Output feedback finite-time control for a bioreactor system based on a finite-time stable observer

This article addresses an adaptive fuzzy practical fixed-time tracking control for nonlinear systems with unknown actuator constraints and uncertainty functions. First, fuzzy logic systems (FLSs) are used to identify uncertain functions.Then, by utilizing FLSs, backstepping technique, and finite-time stability theory, an adaptive fuzzy practical fixed-time control is proposed to obtain satisfactory tracking performance even when the actuator faults. The theoretical analysis verified that the closed-loop systems is practical fixed-time stable under the proposed control strategy, the tracking error converges to a small neighborhood of the origin in a fixed time, and the convergence time is independent of the state conditions. Finally, both numerical simulation and physical example demonstrates the effectiveness of the proposed control strategy.

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“…where 𝜓(t) ∈ (0 Electromechanical systems, 29 robotic systems, 34 and so forth can be described by system (1).…”

Section: System Descriptionmentioning

confidence: 99%

“…In the past decade, compared with asymptotic stability control, finite‐time control has received much attention due to its higher control precision and faster response speed (see, e.g., References 1–5). Bhat and Bernstein 6 proposed the concept of finite‐time control.…”

Section: Introductionmentioning

confidence: 99%

Adaptive fuzzy practical fixed‐time control for uncertain nonlinear systems with actuator constraints

You

Cao

et al. 2022

Adaptive Control & Signal

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“…Las últimas tres variables dependen de la concentración de glucosa (S), como es descrito por Ec. (2). La relaciónu/Ves la velocidad de dilución.…”

Section: Bioreactor Fed Batchunclassified

Control of a Fed-Batch Fermenter Based on a Linear Algebra Strategy

Rómoli¹,

Scaglia²,

Serrano³

et al. 2014

IEEE Latin Am. Trans.

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Based on a linear algebra approach, this paper aims at developing a novel control law able to track reference profiles that were previously-determined to optimize the protein production in a fed-batch fermenter. A main advantage of the proposed strategy is that the control actions are obtained by solving a system of linear equations. The optimal controller parameters are selected through Monte Carlo Experiments in order to minimize a proposed cost index. The controller performance is evaluated through several tests, and compared with other controller reported in the literature.Keywords-Fed-batch bioreactors, Control system design, Nonlinear model, Linear algebra. I. INTRODUCCIÓNA INDUSTRIA bioquímica ha crecido significativamente a través de las últimas dos décadas[1-3], con un creciente interés en la síntesis de grandes cantidades de productos por medio de microorganismos [4]. Usualmente, muchos procesos de la industria bioquímica son operados de forma fedbatch [5]. La operación fed-batch es una de las más populares en la industria bioquímica. En esta clase de bioreatores el sustrato es alimentado gradualmente dentro del reactor, pero el producto es unicamenteremovido al finalizar el proceso. El principal objetivo es la de evitar la sobrealimentación del sustrato, el cual puede inhibir el crecimiento de losmicoorganismos.Por otra lado, los procesos fed-batch presentan a veces algunos problemas desafiantes.Por ejemplo, la mayoría de sus modelos dinámicos son no lineales y rigidos,y generalmente incluyen parámetros que varían con el tiempo [3]. Estos problemas hacen que el control del proceso sea una tarea ardua [6].Un ítem importante en los problemas de control óptimos consiste en el seguimiento de los cambios en el set point sin producir oscilaciones indeseadas o evitar tiempos de operación largos para reducir los errores de seguimiento. Existen muchos factores que complican particularmente el control de los fermentadores, por ejemplo los procesos exhiben comportamiento dinámico no lineal; rara vez están disponibles modelos precisos de los procesos debido a la complejidad de las reacciones bioquímicas implicadas; y generalmente los parámetros que varían con el tiempo son desconocidos [5].Considere un reactor fed-batch con la meta de optimización de maximizar la cantidad de una proteína secretada al final del proceso. Este problema de control óptimo ha sido estudiado por varios autores [7-10]. El principal aporte del presente trabajo es diseñar un controlador capaz de lograr reproducibilidad entre lotes sucesivos al tiempo que se siguen perfiles óptimos determinados por otros autores.Respecto a esto último, se propone un acercamiento comprensible para el seguimiento de los perfiles óptimos. Para cumplir tal objetivo, se asume lo siguiente: (i) el procesoes adecuadamente modelado a través de un modelo matemático; (ii) los perfiles óptimos deseados de las concentraciones son conocidos; y (iii) la acción de control que mueve al sistema desde su estado actual hacia el deseado puede ser calculada.En la metodología pro...

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“…Some output feedback finite-time controllers based on finite-time stable observers are presented for different kinds of systems [7,8,9]. A finite-time observer is proposed for a bioreactor system and then an output feedback finite-time controller is developed [10]. Finite-time convergent observers are designed for a class of lower-triangular nonlinear systems with bounded solution trajectories by using the homogeneous domination approach in [11].…”

Section: Introductionmentioning

confidence: 99%

Nonlinear observer design for a solar thermal water heater system

Zhao

Rosas

Qian

2015

The 27th Chinese Control and Decision Conference (2015 CCDC)

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A nonlinear observer is constructed to observe the two unobservable states of the solar thermal system from the heat exchanger. At first, we discuss the observability of the model and four cases are discussed based on the variation of the model parameters. Then, we design full-order observer when the system is observable. Especially, we design a finite-time observer for one case. At last, a simulation is created for the solar thermal system model. The result is that the unobservable states of the solar thermal system can be estimated fairly closely to the model data by using the nonlinear observer.

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Output feedback finite-time control for a bioreactor system based on a finite-time stable observer

Cited by 4 publications

References 43 publications

Adaptive fuzzy practical fixed‐time control for uncertain nonlinear systems with actuator constraints

Adaptive fuzzy practical fixed‐time control for uncertain nonlinear systems with actuator constraints

Control of a Fed-Batch Fermenter Based on a Linear Algebra Strategy

Nonlinear observer design for a solar thermal water heater system

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