Nonlinear output feedback control of a class of polymerization reactors

Abstract

This paper presents an approach to the problem of nonlinear output feedback control. A nonlinear output feedback control law is derived within the framework of input-output linearization. It includes an input-output linearizing state feedback, a linear system describing the linear input-output closed-loop response under the state feedback, and a reduced order nonlinear state observer. The nonlinear output feedback control law is applied to a class of free-radical polymerization reactors that usually exhibit multiple steady states. For this class of processes, the global asymptotic stability of the closed-loop system is proven. The performance of the controller is shown by numerical simulation of a styrene polymerization reactor.Index Terms-Global asymptotic stability, input-output linearization, model-based control, nonlinear control, output feedback control, polymerization reactor control, state observer. NOMENCLATUREConcentration of initiator in the outlet stream, kmol m −3 . Concentration of initiator in the initiator inlet stream, kmol m −3 . Concentration of monomer in the outlet stream, kmol m −3 . Concentration of monomer in the monomer inlet stream, kmol m −3 . Monomer concentration set point, kmol m −3 . Concentration of solvent in the outlet stream, kmol m −3 . Concentration of solvent in the initiator inlet stream, kmol m −3 . Concentration of solvent in the solvent inlet stream, kmol m −3 .Heat capacity of the reacting mixture, kJ · kg −1 · K −1 . Observer error. Initiator efficiency. Flow rate of the monomer inlet stream, m 3 · s −1 . Flow rate of the initiator inlet stream, m 3 · s −1 . Flow rate of the solvent inlet stream, m 3 · s −1 . Rate constant for chain-transfer-to-monomer reactions, m 3 kmol −1 s −1 . Rate constant for chain-transfer-to-solvent reactions, m 3 kmol −1 s −1 . Dissociation rate constant for initiator, s −1 .

Integrated fault‐detection and fault‐tolerant control of process systems

“…In the remainder of this section, we first review an output feedback controller design, proposed in, 20 based on a combination of a high-gain observer and a state feedback controller (see also 52,53,54,55,56 for results on observer designs and output feedback control for unconstrained nonlinear systems), and characterize the stability properties of the closed-loop system under output feedback control. Then, we present the faultdetection filter and fault-tolerant controller and demonstrate its application via a simulation example.…”

Integrated Fault-Detection and Fault-Tolerant Control of Process Systems

“…In the remainder of this section, we first review an output feedback controller design, proposed in, 20 based on a combination of a high-gain observer and a state feedback controller (see also 52,53,54,55,56 for results on observer designs and output feedback control for unconstrained nonlinear systems), and characterize the stability properties of the closed-loop system under output feedback control. Then, we present the faultdetection filter and fault-tolerant controller and demonstrate its application via a simulation example.…”

Comment on steroid hormones and disease activity during pregnancy in systemic lupus erythematosus

“…In the remainder of this section, we first review an output feedback controller design, proposed in,20 based on a combination of a high‐gain observer and a state feedback controller (see also52, 53, 54, 55, 56 for results on observer designs and output feedback control for unconstrained nonlinear systems), and characterize the stability properties of the closed‐loop system under output feedback control. Then, we present the fault‐detection filter and fault‐tolerant controller and demonstrate its application via a simulation example.…”