TRANSFER FUNCTION IDENTIFYING DEVICE AND ACTIVE TYPE NOISE ELIMINATING DEVICE

Japanese Patent JP3725959

B2

PROBLEM TO BE SOLVED: To identify a secondary sound path (a transfer function) without being adversely affected by disturbance noise.
SOLUTION: Pseudo signals mk outputted from a pseudo signal generator 10 are supplied to a secondary sound source speaker 6 through an equalizer 11, radiated into a secondary sound path C as identifying sounds and received by an error microphone 7. The output signals of the microphone 7 and the signals, which are obtained by processing the signals mk by an FIR filter 8, are compared in a computing element 12 and the difference between the above two signals, i.e., error signals εk are obtained. An LMS computing section 11 processes the signals mk and εk in accordance with an LMS algorithm, for example, and identifies [EQ×C] as the synthetic transfer function of the path C and a transfer function EQ of the equalizer 11. The equalizer 11 compensates for the frequency characteristics of the signals mk at each frequency, which is the object of the identification, so that the identified sounds are not buried in exhaust sounds. Therefore, an accurate identification is conducted at each frequency.

JPH09101790	ACTIVE NOISE ELIMINATOR
WO/2019/080505	ACTIVE NOISE REDUCTION METHOD AND SYSTEM, AND NEW ENERGY VEHICLE

Kiyohiro Kurisu
Takeshi Fujita
Toshiyuki Tachibana
Minoru Okubo
Shinichiro Ishida

JP8192197A

December 14, 2005

March 14, 1997

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TOA Co., Ltd.
Yanmar Co., Ltd.

F01N1/00; G10K11/16; G10K11/178; H03H17/02; H03H21/00; (IPC1-7): G10K11/178; F01N1/00; G10K11/16; H03H17/02; H03H21/00

JP7248781A
JP5249986A
JP5265468A

Masatoshi Kimura

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