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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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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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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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Reliability Design of Manipulator Joint for China space Station 2

Reliability Design of Manipulator Joint for China Space Stat...

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2nd International Conference on Artificial Intelligence, Automation, and High-Performance Computing, AIAHPC 2022

作者： Li, Delun Zhu, Chao Zhang, Yun Bai, Mei Huang, Zhipeng Xie, Zongwu Liu, Teng Fu, Hao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering CAST Beijing100094 China Beijing Satellite Manufacturing Co. Ltd. Beijing100094 China Beijing Institute of Space Environment Engineering Beijing100094 China

ISBN: (纸本)9781510657717

The TianHe manipulator is responsible for major tasks such as China space Station construction, operation, and supporting astronaut's extravehicular operations. The joint is the direct execution part of the manipulator to realize flexible movement, and it is the key component to ensure the core functions and performance of the China space Station manipulator, The composition of the joint is complex, and the experience of its reliability design is very poor. So the research of reliability design method for the joint is of great significance. Starting from the joint reliability design method, this paper uses various methods such as redundant design, margin design, and environmental adaptability design to complete the joint reliability design comprehensively. The ideas and methods for reliability design for the joint of the China space Station manipulator introduced in this paper have important reference value for the reliability design for the space complicated electromechanical products. © 2022 SPIE. All rights reserved.

关键词： space stations

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A sub-pixel SAR and optical image registration method 66

A sub-pixel SAR and optical image registration method

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66th International Astronautical Congress 2015: space - The Gateway for Mankind's Future, IAC 2015

作者： Zhang, Hanmo Lu, Shan You, Hongjian Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai Aerospace Control Technology Institution China Key Laboratory of Geo-Spatial Information Processing and Application System Technology Institute of Electronics Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781510818934

Automatic image registration method is important because data amount acquired and processed is increasingly heavy. For SAR and optical sensor images, it is important to align the same object shown in different images from multi sensors. Considering extracting and matching features in SAR and optical images, a template registration strategy is proposed in this paper. A particular similarity measurement which is robust in matching remote sensing images of general sceneries is hardly to construct. Being the invertible and essential tendency nowadays in the field of earth observation, high pixel-resolution images can offer much more information of the ground. Thus subpixel image registration methods have been researched, among which can successfully achieve 1/50 pixel level accuracy in matching homologous sensor image. This paper firstly investigated the performance of 2D Gaussian fitting for low correlated synthetic images and real satellite images acquired by Radat SAT-2, COSMO and TerraSAR-X satellites. Three algorithms for subpixel locating have been utilized with consideration of the low correlated coefficient peak and corrupted shape of neighbourhood around it. The results show 2D Gaussian fitting is the most efficient on noisy coefficient maps. Then a subpixel image registration method for SAR and optical images is proposed. Normalized gradient correlation (NGC) algorithm is used to solve the problem of different intensity property at first, and by combining 2D Gaussian fitting to relocate matched points at a subpixel level accuracy. Experiment results have shown that the proposed method has enough capabilities in handling differences between images from multi-sensors. The proposed approach has been found to be simple and efficient in implementation with a low computation load. And the most important performance is the results presented here have achieved matching accuracy within 1 pixel.

关键词： Image registration

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The current feedforward compensation method for the cogging torque of permanent magnet synchronous motors

The current feedforward compensation method for the cogging ...

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IEEE International Conference on Cyber technology in Automation, Control, and intelligent systems

作者： Liu Xin Zhou Dong Zhang Pei Wang Rui Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Beijing PR China

ISBN: (数字)9781728107707

ISBN: (纸本)9781728107714

The cogging torque is the inherent characteristic of permanent motors with the cogging. The cogging torque reduces the stability of the motor, especially in the status of the low speed. A compensation method based on the current feedforward is proposed in terms with the function between the torque and Q-Current by the method of space Vector PWM of the permanent magnet synchronous motors. The relation equation between the cogging torque and the rotor angle is obtained by the experimental analysis. And then, the transfer function of the current closed-loop system is obtained by using the experiment data and the system identification method. The cogging torque compensation current is calculated by the forecast for the position of the rotor. The experiment results show that the presented method can effectively improve the stability of the motor speed.

关键词： Torque Forging Permanent magnet motors Synchronous motors Rotors Transfer functions Feedforward systems

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Optimization Design of Bracket and Thermal Controller Structures Based on Lattice Sandwich Cells

Optimization Design of Bracket and Thermal Controller Struct...

