Model Identification And Zero Phase Error Control Of Electro-hydraulic Servo System

The background of this thesis is electro-hydraulic fatigue testing machine project of Beijing science and technique committee,the control object is dissymmetrical hydraulic cylinder system.Aiming at the phase error in position system of fatigue testing machine it designed system identification experiment to get the system mathematic model by using least square identification method and it revised this model later.The zero phase error controller(ZPEC)was designed based on this model and zero phase error control algorithm.To do experiment research it programmed the control software under WINCE operate system.In this thesis,it programmed the least square method in C++ code by both using VC6 and MATLAB development environment and developed the control software package for system identification experiment.The system identification model was revised by comparing with the response of real system,the result proved the validity of the identification model.Based on reverse system design method,it designed ZPEC to resolve the phase error problem.To research this control method it simulated the system with this ZPEC, the result prove the validity of ZPEC.The hardware of digital controller was designed in this thesis,a WINCE operate system and control software was developed by using EVC developing environment.To insure the accuracy of control and meet the requirement of real time it designed parameter adaptive control algorithms which can adjust the gain adaptively.In the end of this thesis,it did research work on test bench and processed the result data by using wavelet filter,the result proved the validity of zero phase error control method in electro-hydraulic servo system.