A new robust auxiliary noise power scheduling for online secondary path modeling in active noise control systems

Auxiliary noise, which is used for online secondary path modeling (OSPM), contributes to the residual noise and consequently reduces the performance of active noise control (ANC) systems. This paper introduces two novel schemes for robust auxiliary noise power scheduling for OSPM. First, two robust adaptive thresholds are proposed to control the injection of auxiliary noise. The auxiliary noise is stopped when the accuracy of the estimated secondary path is sufficient. However, when a sudden change in the secondary path occurs, the auxiliary noise is injected again. Second, a noise power scheduling strategy, which is based on the power of reference noise when auxiliary noise is injected is also proposed. In this way a fast convergence property can be obtained. Computer simulations demonstrate the effectiveness of the proposed approach.