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Frontiers in Energy 2020年第1期14卷 180-191页

作者： Ridha CHEIKH Arezki MENACER L.CHRIFI-ALAOUI Said DRID Department of Electrical Engineering LGEB Laboratory Biskra UniversityBiskra 07000Algeria Laboratory of Innovative Technology(LTI) University of Picardie Jules VemeIUT de l'Aisne 02880 CuffiesFrance Unite de Developpement des Equipements Solaires UDESCentre de Developpement des Energies RenouvelablesCDER 42415 TipazaAlgeria LSPIE Laboratory Department of Electrical EngineeringUniversity of Batna2Rue Chahid Med El-Hadi Boukhlof 05000Algeria

In this paper,the method for the nonlinear control design of a permanent magnet synchronous generator based-wind energy conversion system(WECS)is proposed in order to obtain robustness against disturbances and harvest a maximum power from a typical stochastic wind environment.The technique overcomes both the problem of nonlinearity and the uncertainty of the parameter compared to such classical control designs based on traditional control techniques.The method is based on the differential geometric feedback linearization technique(DGT)and the Lyapunov theory.The results obtained show the effectiveness and performance of the proposed approach.

关键词： permanent magnet synchronous generator wind energy conversion system stochastic differential geometric feedback linearization maximum power point tracking Lyapunov robust control

Multiple Lagrange stability and Lyapunov asymptotical stability of delayed fractional-order Cohen-Grossberg neural networks

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Chinese Physics B 2020年第2期29卷 196-205页

作者：黄玉娇袁孝焰杨旭华龙海霞肖杰 Zhijiang College Zhejiang University of TechnologyHangzhou 310024China College of Computer Science and Technology Zhejiang University of TechnologyHangzhou 310023China

This paper addresses the coexistence and local stability of multiple equilibrium points for fractional-order Cohen-Grossberg neural networks(FOCGNNs)with time delays.Based on Brouwer's fixed point theorem,sufficient conditions are established to ensure the existence of Πi=1^n(2Ki+1)equilibrium points for FOCGNNs.Through the use of Hardy inequality,fractional Halanay inequality,and Lyapunov theory,some criteria are established to ensure the local Lagrange stability and the local Lyapunov asymptotical stability of Πi=1^n(Ki+1)equilibrium points for FOCGNNs.The obtained results encompass those of integer-order Hopfield neural networks with or without delay as special cases.The activation functions are nonlinear and nonmonotonic.There could be many corner points in this general class of activation functions.The structure of activation functions makes FOCGNNs could have a lot of stable equilibrium points.Coexistence of multiple stable equilibrium points is necessary when neural networks come to pattern recognition and associative memories.Finally,two numerical examples are provided to illustrate the effectiveness of the obtained results.

关键词： fractional-order Cohen-Grossberg neural networks multiple Lagrange stability multiple Lyapunov asymptotical stability time delays

Stability Analysis of Systems With Time-varying Delay via a Novel Lyapunov Functional

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IEEE/CAA Journal of Automatica Sinica 2019年第4期6卷 1068-1073页

作者： Yun Chen Gang Chen the School of Electrical and Information Engineering Hunan University of TechnologyZhuzhou 412007 the Key Laboratory for Electric Drive Control and Intelligent Equipment of Hunan Province Zhuzhou 412007China

This paper investigates the stability problem for time-varying delay systems.To obtain a larger delay bound,this paper uses the second-order canonical Bessel-Legendre(BL)inequality.Secondly,using four couples of integral terms in the augmented Lyapunov-Krasovskii function(LKF)to enhance the relationship between integral functionals and other vectors.Furthermore,unlike the construction of the traditional LKF,a novel augmented LKF is constructed with two new delayproduct-type terms,which adds more state information and leads to less conservative results.Finally,two numerical examples are provided to demonstrate the effectiveness and the significant improvement of the proposed stability criteria.

