Brian H. Houston
Douglas M. Photiadis
J. A. Bucaro
Robert D. Corsaro
Naval Res. Lab., Washington, DC 20375-5350
Larry A. Kraus
SFA, Inc., Landover, MD 20785
The use of active control of acoustic impedance is of general interest due to a variety of potential defense and civilian applications. These include control systems to minimize aircraft and rocket payload section interior acoustic levels. Control of impedance at a boundary is one of the most challenging in active control due to the collocation of sensors and actuators (implicit in this is feedback control). Some of the technical issues include---the selection of the appropriate physical control law, the degree of inter-connectivity (local versus global control), device linearity, component and processor delays, system identification, nonminimal phase-zero constraints the coupling matrix, and performance versus robustness tradeoffs. Recently, new active boundary control (ABC) experiments were carried out at NRL's Laboratory for Structural Acoustics on a 15-tile array system. The results of these experiments will be discussed with a focus on the application of H[sub (infinity)] control engineering techniques and the physics involved.