ACTIVE TYPE NOISE CONTROLLER - 日産自動車株式会社

Title:

ACTIVE TYPE NOISE CONTROLLER

Document Type and Number:

Japanese Patent JP3046101

Kind Code:

B2

Abstract:

PURPOSE: To detect the deterioration of frequency characteristics of a system by comparing the difference between transfer functions before and after the identification of the filter coefficient of a digital filter with a specific value.
CONSTITUTION: When a model spatial transfer function which is modeled into the actual spatial transfer function between a control sound source and a residual noise detecting means is identified (steps S4-S6), the difference between the model spatial transfer function COLD' at the time of the last identification and the model spatial transfer function CNEW' at the time of the current identification is calculated (step S8) and when the number of times where the absolute time of the difference is larger than a 1st threshold value X (step S9) or less than the 1st threshold value and larger than a 2nd threshold value Y (steps S9 and S10) is larger than No (step S14), deterioration of frequency characteristics of the whole system is decided.

Inventors:

Hiroshi Murakami
Yasutake Ishikawa
Kenji Sato

Application Number:

JP18461891A

Publication Date:

May 29, 2000

Filing Date:

July 24, 1991

Export Citation:

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