Control system and method for high-flow multi-working-condition test pressure automatic compensation

Abstract

The invention relates to a control system and method for automatic pressure compensation in a large-flow multi-working-condition test. The system comprises a PLC, an HMI human-computer interaction interface, a linear power supply, a process unit, a feedback unit and a tested product valve. Wherein the HMI is used for inputting various working condition parameters by a user and forwarding the working condition parameters to the PLC; the PLC is responsible for processing an input instruction of the HMI, receiving acquired data of the feedback unit, executing a control program to generate a related control instruction, and sending the related control instruction to the process unit; the process unit is arranged in a process pipeline and is used for adjusting test working condition data of the pipeline, receiving an instruction of the PLC to adjust a test working condition and sending the test working condition data to the feedback unit; the feedback unit collects test working condition data of the process unit and sends the collected data to the PLC; the feedback unit is connected with a tested product valve and collects test data when the product valve works.

Description

Technical Field

[0001] This invention relates to a control system and method for automatic pressure compensation in high-flow-rate, multi-condition testing, and more particularly to an automatic pressure compensation control method based on a programmable logic controller (PLC) for solenoid valve testing under high-flow-rate, multi-condition conditions where the dynamic-static pressure difference is a significant factor. This invention belongs to the field of solenoid valve testing. Background Technology

[0002] As the core propulsion system of a spacecraft, the engine's performance and reliability directly affect the success of space missions. In the research and testing of attitude and orbit control engines, the performance testing of solenoid valves is a crucial step in ensuring the coordinated operation of all engine components. Solenoid valves are responsible for controlling the flow of fuel and oxidizer, regulating flow and pressure, and their responsiveness and reliability have a significant impact on the overall performance of the engine.

[0003] To accurately obtain the performance indicators of solenoid valves, the system pressure needs to be adjusted to a specified pressure before testing. Tests are then conducted to assess the solenoid valve's performance and pulse response. During the test, the system pressure and flow rate need to be adjusted in real-time according to the test requirements. Traditional testing systems typically use manual control of general-purpose valves. Specifically, traditional systems achieve pressure compensation and system flow control through hardware components such as manual pressure reducers and flow control valves. While this method is simple, when dealing with complex operating conditions, test personnel need to adjust the pressure reducer in real-time to maintain a stable system pressure output during media flow. Since solenoid valves require adjustment to multiple test conditions during testing, the smoothness of manual adjustment depends on the operator's skill level. Furthermore, the transition between multiple conditions can easily lead to adjustment errors or poor accuracy, affecting the accuracy of solenoid valve data interpretation. In addition, manually adjusted testing systems have low automation levels and cannot achieve real-time parameter feedback and dynamic adjustment. This not only reduces testing efficiency but also increases the risk of human error, thus affecting the product's test results. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a control method for automatic pressure compensation in a large-flow, multi-condition test system, thereby improving the problems of outdated automation technology, poor adjustment accuracy, and low test efficiency in the performance testing of solenoid valves.

[0005] The technical solution of this invention is: Firstly, a control method for automatic pressure compensation in a high-flow-rate, multi-condition testing system is provided, including: The system includes a PLC controller, an HMI (human-machine interface), a linear power supply, a process unit, a feedback unit, and the valve of the product under test; among which: The HMI (Human Machine Interface) is used by users to input various operating parameters, which are then forwarded to the PLC controller. The PLC controller is responsible for processing input commands from the HMI (Human Machine Interface), receiving data collected by the feedback unit, executing the control program to generate relevant control commands, and sending them to the process unit. The process unit is set in the process pipeline and receives instructions from the PLC controller to adjust the test conditions; The feedback unit acquires the test condition data of the process unit in real time and sends the test condition data to the PLC controller in real time, realizing real-time feedback of system condition data; the linear power supply provides power to the PLC controller, HMI human-machine interface, process unit and feedback unit.

[0006] Preferably, the system also includes a DC regulated voltage; The product valve is located downstream of the process unit, and a DC regulated voltage supplies power to the product valve under test.

[0007] Preferably, the process unit includes: a process solenoid valve, a regulating mechanism, and a media container connected by pipelines; wherein: The process solenoid valve is installed in the process pipeline and connected to the PLC controller via a relay: The PLC controller sends switching commands to the relay, which drives the process solenoid valve to switch on or off. The regulating mechanism includes regulating valves and pressure reducing valves, both installed in the process pipeline, receiving control from the PLC controller, and performing flow regulation and pressure regulation respectively; The media container provides the required flow rate of media to the process piping.

