Fuzzy internal model control for electro-hydraulic servo systems

Electro-hydraulic servo systems have been frequently used in the position servo system in industry and other relative field, because of their high power capability, fast response characteristics and good positioning capability. Hydraulic servo systems, however, inherently have many uncertainties, time varying and highly nonlinear characteristics due to the flow-pressure relationship, oil leakage, oil temperature variation, load disturbances and so on. In this paper a method for control of Electro-hydraulic servo systems is prompted in which a foreword internal model controller and a feedback fuzzy controller are designed. The transfer-function-based factorization approach in the frequency domain is used to analyse the stability of the system. Simulation experiments show better dynamic performance and disturbance rejection.