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1

Mathematical models of a pneumatic cascade and pneumatic membrane actuator described with a fractional calculus

Luft M., Łukasik Z., Pietruszczak D.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2020

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Vol. 14. no. 3

643--648

EN

The paper presents the analysis of dynamic properties of pneumatic systems such as: cascade connection of membrane pressure transmitters and a pneumatic membrane actuator by means of differential equations of integer and non-integer order. The analyzed systems were described from the time perspective by means of step response, and in terms of frequency with the help of the Bode plot, i.e. logarithmic magnitude and phase responses. Each response was determined using differential equations of non-integer order. To determine the responses, the interactive Simulink package was an irreplaceable programming tool built on the basis of the MATLAB program, which enables the analysis and synthesis of continuous dynamic systems.

2

The fourth-order ordinary differential equation with the fractional initial/boundary conditions

Siedlecki Jarosław

Journal of Applied Mathematics and Computational Mechanics

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2020

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Vol. 19, nr 1

79--87

EN

The initial/boundary value problem for the fourth-order homogeneous ordinary differential equation with constant coefficients is considered. In this paper, the particular solutions an ordinary differential equation with respect to the set of boundary conditions are studied. At least one of the boundary conditions is described by a fractional derivative. Finally, a few illustrative examples of particular solutions to the considered problem are shown.

3

Application of fractional calculus in iterative sliding mode synchronization control

Zhang Xin, Wen-Ru Lu, Zhang Liang, Xu Wen-Bo

Archives of Electrical Engineering

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2020

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Vol. 69, nr 3

499--519

EN

In order to control joints of manipulators with high precision, a position tracking control strategy combining fractional calculus with iterative learning control and sliding mode control is proposed for the control of a single joint of manipulators. Considering the coupling between joints of manipulators, a fractional-order iterative sliding mode crosscoupling control strategy is proposed and the theoretical proof of its progressive stability is given. The paper takes a two-joint manipulator as the research object to verify the control strategy of a single-joint manipulator. The results show that the control strategy proposed in this paper makes the two-joint mechanical arm chatter less and the tracking more accurate. The synchronous control of the manipulator is verified by a three-joint manipulator. The results show that the angular displacement adjustment times of the threejoint manipulator are 0.11 s, 0.31 s and 0.24 s, respectively. 3.25 s > 5 s, 3.15 s of a PD cross-coupling control strategy; 2.85 s, 2.32 s, 4.22 s of a PD iterative cross-coupling control strategy; 0.14 s, 0.33 s, 0.28 s of a fractional-order sliding mode cross-coupling control strategy. The root mean square error of the position error of the designed control strategy is 6.47 × 10−6 rad, 3.69 × 10−4 rad, 6.91 × 10−3 rad, respectively. The root mean square error of the synchronization error is 3.96×10−4 rad, 1.36×10−3 rad, 7.81×10−3 rad, superior to the other three control strategies. The results illustrate the effectiveness of the proposed control method.

4

On the existence of optimal consensus control for the fractional Cucker-Smale model

Almeida R., Kamocki R., Malinowska A. B., Odzijewicz T.

Archives of Control Sciences

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2020

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Vol. 30, No. 4

625--651

EN

This paper addresses the nonlinear Cucker-Smale optimal control problem under the interplay of memory effect. The aforementioned effect is included by employing the Caputo fractional derivative in the equation representing the velocity of agents. Sufficient conditions for the existence of solutions to the considered problem are proved and the analysis of some particular problems is illustrated by two numerical examples.

5

Description of selected pneumatic elements and systems using fractional calculus

Pietruszczak Daniel, Nowocień Artur

Journal of Automation, Electronics and Electrical Engineering

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2019

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Vol. 1, No. 1

43--49

EN

The paper presents the application of fractional calculus to describe the dynamics of selected pneumatic elements and systems. In the construction of mathematical models of the analysed dynamic systems, the Riemann-Liouville definition of differintegral of non- integer order was used. For the analysed model, transfer function of integer and non-integer order was determined. Functions describing characteristics in frequency domains were determined, whereas the characteristics of the elements and systems were obtained by means of computer simulation. MATLAB programme were used for the simulation research.