[0008] Preferably, the feedback unit includes: a pressure sensor, a mass flow meter, and a valve position feedback mechanism; wherein: Pressure sensors and mass flow meters are installed in the process pipeline and connected to the PLC controller to collect and test pipeline pressure at different locations in the system, flow measurement values ​​during the test process, and inlet and outlet pressures of the valves of the product under test, and send them to the PLC controller. The valve position feedback unit is connected to the PLC controller, as well as the product valves, process solenoid valves, regulating valves, and pressure reducing valves of the process unit, to obtain the real-time operating status of each valve.

[0009] Preferably, the PLC controller provides analog and digital interfaces. The analog interface interacts with the feedback unit, and the digital interface interacts with the relay of the process solenoid valve.

[0010] Preferably, the PLC controller includes: a basic switch control module, a fitting data module, a parameter dynamic judgment module, an automatic compensation module, an analog quantity calculation module, and a key parameter storage module; wherein: The basic switch control module is responsible for the system's initialization self-test, sending switch commands to the relays of the process solenoid valves to control their opening and closing; and sending opening commands to the pressure reducing valves to adjust the pressure reference. The fitting data module receives the collected data from the feedback unit, performs fitting calculations on the output opening value of the control valve and the actual opening value reached, and uses the PID control algorithm to make the output opening command of the fitting data module for the control valve consistent with the actual opening value reached. The parameter dynamic judgment module compares the collected pipeline pressure with the operating condition set value in milliseconds: if the comparison value is within the set error range, the pre-adjustment is deemed qualified; if it exceeds the error range, the automatic compensation module is activated. The automatic compensation module continuously performs dynamic compensation until the pressure feedback value stabilizes within the allowable error range of the operating condition setpoint, forming a closed-loop control logic; an adaptive algorithm is used to optimize the adjustment of the regulating valve, so that the adjustment amplitude decreases as the deviation decreases, avoiding overshoot. The key parameter storage module records in real time the time, opening change, and pressure response curve of each adjustment by the automatic compensation module, which is used to assist the automatic compensation module in calculating the adjustment parameters for the next compensation.

[0011] Preferably, the PLC controller also includes an analog output module, which is used to convert the output opening command of the regulating valve into a 4mA to 20mA signal and output it through the analog output interface.

[0012] Preferably, the basic switch control module performs a system initialization self-test, specifically as follows: The basic switch control module checks the initial state of the valve position feedback mechanism and all process solenoid valves, regulating valves, and pressure reducing valves one by one; at the same time, it performs zero-point calibration on the pressure sensor and mass flow meter to eliminate zero-point drift error and ensure the reference accuracy of subsequent data acquisition. If the self-test detects an abnormality, the system will immediately display a pop-up window on the HMI (Human-Machine Interface) indicating the location and type of the fault. The operator will then troubleshoot the fault and re-trigger the self-test until all indicators meet the startup conditions.

[0013] Secondly, a control method for automatic pressure compensation in high-flow-rate, multi-condition test experiments is provided, characterized by comprising: S0: The operator enters various operating parameters through the HMI human-machine interface and performs a system self-test through the basic switch control module of the PLC controller; after the self-test is passed, proceed to S1. S1, the basic switch control module of the PLC controller controls the pressure reducing valve of the feedback unit to adjust the pressure of the process pipeline to the reference pressure value required by the test system and reach a steady state; S2. The regulating valve is automatically adjusted by fitting the data block program. The pressure feedback value is judged by the parameter dynamic judgment module. If the pressure feedback value is lower or higher than the set pressure value range, the automatic compensation module is started and the adjustment is continued until the pressure feedback value falls into the pressure value range. At this time, the adjustment action stops and the system pre-adjustment is completed. S3. Open the product valve and maintain it for a certain period of time, and record the working data of the product valve under the current working conditions. During the process, the PLC controller continuously monitors whether the pressure feedback value in the pipeline is within the set pressure range of the working conditions. If it is not within the pressure range, it is adjusted by the automatic pressure compensation module until the pressure reaches the required value of the working conditions, at which point the automatic compensation module stops. S4. After the current working condition test is completed, return to step S1 and start the adjustment process for the next working condition based on the data stored in the key parameter storage module, until all working condition tests are completed.

