Multi-level in-depth security protection system for precise liquid injection process

Abstract

The application discloses a multi-level deep security protection system for a precise liquid injection process, relates to the technical field of vacuum injection safety protection, and solves the problems of fragmentation, single-point dependence and poor fault traceability of existing protection measures. The system comprises three layers of protection structures of electricity and machinery, logic control, information and authority, and layer-by-layer progressive and collaborative position compensation, and constructs a safety closed loop of pre-prevention, in-block and post-trace. The electrical layer is a hardware barrier, and contains components such as backflow prevention valve groups; the logic layer takes PLC as a core, executes multi-factor composite process interlocking, realizes state checking and fault prediction; and the information layer realizes hierarchical authority management, device visualization and fault traceability. When a single layer fails locally, the remaining layers can compensate across layers. In the scene of cooling liquid injection of a new energy supercharged host, the unplanned downtime rate of the device is reduced by 80%, the fault troubleshooting time is shortened by 75%, and the system is suitable for the precise liquid injection production demand of high-end industries such as new energy and electronic manufacturing.

Description

Technical Field

[0001] This invention relates to the field of vacuum injection safety protection technology, specifically to a multi-level, in-depth safety protection system and method for precision injection processes, applicable to safety protection scenarios of injection equipment in high-end industries such as new energy and electronic manufacturing. Background Technology

[0002] In the field of automated vacuuming and liquid injection equipment, precision liquid injection processes place extremely high demands on the safety, reliability, and maintainability of the equipment. To ensure the smooth operation of the process, the industry has developed three typical safety protection methods, but all have significant limitations: Firstly, hardware electrical interlocks achieve safety interlocking through relay circuits. Pure hardware operation is reliable, but the function is rigid and singular, only able to realize single-condition judgment. Parameter adjustment requires modification of physical components, which cannot adapt to modern process flows with complex timing and multi-condition judgment.

[0003] Secondly, PLC-based software interlocks are highly flexible and can achieve complex logic control, but the core safety functions rely entirely on the operation of the PLC and the accuracy of a single sensor, which poses a risk of common cause failure. Sensor failure or program abnormality will directly lead to the failure of the safety barrier.

[0004] Third, independent audible and visual alarms can only issue a reminder after the equipment malfunctions, lacking the ability to prevent problems before they occur and intervene during the incident. Moreover, the alarm information is transient, making it difficult to record and trace, and thus has limited value for analyzing the root cause of the fault.

[0005] Existing technical solutions generally suffer from fragmented protective measures, reliance on single points for critical functions, weak intelligent diagnostics, poor fault traceability, and a lack of dedicated protection for core components, failing to construct a complete safety closed loop of "prevention before the event - interruption during the event - traceability after the event." When faced with complex faults such as valve malfunction, media backflow, sensor drift, and human error, existing protective measures are insufficient, easily leading to equipment damage, product scrapping, and even safety accidents. There is an urgent need for a multi-level, collaborative, reliable, intelligent, and traceable safety protection system to fill this technological gap in the industry. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-level, in-depth safety protection system for precision liquid injection processes, thereby solving the above-mentioned technical problems: The above-mentioned objectives of the present invention are achieved by the following technical means: A multi-level in-depth security protection system for precision liquid injection processes is characterized in that the system includes an electrical and mechanical security layer, a logic control security layer, and an information and access security layer. Even if a single layer experiences a partial failure, the other layers can still trigger protective actions to ensure that the system returns to a safe state, thus forming a complete in-depth defense system. The electrical and mechanical safety layer, serving as a hardware-based protective layer for proactive prevention, includes a backflow-prevention dual isolation valve group 1, a vacuum protection valve group 2, and an emergency physical circuit breaker component 3. The emergency physical circuit breaker component 3 is an emergency stop button 31, installed on the equipment operation panel and connected to the PLC via an RS4815 bus. The backflow-prevention dual isolation valve group 1 consists of a backflow-prevention electric valve 11 and a one-way valve 12 connected in series in an injection pipeline connecting the injection port of the injection target 4 and the outlet of the injection pump 5. The input end of the injection pump 5 is connected to the storage tank 6 via a pipeline. The backflow-prevention electric valve 11 and the injection pump 5 are connected to the PLC via an RS4815 bus. The vacuum protection valve group 2 includes a vacuum water-oil separator 21 and an anti-attenuation electric valve 22 connected in series in a vacuum extraction pipeline connecting the air extraction port of the injection target 4 and the inlet of the vacuum pump 7. The anti-attenuation electric valve 22, the vacuum water-oil separator 21, and the vacuum pump 7 are connected to the PLC via an RS4815 bus. The logic control safety layer serves as a protective layer for in-process interruption. It uses a PLC as the controller to collect real-time data from the vacuum pressure gauge 81 located in the vacuum pipeline, the flow meter 82 located in the liquid injection pipeline, the liquid level sensor 83 located in the liquid storage tank 6, and the status of the emergency stop button 31 via the RS4815 bus. It executes multi-factor composite process interlocking to realize the status verification, action compensation, and fault prediction of the electrical and mechanical safety layer. The information and access security layer, as a security management layer, is used for post-event traceability. It communicates with the PLC via RS4815 bus through the human-machine interaction terminal 9, sets up user hierarchical access management, and has functions such as equipment status visualization, contextual alarms, and fault data traceability.

[0007] Furthermore, the one-way valve 12 is located at the port of the injection pipeline near the injection target 4. The mounting reference planes of the anti-backflow electric valve 11, the injection pump 5, and the flow meter 82 are at the same horizontal plane. The injection pipeline includes an n-shaped tube. The top of the n-shaped tube is higher than the highest working liquid level of the storage tank 6. The inlet of the n-shaped tube leads to the bottom of the storage tank 6. The outlet of the n-shaped tube is set at the same horizontal height as the fluid flow center axis of the anti-backflow electric valve 11, the injection pump 5, and the flow meter 82.

[0008] Furthermore, the anti-backflow dual isolation valve group 1, together with the liquid injection pipeline layout, forms a quadruple redundant anti-backflow protection system. The first layer is the active shut-off of the anti-backflow electric valve 11, the second layer is the passive check valve 12, the third layer is the elimination of static pressure difference by setting the anti-backflow electric valve 11, the liquid injection pump 5, the flow meter 82 and the liquid storage tank 6 at the same level, and the fourth layer is the liquid seal gas resistance and gravity blocking formed by the n-shaped tube structure. The four layers of protection provide a step-by-step bottom-up solution to completely block the backflow of the medium under extreme working conditions.

[0009] Preferably, the vacuum water-oil separator 21 is equipped with a transparent window and a manual / automatic drain valve, which are installed in series at the front end of the air inlet of the vacuum pump 7 to intercept liquid media; the anti-attenuation electric valve 22 is installed in series at the front end of the inlet of the vacuum water-oil separator 21 to isolate gas and prevent the vacuum pressure on the pipeline from attenuating when the vacuum pump 7 stops evacuating.

[0010] Preferred, The equipment operation panel is also equipped with a vacuum button 23 connected to the PLC via an RS4815 bus for manual intervention in the vacuum process. The equipment operation panel is also equipped with a liquid injection button 13 connected to the PLC via an RS4815 bus for manual intervention in the liquid injection process. The emergency stop button 31 can directly cut off the power supply when triggered, thereby disconnecting the power circuit from the hard wire.

[0011] Preferably, the multi-factor composite process interlock adopts "AND" logic. The multi-factor composite process interlock conditions include vacuum pressure reaching the standard, liquid level safety point reaching the standard, flow rate reaching the standard, emergency stop not being triggered, and the preceding vacuuming process being completed. If any condition is not met, the liquid injection function output is blocked.

[0012] Furthermore, during the injection process to target 4, real-time data from vacuum pressure gauge 81 and flow meter 82 are collected by PLC. The vacuuming rate and injection rate are monitored collaboratively using communication status and data rationality as dual criteria. Warning thresholds and alarm thresholds are set to achieve abnormal trend warnings and timeout alarms.

[0013] Furthermore, The communication status includes self-diagnostic logic: determining whether communication has failed by judging the response to PLC query commands; The data rationality includes self-diagnostic logic: determining whether the data is abnormal by detecting the data range, change amount, and jump variables.

[0014] Preferably, the user hierarchical permission management is divided into three levels: operator, engineer, and administrator. Operators only have regular operation and status viewing permissions, engineers can modify process parameters, and administrators can manage user accounts and perform data backup and recovery.

[0015] Preferably, the contextual alarm function of the information and permission security layer automatically collects and stores multi-parameter data snapshots at the moment of alarm triggering, including vacuum pressure value, real-time flow value, valve switch status, liquid level height, and process runtime. The data snapshots are stored in association with the alarm code and alarm time on the human-machine interface terminal, and only administrator accounts can perform the USB flash drive export operation of the data snapshots.

[0016] The beneficial effects of adopting the above technical solution are as follows: 1. It solves the problems of fragmented safety protection measures for precision liquid injection process in existing technologies, reliance on single points for key functions, weak intelligent diagnosis, poor fault traceability, and lack of special protection for core components. It constructs a complete safety closed loop of "prevention before the event - interruption during the event - traceability after the event" and avoids the risk of common cause failure.

[0017] 2. Construct a three-tiered defense-in-depth system, with each tier building upon the previous one, complementing and coordinating with the others. Even if a single tier experiences a partial failure, the other tiers can still trigger protective actions, ensuring that the system always remains in a safe state and reducing the rate of unplanned equipment downtime.

[0018] 3. Through optimization of the injection pipeline structure and a quadruple redundant anti-backflow protection system, the backflow of the medium under extreme working conditions is completely blocked, while there is no additional flow resistance or loss of metering accuracy, meeting the high-precision injection requirements of high-end industries.

[0019] 4. Optimize the vacuum protection valve group to form a "three-stage interception of liquid medium + dual pressure maintenance of vacuum" system, which improves the vacuum pressure maintenance time after the vacuum pump stops, reduces the failure rate of vacuum pump equipment, and meets the requirements for high-precision vacuum control.

[0020] 5. Optimize the manual intervention and emergency circuit breaker components on the equipment control panel to achieve dual control of "manual operation + logic verification". The emergency stop button has a hard-wired power-off function, which improves the safety of manual operation and the reliability of emergency handling.

[0021] 6. Achieve multi-factor composite process interlocking, realize parallel monitoring of multiple safety conditions through strict "AND" logic, 100% eliminate illegal injection, millisecond-level in-process interruption, and improve fault handling efficiency.

[0022] 7. Construct a collaborative monitoring system based on the dual criteria of "communication status and data rationality" to provide early warning of abnormal trends in the process and fallback alarms for timeout faults, thereby reducing the risk of product scrap and equipment damage and achieving an extremely low false alarm rate.

[0023] 8. Design a sensor failure self-diagnosis module to achieve rapid identification and safe handling of sensor failures, with short average diagnosis time and high accuracy, thereby enhancing the overall robustness and reliability of the system.

[0024] 9. Establish a three-tiered user access control system to achieve comprehensive and refined control over equipment operation, process parameter configuration, and system backend management, reducing the risk of unauthorized operation and accidental modification of process parameters to zero.

