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Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

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Chinese Journal of Aeronautics 2024年第6期37卷 127-136页

作者： Xian YU Zhiwei LIU Jiaming LENG Mingjing QI Xiaojun YAN school of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China national Key Laboratory of science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijng 100191China beijing Key Laboratory of Aero-Engine structure and strength Beihang UniversityBeijing 100191China

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the *** this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled *** micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 *** distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size *** enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 ***,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements *** findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

关键词： Microairvehicle Aircraft control self-powered micro blimp Flapping-wing thruster Wireless flight

Design of a bio-inspired,Two-winged,Flapping-wing Micro Air Vehicle with High-lift Performance

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Journal of bionic Engineering 2024年第3期21卷 1191-1207页

作者： Kai Hu Huichao Deng shengjie Xiao Gongyu Yang Yuhong sun space Robot Laboratory The School of Mechanical EngineeringBeihang UniversityBeijing100191China

In this paper,we present the development of our latest flapping-wing micro air vehicle(FW-MAV),named Explobird,which features two wings with a wingspan of 195 mm and weighs a mere 25.2 g,enabling it to accomplish vertical take-off and hover *** devised a novel gear-based mechanism for the flapping system to achieve high lift capability and reliability and conducted extensive testing and analysis on the wings to optimise power matching and lift *** Explobird can deliver a peak lift-to-weight ratio of 1.472 and an endurance time of 259 s during hover flight powered by a single-cell LiPo *** the inherent instability of the prototype,we discuss the derivatives of its longitudinal system,underscoring the importance of feedback control,position of the centre of gravity,and increased *** demonstrate the effect of damping enhancement on stability,we also designed a passive stable ***,the vehicle is actively stabilised in roll by adjusting the wing root bars and in pitch through high-authority tail control,whereas yaw is passively *** a series of flight tests,we successfully demonstrate that our prototype can perform vertical take-off and hover flight under wireless *** promising results position the Explobird as a robust vehicle with high lift capability,paving the way towards the use of FW-MAVs for carrying load equipment in multiple tasks.

关键词： Flapping wing biologically inspired robots Mechanical design Flight dynamics Damping enhancement

A novel domain decomposition-based model for efficient dynamic predictions of large composite machine tools

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science china(Technological sciences) 2024年第6期67卷 1765-1782页

作者： YU Yangbo JI Yu Lei CHEN YanRen XU Kun bI QingZhen state Key Laboratory of Mechanical system and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

We propose a large combined moving component composed of carbon fiber reinforced polymer(CFRP)laminates for making lightweight machine tools with high dynamic *** accurate dynamic prediction of composite machine tools is essential for the new generation machine *** paper aims to address two challenges in numerical dynamic modeling and the design of composite machine tools to enhance development efficiency.(1)Anisotropic composite laminates,which form the composite machine tool,exhibit coupling in various *** propose the generalized continuity condition of the boundary to tackle this dynamic modeling challenge.(2)Composite machine tools feature numerous composite-metal coupled *** mechanical model correction of isotropic metals is performed to address their *** take the example of a five-axis gantry machine tool with composite moving parts,establish a dynamic model for efficient prediction,and verify it through simulation and *** proposed method yields remarkable results,with an average relative error of only 3.85%in modal frequency prediction and a staggering 99.7%reduction in solution time compared to finite element *** further discuss the dynamic performance of the machine tool under varied stacking angles and layer numbers of the composite machine *** propose general design criteria for composite machine tools to consider the modal frequency and manufacturing cost of machine tools.

关键词： machine tool dynamics carbon fiber reinforced polymer composite laminates

Damping Characteristic Analysis and Optimization of Wind-thermal-bundled Power Transmission by LCC-HVDC systems

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Journal of Modern Power systems and Clean Energy 2024年第1期12卷 299-312页

作者： Liwen Zheng shiying Ma the Power system Department China Electric Power Research InstituteBeijing 100192China

