A shield slurry chamber pressure control system and method

Abstract

This invention relates to a pressure control system and method for a slurry chamber in a tunnel boring machine (TBM), comprising a host computer monitoring system, a main PLC for the TBM, and a pressure-maintaining system PLC. The host computer monitoring system is connected to both the main PLC and the pressure-maintaining system PLC for data exchange. The host computer monitoring system reads data from the air cushion chamber and slurry chamber in real time from the main PLC and the pressure-maintaining system PLC, calculates a new air cushion chamber pressure setpoint, sends it to the pressure-maintaining system PLC, and controls the pressure-maintaining system to adjust the air cushion chamber pressure. This invention abandons the traditional method of statically setting the air cushion chamber pressure setpoint, treating the air cushion chamber pressure as a dynamically adjustable variable that is precisely compensated for based on real-time deviations in the slurry chamber pressure. This solves the technical problems of existing slurry shield TBM pressure-maintaining technologies, such as misalignment between control targets and objectives, and the inability to adjust the air cushion chamber pressure in real time according to changes in the slurry chamber pressure.

Description

Technical Field

[0001] This invention relates to the field of pressure control technology in shield tunnel construction, and more specifically, to a pressure control system and method for a shield slurry chamber. Background Technology

[0002] The core objective of slurry chamber pressure control in tunnel boring machines (TBMs) is to maintain tunnel face stability through a relative balance between slurry chamber pressure and tunnel face pressure. The pressure stabilization principle is as follows: Figure 1 As shown: The shield tunneling air cushion chamber 2 and the slurry chamber 1 are connected by a bottom slurry gate, forming a U-shaped connector. The pressure-maintaining system 4 introduces compressed air into the air cushion chamber 2, forming a compressed air cushion 3 at the top of the air cushion chamber. The pressure-maintaining system 4 maintains the air cushion pressure by controlling the air intake and exhaust volume. During shield tunneling, various factors such as changes in the amount of excavated soil, deformation of the tunnel face, and differences in the intake and exhaust volumes can cause changes in the liquid level of the air cushion chamber. Due to the compressibility of air, the compressed air cushion can absorb these fluctuations like a spring. Combined with the pressure-stabilizing and regulating effect of the pressure-maintaining system, the pressure in the slurry chamber is maintained at a relatively stable value.

[0003] Current mainstream control systems typically employ an "air cushion indirect pressure stabilization" mode: Before tunneling begins, operators set a fixed target pressure value for the air cushion chamber on the human-machine interface of the pressure-maintaining system based on theoretical calculations and experience. This set value is generally not adjusted during subsequent tunneling cycles. The pressure-maintaining system stabilizes the actual pressure of the air cushion chamber near the set target value by adjusting the opening of the inlet and outlet valves, thereby aiming to maintain stable pressure in the slurry chamber through the transmission of the slurry medium.

[0004] However, this existing technology has significant drawbacks: the control target and the ultimate goal are misaligned; the direct control object of the system is the pressure of the air cushion chamber, but the actual requirement for maintaining the stability of the excavation face is the stability of the slurry chamber pressure. During shield tunneling, factors such as cutterhead rotation, changes in propulsion speed, fluctuations in slurry circulation flow, and changes in geological conditions cause continuous and random disturbances to the slurry chamber, leading to frequent deviations in slurry chamber pressure from the ideal value. Although the slurry chamber pressure is the direct force for stabilizing the tunnel face, traditional pressure control techniques that use the air cushion chamber pressure as the direct control target cannot respond to these disturbances in a timely and effective manner. Even if the air cushion chamber pressure is very stable, the slurry chamber pressure is still subject to considerable fluctuations due to various random factors such as the air cushion chamber liquid level and slurry density.

[0005] In addition, existing slurry shield tunneling pressure maintenance systems are typically independent systems controlled entirely by pneumatics, operated by personnel on dedicated control panels. This makes integration with the tunnel boring machine's control system for real-time pressure adjustment difficult. While the main operator can observe changes in the slurry chamber pressure via a host computer, it is difficult to indirectly maintain pressure stability by continuously adjusting the air cushion chamber pressure manually in real-time. This increases the risk of excavation face instability, ground subsidence, or excessive heave. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to propose a shield tunnel slurry chamber pressure control system that can solve the technical problems of misalignment between the control target and the control purpose in existing slurry shield tunnel pressure maintenance technologies, and the inability to adjust the air cushion chamber pressure in real time according to changes in slurry chamber pressure.

