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1

Hybrid synchronization and parameter estimation of a complex chaotic network of permanent magnet synchronous motors using adaptive integral sliding mode control

Siddique Nazam, Rehman Fazal U.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 3

art. no. e137056

EN

The synchronisation of a complex chaotic network of permanent magnet synchronous motor systems has increasing practical importance in the field of electrical engineering. This article presents the control design method for the hybrid synchronization and parameter estimation of ring-connected complex chaotic network of permanent magnet synchronous motor systems. The design of the desired control law is a challenging task for control engineers due to parametric uncertainties and chaotic responses to some specific parameter values. Controllers are designed based on the adaptive integral sliding mode control to ensure hybrid synchronization and estimation of uncertain terms. To apply the adaptive ISMC, firstly the error system is converted to a unique system consisting of a nominal part along with the unknown terms which are computed adaptively. The stabilizing controller incorporating nominal control and compensator control is designed for the error system. The compensator controller, as well as the adopted laws, are designed to get the first derivative of the Lyapunov equation strictly negative. To give an illustration, the proposed technique is applied to 4-coupled motor systems yielding the convergence of error dynamics to zero, estimation of uncertain parameters, and hybrid synchronization of system states. The usefulness of the proposed method has also been tested through computer simulations and found to be valid.

2

Pipelined pseudo-random number generator with the efficient post-processing method

Dąbal P.

International Journal of Microelectronics and Computer Science

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2015

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Vol. 6, nr 2

43--48

EN

This brief proposes a novel architecture of the chaotic pseudo-random bit generators (PRBGs) based on the chaotic nonlinear model and pipelined data processing. We investigated PRBG built on the chaotic logistic map and frequency dependent negative resistances (FDNR). A significant enhancement in terms of output throughput has been achieved by combining the advantages of pipelining with post-processing based on fast logical operations like bit shifting and XOR. The proposed method has been implemented using programmable SoC Zynq device from Xilinx. We verified output pseudo-random bit stream by standard statistical tests NIST SP800-22. We also present detailed comparison of the proposed post-processing method with the methods reported previously by the other authors. In particular, we compared the maximum output throughput and amount of total logical resources required by PRBG implementation in the programmable SoC device. For PRBGs based on the logistic chaotic map and frequency dependent negative resistance (FDNR) we obtained speed-up factors equal to 33% and 14%, respectively. By composing the output stream of 3 data channels in PRBG with FDNR element, we get the maximum throughput equal to 38.43 Gbps. That is significantly greater comparing to the chaotic PRBGs described so far.

3

Controlling Chaotic Systems Using Aggregated Linear Quadratic Regulator

Wang D., Ha P.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 7b

336--340

EN

A systematic design method for controlling chaotic systems is presented in this paper. The aggregated multiple local models are adopted to express chaotic systems. The Linear Quadratic Regulator (LQR) theory is proposed to design state feedback control system for each local model. Multi-model control strategy has come into being by combining of T-S fuzzy model and LQR. The global stability of closed loop control system can guarantee and it is illustrated with several chaotic systems as examples.

PL

Zaproponowano projekt sterowania systemem chaotycznym. Zaadaptowano wypadkowe (aggregated) połączenie wielu lokalnych modeli do opisu system chaotycznego. Każdy lokalny model jest sterowany z wykorzystaniem teorii LQR – linear quadratic regulator.

4

On fractal dimension estimation

Pánek D., Kropik P., Predota A.

Przegląd Elektrotechniczny

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2011

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R. 87, nr 5

120-122

EN

The paper deals with an algorithm for Hausdorff dimension estimation based on box-counting dimension calculation. The main goal of the paper is to propose a new approach to box-counting dimension calculation with less computational demands.

PL

W artykule opisano algorytm estymacji wymiaru Hausdorffa oparty o wyznaczanie wymiaru pudełkowego. Głównym celem pracy jest zaproponowanie nowego podejścia do wyznaczania wymiaru pudełkowego, które ma znacznie mniejszą złożoność obliczeniową.

5

On improved image encryption scheme based on chaotic map lattices

Jastrzębski K., Kotulski Z.

Engineering Transactions

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2009

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Vol. 57, iss. 2

89-104

EN

In this paper we examine one of the recently proposed chaotic image encryption algorithms, based on chaotic map lattices (CML). We show certain problems with the chaotic map, as well as errors in the designed algorithm. Then we propose a way to improve it and present a new version of algorithm and its implementation. At the end, we show the results of a security analysis and a comparison of both schemes. These results were obtained in the MSc Thesis.