Robust Control Of Hydraulic Servo Driving Position Loop System

Based on the continuous casting device in the laboratory of our school, the theory of robust control is applied to position loop system driven by hydraulic servo. It is difficult for a hydraulic servo system to solve the problem of the uncertainties caused by the parameter variety and disturbance. Robust control theory can design a controller whose structure and parameters is unchanged when the controlled system is under the worst conditions, making the closed loop system maintain the performance with uncertainties produced by parameters uncertainty and load disturbance. Therefore, it is very practical to do the research to apply robust control to this system.According to the theoretical analysis of the frequency graph tested by 1250 frequency detector, the mathematical model can be deduced. On the basis of the summary of the characteristics and applications of robust control theory, Ha mixed sensitivity control theory and the regular of choosing the weighting functions, Hn~fi synthesis and the so called extended H?theory are presented in particular. Aiming at the real condition, for effective and forthright robust controller are formulated. Considering the presence of the uncertainties of parameter variety and disturbance, the computer simulation on the basis of the tested mathematical model has been carried on.The study of the control strategies and the results of simulation have proved that these robust controllers have good control abilities both in the dynamic and static state. With the parameter variety, unmodelled dynamic and load disturbance, the controllers can still guarantee the excellent response performance and control accuracy, which proves the feasibility of these control methods. In addition, controllers by model reduction can be realized with simulator or digital system, So they have significant practical value.