Design Of The Hydraulic System And Research Of The Control For Electro-hydraulic Servo Dynamic Testing Machine

In modern industrial production, varities of materials, components, machine components or even entire buildings need to be tested to determine their mechanical properties, so the development of the testing machine,to some extent,reflects the the level of a country's industries, especially the development of dynamic testing machine is representative of research situation of the mechanics of materials in this country.In the dynamic testing, testing machine is the most popular equipment in testing the capacity of material.And the the performance of the dynamic testing machine depends largely on the design of the hydraulic system and control method of choice.The task in this paper included designing hydraulic system, calculating the primary parameter of the system, drawing the hydraulic system elementary diagram, selecting the hydraulic elements accroding to the designing demands, based on which the initial construction design of the hydraulic system of the dynamic testing machine was carried out. The transfer function of the system was built and the stability and the dynamic characteristics of the system were analyzed in the basis of the model of four-way valve controlled symmetrical cylinder.Electro-hydraulic servo system has many advantages such as high control precision,fast response speed,big output power,disposing signal agilely,and achiecing various parameters' feedback easily and so on. In general, the normal PID can meet the requires of the control,but overshoot of the normal PID control is too large,so can not achieve precise control of nonlinear systems. That decided mainly by the typical unknown and uncertain nonlinear system of electro-hydraulic servo system,which gains precise maths model of system difficulty.Though the maths model can be set up,its model is always so complex that it makes the analysis,design and practice of the traditional control method baded on precise maths model more difficult. However, fuzzy PID controller can finish on-line self-regulation and self-optimisum to PID parameters. In the performance aspect of the system dynamic and static states, it gets a better control effect, the control accuracy is very high.This paper designed an fuzzy controller based on neural network is presented that integarates fuzzy control with NN.A simulation model of typical system is realized successfully with Simulink in MATLAB. The result of dynamic simulation meet the designing demands.