Research And Design On Shield Tunneling Simulation System

Shield tunneling machine is a kind of engineering machine mainly used for digging tunnels, which is widely used in these areas such as subway, road, city planning, pipeline tunnel. With the development of the economy, the growth of the needs for the underground programs, the number of the shield tunneling machine will be in a great need in the next few years, but the relevant core technology is monopolized by Germany, Japan, and European etc. In recent years, we mainly study and absorb the core technology of the shield machine by importing the shield tunneling machine abroad. In order to achieve tailor-made design, it is neccesary to make sure the various relationships of soil load, where the shield machine works. Due to the complexity of work environment, randomness and variability of the soil load, the mathematical model of the soil load is still immature. Considering the high cost, complicated structure, it is necessary to set up the test rig to study the core technology which will help us to master the core technology in a wide aspect, solve the key problem, reduce the risk on field experiments, cut down the cost of manufacturing the whole shield machine.Based on the research on the shield tunneling machine, a test rig which is simple to operate and highly integrated is set up in order to fulfill the proposed targets in national 973 projects. From the test rig, energy analysis on the frequency control and variable displacement speed of the cutter system at different load conditions will be done, the soil load model of the shield machine will be concluded, the response time when the shield machine switches from one mode to another mode will studied, the law of force and energy transfer in the shield machine will be revealed. On this basis, considering the variability and randomness of the load of shield machine, the synchronization of the thrust system, and the response of the cutter system, the relationship among the different system of the shield machine are studied. The main contents are as follows:In the first chapter, the work principle of the shield tunneling machine is firstly introduced, and then the historical and present development state of the shield tunneling machine is described. Moreover the established test rig on the shield tunneling machine is elaborated. Finally the significance and main research content of this subject is discussed.In the second chapter, the test rig which uses hydraulic load, inertial load and mechanical load to simulate the load of the shield machine, and a selection of key hydraulic components are firstly introduced. Then the three-dimensional integrated design of the critical slip of the hydraulic system and the overall layout of the test rig is elaborated by use of Solidworks software. Furthermore the principal design of the electronic control parts is finished. The interface design of the test rig is accomplished using the Lab VIEW software, finally.In the third chapter, synchronization of the hydraulic cylinders of the trust systems was studied. A coordinating control method for flow synchronization was presented at first, and then the performance of pressure synchronization and flow synchronization was compared using the AMESim software. Furthermore the work principal of an adaptive PID controller is introduced. According to the actual parameter and request of system, the simulation model was built in AMESim, and a expert-PID control model based on the control of flow by controlling thrust displacement was built in Matlab through the interface programme between AMESim and Matlab, Finally.The fourth chapter is mainly concerned with the technology about how to improve the response of the cutter system when the shield machine encounters a sudden load. By analyzing the conventional control method of the displacement of the pump with the electrical control, a new control method named as hydraulic controlled and regulated directly method is proposed. In order to make a comparison between the two control methods, the two simulation models of pumps are constructed in AMESim software. At last, the stroking mechanism of the pump is designed using the Solidworks software.In the fifth chapter, thrust system shield tunneling machine, cutter system, screw conveyor system are modeled based on soil Mechanics and force analysis of the whole part at first. Then the relationship among the pressure of thrust system and cutter system, flow of thrust system and cutter system is concluded and testified using the experimental data. At last, an earth pressure balance model with Forward-Backward control method is built by detecting real-time the thrust pressure, speed of cutter head and pressure in soil room and controlling the speed of screw conveyor.