ῶ㡢ศᕸ

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ŽŠ‘’“Š”

(a) Impluse response

•–—

•˜—

•™—

•š—

•›—

•œ—

•—

— ———— œ————

žŸ ¡¢ £¤¥¦§¨©

ª

«

¬

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®

¯

°

±

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§šš

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(b) GAIN

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ÁÂÃÄÅÃÆÇÈÉÊËÌ Í

Î Ï Ð Ñ Ò Ó Ô

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(c) GAIN (Expanding)

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Þ ÜÞÞÞÞ àÞÞÞÞ

áâãäåãæçèéêëì í

î ï ð ñ ò ó ô õ ö

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êàà

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êøø

ê

ùúûãâüýãþ

(d) PHASE

ÿ ÿ

!"

(e) PHAS (Expanding)

Fig. 4.13 : Fixed filter for AAS-Unit Type H

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$

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(a) Impulse response

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; ?;;; B;;;;

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(b) GAIN

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v w x y z {

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(c) GAIN (Expanding)

ƒ„…†

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‰Š‹Œ‹Ž‘’“”

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(d) PHASE

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(e) PHAS (Expanding)

Fig. 4.14 : Fixed filter for AAS-Unit Type L

ÍÎÏ ÍÐÏ ÍÑÏ ÍÒÏ ÍÓÏ ÍÔÏ ÍÕÏ

Ï ÓÏÏ ÖÏÏÏ ÖÓÏÏ ×ÏÏÏ ×ÓÏÏ ÕÏÏÏ

ØÙÚÛÜÚÝÞßàáâã ä

å æ ç è é ê å ë ì í î ï ð ñ å ò ò í ñ å ó å ê å æ

ô ï õ ö

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(a) Error point 1

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* + , -( , .

/

* 0 1

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6789:;

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3?AB

(b) Error point 1 (Expanding)

CDE CFE CGE CHE CIE CJE CKE

E IEE LEEE LIEE MEEE MIEE KEEE

NOPQRPSTUVWXY Z

[

\ ]

^ _

` [ a b c d e f g [ h h c g [ i [

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mnopN N

mnopn

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wsTxyOzRS{

nz|}P

(c) Error point 2

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‰Š‹Œ‹Ž‘’“”

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(d) Error point 2 (Expanding)

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» ¿»» »»» ¿»» û»» ÿ»» Á»»»

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Ñ Ò Ó Ô Õ Ö Ñ

× Ø Ù Ú Û Ü Ý Ñ Þ Þ Ù Ý Ñ ß Ñ Ö Ñ Ò

à Û á â

ãäåæÄ Ä

ãäåæ ä

ãäåæ ä

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äðòóÆ

(e) Error point 3

ôõö ô÷ö ôøö ôùö ôúö ôûö ôüö

ö ýöö þöö üöö ûöö úöö

ÿ

! ÿ ÿ

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+-.

(f) Error point 3 (Expanding)

/01 /21 /31 /41 /51 /61 /71

1 511 8111 8511 9111 9511 7111

:;<=><?@ABCDE F

G H I J K L G M N O P Q R S G T T O S G U G L G H

V Q W X

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(g) Error point 4

jkl jml jnl jol jpl jql jrl

l sll tll rll qll pll

uvwxywz{|}~€



‚

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„ …

†

‡

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(h) Error point 4 (Expanding)

Fig. 4.15 : The sound pressure spectrum at the error points of AAS Type H under the condition of ANC ON and OFF

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(a) Error point 1

àáâ àãâ àäâ àåâ àæâ àçâ

â éââ êââ èââ çââ æââ

ëìíîïíðñòóôõö

÷ ø ù ú û ü ý ø þ ÿ ø ø ø ý

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(b) Error point 1 (Expanding)

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(c) Error point 2

VWX VYX VZX V[X V\X V]X V^X

X _XX `XX ^XX ]XX \XX

abcdecfghijkl m

n o p q r s n t u v w x y z n { { v z n

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(d) Error point 2 (Expanding)