关键词： Integral inequality Lyapunov theorem stability time-delay systems

Construction of a new Lyapunov function for a dissipative gyroscopic system using the residual energy function

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Frontiers of Information Technology & Electronic Engineering 2020年第4期21卷 629-634页

作者： Cem CiVELEK Ozge CiHANBEGENDi Faculty of Engineering Department of Electrical and Electronics EngineeringEge UniversityBornova-izmir 35100Turkey Faculty of Engineering Department of Electrical and Electronics EngineeringDokuz Eylul UniversityBuca-izmir 35160Turkey

In a dissipative gyroscopic system with four degrees of freedom and tensorial variables in contravariant(right upper index)and covariant(right lower index)forms,a Lagrangian-dissipative model,i.e.,{L,D}-model,is obtained using second-order linear differential equations.The generalized elements are determined using the{L,D}-model of the system.When the prerequisite of a Legendre transform is fulfilled,the Hamiltonian is found.The Lyapunov function is obtained as a residual energy function(REF).The REF consists of the sum of Hamiltonian and losses or dissipative energies(which are negative),and can be used for stability by Lyapunov’s second method.Stability conditions are mathematically proven.

关键词： Lyapunov function Residual energy function Stability of dissipative gyroscopic system

无线自回传网络中基于Lyapunov的虚拟资源分配算法

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北京邮电大学学报 2018年第1期41卷 43-50页

作者：唐伦杨希希施颖洁陈前斌重庆邮电大学信息与通信工程学院

为提高网络部署的灵活性,保障多样化虚拟网络的需求,针对无线自回传网络场景提出一种基于Lyapunov的虚拟资源分配策略.联合考虑系统稳定性、虚拟网络最小速率需求和小蜂窝回传容量限制,对无线接入资源和回传带宽进行联合分配,建立虚拟... 详细信息

为提高网络部署的灵活性,保障多样化虚拟网络的需求,针对无线自回传网络场景提出一种基于Lyapunov的虚拟资源分配策略.联合考虑系统稳定性、虚拟网络最小速率需求和小蜂窝回传容量限制,对无线接入资源和回传带宽进行联合分配,建立虚拟网络效用最大化模型;其次,运用Lyapunov优化理论设计了一种基于当前信道状态和队列状态的实时调度算法;最后,通过拉格朗日对偶算法和基于相似度随机变异的粒子群算法进行迭代求解.仿真结果表明,该方案可在保证系统队列稳定性的同时提高无线虚拟网络的平均总收益.

关键词：无线虚拟网络自回传实时调度 Lyapunov 队列稳定性

A New Lyapunov Based Robust Control for Uncertain Mechanical Systems

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自动化学报 2014年第5期40卷 875-882页

作者： ZHEN Sheng-Chao ZHAO Han CHEN Ye-Hwa HUANG Kang School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China The George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta Georgia 30332 USA

We design a new robust controller for uncertain mechanical systems. The inertia matrix0s singularity and upper bound property are first analyzed. It is shown that the inertia matrix may be positive semi-definite due to over-simplified model. Further-more, the inertia matrix0s being uniformly bounded above is also limited. A robust controller is proposed to suppress the effect of uncertainty in mechanical systems with the assumption of uniform positive definiteness and upper bound of the inertia matrix. We theoretically prove that the robust control renders uniform boundedness and uniform ultimate boundedness. The size of the ultimate boundedness ball can be made arbitrarily small by the designer. Simulation results are presented and discussed.

关键词：鲁棒控制器 Lyapunov 机械系统惯性矩阵一致有界系统不确定性一致最终有界仿真结果

Stability analysis via the concept of Lyapunov exponents―a case study

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High Technology Letters 2018年第2期24卷 156-162页

作者：陈城 Xu Jinfa Liu Yunping Li Xianying Zhang Yonghong National Key Laboratory of Rotorcraft Aeromechanics Nanjing University of Aeronautics & Astronautics College of Information and Control Nanjing University of Information Science and TechnologyCollaborative Innovation Center of Atmospheric Environment and Equipment in Jiangsu Province

