Implementation of a novel two-attractor grid multi-scroll chaotic system

This paper proposed a method of generating two attractors in a novel grid multi-scroll chaotic system. Based on a newly generated three-dimensional system, a two-attractor grid multi-scroll attractor system can be generated by adding two triangular waves and a sign function. Some basic dynamical properties, such as equilibrium points, bifurcations, and phase diagrams, were studied. Furthermore, the system was experimentally confirmed by an electronic circuit. The circuit simulation results and numerical simulation results verified the feasibility of this method.

Design and implementation of a novel multi-scroll chaotic system

This paper proposes a novel approach for generating a multi-scroll chaotic system. Together with the theoretical design and numerical simulations, three different types of attractor are available, governed by constructing triangular wave, sawtooth wave and hysteresis sequence. The presented new multi-scroll chaotic system is different from the classical multi-scroll chaotic Chua system in dimensionless state equations, nonlinear functions and maximum Lyapunov exponents. In addition, the basic dynamical behaviours, including equilibrium points, eigenvalues, eigenvectors, eigenplanes, bifurcation diagrams and Lyapunov exponents, are further investigated. The success of the design is illustrated by both numerical simulations and circuit experiments.

MULTI-SCROLL HYPERCHAOTIC SYSTEM BASED ON COLPITTS MODEL AND ITS CIRCUIT IMPLEMENTATION

Based on the framework of Colpitts oscillator, a four-dimensional multi-scroll hyperchaotic system is proposed, which generates (2M+1)×(2N+1)-scroll chaotic and hyperchaotic attractors. The key strategy is to increase the number of index-2 equilibrium points by introducing two unit saw-tooth functions to extend and modify the Colpitts oscillator model. By using bifurcation diagram and phase portrait, the dynamical characteristics of the multi-scroll hyperchaotic system are briefly studied. Moreover, micro-controller based circuit realization is introduced and the experimental results dem-onstrate that 7×5-scroll chaotic and hyperchaotic attractors can be obtained in the digital circuit.

A new multi-scroll chaotic generator

In this paper a new simple multi-scroll chaotic generator is studied. The characteristic of this new multi-scroll chaotic generator is that it is easy to generate different number of scroll chaotic attractors through modifying the nature number n after fixing the suitable system parameters and it does not need complex mathematical derivation. Various number of scroll chaotic attractors are illustrated not only by computer simulation but also by the realization of an electronic circuit experiment on Electronic Workbench （EWB）.

Adaptive generalized synchronization between Chen system and a multi-scroll chaotic system

Based on Lyapunov theory, the adaptive generalized synchronization between Chen system and a multi-scroll chaotic system is investigated. According to the form of target function a proper adaptive controller is designed, by which the controlled Chen system can be synchronized with a multi-scroll chaotic system including unknown parameters. The Lyapunov direct method is exploited to prove that the synchronization error and parameter identification error both converge to zero. Numerical simulation results verify the feasibility of the proposed method further.

A novel multi-scroll chaotic generator:Analysis, simulation, and implementation

Based on a new three-dimensional autonomous linear system and designing a specific form of saturated function series and a sign function with two variables of system, which are employed to increase saddle-focus equilibrium points with index 2, a novel multi-scroll chaotic system is proposed and its typical dynamical characteristics including bifurcation diagram, Poincare map, and the stability of equilibrium points are analyzed. The hardware circuit is designed and the experimental results are presented for confirmation.

Multi-scroll hidden attractors and multi-wing hidden attractors in a 5-dimensional memristive system

A novel 5-dimensional（5D） memristive chaotic system is proposed, in which multi-scroll hidden attractors and multiwing hidden attractors can be observed on different phase planes. The dynamical system has multiple lines of equilibria or no equilibrium when the system parameters are appropriately selected, and the multi-scroll hidden attractors and multi-wing hidden attractors have nothing to do with the system equilibria. Particularly, the numbers of multi-scroll hidden attractors and multi-wing hidden attractors are sensitive to the transient simulation time and the initial values. Dynamical properties of the system, such as phase plane, time series, frequency spectra, Lyapunov exponent, and Poincar′e map, are studied in detail. In addition, a state feedback controller is designed to select multiple hidden attractors within a long enough simulation time. Finally, an electronic circuit is realized in Pspice, and the experimental results are in agreement with the numerical ones.

A multi-directional controllable multi-scroll conservative chaos generator:Modelling,analysis,and FPGA implementation

Combing with the generalized Hamiltonian system theory,by introducing a special form of sinusoidal function,a class of n-dimensional(n=1,2,3)controllable multi-scroll conservative chaos with complicated dynamics is constructed.The dynamics characteristics including bifurcation behavior and coexistence of the system are analyzed in detail,the latter reveals abundant coexisting flows.Furthermore,the proposed system passes the NIST tests and has been implemented physically by FPGA.Compared to the multi-scroll dissipative chaos,the experimental portraits of the proposed system show better ergodicity,which have potential application value in secure communication and image encryption.

