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A novel space target-tracking method based on generalized Gaussian distribution for on-orbit maintenance robot in Tiangong-2 space laboratory

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Science China(Technological Sciences) 2019年第6期62卷 1045-1054页

作者： MO Yang JIANG ZhiHong LI Hui YANG Hong HUANG Qiang School of Mechatronic Engineering Beijing Institute of Technology Beijing 100081 China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing 100081 China Key Laboratory of Biomimetic Robots and Systems Ministry of Education Beijing 100081 China Institute of Manned Spacecraft System Engineering China Academy of Space Technology Beijing 100080 China

Accurate target tracking based on visual images is the key for intelligent robots to assist or replace astronauts to work in space station. However, the special space environment such as non-uniform illumination and high-energy particle radiation is a huge challenge, which may lead to complex noise coupling in vision image. This paper proposes a novel method for accurate target tracking, the essence of which is the Retinex image enhancement algorithm in CIELAB color space(LAB-GRetinex) and the generalized maximum correntropy Kalman filter(GMCKF) which are all based on generalized Gaussian distribution. The LABGRetinex algorithm chooses the CIELAB color space, which is closer to the human vision, as the processing color space, and the generalized Gaussian distribution can estimate the light image accurately, so the influence of non-uniform illumination can be reduced effectively. Meanwhile, the GMCKF algorithm adopts the generalized correntropy criterion based on the generalized Gaussian distribution to replace the minimum mean square error(MMSE) criterion to realize the optimal filtering effect under the complex non-Gaussian noise, which can improve the target tracking accuracy. Sufficient ground simulation experiments and application experiments in the Tiangong-2 space laboratory verify the effectiveness of the proposed algorithm which can track the target accurately in the special space environment and provide the precise pose information for on-orbit robot maintenance verification. This research lays a technical foundation for the application of intelligent robot in the construction and operation on space station in the future.

关键词： space robot LAB-GRetinex GMCKF target tracking

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Distribution of Dislocation-Twin Interaction in Twip Steel Under Different Loading Modes

SSRN

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SSRN 2022年

作者： Guo, Xiangru Mao, Ningdong Sun, Chaoyang Wang, Chunhui Cui, Yinan Xiong, Zhiping Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China School of Mechanical Engineering University of Science and Technology Beijing Beijing100083 China Applied Mechanics Lab School of Aerospace Engineering Tsinghua University Beijing100084 China National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing Institute of Technology Beijing100081 China

The tension-compression asymmetry and orientation effect of dislocation-twin boundary (TB) interactions in twinned TWIP steels were investigated using the discrete dislocation dynamics simulations and Schmid's law. The different types of dislocations dominate the TB migration in the twinned TWIP steel during tension and compression with the same loading orientation, and the asymmetric dislocation reactions at TB were attributed to the different leading partials produced after the dissociation of dislocation under different loading modes (tension or compression). Moreover, the complex dislocation-TB interactions, such as dislocations traversing TB, cross slip, dissociation, pile up and so on, were determined by considering the orientation effect of dislocation activation and the asymmetry of dislocation dissociation. The research advances the understanding of asymmetric behavior of twin and its influence on the macro hardening in plastic deformation of TWIP steels. © 2022, The Authors. All rights reserved.

关键词： Dissociation

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Experimental investigation of evolution of dynamics in short-resonant-cavity DFB laser with optical feedback

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Optics & Laser technology 2025年 191卷

作者： Wenchao Chen Yuanyuan Guo Zhiwei Jia Longsheng Wang Anbang Wang Yuncai Wang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan 030024 China College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Photonic Technology for Integrated Sensing and Communication Ministry of Education Guangdong University of Technology Guangzhou 510006 China Guangdong Provincial Key Laboratory of Information Photonics Technology Guangdong University of Technology Guangzhou 510006 China Institute of Advanced Photonics Technology & School of Information Engineering Guangdong University of Technology Guangzhou 510006 China

