An energetic fluid vacuum intelligent pouring system and a multivariable collaborative control method

Abstract

The application relates to the technical field of material automatic pouring control, in particular to an intelligent vacuum pouring system for energetic fluid and a multivariable collaborative control method, which comprises the following modules: an electrical control module, which is configured to analyze multi-dimensional state parameters by using a multi-parameter collaborative control strategy and generate fluid segmented pouring control information; a fluid pouring module, which performs dynamic opening degree control on a flow regulating valve according to a pouring flow setting value of a current pouring stage and PID adjusting parameters; a vacuum adjusting module, which is configured to have a vacuum degree closed-loop control strategy and determine dynamic adjusting parameters of a vacuum valve according to real-time vacuum degree information and a preset vacuum degree setting value; an air pressure adjusting module, which performs graded vacuum releasing treatment according to a preset gradient, cavity nitrogen replacement and micro-positive pressure pressure maintaining treatment; and a safety protection module, which triggers corresponding safety interlocking actions when any monitoring parameter exceeds a preset safety threshold. The application has the effect that the energetic fluid pouring forming can be automatically and accurately coordinated and controlled.

Description

Technical Field

[0001] This application relates to the field of automated material casting control technology, and in particular to an intelligent vacuum casting system for energetic fluids and a multivariable collaborative control method. Background Technology

[0002] The energetic fluid vacuum casting system is an intelligent device used to monitor and control the casting process of energetic fluids such as explosives and propellants in a vacuum environment. The energetic fluid vacuum casting system includes a fluid casting module, a vacuum regulation module, a gas pressure regulation module, an electrical control module, and a safety protection module. When the energetic fluid enters the mold for casting, the electrical control module coordinates and controls the operation of the fluid casting module and the vacuum regulation module based on parameters such as casting volume, liquid level, and vacuum degree fed back by sensors. At the same time, it works with the gas pressure regulation module to perform nitrogen replacement and micro-positive pressure holding treatment on the casting environment, thereby achieving high-precision casting and molding of energetic fluids and full-process inertial safety protection.

[0003] In related technologies, the vacuum casting system for energetic fluids mainly adopts the traditional multi-system decentralized control method. The parameters such as casting flow rate and vacuum degree are controlled separately through independent loops. In order to complete the casting, the operator usually uses a single flow rate for continuous casting and maintains the state of each parameter by manual adjustment or simple switch control based on experience. In the process of devastating after casting, the vacuum is often broken directly to introduce air. Moreover, due to the lack of effective pressure holding and inertial protection, the entire production process relies heavily on manual intervention and experience judgment.

[0004] Regarding the aforementioned technologies, due to the strong coupling relationship between parameters such as vacuum degree, pouring pressure, and flow rate, and the independent nature of each control system, single-flow pouring easily leads to fluid splashing and air bubble entrapment, severely affecting molding quality and product performance. Operators need to frequently intervene manually, and manual or simple switch control has poor precision and large deviations, making it difficult to meet the precision molding requirements of energetic fluids. At the same time, directly breaking the vacuum during vacuum release easily introduces air, posing a significant risk of combustion and explosion when energetic fluids come into contact with oxygen. In addition, the lack of pressure holding measures after pouring easily leads to mold cavity deformation due to pressure difference or fluid backflow. As a result, the existing system as a whole suffers from poor molding quality, low control precision, significant safety hazards, and insufficient automation, which is not conducive to meeting the high-precision, high-safety, and high-efficiency production requirements of energetic material production lines. Summary of the Invention

[0005] To facilitate automatic and precise coordinated control of energetic fluid casting, this application provides an energetic fluid vacuum intelligent casting system and a multivariable collaborative control method.

[0006] Firstly, this application provides an energetic fluid vacuum intelligent casting system: An energetic fluid vacuum intelligent casting system includes: The electrical control module is equipped with a multi-parameter collaborative control strategy. It analyzes and generates fluid segmentation pouring control information based on preset multi-dimensional state parameters, which is used to adjust fluid pouring, vacuum regulation and air pressure control. The fluid casting module is equipped with a segmented casting strategy. It determines the current casting stage based on the ratio of the real-time casting weight fed back by the weight sensor to the preset full cavity standard weight, and dynamically controls the opening of the flow regulating valve based on the current casting stage and the corresponding casting flow rate set value and PID adjustment parameters in the preset parameter library. The vacuum regulation module is equipped with a vacuum closed-loop control strategy. It performs deviation analysis based on the real-time vacuum information fed back by the vacuum sensor and the preset vacuum setting value to determine the dynamic adjustment parameters of the vacuum valve and maintain the vacuum negative pressure state of the pouring environment. The pressure regulation module is equipped with a vacuum pressure maintenance coordination strategy. After the casting is completed, it performs staged vacuum release according to a preset gradient, and introduces nitrogen to replace the cavity with nitrogen and perform micro-positive pressure maintenance to achieve inert gas protection throughout the process. The safety protection module is equipped with a protection detection strategy to monitor oxygen content, vacuum degree and pressure parameters in real time. When any monitored parameter exceeds the preset safety threshold, the corresponding safety interlock action is triggered.