‘’“

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(e) Error point 3

ÌÍÎ ÌÏÎ ÌÐÎ ÌÑÎ ÌÒÎ ÌÓÎ ÌÔÎ

Î ÕÎÎ ÖÎÎ ÔÎÎ ÓÎÎ ÒÎÎ

×ØÙÚÛÙÜÝÞßàáâ ã

ä å æ ç è é ä ê ë ì í î ï ð ä ñ ñ ì ð ä ò ä é ä å

ó î ô õ

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(f) Error point 3 (Expanding)

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1234

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(g) Error point 4

BCD BED BFD BGD BHD BID BJD

D KDD LDD JDD IDD HDD

M NOPQORSTUVWX Y

Z [

\ ]

^ _ Z

` a b c d e f Z g g b f Z h Z _ Z [

i d j k

lmnoM M

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(h) Error point 4 (Expanding)

Fig. 4.16 : The sound pressure spectrum at the error points of AAS Type L under the condition of ANC ON and OFF

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(a) Fixed point a

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(b) Fixed point a(Expanding)

Õ ÖÕ

×Õ ØÕ ÙÕ ÚÕ ÛÕ

Õ ÚÕÕ ÖÕÕÕÖÚÕÕ×ÕÕÕ×ÚÕÕØÕÕÕ

ÜÝÞßàÞáâãäåæç è

é ê ë ì í î ï ð ð ê î ï ñ ï ò ï ó ô ì õ ö

÷øùúÜÜ

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ûüýþÞ ÿÜ

(c) Fixed point b

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(d) Fixed point b (Expanding)

- .- /- 0- 1- 2-

3-- 2-- .---.2--/---/2--

0---4 567869:;<=>?

@ A B C D E F G H H B F G I G J G K L D M N

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(e) Fixed point c

Y ZY [Y

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m n o p q r s t t n r s u s v s w x p y z

{|}~` `

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(f) Fixed point c (Expanding)

Fig. 4.17 : The sound pressure spectrum at the fixed points under the condition of ANC ON and OFF

(a) 100Hz

[>P@

\>P@

>+]@

>G%@

(b) 125Hz

[>P@

\>P@

>+]@

>G%@

(c) 160Hz

[>P@

\>P@

>+]@

>G%@

(d) 200Hz

[>P@

\>P@

>+]@

>G%@

(e) 250Hz

[>P@

\>P@

>+]@

>G%@

(f) 315Hz

Fig. 4.18 : Sound attenuation level contours under Normal filter (100Ң 315Hz)

(a) 400Hz

[>P@

\>P@

>+]@

>G%@

(b) 500Hz

[>P@

\>P@

>+]@

>G%@

(c) 630Hz

[>P@

\>P@

>+]@

>G%@

(d) 800Hz

[>P@

\>P@

>+]@

>G%@

(e) 1000Hz

[>P@

\>P@

>+]@

>G%@

(f) 1250Hz

Fig. 4.19 : Sound attenuation level contours under Normal filter (400Ң 1250Hz)

(a) 1600Hz

[>P@

\>P@

>+]@

>G%@

(b) 2000Hz

Fig. 4.20 : Sound attenuation level contours under Normal filter (1600㸪2000Hz)

(a) ANC OFF 100Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 100Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 125Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 125Hz

Fig. 4.21 : Sound pressure level contours under Normal filter (100㸪125Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 160Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 160Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 200Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 200Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 250Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 250Hz

Fig. 4.22 : Sound pressure level contours under Normal filter (160㸪200㸪250Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 315Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 315Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 400Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 40Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 500Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 500Hz

Fig. 4.23 : Sound pressure level contours under Normal filter (315㸪400㸪500Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 630Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 630Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 800Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 800Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 1000Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 1000Hz

Fig. 4.24 : Sound pressure level contours under Normal filter (630㸪800.1000Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 1250Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 1250Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 1600Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 1600Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 2000Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 2000Hz

Fig. 4.25 : Sound pressure level contours under Normal filter (1250㸪1600㸪2000Hz)