We conducted experiments to investigate the evolution of dynamics in short-resonant-cavity distributed feedback laser subject to optical feedback. Results reveal that the transition of the laser into chaos involves a regular switching between the stable state and quasi-periodic state. When exiting the chaotic state, the laser exhibits a switching between stable state and chaotic state, ultimately evolving into feedback locking. A new dynamic evolution path of the DFB laser has been proposed: stable state → switching between the stable state and quasi-periodic state → quasi-periodic state → chaotic state → switching between stable state and chaotic state → feedback locking. The influences of feedback strength on the duty cycle of quasi-periodic oscillation are examined. Moreover, a mapping of dynamics with respect to feedback strength and bias current is presented.

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Trajectory Planning Simulation of 3-DoF Parallel Wrist Mechanisms Based on SimMechanics 9

Trajectory Planning Simulation of 3-DoF Parallel Wrist Mecha...

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9th IEEE International Conference on Cyber technology in Automation, Control and intelligent systems, CYBER 2019

作者： Yang, Chen Xin, Liu Shimin, Wei Ying, Zhang Qineng, Huang School of Automation Beijing University of Posts and Telecommunications Beijing100876 China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Beijing100094 China

ISBN: (纸本)9781728107691

In this paper, the trajectory planning problem of a 3-DoF parallel wrist mechanism based on SimMechanics is proposed, which is a symmetric spherical 3-RRR parallel mechanism. The formulation of the inverse kinematics for the mechanism is firstly established by D-H matrix method, and the analytical solution is obtained. Then, the trajectory planning analysis of the mechanism is performed. Finally, the mechanism model is constructed based on the SimMechanics module of Matlab/Simulink, and the trajectory planning simulation of the mechanism is carried out. The simulation results agree well with the theoretical results, which indicate that the proposed method is feasible and convenient for the trajectory simulation of parallel mechanisms. © 2019 IEEE.

关键词： Inverse kinematics

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Electrochemical Energy Storage toward Extreme Conditions: Driving Human Exploration beyond Current Boundaries

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Chemical reviews 2025年 2025 May 30页

作者： Yanxin Shang Yongxin Huang Li Li Feng Wu Renjie Chen Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China. Shandong Key Laboratory of Advanced Chemical Energy Storage and Intelligent Safety Advanced Technology Research Institute Beijing Institute of Technology Jinan 250300 China. Innovative Research Team in High-Safety Energy Storage System and Smart Microgrids of Guangdong Province Beijing Institute of Technology (Zhuhai) Zhuhai 519088 China. Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081 China.

Major projects reliant on electric energy support, such as manned spaceflight, ocean exploration, and polar development, will encounter extreme environmental challenges. The most representative scenarios, including deep space, deep sea, deep earth, and polar regions, will be systematically discussed in this review. The interaction of multiple environmental factors under complex working conditions leads to multifaceted failures that significantly compromise the performance of electrochemical energy storage systems (EESSs). Specifically, this review examines EESSs operating under extreme conditions, including extreme temperatures, extreme pressures, electromagnetic radiations and so on. It addresses key challenges and summarizes solutions based on a mechanistic understanding of new electrochemical reactions and strategies to enhance electrochemical performance. Additionally, it provides a comprehensive overview of experimental and simulated technology, from the microscopic physicochemical mechanisms level to whole battery chemistry, and explores potential applications for EESSs in the future. Finally, this review offers prospective analyses of the demand for EESSs in future space exploration, involving missions to the Lunar surface, Mars and asteroids. This review provides both a theoretical and technical foundation for developing high-performance battery materials in extreme environments. It contributes to advancing diverse application scenarios for high-power EESSs.

关键词： Battery storage

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RCGA-Net: An Improved Multi-hybrid Attention Mechanism Network in Biomedical Image Segmentation

RCGA-Net: An Improved Multi-hybrid Attention Mechanism Netwo...

