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Transfer learning with a spatiotemporal graph convolution network for city flowprediction

Frontiers of Information technology & Electronic Engineering 2025年第1期26卷 79-92页

作者： Binkun LIU Yu KANG Yang CAO Yunbo ZHAO Zhenyi XU Department of Automation University of Science and Technology of ChinaHefei 230026China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai 200240China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China Institute of Advanced Technology University of Science and Technology of ChinaHefei 230088China

Recently,deep learning based city flow prediction has been extensively used in the establishment of *** methods are data-hungry,making them unscalable to areas lacking *** transfer learningcan use data-rich source domains to assist target domain cities in city flow prediction,the performance of existingmethods cannot meet the needs of actual use,because the long-distance road network connectivity is *** this problem,we propose a transfer learning method based on spatiotemporal graph convolution,in which weconstruct a co-occurrence space between the source and target domains,and then align the mapping of the sourceand target domains’data in this space,to achieve the transfer learning of the source city flow prediction modelon the target ***,a dynamic spatiotemporal graph convolution module along with a temporalencoder is devised to simultaneously capture the concurrent spatiotemporal features,which implies the inherentrelationship among the road network structures,human travel habits,and city bike ***,these concurrentfeatures are leveraged as cross-city invariant representations and nonlinearly spanned to a co-occurrence *** domain features are thereby aligned with the source domain features in the co-occurrence space by using aMahalanobis distance loss,to achieve cross-city bike flow *** proposed method is evaluated on the publicbike flow datasets in Chicago,New York,and Washington in 2015,and significantly outperforms state-of-the-arttechniques.

关键词： Transfer learning City flow prediction Spatiotemporal graph convolution

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Time-frequency analysis and spiking neural network for motor imagery EEG classification

Time-frequency analysis and spiking neural network for motor...

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2022 Chinese Automation Congress, CAC 2022

作者： Liu, Zhenfei Wang, Lina Xu, Song Beijing Aerospace Automatic Control Institute National Key Laboratory of Science and Technology on Aerospace Intelligence Control Beijing China

ISBN: (纸本)9781665465335

Accurate recognition of electroencephalogram (EEG) is an important issue in motor imagery (MI)-based brain-computer interface (BCI) system. However, due to the non-linear and low signal-to-noise characteristics of EEG signal, the recognition of MI EEG signal remains a tricky problem. In this paper, a novel framework based on time-frequency analysis and spiking neural network (SNN) is proposed for feature extraction and classification of MI EEG signal. Specifically, the multi-wavelet basis functions (MWBF) are first employed for the approximation of coefficients in the time-varying autoregressive (TVAR) model. An effective regularized orthogonal least squares (ROLS) algorithm is then applied to significantly simplify the model structure. In addition, a power spectral density (PSD) function is defined to obtain high-resolution time-frequency features. Especially, to adequately exploit the spatio-temporal properties of the obtained features, a powerful SNN model is constructed for accurate classification. The proposed method is validated on a widely used dataset, and the results indicate that the classification performance of the proposed method is significantly better than other state-of-the-art methods. © 2022 IEEE.

关键词： Classification (of information)

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Rheological mechanical properties and its constitutive relation of soft rock considering influence of clay mineral composition and content

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International Journal of Coal science & technology 2023年第4期10卷 62-76页

作者： Xuebin Li Xuesheng Liu Yunliang Tan Ai Chen Honglei Wang Xin Wang Shenglong Yang College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Disaster Prevention and Control Shandong University of Science and TechnologyQingdao 266590China Ningxia Coal Industry Co. Ltd.of China Energy GroupYinchuan 750000China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan 430074China