[>P@

\>P@

>+]@

>G%@

(a) 100Hz

[>P@

\>P@

>+]@

>G%@

(b) 125Hz

[>P@

\>P@

>+]@

>G%@

(c) 160Hz

[>P@

\>P@

>+]@

>G%@

(d) 200Hz

[>P@

\>P@

>+]@

>G%@

(e) 250Hz

[>P@

\>P@

>+]@

>G%@

(f) 315Hz

Fig. 4.26 : Sound attenuation level contours under same filter (100Ң 315Hz)

[>P@

\>P@

>+]@

>G%@

(a) 400Hz

[>P@

\>P@

>+]@

>G%@

(b) 500Hz

[>P@

\>P@

>+]@

>G%@

(c) 630Hz

[>P@

\>P@

>+]@

>G%@

(d) 800Hz

[>P@

\>P@

>+]@

>G%@

(e) 1000Hz

[>P@

\>P@

>+]@

>G%@

(f) 1250Hz

Fig. 4.27 : Sound attenuation level contours under same filter (400Ң 1250Hz)

(a) 1600Hz

[>P@

\>P@

>+]@

>G%@

(b) 2000Hz

Fig. 4.28 : Sound attenuation level contours under Same filter (1600㸪2000Hz)

(a) ANC OFF 100Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 100Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 125Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 125Hz

Fig. 4.29 : Sound pressure level contours under Same filter (100㸪125Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 160Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 160Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 200Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 200Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 250Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 250Hz

Fig. 4.30 : Sound pressure level contours under Same filter (125㸪200㸪250Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 315Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 315Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 400Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 400Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 500Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 500Hz

Fig. 4.31 : Sound pressure level contours under Same filter (315㸪400㸪500Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 630Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 630Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 800Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 800Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 1000Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 1000Hz

Fig. 4.32 : Sound pressure level contours under Same filter (630㸪800.1000Hz)

[>P@

\>P@

>+]@

>G%@

(a) ANC OFF 1250Hz

[>P@

\>P@

>+]@

>G%@

(b) ANC ON 1250Hz

[>P@

\>P@

>+]@

>G%@

(c) ANC OFF 1600Hz

[>P@

\>P@

>+]@

>G%@

(d) ANC ON 1600Hz

[>P@

\>P@

>+]@

>G%@

(e) ANC OFF 2000Hz

[>P@

\>P@

>+]@

>G%@

(f) ANC ON 2000Hz

Fig. 4.33 : Sound pressure level contours under Same filter (1250㸪1600㸪2000Hz)

4.11 ⪃ᐹ

AAS Type2࡟ࡼࡗ࡚300[Hz]Ң 2[kHz]ࡢᖏᇦ࡛5Ң 18[dB]ࡢῶ㡢ຠᯝࢆᚓࡿࡇ࡜ࡀ࡛

ࡁ㸪ᗈ࠸ᖏᇦ࡛ࡢῶ㡢ຠᯝ࡜ῶ㡢ศᕸࢆ☜ㄆ࡛ࡁ㸪┠ᶆࡢ500[Hz]௨ୗࡢῶ㡢ᛶ⬟

ࡢᨵၿࡀྍ⬟࡜࡞ࡗࡓ㸬ࡲࡓ㸪ྠ୍໬ࣇ࢕ࣝࢱࡢᐇ㦂࡛ࡶྠᵝ࡞⤖ᯝࢆᚓࡿ㸬ࡋ࠿

ࡋ㸪4.7⠇࡛ࡢప࿘Ἴ⏝AASࡢヨ㦂⤖ᯝ㸪3.6⠇ࡢ㧗࿘Ἴ⏝ࡢAAS࡛ࡢ⤖ᯝ࡜AAS Type 2ࡢ⤖ᯝࢆẚ㍑ࡍࡿ࡜㸪150Ң 500[Hz]࡜1.6Ң 2[kHz]ࡢ࿘Ἴᩘᖏᇦ࡛㸪ῶ㡢ຠᯝ

