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SSRN 2024年

作者： Chi, Cheng Jiang, Shengyuan Chi, Guanxin Tang, Junyue Xiao, Junxiao Zhu, Jiachen Chi, Runqiang Fan, Jinbiao Huang, Zexi Deng, Zongquan State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China College of Mechanical Engineering Yanshan University Qinhuangdao066004 China National Key Laboratory for Electronic Measurement Technology North University of China Taiyuan030051 China

A large quantity of friction-induced heat is generated during penetration, notably increasing the projectile's surface temperature. Considering that the temperature variation depends on the physical properties of the penetrating target, this factor can be helpful for extraterrestrial object detection. This study studied the heat generation patterns and temperature distribution on the projectile surface when penetrating the lunar soil. For discrete medium penetration, large deviations appear in temperature prediction due to particle extrusion flow. Thus, we established a heat flux density model on the projectile surface by introducing a relative velocity factor for correction. The particle flow characteristics simulation and fitting model of the introduced factor were also obtained. We constructed a theoretical relationship between the resistance and stress model parameters through dynamic modeling. Experimental projectiles recording penetration acceleration and temperature at the points of interest on the projectile surface were designed and tested to obtain recorded data. The temperature field in this process was simulated in COMSOL software to calculate the projectile surface's heat flux density and temperature distribution. The results indicate that the developed model is effective. This research infers the physical characteristics of the penetrating target under given penetration conditions and provides more dimensional information for lunar soil exploration. © 2024, The Authors. All rights reserved.

关键词： Temperature distribution

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Reinforcement Learning for Dynamic Task Execution: A Robotic Arm for Playing Table Tennis

Reinforcement Learning for Dynamic Task Execution: A Robotic...

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IEEE International Conference on robotics and Biomimetics

作者： Zida Zhao Haodong Huang Shilong Sun Jing Jin Wenjie Lu School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen China Harbin Institute of Technology Shenzhen State Key Laboratory of Robotics and Systems (HIT) Suzhou Research Institute of HIT

ISBN: (数字)9798331509644

ISBN: (纸本)9798331509651

Dynamic tasks like table tennis pose a significant challenge for robots, although relatively easy for humans to learn. These tasks require precise control of rapid movements and timing in situations where the estimation of the flying ball and the robot's state is imprecise. Traditional model-based control methods struggle to accurately model and adapt to these dynamic changes, leading to difficulties and challenges in practical applications. To address this issue, a table tennis hitting method for a robotic arm based on reinforcement learning (RL) is proposed in this paper. Firstly, a simulation model of a robotic arm with eight degrees of freedom for playing table tennis was constructed. Secondly, a simple and effective reward function was designed to accomplish the task of hitting the table tennis ball with the robotic arm. Finally, two sets of experiments involving single and random ball launches were designed. Experimental results demonstrate that the proposed method enables the robotic arm to accurately hit the table tennis ball, showcasing the potential of RL in dynamic tasks.

关键词： Adaptation models Sports equipment Filtering Estimation Reinforcement learning Manipulators Robustness Timing PD control Sports

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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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Machine learning-supported CFD optimization of heat transfer in a pipe with a corrugated wall shape 26

Machine learning-supported CFD optimization of heat transfer...

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26th Fluid Mechanics Conference, FMC 2024

作者： Kamiński, P. Li, Y. Wawrzak, K. Tyliszczak, A. Noack, B.R. Department of Thermal Machinery Czȩstochowa University of Technology al. Armii Krajowej 21 Czȩstochowa42-201 Poland Artificial Intelligence and Aerodynamics School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen518055 China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology Shenzhen518055 China

The paper focuses on using machine learning to optimize the corrugation of a heated pipe wall to improve the uniformity of temperature distribution while minimizing pressure losses. The corrugation is characterized by a five-parameter function, allowing for extensive variations in wall shape. The machine learning process employs the Bayesian optimization method, iteratively working alongside the ANSYS Fluent code to perform RANS computations. A two-parameter cost function, which includes temperature variation and pressure drop, is used to define the optimization goal. The study demonstrates that substantial variations in flow patterns occur depending on the type of corrugation. An optimal set of corrugation parameters, ensuring the most uniform temperature distribution with minimal pressure losses, is determined within an optimization loop consisting of 1200 RANS simulations. The optimal configuration is characterized by a smooth waviness oriented outside the original wall location in a straight pipe. It ensures more than three times smaller temperature variation at only minor increase in the pressure drop. © Published under licence by IOP Publishing Ltd.

