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Targets capture by distributed active swarms via bio-inspired reinforcement learning

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 210-221页

作者： Kun Xu Yue Li Jun Sun Shuyuan Du Xinpeng Di Yuguang Yang Bo Li institute of Biomechanics and Medical Engineering Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua University institute of Nuclear and New Energy technology Tsinghua University shanghai aerospace Control technology institute shanghai Key Laboratory of aerospace Intelligent Control technology College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Natural swarms arranged from cells to herds are usually decentralized but display intriguing collective intelligence in coordinating individuals across large scales to efficiently achieve their common goals. Learning from nature may provide new strategies for controlling collective dynamics of synthetic swarms to accomplish specific functions. Here, we present a bioinspired computational framework that steers distributed active swarms to collectively capture and merge targets via reinforcement learning. We exploit collective milling structures of natural herds to cage the targets, and adopt a switching control policy inspired by sperms' chiral dynamics to optimize the trajectories of individuals, through which the active swarms can selforganize to enclose single or multiple distant targets in a dynamical, adaptive and scalable manner. There exists a critical swarm size, beyond which the excessive competition between agents would generate large mechanical forces, leading to capture instability but enabling the transition from short-distance to long-distance merging capture of multiple targets. This work provides physical insights into distributed active swarms and could offer a multilevel, decentralized strategy toward controlling swarm robotics in wide applications such as bio-medical devices, machine immunity, and target clearance.

关键词： swarm intelligence robotics multi-tasks artificial intelligence bionics

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Solution‑Processed Thin Film Transparent Photovoltaics:Present Challenges and Future Development

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Nano-Micro Letters 2025年第2期17卷 566-600页

作者： Tianle Liu Munerah M.S.Almutairi Jie Ma Aisling Stewart Zhaohui Xing Mengxia Liu Bo Hou Yuljae Cho UM-SJTU Joint institute Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China School of Physics and Astronomy Cardiff UniversityCardiff CF243AAWalesUK Department of Electrical and computer Engineering Yale UniversityNew HavenCT 06511USA Energy Sciences institute Yale UniversityWest HavenCT 06516USA Future Photovoltaics Research Center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Electrical energy is essential for modern society to sustain economic *** soaring demand for the electrical energy,together with an awareness of the environmental impact of fossil fuels,has been driving a shift towards the utilization of solar ***,traditional solar energy solutions often require extensive spaces for a panel installation,limiting their practicality in a dense urban *** overcome the spatial constraint,researchers have developed transparent photovoltaics(TPV),enabling windows and facades in vehicles and buildings to generate electric *** TPV advancements are focused on improving both transparency and power output to rival commercially available silicon solar *** this review,we first briefly introduce wavelength-and non-wavelengthselective strategies to achieve *** of merit and theoretical limits of TPVs are discussed to comprehensively understand the status of current TPV *** we highlight recent progress in different types of TPVs,with a particular focus on solution-processed thin-film photovoltaics(PVs),including colloidal quantum dot PVs,metal halide perovskite PVs and organic *** applications of TPVs are also reviewed,with emphasis on agrivoltaics,smart windows and ***,current challenges and future opportunities in TPV research are pointed out.

关键词： Transparent semiconductors Solution-processable transparent solar cell Emerging solar cell materials Buildingintegrated photovoltaics

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Optimal linear attitude estimators via geometric analysis

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第11期12卷 873-882页

作者： De-ren GONG Xiao-wei SHAO Wei LI Deng-ping DUAN institute of aerospace Science ＆ technology Shanghai Jiao Tong University Shanghai 200240 China

Three optimal linear attitude estimators are proposed for single-point real-time estimation of spacecraft attitude using a geometric approach. The final optimal attitude is represented by modified Rodrigues parameters （MRPs）. After introducing incidental right-hand orthogonal coordinates for each pair of measured values, three error vectors are obtained by the use of dot or/and cross products. Corresponding optimality criteria are rigorously quadratic and unconstrained, which do not coincide with Wahba＇s constrained criterion. The singularity, which occurs when the principal angle is close to n, can be easily avoided by one proper rotation. Numerical simulations show that the proposed three optimal linear estimators can provide a precision comparable with those complying with the Wahba optimality definition, and have faster computational speed than the famous quatemion estimator （QUEST）.