[0007] The purpose of this invention is to propose a method for controlling the pressure of the slurry chamber in tunnel boring machines (TBMs), which can solve the technical problems of misalignment between the control target and the control purpose in existing slurry shield pressure-maintaining technologies, and the inability to adjust the pressure of the air cushion chamber in real time according to changes in the slurry chamber pressure.

[0008] This invention provides the following technical solution: A pressure control system for a shield tunneling slurry chamber includes a host computer monitoring system, a shield machine main PLC, and a pressure holding system PLC; the shield machine main PLC is used to monitor key status parameters of the shield machine, and the pressure holding system PLC is used to monitor pressure holding system data and send control commands to the pressure holding system. The host computer monitoring system is connected to the main PLC of the tunnel boring machine and the pressure holding system PLC for data exchange. The host computer monitoring system reads the pressure monitoring data of the air cushion chamber and the slurry chamber from the main PLC of the tunnel boring machine and the pressure holding system PLC in real time, calculates the new air cushion chamber pressure set value and sends it to the pressure holding system PLC. The pressure holding system PLC controls the pressure holding system to adjust the pressure of the air cushion chamber.

[0009] Furthermore, the host computer monitoring system includes a data service module, a core control module, and a setpoint dynamic distribution module. The data service module is used to read data from the main PLC of the tunnel boring machine and the PLC of the pressure holding system in real time and synchronously. The core control module has a built-in incremental PID controller, which calculates and outputs the dynamic compensation value of the air cushion chamber pressure by inputting the deviation of the slurry chamber pressure value into the built-in incremental PID controller. Then, the air cushion chamber pressure reference value is added to the air cushion chamber pressure dynamic compensation value to obtain the new air cushion chamber pressure setpoint. The setpoint dynamic distribution module is used to send the new air cushion chamber pressure setpoint to the pressure holding system PLC.

[0010] Furthermore, the host computer monitoring system also includes a safety arbitration and mode management module. The safety arbitration and mode management module is used to determine whether the pressure holding system simultaneously meets the compensation conditions of being in automatic mode, having normal communication, and having valid sensor data. If the compensation conditions cannot be met simultaneously, the input of the new air cushion chamber pressure setting value to the pressure holding system PLC will be suspended, and the pressure holding system will maintain its existing working state.

[0011] The present invention also provides the following technical solution: a method for controlling the pressure of a shield tunnel slurry chamber, implemented based on a shield tunnel slurry chamber pressure control system of the present invention, comprising the following steps: S1. Data Acquisition: The host computer monitoring system synchronously reads the actual pressure values ​​of the mud and water chamber and the air cushion chamber at fixed intervals. S2, Status Arbitration: Checks whether the pressure holding system simultaneously meets the compensation conditions of being in automatic mode, normal communication, and valid sensor data. If any compensation condition is not met, the calculation is paused, the input of the new air cushion pressure setting value to the pressure holding system PLC is stopped, and the existing working state of the pressure holding system is maintained. S3. Compensation Calculation: When the compensation conditions are met simultaneously and the state arbitration is passed, the core control module calculates the pressure deviation of the mud and water chamber. The pressure deviation of the mud and water chamber is the deviation between the set value of the mud and water chamber pressure and the actual value of the mud and water chamber pressure. The pressure deviation of the mud and water chamber is input into the built-in incremental PID control algorithm to calculate the air cushion chamber pressure compensation value required to eliminate the pressure deviation of the mud and water chamber. S4. Synthesis and issuance of new set value: The pressure compensation value of the air cushion chamber is added to the pressure reference value of the air cushion chamber to obtain the new pressure set value of the air cushion chamber. Then, the new pressure set value of the air cushion chamber is written into the pressure holding system PLC and a trigger signal is sent to drive the pressure holding system PLC to start a new round of pressure adjustment. S5. Cyclic Execution: Return to step S1 and continuously cycle through steps S1-S5 to achieve dynamic, closed-loop adjustment and control of the slurry chamber pressure.