Rheological mechanical properties of the soft rock are afected signifcantly by its main physical characteristics-clay *** this study,taking the mudstone on the roof and foor in four typical mining regions as the research object,frstly,the clay mineral characteristic was analyzed by the X-ray difraction ***,rheological mechanical properties of mudstone samples under diferent confning pressures are studied through triaxial compression and creep *** results show that the clay mineral content of mudstone in diferent regions is diferent,which leads to signifcant diferences in its rheological properties,and these diferences have a good correlation with the content of montmorillonite and illite-montmorillonite mixed *** the montmorillonite content as an example,compared with the sample with 3.56%under the lower stress level,the initial creep deformation of the sample with 11.19%increased by 3.25 times,the viscosity coefcient and longterm strength decreased by 80.59%and 53.94%,***,based on the test results,the damage variation is constructed considering the montmorillonite content and stress level,and the M–S creep damage constitutive model of soft rock is ***,the test results can be ftted with determination coefcients ranging from 0.9020 to 0.9741,which proves that the constitutive relation can refect the infuence of the clay mineral content in the samples *** study has an important reference for revealing the long-term stability control mechanism of soft rock roadway rich in clay minerals.

关键词： Clay mineral Physical characteristic Creep Damage Constitutive model

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Metric localization for lunar rovers via cross-view image matching

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Visual Intelligence 2024年第1期2卷 1-14页

作者： Chen, Zihao Li, Kunhong Li, Haoran Fu, Zhiheng Zhang, Hanmo Guo, Yulan School of Electronics and Comunication Engineering the Shenzhen Campus of Sun Yat-sen University Sun Yat-sen University Shenzhen 510275 China Peng Cheng Laboratory Guangdong Shenzhen 518055 China Department of Computer Science and Software Engineering The University of Western Australia Perth 6009 Australia Department of Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai Aerospace Control Technology Institute Shanghai 201109 China College of Electronic Science and Technology National University of Defense Technology Hunan Changsha 410073 China

Accurate localization is critical for lunar rovers exploring lunar terrain features. Traditionally, lunar rover localization relies on sensor data from odometers, inertial measurement units and stereo cameras. However, localization errors accumulate over long traverses, limiting the rover’s localization accuracy. This paper presents a metric localization framework based on cross-view images (ground view from a rover and air view from an orbiter) to eliminate accumulated localization errors. First, we employ perspective projection to reduce the geometric differences in cross-view images. Then, we propose an image-based metric localization network to extract image features and generate a location heatmap. This heatmap serves as the basis for accurate estimation of query locations. We also create the first large-area lunar cross-view image (Lunar-CV) dataset to evaluate the localization performance. This dataset consists of 30 digital orthophoto maps (DOMs) with a resolution of 7 m/pix, collected by the Chang’e-2 lunar orbiter, along with 8100 simulated rover panoramas. Experimental results on the Lunar-CV dataset demonstrate the superior performance of our proposed framework. Compared to the second best method, our method significantly reduces the average localization error by 26% and the median localization error by 22%. © The Author(s) 2024.

关键词： Aerial patch Cross-view metric localization (CVML) Lunar rover Panorama Perspective projection

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Neural Dynamics for Cooperative Motion control of Omnidirectional Mobile Manipulators in the Presence of Noises: A Distributed Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1605-1620页

作者： Yufeng Lian Xingtian Xiao Jiliang Zhang Long Jin Junzhi Yu Zhongbo Sun the Department of Control Engineering Changchun University of TechnologyChangchun 130012China IEEE the College of Information Science and Engineering Northeastern UniversityShenyang 110819 the National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China the School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China the State Key Laboratory for Turbulence and Complex Systems Department of Advanced Manufacturing and RoboticsCollege of EngineeringPeking UniversityBeijing 100871China

This paper presents a distributed scheme with limited communications, aiming to achieve cooperative motion control for multiple omnidirectional mobile manipulators(MOMMs).The proposed scheme extends the existing single-agent motion control to cater to scenarios involving the cooperative operation of MOMMs. Specifically, squeeze-free cooperative load transportation is achieved for the end-effectors of MOMMs by incorporating cooperative repetitive motion planning(CRMP), while guiding each individual to desired poses. Then, the distributed scheme is formulated as a time-varying quadratic programming(QP) and solved online utilizing a noise-tolerant zeroing neural network(NTZNN). Theoretical analysis shows that the NTZNN model converges globally to the optimal solution of QP in the presence of noise. Finally, the effectiveness of the control design is demonstrated by numerical simulations and physical platform experiments.

