Lintao Wang

The Development of a High-Speed Segment Erecting System for Shield Tunneling Machine

The present study is focused on developing an effective high-speed segment erecting system, which is specific for modern shield tunneling machine. The big steady-state error and large impact force caused by high motion speed and large inertia load are main restrictions for the conventional segment erector to realize high-speed segment erecting. To overcome the bottleneck, a new hydraulic system that is based on electrohydraulic proportional control technology is designed, the actuator speed of which is adjustable and controllable. The kinematic and dynamic models are established to determine the displacement of each actuator and calculate joint force, respectively. A combined motion law is then selected to reduce joint force during acceleration and deceleration stages. Furthermore, a superior control strategy that is able to precisely and smoothly control the segment erector at high speed is chosen by comparing the experimental performances of four different control strategies. Experiments are carried out on a segment erector test rig. The experimental results show exceptional performances of the speed and position compound control system in terms of accuracy and impact force. The maximum rotation speed of the new system can be increased to more than three times of that of the present erecting system. In addition, high steady-state accuracy can be achieved with the new system while its impact force is just about one-third of the position control system.

Positioning speed and precision control of a segment erector for a shield tunneling machine

This paper deals with a positioning speed and precision control system for the assembly of segments of a shield tunneling machine. First, we design a six degrees of freedom segment erector with electrohydraulic drive. Then, the segment positioning process and the dynamics model of the electrohydraulic system are analyzed theoretically. Segment positioning control system is designed, making comparisons between speed and displacement/angle control in terms of efficiency and precision. Several reference speed run curves are selected to control the segment positioning process. Simulations are carried out to achieve the selected optimal run speed of the segment. The simulation results verify the validity of the proposed control system.

The Vibration Analysis of TBM Tunnelling Parameters Based on Dynamic Model

In TBM tunneling process, the excessive vibration often leads to serious damage in some of TBM main components. Appropriate tunneling parameters such as cutterhead rotation speed, advancing speed, etc have a significant influence on TBM vibration. This study is based on a TBM muti-degree of freedom nonlinear dynamic model. The total force in three direction and torque on cutterhead are calculated according to the real data. The subsequent calculation shows that keeping the rotation speed in the range of 5.88---6.2i??rpm can make the cutterhead vibration at a low level. And the effect of different TBM advancing speed is analyzed under this appropriate rotation speed. It shows that there is no significant change in the axial and vertical vibration condition of cutterhead and main frame with the advancing speed changing from 2---3.2i??m/h but the horizontal vibration obviously increases. The deviation analysis of TBM motors input torque is also carried out. The vibration situation of each pinion is analyzed which determines No 7,8,9 pinions are particularly affected.

Rotation and gate movement compound control of screw conveyor hydraulic system with disturbance compensation

This paper presents a new electro-hydraulic control system for screw conveyor device of shield tunnelling machine. The control model of the system is established, in which arotation and gate movement compound control approach is applied. It utilizes the motor speed feedback to design an outer loop and cylinder velocity feedback as an inner loop to realize flow rate disturbance compensation. Simulations are done and results are presented to verify the effectiveness and rationality of the proposed driving system and its control strategy.

Hierarchical Modeling and Dynamic Analysis of Hoist System in Electric Mining Shovel

The hoist system of electric mining shovel (EMS) always encounters excessive vibration in present work. However, the shortage of suitable dynamic model has been the bottleneck of reducing vibration. In order to analyze the vibration of the EMS hoist system, a coupled dynamic model is proposed using the hierarchical modeling method, which contains couplings of bolt, bear, coupling, rope, and gear mesh. The components were equivalent to mass elements with several nodes corresponding to their structure. Considered helical gears and motors, a dynamic gear transmission model with couplings of bending, torsion, and axes was developed. Based on the dynamic model, the modal characteristics were calculated, and the vibration modes were classified to five types. Under the ripple drive torque simulated by Simulink, the dynamic characteristics of the hoist system in time domain and frequency domain were obtained using numerical integration with the Runge–Kutta method in Matlab. At last, the model validity was verified by contrasting the responses under actual test and the model. The dynamic model and study results can provide support for dynamic characteristic evaluation and dynamic optimization of the EMS hoist system.

Surrogate-Based Multisource Sensitivity Analysis of TBM Driving System

TBM cutterhead driving system is generally an extraordinarily large and complex machine containing lots of parameters; understanding and assessment of its dynamic characteristics are a great challenge as each of these parameters has uncertainty. In this work, a hierarchical modeling method for the dynamic model of the complex gear transmission system is proposed based on the generalized finite element modeling idea. On this basis, the whole machine dynamic model of cutterhead driving system is established; both the characteristics of vibration responses and the meshing force are revealed. Vibration responses under the action of simulated load are estimated and verified by comparing with the data measured on the tunneling field, where the error is about 18%~50%. With the vibration response of the key nodes and the dynamic meshing force for the system dynamic characteristic evaluation index, considering the change of input parameters such as external loads, material parameters, meshing parameters, and coupling parameters, the global parameter sensitivity of system dynamic characteristics is analyzed based on the technology of surrogate model. Finally, variation of dynamic characteristics considering the interaction of polytypic parameters is obtained.

