Robust Control Design for Active Noise Control Systems of Ducts with a Ventilation System Using a Pair of Loudspeakers

In this paper we deal with design problems of active noise control systems with a pair of loudspeakers, in order to improve the system performance achieved by a single loudspeaker presented in our previous study where advantages of robust control (sampled-data H∞ control) design have been shown by comparing to the existing adaptive control based design. Firstly, as a pair of loudspeakers, the Swinbanks’ source is composed of an appropriate delay and two loudspeakers whose dynamic characteristics are equivalent, then similar advantages of robust control design are shown by experimental results with the ventilation system. Secondly, the pair of loudspeakers is considered as two independent actuators to meet dynamic characteristic difference of the loudspeakers, then less-conservative SIMO controller is designed by robust control design to improve system performance.