[0025] 10. Implement contextual alarm and fault data traceability functions, achieve accurate root cause analysis of faults through multi-parameter data snapshots, shorten fault troubleshooting time, ensure the safety and integrity of traceability data, and adapt to the needs of automated mass production processes. Attached Figure Description

[0026] Figure 1 This is a logical schematic diagram of the multi-level in-depth safety protection system for precision liquid injection processes; Figure 2 This is a schematic diagram of the injection pipeline; Figure 3 This is a schematic diagram of the vacuum piping system; Figure 4 This is a schematic diagram of the interlocking process of a multi-factor composite process; Figure 5 This is a schematic diagram of the process for determining both vacuuming and liquid injection time and flow rate. Figure 6 This is a schematic diagram of the sensor failure self-diagnosis logic.

[0027] Among them, there is a double isolation valve assembly for preventing backflow 1; an electric valve for preventing backflow 11; a check valve 12; a liquid injection button 13; a vacuum protection valve assembly 2; a vacuum water-oil separator 21; an electric valve for preventing attenuation 22; a vacuum button 23; an emergency physical circuit breaker component 3; an emergency stop button 31; a liquid injection target 4; a liquid injection pump 5; a liquid storage tank 6; a vacuum pump 7; a vacuum pressure gauge 81; a flow meter 82; a liquid level sensor 83; and a human-machine interface terminal 9. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] The component brands, models, thresholds, liquid levels, target values, etc. involved in the following examples are merely illustrative. Based on actual application scenarios, specific brands, models, parameters, etc. can be selected as needed.

[0030] Example 1 This embodiment addresses the problems in existing technologies regarding safety protection for precision liquid injection processes, such as fragmented protective measures, reliance on single points for key functions, and poor traceability of faults. It designs and implements a multi-level, in-depth safety protection system for precision liquid injection processes, constructing a complete safety closed loop of pre-event prevention, in-event interruption, and post-event traceability.

[0031] The system in this embodiment includes, for example: Figure 1 The electrical and mechanical security layer, logic control security layer, and information and access security layer shown are three layers that are progressive, complementary, and coordinated. Even if a single layer fails locally, the other layers can still trigger protective actions to ensure that the system is always in a safe state, forming a complete defense-in-depth system.

[0032] I. Core Configuration at Each Level 1. Electrical and mechanical safety layer (prevention – hardware barrier) As a basic hardware protection layer, it includes a backflow prevention dual isolation valve group 1, a vacuum protection valve group 2, and an emergency physical circuit breaker component 3. The backflow prevention dual isolation valve group 1 consists of a backflow prevention electric valve 11 and a one-way valve 12 connected in series, arranged in series along the injection target 4, one-way valve 12, backflow prevention electric valve 11, and injection pump 5 in the injection pipeline. The input end of injection pump 5 is connected to the storage tank 6 via a pipeline. The backflow prevention electric valve 11 and injection pump 5 are connected to the PLC via an RS4815 bus. The vacuum protection valve group 2 consists of a vacuum water-oil separator 21 and an anti-attenuation electric valve 22 connected in series, arranged in series along the vacuum pump 7 along the injection target 4, anti-attenuation electric valve 22, vacuum water-oil separator 21, and vacuum pump 7 in the vacuum pump pipeline. All related components are connected to the PLC via an RS4815 bus. The emergency physical circuit breaker component 3 is an emergency stop button 31, installed on the equipment operation panel and connected to the PLC via an RS4815 bus.

[0033] 2. Logic Control Security Layer (In-Event Interception - Intelligent Protection) With PLC as the core controller, the system collects real-time data from the vacuum pressure gauge 81 of the vacuum pumping pipeline, the flow meter 82 of the liquid injection pipeline, the liquid level sensor 83 of the liquid storage tank 6, and the status of the emergency stop button 31 via RS4815 bus. It then executes multi-factor composite process interlocking to achieve status verification, action compensation, and fault prediction of the electrical and mechanical safety layers.

[0034] 3. Information and Access Security Layer (Post-Event Traceability - Management Closed Loop) The human-machine interface terminal 9 communicates with the PLC via RS4815 bus, sets up user hierarchical permission management, and has functions such as equipment status visualization, contextual alarms, and fault data tracing.

[0035] II. Working Principle of Fluid Injection Taking the injection of coolant into the supercharger as an example, the injection target 4 is the coolant tank of the supercharger. The injection pipeline and the vacuum pipeline are connected to the injection port and the vacuum port of the coolant tank, respectively. The specific workflow is as follows: 1. Vacuuming: The PLC controls the anti-attenuation electric valve 22 to be normally open and the vacuum pump 7 to be turned on, while the anti-backflow electric valve 11 is normally closed and the liquid injection pump 5 is turned off to evacuate the coolant tank; the vacuum pressure gauge 81 monitors the vacuum pressure in real time, and after reaching the predetermined threshold, the PLC controls the anti-attenuation electric valve 22 to be normally closed and the vacuum pump 7 to be turned off.

[0036] 2. Liquid injection: The PLC controls the injection pump 5 to start and the anti-backflow electric valve 11 to be normally open. Under the action of vacuum negative pressure and the pushing force of the injection pump, the coolant is injected into the coolant tank through the flow meter 82, the anti-backflow electric valve 11, and the check valve 12. The flow meter 82 measures the injection volume in real time. After reaching the predetermined threshold, the PLC controls the anti-backflow electric valve 11 to be normally closed and the injection pump 5 to be shut down.

[0037] 3. Replacement preparation: After completing the liquid injection of a single supercharger, replace it with a new supercharger at the liquid injection station and wait for the next liquid injection cycle.

[0038] III. Core Configuration and Division of Labor of the Three-Layer Structure (New Energy Supercharging Main Unit Coolant Injection Scenario) 1. Electrical and mechanical safety layer: A two-position, normally closed anti-backflow electric valve 11 and a spring-return stainless steel check valve 12 are selected to form an anti-backflow valve group; the vacuum protection valve group is connected in series in the order of liquid injection target → anti-attenuation electric valve 22 → vacuum water-oil separator 21 → vacuum pump 7; an emergency stop button 31 independent of the PLC control circuit is configured, which directly cuts off the power supply of the equipment after being triggered; the sensing hardware selected is a vacuum pressure gauge 81, a flow meter 82, and a liquid level sensor 83 (the minimum safe liquid level of the storage tank is set to 35.2L).

[0039] 2. Logic control safety layer: Select Xinje XD3 series or Mitsubishi FX3U series PLC as the core controller, and collect sensor data through RS485 bus; set vacuum degree compliance threshold ≤-90.0kPa, liquid injection flow rate 0.556L / s, sensor hardware communication timeout time 300ms, and execute the core function of multi-factor composite process interlock.

[0040] 3. Information and Access Control Security Layer: The MCGSTPC7062Ti touchscreen is selected as the human-machine interaction terminal 9. Three-level access control is set up for operators, engineers and administrators to realize the functions of security status visualization, alarm data snapshot storage and USB flash drive log export, and support fault scenario reproduction and root cause analysis.

[0041] IV. Collaborative Operation Process of the Three-Layer Structure under Normal Operating Conditions 1. Pre-operation prevention phase: After the operator logs into the human-machine interface terminal and the system completes the permission verification, only the routine operation and status viewing functions are enabled; the electrical layer performs hardware self-test and uploads the self-test data to the PLC; the logic layer performs multi-factor interlock pre-judgment, and after the conditions are met, a "start allowed" flag is generated and fed back to the information layer, and the terminal displays "logic layer ready" with a green indicator light.

[0042] 2. In-process control stage 2.1. Vacuum Pumping Sub-process: The PLC issues a command to start the vacuum pump 7 and the anti-attenuation electric valve 22, and the vacuum water-oil separator 21 simultaneously intercepts residual liquid in the pipeline; the logic layer collects vacuum pressure gauge data in real time, and issues a command to shut down the vacuum pump and the anti-attenuation electric valve after reaching -90.0 kPa; the information layer displays the vacuum degree value and equipment operation status animation in real time, and records process data synchronously.

[0043] 2.2. Liquid Injection Sub-process: The PLC issues a command to start the liquid injection pump 5 and the anti-backflow electric valve 11, and the coolant opens the one-way valve 12 to inject into the target liquid injection point; the flow meter collects the flow rate data, and after the cumulative liquid injection volume reaches 32L, the PLC issues a command to shut down the liquid injection pump and the anti-backflow electric valve, and the one-way valve automatically closes to prevent backflow; the information layer displays that the liquid injection is complete and automatically archives the full data of this process.

[0044] 2.3. Post-event traceability stage: After the injection is completed, the information layer automatically generates production records. Administrators can log in to the terminal to export historical data to a USB flash drive for process optimization and quality traceability. Unauthorized personnel do not have data export permissions.

[0045] V. Cross-level backup protection mechanism for local failures at a single level 1. Partial failure of electrical layer (short circuit in control circuit of anti-backflow electric valve 11): After the liquid injection is completed, the anti-backflow electric valve opens by mistake. The one-way valve closes by spring force to form a physical barrier and block the outflow of medium. The logic layer detects that the flow rate is 0 in the standby state but the valve group feedback is open, immediately cuts off the power supply to the valve group and triggers an alarm. The information layer automatically generates an alarm data snapshot, the terminal pops up an alarm window and notifies the engineer to handle it.

[0046] 2. Logic layer partial failure (vacuum pressure gauge 81 data freeze): During the vacuuming process, the pressure gauge data freezes at -50kPa. After the logic layer self-diagnosis module detects the abnormal data, it triggers alarm code A203, immediately stops the vacuum pump and closes the anti-attenuation electric valve; the electrical layer executes the actions according to the instructions, and the vacuum water-oil separator completes the collection of residual liquid; the information layer stores a snapshot of the data at the moment of the fault, restricts the device restart permission, and only engineers can unlock the calibration.

[0047] 3. Partial failure of information layer (communication interruption of human-machine interface terminal 9): During the liquid injection process, the communication between the terminal and the PLC is interrupted. The logic layer is unaffected and continues to perform monitoring and interlocking. After the liquid injection volume reaches the target, the shutdown command is issued normally. The electrical layer completes the start and stop actions according to the command to ensure no medium backflow. After the communication is restored, the information layer automatically synchronizes the process data stored in the PLC and completes the production and alarm logs.

[0048] VI. Implementation Results This embodiment addresses the core pain points of existing precision liquid injection process safety protection through a three-tiered defense-in-depth scheme, achieving systematic and quantifiable technical effects: it constructs a closed-loop safety protection system encompassing pre-event prevention, in-event interruption, and post-event traceability, mitigating the risk of common-cause failures; in the scenario of coolant injection for new energy supercharging main units, it reduces unplanned equipment downtime by 80% and shortens the average fault troubleshooting time by 75%, meeting the mass production requirements of precision liquid injection processes in high-end industries; simultaneously, it develops specialized technical advantages in hardware protection, logic control, information management, and extreme operating condition protection, achieving specialized protection against core process risks, intelligent prediction of abnormal operating conditions, full traceability of faults, and cross-level compensation for single-level failures.

