Patent ID: 7343016
Filing Date: 2008-03-11
Classification: G10K

Abstract:
1. An active noise and vibration control system for generating an antinoise signal to attenuate a narrowband noise signal propagating through a medium, said active noise and vibration control system performing on-line noninvasive secondary path modeling, said system, comprising: a reference sensor operable to receive a reference signal related to a primary noise and to generate a primary signal in response; a secondary source operable to generate an antinoise corresponding to a secondary signal that attenuates the primary noise; an error sensor operable to receive a residual signal that is a superposition of said primary noise and a secondary noise at the location of said error sensor, and to generate an error signal in response thereto; and a controller operable to receive said primary signal and said error signal and to generate said secondary signal while performing on-line noninvasive secondary path modeling, said controller comprising an on-line noninvasive secondary path modeler operable to receive said primary signal, said secondary signal, and said error signal for the purpose of calculating a secondary path model, wherein said online noninvasive secondary path modeler captures first and second data sets comprising said reference signal, said error signal and said generated secondary signal, to calculate a transfer function of a secondary path, and to alter an output of said secondary source by adjusting output filter coefficients of a control filter in amplitude, in phase, or in both amplitude and phase between acquisition of said first and second data sets, thereby imposing linear independence on said first and second data sets, wherein said secondary path modeler uses said control filter and said first and second data sets to calculate said secondary path model algebraically in a system of first and second equations-two unknowns, P(k) and S(k), as follows: where {X A (k),Y A (k),E A (k)} corresponds to said first data set and {X B (k),Y B (k),E B (k)} corresponds to said second data set, Y A (k) and Y B (k) represent outputs of said control filter according to the equations: where W(k) is the FFT of said control filter's impulse response, wherein said linear independence of said first and second equations is achieved by ensuring the inequality of W A (k)≠W B (k), wherein a solution of said first and second equations is given by: and wherein an equation derived from said algebraic calculation is modified to account for spectral leakage and narrowband effects.