Lettuce rapid carbon assimilation light formula based on 450 / 460nm laser and 660nm LED pulse time sequence coupling and regulation and control method

Abstract

The invention relates to the technical field of agricultural biology, and discloses a lettuce rapid carbon assimilation light formula based on 450 / 460 nm laser and 660 nm LED pulse time sequence coupling and a regulation and control method, and the regulation and control method comprises the following steps: S1, collecting the net photosynthetic rate (Pn), chlorophyll fluorescence parameters (Fv / Fm, phi PSII), intercellular CO2 concentration (Ci) and leaf surface temperature (Tleaf) of lettuce functional leaves in real time; the environment parameters comprise environment temperature (Tenv), environment relative humidity (RH) and environment CO2 concentration (Cenv); and S2, inputting the real-time data into a preset photosynthetic stage recognition model, and outputting the current photosynthetic stage of the lettuce, the photosynthetic stage at least comprising an activation stage, an efficient carbon sequestration stage, a saturation stage and a photosuppression risk stage. Through a multi-parameter real-time monitoring and stage recognition model, the light pulse time sequence can be accurately matched with the instantaneous state of a lettuce photosynthetic mechanism, and energy waste or light suppression caused by a fixed formula in different time periods is avoided.

Description

TECHNICAL FIELD

[0001] The application relates to the field of agricultural biotechnology, and particularly relates to a lettuce rapid carbon assimilation light formula and regulation method based on 450 / 460 nm laser and 660 nm LED pulse time sequence coupling. BACKGROUND

[0002] The lettuce rapid carbon assimilation light formula and regulation method based on 450 / 460 nm laser and 660 nm LED pulse time sequence coupling is a high-efficiency plant light environment regulation technology which combines precise spectrum modulation and dynamic energy supply. The method is based on the high directionality and high photon flux characteristics of 450 nm (blue light) and 460 nm (near blue light) lasers, and combines the high photosynthetic quantum efficiency advantage of 660 nm (red light) LED. Through the design of specific duty cycle, frequency and phase difference of pulse time sequence, for example, the high-frequency short pulse is used to drive the blue light laser to excite the electron transfer activity of the chloroplast PSII reaction center, and the red light LED is triggered synchronously or with a microsecond lag to supplement the energy demand of PSI cycle and Calvin cycle, so that the dynamic coupling mode of "blue light excitation activity-red light collaborative carbon fixation" is formed. In terms of regulation, the lettuce photosynthetic rate (such as LI-6800 photosynthetic instrument data), chlorophyll fluorescence parameters (Fv / Fm, PhiPSII) and carbohydrate accumulation rate are monitored in real time, and the pulse intensity (such as the peak power of blue light laser 50-200 mW, the red light LED irradiance 100-300 μmol·m -2 ·s -1 ), time sequence phase (such as blue light leading red light by 10-50 μs triggering) and time length ratio (such as strengthening blue light pulse ratio to 60% for 2 hours before the light period, and balancing the red and blue ratio to 1:1.2 for 4 hours after the light period) are dynamically optimized by algorithm, so that the Rubisco enzyme activity and CO2 fixation efficiency are maximized while avoiding photoinhibition, the rapid accumulation of lettuce biomass (especially leaf soluble sugar and starch) is realized, the growth cycle can be shortened by 15%-25% compared with traditional continuous light, and the precise light environment solution is provided for efficient seedling raising and low-carbon production of facility agriculture.

[0003] Currently, in the field of plant factory and facility agriculture, in order to improve the photosynthetic carbon assimilation efficiency and growth rate of leafy crops (such as lettuce), some studies have attempted to combine different waveband light sources, among which the pulse timing coupling scheme based on 450 / 460 nm laser and 660 nm LED has gradually attracted attention. 450 / 460 nm laser has the characteristics of strong directivity and high photon density, which can effectively stimulate the electron transfer of the reaction center of photosystem II (PSII) of chloroplast; while 660 nm LED is often used to promote the carbon fixation process in the photosystem I (PSI) cycle and the Calvin cycle due to its high matching degree with the absorption peak of chlorophyll a and high photosynthetic quantum efficiency. By coupling the two according to a certain pulse timing, the dynamic coordination of photosynthetic electron flow and carbon assimilation process can be theoretically achieved, thereby improving the carbon assimilation rate and biomass accumulation of lettuce. However, the existing such technologies still have the following significant defects in application:

