Theoretical and Experimental Analysis of a Skyhook Damper for Active Control of Sound Transmission
* Presenting author
In this paper active control of sound transmission through a double panel is considered. The active control system consists of one accelerometer mounted on the radiating panel whose time-integrated and amplified output is used as the error signal to drive a voice-coil actuator that reacts between the source and the radiating panel. Effects of one such active damper in the centre of the double panel system are considered, although, in principle, it could be repeated in the x-y plane and then used in the centralised, distributed or a decentralised manner. Theoretical and an experimental results are presented and compared. In the theoretical part, the mobility matrix model is used to investigate the stability of the feedback loop and to calculate the sound transmission ratio with and without control. It is shown that large reductions of the sound transmission ratio are possible, however only if the natural frequency of the fundamental source panel mode is higher than the natural frequency of the fundamental radiating panel mode. This is also discussed and shown analytically on a reduced order model. The experimental part of the study is carried out on the prototype active panel system and the measured result fully corroborate theoretical predictions.