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2021 IEEE International Conference on Bioinformatics and Biomedicine, BIBM 2021

作者： Xiao, Feng Shen, Cong Chen, Yu Yang, Tian Chen, Shengyong Liao, Zhijun Tang, Jijun Tianjin University of Technology School of Computer Science and Engineering Tianjin China Engineering Research Center of Learning-Based Intelligent System Ministry of Education Tianjin China School of Basic Medical Sciences Fujian Medical University Fujian Fuzhou China College of Intelligence and Computing Tianjin University Tianjin China Key Laboratory of Systems Bioengineering Ministry of Education Tianjin China Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Guangdong Shenzhen China Department of Computer Science and Engineering University of South Carolina ColumbiaSC United States

ISBN: (纸本)9781665401265

Drawing support from an effective Medical Image Segmentation (MIS) is conducive to a substantial diagnostic basis for the physicians to identify the focus lesion in the patient body and give the subsequent clinical assessment of the patient status. Although various works have tried the challenging quantitative analysis problem, it is still difficult to conduct precise automatic segmentation, especially the soft tissue organs. In this decade, with the increased amount of available datasets, deep learning-based networks have achieved remarkable performance in image processing. Inspired by the state-of-the-art deep learning works, in this paper, we propose an end-to-end multi-layer network named RCGA-Net. It consists of an encoder-decoder backbone that integrates a coordinate attention mechanism based on space and channel and a global context extraction module to highlight more valuable information. To evaluate the performance of RCGA-Net, we apply it to different kinds of clinical and experimental MIS tasks to testify its generalization ability. Extensive experiments represent that our schema has taken the outperform or compatible results among the comparison methods group. Specifically, the numeric result of RCGA-Net on the pulmonary dataset has achieved a 99.12% optimum F1-score. © 2021 IEEE.

关键词： Diagnosis

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High-Order Continuous-Variable Coherence of Phase-Dependent Squeezed State

arXiv

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arXiv 2021年

作者： Guo, Yanqiang Zhang, Haojie Guo, Xiaomin Zhang, Yuchi Zhang, Tiancai Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China State Key Laboratory of Cryptology Beijing100878 China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan030006 China

We study continuous variable coherence of phase-dependent squeezed state based on an extended Hanbury Brown-Twiss scheme. High-order coherence is continuously varied by adjusting squeezing parameter r, displacement α, and squeezing phase θ. We also analyze effects of background noise γ and detection efficiency η on the measurements. As the squeezing phase shifts from 0 to π, the photon statistics of the squeezed state continuously change from the anti-bunching (g(n) (n) > n!) which shows a transition from particle nature to wave nature. The experiment feasibility is also examined. It provides a practical method to generate phase-dependent squeezed states with high-order continuous-variable coherence by tuning squeezing phase θ. The controllable coherence source can be applied to sensitivity improvement in gravitational wave detection and quantum imaging. Copyright © 2021, The Authors. All rights reserved.

关键词： Quantum optics

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High detectivity photodetectors based on perovskite nanowires with suppressed surface defects

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Photonics Research 2020年第12期8卷 1862-1874页

