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An introductory review of swarm technology for spacecraft on-orbit servicing

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International Journal of mechanical System Dynamics 2024年第1期4卷 3-21页

作者： El Ghali Asri Zheng H.Zhu department of mechanical engineering York UniversityTorontoOntarioCanada

This review paper presents a comprehensive evaluation and forward-looking perspective on the underexplored topic of servicing target objects using spacecraft *** targets can be known or unknown,cooperative or uncooperative,and pose significant challenges in modern space operations due to their inherent complexity and *** servicing space objects is vital for active debris removal and broader on-orbit servicing tasks such as satellite maintenance,repair,refueling,orbital assembly,and *** effort has been invested in the literature to explore the servicing of targets using a single *** its advantages and benefits,this paper expands the discussion to encompass a swarm approach to the *** review covers various single-spacecraft approaches and presents a critical examination of the existing,although limited,body of work dedicated to servicing orbital objects using multiple *** focus is also broadened to include some influential studies concerning the characterization,capture,and manipulation of physical objects by general multiagent systems,a subject with significant parallels to the core interest of this ***,this article also delves into the realm of simultaneous localization and mapping,highlighting its application within close-proximity operations in space,especially when dealing with unknown uncooperative *** attention is paid to the benefits that this field can receive from distributed multiagent ***,an exploration of the promising field of swarm robotics is presented,with an emphasis on its potential to revolutionize the servicing of orbital target ***,a survey of general research directly engaging swarms in the orbital context is *** review aims to bridge the knowledge gap and stimulate further research in the underexplored domain of servicing space targets with spacecraft swarms.

关键词： space robotics on-orbit servicing close-proximity operations guidance and navigation swarm robotics multiagent systems object capture and manipulation simultaneous localization and mapping

Supergravity effects on flame propagation and structure in hydrogen/air mixtures

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Acta Mechanica Sinica 2024年第6期40卷 31-38页

作者： Wenkai Liang Chung K.Law Center for Combustion Energy Department of Energy and Power EngineeringTsinghua UniversityBeijing100080China department of mechanical and Aerospace engineering Princeton UniversityPrinceton08544USA

In the current work,we investigated hydrogen/air flame propagation under supergravity *** show that when gravity is in the same/opposite direction as flame propagation,it leads to acceleration/deceleration of the flame,and that such an effect could substantially modify the flame propagation and structure at high gravity ***,for the absolute and relative flame propagation speeds,the gravity-affected flame speed shows opposite trends as the absolute flame speed is more affected by the local induced flow field,while the relative flame speeds are controlled by the super-adiabatic or sub-adiabatic flame *** gravity-affected thermal and chemical flame structures are also examined through the influence of the mixture equivalence ratio,pressure,and flame stretch.

关键词： Supergravity Flame acceleration Laminar flame speed Flame stretch Hydrogen

Sustainable Biocomposites Materials for Automotive Brake Pad Application:An Overview

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Journal of Renewable Materials 2024年第3期12卷 485-511页

作者： Joseph O.Dirisu Imhade P.Okokpujie Olufunmilayo O.Joseph Sunday O.Oyedepo Oluwasegun Falodun Lagouge K.Tartibu Firdaussi D.Shehu department of mechanical engineering Covenant UniversityOtaOgunNigeria department of mechanical and Mechatronics engineering AFE Babalola UniversityAdoEkitiNigeria department of mechanical and Industrial engineering Technology University of JohannesburgJohannesburg2028South Africa School of Chemical and Metallurgical engineering University of the WitwatersrandJohannesburgSouth Africa

Research into converting waste into viable eco-friendly products has gained global *** natural fibres and pulverized metallic waste becomes necessary to reduce noxious environmental emissions due to indiscriminately occupying the *** study reviews the literature in the broad area of green composites in search of materials that can be used in automotive brake *** made by biocomposite,rather than fossil fuels,will be favoured.A database containing the tribo-mechanical performance of numerous potential components for the future green composite was established using the technical details of bio-polymers and natural *** development of materials with diverse compositions and varying proportions is now conceivable,and these materials can be permanently connected in fully regulated *** explanation demonstrates that all of these variables affect friction coefficient,resistance to wear from friction and high temperatures,and the operating life of brake pads to varying *** this study,renewable materials for the matrix and reinforcement are screened to determine which have sufficient strength,coefficient of friction,wear resistance properties,and reasonable costs,making them a feasible option for a green *** most significant,intriguing,and unusual materials used in manufacturing brake pads are gathered in this review,which also analyzes how they affect the tribological characteristics of the pads.