A new multi-scroll chaotic system

This paper proposes a new simple autonomous chaotic system which can generate multi-scroll chaotic attractors. The characteristic of this new multi-scroll chaotic system is that the 4n ＋ 2rn ＋ 4-scroll chaotic attractors are generated easily with n and m vaxying under n ≤ m. Various number of scroll chaotic attractors are illustrated not only by computer simulation but also by the realization of an electronic circuit experiment on EWB （Electronics Workbench）.

Novel two-directional grid multi-scroll chaotic attractors based on the Jerk system

A new method is presented to generate two-directional (2D) grid multi-scroll chaotic attractors via a specific form of the sine function and sign function series, which are applied to increase saddle points of index 2. The scroll number in the x-direction is modified easily through changing the thresholds of the specific form of the sine function, while the scroll number in the y-direction is controlled by the sign function series. Some basic dynamical properties, such as equilibrium points, bifurcation diagram, phase portraits, and Lyapunov exponents spectrum are studied. Furthermore, the electronic circuit of the system is designed and its simulation results are given by Multisim 10.

Design and FPGA implementation of a memristor-based multi-scroll hyperchaotic system

A novel memristor-based multi-scroll hyperchaotic system is proposed.Based on a voltage-controlled memristor and a modulating sine nonlinear function,a novel method is proposed to generate the multi-scroll hyperchaotic attractors.Firstly,a multi-scroll chaotic system is constructed from a three-dimensional chaotic system by designing a modulating sine nonlinear function.Then,a voltage-controlled memristor is introduced into the above-designed multi-scroll chaotic system.Thus,a memristor-based multi-scroll hyperchaotic system is generated,and this hyperchaotic system can produce various coexisting hyperchaotic attractors with different topological structures.Moreover,different number of scrolls and different topological attractors can be obtained by varying the initial conditions of this system without changing the system parameters.The Lyapunov exponents,bifurcation diagrams and basins of attraction are given to analyze the dynamical characteristics of the multi-scroll hyperchaotic system.Besides,the field programmable gate array(FPGA)based digital implementation of the memristor-based multi-scroll hyperchaotic system is carried out.The experimental results of the FPGA-based digital circuit are displayed on the oscilloscope.

仓储物流机器人多启发蚁群路径规划与避障

为了实现仓储物流机器人在动态环境下高效安全工作,提出了基于多启发蚁群算法的全局路径规划方法和基于滚动窗口的避障策略。针对仓储物流环境中的障碍物特点进行了分析和分类,建立了环境的动态栅格模型。为了提高蚁群算法初期搜索效率,给出了信息素的梯度分布初始化方法;同时引入距离启发因子和平滑启发因子,提出了多启发因群算法,并用于全局路径规划。根据机器人和工作人员不同的行为特点,制定了基于滚动窗口理论的动态避障策略。经验证,与传统蚁群算法比,多启发蚁群算法规划的路径长度更短、拐点更少、收敛更快;在仓储物流动态环境下,滚动窗口避障策略能够保证机器人沿较优路径安全行驶,证明了避障策略的可行性。

一类多涡卷Chua系统及其在图像加密中的应用

为使混沌序列表现出更复杂的特性,在典型的Chua系统上引入了分段线性函数,使所得的系统产生可控数量的多涡卷吸引子。对该系统进行动力学分析,分析结果表明,该系统混沌特性分布广泛,具有丰富的动力学行为。在此基础上,提出了一种基于Zigzag置乱和DNA编码的加密算法,并从多个方面对该算法的安全性进行了分析。仿真结果验证了该方法不仅能对图像进行有效加密,而且能有效抵抗各种常见的攻击,为图像加密提供了理论依据。

源网荷储协同的主动配电网多时间尺度优化调度

针对源网荷储一体化,降低预测误差对配网调度的影响,提出一种源网荷储协同的主动配电网多时间尺度优化调度策略。首先,建立电动汽车参与调度的响应模型,并根据柔性负荷的运行特性进行分类,以适应多时间尺度。在日前时间尺度上,建立配电网运行成本最小的调度计划;日内尺度上,综合考虑经济性及增加新能源消纳量等目标,采用滚动优化思想对有较大预测误差的日前调度计划进行修正;在实时阶段,结合日内计划,建立计及出力偏差最小的微调模型。最后,利用熵权法对各目标赋权,采用Yalmip+Cplex对模型求解,验证了调度策略的经济性。

