Soil respiration parameter detection method and system based on multi-breathing-chamber closed-loop gas circuit time-sharing cooperative control

Abstract

The invention relates to a soil respiration parameter detection method and system based on time-sharing cooperative control of closed-loop gas circuits of multiple breathing chambers. The method comprises the steps that an air pump is started, air valve control signals are sent to an air valve decoder, corresponding air valve pairs are driven to be opened synchronously, and selected breathing chamber units are connected into a loop; a box body closing signal is sent to the breathing chamber decoder, the selected breathing chamber unit is driven to be closed, meanwhile, the corresponding air valve pair is maintained to be opened, air of the selected breathing chamber unit circulates in the air path detection loop, and soil breathing parameters are collected and analyzed in real time through the detection and analysis assembly; when the preset measurement duration is reached, loop gas washing is executed; and the air valve pairs are sequentially updated and activated, so that the breathing chamber units repeatedly execute the operation sequence until all the breathing chamber units are detected, and then the air pump is closed. According to the invention, high-precision, high-efficiency and low-interference automatic dynamic monitoring of soil respiration parameters is realized, and technical support is provided for applications such as agro-ecological management and carbon cycle model construction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil detection, and in particular to a soil respiration parameter detection method and system based on multi-respiration chamber closed-loop air path time-sharing cooperative control. BACKGROUND

[0002] Soil respiration is one of the important circulation pathways in global carbon cycle, and is an important biological indicator of soil quality and fertility. It is a key parameter for evaluating carbon flux of terrestrial ecosystems. Its accurate measurement has important scientific value for global carbon cycle model construction and agricultural ecological management.

[0003] In the prior art, the detection of soil respiration parameters mainly relies on detection devices based on closed static chamber method. In the closed static chamber method, the respiration chamber unit is completely closed to accumulate CO2, and the respiration rate is calculated by periodically sampling and analyzing the gas concentration change rate. However, due to the diffusion inhibition effect caused by the increase of gas concentration gradient in a closed state, and the interference of soil microbial activity caused by long-term closure, the superposition of these two effects makes the final calculated respiration rate prone to nonlinear measurement deviation, especially in long-term observation, the error accumulation phenomenon is more significant.

[0004] In addition, the closed static chamber method can only detect a fixed point, and if multi-point measurement is required, manual repeated operation is required to switch the detection position, which not only greatly reduces the detection efficiency, but also introduces external environmental disturbance due to frequent opening and closing of the air chamber. More importantly, the intervention of the operator will directly lead to inconsistent sampling intervals, fluctuations in the degree of closure, and other problems, making the repeatability of the measurement results subject to human factors, and it is difficult to meet the strict requirements of large-scale ecological monitoring on data consistency. SUMMARY

[0005] (I) Technical problems to be solved In view of the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a soil respiration parameter detection method and system based on multi-respiration chamber closed-loop air path time-sharing cooperative control, which solves the problem of nonlinear measurement deviation of respiration rate caused by diffusion inhibition effect and microbial activity interference of closed static chamber method, and the problem of low detection efficiency and difficult to meet the large-scale ecological monitoring demand of data consistency caused by single-point detection and manual operation dependence.

[0006] (II) Technical solutions In order to achieve the above-mentioned purposes, the main technical solutions adopted by the present application include: In a first aspect, the embodiments of the present application provide a soil respiration parameter detection method based on multi-chamber closed-loop air path time-sharing cooperative control. The method is suitable for an air path detection loop comprising an air pump, multiple independent chamber units, and a detection and analysis component. Each chamber unit is configured with an interlocking air valve group, and a cooperative control mechanism between air valve on-off and chamber unit opening and closing actions is established through a decoder. The detection and analysis component executes the following method: The air pump is enabled, an air valve control signal is sent to the air valve decoder, a corresponding air valve pair is synchronously opened, and a selected chamber unit is connected to the loop. A box closing signal is sent to the chamber decoder, the selected chamber unit is closed, the corresponding air valve pair is kept open, the gas in the selected chamber unit is circulated in the loop, and the soil respiration parameters are collected and analyzed in real time by the detection and analysis component. When the preset measurement duration is reached, the selected chamber unit is unclosed, the corresponding air valve pair is kept open to perform loop gas washing, and the corresponding air valve pair is then turned off after a delay. An incremental encoding signal is sent to the air valve decoder, each air valve pair is activated in turn through sequential updating of binary bit combinations, each chamber unit repeatedly executes the operation sequence including parameter detection under closure and loop gas washing in a predetermined order, and the air pump is turned off after all chamber units are detected.

[0007] Optionally, the air pump is enabled, an air valve control signal is sent to the air valve decoder, a corresponding air valve pair is synchronously opened, and a selected chamber unit is connected to the loop, including: The air pump is enabled in response to a power-on signal, and the control port of the air valve decoder is initialized to a default level state. A three-bit logic encoding group is sent to the control port of the air valve decoder, so that the air valve decoder maps the input three-bit logic encoding group to the gate signal of the selected air valve according to a preset first encoding rule. Based on the gate signal, the selected air valve pair corresponding to the relay is driven to perform an exclusive switching operation, the first A / B air valve pair associated with the first chamber is synchronously turned on, and the de-energization signal is synchronously sent to the relays corresponding to the remaining unselected air valve pairs to perform air path mutual exclusion locking operation, and the remaining unselected air valves are forcibly closed. Under the drive of the air pump and the conduction of the first A / B air valve pair, a loop containing the first chamber is formed in the air path detection loop, and the corresponding chamber unit and the detection and analysis component are connected in air.

[0008] Optionally, the first encoding rule includes: The three-bit logic encoding group and each A / B air valve pair are configured with a one-to-one discrete mapping relationship, and each encoding group is assigned a unique air valve gating identifier. Each coding group is encoded and mapped according to the binary bit weighting rule. The linear selection of the physical channel of the breathing chamber unit is achieved by the combination and increment of the coding bit level states. Only one coding group is allowed to be active at any given time, while the remaining coding groups are automatically deactivated to maintain the independence of the gating channel.

