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arXiv 2024年

作者： Raducan, S.D. Jutzi, M. Cheng, A.F. Zhang, Y. Barnouin, O. Collins, G.S. Daly, R.T. Davison, T.M. Ernst, C.M. Farnham, T.L. Ferrari, F. Hirabayashi, M. Kumamoto, K.M. Michel, P. Murdoch, N. Nakano, R. Pajola, M. Rossi, A. Agrusa, H.F. Barbee, B.W. Syal, M. Bruck Chabot, N.L. Dotto, E. Fahnestock, E.G. Hasselmann, P.H. Herreros, I. Ivanovski, S. Li, J.-Y. Lucchetti, A. Luther, R. Ormö, J. Owen, M. Pravec, P. Rivkin, A.S. Robin, C.Q. Sánchez, P. Tusberti, F. Wünnemann, K. Zinzi, A. Epifani, E. Mazzotta Manzoni, C. May, B.H. Physics Institute University of Bern Switzerland Johns Hopkins University Applied Physics Laboratory LaurelMD United States Department of Aerospace Engineering University of Maryland College ParkMD United States Department of Earth Science and Engineering Imperial College London United Kingdom Department of Aerospace Science and Technology Politecnico di Milano Italy Guggenheim School of Aerospace Engineering Georgia Institute of Technology AtlantaGA United States Department of Aerospace Engineering Auburn University AuburnAL United States Lawrence Livermore National Laboratory LivermoreCA United States Université Côte dAzur Observatoire de la Côte dAzur CNRS Laboratoire Lagrange Nice France University of Tokyo Department of Systems Innovation School of Engineering Tokyo Japan Université de Toulouse Toulouse France INAF OAPD Astronomical Observatory of Padova Italy IFAC CNR FI Sesto Fiorentino Italy NASA Goddard Space Flight Center GreenbeltMD United States INAF Osservatorio Astronomico di Roma Italy Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States CSIC INTA Carretera de Ajalvir km4 Torrejón de Ardoz28850 Spain INAF Osservatorio Astronomico di Trieste Trieste Italy Planetary Science Institute TucsonAZ United States Museum für Naturkunde Leibniz Institute for Evolution and Biodiversity Science Berlin Germany Astronomical Institute The Czech Academy of Sciences Czech Republic Colorado Center for Astrodynamics Research University of Colorado Boulder BoulderCO United States Agenzia Spaziale Italiana Space Science Data Center Italy London Stereoscopic Company London United Kingdom

On September 26, 2022, NASA’s Double Asteroid Redirection Test (DART) mission successfully impacted Dimorphos, the natural satellite of the binary near-Earth asteroid (65803) Didymos. Numerical simulations of the impact provide a means to explore target surface material properties and structures, consistent with the observed momentum deflection efficiency, ejecta cone geometry, and ejected mass. Our simulation, which best matches observations, indicates that Dimorphos is weak, with a cohesive strength of less than a few pascals (Pa), similar to asteroids (162173) Ryugu and (101955) Bennu. We find that a bulk density of Dimorphos, ρB, lower than ≈ 2400 kg/m3, and a low volume fraction of boulders ( 40 vol%) on the surface and in the shallow subsurface, are consistent with measured data from the DART experiment. These findings suggest Dimorphos is a rubble pile that might have formed through rotational mass shedding and re-accumulation from Didymos. Our simulations indicate that the DART impact caused global deformation and resurfacing of Dimorphos. ESA’s upcoming Hera mission may find a re-shaped asteroid, rather than a well-defined crater. © 2024, CC BY.

