## 4pNS4. An adaptive algorithm with error path estimation for active control of periodic noise.

### Session: Thursday Afternoon, December 5

### Time: 2:45

**Author: Nobuyuki Seguchi**

**Location: Dept. of Comput. Sci., Kumamoto Univ., 2-39-1 Kurokami, Kumamoto, 860 Japan**

**Author: Yasuyuki Shimada**

**Location: Dept. of Comput. Sci., Kumamoto Univ., 2-39-1 Kurokami, Kumamoto, 860 Japan**

**Author: Yoshitaka Nishimura**

**Location: Dept. of Comput. Sci., Kumamoto Univ., 2-39-1 Kurokami, Kumamoto, 860 Japan**

**Author: Tsuyoshi Usagawa**

**Location: Dept. of Comput. Sci., Kumamoto Univ., 2-39-1 Kurokami, Kumamoto, 860 Japan**

**Author: Masanao Ebata**

**Location: Dept. of Comput. Sci., Kumamoto Univ., 2-39-1 Kurokami, Kumamoto, 860 Japan**

**Abstract:**

When active noise control (ANC) systems are actually implemented, it is
necessary to take account of the modeling error of an error path. The modeling
error limits the performance of ANC and it makes the system unstable at worst.
The characteristics of the error path cannot be assumed to be stable, so that
on-line estimation is preferred for actual applications such as an active
control system of the exhaust noise of an engine. An adaptive algorithm called
the delayed-X harmonics synthesizer (DXHS) algorithm for periodic noise has been
proposed. This algorithm controls amplitude and phase parameters for each
harmonic component. The original algorithm controls parameters represented in
polar coordinates with constant delay parameters. This paper presents an
extended algorithm to estimate delay parameters of the error path on-line. Delay
parameters, which are important for the stability, are introduced as a phase,
while other parameters are represented in orthogonal coordinates. The
performance of the algorithm is evaluated by computer simulations. When SNR at
the control point is 0 dB, the estimate delay is nearly the same value as the
actual delay, and the system converges very stably.

ASA 132nd meeting - Hawaii, December 1996