A NARROWBAND ACTIVE NOISE CONTROL SYSTEM WITH SIMULTANEOUS ONLINE SECONDARY- AND FEEDBACK-PATH MODELING USING ADAPTIVE IIR NOTCH FILTER

摘要

In this paper, a new narrowband active noise control (NANC) system with a single frequency channel is proposed which consists of an online secondary-path modeling (SPM) subsystem and an online feedback-path modeling (FBPM) subsystem. The online SPM and FBPM subsystems are simultaneously adjusted in harmony in the hope of effectively suppressing the target sinusoidal noise, with the former aiming at obtaining a reasonably good SP estimate for updating the ANC controller and the latter trying to remove the FBP influence on the system performance. An auxiliary white Gaussian noise scaled by a nonlinear function of the residual noise is injected into the secondary source to implement the online SPM and FBPM. An adaptive second-order IIR notch filter is placed in front of the controller to reduce the coupling between the FBPM subsystem and the controller. A first-order FIR filter or magnitude and phase adjuster (MPA) is adopted as the controller. The FXLMS and LMS algorithms are applied to the ANC controller, the FBPM and the SPM subsystems, respectively. Extensive simulations reveal the effectiveness and computational advantage of the proposed ANC system.