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Thermal performance of a 3D printed lattice-structure heat sink packaging phase change material

Chinese Journal of Aeronautics 2021年第5期34卷 373-385页

作者： Yuandong GUO Huning YANG Guiping LIN Haichuan JIN Xiaobin SHEN Jiang HE Jianyin MIAO Laboratory of Fundamental Science on Ergonomics and Environmental Control School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100083China Beijing Key Laboratory of Space Thermal Control Technology Beijing Institute of Spacecraft System EngineeringChina Academy of Space TechnologyBeijing 100094China

Thermal storage technology is becoming more and more significant with the increase of high-power equipment in space *** this paper,3 D printing technology and Phase Change Material(PCM)were combined into a Thermal Energy Storage(TES)system,which could fulfill the requirements of light weight and high thermal conductivity.A 3 D-printed lattice-structure TES plate with N-tetradecane as the PCM and aluminum alloy as the thermal conductivity enhancer was manufactured,and experimentally tested in a thermal vacuum *** addition,a simplified simulation model of the lattice cell was established to clearly analyze the heat transfer process of the TES *** effects of initial temperature distribution and heat load gradient on the thermal storage performances were investigated experimentally and *** equivalent thermal conductivity of the 3 D-printed lattice-structure TES plate turns out to be 13 times of the pure PCM thanks to the aluminum *** heat transfer enhancement appears at the end of the phase change stage due to the sudden mixture of the PCM with different *** simulation results agree well with the experimental *** equivalent thermal conductivity obtained by the phase change simulations are a little higher than those of the experiments,which is mainly caused by the initial uneven temperature distribution in the ***,the effects of non-uniform heat load and the presence of the PCM in the TES plate are *** work successfully validates the feasibility and effectiveness of 3 D printing technology and TES technology for the temperature control in space applications.

关键词： 3D printing Experiment Lattice-cell structure Phase change material Simulation Thermal energy storage

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An Assist-as-Needed Variable Admittance controller for Adaptive Support of Mobile Walking Assistive Robots 30

An Assist-as-Needed Variable Admittance Controller for Adapt...

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30th International Conference on Mechatronics and Machine Vision in Practice, M2VIP 2024

作者： Chen, Xinxing Zheng, Yue Su, Zongming Leng, Yuquan Huang, Jian Fu, Chenglong Guangdong Provincial Key Laboratory of Human-Augmentation and Rehabilitation Robotics in Universities Southern University of Science and Technology Shenzhen China Huawei Technologies Technology Planning Department Shenzhen China Key Laboratory for Image Processing and Intelligent Control School of Artificial Intelligence and Automation Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9798350391916

Mobile walking assistive robots have been widely used for monitoring patients' gait patterns and providing support to prevent falls. Traditional approaches often separate the operational modes of these robots into human-following and supporting modes, which can lead to discontinuities in assistance and potentially compromise safety. This paper proposes a novel assist-as-needed control strategy that incorporates a Balance Index (BI) to dynamically adjust the robot's support based on the user's balance capability. The BI is calculated using the interaction force between the user and the robot along the z-axis and the gait symmetry index (GSI). The proposed variable admittance controller modifies its parameters based on the BI, ensuring seamless transitions between compliance and support modes. Experimental validation was conducted with a healthy subject walking both with and without a knee fixation brace. The results demonstrate that the robot provides minimal interference during natural gait and increased support during impaired gait, validating the effectiveness of the proposed control strategy in enhancing user safety and promoting natural walking patterns. © 2024 IEEE.

关键词： Assistive technology

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Simulation of Fault Diagnosis Model for Managing Aeronautical Multivariate Heterogeneous Inputs

Simulation of Fault Diagnosis Model for Managing Aeronautica...

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2023 International Conference on Pattern Recognition, Machine Vision and intelligent Algorithms, PRMVIA 2023

作者： Zhang, Ying Peng, Di Meng, Gong Zhao, Qian Li, Tiantian Beijing Aerospace Automatic Control Institute Beijing China National Key Laboratory of Science and Technology on Aerospace Intelligent Control Beijing China China Academy of Launch Vehicle Beijing China

ISBN: (纸本)9798350346596

This paper studies the fault diagnosis model of aeronautical multivariate heterogeneous input data. Because of the gyroscope's powerful nonlinear mapping capabilities, it is a natural fit for modeling failure detection, this article combined with a variety of aviation gyro input data with fault monitoring methods, a model simulation method for multivariate heterogeneous input data in different states is proposed, which are one-dimensional and multi-dimensional data fault diagnosis in the standby state of the aircraft, and multi-sensor fault detection in the flight state or stationary state, which can effectively meet the needs of managing the fault diagnosis of multi-heterogeneous input of aviation. © 2023 IEEE.

关键词： Failure analysis

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Exponentially Smooth Rocket Mode Switching Algorithm Simulation

Exponentially Smooth Rocket Mode Switching Algorithm Simulat...

