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A Stability-Guaranteed Model Predictive Control for Autonomous Surface Vessel Trajectory Tracking Based on Lyapunov Theory

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IEEE Transactions on Transportation Electrification 2025年第3期11卷 7885-7896页

作者： Chen, Linying Qiu, Qianqian Li, Mengxia Chen, Pengfei Huang, Yamin Mou, Junmin Wuhan University of Technology State Key Laboratory of Maritime Technology and Safety Wuhan430063 China Wuhan University of Technology School of Navigation Wuhan430063 China Wuhan University of Technology Intelligent Transportation Systems Research Center Wuhan430063 China

This article explores the trajectory tracking problem of an autonomous surface vessel (ASV). As an optimization-based time-domain method, model predictive control (MPC) has incomparable advantages in solving constrained multiple-input–multiple-output system problems. However, ensuring the stability of the MPC is challenging. This article proposes a stability-guaranteed MPC (SMPC) method by adding the Lyapunov constraint into the linearized MPC framework. The Lyapunov constraint transformed from the backstepping control law restricts the first action of MPC to guarantee the closed-loop stability. Furthermore, the stability and recursive feasibility conditions are theoretically derived. Simulation results demonstrate that the proposed SMPC has better tracking and robustness compared with the backstepping methods. © 2015 IEEE.

关键词： Predictive control systems

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A study of boundary conditions for pedestrian thorax impact test

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International Journal of Vehicle systems Modelling and Testing 2024年第2期18卷 120-133页

作者： Long, Yongcheng Liu, Yu Xiao, Yu Ruan, Zhisheng Xiao, Zhi Zhang, Guanjun Huang, Jing State Key Laboratory of Intelligent Vehicle Safety Technology Chongqing401122 China China Automotive Engineering Research Institute Co. Ltd. Chongqing401122 China Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Changsha410082 China

Thorax injury is one of the main injuries during pedestrian impacts, and it is important to determine the boundary conditions for pedestrian thorax impactor tests. A series of virtual cases were built up to simulate the vehicle-pedestrian impact accidents. Then, the kinematic process was analysed during the vehicle-pedestrian impacts, and thorax impact parameters were extracted. Finally, the statistical characteristics of these impact parameters were obtained for thorax impactor tests. The results show that vehicle type affects the pedestrian impact kinematics and thorax impact parameters significantly. The range of thorax wrap-around distance is 928~1915 mm and 1018~1762 mm during sedan-pedestrian impact and SUV-pedestrian impact respectively. The average thorax impact speeds are about 5.8 m/s and 4.8 m/s in sedan-pedestrian impact and in SUV-pedestrian impact respectively. The average thorax impact velocity angles are 26.8° and 19.5° respectively. These results can provide the effective reference data for pedestrian thorax impactor tests. Copyright © 2024 Inderscience Enterprises Ltd.

关键词： Kinematics

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Effect of gap and overlap on mode Ⅱ interlaminar fracture toughness of automated fiber placement prepreg laminates

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Chinese Journal of Aeronautics 2023年第6期36卷 390-401页

作者： Fan ZHANG Xin LIU Yaoyao YE Qisen CHEN Qiang XU Yunbo BI China State Key Laboratory of Fluid Power and Mechatronic System School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China

Automated Fiber Placement(AFP)technology facilitates the manufacturing process of composite structures with complex geometry owing to its high efficiency and *** unavoidable imperfections induced by the automated layup method bring challenges to the stability of the final mechanical properties of *** influence of AFP-induced gaps and overlaps on the modeⅡinterlaminar fracture process of oven-cured laminates is experimentally investigated and explicitly ***-Notched Flexure(ENF)tests were performed to measure the interlaminar fracture toughness of unidirectional laminates under three different defect configurations,namely"Gap""Overlap"and"Gap&Overlap".A marginal decline(about-1.2%in non-precracked tests,-5.1%in precracked tests)and an obvious increase(about 15.2%in nonprecracked tests,5.2%in precracked tests)in fracture toughness were observed for the"Gap"group and the"Overlap"group,*** studies which involve the metallographic observation and Scanning Electron Microscopy(SEM)observation revealed that the increases in fracture area and crack length helped improve the fracture toughness of the Overlap"***,the resin-rich area with high porosity induced by gaps was detrimental to the delamination *** capture the interlaminar stress distribution local to imperfections,a three-dimensional numerical model was *** defects facilitate the local delamination process,and the overlap defect postpones the damage onset and the propagation.

