Active sound control with smart foams using piezoelectric sensoriactuator

Smart foam offers a lightweight, efficient noise control solution by combining the complimentary advantages of passive dissipation in the foam material with the actuation authority of the active piezoelectric component, under appropriate control input. This study aims to implement the sensoriactuator operation of the active piezoelectric component to obtain an alternate error signal from its mechanical strain response. This can potentially replace the use of far-field microphone error sensors in active noise control applications, and hence improve the compactness of the system. The piezoelectric sensoriactuator has been implemented with the hybrid analog–digital compensation of the quasi-stable feedthrough capacitance of the actuator using an adaptive algorithm. The mechanical charge response, thus obtained, has been minimized using an adaptive algorithm and its effect on the transmission loss has been studied. Additionally, it has also been utilized in absorption and transmission control problems, using a virtual sensing strategy, with the aim of obtaining the desired control performance by minimizing an estimated virtual error signal. The experimental results are supplemented with finite element simulation of the coupled noise control system, and it provides a significant insight into the physical problem of the realization of the smart foam sensoriactuator.