关键词： Asteroids

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Robust multi-agent differential games for general linear systems with model uncertainties ⁎

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IFAC-PapersOnLine 2020年第2期53卷 6691-6696页

作者： Fei Liu Xiwang Dong Qingdong Li Zhang Ren School of Automation Science and Electrical Engineering Beihang University Beijing 100191 P.R. China Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang University Beijing 100191 P.R. China

The problem of infinite-horizon multi-agent differential games is investigated, where the process can be modeled by a set of uncertain linear dynamics. The players are divided into two teams, one of which consists of a fixed number of follower agents while the other has one leader agent. The two teams constitute the adversaries. The multi-agent differential games can be transformed into a two-player game. The dynamics of the agents are subjected to norm-bound model uncertainties. Based on quadratic stabilization techniques, a set of saddle point strategies of the game is designed to stabilize the closed-loop multi-agent system, where the weighting matrices of the cost function are properly selected. For any given cost function, by modifying the solution of the linear quadratic differential game of the nominal model, the sufficient conditions are presented such that the stabilization of the system is guaranteed and the uncertainties are compensated. It is proved that the modified solution achieves optimality. A numerical example is given to verify the effectiveness of the theoretical results.

关键词： multi-agent system leader-following consensus differential games model uncertainties Nash solution

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Pose Estimation for Non-cooperative Spacecraft based on Deep Learning

Pose Estimation for Non-cooperative Spacecraft based on Deep...

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第三十九届中国控制会议

作者： Wenxiu Huan Mingmin Liu Qinglei Hu School of Automation Science and Electrical Engineering Beihang University Shanghai Aerospace Control Technology Institute Beijing Advanced Innovation Center for Big-Data Based Precision Medicine Beihang University

The pose estimation of non-cooperative space-borne object is of vital importance for on-orbit service and spacecraft approaching missions. Based on images taken by a monocular camera, an estimate algorithm is proposed to estimate the relative position and the relative attitude of non-cooperative spacecraft. The approach utilizes the off-the-shelf target detection network and key point regression network to predict 2D key points coordinates and combines the multiple view triangulation to reconstruct 3D model. Nonlinear least squares method is used to minimize 2D-3D corresponding coordinates to predict position and attitude. The proposed method effectively combines deep learning and geometric optimization algorithms, which is an innovative application of deep learning in the aerospace field. Finally, simulations are performed to prove the effectiveness of the theoretical results.

关键词： Non-cooperative Spacecraft Pose Estimation Convolution Neural Network Geometry Optimization

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A robust and generalized framework for adversarial graph embedding

arXiv

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arXiv 2021年

作者： Li, Jianxin Fu, Xingcheng Peng, Hao Wang, Senzhang Zhu, Shijie Sun, Qingyun Yu, Philip S. He, Lifang Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang University Beijing100083 China State Key Laboratory of Software Development Environment Beihang University Beijing100083 China School of Computer Science and Engineering Central South University Changsha410083 China Department of Computer Science University of Illinois at Chicago ChicagoIL60607 United States Department of Computer Science and Engineering Lehigh University BethlehemPA18015 United States

Graph embedding is essential for graph mining tasks. With the prevalence of graph data in real-world applications, many methods have been proposed in recent years to learn high quality graph embedding vectors various types of graphs. However, most existing methods usually randomly select the negative samples from the original graph to enhance the training data without considering the noise. In addition, most of these methods only focus on the explicit graph structures and cannot fully capture complex semantics of edges such as various relationships or asymmetry. In order to address these issues, we propose a robust and generalized framework for adversarial graph embedding based on generative adversarial networks. Inspired by generative adversarial network, we propose a robust and generalized framework for adversarial graph embedding, named AGE. AGE generates the fake neighbor nodes as the enhanced negative samples from the implicit distribution, and enables the discriminator and generator to jointly learn each node's robust and generalized representation. Based on this framework, we propose three models to handle three types of graph data and derive the corresponding optimization algorithms, i.e., UG-AGE and DG-AGE for undirected and directed homogeneous graphs, respectively, and HIN-AGE for heterogeneous information networks. Extensive experiments show that our methods consistently and significantly outperform existing state-of-the-art methods across multiple graph mining tasks, including link prediction, node classification, and graph reconstruction. Copyright © 2021, The Authors. All rights reserved.

