>> [lp,mp]=pade(0.25,8);
>> l=4*lp;
>> m=conv([4 4 1 0],mp);
>> t=0:0.1:50;
>> y0=step(l,m,t);
>> plot(t,y0);grid
>> [t' y0]
>> t1=30;
>> y1=103;
>> t2=45;
>> y2=163;
>> a=(y1-y2)/(t1-t2)

>> b=-(a*t1)+y1

>> Tc=1/a

>> tau=(-b)/a

>> [lp2,mp2]=pade(4.25,8);
>> m2=conv([0.25 0],mp2);
>> y3=step(lp2,m2,t);
>> plot(t,y0,t,y3);grid
>> kp=0.65*(Tc/tau)

>> Td=0.23*tau

>> Ti=5*tau

>> ki=kp/Ti

>> kd=kp*Td

>> N=5/Td