[0007] By adopting the above technical solutions, a multi-parameter collaborative control strategy is used to coordinate the entire process control of pouring flow, cavity vacuum, and pressure holding atmosphere. Combined with segmented pouring control based on weight feedback, closed-loop adjustment of vacuum, graded vacuum release and nitrogen replacement pressure holding linkage, and a safety interlocking mechanism for multi-parameter monitoring, multi-dimensional collaborative management and control of the energetic fluid pouring process is achieved. This helps to balance material filling efficiency and product molding accuracy, ensure the negative pressure stability of the pouring environment and the inertial protection effect during the curing stage, cover the safety protection requirements of all working conditions, and improve the automation level and batch consistency of the pouring process.

[0008] Optional segmented casting strategies include: Based on the ratio of real-time pouring volume to preset full-cavity pouring volume, at least two pouring stages with linearly decreasing pouring volume are constructed. Each pouring stage is configured with a corresponding pouring mode, which is equipped with a corresponding pouring flow rate, pouring speed and PID adjustment parameters. The proportion of the pouring weight is inversely proportional to the set value of the pouring flow rate.

[0009] By adopting the above technical solution, the pouring stages are divided based on the ratio of real-time pouring weight to the standard weight of the cavity. Each stage is matched with corresponding pouring flow rate, pouring speed and PID adjustment parameters. The pouring flow rate gradually decreases as the proportion of pouring weight increases, which helps to break through the limitations of the single flow pouring mode, adapt to the process requirements of different filling stages of materials, and realize dynamic flow control of the pouring process.

[0010] Optionally, the casting stage includes at least a rapid feeding stage, a precision molding stage, and a replenishment and finishing stage that are connected in sequence. The rapid feeding stage corresponds to the high-flow casting mode, the precise molding stage corresponds to the low-flow casting mode, and the replenishment and finishing stage corresponds to the micro-replenishment casting mode. The casting flow rate of the three stages decreases sequentially.

[0011] By adopting the above technical solution, the casting process is divided into a rapid feeding stage, a precise molding stage, and a replenishment and finishing stage that are connected in sequence. The three stages correspond to a progressively decreasing casting flow rate mode, which helps to ensure material filling efficiency in the early stage of casting and ensure filling accuracy and molding quality in the middle and late stages of casting, thereby achieving a balance and optimization between casting efficiency and product molding accuracy.

[0012] Optionally, the triggering condition for the rapid feeding stage is that the weight ratio of the casting is less than a preset first threshold. The triggering condition for the precision molding stage is that the proportion of the casting weight is greater than or equal to a preset first threshold and less than a preset second threshold. The triggering condition for the material replenishment and finishing stage is that the weight ratio of the poured material is greater than or equal to a preset second threshold and less than a preset third threshold; the first threshold, the second threshold and the third threshold increase sequentially, and the third threshold corresponds to the standard weight of the full cavity.

[0013] By adopting the above technical solution, the switching trigger conditions for each pouring stage are set by progressively increasing weight percentage thresholds, with the third threshold corresponding to the standard weight of the full cavity. This helps to ensure that the stage switching action corresponds precisely to the actual filling progress of the material, avoids process errors caused by fixed-duration switching, and ensures the accuracy of the connection between each pouring stage and the consistency of the process between different batches.

[0014] Optionally, the electrical control module is further configured with a PID parameter adaptive adjustment strategy, including: Match the proportional coefficient, integral coefficient, and derivative coefficient from the preset PID parameter library according to the current pouring stage; The rapid feeding stage employs a combination of a smaller proportional coefficient, a larger integral coefficient, and a larger differential coefficient. The precision forming stage employs a combination of moderate proportional coefficients, relatively small integral coefficients, and moderate differential coefficients. The replenishment and finishing stage uses a combination of a large proportional coefficient, a zero integral coefficient, and a small differential coefficient.

[0015] By adopting the above technical solution, different combinations of PID parameters are adaptively matched to meet the flow characteristics and control requirements of different pouring stages. This makes the control parameters compatible with the pouring conditions of each stage, which helps to improve the problem of slow response of a single PID parameter in the high flow stage and easy overshoot in the low flow stage, thereby improving the stability and accuracy of flow control throughout the entire pouring process.

[0016] Optionally, the electrical control module is also configured with a multi-parameter PID coordinated adjustment strategy, including: Using flow rate or weight as the core controlled variable and vacuum degree and casting pressure as the driven variables, a multivariable coupled PID closed-loop control architecture with outer loop weight control and inner loop flow control is constructed. The outer loop uses an asymmetric PID algorithm, and the inner loop uses an incremental PID algorithm with integral separation. Based on the deviation signal obtained from the set value and the actual measured value at the current moment, and combined with the proportional coefficient, integral coefficient and derivative coefficient matched in the current pouring stage, the proportional adjustment amount, integral adjustment amount and derivative adjustment amount are calculated respectively. The valve opening increment at the current moment is obtained by combining the three types of adjustment quantities and output to the flow control valve to perform opening adjustment.

[0017] By adopting the above technical solution, a dual closed-loop multivariable coupled control architecture with outer loop weight control and inner loop flow control is constructed. The outer loop adopts an asymmetric PID algorithm, and the inner loop adopts an incremental PID algorithm with integral separation. The vacuum degree and pouring pressure are combined as follower variables to participate in the coordinated regulation, and finally synthesize the output valve opening increment. This helps to reduce the disturbance effect caused by multi-parameter coupling, improve the response speed and control accuracy of flow regulation, and ensure the smooth transition of the segmented pouring process.

