Sensor scheme design for active structural acoustic control

Efficient sensing schemes for the active reduction of sound radiation from plates are presented based on error signals derived from spatially weighted plate velocity or near-field pressure. The schemes result in near-optimal reductions as compared to weighting procedures derived from eigenvector or singular vector analysis of the radiation operator. Efficient control configurations are suggested using a, possibly analog, front-end implementing a bank of spatial weighting functions and a digital controller with a minimized number of input and output channels. The performance of different weighting functions is compared, as well as the performance of different frequency-dependent filtering functions. Design rules are given for the sensor spacing, the number of weighting functions, the number of actuators, and the corresponding controller dimensionality.