4,550 research outputs found
Synchronization of chaotic systems using time-delayed fuzzy state-feedback controller
This paper presents the fuzzy-model-based control approach to synchronize two chaotic systems subject to parameter uncertainties. A fuzzy state-feedback controller using the system state of response chaotic system and the time-delayed system state of drive chaotic system is employed to realize the synchronization. The time delay which complicates the system dynamics makes the analysis difficult. To investigate the system stability and facilitate the design of fuzzy controller, T-S fuzzy models are employed to represent the system dynamics of the chaotic systems. Furthermore, the membership grades of the T-S fuzzy models become uncertain due to the existence of parameter uncertainties which further complicates the system analysis. To ease the stability analysis and produce less conservative analysis result, the membership functions of both T-S fuzzy models and fuzzy controller are considered. Stability conditions are derived using Lyapunov-based approach to aid the design of fuzzy state-feedback controller to synchronize the chaotic systems. A simulation example is presented to illustrate the merits of the proposed approach
Finite-time synchronization of tunnel diode based chaotic oscillators
This paper addresses the problem of finite-time synchronization of tunnel
diode based chaotic oscillators. After a brief investigation of its chaotic
dynamics, we propose an active adaptive feedback coupling which accomplishes
the synchronization of tunnel diode based chaotic systems with and without the
presence of delay(s), basing ourselves on Lyapunov and on Krasovskii-Lyapunov
stability theories. This feedback coupling could be applied to many other
chaotic systems. A finite horizon can be arbitrarily established by ensuring
that chaos synchronization is achieved at a pre-established time. An advantage
of the proposed feedback coupling is that it is simple and easy to implement.
Both mathematical investigations and numerical simulatioComment: 11 pages, 43 figure
Complex Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators
We describe a flexible and modular delayed-feedback nonlinear oscillator that
is capable of generating a wide range of dynamical behaviours, from periodic
oscillations to high-dimensional chaos. The oscillator uses electrooptic
modulation and fibre-optic transmission, with feedback and filtering
implemented through real-time digital-signal processing. We consider two such
oscillators that are coupled to one another, and we identify the conditions
under which they will synchronize. By examining the rates of divergence or
convergence between two coupled oscillators, we quantify the maximum Lyapunov
exponents or transverse Lyapunov exponents of the system, and we present an
experimental method to determine these rates that does not require a
mathematical model of the system. Finally, we demonstrate a new adaptive
control method that keeps two oscillators synchronized even when the coupling
between them is changing unpredictably.Comment: 24 pages, 13 figures. To appear in Phil. Trans. R. Soc. A (special
theme issue to accompany 2009 International Workshop on Delayed Complex
Systems
Identification of delays and discontinuity points of unknown systems by using synchronization of chaos
In this paper we present an approach in which synchronization of chaos is
used to address identification problems. In particular, we are able to
identify: (i) the discontinuity points of systems described by piecewise
dynamical equations and (ii) the delays of systems described by delay
differential equations. Delays and discontinuities are widespread features of
the dynamics of both natural and manmade systems. The foremost goal of the
paper is to present a general and flexible methodology that can be used in a
broad variety of identification problems.Comment: 11 pages, 3 figure
Secure Communication Based on Hyperchaotic Chen System with Time-Delay
This research is partially supported by National Natural Science Foundation of China (61172070, 60804040), Fok Ying Tong Education Foundation Young Teacher Foundation(111065), Innovative Research Team of Shaanxi Province(2013KCT-04), The Key Basic Research Fund of Shaanxi Province (2016ZDJC-01), Chao Bai was supported by Excellent Ph.D. research fund (310-252071603) at XAUT.Peer reviewedPostprin
Synchronization of coupled neural oscillators with heterogeneous delays
We investigate the effects of heterogeneous delays in the coupling of two
excitable neural systems. Depending upon the coupling strengths and the time
delays in the mutual and self-coupling, the compound system exhibits different
types of synchronized oscillations of variable period. We analyze this
synchronization based on the interplay of the different time delays and support
the numerical results by analytical findings. In addition, we elaborate on
bursting-like dynamics with two competing timescales on the basis of the
autocorrelation function.Comment: 18 pages, 14 figure
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