- posted
17 years ago

plot that one gets dragged through in control engineering school? I

mean the one where you have the sum of a polynomial plus a polynomial

times a constant, i.e. it's linear in the parameter being varied.

Just "root locus" plot won't do, because you can have a polynomial that

isn't linear in the parameter and make a perfectly nice little plot, you

just can't flog the subject endlessly until your students can draw plots

by hand in their sleep for systems with 10 poles and 5 zeros or whatever

other perverse variations your sadistic mind can dream up.

And yes, almost nobody uses them in control design. I'm presenting them

because it's a handy way to understand certain compensation schemes and

because its a very powerful way of visualizing what happens to your

system stability when you vary some parameter.