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Distributed Adaptive Output Consensus of Unknown Heterogeneous Non-Minimum Phase Multi-Agent Systems

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自动化学报：英文版 2023年第4期10卷 997-1008页

作者： Wenji Cao Lu Liu Gang feng Department of Biomedical Engineering City University of Hong KongHong Kong SARChina

This article addresses the leader-following output consensus problem of heterogeneous linear multi-agent systems with unknown agent parameters under directed graphs.The dynamics of followers are allowed to be non-minimum phase with unknown arbitrary individual relative degrees.This is contrary to many existing works on distributed adaptive control schemes where agent dynamics are required to be minimum phase and often of the same relative degree.A distributed adaptive pole placement control scheme is developed,which consists of a distributed observer and an adaptive pole placement control law.It is shown that under the proposed distributed adaptive control scheme,all signals in the closed-loop system are bounded and the outputs of all the followers track the output of the leader asymptotically.The effectiveness of the proposed scheme is demonstrated by one practical example and one numerical example.

关键词： Adaptive pole placement control heterogeneous multi-agent systems leader-following output consensus non-minimum phase

Lyapunov-Based Output Containment Control of Heterogeneous Multi-Agent Systems With Markovian Switching Topologies and Distributed Delays

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IEEE/CAA Journal of Automatica Sinica 2023年第6期10卷 1421-1433页

作者： Haihua Guo Min Meng Gang feng the Department of Biomedical Engineering City University of Hong KongHong KongChina the Department of Control Science and Engineering College of Electronics and Information Engineeringand Shanghai Research Institute of Intelligent Autonomous SystemsTongji UniversityShanghai 200092China

This paper considers the mean square output containment control problem for heterogeneous multi-agent systems(MASs)with randomly switching topologies and nonuniform distributed delays.By modeling the switching topologies as a continuous-time Markov process and taking the distributed delays into consideration,a novel distributed containment observer is proposed to estimate the convex hull spanned by the leaders'states.A novel distributed output feedback containment controller is then designed without using the prior knowledge of distributed delays.By constructing a novel switching Lyapunov functional,the output containment control problem is then solved in the sense of mean square under an easily-verifiable sufficient condition.Finally,two numerical examples are given to show the effectiveness of the proposed controller.

关键词： Heterogeneous multi-agent systems Lyapunov method Markovian switching topologies output containment control time delays

Energy-efficient URLLC service provisioning in softwarization-based networks

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Science China(Information Sciences) 2021年第8期64卷 35-55页

作者： Mengjie LIU Gang feng Weihua ZHUANG National Key Laboratory on Communications University of Electronic Science and Technology of China Department of Electrical and Computer Engineering University of Waterloo

Software defined networking(SDN) and network function virtualization(NFV) as new technologies have shown great potential in improving the flexibility of resource management for network service provisioning. As traffic dynamics may cause violation of rigid service requirements, especially for ultrareliability and low-latency communication(URLLC) service, it is essential yet challenging to dynamically allocate an appropriate amount of resources(including computation, transmission, and energy) to network functions(NFs) in softwarization-based networks. Meanwhile, with the explosion of high resource-demanding applications, the energy efficiency of communication networks deserves significant attention. In this paper,we investigate the dynamic network function resource allocation(NFRA) problem with aim to minimize longterm energy consumption while guaranteeing the requirements of URLLC services in softwarization-based networks. To cater for efficient on-line NFRA decisions, we design a distributed dynamic NF resource allocation(DDRA) algorithm based on dynamic value iteration(DVI). The convergence of the DDRA algorithm is proved. We conduct simulation experiments based on real-world data traces for performance evaluation.The numerical results demonstrate that the proposed DDRA algorithm achieves around 25% and 20% energy consumption reduction when compared with two benchmark algorithms, respectively.

关键词： softwarization-based networks SDN/NFV URLLC energy efficiency dynamic resource allocation distributed value iteration

The use of phalangeal plate as“hook plate”and external fixation to treat complex distal radius fracture fragments

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World Journal of Emergency Medicine 2022年第4期13卷 322-325页

作者： Xiang-feng Zhang Edem Prince Ghamor-Amegavi He-jia Hu Gang feng Department of Orthopedic Surgery the Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009China

Distal radius fracture is the most common fracture site of the human skeleton[1]and often occurs in young people resulting from high energy injury caused by severe trauma.However,complex distal radial intra-articular fractures(AO type C3)are relatively rare and account for about 5%of all distal radius fractures.[2]Fracture comminution at the joint surface is the primary manifestation of these fractures,followed by avulsion of the bone fragments with displacement seen at both the metacarpal and ulnar bone.Treatment of these displaced and unstable fractures remains a challenge.The nature of the articular surface fracture indicates the use of either the open or close reduction technique.Treatment protocols focus on extra-articular reduction and restoration of radial length,maintaining the volar tilt.[3,4]It has been noted that incongruity of the intra-articular distal radius fracture is relevant to the development of arthritis.[5,6]

关键词： unstable radius fracture

Physical Safety and Cyber Security Analysis of Multi-Agent Systems:A Survey of Recent Advances

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IEEE/CAA Journal of Automatica Sinica 2021年第2期8卷 319-333页

作者： Dan Zhang Gang feng Yang Shi Dipti Srinivasan the Research Center of Automation and Artificial Intelligence Zhejiang University of TechnologyHangzhou310023 Key Laboratory of Advanced Control and Optimization for Chemical Processes(East China University of Science and Technology) Ministry of EducationShanghai 200237China the Department of Biomedical Engineering City University of Hong KongHong KongChina the Department of Mechanical Engineering University of VictoriaCanada the Department of Electrical and Computer Engineering National University of SingaporeSingapore

