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Design of a 6-DOF Heavy-Duty and High-Precision 3–3 Orthogonal Parallel robot With Flexible Hinges

Journal of Mechanical Design 2025年第9期147卷 093304页

作者： Qi, Chenkun Lin, Jianfeng Hu, Yan Zhou, Songlin Gao, Feng State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China Xiamen Key Laboratory of Robot Systems and Digital Manufacturing School of Mechanical and Automotive Engineering Xiamen University of Technology Xiamen 361024 China

Parallel robot is important in high-precision application. The current studies focus on the high-precision robot with light payload capability. It is insufficient for the support of a space optical telescope. When designing a robot with a large payload, performance redundancy of the robot needs to be reduced because the high payload and precision will cause high cost. In this paper, a six degrees-of-freedom heavy-duty and high-precision 3–3 orthogonal parallel robot with flexible hinges is presented. A performance redundance minimization-based type selection method is proposed by the isotropy comparison. The performance of between Stewart and orthogonal mechanisms is compared based on local transmission index, force and torque payload isotropy, displacement, and rotation accuracy isotropy. A performance mean maximization and standard deviation minimum dimensional optimization method is proposed. Two new indexes named payload distribution index and accuracy distribution index are proposed to evaluate the performance redundancy of the mechanism. The mechanism parameters are designed based on performance atlas using workspace volume index, global transmission index, global payload index, global accuracy index, payload distribution index, and accuracy distribution index. A new modeling method considering the nun-functional motion of spherical joints with stiffness compensation is proposed. Modeling and control experiments on the robot demonstrate the effectiveness of the proposed method.

关键词： Rotation Chain Design mechanism design Displacement heavy payload Torque Optimization Hinges robots Modeling performance redundance minimization parallel mechanism Isotropy Stiffness

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SS-DGD: Scalable Short-Entry Dual-Grain Coherence Directoris 16

SS-DGD: Scalable Short-Entry Dual-Grain Coherence Directoris

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16th IEEE International Conference on Solid-state and Integrated Circuit Technology, ICSICT 2022

作者： Tang, Yuxin Qiu, Yudi Liu, Yanwei Jiao, Jie Zhang, Peng Fan, Yibo Fudan University State Key Laboratory of Asic and System Department of Microelectronics Shanghai China Peking University Advanced Institute of Information Technology Beijing China

ISBN: (数字)9781665469067

ISBN: (纸本)9781665469067

As the number of cores in a chip multiprocessor increase, the directory area overhead becomes excessive. Current research shows that directory area can be reduced by tracking private entries with coarse-grain region entries. The insight is that contiguous memory blocks are often accessed by a single core. In order to indicate which blocks the region owner has cached, a bit vector format is applied in the dual-grain directory (DGD). However, this limits scalability and is incompatible with the latest scalable directories. In this paper, we propose a scalable short-entry dual-grain coherence directory (SS-DGD). In private region entries, a counter is used instead of the original bit vector. To reduce the directory area, we use a separate short-entry directory to store private block entries with a pointer format and region entries with counters. The detailed simulation-based study in 64-core CMPs shows that our proposal can reduce the area overhead by 29.9% compared with DGD. © 2022 IEEE.

关键词： Computer architecture

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Wideband Channel Measurement and Characterization Based on 5G Passive Sounding in Railway Scenarios

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China Communications 2025年第4期22卷 13-26页

作者： Zheng Peng Fei Dan Chen Chen Chen Haoran Huang Yanyan Ai Bo School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China State Key Laboratory of Advanced Rail Autonomous Operation Beijing Jiaotong UniversityBeijing 100044China Nanjing Rongcai Transportation Technology Research Institute Co. LtdNanjing 211121China Frontiers Science Center for Smart High-Speed Railway System Beijing Jiaotong UniversityBeijing 100044China