关键词： Automated Fiber Placement(AFP) Defects Delamination Fracture toughness Laminates

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Discriminative feature encoding for intrinsic image decomposition

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Computational Visual Media 2023年第3期9卷 597-618页

作者： Zongji Wang Yunfei Liu Feng Lu Key Laboratory of Network Information System Technology(NIST) Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing 100191China Peng Cheng Laboratory Shenzhen 518000China

Intrinsic image decomposition is an important and long-standing computer vision *** an input image,recovering the physical scene properties is *** physically motivated priors have been used to restrict the solution space of the optimization problem for intrinsic image *** work takes advantage of deep learning,and shows that it can solve this challenging computer vision problem with high *** focus lies in the feature encoding phase to extract discriminative features for different intrinsic layers from an input *** achieve this goal,we explore the distinctive characteristics of different intrinsic components in the high-dimensional feature embedding *** define feature distribution divergence to efficiently separate the feature vectors of different intrinsic *** feature distributions are also constrained to fit the real ones through a feature distribution *** addition,a data refinement approach is provided to remove data inconsistency from the Sintel dataset,making it more suitable for intrinsic image *** method is also extended to intrinsic video decomposition based on pixel-wise correspondences between adjacent *** results indicate that our proposed network structure can outperform the existing state-of-the-art.

关键词： intrinsic image decomposition deep learning feature distribution data refinement

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Distributed Hovering Formation Method based on Multi-objective Trajectory Optimization for UAVs 43

Distributed Hovering Formation Method based on Multi-objecti...

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43rd Chinese Control Conference, CCC 2024

作者： Xu, Jiajun Hu, Chaofang Wang, Didi Tianjin University Tianjin Key Laboratory of Intelligent Unmanned Swarm Technology and System School of Electrical and Information Engineering Tianjin300072 China

ISBN: (纸本)9789887581581

A novel distributed formation algorithm based on multi-objective trajectory optimization is proposed for unmanned aerial vehicle (UAV) hovering formation. The formation problem is transformed into maintenance of the hovering distance and standoff distance. And the desired cruise speed and steering rate are incorporated to ensure flight stability. All expected values of objectives are fuzzified as fuzzy parameters and the relaxation variables are introduced as optimization parameters to address language preference differences among objectives. Thus a multi-objective optimization (MOO) model under parameter ambiguity and language preference is constructed. On the basis, the UAV distributed formation trajectory optimization method is developed by combining the MOO model with the receding horizon optimization. Finally, the performance of the proposed algorithm is demonstrated in the simulation. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Multiobjective optimization

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Responses of soil stoichiometry and soil enzyme activities in the different distance around opencast coal mine of the Hulun Buir Grassland of China

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International Journal of Coal Science & technology 2024年第1期11卷 221-231页

作者： Yinli Bi Nan Guo Yanxu Zhang Xianglei Li Ziheng Song State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and Technology(Beijing)Beijing100083China Institute of Ecological Environment Restoration in Mine Areas of West China Xi’an University of Science and TechnologyXi’an710054China

The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.

关键词： Opencast coal mine Soil stoichiometry Soil enzyme activities Distance Grassland

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SFLR: An Efficient LiDAR-based Lane Detection Network with Small Feature Map and Large Receptive Field 43

SFLR: An Efficient LiDAR-based Lane Detection Network with S...

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43rd Chinese Control Conference, CCC 2024

作者： Wang, Yanzhang Wang, Yijing Li, Zheng Zuo, Zhiqiang Tianjin University Tianjin Key Laboratory of Intelligent Unmanned Swarm Technology and System School of Electrical and Information Engineering Tianjin300072 China

ISBN: (纸本)9789887581581

Lane detection plays a crucial role in autonomous driving. Compared to camera-based schemes, LiDAR-based lane detection methods show more robustness to changeable environments. However, LiDAR-based ones have high computational complexity, which makes them difficult to meet real-time requirements. Motivated by that, this paper proposes a LiDAR-based lane detection network with small feature map and large receptive field (SFLR). First, an efficient down-sampling module is developed to reduce the feature map size while minimizing information loss. After that, a novel feature extraction module processes the small-sized feature map to extract features, significantly enlarging the model's receptive field. Comparative and ablative experiments demonstrate that our approach reduces by 75% floating-point operations (FLOPs) compared to state-of-the-art LiDAR-based methods with comparable F1-score. Additionally, the proposed network has 1.5 × and 5.5 × faster inference speed on CPU and GPU, respectively. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Autonomous vehicles

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A thermodynamics-consistent spatiotemporally-nonlocal model for microstructure-dependent heat conduction