Multi-agent systems(MASs)are typically composed of multiple smart entities with independent sensing,communication,computing,and decision-making capabilities.Nowadays,MASs have a wide range of applications in smart grids,smart manufacturing,sensor networks,and intelligent transportation systems.Control of the MASs are often coordinated through information interaction among agents,which is one of the most important factors affecting coordination and cooperation performance.However,unexpected physical faults and cyber attacks on a single agent may spread to other agents via information interaction very quickly,and thus could lead to severe degradation of the whole system performance and even destruction of MASs.This paper is concerned with the safety/security analysis and synthesis of MASs arising from physical faults and cyber attacks,and our goal is to present a comprehensive survey on recent results on fault estimation,detection,diagnosis and fault-tolerant control of MASs,and cyber attack detection and secure control of MASs subject to two typical cyber attacks.Finally,the paper concludes with some potential future research topics on the security issues of MASs.

关键词： Consensus deception attack deny-of-service(DoS)attack fault detection fault estimation fault tolerant control multiagent systems

Opportunistic admission and resource allocation for slicing enhanced IoT networks

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Digital Communications and Networks 2023年第6期9卷 1465-1476页

作者： Long Zhang Bin Cao Gang feng National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu611731China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China

Network slicing is envisioned as one of the key techniques to meet the extremely diversified service requirements of the Internet of Things(IoT)as it provides an enhanced user experience and elastic resource configuration.In the context of slicing enhanced IoT networks,both the Service Provider(SP)and Infrastructure Provider(InP)face challenges of ensuring efficient slice construction and high profit in dynamic environments.These challenges arise from randomly generated and departed slice requests from end-users,uncertain resource availability,and multidimensional resource allocation.Admission and resource allocation for distinct demands of slice requests are the key issues in addressing these challenges and should be handled effectively in dynamic environments.To this end,we propose an Opportunistic Admission and Resource allocation(OAR)policy to deal with the issues of random slicing requests,uncertain resource availability,and heterogeneous multi-resources.The key idea of OAR is to allow the SP to decide whether to accept slice requests immediately or defer them according to the load and price of resources.To cope with the random slice requests and uncertain resource availability,we formulated this issue as a Markov Decision Process(MDP)to obtain the optimal admission policy,with the aim of maximizing the system reward.Furthermore,the buyer-seller game theory approach was adopted to realize the optimal resource allocation,while motivating each SP and InP to maximize their rewards.Our numerical results show that the proposed OAR policy can make reasonable decisions effectively and steadily,and outperforms the baseline schemes in terms of the system reward.

关键词： Slice IoT Markov decision process Game theory Admission and resource allocation

Effects of sweep angles on turbulent separation behaviors induced by blunt fin

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Chinese Journal of Aeronautics 2022年第3期35卷 90-97页

作者： Dundian gang Shihe YI feng ZHANG Haibo NIU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410072China

An experimental study was conducted on turbulent separation behaviors induced by blunt fins with different sweep angles at Mach number 6.0.The Nano-particle based Planar Laser Scattering technique(NPLS)was applied to visualize the flowfield,complemented by pressure tests.Sweep angles of the fins were 10°,20°,...,60°,with the same leading edge diameter of 10 mm.Fine structures of the interference flowfield induced by blunt fins have been obtained,including the shock systems and vortexes.It was found that the features and shapes of the detached shock depended on sweep angle.When sweep angle30°.Two peak values were detected on the centerline pressure distribution.The first peak did not rely on sweep angle,while the second peak value decreased with increasing sweep angle.

关键词： Blunt fin Flow separation Hypersonic turbulent boundary layer NPLS SIFT

Consensus of single integrator multi-agent systems with directed topology and communication delays

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Control Theory and Technology 2016年第1期14卷 21-27页

作者： Xiang XU Lu LIU Gang feng Department of Mechanical and Biomedical Engineering City University of Hong Kong Kowloon Hong Kong China

In this paper, a distributed control scheme has been developed for consensus of single integrator multi-agent systems with directed fixed communication topology for arbitrarily large constant, time-varying or distributed communication delays. It is proved that the closed loop control system can reach consensus with an exponential convergence rate if and only if the topology is quasi-strongly connected. Simulation results are also provided to demonstrate the effectiveness of the proposed controller.

关键词： Consensus directed fixed topology single integrator multi-agent systems communication delays

Constraining nuclear symmetry energy with the charge radii of mirror-pair nuclei

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Nuclear Science and Techniques 2023年第8期34卷 154-163页

作者： Rong An Shuai Sun Li-gang Cao feng-Shou Zhang Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Key Laboratory of Beam Technology of Ministry of Education Institute of Radiation TechnologyBeijing Academy of Science and TechnologyBeijing 100875China CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of LanzhouLanzhou 730000China

The nuclear charge radius plays a vital role in determining the equation of state of isospin asymmetric nuclear matter.Based on the correlation between the differences in charge radii of mirror-partner nuclei and the slope parameter(L)of symmetry energy at the nuclear saturation density,an analysis of the calibrated slope parameter L was performed in finite nuclei.In this study,relativistic and nonrelativistic energy density functionals were employed to constrain the nuclear symmetry energy through the available databases of the mirror-pair nuclei^(36)Ca–^(36)S,^(38)Ca–^(38)Ar,and ^(54)Ni–^(54)Fe.The deduced nuclear symmetry energy was located in the range 29.89–31.85 MeV,and L of the symmetry energy essentially covered the range 22.50–51.55 MeV at the saturation density.Moreover,the extracted L_(s) at the sensitivity density p_(s)=0.10 fm^(-3) was located in the interval range 30.52–39.76 MeV.

关键词： Symmetry energy Charge radii Mirror nuclei