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第三届中国国际复合材料科技大会

作者： Xiaoyu Zhang Hao Zhou Huizhong Zeng Yaobing Wang Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering CAST

Structures with minimum weight is highly desired by spacecraft designers. Lattice sandwich cells with advantage of lightweight, multi-function and high stiffness provide wide application potential in spacecraft engineering. For a long time, the applications of lattice sandwich structures in spacecraft are limited due to the difficulties in manufacturing technique. In the past decade, the development of additive manufacturing techniques make the high-precision lattice structures become reality. In present work, the design of the thermal controller structure based on lattice cells and the bracket structures based on lattice cells are achieved using macroscale topology optimization, microscale lattice substitution and design of connection region. All the structures are necessary in spacecraft engineering. They play the role of thermal control and mechanical support of various equipments. All the structures are manufactured with AlSi10Mg by direct metal laser melting. The weight of structures made of lattice cells is much lighter than traditional structures made of solid materials or honey comb plates. The weight reduction are extremely important for the achievement of the spacecraft system engineering. The 3D printed structure can reduce the risk of leakage of phase change materials inside thermal controller because of absence of welding joint.

关键词： Bracket Thermal Controller Lattice Sandwich

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Additive Manufacturing spacecraft Structure Made of Lattice Sandwichs

Additive Manufacturing Spacecraft Structure Made of Lattice ...

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第三届中国国际复合材料科技大会

作者： Hao Zhou Xiaoyu Zhang Fuming Zeng Wenhua Shi Huizhong Zeng Yaobing Wang Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering CAST

Lattice sandwich structures have great advantage in lightweight, multi-function and high stiffness, which provide wide application potential in spacecraft engineering. However, the report of applications of lattice sandwich structures in spacecraft mainstructure is not available due to the difficulties in the manufacturing dimensional precision and the complex connection between parts. In recent years, the development of additive manufacturing techniques, such as selective laser melting, make the high-precision lattice structures become reality. In this work, the design of the first additive manufacturing satellite structure based on lattice cells are achieved using macroscale topology optimization, microscale lattice substitution and design of connection region. The structure is manufactured with AlSi10Mg by direct metal laser melting. The dimensions of the satellite structure are 400×400×400 mm. The main structure plays the role of mechanical support of various equipments. The weight of structures made of lattice cells is much lighter than traditional structures made of solid materials or honey comb plates. The mass of the structure and its carrying capacity are 8 kg and 104 kg, respectively. The structure mass-tosatellite mass ratio is 7.7%, which is lighter than most traditional satellite made of honeycomb sandwich panels, about 15～25%. The weight reduction is extremely important for the achievement of the spacecraft system engineering. The vibration test verified that the satellite structure could endure the vibration loads resulted from the rocket launching.

关键词： spacecraft Structure Lattice Sandwich Selective Laser Melting

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Development of a Landing Leg with Active Buffering and Anchoring Functions Applied to the Small Body Landing Mechanism

Development of a Landing Leg with Active Buffering and Ancho...

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IEEE International Conference on Mechatronics and Automation

作者： Zhijun Zhao Tao Xiao Zixin Tang Xiangyu Gao Xin Liu Wenming Zhang Bin Liu Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing China

ISBN: (数字)9781728164168

ISBN: (纸本)9781728164175

It is microgravity on the small body, and its medium is unknown and diverse. The lander is easy to rebound or tip over when landing and easy to drift away after landing. Thus, the lander should have the functions such as cushioning, terrain adapting and anchoring. At present, the moon and Mars landers mostly use honeycomb aluminum to achieve passive buffering. Honeycomb aluminum has good buffering effect under heavy load. This paper proposes an electromagnetic damping and anchoring leg for the small body lander. The leg integrates the folding mechanism and the buffering mechanism as a part and can sense the landing force. This force signal is used to realize the buffering function of the landing leg. An ultrasonic drill is attached at the end of the landing leg to realize anchoring after landing. Landing and anchoring performances of the landing leg are tested.

关键词：

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Landing Performance Simulation of an Asteroid Landing Mechanism

Landing Performance Simulation of an Asteroid Landing Mechan...

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IEEE International Conference on Information and Automation

作者： Zhijun Zhao Delun Li Baofeng Yuan Sheng Gao Jingdong Zhao Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering State Key Laboratory of Robotics and System Harbin Institute of Technology

ISBN: (纸本)9781467391054

Asteroid landing is a new research field in deep space exploration, which has important scientific and economic values in learning the origin of the solar system and exploring the asteroid. It is microgravity and little media properties are obtained on the asteroid surface, thus good landing performance is demanded to realize safe landing of the landing mechanism. Landing mechanism in the paper has three legs, and the damping device is located between the landing gear and the equipment base. Simulation method is introduced to analyze the landing performance of the landing mechanism. Landing performance of the landing mechanism on 30° landing slope with the largest landing velocity is simulated in three typical landing modes, and the landing performance is reflected by stability time of the landing gear and overloading acceleration of the equipment base. Landing simulation has important significance in learning landing performance and guiding the landing of the landing mechanism.

关键词： Asteroid Landing mechanism Landing performance Simulation

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