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Position Measurement Based Slave Torque Feedback Control for Teleoperation systems With Time-Varying Communication Delays

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 388-402页

作者： Xian Yang Jing Yan Changchun Hua Xinping Guan the Institute of Information Science and Engineering Yanshan University the Key Laboratory for Computer Virtual Technology and System Integration of Hebei Province Qinhuangdao 066004China IEEE the Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China

Bilateral teleoperation system is referred to as a promising technology to extend human actions and intelligence to manipulating objects *** the tracking control of teleoperation systems,velocity measurements are necessary to provide feedback ***,due to hardware technology and cost constraints,the velocity measurements are not always *** addition,the time-varying communication delay makes it challenging to achieve tracking *** paper provides a solution to the issue of real-time tracking for teleoperation systems,subjected to unavailable velocity signals and time-varying communication *** order to estimate the velocity information,immersion and invariance(I&I)technique is employed to develop an exponential stability velocity *** the proposed velocity observer,a linear relationship between position and observation state is constructed,through which the need of solving partial differential and certain integral equations can be ***,the mean value theorem is exploited to separate the observation error terms,and hence,all functions in our observer can be analytically *** the estimated velocity information,a slave-torque feedback control law is presented.A novel Lyapunov-Krasovskii functional is constructed to establish asymptotic tracking *** particular,the relationship between the controller design parameters and the allowable maximum delay values is ***,simulation and experimental results reveal that the proposed velocity observer and controller can guarantee that the observation errors and tracking error converge to zero.

关键词： Asymptotic stability bilateral teleoperation time-varying delay velocity observer

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Learning Agile Quadrotor Flight in Restricted Environments with Safety Guarantees

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年第9期9卷 1-8页

作者： Chen, Shiyu Li, Yanjie Lou, Yunjiang Lin, Ke Wu, Xinyu Department of Control Science and Engineering Harbin Institute of Technology Shenzhen and Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Shenzhen China Guangdong Provincial Key Laboratory of Robotics and Intelligent System Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China

With the increasing requirement for agile and efficient controllers in safety-critical scenarios, controllers that exhibit both agility and safety are attracting attention, especially in the aerial robotics domain. This paper focuses on the safety issue of Reinforcement Learning (RL)-based control for agile quadrotor flight in restricted environments. To this end, we propose a unified Adaptive Safety Predictive Corrector (ASPC) to certify each output action of the RL-based controller in real-time, ensuring its safety while maintaining agility. Specifically, we develop the ASPC as a finite-horizon optimal control problem, formulated by a variant of Model Predictive Control (MPC). Given the safety constraints determined by the restricted environment, the objective of minimizing loss of agility can be optimized by reducing the difference between the actions of RL and ASPC. As the safety constraints are decoupled from the RL-based control policy, the ASPC is plug-and-play and can be incorporated into any potentially unsafe controllers. Furthermore, an online adaptive regulator is presented to adjust the safety bounds of the state constraints with respect to the environment changes, extending the proposed ASPC to different restricted environments. Finally, simulations and real-world experiments are demonstrated in various restricted environments to validate the effectiveness of the proposed ASPC. IEEE

关键词： Reinforcement learning

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Clipping discrete multi-tone for peak-power-constraint IM/DD optical systems

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science China(information sciences) 2023年第5期66卷 227-237页

作者： Ji ZHOU Liangchuan LI Jiale HE Xiaofeng LU Yu BO Guanyu WANG Yuanda HUANG Gengchen LIU Yanzhao LU Shecheng GAO Yuanhua FENG Shancheng ZHAO Weiping LIU Changyuan YU Zhaohui LI Department of Electronic Engineering College of Information Science and Technology Jinan University Optical Research Department Huawei Technologies Co. Ltd. Department of Electronic and Information Engineering The Hong Kong Polytechnic University Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)

High peak-to-average power ratio(PAPR) is a major drawback of discrete multi-tone(DMT) in peak-power-constraint(PPC) intensity-modulation/direct-detection(IM/DD) optical systems. Symmetric clipping operation is a frequently-used and practical method for mitigating the PAPR of the DMT ***, clipping noise is inevitably induced by the symmetric clipping operation, thereby deteriorating the system's performance. In this paper, we study the statistical characteristics of the clipping noise in *** on the statistical characteristics, clipping-noise-cancellation(CNC) algorithms are proposed to mitigate the clipping noise in the clipping DMT systems. Theoretically, the clipping noise can be completely removed using the low-density-parity-check-assisted CNC algorithm(LDPC-assisted CNC algorithm). To verify the superiority of the clipping DMT with the CNC algorithm, we conduct an experiment with a50 Gb/s DMT system using 10G-class commercial devices for the scenario of PPC passive optical *** receiver sensitivity of the clipping DMT system with the CNC algorithm can reach-24 d Bm at a 20%soft-decision forward-error-correction limit, which is 2.5 d B higher than that of the DMT system without clipping operation. The clipping operation and the CNC algorithm are added after the original digital signal processing, thereby demonstrating the potential to efectively overcome the drawback in DMT signals and other high-PAPR signals.

