Abstract
In this paper, a kind of active noise barrier (ANB) using active noise control (ANC) technique to improve noise insulation performance in low frequencies is proposed. The ANB consists of an ordinary noise barrier, three active noise control units (ANCU) and a DSP (IMS 320C6713 DSK). Feedback ANC system is used in the ANCUs. In order to achieve higher noise attenuation, fast transversal filter (FTP) adaptive algorithm is introduced into the feedback ANC system. Then, numerical and experimental study on an active noise barrier is conducted. As a result, the active noise barrier shows better noise insulation performance in low frequencies. Moreover, in this paper, basic concept of a new type hybrid ANC system which is a combination of the feedforward and feedback control structures is proposed. The feedback controller provides active noise insulation, and the feedforward controller whose reference signal is synthesized in the feedback controller cancels noise at a specific position where its error microphone is. Effectiveness of the hybrid ANC system is verified by experiment. The result shows that the hybrid ANC system can reduce noise better than single feedforward or feedback ANC systems.
