Micro-vibration suppressing using electromagnetic absorber and magnetostrictive isolator combined platform

Abstract

This paper presents an electromagnetic absorber and magnetostrictive isolator (EAMI) combined platform with passive absorbers for vertical micro-vibration suppressing in low-medium frequency band, and this platform holds the both advantages of absorber’s convenient installation and giant magnetostrictive actuator (GMA) isolator’s large bearing capacity. The electromagnetic stiffness can be almost linearly tuned, and the nonlinearity of structural stiffness can be reduced significantly using the helical structural design. The double output GMA is developed to satisfy the motion consistency of each displacement amplifier’s output point, and the parameters of GMAs and amplifiers are determined by numerical simulations. The electromagnetic absorber and magnetostrictive isolator are controlled separately. The frequency estimator is used to achieve variable frequency vibration suppressing for the electromagnetic absorber, and the modified generalized prediction control algorithm (MGPC) is adopted to realize the precision pointing and vibration control for the magnetostrictive isolator. Passive absorbers are designed to achieve significantly vibration attenuation in a narrow bandwidth. The experimental test results indicate that the vibration amplitude of 100 kg load can be significantly attenuated more than 16 dB and 19 dB by the magnetostrictive isolator and passive absorbers, respectively. Meanwhile, the electromagnetic absorber can suppress variable frequency vibration of 0.25 Hz frequency resolution more than 8 dB.