[0009] Optionally, a housing closure signal is sent to the breathing chamber decoder to drive the selected breathing chamber unit to close, while simultaneously maintaining the corresponding air valve pair open, allowing the gas in the selected breathing chamber unit to circulate in the loop. Soil respiration parameters are then collected and analyzed in real time by the detection and analysis components, including: Initialize the control port of the respiratory chamber decoder to the default level. In response to the enclosure closure signal, a four-bit logic code group is input to the control port of the breathing chamber decoder, so that the breathing chamber decoder maps the input four-bit logic code group into the airtight control signal of the selected breathing chamber according to the preset second encoding rule; Based on the sealing control signal of the selected breathing chamber, the corresponding relay is driven to operate, so that the first breathing chamber performs mechanical sealing operation. At the same time, the power failure signal is sent synchronously to the relays corresponding to the other unselected breathing chambers to perform airway mutual exclusion locking operation, forcibly keeping the other breathing chamber units in the open state. While maintaining the first A / B solenoid valve pair in the OFF state, a directional gas circulation channel is formed that flows through the sealed breathing chamber unit; After the gas in the directional gas circulation channel is purified, circulating gas samples are continuously collected by the detection and analysis components. Based on the time-varying characteristics of the obtained CO2 concentration, the spatiotemporal relationship between the gas path volume and the surface area of ​​the covered soil, and after temperature and pressure correction, the soil respiration rate is obtained.

[0010] Optionally, the second encoding rule includes: The four-bit logic code group consists of a mode enable bit and three address bits; When the mode enable bit is low, all the relays in the breathing chambers are de-energized synchronously, forcing all breathing chamber units to remain in the open state. When the mode enable bit is high, the breathing chamber unit is selected according to the level combination of the three address bits, and the corresponding relay is triggered to close the target breathing chamber unit. Among them, the mapping relationship between the level combination of the three address bits and the breathing chamber number satisfies the binary bit weight arrangement rule, with the low bit to the high bit corresponding to the increasing breathing chamber unit address code; The mode enable bit and the three address bits work together to enable independent gating control of the breathing chamber unit, ensuring that only a single breathing chamber is in a closed measurement state at any given time.

[0011] Optionally, when the preset measurement time is reached, the selected breathing chamber unit is de-sealed while the corresponding valve pair remains open to perform loop purging, and then the corresponding valve pair is shut off after a delay, including: When the measurement time of the selected breathing chamber unit reaches the preset measurement threshold, a release command is sent to the breathing chamber decoder to drive the corresponding relay to release the sealed state of the selected breathing chamber. Maintain the first A / B gas valve pair in the open state, and use the air pump to drive the airflow to continuously circulate and flush the residual gas in the gas detection circuit; When the cumulative delay reaches the preset gas washing time threshold, the corresponding relay is driven to shut off the first A / B gas valve pair, blocking the gas circulation channel and completing the current breathing chamber unit measurement cycle. Reset the measurement and gas washing timer, release the logic code group of the breathing chamber decoder, and return to the standby initialization state.

[0012] Optionally, it also includes: In response to the power-on signal, an enable command is sent to the temperature control interface of the intelligent data acquisition and control unit in the detection and analysis component to control the heating component of the infrared analyzer attached to the detection and analysis component to start. The real-time temperature data stream is continuously acquired by a temperature sensor attached to the surface of the infrared analyzer housing. When the temperature fluctuation exceeds the set threshold, the heating power output of the heating component is dynamically adjusted based on the deviation value. During the process of the valve decoder executing incremental coding to switch the operation sequence of each breathing chamber unit, the heating component is kept continuously powered so that the analyzer is in a constant temperature working environment during the closed detection and pipeline gas washing stages. When the air pump shut-off signal is received, indicating that all breathing chamber detections are complete, a delay protection timer is started. After the preset thermal inertia buffer time is reached, the power supply to the heating component is cut off, and the logic enable flag of the temperature control interface of the intelligent data acquisition and control unit is reset.

[0013] Secondly, embodiments of the present invention provide a soil respiration parameter detection system with multi-chamber closed-loop gas path time-sharing coordinated control, comprising: The air circulation assembly includes an air pump and multiple breathing chamber units connected in parallel. Each breathing chamber unit is equipped with an interlocked air valve group. Each air valve group includes a pair of synchronously opening and closing air valves that are respectively set at the input and output ends of the breathing chamber unit, used to connect or isolate the corresponding breathing chamber unit from the air detection circuit. The detection and analysis component includes a gas filter, an infrared analyzer, and an intelligent data acquisition and control unit. The input end of the gas filter is connected to the gas valve of the output pipeline of the breathing chamber unit. The input end of the infrared analyzer is connected to the output end of the gas filter. The output end of the infrared analyzer is connected to the gas pump inlet and the intelligent data acquisition and control unit respectively, forming a closed-loop detection circuit. The intelligent data acquisition and control unit is used to execute the method described above.

[0014] Optionally, it also includes: a dynamic temperature control module, which includes a heating component and a temperature sensor attached to the housing of the infrared analyzer. The temperature sensor collects the operating temperature of the analyzer in real time and feeds it back to the intelligent data acquisition and control unit. The intelligent data acquisition and control unit dynamically adjusts the heating power of the heating component based on the temperature deviation to maintain the constant operating temperature of the infrared analyzer.

[0015] (III) Beneficial Effects The beneficial effects of this invention are: First, the present invention adopts a detection mechanism that combines a closed-loop gas path structure with a dynamic gas chamber. The gas is continuously circulated between the selected breathing chamber unit and the analysis component by a gas pump, which effectively maintains the dynamic balance of gas exchange between the inside and outside of the breathing chamber, thereby suppressing the abnormal accumulation of gas concentration gradient in the closed state and significantly reducing the interference of diffusion inhibition effect on measurement accuracy.

