Abstract: The structure and principle of the GMM actuator and the new nozzle flapper servo valve with GMA are presented; its features and key techniques such as temperature compensation, pre-pressure exertion and bias magnetic excitation are discussed, and the dynamic mathematic model is established; the measuring system is built to test its dynamic characteristics, and experiments are carried out on the step response and amplitude frequency response of theflapper-nozzle servo valve based on GMA. It is shown that its rising time is about 1 ms, and its frequency response can reach 680 Hz (–3 dB). The experimental results agree well with the simulation, which proves the correctness of the mathematical model. And the results show that the new electromechanical converter based on GMM, which can take the place of traditional converters like torque motor, can enhance the response and precision of electrohydraulic servo valve.

Key words: Actuator, Dynamic characteristics, Giant magnetostrictive, Nozzle flapper servo valve, Simulation and experiment