Experiment and design of a hybrid piezoelectric air-spring vibration isolation system

Abstract

To address the issue of low-frequency micro-vibrations affecting the performance of large precision instruments, this paper proposes a hybrid active-passive vibration isolation system. While air springs are widely elected as excellent passive isolation elements, their nonlinear characteristics and resonance limit their effectiveness in isolating low-frequency vibrations. To enhance the vibration isolation performance, piezoelectric actuators are serially connected to the air springs. Theoretical modeling of the air spring stiffness and natural frequency is conducted, followed by a further analysis of its transmissibility using the multiple scales method. Due to the nonlinear nature of the vibration isolation system, a minimum variance self-tuning control is employed to adjust controller parameters in real-time. To validate the isolation performance of the hybrid isolator, tests and experiments are conducted. The experimental results demonstrate that the hybrid isolator exhibits good control effectiveness against both single-frequency and random disturbances near resonance frequencies, affirming its practicality and efficacy. This system holds promising application prospects in vibration isolation for experimental tables, ships, and large-scale equipment.