[0016] Secondly, the time-sharing collaborative control mechanism of the present invention synchronously triggers the opening and closing of the air valve and the sealing action of the breathing chamber through the decoder, so that each breathing chamber unit is connected to the air path detection circuit in sequence according to the preset time sequence. This can realize multi-point automated round-robin detection, and avoid abnormal fluctuations in microbial activity caused by long-term sealing by precisely controlling the sealing time of a single breathing chamber, thereby reducing the risk of cumulative nonlinear measurement deviation.

[0017] Furthermore, the design of immediately performing loop purging after parameter testing and delaying the valve closure can efficiently remove residual gas to prevent cross-contamination, and also ensure the independence of subsequent test data through gas path self-cleaning.

[0018] Ultimately, based on incremental control signals using binary encoding, the multi-breathing chamber units are driven to sequentially execute a "detection-washing" operation sequence. This not only enables continuous multi-point measurements without manual intervention, significantly improving detection efficiency and eliminating environmental disturbances and data fluctuations introduced by human operation, but also ensures the airtightness and thoroughness of gas washing during the detection process of each unit through an interlocking and coordinated mechanism between the valve group and the breathing chamber actions, further guaranteeing the consistency of measurement data from multiple batches. This invention ultimately achieves high-precision, high-efficiency, and low-interference automated dynamic monitoring of soil respiration parameters, providing reliable technical support for large-scale applications in fields such as agricultural ecological management and carbon cycle model construction. Attached Figure Description

[0019] Figure 1 A schematic diagram of the detection loop for a soil respiration parameter detection method with time-sharing coordinated control of a multi-breathing chamber closed-loop air path provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall process of the soil respiration parameter detection method with time-sharing coordinated control of multi-breathing chamber closed-loop air path provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the specific process of step S1 in the soil respiration parameter detection method of multi-breathing chamber closed-loop air path time-sharing coordinated control provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the valve control principle of the soil respiration parameter detection method with time-sharing coordinated control of multi-breathing chamber closed-loop air path provided in an embodiment of the present invention; Figure 5 A schematic diagram of step S2 of the soil respiration parameter detection method with time-sharing coordinated control of multi-breathing chamber closed-loop air path provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the control principle of the breathing chamber unit in the soil breathing parameter detection method with time-sharing coordinated control of multiple breathing chambers and closed-loop air paths provided in an embodiment of the present invention. Figure 7 This is a schematic diagram of the specific process of step S3 in the soil respiration parameter detection method with time-sharing coordinated control of multi-breathing chamber closed-loop air path provided in an embodiment of the present invention. Figure 8 A schematic diagram of the heating component for a soil respiration parameter detection method with time-sharing coordinated control of multi-breathing chamber closed-loop air path provided in an embodiment of the present invention; Figure 9 A schematic diagram of the pipeline connection for the soil respiration parameter detection method with time-sharing coordinated control of multi-breathing chamber closed-loop air path provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the overall structure of a soil respiration parameter detection system with time-sharing coordinated control of a multi-breathing chamber closed-loop air path provided in an embodiment of the present invention. Detailed Implementation

[0020] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 and Figure 2As shown, this invention proposes a method for detecting soil respiration parameters using a multi-breathing-chamber closed-loop airflow time-sharing coordinated control. This method is applicable to airflow detection loops comprising an air pump, multiple independent respiration-chamber units, and a detection and analysis component. Each respiration-chamber unit is equipped with an interlocked valve group, and a coordinated control mechanism for valve on / off and respiration-chamber unit opening / closing is established via a decoder. The detection and analysis component executes the following steps: activating the air pump, sending a valve control signal to the valve decoder to drive the corresponding valve pair to open synchronously, thus connecting the selected respiration-chamber unit to the loop; and sending a housing closure signal to the respiration-chamber decoder to drive the selected respiration-chamber unit... The system is sealed while maintaining the corresponding air valve pair open, allowing the gas in the selected breathing chamber unit to circulate in the loop. Soil breathing parameters are collected and analyzed in real time by the detection and analysis components. When the preset measurement time is reached, the sealed state of the selected breathing chamber unit is released while the corresponding air valve pair remains open to perform loop purging. After a delay, the corresponding air valve pair is shut off. An incremental encoding signal is sent to the air valve decoder, which sequentially activates each air valve pair through the successive updates of binary bit combinations. This causes each breathing chamber unit to repeatedly execute the operation sequence, including parameter detection and loop purging under sealed conditions, in a predetermined order until all breathing chamber units are detected and the air pump is shut off.

[0022] First, the present invention adopts a detection mechanism that combines a closed-loop gas path structure with a dynamic gas chamber. The gas is continuously circulated between the selected breathing chamber unit and the analysis component by a gas pump, which effectively maintains the dynamic balance of gas exchange between the inside and outside of the breathing chamber, thereby suppressing the abnormal accumulation of gas concentration gradient in the closed state and significantly reducing the interference of diffusion inhibition effect on measurement accuracy.

[0023] Secondly, the time-sharing collaborative control mechanism of the present invention synchronously triggers the opening and closing of the air valve and the sealing action of the breathing chamber through the decoder, so that each breathing chamber unit is connected to the air path detection circuit in sequence according to the preset time sequence. This can realize multi-point automated round-robin detection, and avoid abnormal fluctuations in microbial activity caused by long-term sealing by precisely controlling the sealing time of a single breathing chamber, thereby reducing the risk of cumulative nonlinear measurement deviation.

[0024] Furthermore, the design of immediately performing loop purging after parameter testing and delaying the valve closure can efficiently remove residual gas to prevent cross-contamination, and also ensure the independence of subsequent test data through gas path self-cleaning.

[0025] Ultimately, based on incremental control signals using binary encoding, the multi-breathing chamber units are driven to sequentially execute a "detection-washing" operation sequence. This not only enables continuous multi-point measurements without manual intervention, significantly improving detection efficiency and eliminating environmental disturbances and data fluctuations introduced by human operation, but also ensures the airtightness and thoroughness of gas washing during the detection process of each unit through an interlocking and coordinated mechanism between the valve group and the breathing chamber actions, further guaranteeing the consistency of measurement data from multiple batches. This invention ultimately achieves high-precision, high-efficiency, and low-interference automated dynamic monitoring of soil respiration parameters, providing reliable technical support for large-scale applications in fields such as agricultural ecological management and carbon cycle model construction.

