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AIAA Guidance, Navigation, and control Conference, 2018

作者： Chen, Haibing Ning, Guodong Sun, Jinfeng Li, Kang Zhang, Shuguang Airworthiness Technologies Research Center School of Transportation Science and Engineering Beihang University Beijing100191 China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing100191 China Aerospace Technology Institute Beijing10007 China School of Transportation Science and Engineering Beihang University Beijing100191 China Beijing Institute of Control Engineering Beijing100080 China

ISBN: (数字)9781624105265

ISBN: (纸本)9781624105265

Spacecraft swarm poses great advantages in various fields that are rapidly evolving with the demands for fulfilling multi-purpose space exploration missions, such as flight observations, environmental awareness, and data transmission. In the paper, a new distributed autonomous control method for spacecraft swarm formation flying is developed based on the theory of artificial potential field and sliding mode control method. Inspired by the dynamic system theory, artificial potential velocity field of the spacecraft swarm is designed by using the nonlinear bifurcation theory to generate desired motion path. The artificial velocity field is mainly used to generate the velocity command, which can set planning path in real time. Each agent in the swarm can be driven to reach some corresponding desired position without external command, which greatly reduces the complexity of the planning algorithm. Sliding mode control is used to ensure the precise tracking control for members and system robustness to eliminate external disturbance and uncertainties. Numerical simulations are presented to show the feasibility of the proposed control strategy, which can achieve various desired swarm formation flying configurations and accomplish formation capture, maintenance and reconstruction successfully. © 2018, American institute of Aeronautics and Astronautics Inc, AIAA. All right reserved.

关键词： Spacecraft

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Hierarchic neighbors embedding

arXiv

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arXiv 2019年

作者： Liu, Shenglan Yu, Yang Liu, Yang Qiao, Hong Feng, Lin Feng, Jiashi School of Computer Science and Technology Faculty of Electronic Information and Electrical Engineering Dalian University of Technology Dalian Liaoning116024 China State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of Sciences Beijing100190 China Department of Electrical and Computer Engineering National University of Singapore Singapore Singapore

Manifold learning now plays a very important role in machine learning and many relevant applications. Although its superior performance in dealing with nonlinear data distribution, data sparsity is always a thorny knot. There are few researches to well handle it in manifold learning. In this paper, we propose Hierarchic Neighbors Embedding (HNE), which enhance local connection by the hierarchic combination of neighbors. After further analyzing topological connection and reconstruction performance, three different versions of HNE are given. The experimental results show that our methods work well on both synthetic data and high-dimensional real-world tasks. HNE develops the outstanding advantages in dealing with general data. Furthermore, comparing with other popular manifold learning methods, the performance on sparse samples and weak-connected manifolds is better for HNE. Copyright © 2019, The Authors. All rights reserved.

关键词： Topology

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Multi-particle quantum walks and Fisher information in one-dimensional lattices

arXiv

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arXiv 2021年

作者： Cai, Xiaoming Yang, Hongting Shi, Hai-Long Lee, Chaohong Andrei, Natan Guan, Xi-Wen State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics APM Chinese Academy of Sciences Wuhan430071 China School of Science Wuhan University of Technology Wuhan430071 China University of Chinese Academy of Sciences Beijing100049 China Zhuhai519082 China Guangzhou510275 China Department of Physics Rutgers University PiscatawayNJ08854 United States NSFC-SPTP Peng Huanwu Center for Fundamental Theory Xi’an710127 China Department of Theoretical Physics Research School of Physics and Engineering Australian National University CanberraACT0200 Australia

Recent experiments on quantum walks (QWs) demonstrated a full control over the statistics-dependent walks of single and two particles in one-dimensional (1D) lattices. However little is known about the general characterization of QWs at the many-body level. Here we rigorously study QWs, Bloch oscillations and quantum Fisher informations (FIs) for three indistinguishable bosons and fermions in 1D lattices using time-evolving block decimation algorithm and many-body perturbation theory. We show that such strongly correlated QWs not only give rise to statistics- and-interaction-dependent ballistic transports of scattering states and of two- and three-body bound states, but also allow a quantum enhanced precision measurement of the gravitational force. In contrast to the QWs of the fermions, the QWs of three bosons exhibit strongly correlated Bloch oscillations, which present a surprising time scaling t3 of FI below a characteristic time t0 and saturate to the fundamental limit of t2 for t > t0. Copyright © 2021, The Authors. All rights reserved.

