Active control of radiation from vibrating structures.

Abstract

In many applications, one faces the challenge of controlling the sound field that is produced by a vibrating structure. There are two general approaches that can be taken to control such a sound field. The first approach involves directly controlling the acoustic field by means of additional acoustic sources, such as loudspeakers, which are controlled in such a way so as to minimize the noise in the acoustic field. The second approach involves controlling the acoustic field indirectly, in that one can control the structural vibration field in a manner so as to minimize the radiation from the structure. This paper will outline some of the possible methods of using active vibration control of the structure so as to minimize the acoustic radiation from the structure. The physical mechanisms that lead to acoustic radiation and that can be controlled by means of an active vibration control system will be discussed. Research issues related to each active control approach, and the conditions that may make one particular approach for implementing active control preferable over other choices will also be discussed.