A novel semi-active quasi-zero stiffness vibration isolation system using a constant-force magnetic spring and an electromagnetic linear motor

Abstract

The performance of conventional vibration isolation systems are limited by the stiffness of the mount required to support the weight of the payload. A potential method for addressing this limitation is to use the phenomenon of quasi-zero stiffness (QZS), which results in a high static stiffness to support the weight of payload and a low dynamic stiffness to achieve a wider vibration isolation range. Recently, QZS systems with various negative stiffness elements and mechanical configurations have been proposed and studied. This paper presents the design and analysis of a novel semi-active QZS vibration isolation system using a commercial constant-force magnetic spring and an electromagnetic linear motor. The proposed system combines the advantages of both passive QZS systems and active damping control, and therefore is cost-effective, energy-efficient, and has the potential of a large bandwidth of vibration isolation as well as a low resonance peak. The use of a commercial magnetic spring not only allows the system to support a large static payload over a wide range of travel but also simplifies the design. In this paper, the design, identification and control aspects of the proposed vibration isolation system are discussed and the system performance is investigated theoretically and experimentally.