The Predict and Invert Feedback Active Noise and Vibration Control Algorithm

Abstract

This work proposes an algorithm for feedback ANC that does not require a prior secondary path model and usually remains stable after fast secondary path changes, as other algorithms proposed for feedforward ANC. This is achieved using a recursive least squares algorithm to model the secondary path and the primary noise with an autoregressive moving average model. The resulting model allows for predicting future values of the primary noise. Finally, the primary noise values predicted are filtered by a non-causal inverse of the secondary path model to generate the anti-noise signal. Simulation results attest to the validity of the algorithm in reducing narrowband noise.