关键词： discrete multi-tone peak-to-average power ratio peak-power constraint clipping-noise cancellation intensity-modulation/direct-detection optical systems

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Confident information Coverage Reliability Evaluation for Sensor Networks of Openly Deployed ICP systems

IEEE Transactions on Industrial Cyber-Physical Systems

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IEEE Transactions on Industrial Cyber-Physical systems 2024年 2卷 565-574页

作者： Chen, Suning Yi, Yuanyuan Yi, Lingzhi Liu, Shenghao Deng, Xianjun Xia, Yunzhi Fan, Xiaoxuan Yang, Laurence T. Park, Jong Hyuk Huazhong University of Science and Technology Hubei Key Laboratory of Distributed System Security Hubei Engineering Research Center on Big Data Security The School of Cyber Science and Engineering Wuhan430074 China Huazhong University of Science and Technology School of Journalism and Information Communication Wuhan430074 China Zhongnan University of Economics and Law School of Information and Safety Engineering Wuhan430073 China Seoul National University of Technology Department of Computer Science and Engineering Seoul01811 Korea Republic of

Industrial Cyber-Physical (ICP) systems are integration of computation and physical processes to help achieve operational excellence. As sensors and actuators compose the openly deployed ICP systems and are often susceptible to interference, it puts forward higher requirements on reliability. Reliable coverage ensures sensors acquiring information and therefore coverage reliability of sensor network is studied from various perspectives. However, most existing reliability evaluation methods ignore the belief degree of coverage which influences the reliability to an extent. To evaluate the coverage reliability from the perspective of belief degree, we firstly define Confident information Coverage Belief Reliability (CICBR) based on the Confident information Coverage (CIC) model and D-S evidence theory, which comprehensively considers the coverage rate, interference from the environment, and belief degree of the result. Next, to evaluate the belief degree more reasonably, an Evidence-discount-based basic probability assignment generating method is proposed based on D-S theory to describe the interference in the belief degree. Moreover, a belief evaluation algorithm is proposed to calculate the belief degree of the coverage. Finally, an evidence-Discount-based Confident information Coverage Belief Reliability Evaluation (D-CICBRE) algorithm is proposed to evaluate CICBR. The simulation result indicates that the proposed method can obtain higher and more reasonable reliability. Therefore, the proposed D-CICBRE algorithm can be used to evaluate the reliability of ICP systems more accurately and reasonably. © 2023 IEEE.

关键词： Sensor networks

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Graph Convolutional Neural Network Based Emotion Recognition with Brain Functional Connectivity Network

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International Journal of Crowd science 2024年第4期8卷 195-204页

作者： Gao, Pengzhi Zheng, Xiangwei Wang, Tao Zhang, Yuang School of Information Science and Engineering Shandong Normal University Jinan250300 China State Key Laboratory of High-End Server & Storage Technology Jinan250300 China

Emotion recognition plays an important role in Human Computer Interaction (HCI) and the evaluation of human behavior based on emotional state is an important research topic. The purpose of emotion recognition is to automatically identify human’s emotional states by analyzing physiological or non-physiological signals. The conventional emotion classification methods cannot comprehensively leverage global and local features which are extracted from Electroencephalogram (EEG) signal generated after being stimulated. Therefore, we propose the graph convolutional neural network based emotion recognition with brain functional connectivity network (GERBN). Firstly, raw EEG data of the public DEAP and SEED datasets is preprocessed and adopted in this study. Secondly, emotion-related brain functional connection pattern is constructed using Phase-Locking Value (PLV) adjacency matrix to measure connectivity between the signals of different EEG channels according to phase synchronization. A novel graph structure is constructed where the EEG electrode channels are defined as the vertex, and the edge is strong connection of the binary brain network. Thirdly, the GERBN model that includes six layers is designed to classify and recognize emotional states on the two-dimensional emotional models of valence and arousal. Finally, extensive experiments are conducted on DEAP and SEED datasets. Experimental results demonstrate that the proposed method can improve classification accuracies, in which average accuracies of 80.43% and 88.47% on DEAP are attained on valence and arousal dimensions, respectively. On the SEED dataset, the accuracy reaches 92.37% higher than some of the other methods. © The author(s) 2024.

