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Multi-UAVs Collaborative Path Planning in the Cramped Environment

IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 529-538页

作者： siyuan feng Linzhi Zeng Jining Liu Yi Yang Wenjie Song School of Automation Beijing Institute of TechnologyNanjing 210039China Nanjing Research Institute of Electronics Technology Nanjing 210039China Yichang Testing Technique Research Institute Yichang 443003China IEEE

Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. However, safe and effective path planning of multiple unmanned aerial vehicles(UAVs)in the cramped environment is always challenging: conflicts with each other are frequent because of high-density flight paths, collision probability increases because of space constraints, and the search space increases significantly, including time scale, 3D scale and model scale. Thus, this paper proposes a hierarchical collaborative planning framework with a conflict avoidance module at the high level and a path generation module at the low level. The enhanced conflict-base search(ECBS) in our framework is improved to handle the conflicts in the global path planning and avoid the occurrence of local deadlock. And both the collision and kinematic models of UAVs are considered to improve path smoothness and flight safety. Moreover, we specifically designed and published the cramped environment test set containing various unique obstacles to evaluating our framework performance thoroughly. Experiments are carried out relying on Rviz, with multiple flight missions: random, opposite, and staggered, which showed that the proposed method can generate smooth cooperative paths without conflict for at least 60 UAVs in a few minutes.The benchmark and source code are released in https://***/inin-xingtian/multi-UAVs-path-planner.

关键词： Collision avoidance conflict resolution multi-unmanned aerial vehicles(UAVs)system path planning

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Calibration and validation of matching functions for ride-sourcing markets

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Communications in Transportation Research 2022年第1期2卷 42-55页

作者： Shuqing Wei siyuan feng Jintao Ke Hai Yang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina Intelligent Transportation Thrust The Hong Kong University of Science and Technology(Guangzhou)GuangzhouChina Department of Civil Engineering The University of Hong KongHong KongChina

Ride-sourcing services have become increasingly important in meeting people's mobility needs since their emergence.Compared to traditional street-hailing taxi services,ride-sourcing services significantly reduce the matching frictions in the markets by matching drivers and passengers with relatively distant distances through an online platform.Motivated by this new feature as well as the need for designing operating and regulating strategies,researchers have attempted to describe these innovative ride-sourcing markets through mathematical models,the core of which is the matching functions for characterizing matching frictions.Previous studies have developed a variety of matching functions for ride-sourcing markets,including perfect matching function,Cobb-Douglas type matching function,queuing models,and some physical models.However,less is known about the applicability and performance of these matching functions,that is,under what situations each of these matching functions well characterizes the real market.To address this issue,this paper makes one of the first attempts to calibrate,validate,and compare the prevailing matching functions in the literature,and ascertain the conditions of their applicability.In particular,we establish a simulator to simulate a total of 420 scenarios of the ridesourcing market under different combinations of supply and demand.The key performance metrics,including the matching rate in the market,passengers'average matching time,passengers'average pick-up time,and passengers'average total waiting time,are utilized to test and compare seven widely used matching functions under various market scenarios.

关键词： Ride-sourcing Matching function Matching friction Calibration Validation

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轴压比和面承板厚度对混合节点抗震性能的影响

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浙江大学学报（工学版） 2024年第6期58卷 1185-1197页

作者：冯思远陶宇宸金振奋赵唯坚浙江大学建筑工程学院浙江杭州310058 浙江大学平衡建筑研究中心浙江杭州310028 浙江大学建筑设计研究院有限公司浙江杭州310027

为了研究新型柱全截面隔板式钢筋混凝土柱-钢梁(RCS)混合框架节点形式的抗震性能,考虑不同轴压比和面承板厚度的影响,对2组共6个3/4比例的梁柱节点进行低周往复加载试验研究.试验中所有试件均发生设计预期的节点剪切破坏,滞回曲线呈弓型... 详细信息

为了研究新型柱全截面隔板式钢筋混凝土柱-钢梁(RCS)混合框架节点形式的抗震性能,考虑不同轴压比和面承板厚度的影响,对2组共6个3/4比例的梁柱节点进行低周往复加载试验研究.试验中所有试件均发生设计预期的节点剪切破坏,滞回曲线呈弓型,表明节点具有良好的抗震性能.试件最终因节点区的混凝土开裂剥落而丧失承载力.试验结果表明,当轴压比为0~0.25时,随着轴压比的增大,RCS节点开裂荷载有所增大,峰值荷载前斜裂缝数量减少、宽度减小,试件的承载力、刚度和耗能能力均有所提高.节点域柱纵筋黏结应力随轴压比增大而减小,表明节点域内黏结状况有明显改善.相较于单向面承板试件,双向面承板试件在承载能力、延性和耗能能力方面均表现出显著提高;当双向面承板厚度由6 mm增加至10 mm时,试件峰值承载力和刚度的提升幅度相对有限.