[0018] Optionally, the vacuum pressure holding coordination strategy includes: In the stage of graded vacuum control, the vacuum level is reduced stepwise according to a preset gradient after casting to avoid the disturbance of the energetic fluid by sudden pressure changes. During the nitrogen replacement control stage, nitrogen is introduced after the vacuum level is reduced to a slight negative pressure to replace the air in the cavity with nitrogen, thereby reducing the oxygen content in the cavity to below the preset threshold. During the micro-positive pressure holding control stage, nitrogen gas is introduced to maintain a micro-positive pressure state within a preset range in the cavity, which is used to prevent mold deformation and fluid backflow.

[0019] By adopting the above technical solution, a linkage control logic is used that sequentially connects graded vacuum release, nitrogen replacement, and micro-positive pressure holding. The vacuum level is reduced in stages, the air in the cavity is replaced, and a micro-positive pressure state is maintained. This helps to avoid pressure changes from causing disturbances to the energetic fluid in the cavity, keeps the oxygen content in the cavity below the safe threshold, prevents mold deformation and fluid backflow, and improves the safety and molding stability of the energetic fluid solidification process.

[0020] Optionally, the protection detection strategy includes: The real-time monitoring value of the oxygen content sensor is compared and analyzed with the preset oxygen content safety threshold. When the oxygen content monitoring value exceeds the preset oxygen content safety threshold, the oxygen content over-limit interlock action is triggered. The vacuum level sensor's real-time monitoring value is compared and analyzed with the preset vacuum level safety range. When the vacuum level monitoring value exceeds the preset vacuum level safety range, a vacuum level abnormality interlock action is triggered. The pressure sensor's real-time monitoring value is compared and analyzed with the preset pressure safety threshold. When the pressure monitoring value exceeds the preset pressure safety threshold, a pressure over-limit interlock control command is triggered.

[0021] By adopting the above technical solution, independent monitoring and interlocking triggering logic is set for the three core safety parameters of oxygen content, vacuum degree and pressure. When different parameters exceed the limit, corresponding interlocking control commands are triggered, which helps to realize multi-dimensional safety status monitoring and graded protection throughout the process. Under abnormal operating conditions, the protection mechanism can be triggered quickly, improving the safety of system operation and the accuracy of fault handling.

[0022] Secondly, this application provides a multivariable collaborative control method for intelligent vacuum casting of energetic fluids, employing the following technical solution: A multivariable collaborative control method for intelligent vacuum casting of energetic fluids includes: The parameter acquisition step is configured with a multi-parameter real-time acquisition strategy to obtain real-time parameter information on pouring weight, liquid level, vacuum degree and pressure. The stage determination step is configured with a segmented pouring stage determination strategy, which is used to determine the current pouring stage based on the ratio of the real-time pouring weight to the preset full cavity standard weight, and match the pouring flow rate set value and PID adjustment parameters for the corresponding stage. The coordinated control steps are configured with a multi-parameter PID coordinated adjustment strategy for controlling the opening of the flow regulating valve, while using vacuum and pressure as feedforward compensation quantities for multi-variable coordinated adjustment. The vacuum release and pressure holding step is equipped with a vacuum pressure holding coordination strategy, which is used to perform a linkage control sequence of staged vacuum release, nitrogen replacement and micro positive pressure holding after casting is completed; The safety monitoring process is equipped with a protective detection strategy to monitor safety parameters in real time throughout the entire process, and trigger a safety interlock action when the parameters exceed the limits.

[0023] By adopting the above technical solutions, a complete control chain is formed, including parameter acquisition, stage judgment, collaborative control, vacuum release and pressure holding, and safety monitoring. Vacuum degree and pressure are used as feedforward compensation quantities to participate in collaborative regulation, which helps to stably achieve segmented and precise casting of energetic fluids and full-process safety protection, and improves the repeatability of the casting process and the quality consistency between batches.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. By utilizing a multi-parameter collaborative control strategy to coordinate the entire process control of pouring flow rate, cavity vacuum degree, and holding pressure atmosphere, combined with weight feedback-based segmented pouring control, vacuum degree closed-loop adjustment, graded vacuum release and nitrogen replacement pressure holding linkage, and a multi-parameter monitoring safety interlock mechanism, multi-dimensional collaborative management and control of the energetic fluid pouring process is achieved. This helps to balance material filling efficiency and product molding accuracy, ensure the negative pressure stability of the pouring environment and the inertial protection effect during the curing stage, and cover the safety protection requirements of all working conditions. Compared with the multi-system decentralized control method in the existing technology, it can further improve the automation level of the pouring process and the consistency of batch operation. 2. The pouring process is divided into multiple stages based on the ratio of real-time pouring weight to the standard weight of the cavity. Each stage is matched with corresponding pouring flow rate, pouring speed and PID adjustment parameters. The pouring flow rate gradually decreases as the proportion of pouring weight increases, which helps to overcome the limitations of the single flow pouring mode, adapt to the process requirements of different filling stages of materials, and realize dynamic flow control of the pouring process. 3. To adapt to the flow characteristics and control requirements of different pouring stages, differentiated PID parameter combinations are adaptively matched to make the control parameters suitable for the pouring conditions of each stage. This helps to improve the problem of slow response of a single PID parameter in the high flow stage and easy overshoot in the low flow stage, thereby improving the flow control stability and control accuracy of the entire pouring process. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the module connections of the energetic fluid vacuum intelligent casting system of this application.

[0026] Figure 2 This is a flowchart of steps S100 to S101 in this application.

[0027] Figure 3 This is a flowchart of steps S200 to S203 in this application.

