New direct adaptive active noise control algorithms in case of uncertain secondary path dynamics

Almost all adaptive feedforward control algorithms for active noise control require a precise model of the secondary path dynamics from the control loudspeaker to the error and reference microphones. This paper is concerned with new direct adaptive algorithms which will be applicable even when the secondary path dynamics are uncertain or unknown. In the first approach, the control algorithm consists of a robust adaptive feedforward control algorithm and robust feedback control scheme permitting bounded uncertainty in the nominal secondary path model. The second one is a fully direct adaptive feedforward control algorithm which is effective in a case when all of the path dynamics are uncertain. Simulation and experimental results validate the effectiveness of the proposed algorithms.