Thrust Hydraulic System Research Articles

SSFLNet: A Novel Fault Diagnosis Method for Double Shield TBM Tool System.

In tunnel boring projects, wear and tear in the tooling system can have significant consequences, such as decreased boring efficiency, heightened maintenance costs, and potential safety hazards. In this paper, a fault diagnosis method for TBM tooling systems based on SAV-SVDD failure location (SSFL) is proposed. The aim of this method is to detect faults caused by disk cutter wear during the boring process, which diminishes the boring efficiency and is challenging to detect during construction. This paper uses SolidWorks to create a complete three-dimensional model of the TBM hydraulic thrust system and tool system. Then, dynamic simulations are performed with Adams. This helps us understand how the load on the propulsion hydraulic cylinder changes as the TBM tunneling tool wears to different degrees during construction. The hydraulic propulsion system was modeled and simulated using AMESIM software. Utilizing the load on the hydraulic propulsion cylinder as an input signal, pressure signals from the two chambers of the hydraulic cylinder and the system's flow signal were acquired. This enabled an in-depth exploration of the correlation between these acquired signals and the extent of the tooling system failure. Following this analysis, a collection of normal sample data and sample data representing different degrees of disk cutter abrasions was amassed for further study. Next, an SSFL network model for locating the failure area of the cutter was established. Fault sample data were used as the input, and the accuracy of the fault diagnosis model was tested. The test results show that the performance of the SSFL network model is better than that of the SAE-SVM and SVDD network models. The SSFL model achieves 90% accuracy in determining the failure area of the cutter head. The model effectively identifies the failure regions, enabling timely tool replacement to avoid decreased boring efficiency under wear conditions. The experimental findings validate the feasibility of this approach.

Determination of thrusts for different cylinder groups during shield tunneling

The hydraulic thrust system that emphasizes grouped controlling of the shield machine is used for driving forward and pose adjustment. To control and regulate the pose of the shield machine precisely, it is of great significance to solve the total thrust and grouped thrusts (thrusts for different cylinder groups) reasonably. This study aims to develop a novel thrust model to calculate the total thrust and grouped thrust. Firstly, a soil-machine interaction model is developed to predict the loads acting on the shield machine during tunneling. Then an inverse kinematic analysis is performed to describe the velocity Jacobian and soil displacement induced by pose adjustment. Based on the kinematic mechanism of the shield machine under soil resistance, a thrust model is proposed to determine the total thrust and grouped thrusts employing static mechanics. In this model, both the soil properties and the shield parameters, such as operating parameters, pose parameters and geometric parameters are considered. The proposed thrust model is verified through a case application and the results indicate that the model could be used for assessing the total thrust and grouped thrusts during shield tunneling, which provides a theoretical basis for pose adjustment and automatic trajectory tracking control of the shield machine.

Investigation into the Electrohydraulic Synchronous Motion Control of a Thrust System for a Tunnel Boring Machine

The thrust system of a tunnel boring machine plays a crucial role by driving the machine ahead and supporting the gripper shoes stably. A thrust hydraulic control system, assembled with a proportional flow control valve and a pressure relief valve, is established with system operating parameters. The mathematical model of a thrust electrohydraulic system is presented. To improve the control characteristics of the thrust system, a self-tuning fuzzy PID controller was introduced in synchronization motion control situations. To attain the best control parameters, three synchronization motion control systems were used to control the thrust propel cylinders. Tests on a Ø2.5 m scaled TBM test rig were carried out to verify the capabilities of the ISCS, SRSCS and CRSCS. Comparative tests were conducted, and the results showed that the thrust system adopting SRSCS achieved the least oscillation and the quickest response. The steady-state displacement error decreased by about 33.3% in contrast to the ISCS and CRSCS.