[0028] Figure 4 This is a flowchart of steps S300 to S302 in this application. Detailed Implementation

[0029] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figure 1-4 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0030] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0031] This application discloses an energetic fluid vacuum intelligent casting system. It utilizes a multi-parameter collaborative control strategy to coordinate the entire process of casting flow rate, cavity vacuum degree, and holding pressure atmosphere. Combined with weight feedback-based segmented casting control, closed-loop vacuum degree adjustment, staged vacuum release and nitrogen replacement pressure holding linkage, and a multi-parameter monitoring safety interlock mechanism, it achieves multi-dimensional collaborative control of the energetic fluid casting process. This improves upon the insufficient parameter coordination caused by decentralized control of multiple systems in existing technologies, avoids fluid splashing and bubble entrapment phenomena easily caused by traditional single-flow casting, and balances material filling efficiency and product molding accuracy. The linkage design of closed-loop vacuum degree adjustment and staged vacuum release and pressure holding solves the safety risks of oxygen contact caused by direct vacuum breaking and the problem of insufficient pressure holding after casting, ensuring the negative pressure stability of the casting environment and the inertial protection effect during the curing stage, reducing mold deformation and fluid backflow. The accompanying multi-parameter safety interlock mechanism covers all working condition protection needs, reduces the frequency of manual intervention, and effectively improves the control accuracy, operational safety, and automation level of the casting process compared to existing decentralized control methods.

[0032] Reference Figure 1 The energetic fluid vacuum intelligent casting system includes the following modules: The electrical control module is equipped with a multi-parameter collaborative control strategy. It analyzes and generates fluid segmentation pouring control information based on preset multi-dimensional state parameters, which is used to adjust fluid pouring, vacuum regulation and air pressure control. The fluid casting module is equipped with a segmented casting strategy. It determines the current casting stage based on the ratio of the real-time casting weight fed back by the weight sensor to the preset full cavity standard weight, and dynamically controls the opening of the flow regulating valve based on the current casting stage and the corresponding casting flow rate set value and PID adjustment parameters in the preset parameter library. The vacuum regulation module is equipped with a vacuum closed-loop control strategy. It performs deviation analysis based on the real-time vacuum information fed back by the vacuum sensor and the preset vacuum setting value to determine the dynamic adjustment parameters of the vacuum valve and maintain the vacuum negative pressure state of the pouring environment. The pressure regulation module is equipped with a vacuum pressure maintenance coordination strategy. After the casting is completed, it performs staged vacuum release according to a preset gradient, and introduces nitrogen to replace the cavity with nitrogen and perform micro-positive pressure maintenance to achieve inert gas protection throughout the process. The safety protection module is equipped with a protection detection strategy to monitor oxygen content, vacuum degree and pressure parameters in real time. When any monitored parameter exceeds the preset safety threshold, the corresponding safety interlock action is triggered.

[0033] As the core control unit of the entire casting system, the electrical control module establishes data communication connections with the fluid casting module, vacuum regulation module, air pressure regulation module and safety protection module, collects the operating status information of each module and sensor monitoring data in real time, and sends control commands to the corresponding actuators.

[0034] Multi-dimensional status parameters include casting weight, cavity vacuum, cavity pressure, oxygen content, casting flow rate, and liquid level. These parameters are collected in real time by corresponding weight sensors, vacuum sensors, pressure sensors, oxygen content sensors, and flow sensors, and transmitted to the electrical control module. Actuators include flow regulating valves, vacuum valves, nitrogen inlet valves, pressure relief valves, and audible and visual alarm devices, each controlled by its corresponding functional module. In this embodiment, the preset full-cavity standard weight can be set according to the mold cavity volume and the density of the energetic fluid; for example, the full-cavity standard weight for single-mold casting is set to 50 kg. The preset vacuum setting value is set to -0.095 MPa to meet the negative pressure degassing environment requirements for energetic fluid casting. The electrical control module compares the real-time collected parameters with the preset target values ​​and generates control increments for each loop through a multi-parameter collaborative control strategy, coordinating the synchronous operation of each module.

[0035] The fluid casting module establishes a control connection with a weight sensor and a flow regulating valve. The weight sensor is located below the mold support platform to collect the weight of the energetic fluid inside the mold in real time and feed it back to the fluid casting module. The segmented casting strategy uses the ratio of the real-time casting weight to the standard weight of the full cavity as the criterion to automatically switch casting stages and match the corresponding control parameters, replacing the traditional single-flow casting method.

[0036] The vacuum regulation module establishes a control connection with the vacuum sensor and vacuum valve. The vacuum sensor is located inside the casting cavity to monitor the vacuum negative pressure value within the cavity in real time. The vacuum closed-loop control strategy adopts a PID control method, dynamically adjusting the opening of the vacuum valve according to the deviation between the real-time vacuum value and the set value. When the vacuum value is lower than the set value, the opening of the vacuum valve is increased to increase the pumping speed. When the vacuum value reaches the set value, the valve position is stabilized to keep the cavity vacuum value within a preset fluctuation range.

[0037] The pressure regulation module establishes a control connection with the nitrogen inlet valve and pressure relief valve, and the vacuum pressure holding coordination strategy covers the entire process of vacuum release, replacement, and pressure holding after the pouring is completed. After the pouring operation is completed, the pressure regulation module performs staged vacuum release, nitrogen replacement, and micro-positive pressure holding actions in a preset sequence to avoid air entry and pressure shock caused by direct vacuum breaking.

