Product uniformity in many plants is determined by the integrity of th
e systems that control key product parameters. Many of these control s
ystems are multitiered, non-linear and often quite complex. Bridging t
he gap between theory and practical application is one of the most cha
llenging tasks engineers and control professionals face. In addition,
many advanced controls work well in concept or simulation but can fail
for a variety of reasons when put into a real operating environment.
This paper focuses on those factors that are critical to implementing
and operating advanced controls. It will examine why many advanced con
trols fail and discuss ways in which we have successfully applied adap
tive supervisory and model based control, as well as non-linear functi
ons to improve controller performance. (C) 1998 Published by Elsevier
Science Ltd.