A microbial culture material fermentation parameter adaptive control system and method

Abstract

The application discloses a microbial culture material fermentation parameter self-adaptive control system and method, and particularly relates to the field of post-treatment of enzymolysis products of agricultural wastes. The system comprises a culture treatment unit, a thermal environment keeping unit, a parameter acquisition unit, a state reconstruction unit, a target process generation unit, a coupling prediction unit, a control decision unit and an execution adjustment unit. The application aims to solve the problem that the existing culture bin or drum-type equipment only has mechanical turning, ventilation or heat preservation functions and is difficult to perform modelized closed-loop control around microbial fermentation parameters.

Description

Technical Field

[0001] This invention relates to the field of microbial culture and post-processing technology of enzymatic hydrolysis products of agricultural waste, and particularly to an adaptive control system and method for fermentation parameters of microbial culture materials. Background Technology

[0002] Agricultural waste such as poultry and livestock manure and straw, after being treated with compound enzyme preparations, can form enzymatic hydrolysis products containing humic substances, fulvic acid, soluble small-molecule organic matter, and microbial nutrient substrates. These enzymatic hydrolysis products typically have a high temperature and high moisture content immediately after enzymatic hydrolysis; for example, the temperature upon entering the storage chamber can be 75-85℃, and the moisture content can be 45%-55%. Direct static cooling or the use of ordinary drum drying can easily lead to excessively rapid temperature drops, missed activation windows for the microorganisms, uneven moisture migration, and decreased enzyme activity.

[0003] Traditional composting or ordinary drum equipment mainly solves the problems of turning and dehydration, but lacks synchronous prediction and closed-loop control of microbial quantity, enzyme activity, moisture content and oxygen supply. Even if the equipment is equipped with temperature or humidity sensors, it usually uses threshold alarms or single-variable control, and cannot automatically change the material residence time according to future compliance trends.

[0004] In large horizontal culture chambers with capacities of 80 tons and 50 meters, there are obvious differences in the material along the axial direction between the feeding zone, intermediate culture zone, and discharge zone. The temperature, moisture content, oxygen concentration, bacterial count, and enzyme activity in different zones do not change synchronously. If a uniform rotation speed and air volume are set for the entire chamber, it is easy to cause some materials to fail to meet the standards or localized over-drying.

[0005] Furthermore, whether an insulation sleeve is installed on the outside of the cylindrical culture chamber, and whether the heat loss of the insulation sleeve is controlled, directly affects the energy consumption for slow cooling and reheating. Simply using the outer shell as a mechanical insulation structure cannot solve the problem of coupling control between reheating, dehumidification, oxygen supply, and microbial proliferation.

[0006] Therefore, there is an urgent need for an automatic control system for fermentation parameters that integrates zone sensing, thermal resistance, heat-water-bacteria-enzyme coupling model, and multi-objective predictive control. Summary of the Invention

[0007] The present invention aims to solve the problem that existing culture chambers or drum-type equipment only have mechanical turning, ventilation or heat preservation functions, and it is difficult to carry out model-based closed-loop control around microbial fermentation parameters.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] An adaptive control system for fermentation parameters of microbial culture materials includes a culture processing unit, a thermal environment maintenance unit, a parameter acquisition unit, a state reconstruction unit, a target process generation unit, a coupling prediction unit, a control decision unit, and an execution adjustment unit. The culture processing unit receives the organic substrate to be cultured and agitates, mixes, and moves it along the discharge direction within the culture space. The thermal environment maintenance unit is at least partially arranged around the culture space to reduce heat exchange between the culture space and the external environment and to provide a controlled transfer channel for heating, ventilation, or dehumidification. The parameter acquisition unit acquires multiple parameters of the organic substrate to be cultured. The state reconstruction unit generates state data characterizing the current culture state based on the multiple parameters. The target process generation unit generates target processes related to cooling, dehydration, oxygen supply, microbial proliferation, and enzyme activity maintenance. The coupling prediction unit predicts the future culture state based on the state data and the target processes. The control decision unit generates coordinated control commands based on the deviation between the future culture state and the target processes. The execution adjustment unit executes the coordinated control commands to ensure that the organic substrate reaches preset culture indicators before discharge.

[0010] Specifically, when the coupling prediction unit predicts that the organic substrate to be cultivated will reach the preset cultivation index ahead of schedule, the control decision unit generates a control instruction to shorten the material residence time; when the coupling prediction unit predicts that the organic substrate to be cultivated will not reach the preset cultivation index within the preset cultivation period, the control decision unit generates a control instruction to extend the material residence time and / or enhance environmental regulation.

[0011] Preferably, the organic substrate to be cultivated is an organic conversion material obtained after biological, enzymatic hydrolysis, thermal treatment, composting pretreatment or a combination thereof.

[0012] The organic substrate to be cultured is given functional microbial agents before or during the culture treatment unit. The functional microbial agents include spore-forming agents, actinomycete agents, yeast agents, compound aerobic agents, or combinations thereof.

[0013] Preferably, the thermal environment maintenance unit includes an insulation sleeve disposed on the outside of the culture chamber. The insulation sleeve includes an inner insulation structure close to the culture chamber and an outer insulation cover disposed on the outside of the inner insulation structure. An insulation interlayer is formed between the inner insulation structure and the outer insulation cover. The insulation interlayer is connected to at least one of a heat energy inlet interface, a ventilation interface, a dehumidification interface, or a waste heat recovery interface.

