Research On Attitude Modeling And Control Of Shiled Machine During Tunneling Process

In recent years,the demand of urban traffic road construction is growing rapidly,however,the available land resources are less and less,so the subway tunnel has become the development trend of urban traffic construction in the future.Shield tunneling technology has become the first choice of subway tunnel construction because of its advantages such as fast excavation speed,small impact on ground buildings and existing roads.In the construction process,the shield machine needs to advance according to the pre-designed track,with strict accuracy requirements.However,in the process of excavation,due to the complex and changeable geological conditions and the influence of random strong load,the actual excavation route often deviates from the designed excavation axis.If the tunneling track can not be corrected in time and quickly,the shield machine will run along the designed axis,which will affect the construction progress,even lead to serious accidents and even the failure of the whole project.Therefore,it has practical significance to adopt appropriate control strategy to achieve accurate and fast attitude correction control.At present,most of the shield attitude correction control is based on the driver's experience,manual control,or PID control based on experience,which is difficult to control the attitude in real time and effectively,and the control effect is not very ideal,so it is easy to form the situation of snake shaped deviation correction.In this paper,the modeling and control strategy of the attitude control system in shield construction are analyzed and studied,hoping to help the attitude control of shield.The main research work is as follows:1.The model of shield attitude control system is established.In order to control the driving track of shield quickly and accurately,it is necessary to control the hydraulic propulsion system accurately.According to a large number of references,it is necessary to control the pressure and flow of the system accurately in the construction process to ensure that the control of pressure and flow can have the characteristics of rapid response speed and small fluctuation.Therefore,the hydraulic flow required by the hydraulic propulsion system is taken as the input,and the pressure and propulsion speed of the hydraulic propulsion system are taken as the output.The mathematical model of the attitude control system is established.2.Based on the study of the relationship between the structure of shield machine and the attitude control of shield machine by hydraulic propulsion system,the factors that cause the shield machine to deviate from the design trajectory are analyzed,and a new attitude control strategy of shield machine based on Improved Particle Swarm Optimization nonlinear PID is proposed.Using particle swarm optimization algorithm to optimize the parameters of nonlinear PID controller,the optimized nonlinear PID controller is designed.3.In this paper,the traditional PID,nonlinear PID and improved particle swarm optimization nonlinear PID algorithm are used to study the attitude control of shield tunneling process.By combining the designed controller with the established attitude correction model,the pressure,speed and track tracking of the hydraulic propulsion system can be controlled.Through the simulation of MATLAB / Simulink,the designed controller can control the pressure and speed of the system well,and can track the given shield driving track quickly.It has the advantages of small overshoot,high control accuracy and good robustness.