With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely *** dynamic interaction mechanisms among permanent magnet synchronous generators(PMsGs),synchronous generators(sGs),and LCC-HVDC system become *** deal with this issue,a path analysis method(PAM)is proposed to study the dynamic interaction mechanism,and the damping reconstruction is used to analyze the damping characteristic of the ***,based on the modular modeling,linearized models for the PMsG subsystem,the LCC-HVDC subsystem,and the sG subsystem are ***,based on the closed-loop transfer function diagram of the system,the disturbance transfer path and coupling relationship among subsystems are analyzed by the PAM,and the damping characteristic analysis of the sG-dominated oscillation mode is studied based on the damping *** with the PAM,the small-signal model of the system is obtained and eigenvalue analysis results are ***,the effect of the control parameters on the damping characteristic is analyzed and the conclusions are verified by time-domain ***,the penalty functions of the oscillation modes and decay modes are taken as the objective function,and an optimization strategy based on the Monte Carlo method is proposed to solve the parameter optimization *** simulation results are presented to validate the effectiveness of the proposed strategy.

关键词： Wind-thermal-bundled power transmission line-commutated converter based high-voltage direct current(LCC-HVDC) path analysis method(PAM) damping characteristic analysis Monte Carlo method

Detection Method for Cascading Failure of Power systems based on Epidemic Model

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CsEE Journal of Power and Energy systems 2024年第3期10卷 1356-1370页

作者： Jian Xu Zhonghao He siyang Liao Yuanzhang sun Liangzhong Yao Deping Ke Jun Yang school of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China IEEE

The early detection of cascading failure plays an important role in the safe and stable operation of the power system with high penetration of renewable *** paper proposes a fault propagation dynamic model based on the epidemic model,and further puts forward a method to detect the development of cascading *** the simulation of the IEEE 39-bus and 118-bus systems,this model is proven to be valid and capable of providing practical technical support for the prevention of cascading failures in power systems with high penetration of renewable *** paper also provides an analysis method for the choice of different protection and control measures at each stage of cascading failure,which has critical significance and follow-up value.

关键词： Cascading failure complex network epidemic model fault propagation renewable energy weight method of game theory

Anion competition for Li^(+)solvated coordination environments in poly(1,3 dioxolane)electrolyte to enable high-voltage lithium metal solid-state batteries

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Journal of Energy Chemistry 2024年第9期96卷 633-641页

作者： Qiujun Wang Yanqiang Ma Xiaomeng Jia Di Zhang Zhaojin Li Huilan sun Qujiang sun bo Wang Li-Zhen Fan Hebei Key Laboratory of Flexible Functional Materials School of Materials Science1nd EngineeringHebei University of Science1nd TechnologyShijiazhuang 050000HebeiChina beijing Advanced Innovation Center for Materials Genome Engineering Institute of Advanced Materials1nd TechnologyUniversity of Science1nd Technology BeijingBeijing 100083China

Gel-based polymer electrolytes are limited by the polarity of the residual solvent,which restricts the coupling-breaking behaviour during Li^(+)conduction,resulting in the Li^(+)transport kinetics being greatly ***,we designed anion competitive gel polymer electrolyte(ACPE)by introducing lithium difluoro(oxalato)borate(LiDFOb)anion into the 1,3-dioxolane(DOL)in situ polymerisation *** enhances the ionic dipole interaction between Li^(+)and the solvent molecules and synergizes with Li^(+)across the solvation site of the polymer ethylene oxide(EO)unit,combination that greatly improves the Li^(+)transport *** a result,ACPE exhibits 1.12 ms cm^(−1)ionic conductivity and 0.75 Li^(+)transfer number at room ***,this intra-polymer solvation sheath allows preferential desolvation of DFOb−,which contributes to the formation of kinetically stable anion-derived interphase and effectively mitigates side *** results demonstrate that the assembled Li||NCM622 solid-state battery exhibits lifespan of over 300 cycles with average Coulombic efficiency of 98.8%and capacity retention of 80.3%.This study introduces a novel approach for ion migration and interface design,paving the way for high-safety and high-energy-density batteries.

