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1.
Synchronization of uncertain fractional-order chaotic systems with disturbance based on a fractional terminal sliding mode controller
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This paper provides a novel method to synchronize uncertain fractional-order chaotic systems with external disturbance via fractional terminal sliding mode control. Based on Lyapunov stability theory, a new fractional-order switching manifold is proposed, and in order to ensure the occurrence of sliding motion in finite time, a corresponding sliding mode control law is designed. The proposed control scheme is applied to synchronize the fractional-order Lorenz chaotic system and fractional-order Chen chaotic system with uncertainty and external disturbance parameters. The simulation results show the applicability and efficiency of the proposed scheme. 相似文献
2.
Hidden attractors in a new fractional–order discrete system: Chaos,complexity, entropy, and control
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This paper studies the dynamics of a new fractional-order discrete system based on the Caputo-like difference operator.This is the first study to explore a three-dimensional fractional-order discrete chaotic system without equilibrium. Through phase portrait, bifurcation diagrams, and largest Lyapunov exponents, it is shown that the proposed fractional-order discrete system exhibits a range of different dynamical behaviors. Also, different tests are used to confirm the existence of chaos,such as 0–1 test and C0 complexity. In addition, the quantification of the level of chaos in the new fractional-order discrete system is measured by the approximate entropy technique. Furthermore, based on the fractional linearization method, a one-dimensional controller to stabilize the new system is proposed. Numerical results are presented to validate the findings of the paper. 相似文献
3.
A new image encryption scheme is proposed based on a delayed fractional-order chaotic logistic system.In the process of generating a key stream,the time-varying delay and fractional derivative are embedded in the proposed scheme to improve the security.Such a scheme is described in detail with security analyses including correlation analysis,information entropy analysis,run statistic analysis,mean-variance gray value analysis,and key sensitivity analysis.Experimental results show that the newly proposed image encryption scheme possesses high security. 相似文献
4.
In this paper a new dynamic system with integer and fractional order is investigated. It is shown that determining the effect of quadratic coefficients to the systematic structure can be converted to determining that of coefficients of the linear part. Under some parametric conditions, the system can produce chaotic attractors similar as Lorenz attractor. A constructive theorem is proposed for generalized synchronization related to the fractional-order chaotic system and an application of this new system is demonstrated. 相似文献
5.
The stability control of fractional order unified chaotic system with sliding mode control theory
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This paper studies the stability of the fractional order unified chaotic system with sliding mode control theory. The sliding manifold is constructed by the definition of fractional order derivative and integral for the fractional order unified chaotic system. By the existing proof of sliding manifold, the sliding mode controller is designed. To improve the convergence rate, the equivalent controller includes two parts: the continuous part and switching part. With Gronwall’s inequality and the boundness of chaotic attractor, the finite stabilization of the fractional order unified chaotic system is proved, and the controlling parameters can be obtained. Simulation results are made to verify the effectiveness of this method. 相似文献
6.
《中国物理 B》2015,(6)
This paper deals with the synchronization of fractional-order chaotic systems with unknown parameters and unknown disturbances.An adaptive control scheme combined with fractional-order update laws is proposed.The asymptotic stability of the error system is proved in the sense of generalized Mittag–Leffler stability.The two fractional-order chaotic systems can be synchronized in the presence of model uncertainties and additive disturbances.Finally these new developments are illustrated in examples and numerical simulations are provided to demonstrate the effectiveness of the proposed control scheme. 相似文献
7.
Image encryption technique based on new two-dimensional fractional-order discrete chaotic map and Menezes–Vanstone elliptic curve cryptosystem
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We propose a new fractional two-dimensional triangle function combination discrete chaotic map(2D-TFCDM) with the discrete fractional difference. Moreover, the chaos behaviors of the proposed map are observed and the bifurcation diagrams, the largest Lyapunov exponent plot, and the phase portraits are derived, respectively. Finally, with the secret keys generated by Menezes–Vanstone elliptic curve cryptosystem, we apply the discrete fractional map into color image encryption. After that, the image encryption algorithm is analyzed in four aspects and the result indicates that the proposed algorithm is more superior than the other algorithms. 相似文献
8.
We demonstrate that the projective synchronization can be observed in coupled fractional-order chaotic systems. A new systematic and powerful coupling scheme is developed to investigate the projective synchronization via the open-plus-closed-loop control, which allows us to arbitrarily manipulate the scaling factor of projective synchronization. The proposed scheme is proved analytically on the basis of the stability theorem of the fractional differential equations. Numerical simulations on the fraction-order chaotic Chen system are presented to justify the theoretical analysis. 相似文献
9.
