Modeling of an Acoustic Path and PID Feedback Control Systems Design for Active Noise Control

Focus is placed on the feedback (FB) active noise control (ANC) in order to reduce costs by simplifying ANC systems, because FB-ANC does not need reference signals. The purpose of this paper is to obtain a low order accurate model of an acoustic plant for FB-ANC and design a simple controller based on this model. The plant in this case is from the input to a single secondary loudspeaker to the output of a single error sensor (microphone). First, as a modeling method, physical modeling is applied. Second, Smith predictor is modified for FB-ANC to eliminate the influence of time delay in an acoustic field, and a PID controller is designed. Finally, effectiveness of the modeling methods and the proposed FB-ANC are demonstrated through numerical experiments using actual data.