A new feedback narrowband active noise control system with online secondary-path modeling based on adaptive notch filtering

Narrowband active noise control (ANC, NANC) systems have been developed for attenuating noises that are generated by rotating machines such as motors, cutting machines, diesel engines, fans, etc. The conventional feedforward NANC systems adopt a non-acoustic sensor to detect and extract the noise signal frequencies for creating the reference sine and cosine waves, leading to high implementation cost as well as performance degradation due to frequency mismatch (FM). In this paper, we propose a new efficient feedback NANC system where an adaptive notch filter bank is utilized to construct the reference sinusoidal signals for the ANC system controller that consists of multiple two-weight magnitude/phase adjusters (MPA). The proposed system is also equipped with an online secondary-path modeling (SPM) subsystem that is capable of compensating the secondary-path drift. Extensive simulations are conducted to confirm the effectiveness of the proposed system.