With the development of wireless communication,the fifth generation mobile communication technology(5G)has emerged as a hot topic in highspeed railway communication system and has moved towards industrial *** the radio propagation characteristics in 5G high-speed train(HST)scenarios is essential for enhancing wireless coverage and overall system *** propose a novel 5G passive sounding scheme to extract channel impulse responses(CIRs)using channel state information reference signals(CSI-RS)from the target 5G base station(BS).Detailed procedures for timefrequency synchronization,CSI-RS detection and extraction are presented through *** the laboratory work involving absolute power calibration,phase coherence calibration and power delay profile(PDP)validation,we validate the accuracy and performance of the developed ***,a measurement campaign was conducted in HST scenarios encompassing both residential and undeveloped *** path loss(PL)model and the channel characteristics including stationarity interval(SI),multipath components(MPCs),shadow fading(SF),Rician K-factor,root mean square(RMS)delay spread and received correlation coefficients are analyzed and *** estimated channel characteristics and the statistical model presented in this paper will contribute to the research on HST radio propagation and the development of 5G railway communication systems.

关键词： 5G channel characterization channel measurement high-speed train passive sounding

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Domain knowledge discovery from abstracts of scientific literature on Nickel-based single crystal superalloys

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Science China(Technological Sciences) 2023年第6期66卷 1815-1830页

作者： LIU Yue DING Lin YANG ZhengWei GE XianYuan LIU DaHui LIU Wei YU Tao AVDEEV Maxim SHI SiQi School of Computer Engineering and Science Shanghai UniversityShanghai 200444China Shanghai Engineering Research Center of Intelligent Computing System Shanghai 200444China State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Materials Genome Institute Shanghai UniversityShanghai 200444China Institute of Functional Materials Central Iron&Steel Research InstituteBeijing 100081China Australian Nuclear Science and Technology Organisation Locked Bag 2001Kirrawee DC NSW 2232Australia School of Chemistry The University of SydneySydney 2006Australia Zhejiang Laboratory Hangzhou 311100China

Despite the huge accumulation of scientific literature,it is inefficient and laborious to manually search it for useful information to investigate structure-activity ***,we propose an efficient text-mining framework for the discovery of credible and valuable domain knowledge from abstracts of scientific literature focusing on Nickel-based single crystal ***,the credibility of abstracts is quantified in terms of source timeliness,publication authority and author’s academic ***,eight entity types and domain dictionaries describing Nickel-based single crystal superalloys are predefined to realize the named entity recognition from the abstracts,achieving an accuracy of 85.10%.Thirdly,by formulating 12 naming rules for the alloy brands derived from the recognized entities,we extract the target entities and refine them as domain knowledge through the credibility *** this,we also map out the academic cooperative“Author-Literature-Institute”network,characterize the generations of Nickel-based single crystal superalloys,as well as obtain the fractions of the most important chemical elements in *** extracted rich and diverse knowledge of Nickel-based single crystal superalloys provides important insights toward understanding the structure-activity relationships for Nickel-based single crystal superalloys and is expected to accelerate the design and discovery of novel superalloys.

关键词： Nickel-based single crystal superalloys text mining named entity recognition credibility analysis domain knowledge

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Fabrication and characterization of high-sensitivity,wide-range,and flexible MEMS thermal flow velocity sensors

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Microsystems & Nanoengineering 2024年第4期10卷 139-151页

作者： Min Li Guangzhao Qin Chen Jia Danyu Zhang Zhikang Li Xiangguang Han Shusheng Xu Libo Zhao Guoxi Luo Cunlang Liu Ping Yang Qijing Lin State Key Laboratory for Manufacturing Systems Engineering International Joint Laboratory for Micro/Nano Manufacturing and Measurement TechnologiesXi’an Jiaotong University(Yantai)Research Institute for Intelligent Sensing Technology and SystemXi’an Jiaotong UniversityXi’an 710049China School of Instrument Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264000China Brightstone Innovation(Yantai)Research Institute for Micronano Sensing Technology Yantai 264006China Xi’an Jingwei Sensing Technology Co. Ltd.Xi’an 712000China

With the rapid development of various fields,including aerospace,industrial measurement and control,and medical monitoring,the need to quantify flow velocity measurements is *** is difficult for traditional flow velocity sensors to fulfill accuracy requirements for velocity measurements due to their small ranges,susceptibility to environmental impacts,and ***,to optimize sensor performance,a flexible microelectromechanical system(MEMS)thermal flow sensor is proposed that combines the working principles of thermal loss and thermal temperature difference and utilizes a flexible cavity substrate made of a low-thermal-conductivity polyimide/SiO_(2)(PI/SiO_(2))composite porous film to broaden the measurement range and improve the *** measurement results show that the maximum measurable flow velocity can reach 30 m/s with a resolution of 5.4mm/*** average sensitivities of the sensor are 59.49 mV/(m s−1)in the medium-to-low wind velocity range of 0–2 m/s and 467.31 mV/(m s^(−1))in the wind velocity range of 2–30 m/*** sensor proposed in this work can enable new applications of flexible flow sensors and wearable devices.