ࡀ5[dB]⛬ࡢຎ໬ࡍࡿ㸬ࡑࡢ⌮⏤ࡣ௨ୗࡢࡼ࠺࡟⪃࠼ࡽࢀࡿ㸬ࡲࡎ㸪➨2❶ࡢ⤖ᯝࡼ

ࡾ㸪ṇ㠃ධᑕ࡟࠾࠸࡚㸪ῶ㡢ྍ⬟࡞࿘Ἴᩘࡣw/λ ≤0.75࡛Ỵࡲࡿࡢ࡛㸪TypeHࡢࣘ

ࢽࢵࢺ࡛ࡣ2040[Hz]௨ୗࢆῶ㡢ྍ⬟ࡔࡀ㸪TypeLࡢࣘࢽࢵࢺ࡛ࡣ763[Hz]௨ୗࢆῶ㡢

ྍ⬟࡜࡞ࡿ㸬ࡲࡓప࿘Ἴഃࡣࢫࣆ࣮࢝ᛶ⬟࡟ࡼࡗ࡚Ỵᐃࡉࢀ㸪TypeLࡢࣘࢽࢵࢺ࡛

ࡣ120[Hz]࠿ ࡽ Ⓨ 㡢 ࡛ ࡁ 㸪TypeH࡛ ࡣ300[Hz]௨ ୗ ࡢ Ⓨ 㡢 ࡀ 㞴 ࡋ ࠸ 㸬ࡋ ࠿ ࡋ ࡞ ࡀ ࡽ 㸪

Fig.4.13ࡼࡾ㸪500[Hz]௨ୗࢆⓎ㡢ࡉࡏࡿࣇ࢕ࣝࢱࢆ⏕ᡂࡋ࡚࠸ࡿ㸬⤖ᯝ㸪ࢫࣆ࣮࢝ࡢ

Ⓨ㡢ᛶ⬟࡟ࡼࡾࢤ࢖ࣥࡣᑠࡉ࠸ࡶࡢࡢ500[Hz]௨ୗࡢ㡢ἼࢆⓎ⏕ࡋ࡚࠸ࡿ㸬ࡑࡢドᣐ

࡟Fig.4.18㸪4.19ࡼࡾ㸪Type Hࡢㄗᕪ࣐࢖ࢡࣟ࣍ࣥ఩⨨௜㏆ࡣῶ㡢㔞ࡀຎ໬ࡋ࡚࠸ࡿ

ࡇ࡜ࡀࢃ࠿ࡿ㸬ࡑࡢࡓࡵ㸪ప࿘Ἴഃࡢຎ໬ࡢཎᅉࡣ㸪Type Hࡢไᚚࢭࣝ࡟ࡼࡿప࿘

Ἴࡢ㡢Ἴࡀእ஘࡜࡞ࡾ㸪Type Lࡢ᳨ฟ࣐࢖ࢡࣟ࣍ࣥࡢಙྕ࡜ࢥࣄ࣮ࣞࣥࢺࡀ࡞࠸ಙ

ྕ࡜ࡋ࡚ㄗᕪ࣐࢖ࢡࣟ࣍ࣥ࡟ධࡿࡓࡵ㸪ῶ㡢ࡍࡿࡇ࡜ࡀ࡛ࡁࡎຎ໬ࡀ⏕ࡌࡿ㸬ྠᵝ

࡟㧗࿘Ἴ࡟ࡘ࠸࡚ࡶ㸪Type Lࡀ㧗࿘ἼࡢἼ㠃ࢆ⏕ᡂ࡛ࡁ࡞࠸≧ែ࡛㧗࿘ἼࢆⓎ㡢ࡍ

ࡿࡇ࡜࡟ࡼࡾ㸪ῶ㡢㔞ࡀຎ໬ࡍࡿ㸬ࡋ࠿ࡋ㸪ప࿘Ἴࡼࡾῶ㡢ຎ໬ࡀᑡ࡞࠸㸬ࡑࡢཎ ᅉࡣ㸪Type Hࡀㄗᕪ࣐࢖ࢡࣟ࣍ࣥ఩⨨࡛ไᚚἼ㠃ࢆ⏕ᡂྍ⬟࡛࠶ࡾ㸪ᚋ᪉ࡢType L ࡢㄗᕪ࣐࢖ࢡࣟ࣍ࣥ࡟ῶ㡢ࡋࡓ㡢Ἴࡀ฿㐩ࡍࡿࡓࡵ࡛࠶ࡿ㸬⤖ᯝ㸪ㄗᕪ࣐࢖ࢡࣟ࣍