关键词： Fisher information matrix

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A Site Distance Effect Induced by Reactant Molecule Matchup in Single-Atom Catalysts for Fenton-Like Reactions

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Angewandte Chemie 2022年第33期134卷

作者： Dr. Bingqing Wang Cheng Cheng Mengmeng Jin Prof. Jia He Prof. Hui Zhang Dr. Wei Ren Jiong Li Prof. Dingsheng Wang Prof. Yadong Li Department of Chemistry Tsinghua University Beijing 100029 China Department of Environmental Science and Engineering School of Resource and Environmental Sciences Wuhan University Wuhan 430079 China School of Materials Science and Engineering Institute for New Energy Materials and Low-Carbon Technologies Tianjin University of Technology Tianjin 300384 China Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resource Recycle Nanchang Hangkong University Nanchang 330063 China Shanghai Synchrotron Radiation Facilities Shanghai Institute of Applied Physics Chinese Academy of Science Shanghai 201204 China

Understanding the site interaction nature of single-atom catalysts (SACs), especially densely populated SACs, is vital for their application to various catalytic reactions. Herein, we report a site distance effect, which emphasizes how well the distance of the adjacent copper atoms (denoted as d Cu1−Cu1 ) matches with the reactant peroxydisulfate (PDS) molecular size to determine the Fenton-like reaction reactivity on the carbon-supported SACs. The optimized d Cu1−Cu1 in the range of 5–6 Å, which matches the molecular size of PDS, endows the catalyst with a nearly two times higher turnover frequency than that of d Cu1−Cu1 beyond this range, accordingly achieving record-breaking kinetics for the oxidation of emerging organic contaminants. Further studies suggest that this site distance effect originates from the alteration of PDS adsorption to a dual-site structure on Cu 1 −Cu 1 sites when d Cu1−Cu1 falls within 5–6 Å, significantly enhancing the interfacial charge transfer and consequently resulting in the most efficient catalyst for PDS activation so far.

关键词： Dual-Site Adsorption Fenton-Like Reactions Peroxydisulfate (PDS) Activation Single-Atom Catalysts Site Distance Effects

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Modeling and SOC estimation of lithium iron phosphate battery considering capacity loss

引用

Protection and control of Modern Power Systems 2018年第1期3卷 61-69页

作者： Junhui Li Fengjie Gao Gangui Yan Tianyang Zhang Jianlin Li School of Electrical Engineering Northeast Electrical Power UniversityJilinChina Dongying Electric Power Supply Company State Grid Shandong Electric Power CompanyDongyingChina State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijingChina

Modeling and state of charge(SOC)estimation of Lithium cells are crucial techniques of the lithium battery management *** modeling is extremely complicated as the operating status of lithium battery is affected by temperature,current,cycle number,discharge depth and other *** paper studies the modeling of lithium iron phosphate battery based on the Thevenin’s equivalent circuit and a method to identify the open circuit voltage,resistance and capacitance in the model is *** improve the accuracy of the lithium battery model,a capacity estimation algorithm considering the capacity loss during the battery’s life *** addition,this paper solves the SOC estimation issue of the lithium battery caused by the uncertain noise using the extended Kalman filtering(EKF)algorithm.A simulation model of actual lithium batteries is designed in Matlab/Simulink and the simulation results verify the accuracy of the model under different operating modes.

关键词： Lithium-iron battery Battery model Capacity fading state of charge estimation

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The Medium Energy (ME) X-ray telescope onboard the Insight-HXMT astronomy satellite

arXiv

引用

arXiv 2019年

作者： Xuelei, Cao Weichun, Jiang Bin, Meng Wanchang, Zhang Tao, Luo Sheng, Yang Chunlei, Zhang Yudong, Gu Liang, Sun Xiaojing, Liu Jiawei, Yang Xian, Li Ying, Tan Shaozhen, Liu Yuanyuan, Du Fangjun, Lu Yupeng, Xu Shuangnan, Zhang Huanyu, Wang Tipei, Li Chengmo, Zhang Xiangyang, Wen Mingyu, Ge Yupeng, Zhou Shaolin, Xiong Shu, Zhang Yongjie, Zhang Zehao, Cheng Fei, Zhang Maoshun, Li Xiaohua, Liang Min, Gao Enbo, Yang Xiaohang, Liu Hongwei, Liu Yirong, Yang Fan, Zhang Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Tsinghua University Beijing100084 China Beijing Key Laboratory of Space Thermal Control Technology Beijing Institute of Spacecraft System Engineering Beijing100094 China University of Science and Technology of China Hefei230022 China Guizhou University Guiyang550025 China Yantai University Yantai264005 China University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing100049 China

The Medium Energy X-ray telescope (ME) is one of the three main telescopes on board the Insight Hard X-ray Modulation Telescope (Insight-HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN detectors sensitive in 5-30 keV with a total geometrical area of 952 cm2. Application Specific Integrated Circuit (ASIC) chips, VA32TA6, is used to achieve low power consumption and low readout noise. The collimators define three kinds of field of views (FOVs) for the telescope, 1°×4°, 4°×4°, and blocked ones. Combination of such FOVs can be used to estimate the in-orbit X-ray and particle background components. The energy resolution of ME is ~3 keV at 17.8 keV (FWHM) and the time resolution is 255 μs. In this paper, we introduce the design and performance of ME. Copyright © 2019, The Authors. All rights reserved.