关键词： Asbestos brake pad biocomposites green composite mechanical properties natural reinforcement waste

Chaotic Aquila Optimization Algorithm for Solving Phase Equilibrium Problems and Parameter Estimation of Semi-empirical Models

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Journal of Bionic engineering 2024年第1期21卷 486-526页

作者： Oguz Emrah Turgut Mert Sinan Turgut Erhan Kırtepe department of Industrial engineering Faculty of Engineering and ArchitectureIzmir Bakircay UniversityMenemenizmirTurkey department of mechanical engineering Faculty of EngineeringEge UniversityBornovaizmirTurkey department of Motor Vehicles and Transportation Technologies Sirnak UniversitySirnakTurkey

This research study aims to enhance the optimization performance of a newly emerged Aquila Optimization algorithm by incorporating chaotic sequences rather than using uniformly generated Gaussian random *** work employs 25 different chaotic maps under the framework of Aquila *** considers the ten best chaotic variants for performance evaluation on multidimensional test functions composed of unimodal and multimodal problems,which have yet to be studied in past literature *** was found that Ikeda chaotic map enhanced Aquila Optimization algorithm yields the best predictions and becomes the leading method in most of the *** test the effectivity of this chaotic variant on real-world optimization problems,it is employed on two constrained engineering design problems,and its effectiveness has been ***,phase equilibrium and semi-empirical parameter estimation problems have been solved by the proposed method,and respective solutions have been compared with those obtained from state-of-art *** is observed that CH01 can successfully cope with the restrictive nonlinearities and nonconvexities of parameter estimation and phase equilibrium problems,showing the capabilities of yielding minimum prediction error values of no more than 0.05 compared to the remaining algorithms utilized in the performance benchmarking process.

关键词： Aquila optimization algorithm Chaotic maps Parameter estimation Phase equilibrium Unconstrained optimization

Quantification of grain boundary effects on the geometrically necessary dislocation density evolution and strain hardening of polycrystalline Mg-4Al using in situ tensile testing in scanning electron microscope and HR-EBSD

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Journal of Magnesium and Alloys 2024年第5期12卷 1815-1829页

作者： Eunji Song Mohsen Taheri Andani Amit Misra department of Materials Science and engineering University of MichiganAnn ArborMI 48109USA department of mechanical engineering University of MichiganAnn ArborMI 48109USA department of mechanical engineering Texas A&M UniversityCollege StationTX 77843USA

In situ tensile testing in a scanning electron microscope(SEM)in conjunction with high-resolution electron backscatter diffraction(HR-EBSD)under load was used to characterize the evolution of geometrically necessary dislocation(GND)densities at individual grain boundaries as a function of applied strain in a polycrystalline Mg-4Al *** increase in GND density was investigated at plastic strains of 0%,0.6%,2.2%,3.3% from the area including 76 grains and correlated with(i)geometric compatibility between slip systems across grain boundaries,and(ii)plastic *** develop expressions for the grain boundary GND density evolution as a function of plastic strain and plastic incompatibility,from which uniaxial tensile stress-strain response of polycrystalline Mg-4Al are computed and compared with experimental *** findings in this study contribute to understanding the mechanisms governing the strain hardening response of single-phase polycrystalline alloys and more reliable prediction of mechanical behaviors in diverse microstructures.

关键词： Mg-Al alloys Grain boundaries Geometrically necessary dislocations Strain gradient plasticity HR-EBSD

An adaptive machine learning-based optimization method in the aerodynamic analysis of a finite wing under various cruise conditions

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 27-34页

作者： Zilan Zhang Yu Ao Shaofan Li Grace X.Gu department of mechanical engineering University of CaliforniaBerkeley 94720USA department of engineering Peking UniversityBeijing 100871China department of Civil and Environmental engineering University of CaliforniaBerkeley 94720USA

Conventional wing aerodynamic optimization processes can be time-consuming and imprecise due to the complexity of versatile flight *** of existing literature has considered two-dimensional infinite airfoil optimization,while three-dimensional finite wing optimizations are subject to limited study because of high computational *** we create an adaptive optimization methodology built upon digitized wing shape deformation and deep learning algorithms,which enable the rapid formulation of finite wing designs for specific aerodynamic performance demands under different cruise *** methodology unfolds in three stages:radial basis function interpolated wing generation,collection of inputs from computational fluid dynamics simulations,and deep neural network that constructs the surrogate model for the optimal wing *** has been demonstrated that the proposed methodology can significantly reduce the computational cost of numerical *** also has the potential to optimize various aerial vehicles undergoing different mission environments,loading conditions,and safety requirements.

