Active-passive hybrid vibration isolation with magnetic negative stiffness isolator based on Maxwell normal stress

A new magnetic negative stiffness isolator based on Maxwell normal stress is proposed to improve the low-frequency vibration isolation performance of a system with high static support stiffness. The isolator can provide high negative stiffness maintaining compact size and light weight. The negative stiffness characteristic of the isolator was first modeled through magnetic circuit analysis. Then, the passive vibration isolation performance of the isolator was validated experimentally. Active control was then introduced into the isolation system to improve its ability to adapt to external disturbances and suppress the system's resonance response. The governing equation of the active-passive hybrid vibration isolation system was established. The simulated and experimental results showed that the magnetic negative stiffness isolator with active-passive hybrid control can greatly reduce the isolation initial frequency and significantly suppress the system resonance response in comparison with passive methods. The present work provides a promising way to realize low-frequency broad-band vibration isolation for systems with high static support stiffness. (C) 2019 Elsevier Ltd. All rights reserved.