[0014] Preferably, the parameter acquisition unit is divided into at least two monitoring zones along the material movement direction. Each monitoring zone is equipped with an online detection device and / or sampling detection interface for collecting at least a number of data, including material temperature, gas phase temperature, moisture content, oxygen concentration, carbon dioxide concentration, pH, microbial quantity, enzyme activity, silo movement parameters, and ventilation parameters.

[0015] Preferably, the state reconstruction unit filters, removes anomalies, assigns confidence weights, and performs soft measurement compensation on data from different monitoring zones and different sensor categories, and forms zone state data corresponding to batch number b, zone number z, and sampling time t; the zone state data includes at least temperature state, moisture state, gas state, and biological activity state.

[0016] Preferably, the target process generation unit generates a phased target process based on the initial state of entering the warehouse, the target state of discharging, the tolerance range of the microbial agent, and the constraints of the cultivation cycle; the phased target process includes at least two of the following: a high-temperature slow cooling stage, a proliferation and oxygen supply stage, a dehydration and stabilization stage, and a standard discharge stage.

[0017] Preferably, the coupled prediction unit includes at least three of the following: a heat prediction sub-model, a moisture migration prediction sub-model, an aeration and oxygen supply prediction sub-model, and a biological activity prediction sub-model. The moisture migration prediction sub-model uses aeration rate, air intake status, dehumidification intensity, and material moisture content as inputs to predict the dehydration trend of the organic substrate to be cultivated. The heat prediction sub-model uses the equivalent thermal resistance of the thermal environment maintenance unit, the external ambient temperature, the insulation layer temperature, the material's self-generated heat, and the supplemental heat as inputs to predict the cooling trend of the organic substrate to be cultivated. The biological activity prediction sub-model is used to predict changes in microbial quantity, enzyme activity, or a combination of both.

[0018] Preferably, the bioactivity prediction sub-model corrects the microbial proliferation rate and enzyme activity change rate based on temperature suitability, moisture content suitability, oxygen supply suitability, and pH suitability; when any suitability is lower than the corresponding threshold, the control decision unit preferentially adjusts the intensity of supplemental heating, ventilation, dehumidification, or turning to bring the suitability back to the target range.

[0019] Preferably, the control decision unit generates a comprehensive compliance index based on the compliance of temperature, moisture content, gas content, microbial quantity, and enzyme activity, and uses the comprehensive compliance index together with the core discharge threshold as the basis for judging material release, accelerated advancement, or delayed cultivation.

[0020] Preferably, the comprehensive compliance index is generated using a weighted method, with the weights for different compliance levels set or updated based on raw material type, microbial agent type, seasonal environment, target product grade, or historical batch data; when the number of microorganisms or enzyme activity cannot be continuously detected online, the comprehensive compliance index uses soft measurement results in the calculation.

[0021] Preferably, the control decision unit adopts a rolling predictive control method, which optimizes state deviation, control action changes, energy consumption and terminal compliance risk within the prediction step size, and solves the cooperative control command within the allowable range of rotation speed, propulsion speed, ventilation volume, air intake temperature, heat replenishment and dehumidification intensity.

[0022] Preferably, the adaptive control system for fermentation parameters of the biological culture material further includes a batch self-learning unit, which updates at least one of the heat exchange parameters, moisture migration parameters, microbial proliferation parameters, enzyme activity change parameters, and sensing reliability parameters in the coupled prediction unit based on the deviation between the discharge detection results and the target discharge state.

[0023] This invention also provides an adaptive control method for fermentation parameters of biological culture materials, the method comprising: S1, receiving an organic substrate to be cultured with initial heat and initial moisture content, and placing it into a culture space in which the thermal environment is maintained by a thermal environment maintenance unit; S2, collecting multiple fermentation parameters and equipment operating parameters of the organic substrate to be cultured during the culture process; S3, reconstructing the current culture state based on the multiple fermentation parameters and equipment operating parameters; S4, predicting the future culture state based on the current culture state and the target process; S5, coordinating and adjusting at least two of the following parameters according to the deviation between the future culture state and the target process: material residence time, agitation intensity, aeration rate, heat supplementation, and moisture removal rate; S6, shortening the material residence time when the predicted target is met ahead of schedule, and extending the material residence time and / or enhancing environmental regulation when the predicted target is not met, until the discharge conditions are met.

[0024] Preferably, the organic substrate to be cultured is an enzymatic hydrolysis product of agricultural waste, with an inlet temperature of 75-85℃ and a moisture content of 45%-55%; the outlet conditions include a moisture content of no more than 30% after culture and a microbial count of no less than 2×10⁻⁶. 8 At least two of the following: CFU / g and enzyme activity of not less than 130 U / g.

[0025] Compared with the prior art, the advantages or beneficial effects of the technical solution of this application include:

[0026] First, this invention does not simply improve the mechanical structure of the culture chamber, but rather integrates culture processing, thermal environment maintenance, multi-parameter acquisition, state reconstruction, target process generation, coupled prediction, control decision-making, and execution regulation into a closed-loop control system. Through the coordinated operation of the above units, collaborative control commands can be dynamically generated based on the actual state of the organic substrate to be cultured during the culture process. This allows the material to simultaneously achieve cooling, dehydration, oxygen supply, microbial proliferation, and enzyme activity maintenance during agitation, mixing, and movement along the discharge direction. This solves the problem that traditional culture equipment mainly relies on fixed time, fixed speed, or manual experience control, making it difficult to balance culture efficiency and stable output quality.

