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Hierarchical control of a class of uncertain linear systems

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Journal of Control and Decision 2016年第2期3卷 119-131页

作者： kaihong yang Haibo Ji Department of Automation University of Science and Technology of ChinaHefeiChina

Hierarchical control method which is based on a hierarchical architecture has been developed to be mainly aimed at large-scale complex *** order to analyse and control this kind of systems,we construct first an appropriate and low-dimensional abstract system,then synthesise and lift the control law from the obtained abstraction to the original *** far as the linear systems with uncertain terms are concerned,this paper studies the robust control problem of high-dimensional uncertain linear systems and derives the results by employing hierarchical ***,the LMI toolbox is allowed to be used for the computation of interface ***,our method framework is illustrated on a five-dimensional uncertain linear system.

关键词： hierarchical control abstraction robust control uncertain linear systems

Online distributed optimization with stochastic gradients:high probability bound of regrets

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Control Theory and Technology 2024年第3期22卷 419-430页

作者： Yuchen yang kaihong Lu Long Wang Center for Systems and Control College of EngineeringPeking UniversityBeijing 100871China College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590ShandongChina

In this paper,the problem of online distributed optimization subject to a convex set is studied via a network of *** agent only has access to a noisy gradient of its own objective function,and can communicate with its neighbors via a *** handle this problem,an online distributed stochastic mirror descent algorithm is *** works on online distributed algorithms involving stochastic gradients only provide the expectation bounds of the *** from them,we study the high probability bound of the regrets,i.e.,the sublinear bound of the regret is characterized by the natural logarithm of the failure probability's *** mild assumptions on the graph connectivity,we prove that the dynamic regret grows sublinearly with a high probability if the deviation in the minimizer sequence is sublinear with the square root of the time ***,a simulation is provided to demonstrate the effectiveness of our theoretical results.

关键词： Distributed optimization Online optimization Stochastic gradient High probability

Guidance Law Based on Block Backstepping and Input-to-State Stability

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Guidance Law Based on Block Backstepping and Input-to-State ...

Flocking Control of Flying Robots considering Model’s Dynamics Processes

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作者： Shenghui Wang Kun Li Haibo Ji kaihong yang Department of Automation University of Science and Technology of China

ISBN: (纸本)9781538629185

A novel three-dimensional nonlinear guidance law is proposed based on block backstepping method and input-to-state stability theory for interception of maneuvering targets（evaders）.By viewing the target acceleration as a bounded disturbance input,input-to-state stability theory is utilized to design a state feedback guidance law so as to achieve robust tracking to the maneuvering *** stability analysis as well as the simulation results shows that the proposed approach can lead to successful interception of maneuvering target.

关键词： Block Backstepping Input-to-State Stability Uncertainties Robustness

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Flocking Control of Flying Robots considering Model’s Dynam...

Aging Behavior of As-Extruded Ti Particles Reinforced VW94 Composites

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作者： Di Jian Ji Haibo Li Kun yang kaihong Yu Wang Department of Automation University of Science and Technology of China

ISBN: (纸本)9781538629185

This paper studies the flocking problem for flying robots in three-dimensional space. Each robot’s attitude dynamics is considered. Motivated by consensus algorithms, we propose a distributed control law to achieve the flocking of flying *** convergence is proved by Lyapunov function and La Salle’s invariance principle. And the simulation results are given to demonstrate the effectiveness of the proposed control law.

关键词： Flocking Flying Robots Attitude Dynamics Synchronization

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 401-406页

作者： Dongmei Pu Xianhua Chen Jingfeng Wang Jun Tan Jianbo Li Hong yang Bo Feng kaihong Zheng Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400045China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China

The ageing behavior of as-extruded Ti_(P)/VW94 composites was *** peak hardness of the composites increases compared to the matrix alloy and the 5%Ti_(P)/VW94 composite presents the highest peak hardness of 148.7 HV after aging for about 50 ***,the hardness increments first decrease and then slightly increase with increasing Ti particle content due to the introduction of high-density dislocations by Ti particles.

关键词： Magnesium matrix composites Ti particles Ageing behavior Hardness

Random gradient-free method for online distributed optimization with strongly pseudoconvex cost functions

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Control Theory and Technology 2024年第1期22卷 14-24页

作者： Xiaoxi Yan Cheng Li kaihong Lu Hang Xu School of Electrical and Information Engineering Jiangsu UniversityZhenjiang212013JiangsuChina College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao266590ShandongChina

This paper focuses on the online distributed optimization problem based on multi-agent systems. In this problem, each agent can only access its own cost function and a convex set, and can only exchange local state information with its current neighbors through a time-varying digraph. In addition, the agents do not have access to the information about the current cost functions until decisions are made. Different from most existing works on online distributed optimization, here we consider the case where the cost functions are strongly pseudoconvex and real gradients of the cost functions are not available. To handle this problem, a random gradient-free online distributed algorithm involving the multi-point gradient estimator is proposed. Of particular interest is that under the proposed algorithm, each agent only uses the estimation information of gradients instead of the real gradient information to make decisions. The dynamic regret is employed to measure the proposed algorithm. We prove that if the cumulative deviation of the minimizer sequence grows within a certain rate, then the expectation of dynamic regret increases sublinearly. Finally, a simulation example is given to corroborate the validity of our results.

