Cascade type dissolved oxygen control method, device and server

Abstract

The application provides a cascade type dissolved oxygen control method and device and a server, and relates to the technical field of bioreactors.The method comprises the following steps: obtaining real-time dissolved oxygen content by using a dissolved oxygen sensor; determining a PID control signal based on the real-time dissolved oxygen content and a preset index of a controller by using a cascade controller; determining the corresponding gas PID output value of each PID controller based on the PID control signal, the real-time dissolved oxygen content, a target dissolved oxygen content, dissolved oxygen adjustment information and the preset index of the PID controller by using a preset output value calculation model of each PID controller in a PID controller set; determining the corresponding output value of each gas actuator based on the gas PID output value sent by the corresponding PID controller of the gas actuator and the preset maximum flow value of the gas actuator by using a preset flow calculation model of each gas actuator in an actuator set, and outputting the corresponding gas according to the output value.The application can significantly improve the accuracy of dissolved oxygen content control and further improve the protection of cells in the bioreactor.

Description

Technical Field

[0001] This invention relates to the technical field of bioreactors, and in particular to a cascade dissolved oxygen control method, apparatus, and server. Background Technology

[0002] In biological cell culture or fermentation, dissolved oxygen levels in the environment are a crucial parameter. Optimal dissolved oxygen levels can increase cell or fermentation yields. Reactor equipment needs to control the dissolved oxygen level at different stages of culture or fermentation to meet the dissolved oxygen requirements during the process. Currently, related technologies propose using air or oxygen as the oxygen transfer gas and controlling dissolved oxygen levels through a single PID control technique. However, this approach is somewhat chaotic and prone to resource waste. When cascade control is selected, the cascade control is associated with the rotation speed. When dissolved oxygen levels are low, the rotation speed is automatically increased to improve stirring efficiency and thus increase dissolved oxygen transfer efficiency in the liquid. However, as the rotation speed increases, this approach can easily damage cells and affect their growth rate. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a cascaded dissolved oxygen control method, device and server, which can significantly improve the accuracy of dissolved oxygen control, thereby improving the protection of cells in bioreactors.

[0004] In a first aspect, embodiments of the present invention provide a cascaded dissolved oxygen control method. The method is applied to a cascaded dissolved oxygen control system, which includes: a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The PID controller set includes multiple PID controllers, and the actuator set includes multiple gas actuators. Each PID controller and gas actuator corresponds one-to-one. The method includes: acquiring real-time dissolved oxygen levels using the dissolved oxygen sensor; determining a PID control signal based on the real-time dissolved oxygen levels and preset indicators of the controllers using the cascaded controllers, wherein the preset indicators of the cascaded controllers include a target dissolved oxygen level; calculating a model based on the preset output values ​​of each PID controller in the PID controller set, and determining the corresponding gas PID output value for each PID controller based on the PID control signal, real-time dissolved oxygen levels, target dissolved oxygen levels, dissolved oxygen regulation information, and the preset indicators of the PID controllers; and determining the corresponding output value of each gas actuator based on the preset flow rate calculation model of each gas actuator in the actuator set, based on the gas PID output value sent by the PID controller corresponding to the gas actuator and the preset maximum flow rate value of the gas actuator, and outputting the corresponding gas according to the output value.

[0005] In one embodiment, the PID controller set includes: a surface-flow air PID controller, a surface-flow oxygen PID controller, a bottom-flow air PID controller, a bottom-flow oxygen PID controller, and a surface-flow nitrogen PID controller. The method includes: acquiring the dissolved oxygen demand for biological cell culture or fermentation; when the dissolved oxygen demand increases, activating the corresponding gas from the PID controller set according to a preset bottom priority.

[0006] The PID controller is used for dissolved oxygen regulation. The bottom priority order, from highest to lowest, is: air supply to the top, oxygen supply to the bottom, air supply to the bottom, and oxygen supply to the bottom. The higher the priority, the more likely dissolved oxygen is regulated.

[0007] The lower the oxygenation efficiency, the more efficient the oxygenation. When the dissolved oxygen demand decreases, dissolved oxygen is regulated by a nitrogen PID controller.

[0008] In one implementation, dissolved oxygen regulation information includes: dissolved oxygen rise dead zone value, dissolved oxygen fall dead zone value, dissolved oxygen rise fine-tuning value, and dissolved oxygen fall fine-tuning value. The cascade controller's preset indicators further include: 0 dissolved oxygen rise fine-tuning range, dissolved oxygen fall fine-tuning range, and dead zone range value. The method includes: setting the target...

[0009] The difference between the dissolved oxygen level and the dead zone interval is determined as the dissolved oxygen rising dead zone value, and the difference between the dissolved oxygen rising dead zone value and the dissolved oxygen rising fine-tuning interval is determined as the dissolved oxygen rising fine-tuning value; the sum of the target dissolved oxygen level and the dead zone interval is determined as the dissolved oxygen falling dead zone value, and the sum of the dissolved oxygen falling dead zone value and the dissolved oxygen falling fine-tuning interval is determined as the dissolved oxygen falling fine-tuning value.

