关联可切换超混沌系统的构建与特性分析

利用拓展系统变量,增加系统的非线性函数和对原系统实施反混沌控制方法,构建了一类关联且有多种切换方式的超混沌系统,对这类系统的分岔图、平衡点的稳定性、Lyapunov指数和动力学行为的演化过程进行了分析.设计了实现切换超混沌系统的电路,利用开关的切换,一个电路能实现多个超混沌系统的功能. 关键词： 超混沌系统 切换 分岔图 Lyapunov指数     

切换统一混沌系统族

拓展统一混沌系统的非线性函数,构建包含6类子系统的切换统一混沌系统族,不仅每个子类系统在参量空间随系统参数的变化实现切换,而且6类子系统在状态空间随系统非线性函数的变化实现连续切换.利用Lyapunov指数谱和分岔图对6类子系统随系统参数变化的整体情况进行分析,用数字信号处理(DSP)芯片对典型混沌系统的分时切换进行硬件实现. 关键词： 统一混沌系统 切换律 Lyapunov指数 数字信号处理     

四维切换超混沌系统

构建了一类关联且有多种切换方式的四维超混沌系统.依据系统的分岔图确定了各个子系统都处于混沌状态时，系统参数的取值范围.分析了这类四维超混沌系统平衡点的性质、超混沌吸引子的相图和Lyapunov指数等特性，设计了实现这类可切换超混沌系统的实际电路，利用系统选择器，一个电路可以实现四个关联子系统的功能. 关键词： 超混沌系统 分岔图 Lyapunov指数 切换     

一个4维超混沌类Lorenz系统动力学分析

利用Matlab软件和理论分析给出了一个新超混沌类Lorenz系统的非线性动力学行为。主要包括对称性、耗散性、平衡点的稳定性、空间相图、时序波形图、Lyapunov指数和Lyapunov维数、分岔图、Poincaré映射图和功率谱图等方面。研究结果展示了系统具有丰富的动力学行为,证实了混沌系统的物理可实现性。     

一个新的混沌系统的构建与实现

参考Chen系统和Liu系统的构建模式, 对Lorenz系统进行改造, 构建一个新的三维自治混沌系统. 讨论了平衡点的性质, 给出了系统的功率谱图、 Poincare截面图, 并利用分岔图和Lyapunov指数谱详细分析了各参数变化对系统动力学行为的影响. 研究发现, 交叉乘积项参数d和平方项参数e变化时, 系统的Lyapunov指数谱保持恒定, 且参数d具有全局非线性调幅功能, 参数e具有局部非线性调幅功能. 另外, 设计了该混沌系统的模拟电路, 实验结果证实了混沌系统的可实现性.     

一个新的三维混沌系统

构造了一个新的三维连续自治混沌系统.该系统含有两个参数、一个反正切函数形式的非线性项.基于线性矩阵不等式方法研究了系统的稳定性.通过理论分析、数值仿真、Lyapunov指数谱、分岔图以及Poincaré截面图分别研究了系统的复杂动力学特性. 关键词： 混沌系统 稳定性 线性矩阵不等式 Lyapunov指数谱     

一个新的三维二次混沌系统及其电路实现

为了产生复杂的混沌吸引子，构造了一个新的三维二次自治混沌系统.该系统含有三个参数，每一个方程含有一个非线性乘积项.利用理论推导、数值仿真、Lyapunov指数谱和分岔图对系统的基本动力学特性进行了分析.结果表明，该系统具有五个平衡点，因而与Lorenz，Rsslor，Chen、Lü等混沌系统是非拓扑等价的；当其参数满足一定条件时，系统是混沌的.与Lorenz等混沌系统相比，该系统具有更大的正Lyapunov指数，能够产生复杂的混沌吸引子和一些有趣的动力学行为.最后，设计了实现该系统的混沌电路，电路实验结 关键词： 三维二次自治系统 混沌 混沌吸引子 电路实现     

