A New Minimization Quantity for Global Active Structural / Acoustic Control

Brigham Young University, Provo UT

Investigators

Abstract

The research objective of this award is to develop an active noise control method that senses and controls a structure in a manner that minimizes acoustic radiation. There are numerous applications where it is desirable to reduce noise radiated from vibrating structures into an enclosed acoustic field, such as a vehicle cabin. The research builds on a newly developed measure of vibration that is referred to as composite velocity. The use of standard vibration measurements for active control systems does not result in a minimization of acoustic radiation, since the structural vibration and the radiated power are not directly correlated. However, composite velocity is directly correlated with acoustic radiation. Furthermore, the composite velocity is quite uniform across the structure, making the method less sensitive to sensor location. These properties will be exploited in complex structures, and the method will be developed for structures including ribbed plates and cylindrical shells, which are typical for important applications such as vehicles and aircraft fuselages. If successful, the results of this research will provide a compact, efficient solution for reducing noise exposure in numerous applications, such as vehicle cabins (automobiles, locomotive engines, and heavy equipment cabins) as well as aircraft cabins. The advantage of this active control approach is that there is little sensitivity to sensor location (meaning the sensor can largely be placed wherever convenient), the system is compact, and the method achieves global reduction of the enclosed sound field. This will result in improved communication, increased comfort, reduced noise fatigue, and improved safety for vehicle occupants. Graduate and undergraduate science and engineering students will benefit through involvement in the research and classroom instruction based on the research. Results will be disseminated to the scientific community, allowing others to explore and further develop the method, as well as providing opportunities for commercial development.