关键词： Linear attitude determination Geometric analysis Gibbs vector Singularity avoidance

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An approach for shape optimization of stratosphere airships based on multidisciplinary design optimization

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第11期10卷 1609-1616页

作者： Ouan-bao WANG Ji-an CHEN Gong-yi FU Deng-ping DUAN institute of aerospace Science & technology Shanghai Jiao Tong University Shanghai 200240 China

Airship shape is crucial to the design of stratosphere airships. In this paper, multidisciplinary design optimization (MDO) technology is introduced into the design of airship shape. We devise a composite objective function, based on this technology, which takes account of various factors which influence airship performance, including aerodynamics, structures, energy and weight to determine the optimal airship shape. A shape generation algorithm is proposed and appropriate mathematical models are constructed. Simulation results show that the optimized shape gives an improvement in the value of the composite objective function compared with a reference shape.

关键词： Airship shape Multidisciplinary design optimization (MDO) Adaptive simulation annealing Stratosphere airship

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Hybrid analytical resolution approach based on ambiguity function for attitude determination

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 1038-1048页

作者： Wen-rui JIN Chuan-run ZHAI Li-duan WANG Yan-hua ZHANG Xing-qun ZHAN institute of aerospace Science & technology Shanghai Jiao Tong University Shanghai 200240 China

When satellite navigation receivers are equipped with multiple antennas, they can deliver attitude information. In previous researches, carrier phase differencing measurement equations were built in the earth-centered, earth-fixed (ECEF) co- ordinate, and attitude angles could be obtained through the rotation matrix between the body frame (BF) and the local level frame (LLF). Different from the conventional methods, a hybrid algorithm is presented to resolve attitude parameters utilizing the single differencing (SD) carrier phase equations established in LLF. Assuming that the cycle integer ambiguity is known, the measure- ment equations have attitude analytical resolutions by using simultaneous single difference equations for two in-view satellites. In addition, the algorithm is capable of reducing the search integer space into countable 2D discrete points and the ambiguity function method (AFM) resolves the ambiguity function within the analytical solutions space. In the case of frequency division multiple access (FDMA) for the Russian Global Orbiting Navigation Satellite System (GLONASS), a receiver clock bias estimation is employed to evaluate its carrier phase. An evaluating variable and a weighted factor are introduced to assess the integer ambiguity initialization. By static and dynamic ground experiments, the results show that the proposed approach is effective, with enough accuracy and low computation. It can satisfy attitude determination in cases of GPS alone and combined with GLONASS.

关键词： Global positioning system (GPS) Russian Global Orbiting Navigation Satellite System (GLONASS) Analytical resolution Attitude determination Ambiguity function method (AFM)

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Turning mechanism and composite control of stratospheric airships

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Journal of Zhejiang University-Science C(computers and Electronics) 2012年第11期13卷 859-865页

作者： Mao-hua ZHANG Deng-ping DUAN Li CHEN institute of aerospace Science and technology Shanghai Jiao Tong UniversityShanghai 200240China institute of aerospace Science and technology Center of Ministry of Education Shanghai 200240China

The parametric model of stratospheric airships is established in the body axes coordinate system. In this paper we study the turning mechanism of stratospheric airships including the generated forces and the key parameters for steady turning. We compare and analyze the different driven-characteristics between aerodynamic control surfaces and vectored thrust in turning. We design a composite control combining aerodynamic control surfaces and vectored thrust according to different dynamic pressure conditions, to achieve coordinated turning under high or low airspeed situations.

关键词： Stratospheric airships Horizontal turn Composite control Control allocation Vectored thrust

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Observer-based control for the platform of a tethered space robot

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Chinese Journal of Aeronautics 2018年第8期31卷 1786-1796页

作者： Guang ZHAI Heming ZHENG Bo ZHANG aerospace Engineering School Beijing Institute of TechnologyBeijing 100081China aerospace System Engineering shanghai Shanghai 201109China

This paper addresses the attitude control problem of a space tethered robot platform in the presence of unknown external disturbance caused by a connecting elastic tether. The tethergenerated unknown disturbance leads to tremendous challenges for attitude control of the *** this work, the perturbed attitude dynamics of the platform are derived with a consideration of the libration of the elastic tether, and then with the purpose of compensating the unknown disturbance, major attention is dedicated to develop a nonlinear disturbance observer based on gyros measurements, after which, an adaptive attitude scheme is proposed by combining the disturbance observer with a sliding mode controller. Finally, benefits from the observer based on an adaptive controller are validated by series of numerical simulations.