Performance Analysis of Electro-Hydraulic Thrust System of TBM Based on Fuzzy PID Controller

The tunnel boring machine (TBM) is widely used in tunnel construction projects. The thrust system plays a crucial role to drive the machine ahead and support gripper shoes stably while tunneling. More and more attention has been paid to the pressure and velocity regulation efficiency as the TBM advances in complex rock conditions to ensure the stabilization of the tunneling process. A thrust hydraulic control system, assembled with a proportional pressure reducing valve, is established with system operating parameters. The mathematical model of the thrust electro-hydraulic system is revealed. To improve the control characteristics of the thrust system, a self-tuning fuzzy PID controller is introduced in the pressure and velocity regulation procedures. After that, tests on a Φ2.5 m scaled TBM test rig are carried out. The test results show that the thrust system adopting the fuzzy PID controller results in less oscillation and a smoother regulation process. It takes less time to reach the target goal of pressure regulation with less vibration during the pressure regenerating periods, and both systems of conventional PID controller and fuzzy PID controller are qualified in velocity regulation movements. The proposed control methods show better benefits in reduction of vibrations and shorter time of regulation to stable conditions, which extends the machine’s life and affects the acceleration of the tunneling process.

Kinematic Analysis and Virtual Prototype Simulation of the Thrust Mechanism for Shield Machine

The hydraulic thrust system of the shield machine is used for driving forward and pose adjustment. It is of great significance to figure out the thrust mechanism and motion characteristics of the shield machine to ensure the safety of tunnel excavation. This study aims to develop a model to explore the influence of thrust cylinder advancement on the motions of the shield machine. Firstly, the study carried out mechanism analysis of the thrust mechanism for the shield machine and established a method to describe the position and attitude of the shield machine during the tunneling process by the homogeneous transformation matrix. Then, a new inverse kinematic model was proposed to quantify the relationship between the telescoping movements of cylinders and shield machine motions, and the Jacobian matrix was derived to solve the instantaneous kinematics analysis. Furthermore, a virtual prototype model was developed to simulate the kinematic behavior of the shield machine and validate the accuracy of the kinematic model. The model provides the basic constraint relations for the practical position control system and lays a strong foundation for the dynamic model and automatic trajectory tracking control of shield machines for future studies. Based on the proposed model, the displacement, velocity, and acceleration of cylinders that drive the shield machine to the target motions can be solved exactly. It can provide a reference for the pose control of the shield machine during the practical shield tunneling.

A novel self-adaptive thrust system of shield machine under complex geological working condition

Thrust system is an important part of the shield machine, which consists of tens of hydraulic cylinders that are grouped for better control. The thrust hydraulic system may perform poorly when it works under unexpected geological working conditions as the control group cannot be adjusted. To improve the thrust performance, a new concept of group-adjustable thrust hydraulic system is proposed. Eight different types of equivalent models for grouped thrust system are presented in terms of parallel mechanism theory. The kinematics and statics are then developed to model the performance of the thrust system further. The uniformity index is introduced to assess the performance of thrusting and then calculated for each grouping modes. The numerical simulations clearly illustrate that the properties of each grouping mode. The uniformity analysis demonstrates that the performance of a certain group mode is determined by its group angle. To help the thrust system adapt to the real-time working condition, the optimization of group angle is established according to the principle of the uniformity minimization. At last, a force accumulation index is proposed to demonstrate the effectiveness of group-adjustable thrust system against the group-fixed one through a case study.

Compliance of hydraulic system and its applications in thrust system design of shield tunneling machine

As the most significant performance, compliance of hydraulic system is defined as the capacity to accommodate the sudden change of the external load. Due to the different requirements of the compliant tasks, the existing method for mechanical systems cannot be used in the analysis and design of the hydraulic system. In this paper, the definition and expression of compliance of hydraulic system are proposed to evaluate the compliance of the hydraulic system operating under sudden change load. Because the unexpected geological conditions during excavation may exert sudden change load to the shield tunneling machine, the compliance theory has found a right application in the thrust hydraulic system. By analyzing the basic operating principle and the commonly used architectures of the thrust hydraulic system, a compliance based thrust hydraulic system design method is presented. Moreover, a tunneling case is investigated in the paper as an example to expound the validation of design procedure. In conclusion, the compliance of the hydraulic system can be served as an evaluation of the capability in conforming to the load impact, giving supports for the design of the thrust hydraulic system of shield tunneling machines.

