Control Method Research Of Electro-hydraulic Force Loading System

With the development of modern industrial society,research on geotechnical properties has spawned.At present,studying the relationship between micro structure and macro property,namely the relationship between the micro scale and the real scale,has been a so important part of rock mechanical research.So the key is to simulate the loading state under natural environment.In order to study the rock sample characteristics under force loading simultaneously,we adopt the eletro-hydraulic force loading system combined with the industrial CT.Use industrial CT technology to see the inner structure of rock in the breaking process,that can help to analyze the mechanical properties.That combination can realize the dynamic monitoring of the rock loading process at a real-time synchronization.In the loading process,the force will affect the rock inter-structure to change,so the control of electro-hydraulic loading system is very important.In this paper,in order to further improve the performance and control precision of force loading system,the force control method has been studied.First of all,the current situation of electric hydraulic loading system and the development of the control methods have been researched.And the main content of research work has been list according to the functional requirements.Secondly,analyze the electro-hydraulic loading system working principle,build the mathematical model of the system,determine the type of pump,valve and cylinder,and related parameters,get the system transfer function,analyze the system features under the environment of Matlab/simulink,and research control strategy according to the results of the analysis.Furthermore,introduce into the traditional PID control based on the ideal model.Meanwhile,in consideration of actual work situation,industrial computed tomography(CT)rotation will cause disturbance and nonlinear problems existing in hydraulic system,thus control method that can solve the problem of uncertainty,has anti-jamming ability and meet the dynamic tracking performance of system is introduced,namely quantitative feedback theory(QFT),so we adopt the control method and design the controller based on QFT for loading system.Finally,build the test bench,and do the experiment to analyze the influence of the controller on the system dynamic performance.Analyze the effect of the controller according to the experimental data and make corresponding changes,to further improve the control effect of the controller.The experiment results shows the controller based on quantitative feedback theory greatly improve system dynamic performance,and satisfy the requirements.