[0049] Example 2 This embodiment is based on the structural optimization design of the injection pipeline in Embodiment 1, such as... Figure 2 As shown, through precise design of hardware layout and pipeline form, the pre-emptive physical protection foundation of electrical and mechanical safety layers is improved, the basic backflow prevention and anti-siphon capability of the system is strengthened, and the problems of spontaneous flow of medium and siphon leakage caused by unreasonable layout of traditional liquid injection pipelines are solved. At the same time, the pipeline structure is adapted to the flow and metering accuracy requirements of precision liquid injection process, and forms a basic linkage with the three-layer in-depth safety protection system.

[0050] I. Core Optimization Design Requirements for Injection Pipelines 1. Precise layout of one-way valve: The one-way valve 12 is set at the port of the injection pipeline near the injection target 4, forming physical protection at the position closest to the source of medium backflow, shortening the flow path of the backflow medium and improving the efficiency of passive check valve response.

[0051] 2. Core components are installed on the same horizontal plane: The installation reference planes of the anti-backflow electric valve 11, injection pump 5, and flow meter 82 are set to the same horizontal plane to eliminate the static pressure difference caused by the vertical height difference between components and to prevent spontaneous siphoning of the medium from the source.

[0052] 3. N-shaped tube structure design: An N-shaped tube structure is added to the liquid injection pipeline. Its top height is higher than the highest working liquid level of the liquid storage tank 6. The liquid inlet extends into the bottom of the liquid storage tank. The liquid outlet is at the same horizontal height as the fluid flow center axis of the anti-backflow electric valve 11, the liquid injection pump 5, and the flow meter 82, forming a liquid seal and air resistance structure. At the same time, it ensures that there is no vertical height difference between it and other core fluid components.

[0053] The optimized pipeline design in this embodiment has no additional flow resistance loss under forward injection conditions. The forward pressure provided by the injection pump can easily drive the medium to flow. The pipeline is filled with medium throughout, which will not affect the metering accuracy of the flow meter and meets the high precision requirements of precision injection processes in fields such as new energy and electronic manufacturing.

[0054] II. Synergistic Integration with the Three-Layer In-Depth Security Protection System 1. Pre-emptive prevention stage: The PLC in the logic control safety layer collects the liquid level height of the storage tank in real time through the liquid level sensor 83 and verifies whether the height difference between the top of the N-shaped tube and the highest working liquid level of the storage tank meets the design requirements; if the liquid level exceeds the threshold or the liquid level is close to or higher than the top of the N-shaped tube, the liquid injection function output is immediately blocked and an abnormal liquid level warning is issued through the human-machine interaction terminal of the information layer.

[0055] 2. Interruption Phase: The PLC monitors the stability of the pipeline flow in real time through the flow meter 82. Combined with the basic flow resistance characteristics of the N-shaped tube, it makes slight closed-loop fine-tuning of the speed of the injection pump 5 to further ensure the accuracy of injection metering. If no abnormal fluctuation in flow is detected, the electrical layer hardware self-test is immediately triggered to check the pipeline connection and component status.

[0056] 3. Post-event traceability stage: The information layer human-machine interaction terminal synchronously records information such as changes in the liquid level of the storage tank, verification data of the height difference of the N-shaped pipe, and full-cycle data of pipeline flow, providing basic data support for process optimization and fault diagnosis.

[0057] III. Implementation Results This embodiment improves the hardware structure of the electrical and mechanical safety layer by optimizing the structure of the injection pipeline, enhancing the anti-backflow and anti-siphon capabilities of the injection pipeline. Moreover, the structural design is fully compatible with the flow rate and metering requirements of precision injection processes, with no additional flow resistance and no loss of metering accuracy, laying the hardware foundation for building a higher-level redundant anti-backflow protection system.

[0058] Example 3 This embodiment integrates the anti-backflow dual isolation valve assembly with the optimized injection pipeline layout of Embodiment 2, such as... Figure 2 As shown, a quadruple redundant backflow protection system is constructed, which effectively solves problems such as medium backflow and siphon leakage caused by the failure of a single or dual valve under extreme conditions. It achieves complete blocking of medium backflow under extreme conditions, further enhances the heterogeneous redundancy protection capability of the electrical and mechanical safety layers, and deeply integrates with the three-layer in-depth safety protection system to form a closer cross-level collaborative protection, thereby enhancing the overall robustness of the system.

[0059] I. Implementation and Core Principles of the Quadruple Redundancy Backflow Protection System This system follows the principles of tiered fallback and heterogeneous redundancy, combining active control with passive protection and a heterogeneous design of hardware valve groups and piping structures to achieve four levels of tiered fallback protection, as detailed below: 1. First layer of protection: Anti-backflow electric valve actively shuts off: The anti-backflow electric valve 11 is precisely controlled by the PLC through the RS4815 bus. After the liquid injection is completed, it is immediately de-energized and reset to the normally closed state. During the liquid injection process, it is opened according to the process instructions, realizing the active blocking of medium backflow under normal operating conditions, which is the first electrical control barrier.

[0060] 2. Second layer of protection: passive check valve: The check valve 12 is a passive protection component with a purely mechanical structure. It has no external control signal and opens under positive pressure of the medium and closes automatically under reverse pressure or when there is no pressure. When the anti-backflow electric valve has an electrical fault, the check valve forms a physical barrier by relying on the spring reset force to passively block the backflow of the medium, which is the first hardware safety net.

[0061] 3. Third layer of protection: horizontal layout eliminates static pressure difference: based on the horizontal installation design of the core components in Example 2, the fluid flow center axis of each component is kept at the same horizontal height, which completely eliminates the static pressure difference caused by the vertical height difference, and avoids the spontaneous siphon effect caused by the potential energy difference from the root. Even if the first two valve group protections fail, there is no potential energy basis for the spontaneous flow of the medium, which is the second hardware bottom-line barrier.

[0062] 4. Fourth layer of protection: N-shaped tube structure liquid seal gas resistance + gravity blocking: The apex of the N-shaped tube is higher than the highest working liquid level of the storage tank. After the liquid injection stops and the injection pump stops, the medium on both sides of the apex of the N-shaped tube falls back naturally under the action of gravity, forming a stable vacuum gas resistance section at the apex, cutting off the fluid communication channel on both sides of the pipeline; the medium in the storage tank cannot cross the apex of the N-shaped tube by its own gravity. Even if the first three layers of protection fail, this gas resistance section can still completely block the backflow of the medium and the siphon leakage, which is the ultimate hardware backup barrier under extreme working conditions.

[0063] Of the four layers of protection mentioned above, the first two are active and passive protection for valve groups, and the latter two are structural protection for pipeline layout. The protection principles of electrical control and mechanical structure are completely different, eliminating the risk of common cause failure and ensuring that if any single or multiple protection links fail, the subsequent links can still play an effective role.

[0064] II. Deep Synergy and Linkage with the Three-Layer In-Depth Security Protection System 1. Collaboration with electrical and mechanical safety layers: The four-fold protection system serves as the core subsystem of the electrical layer, with all hardware components included in the electrical layer's hardware self-test scope; the PLC collects the status of the anti-backflow electric valve and flow meter data in real time via the bus to determine the protection status. If an abnormality is detected in the valve group, it immediately relies on the two layers of protection behind the pipeline structure as a backup and triggers a hardware fault warning.

[0065] 2. Collaboration with the logic control safety layer: The PLC incorporates the status of the four-fold protection system into the multi-factor composite process interlock verification range. If any abnormality is detected in any protection link, the liquid injection function output is immediately blocked. During the liquid injection process, the risk of backflow is predicted and active blocking is achieved in the process by comparing and analyzing the flow data and the valve group status.

[0066] 3. Collaboration with the Information and Access Security Layer: The human-machine interface terminal of the information layer displays the status of each link of the four-fold protection system in real time. If a link is abnormal, an alarm window will pop up immediately and the abnormal link will be marked. It will automatically collect snapshots of multiple parameters such as valve group status, flow data, and liquid level at the moment of the abnormality and store them in association with alarm code and time. Only administrators can export data snapshots to provide a basis for root cause analysis of faults and optimization of the protection system.

[0067] III. Verification of Protection Effectiveness under Extreme Failure Conditions Taking the injection of coolant into the new energy supercharger as an application scenario, the extreme working condition of double failure of the anti-backflow electric valve 11 and the one-way valve 12 is simulated: during the standby stage after the injection is completed, the anti-backflow electric valve is opened by mistake due to a short circuit, and the one-way valve cannot be closed due to the valve core being stuck. The protection of the two-stage valve group is completely failed, the injection target cavity is under pressure, and a connecting channel is formed between the liquid storage tank and the injection target.

[0068] Protection Response: The third layer of protection immediately takes effect, with the horizontal layout ensuring no static pressure difference in the pipeline and no potential energy basis for spontaneous backflow of the driving medium; the fourth layer of protection, the N-shaped air resistance section, completely cuts off the backflow channel, achieving 100% physical isolation; the logic layer detects that the flow rate is 0 in standby mode but the valve group feedback is open, immediately determines that the valve group has a double failure, triggers alarm code A105, cuts off the power supply to the valve group and blocks the liquid injection function; the information layer automatically collects a snapshot of full parameter data at the moment of the fault, associates and stores it and locks the equipment operation permissions, which can only be unlocked and repaired by engineers.

[0069] Verification results: Under the extreme condition of double valve failure, the backflow of the medium was completely blocked by the double protection of the pipeline structure. There was no backflow of the medium, and the equipment and process were not affected. The step-by-step fallback effect of the quadruple redundancy backflow protection system was fully verified.

[0070] IV. Implementation Results The quadruple redundancy backflow protection system constructed in this embodiment upgrades from "dual protection of valve groups" to "quadruple heterogeneous redundancy protection of valve groups and pipelines," significantly improving the backflow protection level. It can stably cope with extreme operating conditions of single or double valve failures and completely solve core problems such as media backflow, siphon leakage, and media cross-contamination. The heterogeneous design avoids the risk of common cause failures at the source and strengthens the hardware protection capability of the electrical layer. At the same time, the system is incorporated into the three-layer system's full-process control, enhancing the cross-layer compensation capability of the three-layer system. Moreover, while achieving a high level of protection, the system has no additional flow resistance and no loss of metering accuracy, meeting the high-precision liquid injection metering requirements of high-end industries within ±0.5% and is compatible with automated mass production processes.

[0071] Example 4 This embodiment is based on Embodiment 1 and focuses on the vacuum protection valve assembly of the vacuum pumping pipeline. Figure 3 The optimized design shown enhances the system's ability to prevent vacuum pressure decay and intercept liquid media, solving problems such as rapid vacuum pressure decay after vacuum pump shutdown, liquid media backflow into the vacuum pump cavity causing equipment damage, and loss of vacuum pumping accuracy. It improves the pre-emptive physical protection barrier of electrical and mechanical safety layers, deepens the redundancy and backup capability of the defense-in-depth system, and adapts to the stringent requirements of precision liquid injection processes for vacuum stability and equipment reliability.

