fs=2048
t=1:512;
t=t*1/2048;
y=sin(2*pi*500*t+sin(2*pi*70*t));
y=hilbert(y);
ydata=abs(y);
ydata=ydata-mean(ydata);
nfft=2048;
p=abs(fft(ydata,nfft));
figure(3);
plot((0:nfft/2-1)/nfft*fs,p(1:nfft/2));
xlabel('频率 f/Hz');
%%%%%%%%%%%%%
故障频率155.4Hz怎么找不到???求指导
fs=12000;
N=2048*4;
t=(0:1/fs:(N-1)/fs);
x=X108_BA_time ;
data=x(1:N);
figure(1);plot(t,data); %时域波形;
wpt=wpdec(data,3,'db10'); %小波包分解;
c40=wpcoef(wpt,[3,0]);
y=hilbert(cc); %hilbert包络分析;
ydata=abs(y);
ydata=ydata-mean(ydata);
nfft=2048;
p=abs(fft(ydata,nfft));
figure(1);
plot((0:nfft/4-1)/nfft*1024,p(1:nfft/4));
xlabel('频率 f/Hz');
ylabel('功率谱 P/W');
title('小波包络谱')
%%%%%%%%%%%%%%%%%%
t=0:0.005:1*pi;
fs=20000;
s=4*sin(2*200*pi*t).*(sin(2*4500*pi*t))+25*(sin(2*4500*pi*t));
subplot(411);plot(t,s);title('原始信号');
%运用小波方法滤波
[c,l]=wavedec(s,1,'db10');
d1=wrcoef('d',c,l,'db10');
a1=0;
subplot(412);plot(d1);title('重构高频信号');
%hilbert变换,求包络线
y=hilbert(d1);
y1=abs(y);
subplot(413);plot(y1);title('包络线');
%FFT求包络谱
nfft=1024;
p=abs(fft(y1,nfft));
figure(2);
plot((0:nfft/2-1)/nfft*fs,p(1:nfft/2));
title('包络谱');xlabel('频率');ylabel('功率谱');
这个程序对么?画出来的对吗?
%%%%%%%%%%%%%%%%%%%%%%%
% 包络算法,未考虑边界条件
d = diff(x6); %对信号x6求导
n = length(d); %求长度
d1 = d(1:n-1);