关键词： Aerodynamic optimization Computational fluid dynamics Radial basis function Finite wing Deep learning neural network

Techno-Economic Optimization of Novel Stand-Alone Renewable Based Electric Vehicle Charging Station near Bahria Town Karachi,Sindh Pakistan

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Energy engineering 2024年第6期121卷 1439-1457页

作者： Aneel Kumar Mahesh Kumar Amir Mahmood Soomro Laveet Kumar department of Electrical engineering Mehran University of Engineering and TechnologyJamshoroPakistan department of mechanical engineering Mehran University of Engineering and TechnologyJamshoroPakistan

Electric vehicles (EVs) are the most interesting and innovative technology in the 21st century because of theirenormous advantages, both technically and economically. Their emissions rate compared to fuel-based vehicles isnegligible as they do not consume fuel and hence do not emit any harmful gases. However, their bulk production,adoption and lack of charging stations increase the stress of power stations due to modern-day lifestyles. If Electricvehicles demand increases drastically then conventional power stations will not bear their demand and if theygenerate electricity by conventional means it will be very costly and may further add greenhouse gases. Therefore,this research provides the techno-economic assessment of a stand-alone renewable-dependent electric vehiclecharging station, excluding any burden on electrical utility. The proposed study is carried out in Bahria Town,Karachi, a city in Pakistan. In this study, HOMER Pro software was utilized for techno-economic assessment. Ahybrid system comprising solar Photovoltaic/Wind Turbine/Fuel cells and battery storage is included in the *** and wind resources were taken from NASA’s website, where charging stations will be integrated. The overallresults show promising in terms of total Net Present Cost and the Cost of Energy which are 2.72M $ and 0.237 $,respectively. The total system generation is 3,598 Megawatt hours per year, and the total energy consumption is 885Megawatt hours per year.

关键词： Electrical vehicle techno economic analysis solar energy wind energy hydrogen energy

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： Lin Zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia School of mechanical and Electronic engineering Wuhan University of TechnologyWuhan430070China department of Aeronautical and Automotive engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

TFN-FICFM:sEMG-Based Gesture Recognition Using Temporal Fusion Network and Fuzzy Integral-based Classifier Fusion

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Journal of Bionic engineering 2024年第4期21卷 1878-1891页

作者： Fo Hu Kailun He Mengyuan Qian Mohamed Amin Gouda College of Information engineering Zhejiang University of TechnologyHangzhou310023China department of mechanical engineering and Automation Northeastern UniversityShenyang110819China

Surface electromyography(sEMG)-based gesture recognition is a key technology in the field of human–computer ***,existing gesture recognition methods face challenges in effectively integrating discriminative temporal feature representations from sEMG *** this paper,we propose a deep learning framework named TFN-FICFM comprises a Temporal Fusion Network(TFN)and Fuzzy Integral-Based Classifier Fusion method(FICFM)to improve the accuracy and robustness of gesture ***,we design a TFN module,which utilizes an attention-based recurrent multi-scale convolutional module to acquire multi-level temporal feature representations and achieves deep fusion of temporal features through a feature pyramid ***,the deep-fused temporal features are utilized to generate multiple sets of gesture category prediction confidences through a feedback ***,we employ FICFM to perform fuzzy fusion on prediction confidences,resulting in the ultimate *** study conducts extensive comparisons and ablation studies using the publicly available datasets Ninapro DB2 and *** demonstrate that the TFN-FICFM model outperforms state-of-the-art methods in classification *** research can serve as a benchmark for sEMG-based gesture recognition and related deep learning modeling.

关键词： Gesture recognition sEMG Deep learning Temporal fusion Fuzzy fusion