In the conventional active noise control for a duct system, the "error path" is usually modeled as FIR filter with many coefficients. In this research, the well known Filtered-X and Filtered-U algorithms are investigated. "Delayed-X" and "Delayed-U" algorithms which are much faster than conventional Filtered-X and Filtered-U methods are proposed. These method are based on the concept that error path can be represented by only two parameters, the delay and gain.
The conventional IIR based control algorithms are suffering because of instability problem and slow convergence. "Accelerating Unit", which can be attached to Filtered-U and Delayed-U algorithms, is developed to alleviate these problems.
Also, "IIR Stabilizer" is proposed to prevent instability due to the pole movement out to the unit circle along the real axis in z plane during RLMS process.
Computer simulation results demonstrate the effectiveness of the proposed methods.
