Kuo, Sen M. (Sen-Maw)
M.S. (Master of Science)
Department of Electrical Engineering
Feedback control systems||Noise control
The research work of this thesis concentrates on feedback active noise control (FANC) systems. The FANC system uses error sensor(s) to perform cancellation and thus avoids the acoustic feedback effect inherent to traditional feedforward active noise control (ANC) systems. The single-channel FANC system is proved to behave similar to an adaptive predictor. The algorithm is extended to a multiple-channel case, which can be applied to cancel noise in a three-dimensional (3-D) environment. The FANC systems cancel periodic and predictable components in the primary signal. Hybrid active noise control (HANC) systems based on the combination of feedforward and feedback ANC principles are proposed. HANC systems employing finite impulse response (FIR) and infinite impulse response (HR) structures are developed. The HANC systems use low order filters and are effective in canceling the predictable components in the primary signal that are not correlated with the reference signal. Traditional off-line modeling schemes for the secondary path are inefficient in the presence of interference. A new technique for modeling the secondary path using an adaptive predictor is presented. It is shown to attenuate the interfering signal significantly during off-line modeling and to provide a good estimate of the secondary path. The idea is extended to an on-line modeling technique which is then implemented in a single-channel FANC system. The results of the computer simulations and real-time experiments reinforce that the algorithms developed in this work are feasible for practical applications.
Vijayan, Dipa, "Feedback active noise control systems" (1994). Graduate Research Theses & Dissertations. 3115.
xviii, 167 pages
Northern Illinois University
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