A simple method to simultaneously achieve synchronization andanti-synchronization in chaotic systems
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In this paper, a novel adaptive control approach is
presented to simultaneously achieve synchronization and
anti-synchronization in partially linear chaotic systems. Through
appropriately separating state vectors of such systems,
synchronization and anti-synchronization could be simultaneously
realized in different subspaces, which may be strictly proven
theoretically. Simulation results for a Lorenz chaotic system and a
new hyper-chaotic system are provided to illustrate the
effectiveness of the proposed method. Finally, a new secure
communication scheme based on such a synchronization phenomenon of
the hyper-chaotic system is demonstrated. Numerical results show
success in transmitting a periodic signal with high security. 相似文献
10.
Hysteresis-induced bifurcation and chaos in a magneto-rheological suspension system under external excitation
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The magneto-rheological damper(MRD) is a promising device used in vehicle semi-active suspension systems, for its continuous adjustable damping output. However, the innate nonlinear hysteresis characteristic of MRD may cause the nonlinear behaviors. In this work, a two-degree-of-freedom(2-DOF) MR suspension system was established first, by employing the modified Bouc–Wen force–velocity(F –v) hysteretic model. The nonlinear dynamic response of the system was investigated under the external excitation of single-frequency harmonic and bandwidth-limited stochastic road surface.The largest Lyapunov exponent(LLE) was used to detect the chaotic area of the frequency and amplitude of harmonic excitation, and the bifurcation diagrams, time histories, phase portraits, and power spectrum density(PSD) diagrams were used to reveal the dynamic evolution process in detail. Moreover, the LLE and Kolmogorov entropy(K entropy) were used to identify whether the system response was random or chaotic under stochastic road surface. The results demonstrated that the complex dynamical behaviors occur under different external excitation conditions. The oscillating mechanism of alternating periodic oscillations, quasi-periodic oscillations, and chaotic oscillations was observed in detail. The chaotic regions revealed that chaotic motions may appear in conditions of mid-low frequency and large amplitude, as well as small amplitude and all frequency. The obtained parameter regions where the chaotic motions may appear are useful for design of structural parameters of the vibration isolation, and the optimization of control strategy for MR suspension system. 相似文献
11.
Design and multistability analysis of five-value memristor-based chaotic system with hidden attractors
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《中国物理 B》2021,30(10):100506-100506
A five-value memristor model is proposed, it is proved that the model has a typical hysteresis loop by analyzing the relationship between voltage and current. Then, based on the classical Liu–Chen system, a new memristor-based four-dimensional(4D) chaotic system is designed by using the five-value memristor. The trajectory phase diagram, Poincare mapping, bifurcation diagram, and Lyapunov exponent spectrum are drawn by numerical simulation. It is found that, in addition to the general chaos characteristics, the system has some special phenomena, such as hidden homogenous multistabilities, hidden heterogeneous multistabilities, and hidden super-multistabilities. Finally, according to the dimensionless equation of the system, the circuit model of the system is built and simulated. The results are consistent with the numerical simulation results, which proves the physical realizability of the five-value memristor-based chaotic system proposed in this paper. 相似文献
12.
Control of a fractional chaotic system based on a fractional-order resistor-capacitor filter
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We present a new fractional-order resistor-capacitor controller and a novel control method based on the fractional- order controller to control an arbitrary three-dimensional fractional chaotic system. The proposed control method is simple, robust, and theoretically rigorous, and its anti-noise performance is satisfactory. Numerical simulations are given for several fractional chaotic systems to verify the effectiveness and the universality of the proposed control method. 相似文献
13.
Dynamic analysis of a new chaotic system with fractional order and its generalized projective synchronization
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Based on the stability theory of the fractional order system,the dynamic behaviours of a new fractional order system are investigated theoretically.The lowest order we found to have chaos in the new three-dimensional system is 2.46,and the period routes to chaos in the new fractional order system are also found.The effectiveness of our analysis results is further verified by numerical simulations and positive largest Lyapunov exponent.Furthermore,a nonlinear feedback controller is designed to achieve the generalized projective synchronization of the fractional order chaotic system,and its validity is proved by Laplace transformation theory. 相似文献
14.
Decentralized state-feedback chaotification method of discrete Takagi-Sugeno fuzzy systems
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A new chaotification method is proposed for making an arbitrarily given discrete Takagi-Sugeno (TS) fuzzy system chaotic. Based on a given discrete TS fuzzy system, the new chaotification method uses the decentralized state-feedback control and the continuous sawtooth function, instead of the modulo operation, to construct a chaotic nonlinear system,which can generate discrete chaos with the arbitrarily desired amplitude bound. We apply the improved Marotto theorem to mathematically prove that the controlled system is chaotic in the sense of Li and Yorke. In particular, an explicit formula for the computation of chaotification parameters is obtained. A numerical example is used to illustrate the theoretical results. 相似文献
15.
