A novel semi-active switching control scheme for magnetorheological elastomer-based vibration isolator under dynamic input saturation

摘要

It is still a challenge to guarantee a robust performance of magnetorheological elastomer (MRE)-based isolators under complex and frequency-varying base excitation, due to the highly nonlinear dynamic behavior of the MRE. The dynamic behavior of the MRE-based isolator should be considered properly in the control law to ensure the effectiveness of the MRE-based isolator. In this research study, first a dynamic modeling of an MRE-based isolator is established to formulate the actuation (transmitted) force of the MRE-based isolator. The MRE induced actuation force is limited to a dynamic input saturation and depends on the applied magnetic field density, geometry of the MRE layers, viscoelastic properties of the MREs and system states. Subsequently, a novel semi-active switching control scheme, which adopts the fastest convergence speed of driving the virtual energy toward zero based on Lyapunov theory, is proposed to improve the mitigation performance of the MRE-based isolator. The proposed control law requires less modeling information and does not require a time-consuming adjustment of control parameters, thereby possessing a broad application prospect in MRE-based isolators. Finally, the performance of the MRE-based isolator using the developed control strategy is compared with those based on passive control with different levels of constant magnetic field density, ON-OFF control and PD control under the harmonic, random and bump shock base excitation. The results show a robust and superior performance of the developed vibration control strategy.