Semiglobal nonlinear control based on complete input—output linearization and its application to the start-up of a continuous polymerization reactor

Robust dynamic state estimation of nonlinear plants

“…plicity of steady states Alvarez et al, 1990 , and a batch or semibatch reactor can have an open-loop unstable-state mo-Ž . tion Alvarez et al, 1994 . The reactor estimation problem follows. Based on the Ž .…”

“…Ž From previous dynamics and control studies Alvarez et al, . 1990Alvarez et al, . , 1994 in the same reactor, we know that, at T and V, the settling time of the monomer dynamics is f125 min; and that, at I, m, and V, the settling time of the temperature dynamics is f 75 min.…”

A robust state estimator design for nonlinear plants

“…The definitions of the vector field sets {fl, f2, f3, f6} and {f4, f5} are given in [3] and [2], respectively.…”

“…As the fraction of polymerized material increases, the density and the viscosity of the reacting mixture increase, diminishing the heat exchange capability of the coolingheating system. Due to the presence of the gel effect, a continuous reactor can have multiplicity of steady-states [ 11, and a batch or semibatch reactor can have an open-loop unstable trajectory [3].…”

Output‐feedback control of nonlinear plants

“…The monomer is methyl methacrylate, and the initiator is AIBN. The model function alities (r1, r,, / 3 and y ) , their parameters, and the operation ' condition are from Alvarez et al (1994). For case I, the reference gains for the controller and observer designs are the ones used by Alvarez et al (1990) in their state-feedback controller for the same polymerization reactor: 6; = 62 = 0.71, T; = r," = 125 min, T; = T; = 50 min, which were set to obtain the fastest state-feedback control response without saturation of controls and to have tolerance to modeling errors.…”