ADAPTIVE SIGNAL PROCESSING SYSTEMS FOR ACTIVE CONTROL OF ACOUSTIC NOISE ON CIRCULAR PATHS

Adaptive active noise control (ANC) syste ms create a silent point at the location of an error microphone. This silent point can creates a surrounding zone of quiet with small dimensions. Moreover, the error microphone has to be located within the zone of quiet, limiting the effective space available in the zone of quiet. This paper develops a new adaptive signal processing system for ANC in a circular path, centred at the error microphone. It is shown that an optimal controller for the creation of a silent point on a circular path around the error microphone can be constructed by the series combination of a digital controller, called the circular controller, and a Wiener-Hopf filter. The transfer function of the circular controller is derived based on the system model in the acoustic domain. An update equation for the automatic adjustment of the Wiener-Hopf filter in the proposed system is developed. The proposed system is verified by using different computer simulations.