关键词： Drops

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Small admixture of nonadiabaticity facilitating topologically protected splitters and routers via optimizing coupling engineering

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Physical Review B 2024年第9期109卷 094303-094303页

作者： Jia-Ning Zhang Jin-Lei Wu Jin-Xuan Han Shuai Tang Jie Song Yong-Yuan Jiang School of Physics Harbin Institute of Technology Harbin 150001 China School of Physics and Laboratory of Zhongyuan Light Zhengzhou University Zhengzhou 450001 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan 030006 China Key Laboratory of Micro-Nano Optoelectronic Information System Ministry of Industry and Information Technology Harbin 150001 China Key Laboratory of Micro-Optics and Photonic Technology of Heilongjiang Province Harbin Institute of Technology Harbin 150001 China

We propose to implement fast and robust quantum state transfer in symmetrical beam splitters and routers through a specific topological edge channel in splicing Su-Schrieffer-Heeger–like models, for which a small admixture of nonadiabatic character into evolution facilitates the accelerated adiabatic pumping process to a great extent. Through optimizing coupling engineering, we develop the acceleration capacity for the symmetrical beam splitting process, and we investigate robustness enhancement against disorders and environment-induced losses. Furthermore, the model manifests good scalability and can be extended to a crossed-chain configuration of realizing a topological router with tunable numbers of output ports. Finally, we discuss the experimentally feasible implementation in quantum optomechanical systems by alternately assembling optical cavities and mechanical oscillators, enabling topologically protected splitters and routers of photons or phonons. This work provides a typical example of a functional quantum device, which could motivate further research into efficient quantum information processing and the construction of large-scale quantum networks.

关键词： Geometric & topological phases Quantum information processing Quantum state transfer

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Landing gear system health assessment based on SVM and XGBoost dual-flow modeling

Landing gear system health assessment based on SVM and XGBoo...

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2024 CSAA/IET International Conference on Aircraft Utility systems, AUS 2024

作者： Chen, Wenjie Chen, Yong Xu, Yongxiang Jia, Zhikai Wan, Zhiping Shanghai Aircraft Design and Research Institute Shanghai5188 China State Key Laboratory of Airliner Integration Technology and Flight Simulation Shanghai200126 China Commercial Aircraft Corporation of China Shanghai200126 China Harbin Institute of Technology Harbin201109 China Limited Shanghai200233 China

The landing gear system stands as one of an airplane's most crucial components, playing a pivotal role during take-off and landing phases. Its failure could result in catastrophic accidents, including belly landings, with severe consequences such as loss of life and aircraft destruction. Comprising a complex integration of mechanical, electrical, and hydraulic components, the landing gear system operates within a non-pneumatic zone, subjected to harsh working environments. Potential safety hazards, including mechanical wear, inadequate lubrication, and hydraulic equipment leakage, can compromise the system's extension capability, and in severe cases, lead to extension or retraction failure. Hence, effective management of landing gear health and early detection of system insecurities are imperative for ensuring aircraft safety. In this paper, a dual-flow model was developed based on SVM and XGBoost, facilitating accurate prediction of landing gear retraction and release times under varying external environmental conditions. This model serves as a foundation for assessing the health state of landing gear systems. © The Institution of Engineering & technology 2024.

关键词： Aircraft accidents

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Learning to Identify Footholds from Geometric Characteristics for a Six-legged Robot over Rugged Terrain

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Journal of Bionic Engineering 2020年第3期17卷 512-522页

作者： Jie Chen Chong Liu Haibin Zhao Yanhe Zhu Jie Zhao School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

Foothold identification is a key ability for legged robots that allows generating terrain adaptive behaviors(e.g.,gait and control parameters)and thereby improving mobility in complex *** this end,this paper addresses the issue of foothold characterization and identification over rugged terrain,from the terrain geometry point of *** a terrain region that might be a potential foothold of a robotic leg,the characteristic features are extracted as two first-order partial derivatives and two curvature parameters of a quadric regression surface at this *** features are able to give an intuitive and,more importantly,accurate characterization towards the specific geometry of the ground *** this basis,a supervised learning technique,Support Vector Machine(SVM),is employed,seeking to Ieam a foothold identification policy from human expert *** a result,an SVM classifier is leamt using the extracted features and human-demonstrated labels,which is able to identify whether or not a certain ground location is suited as a safe foot support for a robotic *** is shown that over 90%identification rate can be achieved with the proposed ***,preliminary experiment is implemented with a six-legged robot to demonstrate the effectiveness of the proposed approach.

关键词： six-legged robot foothold characterization foothold identification geometric characteristics support vector machine

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Research on Motion Mode Conversion Control of Wheel-legged Biped Robot

Research on Motion Mode Conversion Control of Wheel-legged B...

