Instability detection and adaptive-adjustment for active noise cancellation system

An active noise cancellation (ANC) system comprising:

• at least one loudspeaker to project anti-noise sound within a passenger cabin of a vehicle in response to receiving an anti-noise signal;
• and
• a controller configured to:
• filter an error signal indicative of noise and the anti-noise sound within the passenger cabin to obtain a noise reduction ratio,
• adjust a step size parameter and a leakage parameter based on a comparison of the noise reduction ratio to a noise threshold, and
• generate the anti-noise signal based on the adjusted step size parameter and the adjusted leakage parameter.

A method for controlling stability in an active noise cancellation (ANC) system, the method comprising:

• receiving an error signal from a microphone indicative of noise and anti-noise sound within a passenger cabin;
• filtering the error signal to obtain a noise reduction ratio;
• detecting an occurrence of noise boosting based on a comparison of the noise reduction ratio to a noise threshold;
• decreasing a step size parameter in response to detection of noise boosting;
• and
• generating an anti-noise signal, to be radiated from a loudspeaker within the passenger cabin as the anti-noise sound, based on the decreased step size parameter.