User`s guide

8 The Root Locus Design GUI
8-30
Try adding a pair of complex zeros just to the left of and a little bit below the
complexclosed-looppolesclosesttotheimaginaryaxis.Theresultingrootlocus
and step response plots are as follows.
If your step responsei s unstabl e, lower the gain. In this example, the resulting
step response is stable, but it still doesn’t meet the design criteria.
As you can see, the compensator design process can involve some trial and
error. You can try dragging the compensator poles, compensator zeros, or the
closed-loop poles around the root locus until you meet the design criteria.
Alternatively, you can edit the compensator using the solution provided in the
next section.
Note: You can follow the same p rocedu re to add a single real pole or zero to
the compensat or by clicking on the re al ax is.
Add compensator zeros here.