[0010] 5. In one embodiment, the step of activating the PID controller corresponding to a gas from the PID controller set according to a preset lower priority to regulate dissolved oxygen includes: when the PID controller corresponding to a high-priority gas is in the activating state, if the gas actuator corresponding to the PID controller maintains a preset maximum flow rate value for output, and the duration of the maximum flow rate value output state reaches a preset time threshold, then it is determined that the gas does not meet the dissolved oxygen control requirements, and the PID controller corresponding to the next priority gas is activated.

[0011] In one embodiment, the method further includes: when the PID controller corresponding to the low-priority gas is in the on state, if the gas actuator corresponding to the PID controller maintains the minimum flow rate output and the duration of the minimum flow rate output state reaches a preset time threshold, then it is determined that the dissolved oxygen requirement has been met, the PID controller corresponding to the current priority gas is turned off, and the process returns to the PID controller corresponding to the previous priority gas.

[0012] In one implementation, the PID control signal includes a start / stop command and a mode command, wherein the mode command includes a manual mode command and an automatic mode command. The method includes: when the PID controller receives a manual mode command sent by the cascade controller, the PID controller enters manual mode, and the gas actuator corresponding to the PID controller stops calculating the output value and maintains the maximum output state to output gas; when the PID controller receives an automatic mode command sent by the cascade controller, the PID controller enters automatic mode, and the gas actuator corresponding to the PID controller maintains the output value calculation and outputs gas according to the output value calculation result.

[0013] In one embodiment, the method includes: when the PID controller corresponding to any priority gas is turned on, controlling the PID controller to adjust dissolved oxygen in automatic mode via an automatic mode command; when the PID controller corresponding to the next priority gas is turned on, controlling the PID controller to adjust dissolved oxygen in manual mode via a manual mode command.

[0014] Secondly, embodiments of the present invention also provide a cascaded dissolved oxygen control device. The device is applied to a cascaded dissolved oxygen control system, which includes: a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The PID controller set includes multiple PID controllers, and the actuator set includes multiple gas actuators. Each PID controller and gas actuator corresponds one-to-one. The device includes: a dissolved oxygen acquisition module, which acquires real-time dissolved oxygen using the dissolved oxygen sensor; a control signal generation module, which determines a PID control signal based on the real-time dissolved oxygen and preset indicators of the controllers through the cascaded controllers, wherein the preset indicators of the cascaded controllers include a target dissolved oxygen level; a PID output value determination module, which determines the gas PID output value corresponding to each PID controller based on the PID control signal, real-time dissolved oxygen, target dissolved oxygen, dissolved oxygen regulation information, and preset indicators of the PID controllers through a preset output value calculation model of each PID controller in the PID controller set; and a gas output module, which determines the output value corresponding to each gas actuator based on the gas PID output value sent by the PID controller corresponding to the gas actuator and the preset maximum flow value of the gas actuator through a preset flow calculation model of each gas actuator in the actuator set, and outputs the corresponding gas according to the output value.

[0015] Thirdly, embodiments of the present invention also provide a server, including a processor and a memory, the memory storing computer-executable instructions executable by the processor, the processor executing the computer-executable instructions to implement any of the methods provided in the first aspect.

[0016] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions, which, when invoked and executed by a processor, cause the processor to implement any of the methods provided in the first aspect.

[0017] The embodiments of the present invention bring the following beneficial effects:

[0018] This invention provides a cascaded dissolved oxygen control method, device, and server. The method is applied to a cascaded dissolved oxygen control system, which includes a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The PID controller set includes multiple PID controllers, and the actuator set includes multiple gas actuators, with a one-to-one correspondence between the PID controllers and the gas actuators. The method utilizes the dissolved oxygen sensor to acquire real-time dissolved oxygen levels. Based on the real-time dissolved oxygen levels and preset controller parameters, the cascaded controller determines the PID control signal. Using a preset output value calculation model for each PID controller in the PID controller set, the gas PID output value corresponding to each PID controller is determined based on the PID control signal, real-time dissolved oxygen levels, target dissolved oxygen levels, dissolved oxygen regulation information, and preset PID controller parameters. Finally, using a preset flow rate calculation model for each gas actuator in the actuator set, the output value corresponding to each gas actuator is determined based on the gas PID output value sent by the corresponding PID controller and the preset maximum flow rate value of the gas actuator. The corresponding gas is then output according to the output value. This invention significantly improves the accuracy of dissolved oxygen control, thereby enhancing the protection of cells within the bioreactor.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1A schematic flowchart of a cascaded dissolved oxygen control method provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of a cascaded dissolved oxygen control system provided in an embodiment of the present invention;

[0024] Figure 3 A schematic flowchart of another cascaded dissolved oxygen control method provided in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of a cascaded dissolved oxygen control device provided in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0028] In biological cell culture or fermentation, dissolved oxygen levels are a crucial parameter. Optimal dissolved oxygen levels can maximize cell or fermentation yield. Reactor equipment needs to control dissolved oxygen levels at different stages of culture or fermentation to meet the oxygen requirements. Currently, commercially available bioreactors use air or oxygen as the oxygen transfer gas for dissolved oxygen control. However, using only PID control technology cannot accurately and timely control dissolved oxygen levels, and may even lead to energy waste due to erratic regulation. On the other hand, cascaded dissolved oxygen control in reactors often involves correlated rotation speed. When dissolved oxygen levels are low, the rotation speed automatically increases to improve stirring efficiency and thus increase dissolved oxygen transfer efficiency in the liquid. However, as the rotation speed increases, the shear rate also increases, which can significantly damage cells and affect cell growth. Therefore, the cascaded dissolved oxygen control method provided in this invention can significantly improve the accuracy of dissolved oxygen control, thereby enhancing the protection of cells within the bioreactor.

