Acoustic-centric modal filter design for active noise control

Abstract

A modal filtering approach to sensing system design in free space active noise control offers the potential of reconciling two design ideals: sensing a global error criterion while using a limited number of inputs to the control system. Previous work in this area has taken a vibration-centric approach to modal filtering, working with either structural elements or structural modes. The requirement of detailed structural knowledge inherent in these approaches limits the prospects of moving the sensing systems from simulation or small-scale laboratory implementations to more practical problems. Presented here is an acoustic-centric approach that overcomes the need for detailed knowledge of the structure, facilitating implementation for larger and/or more practical problems. The approach also overcomes the need for system re-design with each new target structure. © 2004 Elsevier Ltd. All rights reserved.