关键词： Li-metal batteries Poly(1,3-dioxolane) In situ polymerization solid-state polymer electrolytes Anion competition

Mass Transfer-Promoted Fe^(2+)/Fe^(3+)Circulation steered by 3D Flow-Through Co-Catalyst system Toward sustainable Advanced Oxidation Processes

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Engineering 2024年第5期36卷 264-275页

作者： Weiyang Lv Hao Li Jinhui Wang Lixin Wang Zenglong Wu Yuge Wang Wenkai song Wenkai Cheng Yuyuan Yao national Engineering Lab of Textile Fiber Materials and Processing Technology(Zhejiang) Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Provincial Innovation Center of Advanced Textile Technology Shaoxing 312000China Jiangsu Ruiya stirring Technology Co. Ltd.Yixing 214200China

Realizing fast and continuous generation of reactive oxygen species(ROss)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological ***,current AOPs assisted by co-catalysts still suffer from the poor mass/electron transfer and non-durable promotion effect,giving rise to the sluggish Fe^(2+)/Fe^(3+)cycle and low dynamic concentration of Fe^(2+)for ROs ***,we present a three-dimensional(3D)macroscale co-catalyst functionalized with molybdenum disulfide(Mos_(2))to achieve ultra-efficient Fe^(2+)regeneration(equilibrium Fe^(2+)ratio of 82.4%)and remarkable stability(more than 20 cycles)via a circulating flow-through *** the conventional batch-type reactor,experiments and computational fluid dynamics simulations demonstrate that the optimal utilization of the 3D active area under the flow-through mode,initiated by the convectionenhanced mass/charge transfer for Fe^(2+)reduction and then strengthened by Mos_(2)-induced flow rotation for sufficient reactant mixing,is crucial for oxidant activation and subsequent ROs ***,the flow-through co-catalytic system with superwetting capabilities can even tackle the intricate oily wastewater stabilized by different surfactants without the loss of pollutant degradation *** findings highlight an innovative co-catalyst system design to expand the applicability of AOPs based technology,especially in large-scale complex wastewater treatment.

关键词： Advanced oxidation processes 3D co-catalyst Flow-through mode Enhanced mass transfer Complex wastewater treatment

A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics

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Petroleum science 2024年第1期21卷 327-342页

作者： Qian Zhang Wen-Dong Wang Yu-Liang su Wei Chen Zheng-Dong Lei Lei Li Yong-Mao Hao Key Laboratory of Unconventional Oil&Gas Development(china University of Petroleum(East china)) Ministry of EducationQingdao266580ShandongChina school of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina shale Oil Development branch Changqing Oilfield CompanyPetroChinaQingyang745708GansuChina Petrochina Research Institute of Petroleum Exploration&Development Beijing100083China

A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic segmented bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (sRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in sRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation.

关键词： Multi-scale coupled flow stress sensitivity shale oil Micro-scale effect Fractal theory

Intelligent Predetermination of Generator Tripping scheme: Knowledge Fusion-based Deep Reinforcement Learning Framework

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CsEE Journal of Power and Energy systems 2024年第1期10卷 66-75页

作者： Lingkang Zeng Wei Yao Ze Hu Hang shuai Zhouping Li Jinyu Wen shijie Cheng state Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronics EngineeringHuazhong University of Science and TechnologyWuhan 430074China Dispatching and Control Center Central China Branch of State Grid Corporation of ChinaWuhan 430077China. Department of Electrical Engineering and Computer science University of TennesseeKnoxvilleTN 37996USA

Generator tripping scheme(GTs)is the most commonly used scheme to prevent power systems from losing safety and ***,GTs is composed of offline predetermination and real-time scenario ***,it is extremely time-consuming and labor-intensive for manual predetermination for a large-scale modern power *** improve efficiency of predetermination,this paper proposes a framework of knowledge fusion-based deep reinforcement learning(KF-DRL)for intelligent predetermination of ***,the Markov Decision Process(MDP)for GTs problem is formulated based on transient instability ***,linear action space is developed to reduce dimensionality of action space for multiple controllable ***,KF-DRL leverages domain knowledge about GTs to mask invalid actions during the decision-making *** can enhance the efficiency and learning ***,the graph convolutional network(GCN)is introduced to the policy network for enhanced learning *** simulation results obtained on New England power system demonstrate superiority of the proposed KF-DRL framework for GTs over the purely data-driven DRL method.

关键词： Deep reinforcement learning generator tripping scheme graph convolutional network invalid action masking knowledgefusion