Mechanism Study Of Two-stage Electro-hydraulic Servo Valve Based On GMM Actuator

Giant Magnetostrictive Material (GMM) is a new type of functional material. It has become a hot topic in high-tech industry in view of its excellent performance,as giant strain, fast response speed, and large output force etc. And its corresponding theory and applications studies are being studied out.In this paper, fully using the excellent performance of GMM, the structure of a new Giant Magnetostrictive Actuator(GMA),used in valve is designed, as well as its static and dynamic theory analysis worked. The mathmatical models are built for simulation analysis,the results of which show that the step rise time Tr and the steady state output force F of GMA are respectively 0.8 ms and 1832N. This means GMA has notable features of high response and large output force.Based on the merits of GMA, the subject aims to improve dynamic characteristics as bandwidth and response speed of traditional electrichydraulic servo valve. In the paper, scheme and concrete structure of a new electrichydraulic servo valve with force feedback is firstly proposed, of which GMA is employed to replace the traditional torque motor, and the specific structure parameters design theory is presented. Secondly,mathematical and dynamic simulation models are built,with a set of raw data introduced for parameters and simulation studies. Finally,simulation results of GMM electrichydraulic servo valve is compared with that of traditional electrichydraulic servo valve. And it shows that of traditional electrichydraulic servo valve, phase marginγ= 83.2°, gain margin Kg=9.26dB, amplitude wideωb=134.3Hz;while of GMM electrichydraulic servo valve, phase marginγ= 85.6°,gain margin Kg=23.5dB, amplitude wideωb=472.6Hz. It is visible that GMM electrichydraulic servo valve has features of faster response speed, higher precision and better stability.Figure [40] table [6] reference [73]...