Model Reference Control for Bulkhead Pressure of EPB Shield in Tunneling

The supporting pressure is achieved through control of the incoming and outgoing materials in the head chamber in shield tunneling, i.e., through regulation of the screw conveyor rotation, thrust force of jacks and the excavation advance rate. The discrete state equation of controlling system is derived based on mechanical equilibrium principle. The objective function of model reference control for bulkhead pressure is proposed. Optimal controlled variables are determined by using weighted least square method. The numerical simulation results show that bulkhead pressure of shield machine can be controlled by individually adjusting speed of screw conveyor in most cases, and the regulation of thrust force of jacks plays a secondary role for controlling bulkhead pressure.