Active interior acoustics control of bandlimited disturbances

Extensions of our previous analytical and experimental investigations into active control of bandlimited disturbances in a three-dimensional enclosure are presented. The frequency range of the bandlimited disturbance is chosen to encompass structural and/or enclosure resonances. Distributed piezoceramic actuators and distributed polyvinylidene fluoride (PVDF) sensors are mounted on one of the enclosure boundaries. Acoustic sensors are used inside and outside the enclosure. An analytical formulation based on a state-space model is developed for local vibration control on an enclosure boundary and/or local noise control inside the enclosure for bandlimited disturbances. The error sensor signals are minimized by using digital feedforward control schemes based on filtered-U gradient descent algorithms. Analytical predictions from the current work are compared with the results obtained in our previous experimental investigations and discussed.