关键词： Application specific integrated circuits

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Stability of linear systems with sawtooth input delay and predictor-based controller

引用

Automatica 2020年 117卷

作者： Haoyuan Sun Jian Sun Jie Chen School of Automation Beijing Institute of Technology Beijing 100081 PR China Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing Institute of Technology Beijing 100081 PR China School of Electronic and Information Engineering Tongji University Shanghai 200082 PR China

In this paper, the stability of linear systems with sawtooth input delay widely existing in networked systems and predictor-based controller is considered. Under the assumption that there exists an instant where the input delay is zero, a necessary and sufficient condition is obtained to guarantee the exponential stability of the closed-loop system, that is, the closed-loop system is stable if and only if the matrix A + B K is Hurwitz. Two simulation examples are given to confirm the validity of the obtained results.

关键词：

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controllability limit of edge dynamics in complex networks

引用

Physical Review E 2019年第2期100卷 022318-022318页

作者： Shao-Peng Pang Wen-Xu Wang Fei Hao School of Electrical Engineering and Automation Qilu University of Technology (Shandong Academy of Science) Jinan Shandong Province 250353 China State Key Laboratory of Cognitive Neuroscience and Learning IDG/McGovern Institute for Brain & Research Beijing Normal University Beijing 100875 China School of Systems Science Beijing Normal University Beijing 100875 China The Seventh Research Division School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China

Edge dynamics is relevant to various real-world systems with complex network topological features. An edge dynamical system is controllable if it can be driven from any initial state to any desired state in finite time with appropriate control inputs. Here a framework is proposed to study the impact of correlation between in- and out-degrees on controlling the edge dynamics in complex networks. We use the maximum matching and direct acquisition methods to determine the controllability limit, i.e., the limit of acceptable change of the edge controllability by adjusting the degree correlation only. Applying the framework to plenty complex networks, we find that the controllability limits are ubiquitous in model and real networks. Arbitrary edge controllability in between the limits can be achieved by properly adjusting the degree correlation. Moreover, a nonsmooth phenomenon occurs in the upper limits, and exponential and power-law scaling behaviors are widespread in the approach or separation speed between the upper and lower limits.

关键词： Degree correlations Degree distributions Dynamics of networks Barabasi-Albert network Erdos-Renyi graph Watts-Strogatz network

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Effect of low pore pressure zone at crack front on rock fracture toughness 52

Effect of low pore pressure zone at crack front on rock frac...

引用

52nd U.S. Rock Mechanics/Geomechanics Symposium

作者： Liu, Zhibin Zhang, Guangqing Zhang, Xiang Yang, Xiao Xu, Shengfan Lv, Yanjun China University of Petroleum-Beijing Changping Beijing China Oil and Gas Technology Research Institute Changqing Oilfield Company CNPC Xi'an China State Key Laboratory of Petroleum Resources and Engineering Changping Beijing China

In rock mechanics pore pressure is a crucial factor and many researchers have considered the influence of uniform pore pressure on fracture toughness. However, few studies concentrate on the influence of non-uniform pore pressure on fracture properties. A three-point bend test device that can independently control the pore pressure and confining pressure is designed and manufactured. Three-point bending tests are performed on homogeneous rock specimens under different pore pressure conditions, and a 2D fluid-solid coupling FEM model is also established. Crack opening displacement measured by LVDT and strain distribution at the crack tip monitored by DIC are used to verify and calibrate the established finite element model and the distribution of nonuniform pore pressure near the tip is obtained during crack propagation. The results show that there is a low pore pressure zone at front of the crack tip during rock fracture process;and this low-pore pressure zone causes a non-uniform pore pressure distribution near the crack tip, causing the rock mode I fracture toughness larger than that of a uniform pore pressure mode I fracture. The increase in the mode I fracture toughness is positively correlated with the pore pressure gradient in the low pore pressure zone. Copyright © 2018 ARMA, American Rock Mechanics Association.

关键词： Pore pressure

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Chinese Named Entity Recognition in Power Domain Based on Bi-LSTM-CRF

Chinese Named Entity Recognition in Power Domain Based on Bi...

引用

作者： Zhenqiang Zhao Zhenyu Chen Jinbo Liu Yunhao Huang Xingyu Gao Fangchun Di Lixin Li Xiaohui Ji School of Information Engineering China University of Geosciences Beijing Key Laboratory of Research and System Evaluation of Power Dispatching Automation Technology(China Electric Power Research Institute) Big Data Center State Grid Corporation of China Power Dispatching and Control Center State Grid Corporation of China Institute of Microelectronics Chinese Academy of Sciences

Efficient recognition of proprietary entities is an important basic work for text data mining and intelligent application in power *** power domain Named Entity Recognition(NER) methods rely on feature engineering seriously,which unable to learn power entity features *** order to learn entity features automatically and extract power domain named entities efficiently,a model based on Bidirectional Long Short-Term Memory Neural Networks(Bi-LSTM) and Conditional Random Field(CRF) was proposed in this *** representations were fed into the neural networks as an additional feature and Skip-gram embeddings were trained on power domain *** results showed the precision rate reaches higher than 88.25% and the recalling rate reaches higher than 88.04%,which confirm the method based on BiLSTM and CRF is effective for named entity recognition in the power domain.

关键词： Named Entity Recognition Power Domain Bi-LSTM CRF

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