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2023 International Conference on Pattern Recognition, Machine Vision and intelligent Algorithms, PRMVIA 2023

作者： Zhang, Ying Shi, Dongqiang Peng, Di Li, Tiantian Zhao, Qian Beijing Aerospace Automatic Control Institute Beijing China National Key Laboratory of Science and Technology on Aerospace Intelligent Control Beijing China China Academy of Launch Vehicle Beijing China

ISBN: (纸本)9798350346596

The rocket has a variety of working modes after delivery, and according to its unique aircraft characteristics, this paper proposes an exponentially smooth rocket mode switching algorithm. The fixed delay caused by mode switching may also affect the startup time of normal working mode, so only enter shallow sleep mode when the idle time is short. When idle for a long time, the system needs to switch to deep sleep mode, where the power consumption of the system is minimized. The delay and power consumption of mode switching are analyzed and verified. After mathematical modeling, the smallest weight parameter of MRE is taken to meet the requirements of reliable and fast switching between multiple working modes of the rocket. © 2023 IEEE.

关键词： Rockets

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Q-learning-based space target selection for CNS/INS integrated navigation

Q-learning-based space target selection for CNS/INS integrat...

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Chinese control and Decision Conference, CCDC

作者： Dong Wang Jing Yang Kai Xiong School of Automation Science and Electrical Engineering Beihang University Beijing China Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering Beijing China

ISBN: (数字)9798350387780

ISBN: (纸本)9798350387797

To solve the problem that intermittent celestial observation will hamper the navigation accuracy of celestial and inertial integrated navigation system (CNS/INS), a Q-learning-based space target selection method is proposed. The visibility situation of space targets is analyzed under given flight mission, which lays the foundation for subsequent pointing optimization. Q-learning algorithm is employed to optimize the sequence of visible space target. The reward function is designed based on the trace of Fisher information matrix and the rotation angle of optical axis which could make a synthetic balance between navigation accuracy and rotation cost. By setting the optimized pointing sequence to CNS/INS integrated navigation system, unintermittent celestial observation can be achieved to guarantee filtering performance with relatively low rotation cost, which has a certain value of practical engineering application. Comparative simulation experiments demonstrate the effectiveness of the proposed method in terms of navigation accuracy and rotation cost.

关键词： Optical filters Accuracy Costs Q-learning Navigation Filtering space missions

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Learning to Mine Context Information for Remote Sensing Small Object Detection

Learning to Mine Context Information for Remote Sensing Sm...

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International Conference on Guidance, Navigation and control, ICGNC 2024

作者： Li, Lang Tang, Jie Chi, Zhiqiang Niu, Yunqiang Ren, Jun Li, Lei Yao, Xiwen Cheng, Gong Han, Junwei School of Automation Northwestern Polytechnical University Xi’an China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China

ISBN: (纸本)9789819622351

Object detection in remote sensing images has advanced significantly, nevertheless, it still faces the dilemma of low performance in detecting small objects. Due to extremely limited area, small objects can easily be submerged in complex backgrounds and suffer from insufficient context semantic information. To alleviate the aforementioned issues, we design a lightweight plug-and-play module named Cascade Local-Global Context Module (CLGCM) to extract context information. The module contains one cascade operation and two novel Sparse Context Blocks. The cascade operation can obtain long-range context semantic information at a small computational cost. And Sparse Context Block focuses on the most relevant semantic information through a sparsification operation. When integrated with Faster-RCNN and Cascade R-CNN, our module further boosts detection performance on the small object detection benchmark, AI-TOD, which significantly outperforms other mainstream algorithms. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Context information Remote sensing images Small object detection

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Zero-shot industrial image denoising with lightweight network

Zero-shot industrial image denoising with lightweight networ...

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2024 International Workshop on Automation, control, and Communication Engineering, IWACCE 2024

作者： Zhou, Chengxu Fan, Xiaojie Wang, Simeng Liu, Hongyan Gu, Ke School of Information Science and Technology Beijing University of Technology Beijing China Engineering Research Center of Intelligent Perception and Autonomous Control of Ministry of Education China Beijing Laboratory of Smart Environmental Protection China Beijing Artificial Intelligence Institute China School of Electronic & Information Engineering Liaoning University of Technology Liaoning China Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of Technology China

ISBN: (数字)9781510685420

ISBN: (纸本)9781510685413

Industrial images are often captured under full-time and full-weather conditions, leading to inevitable noise during the imaging process, which can impact subsequent detection algorithms. In recent years, image denoising with neural networks has been the rapid development. However, training such networks typically requires a large dataset, which is scarce in publicly available industrial image databases. In this paper, we propose a novel approach termed Zero-Shot Industrial Image Lightweight Denoising (ZSILD) network, which effectively denoises single noisy industrial image without the need for datasets. First, we sample the paired neighbour pixels of a random noisy industrial image, which are then utilized to train a lightweight denoising network. Second, we design a lightweight depthwise convolutions network based on bottleneck residual structure with shortcut connections. Finally, this network is trained on the sampled pairs using a novel loss function aimed at enhancing denoising performance. Our experiments conduct on real-world industrial ambient noise demonstrate that our ZSILD method outperforms existing denoising techniques, all while requiring comparatively minimal computational resources. © 2024 SPIE. All rights reserved.