[0004] Insufficient matching accuracy of pulse timing and physiological response: Most schemes use fixed pulse frequency, duty cycle and timing phase difference, without fully considering the dynamic changes of photosynthetic mechanism state and metabolic demand of lettuce at different growth stages (such as seedling stage, vigorous growth period) or different environmental factors (temperature, CO2 concentration), resulting in that the light energy cannot be efficiently utilized at some time periods, and even causing photoinhibition or photooxidative damage;

[0005] Contradiction between energy distribution and heat management of spectral coupling: Although the high photon flux of 450 / 460 nm laser can quickly activate PSII, continuous or high-frequency pulse can easily cause local light energy surplus, and when 660 nm LED is used to supplement red light energy, if the pulse timing is not matched with blue light, it can easily lead to uneven temperature distribution on the leaf surface, affecting stomatal conductance and CO2 diffusion efficiency, and thus limiting the continuous improvement of carbon assimilation;

[0006] Real-time deficiency of regulation depending on offline parameters: Most existing methods are based on pre-set empirical light recipes (such as fixed red-to-blue ratio, pulse length) for regulation, lack of online monitoring and feedback on real-time photosynthetic parameters of lettuce (such as net photosynthetic rate, chlorophyll fluorescence parameters, intercellular CO2 concentration), and are difficult to dynamically adjust pulse parameters according to the actual carbon assimilation state of the plant, resulting in insufficient "precision" and "adaptability" of the light environment;

[0007] High complexity of device integration and control: The pulse driving of laser and LED needs to match different power supplies and control systems respectively, and the synchronization accuracy of the controller is extremely high (usually in microseconds) for timing coupling, and the existing hardware architecture is prone to timing drift or signal interference, which increases the system cost and maintenance difficulty and limits the large-scale promotion;

[0008] The carbon assimilation efficiency is limited in the increase range and poor in stability: although part of the experiments show that the scheme can short-term increase the photosynthetic rate of lettuce, under the continuous production conditions, due to the above matching accuracy, real-time regulation and heat management and other problems, the gain of carbon assimilation efficiency is easy to decay with the extension of culture time, and the response consistency of different batches of lettuce is poor, which is difficult to meet the needs of stable and high yield of industrialized production.

[0009] Therefore, we propose a lettuce rapid carbon assimilation light formula and regulation method based on 450 / 460nm laser and 660nm LED pulse timing coupling. SUMMARY

[0010] To achieve the above object, the present application provides the following technical scheme: a lettuce rapid carbon assimilation light formula and regulation method based on 450 / 460nm laser and 660nm LED pulse timing coupling, comprising the following steps:

[0011] S1: real-time acquisition of the net photosynthetic rate (Pn), chlorophyll fluorescence parameters (Fv / Fm, ΦPSII), intercellular CO2 concentration (Ci), leaf surface temperature (Tleaf) of lettuce functional leaves, and environmental parameters including environmental temperature (Tenv), environmental relative humidity (RH) and environmental CO2 concentration (Cenv);

[0012] S2: inputting the real-time data into a preset photosynthesis stage identification model to output the photosynthesis stage of the current lettuce, wherein the photosynthesis stage at least includes the activation period, the efficient carbon fixation period, the saturation period and the light inhibition risk period;

[0013] S3: calling the corresponding pulse parameter configuration table according to the photosynthesis stage to dynamically generate the pulse parameters of 450 / 460nm laser and 660nm LED, wherein the pulse parameters include pulse frequency (f), single pulse width (t_pulse), duty cycle (D), phase difference (Δt_phase), peak power (P_peak) or irradiance (I_red), wherein the phase difference is defined as the time offset of the rising edge of the blue light pulse relative to the rising edge of the red light pulse;

[0014] S4: outputting the light signal according to the pulse parameters by using a high-precision synchronous driving module to form a timing coupling light field of blue light and red light acting on the canopy of lettuce;

[0015] S5: real-time monitoring Tleaf and comparing with the safety threshold (T_safe), when Tleaf≥T_safe, starting the energy-heat synergistic management strategy to inhibit the heat stress by reducing the peak power of blue light or inserting the cooling interval;

[0016] S6: periodically calculate the change rate of Pn and Ci (dPn / dt, dCi / dt), determine the effectiveness of the light formula according to the change rate, and make closed-loop parameter correction to maintain or enter the high-efficiency carbon assimilation state of the lettuce.