[0027] Secondly, this invention provides a stable and controllable thermal environment for the cultivation space by incorporating a thermal environment maintenance unit. This unit, at least partially surrounding the cultivation space, reduces heat exchange between the cultivation space and the external environment and provides a controlled transfer channel for heating, ventilation, or dehumidification. Therefore, after the high-temperature organic substrate enters the cultivation chamber, instead of simple, rapid heat dissipation, the temperature is slowly lowered and the heat is adjusted according to the microbial cultivation needs. This avoids both excessively rapid temperature drops leading to insufficient microbial proliferation window and excessively high local temperatures causing decreased bacterial activity or enzyme loss.

[0028] Third, this invention improves the temperature stability and energy efficiency of large-scale culture chambers through the combination of an insulation jacket, an inner insulation structure, an outer insulation cover, and an insulation interlayer. The insulation interlayer can connect to heat supply interfaces, ventilation interfaces, dehumidification interfaces, or waste heat recovery interfaces, enabling the culture chamber to not only have a heat preservation function but also to be linked with the processes of heat supply, ventilation, dehumidification, and waste heat recovery. This structure can reduce the impact of changes in external ambient temperature on the culture process, reduce heat supply energy consumption, and make the material cooling process more gradual and predictable, making it particularly suitable for the continuous culture of organic conversion materials with initial heat and initial moisture content.

[0029] Fourth, this invention improves the anti-interference capability of the control system by filtering, anomaly removal, confidence weighting, and soft measurement compensation of multi-source data through a state reconstruction unit. In actual fermentation processes, sensors are easily affected by dust, moisture, high temperatures, material coverage, and differences in local ventilation. Directly using raw detection values ​​can easily lead to frequent fluctuations in control actions. This invention generates partition state data corresponding to batch number, partition number, and sampling time through state reconstruction, and incorporates temperature, moisture, gas, and biological activity states into the judgment, reducing the impact of occasional abnormal detection values ​​on the control results and making the system control more stable and reliable.

[0030] Fifth, this invention generates phased target processes through a target process generation unit, making cultivation control more aligned with the laws of microbial fermentation. The target process is not simply setting a final output index, but rather, based on the initial state upon entering the storage chamber, the target output state, the tolerance range of the microbial agent, and the constraints of the cultivation cycle, it forms phased targets such as a high-temperature slow cooling phase, a proliferation and oxygen supply phase, a dehydration and stabilization phase, and a target-reaching output phase. This allows for highlighting key control objectives such as gradual temperature reduction, oxygen supply and proliferation, moisture reduction, and target-reaching release at different stages, avoiding problems such as excessive dehumidification in the early stages of cultivation, insufficient oxygen supply in the middle stages, or outputting before the indicators stabilize in the later stages. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the adaptive control system architecture for fermentation parameters of biological culture materials according to the present invention.

[0032] Figure 2 Line drawing of an application scenario where materials are loaded into an insulated culture chamber.

[0033] Figure 3 This is a flowchart of an automatic control method for fermentation parameters.

[0034] Figure 4 This is a schematic diagram of the phased target process and achievement control. Detailed Implementation

[0035] The following detailed description of the embodiments of this application, in conjunction with the accompanying drawings, will provide a thorough understanding of how this application uses technical means to solve technical problems and achieve corresponding technical effects, enabling its implementation. The embodiments of this application and the various features within them can be combined with each other without conflict, and all resulting technical solutions are within the protection scope of this application.

[0036] It should be clearly stated that the embodiments described below are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] Example 1: Structure, Insulation, Heat Exchange, and Material Loading of the Culture Chamber

[0038] like Figure 2 As shown, the cultivation unit in this embodiment adopts a horizontal cylindrical rotating stepping culture chamber. The cylindrical rotating culture chamber is arranged in a long cylindrical shape along its length and is driven by a frequency conversion drive component to rotate continuously or intermittently around a horizontal axis in a preset single direction. The organic substrate to be cultivated is quantitatively fed into the cylindrical rotating culture chamber through a premix hopper, an inclined conveyor, a feeding hopper, and a screw metering feeder, so that the feed rate can match the effective residence time in the chamber.

[0039] For cases where the temperature of the organic substrate to be cultured can reach 75-85℃ upon entering the culture chamber, the microbial agent is added in stages. Heat-resistant spore-forming microbial agents are added first, either before or during entry into the chamber. Once the material temperature in the slow cooling zone has decreased to the allowable inoculation temperature of the corresponding microbial agent, yeast, actinomycete, or compound aerobic microbial agents are added through a second inoculation port located in the intermediate culture zone. This second inoculation port can be connected to a metering pump and an atomizing nozzle, allowing the microbial solution to be dispersed along the cross-section of the material. For microbial agents that need to be added all at once during the high-temperature stage, a heat-resistant embedding carrier can be used for protection.

[0040] The cylindrical rotary culture chamber is equipped with spiral guide plates inside. These plates lift, drop, and mix the material as the chamber rotates in one direction. To allow for separate adjustment of the tumbling intensity and axial propulsion speed, the cylindrical rotary culture chamber also features an independent propulsion mechanism. This mechanism can be one of the following: an independently driven axial screw, a reciprocating pusher mechanism, an adjustable-angle guide assembly, a frequency-controlled discharge screw, or a controllable discharge gate. Therefore, the chamber's rotation speed primarily controls the tumbling and mixing intensity, while the independent propulsion mechanism primarily controls the material's movement speed and residence time along the discharge direction, preventing the rotation speed and residence time from being coupled together due to reliance solely on the inclined guide plates.

