l=0.5;
m=conv([0.67 1],[0.67 1]);
t=0:0.1:10;
y=step(l,m,t);
plot(t,y),grid;
dt=0.1;
for i=1:100;
yp(i)=(y(i+1)-y(i))/dt;
end
yp(101)=yp(100);
plot(t,y,t,yp),grid
[t' y yp']
max(yp)
0.25*max(y)
% y dla max(yp) wyosi 0.1129
% 25% z y wynosi 0.125
%
% stosuje regulator PI
t10=0.35;
t90=2.6;
T=(t90-t10)/2.2;
tau=t10-(T*0.1);

[lp,mp]=pade(tau,8);
m2=conv(mp,[T 1]);
l2=l*lp;
y2=step(l2,m2,t);
plot(t,y,t,y2),grid;

Kp=0.34*T/(tau*0.5);
Ti=T;
P=Kp;
I=Kp/Ti;