[0017] Preferably, the photosynthesis stage recognition model in step S2 is a classifier based on a decision tree or a deep neural network, and the training samples come from lettuce photosynthetic gas exchange and fluorescence data under different growth dates and different environmental conditions. The model output confidence is ≥85% to execute the corresponding pulse parameter configuration.

[0018] Preferably, in step S3, the pulse parameter configuration table includes:

[0019] Activation period: f=500-600Hz, D_blue=50%-70%, Δt_phase=blue light leading red light 10-30μs, P_peak(450nm)=100-150mW, P_peak(460nm)=80-120mW, I_red=150-250μmol·m -2 ·s -1 ;

[0020] High-efficiency carbon fixation period: f=350-450Hz, D_blue=30%-50%, Δt_phase=blue light lagging red light 10-20μs, P_peak(450nm)=80-120mW, P_peak(460nm)=60-100mW, I_red=200-300μmol·m -2 ·s -1 ;

[0021] Saturation period: f=300-400Hz, D_blue=20%-40%, Δt_phase=synchronous or blue light lagging red light 20-40μs, P_peak reduced by 10%-20%;

[0022] Light inhibition risk period: f≤300Hz, D_blue≤30%, I_red is increased to the maximum tolerance value, and a cooling interval is started.

[0023] Preferably, in step S4, the high-precision synchronous driving module includes: a constant temperature crystal oscillator (±1ppm) as a time reference; a FPGA or a high-speed MCU for pulse waveform generation and output; blue laser drive and red LED drive are connected through optoelectronic isolation modules to ensure electrical isolation and anti-interference; a timing drift detection circuit compares the two pulse trigger times in real time, and automatically calibrates when the deviation exceeds ±1μs.

[0024] Preferably, in step S5, T_safe is set based on the lettuce variety and growth period, generally 26–28°C. When Tleaf ≥ T_safe, at least one of the following measures is performed:

[0025] Reduce P_peak(450nm) and P_peak(460nm) simultaneously by 10% to 30%;

[0026] A 1-5 ms zero-intensity interval is inserted after each blue light pulse as a cooling window;

[0027] Reduce D_blue by 5% to 15% while keeping red light unchanged to transfer heat energy.

[0028] Preferably, the decision logic for closed-loop correction in step S6 is as follows:

[0029] If dPn / dt < 0 and dCi / dt > 0, it is determined to be a light suppression trend, and f and D_blue are immediately reduced while I_red is increased;

[0030] If dPn / dt>0 and dCi / dt<0, it is determined to be the carbon assimilation acceleration period, and D_blue and P_peak can be appropriately increased;

[0031] If dPn / dt≈0 and dCi / dt≈0, it is determined to be in steady state, and the current parameters are maintained.

[0032] Each correction should not exceed ±20% of the original parameter, and the parameter should be reassessed every hour.

[0033] Preferably, it also includes an anomaly protection mechanism: when sensor data is missing for more than 3 consecutive sampling periods or Pn is lower than a threshold (e.g., 1 μmol·m⁻¹), -2 ·s -1 When the alarm is triggered, the system switches to the preset safety light formula and issues an alarm.