[0041] The cylindrical rotating culture chamber is equipped with an inner insulation structure and a fixed outer insulation shell. The inner insulation structure inhibits heat loss from the chamber, while the outer insulation shell isolates the external environment and forms an insulation interlayer. To avoid the insulation layer blocking the heat replenishment path, the heat inlet does not directly supply heat to the interior of the insulation material, but connects to an independent heat exchange duct that passes through the inner insulation structure. This independent heat exchange duct forms a heat exchange cavity circumferentially on the outer wall of the cylindrical rotating culture chamber, through which clean hot air or heat exchange medium indirectly exchanges heat with the outer wall of the chamber. The insulation interlayer serves as a buffer for residual heat and isolates the chamber from external temperatures. The return air after heat exchange can be returned to the heat exchanger via a residual heat recovery interface.

[0042] The process air required for cultivation and the circulating air in the insulation jacket use independent air paths. The process air enters the cylindrical rotating culture chamber through the air inlet temperature control component and the hollow air inlet shaft, and then enters the material layer through the axially arranged air distribution holes; the exhaust gas carrying water vapor and carbon dioxide is discharged through an independent dehumidification pipeline, and passes sequentially through a dust collector, condenser or deodorization device. Therefore, the airflow in the insulation jacket does not directly replace the oxygen supply airflow entering the material layer.

[0043] The cylindrical rotary culture chamber is divided into a feeding slow-cooling zone, an intermediate propagation zone, and a discharging stabilization zone along the material movement direction. Each monitoring zone is equipped with a fixed hollow probe and sampling interface. Temperature, gas phase temperature, oxygen concentration, and carbon dioxide concentration probes can be installed on the hollow probe; the probe extends into the chamber from the end of the chamber through a rotary seal and does not rotate with the chamber. The moisture content probe can be installed inside an impact-resistant protective cover. The chamber's motion parameters are collected by a rotary encoder and a propulsion mechanism encoder. For the wireless sensing nodes that rotate with the chamber, battery power or inductive power can be used, and the detection data is correlated with the corresponding axial zone based on the encoder angle.

[0044] When the length of the cylindrical rotary culture chamber reaches 50m, multiple sets of tires and support rollers are installed on the outer periphery of the chamber. The drive end is equipped with a gear ring drive or friction drive assembly, and a limit wheel is installed axially. Thermal expansion compensation gaps are reserved at the feed or discharge end. Rotary seals are installed at the feed and discharge ends, and the chamber body is equipped with inspection doors, cleaning spray nozzles, overload protection, and material blockage detection devices, thereby ensuring the coaxiality, sealing, and ease of maintenance of the large long cylindrical chamber during rotation.

[0045] Example 2: System Architecture and State Variables

[0046] like Figure 1 As shown, the parameter acquisition unit, state reconstruction unit, target process generation unit, coupling prediction unit, and control decision unit can be deployed in a control platform composed of an industrial control computer, edge computing controller, or programmable controller and host computer. The parameter acquisition unit communicates with the online sensor group via industrial bus or industrial Ethernet, and the control decision unit sends setpoints to the silo drive mechanism, independent propulsion mechanism, process air supply component, air inlet temperature control component, heat exchange and heat replenishment component, and dehumidification component through the control cabinet.

[0047] For the The first batch, the first Each monitoring zone, at the sampling time The state vector is defined as:

[0048]

[0049] in, For material temperature, The gas phase temperature, The wet basis moisture content of the material. Oxygen concentration, This refers to the concentration of carbon dioxide. pH level For the number of microorganisms, For the target enzyme activity, This refers to the residence or movement status of materials within the corresponding monitoring zone.

[0050] The control variable vector is defined as follows:

[0051]

[0052] in, The unidirectional rotational speed of the chamber. This refers to the material propulsion speed corresponding to the independent propulsion mechanism. This refers to the process ventilation rate entering the culture chamber. For process air inlet temperature, To provide additional heat for heat exchange ducts or heat exchange jackets. The exhaust gas moisture emission intensity. The above variables use a unified batch, partition, and time index to ensure time-series correspondence between detection data, target processes, prediction results, and execution instructions.

[0053] Example 3: Partition Monitoring, Trust Weighting, and State Reconstruction

[0054] Each monitoring zone preferably has multiple material temperature and moisture content monitoring points, as well as monitoring points for gas phase temperature, oxygen concentration, and carbon dioxide concentration. pH, microbial count, and target enzyme activity are measured using at least one of online detection, bypass detection, or timed sampling. Online microbial count can be estimated based on optical scattering, fluorescence response, dielectric properties, or oxygen consumption rate; target enzyme activity can be measured using a bypass reaction unit.

[0055] The state reconstruction unit first performs time alignment, range checks, rate of change checks, and model residual checks on each sensor data point. When a sensor exhibits drift, abrupt jumps, prolonged periods without updates, significant inconsistencies with adjacent detection points, or exceeds physically permissible limits, the reliability of the corresponding data is reduced. Reliability of Class Detection Data The value ranges from 0 to 1. The lower the confidence level, the smaller the impact of the data on the state reconstruction result.

[0056] In one implementation, the partitioned state data is obtained using a weighted estimation with confidence and temporal continuity constraints:

[0057]

[0058] in, This is the reconstructed partition state. For the first The number of data categories involved in the reconstruction of each monitoring partition For the first Class detection data, This represents the mapping relationship between state variables and detection variables. For time continuity coefficient, This is the state change weight matrix.

[0059] When microbial quantity or target enzyme activity cannot be continuously monitored online, a soft sensor model is used to generate estimates. The input to the soft sensor model includes at least the material temperature, moisture content, oxygen concentration, carbon dioxide concentration, pH, aeration rate, rotation speed, propulsion speed, and the most recent sampling result from multiple consecutive sampling periods. The output is an estimate of microbial quantity or target enzyme activity. The model can employ partial least squares regression, ridge regression, support vector regression, or recursive state estimation models, and is calibrated using historical samples with synchronized sampling results. Upon arrival of new measured results, the model bias is updated based on the deviation between the measured value and the soft sensor value; when the validation error exceeds a preset range, the reliability of the soft sensor result is reduced, and resampling is triggered.

