Road noise cancellation shaping filters

A method for automatically adjusting a road noise cancellation (RNC) shaping filter comprising:

• projecting anti-noise sound within a passenger cabin of a vehicle in response to an anti-noise signal;
• receiving a noise signal indicative of road induced noise within the passenger cabin, wherein the noise signal is determined using vibration data measured via a vibration sensor including a linear variable differential transformer;
• receiving an error signal indicative of noise and the anti-noise sound within the passenger cabin;
• determining a coherence value between the noise signal and the error signal;
• estimating a noise reduction value based on the coherence value;
• filtering the noise signal and the error signal based on the estimated noise reduction value;
• and
• generating the anti-noise signal based on the filtered noise signal and the filtered error signal.

A road noise cancellation (RNC) system comprising:

• at least one loudspeaker to project anti-noise sound within a passenger cabin of a vehicle in response to an anti-noise signal;
• at least one microphone to provide an error signal indicative of the noise and the anti-noise sound within the passenger cabin;
• and
• a controller programmed to:
• determine a noise signal indicative of road induced noise using an output signal measured via a load cell;
• determine a coherence value between the noise signal and an error signal indicative of noise and the anti-noise sound within the passenger cabin;
• estimate a noise reduction value based on the coherence value;
• filter at least one of the noise signal and the error signal based on the estimated noise reduction value;
• and
• generate the anti-noise signal based on the at least one of the filtered noise signal and the filtered error signal.