능동소음제어를 위한 안정화된 퍼지 논리 적응필터

In active noise control systems, IIR filter has a pole which causes a problem in stability on being used for adaptive algorithm. For IIR filter, sometimes its pole could be placed with out of a unit circle in a z-plane in the transition state before adaptive algorithm converges to the optimum value, which causes the system to be diverged. Fuzzy LMS algorithm has a better convergence property than conventional LMS algorithms, but is difficult to applying IIR filter because of stability problems. Stabilized adaptive algorithm is reinforced stability by moving the poles of IIR filter toward the origin in the beginning of the operation of the system, and by introducing forgetting factor to maintain the optimum convergence when it reaches to the steady state. In this paper, We proposed stabilized fuzzy logic adaptive IIR filters, for single channel active noise control systems with ill conditioned signal case. Computer simulations were performed to show the effectiveness of a proposed algorithms.