[0038] The safety protection module is connected to the oxygen content sensor, vacuum sensor, pressure sensor, and on-site interlocking devices. The protection detection strategy monitors these three core safety parameters in real time throughout the entire lifecycle. When any parameter exceeds the safety threshold, the safety protection module directly triggers the corresponding interlocking action and simultaneously uploads the abnormal signal to the electrical control module. The electrical control module then coordinates the shutdown of the pouring and vacuum systems to achieve graded safety protection.

[0039] In addition, refer to Figure 2 The segmented casting strategy includes the following steps: Step S100: Based on the ratio of real-time pouring volume to preset full-cavity pouring volume, construct at least two pouring stages with linearly increasing or decreasing pouring volumes. Step S101: Each pouring stage is set with a corresponding pouring mode. The pouring mode is configured with a corresponding pouring flow rate, pouring speed and PID adjustment parameters. The proportion of pouring weight is inversely proportional to the set value of the pouring flow rate.

[0040] The casting stage includes at least the rapid feeding stage, the precision molding stage, and the replenishment and finishing stage, which are connected in sequence. The rapid feeding stage corresponds to the high-flow casting mode, the precise molding stage corresponds to the low-flow casting mode, and the replenishment and finishing stage corresponds to the micro-replenishment casting mode. The casting flow rate decreases sequentially in the three stages.

[0041] The trigger condition for the rapid feeding stage is that the weight percentage of the casting is less than the preset first threshold. The triggering condition for the precision molding stage is that the weight ratio of the casting is greater than or equal to the preset first threshold and less than the preset second threshold. The trigger condition for the material replenishment and finishing stage is that the proportion of the pouring weight is greater than or equal to the preset second threshold and less than the preset third threshold. The first threshold, the second threshold, and the third threshold increase sequentially, with the third threshold corresponding to the standard weight of the full cavity.

[0042] Specifically, the preset parameter library stores process parameter sets corresponding to different pouring stages. Each parameter set includes a pouring flow rate setpoint, a pouring speed reference value, and PID adjustment parameters. The fluid pouring module calculates the ratio R = Wt / Ws of the current pouring weight Wt to ​​the standard weight of the full cavity in real time. Based on the range of the ratio R, it determines the current pouring stage and calls the corresponding parameter set to execute flow control.

[0043] In this embodiment, the casting stage includes at least a rapid feeding stage, a precise molding stage, and a replenishment and finishing stage that are sequentially connected. The rapid feeding stage corresponds to a high-flow-rate casting mode, the precise molding stage corresponds to a low-flow-rate casting mode, and the replenishment and finishing stage corresponds to a micro-replenishment casting mode, with the casting flow rate decreasing sequentially in each stage.

[0044] The rapid feeding stage is triggered when the weight percentage of the cast material is less than a preset first threshold; the precision molding stage is triggered when the weight percentage of the cast material is greater than or equal to the preset first threshold and less than a preset second threshold; the replenishment and finishing stage is triggered when the weight percentage of the cast material is greater than or equal to the preset second threshold and less than a preset third threshold. The first, second, and third thresholds increase sequentially, with the third threshold corresponding to the standard weight of the full cavity. For example, the first threshold is set to 80%, the second threshold to 96%, and the third threshold to 100%. When the weight percentage of the cast material is less than 80%, the system is in the rapid feeding stage, pouring at the rated maximum flow rate to quickly fill the mold cavity; when the percentage reaches 80% and is less than 96%, it switches to the precision molding stage, reducing the pouring flow rate to improve filling accuracy and reduce fluid splashing and air bubble entrapment; when the percentage reaches 96% and is less than 100%, it switches to the replenishment and finishing stage, replenishing with a small flow rate to avoid overfilling and ensure the cavity is full.

[0045] The electrical control module is also equipped with a PID parameter adaptive adjustment strategy, which includes the following steps: Match the proportional coefficient, integral coefficient, and derivative coefficient from the preset PID parameter library according to the current pouring stage; The rapid feeding stage uses a combination of a smaller proportional coefficient, a larger integral coefficient, and a larger differential coefficient. The precision molding stage employs a combination of moderate proportional coefficients, relatively small integral coefficients, and moderate differential coefficients. The replenishment and finishing stage uses a combination of a larger proportional coefficient, a zero integral coefficient, and a smaller differential coefficient.

[0046] The preset PID parameter library stores PID parameter sets corresponding to each casting stage. For example, in the rapid feeding stage, the proportional coefficient Kp is set to 0.8, the integral coefficient Ki to 1.2, and the derivative coefficient Kd to 1.0. This parameter combination provides a smooth response and strong anti-interference capability, suitable for stable feeding requirements under high flow rates. In the precise molding stage, the proportional coefficient Kp is set to 1.5, the integral coefficient Ki to 0.5, and the derivative coefficient Kd to 0.8. This parameter combination balances response speed and control accuracy, suitable for precise adjustment requirements under small to medium flow rates. In the replenishment and finishing stage, the proportional coefficient Kp is set to 2.5, the integral coefficient Ki to 0, and the derivative coefficient Kd to 0.3. This parameter combination eliminates the integral action to avoid overshoot, relying on proportional adjustment to achieve precise control of micro-replenishment.

[0047] When the casting stage changes, the electrical control module automatically loads the corresponding PID parameter group to achieve adaptive matching between control parameters and operating conditions.

