Active/Passive Attenuation of Sound in Aircraft Interiors

Active Control eXperts (ACX), Inc. proposes a Phase I research and development effort for the development, conceptual design, and proof-of-concept experiment of a hybrid active/passive sound attenuation system for aircraft interiors. While the attenuation of structural vibration and structure-borne sound using passive means is the current state-of-the-art, and active structural acoustic control (ASAC) has received wide attention in the academic community in the past decade, a functional system combining the relative advantages of both approaches has yet to be developed and tested. A successful development and demonstration of such a system will, therefore, constitute a major innovation in the field of structure-borne sound control. The proposed system is a complete sound attenuation solution, including passive-only, active-only, and hybrid surface mounted patches. These patches are completely encapsulated and ready to be bonded to the fuselage panels. The system further includes error sensor, pre-amplifiers, control implementation electronics, and power electronics for the active and hybrid patches. In addition, a comprehensive design methodology is developed for the optimal placement and sizing of the three types of patches, as well as for control law design. The development of such methodology, backed up by commercial manufacturing capability and solid design techniques, will greatly advance the goal of reducing noise pollution in aircraft interiors.