带有不确定参数的一类混沌金融系统的广义投影同步

针对带有不确定参数的一类混沌金融系统,提出了实现驱动系统和响应系统广义投影同步的自适应控制策略,并基于Lyapunov稳定性理论给出和验证了广义投影同步稳定性判据.数值仿真验证了控制策略和理论分析的有效性.     

一类非线性时滞混沌系统的自适应脉冲同步

针对一类非线性时滞混沌系统,提出了一种新的自适应脉冲同步方案.首先基于Lyapunov稳定性理论、自适应控制理论及脉冲控制理论设计了自适应控制器、脉冲控制器及参数自适应律,然后利用推广的Barbalat引理,理论证明响应系统与驱动系统全局渐近同步,并给出了相应的充分条件.方案利用参数逼近Lipschitz常数,从而取消了Lipschitz常数已知的假设.两个数值仿真例子表明本方法的有效性.     

一个四翼混沌系统的广义控制与同步

针对四翼混沌系统的控制和同步问题,采用反馈控制方法将系统的混沌运动控制到稳定态;根据Routh-Huriwtz准则获得了系统达到控制目标时反馈系数所满足的条件,通过设计控制器研究系统的广义控制与同步.在此基础上给出了响应系统同时含有控制变量时,系统的广义混合控制与同步运动行为,并从理论分析和Maple数值仿真验证了同步方法的可行性.     

一类分数阶超混沌系统修正函数投影同步的滑模控制

对一类具有未知参数的分数阶超混沌系统的修正函数投影同步进行研究.通过设计响应系统的补偿器,进而得到修正函数投影同步的误差系统.基于自适应滑模控制理论和分数阶微分系统的稳定性理论,设计了一种自适应同步的控制方案.通过选取自适应滑模控制器以及参数自适应控制率,最终实现了驱动系统和响应系统修正函数投影同步,并可以对不确定参数进行估计.最后针对结论,以分数阶超混沌L(u|¨)系统为例,利用Adams-Bashfortlh-Moultom算法进行数值仿真,其结果说明了该方法的有效性和可行性.     

受扰不确定混沌系统的双路组合函数投影同步

研究了具有未知参数和外界扰动的多个混沌系统之间的双路组合函数投影同步问题.首先给出了由四个混沌驱动系统和两个混沌响应系统组成的双路组合函数投影同步系统的定义,然后以Lyapunov稳定性理论和不等式变换方法为分析依据,设计了鲁棒自适应控制器和参数自适应律,使得两路同步系统中的响应系统和驱动系统按照相应的函数比例因子矩阵实现同步,并有效克服未知有界干扰和未知参数的影响.相应的理论分析和数值仿真证明了该同步方案的可行性和有效性.     

新的分数阶混沌系统及其同步

提出一个新的分数阶混沌系统,该系统含有三个参数,三个非线性项.通过理论分析,给出了分数阶混沌系统存在混沌吸引子的必要条件,通过数值仿真给出了混沌吸引子的图像,接着设计自适应同步控制器和参数自适应律,实现分数阶混沌系统的同步,数值仿真的结果表明设计控制器很好的实现了驱动系统和响应系统的同步.     

一类不确定混沌系统的自适应同步

讨论了混沌系统的同步问题 .对一类不确定混沌系统 ,提出了一个新的自适应同步方法 ,可使响应系统在自适应控制器的控制下 ,实现与不确定混沌系统的同步 .最后给出了一个设计实例 .     

不同超混沌系统的最优同步

在参数未知的情况下,通过设计最优控制器和参数自适应律实现了新的四维混沌系统与超混沌吕系统的同步.接着根据Lyapunov稳定性原理和Hamilton-Jacobi-Bellman方程,选取Lyapunov函数和合适的性能指标函数从理论上证明这种方法的有效性.理论证明结果表明所设计的控制器能使性能指标函数取得最小值,是最优的.最后又通过matlab软件对同步系统进行数值仿真,仿真结果显示驱动系统与响应系统能够很好地达到了同步,表明方法是可行有效的.     

异维混沌动力系统的有限时间广义同步

本文研究了异维混沌动力系统的有限时间广义同步的问题.利用有限时间Lyapunov稳定性定理、Jensen不等式等理论方法,通过设置不同的控制器,从理论上提出了一般的异维驱动系统和响应系统的有限时间广义同步的两种方案,并且对方案二中的影响同步时间因素做了理论分析和证明.最后,数值模拟验证了提出理论的正确性和可行性.     

连续动力系统的广义同步

讨论连续的混沌动力系统之间的广义同步．利用Liapunov稳定性理论,通过构造适当的耦合项,得到了一个关于驱动响应系统广义同步的充分条件．并通过对两个例子的数字模拟,说明了充分条件的有效性．     

Generalized projective synchronization in time-delayed chaotic systems

We report on generalized projective synchronization between two identical time delay chaotic systems with single time delays. It overcomes some limitations of the previous work where generalized projective synchronization has been investigated only in finite-dimensional chaotic systems, so we can achieve generalized projective synchronization in infinite-dimensional chaotic systems. This method allows us to arbitrarily direct the scaling factor onto a desired value. Numerical simulations show that this method works very well.     

