%--------------------------------------------------------------------------
%?One?of?my?friends?asked?me?about?the?FxLMS?algorithm.?So?in?return?
%?I?provided?him?a?little?example?of?a?single?channel?feed-forward?active?
%?noise?control?system?based?on?the?FxLMS.?You?can?find?many?good?
%?information?in?“Active?Noise?Control?Systems?-?Algorithms?and?DSP?
%?Implementations“?written?by?S.?M.?Kuo?and?D.?R.?Morgan?in?1996.
%
%?Here?is?the?sketch?of?the?system.?
%
%??????????????+-----------+???????????????????????+???
%?x（k）?---+--->|???P（z）????|--yp（k）---------------->?sum?--+--->?e（k）
%?????????|????+-----------+??????????????????????????^-???|
%?????????|???????????????????????????????????????????|????|
%?????????|????????\????????????????????????????????ys（k）??|?????
%?????????|????+-----------+??????????+-----------+???|????|
%?????????+--->|???C（z）????|--yw（k）-->|???S（z）????|---+????|
%?????????|????+-----------+??????????+-----------+????????|
%?????????|????????????\???????????????????????????????????|
%?????????|?????????????\----------------\?????????????????|
%?????????|???????????????????????????????\????????????????|
%?????????|????+-----------+??????????+-----------+????????|
%?????????+--->|???Sh（z）???|--xs（k）-->|????LMS????|<-------+
%??????????????+-----------+??????????+-----------+????????
%?
%?I?used?FIR?filter?to?model?P（z）?C（z）?S（z）?and?Sh（z）.
%?
%?Imagine?that?the?noise?x（k）?is?propagating?from?the?source?to?the?sensor
%?through?the?fluid?medium?P（z）.?The?sensor?measures?the?arriving?noise?as?
%?yp（k）.?
%
%?To?reduce?noise?we?generate?another?‘noise‘?yw（k）?using?the?controller?
%?C（z）.?We?hope?that?it?destructively?interferes?x（k）.?It?means?that?the?
%?controller?has?to?be?a?model?of?the?propagation?medium?P（z）.?Least?mean?
%?square?algorithm?is?applied?to?adjust?the?controller?coefficient/weight.
%
%?However?there?is?also?fluid?medium?S（z）?that?stay?between?the?actuator?
%?and?sensor.?We?called?it?the?secondary?propagation?path.?So?to?make?the?
%?solusion?right?we?need?to?compensate?the?adjustment?process?using?Sh（z）?
%?which?is?an?estimate?of?S（z）.
%?
%?Let‘s?start?the?code?:）
%
%?Developed?by?Agustinus?Oey?????????????????????????
%?Center?of?Noise?and?Vibration?Control?（NoViC）???????????????????????????
%?Department?of?Mechanical?Engineering????????????????????????????????????
%?Korea?Advanced?Institute?of?Science?and?Technology?（KAIST）??????????????
%?Daejeon?South?Korea?
%--------------------------------------------------------------------------

%?Set?simulation?duration?（normalized）?
clear
T=1000;?

%?We?do?not?know?P（z）?and?S（z）?in?reality.?So?we?have?to?make?dummy?paths
Pw=[0.01?0.25?0.5?1?0.5?0.25?0.01];
Sw=Pw*0.25;

%?Remember?that?the?first?task?is?to?estimate?S（z）.?So?we?can?generate?a
%?white?noise?signal
x_iden=randn（1T）;

%?send?it?to?the?actuator?and?measure?it?at?the?sensor?position?
y_iden=filter（Sw?1?x_ide

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1526??2010-11-23?01:28??try_fxlms\license.txt

?????文件???????5447??2013-10-30?10:24??try_fxlms\try_fxlms.m

?????目錄??????????0??2013-10-30?10:39??try_fxlms

-----------?---------??----------?-----??----

?????????????????6973????????????????????3