Active structural acoustic control using structural vibration sensing

In viewing the ANC and ASAC applications to date, much of work has assumed that the sound pressure to be controlled can be measured directly with the microphones. But in some cases, there are impossible to directly measure the quantity to be controlled. In this paper, a methodology for active structural acoustic control using structural vibration sensing has been presented. The output of acceleration sensor is used to predicted sound pressure, and the H∞ robust control algorithm is employed for feedback controller synthesis. The control algorithm is implemented using a DSP (TMS320C30). Experiments are carried out to validate the methodology for attenuation of the internal field in a rectangular enclosure. A sinusoidal noise and a broadband random noise are chosen as the primary excitation in experiments. The results showed that the methodology achieves narrowband attenuation up to 6 dB, and broadband attenuation up to approximately 4 dB in the band 20-300 Hz.