[0029] See Figure 1 The diagram shows a cascaded dissolved oxygen control method, which mainly includes the following steps S102 to S108:

[0030] Step S102: Obtain real-time dissolved oxygen levels using a dissolved oxygen sensor. The method is applied to a cascaded dissolved oxygen control system, which includes: a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The PID controller set includes multiple PID controllers, and the actuator set includes multiple gas actuators. There is a one-to-one correspondence between the PID controllers and the gas actuators. The dissolved oxygen sensor is used to measure real-time dissolved oxygen levels and is connected to the cascaded controller.

[0031] Step S104: Based on the real-time dissolved oxygen level and the preset indicators of the controller, the cascade controller determines the PID control signal. The preset indicators of the cascade controller include the target dissolved oxygen level. The cascade controller receives the real-time value (PV) measured by the dissolved oxygen sensor and outputs the PID controller control signal according to the dissolved oxygen target value (SV), dissolved oxygen rise fine-tuning range (AU), dissolved oxygen fall fine-tuning range (AD), dead zone range value (DP), switching time (T) of each gas, and cascade enable status (EB) of each gas set on its own controller. In one embodiment, the PID control signal includes a start / stop command and a mode command. The mode command includes a manual mode command and an automatic mode command. The cascade controller sends the start / stop command, manual mode command, automatic mode command, real-time dissolved oxygen level, and target dissolved oxygen level to the corresponding PID controller.

[0032] Step S106: Using the preset output value calculation model of each PID controller in the PID controller set, based on the PID control signal, real-time dissolved oxygen, target dissolved oxygen, dissolved oxygen regulation information, and preset indicators of the PID controller, determine the gas PID output value corresponding to each PID controller. The PID controller set includes: surface air PID controller, surface oxygen PID controller, bottom air PID controller, bottom oxygen PID controller, and surface nitrogen PID controller. In one embodiment, the calculation logic within different PID controllers is the same, but the parameters included in the calculation logic are different.

[0033] In another implementation, see Figure 2The diagram illustrates the structure of a cascaded dissolved oxygen control system. The air-passing PID controller receives the real-time value (PV) measured by the dissolved oxygen sensor, the PID control target value (SV), dissolved oxygen rise dead zone value (UDP), dissolved oxygen rise fine-tuning value (UAP), start / stop command (START), and mode command (MODE) output from the cascaded controller. It then calculates the air-passing PID output value based on the gain (P), integral time (I), derivative time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller. The oxygen-passing PID controller also receives the real-time value (PV) measured by the dissolved oxygen sensor, the PID control target value (SV), dissolved oxygen rise dead zone value (UDP), dissolved oxygen rise fine-tuning value (UAP), start / stop command (START), and mode command (MODE) output from the cascaded controller. It then calculates the oxygen-passing PID output value based on the gain (P), integral time (I), derivative time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller. The surface-level oxygen PID controller receives the real-time value (PV) measured by the dissolved oxygen sensor, the PID control target value (SV), dissolved oxygen rise dead zone value (UDP), dissolved oxygen rise fine adjustment value (UAP), start / stop command (START), and mode command (MODE) output from the cascade controller. It then calculates the bottom-level air PID output value based on the gain (P), integral time (I), derivative time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller.

[0034] Step S108: Based on the preset flow calculation model of each gas actuator in the actuator set, the output value of the gas actuator is determined according to the gas PID output value sent by the PID controller corresponding to the gas actuator and the preset maximum flow value of the gas actuator. The corresponding gas is output according to the output value. In one embodiment, the output value of the gas actuator = the gas PID output value of the PID controller * the maximum flow value set by the gas actuator (MAX FLOW).

[0035] The cascaded dissolved oxygen control method provided in this embodiment of the invention can significantly improve the accuracy of dissolved oxygen control, thereby enhancing the protection of cells within the bioreactor.

