Nonlinear Control of Neutralization Processes by Gain-Scheduling Trajectory Control

Abstract

A new approach to the nonlinear control of neutralization processes in continuous stirred tank reactors is presented. The controller design is based on a process model in terms of the standard titration curve of the process which was proposed by Wright and Kravaris (Wright, R. A.; Kravaris, C. Ind. Eng. Chem. Res. 1991, 30, 1561−1572). The central idea of this paper is to combine exact feedback linearization and gain-scheduling techniques to obtain a nonlinear control scheme which preserves the advantages and overcomes some of the problems of the two single concepts. In a first step, a nonlinear state feedback controller is computed by exact input/output linearization of the process model to shape the nominal closed-loop system. The required state variables are computed by an on-line simulation of the process model. This part of the controller thus is a pure nonlinear feedforward compensator for the nominal plant. To act against disturbances and model uncertainty, a nonlinear gain-scheduled reference cont...