PL

W artykule przedstawiono zastosowanie rachunku różniczkowego niecałkowitych rzędów (ang. fractional calculus) do opisu dynamiki zjawisk układów pneumatycznych wybranych elementów i układów. W budowie modeli matematycznych, analizowanych układów dynamicznych, wykorzystano definicję Riemanna–Liouville’a pochodno–całki niecałkowitego rzędu. Dla analizowanego modelu, wyznaczono transmitancję operatorową całkowitego i niecałkowitego rzędu. Wyznaczono zależności opisujące charakterystyki częstotliwościowe, na drodze symulacji komputerowej uzyskano charakterystyki analizowanych układów. Do badań symulacyjnych wykorzystano oprogramowanie MATLAB.

6

Investigation of free vibration and buckling of Timoshenko nano-beam based on a general form of eringen theory using conformable fractional derivative and Galerkin method

Mohammadi Farogh Souf, Rahimi Zaher, Sumelka Wojciech, Yang Xiao-Jun

Engineering Transactions

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2019

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Vol. 67, iss. 3

347--367

EN

The purpose of this paper is to study the free vibration and buckling of a Timoshenko nano-beam using the general form of the Eringen theory generalized based on the fractional derivatives. In this paper, using the conformable fractional derivative (CFD) definition the generalized form of the Eringen nonlocal theory (ENT) is used to consider the effects of integer and noninteger stress gradients in the constitutive relation and also to consider small-scale effect in the vibration of a Timoshenko nano-beam. The governing equation is solved by the Galerkin method. Free vibration and buckling of a Timoshenko simply supported (S) nano-beam is investigated, and the influence of the fractional and nonlocal parameters is shown on the frequency ratio and buckling ratio. In this sense, the obtained formulation allows for an easier mapping of experimental results on nano-beams. The new theory (fractional parameter) makes the modeling more flexible. The model can conclude all of the integer and non-integer operators and is not limited to the special operators such as ENT. In other words, it allows to use more sophisticated/flexible mathematics to model physical phenomena.

7

Optimal input signal design for fractional-order system identification

Jakowluk W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 1

37--44

EN

The optimal design of excitation signal is a procedure of generating an informative input signal to extract the model parameters with maximum pertinence during the identification process. The fractional calculus provides many new possibilities for system modeling based on the definition of a derivative of noninteger-order. A novel optimal input design methodology for fractional-order systems identification is presented in the paper. The Oustaloup recursive approximation (ORA) method is used to obtain the fractional-order differentiation in an integer order state-space representation. Then, the presented methodology is utilized to solve optimal input design problem for fractional-order system identification. The fundamental objective of this approach is to design an input signal that yields maximum information on the value of the fractional-order model parameters to be estimated. The method described in this paper was verified using a numerical example, and the computational results were discussed.

8

Fractional order model of measured quantity errors

Cioć R., Chrzan M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 6

1023--1030

EN

The paper presents an interpretation of fractional calculus for positive and negative orders of functions based on sampled measured quantities and their errors connected with digital signal processing. The derivatives as a function limit and the Grunwald-Letnikov differintegral are shown in chapter 1 due to the similarity of the presented definition. Notation of fractional calculus based on the gradient vector of measured quantities and its geometrical and physical interpretation of positive and negative orders are shown in chapter 2 and 3.

9

Problems in solving fractional differential equations in a microcontroller implementation of an FOPID controller

Matusiak Mariusz, Ostalczyk Piotr

Archives of Electrical Engineering

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2019

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Vol. 68, nr 3

565--577

EN

The article focuses on the fractional-order backward difference, sum, linear time-invariant equation analysis, and difficulties of the fractional calculus microcontroller implementation with regard to designing a fractional-order proportional integral derivative (FOPID) controller. In opposite to the classic proportional integral derivative (PID), the FOPID controller is defined by five independent parameters. Hence, it is more customizable and, potentially, more precise on condition that the values of fractional integration and differentiation orders are properly selected. However, a number of operations and the time required to calculate the output signal continuously increase. This can be a significant problem considering the limitations of a microcontroller, including memory size and a constant sampling time of the set-up analog-to-digital (ADC) converters. In the article, three solutions are considered, and results obtained in the experiments are presented.