[0048] Reference Figure 3 The electrical control module is also equipped with a multi-parameter PID coordinated adjustment strategy, which includes the following steps: Step S200: Using flow rate or weight as the core controlled variable and vacuum degree and casting pressure as the driven variables, construct a multivariable coupled PID closed-loop control architecture with outer loop weight control and inner loop flow rate control. Step S201: The outer loop uses an asymmetric PID algorithm, and the inner loop uses an incremental PID algorithm with integral separation. Step S202: Obtain the deviation signal based on the current set value and the actual measured value, and calculate the proportional adjustment amount, integral adjustment amount and derivative adjustment amount respectively by combining the proportional coefficient, integral coefficient and derivative coefficient matched in the current pouring stage; Step S203: After combining the three types of adjustment quantities, the valve opening increment at the current moment is obtained and output to the flow control valve to perform opening adjustment.

[0049] Specifically, the outer loop weight control uses the real-time pouring weight as the controlled object, and outputs a flow rate setpoint to the inner loop based on the deviation between the setpoint and the measured weight. The inner loop flow control uses the real-time pouring flow rate as the controlled object, and outputs a valve opening control signal based on the deviation between the setpoint and the measured flow rate. This dual-closed-loop architecture ensures both the control accuracy of the final pouring weight and improves the dynamic response speed of the flow rate.

[0050] The outer loop employs an asymmetric PID algorithm, which, considering the unidirectional increase in weight, sets different proportional gains for positive and negative deviations to avoid control oscillations caused by reverse adjustment. The inner loop uses an incremental PID algorithm with integral separation, which presets an integral separation threshold. When the flow deviation exceeds 10% of the set value, the integral action is canceled to avoid integral saturation during startup and phase switching; when the deviation is less than the integral separation threshold, the integral action is engaged to eliminate steady-state error.

[0051] Vacuum level and pouring pressure are introduced into the control architecture as momentum, participating in the opening correction as feedforward compensation quantities. When the cavity vacuum level is lower than the set value, the opening of the flow regulating valve is appropriately reduced to decrease the pouring speed and reduce fluid splashing and bubble generation; when abnormal pressure fluctuations occur in the cavity, the opening of the flow valve is adjusted synchronously to counteract the interference of pressure fluctuations on the pouring flow.

[0052] The proportional control quantity is obtained by multiplying the proportional coefficient by the current deviation value, reflecting the immediate adjustment effect of the deviation; the integral control quantity is obtained by multiplying the integral coefficient by the accumulated historical deviation value, used to eliminate steady-state deviation; the derivative control quantity is obtained by multiplying the derivative coefficient by the rate of change of the process variable, used to predict the trend of deviation change and suppress overshoot. These three types of control quantities are combined to obtain the valve opening increment for the current control cycle. The electrical control module updates the output opening of the flow control valve according to the opening increment, completing one closed-loop regulation.

[0053] The incremental PID calculation model uses the following formula: ; in, Let $k$ be the valve opening increment at time $k$. This is the proportionality coefficient. The integral coefficient is... Let be the differential coefficient, and e(k) be the deviation value at time k. Let PV(k) be the deviation value at time j, PV(k) be the process variable value at time k, and PV(k-1) be the process variable value at time k-1.

[0054] Reference Figure 4 The vacuum pressure holding coordination strategy includes the following steps: Step S300: Staged vacuum control phase, after casting is completed, the vacuum level is reduced stepwise according to a preset gradient to avoid pressure changes from disturbing the energetic fluid; Step S301: Nitrogen replacement control stage. When the vacuum level is reduced to a slight negative pressure, nitrogen is introduced to replace the air in the cavity with nitrogen, so that the oxygen content in the cavity drops below the preset threshold. Step S302: Micro-positive pressure holding control stage, nitrogen gas is introduced to maintain the cavity in a micro-positive pressure state within a preset range, which is used to prevent mold deformation and fluid backflow.

[0055] Specifically, after the pouring is completed and the flow regulating valve is closed, the pressure regulating module initiates a staged vacuum release process. For example, the initial vacuum is -0.095 MPa, with a three-stage pressure release: the first stage releases to -0.06 MPa and holds for 30 seconds; the second stage releases to -0.03 MPa and holds for 30 seconds; the third stage releases to a slightly negative pressure state of -0.01 MPa. This staged pressure release avoids problems such as surface turbulence, bubble precipitation, and splashing of the energetic fluid caused by sudden pressure changes.

[0056] After entering the nitrogen purging control stage, the nitrogen inlet valve opens, allowing high-purity nitrogen to be introduced into the chamber at a set flow rate to replace the residual air. For example, the nitrogen inlet flow rate is set to 20 L / min, and the purging time is set to 5 min. After the purging is completed, the oxygen content in the chamber drops to below 2%, forming an inert gas protective environment to prevent the energetic fluid from coming into contact with oxygen and causing safety risks.

[0057] During the micro-positive pressure holding control stage, the air pressure regulating module controls the nitrogen inlet valve and the pressure relief valve in a coordinated manner to maintain the pressure inside the cavity within a micro-positive pressure range of 0.01~0.03MPa. This micro-positive pressure state serves two purposes: firstly, it prevents outside air from seeping back into the cavity, maintaining an inert atmosphere; secondly, it applies positive pressure to the mold cavity, suppressing deformation caused by internal stress and preventing the backflow of energetic fluids.