࡛ࣥࡢࢤ࢖ࣥࡀᑠࡉࡃ㸪Filtered-X-LMS࢔ࣝࢦࣜࢬ࣒࡟ࡼࡿ㐺ᛂྠᐃ࡛ࡣ㸪Fig.4.14 ࡀ♧ࡍ࡜࠾ࡾ㸪ไᚚࣇ࢕ࣝࢱࡢ㧗࿘Ἴᡂศࡢࢤ࢖ࣥࡀቑ࠼࡞࠸㸬ゝ࠸᥮࠼ࢀࡤ㸪㧗

࿘Ἴᡂศࡣ࠶ࡲࡾⓎ㡢ࡋ࡞࠸ࣇ࢕ࣝࢱ࡜࡞ࡿ㸬

௨ୖࡇ࡜࠿ࡽ㸪ྛࣘࢽࢵࢺࡢไᚚࣇ࢕ࣝࢱࡀ཰᮰ࡋ㸪ᅛᐃࣇ࢕ࣝࢱ࡟ࡼࡾῶ㡢ྍ⬟࡛

࠶ࡾ㸪300[Hz]Ң 500[Hz]࡟࠾ࡅࡿῶ㡢ຠᯝࡀᨵၿࡉࢀࡓ㸬ࡼࡗ࡚㸪AASࡢᑐ㇟࿘Ἴᩘ

ᖏᇦࡢᗈᇦ໬ࡍࡿᨵၿ᪉ἲ࡜࡞ࡗࡓ㸬ࡲࡓ㸪ῶ㡢ᛶ⬟ࢆࡉࡽ࡟ᨵၿࡍࡿ࡟ࡣ㸪AAS

Type1’࡛ࡣᑠᆺ࠿ࡘప࿘Ἴ࡟࠾ࡅࡿⓎ㡢ᛶ⬟ࡢ㧗࠸ࢫࣆ࣮࢝ࢆ㛤Ⓨࡍࡿᚲせࡀ࠶

ࡿ㸬AAS Type2࡛ࡣྛ✀㢮ࡢAASࣘࢽࢵࢺᮏ᮶ࡢᛶ⬟ࢆ᭱኱㝈࡟ࡍࡿࡓࡵ࡟ࡣ㸪2 ࡘ㸦ࡲࡓࡣ3ࡘ௨ୖࡢ㸧㐺ษ࡞ࣘࢽࢵࢺ㛫㝸wࢆ㑅ᐃࡋ㸪ไᚚ᪉ἲࡢᨵⰋࡀᚲせ࡜

⪃࠼ࡽࢀࡿ㸬

4.12 ⤖ゝ

ᮏ◊✲࡛ࡣ㸪࢔ࢡࢸ࢕ࣈ㡢㡪ࢩ࣮ࣝࢹࣥࢢ(Active Acoustic Shielding:AAS)ࡢప࿘

Ἴᖏᇦ࡟࠾ࡅࡿῶ㡢ᛶ⬟ᨵၿࢆࡍࡿࡓࡵ࡟㸪ᚑ᮶ᆺࢫࣆ࣮࢝ኚ᭦ࢱ࢖ࣉ࡜᪂ࡋ࠸ࢥ

ࣥࢭࣉࢺ࡜ࡋ࡚㧗࣭ప࿘Ἴᖏᇦ」ྜᆺAAS Type 2 ࢆⓎ᱌ࡋ㸪ྛAASࣘࢽࢵࢺࡢ〇 స㸪ࡲࡓ㸪ࡑࡢῶ㡢ᛶ⬟ࢆᐇ㦂࡟ࡼࡾ☜ㄆࡋ㸪௨ୗࡢ⤖ㄽࢆᚓࡓ㸬

࣭ ᚑ᮶ᆺAASࢭࣝࡢࢫࣆ࣮࢝ኚ᭦ᆺAAS Type1’ ࡛ࡣ㸪300[Hz]Ң 2[kHz]࡟࠾࠸࡚

10Ң 20[dB]ࡢῶ㡢ຠᯝࡀ☜ㄆࡉࢀࡓ㸬ࡋ࠿ࡋ㸬ࢫࣆ࣮࢝ࢧ࢖ࢬ࡜AASࢭࣝ㓄⨨

㛫㝸ࡢවࡡྜ࠸࡟ࡼࡾ㸪ࡇࡢ᪉ἲ࡛ࡢ᭦࡞ࡿᛶ⬟ᨵၿࡣ㝈⏺ࡀ࠶ࡿ㸬

࣭ 㧗࣭ప࿘Ἴᖏᇦ」ྜᆺAAS Type 2ࢆⓎ᱌ࡋྛࣘࢽࢵࢺࢆ〇సࡋࡓ㸬

࣭ ప࿘Ἴ⏝ᖏᇦ⏝AASࣘࢽࢵࢺ(Type L)༢య࡛ࡢᐇ㦂ࢆ⾜࠸㸪150[Hz]Ң 500[Hz]

ᖏᇦࢆ10Ң 20[dB]ࡢῶ㡢ຠᯝࢆᚓࡿࡇ࡜ࡀ࡛ࡁ㸪ప࿘Ἴ⏝ᖏᇦ⏝AASࡣ100[Hz]

ᖏᇦ௜㏆࠿ࡽῶ㡢ྍ⬟࡛࠶ࡿࡇ࡜ࡀ☜ㄆࡉࢀࡓ㸬

࣭ 㧗࣭ప࿘Ἴ」ྜᆺAAS㸦Type 2㸧࡟ࡼࡿᐇ㦂ࢆ⾜࠸㸪ᚋ᪉ࣔࢽࢱ࣮Ⅼ࡛300[Hz]Ң 2[kHz]ࡢᖏᇦ࡛5Ң 20[dB]ࡢῶ㡢ຠᯝࡀ☜ㄆࡉࢀ㸪ῶ㡢ศᕸ࡟ࡘ࠸࡚ࡶ㸪160[Hz]