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1929-1948页

作者： Yu ZHANG Daming NIE Xuyao MAO Li LI Zhejiang Lab Hangzhou310058China Wuhan Second Ship Design and Research Institute Wuhan430064China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

The spatiotemporally-nonlocal phenomena in heat conduction become significant but challenging for metamaterials with artificial ***,the microstructure-dependent heat conduction phenomena are captured under the hypothesis of spatiotemporally local *** capture the microstructure-dependent heat conduction phenomena,a generalized nonlocal irreversible thermodynamics is proposed by removing both the temporally-local and spatially-local equilibrium hypotheses from the classical irreversible *** generalized nonlocal irreversible thermodynamics has intrinsic length and time parameters and thus can provide a thermodynamics basis for the spatiotemporally-nonlocal law of heat *** remove the temporallylocal equilibrium hypothesis,the generalized entropy is assumed to depend not only on the internal energy but also on its first-order and high-order time *** remove the spatially local equilibrium hypothesis,the thermodynamics flux field in the dissipation function is assumed to relate not only to the thermodynamics force at the reference point but also to the thermodynamics force of the neighboring *** the developed theoretical framework,the thermodynamics-consistent spatiotemporally-nonlocal models can then be developed for heat transfer *** examples are provided to illustrate the applications of steady-state and transient heat conduction problems.

关键词： nonlocality spatiotemporal nonlocality irreversible thermodynamics heat transfer metamaterial

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UNIfied Conference of International Workshop on Defence Applications of Multi-Agent systems, DAMAS 2023, International Conference on Maintenance Engineering, IncoME-V 2023, International conference on the Efficiency and Performance Engineering Network, TEPEN 2023

作者： Xiao, Yuan Feng, Kun State Key Laboratory of High-End Compressor and System Technology Beijing University of Chemical Technology Beijing100029 China

ISBN: (纸本)9783031494123

Effective fault characteristic extraction is crucial for the diagnosis of gearbox bearing. Minimum entropy deconvolution (MED) is a popular method for fault feature extraction. However, the deconvolution results are sensitive to the choice of inverse filter parameters. To overcome this limitation, an adaptive minimum entropy deconvolution (AMED) is proposed. AMED searches for the optimal filter length when the energy proportion of the fault-related features in the vibration signal is highest. In addition, this paper explores the use of autocorrelation of the envelope signal to further strengthen the fault characteristic frequencies in the signal. The properties of autocorrelated envelopes is integrated with the AMED approach to develop a novel weak bearing fault diagnosis method. Simulation and experimental results validate that the proposed method is effective in enhancing the weak features of the bearing associated with the failure, and a comparison with several existing methods demonstrates the advantages of the proposed method. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Failure analysis

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Near-infrared responsive polycaprolactone coatings for magnesium implants:Photodynamic antibacterial and controllable dissolution

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Journal of Magnesium and Alloys 2025年第4期13卷 1671-1684页

作者： Xi Liu Jinglong Pan You Lv Xu Wanga Xiaoze Ma Xinxin Zhang Guangyi Cai Zehua Dong Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of EngineeringWuhan 430033China

Magnesium implants have received widespread attention in orthopaedic ***,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their *** this study,a kind of unique core-shell heterojunction CuS@PPy nanostructures was synthesized and then incorporated in polycaprolactone(PCL)to construct an intelligent coating(CuS@PPy/PCL)on micro-arc-oxidized Mg *** PCL-based coating can realize near-infrared(NIR)-driven antibacterial and controllable Mg dissolution according to different bone healing *** the beginning of bone remodelling,the coating exhibits promising antibacterial properties with 99.67%and 99.17%efficacy against *** and ***,respectively,thanks to the singlet oxygen(^(1)O_(2))and alkoxyl radicals(RO·)generated by the photodynamic effect of CuS@PPy heterojunction under low-power NIR light(1.5 W/cm^(2)).In the bone reparative stage,the PCL-based coating can maintain high corrosion resistance to meet the mechanical requirements of Mg implants in human body ***,after the complete rehabilitation of bones,through a high-power(2 W/cm^(2))NIR light,the PCL-based coating changed from an elastic to a viscous flow state(44.7℃)under the photothermal effects of CuS@PPy,leading to quick degradation of the PCL-based coating and following accelerating dissolution of the Mg implant(avoiding secondary surgery).Hopefully,this NIR-responsive coating may provide an innovative method for the antibacterial and controllable dissolution of Mg implants.

关键词： Magnesium Near infrared irradiation Photodynamic antibacterial Photothermal effect Controlled dissolution

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