关键词：钢筋混凝土柱-钢梁梁柱节点轴压比面承板抗震性能

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教师的四种角色与五重教育境界——兼论智慧教育时代教育学的挑战与重塑

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现代远程教育研究 2024年第2期36卷 28-35页

作者：李树英冯思圆深圳大学教育学部广东深圳518060

数字化、智慧化教育技术的广泛应用开启了全新的智慧教育时代,变革中的教育模式与场景为教师发展以及教育学建设带来了新的机遇与挑战。从教育与技术演进互动的视角出发,教师角色在不同时期经历了由“讲坛上的圣者”到“学生身旁的指引... 详细信息

数字化、智慧化教育技术的广泛应用开启了全新的智慧教育时代,变革中的教育模式与场景为教师发展以及教育学建设带来了新的机遇与挑战。从教育与技术演进互动的视角出发,教师角色在不同时期经历了由“讲坛上的圣者”到“学生身旁的指引者”再到“翅膀上的幽灵”的转变,并在生成式人工智能技术广泛应用的未来存在“人工智能的竞争者”“人工智能的副驾驶”“机器中的灵魂”等多种可能趋势。教师所能达成的教育境界也从“言传身教”“教书”到“教会学习”“赋能学习”乃至“教育即生活”不断发展。在数字化转型进程中,教师需要积极应对技术环境对固有教育模式所带来的挑战,如利用新技术拓展教育的受众、构建动态知识体系、与学生共同探索与学习、实现精准化的教育赋能等,实现教育境界的数字化重塑。而教师角色与教育境界的变化也意味着教育学迎来了重塑与发展的契机。教育学在智慧教育时代应回归“教育即生活”理念,探索创新教育人才培养模式,培养适应智慧教育场景的教师。教师是危机中的领导者,也是未来的重塑者,如何帮助教师在智慧教育时代发挥重要作用,发挥教育者无法被人工智能替代的教育智慧,将是教育学发展与重塑的重要主题。

关键词：教师角色教育境界教师发展智慧教育生成式人工智能

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Effects of long term isolation on the emotion change of ‘‘Lunar Palace 365” crewmembers

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Science Bulletin 2019年第13期64卷 881-884页

作者： Zikai Hao Yinzhen Zhu siyuan feng Chen Meng Dawei Hu Hui Liu Hong Liu Beijing Advanced Innovation Centre for Biomedical Engineering Beihang UniversityBeijing 102402China Institute of Environmental Biology and Life Support Technology School of Biological Science and Medical EngineeringBeihang UniversityBeijing 100083China State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing 100083China International Joint Research Center of Aerospace Biotechnology & Medical Engineering. Beihang University Beijing 100083China

The psychological health risk is one of the most serious and difficult risks to mitigate during manned deep space exploration[1].In a space capsule or station,the environment is isolated,and communication with the outside is limited to telephone or delayed video.The monotonous working schedule also aggravates loneliness and homesickness,which could trigger negative moods,such as depression and anxiety.Therefore,an astronaut’s unstable emotional state could be a threat to the safety and performance of a space mission.

关键词： Effects schedule trigger most is be

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国土空间治理体系和治理能力现代化的思考

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中国行政管理 2024年第4期40卷 129-140页

作者：严金明冯思远夏方舟中国人民大学公共管理学院北京100872

国土空间治理是国家治理体系和治理能力现代化建设的重要组成部分,如何全面提升国土空间治理体系和治理能力现代化水平是当前理论和实践面临的重大议题。本文以“制度分析与发展”框架为基础构建了治理现代化理论框架,探讨了国土空间治... 详细信息

国土空间治理是国家治理体系和治理能力现代化建设的重要组成部分,如何全面提升国土空间治理体系和治理能力现代化水平是当前理论和实践面临的重大议题。本文以“制度分析与发展”框架为基础构建了治理现代化理论框架,探讨了国土空间治理体系和治理能力现代化的核心内涵。研究提出,国土空间治理体系是以政府、市场、社会治理主体形成的一整套紧密相连、相互协调的国土空间开发利用保护相关的体制机制、法律法规安排,其现代化内涵即要建立符合制度化、法治化、高效化、科学化、民主化等现代化准则要求的“三元四体系”;国土空间治理能力是多元主体基于治理体系、运用相关治理工具开展国土空间治理各方面事务的能力,其现代化内涵是治理主体按照系统化、创新化、标准化、精细化和持续化等现代化准则的要求,不断推进“三元九能力”提升和重构的过程。

关键词：国土空间治理治理体系治理能力现代化

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Effects of 3-D deformation of elastic wings on aerodynamic performance of an aircraft model

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Science China(Technological Sciences) 2023年第5期66卷 1365-1377页

作者： GUO Qinfeng feng siyuan WANG JinJun Fluid Mechanics Key Laboratory of Education Ministry Beijing University of Aeronautics and AstronauticsBeijing 100191China