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IEEE International Conference on Mechatronics and Automation

作者： Yili Fu Xu Li Xinyu Dong Intelligent Robot Research Center Zhejiang Laboratory Hangzhou China State Kay Laboratory of Robotics and System Harbin Institute of Technology Harbin Heilongjiang Province China Harbin Institute of Technology Harbin Heilongjiang Province China

The bipedal wheel-legged robot with auxiliary legs studied in this paper has two motion modes, two wheels and four wheels, and can transform motion modes according to operation requirements. This paper focuses on how to realize motion mode transformation control under stable equilibrium. Firstly, kinematics analysis and dynamics modeling of the robot are carried out to complete the motion description and dynamics description of the robot in Cartesian space. Then the robot is simplified into a wheeled inverted pendulum model, and the driving wheel and other parts are decoupled to analyze its dynamic characteristics. In this paper, LQR controller will be used to ensure the robot is always in a balanced state, and then priority task space control (PTSC) based on quadratic programming (QP) will be adopted to track the robot trajectory. Finally, the smooth transformation of the robot under two motion modes of two wheels and four wheels is completed by experiments, which verifies the effectiveness of the control algorithm designed in this paper.

关键词：

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First Demonstration of Wafer-level Arrayed β-Ga2O3 Thin Films and MOSFETs on Diamond by Transfer Printing technology

First Demonstration of Wafer-level Arrayed β-Ga2O3 Thin Fil...

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2024 IEEE International Electron Devices Meeting, IEDM 2024

作者： Zhao, Tiancheng Yu, Xinxin Xu, Wenhui He, Yang Qu, Zhenyu Shen, Rui Wang, Ruize Guo, Huaixin Sun, Huarui Li, Zhonghui Zhou, Min You, Tiangui Ou, Xin State Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai200050 China CETC Key Laboratory of Carbon-based Electronics Nanjing Electronic Devices Institute Nanjing210016 China National Key Laboratory of Solid-State Microwave Devices and Circuits Nanjing210016 China School of Science Ministry of Industry and Information Technology Key Laboratory of Micro-Nano Optoelectronic Information System Harbin Institute of Technology Shenzhen518055 China

ISBN: (纸本)9798350365429

We, for the first time, fabricated wafer-level arrayed βGa2O3 single crystal thin films on diamond substrate using transfer printing technology. The transfer-printed β-Ga2O3 thin film possesses a thickness of 260 nm, a XRD rocking curve FWHM of ~78 arcsec, and a surface roughness of 0.36 nm. The amorphous interface layer after post-annealing is less than 2 nm. The thermal boundary resistance is extracted to 21.7 m2·K/GW, which is the lowest value reported for single-crystal β-Ga2O3 integrated with diamond. Thanks to the high thermal conductivity of diamond and the high-quality hetero-interface, the performance of β-Ga2O3-on-diamond RF MOSFETs is significantly enhanced. The maximum on-state current is 810 mA/mm, and the fmax before de-embedding reaches 61 GHz, which is the highest recorded value to date. Infrared thermal imaging shows that integrating with diamond significantly reduces the junction temperature of β-Ga2O3 devices. The Rth of β-Ga2O3-ondiamond devices is merely 5.52 K·mm/W, setting a new record for βGa2O3-based devices. These results demonstrate that hetero-integration with diamond via wafer-level transfer printing technology provides an effective thermal management platform for β-Ga2O3, facilitating its advancement in high-power and RF devices. © 2024 IEEE.

关键词： Substrates

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Accelerating Visual Reinforcement Learning with Separate Primitive Policy for Peg-in-Hole Tasks

arXiv

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arXiv 2025年

作者： Xu, Zichun Wang, Zhaomin Li, Yuntao Zhuang, Lei Zhao, Zhiyuan Yang, Guocai Zhao, Jingdong State Key Laboratory of Robotics and Systems Harbin Institute of Technology Heilongjiang Province Harbin150001 China School of Mechanical Engineering Shandong University Jinan250061 China

For peg-in-hole tasks, humans rely on binocular visual perception to locate the peg above the hole surface and then proceed with insertion. This paper draws insights from this behavior to enable agents to learn efficient assembly strategies through visual reinforcement learning. Hence, we propose a Separate Primitive Policy (S2P) to simultaneously learn how to derive location and insertion actions. S2P is compatible with model-free reinforcement learning algorithms. Ten insertion tasks featuring different polygons are developed as benchmarks for evaluations. Simulation experiments show that S2P can boost the sample efficiency and success rate even with force constraints. Real-world experiments are also performed to verify the feasibility of S2P. Ablations are finally given to discuss the generalizability of S2P and some factors that affect its performance. Copyright © 2025, The Authors. All rights reserved.

关键词： Reinforcement learning

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