关键词： Electroencephalography

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Outage Behaviors of Active Intelligent Reflecting Surface Enabled NOMA Communications

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Computer Modeling in engineering & sciences 2023年第10期137卷 789-812页

作者： Zhiping Lu Xinwei Yue Shuo Chen Weiguo Ma School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsState Key Laboratory of Wireless Mobile CommunicationsChina Academy of Telecommunications Technology(CATT)BeijingChina School of Information and Communication Engineering Beijing Information Science and Technology UniversityBeijing100101China

Active intelligent reflecting surface(IRS)is a novel and promising technology that is able to overcome the multiplicative fading introduced by passive *** this paper,we consider the application of active IRS to nonorthogonalmultiple access(NOMA)networks,where the incident signals are amplified actively through integrating amplifier to reflecting *** specifically,the performance of active/passive IRS-NOMA networks is investigated over large and small-scale fading *** to characterize the performance of active IRSNOMA networks,the exact and asymptotic expressions of outage probability for a couple of users,i.e.,near-end user n and far-end user m are derived by exploiting a 1-bit coding *** on approximated analyses,the diversity orders of user n and user m are obtained for active *** addition,the system throughput of active IRS-NOMA is discussed in the delay-sensitive *** simulation results are carried out to verify that:i)The outage behaviors of active IRS-NOMAnetworks are superior to that of passive IRS-NOMAnetworks;ii)As the reflection amplitude factors increase,the active IRS-NOMAnetworks are capable of furnishing the enhanced outage performance;and iii)The active IRS-NOMA has a larger system throughput than passive IRS-NOMA and conventional communications.

关键词： Active intelligent reflecting surface amplification noise non-orthogonal multiple access outage probability

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Observation of dark edge states in parity-time-symmetric quantum dynamics

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National science Review 2023年第8期10卷 156-165页

作者： Peng Xue Xingze Qiu Kunkun Wang Barry C. Sanders Wei Yi Beijing Computational Science Research Center Key Laboratory of Quantum Information University of Science and Technology of China Chinese Academy of Sciences Synergetic Innovation Center in Quantum Information and Quantum Physics University of Science and Technology of China Chinese Academy of Sciences School of Physics and Optoelectronic Engineering Anhui University Shanghai Branch National Laboratory for Physical Sciences at MicroscaleUniversity of Science and Technology of China Institute for Quantum Science and Technology University of Calgary Program in Quantum Information Science Canadian Institute for Advanced Research

Topological edge states arise in non-Hermitian parity-time(PT)-symmetric systems, and manifest themselves as bright or dark edge states, depending on the imaginary components of their eigenenergies. As the spatial probabilities of dark edge states are suppressed during the non-unitary dynamics, it is a challenge to observe them experimentally. Here we report the experimental detection of dark edge states in photonic quantum walks with spontaneously broken PT symmetry, thus providing a complete description of the topological phenomena therein. We experimentally confirm that the global Berry phase in PT-symmetric quantum-walk dynamics unambiguously defines topological invariants of the system in both the PT-symmetry-unbroken and-broken regimes. Our results establish a unified framework for characterizing topology in PT-symmetric quantum-walk dynamics, and provide a useful method to observe topological phenomena in PT-symmetric non-Hermitian systems in general.

关键词： parity-time symmetry photonic quantum walks dark edge states topological invariants

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Policy iteration-based adaptive optimal control for Markov jump systems: a transition-probability-free asynchronous approach

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science China(information sciences) 2024年第11期67卷 363-364页

作者： Weidi CHENG Chengcheng REN Shuping HE Changyin SUN Key Laboratory of Intelligent Computing and Signal Processing (Ministry of Education) School of Electrical Engineering and Automation Anhui University Anhui Engineering Laboratory of Human-Robot Integration System and Intelligent Equipment School of Electrical Engineering and Automation Anhui University Information Materials and Intelligent Sensing Laboratory of Anhui Province Engineering Research Center of Autonomous Unmanned System Technology (Ministry of Education) School of Artificial Intelligence Anhui University

The controller and filter design problems of Markov jump systems(MJSs) have gained significant attention over the past few decades. These studies include various aspects,including stochastic stabilization [1], optimal tracking control [2], and dissipative filter design [3]. Although numerous publications address the optimal controller design for MJSs, the issue of hidden MJSs, particularly those with mismatched jumping modes between the system and the controller, has rarely been explored.