[0060] Example 4: Generation of Phased Target Process

[0061] The target process generation unit determines the stage switching time and stage target status for each monitoring zone based on the initial material temperature, initial moisture content, type of microbial agent, microbial agent tolerance temperature, standard culture period, and discharge target. Stage switching can be triggered by the running time, or by the material temperature, moisture content, oxygen concentration, or microbial quantity entering the corresponding interval.

[0062] For the The first training stage, the... The first batch, the first The target status of each monitoring zone is generated using a continuous transition method:

[0063]

[0064]

[0065] in, and The first The initial and final target states of a phase. and These are the start and end times of the phase. This is a smooth transition function.

[0066] During the high-temperature slow cooling stage, only heat-resistant microbial agents are added and rapid ventilation is restricted, allowing the material to reach the inoculation temperature allowed by subsequent microbial agents at a preset slow cooling rate. During the proliferation and oxygen supply stage, non-heat-resistant functional microbial agents are added through a second inoculation interface, while maintaining suitable temperature, moisture content, and oxygen concentration. During the dehydration and stabilization stage, the moisture removal capacity is gradually increased, while limiting the cooling rate and the risk of enzyme activity decay. During the standard discharge stage, the target state is converted into discharge temperature, discharge moisture content, microbial quantity, and target enzyme activity requirements.

[0067] Example 5: Heat-Water-Oxygen-Bacteria-Enzyme Coupling Prediction

[0068] The coupled prediction unit predicts the future cultivation state based on the reconstructed partition state and control variables. To ensure the heat compensation model matches the actual insulation structure, the material temperature state in the chamber and the temperature state in the heat exchange chamber are set. The first batch, the first The heat changes in each monitoring zone are expressed as follows:

[0069]

[0070]

[0071] in, For independent heat exchange ducts or heat exchange chamber temperatures, The equivalent heat capacity of the material, For the equivalent heat capacity of the heat exchange cavity, The heat released by biological metabolism and enzymatic reactions The equivalent thermal resistance between the material and the heat exchange chamber. The equivalent thermal resistance between the heat exchange cavity and the external environment. The latent heat of vaporization of water. The evaporation rate is the rate at which water is evaporated.

[0072] Changes in material moisture content, oxygen concentration, microbial quantity, and target enzyme activity are expressed as follows:

[0073]

[0074]

[0075]

[0076]

[0077] in, Using wet basis moisture content, The standard volumetric flow rate entering the culture chamber per unit time is used. The normalized opening degree of the dehumidification actuator or the converted dehumidification airflow rate; and Calibration is achieved through a weighing water loss test. The relative humidity of the incoming air. For microbial oxygen consumption rate, For environmental carrying capacity, The microbial attenuation coefficient, This represents the contribution coefficient of microbial proliferation to the formation of target enzyme activity. The coefficient representing the decrease in target enzyme activity is denoted as .

[0078] In one implementation, the environmental suitability functions take the following form:

[0079]

[0080]

[0081]

[0082]

[0083] The optimal value and width parameters are determined based on the tolerance range of the bacterial agent used or historical batch calibration data. The coupled prediction unit discretizes equations (5) to (7) according to the sampling interval and resets the prediction starting point after each new detection data is obtained.

[0084] Example 6: Comprehensive Compliance Index and Output Judgment

[0085] The control decision unit calculates the compliance rates for temperature, moisture content, oxygen supply, microbial quantity, and target enzyme activity, respectively. Each compliance rate is normalized to 0–1. For temperature indicators with target ranges, a compliance rate of 1 is defined as the measured value falling within the target range; for moisture content indicators with upper limit requirements, a compliance rate of 1 is defined as the measured value not exceeding the upper limit; and for microbial quantity and target enzyme activity indicators with lower limit requirements, a compliance rate of 1 is defined as the measured value reaching or exceeding the corresponding lower limit.

[0086] No. The first batch, the first The comprehensive compliance index of each monitoring zone is expressed as:

[0087]

[0088] in, , , , and These are respectively temperature, moisture content, oxygen supply, microbial quantity, and the degree to which the target enzyme activity meets the standards. , , , and The corresponding weights are set according to the type of raw material, type of microbial agent, grade of target product, and seasonal environment, and can be updated in a bounded manner based on historical batch results.

[0089] The discharge criteria employ a dual approach, considering both a comprehensive release threshold and a core quality indicator threshold. Only when the comprehensive compliance index of the discharge zone is met will the discharge be allowed to proceed. Normal or early discharge is allowed only when the overall release threshold is not lower than the threshold and the preset core indicators of microbial quantity, target enzyme activity and moisture content reach their respective thresholds; when the overall compliance index reaches the release threshold but any core indicator is insufficient, the system continues to cultivate.

[0090] Figure 4 This is used to illustrate the trend of each achievement level changing over time during a 24-hour culture cycle. Figure 4 The data in the figure represents the model calculation results obtained after setting three sets of parameter perturbation simulation conditions under the same initial material conditions. The data points in the figure represent the mean of the three sets of simulation results, and the error bars represent the standard deviation of the simulation results. These data are not considered as unverified experimental data. The compliance rates of temperature, moisture content, microbial quantity, and target enzyme activity all gradually approach 1 during the cultivation process. When the prediction results show that the material cannot meet the standards within the standard cultivation period, the system reduces the propulsion speed and extends the residence time. When the comprehensive compliance index and core quality indicators of the discharge zone meet the requirements ahead of schedule, the system increases the propulsion speed and discharges the material earlier.

