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7th International Conference on Electromechanical Control technology and Transportation, ICECTT 2022

作者： Zhang, Wenming Zhang, Yun Chen, Ming Zeng, Lei Gao, Sheng Jiang, Xufu Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing China Beijing Satellite Manufacturing Limited Company Beijing China

ISBN: (纸本)9781510656659

The ball screw is a commonly used transmission component. When applied to the spacecraft mechanism, it is necessary to comprehensively consider space environmental factors such as on-orbit high and low temperature, vacuum, atomic oxygen, electron irradiation, single particle, ultraviolet and infrared irradiation. In view of the long-life application requirements of ball screws for spacecraft mechanism, the factors affecting the life of the ball screws are analyzed. Two design schemes are proposed according to the lubrication method of the ball screws and the material of ball for a ball screws of a certain spacecraft mechanism. The design scheme of ceramic ball + raceway sputtering MoS2 lubrication has been confirmed by the test. The design can work for no less than 7000 times under the specified load, which meets the requirements of the flight model on-orbit. Through the ball screw long-life test, it can be seen that the load capacity and service life of the solid lubricated ball screw are significantly reduced. In the development process of the spacecraft mechanism ball screw, a special life test must be carried out to verify whether the ball screw can meet the on-orbit requirements. © 2022 SPIE

关键词： Layered semiconductors

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A Legged Small Celestial Body Landing Mechanism:Landing Simulation and Experimental Test

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space(Science & technology) 2023年第1期3卷 453-463页

作者： Zhijun Zhao Shuang Wu Jingdong Zhao Yaobing Wang Chuncheng Zhao Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Beijing Institute of Spacecraft System EngineeringBeijing 100094China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150006China Department of Aerospace Science and Technology Polytechnic University of MilanMilan 20133Italy

Landing mechanism tends to rebound and turn over,and the stability time is long when landing on the small celestial *** landing performance in different conditions is necessary to be evaluated to guide the ***,landing performance evaluation is realized by *** factors affecting the landing performance including cardan element damping,foot anchors,retro-rocket thrust,landing slope angle,and landing attitude are analyzed.A microgravity platform is built to test the landing mechanism,and the consistency between the simulation and the experiment is *** the basis of simulation and experiment,some landing suggestions are proposed to improve the landing performance.

关键词： thrust mechanism landing

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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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Optimized laplacian sparse coding for image classification 8th

Optimized laplacian sparse coding for image classification

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8th International Conference on Image and Graphics, ICIG 2015

作者： Chen, Lei Gao, Sheng Yuan, Baofeng Qi, Zhe Liu, Yafang Wang, Fei Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing100094 China Xi’an Jiaotong University Xi’an Shaanxi710049 China

ISBN: (纸本)9783319219622

Laplacian sparse coding exhibits good performance for image classification, because of its outstanding ability to preserve the locality and similarity information of the codes. However, there still exists two drawbacks during the Laplacian graph construction: (1) It has expensive computational cost, which significantly limits the applicability of the Laplacian sparse coding to large-scale data sets. (2) Euclidean distance does not necessarily reflect the inherent distribution of the data. To construct a more robust Laplacian graph, we introduce a local landmarks approximation method instead of the traditional k-nearest neighbor algorithm, and design a new form of adjacency matrix. Based on the Nesterov’s gradient projection algorithm, we develop an effective numerical solver to optimize the local landmarks approximation problem with guaranteed quadratic convergence. The obtained codes have more discriminating power compared with traditional sparse coding approaches for image classification. Comprehensive experimental results on publicly available datasets demonstrate the effectiveness of our method. © Springer International Publishing Switzerland 2015.

关键词： Codes (symbols)

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Research on obstacle detection and path planning based on visual navigation for mobile robot 4

Research on obstacle detection and path planning based on vi...

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2020 4th International Conference on Electrical, Mechanical and Computer Engineering, ICEMCE 2020

作者： Zheng, Yixiao Yan, Bixi Ma, Chao Wang, Xinyu Xue, Haoyang School of Instrument Science and Optoelectronic Engineering Beijing Information Science and Technology University Beijing China Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing China

Both obstacle and path planning are of significance for autonomous visual navigation of a mobile robot which is able to realize free movement and obstacle avoidance. In this paper, a scheme of obstacle detection which is based on binocular vision to identify obstacles is constructed and it is combined with improved A* algorithm for obstacle avoidance motion for mobile robot platform. First, a binocular vision system to detect the robot's perception of the environment is used and the visual information is obtained. Then a Gaussian filter is used to reduce the noise in the image, and the grayscale image is obtained through the binocular vision system. The gray scale map is matched with SAD (Sum of Absolute Differences) in order to obtain the disparity image with comparison. Second, the location information of the obstacle is extracted through the environmental depth information contained in the disparity image, and the improved A* algorithm is used as the path planning algorithm in this paper, which can modify the path of the planning error. Furthermore, the detection experiment of the robot visual obstacle avoidance system was established and the optimal path was obtained. The examples show that, the obstacle avoidance system can complete the task of obstacle detection and give a better path for the mobile robot. © 2020 Journal of Physics: Conference Series.

关键词： Mobile robots

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Comparative Analysis on Few Typical Algorithms of Gesture Recognition for Human-robot Interaction 20

Comparative Analysis on Few Typical Algorithms of Gesture Re...