[0026] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0027] Specifically, this invention provides a method for detecting soil respiration parameters using a multi-breathing-chamber closed-loop airflow time-sharing coordinated control system. First, multiple independent breathing-chamber units are arranged in a preset grid layout, covering representative points in the target soil area (e.g., randomly distributed or based on soil heterogeneity zoning), ensuring that the bottom of each unit is tightly fitted to the soil surface. Then, the following method is executed: S1. Activate the air pump and send an air valve control signal to the air valve decoder to drive the corresponding air valve pair to open synchronously, so that the selected breathing chamber unit is connected to the circuit.

[0028] Furthermore, such as Figure 3 As shown, step S1 includes: S11. In response to the power-on signal, the air pump is enabled, and the control port of the air valve decoder is initialized to the default level state.

[0029] S12. Send a three-bit logic code group to the control port of the valve decoder so that the valve decoder maps the input three-bit logic code group to the on signal of the selected valve according to the preset first encoding rule.

[0030] It is important to understand that the first coding rule includes: a discrete mapping relationship with each A / B valve pair configuration, with each three-bit logical coding group having a one-to-one correspondence; each coding group is assigned a unique valve selection identifier; each coding group is encoded and mapped according to the binary bit weighting rule, and the linear selection of the physical channel of the breathing chamber unit is achieved by combining and incrementing the coding bit level states; only one coding group is allowed to be effective at any given time, and the remaining coding groups are automatically deactivated to maintain the independence of the selected channel.

[0031] like Figure 4 As shown, the valve decoder (model 74LS138) is connected to the C1, C2, and C3 ports of the intelligent data acquisition and control unit via three control ports IO1, IO2, and IO3, receiving control signals generated by a three-bit logic code group (high / low level combination). Based on the binary bit weighting rules of the input code, the valve decoder maps the 3-bit input signal to 8 output states (OUT1 to OUT8). Each output state drives the corresponding A / B valve pair via an independent relay. Specifically, when the system is powered on and initialized, control ports C1, C2, and C3 are set to the default level (e.g., low level). At this time, the decoder output state corresponds to the opening of the A1 / B1 valve in the first breathing chamber, while the remaining valves are closed.

[0032] Next, based on the discrete mapping rule of the three-bit code group, each code group (e.g., C1=low, C2=low, C3=low) uniquely corresponds to the conduction of one valve pair, while the remaining valves are forcibly closed. For example, when C1 is high, C2 is low, and C3 is low, the decoder output state switches to open valve A2 / B2; similarly, if C3 rises to high, the combination of code groups is mapped sequentially to the selection of valve pairs A5 / B5 to A8 / B8. Specifically, the correspondence between the output state of the control port of the valve decoder and the valves is shown in Table 1. Table 1. Relationship between the output state of the valve decoder control port and the state of the valve.

[0033] Under this logic, the valve decoder achieves linear switching of the breathing chamber unit through the incrementing of code groups (e.g., 000→001→010…). It is important to note that only one code group is allowed to be active at any given time; the remaining code groups are automatically disabled to ensure the mutual exclusivity of valve selection. Furthermore, by adjusting the high or low level duration of ports C1, C2, and C3, the conduction duration of the target valve can be precisely controlled, thereby adapting to the airway switching timing requirements of different breathing chamber units.

[0034] S13. Based on the conduction signal, drive the relay corresponding to the selected air valve to perform an exclusive switching operation, so that the first A / B air valve pair associated with the first breathing chamber is synchronously turned on, and at the same time, the power failure signal is synchronously sent to the relays corresponding to the other unselected air valves to perform the air path mutual exclusion locking operation and forcibly close the other unselected air valves.

[0035] S14. With the air pump driving and the first A / B air valve pair conducting, a circuit including the first breathing chamber is formed in the air path detection circuit, realizing the air path connection between the corresponding breathing chamber unit and the detection and analysis component. At this time, the air paths of other breathing chambers are completely isolated because the relay de-energization control signal keeps them in the normally open state, and the detection stage for the first breathing chamber begins. This process strictly follows the unique mapping rule between the three-bit code group and the air valve state (as shown in Table 1), and the physical exclusivity and logical mutual exclusion of air path switching are guaranteed by the discreteness of the code group.

[0036] S2. Send a box closure signal to the breathing chamber decoder to drive the selected breathing chamber unit to close, while keeping the corresponding air valve pair open, so that the gas in the selected breathing chamber unit circulates in the loop, and the soil breathing parameters are collected and analyzed in real time through the detection and analysis component.

[0037] Furthermore, such as Figure 5 As shown, step S2 includes: S21. Initialize the control port of the respiratory chamber decoder to the default level.

[0038] S22. In response to the enclosure closure signal, a four-bit logic code group is input to the control port of the breathing chamber decoder, so that the breathing chamber decoder maps the input four-bit logic code group into the sealing control signal of the selected breathing chamber according to the preset second encoding rule.

[0039] It is important to understand that the second encoding rule includes: a four-bit logic encoding group consisting of a mode enable bit and three address bits; when the mode enable bit is low, all relays in the breathing chambers are synchronously de-energized, forcibly keeping all breathing chamber units in the open state; when the mode enable bit is high, the breathing chamber unit is selected according to the level combination of the three address bits, and the corresponding relay is triggered to close the target breathing chamber unit; the mapping relationship between the level combination of the three address bits and the breathing chamber number satisfies the binary bit weighting rule, with the low-order bits corresponding to the increasing address code of the breathing chamber unit from low to high; the synergistic effect of the mode enable bit and the three address bits enables independent selection control of the breathing chamber unit, ensuring that only a single breathing chamber is in a closed measurement state at any given time.