[0091] Example 7: Multi-objective rolling predictive control

[0092] The control decision unit employs a rolling predictive control method to forecast the state of each monitoring zone within a future prediction step, and solves for the coordinated control sequence within the allowable ranges of unidirectional rotation speed, independent propulsion speed, process ventilation, inlet air temperature, heat exchange and replenishment, and dehumidification intensity. The optimization objective simultaneously considers state deviation, control action changes, energy consumption, and terminal compliance risks; its objective function is expressed as:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] in, To predict the step size, To control the step size, To monitor the number of partitions, This is the state deviation weight matrix. To control the weight matrix of action changes, The cost of air supply, heating, dehumidification, and drive energy consumption. To predict the comprehensive compliance index of the discharge zone at the end of the step length, and These are the weighting coefficients.

[0099] Solution for control decision unit:

[0100]

[0101] in, This is the optimal control sequence. This is the feasible control set. The feasible control set is represented as:

[0102]

[0103] in, and These include the lower and upper limits of the chamber rotation speed, independent propulsion speed, process ventilation, inlet air temperature, heat exchange and replenishment heat, and dehumidification intensity. This represents the maximum allowable change between adjacent control cycles. After obtaining the optimal control sequence, only the first control variable is sent to the execution control unit; at the next sampling time, data is reacquired, the state is reconstructed, and the solution is obtained again.

[0104] Example 8: Control of Early Target Achievement, Expected Failure to Achieve Target Achievement, and Abnormal Operating Conditions

[0105] This embodiment adds adaptive residence time logic based on Embodiment 7. The system simultaneously compares the current discharge zone compliance status, the predicted step length endpoint compliance status, the minimum cultivation residence time, and the status of core quality indicators.

[0106] When the current comprehensive compliance index of the discharge zone reaches the comprehensive release threshold, the core quality indicators meet the requirements, and the material has exceeded the minimum cultivation residence time, the control decision unit increases the propulsion speed of the independent propulsion mechanism or increases the rotation speed of the discharge screw to discharge the qualified material in advance; the silo body still maintains rotation in one direction, and the rotation speed and process ventilation are not lower than the minimum values ​​required to prevent agglomeration and oxygen deficiency.

[0107] When the current comprehensive compliance index has not yet reached the comprehensive release threshold, but the predicted step length endpoint is expected to reach the comprehensive release threshold, the system maintains normal progress and uses minor ventilation, heating, or dehumidification adjustments to reduce energy consumption and control fluctuations. When the comprehensive compliance index at the predicted step length endpoint is lower than the comprehensive release threshold, or when core indicators such as predicted microbial quantity, target enzyme activity, or moisture content fail to meet the targets on schedule, the control decision unit reduces the independent progress speed or temporarily suspends progress, and selects the corresponding action based on the source of the deviation.

[0108] When the temperature is below the target range and the moisture content is normal, heat is supplied to the outer wall of the silo through an independent heat exchange duct; when the moisture content is too high and the oxygen concentration is too low, the process ventilation rate entering the material layer inside the silo is increased and the exhaust gas dehumidification is enhanced; when the material temperature is high and there is a risk of decay in the target enzyme activity, heat supply is stopped and intermittent ventilation is adopted; when the material mixing uniformity is insufficient, the unidirectional rotation speed of the silo is increased, but the independent propulsion speed is not changed.

[0109] To prevent acceleration and deceleration commands from repeatedly switching around the threshold, the system sets a hysteresis range and a minimum action hold time, and sets upper and lower limits and rate of change limits for each executed variable. When the reliability of a key sensor is lower than the preset threshold, the system uses soft measurement values ​​to maintain control; when both measured and soft measurement values ​​are unavailable, the system switches to the safe process curve for the corresponding raw material and microbial agent and issues an alarm. If the temperature exceeds the safety upper limit, the silo drive is overloaded, ventilation fails, the rotary seal malfunctions, or the discharge end is blocked, the system stops propulsion and executes ventilation cooling or shutdown protection procedures.

[0110] Example 9: Batch Self-Learning and Parameter Correction

[0111] The batch self-learning unit reads the measured discharge temperature, moisture content, microbial quantity, and target enzyme activity after each batch of material is discharged, and compares them with the corresponding predicted and target values. The parameters used for updating include at least one of the following: equivalent thermal resistance, drying coefficient, oxygen consumption parameter, maximum proliferation coefficient, target enzyme activity decay coefficient, fitness function parameter, and sensing reliability benchmark.

[0112] Parameter updates are represented as:

[0113]

[0114] in, For the first Model parameters used in each batch The batch loss function is composed of prediction errors based on discharge temperature, moisture content, microbial quantity, and target enzyme activity. For learning rate, For batch data validity weights, This indicates that the updated parameters will be restricted to the set of parameters allowed by the project. Inside.

[0115] Before updating parameters, the validity of the output detection data should be checked. If a batch experiences sensor malfunction, abnormal raw material composition, unplanned downtime, or manual intervention, the following measures should be taken: Alternatively, the batch update can be omitted. Each updated model is first tested using historical validation data, and only when the prediction error does not increase and the parameters do not exceed the engineering allowable range is it written into the next batch controller.