10

Axial vibration of bars using fractional viscoelastic material models

Łabędzki P., Pawlikowski R., Radowicz A.

Vibrations in Physical Systems

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2018

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Vol. 29

1--8

EN

This paper presents dynamic analysis of a bar with one end fixed and other free, loaded with force at its free end. The viscoelastic material of the bar is described by fractional models (Scot-Blair, Voigt, Maxwell and Zener models). Rayleigh-Ritz and Laplace transform methods were applied to obtain closed-form solution of the considered problem.

11

Two-stage scheme for identification of parallel Scott-Blair fractional model of viscoelastic biological materials

Stankiewicz A.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2018

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Vol. 7, No 1

87--96

EN

Fractional calculus considers derivatives and integrals of an arbitrary order. This article focuses on fractional parallel Scott-Blair model of viscoelastic biological materials, which is a generalization of classic Kelvin-Voight model to non-integer order derivatives suggested in the previous paper. The parallel Scott-Blair model admit the closed form of analytical solution in terms of two power functions multiplied by Debye type weight function. To build a parallel Scott-Blair model when only discrete-time measurements of the relaxation modulus are accessible for identification is a basic concern. Based on asymptotic models a two-stage approach is proposed for fitting the measurement data, which means that in the first stage the data are fitted by solving two dependent, but simple, linear least-squares problems in two separate time intervals. Next, at the second stage of the identification procedure the exact parallel Scott-Blair model optimal in the least-squares sense is computed. The log-transformed relaxation modulus data is used in the first stage of identification scheme, while the original relaxation modulus data is applied for the second stage identification. A complete identification procedure is presented. The usability of the method to find the parallel Scott-Blair fractional model of real biological material is demonstrated. The parameters of the parallel Scott-Blair model of a sample of sugar beet root, which very closely approximate the experimental relaxation modulus data, are given.

12

Parallel Scott-Blair fractional model of viscoelastic biological materials

Stankiewicz A.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2018

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Vol. 7, No 1

107--115

EN

Fractional calculus is a mathematical approach dealing with derivatives and integrals of arbitrary and also complex orders. Therefore, it adds a new means to understand and describe the nature and behavior of complex dynamical systems. Here we use the fractional calculus for modeling mechanical viscoelastic properties of materials. In the present work, after reviewing some of the main viscoelastic fractional models, a new parallel model is employed, connecting in parallel two Scott-Blair models with additional multiplicative weight functions. The model is presented in terms of two power functions weighted by Debye-type functions extend representation, understanding and description of complex systems viscoelastic properties. Monotonicity of the model relaxation modulus is studied and some upper bounds for the minimal time value, above which the model relaxation modulus is monotonically decreasing are given and compared both analytically and numerically. The comparison with the results of relaxation tests executed on some real phenomena has shown that the parallel Scott-Blair model involving fractional derivatives has been in a good agreement.

13

On the monotonicity of the relaxation spectrum of fractional Maxwell model of viscoelastic materials

Stankiewicz A.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2018

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Vol. 7, No 1

117--125

EN

This article focuses on the relaxation spectrum of fractional Maxwell model, which is a generalization of classic viscoelastic Maxwell model to non-integer order derivatives. The analytical formula for the spectrum of relaxation frequencies is derived. Theoretical analysis of the relaxation spectrum monotonicity is conducted by using simple analytical methods and illustrated by means of numerical examples. The necessary and sufficient conditions for the existence and uniqueness of the maximum of relaxation spectrum are stated and proved. The analytical formulas for minimum and maximum of the relaxation spectrum are derived. Also, a few useful properties concerning the relaxation spectrum monotonicity and concavity are given in the mathematical form of simple inequalities expressed directly in terms of the fractional Maxwell model parameters, which can be used to simplify the calculations and analysis.

