Research Of Thrust Hydraulic System Of Earth Pressure Balance Shield Machine

Along with the rapid development of the city metro in our country, tunnel construction technology with shield is more and more being developed and applied, because of its unique characteristics and advantages such as intelligence, safety and quickness, etc. The shield tunnelling is a type of complicated engineering equipment that is widely used in the underground tunnel excavation, which is related with subjects of machinery, electronics, hydraulics, measurement and control. The thrust system is a key part of the shield tunnelling machine and the exact control of it is the key to whether the shield machine can work normally.The paper depicted a survey of shield machine's history on domestic and international current status, elucidated its meaning of its development in our nation. Based on the investigation and research on shield machine's technology, the paper designed the hydraulic thrust system. According to the tunnelling requirements of shield, the zone control method is adopted to control the thrust hydraulic cylinders. Speed and pressure of thrust hydraulic cylinders were real-time controlled by applying electro-hydraulic proportional control technology and proportional pressure and flow compound control strategy was also put forward.The paper builds up the mathematical models of the compound control system for thrust pressure and thrust velocity, carries out the simulations of open-loop control system, PID control system, self-adaptive fuzzy PID control system, using MATLAB according to the models. The results shows both the PID control and self-adaptive fuzzy control can highlight the quality of the control. However in the performance aspect of the system dynamic and static states, it gets a better control effect; the control accuracy is very high. The self-adaptation and self-study function are comparably strong.The paper designs the control system of the thrust hydraulic system of the shield machine using PLC, and realizes the control of the mode of thrust and shield erector.