Supervision System Design For Earth Pressure Balance Shields

Most supervision systems used in domestic are imported from aboard, technology blockade is very serious. And currently most domestic construction operation is manual control whose control precision is low and risk is high. With the aim of ensuring the safety of shielding process, highly automated, full-featured, this paper has especially important practical engineering significance.Firstly, this paper introduces the composition and the working process of shield machine, combined with the actual needs of the construction, analyze the demands for this supervision system. In order to achieve automatic control of shield machines, this supervision system should have the following functions:data acquisition, data display, data management, alarm, simulation and calculation model and advanced control of shield machine. In order to achieve the required functionality, the overall structure of the supervision system is divided into four layers:tunneling monitoring layer, data management layer, simulation layer and information remote release layer. Among them, tunneling monitoring layer controls and monitors the process with WinCC and collects data with PLC; data management layer is based on OPC protocol combined with real time data base and relational data base, which solves the difficult problem of shield machine system data management; in simulation layer, Matlab is a calculated tool in the background which communicates with the relational data base and WinCC with OPC protocol, under the help of this layer, the implementation of advanced control is convenient; information remote release layer provides remote data web application, so that the remote operator can view and deal with real time information. In addition, in order to facilitate system development, this system is divided into six modules:user management module, shield machine subsystem module, redundancy module, database module, calculation and simulation module and communication module. In the view of the low manual control precision of the sealed earth pressure, this paper establish earth pressure prediction model used BP neural network and achieve real-time communication between Matlab and WinCC. This study provides more accurate reference information for the operator in decision-making program. The paper uses WinCC TAG Simulator function to test the system and the validity of earth pressure prediction model, the results show that:the system design is reasonable and practicable, meeting monitoring requirements the shield tunneling process.