Active noise control for a washing machine

Abstract

An actively controlled thin barrier may provide better noise reduction results than common passive solutions. The performance of such active method has been confirmed by the authors using a dedicated noise-cancelling laboratory casing. Now, such approach is developed and applied to a real device casing, what is a significant step toward commercialisation of the active casing method. An adaptive FXLMS algorithm with practical modifications is proposed for the active control of the casing to provide noise reduction. A feed-forward structure is used, with a reference microphone located inside the real device. Additionally, an Internal Model Control system with reference signal estimation is also implemented for a comparison. The performance of the resulting control systems is experimentally verified for a real washing machine (an off-the-shelf product), using a loudspeaker placed inside the washing machine to provide reproducible noise. Obtained results are reported and discussed.