Simulation Modeling And Analysis Of Hydraulic System Of Shield Machine

In order to prevent the.muddy pipe system failure because of the bulk boulder from cutter head when the shield machine works in the tunnel operation,the lithotripter which is arranged at the inlet of the muddy pipe system is used to break the bulk boulder.The head of the shield machine will produce a large vibration phenomenon when the lithotripter is working,which is mainly caused by the secondary crash of the bulk boulder by the lithotripter.The tunnel efficiency and lifetime of shield machine are greatly affected because the vibration of the shield head is more severe,the fatigue damage is more serious at the joint of the lithotripter and hydraulic cylinder.Aiming at this problem,this paper studies how to restrain the vibration and shock of the joint of lithotripter and hydraulic cylinder in the start and crush stage by combining the structural parameters optimization of hydraulic system with the compensation control of self-tuning algorithm.The main research work of this paper is as follow:(1)Firstly,the working principle of lithotripter hydraulic system is introduced in details,and the simulation model of lithotripter hydraulic system is built based on AMESim.The size of hydraulic system model is set up according to the actual structure size of hydraulic components,and the working situation of the lithotripter is reflected through the model operation.(2)The solid structure of the lithotripter is modeled and assembled based on the 3D modeling software.The 3D model is introduced into the dynamics simulation and analysis software Adams,and the speed of the hydraulic cylinder which is simulated with the software AMESim as a driver,and the material property,density,constraint and load which are in accord with the practice are set,and the dynamic simulation and the stress analysis are carried out on the hinge of the jaw plate and the hydraulic cylinder.(3)The acceleration of the hydraulic cylinder as the criterion of vibration and shock based on the dynamic characteristic analysis.The sensitive structural parameters which affect the dynamic characteristics of the lithotripter under the starting stage are found out.The influence degree of the sensitive structure parameters on the start stage of the system is analyzed by the multi-factors orthogonal test method,and the optimum combination of the sensitive structure parameters is optimized.(4)According to the principle of self-tuning control and the practical application background of this paper,the self-tuning fuzzy PID controller is designed.The AMESim-Simulink joint simulation model of hydraulic system is established with the joint simulation technology,the start and crush stage of the system are simulated.Through comparing the simulation results,it is analyzed that the existence of the self-tuning fuzzy PID controller will affect the control and compensation function of the dynamic characteristics of the lithotripter.(5)A prototype experimental of the lithotripter is designed to verify the actual suppression effect of structural parameters optimization and control compensation algorithm on the vibration and shock.