[0034] A lettuce rapid carbon assimilation light regulation system for implementing the above-described method includes:

[0035] Multi-parameter sensor array: includes a photosynthetic gas exchange measurement unit (LI-6800 or equivalent device), a chlorophyll fluorescence measurement unit, an infrared temperature sensor array, and an ambient CO2 / temperature and humidity sensor;

[0036] Data processing and stage identification unit: embedded controller or industrial PC, running the photosynthetic stage identification model;

[0037] Pulse parameter calculation and instruction generation unit: calculates real-time pulse parameters by looking up tables and interpolating based on stage identification results;

[0038] High-precision synchronous drive control unit: includes a temperature-controlled crystal oscillator, FPGA / high-speed MCU, opto-isolation and drift calibration circuit;

[0039] Light source components: 450nm and 460nm laser modules, 660nm high-power LED array, both supporting external PWM / analog dimming;

[0040] Temperature feedback adjustment module: dynamically adjusts the drive current or inserts cooling gaps based on Tleaf;

[0041] Human-computer interaction and data storage module: touch screen or remote terminal, used for parameter setting, curve display and historical data storage.

[0042] Compared with existing technologies, this invention provides a rapid carbon assimilation photopolymerization formulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses, which has the following beneficial effects:

[0043] 1. This method for rapid carbon assimilation photoformulation and control in lettuce, based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses, can precisely match the pulse timing with the instantaneous state of the lettuce photosynthetic apparatus through multi-parameter real-time monitoring and stage identification models. This avoids energy waste or light inhibition caused by fixed formulations at different times. Experiments show that this method can increase photosynthetically active radiation (PAR) utilization by 18%–28%. By introducing leaf surface temperature feedback and cooling interval strategies, Tleaf can be stabilized in the optimal range of 22–26℃, avoiding a decrease in stomatal conductance and inhibition of Rubisco activity due to local overheating, thereby ensuring CO2 supply and carbon fixation efficiency.

[0044] 2. This rapid carbon assimilation photoformulation and control method for lettuce based on the timing coupling of 450 / 460nm laser and 660nm LED pulses, based on the feedback mechanism of dPn / dt and dCi / dt, can automatically eliminate the photoinhibition trend and capture the carbon assimilation acceleration window, enabling lettuce to maintain a high net photosynthetic rate throughout the entire growth period. It solves the efficiency decay problem of traditional fixed formulations with cultivation time. The microsecond-level synchronous drive combined with drift detection and calibration ensures that the timing deviation of blue and red light pulses is ≤±1μs, significantly reducing energy competition and light system imbalance caused by timing misalignment. The abnormal protection mechanism ensures safe operation even in sensor failure or extreme environments.

[0045] 3. This rapid carbon assimilation light formulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses, under conditions of 25℃ and 800ppm CO2, compared with conventional continuous light, shows: a 20%–35% increase in daily fresh weight growth rate (average of +33% in the examples); a 25%–30% increase in soluble sugar content and a 20%–28% increase in starch content; and a 15%–25% reduction in the growth cycle (from 28 days to 21 days). The method framework can be transferred to other leafy vegetables (such as spinach and arugula) or different light source combinations, and the modular design of software and hardware facilitates upgrades and mass deployment, making it suitable for high-density planting scenarios such as plant factories and vertical farms. Detailed Implementation

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example

[0048] An Example of a Photopolymer Formulation and Control Method for Rapid Carbon Assimilation in Lettuce Based on the Timing Coupling of 450 / 460nm Laser and 660nm LED Pulses

[0049] A rapid carbon assimilation photopolymerization formulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses includes the following steps:

[0050] S1: Real-time acquisition of net photosynthetic rate (Pn), chlorophyll fluorescence parameters (Fv / Fm, ΦPSII), intercellular CO2 concentration (Ci), leaf surface temperature (Tleaf) of functional lettuce leaves, as well as environmental parameters including ambient temperature (Tenv), ambient relative humidity (RH) and ambient CO2 concentration (Cenv).

[0051] S2: Input the real-time data into a preset photosynthetic stage identification model and output the current photosynthetic stage of the lettuce. The photosynthetic stage includes at least the activation period, the efficient carbon fixation period, the saturation period, and the photoinhibition risk period.

[0052] S3: Based on the photosynthesis stage, call the corresponding pulse parameter configuration table to dynamically generate pulse parameters for 450 / 460nm laser and 660nm LED. The pulse parameters include pulse frequency (f), single pulse width (t_pulse), duty cycle (D), phase difference (Δt_phase), peak power (P_peak) or irradiance (I_red), where the phase difference is defined as the time offset between the rising edge of the blue light pulse and the rising edge of the red light pulse.

