% 求超前校正器的傳遞函數
n1=conv([0 40],[6.667 1]);
d1=conv(conv(conv([1 0],[1 1]),[1 4]),[63.33 1]);
sope=tf(n1,d1);
wc=1.5;
num=sope.num{1};
den=sope.den{1};
na=polyval(num,j*wc);
da=polyval(den,j*wc);
g=na/da;
g1=abs(g);
h=20*log10(g1);
a=10^(h/10);
wm=wc;
T=1/(wm*(a)^(1/2));
alphat=a*T;
Gc=tf([T 1],[alphat 1])