关键词： Cooperative motion control noise-tolerant zeroing neural network(NTZNN) omnidirectional mobile manipulator(OMM) repetitive motion planning

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Transient Power Sharing control Algorithm between Virtual Synchronous Generator and Diesel Generator in Isolated Microgrid 5

Transient Power Sharing Control Algorithm between Virtual Sy...

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5th IEEE International Electrical and Energy Conference, CIEEC 2022

作者： Li, Chun Ma, Fan Hu, Qi Hao, Xiaoliang Xiao, Runlong Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan China

ISBN: (数字)9781665411042

ISBN: (纸本)9781665411042

Mixed-source isolated microgrid is usually composed of renewable energy, energy storage devices and diesel generators (DGs). Virtual synchronous generator (VSG) has been developed recently years. In such an isolated microgrid, transient power cannot be shared due to the faster response of the VSGs, which may cause the overcurrent of the VSGs. Inverter capacity can not be fully utilized. To solve this problem, first, the cause of unequal transient load sharing is analyzed. Then, an improved VSG control algorithm is proposed. The speed governor characteristics of DG is added in VSG, and the virtual impedance of VSG is designed. Finally, the proposed control algorithm is validated by simulation. © 2022 IEEE.

关键词： Synchronous generators

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Dynamic stiffness simulation analysis of hydraulic dual-parallel actuation systems using Amesim

Dynamic stiffness simulation analysis of hydraulic dual-para...

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2024 CSAA/IET International Conference on Aircraft Utility Systems, AUS 2024

作者： Li, Chuandong Wu, Shuai Wei, Renlei Chen, Taiqi Qin, Mingyuan Chu, Bing Yang, Yuliang Luo, Jianing School of Automation Science and Electrical Engineering Beihang University Beijing100191 China National Key Laboratory of Aircraft Integrated Flight Control Beihang University Beijing100191 China AVIC Shenyang Aircraft Design and Research Institute Ministry of Industry and Information Technology Beijing100191 China Key Laboratory of Advanced Aircraft Systems Beihang University Ministry of Industry and Information Technology Beijing100191 China

In the field of flight control systems, actuators play a crucial role, and dynamic stiffness stands as one of the pivotal metrics to gauge their performance, reflecting the actuators' resilience to external disturbances. Hence, investigating dynamic stiffness is paramount for enhancing the overall performance of flight control systems. This study focuses on a hydraulic dual-parallel actuator system, wherein a mathematical model is established to derive the expression for dynamic stiffness. Leveraging the Amesim software, a simulation model of the parallel actuator system is constructed to conduct an in-depth analysis of its dynamic stiffness characteristics. During simulation, sinusoidal loading forces of varying frequencies are applied at the output end of the actuator system, and displacement response data is collected. Subsequently, the Fast Fourier Transform (FFT) is employed to obtain dynamic stiffness, enabling an analysis of its variations. The relationship between the system's natural frequency and dynamic stiffness is explored, along with an investigation into the primary factors influencing dynamic stiffness. Simulation results indicate that enhancing both support and connection stiffness,reducing load mass and enlarging the piston area can enhance the system's dynamic stiffness, thereby meeting the performance requirements of flight control systems. © The Institution of Engineering & technology 2024.

关键词： Fast Fourier transforms

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RESEARCH PROGRESS AND PROSPECT OF THE HYPERSONIC FLIGHT VEHICLE FAULT-TOLERANT control METHODS 3

RESEARCH PROGRESS AND PROSPECT OF THE HYPERSONIC FLIGHT VEHI...

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3rd International Conference on Mechanical, Aerospace and Automotive Engineering, CMAAE 2023

作者： Fan, Xiaoshuai Qi, Xiaoman Zhang, Shifeng Jiang, Zhenyu College of Aerospace Science and Engineering National University of Defense Technology Changsha China Hunan Provincial Key Laboratory Of Aerospace Cross-Domain Flight Vehicle System and Control Technology Changsha China