[0053] S4: A high-precision synchronous drive module is used to output optical signals according to the pulse parameters, forming a time-coupled light field of blue light and red light that acts on the canopy of lettuce.

[0054] S5: Monitor Tleaf in real time and compare it with the safety threshold (T_safe). When Tleaf≥T_safe, start the energy-thermal collaborative management strategy to suppress thermal stress by reducing the peak power of blue light or inserting a cooling interval.

[0055] S6: Periodically calculate the rate of change of Pn and Ci (dPn / dt, dCi / dt), determine the effectiveness of the light formulation based on the rate of change, and make closed-loop parameter corrections to enable lettuce to maintain or enter a state of efficient carbon assimilation.

[0056] Specifically, the photosynthetic stage identification model in step S2 is a classifier based on decision trees or deep neural networks. Its training samples are derived from photosynthetic gas exchange and fluorescence data of lettuce under different growth dates and environmental conditions. The corresponding pulse parameter configuration can only be executed if the model output confidence is ≥85%.

[0057] Specifically, in the pulse parameter configuration table described in step S3:

[0058] Activation period: f = 500–600 Hz, D_blue = 50%–70%, Δt_phase = blue light leads red light by 10–30 μs, P_peak (450 nm) = 100–150 mW, P_peak (460 nm) = 80–120 mW, I_red = 150–250 μmol·m -2 ·s -1 ;

[0059] High-efficiency carbon fixation period: f = 350–450 Hz, D_blue = 30%–50%, Δt_phase = blue light lags red light by 10–20 μs, P_peak (450 nm) = 80–120 mW, P_peak (460 nm) = 60–100 mW, I_red = 200–300 μmol·m -2 ·s -1 ;

[0060] Saturation period: f = 300-400Hz, D_blue = 20%-40%, Δt_phase = synchronous or blue light lags red light by 20-40μs, P_peak decreases by 10%-20%;

[0061] Light suppression risk period: f≤300Hz, D_blue≤30%, I_red increased to maximum tolerance value, and cooling interval activated.

[0062] Specifically, the high-precision synchronous drive module in step S4 includes: a temperature-controlled crystal oscillator (±1ppm) as a time reference; an FPGA or high-speed MCU to generate and output pulse waveforms; blue laser drive and red LED drive connected via opto-isolation modules to ensure electrical isolation and anti-interference; and a timing drift detection circuit that compares the trigger times of the two pulses in real time and automatically calibrates when the deviation exceeds ±1μs.

[0063] Specifically, in step S5, T_safe is set based on the lettuce variety and growth period, generally between 26 and 28°C. When Tleaf ≥ T_safe, at least one of the following measures is implemented:

[0064] Reduce P_peak(450nm) and P_peak(460nm) simultaneously by 10% to 30%;

[0065] A 1-5 ms zero-intensity interval is inserted after each blue light pulse as a cooling window;

[0066] Reduce D_blue by 5% to 15% while keeping red light unchanged to transfer heat energy.

[0067] Specifically, the decision logic for closed-loop correction in step S6 is as follows:

[0068] If dPn / dt < 0 and dCi / dt > 0, it is determined to be a light suppression trend, and f and D_blue are immediately reduced while I_red is increased;

[0069] If dPn / dt>0 and dCi / dt<0, it is determined to be the carbon assimilation acceleration period, and D_blue and P_peak can be appropriately increased;

[0070] If dPn / dt≈0 and dCi / dt≈0, it is determined to be in steady state, and the current parameters are maintained.

[0071] Each correction should not exceed ±20% of the original parameter, and the parameter should be reassessed every hour.

[0072] Specifically, it also includes an anomaly protection mechanism: when sensor data is missing for more than 3 consecutive sampling periods or Pn is lower than a threshold (e.g., 1 μmol·m⁻¹), -2 ·s -1 When the alarm is triggered, the system switches to the preset safety light formula and issues an alarm.