The dynamics characteristics of the robotic arm system are usually highly nonlinear and strongly coupling,which will make it difficult to analyze the stability by the methods of solving kinetic equations or constructing Lyapunov function,especially,these methods cannot calculate the quantitative relationship between mechanical structures or control input and dynamics parameters and stability.The theoretical analysis process from symbol dynamics modeling of the robotic arm system to the movement stability is studied by using the concept of Lyapunov exponents method. To verify the algorithm effectiveness,the inner relation between its joint input torque and stability or chaotic and stable motion of the 2-DOF robotic arm system is analyzed quantitatively. As compared with its counterpart of Lyapunov's direct method,the main advantage of the concept of Lyapunov exponents is that the methods for calculating the exponents are constructive to provide an effective analysis tool for analyzing robotic arm system movement stability of nonlinear systems.

关键词： Lyapunov 稳定性分析运动稳定性动力学特征案例控制输入动力学参数机械结构

HHT端点效应的最大Lyapunov指数边界延拓方法

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仪器仪表学报 2011年第6期32卷 1330-1336页

作者：蔡艳平李艾华张玮许平第二炮兵工程学院502教研室西安710025 西安交通大学电信学院西安710049 西安交通大学机械制造系统工程国家重点实验室西安710049

针对HHT(Hilbert-Huang transfrom)的端点效应问题,提出基于最大Lyapunov指数预测模型的HHT边界延拓方法。该方法通过相空间重构,并利用时间序列相似点的演化行为,采用最大Lyapunov指数预测模型来对时间序列的端点进行预测,有效避免了... 详细信息

针对HHT(Hilbert-Huang transfrom)的端点效应问题,提出基于最大Lyapunov指数预测模型的HHT边界延拓方法。该方法通过相空间重构,并利用时间序列相似点的演化行为,采用最大Lyapunov指数预测模型来对时间序列的端点进行预测,有效避免了不同边界条件的三次样条插值和Hilbert变换频谱泄露对HHT分析结果产生的影响。在此基础上,为了评价所提方法的有效性,提出了IMF分量归一化相关系数和IMF分量信噪比的性能评价指标,通过与标准HHT、镜像延拓HHT的仿真对比分析,结果表明所提方法抑制端点效应的性能优于二者。最后将其应用在转子油膜涡动故障试验分析中,结果表明基于最大Lyapunov指数边界延拓的HHT分析结果比镜像延拓后的分析结果更能够准确地描述油膜涡动故障特征。

关键词： HHT 经验模态分解端点效应边界延拓 Lyapunov 故障诊断

砂岩全应力-应变曲线二分段特征的Lyapunov定性分析

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岩土力学 2008年第7期29卷 1884-1888页

作者：刘传孝刘福胜蒋金泉戴景军山东农业大学水利土木工程学院泰安271018 山东科技大学泰安校区泰安271019

提出砂岩全应力-应变曲线的二分法原则,应用混沌动力学Lyapunov评价准则定性研究得到了曲线新的分段特征:试验曲线的所有峰前段均处于混沌状态,证明岩石节理裂隙这一复杂系统的非线性状态演化是客观存在、线性是近似的;节理裂隙系统有85... 详细信息

提出砂岩全应力-应变曲线的二分法原则,应用混沌动力学Lyapunov评价准则定性研究得到了曲线新的分段特征:试验曲线的所有峰前段均处于混沌状态,证明岩石节理裂隙这一复杂系统的非线性状态演化是客观存在、线性是近似的;节理裂隙系统有85%演化到峰后段时呈有序定常态,表明节理裂隙贯通后的岩石已呈现宏观破坏,线性特征明显;围压作用将延长节理裂隙的贯通过程,使之在峰后呈抵抗性破坏特征;峰后应变长度占总应变长度的2/3及以上时,该阶段节理裂隙系统的状态将主导其演化全过程的状态特征。

关键词：二分法应力-应变曲线 Lyapunov 定性

Stability Analysis of Milling Process With Time-Varying Delays Via Lyapunov-Krasovskii Functional

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Stability Analysis of Milling Process With Time-Varying Dela...