[0012] Furthermore, the specific calculation steps for the air cushion chamber pressure compensation value during the control period k in step S3 are as follows: S31. Calculate the deviation: e(k)=SP_slurry-PV_slurry(k); Where e(k) is the pressure deviation of the slurry tank during control period k, SP_slurry is the setpoint of the slurry tank pressure, and PV_slurry(k) is the actual value of the slurry tank pressure during control period k. S32. Calculate the control increment: Δu(k)=Kp*[e(k)-e(k-1)]+Ki*e(k)+Kd*[e(k)-2*e(k-1)+e(k-2)]; Where Δu(k) is the pressure increment of control period k, Kp is the proportional coefficient, Ki is the integral coefficient, Kd is the differential coefficient, e(k-1) is the pressure deviation of the slurry tank in the previous control period k, and e(k-2) is the pressure deviation of the slurry tank in the two control periods before control period k. S33. Calculate the dynamic compensation value; ΔP(k) = ΔP(k-1) + Δu(k); Wherein, ΔP(k) is the dynamic compensation value of the air cushion chamber in control period k, and ΔP(k-1) is the dynamic compensation value of the air cushion chamber in the control period preceding control period k.

[0013] Furthermore, the built-in incremental PID control algorithm in step S3 includes a dead zone handling step, specifically, when |e(k)| is less than the lower limit of the set threshold, Δu(k) = 0.

[0014] Furthermore, the built-in incremental PID control algorithm in step S3 has a rate-of-change limiting step, specifically, when |ΔP(k)-ΔP(k-1)|>incremental limit value, Δu(k) takes the incremental limit value.

[0015] Furthermore, the built-in incremental PID control algorithm in step S3 includes an integral anti-saturation step, specifically, when |e(k)| ≥ the upper threshold and / or ΔP(k) ≥ the amplitude limit for n consecutive control cycles, Ki*e(k) is set to 0 in the current control cycle k.

[0016] Furthermore, the calculation steps for the new air cushion chamber pressure setpoint in step S4, controlling cycle k, are as follows: SP_air(k) = Air cushion chamber pressure reference value + ΔP(k); Where SP_air(k) is the new air cushion pressure setting value for control period k, the air cushion pressure reference value is the preset value or calculated in real time, and ΔP(k) is the dynamic compensation value of the air cushion for control period k.

[0017] Beneficial effects: The core of this invention lies in the dynamic compensation algorithm implemented by the core control module within the host computer monitoring system. This algorithm abandons the traditional method of statically setting the air cushion chamber pressure setpoint, treating the air cushion chamber pressure setpoint as a dynamically adjustable variable that is precisely compensated based on the real-time deviation of the mud-water chamber pressure. By dynamically adjusting the air cushion chamber pressure setpoint, the pressure-holding system is guided to change the air cushion chamber pressure, thereby influencing the mud-water chamber pressure through the principle of communicating vessels and achieving final control of the mud-water chamber pressure, forming a real-time, closed-loop control system with the mud-water chamber pressure as the final controlled variable. Overall, it has the following advantages. (1) Precise control target and significantly improved stability: The direct target of shield pressure control is corrected from "air cushion chamber pressure" to "slurry chamber pressure", which fundamentally solves the problem of misalignment between the control target and engineering requirements in the original control technology. The system can actively sense and compensate for the random fluctuations in slurry chamber pressure caused by tunneling activities, so that the excavation face pressure is always maintained in a high-precision and stable state, which can effectively reduce the risk of ground deformation. (2) High system reliability and low implementation risk: The present invention adopts a hierarchical architecture of "intelligent decision-making by host computer + rapid execution by dedicated PLC". The host computer monitoring system is responsible for advanced algorithms and dynamic settings, while the pressure holding system PLC is responsible for the rapid and stable control of the underlying execution units (such as valves). This architecture requires less modification to the existing shield machine and does not require modification of the original reliable internal core control logic of the pressure holding system PLC, which is convenient for modification and implementation in existing projects. Even if the host computer fails, the system will automatically degrade to the traditional "air cushion chamber constant pressure" mode to fully ensure inherent safety. (3) Strong adaptability and good practicality: The incremental PID algorithm is combined with dead zone and rate of change limit functions, which does not have strict requirements on the system response speed and can adapt to the communication delay and equipment inertia in the industrial field; the parameter tuning direction focuses on "stability first and then accuracy", which is easy to debug and apply on site; the hierarchical architecture of the host computer monitoring system and the pressure holding system PLC also facilitates the upgrade and optimization of the host computer software level, and in the long run, it reserves room for improvement for the introduction of more advanced control algorithms such as model predictive control. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the pressure stabilization principle of the slurry chamber in existing shield tunneling technology; Figure 2 This is a control principle diagram of a specific embodiment 1 of the shield tunnel slurry chamber pressure control system of the present invention; Figure 3 This is a control flowchart of a specific embodiment 1 of the shield tunnel slurry chamber pressure control method of the present invention; Figure 4 This is a schematic diagram of the built-in incremental PID control algorithm in a specific embodiment 1 of the shield tunnel slurry chamber pressure control method of the present invention. 1-Mud and water chamber; 2-Air cushion chamber; 3-Compressed air cushion; 4-Pressure holding system. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings.