Substitutability analysis of a numerically simulated surface and an actual rough surface

This paper develops a method to generate a numerically simulated surface to replace an actual rough surface, and then the contact performance of the mating surfaces is analyzed. First, we use a 3D surface profilometer to obtain the morphology information of an actual rough surface. Second, a numerically simulated rough surface is generated by using the Gaussian simulation theory, which correspond to the same surface morphology features as the actual rough surface. Third, the reverse engineering technology is used to generate the rough surface model and the interface contact models for the morphology features of the actual rough surface and the numerically simulated surface, respectively. Finally, we compare the contact stiffness and the contact area of the numerically simulated surface and the actual rough surface. The mean errors of the contact pressure for the numerically simulated surface and the actual rough surface are 30.31% (grinding rough surface) and 25.12% (milling rough surface), and the mean errors of the contact area percentage for different contact states are 28.46%, 33.85%, and 35.51% (grinding rough surface) and 27.37%, 21.37%, and 23.42% (milling rough surface), respectively. These results indicate that there are differences between the surface morphology of the numerically simulated surface and the actual rough surface. Therefore, in terms of surface morphology, the numerically simulated surface cannot be used to replace the actual rough surface. This paper lays a theoretical foundation for the accurate substitution of an actual rough surface.This paper develops a method to generate a numerically simulated surface to replace an actual rough surface, and then the contact performance of the mating surfaces is analyzed. First, we use a 3D surface profilometer to obtain the morphology information of an actual rough surface. Second, a numerically simulated rough surface is generated by using the Gaussian simulation theory, which correspond to the same surface morphology features as the actual rough surface. Third, the reverse engineering technology is used to generate the rough surface model and the interface contact models for the morphology features of the actual rough surface and the numerically simulated surface, respectively. Finally, we compare the contact stiffness and the contact area of the numerically simulated surface and the actual rough surface. The mean errors of the contact pressure for the numerically simulated surface and the actual rough surface are 30.31% (grinding rough surface) and 25.12% (milling rough surface), and the mean e...

Workspace analysis of the Π-type thrust mechanism for designing a shield tunneling machine

To avoid interferences between the mechanical parts of the shield tunneling machine and their adjacent objects, the actual workspace of the thrust mechanism ought to be kept as a subspace of its reachable workspace. Hence, method to determine the reachable workspace of the thrust mechanism is the chief problem to be settled. This paper is focused on providing an effective method to determine the reachable workspace of the Π-type thrust mechanism. The main structure of the thrust mechanism is analyzed, and coordinate systems are built up to describe the pose and workspace of the thrust mechanism. Constraint conditions are derived and the formulation of each constraint condition is carried out to facilitate the analysis of the reachable workspace of the thrust mechanism. Meanwhile, a reachable workspace determination algorithm is introduced based on interval analysis method. Finally, applications are carried out on determining the workspace of the Φ6.46m STM to verify the validity of this method.

Dynamic analysis of multi-stage planetary reducer in TBM cutter head driving system

The failure of reducer in tunnel boring machine (TBM) cutter head driving system has not been properly solved owing to the complex influence factors. In this paper, a dynamic model of multi-stage planetary reducer is established and a simulation model of direct torque control (DTC) system is developed to simulate the actual driving torque. By taking account of motor operating characters and nonlinear factors such as time-varying mesh stiffness and transmission error, inherent property and dynamic response of multi-stage planetary reducer are analyzed. Inherent property shows the vibration modes can be classified into the rigid motion mode, rotational vibration mode and planet vibration mode. Dynamic responses show all the vibrations appear in the low frequency domain and approach to the low-order natural frequency. The vibration amplitude of 2th-stage component is the smallest among all the three stages. The modal properties and dynamic response characteristics analyzed in this paper provide effective support for the dynamic design of multi-stage planetary reducer in TBM cutter head driving system.

Sensitivity Analysis of Major Equipment Based on Radial Basis Function Metamodel

A major equipment is generally an extraordinarily large and complex machine containing lots of parameters, understanding and assessment the performance of a major equipment is a great challenge as each of these parameters has uncertainty. In this work, a metamodel-based global sensitivity analysis MBGSA method is proposed for understanding the influence of the parameters on the different outputs. The MBGSA consists of global sensitivity analysis GSA method to identify the impact of each parameters on each of the outputs, moderate-fidelity computational models to mimic the physical model, and metamodeling technique that constructs the mapping between input and output with a limited sampling data. An example on applying the MBGSA in the dynamics analysis of a tunnel boring machines driving system is presented, where hierarchical dynamics model, radial basis function RBF metamodel and Sobols GSA are bonded together to achieve the aim. The results indicate that the proposed MBGSA is available and efficient for the analysis of TBM and thus can be of great help for other large and complex major equipments at the early stage of design.