A New Hybrid Active Noise Control System With Input-Power-Controlled Online Secondary-Path Modeling

A new hybrid active noise control (ANC, HANC) system is proposed in this paper that is equipped with an input-power-controlled online secondary-path modeling (OSPM) subsystem. An FIR linear prediction filter (LPF) is newly included that takes the FIR supporting filter (SF) error as its desired signal and separates the remaining target narrowband noise component from all the other broadband noise components. Placed right after the LPF is the OSPM subsystem. The SF and LPF output signals, namely the target broadband and narrowband components that remain in the residual error are not only used to update the feedforward and feedback ANC (FFANC, FBANC) subcontroller, respectively, but are also adopted to control the power of the OSPM-exclusive auxiliary white Gaussian noise (AWGN) to pursue a trade-off between the OSPM quality and the AWGN contribution to the residual error. The OSPM error is utilized to simultaneously update not only the OSPM subsystem but also the SF and the LPF. Due to inclusion of the LPF, the adverse coupling effects among the FFANC, the FBANC and the OSPM is reduced substantially, leaving a possibility for improving the HANC overall convergence and noise reduction performance (NRP). Furthermore, preliminary steady-state analysis of the LPF is also conducted to reveal its properties and effectiveness. Extensive simulations with both synthetical and real settings are provided and conducted to verify that the proposed HANC system is superior to existing solutions.