Research On The Self-balancing Rock Press And Hydraulic Loading Control System

In recent years,due to the rapid development of engineering construction in China,the engineering geological conditions are becoming more and more complicated,the tunnel is developing to the big section,and the mine roadway is developing deep in the kilometer.There are increasing incidents of some geological disasters.The rocks in deep strata are in a complex and multiple-field coupling environment,under the action of temperature,pressure,magnetic field,gas-liquid and other factors,the study of rock permeability and mechanical properties is an unprecedented challenge for geotechnical engineering workers.Three-axis Press is an important tool to study the mechanical properties of rock.Only by simulating the state of underground environment more accurately can we understand the microscopic movement law of rock underground.The main part of the Rock Triaxial Press has the pressure chamber part and the loading system part of the lower loading cylinder.The pressure chamber part can simulate the real environment of the rock underground,the loading system can detect what kind of force the rock is subjected to,the displacement and deformation,and so on,its performance directly determines the overall working performance of the test system.Based on the conventional three-axis rock mechanics Press,this paper mainly completes the following work:1)The new pressure chamber system is designed,and the materials used in the pressure chamber are selected.The new type of lower self-balancing pressure chamber ensures the separation of axial loading and confining pressure loading,makes the two not affect each other,reduces the deformation of the pressure chamber,increases the stiffness of the pressure chamber,and analyzes the mechanical simulation strength of the main parts inside the pressure chamber.2)The new rock deformation measuring device is designed,which solves the error caused by the deformation and end effect of each component,and completes the whole design of the self-balancing rock press.3)This paper introduces the working principle of the hydraulic loading system,because the loading servo cylinder is an asymmetric cylinder,so we use the principle of asymmetric cylinder to model the axial loading system mathematically,and make an analysis of the convergence and stability of the system.4)The iterative learning control method is selected to effectively solve the problems of non-linearity,modeling difficulty,strong cross coupling,parameter uncertainty and high precision synchronous tracking of hydraulic servo system,so that the system can maintain good stability and robustness.5)Using AMESim and Simulink for joint simulation,the simulation results show that the control precision of the controller system designed by iterative learning control method meets the requirements.For the load waveform test of hydraulic servo loading system,it can meet the requirement of synchronous tracking error well.By comparing and analyzing the test results of the prototype,the conclusion of the joint simulation is verified.Some studies of this paper provide reference for the improvement of the three-axis rock press,and also have certain reference significance for the application of the Iterative learning control form in the test press...