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2001 | Buch

Nonlinear and Robust Control of PDE Systems

Methods and Applications to Transport-Reaction Processes

verfasst von: Panagiotis D. Christofides

Verlag: Birkhäuser Boston

Buchreihe : Systems & Control: Foundations & Applications

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Über dieses Buch

The interest in control of nonlinear partial differential equation (PDE) sys­ tems has been triggered by the need to achieve tight distributed control of transport-reaction processes that exhibit highly nonlinear behavior and strong spatial variations. Drawing from recent advances in dynamics of PDE systems and nonlinear control theory, control of nonlinear PDEs has evolved into a very active research area of systems and control. This book­ the first of its kind- presents general methods for the synthesis of nonlinear and robust feedback controllers for broad classes of nonlinear PDE sys­ tems and illustrates their applications to transport-reaction processes of industrial interest. Specifically, our attention focuses on quasi-linear hyperbolic and parabolic PDE systems for which the manipulated inputs and measured and controlled outputs are distributed in space and bounded. We use geometric and Lyapunov-based control techniques to synthesize nonlinear and robust controllers that use a finite number of measurement sensors and control actuators to achieve stabilization of the closed-loop system, output track­ ing, and attenuation of the effect of model uncertainty. The controllers are successfully applied to numerous convection-reaction and diffusion-reaction processes, including a rapid thermal chemical vapor deposition reactor and a Czochralski crystal growth process. The book includes comparisons of the proposed nonlinear and robust control methods with other approaches and discussions of practical implementation issues.

Inhaltsverzeichnis

Frontmatter
Chapter 1. Introduction
Abstract
Transport-reaction processes are characterized by the coupling of chemical reaction with significant convection, diffusion, and dispersion phenomena, and are essential in making many high-value industrial products. Examples include the plug-flow and packed-bed reactors used to produce specialty chemicals, the Czochralski crystallization of high-purity crystals, and the chemical vapor deposition of thin films for microelectronics manufacturing, as well as the solidification of liquid solution coatings for photographic films
Panagiotis D. Christofides
Chapter 2. Feedback Control of Hyperbolic PDE Systems
Abstract
Transport-reaction processes in which the diffusive and dispersive phenomena are negligible compared to the convective phenomena can be adequately described by systems of first-order hyperbolic PDEs. Representative chemical processes modeled by such systems include heat exchangers [115], plug-flow reactors [115], fixed-bed reactors [130], pressure swing adsorption processes [119], and so forth.
Panagiotis D. Christofides
Chapter 3. Robust Control of Hyperbolic PDE Systems
Abstract
In the previous chapter, we addressed the control of hyperbolic PDE systems without accounting explicitly for the presence of uncertainty (i.e., presence of mismatch between the model used for controller design and the actual process model) in the design of the controller. This chapter focuses on systems of quasi-linear first-order hyperbolic PDEs with uncertainty for which the manipulated variables and the controlled variables are distributed in space. The objective is to develop a framework for the synthesis of distributed robust controllers that handle explicitly time-varying uncertain variables and unmodeled dynamics. For systems with uncertain variables, the problem of complete elimination of the effect of uncertainty on the output via distributed feedback is initially considered; a necessary and sufficient condition for its solvability, as well as explicit controller synthesis formulas, is derived. Then, a distributed robust controller is derived that guarantees boundedness of the state and achieves asymptotic output tracking with arbitrary degree of asymptotic attenuation of the effect of uncertain variables on the output of the closed-loop system
Panagiotis D. Christofides
Chapter 4. Feedback Control of Parabolic PDE Systems
Abstract
In Chapters 2 and 3, we presented nonlinear and robust control methods for systems of first-order hyperbolic PDEs. In the remainder of this book, we focus our attention on nonlinear and robust control of parabolic PDE systems. Such systems arise naturally in the modeling of transport-reaction processes with significant diffusive and dispersive mechanisms (e.g., packed-bed reactors, rapid thermal processing systems, chemical vapor deposition reactors, etc.). In contrast to hyperbolic PDEs, the main feature of parabolic PDEs is that the eigenspectrum of the spatial differential operator can be partitioned into a finite-dimensional slow one and an infinite-dimensional stable fast complement [65, 12, 133]. This motivates addressing the controller synthesis problem for parabolic PDEs on the basis of finite-dimensional systems that accurately describe their dynamic behavior
Panagiotis D. Christofides
Chapter 5. Robust Control of Parabolic PDE Systems
Abstract
This chapter focuses on the control problem for quasi-linear parabolic PDEs with time-varying uncertain variables, for which the eigenspectrum of the spatial differential operator can be partitioned into a finite-dimensional (possibly unstable) slow one and an infinite-dimensional stable fast complement. The objective is to develop a general and practical methodology for the synthesis of nonlinear robust state and output feedback controllers that guarantee boundedness of the state and output tracking with arbitrary degree of asymptotic attenuation of the effect of the uncertain variables on the output of the closed-loop system
Panagiotis D. Christofides
Chapter 6. Nonlinear and Robust Control of Parabolic PDE Systems with Time-Dependent Spatial Domains
Abstract
There is a large number of industrial control problems which involve highly nonlinear transport-reaction processes with moving boundaries such as crystal growth, metal casting, gas-solid reaction systems, and coatings. In these processes, nonlinear behavior typically arises from complex reaction mechanisms and their Arrhenius dependence on temperature, while motion of boundaries is usually a result of phase change (like melting or solidification), chemical reaction, and/or mass and heat transfer. The mathematical models of transport-reaction processes with moving boundaries are usually obtained from the dynamic conservation equations and consist of nonlinear parabolic PDEs with time-dependent spatial domains
Panagiotis D. Christofides
Chapter 7. Case Studies
Abstract
In this chapter, we present applications of the nonlinear control methods for parabolic PDE systems with fixed and moving spatial domains presented in Chapters 4 and 6 to the rapid thermal chemical vapor deposition process introduced in subsection 1.2.2 and a Czochralski crystal growth process, respectively. The results on nonlinear control of rapid thermal chemical vapor deposition were first presented in [10, 9, 11], and the results on nonlinear control of Czochralski crystal growth in [8].
Panagiotis D. Christofides
Backmatter
Metadaten
Titel
Nonlinear and Robust Control of PDE Systems
verfasst von
Panagiotis D. Christofides
Copyright-Jahr
2001
Verlag
Birkhäuser Boston
Electronic ISBN
978-1-4612-0185-4
Print ISBN
978-1-4612-6652-5
DOI
https://doi.org/10.1007/978-1-4612-0185-4