Dissipative Feedback Control of a Reverberant Enclosure Using a Constant Volume Velocity Source

Abstract

Loudspeakers are commonly used as actuators in active noise control applications. In this work, a loudspeaker is compensated so that it approximates a constant volume velocity source over the piston mode frequency range (up to approximately 600 Hz). This moves the speaker dynamics out of the desired control bandwidth (20 Hz–500 Hz). A static gain feedback controller using the compensated speaker is applied to a rigid-wall enclosure to reduce the acoustic potential energy of the system while being subjected to low frequency broadband noise. The results are compared to the performance of a similar control law using an uncompensated speaker, and a model based H2 optimal controller. The results indicate that the controller using the compensated speaker offers definite advantages in terms of stability and performance, while requiring a minimal amount of control effort.