Ң 2[kHz]ࡢᖏᇦ࡛5Ң 18[dB]ᚓࡿࡇ࡜ࡀ☜ㄆࡉࢀࡓ㸬

࣭ ྛไᚚ㸦ᅛᐃ㸧ࣇ࢕ࣝࢱᖹᆒ໬ࡋࡓྠ୍ࣇ࢕ࣝࢱࢆ⏝࠸ࡓᐇ㦂࡟࠾࠸࡚ࡶྠᵝ

࡞⤖ᯝࡀᚓࡿࡇ࡜ࡀ࡛ࡁࡓ㸬

௨ୖࡢ⤖ᯝࡼࡾ㸪AASࡢప࿘Ἴᖏᇦ࡟࠾ࡅࡿῶ㡢ᛶ⬟ᨵၿࡀࡀ☜ㄆࡉࢀࡓ㸬

ㄢ㢟࡜ࡋ࡚ࡣ㸪AAS Type 2 ࡢྛࣘࢽࢵࢺ㛫ࡢᙳ㡪ࢆ⪃៖ࡋࡓไᚚᡭἲࡢᨵၿࡀᚲ せ࡛࠶ࡿ 㸬

➨ 5 ^❶

AAS ኱つᶍ໬࡟࠾ࡅࡿไᚚ᪉ἲࡢᨵၿ

5.1 ⥴ゝ

̭ᮏ❶࡛ࡣ㸪AASࡢ❆㠃✚ࡀቑຍࡋࡓሙྜ㸪ࢩࢫࢸ࣒ࡢ኱つᶍ໬ࢆ㜵ࡄᡭἲ࡜ࡋ

࡚ᥦ᱌ࡋࡓ㸪M[(1-1)-L’] Filtered-X-LMS࢔ࣝࢦࣜࢬ࣒࡟ࡼࡿไᚚ᪉ἲࡢᨵၿ࡟ࡘ࠸

࡚㏙࡭ࡿ㸬➨1❶࡛㏙࡭ࡓAASࡢࢥࣥࢭࣉࢺࡼࡾ㸪AASࡢῶ㡢ྍ⬟࡞࿘Ἴᩘᖏᇦࡢ

ୖ㝈ࡣAASࡢࢭࣝ㓄⨨㛫㝸࡟ࡼࡗ࡚Ỵࡲࡿ㸬ࡑࡢࡓࡵ㸪❆ࡢࢧ࢖ࢬࡀቑຍࡍࡿሙྜ㸪 ᛶ⬟ࢆಖࡘࡓࡵ࡟ࡣ㸪㓄⨨㛫㝸ࢆಖࡕ㸪ࢭࣝᩘࢆቑࡸࡍᚲせࡀ࠶ࡿ㸬➨3❶࡛ࡣ❆

ࢧ࢖ࢬࡣ250[mm]࡜ᑠࡉ࡞ࣔࢹ࡛ࣝ⾜ࢃࢀ㸪4(1-1)-4Filtered-X-LMS࢔ࣝࢦࣜࢬ࣒࡟