Synchronizing the noise-perturbed Genesio chaotic system by sliding mode control

This paper investigates the chaos synchronization between Genesio chaotic systems with noise perturbation. It is proved theoretically that the synchronization between such noise-perturbed systems can be implemented by choosing a suitable sliding mode surface and designing a sliding mode controller. Numerical simulations show the effectiveness of the theoretical analysis. This proposed method is important because it can be applied to many other chaotic systems.     

Global synchronization criteria for a class of third-order non-autonomous chaotic systems via linear state error feedback control

This paper investigates the global synchronization of a class of third-order non-autonomous chaotic systems via the master–slave linear state error feedback control. A sufficient global synchronization criterion of linear matrix inequality (LMI) and several algebraic synchronization criteria for single-variable coupling are proven. These LMI and algebraic synchronization criteria are then applied to two classes of well-known third-order chaotic systems, the generalized Lorenz systems and the gyrostat systems, proving that the local synchronization criteria for the chaotic generalized Lorenz systems developed in the existing literature can actually be extended to describe global synchronization and obtaining some easily implemented synchronization criteria for the gyrostat systems.     

离散系统的广义同步

讨论两个离散系统之间的广义同步．通过构造合适的非线性耦合项,导出了驱动响应系统获得广义同步的充分条件．在一个正不变的有界集上,许多混沌映射满足这些充分条件．通过3个例子,说明了充分条件的有效性．     

Generalized synchronization of chaos based on suitable separation

In this Letter, generalized synchronization with a kind of function relationship between the states of drive and response chaotic systems is achieved. From matrix measure theory, some sufficient conditions for generalized synchronization are derived through suitable separation by decomposing the system as the linear part and the nonlinear one. Simulation results are provided for illustration and verification of the proposed method.     

The function cascade synchronization method and applications

In this paper, a new function cascade synchronization method of chaos system is proposed to achieve generalized projective synchronization for chaotic systems. Based on Laypunov stability, the proposed synchronization technique is applied to three famous chaotic systems: the unified chaotic system, Liu system and Rössler system, which can make the states of two identical chaotic systems asymptotically synchronized by choosing different special suitable error functions. Numerical simulations are presented to show the effectiveness.     

Synchronization of chaotic systems using feedback controller: An application to Diffie–Hellman key exchange protocol and ElGamal public key cryptosystem

In this paper, designing an appropriate linear and nonlinear feedback control, the two identical integer order chaotic systems are synchronized by analytically and numerically. It has been realizing that, synchronization using linear feedback control method is efficient than nonlinear feedback control method due to the less computational complexity and the synchronization error. ElGamal public key cryptosystem is described through the proposed Diffie–Hellman key exchange protocol based on the synchronized chaotic systems using linear feedback control and their security are analyzed. The numerical simulations are given to validate the correctness of the proposed synchronization of chaotic systems and the ElGamal cryptosystem.     

Adaptive generalized function projective synchronization of uncertain chaotic systems

This paper mainly investigates adaptive generalized function projective synchronization of two different uncertain chaotic systems, which is a further extension of many existing projection synchronization schemes, such as modified projection synchronization, function projective synchronization and so on. On the basis of Lyapunov stability theory, an adaptive controller for the synchronization of two different chaotic systems is designed, and some parameter update laws for estimating the unknown parameters of the systems are also gained. This technique is applied to achieve synchronization between Lorenz and Rössler chaotic systems. The numerical simulations demonstrate the validity and feasibility of the proposed method.     

Generalizations of the concept of marginal synchronization of chaos

Generalizations of the concept of marginal synchronization between chaotic systems, i.e. synchronization with zero largest conditional Lyapunov exponent, are considered. Generalized marginal synchronization in drive–response systems is defined, for which the function between points of attractors of different systems is given up to a constant. Auxiliary system approach is shown to be able to detect this synchronization. Marginal synchronization in mutually coupled systems which can be viewed as drive–response systems with the response system influencing the drive system dynamics is also considered, and an example from solid-state physics is analyzed. Stability of these kinds of synchronization against changes of system parameters and noise is investigated. In drive–response systems generalized marginal synchronization is shown to be rather sensitive to the changes of parameters and may disappear either due to the loss of stability of the response system, or as a result of the blowout bifurcation. Nonlinear coupling of the drive system to the response system can stabilize marginal synchronization.     

Multi-stable chaotic attractors in generalized synchronization

In this work, for given driving and response systems, the phenomenon of multi-stable chaotic attractors existing in generalized synchronization is studied. Consider the driving system descried by a Rössler system, and the response system being a multi-scroll chaotic system, some numerical simulations are proposed. The results show that by choosing suitable coupled parameters, there are multi-stable chaotic attractors in the response system, and each of them synchronizes with the driving system. Moreover, the basins of attraction on the parameter plane and initial condition plane are analyzed.