2 Proportional controller design by root-locus

The root locus displays the locii of the closed loop system poles for a controller

K(s) = kp

as the value of k,, increases from zero for the system shown in Figure 1.

Plot the root locus of the plant by

rlocus (G)

The command

sgrid

draws in lines of constant damping ratio and natural frequency wn. The damping ratio lines are drawn from < = 0

to 1 in steps of 0.1.

2