作者： GUOHUI LI RUI GAO YUE HAN AIPING ZHAI YUCHENG LIU YUE TIAN BINING TIAN YUYING HAO SHENGZHONG LIU YUCHENG WU YANXIA CUI College of Physics and Optoelectronics Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of EducationKey Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Applied Surface and Colloid Chemistry MOEShaanxi Key Laboratory for Advanced Energy DevicesShaanxi Engineering Laboratory for Advanced Energy TechnologySchool of Materials Science and EngineeringShaanxi Normal UniversityXi’an 710119China Dalian National Laboratory for Clean Energy iChEMDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Solution-processable,single-crystalline perovskite nanowires are ideal candidates for developing low-cost photodetectors,but their detectivities are limited due to a high level of unintentional *** the surfaceinitiated solution-growth method,we fabricated high-quality,single-crystalline,defects-suppressed MAPbI_(3) nanowires,which possess atomically smooth side surfaces with a surface roughness of 0.27 nm,corresponding to a carrier lifetime of 112.9 *** forming ohmic MAPbI_(3)∕Au contacts through the dry contact method,highperformance metal–semiconductor–metal photodetectors have been demonstrated with a record large linear dynamic range of 157 dB along with a record high detectivity of 1.2×10^(14) Jones at an illumination power density of 5.5 nW∕cm^(2).Such superior photodetector performance metrics are attributed to,first,the defects-suppressed property of the as-grown MAPbI_(3) nanowires,which leads to a quite low noise current in the dark,and second,the ohmic contact between MAPbI_(3) and Au interfaces,which gives rise to an improved responsivity compared with the Schottky contact *** realized high-performance MAPbI_(3) nanowire photodetector advances the development of low-cost photodetectors and has potential applications in weak-signal photodetection.

关键词： nanowires perovskite surface

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A Survey of Space robotic Technologies for On-Orbit Assembly

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空间科学与技术（英文） 2023年第3期3卷 291-303页

作者： Delun Li Lou Zhong Wei Zhu Zhipeng Xu Qirong Tang Wenhao Zhan Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System EngineeringCASTBeijingChina College of Mechanical Engineering Tongji UniversityShanghaiChina National Key Laboratory of Human Factors Engineering China Astronaut Research and Training CenterBeijingChina

The construction of large structures is one of the main development trends of the space exploration in the future,such as large space stations,large space solar power stations,and large space *** is one of important development tendency,which aims to make full use of space robots to assemble space structures autonomously in the aerospace *** that on-orbit assembly is an effective method to solve the problem of construction of large-scale spatial structures,it is necessary to motivate and facilitate the research of space robotics technologies for on-orbit ***,in this paper,the development status of space robot technology and the relevant space robot on-orbit assembly technology in recent decades are ***,based on the space robot motion planning and assembly sequence planning,the development of space robot planning algorithms is *** space robot assembly task,the space robot assembly method is *** the control point of view,how to solve the vibration suppression and compliant assembly of on-orbit assembly is reviewed,which provides a reference for the autonomous intelligent assembly of space robots for large-scale structures in *** order to simulate the space assembly scene on the ground,this paper introduces the development of ground verification experiments and provides ideas for the effective verification of space on-orbit assembly *** summary,though some of these problems have been satisfactorily solved in the past research,further research is still necessary in the ***,it looks forward to the future research direction of space machine on-orbit assembly.

关键词： technologies space assembly on-orbit robotic survey

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Learning a faster locomotion gait for a quadruped robot with model-free deep reinforcement learning

Learning a faster locomotion gait for a quadruped robot with...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Hu, Biao Shao, Shibo Cao, Zhengcai Xiao, Qing Li, Qunzhi Ma, Chao Beijing University of Chemical Technology College of Information Science and Technology Beijing100029 China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing China

ISBN: (纸本)9781728163215

Quadruped robots have great agility, flexibility and stability, which enables them to walk through uneven terrain. Motion control of legged robots is always a difficult problem. Previous approaches mostly either use a predefined gait that results in clumsy and unnatural behavior, or use reinforcement learning approach to generate a gait strategy that needs longtime computation and elegant network design. In this paper, we present an effective approach that uses deep reinforcement learning with prior knowledge to optimize the gait of quadruped robot. By using a specific quadruped robot walking gait as a priori knowledge, this approach adopts the technique of distributed proximal policy optimization to optimize the search for better gait. The proposed approach does not require modelling of complex robots, and has good network convergence speed and learning effect. Simulation results demonstrate that our proposed approach converges faster than other deep reinforcement learning methods without prior knowledge. Besides, our achieved gait has higher speed that is 50% faster than the trot gait without optimization. © 2019 IEEE.

关键词： Reinforcement learning

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