一类相对转动非线性动力系统的混沌运动

研究一类具有同宿轨道、异宿轨道的相对转动非线性动力系统的混沌运动. 建立具有非线性刚度、非线性阻尼和外扰激励作用的一类两质量相对转动非线性动力系统的动力学方程. 利用Melnikov方法讨论了系统的全局分岔和系统进入混沌状态的可能途径,给出了系统发生混沌的必要条件,并利用最大Lyapunov指数图,分岔图,Poincare截面图和相轨迹图进一步分析了系统的混沌行为. 关键词： 相对转动 非线性动力系统 混沌 Melnikov方法     

一类非线性相对转动系统的组合共振分岔与混沌

研究一类具有异宿轨道的非线性相对转动系统的分岔与混沌运动. 应用耗散系统的拉格朗日方程建立一类组合谐波激励作用下非线性相对转动系统的动力学方程. 利用多尺度法求解相对转动系统发生组合共振时满足的分岔响应方程并进行奇异性分析, 得到了系统稳态响应的转迁集. 根据相对转动系统异宿轨道参数方程, 求解了异宿轨道的Melnikov函数, 并给出了系统发生Smale马蹄变换意义下混沌的临界条件. 最后采用数值方法, 通过分岔图, 最大Lyapunov指数图, 相轨迹图和庞加莱截面图研究系统参数对混沌运动的影响.     

具有恒Lyapunov指数谱的新三维混沌系统分析与电路实现

构造一个新三维自治混沌系统,它是Lorenz系统、Chen系统和Lü系统的通式.通过其Lyapunov维数、Lyapunov指数谱、分岔图分析了当系统不同参数变化时的动力学特性.其Lyapunov指数谱说明该系统存在双恒Lyapunov指数混沌锁定;分岔图和状态变量幅值演变说明锁定后混沌系统的幅值与相位可以调节.最后,设计了该混沌系统的电路实现并用Multisim软件对该电路进行仿真,结果验证了理论分析与电路仿真具有一致性.     

A novel four-wing chaotic attractor generated from a three-dimensional quadratic autonomous system

This paper presents a new 3D quadratic autonomous chaotic system which contains five system parameters and three quadratic cross-product terms, and the system can generate a single four-wing chaotic attractor with wide parameter ranges. Through theoretical analysis, the Hopf bifurcation processes are proved to arise at certain equilibrium points. Numerical bifurcation analysis shows that the system has many interesting complex dynamical behaviours; the system trajectory can evolve to a chaotic attractor from a periodic orbit or a fixed point as the proper parameter varies. Finally, an analog electronic circuit is designed to physically realize the chaotic system; the existence of four-wing chaotic attractor is verified by the analog circuit realization.     

Dynamic analysis and synchronization control of an unusual chaotic system with exponential term and coexisting attractors

This paper reports a new four-dimensional chaotic system consisting of an exponential nonlinear term, two quadratic nonlinear terms and five linear terms. The system has only one equilibrium and performs stability, periodicity and chaos with the variation of the parameters. It losses its stability with the occurrence of Hopf bifurcation and goes into chaos via period-doubling bifurcation. One more interesting feature of the system is that it can generate multiple coexisting attractors for different initial conditions, such as two strange attractors with one limit cycle, one strange attractor with two limit cycles, etc. The dynamic properties of the system are presented by numerical simulation includes bifurcation diagrams, Lyapunov exponent spectrum and phase portraits. An electronic circuit is constructed to implement the chaotic attractor of the system. Based on the linear quadratic regulator (LQR) method, the synchronization control of the system is investigated.     

A novel four-wing non-equilibrium chaotic system and its circuit implementation

In this paper, we construct a novel, 4D smooth autonomous system. Compared to the existing chaotic systems, the most attractive point is that this system does not display any equilibria, but can still exhibit four-wing chaotic attractors. The proposed system is investigated through numerical simulations and analyses including time phase portraits, Lyapunov exponents, bifurcation diagram, and Poincaré maps. There is little difference between this chaotic system without equilibria and other chaotic systems with equilibria shown by phase portraits and Lyapunov exponents. But the bifurcation diagram shows that the chaotic systems without equilibria do not have characteristics such as pitchfork bifurcation, Hopf bifurcation etc. which are common to the normal chaotic systems. The Poincaré maps show that this system is a four-wing chaotic system with more complicated dynamics. Moreover, the physical existence of the four-wing chaotic attractor without equilibria is verified by an electronic circuit.     