[0073] A lettuce rapid carbon assimilation light regulation system for implementing the above method includes:

[0074] Multi-parameter sensor array: includes a photosynthetic gas exchange measurement unit (LI-6800 or equivalent device), a chlorophyll fluorescence measurement unit, an infrared temperature sensor array, and an ambient CO2 / temperature and humidity sensor;

[0075] Data processing and stage identification unit: embedded controller or industrial PC, running the photosynthetic stage identification model;

[0076] Pulse parameter calculation and instruction generation unit: calculates real-time pulse parameters by looking up tables and interpolating based on stage identification results;

[0077] High-precision synchronous drive control unit: includes a temperature-controlled crystal oscillator, FPGA / high-speed MCU, opto-isolation and drift calibration circuit;

[0078] Light source components: 450nm and 460nm laser modules, 660nm high-power LED array, both supporting external PWM / analog dimming;

[0079] Temperature feedback adjustment module: dynamically adjusts the drive current or inserts cooling gaps based on Tleaf;

[0080] Human-computer interaction and data storage module: touch screen or remote terminal, used for parameter setting, curve display and historical data storage.

[0081] In this invention, a multi-parameter real-time monitoring and stage identification model can precisely match the light pulse timing with the instantaneous state of the lettuce photosynthetic apparatus, avoiding energy waste or light inhibition caused by fixed formulations at different times. Experiments show that this method can increase the utilization rate of photosynthetically active radiation (PAR) by 18%–28%. By introducing leaf surface temperature feedback and cooling interval strategies, Tleaf can be stabilized in the optimal range of 22–26℃, avoiding the decrease in stomatal conductance and Rubisco activity inhibition caused by local overheating, thereby ensuring CO2 supply and carbon fixation efficiency. Based on the feedback mechanism of dPn / dt and dCi / dt, the light inhibition trend can be automatically eliminated and the carbon assimilation acceleration window can be captured, enabling lettuce to maintain a high net photosynthetic rate throughout the entire growth period. This solves the efficiency decay problem of traditional fixed formulations with cultivation time. Microsecond-level synchronous drive combined with drift detection and calibration ensures that the timing deviation of blue and red light pulses is ≤ ± The 1μs time significantly reduces energy competition and light system imbalance caused by timing misalignment; the abnormal protection mechanism ensures safe operation even in sensor failure or extreme environments. Under conditions of 25℃ and 800ppm CO2, compared with conventional continuous illumination: the daily average fresh weight growth rate is increased by 20% to 35% (average of the examples: +33%); the soluble sugar content is increased by 25% to 30%, and the starch content is increased by 20% to 28%; the growth cycle is shortened by 15% to 25% (from 28 days to 21 days). The method framework can be transferred to other leafy vegetables (such as spinach and arugula) or different light source combinations, and the modular design of software and hardware facilitates upgrades and batch deployment, making it suitable for high-density planting scenarios such as plant factories and vertical farms.

[0082] 1. System Composition and Connection

[0083] Sensor array arrangement: Select representative leaves in the middle of the lettuce canopy and install a leaf chamber type photosynthetic gas exchange probe (LI-6800), a fluorescence probe and an infrared temperature sensor. The environmental sensor is placed in the center of the top of the cultivation rack.

[0084] Control core: An industrial PC is used to run a Python / TensorFlowLite model for stage recognition, an STM32H7 MCU is responsible for real-time data acquisition and instruction forwarding, and an FPGA (Artix-7) is used to generate pulses.

[0085] Light source arrangement: The laser module guides light to the top uniform scattering plate through optical fiber, and the LED array is directly installed on the light panel. The two sets of light sources are spatially superimposed to cover the entire cultivation area.

[0086] 2. Example of the operation process

[0087] (1) Initialization: During the loading phase, identify the model and pulse parameter configuration table, set T_safe = 27℃, and the sampling period is 5min.

[0088] (2) Data acquisition and identification: Read Pn, Fv / Fm, Ci, Tleaf, Tenv, RH, Cenv; the model outputs "high-efficiency carbon fixation period" with a confidence level of 92%.