[0020] Specific embodiment 1 of the shield tunnel slurry chamber pressure control system of the present invention: like Figure 2As shown, the shield tunneling slurry chamber pressure control system of the present invention includes a host computer monitoring system, a shield machine main PLC, and a pressure holding system PLC. The shield machine main PLC is connected to the shield machine circulation system and the slurry chamber air pressure sensor. The slurry chamber air pressure sensor is installed inside the air cushion chamber for real-time detection of the slurry chamber pressure. The circulation system includes a level gauge, a density meter, circulation pipelines, a slurry inlet pump, and a slurry outlet pump. The level gauge and density meter are installed inside the air cushion chamber; the level gauge is used to measure the liquid level inside the air cushion chamber, and the density meter is used to monitor the slurry density. The shield machine main PLC monitors key status parameters of the shield machine, and its key status data mainly include the air cushion chamber liquid level, slurry chamber pressure, and slurry density.

[0021] The pressure-holding system PLC is connected to the pressure-holding system, which includes an air compressor, an inlet valve, an exhaust valve, and an air cushion pressure sensor installed on top of the air cushion chamber. The air cushion pressure sensor is used to monitor the pressure of the air cushion chamber in real time. In this embodiment, the pressure-holding system can adopt the technical solution provided by a fully electrically controlled intelligent interconnected shield tunneling pressure-holding system disclosed in patent authorization number CN216811688U, dated June 24, 2022. Its operating mode is configured as automatic pressure regulation mode. The pressure-holding system PLC receives the status data of the pressure-holding system and sends control commands to it. The data monitoring of the pressure-holding system by the PLC mainly includes the pressure of the air cushion chamber. The pressure-holding system PLC sends control commands to the pressure-holding system and adjusts the air intake and exhaust volumes by regulating the opening of the inlet and exhaust valves, thereby adjusting the air cushion chamber pressure.

[0022] The host computer monitoring system connects to the main PLC of the tunnel boring machine (TBM) and the pressure holding system via industrial communication networks (such as OPC UA and Modbus TCP) for data exchange. The host computer monitoring system reads real-time data from the main PLC and the pressure holding system PLC of the TBM and the slurry chamber (such as the actual pressure values ​​of the slurry chamber and the air cushion chamber), calculates the new air cushion chamber pressure setpoint, and sends it to the pressure holding system PLC. The pressure holding system PLC then controls the pressure holding system to adjust the air cushion chamber pressure.

[0023] The host computer monitoring system includes a data service module, a core control module, and a dynamic setpoint distribution module. The data service module reads data from the main PLC of the tunnel boring machine and the pressure-maintaining system PLC in real time and synchronously. The core control module has a built-in incremental PID controller with a built-in incremental PID algorithm. It calculates and outputs a dynamic compensation value for the air cushion chamber pressure by inputting the deviation of the slurry chamber pressure value to the built-in incremental PID controller. Then, it adds the air cushion chamber pressure reference value to the dynamic compensation value to obtain the new air cushion chamber pressure setpoint. The dynamic setpoint distribution module sends the new air cushion chamber pressure setpoint to the pressure-maintaining system PLC. Together, the data service module and the dynamic setpoint distribution module constitute the communication and data service module for read / write communication with the pressure-maintaining system PLC and the main PLC of the tunnel boring machine.

