Active Control of Quazi-Zero Stiffness Isolators

Various quasi-zero stiffness (QZS) passive vibration isolators were developed for protecting a system against vibration. This paper presents active control of a QZS vibration isolator. First, a unified model of QZS passive vibration isolators with symmetric nonlinearity is presented, which is a Duffing equation with odd power polynomials. Based the unified model, vertical and horizontal actuations are proposed for active control of QZS isolators. Finally, active control scheme for a QZS vibration isolator are presented and the isolation performances are compared with simulations.