关键词： Directed graphs

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Uplink Precoding Design for Cell-Free Massive MIMO with Iteratively Weighted MMSE

arXiv

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arXiv 2023年

作者： Wang, Zhe Zhang, Jiayi Ngo, Hien Quoc Ai, Bo Debbah, Mérouane The School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China The Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China The Institute of Electronics Communications and Information Technology Queen’s University BelfastBT3 9DT United Kingdom The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China Frontiers Science Center for Smart High-Speed Railway System The Henan Joint International Research Laboratory of Intelligent Networking and Data Analysis Zhengzhou University Zhengzhou450001 China The Research Center of Networks and Communications Peng Cheng Laboratory Shenzhen518066 China The Technology Innovation Institute Abu Dhabi United Arab Emirates CentraleSupélec University Paris-Saclay Gif-sur-Yvette91192 France

In this paper, we investigate a cell-free massive multiple-input multiple-output system with both access points and user equipments equipped with multiple antennas over the Weichselberger Rayleigh fading channel. We study the uplink spectral efficiency (SE) for the fully centralized processing scheme and large-scale fading decoding (LSFD) scheme. To further improve the SE performance, we design the uplink precoding schemes based on the weighted sum SE maximization. Since the weighted sum SE maximization problem is not jointly over all optimization variables, two efficient uplink precoding schemes based on Iteratively Weighted sum-Minimum Mean Square Error (I-WMMSE) algorithms, which rely on the iterative minimization of weighted MSE, are proposed for two processing schemes investigated. Furthermore, with maximum ratio combining applied in the LSFD scheme, we derive novel closed-form achievable SE expressions and optimal precoding schemes. Numerical results validate the proposed results and show that the I-WMMSE precoding schemes can achieve excellent sum SE performance with a large number of UE antennas. Copyright © 2023, The Authors. All rights reserved.

关键词： MIMO systems

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High-precision intelligent track prediction under multi-dimensional conditions

High-precision intelligent track prediction under multi-dime...

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第三十九届中国控制会议

作者： Yilin Yang Qinghua Zhu Qinglei Hu Xin Wen School of Automation Science and Electrical Engineering Beihang University Shanghai Aerospace Control Technology Institute Beijing Advanced Innovation Center for Big-Data Based Precision Medicine Beihang University

In order to maintain national maritime security, it is particularly important to master the navigation rules of ships on important maritime military routes. Traditional trajectory prediction methods cannot flexibly implement the function of autonomous re-prediction based on emergencies. This paper considers the large amount of trajectory data of maritime moving targets and the existence of multi-dimensional factors and presents a high-precision track prediction model under multi-dimensional factors. This algorithm uses the Douglas-Peucker algorithm to compress the track data and uses the DBSCAN（Density-Based Spatial Clustering of Applications with Noise） algorithm for trajectory clustering and predicts the trajectory through the LRCN（Long-term Recurrent Convolutional Networks） prediction model. Simulation results show that using this algorithm greatly reduces the amount of calculations and can achieve a high-precision prediction;Under emergency cases, the algorithm can achieve autonomous re-prediction with high accuracy.

关键词： Track prediction Trajectory compression Clustering Neural Networks

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Circle Involute-Based Path Planning and Tracking for Impact Angle Control

Circle Involute-Based Path Planning and Tracking for Impact ...

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第32届中国控制与决策会议

作者： Ziqi Wang Qingei Hu Tuo Han Kewei Zhong School of Automation Science and Electrical Engineering Beihang University Beijing Advanced Innovation Center for Big-Data Based Precision Medicine Beihang University Shanghai Aerospace Control Technology Institute

In this paper,a guidance law considering impact angle constraint for missiles with time-varying velocity is proposed via geometric *** guidance concept is based on the geometric property of the circle involute.A simple path planning approach is proposed to find the desired involute trajectory that connects the missile and target while satisfying the impact angle *** the desired involute trajectory is determined,the reference line-of-sight（LOS） profiles with respect to the downrange are obtained ***,a robust guidance law is constructed to achieve the precise tracking of the reference LOS profiles that finally guides missiles with time-varying velocity to meet the impact angle *** simulations under various scenarios are conducted to validate the proposed guidance law.