一种分数阶混沌系统的通用增强型FPGA实现

针对目前分数阶混沌系统的FPGA设计实现通用程度不高的问题,文中给出了一种通用增强型FPGA算法。首先给出基于G-L定义的分数阶微分算法原理,再将一个已知的三维整数阶混沌系统扩展至分数阶多涡卷混沌系统,通过平衡点、分岔图及最大李氏指数谱分析了其动力学特性,最后运用可变长度移位寄存器,设计分数阶微分的通用增强型FPGA算法,并将其应用至分数阶多涡卷混沌系统。实验结果与数值仿真结果一致,该算法当修改参数时,无需设计新的代码,并能够动态调节记忆长度,且对步长没有严格限制。

基于Workbench涡旋压缩机涡旋齿流-热-固多场耦合分析

涡旋压缩机内部流场变化对涡旋齿受力变形情况具有重要影响。通过对涡旋压缩机进行流场分析,探究了压缩腔内压力、温度分布情况,并根据流场分析结果,对不同材质的动涡旋盘进行流-热-固多场耦合分析。研究表明:压缩腔的压力和温度在齿高方向并不相同;多场耦合下QT400-15比HT200更合适作为涡旋盘的制造材料;多场耦合下涡旋齿的最大应力出现在齿根部位,顶部变形最大;由于温度场载荷与气体力载荷所产生的主要应力与变形方向不同,因此温度场载荷和气体力载荷之间的叠加差值大于其耦合差值。

电动汽车涡旋压缩机驱动轴承的力学特性分析

文章旨在深入探讨电动涡旋压缩机在运行中受到气体力的干扰所引发的轴承磨损问题,详细阐述了气体力对传动系统平衡状态的干扰,并剖析了振动对驱动轴承和整机性能所造成的负面影响。为了提高涡旋压缩机转子系统的精度和可靠性,利用三维建模软件CATIA和多体动力学分析软件ADAMS分别建立了转子系统的三维机构模型和多体动力学模型。通过特定转速下的仿真分析,重点研究了驱动轴承受力情况,并通过设计研究,对相关部件进行参数优化。研究结果显示,驱动轴承的受力呈现明显的大幅度周期性变化,特别是在x和y方向上的受力较大,造成系统的二次不平衡。通过优化减小了可驱动轴承的受力,从而减小了轴承的摩擦磨损,提高了其使用寿命,改善了涡旋压缩机运行的稳定性,降低系统的振动和噪声。

涡旋式压缩机增加油泵过滤网对多联机运行可靠性的影响

针对多联机管路焊接加工时会产生氧化皮等杂质,提出一种可靠的压缩机抗杂质方法,即在涡旋式压缩机底部增加油泵过滤网,同时将油泵吸入口高度提高7 mm。经压缩机单体验证,采用该方法,压缩机抗杂质能力有明显提高。同时,将改善后压缩机应用于多联机,在长配管条件下进行名义工况和低温工况试验验证,结果表明,该改善方法满足压缩机油位可靠性要求,可以进行推广应用。

圆渐开线变截面涡旋压缩机型线的参数优化

圆渐开线变截面涡旋压缩机的优化设计均以几何性能为目标。为了得到在几何性能和力学性能方面更为优越的涡旋压缩机,文章建立圆渐开线变截面涡旋压缩机压缩比和轴向气体力的数学模型,分析压缩比和轴向气体力随型线参数的变化趋势;结合几何性能和力学性能,以压缩比倒数和轴向气体力为目标函数,利用多目标遗传算法对其进行优化,得到不同参数变化下的非劣解集。对优化型涡旋盘与未优化涡旋盘进行的定量分析结果表明,优化型涡旋盘的压缩比提高了16.14%,轴向气体力降低了5.62%,证明了优化的可行性。该研究为圆渐开线变截面涡旋压缩机设计时型线参数的选取提供了一定的参考。

可控网格多涡卷混沌系统族及其硬件电路实现

为加强混沌系统在通信链路的抗干扰和抗截获等性能,提高混沌系统性态的复杂度,基于典型蔡氏电路和阶梯函数,构造了一类数量可控的新型网格多涡卷混沌系统族。首先利用两组阶梯函数作为系统的非线性控制器,分别控制网格多涡卷混沌吸引子的奇偶列数和排列行数,并保持混沌吸引子中涡卷与键带的相互间置,以实现网格多涡卷的任意奇偶列数;然后对系统的平衡点、李雅普诺夫指数和吸引子等动力学特性进行理论分析和数值仿真实现;最后通过现场可编程门阵列(FPGA)给出最多4行12列网格多涡卷的硬件实验结果。软硬件实验结果和理论分析结果完全一致,进一步验证了所提系统的物理可实现性。