After 180 seconds, the host will record the data collected during that time. The average value (or steady-state value) of the parameters, along with the timestamp, the leaf chamber ID "A", and the corresponding environmental parameter settings, are packaged into a single data record. This record is stored on the host's local SD card and simultaneously uploaded to the cloud database via a 5G module. Subsequently, the host automatically triggers a switch, disconnecting leaf chamber A from valve group 130 and connecting to leaf chamber B, repeating steps (b) to (d). This cycle repeats, completing a full measurement cycle for all six leaf chambers. Each cycle takes (20s + 180s) * 6 = 1200 seconds (20 minutes). The system will automatically loop this process indefinitely, achieving unattended continuous monitoring.

[0054] Example 6 Furthermore, prior to performing the polling measurement, a system calibration and standardization step is included, which at least includes: Zero-point calibration: With the blade chamber unloaded and the system gas circulation stable, adjust the gas analysis unit to align the reference channel with the sample channel. The concentration reading difference is zero; Concentration span calibration: At least two known concentrations of different gas are generated through the gas supply and mixing unit. A standard gas is introduced into the gas analysis unit to establish and verify the linear relationship between the measured value and the true value; Leaf chamber environmental parameter calibration: Using external standard measuring instruments, the light intensity of the light sensor in each leaf chamber is calibrated, the temperature sensor is calibrated, and a mapping relationship table between the driving signal of the LED light source in each leaf chamber and the actual light intensity is established.

[0055] Perform calibration during the initial system installation or routine maintenance.

[0056] Zero-point calibration: Keep all blade chambers empty (no blades clamped), and the system operates normally. Observe the analyzer output. Value. Because there is no consumption of photosynthesis. Theoretically, reference gas and sample gas The concentration should be the same. It should be 0. If a stable, small offset exists (e.g., +0.2ppm), perform a "zero-point calibration" operation in the software calibration interface. The software will store the offset value in memory and automatically subtract it from all subsequent measurements.

[0057] Concentration span calibration: The host software controls the gas source unit to generate gas of known concentrations. Gas. For example, using pure gas. He Chun Standard gases of 0 ppm, 400 ppm, and 800 ppm are prepared using MFC and sequentially introduced into the analyzer (the reference gas inlet can also be temporarily connected to the standard gas at this time). The analyzer readings are recorded, and the software will establish a calibration curve (usually a linear fit) between the readings and the actual concentrations, and save the calibration coefficients.

[0058] Environmental parameter calibration: Using a calibrated handheld quantum meter, insert its sensor into the center of a leaf chamber. In the software, progressively adjust the PWM value of the LED light source in the leaf chamber (e.g., from 10% to 100%), recording the actual PAR value measured by the handheld quantum meter at each PWM value. The software will create a lookup table of "PWM% - Actual PAR" and apply it to the leaf chamber. Similarly, use a standard platinum resistance thermometer to calibrate the air temperature sensor and leaf temperature thermocouple in the leaf chamber at multiple points (e.g., setting 5℃, 25℃, and 40℃ in a water bath) to correct for measurement errors.

[0059] Example 7 Furthermore, in the differential measurement and parameter calculation step, the gas analysis unit simultaneously measures the water vapor concentration difference between the reference gas and the sample gas. and combined Calculate the transpiration rate of the blade based on the air supply flow rate F and the water vapor pressure difference between the inside and outside of the blade chamber. ) and porosity ( ).

[0060] In step (c) of the corresponding embodiment 5 above, the analyzer simultaneously outputs... and In calculating the transpiration rate When, the formula is: ,in The gas supply flow rate is (mol / s). The area is the blade area (m²). Atmospheric pressure (Pa). Pore conductance. Then, based on models such as Ball-Berry, combined with the calculated... , and inside and outside the leaf chamber The concentration and water vapor pressure difference are further calculated. Therefore, this system can provide a complete set of gas exchange parameters.

[0061] Example 8 Furthermore, it also includes remote monitoring and management steps: The wireless communication module continuously uploads the environmental data and status information of each leaf chamber monitored in real time, as well as the physiological parameter data calculated by the host, to the cloud server or remote terminal. Control commands are sent to the host and / or designated leaf chamber via the cloud server or remote terminal to control the measurement program and target. Remote configuration, modification, or batch management of concentration, light intensity, and temperature settings for each leaf chamber.