ࡼࡾไᚚྍ⬟࡛࠶ࡗࡓ㸬ࡋ࠿ࡋ࡞ࡀࡽ㸪ᐇ⏝ⓗ࡟ࡣࡉࡽ࡟኱ࡁ࡞❆ࡀᚲせ࡛࠶ࡿ㸬 ࡇࡢሙྜ㸪AASࢭࣝࡢ㓄⨨㛫㝸wࢆኚ࠼ࡎ࡟AASࢭࣝࡢಶᩘࡣቑࡸࡍᚲせࡀ࠶ࡿ㸬

➨3❶࡛㏙࡭ࡓୖグᡭἲ࡛ࡣ㸪᭱⤊ⓗ࡟ࡣྛAASࢭࣝࡀ㐺ᛂྠᐃ࡛ồࡲࡿఏ㐩㛵ᩘ

H(ω)࡟ࡼࡾ⊂❧࡟ไᚚྍ⬟࡛ࡣ࠶ࡿࡀ㸪ไᚚࢭࣝࡀM ಶࡢሙྜ㸪ྛไᚚఏ㐩㛵ᩘ

H(ω)ࢆ㐺ᛂྠᐃࡍࡿࡓࡵ࡟㸪ྛAASࢭࣝࡣMಶࡢㄗᕪఏ㐩⤒㊰Cˆ(ω)ࢆྠᐃࡍࡿ

ᚲせࡀ࠶ࡾ㸪ィM ࡢ㸰஌ಶࡢㄗᕪ⤒㊰ఏ㐩≉ᛶࡢྠᐃࡀᚲせ࡜࡞ࡗ࡚ࡋࡲ࠸㸪ࢩࢫ ࢸ࣒ࡀ኱つᶍ࡟࡞ࡿ㸬ࡑࡇ࡛㸪ከࢳࣕࣥࢿࣝไᚚࢩࢫࢸ࣒ࡢつᶍቑ኱ࢆ㜵ࡄ㸪᪂ࡓ࡞

ไᚚᡭἲ࡜ࡋ࡚M[(1-1)-L̓] FX-LMS࢔ࣝࢦࣜࢬ࣒ࢆᥦ᱌ࡋ㸪ᐇ㦂࡜ࢩ࣑࣮ࣗࣞࢩࣙ

ࣥ࡟ࡼࡾᛶ⬟࡜ࡑࡢ᭷⏝ᛶࢆ☜ㄆࡍࡿ㸬

ᮏ᮶ࡢࢥࣥࢭࣉࢺ࡛࠶ࡿ㸪᭱⤊ⓗ࡟1ࢭࣝ㸦᳨ฟ࣐࢖ࢡࣟ࣍ࣥ࡜ไᚚࢫࣆ࣮࢝ࡢ ࢭࢵࢺ㸧ࢆఏ㐩㛵ᩘH(ω)࡛⊂❧࡟ไᚚࡍࡿࡓࡵࡢ㐺ᛂྠᐃ᪉ἲࢆᨵၿࡍࡿ㸬ୖグ ࡢ᪂࢔ࣝࢦࣜࢬ࣒ࡣ㸪ྛAASࢭࣝࡀ㏆ഐࡢㄗᕪ࣐࢖ࢡࣟ࣍ࣥࡢಙྕ࡜㏆ഐࡢㄗᕪ⤒