[0072] I. Optimized Configuration of Vacuum Protection Valve Assembly In this embodiment, the vacuum protection valve group 2 is composed of a vacuum water-oil separator 21 and an anti-attenuation electric valve 22 connected in series. The anti-attenuation electric valve 22 is connected in series at the inlet of the vacuum water-oil separator 21, and the vacuum water-oil separator 21 is connected in series at the inlet of the vacuum pump 7. The vacuum water-oil separator 21 is equipped with a transparent window and a manual / automatic drain valve to realize visual monitoring and convenient discharge of liquid media. The anti-attenuation electric valve 22 is a high-sealing-level two-position two-normally closed electric valve to realize rapid opening and closing of the vacuum pipeline and high airtightness isolation. The two work together to form a dual hardware protection of "media interception + vacuum pressure maintenance", and are deeply linked with the logic control security layer and the information and permission security layer to build a full-process safety protection system for the vacuum pipeline.

[0073] II. Core Protection Principle of Vacuum Protection Valve Assembly Vacuum water-oil separator liquid medium three-stage interception principle Vacuum oil-water separator 21, as the core component for liquid medium interception, directly intercepts liquid media such as coolant, condensate, and oil carried out from the liquid injection target cavity during the vacuuming process, preventing them from entering the vacuum pump cavity and causing equipment failure, thus achieving three-stage interception: 1. Primary inertial separation: After the gas-liquid mixed medium enters the separator, the flow channel expands and changes direction. Due to inertia, the liquid medium impacts the inner wall of the separator, initially separates from the gas, and settles to the bottom along the wall. 2. Secondary filtration and separation: The gas after inertial separation passes through the high-precision filter element inside the separator, where tiny droplets are adsorbed and condensed, further removing liquid impurities; 3. Three-stage sedimentation storage: The separated liquid medium gathers in the storage chamber at the bottom of the separator for temporary storage, avoiding overflow and backflow of the medium in a short period of time.

[0074] The separator's transparent window enables real-time monitoring of the liquid storage volume, and the manual / automatic drain valve allows for flexible selection of the draining method: the automatic drain valve can be set with thresholds and time via PLC to achieve automatic discharge of liquid media, adapting to automated mass production; the manual drain valve serves as a redundant draining channel, allowing for manual intervention in case of automatic drain valve failure, ensuring uninterrupted media interception function.

[0075] Anti-attenuation electric valve vacuum pressure holding principle The anti-attenuation electric valve 22 is installed close to the suction port of the liquid injection target 4. Its core function is to quickly cut off the vacuum pipeline after the vacuum pump 7 stops evacuating, so as to achieve dual pressure maintenance of vacuum: when the vacuum pressure gauge 81 detects that the pipeline has reached the preset vacuum target value, the PLC immediately issues a command to control the anti-attenuation electric valve 22 to close quickly, completely isolating the liquid injection target cavity from the subsequent pipeline, forming an independent sealed vacuum cavity, blocking gas leakage, and preventing the vacuum pressure from diffusion and attenuation.

[0076] During the vacuuming stage, the anti-attenuation electric valve 22 remains open, which does not affect gas flow or reduce the vacuuming rate. When the vacuum pump fails or stops in an emergency, the valve can be quickly closed under the control of the PLC to achieve emergency pressure maintenance of the vacuum, thus buying time for process handling and equipment maintenance and reducing product scrap losses.

[0077] III. Verification of Redundancy Protection Effectiveness under Extreme Failure Conditions Taking the injection of coolant into the new energy supercharger as a scenario, the extreme failure condition of the vacuum pipeline was simulated: after vacuuming to -90.0 kPa, the vacuum pump stopped normally, the anti-attenuation electric valve 22 failed due to the aging of the seal, and at the same time, the automatic drain valve of the vacuum water-oil separator 21 was stuck in the open state, resulting in a dual failure of vacuum pressure holding and leakage of the drain channel.

[0078] 1. Protection Response: Electrical and Mechanical Safety Layer Hardware Backup: The three-stage interception mechanism of the vacuum water-oil separator remains effective. The filter element and sedimentation structure intercept liquid media, preventing it from flowing back into the vacuum pump; the manual drain valve is normally closed, forming a redundant sealing barrier to block large-scale backflow of external air and delay vacuum pressure decay; the anti-degradation electric valve remains closed even if the seal fails, and the valve core blocks most gas leakage, achieving basic vacuum pressure maintenance in combination with pipeline airtightness.

[0079] 2. Logic control safety layer active compensation: When the PLC detects that the vacuum pressure decay rate far exceeds the warning threshold, it immediately determines the fault and triggers alarm code A305, blocking the liquid injection function output; at the same time, it controls the vacuum pump to restart, and the anti-decay electric valve repeatedly opens and closes to try to eliminate the jam. If it cannot be restored, it executes the equipment safety shutdown.

[0080] 3. Information and Access Control Security Layer: Full Data Traceability: The human-machine interface terminal automatically collects snapshots of all parameters, such as vacuum pressure decay rate, valve status, and separator liquid level, at the moment of alarm. The system locks equipment operation permissions, allowing only engineers to unlock and perform maintenance. Administrators can export fault data snapshots to analyze fault causes and develop optimization plans. Alarm information is alerted through both audible and visual prompts and terminal pop-ups to notify on-site personnel to intervene.

[0081] IV. Implementation Results This embodiment optimizes the function and refines the installation logic of the vacuum protection valve group, forming a quadruple redundant vacuum protection system of "three-level interception of liquid media + dual pressure maintenance of vacuum pressure," achieving a comprehensive upgrade in the protection capability of the vacuum pipeline: the vacuum pressure maintenance time after the vacuum pump stops is increased by more than 90%, and the failure rate of the vacuum pump equipment is reduced by 85%; the manual / automatic drain valve of the separator and the high airtightness design of the valves are adapted to the requirements of automated mass production and precision processes, meeting the high-precision control requirements of ±0.5kPa vacuum degree; the transparent window enables visual monitoring of equipment status, and the full-process fault traceability reduces the average fault troubleshooting time by more than 70%, improving equipment maintainability; at the same time, it strengthens the pre-emptive physical protection capability of the electrical layer for the vacuum process, deeply collaborates with the logic layer and information layer, enhances the system's cross-level compensation capability, and is fully adapted to the mass production requirements of high-end industry precision liquid injection processes.

[0082] Example 5 This embodiment optimizes the functions of the manual intervention control components and emergency stop button on the equipment operation panel based on embodiment 1, improves the manual operation protection and emergency circuit breaking capabilities of the electrical and mechanical safety layers, makes the operation of the manual intervention process more precise, and the physical circuit breaking in emergency situations more reliable. At the same time, it forms a close collaborative protection with the logic control safety layer and the information and permission safety layer, further consolidating the hardware foundation of the multi-level in-depth security protection system.

[0083] This embodiment uses the injection of coolant into the main unit of a new energy supercharger as an application scenario, such as... Figure 1 As shown, a vacuum button 23 and a liquid injection button 13 are added to the equipment operation panel, and the hard-wired power-off function of the emergency stop button 31 is enhanced. All buttons communicate and are linked with the PLC through the RS4815 bus.

[0084] I. Configuration and Functional Design of Core Components of the Control Panel Vacuuming Button 23: Installed in the dedicated operation area for the vacuuming process, it communicates bidirectionally with the PLC. The button has a built-in status indicator light—a solid green light indicates manual intervention is possible, a flashing red light indicates the process is running, and a gray light indicates the process is locked and cannot be intervened. This button provides a manual intervention channel for the vacuuming process. Upon triggering, the PLC immediately receives the command and executes the vacuuming procedure, while simultaneously feeding back the action status to the indicator light.

[0085] Injection Button 13: Installed in the dedicated operation area for the injection process, it communicates bidirectionally with the PLC. A solid green indicator light indicates that the injection interlock conditions are met and manual intervention is possible; a flashing red light indicates that the process is running; and a flashing yellow light indicates that the interlock conditions are not met and intervention is not possible. This button provides a manual intervention channel for the injection process. The button only has an effective triggering function when all the interlock conditions of the multi-factor composite process at the logic layer are met, thus preventing unauthorized injection caused by human error.

[0086] Emergency Stop Button 31: Installed in a prominent and easily accessible position on the operation panel, it adopts a hard-wired independent circuit design; in addition to communicating with the PLC via RS4815 bus to transmit the trigger status, the core has a hard-wired power-off function to directly cut off the equipment's power circuit, independent of the PLC control circuit. Even if the PLC experiences program crashes, communication interruptions, or other faults, triggering this button can still quickly cut off the equipment's main power supply.

[0087] II. Synergistic Interaction Between Core Components and the Three-Layer Protection System Interlocking between manual intervention button and logic control layer 1. The manual triggering functions of vacuum button 23 and liquid injection button 13 are fully controlled by PLC, realizing dual control of "manual operation + logic verification": 1.1. Before the vacuum button is triggered, the PLC automatically checks the basic conditions such as the docking status of the liquid injection target, the emergency stop not being triggered, and the vacuum protection valve group being fault-free. If these conditions are met, the vacuum action is executed; if not, the action is refused and the yellow indicator light on the button flashes to indicate this, while the prompt information is displayed on the terminal. 1.2. Before the injection button is triggered, the PLC strictly performs multi-factor composite process interlock verification (vacuum pressure meets the standard, liquid level safety point meets the standard, flow rate meets the standard, emergency stop is not triggered, and the preceding vacuuming process is completed). If any condition is not met, the button trigger is invalid, ensuring that the safety standards for manual injection and automatic injection are consistent.

[0088] 2. Cross-level linkage protection for emergency stop button 31 After the emergency stop button is triggered, cross-level synchronous linkage is achieved, including power-off of the electrical layer hardwire, action compensation in the logic layer, and record tracing in the information layer. 2.1. Electrical and mechanical safety layer: The power supply to the injection pump, vacuum pump and all electric valves is cut off immediately upon triggering. The anti-backflow electric valve and anti-attenuation electric valve are automatically reset to the normally closed state, and the check valve remains closed. All process actions are stopped urgently from the hardware level, and the flow of media and the vacuuming process are blocked. 2.2. Logic Control Safety Layer: The PLC detects the emergency stop trigger state in real time, immediately executes all process shutdown procedures, blocks all function outputs of vacuuming and liquid injection, and freezes and saves all sensor data to avoid data loss; 2.3. Information and Access Security Layer: The human-machine interface terminal immediately pops up a red emergency stop alarm window, automatically collects and stores a snapshot of all parameters such as valve status, pump operating status, vacuum pressure, flow rate, and liquid level at the moment the emergency stop is triggered, associates the alarm code with the trigger time, and locks all operating permissions of the equipment. Only engineers can unlock and reset the emergency stop button with a password.

[0089] III. Implementation Results This embodiment achieves the following technical effects by optimizing the manual intervention and emergency circuit breaker components of the operation panel: The status indication and logic interlock verification of the vacuuming and liquid injection buttons solve the problems of traditional manual operation lacking status prompts and being prone to accidental triggering, improving the accuracy and safety of manual operation and adapting to the manual operation needs of scenarios such as equipment debugging and emergency fault handling; The hard-wired power-off function of the emergency stop button breaks through the limitations of traditional soft circuit breaking that relies solely on the PLC, achieving dual emergency circuit breaking of "hard-wired physical circuit breaking + soft logic program shutdown," ensuring safe equipment shutdown in emergency situations even if the PLC fails, eliminating safety accidents from a hardware perspective; All components of the operation panel achieve bidirectional communication and linkage with the three-layer protection system, seamlessly connecting the hardware operation components of the electrical layer with the intelligent control of the logic layer and the traceability management of the information layer, further strengthening the redundant protection capabilities of multi-level, in-depth defense.