Thrust Hydraulic System of Casing Rotater with Flow Adaptive Control

Thrust system is the key system of casing rotator. A thrust hydraulic system with flow adaptive control is designed, operating principle and control method are elaborated as well. In order to investigate the dynamic characteristics of the thrust hydraulic system, simulation analyses with the combined platform of AMESim and MATLAB/Simulink are carried out. The simulation results show that the designed thrust hydraulic system can meet the driving velocity requirement and reduce the overflow loss.

Study on Coordinated Control Theory of Shield Thrust Hydraulic System

In order to improve the dynamic coordinated control performance of shield thrust hydraulic cylinder during the shield construction process, we used the shield electro-hydraulic control synthetic experimental platform as research object. The simulation models of thrust system and external loading were built in AMESim. The result of PID closed-loop simulation indicated that thrust system can enable the compound control of thrust pressure and velocity by using the compound control technique of pressure and flow. In view of the complex and varied external load condition of shield thrust system, we simulated the fuzzy and fuzzy-PID control strategy of thrust system in passive automatic adjustment mode, based on the Joint Modeling and Simulation Environment (JMASE) of AMESim and Matlab/Simulink. The multi-external loads of thrust system mainly contained unequal-fixed load, equal-variable load and unequal-variable load. Finally, a coordinated control theory of shield thrust system was put forward. Such theory could provide some theoretical guidance for the design of shield machine and control of shield construction.

Automatic trajectory tracking control of shield tunneling machine under complex stratum working condition

Automatic trajectory tracking control is a significant task of thrust system during tunnel excavation. Tasks of steering and posture adjustment of the shield machine can be achieved by properly adjusting the distribution of thrust pressure in corresponding working zones. Principle of hydraulic thrust system and hydraulic load simulation test rig of shield machine are illustrated at first. Then a set of scientific and complete orientation and posture rectification strategies has been put forward to eliminate the position and angle deviations simultaneously. Based on construction site investigation, mechanical structure diagram and kinematics model of the thrust system have been established. Then, the numerical results of path planning under steering or rectifying working condition are demonstrated. An integrated control system, which consists of one trajectory planning controller for both cylinders and an individual cylinder controller for each of hydraulic cylinders, is proposed to achieve the automatic control of the thrust trajectory. A cascade control strategy, which comprises feedforward controller of fixed-value compensation and feedback controller of Variable-gain proportion–integration–differentiation (PID), is applied to achieve the precise tracking control of the given trajectory. Experimental studies on automatic trajectory tracking control under several typical working conditions are done at last.

Simulation analysis of pressure regulation of hydraulic thrust system on a shield tunneling machine

Hydraulic thrust system is an important system in a shield tunneling machine. Pressure regulation of thrust cylinders is the most important function for thrust system during tunnel excavation. In this paper, a hydraulic thrust system is explained, and a corresponding simulation model is carried out in order to study the system characteristics. Pressure regulation of a certain group’s cylinders has little influence on regulation of the other groups’ cylinders. The influence will not affect the process much during tunnel excavation. Pump displacement may have a greater effect on pressure regulation and oil supply flow rate should be adaptive to the system’s demand. A exacting situation is simulated to explain how pressure regulation works during tunnel excavation.

Theoretical Analysis and Experimental Study on Automatic Trajectory Tracking Control of a Shield Tunneling Machine under Pressure Regulation Working Mode

Hydraulic thrust system is a critical part of shield tunneling machine. Automatic trajectory tracking control is a significant task of thrust system during tunnel excavation. In this article, plane mechanical structure diagram of the thrust system and path planning method are illustrated at first. An integrated control system is proposed to achieve the automatic control of the thrust trajectory. The control system consists of one trajectory planning controller for both cylinders and an individual cylinder controller for each of hydraulic cylinders. Trajectory planning controller is used to generate respective displacement signals of double-cylinder in every thrust stroke and each of cylinder controllers is used to realize the precise control of the given thrust trajectory. Variable-gain PID control strategy applied to achieve the precise tracking control of thrust trajectory under several typical working conditions are done at last. The experimental results demonstrate that variable-gain PID control have good performances with short response time and small overshoot regardless of changes of working conditions.

