Noise reduction system, method of operating the system and use of the system
Assigneerecalm GmbH
InventorMarc VON ELLING
Life of this patent
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Abstract
A noise reduction system for actively compensating background noise generated by a noise source in a noise reduction area in a passenger transport area of a vehicle. The system includes a microphone array having a reference microphone. An averaging unit is configured to calculate an average error signal, which is calculated based on at least the error signal of a virtual microphone and a direct residual signal of a directed monitor microphone.
Claims14
A noise reduction system for actively compensating background noise generated by a noise source in a noise reduction area in a passenger transport area of a vehicle, the system comprising:
- a controller comprising hardware;
- a reference sensor for detecting the background noise of the noise source;
- a sound generator for generating anti-noise for superimposing the anti-noise with the background noise in the noise reduction area for active reduction of the background noise;
- a monitor-microphone array having a plurality of monitor microphones, the monitor-microphone array being disposed adjacent to the noise reduction area and being configured to pick up background noise emitted by the noise source and anti-noise emitted by the sound generator, the monitor-microphone array comprises a direct monitor microphone;
- wherein a virtual sensing algorithm is implemented in the controller, the controller being configured to:
- estimate an error signal at a position of a virtual microphone, wherein the virtual microphone is located in the noise reduction area and the error signal is indicative of a difference between the background noise and the anti-noise at the position of the virtual microphone;
- generate an anti-noise signal for driving the sound generator in that it generates the anti-noise;
- calculate an average error signal, which is indicative of a difference between the background noise and the anti-noise at a position in the noise reduction area;
- calculate the average error signal by further taking into account a direct residual signal of the direct monitor microphone;
- and
- update parameters of the anti-noise unit based on the average error signal so as to minimize the average error signal.
A method of operating a noise reduction system for actively compensating background noise generated by a noise source in a noise reduction area in a passenger transport area of a vehicle, the system comprising a controller comprising hardware, a reference sensor for detecting the background noise of the noise source, a sound generator for generating anti-noise for superimposing the anti-noise with the background noise in the noise reduction area for active reduction of the background noise, and a monitor-microphone array having a plurality of monitor microphones, the monitor-microphone array being disposed adjacent to the noise reduction area and being configured to pick up background noise emitted by the noise source and anti-noise emitted by the sound generator, the monitor-microphone array comprises a direct monitor microphone, the method comprising:
- implementing a virtual sensing algorithm to estimate an error signal at a position of a virtual microphone, wherein the virtual microphone is located in the noise reduction area and the error signal is indicative of a difference between the background noise and the anti-noise at the position of the virtual microphone;
- generating an anti-noise signal for driving the sound generator in that it generates the anti-noise;
- calculating an average error signal, which is indicative of a difference between the background noise and the anti-noise at a position in the noise reduction area;
- calculating the average error signal by further taking into account a direct residual signal of the direct monitor microphone;
- and
- updating parameters of the anti-noise unit based on the average error signal to minimize the average error signal.
Dependencies are inferred from the claim text.