㊰ఏ㐩㛵ᩘࡢࡳ౑⏝ࡋ࡚ไᚚఏ㐩ࣇ࢕ࣝࢱࡀ㐺ᛂྠᐃࡉࢀࡿ㸬ࡑࡢ௚ࡢไᚚⅬಙྕ

ࢆ┬ࡃ⌮⏤࡜ࡋ࡚㸪㓄⨨ࡢ᮲௳ࡼࡾ㸪ྛࢭࣝࡀⓎ⏕ࡍࡿ㡢Ἴࡀ㐲᪉࡬୚࠼ࡿᐤ୚ࡣ ᑠࡉࡃ㸪ྠᵝ࡟㐲᪉ࡢࢭࣝ࠿ࡽ⮬ࢭࣝṇ㠃ࡢㄗᕪ࣐࢖ࢡࣟ࣍ࣥ࡬ࡢᐤ୚ࡣᑠࡉ࠸࡜

⪃࠼ࡽࢀ㸪ࡇࡢᡭἲ࡟⮳ࡗࡓ㸬ࡇࡢሙྜ㸪㐺ᛂྠᐃ᫬࡟ࡣ㸪MಶࡢࢭࣝࡀྛࠎL’ࢳࣕ

ࣥࢿࣝࡢㄗᕪ⤒㊰㏻㐣ಙྕࡢࡳࢆ⪃៖ࡍࡿ㸬ࡘࡲࡾ㸪ྛࠎࡀ1-1-L’Filtered-X-LMS࢔

ࣝࢦࣜࢬ࣒࡛ືసࡉࡏࡿ㸬ࡲࡓྛࠎࡢࢩࢫࢸ࣒ࡣ⊂❧࡟ᖹ⾜ࡋ࡚ືసࡉࡏࡿ㸬᭱⤊

ⓗ࡟ࡣᚑ᮶࡜ྠᵝ࡟1-1ࡢࢩࢫࢸ࣒(᳨ฟ࣐࢖ࢡ࣍ࣥ࡜ไᚚࢫࣆ࣮࢝㸧࡜࡞ࡾྛࢭࣝ

ࡣᅛᐃࣇ࢕ࣝࢱ࡛ࣇ࢕࣮ࢻࣇ࢛࣮࣡ࢻไᚚࡍࡿࡇ࡜࡛㸪ῶ㡢ศᕸࢆᚓࡿ㸬̭ᮏ❶࡛ࡣ

ࡲࡎM[(1-1)-L] Filtered-X-LMS࢔ࣝࢦࣜࢬ࣒࡟࡟ࡘ࠸࡚㏙࡭ࡿ㸬ḟ࡟6ࢳࣕࣥࢿࣝ

AASࣔࢹࣝࢆ〇సࡋ㸪᪂ᡭἲࡢᐇ㦂ࢆ⾜࠺㸬ࡘ࡙࠸࡚ᩘ್ࢩ࣑࣮ࣗࣞࢩࣙࣥ࡟ࡼࡗ

࡚ไᚚⅬ࡟࠾ࡅࡿῶ㡢ຠᯝ࡟ཬࡰࡍྛไᚚࣃ࣓࣮ࣛࢱࡢᙳ㡪ࢆ☜ㄆࡍࡿ㸬᭱ᚋ࡟ࡑ ࡢ⤖ᯝࢆẚ㍑᳨࣭ウࡍࡿࡇ࡜࡟ࡼࡾ㸪᪂ไᚚᡭἲࡢᐇ⌧ᛶࢆ᳨ウࡍࡿ㸬

5.2 ศᩓไᚚࢆ⏝࠸ࡓ ANC ᡭἲ ( M [(1-1)- L

]

ドキュメント内 Basic Study on Active Acoustic Shielding (ページ 87-110)