关键词： Markov processes

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Monolayer MoS_(2)-based transistors with low contact resistance by inserting ultrathin Al_(2)O_(3)interfacial layer

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science China(Technological sciences) 2023年第6期66卷 1831-1840页

作者： CHEN Gang LIN Xin LIU Yuan WANG Fang HU Kai SHAN Xin WU ZeYu ZHANG YuPeng NIE WeiCan ZHONG JiXiang REN TianLing ZHANG KaiLiang Tianjin Key Laboratory of Film Electronic&Communication Devices School of Integrated Circuit Science and EngineeringTianjin University of TechnologyTianjin 300384China School of Materials Science and Engineering Tianjin University of TechnologyTianjin 300384China Tianjin Key Laboratory of Composite and Functional Materials Key Laboratory of Advanced Ceramics and Machining Technology(Ministry of Education)School of Materials Science and EngineeringTianjin UniversityTianjin 300072China School of Integrated Circuits Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijing 100084China

Transition metal dichalcogenides(TMDCs)are promising high performance electronic materials due to their interesting semiconductor ***,it is acknowledged that the effective electrical contact between TMDCs-layered materials and metals remains one of the major *** this work,the homogeneous monolayer MoS_(2)films with high crystalline quality were prepared by chemical vapor deposition method on SiO2/Si *** back-gate field-effect transistors(FETs)were fabricated by inserting an ultrathin Al_(2)O_(3)interlayer between the metal electrodes and MoS_(2)*** the addition of an ultrathin 0.8 nm Al_(2)O_(3)interlayer,the contact resistance decreased dramatically from 59.9 to 1.3 kΩμm and the Schottky barrier height(SBH)dropped from 102 to 27 meV compared with devices without the Al_(2)O_(3)*** the same time,the switching ratio increased from~106to~108,and both the on-current and field-effect mobility were greatly *** find that the ultrathin Al_(2)O_(3)interlayer can not only reduce the SBH to alleviate the Fermi level pinning phenomenon at the interface,but also protect the channel materials from the influence of air and moisture as a covering *** addition,the lattice and band structures of Al_(2)O_(3)/MoS_(2)film were calculated and analyzed by first-principles *** is found that the total density of states of the Al_(2)O_(3)/MoS_(2)film exhibits interfacial polarized metals property,which proves the higher carrier transport *** with Al_(2)O_(3)interlayers have excellent stability and repeatability,which can provide effective references for future low power and high performance electronic devices.

关键词： MoS_(2) Schottky barrier height contact resistance Al_(2)O_(3)interlayer first-principles calculation

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Fabrication of dense SiBCN monolith at a lower temperature and its high-temperature performance

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Journal of Advanced Ceramics 2024年第8期13卷 1198-1211页

作者： Zi-Bo Niu Daxin Li Dechang Jia Zhihua Yang Kunpeng Lin Yan Wang Paolo Colombo Ralf Riedel Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced Structural-Function Integrated Materials and Green Manufacturing Technology Ministry of Industry and Information TechnologyHarbin 150080China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150080China Department of Industrial Engineering University of PadovaPadova 3513iItaly Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity Park 16802USA Institute of Materials Science Darmstadt University of TechnologyDarmstadt 64287Germany School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

In this study,a crack-free pyrolysis process of partially cured precursor powder compacts was developed to prepare dense silicon boron carbonitride(SiBCN)monoliths at much lower temperatures(1300℃),thereby circumventing the challenges of sintering densification(>1800℃).Unlike the elastic fracture in over-cured precursors or the viscoelastic deformation in under-cured precursors,the partially cured precursor,exhibiting elastic-plastic deformation behavior,facilitates limited nanoscale pore formation in a dense structure,achieving a balance between crack-free pyrolysis and *** to SiBCN derived from the over-cured precursor(σ=~159 MPa,K_(IC)=1.9 MPa:m^(1/2),Vickers hardness(HV)=7.8 GPa,and E=122 GPa),the resulting SiBCN monolith exhibited significantly improved mechanical properties(σ=~304 MPa,K_(IC)=3.7 MPa-m12,HV=10.6 GPa,and E=161 GPa)and oxidation *** addition,this study investigated the high-temperature performance of SiBCN monoliths,including crystallization and oxidation,and determined the oxidation kinetics induced by pore structure healing and the different oxidation mechanisms of Si-C-N and B-C-N clusters in the amorphous *** to its unique composition and structure,the SiBCN ceramic oxide layer exhibits exceptional self-healing effects on repairing the nanoporous system in the initial stage and shows outstanding high-temperature stability during prolonged oxidation,mitigating adverse effects from bubble formation and *** to the nanoporous structure,the oxidation rate is initially controlled by gas diffusion following a linear law before transitioning to oxide layer diffusion characterized by a parabolic ***,due to different valence bond configurations,Si-C-N transforms into an amorphous SiCNO structure after phase separation,unlike the nucleation and growth of residual B-N-C.

关键词： silicon boron carbonitride(SiBCN)ceramics crack-free pyrolysis amorphous structure oxidation mechanisms kinetic law

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