Controller design: moving from theory to practice

It is suggested that modern controller design packages often fall short of offering what is truly practical: lower order controllers, discrete-time controllers operating in a sampled-data loop, and finite word length (FWL) realizations of controllers with the FWL property minimally impacting closed-loop performance. Several methods for achieving these objectives are considered. The methods deal with controller complexity, transfer function matching, stability robustness, signal spectrum matching, fractional representations of open-loop unstable controllers, discrete time controllers, and realizing digital controllers.>