[0089] (3) Parameter generation and output: Call the high-efficiency carbon fixation period configuration: f = 400Hz, D_blue = 45%, Δt_phase = blue light lags red light by 15μs, P_peak(450nm) = 110mW, P_peak(460nm) = 90mW, I_red = 260μmol·m -2 ·s -1 FPGA outputs synchronization pulses.

[0090] (4) Thermal management intervention: After running for 1.5 hours, Tleaf rises to 28.3°C, triggering cooling: P_peak decreases by 20% and a 3ms zero-light interval is inserted every 10 pulses.

[0091] (5) Closed-loop correction: dPn / dt = -1.0 μmol·m⁻¹ was detected after 2 hours. -2 ·s -1 •h⁻¹, dCi / dt=+6μmol·mol⁻¹·h⁻¹ → Determine the light suppression trend, reduce f to 350Hz, reduce D_blue to 35%, and increase I_red to 290μmol·m⁻¹ -2 ·s -1 .

[0092] (6) Stable operation: After correction, Pn rises back to the original level, Ci decreases, and enters the steady state period, maintaining the parameters until the next stage of transformation.

[0093] 3. Anomaly Protection Demonstration

[0094] If the infrared temperature sensor communication is interrupted for more than 3 cycles, the system will automatically switch to a safe formula (f = 300Hz, D_blue = 25%, I_red = 200μmol·m). -2 ·s -1 The system will display an alarm prompt on the interface indicating that maintenance is required.

[0095] 4. Experimental verification

[0096] Control group: Traditional continuous illumination (red:blue = 7:3, light intensity 300 μmol·m⁻¹) -2 ·s -1 )

[0097] Experimental group: Method of the present invention

[0098] Results: On day 21, the fresh weight of the experimental group reached 68.4 g / plant, while that of the control group was 51.6 g / plant, an increase of 32.6%; the soluble sugar content of the experimental group was 8.9 mg / gFW, while that of the control group was 6.8 mg / gFW, an increase of 30.9%.

[0099] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses, characterized in that: Includes the following steps: S1: Real-time acquisition of net photosynthetic rate (Pn), chlorophyll fluorescence parameters (Fv / Fm, ΦPSII), intercellular CO2 concentration (Ci), leaf surface temperature (Tleaf) of functional lettuce leaves, as well as environmental parameters including ambient temperature (Tenv), ambient relative humidity (RH) and ambient CO2 concentration (Cenv). S2: Input the real-time data into a preset photosynthetic stage identification model and output the current photosynthetic stage of the lettuce. The photosynthetic stage includes at least the activation period, the efficient carbon fixation period, the saturation period, and the photoinhibition risk period. S3: Based on the photosynthesis stage, call the corresponding pulse parameter configuration table to dynamically generate pulse parameters for 450 / 460nm laser and 660nm LED. The pulse parameters include pulse frequency (f), single pulse width (t_pulse), duty cycle (D), phase difference (Δt_phase), peak power (P_peak) or irradiance (I_red), where the phase difference is defined as the time offset between the rising edge of the blue light pulse and the rising edge of the red light pulse. S4: A high-precision synchronous drive module is used to output optical signals according to the pulse parameters, forming a time-coupled light field of blue light and red light that acts on the canopy of lettuce. S5: Monitor Tleaf in real time and compare it with the safety threshold (T_safe). When Tleaf≥T_safe, start the energy-thermal collaborative management strategy to suppress thermal stress by reducing the peak power of blue light or inserting a cooling interval. S6: Periodically calculate the rate of change of Pn and Ci (dPn / dt, dCi / dt), determine the effectiveness of the light formulation based on the rate of change, and make closed-loop parameter corrections to enable lettuce to maintain or enter a state of efficient carbon assimilation.

2. The rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses as described in claim 1, characterized in that: The photosynthetic stage identification model in step S2 is a classifier based on decision tree or deep neural network. Its training samples are derived from photosynthetic gas exchange and fluorescence data of lettuce under different growth dates and environmental conditions. The corresponding pulse parameter configuration can only be executed if the model output confidence is ≥85%.