关键词： Multi-agent system Online distributed optimization Pseudoconvex optimization Random gradient-free method

Interfacial Reaction of Ti6Al4V Lattice Structure-Reinforced VW92 Alloy Matrix Composites

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 570-576页

作者： Haijun Wang Renju Cheng Xianhua Chen Mingbo yang Daiyi Deng Lirui Liu Yongfeng Zhou Yanlong Ma kaihong Zheng Fusheng Pan College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China

A novel melting infiltration by ultrasonic vibration was investigated and applied to fabricate Ti6Al4V(TC4)lattice structure-reinforced Mg-10Gd-2Y-1Zn-xZr(refer to VW92 hereafter,x=0,0.5 wt%)alloy matrix *** edge-to-edge matching model indicates that the well-matching and possible orientation relationships(ORs)between theα-Mg andα-Ti,[10-10]_(α-Mg)//[11-23]_(α-Ti) in(0002)_(α-Mg)//(10-10)_(α-Ti) possesses the smallest misfit of 0.4%(f_(r)),and thus theα-Mg grains can nucleate on the TC4 lattice *** reaction occurred in the TC4/VW92+0.5 wt%Zr composites,and the reaction product was confirmed to be Al_(2)Zr_(3),AlZr_(2) andα-Ti(Zr)particles formed by continuous solution of *** the interfacial products,the AlZr_(2) phase is a brittle phase with high-volume fraction,which is not conducive to the load *** generally speaking,theα-Ti(Zr)and theα-Mg tend to form a coherent interface,which is beneficial for improving the interfacial bonding strength of composites.

关键词： TC4 VW92 composites TC4 lattice structure Interfacial reaction Mismatch

Zeroth-Order Methods for Online Distributed Optimization with Strongly Pseudoconvex Cost Functions

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Journal of Systems Science and Information 2024年第1期12卷 145-160页

作者： Xiaoxi YAN Muyuan MA kaihong LU School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212013China School of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

This paper studies an online distributed optimization problem over multi-agent *** this problem,the goal of agents is to cooperatively minimize the sum of locally dynamic cost *** from most existing works on distributed optimization,here we consider the case where the cost function is strongly pseudoconvex and real gradients of objective functions are not *** handle this problem,an online zeroth-order stochastic optimization algorithm involving the single-point gradient estimator is *** the algorithm,each agent only has access to the information associated with its own cost function and the estimate of the gradient,and exchange local state information with its immediate neighbors via a time-varying *** performance of the algorithm is measured by the expectation of dynamic *** mild assumptions on graphs,we prove that if the cumulative deviation of minimizer sequence grows within a certain rate,then the expectation of dynamic regret grows ***,a simulation example is given to illustrate the validity of our results.

关键词： multi-agent systems strongly pseudoconvex function single-point gradient estimator online distributed optimization

Influence of Micro/Nano-Ti Particles on the Corrosion Behavior of AZ31-Ti Composites

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 484-498页

作者： Jinchao Jiao Jin Zhang Yong Lian Shengli Han kaihong Zheng Fusheng Pan Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 10083China Beijing Key Laboratory for Corrosion Erosion and Surface Technology Beijing 100083China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 404100China

Adding Ti particles to magnesium alloy simultaneously enhances its strength and ***,how these particles influence on Mg alloy’s corrosion performance is seldom *** corrosion behavior of AZ31-Ti composites containing titanium nanoparticles(1.5 and 5 wt%)and micron particles(10 wt%)prepared by powder metallurgical in 3.5 wt%NaCl solution was *** results indicate that Ti particles serve as the primary location for the cathodic hydrogen reduction reaction,resulting in intense galvanic corrosion between the Ti and Mg *** nanoparticles distributed at the interface of the original AZ31 powder were in a discontinuous mesh structure,thus failing to act as a barrier against *** corrosion products with the existence of numerous cracks gradually peel off during the corrosion process and cannot protect the *** average corrosion rate P_(w) of AZ31,AZ31-1.5%Ti,AZ31-5%Ti,and AZ31-10%Ti after 7 days of immersion is 27.55,105.65,283.67,and 99.35 mm/y,***,AZ31-Ti composites can be considered as potential candidates for degradable fracturing ***,it is recommended to improve their corrosion resistance through surface treatment.

关键词： AZ31-Ti composite Nano-Ti Micro-Ti Corrosion behavior Scanning Kelvin probe force microscopy(SKPFM)