Published in Proceedings of the 2000 ASME International Mechanical Engineering Congress and Exposition, Volume 61, November 5, 2000, pages 179-186. Copyright © 2000 ASME. Please contact ASME at firstname.lastname@example.org for permission to reuse this article. Publisher website: http://store.asme.org
NOTE: At the time of publication, the author Charles Birdsong was not yet affiliated with Cal Poly.
Two electro-mechanical actuators are examined for a semi-active Helmholtz resonator acoustic device. The device is used to reflect narrow band noise back to the source in an acoustic duct. The controller and actuator are used to tune the system on-line allowing optimum performance over a range of operating conditions. Actuator. dynamics play an important role in the controller design and the operation of the device. Two variations of an electro-mechanical actuator are considered here. The first uses a dual voice coil speaker with local feedback compensation and the second uses the same speaker without the compensation. It is shown that both arrangements are effective but with competing advantages. The compensated actuator provides more control authority but adds considerable background noise while the uncompensated actuator provides less control authority but adds no background noise. The choice of actuator depends on the noise control objectives of the particular application.