[0036] This invention also provides an implementation method for calculating dissolved oxygen regulation information, which includes: dissolved oxygen rise dead zone value, dissolved oxygen fall dead zone value, dissolved oxygen rise fine adjustment value, and dissolved oxygen fall fine adjustment value. The preset index of the cascade controller also includes: dissolved oxygen rise fine adjustment range, dissolved oxygen fall fine adjustment range, and dead zone range value, as detailed in (1) to (4) below:

[0037] (1) The difference between the target dissolved oxygen level and the dead zone value is determined as the dissolved oxygen rise dead zone value, i.e.:

[0038] Dissolved oxygen rise dead zone (UDP) = Target dissolved oxygen value (SV) - Dead zone interval value (DP)

[0039] (2) The difference between the dissolved oxygen rise dead zone value and the dissolved oxygen rise fine-tuning range is determined as the dissolved oxygen rise fine-tuning value, i.e.:

[0040] Dissolved oxygen rise adjustment value (UAP) = Dissolved oxygen rise dead zone value (UDP) - Dissolved oxygen rise adjustment range (AU)

[0041] (3) The sum of the target dissolved oxygen level and the dead zone value is determined as the dissolved oxygen decrease dead zone value, i.e.:

[0042] Dissolved oxygen decline dead zone (DDP) = Target dissolved oxygen value (SV) + Dead zone interval value (DP)

[0043] (4) The sum of the dissolved oxygen decrease dead zone value and the dissolved oxygen decrease fine-tuning interval is determined as the dissolved oxygen decrease fine-tuning value, i.e.:

[0044] Dissolved oxygen decrease adjustment value (DAP) = Dissolved oxygen decrease dead zone value (DDP) + Dissolved oxygen decrease adjustment range (AD)

[0045] In one implementation, the cascade enable status (EB) of each gas can mask the priority of the current gas. That is, if the cascade of surface oxygen is not enabled, when the surface air is turned on and a jump is required, the surface oxygen will be skipped and the bottom air will be controlled. If the cascades of both surface oxygen and bottom air are not enabled, when the surface air is turned on and a jump is required, both surface oxygen and bottom air will be skipped and the bottom oxygen will be controlled. In another implementation, the cascade controller will only output the relevant control signals of the cascade enabled gas.

[0046] This invention also provides an implementation method for dissolved oxygen regulation based on gas priority, as detailed in (a) to (c) below:

[0047] (a) Obtain the dissolved oxygen demand for biological cell culture or fermentation. In one embodiment, due to factors such as different oxygen contents in gases, different ways of introducing gases into the reactor, and bubble shear force, each gas control will set the underlying priority. During the rising stage of the dissolved oxygen demand (i.e., PV < UDP): surface aeration with air priority > surface aeration with oxygen priority > bottom aeration with air priority > bottom aeration with oxygen priority; during the falling stage of the dissolved oxygen demand (i.e., PV > DDP): surface aeration with nitrogen. When the dissolved oxygen control is in the rising demand stage, logical judgment is performed through a cascade controller. Surface aeration with air is preferentially started. After meeting the cascade jump logic condition, surface aeration with oxygen of the next priority is then started, and so on according to the priority. When the dissolved oxygen control is in the falling demand stage, adjustment is made by controlling surface aeration with nitrogen.

[0048] (b) When the dissolved oxygen demand rises, according to the preset underlying priority, the PID controller corresponding to the gas is activated from the set of PID controllers for dissolved oxygen adjustment. Among them, the underlying priority is sorted from high to low as: surface aeration with air, surface aeration with oxygen, bottom aeration with air, bottom aeration with oxygen. The higher the priority, the lower the oxygen increase efficiency during dissolved oxygen adjustment. In one embodiment, when the PID controller corresponding to the gas with high priority is in the activated state, if the gas actuator corresponding to the PID controller maintains the preset maximum flow value for output and the duration of the maximum flow value output state reaches the preset time threshold, it is determined that the gas does not meet the control demand for dissolved oxygen content, and the PID controller corresponding to the gas of the next priority is activated. In another embodiment, when the PID controller corresponding to the gas with low priority is in the activated state, if the gas actuator corresponding to the PID controller maintains the minimum flow value output and the duration of the minimum flow value output state reaches the preset time threshold, it is determined that the dissolved oxygen demand is met, the PID controller corresponding to the gas of the current priority is closed, and the PID controller corresponding to the gas of the previous priority is returned to.

[0049] In one embodiment, the gas actuators include: surface aeration with air actuator, surface aeration with oxygen actuator, bottom aeration with air actuator, bottom aeration with oxygen actuator. The surface aeration with air actuator is used to receive the surface aeration with air PID output value and calculate the actuator output value according to the maximum flow value (MAX FLOW) set on its own actuator; the surface aeration with oxygen actuator is used to receive the surface aeration with oxygen PID output value and calculate the actuator output value according to the maximum flow value (MAX FLOW) set on its own actuator; the bottom aeration with air actuator is used to receive the bottom aeration with air PID output value and calculate the actuator output value according to the maximum flow value (MAXFLOW) set on its own actuator; the bottom aeration with oxygen actuator is used to receive the bottom aeration with oxygen PID output value and calculate the actuator output value according to the maximum flow value (MAX FLOW) set on its own actuator.

