Patent ID: 11961503
Assignee: HARMAN BECKER AUTOMOTIVE SYSTEMS GMBH
Field: Other consumer goods (Other fields)
Classification: CPC G | IPC A  G

Claim 0:
1. An automatic noise control system comprising:
an acceleration sensor configured to evaluate an amplitude of an acceleration acting thereon and to generate a reference signal representative of the amplitude of the acceleration, the acceleration being representative of unwanted noise sound generated by a noise source;
a noise control filter operatively coupled with the acceleration sensor and configured to filter the reference signal with a noise control transfer function to generate an anti-noise signal;
a loudspeaker operatively coupled with the noise control filter and configured to convert the anti-noise signal into anti-noise sound;
a microphone configured to receive a noise sound after being transferred via a primary path according to a primary path transfer function from the noise source to the microphone and the anti-noise sound after being transferred via a secondary path according to a secondary path transfer function from the loudspeaker to the microphone, and further configured to convert a sum of the received noise sound and the received anti-noise sound into an error signal;
a filter controller operatively coupled with the noise control filter, the microphone and the acceleration sensor, and configured to control the noise control transfer function of the noise control filter based on the error signal from the microphone and the filtered reference signal or the unfiltered reference signal from the acceleration sensor so that the anti-noise sound after being transferred via the secondary path is the inverse of the noise sound after being transferred via the primary path; and
a leakage controller operatively coupled with the filter controller, the acceleration sensor, and the microphone, and configured to apply via the filter controller to the noise control transfer function of the noise control filter a leakage based on the error signal from the microphone and the filtered reference signal or the unfiltered reference signal from the acceleration sensor, wherein the leakage controller comprises:
an additional noise control filter operatively coupled with the acceleration sensor and configured to filter the filtered reference signal or the unfiltered reference signal from the acceleration sensor with a transfer function that is identical with the noise control transfer function of the noise control filter to generate an additional anti-noise signal;
a subtractor operatively coupled with the additional noise control filter and the microphone, and configured to subtract the additional anti-noise signal provided by the additional noise control filter based on the error signal provided by the microphone to generate an estimated disturbing signal, the estimated disturbing signal being an estimation of a disturbing sound, which is the noise sound after being transferred via the primary path from the noise source to the microphone; and
an adaptation controller operatively coupled with the filter controller and the microphone, and configured to compare the error signal with the estimated disturbing signal and to control the filter controller to apply the leakage dependent on the comparison.