[0116] Example 10: Engineering Application of an 80-ton-class Culture Chamber

[0117] This embodiment employs an 80-ton horizontal cylindrical rotary stepping culture chamber. The cylindrical rotary culture chamber is 50m long and 4m in diameter, with the main body made of 304 stainless steel. Multiple sets of tires and support rollers are installed along its length, along with axial limiting wheels and a thermal expansion compensation structure. A fixed outer insulation shell is installed on the outside of the chamber, forming a chamber-shaped structure of approximately 52m × 6m × 6m using insulation panels and a supporting frame. Independent heat exchange air ducts pass through the insulation structure and form heat exchange chambers along the outer wall of the chamber.

[0118] The organic substrate to be cultured is agricultural organic conversion material that has undergone enzymatic hydrolysis. The temperature upon entering the silo is approximately 80℃, and the moisture content of the wet substrate is approximately 50%. A heat-resistant spore-forming functional microbial agent is added upon entry to achieve an initial microbial count of [missing information]. ~ When the material temperature in the slow cooling zone drops below 45℃, a non-thermosensitive functional microbial agent can be added through the second inoculation interface. The standard culture cycle is set at 24 hours, the target wet substrate moisture content is not higher than 30%, and the target microbial count is not lower than [specified value]. .

[0119] In this embodiment, cellulase activity is used as an example indicator of target enzyme activity. Sodium carboxymethyl cellulose is used as the substrate, and the reaction is carried out at pH 4.8 and 50°C for 30 minutes. The amount of enzyme required to catalyze the production of 1 μmol of reducing sugar per minute is defined as 1 U. The enzyme activity is calculated per gram of dry material, and the target value is set to be no less than 130 U / g. When using other target enzymes, the enzyme activity units and target thresholds are redefined according to the corresponding substrate and standard detection method.

[0120] In the feeding slow cooling zone, the focus is on monitoring the high-temperature slow cooling state and the activation state of the heat-resistant bacterial agent; in the intermediate proliferation zone, the focus is on monitoring oxygen concentration, carbon dioxide concentration, microbial quantity and target enzyme activity, and the second stage of inoculation is carried out; in the discharge stabilization zone, the focus is on monitoring moisture content, microbial quantity, target enzyme activity and comprehensive compliance index.

[0121] For example, when the system predicts that the comprehensive compliance index of the discharge zone at the end of 24 hours is lower than the comprehensive release threshold after 18 hours of operation, and the main deviations are due to high moisture content and low oxygen concentration, the independent propulsion speed is reduced and the process ventilation and exhaust gas dehumidification intensity are increased. If the main deviations are due to the temperature being lower than the suitable range for the microbial agent, heat is supplemented through independent heat exchange ducts while limiting process ventilation and cooling, instead of directly sending heat into the insulation material.

[0122] After 20 hours of operation, if the overall compliance index of the discharge zone reaches the overall release threshold, and the number of microorganisms, target enzyme activity, and moisture content all reach the core threshold, and the minimum culture retention time is met, then the independent propulsion speed is increased and early discharge is implemented. If the overall compliance index reaches the release threshold but the target enzyme activity has not yet reached the core threshold, then culture continues, and early release is not implemented.

[0123] The control trajectory in this embodiment is used to illustrate the engineering parameter settings and control logic; in the absence of actual parallel test data, Figure 4 For simulation purposes only, the simulation error bars are not represented as actual experimental errors.

[0124] Example 11: Control Method Flow

[0125] The control method in this embodiment includes the following steps.

[0126] S1: Read the raw material type, inoculant type, batch number, inlet temperature, inlet moisture content, and target product grade; premix and meter the heat-resistant inoculant with the high-temperature material, and perform the second-stage inoculation according to the subsequent temperature conditions.

[0127] S2 collects data on material temperature, gas phase temperature, moisture content, oxygen concentration, carbon dioxide concentration, pH, microbial quantity, target enzyme activity, unidirectional rotation speed of the silo, independent propulsion speed, and gas path operating parameters according to multiple monitoring zones set along the material movement direction.

[0128] S3 performs time-series alignment, anomaly identification, and credibility weighting on multi-source data, and performs soft measurement compensation for temporarily missing microbial quantities or target enzyme activities to form partitioned state data.

[0129] S4 generates a phased target process based on the initial state upon entering the warehouse, the tolerance range of the microbial agent, the stage inoculation conditions, the standard culture cycle, and the discharge target.

[0130] S5 uses the coupling relationship between material temperature, heat exchange chamber temperature, moisture migration, oxygen supply, microbial quantity and target enzyme activity to predict future culture status.

[0131] S6 generates a comprehensive compliance index based on temperature, moisture content, oxygen supply, microbial quantity, and target enzyme activity compliance, and determines whether the core quality indicators meet the requirements.

[0132] S7 solves the multi-objective rolling predictive control problem within the amplitude and rate of change constraints of the executed variables, and obtains the coordinated control sequence of the unidirectional rotation speed of the silo, independent propulsion speed, process ventilation, inlet air temperature, heat exchange and replenishment heat and dehumidification intensity.

[0133] S8 executes only the first control quantity corresponding to the current control cycle, and re-executes S2 to S7 at the next sampling time.

[0134] S9: When the target is predicted to be achieved ahead of schedule, increase the independent propulsion speed and shorten the dwell time; when the target is predicted to be not achieved on schedule, reduce the independent propulsion speed, extend the dwell time and / or enhance the corresponding environmental adjustment; when a critical failure occurs, execute the safety process curve or shutdown protection.

[0135] S10: After discharge, read the measured quality indicators and write them back to the batch database to perform bounded updates on model parameters and sensor reliability benchmarks.