[0024] The host computer monitoring system also includes a safety arbitration and mode management module. The safety arbitration and mode management module is used to determine whether the pressure holding system simultaneously meets the compensation conditions of being in automatic mode, having normal communication, and having valid sensor data. If the compensation conditions cannot be met simultaneously, the input of the new air cushion chamber pressure setting value to the pressure holding system PLC will be suspended, and the pressure holding system will maintain its existing working state and issue an alarm.

[0025] Based on a shield tunnel slurry chamber pressure control system, this invention provides a shield tunnel slurry chamber pressure control method, but this method is not limited to the aforementioned shield tunnel slurry chamber pressure control system. A specific embodiment 1 of this shield tunnel slurry chamber pressure control method is shown below. Figure 3 The steps shown are as follows: S1. Data acquisition: The host computer monitoring system synchronously reads the actual pressure values ​​of the mud and water chamber and the air cushion chamber at a fixed cycle. The fixed cycle can be a value between 1 and 5 seconds. S2, Status Arbitration: Checks whether the pressure holding system simultaneously meets the compensation conditions of being in automatic mode, normal communication, and valid sensor data. If any compensation condition is not met, the calculation is paused, the input of the new air cushion pressure setting value to the pressure holding system PLC is stopped, the existing working state of the pressure holding system is maintained, and an alarm is triggered. S3. Compensation Calculation: After the compensation conditions are met simultaneously and the state arbitration is passed, the core control module calculates the slurry chamber pressure deviation. The slurry chamber pressure deviation is the deviation between the setpoint and the actual pressure of the slurry chamber. The built-in incremental PID control algorithm is then input to calculate the air cushion chamber pressure compensation value required to eliminate the slurry chamber pressure deviation. Figure 4 The specific calculation steps for the air cushion chamber pressure compensation value of the control period k shown are as follows: S31. Calculate the deviation: e(k)=SP_slurry-PV_slurry(k); Where e(k) is the pressure deviation of the slurry tank during control period k, SP_slurry is the setpoint of the slurry tank pressure, and PV_slurry(k) is the actual value of the slurry tank pressure during control period k. S32. Calculate the control increment: Δu(k)=Kp*[e(k)-e(k-1)]+Ki*e(k)+Kd*[e(k)-2*e(k-1)+e(k-2)]; Where Δu(k) is the pressure increment of control period k, Kp is the proportional coefficient, Ki is the integral coefficient, Kd is the differential coefficient, e(k-1) is the pressure deviation of the slurry tank in the previous control period k, and e(k-2) is the pressure deviation of the slurry tank in the two control periods before control period k. S33. Calculate the dynamic compensation value; ΔP(k) = ΔP(k-1) + Δu(k); Wherein, ΔP(k) is the dynamic compensation value of the air cushion chamber in control period k, and ΔP(k-1) is the dynamic compensation value of the air cushion chamber in the control period preceding control period k.

[0026] The built-in incremental PID control algorithm in this embodiment also includes a dead zone handling step, a rate of change limiting step, and an integral anti-saturation step.

[0027] Dead zone handling steps: When |e(k)| is less than the lower limit of the set threshold (e.g., 0.03 bar), Δu(k) = 0. This avoids frequent fine-tuning of the control system near the equilibrium point, reduces valve actuation, and improves system lifespan.

[0028] Change rate limiting step: When |ΔP(k)-ΔP(k-1)|>the incremental limit value (e.g., 0.05 bar), Δu(k) takes the incremental limit value; to ensure that the pressure set value of the air cushion chamber changes smoothly and avoids impact on the pressure holding system.

[0029] Integral anti-saturation step: When |e(k)| ≥ the upper limit of the threshold and / or ΔP(k) ≥ the limit value for n consecutive control cycles, the integral term Ki*e(k) in the current control cycle k is set to 0, that is, when the deviation is continuously large and / or the output ΔP(k) has reached the limit value, the integral action is paused to prevent the integral term from accumulating and causing excessive overshoot when the system recovers; n is usually taken as 2-5.

[0030] S4. New Setpoint Synthesis and Issuance: The new air cushion pressure setpoint is obtained by adding the air cushion pressure compensation value to the air cushion pressure reference value. The calculation steps for the new air cushion pressure setpoint during control period k are as follows: SP_air(k) = Air cushion chamber pressure reference value + ΔP(k); Where SP_air(k) is the new air cushion pressure setting value for control period k, the air cushion pressure reference value is the preset value or calculated in real time, and ΔP(k) is the dynamic compensation value of the air cushion for control period k.