[0050] (c) When the dissolved oxygen demand decreases, the dissolved oxygen is regulated by the surface nitrogen injection PID controller. In one embodiment, the dissolved oxygen level can be reduced by delivering nitrogen. The surface nitrogen injection PID controller is used to receive the real-time value (PV) measured by the dissolved oxygen sensor, the PID control target value (SV) output by the cascade controller, the dissolved oxygen decrease dead zone value (DDP), the dissolved oxygen decrease fine-tuning value (DAP), the start / stop instruction (START), the mode instruction (MODE), and calculate the surface nitrogen injection PID output value according to the gain (P), integral time (I), derivative time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller. In another embodiment, when the real-time dissolved oxygen level (PV) is in the fine-tuning range (i.e., UAP <= PV < UDP), the first-priority gas output control reaches the maximum flow rate, and after the maximum flow rate output state duration reaches the switching time (T), if it is determined that the maximum output of this gas still cannot meet the control demand for the dissolved oxygen level, then the gas control of the next priority level is entered to increase the regulation speed of the dissolved oxygen level and achieve the purpose of accuracy and speed. Conversely, when the low-priority gas output reaches the minimum flow rate, and after the minimum flow rate output state duration reaches the switching time (T), if it is determined that the current dissolved oxygen demand has been met, the gas control of a higher priority level can be returned to reduce energy consumption and achieve the purpose of energy conservation and accurate regulation.

[0051] The embodiment of the present invention also provides an implementation method for the PID controller to switch working modes. When the PID controller receives the manual mode instruction sent by the cascade controller, the PID controller enters the manual mode, and the gas actuator corresponding to the PID controller stops calculating the output value and maintains the maximum output state to output gas. When the PID controller receives the automatic mode instruction sent by the cascade controller, the PID controller enters the automatic mode, and the gas actuator corresponding to the PID controller maintains the calculation of the output value and outputs gas according to the calculation result of the output value. In one embodiment, when the PID controller corresponding to any priority level gas is turned on, the automatic mode instruction is used to control the PID controller to regulate the dissolved oxygen level in the automatic mode. When the PID controller corresponding to the next priority level gas is turned on, the manual mode instruction is used to control the PID controller to regulate the dissolved oxygen level in the manual mode. In another embodiment, the PID controller is controlled by the MODE instruction output by the cascade controller. When entering the manual mode, the PID controller always maintains the maximum output and no longer automatically calculates the output value according to the set parameters. When entering the automatic mode, the PID control automatically calculates according to the set parameters. The PID output value is a percentage from 0 to 100% and is limited by MAX and MIN, where MIN <= PID output value <= MAX, and both MAX and MIN are values between 0 and 100%.

[0052] To facilitate understanding of the cascaded dissolved oxygen control method provided in the above embodiments, this invention provides an application example of the cascaded dissolved oxygen control method, see below. Figure 3 The flowchart of another cascaded dissolved oxygen control method is shown. This method mainly includes the following steps S302 to S308:

[0053] In step S302, the dissolved oxygen sensor measures the real-time dissolved oxygen value, and the cascade controller acquires the real-time dissolved oxygen value. In practical applications, the dissolved oxygen sensor is connected to the cascade controller to transmit the real-time dissolved oxygen signal to the cascade controller; the cascade controller is connected to the PID controller of each gas to transmit the corresponding control signal to each PID controller; the PID controller is connected to its corresponding actuator to transmit the calculated PID output value to the actuator; the actuator is the final driver that executes the calculated flow rate output.

[0054] Step S304: The cascade controller outputs a PID controller control signal based on the set dissolved oxygen target value, dissolved oxygen rise fine-tuning range, dissolved oxygen fall fine-tuning range, dead zone value, switching time, and the cascade enabling status of each gas. In one embodiment, the PID controller outputs the control signal required by the PID controller based on the actual dissolved oxygen value, the set dissolved oxygen rise fine-tuning range, dissolved oxygen fall fine-tuning range, dead zone value, switching time, and the cascade enabling status of each gas. The PID controller control signal includes the controller's PID control target value (SV), dissolved oxygen rise dead zone value (UDP), dissolved oxygen fall dead zone value (DDP), dissolved oxygen rise fine-tuning value (UAP), dissolved oxygen fall fine-tuning value (DAP), start / stop command (START), and mode command (MODE).

[0055] In step S306, each PID controller outputs parameters such as the received target value, fine-tuning value, dead zone value, start / stop command, mode command, and set gain, integral time, derivative time, period, and maximum / minimum output. In one embodiment, the output value of each PID controller is calculated based on the above control signals and set gain (P), integral time (I), derivative time (D), period time (CT), maximum output value (MAX), and minimum output value (MIN).

[0056] In practical applications, when PV < UAP, the cascade controller issues a start command to the controller with the highest priority in the cascade-enabled gas control, cuts the PID controller mode to the manual mode and maintains 100% output, and does not start the remaining cascade gas controls. For example, when all gases are cascade-enabled, the cascade controller will output a start command for the air PID controller of the meter pass and the MODE is in the manual mode, and the air PID controller of the meter pass outputs the maximum value; in one embodiment, when PV rises to the fine-tuning range (i.e., UAP <= PV < UDP), the cascade controller changes the air PID controller of the meter pass to the automatic mode. At this time, the air PID controller of the meter pass calculates the air PID output value of the meter pass according to the control target value (SV), the real-time dissolved oxygen content (PV), and the gain (P), integral time (I), differential time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller; at this time, as the air PID output value of the meter pass increases and reaches the maximum value, the calculation of the switching time (T) starts. After T arrives, the air PID controller of the meter pass feeds back a signal to the cascade controller, and the cascade controller switches the mode of the air PID controller of the meter pass to the manual mode and maintains its maximum output state. At the same time, it issues a START command and an automatic mode command to the oxygen PID controller of the meter pass, the gas controller of the next priority. At this time, the oxygen PID controller of the meter pass calculates the oxygen PID output value of the meter pass according to the control target value (SV), the real-time dissolved oxygen content (PV), and the gain (P), integral time (I), differential time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller. If PV has not reached the value of UDP at this time, the switching of the next lower priority will also be judged using the same logic.