[0040] like Figure 6 As shown, the control port of the breathing chamber decoder has one more control port IO4 than the control port of the air valve decoder. The breathing chamber decoder receives the level signals of ports C5, C6, C7, and C8 of the intelligent data acquisition and control unit through four control ports (IO1, IO2, IO3, and IO4). Among them, IO1-IO3 control eight state outputs (OUT1 to OUT8) to drive eight relays to close the target breathing chamber. IO4 (C8 port) is a mode enable bit, and its level state directly determines the overall opening and closing logic of the breathing chamber unit. The correspondence between the output state of the breathing chamber decoder control port and the air valve is shown in Table 2.

[0041] Table 2. Correspondence between the output states of the respiratory chamber decoder control port and the air valves.

[0042] Therefore, the four-bit logic encoding group of the respiratory chamber decoder works in concert with the mode enable bit (C8) and the three address bits (C5-C7). The mode enable bit (C8) has higher priority than the address bits. When C8 is low, all respiratory chamber relays are forced to de-energize to remain open. When C8 is high, the three address bits (C5-C7) select a single respiratory chamber to close using binary bit weight encoding (the low-order bits correspond to the increasing respiratory chamber address). The remaining respiratory chambers remain open. By controlling the level combination and timing of the C5-C8 ports, time-division multiplexing and mutual exclusion locking of the respiratory chamber units are achieved.

[0043] S23. Based on the airtight control signal of the selected breathing chamber, drive the corresponding relay to perform mechanical sealing operation of the first breathing chamber, and at the same time send the power failure signal to the relays corresponding to the other unselected breathing chambers to perform airway mutual exclusion locking operation, forcibly keeping the other breathing chamber units in the open state.

[0044] S24. While maintaining the first A / B solenoid valve in the conducting state, a directional gas circulation channel is formed that flows through the sealed breathing chamber unit.

[0045] S25. After the gas in the directional gas circulation channel is purified, the circulating gas sample is continuously collected by the detection and analysis component. Based on the time-varying characteristics of the obtained CO2 concentration, the spatiotemporal relationship between the gas path volume and the surface area of ​​the covered soil, and after temperature and pressure correction, the soil respiration rate is obtained.

[0046] In this step, the gas in the directional gas circulation channel is purified to eliminate background interference. Then, the circulating gas is continuously sampled using a detection and analysis component to monitor the time-varying characteristics of CO2 concentration in the gas path in real time. Parameters such as gas path volume (V), cover soil surface area (A), gas temperature (T), and actual atmospheric pressure (P) are simultaneously collected, combined with standard atmospheric pressure (…). ) and standard temperature ( Establish a basic dataset. Calculate the soil respiration rate based on the following formula: ; In the formula, F is the soil respiration rate (μmol•m). -2 •s -1 ), It is the CO2 concentration difference (μmol•mol) between the inlet and outlet of the breathing chamber. -1), Δt is the time difference corresponding to the change in CO2 concentration during the measurement process, and V is the volume (m³) of the gas path (the volume of the gas path is the entire measurement circuit, including the breathing chamber + gas path, which is the volume of the path the gas travels throughout the entire measurement process). 3 A is the surface area of ​​the covered soil (m²) 2 P0 is the standard atmospheric pressure (kPa), P is the actual atmospheric pressure inside the chamber (kPa), T is the gas temperature (K), T0 is the temperature under standard conditions (K), and 22.4 is the molar volume of the gas under ideal conditions.

[0047] S3. When the preset measurement time is reached, the selected breathing chamber unit is released from its sealed state and the corresponding valve pair is kept open to perform loop purging, and then the corresponding valve pair is shut off after a delay.

[0048] Furthermore, such as Figure 7 As shown, step S3 includes: S31. When the measurement time of the selected breathing chamber unit reaches the preset measurement threshold, a release command is sent to the breathing chamber decoder to drive the corresponding relay to release the sealed state of the selected breathing chamber.

[0049] S32. Maintain the first A / B gas valve pair in the open state, and use the gas pump to drive the airflow to continuously circulate and flush the residual gas in the gas path detection circuit.

[0050] S33. When the cumulative delay reaches the preset gas washing time threshold, drive the corresponding relay to shut off the first A / B gas valve pair, block the gas circulation channel, and complete the current breathing chamber unit measurement cycle.

[0051] S34. Reset the measurement and gas washing timer, release the logic code group of the breathing chamber decoder, return to the standby initialization state, and wait for the next round of measurement tasks to be triggered.

[0052] S4. Send an incremental encoding signal to the air valve decoder, and activate each air valve pair in sequence through the successive update of binary bit combinations, so that each breathing chamber unit repeatedly executes the operation sequence including closed-loop parameter detection and loop washing in a predetermined order until the detection of all breathing chamber units is completed and the air pump is turned off.

[0053] During the cyclic measurement process, in response to the logic state signal of the current breathing chamber unit completing the operation sequence, an encoded signal with an incrementing preset step size is sent to the valve decoder. The decoder parses the incremented encoded signal to generate the corresponding valve pair selection signal, which opens only the valve pair associated with the current target breathing chamber unit, while the other valve pairs remain closed.

[0054] After each unit completes parameter detection in a closed state (e.g., 150 seconds), it executes a pipeline gas washing process (e.g., 50 seconds), and then cuts off the power supply to the corresponding gas valve pair to terminate the gas circulation. When the encoded signal increases to its maximum value and the operation sequence of all breathing chamber units is marked as complete, the SW12 control port of the intelligent data acquisition and control unit outputs a low-level signal, which, through a voltage divider circuit (12V divided to 3.3V by a 300kΩ and a 100kΩ resistor), shuts off the gas pump power supply, forcing the gas pump to stop running to reduce system standby power consumption. When the next measurement task is triggered, the SW12 control port returns to a high level to restart the gas pump.