[0090] Example 6 like Figure 4 As shown, this embodiment is based on the three-level in-depth safety protection system architecture of Embodiment 1. It uses Xinje XD3 series PLC as the core controller and achieves parallel monitoring and composite verification of multiple conditions such as vacuum pressure, liquid level safety, emergency stop status, and previous process through strict "AND" logic. This ensures that the liquid injection function is allowed to start only when all safety conditions are met at the same time. It realizes precise interruption of the liquid injection process in the process from the logic level and completely eliminates the risk of misoperation when single or multiple safety conditions are missing.

[0091] This embodiment takes the injection of coolant into the supercharger as the application scenario. The injection target is the coolant tank of the supercharger. The single injection volume is 32L, the vacuum target value is -90.0kPa, and the entire process of multi-factor composite process interlocking is implemented.

[0092] I. Core Configuration of Multi-Factor Composite Process Interlock 1. Controller and communication link: The Xinje XD3 series PLC is selected as the core, and the sensor hardware data is collected through RS485 bus. The communication baud rate is 9600bps, with 8 data bits, 1 stop bit, and no parity. The PLC main loop (OB1) executes interlock logic with a scan cycle of 100ms to ensure real-time status updates.

[0093] 2. Sensing and triggering hardware: PTJ500 vacuum pressure gauge 81 (range -100~0kPa), digital liquid level sensor 83 (minimum safe liquid level of storage tank 35.2L), and normally closed emergency stop button 31 are selected. All hardware is connected to the PLC digital input module (DI) and analog input module (AI) via bus.

[0094] 3. Execution and feedback components: The injection pump 5 and the anti-backflow electric valve 11 are connected to the Y5 and Y7 ports of the PLC digital output module (DO) respectively. The PLC controls the start and stop of the components by outputting high and low levels; the operating status of the components is fed back to the PLC through feedback signals to realize the status closed loop.

[0095] 4. Human-Machine Interaction Terminal: The MCGSTPC7062Ti touch screen is selected, which communicates with the PLC via RS4815 bus to display the interlock condition status and trigger alarm information in real time, providing visual guidance for on-site operation.

[0096] Interlock Condition Definition: Strictly following "AND" logic, four core safety conditions are defined. If any condition is not met, the fluid injection function output is blocked, as detailed in the table below:

[0097] II. Execution Flow of Multi-Factor Composite Process Interlock Logic With "real-time status acquisition → independent condition judgment → compound logic operation → output control and status indication" as the core, the system achieves full-process automation and high-precision management and control. Specific steps include: 1. Real-time status acquisition: Within each 100ms scan cycle, the PLC synchronously acquires the raw status data of all interlock conditions via RS485 bus, including the analog data of the vacuum pressure gauge, the digital data of the liquid level sensor and the emergency stop button, and the completion flag of the vacuuming process inside the PLC. All data is uploaded to the human-machine interface terminal of the information layer in real time.

[0098] 2. Independent condition judgment: The PLC performs independent threshold and status verification on the collected raw data, and generates a separate qualified flag bit (BOOL type, 1 for qualified, 0 for unqualified) for each interlock condition; if the condition is not met, the PLC immediately generates the corresponding abnormal prompt code to provide a basis for subsequent alarms.

[0099] 3. Compound Logic Operation: The PLC performs a strict AND operation, combining four independent qualified flag bits to generate the injection enable flag Enable_Injection. The logical expression is: Enable_Injection = P_OK AND Level_OK AND EStop_OK AND Seq_OK. The injection enable flag is 1 only when all flag bits are 1, indicating that the injection process meets all safety conditions; if any flag bit is 0, the injection function output is blocked.

[0100] 4. Output control and status indication Liquid injection permitted: When the liquid injection enable flag is 1, the PLC outputs a high level to the Y5 and Y7 ports to start the liquid injection pump and the anti-backflow electric valve; the human-machine interface terminal displays a green "Liquid injection permitted / Liquid injection in progress" status, and all interlock conditions are marked as qualified in green.

[0101] Liquid injection block: When the liquid injection enable flag is 0, the PLC resets ports Y5 and Y7, cutting off the power supply to the liquid injection pump and the anti-backflow electric valve; the human-machine interface terminal will alarm with red markings for unmet conditions, pop up a text prompt box to display the specific abnormal reason, and trigger a buzzer to sound softly to remind the operator.

[0102] If any interlock condition fails suddenly during the injection process, the PLC will recalculate the logic within one scan cycle (100ms), immediately set the injection enable flag to 0, and cut off the injection output to achieve millisecond-level in-process interruption.

[0103] III. Verification of Interlocking Application in Multi-Factor Composite Processes Real-world testing was conducted on the coolant injection production line for new energy superchargers, simulating four typical operating conditions: all conditions met, single condition missing, multiple condition missing, and sudden failure during injection. All test results met expectations. 1. All conditions are met: all qualified flag bits are 1, the liquid injection enable flag is 1, the PLC starts the liquid injection process normally, and there are no alarm messages on the terminal; 2. Single condition missing (vacuum degree not up to standard): The vacuum pressure qualification indicator is 0, the liquid injection enable indicator is 0, the PLC locks the liquid injection function, and the terminal accurately prompts "vacuum degree not up to standard"; 3. Multiple conditions missing (insufficient liquid level + emergency stop trigger): The liquid level and emergency stop qualification indicators are both 0, the liquid injection enable indicator is 0, the PLC blocks the liquid injection function and triggers an audible and visual alarm, and the terminal provides graded prompts for the cause of the fault. 4. Sudden failure of conditions during liquid injection (manually triggered emergency stop): The PLC recalculates the logic within 100ms, cuts off the liquid injection output, and the terminal immediately pops up a red emergency stop alarm window, achieving millisecond-level emergency interruption.

[0104] IV. Implementation Results This embodiment achieves precise and efficient control of the injection process through the implementation of multi-factor composite process interlocking. It deeply collaborates with the three-layer protection system, achieving significant results: Through strict AND logic composite, it enables parallel monitoring and full-condition verification of multiple safety conditions, 100% eliminating unauthorized injection; the PLC's 100ms scanning cycle achieves millisecond-level real-time blocking, solving the problem of delayed response in traditional protection methods and minimizing the risk of equipment damage and product scrap; independent condition judgment and hierarchical prompts accurately locate the root cause of anomalies, improving the fault handling efficiency of on-site operators by over 90%; using electrical layer hardware as the data source, it achieves real-time verification of hardware status and action compensation, while synchronizing all status and alarm information to the information layer, forming a complete closed loop of "hardware data acquisition → logic judgment and control → information traceability management"; the interlocking logic is executed automatically throughout the process, and parameters can be flexibly modified through engineer permissions to adapt to different injection process requirements, meeting the automated mass production needs of high-end industries.

[0105] Example 7 like Figure 5 As shown, this embodiment, based on embodiment 6, designs intelligent monitoring and fault early warning functions for key processes of vacuuming and liquid injection in the logic control safety layer. Using Xinje XD3 series PLC as the core controller, it constructs a collaborative monitoring system based on dual criteria of "communication status - data rationality". Through a dual logic architecture of "real-time rate monitoring - dynamic threshold comparison - timeout bottom line protection", it realizes early warning of abnormal trends in the process and alarm for timeout faults, further strengthening the in-process blocking and active protection capabilities of the logic control safety layer and improving the multi-level in-depth safety protection system.

[0106] This embodiment takes the injection of coolant into the supercharger as the application scenario. The injection target is the supercharger coolant tank, the single injection volume is 32L, the vacuum target value is -90.0kPa, the maximum process time threshold T_max=240s, and the entire process is implemented based on the dual criteria of vacuuming and injection time-flow rate.

[0107] I. Core Configuration and Basic Parameter Settings 1. Controller and communication link: Xinje XD3 series PLC is selected as the core controller. The vacuum pressure transmitter and turbine flow meter are connected through dual RS485 buses respectively. The communication parameters are the same as in Example 6. The PLC main loop (OB1) executes the monitoring logic with a scan cycle of 100ms. The diagnostic logic is executed with a cycle of 200ms to ensure real-time status updates and rapid response to anomalies.

[0108] 2. Sensing and Actuation Hardware: PTJ500 vacuum pressure transmitter (installed in the vacuum pipeline) and LWGY turbine flow meter (range 0.5~10m³ / h, installed in Φ10mm liquid injection pipeline) are selected; the actuation components include vacuum pump, anti-attenuation electric valve, liquid injection pump, and anti-backflow electric valve, all of which are connected to the PLC digital output module port to realize closed-loop control of start / stop and switching.

[0109] 3. Human-Machine Interaction Terminal: The MCGSTPC7062Ti touch screen is selected, which communicates with the PLC via RS4815 bus to display process monitoring data and early warning / alarm information in real time, and simultaneously realizes alarm data snapshot storage and historical data traceability.

[0110] 4. Core Process and Monitoring Threshold Settings: The flow rate setpoint during the injection stage is Q_set = 0.556 L / s. Other core parameters are shown in the table below:

[0111] All thresholds can be flexibly modified via the human-computer interaction terminal with engineer permissions to adapt to different process scenarios.

[0112] II. Collaborative Monitoring Architecture Based on "Communication Status - Data Reasonableness" Dual Criteria In this embodiment, the monitoring logic executes two dimensions of judgment in parallel. First, it ensures the authenticity and reliability of the data source through dual-dimensional diagnosis of communication status and data rationality. Then, it achieves intelligent control of the process through dual-threshold monitoring of process trend and timeout, which completely solves the pain points of traditional solutions that rely on the accuracy of a single sensor and are prone to monitoring misjudgment / missed judgment.

[0113] 1. Communication Status - Data Rationality Dual-Dimensional Diagnostic Criteria This criterion serves as a pre-verification step for the monitoring logic. It is executed first in each diagnostic cycle, and the process monitoring phase can only proceed if the sensor data is deemed valid. 1.1. Communication Status Diagnosis: The PLC sends a Modbus query command to the vacuum pressure transmitter and turbine flow meter every 200ms. If no correct response is received within 300ms, it is counted as one communication failure. Three consecutive communication failures are judged as sensor communication failure and trigger the corresponding alarm code (vacuum transmitter communication failure A201, flow meter communication failure A202).

[0114] 1.2. Data rationality diagnosis: The valid data returned by the sensor is triple-checked. If any check fails, it is determined to be abnormal data and triggers the corresponding alarm code (vacuum transmitter data abnormality A203, flow meter data abnormality A204): over-range check (checking whether the data exceeds the preset valid value range), data freeze check (data change is lower than the threshold for 2 consecutive seconds), and jump abnormal check (data jump is too large in adjacent cycles and lasts for 3 cycles).

[0115] 1.3. Diagnostic Failure Safety Action: When a sensor communication failure or data abnormality is detected, the PLC immediately triggers the corresponding alarm, stops the current vacuuming / liquid injection process, shuts down the corresponding pump and electric valve, resets the pre-qualification flag of the multi-factor interlock logic, and blocks the liquid injection function output.

