Time-domain versus frequency-domain effort weighting in active noise control

Emmanuel Friot (1)

1 Sons

Active Noise Control aims at reducing the noise at a set of error sensors, but is is often designed by minimizing an error index which also includes a weighted penalty on the actuator inputs. In this way the control tends to be more robust and the effort-weighting parameter allows to monitor the maximum voltages which are applied to the control sources. Two similar effort-weighting techniques have been widely implemented in active control studies: optimal control can be computed using Tikhonov regularization in frequency-domain simulations and using the leaky Filtered-reference least mean square algorithm for real-time feedforward control. This paper introduces the relationship between the two effort-weighting parameters which lead, in the case of a single-tone noise, to exactly the same error index both in the time and in the frequency domain; the best real-time leakage factor can then be computed from frequency-domain optimization. The paper also discusses numerical simulations of a single-channel set-up which show that, with these two related parameters, the control performances are indeed very close except for the case of a control filter with a very short impulse response when control is slightly more conservative in the time domain than in the frequency-domain simulations.

Mots clés: Active noise control; penalization; leakage; FxLMS

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Emmanuel Friot. Time-domain versus frequency-domain effort weighting in active noise control. 2014. ⟨hal-01056910v1⟩