[0057] In another embodiment, when PV >= UDP and PV <= DDP, it means that the dissolved oxygen control dead zone range has been entered at this time. At this time, all gas PID controllers are closed and all gas feeding into the bioreactor is stopped; when PV > DDP and PV <= DAP, it means that the dissolved oxygen content is higher than the set value at this time, and the demand for dissolved oxygen decrease starts. At this time, the cascade controller closes the air and oxygen controllers, opens the nitrogen PID controller of the meter pass, and gives an automatic mode command. At this time, the nitrogen PID controller of the meter pass calculates the nitrogen PID output value of the meter pass according to the control target value (SV), the real-time dissolved oxygen content (PV), and the gain (P), integral time (I), differential time (D), cycle time (CT), maximum output value (MAX), and minimum output value (MIN) set on its own controller, and nitrogen starts to be fed into the reactor to control the decrease of the dissolved oxygen content; when PV > DAP, the cascade controller switches the nitrogen PID controller of the meter pass to the manual mode and controls it to maintain the maximum output.

[0058] In step S308, each actuator calculates and outputs the required flow rate of the gas based on the received PID output value and the set maximum flow rate value. In one embodiment, the actuator output value is calculated based on each PID output value and the set maximum flow rate value (MAX FLOW).

[0059] In summary, this invention can significantly improve the accuracy of dissolved oxygen control, thereby enhancing the protection of cells within the bioreactor.

[0060] Regarding the cascaded dissolved oxygen control method provided in the foregoing embodiments, this invention provides a cascaded dissolved oxygen control device. This device is applied to a cascaded dissolved oxygen control system, which includes: a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The PID controller set includes multiple PID controllers, and the actuator set includes multiple gas actuators. There is a one-to-one correspondence between the PID controllers and the gas actuators. (See [link to previous documentation]). Figure 4 The diagram shows a cascaded dissolved oxygen control device, which includes the following components:

[0061] Dissolved oxygen acquisition module 402 uses a dissolved oxygen sensor to acquire real-time dissolved oxygen levels.

[0062] The control signal generation module 404 determines the PID control signal based on the real-time dissolved oxygen level and the preset indicators of the controller through the cascade controller. The preset indicators of the cascade controller include the target dissolved oxygen level.

[0063] The PID output value determination module 406 determines the gas PID output value corresponding to each PID controller by using the preset output value calculation model of each PID controller in the PID controller set, based on the PID control signal, real-time dissolved oxygen, target dissolved oxygen, dissolved oxygen regulation information and preset index of the PID controller.

[0064] The gas output module 408 determines the output value of the gas actuator based on the preset flow calculation model of each gas actuator in the actuator set, the gas PID output value sent by the PID controller corresponding to the gas actuator and the preset maximum flow value of the gas actuator, and outputs the corresponding gas according to the output value.

[0065] The data processing device provided in this application embodiment utilizes multi-gas control in a free cascade manner and multi-gas PID operation control to solve the problem that a single PID adjustment technology cannot control dissolved oxygen in a timely and accurate manner, and to avoid the problem that increasing the rotation speed will cause the cells to be subjected to increased shear force.

[0066] In one embodiment, the PID controller set includes: a surface-to-air PID controller, a surface-to-oxygen PID controller, a bottom-to-air PID controller, a bottom-to-oxygen PID controller, and a surface-to-nitrogen PID controller. The control signal generation module 404 is further used to: acquire the dissolved oxygen demand for biological cell culture or fermentation; when the dissolved oxygen demand increases, according to a preset bottom priority, activate the PID controller corresponding to the gas from the PID controller set to regulate dissolved oxygen, wherein the bottom priority is ordered from high to low as: surface-to-air, surface-to-oxygen, bottom-to-air, bottom-to-oxygen, with higher priority resulting in lower oxygenation efficiency during dissolved oxygen regulation; when the dissolved oxygen demand decreases, dissolved oxygen is regulated through the surface-to-nitrogen PID controller.

[0067] In one embodiment, the dissolved oxygen regulation information includes: dissolved oxygen rise dead zone value, dissolved oxygen fall dead zone value, dissolved oxygen rise fine-tuning value, and dissolved oxygen fall fine-tuning value. The preset index of the cascade controller also includes: dissolved oxygen rise fine-tuning range, dissolved oxygen fall fine-tuning range, and dead zone range value. The PID output value determination module 406 is further used to: determine the difference between the target dissolved oxygen amount and the dead zone range value as the dissolved oxygen rise dead zone value, and determine the difference between the dissolved oxygen rise dead zone value and the dissolved oxygen rise fine-tuning range as the dissolved oxygen rise fine-tuning value; determine the sum of the target dissolved oxygen amount and the dead zone range value as the dissolved oxygen fall dead zone value, and determine the sum of the dissolved oxygen fall dead zone value and the dissolved oxygen fall fine-tuning range as the dissolved oxygen fall fine-tuning value.