Non-linear adaptive controller with a variable adaptation rate for a simulated model of an electrohydraulic actuator

An adaptive control method is presented for a single-rod electrohydraulic system with a heavy load force acting on the cylinder piston. Previous adaptive control approaches always used adaptation law to estimate the system parametric uncertainties. However, in a practical hydraulic thrust system with a heavy resistant load force, the system parametric uncertainties can be neglected with respect to the greater load force. The objective of the paper is to present a non-linear adaptive controller with adaptation laws to track the changeable load force automatically. The main feature of the scheme is that an exponential-form function has been introduced to construct an invariable convergence rate of the adaptive controller, by which the conflicting system performances could be satisfied harmonically. The simulation results for an electrohydraulic actuator show that the non-linear control algorithm, together with the variable adaptation scheme, achieves a good synthetic performance in keeping the cylinder thrusting in a smooth and optimal energy-saving operating state.

Precise Control of Thrust Force on the Shield Tunneling Machine

Hydraulic thrust system is a critical part of shield tunneling machine. The precise control of the thrust force is a significant task of thrust system during tunneling excavation. In this paper, an operation principle of the hydraulic thrust system test rig is illustrated. Taking into account the variable deadband nonlinear characteristics of proportional relief valve which is used for regulating the thrust pressure, several compensation control strategies are adopted to achieve the precise control of thrust force. Analysis and comparison which bases on simulation and experiment is done at last. The result shows that Fuzzy control can both eliminate the error and reduce the adjustment time which can basically meet the requirement of practical tunnel excavation.

Motion control of thrust system for shield tunneling machine

The thrust hydraulic system of the prototype shield machine with pressure and flow compound control scheme was introduced. The experimental system integrated with proportional valves for study was designed. Dynamics modeling of multi-cylinder thrust system and synchronous control design were accomplished. The simulation of the synchronization motion control system was completed in AMESim and Matlab/Simulink software environments. The experiment was conducted by means of master/slave PID with dead band compensating flow and conventional PID regulating pressure. The experimental results show that the proposed thrust hydraulic system and its control strategy can meet the requirements of tunneling in motion and posture control for the shield machine, keeping the non-synchronous error within ±3 mm.

Electro-hydraulic proportional control of thrust system for shield tunneling machine

In this paper, a thrust hydraulic system of shield tunneling machine with pressure and flow compound control scheme is proposed. In the control system, the task of real-time measuring of the pressure and the displacement of hydraulic cylinder in each thrust group is accomplished by pressure sensor and displacement sensor respectively, forming the closed-loop pressure and speed control with proportional valves. Thrust system mathematical modeling including hydraulic system and multi-cylinder acting dynamics is presented. Synchronization motion control between cylinders is also achieved by means of master–slave PID with dead band compensating displacement error. Experiments of thrust pressure and speed control as well as cylinder synchronization are conducted on the shield simulation test rig. The experimental results show that the proposed thrust hydraulic system and its control can meet the requirements of tunneling.

THRUST HYDRAULIC SYSTEM OF SHIEID TUNNEL BORING MACHINE WITH PRESSURE AND FLOW COMPOUND CONTROL

Thrust system is a key system of shield tunnel boring machine. A thrust hydraulic system with pressure and flow compound control is designed. Distributed control of thrust hydraulic cylinders is carried out, working principle and control method of the thrust hydraulic system are also expounded. In order to investigate the pressure and flow characteristics of the thrust hydraulic system, simulation analyses are carried out with the AMESim simulation tool. At the same time, the experiments are done in the engineering application. The simulation results and the practical applications show that the designed thrust hydraulic system can real-time control the thrust pressure and the thrust speed, which can also meet the thrust requirements of the shield.