Z. Wu et al., TIME-DOMAIN ANALYSIS AND SYNTHESIS OF ACTIVE NOISE-CONTROL SYSTEMS INDUCTS, The Journal of the Acoustical Society of America, 101(3), 1997, pp. 1502-1511
This paper presents time-domain analysis and synthesis of active low-f
requency noise control systems in rigid-walled ducts. In contrast to f
requency-domain analysis, time-domain modeling provides a direct physi
cal insight of the noise cancellation mechanism, where noise signals a
re assumed to be arbitrary real functions of time instead of harmonics
. The time-domain analysis is based on a state-space model which is de
rived from the governing wave equation using combined numerical (finit
e difference) and analytical techniques. Optimal feedback control laws
are synthesized for a variety of active noise control systems with di
fferent sensor and source arrangements. The responses of closed-loop s
ystems are simulated, and the results are compatible with those of tra
nsfer function synthesis. In addition, the active control systems so d
esigned have the potential of providing global, broadband, and optimal
noise reductions without running into the annoying feedback problems
in most feedforward control systems. (C) 1997 Acoustical Society of Am
erica.