Modeling and controlling a semi-active nonlinear single-stage vibration isolator using intelligent inverse model of an MR damper

Abstract

Semi-active systems with variable stiffness and damping have demonstrated excellent performance. The aim of this study is to investigate the new configuration of a semi-active single-stage nonlinear vibration isolation system with a Magneto-Rheological (MR) damper to reduce the magnitude of force transmissibility over the both resonant and non-resonant regions. The magnitude of force transmissibility is widely used to performance measurement for the isolation system. In current study, to achieve this reduction, two horizontal springs and one MR damper were added to the isolator. Theoretical analysis reveals that the nonlinear system with MR damper can produce ideal vibration isolation. However, due to the nonlinear characteristics behavior of the MR damper, conventional control algorithms to reach the desired are cumbersome. To address this issue, an artificial intelligent strategy using wavelet network and fuzzy logic controller is considered to be constructed to copy the inverse dynamics of the MR damper and the nonlinear isolator. Accordingly, simulation results demonstrated that the intelligent algorithm has acceptable performance.