[0062] Combining the communication function of Embodiment 4, all data is uploaded to the cloud in real time throughout the entire measurement process of Embodiment 5. Users can log in to the cloud platform from anywhere in the world to view the real-time C curves of the six leaf chambers updating on the same coordinate graph. The user noticed that the Pn value curve of leaf chamber C was abnormally stable and suspected that the light intensity might be set too low. Without going to the field, the user directly selected leaf chamber C on the cloud platform interface and changed its light intensity setting from 300 to 600. The user clicks "Send". The command is transmitted to host 100 via the cloud. Before the next polling cycle begins, host 100 sends the new command to the controller of leaf chamber C via wireless network. When the valve group switches to leaf chamber C again, leaf chamber C is already operating stably under the new light intensity, and the measured value is the photosynthetic rate under the new conditions. This achieves a truly remote interactive experiment.

[0063] Example 9 Furthermore, the data storage in the data archiving and polling iteration steps adopts a dual-channel synchronous or asynchronous backup mode of local storage and cloud storage; wherein, local storage is used to cope with network interruptions, and cloud storage is used to support multi-terminal data sharing and long-term traceability.

[0064] In step (d) of corresponding embodiment 5, data is written to two targets. First, the host's built-in SD card, a highly reliable local storage system, ensures data is not lost even during temporary network signal interruptions in the field. Once the network is restored, the backlogged data can be automatically uploaded to the cloud. Second, it is directly uploaded to a cloud database (such as Alibaba Cloud RDS) via the 5G network. Cloud storage facilitates simultaneous access by multiple project team members for online preliminary analysis and data visualization, and also serves as an off-site backup to prevent complete data loss due to accidental damage to local devices. This dual-mode "local + cloud" storage strategy balances reliability and convenience.

[0065] Example 10 Furthermore, the rinsing duration and effective measurement time window The length of the return pipeline is dynamically calculated or selected from a preset program by the main control and data processing unit based on one or more factors, including the physical length of the return pipeline, the system gas flow rate, and the required measurement accuracy.

[0066] Rinse time and measurement time It's not a fixed value, but a configurable parameter. The system software provides an "Advanced Settings" interface. Users can configure it according to their needs. Based on pipeline length: If the return pipeline is long (e.g., 5 meters), the software will suggest or automatically use the longer one. (e.g., 30 seconds) to ensure thorough flushing. Conversely, a shorter flushing time can be used for shorter pipelines. (e.g., 15 seconds).

[0067] Based on flow rate and accuracy: If the experiment requires extremely high accuracy, the user can choose a longer flow rate. (e.g., 300 seconds) to obtain a more stable average data, but at the cost of polling speed. If the experiment focuses on dynamic response, a shorter polling time can be chosen. (e.g., 120 seconds) to improve time resolution.

[0068] Preset programs: The software also provides several preset programs, such as "Standard Precision Mode" ( =20s, =180s), "High-throughput mode" ( =15s, =120s) and "Ultra-high precision mode" =30s, =300s), which users can select with a single click. The main control unit executes the corresponding time control in a polling loop based on the user's selection or the result of automatic calculation.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A scalable distributed multi-leaf chamber open-path photosynthesis measurement system, characterized in that, include: A host, and At least two leaf chambers; The host includes: The gas supply and mixing unit is configured to provide a reference gas source and pure gas. The gas source is used to mix the two in a preset ratio to create a product with a target... A mixture of gases of varying concentrations; The gas analysis unit is configured for high-precision measurement of the gas flow between the reference gas and the sample gas. Concentration difference; The multi-way automatic switching valve group is configured to selectively switch between multiple return air paths, with each return air path corresponding to one of the blade chambers; The main control and data processing unit is configured to control system operation, execute switching logic, collect data, and calculate photosynthetic physiological parameters. The leaf chamber is a distributed environmental control unit, and each leaf chamber independently includes: The leaf chamber and leaf clamping mechanism are used to accommodate and fix plant leaves; The distributed environmental control module includes at least an LED light source module with adjustable light intensity and a temperature control module with controllable temperature. The local sensing module includes at least sensors for monitoring the ambient temperature and humidity inside the leaf chamber; An independent power supply module is used to supply power to the various electrical components in the blade chamber; The main unit supplies the mixed gas to each blade chamber through the gas supply pipeline, and each blade chamber returns the gas exchanged by the blades to the main unit through its own return pipeline, forming an open passage structure.

2. The system according to claim 1, characterized in that, The return pipeline between each leaf chamber and the multi-way automatic switching valve group has a substantially consistent physical length; and / or, the system further includes a negative pressure generating unit disposed in the return pipeline system to provide a stable driving pressure for gas return.

3. The system according to claim 1 or 2, characterized in that, The multi-way automatic switching valve group is further connected to a bypass cleaning gas path. The bypass cleaning gas path is configured to introduce the mixed gas supplied by the gas source and the mixing unit, or the clean gas obtained by diverting the mixed gas, into the flow path of the gas analysis unit for rinsing after switching to the target leaf chamber and before formal measurement.

