Active noise control using variable step-size adaptation
First Claim
1. A method that actively cancels noise in a vehicle using a plurality of microphones and a plurality of loudspeakers comprising:
- generating one or more control output signals to drive the plurality of loudspeakers; and
adapting a plurality of control coefficients of a control filter based on a plurality of secondary path transfer functions that model the acoustic paths between each loudspeaker and each microphone of the plurality of microphones;
where the rate the plurality of control coefficients of the control filter adapt is time-varying and frequency dependent; and
where the rate the plurality of control coefficients of the control filter adapt is based on an adaptive step size based on a predetermined secondary acoustic path.
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Abstract
A system and method (referred to as the system) that actively reduces noise in a vehicle. The system generates one or more control output signals to drive multiple loudspeakers; and adapts multiple control coefficients of a control filter based on multiple secondary path transfer functions. The secondary path transfer functions model the acoustic paths between each loudspeaker and multiple microphones. The multiple control coefficients are time varying and frequency dependent and the rate the plurality control coefficients adapt is based on an adaptive step size based on one or more step size criteria.
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Citations
21 Claims
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1. A method that actively cancels noise in a vehicle using a plurality of microphones and a plurality of loudspeakers comprising:
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generating one or more control output signals to drive the plurality of loudspeakers; and adapting a plurality of control coefficients of a control filter based on a plurality of secondary path transfer functions that model the acoustic paths between each loudspeaker and each microphone of the plurality of microphones; where the rate the plurality of control coefficients of the control filter adapt is time-varying and frequency dependent; and where the rate the plurality of control coefficients of the control filter adapt is based on an adaptive step size based on a predetermined secondary acoustic path. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A non-transitory machine-readable medium encoded with machine-executable instructions, where execution of the machine-executable instructions:
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generates one or more control output signals to drive a plurality of loudspeakers; and adapts a plurality of control coefficients of a control filter based on a plurality of secondary path transfer functions that model the acoustic paths between each loudspeaker and a plurality of microphones; where the rate the plurality of control coefficients of the control filter adapt is time-varying and frequency dependent; and where the rate the plurality of control coefficients of the control filter adapt is based on an adaptive step size based on a step size criterion. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An active noise control system comprising:
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control filter means that generates one or more control output signals to drive a plurality of loudspeakers in response to an external audio source; and control filter update means that adapts a plurality of control coefficients of the control filter means based on a plurality of secondary path transfer functions that model the acoustic paths between a plurality of loudspeakers and a plurality of microphones; and divergence detection means that controls the adaption rate of the plurality of control coefficients in response to a step size criteria; where the plurality of plurality control coefficients are time varying and frequency dependent.
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Specification