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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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Figure-ground image segmentation via semantic information

Figure-ground image segmentation via semantic information

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2019 IEEE International Conference on Real-Time Computing and robotics, RCAR 2019

作者： Yuan, Ding Qiang, Jingjing Li, Jianfei Zhang, Hong Luo, Xiaoyan school of Astronautics Beihang University Beijing China Institute of Shanghai Academy of Space Flight Technology China Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Institute of Spacecraft System Engineering CAST China

ISBN: (纸本)9781728137261

—Image segmentation is a technique to segment the image into particular regions which are consistent in some specific characteristics. It is still a non-trivial task to segment the foreground from the background completely, as these regions are seldom uniform in color or texture which are defined as commonly-used low-level features adopted in the traditional techniques. In this work we present a new segmentation framework by employing the semantic information, which is classified as the high-level visual features and holds important clue to indicate the foreground from the background. Firstly, the image is segmented hierarchically by using the semantic edge constraint, and the result is represented as an Ultrametric Contour Map (UCM). Then the UCM is employed in the segmentation energy function as the data term and smoothness term. Finally, the optimal segmentation labels are obtained via the Graph-cut. Experiments achieve good performance testing on the MSRC 21 dataset. © 2018 IEEE

关键词： Textures

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Construction of the rat brain spatial cell firing model on a quadruped robot

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CAAI Transactions on Intelligence technology 2022年第4期7卷 732-743页

作者： Naigong Yu Yishen Liao Hejie Yu Ouattara Sie Faculty of Information Technology Beijing University of TechnologyBeijingChina Beijing Key Laboratory of Computational Intelligence and Intelligent System BeijingChina Engineering Research Center of Digital Community Ministry of EducationBeijingChina College of Robotic UniversitéFélix Houphouet-BoignyAbidjanCote d'Ivoire

Physiological studies have shown that rats in a dark environment rely on the limbs and vestibule for their self-motion information,which can maintain the specific firing patterns of grid cells and hippocampal CA3 place *** the development stage of rats,grid cells are considered to come from place cells,and place cells can be encoded by hippocampal theta *** on these,the quadruped robot is used as a platform in this ***,the sensing information of the robot's limbs and inertial measurement unit is obtained to solve its position in the *** the position information is encoded by theta cells and mapped to place cells through a neural *** obtaining the place cells with singlepeak firing fields,Hebb learning is used to adjust the connection weight of the neural network between place cells and grid *** order to verify the model,3-D simulation experiments are designed in this *** experiment results show that with the robot exploring in space,the spatial cells firing effects obtained by the model are consistent with the physiological research facts,which lay the foundation for the bionic environmental cognition model.

关键词： robot neural firing

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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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Design and Validation of Maintenance system for space Manipulator Grapple Fixture 14

Design and Validation of Maintenance System for Space Manipu...

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14th International Conference on Reliability, Maintainability and Safety, ICRMS 2023

作者： Zeng, Lei Gao, Ben Zhu, Chao Hu, Chengwei Xiong, Minghua Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing100094 China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin300458 China

ISBN: (纸本)9798350329988

The space manipulator plays an integral role in the assembly and construction of the China space station. The grapple fixture is positioned at designated locations on the space station as the foundation for the space manipulator. It is utilized in conjunction with the space manipulator to capture target objects and complete crawling tasks. The performance of the space manipulator is directly impacted by the grapple fixture, and a failure of the grapple fixture can even jeopardize the space station mission. This paper analyzed the maintenance requirements of the grapple fixture, proposed a maintenance system for it, and executed replacement tasks with the assistance of maintenance tools and astronauts in orbit. The feasibility of this approach is verified through ground testing and simulation analysis. The results will serve as a valuable reference and engineering guidance for future space manipulator maintenance. © 2023 IEEE.

关键词： Fixtures (tooling)

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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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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 experimental verification of microgravity simulation system for lunar sampling manipulator 7

Design and experimental verification of microgravity simulat...

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

作者： Chen, Ming Zeng, Lei Ni, Wencheng Zhang, Yun Zhao, Jianfei Jiang, Shuiqing Beijing Key Laboratory of Space Intelligent Robot System Technology and Application Beijing Space Vehicle General Design Department Beijing China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin300458 China

ISBN: (纸本)9781510656659

According to the requirements of ground test task of lunar sampling manipulator, a microgravity simulation system based on suspension method is designed and developed. The system is mainly composed of Position tracking system, Force compensation system, Suspension system, Posture measurement system and Integrated control system. The simulation system has completed the ground test and ground verification of lunar sampling manipulator, which has been successfully launched, and successfully completed the on-orbit mission. The microgravity simulation system of manipulator has good universality and expansibility, and can be applied to the ground test of other space manipulator products. © 2022 SPIE

关键词： Microgravity

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