A narrowband active noise control system with a frequency estimation algorithm based on parallel adaptive notch filter

Active noise control (ANC) instead of traditional passive method shows good low-frequency performance especially for periodic noise signals. To obtain accurate reference signal and remove the secondary feedback effect, frequency estimation algorithms are often used in narrowband ANC systems. In this work, a parallel adaptive notch filter (parallel ANF, PANF) algorithm is proposed to obtain accurate estimation of frequency which is used for generating reference signal in a sinusoidal form. In the proposed PANF algorithm, multiple tones are separated in the feedback reconstruction process to reduce the frequency-interfering effect. As a result, the estimation of multiple frequencies has high accuracy as well as the triangular cascaded ANF (TCANF) algorithm and the computation burden is greatly reduced to the level of the linear cascaded ANF (LCANF) algorithm. Detailed performance analysis is conducted to acquire the deviation of frequency estimation algorithm and the mean square error (MSE) of the ANC system. Finally, extensive simulations and narrowband ANC experiments are carried out in a pipe system to verify theoretical results.