The effects of internal resonances in vibration isolators under absolute velocity feedback control

Abstract

Conventional vibration isolators are usually assumed to be massless for modelling purposes, which tends to overestimate the isolator performance because the internal resonances (IRs) due to the inertia of the isolator are neglected. Previous research on the IR problem does not clarify all the characteristics of distributed parameter isolators. Furthermore, with the development of active vibration isolation, which can avoid the compromise in the choice of damping in conventional passive isolation systems, the effects of IRs in isolators on the control performance and stability for commonly used control strategies need to be quantified. In this study the effects of IRs on the control performance and stability of an absolute velocity feedback (AVF) control system are presented. A stability condition for AVF control system is proposed and a simple approach to stabilize the control system is studied. Experimental work to validate the theoretical results is also presented