[0136] Through the above steps, the organic substrate to be cultivated can be automatically controlled in a closed loop from staged inoculation, silo entry, zoned cultivation, state prediction, and coordinated adjustment to reach the target discharge.

[0137] In summary, this invention possesses industrial applicability and can be used for the large-scale microbial cultivation of enzymatic hydrolysis products, biological pretreatment products, composted intermediate materials, and other moist organic matrices from agricultural organic waste. The temperature, humidity, and gas sensors, frequency converters, ventilation and dehumidification systems, heating systems, and industrial control components used in the system can all be implemented using existing industrial equipment. Microbial quantity and enzyme activity can be obtained online, via bypass, sampling, or soft measurement methods, thus possessing a clear engineering foundation and industrial application value.

Claims

1. An adaptive control system for fermentation parameters of microbial culture materials, characterized in that, It includes a cultivation and processing unit, a thermal environment maintenance unit, a parameter acquisition unit, a state reconstruction unit, a target process generation unit, a coupled prediction unit, a control decision-making unit, and an execution and regulation unit; The cultivation processing unit receives the organic substrate to be cultivated and agitates, mixes, and moves it along the discharge direction within the cultivation space. The thermal environment maintenance unit is at least partially arranged around the cultivation space to reduce heat exchange between the cultivation space and the external environment and to provide a controlled transfer channel for heating, ventilation, or dehumidification. The parameter acquisition unit acquires multiple parameters of the organic substrate to be cultivated. The state reconstruction unit generates state data characterizing the current cultivation state based on the multiple parameters. The target process generation unit generates target processes related to cooling, dehydration, oxygen supply, microbial proliferation, and enzyme activity maintenance. The coupling prediction unit predicts the future cultivation state based on the state data and the target processes. The control decision unit generates coordinated control commands based on the deviation between the future cultivation state and the target processes. The execution adjustment unit executes the coordinated control commands to ensure that the organic substrate to be cultivated reaches the preset cultivation index before discharge.

2. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The organic substrate to be cultured is an organic conversion material that has undergone enzymatic hydrolysis for 3 hours. The organic substrate to be cultured is given functional microbial agents before or during the culture treatment unit. The functional microbial agents include spore-forming agents, actinomycete agents, yeast agents, compound aerobic agents, or combinations thereof.

3. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The thermal environment maintenance unit includes an insulation sleeve disposed on the outside of the culture chamber. The insulation sleeve includes an inner insulation structure close to the culture chamber and an outer insulation cover disposed on the outside of the inner insulation structure. An insulation interlayer is formed between the inner insulation structure and the outer insulation cover. The insulation interlayer is connected to at least one of a heat energy inlet interface, a ventilation interface, a dehumidification interface, or a waste heat recovery interface.

4. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The parameter acquisition unit is divided into at least two monitoring zones along the material movement direction. Each monitoring zone is equipped with an online detection device and / or sampling detection interface for collecting at least a number of data, including material temperature, gas phase temperature, moisture content, oxygen concentration, carbon dioxide concentration, pH, microbial quantity, enzyme activity, silo movement parameters, and ventilation parameters.

5. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The state reconstruction unit filters, removes anomalies, assigns confidence weights, and performs soft measurement compensation on data from different monitoring zones and different sensor categories, and forms zone state data corresponding to batch number b, zone number z, and sampling time t. The partition status data includes at least temperature status, moisture status, gas status, and biological activity status.

6. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The target process generation unit generates a phased target process based on the initial state of entering the warehouse, the target state of discharging, the tolerance range of the microbial agent, and the constraints of the cultivation cycle. The phased target process includes at least two of the following: a high-temperature slow cooling stage, a proliferation and oxygen supply stage, a dehydration and stabilization stage, and a standard discharge stage.

7. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The coupled prediction unit includes at least three of the following: heat prediction sub-model, water migration prediction sub-model, ventilation and oxygen supply prediction model, and biological activity prediction model; The moisture migration prediction sub-model uses aeration rate, air intake status, dehumidification intensity and material moisture content as inputs to predict the dehydration trend of the organic substrate to be cultivated. The heat prediction sub-model uses the equivalent thermal resistance of the thermal environment maintenance unit, the external ambient temperature, the temperature of the insulation interlayer, the self-generated heat of the material, and the supplementary heat as inputs to predict the cooling trend of the organic matrix to be cultivated. The bioactivity prediction sub-model is used to predict changes in microbial populations, enzyme activity, or a combination of both.

8. The adaptive control system for fermentation parameters of microbial culture materials according to claim 7, characterized in that, The bioactivity prediction sub-model corrects the microbial proliferation rate and enzyme activity change rate based on temperature suitability, moisture content suitability, oxygen supply suitability, and pH suitability. When any suitability is lower than the corresponding threshold, the control decision unit prioritizes adjusting the intensity of supplemental heating, ventilation, dehumidification, or turning to bring the suitability back to the target range.

9. The adaptive control system for fermentation parameters of microbial culture materials according to claim 1, characterized in that, The control decision unit generates a comprehensive compliance index based on the compliance of temperature, moisture content, gas content, microbial quantity, and enzyme activity. The comprehensive compliance index, together with the core discharge threshold, serves as the basis for determining whether to release materials, accelerate the process, or extend the cultivation period.

10. The adaptive control system for fermentation parameters of microbial culture materials according to claim 9, characterized in that, The comprehensive compliance index is generated using a weighted method. The weights for different compliance levels are set or updated based on the type of raw materials, type of microbial agent, seasonal environment, target product grade, or historical batch data. When the number of microorganisms or enzyme activity cannot be continuously detected online, the comprehensive compliance index uses soft measurement results in the calculation.

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