Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10289244 | Journal of Sound and Vibration | 2013 | 10 Pages |
Abstract
A new method is presented to obtain a local active noise control that is optimal in stochastic environment. The method uses numerical acoustical modeling that is performed in the frequency domain by using a sequence of finite element discretizations of the Helmholtz equation. The stochasticity of domain geometry and primary noise source is considered. Reference signals from an array of microphones are mapped to secondary loudspeakers, by an off-line optimized linear mapping. The frequency dependent linear mapping is optimized to minimize the expected value of error in a quiet zone, which is approximated by the numerical model and can be interpreted as a stochastic virtual microphone. A least squares formulation leads to a quadratic optimization problem. The presented active noise control method gives robust and efficient noise attenuation, which is demonstrated by a numerical study in a passenger car cabin. The numerical results demonstrate that a significant, stable local noise attenuation of 20-32Â dB can be obtained at lower frequencies (<500Hz) by two microphones, and 8-36Â dB attenuation at frequencies up to 1000Â Hz, when 8 microphones are used.
Related Topics
Physical Sciences and Engineering
Engineering
Civil and Structural Engineering
Authors
T. Airaksinen, J. Toivanen,