Active control of scattered acoustic radiation: a real-time implementation

摘要

This paper presents an active noise control experiment designed to validate areal-time control strategy for reduction of the noise scattered from athree-dimensional body. The control algorithm relies on estimating thescattered noise by linear filtering of the total noise measured around thebody; suitable filters are identified from off-line measurements. A modifiedFiltered-Error Least-Mean-Squares algorithm then leads to the adaptive filterswhich drive the secondary sources. The paper provides the numerical simulationsusing a Boundary Element Method which helped in designing a feasible experimentin an anechoic chamber with a limited number of control sources. Eventually areal-time pure-tone implementation with 14 ordinary loudspeakers and a largebody is shown to yield on average a 10 dB reduction of the scattered noise atthe error sensors, which is close to the optimum reduction predicted by thenumerical simulations for the sensor arrangement.