The wind tunnel experiment is conducted on a simplified aircraft model with rigid and two kinds of elastic wings to investigate the effect of wing 3-D deformation on the aircraft aerodynamic performance.The results show that two elastic wings exhibit different aerodynamic performances,which are classified as the lift-enhancement wing and the drag-reduction wing.For the liftenhancement wing,the stall angle is delayed from 8°to 15°with a corresponding lift increment of 64.3%compared with the rigid wing.It is shown that the lift enhancement of the aircraft model is accompanied by the torsional vibration mode of the wing,which results in the significant improvement of wing circulation.For the drag-reduction wing,the aerodynamic performance is dominated by the time-averaged deformation,which couples the bending and twisting.The wing twist reduces the effective angle of attack,as well as the frontal area,and contributes to the decreased wake deficit.Meantime,the bent wings function as barriers to the cross flow resulting in a reduction of lift-induced drag.As a result,the drag coefficient is reduced from 0.115 to 0.098 with a reduction of 14.8%at angle of attack of 12°.

关键词： wind tunnel experiment elastic wing aerodynamic force wing deformation wake flow field

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仙林大学城空间生产过程与机制研究

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现代城市研究 2024年第2期39卷 24-28,35页

作者：管曼玲张艺凡冯思源孙世界东南大学建筑学院

文章以“权力—资本—效益”分析框架研究南京仙林大学城的空间生产过程与作用机制。仙林大学城的发展包括3个阶段:多重效益驱使的选址阶段、权力与资本博弈下的开发阶段、多方主体合作发展的运营阶段。需求驱动和资本增值是大学城空间... 详细信息

文章以“权力—资本—效益”分析框架研究南京仙林大学城的空间生产过程与作用机制。仙林大学城的发展包括3个阶段:多重效益驱使的选址阶段、权力与资本博弈下的开发阶段、多方主体合作发展的运营阶段。需求驱动和资本增值是大学城空间生产的机制。政府统筹下的城市建设加上多方参与的城市实践有利于调节市场运行规律,避免投资风险,促进空间生产的良性循环。文化效益和环境效益是大学城开发建设过程中提升城市品质、促进转型发展的关键。

关键词：空间生产权力与资本资本增值仙林大学城南京

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Influence of membrane wing active deformation on the aerodynamic performance of an aircraft model

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Science China(Technological Sciences) 2022年第10期65卷 2474-2484页

作者： feng siyuan GUO Qinfeng WANG JinJun XU Yang Fluid Mechanics Key Laboratory of Education Ministry Beijing University of Aeronautics and AstronauticsBeijing 100191China

The aerodynamic performance of a simplified aircraft model with a pair of actively deformed membrane wings is investigated experimentally in this work. The active deformation is achieved with Macro fiber composite(MFC) actuators, which are attached to the upper surface of the wings and occupied 13.7% of the wing surface area. Wind tunnel experiments are conducted to evaluate the influence of membrane active deformation on the aerodynamic performance of the aircraft. The results show that the membrane deforms and vibrates under the actuation which can effectively suppress the leading-edge separation and facilitate the reattachment. Therefore, compared with the rigid wing model, the lift coefficient of the actively deformed membrane wing model is enhanced remarkably from the angle of attack of 7° to 22°. The stall angle is delayed by 2°, and a maximum lift coefficient enhancement of 32.5% is reached, which shows a wide potential application in improving the aerodynamic performance of modern aircraft.

关键词： fluid-structure interaction flexible membrane wing active control force measurement flow field measurement

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Interfacial Interaction of CFRP Reinforced Steel Beam Structures

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Journal of Architectural Environment & Structural Engineering Research 2020年第4期3卷 2-8页

作者： Huaping Wang Hengyang Li siyuan feng Tao Song School of Civil Engineering and Mechanics Lanzhou UniversityLanzhouGansu730000China Key Lab of Structures Dynamic Behavior and Control(Harbin Institute of Technology) Ministry of EducationHarbinHeilongjiang150090China

Due to the increase of service life,the phenomenon of performance degradation of bridge structures becomes more and more common.It is important to strengthen the bridge structures so as to restore the resistance level and extend the normal service life.Carbon fiber reinforced polymer(CFRP)materials are thus used for the assembly reinforcement of bridges for the advantages of high strength,light weight,corrosion resistance and long-term stability of physical and chemical properties,etc.In view of this,based on the previous theoretical study and the established formula of the interfacial shear stress of CFRP reinforced steel beam and the normal stress of CFRP plate,this paper discusses the sensitive parameters that affect the interfacial interaction of CFRP strengthened beam structures.Through the analysis,the priority design indicators and suggestions are accordingly given for the design of reinforced beam structures.Young’s modulus of CFRP composite and shear modulus of the adhesive have the greatest influence on the interfacial interaction,which should be carefully considered.It is suggested that CFRP material with Ec close to 300 GPa and thickness no less than 3 mm,and adhesive material with Ga less than 5 GPa and 3-mm thickness can be adopted in CFRP reinforced steel beam.The conclusions of this paper can provide guidance for the interfacial damage control of CFRP reinforced steel beam structures.

关键词： CFRP reinforced steel beam Interfacial interaction Shear stress Parametric analysis Design instruction

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