关键词： Guidance Law Path Planning Impact Angle Geometric Methods

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Robust Attitude Control for Hypersonic Vehicles with Coupling Analysis

Robust Attitude Control for Hypersonic Vehicles with Couplin...

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第三十九届中国控制会议

作者： Ruihao Cao Yong Xi Qinglei Hu Tuo Han School of Automation Science and Electrical Engineering Beihang University Shanghai Aerospace Control Technology Institute Beijing Advanced Innovation Center for Big-Data Based Precision Medicine Beihang University

The attitude control issue for hypersonic vehicles（HSV） with coupling analysis is presented in this paper. An auxiliary variable is introduced to identify the effects of coupling terms that are negative or beneficial for the attitude stabilization. To handle the environmental uncertainties and aerodynamic perturbations involved in the hypersonic vehicles flight control system,a modified gain adaptation strategy is presented to tackle these terms that are limited but with unknow bounds. Then, a robust control scheme containing the coupling effect identified terms is constructed to deal with the robustness and coupling issues. It is proved that the utilized control scheme can enforce the tracking errors to a small vicinity of the origin in finite time. Finally, numerical simulations are conducted to demonstrate the provided controller.

关键词： Hypersonic vehicles Attitude tracking control Gain adaptation Robustness

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Three-Dimensional Impact Time and Angle Guidance via Controlling Line-of-Sight Dynamics

Three-Dimensional Impact Time and Angle Guidance via Control...

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第32届中国控制与决策会议

作者： Tuo Han Yong Xi Guangshan Chen Qinglei Hu School of Automation Science and Electrical Engineering Beihang University Shanghai Aerospace Control Technology Institute Beijing Advanced Innovation Center for Big-Data Based Precision Medicine Beihang University

In this paper,a three-dimensional guidance law is developed for intercepting a maneuvering target with impact angle constraint at a specified impact *** achieve this goal,the LOS error dynamics is utilized to track a constant LOS signal and a quadratic LOS profile in the pitch and yaw planes,*** designated LOS profile in the yaw plane has a simple structure,i.e.,a quadratic polynomial in *** nullify the LOS tracking errors in finite time,the non-singular terminal sliding mode technique is utilized to obtain the guidance ***,a set of reliable LOS profiles are systematically determined to ensure the feasibility of the guidance *** proposed guidance law can guarantee the desired impact angles and zero miss distance as mandatory ***,a single tuning parameter provides an additional freedom to meet the desired impact ***,numerical results with various engagement scenarios are provided to validate effectiveness of the proposed guidance law.

关键词： Three-Dimensional Guidance Impact Time Impact Angle Line-of-Sight Shaping

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Cubic Range Shaping Guidance for Maneuvering Targets with Impact Time Constraint

Cubic Range Shaping Guidance for Maneuvering Targets with Im...

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第32届中国控制与决策会议

In this paper,a cubic range shaping guidance with impact time constraint is proposed for intercepting maneuvering *** meet the desired impact time,the range dynamics is employed to track the desired range profiles created via a cubic range shaping *** coefficients involved in the range profiles are partially solved with boundary ***,a robust impact time guidance law is constructed to ensure bounded range tracking errors and estimate the target maneuvers as well using inertial delay control and sliding mode *** implemented guidance law involves a single parameter that is limited in a compact region,thus making it easy to be ***,numerical simulations with various cases are conducted to verify the proposed guidance law.

关键词： Guidance Law Range Shaping Impact Time

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