[0055] Furthermore, the method of the present invention also includes: in response to a power-on signal, sending an enable command to the temperature control interface of the intelligent data acquisition and control unit in the detection and analysis component to control the heating component of the infrared analyzer attached to the detection and analysis component to start; continuously acquiring real-time temperature data streams through a temperature sensor attached to the surface of the infrared analyzer housing, and dynamically adjusting the heating power output of the heating component based on the deviation value when a temperature fluctuation is detected to exceed a set threshold; maintaining the continuous power supply of the heating component during the process of the gas valve decoder executing incremental encoding to switch the operation sequence of each breathing chamber unit, so that the analyzer is in a constant temperature working environment during the closed detection and pipeline gas washing stages; when a gas pump shutdown signal is received indicating that all breathing chamber detections are completed, starting a delay protection timer, cutting off the power supply to the heating component after reaching a preset thermal inertia buffer time, and simultaneously resetting the logic enable flag of the temperature control interface of the intelligent data acquisition and control unit.

[0056] like Figure 8 As shown, to suppress the impact of outdoor temperature fluctuations on the measurement accuracy of the infrared analyzer, a constant temperature control circuit is constructed based on the LM317 adjustable voltage regulator chip. The heating component, which includes a thermistor and a heating chip, is driven by an enable signal output from the C4 port of the intelligent data acquisition and control unit. In practice, the heating chip of the infrared analyzer is bonded and fixed using a high-temperature resistant (e.g., 200℃) thermally conductive adhesive to ensure efficient heat transfer between it and the housing surface and the temperature sensor. Here, the temperature sensor can be a thermistor, thermocouple, etc. The heating power supply is provided by an 8V regulated output from the LM317 chip (a heat sink is required to control the temperature rise). Simultaneously, the thermistor monitors the analyzer housing temperature in real time and feeds it back to the intelligent data acquisition and control unit, forming a closed-loop control circuit.

[0057] After the system is powered on, the C4 port immediately outputs a high level to activate the LM317 power supply, and the heating component starts to heat up. When the shell temperature deviates from the set threshold of 50°C, the PWM duty cycle of the C4 port is dynamically adjusted through a PID algorithm to correct the heating power and maintain the analyzer's operating temperature. During the cyclic measurement of the breathing chamber unit (including the airtightness detection and pipeline gas washing stages), the heating component is continuously powered on to avoid temperature control interruption. After all breathing chambers have been detected and the air pump is turned off, a delay timer is started to wait for the preset thermal inertia buffer time (to ensure that the analyzer cools down slowly), and finally the enable signal of the C4 port and the power supply to the LM317 are cut off to complete the constant temperature control cycle.

[0058] Furthermore, this embodiment of the invention provides a soil respiration parameter detection system with multi-breathing chamber closed-loop gas path time-sharing coordinated control, comprising: a gas path circulation component, including an air pump and multiple respiration chamber units connected in parallel, each respiration chamber unit being configured with an interlocked air valve group, each air valve group including a pair of synchronously opening and closing air valves respectively set at the input and output ends of the respiration chamber unit, used to connect or isolate the corresponding respiration chamber unit to the gas path detection loop; a detection and analysis component, including a gas filter, an infrared analyzer, and an intelligent data acquisition and control unit, the input end of the gas filter being connected to the air valve of the output pipeline of the respiration chamber unit, the input end of the infrared analyzer being connected to the output end of the gas filter, and the output end of the infrared analyzer being connected to the air pump inlet and the intelligent data acquisition and control unit respectively, forming a closed-loop detection loop, the intelligent data acquisition and control unit being used to execute the method described above; and further comprising: a dynamic constant temperature module, including a heating component attached to the housing of the infrared analyzer and a temperature sensor, the temperature sensor acquiring the operating temperature of the analyzer in real time and feeding it back to the intelligent data acquisition and control unit, the intelligent data acquisition and control unit dynamically adjusting the heating power of the heating component based on the temperature deviation to maintain a constant operating temperature of the infrared analyzer.

[0059] like Figure 9 As shown, a modular structure is used to achieve closed-loop control and multi-parameter detection of the gas path. The pipeline connection is assembled in the following order: "inlet valve → filter → infrared analyzer → pressure sensor → flow meter → air pump → outlet valve" to form the main gas detection loop. It should be noted that, for ease of use, the positions of the flow meter and the air pump can be interchanged. Figure 9 It's just one application, and Figure 1 There is no conflict. Figure 9 The blue arrows indicate the gas flow direction. The infrared analyzer is an infrared CO2 analyzer. The heating chip of the infrared CO2 analyzer is tightly bonded to the housing surface using 200℃ heat-resistant thermally conductive adhesive. The thermistor is synchronously fixed to form a closed-loop regulation circuit. The connection relationships of each part are described in detail below: In the wiring of the infrared CO2 analyzer, the red and black wires are used as the positive power supply terminals connected to +12V and the negative power supply terminals grounded, respectively. The white signal wire is connected in series with a 100Ω resistor to convert it to a voltage of 0.4-2V and then connected to channel 1H of the CR1000 intelligent data acquisition and control unit. The brown wire is used as the signal ground, while the heating temperature monitoring signal is input to channel 2H of the CR1000 intelligent data acquisition and control unit.

[0060] In the wiring of the heating chip, the 12V main power supply is directly connected to the heating chip. The PWM control signal is output from the C4 port of the CR1000 intelligent data acquisition and control unit to adjust the heating power. The 8V power supply of the heating chip is regulated by the LM317 (red wire to 8V+, black wire to 8V-). A heat sink is required to control the temperature rise.

[0061] The SW12 port of the CR1000 intelligent data acquisition and control unit is the air pump control port. After a voltage divider between 100KΩ and 300KΩ, the SW12 port is connected to a pre-deployed air pump control module, which is directly connected to the air pump. The SW12 port of the CR1000 intelligent data acquisition and control unit indirectly controls the air pump's start-up through the air pump control module, preventing the CR1000 intelligent data acquisition and control unit from directly driving the load, thus providing isolation and protection. When SW12 outputs a high level, the air pump control module responds and drives the air pump to start.

