Research On Electro-hydraulic Vibration Control Technology Of Track Subgrade Dynamic Response Test System

High speed rail is the main direction of China's railway development.By the end of2015,the national high-speed rail operation mileage has exceeded 19 thousand km.Although China's high-speed railway has developed rapidly,due to the late start,the subgrade dynamic response theory and experimental technology cannot keep up with the development needs of high-speed railway,as the train speed continues to increase,the impact on the roadbed is also increasing.Therefore,it is an urgent problem to be solved in the development of high-speed railways in China by studying the dynamic response law of roadbed through the in-situ test of track subgrade to ensure the stable operation of high-speed trains.This paper intended to combine the characteristics of the track subgrade dynamic response test system and the electro-hydraulic excitation control technology,the research on the electro-hydraulic excitation control strategy of the track subgrade dynamic response test system was carried out as follows:?1?The overall design of the electro-hydraulic system of the track subgrade dynamic response test system was carried out,and the main components technical parameters of the electro-hydraulic system were determined,and the system was divided into two parts:the static pressure cylinder electro-hydraulic proportional system and the dynamic pressure cylinder electro-hydraulic servo system.?2?Established the mathematical model and AMESim model of the electro-hydraulic proportional pressure reducing valve,and it's dynamic and static characteristics were simulated.Proposed a robust output feedback control method for electro-hydraulic proportional pressure reducing valve based on observer,the design structure of observer and the method of obtaining the observer gain L and the controller gain K were given.Based on the identification parameters of the static pressure cylinder electro-hydraulic proportional system AMESim and Simlink co-simulation model,designed a model reference adaptive control algorithm based on robust output feedback control?ROFMRAC?,verified the stability and validity of the algorithm.?3?The dynamic pressure cylinder electro-hydraulic servo system was decomposed into three parts:servo valve system transfer function G_SVK,flow non-linear part g?u?and dynamic pressure cylinder transfer function G_QL.Designed an identification experiment based on AMESim and Simulink co-simulation model of dynamic pressure cylinder electro-hydraulic servo system.Carried out traditional identification based on OE,ARX,Transfer Functions models,least squares,forecast error algorithms by using MATLAB identification toolbox.Proposed a particle swarm adaptive differential evolution algorithm,and the simulation results show that the particle swarm adaptive differential evolution algorithm has higher recognition accuracy and faster convergence speed.According to the transfer function parameters identified by the particle swarm adaptive differential evolution algorithm,the parameters and expressions of the open-loop transfer function of the dynamic cylinder electro-hydraulic servo system were given,and the description of the state equation was finally determined.?4?Constructed the robust sliding mode adaptive control strategy of the dynamic pressure cylinder electro-hydraulic servo system,reduced the influence of parameter uncertainty on the system control performance by using the parameter adaptive estimation,and tracking the target expected variable X_d though converge the sliding mode switching function.Using the double sliding mode structure,respectively constructed the sliding mode adaptive control of the dynamic pressure cylinder displacement subsystem and the backstepping sliding mode adaptive control of the dynamic pressure cylinder output pressure subsystem,obtained an approximate expression of the dynamic pressure cylinder desired displacement?_d1,thereby reducing the number of set desired variable to one.Based on the backstepping sliding mode adaptive control of the dynamic pressure cylinder,proposed a RBF neural network backstepping sliding mode adaptive control by introducing two RBF neural networks to approximate the uncertainties f₁ and f₂ of the system,reduced the number of adaptive parameters to 2,greatly simplified the difficulty of controller parameter design,and verified the control performance of the algorithm by simulation.?5?Build the semi-physical simulation experiment platform of the track subgrade dynamic response test system,developed it's control software using MATLAB,carried out the semi-physical simulation experiments of the static pressure cylinder electro-hydraulicproportionalsystemandthedynamicpressurecylinder electro-hydraulic servo system.The test results show that the control algorithm studied in this paper has good pressure tracking performance,and can provide reference for building high-speed railway track subgrade dynamic response test system.