4. The system according to claim 1, characterized in that, The local sensing module of the blade chamber also includes a blade temperature measurement unit, which is configured to measure the temperature of the blade surface. The blade temperature measurement unit includes a contact temperature measuring component that uses a thermocouple or thermistor that is in direct contact with the lower surface of the blade, or a non-contact infrared temperature measuring component. Furthermore, the system also includes a wireless communication module, configured to realize bidirectional data communication and command transmission between the host, the blade chamber and a remote control terminal or cloud platform.

5. A method for measuring photosynthesis in a multi-leaf chamber with an open pathway based on the system described in any one of claims 1 to 4, characterized in that, Includes the following steps: (a) Gas supply and environmental setup procedures: The gas supply and mixing unit of the main unit generates and stably outputs a mixed gas of a set concentration, which is then synchronously delivered to all blade chambers through the gas supply pipeline. Meanwhile, each leaf chamber independently adjusts and maintains its internal light intensity and temperature through its distributed environmental control module according to the preset experimental plan; (b) Blade selection and gas path preparation steps: The main control and data processing unit controls the multi-channel automatic switching valve group to select and connect the i-th leaf chamber to be tested (i=1,2,…,N, where N is the total number of leaf chambers) according to the preset polling order. After the gas path switching is completed, a gas path flushing operation is performed. Clean gas from the gas supply and mixing unit is used to flush the common flow path from the valve group outlet to the gas analysis unit inlet for a duration of , in order to eliminate the residue from the previous measurement. (c) Differential measurement and parameter calculation steps: During the rinsing duration After completion, enter the effective measurement time window. ; exist Inside, the gas analysis unit synchronously or alternately measures the reference gas from the main unit and the return sample gas from the i-th leaf chamber, obtaining real-time data. Concentration difference ; Simultaneously, real-time environmental parameters monitored by the local sensing module of the i-th leaf chamber are collected, including at least the light intensity ( ), air temperature ( ) and relative humidity ( ); based on Given the known air supply flow rate (F) and the environmental parameters, the net photosynthetic rate of the leaf in the i-th leaf chamber is calculated in real time. ); (d) Data archiving and polling iteration steps: The i-th leaf chamber is in The average values ​​of physiological parameters and related environmental parameters calculated within the time window are stored together with the timestamp and leaf chamber identifier; After the measurement of the i-th leaf chamber is completed, the main control and data processing unit controls the multi-channel automatic switching valve group to switch to the next leaf chamber to be measured (i+1), and repeats steps (b) to (d) until a complete polling measurement of all N leaf chambers is completed, and then automatically starts the next cycle.

6. The method according to claim 5, characterized in that, Prior to performing the polling measurement, a system calibration and standardization step is included, which includes at least the following: Zero-point calibration: With the blade chamber unloaded and the system gas circulation stable, adjust the gas analysis unit to align the reference channel with the sample channel. The concentration reading difference is zero; Concentration span calibration: At least two known concentrations of different gas are generated through the gas supply and mixing unit. A standard gas is introduced into the gas analysis unit to establish and verify the linear relationship between the measured value and the true value; Leaf chamber environmental parameter calibration: Using external standard measuring instruments, the light intensity of the light sensor in each leaf chamber is calibrated, the temperature sensor is calibrated, and a mapping relationship table between the driving signal of the LED light source in each leaf chamber and the actual light intensity is established.

7. The method according to claim 5, characterized in that, In the differential measurement and parameter calculation step, the gas analysis unit simultaneously measures the water vapor concentration difference between the reference gas and the sample gas. and combined Calculate the transpiration rate of the blade based on the air supply flow rate F and the water vapor pressure difference between the inside and outside of the blade chamber. ) and porosity ( ).

8. The method according to claim 5, characterized in that, It also includes remote monitoring and management steps: The wireless communication module continuously uploads the environmental data and status information of each leaf chamber monitored in real time, as well as the physiological parameter data calculated by the host, to the cloud server or remote terminal. Control commands are sent to the host and / or designated leaf chamber via the cloud server or remote terminal to control the measurement program and target. Remote configuration, modification, or batch management of concentration, light intensity, and temperature settings for each leaf chamber.

9. The method according to claim 5, characterized in that, The data storage in the data archiving and polling iteration steps adopts a dual-channel synchronous or asynchronous backup mode of local storage and cloud storage; local storage is used to cope with network interruptions, and cloud storage is used to support multi-terminal data sharing and long-term traceability.

10. The method according to claim 5, characterized in that, The flushing duration and effective measurement time window The length of the return pipeline is dynamically calculated or selected from a preset program by the main control and data processing unit based on one or more factors, including the physical length of the return pipeline, the system gas flow rate, and the required measurement accuracy.

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