使用小波包变换分析信号的MATLAB程序

下面是使用小波包变换分析两个信号的特征向量和各频率成分的功率谱！



%t=0.001:0.001:1;
t=1:1000;
s1=sin(2*pi*50*t*0.001)+sin(2*pi*120*t*0.001)+rand(1,length(t));

for t=1:500;
s2(t)=sin(2*pi*50*t*0.001)+sin(2*pi*120*t*0.001)+rand(1,length(t));
end

for t=501:1000;
s2(t)=sin(2*pi*200*t*0.001)+sin(2*pi*120*t*0.001)+rand(1,length(t));
end


subplot(9,2,1)
plot(s1)
title('原始信号')
ylabel('S1')

subplot(9,2,2)
plot(s2)
title('故障信号')
ylabel('S2')

wpt=wpdec(s1,3,'db1','shannon');

%plot(wpt);
s130=wprcoef(wpt,[3,0]);
s131=wprcoef(wpt,[3,1]);
s132=wprcoef(wpt,[3,2]);
s133=wprcoef(wpt,[3,3]);
s134=wprcoef(wpt,[3,4]);
s135=wprcoef(wpt,[3,5]);
s136=wprcoef(wpt,[3,6]);
s137=wprcoef(wpt,[3,7]);
s10=norm(s130);
s11=norm(s131);
s12=norm(s132);
s13=norm(s133);
s14=norm(s134);
s15=norm(s135);
s16=norm(s136);
s17=norm(s137);

st10=std(s130);
st11=std(s131);
st12=std(s132);
st13=std(s133);
st14=std(s134);
st15=std(s135);
st16=std(s136);
st17=std(s137);

disp('正常信号的特征向量');
snorm1=[s10,s11,s12,s13,s14,s15,s16,s17]
std1=[st10,st11,st12,st13,st14,st15,st16,st17]

subplot(9,2,3);plot(s130);
ylabel('S130');
subplot(9,2,5);plot(s131);
ylabel('S131');
subplot(9,2,7);plot(s132);
ylabel('S132');
subplot(9,2,9);plot(s133);
ylabel('S133');
subplot(9,2,11);plot(s134);
ylabel('S134');
subplot(9,2,13);plot(s135);
ylabel('S135');
subplot(9,2,15);plot(s136);
ylabel('S136');
subplot(9,2,17);plot(s137);
ylabel('S137');


wpt=wpdec(s2,3,'db1','shannon');

%plot(wpt);
s230=wprcoef(wpt,[3,0]);
s231=wprcoef(wpt,[3,1]);
s232=wprcoef(wpt,[3,2]);
s233=wprcoef(wpt,[3,3]);
s234=wprcoef(wpt,[3,4]);
s235=wprcoef(wpt,[3,5]);
s236=wprcoef(wpt,[3,6]);
s237=wprcoef(wpt,[3,7]);

s20=norm(s230);
s21=norm(s231);
s22=norm(s232);
s23=norm(s233);
s24=norm(s234);
s25=norm(s235);
s26=norm(s236);
s27=norm(s237);

st20=std(s230);
st21=std(s231);
st22=std(s232);
st23=std(s233);
st24=std(s234);
st25=std(s235);
st26=std(s236);
st27=std(s237);

disp('故障信号的特征向量');
snorm2=[s20,s21,s22,s23,s24,s25,s26,s27]
std2=[st20,st21,st22,st23,st24,st25,st26,st27]


subplot(9,2,4);plot(s230);
ylabel('S230');
subplot(9,2,6);plot(s231);
ylabel('S231');
subplot(9,2,8);plot(s232);
ylabel('S232');
subplot(9,2,10);plot(s233);
ylabel('S233');
subplot(9,2,12);plot(s234);
ylabel('S234');
subplot(9,2,14);plot(s235);
ylabel('S235');
subplot(9,2,16);plot(s236);
ylabel('S236');
subplot(9,2,18);plot(s237);
ylabel('S237');

%fft

figure
y1=fft(s1,1024);
py1=y1.*conj(y1)/1024;
y2=fft(s2,1024);
py2=y2.*conj(y2)/1024;

y130=fft(s130,1024);
py130=y130.*conj(y130)/1024;
y131=fft(s131,1024);
py131=y131.*conj(y131)/1024;
y132=fft(s132,1024);
py132=y132.*conj(y132)/1024;
y133=fft(s133,1024);
py133=y133.*

conj(y133)/1024;
y134=fft(s134,1024);
py134=y134.*conj(y134)/1024;
y135=fft(s135,1024);
py135=y135.*conj(y135)/1024;
y136=fft(s136,1024);
py136=y136.*conj(y136)/1024;
y137=fft(s137,1024);
py137=y137.*conj(y137)/1024;

y230=fft(s230,1024);
py230=y230.*conj(y230)/1024;
y231=fft(s231,1024);
py231=y231.*conj(y231)/1024;
y232=fft(s232,1024);
py232=y232.*conj(y232)/1024;
y233=fft(s233,1024);
py233=y233.*conj(y233)/1024;
y234=fft(s234,1024);
py234=y234.*conj(y234)/1024;
y235=fft(s235,1024);
py235=y235.*conj(y235)/1024;
y236=fft(s236,1024);
py236=y236.*conj(y236)/1024;
y237=fft(s237,1024);
py237=y237.*conj(y237)/1024;

f=1000*(0:511)/1024;
subplot(1,2,1);
plot(f,py1(1:512));
ylabel('P1');
title('原始信号的功率谱')
subplot(1,2,2);
plot(f,py2(1:512));
ylabel('P2');
title('故障信号的功率谱')

figure

subplot(4,2,1);
plot(f,py130(1:512));
ylabel('P130');
title('S130的功率谱')
subplot(4,2,2);
plot(f,py131(1:512));
ylabel('P131');
title('S131的功率谱')
subplot(4,2,3);
plot(f,py132(1:512));
ylabel('P132');
subplot(4,2,4);
plot(f,py133(1:512));
ylabel('P133');
subplot(4,2,5);
plot(f,py134(1:512));
ylabel('P134');
subplot(4,2,6);
plot(f,py135(1:512));
ylabel('P135');
subplot(4,2,7);
plot(f,py136(1:512));
ylabel('P136');
subplot(4,2,8);
plot(f,py137(1:512));
ylabel('P137');
figure

subplot(4,2,1);
plot(f,py230(1:512));
ylabel('P230');
title('S230的功率谱')
subplot(4,2,2);
plot(f,py231(1:512));
ylabel('P231');
title('S231的功率谱')
subplot(4,2,3);
plot(f,py232(1:512));
ylabel('P232');
subplot(4,2,4);
plot(f,py233(1:512));
ylabel('P233');
subplot(4,2,5);
plot(f,py234(1:512));
ylabel('P234');
subplot(4,2,6);
plot(f,py235(1:512));
ylabel('P235');
subplot(4,2,7);
plot(f,py236(1:512));
ylabel('P236');
subplot(4,2,8);
plot(f,py237(1:512));
ylabel('P237');
figure
%plottree(wpt)