[0062] Solenoid valves and motor drives are centrally managed through the pneumatic control module and the breathing chamber control module, respectively. The D1-D3 ports of the solenoid valve assembly are connected to the C1-C3 terminals of the CR1000 intelligent data acquisition and control unit. Eight pairs of valves (1+ / - to 8+ / -) are paired and connected according to the breathing chamber unit. The D1-D4 ports of the breathing chamber motor correspond to C5-C8. The positive and negative terminals (white / red wires) of each motor are connected to the terminal block according to their numbers. Sensor signals are uniformly converged to the CR1000 intelligent data acquisition and control unit. The air pressure sensor is connected to channel 1L, and the breathing chamber air temperature sensors are connected sequentially starting from channel 2L.

[0063] After the system is powered on, the system power control module distributes power to each component. The heating component automatically activates and maintains a constant temperature of 50°C for the CO2 analyzer using a PID algorithm. After the gas path and breathing chamber control module switches to Auto mode, the air pump runs in a 200-second sequence: the first 1-150 seconds close the selected breathing chamber for data acquisition, and the next 151-200 seconds open the air valve to perform pipeline purging. Each module is equipped with a status indicator light, which illuminates when the corresponding channel is active. After all breathing chamber units have been tested, the air pump power is automatically turned off, while the heating component continues to run until the delay protection timer ends. After thermal inertia buffering, the power is cut off to ensure that the infrared CO2 analyzer maintains temperature stability during the subsequent standby phase. The overall structure is as follows: Figure 10 The actual layout is shown.

[0064] The CR1000 intelligent data acquisition and control unit is configured as a control panel, which can control the operation of the entire system by inputting program commands. The descriptions of its various channels are shown in Table 3 below: Table 3 Channel Description of Intelligent Data Acquisition and Control Unit

[0065] It should be noted that the infrared CO2 analyzer used is the German Schutz S-Connect, whose main technical parameters are as follows: measurement range: 0~5000ppm; output voltage: 0.4~2VDC; power supply voltage: 12VDC; power consumption: maximum 130mA; warm-up time: <2 minutes (cold start); flow control: 0.6L / min; resolution: 1ppm; accuracy: <±2%. The trachea has an inner diameter of 4mm and an outer diameter of 6mm; the breathing chamber unit has an inner diameter of 128mm and an outer diameter of 130mm.

[0066] Since the systems / devices described in the above embodiments of the present invention are systems / devices used to implement the methods of the above embodiments of the present invention, those skilled in the art can understand the specific structure and modifications of the systems / devices based on the methods described in the above embodiments of the present invention, and therefore will not be repeated here. All systems / devices used in the methods of the above embodiments of the present invention fall within the scope of protection of the present invention.

[0067] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0068] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program signals.

[0069] It should be noted that any reference numerals placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In claims that enumerate several means, several of these means may be embodied by the same hardware. The use of the terms first, second, third, etc., is merely for convenience of expression and does not indicate any order. These terms can be understood as part of the component names.

[0070] Furthermore, it should be noted that in the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0071] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the claims should be interpreted to include both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0072] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, then this invention should also include these modifications and variations.

Claims

1. A method for detecting soil respiration parameters using a multi-chamber closed-loop gas path time-sharing coordinated control, characterized in that, This is applicable to air circuit detection loops that include an air pump, multiple independent breathing chamber units, and detection and analysis components. Each breathing chamber unit is equipped with an interlocked valve group, and a coordinated control mechanism between the valve on / off state and the opening / closing action of the breathing chamber unit is established through a decoder. The detection and analysis components execute the following method: The air pump is activated, and an air valve control signal is sent to the air valve decoder to drive the corresponding air valve pair to open synchronously, so that the selected breathing chamber unit is connected to the circuit. Send a box closure signal to the breathing chamber decoder to drive the selected breathing chamber unit to close, while keeping the corresponding air valve pair open, so that the gas in the selected breathing chamber unit circulates in the loop, and the soil breathing parameters are collected and analyzed in real time through the detection and analysis component. When the preset measurement time is reached, the selected breathing chamber unit is released from its sealed state and the corresponding valve pair is kept open to perform loop purging, and then the corresponding valve pair is shut off after a delay. An incremental encoding signal is sent to the valve decoder, which sequentially activates each valve pair through the successive updates of binary bit combinations. This causes each breathing chamber unit to repeatedly execute an operation sequence that includes parameter detection under closed conditions and loop washing in a predetermined order, until the air pump is shut off after all breathing chamber units have been tested.

2. The method for detecting soil respiration parameters with time-sharing coordinated control of multi-breathing chamber closed-loop air path as described in claim 1, characterized in that, The air pump is activated, and an air valve control signal is sent to the air valve decoder to drive the corresponding air valve pair to open synchronously, thus connecting the selected breathing chamber unit to the circuit, including: The air pump is activated in response to the power-on signal, and the control port of the air valve decoder is initialized to the default level state. Send a three-bit logic code group to the control port of the valve decoder so that the valve decoder maps the input three-bit logic code group to the on signal of the selected valve according to the preset first encoding rule. Based on the conduction signal, the relay corresponding to the selected air valve performs an exclusive switching operation, which synchronously turns on the first A / B air valve pair associated with the first breathing chamber. At the same time, the power failure signal is synchronously sent to the relays corresponding to the other unselected air valves to perform the air path mutual exclusion lock operation and forcibly close the other unselected air valves. With the air pump driving and the first A / B air valve pair conducting, a circuit including the first breathing chamber is formed in the air path detection circuit, realizing the air path connection between the corresponding breathing chamber unit and the detection and analysis component.

3. The method for detecting soil respiration parameters with time-sharing coordinated control of multi-breathing chamber closed-loop air path as described in claim 2, characterized in that, The first encoding rule includes: Each three-digit logic code group has a one-to-one discrete mapping relationship with each A / B valve pair configuration, and each code group is assigned a unique valve selection identifier. Each coding group is encoded and mapped according to the binary bit weighting rule. The linear selection of the physical channel of the breathing chamber unit is achieved by the combination and increment of the coding bit level states. Only one coding group is allowed to be active at any given time, while the remaining coding groups are automatically deactivated to maintain the independence of the gating channel.