[0031] Then, the new air cushion chamber pressure setting value is written into the pressure holding system PLC and a trigger signal is sent to drive the pressure holding system PLC to start a new round of pressure adjustment.

[0032] S5. Cyclic Execution: Return to step S1 and continuously cycle through steps S1-S5 to achieve dynamic, closed-loop adjustment and control of the slurry chamber pressure.

[0033] The core principles and technical advantages of this invention are as follows: (1) The pressure of the mud and water chamber is used as the direct feedback quantity in the control logic, and the pressure setting value of the air cushion chamber is dynamically adjusted according to the pressure deviation of the mud and water chamber, forming a real-time closed-loop control loop with the stabilization of the mud and water chamber pressure as the final control target.

[0034] (2) The system adopts a collaborative architecture of “host computer + pressure holding PLC + shield machine main PLC”. The host computer monitoring system is responsible for advanced calculation and decision-making, and the pressure holding PLC is a fast and reliable actuator. The two communicate through industrial network, which is stable and reliable, and realizes the separation of core calculation and execution links.

[0035] (3) The core of the dynamic compensation method is to calculate the pressure deviation e of the mud and water chamber, calculate the dynamic compensation value ΔP through the built-in incremental PID control algorithm, and then synthesize the new air cushion chamber pressure set value in real time and send it to the pressure holding system as the air cushion chamber pressure target value for execution.

[0036] (4) An incremental digital PID algorithm is adopted, and dead zone processing steps and rate of change limiting steps are integrated. Dead zone processing avoids frequent adjustments under perturbation, and rate of change limiting can ensure smooth control commands to adapt to the characteristics of large inertia and delay in industrial sites, and prioritize system stability.

[0037] (5) Set up a safety arbitration and downgrade mechanism. The system sets up a safety arbitration and mode management module to monitor the working mode, communication status and data validity of the pressure holding system. If any item is abnormal, the dynamic compensation will be automatically suspended and the pressure holding system will be downgraded to maintain the last command or switched to the traditional air cushion constant pressure mode to ensure inherent safety.

[0038] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A pressure control system for a shield tunnel slurry chamber, characterized in that, It includes a host computer monitoring system, a shield machine main PLC, and a pressure holding system PLC; the shield machine main PLC is used to monitor the key status parameters of the shield machine, and the pressure holding system PLC is used to monitor the pressure holding system data and send control commands to the pressure holding system; The host computer monitoring system is connected to the main PLC of the tunnel boring machine and the pressure holding system PLC for data exchange. The host computer monitoring system reads the pressure monitoring data of the air cushion chamber and the slurry chamber from the main PLC of the tunnel boring machine and the pressure holding system PLC in real time, calculates the new air cushion chamber pressure set value and sends it to the pressure holding system PLC. The pressure holding system PLC controls the pressure holding system to adjust the pressure of the air cushion chamber.

2. The shield tunneling slurry chamber pressure control system as described in claim 1, characterized in that, The host computer monitoring system includes a data service module, a core control module, and a setpoint dynamic distribution module. The data service module is used to read data from the main PLC of the tunnel boring machine and the PLC of the pressure holding system in real time and synchronously. The core control module has a built-in incremental PID controller. By inputting the pressure deviation of the mud chamber into the built-in incremental PID controller, it calculates and outputs the dynamic compensation value of the air cushion chamber pressure. Then, it adds the air cushion chamber pressure reference value and the air cushion chamber pressure dynamic compensation value to obtain the new air cushion chamber pressure setpoint. The setpoint dynamic distribution module is used to send the new air cushion chamber pressure setpoint to the pressure holding system PLC.

3. The shield tunneling slurry chamber pressure control system as described in claim 2, characterized in that, The host computer monitoring system also includes a safety arbitration and mode management module. The safety arbitration and mode management module is used to determine whether the pressure holding system simultaneously meets the compensation conditions of being in automatic mode, having normal communication, and having valid sensor data. If the compensation conditions cannot be met simultaneously, the input of the new air cushion chamber pressure setting value to the pressure holding system PLC will be suspended, and the pressure holding system will maintain its existing working state.