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4th International Conference on Computer Science and Application Engineering, CSAE 2020

作者： Ma, Chao Tan, Qimeng Xu, Chaofan Zhao, Jingyi Wang, Xinyu Sun, Jing Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing China School of Instrument Science and Optoelectronic Engineering Beijing Information Science and Technology University Beijing China

ISBN: (纸本)9781450377720

Human-robot interaction (HRI) is considered as one of the key techniques of space intelligence robots. Few typical features of complicated human actions need to be captured and understood accurately by intelligent robot to ensure free communication and interaction between both above in real-time, especially for identifying and tracking hand state. There are four approaches for gesture recognition, including algorithm based on Kinect V2 SDK, model-based particle swarm optimization algorithm (PSO), deep learning algorithm and gesture module based on Baidu AI platform. These have been selected to compare in the form of principle, calculating time, robustness, range, environmental adaptability and correct rate respectively. The comparative results have generalized that both the second and the third algorithm have better performance than other algorithms in the above aspects such as calculating efficiency, robustness, detecting range, external disturbance and correct ratio. Particularly, the second algorithm is not only suitable for close range, but also suitable for multi-view cases. However, the third algorithm can have better performance, but depends on precise network model and weights by introducing lots of positive and negative gesture samples. © 2020 ACM.

关键词： Human robot interaction

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Design and analysis of a flying-crawling spherical robot for multi-mode movement

Design and analysis of a flying-crawling spherical robot for...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Lu, Pengfei Xu, Kun Ding, Xilun Jiang, Shuiqing Tang, Zixin Wang, Yaobing Beihang University Robotics Institute of School of Mechanical Engineering and Automation Beijing China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing China

ISBN: (纸本)9781728163215

A novel spherical robot named flying-crawling spherical robot is designed in this paper. It can fly or roll on ground with its single rotor and eight tail fins. When its limbs stretch out it can crawl on the supporting surface. Besides, with its limbs the robot can realize carrying objects, landing on uneven ground and walking on the supporting surface. Dynamic model of the robot in flight mode is established and the motion characteristics are analyzed. A PID control system is designed to enable the robot to achieve stable flight. Trot gait planning of the robot is given and a PID controller is designed for tail fins assistant in crawling mode. Corresponding simulations are carried out and the simulation results verify the proposed methods. © 2019 IEEE.

关键词： Three term control systems

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Resonance frequency prediction approach of lattice structure fabricated by selective laser melting

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Advances in Astronautics Science and technology 2022年第4期5卷 309-316页

作者： Zhou, Hao Jia, Heran Zeng, Huizhong Tu, Yonggang Li, Linli Zhang, Xiaoyu Lei, Hongshuai Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering China Academy of Space Technology No. 104 Youyi Road Beijing 100094 China Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures Beijing Institute of Technology No. 5 Zhongguancun South Street Beijing 100081 China

Lightweight structures composed of a closed shell and internal lattice infill are highly desirable in satellites on account of their superior specific stiffness and buckling strength, which are brought about by the sandwich effect. These lattice structures can be fabricated by various additive manufacturing techniques, such as selective laser melting (SLM). However, the sub-millimeter-scale shell thickness and lattice strut diameter of the fabricated structure often deviate from the designed dimensions and lead to noteworthy discrepancies between the resonance frequencies of the fabricated structure and those of the initial design model. In this work, a bracket structure for a satellite is designed via topology optimization-based lattice infill approach and fabricated using SLM. A resonance frequency prediction approach based on X-ray micro-computed tomography and the stiffness equivalence is then proposed. Vibration tests are conducted to obtain the resonance frequencies of the fabricated structure. The prediction errors of resonance frequencies for the first three modes are less than 1%, whereas that of the traditional approach based on finite element analysis is as large as 14%. © 2022, Chinese Society of Astronautics.

关键词： Additive manufacturing Geometric reconstruction Lattice structure Prediction approach Resonance frequency

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Combine Neural Radiance Fields in Different Reference Coordinates

Combine Neural Radiance Fields in Different Reference Coordi...

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2023 China Automation Congress, CAC 2023

作者： Zhang, Weili Li, Zhongheng Guo, Yu Wang, Fei Institute of Artificial Intelligence and Robotics Xi'An Jiaotong University Xi'an China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing China

ISBN: (纸本)9798350303759

Neural Radiance Fields (NeRF) leverage deep learning networks to restore high-quality implicit representations of 3D scenes from 2D images, surpassing traditional texture mapping in rendering quality. Typically, reconstructed images by NeRF exist in a reference coordinate system, necessitating consideration of each surface's information in a single shot. Overlapping parts in adjacent images are addressed by obtaining the camera pose through sparse COLMAP reconstruction. However, occluded regions, caused by contact with support surfaces, pose challenges for complete reconstruction. To address this, we propose a scene fusion algorithm based on NeRF, facilitating the amalgamation of neural radiance fields under different reference coordinate systems. This reduces data requirements and shooting conditions, enhancing the implicit 3D reconstruction of real objects. By estimating the translation and rotation relationship between image capture angles and the NeRF model, we fuse neural radiance fields in distinct reference coordinate systems, completing object surface information. Evaluation is conducted on both NeRF synthetic dataset and real objects. © 2023 IEEE.

关键词： Cameras

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Research on autonomous navigation of mobile robot based on multi ultrasonic sensor fusion

Research on autonomous navigation of mobile robot based on m...

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IEEE Information technology and Mechatronics Engineering Conference (ITOEC)

作者： Rui Wang Lei Chen Jie Wang Pei Zhang Qimeng Tan Dong Pan Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing China

ISBN: (纸本)9781538653746

Based on the mobile robot platform with multi-ultrasonic ranging sensors, a method is proposed to obtain local maps by ultrasonic ranging, and to obtain global maps through detection in the process of motion, so as to complete path planning and navigation. This method effectively fuses multi-sensor to detect obstacles around the mobile robot. The global map is constructed by local map, which overcomes the shortcoming of ultrasonic ranging. The method is easy to implement. The validity of this method is verified by a certain type of mobile robot platform.

关键词： Distance measurement Acoustics Mobile robots Robot sensing systems Navigation Path planning

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