关键词： Adaptive control Attitude dynamics Disturbance observerSliding mode controlTethered space robot

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An improved equivalent beam model of large periodic beam-like space truss structures

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Chinese Journal of Aeronautics 2023年第12期36卷 297-308页

作者： Dongfang ZHU Xiaoxuan YAN Jun SUN Fucheng LIU Dongxing CAO shanghai aerospace Control technology institute Shanghai 201109China shanghai Key Laboratory of aerospace Intelligent Control technology Shanghai 201109China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

Space truss structures are essential components for space-based remote sensing loads with high spatial and temporal *** achieve high-precision vibration control,an accurate and efficient dynamics model is *** addition to the current equivalent beam model(EBM)based on the classical continuum theory,an improved equivalent beam model(IEBM)is proposed that considers the impact of the distinction between trusses and beams on torsional and shear deformations,as well as the impact of shear deformation on flexural *** to the displacement expressions of spatial beams,torsional,shear,and bending correction coefficients are introduced to derive expressions of strain energy and kinetic *** energy equivalence principle is then utilized to calculate the elasticity and inertia matrices,and dynamics equations are established using the finite element ***,an IEBM is constructed by employing the particle swarm optimization approach to determine the correction coefficients with the truss natural frequency as the optimization *** natural vibration characteristics of the structure are estimated for various material *** with the full-scale finite element model,the EBM reaches a maximum error of 80%for a low modulus of elasticity,while the maximum error of the IEBM is less than 2%for any given parameters,indicating its superior accuracy to the EBM.

关键词： Energy equivalence principle Improved equivalent beam model(IEBM) Natural vibration characteristic Particle swarm optimization approach Truss structure

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Simulation Analysis on Mechanical Property Characterization of Carbon Nanotubes Reinforced Epoxy Composites

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computer Modeling in Engineering & Sciences 2020年第10期125卷 145-171页

作者： Dan Li LiDing Zhengang Liu Qiang Li Kaiyun Guo Hailin Cao Shenzhen Academy of aerospace technology Shenzhen518057China shanghai aerospace Control technology institute Shanghai201109China shanghai institute of Satellite Engineering Shanghai201109China Harbin institute of technology(Shenzhen) Shenzhen518055China

Carbon nanotube(CNT)-reinforced composites have ultra-high elastic moduli,low densities,and fibrous *** paper presents the multi-scale finite element modeling of CNT-reinforced polymer composites from micro-to *** nanocomposites were modeled using representative volume elements(RVEs),and finite element code was written to simulate the modeling and loading procedure and obtain equivalent mechanical properties of the RVEs with various volume fractions of CNTs,which can be used directly in the follow-up simulation studies on the macroscopic model of CNT-reinforced *** using the programming to simulate the deformation and fracture process of the CNT-reinforced epoxy composites,the mechanical parameters and stress-strain curves of the composites on themacro-scale were obtained by endowing the elements of the lattice models withRVE *** experiments of the CNT-reinforced composites were also carried *** validity of the finite element simulation method was verified by comparing the results of the simulations and *** element models of functionally graded CNT-reinforced composites(FG-CNTRC)with different distributions were established,and the tensile and three-point-bending conditions for various graded material models were simulated by the methods of lattice model and birth-death element to obtain the tensile and bending *** addition,the influence of the distribution and volume ratio of the CNTs on the performance of the graded composite material structures was also analyzed.

关键词： Finite element method lattice modeling carbon nanotube mechanical properties gradient composites

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Feature-aided pose estimation approach based on variational auto-encoder structure for spacecrafts

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Chinese Journal of Aeronautics 2024年第8期37卷 329-341页

作者： Yanfang LIU Rui ZHOU Desong DU Shuqing CAO Naiming QI Department of aerospace Engineering Harbin Institute of TechnologyHarbin 150001China Suzhou Research institute of HIT Suzhou 215104China shanghai institute of Spaceflight Control technology Shanghai 201109China shanghai Key Laboratory of aerospace Intelligent Control technology Shanghai 201109China

Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit *** from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yielded impressive achievements for spacecraft pose *** improve the robustness and interpretability of CNNs,this paper proposes a Pose Estimation approach based on Variational Auto-Encoder structure(PE-VAE)and a Feature-Aided pose estimation approach based on Variational Auto-Encoder structure(FA-VAE),which aim to accurately estimate the 6 DoF pose of a target *** methods treat the pose vector as latent variables,employing an encoder-decoder network with a Variational Auto-Encoder(VAE)*** enhance the precision of pose estimation,PE-VAE uses the VAE structure to introduce reconstruction mechanism with the whole ***,FA-VAE enforces feature shape constraints by exclusively reconstructing the segment of the target spacecraft with the desired *** evaluation against leading methods on public datasets reveals similar accuracy with a threefold improvement in processing speed,showcasing the significant contribution of VAE structures to accuracy enhancement,and the additional benefit of incorporating global shape prior features.

关键词： Pose estimation Variational auto-encoder Feature-aided Pose Estimation Approach On-orbit measurement tasks Simulated and experimental dataset

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