4. A method for controlling the pressure of a slurry chamber in a tunnel boring machine, characterized in that, The implementation of the shield tunnel slurry chamber pressure control system according to any one of claims 1-3 includes the following steps: S1. Data Acquisition: The host computer monitoring system synchronously reads the actual pressure values ​​of the mud and water chamber and the air cushion chamber at fixed intervals. S2, Status Arbitration: Checks whether the pressure holding system simultaneously meets the compensation conditions of being in automatic mode, normal communication, and valid sensor data. If any compensation condition is not met, the calculation is paused, the input of the new air cushion pressure setting value to the pressure holding system PLC is stopped, and the existing working state of the pressure holding system is maintained. S3. Compensation Calculation: When the compensation conditions are met simultaneously and the state arbitration is passed, the core control module calculates the pressure deviation of the mud and water chamber. The pressure deviation of the mud and water chamber is the deviation between the set value of the mud and water chamber pressure and the actual value of the mud and water chamber pressure. The pressure deviation of the mud and water chamber is input into the built-in incremental PID control algorithm to calculate the air cushion chamber pressure compensation value required to eliminate the pressure deviation of the mud and water chamber. S4. Synthesis and issuance of new set value: The pressure compensation value of the air cushion chamber is added to the pressure reference value of the air cushion chamber to obtain the new pressure set value of the air cushion chamber. Then, the new pressure set value of the air cushion chamber is written into the pressure holding system PLC and a trigger signal is sent to drive the pressure holding system PLC to start a new round of pressure adjustment. S5. Cyclic Execution: Return to step S1 and continuously cycle through steps S1-S5 to achieve dynamic, closed-loop adjustment and control of the slurry pressure.

5. The experimental method for controlling the pressure of the slurry chamber in a slurry shield tunnel as described in claim 4, characterized in that, The specific calculation steps for the air cushion chamber pressure compensation value of control period k in step S3 are as follows: S31. Calculate the deviation: e(k)=SP_slurry-PV_slurry(k); Where e(k) is the pressure deviation of the slurry tank during control period k, SP_slurry is the setpoint of the slurry tank pressure, and PV_slurry(k) is the actual value of the slurry tank pressure during control period k. S32. Calculate the control increment: Δu(k)=Kp*[e(k)-e(k-1)]+Ki*e(k)+Kd*[e(k)-2*e(k-1)+e(k-2)]; Where Δu(k) is the pressure increment of control period k, Kp is the proportional coefficient, Ki is the integral coefficient, Kd is the differential coefficient, e(k-1) is the pressure deviation of the slurry tank in the previous control period k, and e(k-2) is the pressure deviation of the slurry tank in the two control periods before control period k. S33. Calculate the dynamic compensation value; ΔP(k) = ΔP(k-1) + Δu(k); Wherein, ΔP(k) is the dynamic compensation value of the air cushion chamber in control period k, and ΔP(k-1) is the dynamic compensation value of the air cushion chamber in the control period preceding control period k.

6. The method for controlling the pressure of a slurry chamber in a shield tunnel as described in claim 5, characterized in that, The built-in incremental PID control algorithm in step S3 includes a dead zone handling step, specifically, when |e(k)| is less than the lower limit of the set threshold, Δu(k) = 0.

7. The method for controlling the pressure of a shield tunnel slurry chamber as described in claim 5, characterized in that, The built-in incremental PID control algorithm in step S3 has a rate-of-change limiting step, specifically, when |ΔP(k)-ΔP(k-1)|>incremental limit value, Δu(k) takes the incremental limit value.

8. The method for controlling the pressure of a slurry chamber in a shield tunnel as described in claim 5, characterized in that, The built-in incremental PID control algorithm in step S3 includes an integral anti-saturation step, which is to take Ki*e(k) as 0 in the current control cycle k when |e(k)| ≥ the upper threshold and / or ΔP(k) ≥ the amplitude limit for n consecutive control cycles.

9. A method for controlling the pressure of a slurry chamber in a shield tunnel as described in any one of claims 5-8, characterized in that, The calculation steps for the new air cushion chamber pressure setpoint in step S4, controlling cycle k, are as follows: SP_air(k) = Air cushion chamber pressure reference value + ΔP(k); Where SP_air(k) is the new air cushion pressure setting value for control period k, the air cushion pressure reference value is the preset value or calculated in real time, and ΔP(k) is the dynamic compensation value of the air cushion for control period k.

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