关键词： flow thermal utilize

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Integrated Comb-Driven Silicon Photonics

Integrated Comb-Driven Silicon Photonics

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2023 Optical Fiber Communications Conference and Exhibition, OFC 2023

作者： Wang, Xingjun Shen, Bitao Shu, Haowen Chang, Lin Tao, Yuansheng Xie, Weiqiang Bowers, John E. Peking University School of Electronics State Key Laboratory of Advanced Optical Communications System and Networks Beijing100871 China University of California Department of Electrical and Computer Engineering Santa BarbaraCA93106 United States

We realize the combination of integrated microcomb and silicon photonics, employing the advanced AlGaAsOI optical nonlinear platform and novel SiPh chips. Data link with 2-Tbps aggregate rate and highly reconfigurable... 详细信息

ISBN: (纸本)9781957171180

关键词： Silicon photonics

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RGB-Based Category-Level Object Pose Estimation via Depth Recovery and Adaptive Refinement

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IEEE robotics and Automation Letters 2025年第6期10卷 5377-5384页

作者： Yang, Hui Sun, Wei Liu, Jian Zheng, Jin Zeng, Zhiwen Mian, Ajmal Hunan University National Engineering Research Center for Robot Visual Perception and Control Technology College of Electrical and Information Engineering Changsha410082 China Hunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Changsha410082 China Central South University School of Architecture and Art Changsha410082 China University of Western Australia Department of Computer Science and Software Engineering CrawleyWA6009 Australia

Category-level pose estimation methods have received widespread attention as they can be generalized to intra-class unseen objects. Although RGB-D-based category-level methods have made significant progress, reliance on depth image limits practical application. RGB-based methods offer a more practical and cost-effective solution. However, current RGB-based methods struggle with object geometry perception, leading to inaccurate pose estimation. We propose depth recovery and adaptive refinement for category-level object pose estimation from a single RGB image. We leverage DINOv2 to reconstruct the coarse scene-level depth from the input RGB image and propose an adaptive refinement network based on an encoder-decoder architecture to dynamically improve the predicted coarse depth and reduce its gap from the ground truth. We introduce a 2D–3D consistency loss to ensure correspondence between the point cloud obtained from depth projection and the objects in the 2D image. This consistency supervision enables the model to maintain alignment between the depth image and the point cloud. Finally, we extract features from the refined point cloud and feed them into two confidence-aware rotation regression branches and a translation and size prediction residual branch for end-to-end training. Decoupling the rotation matrix provides a more direct representation, which facilitates parameter optimization and gradient propagation. Extensive experiments on the REAL275 and CAMERA25 datasets demonstrate the superior performance of our method. Real-world estimation and robotic grasping experiments demonstrate our model robustness to occlusion, clutter environments, and low-textured objects. Our code and robotic grasping video are available at DA-Pose. © 2016 IEEE.

关键词： Depth perception

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Energy modeling and optimization of building condenser water systems with all-variable speed pumps and tower fans:A case study

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Building Simulation 2024年第7期17卷 1085-1111页