14

The analysis of non-linear free vibration of FGM nano-beams based on the conformable fractional non-local model

Rahimi Z., Sumelka W., Shafiei S.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 5

737--745

EN

Continuum models generalized by fractional calculus are used in different mechanical problems. In this paper, by using the conformable fractional derivative (CFD) definition, a general form of Eringen non-local theory as a fractional non-local model (FNM) is formulated. It is then used to study the non-linear free vibration of a functional graded material (FGM) nano-beam in the presence of von-Kármán non-linearity. A numerical solution is obtained via Galerkin and multiple scale methods and effects of the integer and non-integer (fractional) order of stress gradient (in the non-local stress-strain relation) on the ratio of the non-local non-linear natural frequency to classical non-linear natural frequency of simply-supported (S-S) and clamped-free (C-F) FGM nano-beams are presented.

15

Stability conditions for fractional-order linear equations with delays

Mozyrska D., Ostalczyk P., Wyrwas M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 4

449--454

EN

The problem of stability of the Gr¨unwald-Letnikov-type linear fractional-order discrete-time systems with delays is discussed. For the stability analysis of the considered systems the Z -transform is used. The sufficient conditions for the asymptotic stability of the considered systems are presented. Using conditions related to eigenvalues of the matrices defining the linear difference systems, one can determine the regions of location of eigenvalues of matrices associated to the systems in order to guarantee the asymptotic stability of the considered systems. Some of these regions are illustrated with relevant examples.

16

Matrix Mittag‑Leffler function in fractional systems and its computation

Matychyn I., Onyshchenko V.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 4

495--500

EN

Matrix Mittag‑Leffler functions play a key role in numerous applications related to systems with fractional dynamics. That is why the methods for computing the matrix Mittag‑Leffler function are so important. The matrix Mittag‑Leffler function is a generalization of matrix exponential function. This implies that some of numerous existing methods for computing the matrix exponential can be adapted for matrix Mittag‑Leffler functions as well. Unfortunately, the technique of scaling and squaring, widely used in computing of the matrix exponential, cannot be applied to matrix Mittag‑Leffler functions, as the latter do not possess the semigroup property. Here we describe a method of computing the matrix Mittag‑Leffler function based on the Jordan canonical form representation. This method is implemented with Matlab code [1].

17

Fractional variable order anti-windup control strategy

Sierociuk D., Malesza W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 4

427--432

EN

In this paper, a novel anti-windup strategy is presented. It is based on using fractional variable order integrator instead of integer order one in PID controller. It is shown that among four different types of variable order derivative definitions, only one gives satisfactory results – comparable, and even slightly better than the classical back-calculation anti-windup algorithm. Results are also presented in the form of simulation plots.

18

Fractional order based velocity control system for a nanorobot in non-Newtonian fluids

Muresan C. I., Birs I. R., Folea S., Ionescu C.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 6

991--997

EN

Customized patient drug delivery overcomes classic medicine setbacks such as side effects, improper drug absorption or slow action. Nanorobots can be successfully used for targeted patient-specific drug administration, but they must be reliable in the entire circulatory system environment. This paper analyzes the possibility of fractional order control applied to the nanomedicine field. The parameters of a fractional order proportional integral controller are determined with the purpose of controlling the velocity of the nanorobot in non-Newtonian fluids envisioning the blood flow in the circulatory system.

19

Economic growth in the European Union modelled with fractional derivatives: first results

Tejado I., Pérez E., Valério D.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 4

455--465

EN

This paper presents models of economic growth for all states of the European Union (EU), since either 1970 or the year of accession to the EU. Both integer and fractional order models are obtained, where the gross domestic product (GDP) is a function of the country’s land area, gross capital formation (GCF), exports of goods and services, and average years of school attendance.

20

Different fractional order models for an experimental smart beam system

Markowski K. A., Birs I., Muresan C. I., Prodan O.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 4

485--493

EN

The applicability of fractional calculus in system engineering outperforms classic identification techniques due to its ability to depict physical phenomena with increased accuracy. The present study explores the increased accuracy and flexibility of a fractional order model applied to an experimental smart beam depicting an airplane wing. The paper details the fractional order system identification of the beam and explores the possibility of realization of the model.