This paper addresses the temperature control problem of certain reaction kinetics networks in non... more This paper addresses the temperature control problem of certain reaction kinetics networks in nonisothermal continuous agitated reactors whose isothermal version exhibits a unique stable critical point. The treatment of the problem incorporates notions from chemical reaction theory (kinetics and stoichiometry) and from nonlinear dynamics. From a chemical reactor network theory viewpoint, a new geometric dynamic characterization, is obtained for the continuous reactor. The nonlinear temperature controller is the result of undoing the structural changes induced by the passage from the isothermal reactor to the nonisothermal one. Finally, the approach is extended to treat the temperature tracking control for a nonisothermal batch reactor.
For single-input single-output input-forced systems [x¿ = f(x,d) + g(x,d) ¿(x,d,u); y = h(x,d)]... more For single-input single-output input-forced systems [x¿ = f(x,d) + g(x,d) ¿(x,d,u); y = h(x,d)] which admit semiglobal complete state linearization, we derive a nonlinear feedforward-feedback control strategy for asymptotically stable output tracking with disturbance rejection. Conditions are derived for system transformation to a linear time-invariant Brunovsky-type controllability-observability form where the problem is solved.
The aim of this paper is to study the robustness of a class of control strategies with bias updat... more The aim of this paper is to study the robustness of a class of control strategies with bias update for blending operation. The class of blender control systems consists of a linear programming endowed with a bias updating scheme to reduce (nonlinear) model/plant mismatch within ...
The authors address the problem of the qualitative determination of the stability region for clos... more The authors address the problem of the qualitative determination of the stability region for closed-loop systems with one bounded input. It is shown that the stability region form depends strongly on the number nu of open-loop system eigenvalues with a positive real part. In particular, if the open-loop system is completely unstable (nu=n) the stability region is bounded and diffeomorphic
Physica A-statistical Mechanics and Its Applications, 2003
... Programa de Investigacion en Matematicas Aplicadas y Computacion, Instituto Mexicano del Petr... more ... Programa de Investigacion en Matematicas Aplicadas y Computacion, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Col. ... In a recent paper [1], we have used Hurst (multifractal) analysis of daily CO price fluctuations to gain some insight into the underlying ...
Feedback stabilization of systems subject to constraints has been a long-standing problem in cont... more Feedback stabilization of systems subject to constraints has been a long-standing problem in control theory. In contrast with the case of LTI plants where several techniques for optimizing performance have recently appeared, very few results are available for the case of nonlinear systems. In this paper we propose a new controller design method, based on the combination of receding horizon and control Lyapunov functions, for nonlinear systems subject to input constraints. The main result of the paper shows that this control law readers the origin an asymptotically stable equilibrium point in the entire region where stabilization with constrained controls is feasible, while, at the same time, achieving near-optimal performance
International Journal of Robust and Nonlinear Control, 1997
Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done duri... more Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done during the first author's sabbatical leave at Departmento de Matema´ticas, Centro de Investigacio´n y Estudios Avanzados del IPN. ...
Physica A-statistical Mechanics and Its Applications, 2003
In the last few years, Econophysics has raised as an alternative scientific methodology to unders... more In the last few years, Econophysics has raised as an alternative scientific methodology to understand the highly complex dynamics of real financial and economic systems. Journal papers (mainly in Physica A) and international meetings have widespread the main ideas and results ...
We address the control problem of output tracking with disturbance rejection and preclusion of in... more We address the control problem of output tracking with disturbance rejection and preclusion of internal dynamics for multi-input multi-output nonlinear plants subjected to known disturbances. The closed-loop output error dynamics is required to be linear and ...
In this work we study the stabilization of continuous stirred tank reactors with unknown reaction... more In this work we study the stabilization of continuous stirred tank reactors with unknown reaction rates. We prove that, under certain general assumptions, the chemical reactor can be stabilized with high-gain feedback. Simulations show that high-gain feedback may lead to hard input saturation and poor closed-loop performance. A reaction rate uncertainty estimator is introduced which, when coupled with a nonlinear feedback, leads to global stability with acceptable control performance. We conclude that state observation is unnecessary for the stabilization of the class of chemical reactor considered here.
... 3235 NONLINEAR BOUNDED CONTROL FOR A CLASS OF CONTINUOUS AGITATED TANK REACTORS JESUS ALVAREZ... more ... 3235 NONLINEAR BOUNDED CONTROL FOR A CLASS OF CONTINUOUS AGITATED TANK REACTORS JESUS ALVAREZ,t JOSE ALVAREZ and RODOLFO SUAREZI Dcpartamento dc TngcnicrIa dc Proccaos, Univcrsidad Atatonoma Mctropolitana-Iztapalapa, Apdo. ...
International Journal of Robust and Nonlinear Control, 1997
Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done duri... more Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done during the first author's sabbatical leave at Departmento de Matema´ticas, Centro de Investigacio´n y Estudios Avanzados del IPN. ...
