Active Suppression of Plate Vibration Excited by Acoustic Pressure in a Chamber: Cluster-mode Approach

Abstract

A cluster-mode control analysis of coupled structural and acoustic vibrations of a double-wall chamber system, which consists of four solid walls and elastic outer and inner plates placed opposite, as well as air occupying the chamber is presented in this article. The outer plate is externally driven to induce acoustic vibrations in the chamber, which consequently force the inner plate to oscillate. To understand complicated mechanical coupling of the structural and acoustic vibrations, the cluster-mode approach of filtering, sensing, and actuating is used. The coupled vibrations of the system are analytically grouped into four clusters in such a way that each clustered mode can be treated independently. As one may have a simpler view on the coupling in each cluster, it is easier to overview the coupled behaviors and control the oscillation of the system effectively. In numerical analysis, a feedforward control to the inner plate and a direct velocity feedback control (DVFBC) to the outer plate are applied. Numerical results show that the introduction of the cluster-mode filtering is useful in comprehending the complicated mechanical behavior of the coupled system. The hybrid use of optimum clustered feedforward control and clustered DVFBC has well suppressed the vibration of the internal plate.