[0058] The protective detection strategy includes the following steps: Step S400: Compare and analyze the real-time monitoring value of the oxygen content sensor with the preset oxygen content safety threshold. When the oxygen content monitoring value exceeds the preset oxygen content safety threshold, trigger the oxygen content over-limit interlock action. Step S401: Compare and analyze the real-time monitoring value of the vacuum sensor with the preset vacuum safety range. When the vacuum monitoring value exceeds the preset vacuum safety range, trigger the vacuum abnormality interlock action. Step S402: Compare and analyze the real-time monitoring value of the pressure sensor with the preset pressure safety threshold. When the pressure monitoring value exceeds the preset pressure safety threshold, trigger the pressure over-limit interlock control command.

[0059] For example, the preset oxygen content safety threshold is set to 2%, the preset vacuum degree safety range is set to -0.098MPa to -0.01MPa, and the preset pressure safety threshold is set to 0.05MPa.

[0060] The oxygen content over-limit interlock actions include cutting off the pouring circuit, opening the nitrogen inlet valve to increase the nitrogen flow, and triggering the on-site audible and visual alarm; the vacuum abnormality interlock actions include adjusting the vacuum valve opening, pausing the pouring process, and checking for vacuum leaks; the pressure over-limit interlock control commands include closing the nitrogen inlet valve, opening the pressure relief valve to release pressure, and triggering the pressure over-limit alarm.

[0061] The safety protection module operates independently of the main control circuit. In abnormal conditions, it can directly trigger interlock protection without waiting for instructions from the electrical control module, thereby improving fault response speed and system safety.

[0062] Based on the same inventive concept, embodiments of the present invention provide a multivariable collaborative control method for intelligent vacuum casting of energetic fluids. The method flow of the multivariable collaborative control method for intelligent vacuum casting of energetic fluids includes the following steps: The parameter acquisition step is configured with a multi-parameter real-time acquisition strategy to obtain real-time parameter information on pouring weight, liquid level, vacuum degree and pressure. The stage determination step is configured with a segmented pouring stage determination strategy, which is used to determine the current pouring stage based on the ratio of the real-time pouring weight to the preset full cavity standard weight, and match the pouring flow rate set value and PID adjustment parameters for the corresponding stage. The coordinated control steps are configured with a multi-parameter PID coordinated adjustment strategy for controlling the opening of the flow regulating valve, while using vacuum and pressure as feedforward compensation quantities for multi-variable coordinated adjustment. The vacuum release and pressure holding step is equipped with a vacuum pressure holding coordination strategy, which is used to perform a linkage control sequence of staged vacuum release, nitrogen replacement and micro positive pressure holding after casting is completed; The safety monitoring process is equipped with a protective detection strategy to monitor safety parameters in real time throughout the entire process, and trigger a safety interlock action when the parameters exceed the limits.

[0063] Specifically, the parameter acquisition process uses various sensors distributed in the casting cavity, pipelines, and molds to synchronously collect various state parameters at a fixed control cycle. The data is then filtered and transmitted to the control unit as the basis for control.

[0064] The stage determination process uses the proportion of pouring weight as the core criterion. The stage determination results are updated in each control cycle. When the proportion crosses the stage threshold, the pouring mode and control parameters are automatically switched to achieve a smooth transition between stages.

[0065] The collaborative control process adopts a dual-closed-loop PID architecture. The outer loop weight control ensures the final casting accuracy, while the inner loop flow control improves the dynamic response speed. At the same time, vacuum degree and pressure feedforward compensation are introduced to reduce the interference of multi-parameter coupling on the casting flow rate and realize the collaborative management of multiple variables.

[0066] The vacuum release and pressure holding step is automatically triggered after the pouring is completed. It completes the staged pressure release, nitrogen replacement and micro-positive pressure holding in a preset sequence. No manual intervention is required throughout the process, ensuring an inert environment and stable pressure during the curing stage.

[0067] Safety monitoring steps are implemented throughout the entire casting process. Three types of safety parameters—oxygen content, vacuum degree, and pressure—are independently monitored and interlocked. In case of abnormal conditions, protective actions are triggered immediately to ensure the safety of the production process.

[0068] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0069] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A vacuum intelligent casting system for energetic fluids, characterized in that, include: The electrical control module is equipped with a multi-parameter collaborative control strategy. It analyzes and generates fluid segmentation pouring control information based on preset multi-dimensional state parameters, which is used to adjust fluid pouring, vacuum regulation and air pressure control. The fluid casting module is equipped with a segmented casting strategy. It determines the current casting stage based on the ratio of the real-time casting weight fed back by the weight sensor to the preset full cavity standard weight, and dynamically controls the opening of the flow regulating valve based on the current casting stage and the corresponding casting flow rate set value and PID adjustment parameters in the preset parameter library. The vacuum regulation module is equipped with a vacuum closed-loop control strategy. It performs deviation analysis based on the real-time vacuum information fed back by the vacuum sensor and the preset vacuum setting value to determine the dynamic adjustment parameters of the vacuum valve and maintain the vacuum negative pressure state of the pouring environment. The pressure regulation module is equipped with a vacuum pressure maintenance coordination strategy. After the casting is completed, it performs staged vacuum release according to a preset gradient, and introduces nitrogen to replace the cavity with nitrogen and perform micro-positive pressure maintenance to achieve inert gas protection throughout the process. The safety protection module is equipped with a protection detection strategy to monitor oxygen content, vacuum degree and pressure parameters in real time. When any monitored parameter exceeds the preset safety threshold, the corresponding safety interlock action is triggered.