[0014] Compared with the prior art, the present invention has the following advantages: (1) No manual adjustment is required; the entire adjustment process can be completed automatically by relying on the control equipment unit, control software unit, data acquisition and feedback unit, and process execution unit. (2) It can provide high testing efficiency under long-term operating conditions, and significantly improve control accuracy and ground test accuracy. Attached Figure Description

[0015] Figure 1 This is a system schematic diagram of the present invention; Figure 2 This is a diagram of the automatic pressure compensation program described in this invention; Figure 3 This is a diagram of the key parameter configuration page in the human-computer interaction interface of the present invention. Detailed Implementation

[0016] To achieve the invention's objective of improving the outdated automation technology, poor adjustment accuracy, and low testing efficiency of solenoid valve performance testing systems, the present invention provides the following technical solution: An automatic pressure compensation control system and algorithm are disclosed, applicable to eliminating the influence of dynamic and static pressure difference under high flow rate and multi-condition testing of solenoid valves. The system comprises a control equipment unit, a control software unit, a data acquisition and feedback unit, and a process execution unit.

[0017] As the core of the entire control system, the control software unit leverages real-time data processing technology and precise equipment coordination control capabilities to achieve comprehensive management and control of the testing process. Its functions encompass information exchange between multiple devices, human-machine interaction, and automatic pressure adjustment at multiple rated operating points during the test, ensuring efficient execution of test commands and stable system operation.

[0018] The control unit consists of a PLC controller, an HMI (Human-Machine Interface), a linear power supply, and a DC regulated power supply. The PLC controller, as the core processing unit, is responsible for processing input commands from the HMI, acquiring feedback unit signals, executing control logic programs and automatic compensation algorithms, and sending control commands to the control valve. The HMI connects to the PLC controller via Ethernet, enabling data exchange between the controlled control valve, its status, the automatic compensation algorithm, and key parameters. The linear power supply provides 24V DC power to the PLC controller, HMI, control valve, and feedback unit via hard wiring. The DC regulated power supply provides a stable 28V power supply to the product's solenoid valves.

[0019] The data acquisition and feedback unit consists of a pressure transmitter, a mass flow meter, and a valve position feedback mechanism. The pressure transmitter collects the inlet and outlet pressures of the solenoid valve and the pipeline pressures at different locations in the test system. The mass flow meter acquires flow measurement parameters during the test. The valve position feedback mechanism is connected to both the analog and digital input interfaces of the PLC controller via wiring to ensure the system can acquire the real-time operating status of each valve.

[0020] The process execution unit includes a media container and process solenoid valves, pressure reducing valves, and regulating valves on the process pipeline. The pipeline process solenoid valves are connected to relays via wiring: control commands are sent to the relays via digital output terminals, and the relays drive the process solenoid valves to complete the corresponding actions. The pressure reducing valves and regulating valves are connected to an analog output module via wiring. Control commands are output as 4-20mA signals from the PLC controller's analog output module and sent to the pneumatic pressure reducing valves and regulating valves to complete processes such as operating condition regulation.

[0021] An automatic compensation control system and algorithm for high-flow, multi-condition test pressure of solenoid valves, comprising the following steps: Step 1: The air source pressure is reduced to the required pressure value for both the pneumatic control valve and the product control air via a pressure reducing valve. The system will automatically adjust the regulating valve based on the set pressure at the product inlet using a data block program until the set pressure value is reached. If the pressure feedback value is lower or higher than the set pressure value, the system will automatically start a compensation program and continue adjusting until the pressure feedback value stabilizes within the set pressure range.

[0022] Step Two: Open the product valve and maintain it for a certain period of time. Calculate the static pressure difference by comparing the set pressure value with the actual dynamic pressure value. Then, add this static pressure difference back to the product inlet set pressure. The system will automatically adjust the regulating valve based on the updated product inlet set pressure through a data block fitting program until the set pressure value is reached. If the pressure feedback value is lower or higher than the set pressure value, the system will activate an automatic compensation program and continue adjusting until the pressure feedback value falls within the calculated pressure value range, at which point the adjustment will stop.

[0023] Step 3: After reopening the product valve and holding it for a certain period of time, the control program will automatically determine whether the pressure feedback value is within the set pressure range for the operating condition. If it is not within this range, the system will adjust the inlet regulating valve through the automatic pressure compensation program until the pressure reaches the required value for the operating condition, at which point the adjustment will stop and the automatic pressure compensation program will exit.

