Choice of F_Q transfer function in Q-design controller

ssylee wrote:

Practically or academically?  (Where have I used that before?)

I'm not sure what you mean by the order of the model, but I assume that
you're constraining the behavior of your F_(s) to keep the plant
drive within bounds -- so do some analysis on the plant transfer
function, or try things out in simulation, and see what works best.  You
want the simplest system that will still attain your goals.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

It isn't clear what you are really trying to do?  One could do many
things.   if the controller is 1/G_o(s) then F(s) could be a low
pass filter to reduce output noise.  Why not simply make F((s) a
constant to increase the gain and get the closed loop control closer
to unity?

You need to give a precise example as the question is vague.
Why bother with Q design in the first place is a better question?

Peter Nachtwey