Research on impedance network modeling and output characteristics of magnetostrictive electro-hydraulic actuator

Abstract

Magnetostrictive electro-hydraulic actuator (M-EHA) is a highly integrated hydraulic servo device with very complex movement and conduction processes. The output performance could be affected by many factors. To design such actuator and analyze its performance with simple and efficient analysis method, an M-EHA impedance network modeling method considering the fluid inertia and the compressibility is proposed. The M-EHA components behavior were respectively described based on the fluid flow continuous equation, the pressure drop equation, and the dynamic motion equation. By employing the electro-mechanical and electro-hydraulic analogies, the impedance network of M-EHA is established and the output performance is analyzed. Through independent impedance analysis of different structures of the M-EHA, the natural frequency and dynamic characteristics of manifold, hydraulic cylinder, and accumulator are obtained respectively, and this provides the theoretical guidance for optimizing the actuator structure and performance. The influence of driving frequency, system bias, and load on the output performance of M-EHA are studied based on the impedance network. Simulations show that the best output performance is obtained under 593 Hz with 1.2 MPa system bias pressure, and the flow is 0.52 L/min.

Keywords

• magnetostrictive electro-hydraulic actuator
• impedance network
• output performance
• electro-mechanical analogy
• electro-hydraulic analogy