[0024] Step 4: When the product inlet pressure reaches the set value required for the operating condition, the system will enter the current pressure operating condition for formal operation until the test ends.

[0025] Step 5: After the first pressure condition test is completed, the system immediately begins the adjustment process for the next pressure condition, repeating steps 1-4 above to complete the ground performance test of the attitude control engine valve for the second pressure condition. This process continues until all condition tests are completed.

[0026] Example: An overall structure of an automatic compensation control system and algorithm for high-flow, multi-condition test pressure of solenoid valves is as follows: Figure 1 As shown, it includes a PLC controller 0, an HMI human-machine interface 1, a linear power supply 2, a relay 3, a process unit 4, a product drive box 5, a product valve 6, a feedback unit 7, and a DC regulated voltage 8.

[0027] The PLC controller 0, as the core of the entire control system, is responsible for processing input commands from the HMI (Human Machine Interface) 1, receiving signals from the feedback unit 7, executing control programs, and sending control commands to the relay 3 and the regulating valve mechanism 4.2. Its functions cover information exchange and human-machine interaction among multiple devices during the test, enabling automatic pressure adjustment at multiple rated operating points, ensuring efficient execution of test commands and stable system operation.

[0028] The HMI (Human Machine Interface) 1 is connected to the PLC controller 0 via Ethernet, enabling functions such as monitoring the status of the controlled valve unit, displaying parameters, manually controlling the valve, and exchanging data on key parameters.

[0029] Linear power supply 2 is connected via lines to PLC controller 0, HMI human-machine interface 1, relay 3, actuator 4.2, product valve 6 and feedback unit 7, respectively, to provide 24V DC power to these devices.

[0030] Relay 3 is connected to PLC controller 0 via a line, and control commands are sent to relay 3 from the digital output interface of PLC controller 0. Process unit 4 consists of a process solenoid valve 41, a regulating mechanism 42, and a media container 43 connected by pipelines. The process solenoid valve 41 is connected to a relay 3 via a line: control commands are sent to the relay via the digital output of the PLC controller 0, and the relay drives the process solenoid valve to perform the corresponding action. The regulating mechanism 42 includes a regulating valve and a pressure reducing valve, both connected to the analog output of the PLC controller 0 via lines; control commands are output as a 4-20mA signal from the analog output module of the PLC controller and sent to the pneumatic pressure reducing valve and the regulating valve to complete processes such as operating condition regulation.

[0031] The product valve control section consists of a product actuator 5 and a product valve 6 connected by a wiring connection. The product actuator 5 is connected to a host computer via a wiring connection: control commands are sent from the host computer to the product actuator, which then drives the product valve to complete the corresponding action.

[0032] Feedback unit 7 consists of pressure sensor 71, mass flow meter 72, and valve position feedback mechanism 73. Pressure sensor 71 and mass flow meter 72 are installed in the process system unit via pipelines and connected to PLC controller 0 via wiring. The collected parameters, including product valve inlet and outlet pressures, pipeline pressures at different locations in the test system, and flow rate measurements during the test, are input to the system via the PLC's analog interface. Valve position feedback mechanism 73 is connected to both the analog and digital input interfaces of PLC controller 0 via wiring, ensuring the system can acquire the real-time operating status of each valve.

[0033] A control algorithm for automatic pressure compensation in a high-flow-rate, multi-condition test system mainly consists of a data block program for automatic adjustment of the regulating valve, a parameter judgment and comparison program, and an automatic compensation program.

[0034] Fitting data algorithm: By fitting the output opening value of the regulating valve with the actual position reached, a PID regulation algorithm is obtained, so that the program output opening value and the actual position reached are consistent.

[0035] Parameter dynamic judgment algorithm: By collecting pipeline pressure, the feedback value is compared with the operating condition set value in milliseconds. If the feedback value is within the error range of the set value, the pre-adjustment is deemed qualified; if it exceeds the range, the system automatically activates the pressure compensation program.

[0036] Automatic compensation algorithm: Employs a "step-by-step approximation" control strategy, such as... Figure 2 As shown, the adjustment range decreases with each reduction in deviation. For example, when the initial deviation is 10%, the opening is adjusted by 5%, and when the deviation is 5%, the opening is adjusted by 2%, thus avoiding overshoot. Simultaneously, the control program records the time, opening change, and pressure response curve for each adjustment in real time, and optimizes the adjustment parameters for the next compensation using an adaptive algorithm. This dynamic compensation process continues until the pressure feedback value stabilizes within the allowable error range of the operating condition setpoint, forming a closed-loop control logic.

