ABSTRACT
Adaptive filters have been widely used in the implementation of adaptive algorithms for active vibration control (AVC). Adaptive filtering offers significant advantages over passive silencers at low frequencies where lower sampling rates are adequate. There is algorithm that combines the traditional feedback control and adaptive filtering approach, and is therefore referred to as the Adaptive Feedback Algorithm. Adaptive feedback control can be seen as adaptive inverse control where an adaptive filter is used to track the inverse model. Adaptive feedback control is efficient for pure sinusoid signals. An approximated model of the system appears in the feedback loop of the adaptive feedback system, which introduces poles to the system. When the adaptive controllers start to adapt their filter weights, it is observed that the reference signal becomes larger than the normal level before the adaptation is triggered. It may be because of the error of magnitude of the secondary path model.
