64 research outputs found
Hybrid Systems and Control With Fractional Dynamics (I): Modeling and Analysis
No mixed research of hybrid and fractional-order systems into a cohesive and
multifaceted whole can be found in the literature. This paper focuses on such a
synergistic approach of the theories of both branches, which is believed to
give additional flexibility and help to the system designer. It is part I of
two companion papers and introduces the fundamentals of fractional-order hybrid
systems, in particular, modeling and stability analysis of two kinds of such
systems, i.e., fractional-order switching and reset control systems. Some
examples are given to illustrate the applicability and effectiveness of the
developed theory. Part II will focus on fractional-order hybrid control.Comment: 2014 International Conference on Fractional Differentiation and its
Application, Ital
Basic Properties and Stability of Fractional-Order Reset Control Systems
Reset control is introduced to overcome limitations of linear control. A
reset controller includes a linear controller which resets some of states to
zero when their input is zero or certain non-zero values. This paper studies
the application of the fractional-order Clegg integrator (FCI) and compares its
performance with both the commonly used first order reset element (FORE) and
traditional Clegg integrator (CI). Moreover, stability of reset control systems
is generalized for the fractional-order case. Two examples are given to
illustrate the application of the stability theorem.Comment: The 12th European Control Conference (ECC13), Switzerland, 201
Hybrid Systems and Control With Fractional Dynamics (II): Control
No mixed research of hybrid and fractional-order systems into a cohesive and
multifaceted whole can be found in the literature. This paper focuses on such a
synergistic approach of the theories of both branches, which is believed to
give additional flexibility and help the system designer. It is part II of two
companion papers and focuses on fractional-order hybrid control. Specifically,
two types of such techniques are reviewed, including robust control of
switching systems and different strategies of reset control. Simulations and
experimental results are given to show the effectiveness of the proposed
strategies. Part I will introduce the fundamentals of fractional-order hybrid
systems, in particular, modelling and stability of two kinds of such systems,
i.e., fractional-order switching and reset control systems.Comment: 2014 International Conference on Fractional Differentiation and its
Application, Ital
Practical application of digital fractional-order controller to temperature control
Príspevok sa zaoberá praktickým návrhom a aplikáciou èíslicového regulátora neceloèíselného rádu na riadenie teploty iarièa. V príspevku je ïalej uvedený matematický popis regulátorov a regulovaných sústav neceloèíselného rádu. Pre pouitie èíslicových regulátorov neceloèíselného rádu je uvedený prísluný algoritmus. Vlastnosti regulaèného obvodu s regulátorom neceloèíselného rádu sú porovnané s regulaèným obvodom s klasickým regulátorom celoèíselného rádu a dosiahnuté výsledky sú uvedené a diskutované v závere príspevku
Fractional Order Hybrid Systems and Their Stability
This paper deals with hybrid systems (HS) with fractional order dynamics and
their stability. The stability of two particular types of fractional order
hybrid systems (FOHS), i.e., switching and reset control systems, is studied.
Common Lyapunov method, as well as its frequency domain equivalence, are
generalized for the former systems and, for the latter, H-condition
is used --frequency domain equivalence of Lyapunov-like method for reset
control systems. The applicability and efficiency of the proposed methods are
shown by some illustrative examples.Comment: 14th International Carpathian Control Conference, Krak\'ow-Rytro,
Poland, May 26-29, 2013. arXiv admin note: text overlap with arXiv:1303.530
ON FRACTIONAL ORDER DISTURBANCE OBSERVER
In this paper, for the first time, the fractional order disturbance observer (FO-DOB) is proposed for vibration suppression applications such as hard disk drive servo control. It has been discovered in a recently published US patent application (US20010036026
Fractional order modelling of contact with the environment in flexible robot applications
[Abstract] The control of flexible robots that interact with the environment presents some difficulties because the mechanical environment is unknown. In this kind of applications, force robust control rather than position control is required. The purpose of this paper is to model the mechanical impedance of the environment contacted by a flexible link based on the well-known spring-damper system typically used in the literature, considering models of both integer and fractional order. In particular, four models are identified: 1) linear regression model, 2) spring-damper model, 3) spring-damper model that also includes a spring for the robotic arm, and 4) fractional order extension of spring-damper model. Experimental results (impacts with ten different objects) are given to identify the parameters of the considered models. The goodness of the adjustment is analyzed by a set of performance indices. The results show that fractional models may have better performance in comparison with classical alternatives proposed in the literature for the objects used in this study.[Resumen] El control de robots flexibles que interactúan con el entorno presenta algunas dificultades porque se desconoce el entorno mecánico. En este tipo de aplicaciones, se requiere un control robusto en lugar de un control de posición. El propósito de este trabajo es modelar la impedancia mecánica del entorno contactado por un enlace flexible basado en el conocido sistema de amortiguador de resortes que se usa típicamente en la literatura, considerando modelos de orden entero y fraccional. En particular, se identifican cuatro modelos: 1) modelo de regresión lineal, 2) modelo de amortiguador de resorte, 3) modelo de amortiguador de resorte que también incluye un resorte para el brazo robótico, y 4) extensión de orden fraccional del modelo de amortiguador de resorte. Se dan resultados experimentales (impactos con diez objetos diferentes) para identificar los parámetros de los modelos considerados. La bondad del ajuste se analiza mediante un conjunto de índices de rendimiento. Los resultados muestran que los modelos fraccionarios pueden tener un mejor rendimiento en comparación con las alternativas clásicas propuestas en la literatura para los objetos utilizados en este estudio.Ministerio de Economía y Competitividad; DPI2016-80547-
- …