4. The method for detecting soil respiration parameters with time-sharing coordinated control of multi-breathing chamber closed-loop air path as described in claim 1, characterized in that, A housing closure signal is sent to the breathing chamber decoder to drive the selected breathing chamber unit to close, while simultaneously keeping the corresponding air valve pair open, allowing the gas in the selected breathing chamber unit to circulate in the loop. Soil respiration parameters are collected and analyzed in real time by the detection and analysis components, including: Initialize the control port of the respiratory chamber decoder to the default level. In response to the enclosure closure signal, a four-bit logic code group is input to the control port of the breathing chamber decoder, so that the breathing chamber decoder maps the input four-bit logic code group into the airtight control signal of the selected breathing chamber according to the preset second encoding rule; Based on the sealing control signal of the selected breathing chamber, the corresponding relay is driven to operate, so that the first breathing chamber performs mechanical sealing operation. At the same time, the power failure signal is sent synchronously to the relays corresponding to the other unselected breathing chambers to perform airway mutual exclusion locking operation, forcibly keeping the other breathing chamber units in the open state. While maintaining the first A / B solenoid valve pair in the OFF state, a directional gas circulation channel is formed that flows through the sealed breathing chamber unit; After the gas in the directional gas circulation channel is purified, circulating gas samples are continuously collected by the detection and analysis components. Based on the time-varying characteristics of the obtained CO2 concentration, the spatiotemporal relationship between the gas path volume and the surface area of ​​the covered soil, and after temperature and pressure correction, the soil respiration rate is obtained.

5. The method for detecting soil respiration parameters with time-sharing coordinated control of multi-breathing chamber closed-loop air path as described in claim 4, characterized in that, The second encoding rule includes: The four-bit logic code group consists of a mode enable bit and three address bits; When the mode enable bit is low, all the relays in the breathing chambers are de-energized synchronously, forcing all breathing chamber units to remain in the open state. When the mode enable bit is high, the breathing chamber unit is selected according to the level combination of the three address bits, and the corresponding relay is triggered to close the target breathing chamber unit. Among them, the mapping relationship between the level combination of the three address bits and the breathing chamber number satisfies the binary bit weight arrangement rule, with the low bit to the high bit corresponding to the increasing breathing chamber unit address code; The mode enable bit and the three address bits work together to enable independent gating control of the breathing chamber unit, ensuring that only a single breathing chamber is in a closed measurement state at any given time.

6. The method for detecting soil respiration parameters with time-sharing coordinated control of multi-breathing chamber closed-loop air path as described in claim 1, characterized in that, When the preset measurement time is reached, the selected breathing chamber unit is de-sealed while the corresponding valve pair remains open to perform loop purging, followed by a delay to shut off the corresponding valve pair, including: When the measurement time of the selected breathing chamber unit reaches the preset measurement threshold, a release command is sent to the breathing chamber decoder to drive the corresponding relay to release the sealed state of the selected breathing chamber. Maintain the first A / B gas valve pair in the open state, and use the air pump to drive the airflow to continuously circulate and flush the residual gas in the gas detection circuit; When the cumulative delay reaches the preset gas washing time threshold, the corresponding relay is driven to shut off the first A / B gas valve pair, blocking the gas circulation channel and completing the current breathing chamber unit measurement cycle. Reset the measurement and gas washing timer, release the logic code group of the breathing chamber decoder, and return to the standby initialization state.

7. The method for detecting soil respiration parameters with time-sharing coordinated control of multi-breathing chamber closed-loop air path as described in claim 1, characterized in that, Also includes: In response to the power-on signal, an enable command is sent to the temperature control interface of the intelligent data acquisition and control unit in the detection and analysis component to control the heating component of the infrared analyzer attached to the detection and analysis component to start. The real-time temperature data stream is continuously acquired by a temperature sensor attached to the surface of the infrared analyzer housing. When the temperature fluctuation exceeds the set threshold, the heating power output of the heating component is dynamically adjusted based on the deviation value. During the process of the valve decoder executing incremental coding to switch the operation sequence of each breathing chamber unit, the heating component is kept continuously powered so that the analyzer is in a constant temperature working environment during the closed detection and pipeline gas washing stages. When the air pump shut-off signal is received, indicating that all breathing chamber detections are complete, a delay protection timer is started. After the preset thermal inertia buffer time is reached, the power supply to the heating component is cut off, and the logic enable flag of the temperature control interface of the intelligent data acquisition and control unit is reset.

8. A soil respiration parameter detection system with time-sharing coordinated control of a multi-breathing chamber closed-loop air path, characterized in that, include: The air circulation assembly includes an air pump and multiple breathing chamber units connected in parallel. Each breathing chamber unit is equipped with an interlocked air valve group. Each air valve group includes a pair of synchronously opening and closing air valves that are respectively set at the input and output ends of the breathing chamber unit, used to connect or isolate the corresponding breathing chamber unit from the air detection circuit. The detection and analysis component includes a gas filter, an infrared analyzer, and an intelligent data acquisition and control unit. The input end of the gas filter is connected to the gas valve of the output pipeline of the breathing chamber unit. The input end of the infrared analyzer is connected to the output end of the gas filter. The output end of the infrared analyzer is connected to the gas pump inlet and the intelligent data acquisition and control unit respectively, forming a closed-loop detection circuit. The intelligent data acquisition and control unit is used to perform the method as described in any one of claims 1-7.

9. The soil respiration parameter detection system with multi-breathing chamber closed-loop gas path time-sharing coordinated control as described in claim 8, characterized in that, Also includes: The dynamic temperature control module includes a heating element and a temperature sensor attached to the infrared analyzer housing. The temperature sensor collects the analyzer's operating temperature in real time and feeds it back to the intelligent data acquisition and control unit. The intelligent data acquisition and control unit dynamically adjusts the heating power of the heating element based on the temperature deviation to maintain the constant operating temperature of the infrared analyzer.

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