[0068] In one embodiment, when performing the step of activating the PID controller corresponding to the gas from the PID controller set according to the preset lower priority to regulate dissolved oxygen, the control signal generation module 404 is further configured to: when the PID controller corresponding to the high priority gas is in the activated state, if the gas actuator corresponding to the PID controller maintains a preset maximum flow rate value for output, and the duration of the maximum flow rate value output state reaches a preset time threshold, then it is determined that the gas does not meet the dissolved oxygen control requirements, and the PID controller corresponding to the next priority gas is activated.

[0069] In one embodiment, the control signal generation module 404 is further configured to: when the PID controller corresponding to the low-priority gas is in the on state, if the gas actuator corresponding to the PID controller maintains the minimum flow rate output and the duration of the minimum flow rate output state reaches a preset time threshold, then it is determined that the dissolved oxygen requirement has been met, the PID controller corresponding to the current priority gas is turned off, and the process returns to the PID controller corresponding to the previous priority gas.

[0070] In one embodiment, the PID control signal includes a start / stop command and a mode command. The mode command includes a manual mode command and an automatic mode command. The gas output module 408 is further configured to: when the PID controller receives a manual mode command from the cascade controller, the PID controller enters manual mode, and the gas actuator corresponding to the PID controller stops calculating the output value and maintains the maximum output state to output gas; when the PID controller receives an automatic mode command from the cascade controller, the PID controller enters automatic mode, and the gas actuator corresponding to the PID controller maintains the output value calculation and outputs gas according to the output value calculation result.

[0071] In one embodiment, the gas output module 408 is further configured to: when the PID controller corresponding to any priority gas is turned on, control the PID controller to adjust dissolved oxygen in automatic mode via an automatic mode command; and when the PID controller corresponding to the next priority gas is turned on, control the PID controller to adjust dissolved oxygen in manual mode via a manual mode command.

[0072] The device provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0073] This invention provides an electronic device, specifically, the electronic device includes a processor and a storage device; the storage device stores a computer program, and the computer program, when run by the processor, executes the method described in any of the above embodiments.

[0074] Figure 5 The present invention provides a schematic diagram of the structure of an electronic device 100, which includes a processor 50, a memory 51, a bus 52 and a communication interface 53. The processor 50, the communication interface 53 and the memory 51 are connected through the bus 52. The processor 50 is used to execute executable modules, such as computer programs, stored in the memory 51.

[0075] The memory 51 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 53 (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc.

[0076] Bus 52 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0077] The memory 51 is used to store programs. After receiving an execution instruction, the processor 50 executes the programs. The method executed by the device for defining the flow process disclosed in any of the foregoing embodiments of the present invention can be applied to the processor 50 or implemented by the processor 50.

[0078] Processor 50 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 50 or by instructions in software form. Processor 50 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 51. The processor 50 reads the information in memory 51 and, in conjunction with its hardware, completes the steps of the above method.

[0079] The computer program product of the readable storage medium provided in the embodiments of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the foregoing method embodiments. For specific implementation, please refer to the foregoing method embodiments, which will not be repeated here.

[0080] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0081] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cascaded dissolved oxygen control method, characterized in that, The method is applied to a cascaded dissolved oxygen control system, which includes: a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The set of PID controllers includes multiple PID controllers, and the set of actuators includes multiple gas actuators. Each PID controller and each gas actuator corresponds one-to-one. The method includes: The dissolved oxygen sensor is used to obtain real-time dissolved oxygen levels. The cascaded controller determines the PID control signal based on the real-time dissolved oxygen level and the controller's preset indicators, wherein the preset indicators of the cascaded controller include: target dissolved oxygen level; Based on the preset output value calculation model of each PID controller in the PID controller set, and based on the PID control signal, the real-time dissolved oxygen level, the target dissolved oxygen level, dissolved oxygen regulation information, and the preset index of the PID controller, the gas PID output value corresponding to each PID controller is determined. The PID controller set includes: a surface-vented air PID controller, a surface-vented oxygen PID controller, a bottom-vented air PID controller, a bottom-vented oxygen PID controller, and a surface-vented nitrogen PID controller. The method includes: acquiring the dissolved oxygen requirement for biological cell culture or fermentation; when the dissolved oxygen requirement increases, activating the corresponding PID controller for the gas from the PID controller set according to a preset bottom priority to regulate dissolved oxygen, wherein the bottom priority is ordered from high to low as: surface-vented air, surface-vented oxygen, bottom-vented air, bottom-vented oxygen, with higher priority resulting in lower oxygenation efficiency during dissolved oxygen regulation; when the dissolved oxygen requirement decreases, regulating dissolved oxygen is performed through the surface-vented nitrogen PID controller. Using the preset flow calculation model of each gas actuator in the actuator set, based on the gas PID output value sent by the PID controller corresponding to the gas actuator and the preset maximum flow value of the gas actuator, the output value of the gas actuator is determined, and the corresponding gas is output according to the output value.