[0037] Analog signal processing program: used to convert control commands into 4mA to 20mA signals and output them through the analog output interface.

[0038] The workflow is divided into three parts: Part One: Trial Initiation and Preliminary Preparation Phase The core logic of the entire test begins with the preset procedure for operating parameters. Operators must accurately input various operating parameters, including target pressure, holding time, pressure gradient, and other key indicators, into the human-machine interface of the control system according to the test outline. After the parameters are set, clicking the "Start Test" command triggers the fully automatic control program, first entering a rigorous self-check phase.

[0039] The self-test process encompasses multi-dimensional status verification: the control program checks the initial state of all process solenoid valves, regulating valves, and pressure reducing valves one by one to ensure they are in the closed position, preventing gas leakage or pressure surges caused by valve malfunctions; simultaneously, it performs zero-point calibration on sensing devices such as pressure transmitters and mass flow meters, using built-in algorithms to eliminate zero-point drift errors and ensure the baseline accuracy of subsequent data acquisition. If any abnormality is detected during the self-test—such as a valve not being fully closed or a sensor zero point exceeding tolerance—the system will immediately display a pop-up window indicating the fault location and type. The operator must then troubleshoot the fault and re-trigger the self-test until all indicators meet the startup conditions.

[0040] After the self-test passes, the system enters the test preparation process: The program first sends a digital control signal to the relay, driving the process solenoid valve to open according to a preset sequence and maintain a stable opening, allowing the high-pressure gas source to be delivered along the process pipeline to the front end of the pressure reducing valve. At this time, the two pressure reducing valves will automatically work according to preset parameters. The first pressure reducing valve reduces the gas source pressure to the rated working pressure of the process system unit, while the second pressure reducing valve precisely adjusts to the reference pressure value required for product control gas, providing a stable pressure source for subsequent operating condition adjustments. When the pipeline pressure sensor reports that the outlet pressure of the pressure reducing valve has reached a steady state, the control program determines that the preparation stage is complete and automatically enters the operating condition pre-adjustment stage.

[0041] Part Two: Operating Pressure Pre-regulation and Dynamic Compensation Process The core objective of the pre-adjustment phase is to rapidly bring the system pressure close to the setpoint through closed-loop control logic. The control program calls a built-in fitting data block. This module, based on historical test data and a fluid dynamics model, performs multi-dimensional fitting calculations on current operating parameters (such as target pressure, medium type, and pipeline resistance coefficient), ultimately outputting the initial opening command for the pneumatic control valve. This command is converted into a 4–20mA standard current signal by the PLC controller's analog output module and transmitted in real-time to the actuator of the pneumatic control valve, driving the valve to operate at the calculated opening degree.

[0042] After the valve action is completed, the system immediately switches to dynamic parameter judgment mode: the pressure transmitter collects pipeline pressure in real time at a sampling frequency of 10Hz, and compares the feedback value with the operating condition setpoint in milliseconds. If the feedback value is within ±0.1MPa of the setpoint, the pre-adjustment is deemed qualified; if it exceeds this range, the system automatically activates the pressure compensation program and enters the fine adjustment stage. The compensation logic adopts a segmented control strategy: when the feedback value is lower than the setpoint, the program calculates the compensation opening based on the deviation (the larger the deviation, the larger the adjustment range), drives the regulating valve to increase the opening, and increases the pipeline air intake; when the feedback value is higher than the setpoint, the regulating valve opening is reduced according to a symmetrical algorithm, and the air intake is reduced.

[0043] like Figure 2 As shown, the compensation process employs a "step-by-step approximation" control strategy—the adjustment amplitude decreases with each reduction in deviation, thereby avoiding overshoot. Simultaneously, the control program records the time, opening change, and pressure response curve for each adjustment in real time, optimizing the adjustment parameters for the next compensation through an adaptive algorithm. This dynamic compensation process continues until the pressure feedback value stabilizes within the allowable error range of the operating condition setpoint. At this point, the program automatically records the adjustment endpoint parameters, marking the end of the pre-adjustment phase.

