Modified phase-scheduled-command FxLMS algorithm for active sound profiling

Abstract

Active sound profiling, or active noise equalization strategies have been proposed to achieve spectral shaping of a primary disturbance signal. The control algorithms proposed to achieve such spectral shaping have either suffered from poor robustness to plant modelling uncertainties or required high levels of control effort. To improve the robustness of active sound profiling to uncertainties in the plant model, whilst avoiding increased control effort, a modified phase-scheduled-command filtered-x least-mean-square (FxLMS) algorithm is proposed in this paper. The new algorithm provides improved stability, whilst requiring the minimum control effort. This improvement is achieved by replacing the plant model with an intelligent adaptive-hysteresis switching mechanism to allow the necessary estimation of the disturbance signal phase. The improved performance and robustness of the proposed algorithm is demonstrated through a series of simulations using measured acoustic responses.