关键词： Image denoising

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Safe Efficient Policy Optimization Algorithm for Unsignalized Intersection Navigation

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2011-2026页

作者： Xiaolong Chen Biao Xu Manjiang Hu Yougang Bian Yang Li Xin Xu State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082 Wuxi Intelligent Control Research Institute(WICRI)of Hunan University Wuxi 214115China College of Intelligence Science and Technology Institute of Unmanned SystemsNational University of Defense TechnologyChangsha 410073China

Unsignalized intersections pose a challenge for autonomous vehicles that must decide how to navigate them safely and *** paper proposes a reinforcement learning(RL)method for autonomous vehicles to navigate unsignalized intersections safely and *** method uses a semantic scene representation to handle variable numbers of vehicles and a universal reward function to facilitate stable learning.A collision risk function is designed to penalize unsafe actions and guide the agent to avoid them.A scalable policy optimization algorithm is introduced to improve data efficiency and safety for vehicle learning at *** algorithm employs experience replay to overcome the on-policy limitation of proximal policy optimization and incorporates the collision risk constraint into the policy optimization *** proposed safe RL algorithm can balance the trade-off between vehicle traffic safety and policy learning *** intersection scenarios with different traffic situations are used to test the algorithm and demonstrate its high success rates and low collision rates under different traffic *** algorithm shows the potential of RL for enhancing the safety and reliability of autonomous driving systems at unsignalized intersections.

关键词： Autonomous driving decision-making reinforcement learning(RL) unsignalized intersection

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Combined Model Predictive control for Geosynchronous Satellite Station Keeping Using Electric Propulsion 42

Combined Model Predictive Control for Geosynchronous Satelli...

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42nd Chinese control Conference, CCC 2023

作者： Shi, Heng Liu, Xiaoxiang Wang, Shuo Mai, Ji Beijing Institute of Control Engineering Beijing100094 China Science and Technology on Space Intelligence Control Laboratory Beijing100094 China Beijing Aerospace Institute for Metrology and Measurement Technology Beijing100076 China

ISBN: (纸本)9789887581543

Novel combined model predictive control method is presented, which includes long-term trajectory planning, outer-loop model predictive trajectory and angular momentum control, and inner-loop attitude control. Firstly, the influence of long-period perturbation characteristics on long term station keeping of geosynchronous satellite is fully considered, and the station keeping trajectory is optimized for 3 months to 6 months. Then, taking the long-term planning results as the reference trajectory and considering the engineering constraint model, the outer-loop control is realized within 7 days to 14 days, so that the position trajectory meets the planning expectations and meets the requirements of orbit and angular momentum optimal control. The inner loop control adopts the attitude control method considering the continuous torque effect of small thrust, so as to meet the requirements of real-time angular momentum and attitude control with higher frequency. The method has been successfully verified by on-orbit flight tests, showing the characteristics of high control accuracy, high fuel utilization efficiency, and being adaptive to various engineering constraints. © 2023 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Model predictive control

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A practical PID variable stiffness control and its enhancement for compliant force-tracking interactions with unknown environments

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science China(Technological sciences) 2023年第10期66卷 2882-2896页

作者： ZHANG Xin ZHOU Hao LIU JinGuo JU ZhaoJie LENG YuQuan YANG ChenGuang State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China School of Computing University of PortsmouthPortsmouth PO13HEUK Shenzhen Key Laboratory of Biomimetic Robotics and Intelligent Systems Department of Mechanical and Energy EngineeringSouthern University of Science and TechnologyShenzhen 518055China Key Laboratory of Autonomous Systems and Networked Control College of Automation Science and EngineeringSouth China University of TechnologyGuangzhou 510640China

Compliant interaction control is a key technology for robots performing contact-rich manipulation *** design of the compliant controller needs to consider the robot hardware because complex control algorithms may not be compatible with the hardware performance,especially for some industrial robots with low bandwidth *** paper focuses on effective and easy-to-use compliant control algorithms for position/velocity-controlled *** by human arm stiffness adaptation behavior,a novel variable target stiffness(NVTS)admittance control strategy is proposed for adaptive force tracking,in which a proportional integral derivative(PID)variable stiffness law is designed to update the stiffness coefficient of the admittance function by the force and position ***,its stability and force-tracking capability are theoretically *** addition,an impact compensator(Impc)is integrated into the NVTS controller to enhance its disturbance-suppression capability when the robot is subjected to strong vibration disturbances in complicated surface polishing *** proposed controllers are validated through four groups of experimental tests using different robots and the corresponding results demonstrate that they have high-accuracy tracking capability and strong adaptability in unknown environments.

关键词： compliant interaction control force tracking PID variable stiffness impact compensator unknown environments

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