This article concerns the problem of nonlinear state-observer design.
It presents a reduced-order nonlinear observer design approach, which
allows adjustment of the rate of the decay of observer error and is ea
sy to use. Furthermore, in many chemical engineering cases, it is stra
ightforward to prove analytically that the observer-error dynamics are
globally asymptotically stable. Several classes of reactors (classica
l chemical reactors, free-radical polymerization reactors, and bio-rea
ctors) are considered to illustrate the application of the observer de
sign approach. The global asymptotic stability of the observer-error d
ynamics is proved for each class of the processes. For many of these p
rocesses, this study presents the first observer with an analytically
proven global convergence. Copyright (C) 1996 Elsevier Science Ltd