2. The method according to claim 1, characterized in that, The dissolved oxygen regulation information includes: dissolved oxygen rise dead zone value, dissolved oxygen fall dead zone value, dissolved oxygen rise fine-tuning value, and dissolved oxygen fall fine-tuning value. The preset indicators of the cascade controller also include: dissolved oxygen rise fine-tuning range, dissolved oxygen fall fine-tuning range, and dead zone range value. The method includes: The difference between the target dissolved oxygen level and the dead zone value is determined as the dissolved oxygen rise dead zone value, and the difference between the dissolved oxygen rise dead zone value and the dissolved oxygen rise fine-tuning range is determined as the dissolved oxygen rise fine-tuning value. The sum of the target dissolved oxygen level and the dead zone value is determined as the dissolved oxygen decrease dead zone value, and the sum of the dissolved oxygen decrease dead zone value and the dissolved oxygen decrease fine-tuning interval is determined as the dissolved oxygen decrease fine-tuning value.

3. The method according to claim 1, characterized in that, The step of activating the corresponding PID controller for the gas from the PID controller set according to a preset underlying priority to regulate dissolved oxygen includes: When the PID controller corresponding to the high-priority gas is in the on state, if the gas actuator corresponding to the PID controller maintains the preset maximum flow rate value for output, and the duration of the maximum flow rate value output state reaches the preset time threshold, then it is determined that the gas does not meet the dissolved oxygen control requirements, and the PID controller corresponding to the next priority gas is turned on.

4. The method according to claim 3, characterized in that, The method further includes: When the PID controller corresponding to the low-priority gas is in the on state, if the gas actuator corresponding to the PID controller maintains the minimum flow rate output and the duration of the minimum flow rate output state reaches a preset time threshold, then it is determined that the dissolved oxygen requirement has been met, the PID controller corresponding to the current priority gas is turned off, and the process returns to the PID controller corresponding to the previous priority gas.

5. The method according to claim 1, characterized in that, The PID control signal includes: start / stop command and mode command, the mode command including manual mode command and automatic mode command, the method including: When the PID controller receives a manual mode command from the cascade controller, the PID controller enters manual mode, and the gas actuator corresponding to the PID controller stops calculating the output value and maintains the maximum output state to output gas. When the PID controller receives the automatic mode command sent by the cascade controller, the PID controller enters the automatic mode, and the gas actuator corresponding to the PID controller continues to calculate the output value and outputs gas according to the calculation result.

6. The method according to claim 5, characterized in that, The method includes: When the PID controller corresponding to any priority gas is turned on, the PID controller is controlled to adjust dissolved oxygen in automatic mode by means of an automatic mode command; When the PID controller corresponding to the next priority gas is activated, the dissolved oxygen is adjusted in manual mode by means of a manual mode command.

7. A cascaded dissolved oxygen control device, characterized in that, The device is applied to a cascaded dissolved oxygen control system, which includes: a dissolved oxygen sensor, a cascaded controller, a set of PID controllers, and a set of actuators. The set of PID controllers includes multiple PID controllers, and the set of actuators includes multiple gas actuators. Each PID controller and each gas actuator corresponds one-to-one. The device includes: The dissolved oxygen acquisition module uses the dissolved oxygen sensor to acquire real-time dissolved oxygen levels. The control signal generation module determines the PID control signal based on the real-time dissolved oxygen level and the controller's preset indicators through the cascaded controller. The preset indicators of the cascaded controller include the target dissolved oxygen level. The PID output value determination module determines the gas PID output value corresponding to each PID controller based on the PID control signal, the real-time dissolved oxygen level, the target dissolved oxygen level, dissolved oxygen regulation information, and the preset index of the PID controller, using the preset output value calculation model of each PID controller in the PID controller set. The PID controller set includes: a surface-vented air PID controller, a surface-vented oxygen PID controller, a bottom-vented air PID controller, a bottom-vented oxygen PID controller, and a surface-vented nitrogen PID controller, to obtain the dissolved oxygen requirements for biological cell culture or fermentation. When the dissolved oxygen requirement increases, the corresponding PID controller for the gas is activated from the PID controller set according to a preset bottom priority to regulate dissolved oxygen. The bottom priority, from high to low, is: surface-vented air, surface-vented oxygen, bottom-vented air, bottom-vented oxygen; the higher the priority, the lower the oxygenation efficiency during dissolved oxygen regulation. When the dissolved oxygen requirement decreases, dissolved oxygen is regulated by the surface-vented nitrogen PID controller. The gas output module determines the output value of each gas actuator based on the preset flow calculation model of each gas actuator in the actuator set, the gas PID output value sent by the PID controller corresponding to the gas actuator and the preset maximum flow value of the gas actuator, and outputs the corresponding gas according to the output value.

8. A server, characterized in that, The method includes a processor and a memory, the memory storing computer-executable instructions executable by the processor, the processor executing the computer-executable instructions to implement the method of any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions that, when invoked and executed by a processor, cause the processor to perform the method according to any one of claims 1 to 6.

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