Control quality enhancement by fractional order controllers

Príspevok sa zaoberá regulátormi neceločíselného rádu. Uvádza matematický popis neceločíselných regulátorov a metódy ich návrhu. Kvalita a robustnosť regulátorov neceločíselného rádu je porovnaná s klasickými celočíselnými regulátormi. Pre pouitie regulátorov neceločíselného rádu je uvedený prísluný algoritmus

Electronic realization of the fractional-order systems

This article is devoted to the electronic (analogue) realization of the fractional-order systems – controllers or controlled objects whose we earlier used, identified, and analyzed as a mathematical models only ��� namely a fractional-order differential equation, and solved numerically using a method based on the truncated version of the Grunwald - Letnikov formula for fractional derivative. The electronic realization of the fractional derivative is based on the continued fraction expansion of the rational approximation of the fractional differentiator from which we obtained the values of the resistors and capacitors of the electronic circuit. Along with the mathematical description are presented also simulation and measurement results

Investigation of polyurethane electrospinning process efficiency

The electrospinning process efficiency of different PUs has been investigated. Specific attention has been paid to understand the role of PU soft segments and synthesis type on the stability of the PU solution and electrospinning process as well as on the quality/property changes of the produced nanofibres. PU samples before and after the process were analyzed rheologicaly and relaxation spectra were determined for all of them from frequency dependent loss and storage moduli measurements. It has been found that rheological analysis of PU, which is used for electrospinning process, can be useful tool from electrospinning process efficiency and optimization point of view. Nanolayers homogeneity during several hours of manufacture in optimized electrospinning process is proved by selected properties from aerosol filtration. © 2009 American Institute of Physics

Morphology of nano and micro fiber structures in ultrafine particles filtration

Selected procedures permitting to prepare homogeneous nanofibre structures of the desired morphology by employing a suitable combination of variables during the electrospinning process are presented. A comparison (at the same pressure drop) was made of filtration capabilities of planar polyurethane nanostructures formed exclusively by nanofibres, space polycarbonate nanostructures having bead spacers, structures formed by a combination of polymethyl methacrylate micro- and nanofibres and polypropylene meltblown microstructures, through which ultrafine particles of ammonium sulphate 20-400 nm in size were filtered. The structures studied were described using a new digital image analysis technique based on black and white images obtained by scanning electron microscopy. More voluminous structures modified with distance microspheres and having a greater thickness and mass per square area of the material, i.e. structures possessing better mechanical properties, demanded so much in nanostructures, enable preparation of filters having approximately the same free volume fraction as flat nanofibre filters but an increased effective fibre surface area, changed pore size morphology and, consequently, a higher filter quality. © 2011 American Institute of Physics

Oscillators Based on Fractional-Order Memory Elements

This paper deals with the new oscillator structures that contain new elements, so-called memory elements, known as memristor, meminductor, and memcapacitor. Such circuits can exhibit oscillations as well as chaotic behavior. New mathematical models of fractional-order elements and whole oscillator circuits are proposed as well. An illustrative example to demonstrate the oscillations and the chaotic behavior through the numerical solution of the fractional-order circuit model is provided

Method for simulation of the fractional order chaotic systems

This paper deals with the method of simulation of fractional order chaotic systems. We present a brief survey of the existing fractional order chaotic systems. These systems are described by three fractional differential equations where order of derivatives is a non-integer, arbitrary order. The total order of chaotic system is less than three. We present an approach where we demonstrate by an illustrative example the method for deriving the model of such a kind of fractional order chaotic system and method for its simulation. This example is well known chaotic system, the so called Chua’s oscillator. We have demonstrated the real measurements and the simulation in the Matlab/Simulink as well

Fractional Order Systems

This book is focused on fractional order systems. Historically, fractional calculus has been recognized since the inception of regular calculus, with the first written reference dated in September 1695 in a letter from Leibniz to L’Hospital. Nowadays, fractional calculus has a wide area of applications in areas such as physics, chemistry, bioengineering, chaos theory, control systems engineering, and many others. In all those applications, we deal with fractional order systems in general. Moreover, fractional calculus plays an important role even in complex systems and therefore allows us to develop better descriptions of real-world phenomena. On that basis, fractional order systems are ubiquitous, as the whole real world around us is fractional. Due to this reason, it is urgent to consider almost all systems as fractional order systems

Fractional-Order Nonlinear Systems: Modeling, Analysis and Simulation /

"Fractional-Order Nonlinear Systems: Modeling, Analysis and Simulation" presents a study of fractional-order chaotic systems accompanied by Matlab programs for simulating their state space trajectories, which are shown in the illustrations in the book. Description of the chaotic systems is clearly presented and their analysis and numerical solution are done in an easy-to-follow manner. Simulink models for the selected fractional-order systems are also presented. The readers will understand the fundamentals of the fractional calculus, how real dynamical systems can be described using fractional derivatives and fractional differential equations, how such equations can be solved, and how to simulate and explore chaotic systems of fractional order. The book addresses to mathematicians, physicists, engineers, and other scientists interested in chaos phenomena or in fractional-order systems. It can be used in courses on dynamical systems, control theory, and applied mathematics at graduate or postgraduate level.   Ivo Petráš is an Associate Professor of automatic control and the Director of the Institute of Control and Informatization of Production Processes, Faculty of BERG, Technical University of Košice, Slovak Republic. His main research interests include control systems, industrial automation, and applied mathematics

Novel Generalized Low-Pass Filter with Adjustable Parameters of Exponential-Type Forgetting and Its Application to ECG Signal

In this paper, a novel form of the Gaussian filter, the Mittag–Leffler filter is presented. This new filter uses the Mittag–Leffler function in the probability-density function. Such Mittag–Leffler distribution is used in the convolution kernel of the filter. The filter has three parameters that may adjust the curve shape due to the filter-forgetting factor. Illustrative examples present the main advantages of the proposed filter compared to classical Gaussian filtering techniques, as well as real ECG-signal denoising. Some implementation notes, along with the Matlab function, are also presented

Travelling track of portal crane

Tato diplomová práce se zabývá návrhem a koncepcí skladové haly a jeřábové dráhy, jejímž cílem je vytvořit venkovní a vnitřní skladovací prostor pokrytý mostovým jeřábem. Dále se zabývá konstrukcí a pevnostním výpočtem jeřábové dráhy a logistickým uspořádáním venkovního prostoru s možností nakládky na kolovou i kolejovou dopravu.This diploma thesis handles with a draft and conception of the warehouse hall and crane track where the main goal is the creation of outside and inside storage space which is covered by the trolley crane. Next point is about construction and stress calculation of the crane track and logistic ordering of the outside space with option of loading on wheel and rail transport.