This paper studies the control of a new chaotic system which can
generate 4-scroll attractors. Based on the properties of a passive
system, it derives the essential conditions under which this new
chaotic system could be equivalent to a passive system and globally
asymptotically stabilize at a zero equilibrium point via smooth
state feedback. Simulation results and circuit experiment show that
the proposed chaos control method is effective. 相似文献
16.
Based on the Chen chaotic system, a new four-dimensional hyperchaotic Chen system is constructed, and the basic dynamic behaviours of the system were studied, and the generalized synchronization has been observed in the coupled four-dimensional hyperchaotic Chen system with unknown parameters. The Routh--Hurwitz theorem is used to derive the conditions of stability of this system. Furthermore based on Lyapunov stability theory, the control laws and adaptive laws of parameters are obtained to make generalized synchronization of the coupled new four-dimensional hyperchaotic Chen systems. Numerical simulation results are presented to illustrate the effectiveness of this method. 相似文献
17.
In this paper we present a new simple controller for a chaotic system, that is, the
Newton--Leipnik equation with two strange attractors: the upper attractor (UA) and
the lower attractor (LA). The controller design is based on the passive technique.
The final structure of this controller for original stabilization has a simple
nonlinear feedback form. Using a passive method, we prove the stability of a
closed-loop system. Based on the controller derived from the passive principle, we
investigate three different kinds of chaotic control of the system, separately: the
original control forcing the chaotic motion to settle down to the origin from an
arbitrary position of the phase space; the chaotic intra-attractor control for
stabilizing the equilibrium points only belonging to the upper chaotic attractor or
the lower chaotic one, and the inter-attractor control for compelling the chaotic
oscillation from one basin to another one. Both theoretical analysis and simulation
results verify the validity of the suggested method. 相似文献
18.
Synchronization between a novel class of fractional-order and integer-order chaotic systems via a sliding mode controller
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<正>In order to figure out the dynamical behaviour of a fractional-order chaotic system and its relation to an integerorder chaotic system,in this paper we investigate the synchronization between a class of fractional-order chaotic systems and integer-order chaotic systems via sliding mode control method.Stability analysis is performed for the proposed method based on stability theorems in the fractional calculus.Moreover,three typical examples are carried out to show that the synchronization between fractional-order chaotic systems and integer-orders chaotic systems can be achieved. Our theoretical findings are supported by numerical simulation results.Finally,results from numerical computations and theoretical analysis are demonstrated to be a perfect bridge between fractional-order chaotic systems and integer-order chaotic systems. 相似文献
19.
Chaotic systems perform well as a new rich source of
cryptography and pseudo-random coding. Unfortunately their digital
dynamical properties would degrade due to the finite computing
precision. Proposed in this paper is a modified digital chaotic
sequence generator based on chaotic logistic systems with a coupling
structure where one chaotic subsystem generates perturbation signals
to disturb the control parameter of the other one. The numerical
simulations show that the length of chaotic orbits, the output
distribution of chaotic system, and the security of chaotic
sequences have been greatly improved. Moreover the chaotic sequence
period can be extended at least by one order of magnitude longer
than that of the uncoupled logistic system and the difficulty in
decrypting increases 2128*2128 times indicating that the
dynamical degradation of digital chaos is effectively improved. A
field programmable gate array (FPGA) implementation of an algorithm
is given and the corresponding experiment shows that the output
speed of the generated chaotic sequences can reach 571.4~Mbps
indicating that the designed generator can be applied to the
real-time video image encryption. 相似文献
20.
Circuitry implementation of a novel four-dimensional nonautonomous hyperchaotic Liu system and its experimental studies on synchronization control
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Based on the three-dimensional Liu chaotic system, this paper
appends a feedback variable to construct a novel hyperchaotic Liu
system. Then, a control signal is further added to construct a novel
nonautonomous hyperchaotic Liu system. Through adjusting the
frequency of the control signal, the chaotic property of the system
can be controlled to show some different dynamic behaviors such as
periodic, quasi-periodic, chaotic and hyperchaotic dynamic
behaviours. By numerical simulations, the Lyapunov exponent
spectrums, bifurcation diagrams and phase diagrams of the two new
systems are studied, respectively. Furthermore, the synchronizing
circuits of the nonautonomous hyperchaotic Liu system are designed
via the synchronization control method of single variable coupling
feedback. Finally, the hardware circuits are implemented, and the
corresponding waves of chaos are observed by an oscillograph. 相似文献