ISBN: (纸本)9781839539954

The research status, mathematical models, and fault-tolerant control methods of hypersonic flight vehicles are reviewed. The current research progress of fault-tolerant control methods for hypersonic flight vehicles is summarized based on the typical hypersonic flight vehicles and their mathematical models. The fault-tolerant control methods are mainly divided into active fault-tolerant control and passive fault-tolerant control. The active fault-tolerant control needs to diagnose fault information and carry out fault-tolerant control strategy based on fault diagnosis results. The passive fault-tolerant control should have strong robustness with the design of the control system, it can adaptively suppress the impact of faults without diagnosis when faults occur. The typical fault-tolerant control methods mainly include approximate linear robust control, linear quadratic optimal control, linear parameter varying control, backstepping control, feedback linearization control, sliding mode control. The present status of fault-tolerant control methods of hypersonic flight vehicles and the application of advanced control methods in hypersonic flight vehicles are showed, then the future development trend is forecasted. © The Institution of Engineering & technology 2023.

关键词： Feedback linearization

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Application and Practice of Smart Education technology in Blended Teaching of Engineering Drawing Course 24

Application and Practice of Smart Education Technology in Bl...

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9th International Conference on Distance Education and Learning, ICDEL 2024

作者： Xu, Jinyou Tian, He Wang, Xiaofei Xue, Yahong Li, Ling Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin University of Technology China School of Environmental Science and Safety Engineering Tianjin University of Technology Tianjin China

ISBN: (纸本)9798400716805

The expeditious progress of information technology has encouraged the digital enhancement of the educational sector. To remedy the issues of the traditional teaching mode, a blended teaching mode of engineering drawing course has been developed with the use of smart education technology. Based on the Outcomes-based Education ( OBE ), the teaching objectives and teaching contents of the course are reconstructed by using the method of reverse design and forward implementation. By leveraging the synergy of online and offline, virtual and real, and quantitative and qualitative evaluation, a blended teaching approach that is both student-centered and teacher-guided is realized. A course knowledge graph has been built, offering fresh concepts for accomplishing personalized learning for students. The teaching practice shows that the blended teaching mode based on intelligent education has created a multi-dimensional autonomous learning space and personalized learning path for students, which effectively improves the enthusiasm and initiative of students to participate in teaching activities, and also improves the information level of teaching process and management, and promotes the organic integration of teaching and learning. © 2024 ACM.

关键词： Contrastive Learning

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Effect of Additive Manufactured Gyroid Porous Structure of Hybrid Gradients on Mechanical and Failure Properties

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Additive Manufacturing Frontiers 2024年第3期3卷 11-24页

作者： Xin Lin Ruitong Zhang Wenfeng Lu Kunpeng Zhu Binbin Dan Precision Manufacturing Institute Wuhan University of Science and TechnologyWuhan430081China Key Laboratory of Metallurgical Equipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081China Institute of Intelligent Machines Hefei Institutes of Physical ScienceChinese Academy of SciencesChangzhou213164China Department of Mechanical Engineering National University of SingaporeSingapore119077Singapore

In bone tissue engineering,good structural and forming qualities are prerequisites for the long-term implantation of *** mitigate the stress-shielding effect between porous bone scaffolds and the human skeleton,this study proposes a method for designing non-linear gradient gyroid porous structures with radial-axial hybrid gra-dients that are precisely controlled by multivariate polynomial functions to simulate human bone *** influence of the volumetric energy density on the forming quality of the porous structures was evaluated by characterizing the internal strut morphology and measuring the strut width and *** element analysis combined with experimental observations revealed that during compression,the thin struts at the top and bottom of the hybrid-gradient porous structure deformed first,and the compressive stress and shear stress were gradually transferred from the thin struts at the upper and lower ends of the structure to the thicker struts in the *** with the axial gradient,the edge struts of the hybrid-gradient porous structures can withstand higher shear and compressive ***,owing to the variation in the radial gradient,compared to struc-tures with 20%axial porosity variation,the hybrid-gradient porous structure with 40%radial porosity variation and 20%axial porosity variation exhibited an 18.10%increase in elastic modulus and a 4.29%increase in yield ***,its effective energy absorption was 20.39%higher than that of the homogeneous *** to radial-gradient porous structures,the hybrid-gradient porous structure showed a lower sensitivity of the elastic modulus and yield strength to the volumetric energy density.

关键词： Gyroid porous structure Hybrid gradient Additive manufacturing Mechanical properties Triple-periodic minimal surfaces

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