2. The energetic fluid vacuum intelligent casting system according to claim 1, characterized in that, The segmented casting strategy includes: Based on the ratio of real-time pouring volume to preset full-cavity pouring volume, at least two pouring stages with linearly decreasing pouring volume are constructed. Each pouring stage is configured with a corresponding pouring mode, which is equipped with a corresponding pouring flow rate, pouring speed and PID adjustment parameters. The proportion of the pouring weight is inversely proportional to the set value of the pouring flow rate.

3. The energetic fluid vacuum intelligent casting system according to claim 2, characterized in that, The casting stage includes at least a rapid feeding stage, a precision molding stage, and a replenishment and finishing stage that are connected in sequence. The rapid feeding stage corresponds to the high-flow casting mode, the precise molding stage corresponds to the low-flow casting mode, and the replenishment and finishing stage corresponds to the micro-replenishment casting mode. The casting flow rate of the three stages decreases sequentially.

4. The energetic fluid vacuum intelligent casting system according to claim 3, characterized in that, The triggering condition for the rapid feeding stage is that the weight percentage of the casting is less than a preset first threshold. The triggering condition for the precision molding stage is that the proportion of the casting weight is greater than or equal to a preset first threshold and less than a preset second threshold. The triggering condition for the material replenishment and finishing stage is that the weight ratio of the poured material is greater than or equal to a preset second threshold and less than a preset third threshold; the first threshold, the second threshold and the third threshold increase sequentially, and the third threshold corresponds to the standard weight of the full cavity.

5. The energetic fluid vacuum intelligent casting system according to claim 3, characterized in that, The electrical control module is also equipped with a PID parameter adaptive adjustment strategy, including: Match the proportional coefficient, integral coefficient, and derivative coefficient from the preset PID parameter library according to the current pouring stage; The rapid feeding stage employs a combination of a smaller proportional coefficient, a larger integral coefficient, and a larger differential coefficient. The precision forming stage employs a combination of moderate proportional coefficients, relatively small integral coefficients, and moderate differential coefficients. The replenishment and finishing stage uses a combination of a large proportional coefficient, a zero integral coefficient, and a small differential coefficient.

6. The energetic fluid vacuum intelligent casting system according to claim 5, characterized in that, The electrical control module is also configured with a multi-parameter PID coordinated adjustment strategy, including: Using flow rate or weight as the core controlled variable and vacuum degree and casting pressure as the driven variables, a multivariable coupled PID closed-loop control architecture with outer loop weight control and inner loop flow control is constructed. The outer loop uses an asymmetric PID algorithm, and the inner loop uses an incremental PID algorithm with integral separation. Based on the deviation signal obtained from the set value and the actual measured value at the current moment, and combined with the proportional coefficient, integral coefficient and derivative coefficient matched in the current pouring stage, the proportional adjustment amount, integral adjustment amount and derivative adjustment amount are calculated respectively. The valve opening increment at the current moment is obtained by combining the three types of adjustment quantities and output to the flow control valve to perform opening adjustment.

7. The energetic fluid vacuum intelligent casting system according to claim 1, characterized in that, The vacuum pressure holding coordination strategy includes: In the stage of graded vacuum control, the vacuum level is reduced stepwise according to a preset gradient after casting to avoid the disturbance of the energetic fluid by sudden pressure changes. During the nitrogen replacement control stage, nitrogen is introduced after the vacuum level is reduced to a slight negative pressure to replace the air in the cavity with nitrogen, thereby reducing the oxygen content in the cavity to below the preset threshold. During the micro-positive pressure holding control stage, nitrogen gas is introduced to maintain a micro-positive pressure state within a preset range in the cavity, which is used to prevent mold deformation and fluid backflow.

8. The energetic fluid vacuum intelligent casting system according to claim 1, characterized in that, The protection and detection strategy includes: The real-time monitoring value of the oxygen content sensor is compared and analyzed with the preset oxygen content safety threshold. When the oxygen content monitoring value exceeds the preset oxygen content safety threshold, the oxygen content over-limit interlock action is triggered. The vacuum level sensor's real-time monitoring value is compared and analyzed with the preset vacuum level safety range. When the vacuum level monitoring value exceeds the preset vacuum level safety range, a vacuum level abnormality interlock action is triggered. The pressure sensor's real-time monitoring value is compared and analyzed with the preset pressure safety threshold. When the pressure monitoring value exceeds the preset pressure safety threshold, a pressure over-limit interlock control command is triggered.

9. A multivariable collaborative control method for intelligent vacuum casting of energetic fluids, applied to the system described in any one of claims 1-8, characterized in that, include: The parameter acquisition step is configured with a multi-parameter real-time acquisition strategy to obtain real-time parameter information on pouring weight, liquid level, vacuum degree and pressure. The stage determination step is configured with a segmented pouring stage determination strategy, which is used to determine the current pouring stage based on the ratio of the real-time pouring weight to the preset full cavity standard weight, and match the pouring flow rate set value and PID adjustment parameters for the corresponding stage. The coordinated control steps are configured with a multi-parameter PID coordinated adjustment strategy for controlling the opening of the flow regulating valve, while using vacuum and pressure as feedforward compensation quantities for multi-variable coordinated adjustment. The vacuum release and pressure holding step is equipped with a vacuum pressure holding coordination strategy, which is used to perform a linkage control sequence of staged vacuum release, nitrogen replacement and micro positive pressure holding after casting is completed; The safety monitoring process is equipped with a protective detection strategy to monitor safety parameters in real time throughout the entire process, and trigger a safety interlock action when the parameters exceed the limits.

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