Design of an EML Actuator and Experimental Verification of Active-Passive Broadband Micro-Vibration Isolation

Space micro-vibration disturbance sources are distributed in low-, medium- and high- frequency bands, and traditional actuators are difficult to meet this ultrawide frequency vibration isolation requirement. Therefore, a method of integrated active-passive broadband vibration isolation based on electric-magnetic-liquid (EML) coupling system was proposed, which leverages an electromagnetic actuator for active vibration control at low-frequencies and employs liquid-damping for passive vibration control at medium- and high- frequencies. Firstly, the overall design of the EML coupling system, including detailed structural design for both the electromagnetic actuator and liquid-damping, were carried out. Secondly, the magnetic circuit optimization for electromagnetic actuator was conducted by adopting finite element method (FEM) and sequential quadratic programming (SQP) algorithm, with the goal of maximizing the electromagnetic output force. Thirdly, dynamic modeling and performance simulation analysis of liquid damping were conducted. Finally, the prototype was fabricated and assembled, and the ground experimental platform was built. The experimental results demonstrated that, in the range of 2–11 Hz, the active-passive integrated isolation effect was markedly superior to that of the purely passive one, which verified the effectiveness of this EML coupling isolation methodology.