[0044] Part Three: Formal Test Execution and Multi-Condition Cycle Procedure: After pre-adjustment, the system automatically switches to the formal test mode: the control program sends a command to the product driver to open the product valve and maintain it for a set time (e.g., 10 seconds). During this time, the pressure sensor synchronously records the dynamic pressure curve under this condition, and the mass flow meter collects the medium flow data in real time. All parameters are stored in the database with timestamps, forming a complete operating condition data archive. During the formal test phase, the system continues to monitor in real time. If a sudden pressure fluctuation exceeds the allowable range (e.g., due to momentary deviation caused by pipeline vibration), a secondary compensation program will be immediately activated to quickly correct the pressure to a stable state, ensuring the validity of the test data.

[0045] Once the test data for the first pressure condition is collected, the system automatically executes the condition switching process: first, it closes the product valve and the process solenoid valve to release the residual pressure in the pipeline to a safe value, and then calls the next set of operating parameters (automatically increasing or decreasing according to the preset pressure gradient), completely replicating the logic of the pre-adjustment stage: from calculating the initial opening from the fitted data block, to dynamic compensation adjustment, to pressure stability determination, until the pressure parameters of the new operating condition meet the test requirements.

[0046] This cyclic process will be executed automatically and strictly according to the preset working condition sequence, such as... Figure 3 As shown, the processing logic for each operating condition is completely consistent with that of the first operating condition, ensuring the horizontal comparability of test data. For example, if the test includes 5 pressure gradients (from 0.5MPa to 2.5MPa, increasing by 0.5MPa per level), the system will sequentially complete 5 rounds of the complete "pre-adjustment → formal test → data recording → operating condition switching" process. When the test data for the last operating condition has been stored, the control program will automatically display "All operating condition tests completed" on the human-machine interface, and at the same time close all valves, cut off the gas supply, and restore the system to the initial standby state.

[0047] The entire test process requires no manual intervention. Through the combination of closed-loop control and adaptive algorithms, the accuracy of pressure regulation (±0.2% FS) is guaranteed, and the automated flow of multi-condition tests is realized, which greatly improves test efficiency and data reliability.

[0048] The above description is merely the specific implementation method and technical principle disclosed in this case. Any modifications based on the technical solution of this invention are included within the protection scope of this invention.

[0049] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A control method for automatic pressure compensation in a high-flow-rate, multi-condition test system, characterized in that... include: The system comprises a PLC controller (0), an HMI (human-machine interface) (1), a linear power supply (2), a process unit (4), a feedback unit (7), and the valve of the product under test; wherein: The HMI (human-machine interface) (1) is used by the user to input various operating parameters and forward them to the PLC controller (0). The PLC controller (0) is responsible for processing the input instructions from the HMI (human-machine interface) (1), receiving the data collected by the feedback unit (7), executing the control program to generate relevant control instructions, and sending them to the process unit (4). The process unit (4) is set in the process pipeline and receives instructions from the PLC controller (0) to adjust the test conditions; The feedback unit (7) acquires the test condition data of the process unit (4) in real time and sends the test condition data to the PLC controller (0) in real time to realize the real-time feedback of the system condition data; the linear power supply (2) supplies power to the PLC controller (0), HMI human-machine interface (1), process unit (4) and feedback unit (7).

2. The control system for automatic pressure compensation in high-flow-rate, multi-condition test according to claim 1, characterized in that: The system also includes a DC regulated voltage (8); The product valve is located downstream of the process unit (4), and the DC regulated voltage (8) supplies power to the product valve under test.

3. The control system for automatic pressure compensation in high-flow-rate, multi-condition test according to claim 1, characterized in that: The process unit (4) includes: a process solenoid valve (41), a regulating mechanism (42), and a media container (43) connected by pipelines; wherein: The process solenoid valve (41) is installed in the process pipeline and connected to the PLC controller (0) through a relay: The PLC controller (0) sends a switching command to the relay, which drives the process solenoid valve (41) to switch on and off. The regulating mechanism (42) includes a regulating valve and a pressure reducing valve, both of which are installed in the process pipeline and receive control from the PLC controller (0) to regulate flow and pressure respectively. The media container (43) provides the required flow rate media to the process piping.

4. A control system for automatic pressure compensation in high-flow-rate, multi-condition test environments according to claim 3, characterized in that: The feedback unit (7) includes: a pressure sensor (71), a mass flow meter (72), and a valve position feedback mechanism (73); wherein: The pressure sensor (71) and mass flow meter (72) are installed in the process pipeline and connected to the PLC controller (0) to collect and test the pipeline pressure at different locations in the system, the flow measurement value during the test process, and the valve inlet and outlet pressure of the product under test, and send them to the PLC controller (0). The valve position feedback machine (73) is connected to the PLC controller (0), and is also connected to the product valve, as well as the process solenoid valve (41), regulating valve and pressure reducing valve of the process unit (4), to obtain the action status of each valve in real time.

