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

Emmanuel Friot (1)

1 Sons

Although Active Noise Control aims at reducing the noise at a set of error sensors, it is often designed by minimizing an error index that includes a weighted penalty on the actuator inputs. In this way, the control tends to be more robust and the effort-weighting parameter allows the maximum voltages applied to the control sources to be monitored. 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, whereas the leaky Filtered-reference least mean squares algorithm can be implemented for real-time feedforward control. This paper makes explicit the relationship between the two effort-weighting parameters which lead, in the case of a single-tone noise, to exactly the same error index in both the time and frequency domains. The best real-time leakage factor can then be computed from frequency-domain optimization. This paper also discusses numerical simulations of a single-channel set-up, showing that with these two related parameters, the control performances are indeed very similar. One exception occurs in the case of a control flter with a very short impulse response, when the control is more conservative in the time-domain simulations than in those of the frequency-domain.

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. 2015. ⟨hal-01056910v2⟩