This paper addresses the temperature control problem of certain reaction kinetics networks in non... more This paper addresses the temperature control problem of certain reaction kinetics networks in nonisothermal continuous agitated reactors whose isothermal version exhibits a unique stable critical point. The treatment of the problem incorporates notions from chemical reaction theory (kinetics and stoichiometry) and from nonlinear dynamics. From a chemical reactor network theory viewpoint, a new geometric dynamic characterization, is obtained for the continuous reactor. The nonlinear temperature controller is the result of undoing the structural changes induced by the passage from the isothermal reactor to the nonisothermal one. Finally, the approach is extended to treat the temperature tracking control for a nonisothermal batch reactor.
For single-input single-output input-forced systems [x¿ = f(x,d) + g(x,d) ¿(x,d,u); y = h(x,d)]... more For single-input single-output input-forced systems [x¿ = f(x,d) + g(x,d) ¿(x,d,u); y = h(x,d)] which admit semiglobal complete state linearization, we derive a nonlinear feedforward-feedback control strategy for asymptotically stable output tracking with disturbance rejection. Conditions are derived for system transformation to a linear time-invariant Brunovsky-type controllability-observability form where the problem is solved.
The aim of this paper is to study the robustness of a class of control strategies with bias updat... more The aim of this paper is to study the robustness of a class of control strategies with bias update for blending operation. The class of blender control systems consists of a linear programming endowed with a bias updating scheme to reduce (nonlinear) model/plant mismatch within ...
The authors address the problem of the qualitative determination of the stability region for clos... more The authors address the problem of the qualitative determination of the stability region for closed-loop systems with one bounded input. It is shown that the stability region form depends strongly on the number nu of open-loop system eigenvalues with a positive real part. In particular, if the open-loop system is completely unstable (nu=n) the stability region is bounded and diffeomorphic
Physica A-statistical Mechanics and Its Applications, 2003
... Programa de Investigacion en Matematicas Aplicadas y Computacion, Instituto Mexicano del Petr... more ... Programa de Investigacion en Matematicas Aplicadas y Computacion, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Col. ... In a recent paper [1], we have used Hurst (multifractal) analysis of daily CO price fluctuations to gain some insight into the underlying ...
Feedback stabilization of systems subject to constraints has been a long-standing problem in cont... more Feedback stabilization of systems subject to constraints has been a long-standing problem in control theory. In contrast with the case of LTI plants where several techniques for optimizing performance have recently appeared, very few results are available for the case of nonlinear systems. In this paper we propose a new controller design method, based on the combination of receding horizon and control Lyapunov functions, for nonlinear systems subject to input constraints. The main result of the paper shows that this control law readers the origin an asymptotically stable equilibrium point in the entire region where stabilization with constrained controls is feasible, while, at the same time, achieving near-optimal performance
International Journal of Robust and Nonlinear Control, 1997
Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done duri... more Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done during the first author's sabbatical leave at Departmento de Matema´ticas, Centro de Investigacio´n y Estudios Avanzados del IPN. ...
Physica A-statistical Mechanics and Its Applications, 2003
In the last few years, Econophysics has raised as an alternative scientific methodology to unders... more In the last few years, Econophysics has raised as an alternative scientific methodology to understand the highly complex dynamics of real financial and economic systems. Journal papers (mainly in Physica A) and international meetings have widespread the main ideas and results ...
We address the control problem of output tracking with disturbance rejection and preclusion of in... more We address the control problem of output tracking with disturbance rejection and preclusion of internal dynamics for multi-input multi-output nonlinear plants subjected to known disturbances. The closed-loop output error dynamics is required to be linear and ...
In this work we study the stabilization of continuous stirred tank reactors with unknown reaction... more In this work we study the stabilization of continuous stirred tank reactors with unknown reaction rates. We prove that, under certain general assumptions, the chemical reactor can be stabilized with high-gain feedback. Simulations show that high-gain feedback may lead to hard input saturation and poor closed-loop performance. A reaction rate uncertainty estimator is introduced which, when coupled with a nonlinear feedback, leads to global stability with acceptable control performance. We conclude that state observation is unnecessary for the stabilization of the class of chemical reactor considered here.
... 3235 NONLINEAR BOUNDED CONTROL FOR A CLASS OF CONTINUOUS AGITATED TANK REACTORS JESUS ALVAREZ... more ... 3235 NONLINEAR BOUNDED CONTROL FOR A CLASS OF CONTINUOUS AGITATED TANK REACTORS JESUS ALVAREZ,t JOSE ALVAREZ and RODOLFO SUAREZI Dcpartamento dc TngcnicrIa dc Proccaos, Univcrsidad Atatonoma Mctropolitana-Iztapalapa, Apdo. ...
International Journal of Robust and Nonlinear Control, 1997
Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done duri... more Page 1. ¹his paper was recommended for publication by editor A. Sideris * This work was done during the first author's sabbatical leave at Departmento de Matema´ticas, Centro de Investigacio´n y Estudios Avanzados del IPN. ...
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