Active noise control of a duct using robust control theory

In this paper, the control of sound propagation in an air-handling duct is investigated. Employing identified discrete t ime models of the duct, robust linear controllers are designed using the combined pole placement/sensitivity function shaping method. T h e particularities of harmonic noise sources are taken into account, avoiding the classical stochastic adaptive and the reference noise based methods, in order t o propose solutions easy to implement in real t ime applications. Extensive results have shown tha t this approach is a relevant candidate to the narrow band problem in active noise control.