4 Example 8-11 OGATA 4ed (Nyquist plot)

Laplace.T	Root-locus	Transient response	Frecuency response

4 Example 8-11 OGATA 4ed(Nyquist plot)

Let's plot Nyquist plot by Scilab.

$\begin{displaymath}G(s)=\frac{1}{s\cdot (s+1)}\end{displaymath}$

Scilab program

clf;

s=%s/(%2*pi);

s1=-s;

g=1/(s*(s+1));

g1=1/(s1*(s1+1));

gs=syslin('c',g);

gs1=syslin('c',g1);

nyquist(gs);

nyquist(gs1);

mtlb_axis([-2 2 -5 5]);

xtitle('Nyquist plot of 1/(s*(s+1))')