[0116] 2. Dual threshold monitoring criteria for process trend and timeout fallback This criterion is the core monitoring logic of the process. Under the premise that the sensor data is valid, the vacuuming and liquid injection processes are monitored in parallel to realize early warning of abnormal trends and fallback alarm for timeout faults.

[0117] 2.1. Vacuuming process: After initialization, vacuum pressure data is collected and verified in real time, and the real-time vacuuming rate and moving average rate are calculated. If the average rate is continuously lower than the warning threshold, the abnormal trend warning V101 is triggered. The running time is accumulated in real time. If the timeout occurs and the target vacuum level is not reached, the timeout alarm A101 is triggered, the vacuum pump is stopped immediately, and the anti-attenuation electric valve is closed. If the target vacuum level is reached and the timeout occurs, the vacuuming is considered successful, and the vacuuming completion flag is set.

[0118] 2.2. Injection Process: The process is initiated only when the multi-factor interlock logic outputs the injection enable flag. After initialization, the flow rate data is collected and verified in real time, and the injection volume is accumulated. The real-time injection rate and the remaining task requirement rate are calculated. If the warning conditions are met, the abnormal trend warning F102 is triggered. The running time is accumulated in real time. If the timeout occurs and the target injection volume is not reached, the timeout alarm A102 is triggered, and the injection pump is stopped immediately and the anti-backflow electric valve is closed. If the target injection volume is reached and the timeout does not occur, the injection is considered successful, and the counter and monitoring flag are reset.

[0119] III. Synergistic Linkage Between Dual-Criterion Monitoring Logic and the Three-Tier Defense-in-Depth System 1. Linkage with electrical and mechanical safety layers: When a trend warning is triggered, the PLC can adjust the pump operating parameters in a coordinated manner to try to eliminate the abnormality; when an alarm is triggered, it immediately controls the corresponding pump and electric valve to perform shutdown and shut-off actions, achieving fault protection through hardware physical isolation, and forming a synergy with the valve group protection of the electrical layer.

[0120] 2. Linkage with the logic control safety layer: The vacuum completion flag is the core prerequisite for the multi-factor composite process interlock logic; when an alarm is triggered during the process, the liquid injection enable flag is immediately reset, and the liquid injection function output is blocked, realizing the deep binding of monitoring logic and interlock logic, forming a dual logic protection of "full process monitoring + conditional hard interlock".

[0121] 3. Linkage with information and access control security layer: When a warning / alarm is triggered, the human-machine interface terminal immediately pops up a corresponding window to display the alarm code, fault description and handling suggestions; at the same time, it collects a snapshot of all parameter data at the moment of the alarm and archives it with the alarm record; only engineers with permissions can reset the warning / alarm, and only administrators with permissions can export historical data and alarm logs to achieve full-process traceability.

[0122] IV. Application Effect Verification Real-world testing was conducted on the coolant injection production line for new energy superchargers, simulating four typical operating conditions: normal process, vacuum leakage, insufficient injection flow, and sensor data freezing. The test results all met expectations: under normal operating conditions, there were no warnings or alarms, and the process was completed smoothly; under vacuum leakage and insufficient injection flow conditions, the system triggered a trend warning in advance, and after the timeout, it triggered a fallback alarm and cut off the process, achieving proactive interruption during the process; under sensor data freezing conditions, the system quickly determined the data anomaly and triggered an alarm, blocking the injection function to prevent erroneous data from causing process loss of control.

[0123] V. Implementation Results The dual-criteria collaborative monitoring logic in this embodiment achieves proactive intelligent protection throughout the entire process cycle. The early warning time for efficiency degradation faults is on average more than 60% earlier than traditional overdue error reporting, significantly reducing the risk of product scrap and equipment damage. Dual-dimensional diagnosis fundamentally avoids the risk of monitoring misjudgments and omissions, with an average sensor failure diagnosis time of ≤2s and a false alarm rate of <0.1%. Deep collaboration with the three-layer protection system further strengthens the system's heterogeneous redundancy and supplementary protection capabilities. Monitoring thresholds can be automatically calculated, parameters can be flexibly modified, and a 100ms scan cycle achieves millisecond-level response, adapting to the high-precision automated mass production process requirements of high-end industries. Clear early warning / alarm codes and data snapshots shorten the average fault investigation time by more than 80%, providing precise data support for process optimization and preventative equipment maintenance.

[0124] Example 8 like Figure 6 As shown, based on Example 7, this embodiment designs a sensor failure self-diagnosis module for the logic control security layer, and conducts online health monitoring of the core sensing units of the vacuuming and liquid injection processes to achieve rapid identification and safe handling of sensor failures. This avoids risks such as process monitoring misjudgment and logic interlock failure caused by sensor failures from the root, and further improves the data source reliability protection of the multi-level in-depth security protection system.

[0125] I. Core Configuration and Basic Parameter Settings The hardware architecture of this embodiment is fully compatible with that of Embodiment 7. The self-diagnostic logic is deeply bound to the process monitoring logic of Embodiment 7 and the multi-factor composite process interlocking logic of Embodiment 6. The Xinje XD3 series PLC is selected as the core controller, and it is connected to the PTJ500 vacuum pressure transmitter and LWGY turbine flow meter through dual RS485 buses. The communication parameters are the same as those in the previous embodiments. The self-diagnostic logic is executed in the PLC with a 200ms cycle. The human-machine interface terminal is an MCGSTPC7062Ti touch screen, which communicates with the PLC in real time to realize status visualization and fault tracing. The diagnostic threshold is consistent with that of Embodiment 7 and can be flexibly adjusted by the engineer's authority.

[0126] II. Execution Flow of Core Logic for Two-Dimensional Self-Diagnosis The self-diagnostic logic in this embodiment is a pre-process control mandatory verification step, which is executed synchronously and in parallel with the process monitoring logic in Embodiment 7. Only when the sensor data is determined to be valid can subsequent process monitoring and interlocking logic operations be performed, forming a progressive protection chain of "data source verification - process monitoring - logic interlocking".

[0127] 1. Communication status self-diagnosis logic The PLC sends Modbus query commands to the vacuum pressure transmitter and turbine flow meter every 200ms and starts timeout counting. If no correct response message is received within the 300ms timeout threshold, it is counted as one communication failure. If three consecutive communication failures are triggered, it is determined that the corresponding sensor communication has failed, and a dedicated alarm code is triggered (vacuum transmitter communication failure A201, flow meter communication failure A202).

[0128] Upon diagnostic triggering, the PLC immediately executes fail-safe actions: stops the currently running vacuuming / liquid injection process, shuts down the corresponding pump and electric valve, resets the pre-qualification flag of the multi-factor interlock logic, and blocks the liquid injection function output until sensor communication is restored and the alarm is manually reset.

[0129] 2. Data rationality self-diagnosis logic For valid communication data returned by the sensor, a triple progressive verification is performed synchronously. If any verification fails, the data is judged to be abnormal, triggering a dedicated alarm code (vacuum transmitter data abnormality A203, flow meter data abnormality A204). 2.1. Over-range calibration: Check whether the detection data exceeds the preset valid value range (vacuum pressure [-100.0, 5.0] kPa, flow meter flow rate [0.0, 10.0] m³ / h); 2.2. Data freeze verification: Within 10 consecutive diagnostic cycles (2s), the change in vacuum pressure data is <0.1kPa and the change in flow meter flow data is <0.01m³ / h; 2.3. Abnormal fluctuation verification: Vacuum pressure fluctuation between adjacent cycles > 10.0 kPa, flow meter flow rate fluctuation between adjacent cycles > 2.0 m³ / h, and the abnormal state continues for 3 diagnostic cycles.

[0130] After the data anomaly is determined, the PLC synchronously executes the same fail-safe action as the communication failure, locking the faulty sensor data and prohibiting it from participating in process control logic operations.

[0131] III. Coordination and Linkage with the Three-Tier Defense System 1. Linkage with electrical and mechanical safety layers: After sensor failure diagnosis is triggered, the PLC immediately drives the anti-backflow dual isolation valve group and vacuum protection valve group to perform shutdown actions, and the injection pump and vacuum pump are shut down in an emergency. Through hardware physical isolation, process risks are blocked, forming a failure fallback coordination.

[0132] 2. Linkage with the logic control safety layer: The self-diagnostic logic provides a preliminary data validity check for process monitoring and multi-factor interlock logic. When the sensor fails, the interlock logic qualification flag and liquid injection enable signal are immediately reset, forming a full-link logic protection of "data source-process-result".

[0133] 3. Linkage with information and access control security layer: When an alarm is triggered, the human-machine interface terminal immediately pops up an alarm window, displaying the alarm code, failure type and handling suggestions, and simultaneously collects and stores a snapshot of all parameter data at the moment of the alarm; only engineers with permissions can reset the alarm, and only administrators with permissions can export diagnostic logs, achieving full-process traceability.

[0134] IV. Application Effect Verification This embodiment has been verified in a production line for injecting coolant into a new energy supercharger. The system can quickly and accurately diagnose three typical sensor failure scenarios: communication line disconnection, sensor output freezing, and signal jump interference. When the communication line is disconnected, the PLC triggers an alarm within 600ms; when the sensor output is frozen, the system detects the abnormality and triggers an alarm within 2s; when there is signal jump interference, the system identifies the abnormality and stops the injection operation within 3 diagnostic cycles. The diagnostic accuracy is 100%, the average diagnostic time is ≤2s, and the false alarm rate is <0.1%.

[0135] This embodiment further enhances the robustness and reliability of the overall system protection through the sensor failure self-diagnosis module, and is fully adapted to the mass production application requirements of high-end industry precision liquid injection process.

[0136] Example 9 This embodiment is based on the system architecture of Embodiment 1, focusing on the three-level user hierarchical permission management of information and permission security layers. By finely dividing the permissions of the three-level operation roles of operators, engineers and administrators, and with the control method of software and hardware linkage, it eliminates the risks of unauthorized operation and accidental modification of process parameters from the source, improves the management closed loop of the multi-level in-depth security protection system, and realizes full-dimensional permission control over equipment operation, process parameter configuration and system backend management.

[0137] I. Core Configuration and Permission System Settings The hardware architecture of this embodiment follows the configuration of Embodiment 1, using the MCGSTPC7062Ti embedded touchscreen as the core component of the human-machine interface terminal. It achieves bidirectional communication with the Xinje XD3 series PLC via an RS4815 bus. The permission verification logic is dually deployed in the touchscreen's local database and the PLC, ensuring that the permission configuration information and verification results are synchronized in real time, avoiding permission control failures caused by single-end data discrepancies.

[0138] A three-tiered, progressive user permission system is established in the human-computer interaction terminal. Higher-level permissions encompass all operational permissions of lower-level permissions. The core permissions for each role are divided as follows: 1. Operator (Permission Level 1): Only has permission to perform routine equipment operations and view the running status. Can perform basic operations such as equipment start-up and shutdown, manual triggering of process flow, and confirmation of on-site alarm information. Has no permission to modify any process parameters or configure the system. The human-machine interface will directly hide all parameter settings and system management entry modules.