作者： Yong Cao Chuang Wang Sheng Wang Xiao Fu Xinguo Ming School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Air-Conditioning Equipment and System Energy Conservation Zhuhai 519070China GREE Electric Appliances Inc.of ZhuhaiZhuhai 519070China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Beijing Advanced Innovation Centerfor Future Urban Design Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The emergence of building condenser water systems with all-variable speed pumps and tower fans allows for increased efficiency and flexibility of chiller plants in partial load operation but also increases the control complexity of condenser water *** study aims to develop an integrated modeling technique for evaluating and optimizing the energy performance of such a condenser water *** proposed system model is based on the semi-physical semi-empirical chiller,pump,and cooling tower models,with capabilities of fully considering the hydraulic and thermal interactions in the condenser water loop,being solved analytically and much faster than iterative solvers and supporting the explicit optimization of the pump and tower fan frequency.A mathematical approach,based on the system model and constrained optimization technique,is subsequently established to evaluate the energy performance of a typical dual setpoint-based variable speed strategy and find its energy-saving potential and most efficient operation by jointly optimizing pumps and tower *** all-variable speed chiller plant from Wuhan,China,is used for a case study to validate the system model’s accuracy and explore its *** results showed that the system model can accurately simulate the condenser water system’s performance under various operating *** optimizing the frequencies of pumps and tower fans,the total system energy consumption can be reduced by 12%–13%compared to the fixed dual setpoint-based strategy with range and approach setpoints of 4℃and 2℃.In contrast,the energy-saving potential of optimizing the cooling tower sequencing is insignificant.A simple joint speed control method for optimizing the pumps and tower fans emerged,i.e.,the optimal pump and fan frequency are linearly correlated(if both are non-extremes)and depend on the chiller part load ratio only,irrespective of the ambient wet-bulb temperature and chilled water supply *** was also foun

关键词： all-variable speed chiller plant model-based optimization hydraulic and thermal coupling analytical solution dual setpoint-based variable speed control optimal joint speed control

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Strategies toward Highly Efficient Monolithic Perovskite/Organic Tandem Solar Cells

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Chinese Journal of Chemistry 2023年第14期41卷 1753-1768页

作者： Shan Jiang Zhiyang Xu Fuzhi Wang Shilei Tian Yang Wang Chenghao Li Zhan'ao Tan State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing102206 China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing100029 China Department of Coal and Syngas Conversion Sinopec Research Institute of Petroleum ProcessingBeijing100083 China

Constructing monolithic tandem solar cells (TSCs) is an effective method to break the Shockley–Queisser (S–Q) radiative efficiency limit for single-junction solar cells. Employing the wide bandgap perovskite materials and low bandgap organic materials as absorber layers for front and rear subcells, respectively, to construct perovskite/organic TSCs can complementarily absorb sunlight in ultraviolet-visible (UV-Vis) range by front perovskite and near-infrared (NIR) range by rear organic molecules, thus reducing the thermalization energy losses. Besides the subcells, the interconnection layer (ICL), which physically and electrically connects the front and rear subcells, is also an important tunnel junction to recombine charges. In this review, we summarize the optimization strategies of wide bandgap perovskites for front subcell, narrow bandgap organic material for rear subcell, and the ICLs employed in monolithic perovskite/organic TSCs.

关键词： Perovskite solar cells Wide bandgap perovskite Low bandgap organic molecule Tandem solar cells Subcells Interconnection layer Efficiency Open-circuit voltage

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Analytical Impact-Excitation Theory of Er/O/B Codoped Si Light-Emitting Diodes

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Physical Review Letters 2024年第24期132卷 246901-246901页

作者： Xiaoming Wang Jiajing He Ao Wang Kun Zhang Yufei Sheng Weida Hu Chaoyuan Jin Hua Bao Yaping Dan State Key Laboratory of Advanced Optical Communication Systems and Networks University of Michigan–Shanghai Jiao Tong University Joint Institute Aerospace Laser Technology and System Department Global Institute of Future Technology State Key Laboratory of Infrared Physics College of Information Science and Electronic Engineering

Er doped Si light-emitting diodes may find important applications in silicon photonics and optical quantum computing. These diodes exhibit an emission efficiency 2 orders of magnitude higher at reverse bias than forward bias due to impact excitation. However, physics of impact excitation in these devices remains largely unexplored. In this work, we fabricated an Er/O/B codoped Si light-emitting diode which exhibits a strong electroluminescence by the impact excitation of electrons inelastically colliding the Er ions. An analytical impact-excitation theory was established to predict the electroluminescence intensity and internal quantum efficiency which fit well with the experimental data. From the fittings, we find that the excitable Er ions reach a record concentration of 1.8×1019 cm−3 and up to 45% of them is in an excitation state by impact excitation. This work has important implications for developing efficient classical and quantum light sources based on rare earth elements in semiconductors.

关键词： Density of states Electrical conductivity Electrical properties Electroluminescence Ion impact & scattering LEDs

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