A Study on Improving the Robustness of Virtual Sensing Methods in ANC Systems

Active noise control (ANC) system generates anti-noise with the same amplitude and opposite phase to reduce unwanted acoustic noise based on acoustic wave superposition. In general, ANC can generate a zone of quiet (ZoQ) around the error microphone position. However, if the microphone cannot be placed at the desired position we want to realize noise reduction, the reduction effect may not be sufficient in the desired position. In such a case, we need to use the virtual sensing method to move the ZoQ to the desired position. Several virtual sensing methods have been proposed, each with different robust performance due to the different way the system is designed. It is known that the noise reduction is degraded when there are perturbations in the environment such as plant and noise. In this paper, we investigate how to improve the robust performance of the virtual sensing method.