[0139] 2. Engineer (Permission Level 2): ​​Includes all operator permissions, plus permission to modify process parameters. Engineers can enter the "Parameter Settings" interface by entering a unique password to adjust various process-related parameters such as vacuum target value, single injection volume, process time threshold, and rate warning threshold according to process requirements. After parameter modification, a second confirmation is required before the system will synchronize the new parameters to the PLC. Engineers do not have permissions for user account management, process data backup, or recovery.

[0140] 3. Administrator (Permission Level 3): Holds the highest system management privileges, including all operational permissions for engineers and the ability to add new system management permissions. Can access the dedicated "System Management" interface to perform operations such as adding, deleting, and modifying user accounts, querying all operation logs, backing up and restoring process operation data, and adjusting the allocation of permissions for each role.

[0141] II. Core Execution Logic of Access Control Access control, as a fundamental core function of the information and access security layer, runs through the entire process of equipment operation and forms a joint protection mechanism with the electrical and mechanical security layer and the logic control security layer. The core execution process is as follows: 1. Permission verification and interface adaptation: Users need to enter their employee ID and corresponding password on the human-computer interaction terminal to complete the login. The system will automatically compare with the local user database to complete the permission verification. Based on the verified permission level, the system will automatically load the adapted operation interface, displaying only the function buttons and operation entry points corresponding to the permissions, achieving the "what you see is what you get" control effect of permissions.

[0142] 2. Operation permission verification: When a user performs any device operation, the system will first perform permission matching verification for the operation. Only after the verification is successful will the corresponding operation instruction be sent to the PLC. If it is an unauthorized operation, the system will directly intercept the operation request and pop up a "insufficient permissions" prompt, and will not send any instructions to the PLC.

[0143] 3. Double Confirmation for Parameter Modification: When engineers modify process parameters, in addition to login access, they must enter a secondary password to complete a second-level permission verification. Only after successful verification can the parameters be modified. After the parameter modification is completed, the system will automatically display a comparison of the parameter changes before and after. Only after the engineer confirms that there are no errors will the new parameters be synchronized to the PLC. At the same time, the system will automatically record the person who modified the parameter, the modification time, and the specific content before and after the modification, forming a traceable parameter change log.

[0144] 4. Highest Privilege Operation Traceability: When an administrator performs highest privilege operations such as user account management and data backup and recovery, the system will record the entire process of the operation in detail, including the operator, operation time, and specific operation content. This type of log will be permanently stored in the system and cannot be modified, realizing full-process traceability control of highest privilege operations.

[0145] III. Coordination and Linkage with the Three-Tier Defense System 1. Linkage with the electrical and mechanical safety layer: If the authorization verification of the operation fails, the human-machine interface terminal will not send any operation instructions for starting or stopping equipment or opening and closing valves to the PLC. All hardware execution units in the electrical and mechanical safety layer will not respond to any action, thus preventing unauthorized hardware operation from the source of the operation instructions.

[0146] 2. Linkage with the logic control safety layer: After the process parameters modified by the engineer are synchronized to the PLC, the multi-factor composite process interlock logic and process monitoring logic of the logic control safety layer will automatically load the new parameters and complete the re-initialization without restarting the equipment, ensuring that the logic control can adapt to the new process requirements in real time after the parameters are modified; at the same time, the PLC will perform a reasonableness check on the received new parameters. If the parameters exceed the threshold range allowed by the process, it will directly reject the reception and feed the result back to the human-machine interface terminal for prompting.

[0147] 3. Integration with the information and access control layer itself: All access control login operations, process parameter modification operations, and account management operations are recorded in real time and stored in the local database of the human-machine interface terminal, forming complete equipment operation logs and system management logs. These logs can only be queried by the administrator and can be exported via USB flash drive, providing complete evidence for subsequent security audits and fault tracing.

[0148] IV. Application Effect Verification This embodiment has been verified on a precision injection production line for coolant in new energy superchargers. The verification results for typical operating scenarios with different access levels are as follows: 1. Unauthorized operator parameter modification: After logging in with their own permissions, if an operator attempts to click the "Parameter Settings" button on the human-computer interaction interface, the system will directly display a "Insufficient permissions, unable to enter" message, with no entry point to the parameter settings interface, thus completely preventing unauthorized operator parameter modification.

[0149] 2. Engineer process parameter adjustment: After logging in with their own privileges and entering their secondary password, the engineer changes the vacuum target value from -90.0 kPa to -92.0 kPa. After confirming the modification, the new parameter is synchronized to the PLC in real time. The vacuum process monitoring logic of the logic control safety layer automatically loads the new vacuum threshold. The equipment can normally execute the vacuum and liquid injection process under the new parameters. At the same time, the system fully records the operator, modification time, and parameter values ​​before and after the change.

[0150] 3. Administrator Account Management: After logging in with the highest privileges, the administrator can add one operator account and set an initial password for it. The system will automatically complete the account creation and corresponding permission allocation, and record the account creator and creation time. The new operator can log in to the system normally using a unique employee ID and password, and can only perform basic operations such as starting and stopping the device and checking its status, without any other extra permissions.

[0151] This embodiment reduces the risk of unauthorized equipment operation and erroneous modification of process parameters to zero through the design and implementation of a three-level user hierarchical permission management system. It achieves refined and standardized control over equipment operation and system management, and is deeply integrated with the three-layer defense-in-depth system of Embodiment 1. It further improves the whole-process security closed loop of "prevention before the event - blocking during the event - traceability after the event", which is fully adapted to the mass production management requirements of precision liquid injection process in high-end industries.

[0152] Example 10 This embodiment, based on the multi-level, in-depth security protection system architecture for precision liquid injection processes in Embodiment 1, focuses on the core functions of contextualized alarms and fault data tracing at the information and access control security layer. It automatically collects and associates multi-parameter data snapshots upon alarm triggering, and, combined with hierarchical access control, achieves accurate tracing and secure export of fault data. This completes the post-event tracing loop of the security protection system, extending fault handling from simple "fault alarms" to precise "root cause analysis." Simultaneously, strict access control ensures the security and integrity of traceable data. This embodiment still uses the precision liquid injection process of coolant for supercharger main units in new energy vehicles as the application scenario. The injection target is the coolant tank of the supercharger main unit, with a single injection volume set at 32L, a vacuum target value of -90.0kPa, and a maximum process time threshold of 240s. The implementation of this function is achieved based on the hardware and logic control architecture of Embodiment 1.

[0153] I. Core Configuration and Basic Settings This embodiment completely adopts the three-layer protection system hardware configuration of Embodiment 1, and only develops exclusive functions for the human-computer interaction terminal of the information and permission security layer. The core configuration and basic control rules are as follows: 1. Hardware and Storage: The MCGSTPC7062Ti embedded touchscreen is selected as the human-machine interface terminal. The terminal has a built-in SQLite local database, which is specifically used to store alarm codes, alarm trigger times, fault data snapshots, equipment operation logs and other information. The human-machine interface terminal achieves bidirectional communication with the Xinje XD3 series PLC through an RS4815 bus. The communication parameters are set to a baud rate of 9600bps, 8 data bits, 1 stop bit, and no parity, to ensure the real-time and stable transmission of alarm signals and process operation data.

[0154] 2. Data snapshot collection scope: The core parameter collection set is preset at the moment of alarm triggering, which comprehensively covers key information on process operation and equipment status, including vacuum pressure value, real-time flow value, on / off status of each electric valve (anti-backflow electric valve, anti-attenuation electric valve, etc.), liquid level in the storage tank, cumulative process running time, operating status of each pump (liquid injection pump, vacuum pump), and cumulative liquid injection / vacuuming volume. The timestamp error of all parameters is controlled within ≤100ms to ensure the synchronization and accuracy of the parameters.

[0155] 3. Access Control Rules: Viewing permissions for data snapshots are granted to engineers and administrators. USB drive export permissions are only granted to administrators. Operators have no permission to view or export snapshots. Alarm logs and data snapshots will be permanently stored in the local database of the human-machine interface terminal, and only administrators can perform manual cleanup operations.

[0156] 4. Alarm Code Mapping: All warning / alarm codes in the logic control safety layer (such as A101 vacuuming timeout, A102 liquid injection timeout, A203 vacuum transmitter data abnormality, etc.) are mapped one by one with the corresponding fault descriptions and on-site handling suggestions. The mapping relationship is stored in the local configuration library of the human-machine interaction terminal, which can be directly retrieved and displayed when an alarm is triggered.

[0157] II. Core Execution Logic of Contextualized Alarms and Data Snapshots The core function of this embodiment is the fully automated execution of the entire process from alarm triggering to snapshot acquisition, associated storage, and traceability export, without manual intervention. Furthermore, it is deeply integrated with the PLC's alarm triggering logic to ensure the real-time nature and accuracy of fault information. The specific execution process is as follows: 1. Alarm signal reception: When the PLC in the logic control safety layer detects abnormal process operation (such as process timeout, sensor failure, abnormal rate, etc.) or hardware failure in the electrical and mechanical safety layer (such as abnormal opening / closing of valve group, etc.), it will immediately trigger the corresponding alarm code and send the alarm code and precise trigger timestamp to the human-machine interface terminal through the RS4815 bus.

[0158] 2. Active Data Snapshot Acquisition: After receiving an alarm signal, the human-machine interface terminal will immediately send a data snapshot acquisition request command to the PLC. Within one scan cycle (100ms), the PLC will package the preset core parameter set at the moment of alarm triggering and feed it back to the human-machine interface terminal, completing the data snapshot acquisition. If it is a sudden emergency fault such as emergency stop triggering, the PLC will actively push the data snapshot to the human-machine interface terminal without the terminal sending a request, realizing rapid data acquisition for emergency faults.

[0159] 3. Associated Storage and Contextualized Display: The human-machine interface terminal associates and binds the collected multi-parameter data snapshots with the corresponding alarm codes, alarm trigger times, and fault descriptions, and stores them uniformly in the local SQLite database to form a complete contextualized alarm record. At the same time, an overlay alarm window pops up on the main interface of the terminal, visually displaying the alarm code, specific fault description, core snapshot parameters (such as the current cumulative injection volume and process runtime for injection timeout alarms), and on-site suggested handling measures, accompanied by a buzzer sound to remind on-site operators to handle the situation in a timely manner.

[0160] 4. Data Traceability and Hierarchical Export: Users can perform multi-dimensional searches using alarm codes, time ranges, fault types, and other criteria on the dedicated "Fault Traceability" interface of the human-computer interaction terminal to quickly query historical contextual alarm records and associated complete data snapshots. After logging in with the highest privileges, administrators can select one or more alarm records to perform USB drive export operations. The system will automatically convert the relevant data into the universal CSV format and save it to the external USB drive. The exported data includes complete parameter snapshots and alarm association information, which can be directly opened and analyzed on the computer.

[0161] III. Coordination and Linkage with the Three-Tier Defense System The contextual alarm and data tracing functions of this embodiment serve as the core functions of the information and access control security layer. They form a two-way collaborative linkage with the electrical and mechanical security layer and the logic control security layer, further improving the entire process of "prevention before the event - blocking during the event - tracing after the event" security closed loop. The specific linkage mechanism is as follows: 1. Linkage with the logic control safety layer: The PLC provides a unique and accurate data source for the process operation / equipment status of the data snapshot. The triggering and cancellation of all alarm codes are uniformly controlled by the PLC, ensuring that the data snapshot is completely synchronized with the actual fault status. The snapshot acquisition command of the human-machine interface terminal is only a data retrieval request and will not affect the normal logic operation of the PLC, avoiding any interference with the core function of interruption during the event.