5. A control system for automatic pressure compensation in high-flow-rate, multi-condition test environments according to claim 4, characterized in that: The PLC controller (0) provides analog and digital interfaces. The analog interface interacts with the feedback unit (7), and the digital interface interacts with the relay of the process solenoid valve (41).

6. A control system for automatic pressure compensation in high-flow-rate, multi-condition test environments according to claim 4, characterized in that: The PLC controller (0) includes: a basic switch control module, a fitting data module, a parameter dynamic judgment module, an automatic compensation module, an analog quantity calculation module, and a key parameter storage module; wherein: The basic switch control module is responsible for the system's initialization self-test, sending switch commands to the relay of the process solenoid valve (41) to control the opening and closing of the process solenoid valve (41); and sending opening commands to the pressure reducing valve to perform pressure reference adjustment. The fitting data module receives the collected data from the feedback unit (7), performs fitting calculations on the output opening value of the control valve and the actual opening value, and uses the PID control algorithm to make the output opening command of the fitting data module for the control valve consistent with the actual opening value. The parameter dynamic judgment module compares the collected pipeline pressure with the operating condition set value in milliseconds: if the comparison value is within the set error range, the pre-adjustment is deemed qualified; if it exceeds the error range, the automatic compensation module is activated. The automatic compensation module continuously performs dynamic compensation until the pressure feedback value stabilizes within the allowable error range of the operating condition setpoint, forming a closed-loop control logic; an adaptive algorithm is used to optimize the adjustment of the regulating valve, so that the adjustment amplitude decreases as the deviation decreases, avoiding overshoot. The key parameter storage module records in real time the time, opening change, and pressure response curve of each adjustment by the automatic compensation module, which is used to assist the automatic compensation module in calculating the adjustment parameters for the next compensation.

7. A control system for automatic pressure compensation in high-flow-rate, multi-condition test environments according to claim 6, characterized in that: The PLC controller also includes an analog output module, which converts the output opening command of the regulating valve into a 4mA to 20mA signal and outputs it through the analog output interface.

8. A control system for automatic pressure compensation in high-flow-rate, multi-condition test environments according to claim 6, characterized in that: The basic switch control module performs a system initialization self-test, specifically: The basic switch control module checks the initial state of the valve position feedback mechanism and all process solenoid valves, regulating valves, and pressure reducing valves one by one; at the same time, it performs zero-point calibration on the pressure sensor and mass flow meter to eliminate zero-point drift error and ensure the reference accuracy of subsequent data acquisition. If the self-test detects an abnormality, the system will immediately display a pop-up window on the HMI (Human-Machine Interface) indicating the location and type of the fault. The operator will then troubleshoot the fault and re-trigger the self-test until all indicators meet the startup conditions.

9. A control method for automatic pressure compensation in high-flow-rate, multi-condition test experiments, characterized in that... include: S0. Operators input various operating parameters through the HMI human-machine interface and perform system self-test through the basic switch control module of the PLC controller. After the self-test passes, proceed to S1; S1, the basic switch control module of the PLC controller controls the pressure reducing valve of the feedback unit to adjust the pressure of the process pipeline to the reference pressure value required by the test system and reach a steady state; S2. The regulating valve is automatically adjusted by fitting the data block program. The pressure feedback value is judged by the parameter dynamic judgment module. If the pressure feedback value is lower or higher than the set pressure value range, the automatic compensation module is started and the adjustment is continued until the pressure feedback value falls into the pressure value range. At this time, the adjustment action stops and the system pre-adjustment is completed. S3. Open the product valve and maintain it for a certain period of time, and record the working data of the product valve under the current working conditions. During the process, the PLC controller continuously monitors whether the pressure feedback value in the pipeline is within the set pressure range of the working conditions. If it is not within the pressure range, it is adjusted by the automatic pressure compensation module until the pressure reaches the required value of the working conditions, at which point the automatic compensation module stops. S4. After the current working condition test is completed, return to step S1 and start the adjustment process for the next working condition based on the data stored in the key parameter storage module, until all working condition tests are completed.

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