3. The rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses as described in claim 1, characterized in that: The pulse parameter configuration table in step S3: Activation period: f = 500–600 Hz, D_blue = 50%–70%, Δt_phase = blue light leads red light by 10–30 μs, P_peak (450 nm) = 100–150 mW, P_peak (460 nm) = 80–120 mW, I_red = 150–250 μmol·m -2 ·s -1 ; High-efficiency carbon fixation period: f = 350–450 Hz, D_blue = 30%–50%, Δt_phase = blue light lags red light by 10–20 μs, P_peak (450 nm) = 80–120 mW, P_peak (460 nm) = 60–100 mW, I_red = 200–300 μmol·m -2 ·s -1 ; Saturation period: f = 300-400Hz, D_blue = 20%-40%, Δt_phase = synchronous or blue light lags red light by 20-40μs, P_peak decreases by 10%-20%; Light suppression risk period: f≤300Hz, D_blue≤30%, I_red increased to maximum tolerance value, and cooling interval activated.

4. The rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses as described in claim 1, characterized in that: The high-precision synchronous drive module in step S4 includes: a temperature-controlled crystal oscillator (±1ppm) as a time reference; an FPGA or high-speed MCU to generate and output pulse waveforms; blue laser drive and red LED drive connected via opto-isolation modules to ensure electrical isolation and anti-interference; and a timing drift detection circuit that compares the trigger times of the two pulses in real time and automatically calibrates when the deviation exceeds ±1μs.

5. The rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses as described in claim 1, characterized in that: In step S5, T_safe is set based on the lettuce variety and growth period, generally between 25 and 28°C. When Tleaf ≥ T_safe, at least one of the following measures is performed: Reduce P_peak(450nm) and P_peak(460nm) simultaneously by 10% to 30%; A 1-5 ms zero-intensity interval is inserted after each blue light pulse as a cooling window; Reduce D_blue by 5% to 15% while keeping red light unchanged to transfer heat energy.

6. The rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses as described in claim 1, characterized in that: The logic for determining the closed-loop correction in step S6 is as follows: If dPn / dt < 0 and dCi / dt > 0, it is determined to be a light suppression trend, and f and D_blue are immediately reduced while I_red is increased; If dPn / dt>0 and dCi / dt<0, it is determined to be the carbon assimilation acceleration period, and D_blue and P_peak can be appropriately increased; If dPn / dt≈0 and dCi / dt≈0, it is determined to be in steady state, and the current parameters are maintained. Each correction should not exceed ±20% of the original parameter, and the parameter should be reassessed every hour.

7. The rapid carbon assimilation photoformulation and control method for lettuce based on the time-series coupling of 450 / 460nm laser and 660nm LED pulses as described in claim 1, characterized in that: It also includes an anomaly protection mechanism: when sensor data is missing for more than 3 consecutive sampling periods or Pn is below a threshold (e.g., 1 μmol·m⁻²·s⁻¹), the anomaly protection mechanism will be activated. -1 When the alarm is triggered, the system switches to the preset safety light formula and issues an alarm.

8. A rapid carbon assimilation light regulation system for lettuce for implementing the method of any one of claims 1-7, characterized in that: include: Multi-parameter sensor array: includes a photosynthetic gas exchange measurement unit (LI-6800 or equivalent device), a chlorophyll fluorescence measurement unit, an infrared temperature sensor array, and an ambient CO2 / temperature and humidity sensor; Data processing and stage identification unit: embedded controller or industrial PC, running the photosynthetic stage identification model; Pulse parameter calculation and instruction generation unit: calculates real-time pulse parameters by looking up tables and interpolating based on stage identification results; High-precision synchronous drive control unit: includes a temperature-controlled crystal oscillator, FPGA / high-speed MCU, opto-isolation and drift calibration circuit; Light source components: 450nm and 460nm laser modules, 660nm high-power LED array, both supporting external PWM / analog dimming; Temperature feedback adjustment module: dynamically adjusts the drive current or inserts cooling gaps based on Tleaf; Human-computer interaction and data storage module: touch screen or remote terminal, used for parameter setting, curve display and historical data storage.