新三维混沌系统及其电路仿真

提出了一个新的不同于Lorenz系统和Chen系统的三维连续自治混沌系统.该系统含有五个参数,其中两个方程中各含有一个非线性乘积项.通过理论推导、数值仿真、Lyapunov指数谱、分岔图、Lyapunov维数、Poincare截面图研究了系统的基本动力学特性,并分析了改变不同参数时系统动力学行为的变化.最后设计了硬件电路并运用电子工作平台Multisim软件对该电路进行仿真实验,证实了该混沌系统的可实现性. 关键词： 混沌系统 Lyapunov指数 Poincare截面图 电路仿真     

具有复合幂函数和共存吸引子的新混沌系统的动力学分析与电路仿真

构造一个具有复合幂函数的三维连续自治混沌系统。系统的状态方程仅有5项，其中一项是指数小于1的复合幂函数。该系统具有结构简单、非双曲平衡点、吸引子共存的性质，展现出了复杂的动力学行为。首先，对系统的动力学行为进行分析，包括李雅普诺夫（Lyapunov）指数谱、分岔图以及庞加莱映射等，结果表明此系统具有混沌特性。然后进行混沌系统的电路设计，电路仿真结果验证了理论分析的正确性。     

n-scroll chaotic attractors from a first-order time-delay differential equation

In this paper, a novel first-order delay differential equation capable of generating n-scroll chaotic attractor is presented. Hopf bifurcation of the introduced n-scroll chaotic system is analytically and numerically determined. The bifurcation diagram and Lyapunov spectrum of the system are calculated and the results show that the system has a chaotic regime in a wider parameter range. Furthermore, period-3 behavior has been observed on the system. Circuit realizations of two-, three-, four-, and five-scroll chaotic attractors are also presented.     

The analysis of a novel 3-D autonomous system and circuit implementation

This Letter presents a new three-dimensional autonomous system with four quadratic terms. The system with five equilibrium points has complex chaotic dynamics behaviors. It can generate many different single chaotic attractors and double coexisting chaotic attractors over a large range of parameters. We observe that these chaotic attractors were rarely reported in previous work. The complex dynamical behaviors of the system are further investigated by means of phase portraits, Lyapunov exponents spectrum, Lyapunov dimension, dissipativeness of system, bifurcation diagram and Poincaré map. The physical circuit experimental results of the chaotic attractors show agreement with numerical simulations. More importantly, the analysis of frequency spectrum shows that the novel system has a broad frequency bandwidth, which is very desirable for engineering applications such as secure communications.     

A novel hyperchaotic system and its circuit implementation

A four-dimensional hyperchaotic system with five parameters is proposed. Its dynamical properties such as dissipativity, equilibrium points, Lyapunov exponent, Lyapunov dimension, bifurcation diagrams and Poincare maps are analyzed theoretically and numerically. Theoretical analyses and simulation tests indicate that the new system's dynamics behavior can be periodic attractor, chaotic attractor and hyperchaotic attractor as the parameter varies. Finally, the circuit of this new hyperchaotic system is designed and realized by Multisim software. The simulation results confirm that the chaotic system is different from the existing chaotic systems and is a novel hyperchaotic system. The system is recommendable for many engineering applications such as information processing, cryptology, secure communications, etc.     

The analysis of complex behaviours of a novel three dimensional autonomous system

This paper introduces a new three dimensional autonomous system with five equilibrium points.It demonstrates complex chaotic behaviours within a wide range of parameters,which are described by phase portraits,Lyapunov exponents,frequency spectrum,etc.Analysis of the bifurcation and Poincar’e map is used to reveal mechanisms of generating these complicated phenomena.The corresponding electronic circuits are designed,exhibiting experimental chaotic attractors in accord with numerical simulations.Since frequency spectrum analysis shows a broad frequency bandwidth,this system has perspective of potential applications in such engineering fields as secure communication.