[0162] 2. Linkage with the electrical and mechanical safety layer: The data snapshot contains the core operating status of all hardware in the electrical and mechanical safety layer (valve group switching, pump operation, emergency stop status, etc.). During fault tracing, the snapshot parameters can be used to directly locate whether the hardware has a physical failure. If the alarm is triggered by a hardware fault, the administrator can quickly determine the status of the faulty hardware through the parameter characteristics in the snapshot (e.g., when the anti-backflow electric valve is accidentally opened, the snapshot will show that the valve group is open but the pipeline flow is 0), providing accurate basis for on-site hardware maintenance.

[0163] 3. Integration with hierarchical permissions of information and permission security layers: The data snapshot viewing and export permissions in this embodiment are fully integrated with the three-level user permission system in embodiment 9. The permission verification results are synchronized in real time. If an unauthorized user attempts to perform snapshot viewing or export operations, the system will directly intercept and prompt insufficient permissions, ensuring that faulty production data is not viewed, modified or exported at will, thus guaranteeing the security and compliance of production data.

[0164] IV. Application Effect Verification To verify the effectiveness and practicality of the contextual alarm and data traceability functions in this embodiment, a real-world test was conducted on the new energy supercharger coolant injection production line. Using the injection timeout alarm A102 as a typical fault scenario, the performance of the entire process was verified. The test process and results are as follows: 1. Fault Trigger: Simulate a fault scenario where the injection pipeline is partially blocked, causing the injection flow rate to drop to 0.06L / s. When the cumulative process running time reaches 240s, the PLC of the logic control safety layer detects that the cumulative injection volume is only 14.4L, which does not reach the process target value of 32L. It then triggers the injection timeout alarm A102 and immediately issues a command to stop the injection pump, close the anti-backflow electric valve, and lock the injection function, thus achieving fault isolation during the event.

[0165] 2. Snapshot Acquisition and Display: After receiving the A102 alarm signal, the human-machine interface terminal completes the acquisition of a data snapshot within 100ms. The core parameters of this snapshot are {vacuum pressure -91.5kPa, real-time flow rate 0.06L / s, anti-backflow electric valve status = open, injection pump status = running, cumulative injection volume 14.4L, process run time 240s, liquid level 40L}. The terminal then pops up a red alarm window, clearly displaying "A102: Injection timeout, it is recommended to check whether the injection pipeline is blocked or whether the injection pump is abnormal", and simultaneously displays the above core snapshot parameters, providing an intuitive reference for on-site operation.

[0166] 3. Data Traceability and Export: Administrators log in to the human-machine interface terminal with the highest privileges, quickly locate the A102 alarm record by searching the time range, view the complete data snapshot, and then perform a USB drive export operation. The system quickly generates a CSV format fault data file, which contains all relevant information such as alarm code, trigger time, complete snapshot parameters, and fault description. Engineers can open the file on a computer and, based on the snapshot's characteristics of "continuously low flow rate and normal operation of valve group and pump body," directly locate the blockage of the injection pipeline as the root cause of this fault, without the need for on-site inspection of each piece of equipment.

[0167] V. Technical Effects This embodiment, based on the three-layer depth protection system of Embodiment 1, completes the design and implementation of contextualized alarm and fault data tracing functions, realizing the accuracy, standardization, and security of the post-event tracing process. It complements the previous embodiment and brings the following core technical effects to the entire multi-level depth security protection system: 1. It achieves precise root cause analysis of faults. Through contextual alarm records of "alarm events + multi-parameter data snapshots", it solves the industry pain point that traditional alarms only indicate the fault type and lack fault context information. It upgrades fault tracing from traditional "fuzzy investigation" to "precise positioning", reducing the average fault investigation time by more than 80%.

[0168] 2. It ensures the authenticity and integrity of traceability data. Data snapshots are collected directly from the PLC without human intervention throughout the process. The timestamp error is ≤100ms, and the data is forcibly associated with alarm codes for storage, avoiding the problems of data tampering and loss. This provides real and effective data support for the company's process optimization and preventive maintenance of equipment.

[0169] 3. It has implemented hierarchical security control of traceability data. Only the administrator has the permission to export data snapshots to USB drives. Engineers can only view snapshot information. Operators have no related permissions. This reduces the risk of production data leakage and misoperation to zero and meets the compliance management requirements of production data for precision liquid injection processes in high-end industries.

[0170] 4. The three-layer protection system has been improved to form a complete safety closed loop. The post-event traceability function of this embodiment, together with the pre-event prevention of the electrical and mechanical safety layer and the in-event blocking of the logic control safety layer, forms a complete "pre-event-in-event-post-event" safety protection closed loop. This enables the entire system to not only achieve rapid detection and blocking of faults, but also to achieve root cause analysis and subsequent optimization of faults, fundamentally reducing the probability of the recurrence of similar faults.

[0171] 5. Highly adaptable to the needs of automated mass production processes, the entire process of contextual alarms and data snapshots is executed automatically without human intervention, and can be adapted to 24-hour uninterrupted automated mass production processes in fields such as new energy and electronic manufacturing; the exported data in CSV format is compatible with various mainstream data analysis software, which facilitates enterprises to conduct unified management and in-depth analysis of production data.

[0172] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A multi-level, in-depth safety protection system for precision liquid injection processes, characterized in that, The system includes an electrical and mechanical security layer, a logic control security layer, and an information and access security layer. Even if a single layer fails partially, the other layers can still trigger protective actions to ensure that the system returns to a safe state, thus forming a complete defense-in-depth system. The electrical and mechanical safety layer, serving as a hardware-based protection layer for preventative purposes, includes a backflow prevention dual isolation valve assembly (1), a vacuum protection valve assembly (2), and an emergency physical circuit breaker component (3). The emergency physical circuit breaker component (3) is an emergency stop button (31), installed on the equipment operation panel and connected to the PLC via an RS4815 bus. The backflow prevention dual isolation valve assembly (1) consists of a backflow prevention electric valve (11) and a check valve (12) connected in series at the injection port of the injection target (4) and the outlet of the injection pump (5). The pipeline connects the input end of the injection pump (5) to the storage tank (6) via a pipeline; the anti-backflow electric valve (11) and the injection pump (5) are connected to the PLC via an RS4815 bus; the vacuum protection valve group (2) includes a vacuum water-oil separator (21) and an anti-attenuation electric valve (22) connected in series in a vacuum pipeline that connects the air extraction port of the injection target (4) and the inlet of the vacuum pump (7); the anti-attenuation electric valve (22), the vacuum water-oil separator (21), and the vacuum pump (7) are connected to the PLC via an RS4815 bus. The logic control safety layer serves as a protective layer for in-process interruption. The PLC, acting as the controller, collects real-time data from the vacuum pressure gauge (81) in the vacuum pipeline, the flow meter (82) in the liquid injection pipeline, the liquid level sensor (83) in the liquid storage tank (6), and the status of the emergency stop button (31) via the RS4815 bus. It executes multi-factor composite process interlocking to achieve status verification, action compensation, and fault prediction of the electrical and mechanical safety layer. The information and permission security layer serves as a security management layer for post-event traceability. The human-machine interaction terminal (9) communicates with the PLC via the RS4815 bus to set up user hierarchical permission management and has the functions of equipment status visualization, contextual alarm and fault data traceability.

2. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 1, characterized in that, The one-way valve (12) is located at the port of the injection pipeline near the injection target (4). The installation reference planes of the anti-backflow electric valve (11), the injection pump (5), and the flow meter (82) are at the same horizontal plane. The injection pipeline includes an n-shaped tube. The top of the n-shaped tube is higher than the highest working liquid level of the storage tank (6). The inlet of the n-shaped tube leads to the bottom of the storage tank (6). The outlet of the n-shaped tube is set at the same horizontal height as the fluid flow center axis of the anti-backflow electric valve (11), the injection pump (5), and the flow meter (82).

3. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 2, characterized in that, The anti-backflow dual isolation valve group (1) and the liquid injection pipeline layout work together to form a four-fold redundant anti-backflow protection system. The first layer is the active shut-off of the anti-backflow electric valve (11), the second layer is the passive check valve (12), the third layer is the anti-backflow electric valve (11), the liquid injection pump (5), the flow meter (82) and the liquid storage tank (6) set at the same level to eliminate static pressure difference, and the fourth layer is the liquid seal gas resistance and gravity blocking formed by the n-shaped pipe structure. The four layers of protection provide a bottom-up solution to achieve complete blocking of medium backflow under extreme working conditions.

4. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 1, characterized in that, The vacuum water-oil separator (21) is equipped with a transparent window and a manual / automatic drain valve, which are installed in series at the front end of the air inlet of the vacuum pump (7) to intercept liquid media; the anti-attenuation electric valve (22) is installed in series at the front end of the inlet of the vacuum water-oil separator (21) to isolate gas and prevent the vacuum pressure on the pipeline from attenuating when the vacuum pump (7) stops evacuating.

5. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 1, characterized in that, The equipment operation panel is also equipped with a vacuum button (23) connected to the PLC via an RS4815 bus for manual intervention in the vacuum process. The equipment operation panel is also equipped with a liquid injection button (13) connected to the PLC via an RS4815 bus for manual intervention in the liquid injection process. The emergency stop button (31) can directly cut off the power supply when triggered, thereby achieving a hard-wire power cut-off in the power circuit.

6. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 1, characterized in that, The multi-factor composite process interlock adopts "AND" logic. The interlock conditions for the multi-factor composite process include vacuum pressure reaching the standard, liquid level safety point reaching the standard, flow rate reaching the standard, emergency stop not being triggered, and the preceding vacuuming process being completed. If any condition is not met, the liquid injection function output will be blocked.

7. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 6, characterized in that, During the injection process into the target (4), real-time data from the vacuum pressure gauge (81) and flow meter (82) are collected by the PLC. The vacuuming rate and injection rate are monitored by communication status and data rationality dual criteria. Warning thresholds and alarm thresholds are set to realize abnormal trend warning and timeout alarm.

8. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 7, characterized in that, The communication status includes self-diagnostic logic: determining whether communication has failed by judging the response to PLC query commands; The data rationality includes self-diagnostic logic: determining whether the data is abnormal by detecting the data range, change amount, and jump variables.

9. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 1, characterized in that, The user hierarchical permission management is divided into three levels: operator, engineer, and administrator. Operators only have regular operation and status viewing permissions, engineers can modify process parameters, and administrators can manage user accounts and perform data backup and recovery.

10. The multi-level, in-depth safety protection system for precision liquid injection processes as described in claim 1, characterized in that, The contextual alarm function of the information and permission security layer automatically collects and stores multi-parameter data snapshots at the moment of alarm triggering, including vacuum pressure value, real-time flow value, valve opening and closing status, liquid level height, and process running time. The data snapshots are stored in association with the alarm code and alarm time on the human-machine interaction terminal, and only administrator accounts can perform the data snapshot export operation to USB flash drive.

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