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Research 2023年第2期6卷 53-63页

作者： Sen Wang Peng Yan Hailin Huang Ning Zhang Bing Li School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen 518052P.R.China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of TechnologyShenzhen 518052P.R.China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001P.R.China

This study created a new type of inflatable metamorphic origami that has the advantage of being a highly simplified deployable system capable of realizing multiple sequential motion patterns with a monolithic actuation.

关键词： simplified lata system

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Cooperative Angles-Only Relative Navigation Algorithm for Multi-Spacecraft Formation in Close-Range

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Computer Modeling in Engineering & Sciences 2023年第1期134卷 121-134页

作者： Sha Wang Chenglong He Baichun Gong Xin Ding Yanhua Yuan State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang050081China Nanjing University of Aeronautics and Astronautics Nanjing210016China Beijing Institute of Control and Electronic Technology Beijing100038China

As to solve the collaborative relative navigation problem for near-circular orbiting small satellites in close-range under GNSS denied environment,a novel consensus constrained relative navigation algorithm based on the lever arm effect of the sensor offset from the spacecraft center of mass is ***,the orbital propagation model for the relative motion of multi-spacecraft is established based on Hill-Clohessy-Wiltshire dynamics and the line-of-sight measurement under sensor offset condition is modeled in Local Vertical Local Horizontal ***,the consensus constraint model for the relative orbit state is constructed by introducing the geometry constraint between the spacecraft,based on which the consensus unscented Kalman filter is ***,the observability analysis is done and the necessary conditions of the sensor offset to make the state observable are ***,digital simulations are conducted to verify the proposed algorithm,where the comparison to the unconstrained case is also *** results show that the estimated error of the relative position converges very quickly,the location error is smaller than 10m under the condition of 10−3 rad level camera and 5m offset.

关键词： Relative navigation spacecraft formation observability analysis angles-only measurement

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Study on the Looseness Caused by Local Slip and Load Bearing Capacity of Threaded Connections Under Transverse Cyclic Loading

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Journal of Tribology 2025年第9期147卷 091103页

作者： Sun, Yu Qin, Wenjie Zhao, Zhenlong Ba, Mingsen School of Mechanical Engineering Beijing Institute of Technology Beijing100081 China State Key Laboratory of Engine and Powertrain System Weifang261000 China Weichai Power Cooperation Limited Shandong Weifang261000 China

Under transverse cyclic loading, slip will occur on the contact surfaces in a threaded connection, causing rotational loosening of the connection. It is necessary to detect and analyze the loosening behavior of threaded connections caused by slippage. In this article, a self-driven sensor based on the principles of triboelectric nanogenerators (TENGs) was used to monitor the rotational looseness of a tight threaded stud connection subjected to transverse cyclic loads. The finite element simulation was conducted on the contact slip in the stud connection in the experiment under transverse cyclic loading to reveal the loosening phenomenon of threaded connections caused by local slip propagation with the increase of load cycles. Under a certain preload, only when the amplitude of the lateral cyclic load does not exceed a critical value, will the thread contact surface not experience local slip propagation. Therefore, a local slip influence coefficient was proposed for calculating the critical transverse cyclic load amplitude, and its influencing factors were discussed. This study provides a new approach to the anti-loosening design of threaded connections. Copyright © 2025 by ASME.

关键词： Cyclic loads

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Research on Size Calibration Algorithm of Dark-field Flaw on Optics Surface Based on Convolutional Neural Network

Research on Size Calibration Algorithm of Dark-field Flaw on...

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2024 Applied Optics and Photonics China: Optical Sensing, Imaging technology, and Applications, AOPC 2024

作者： Wang, Bei Yin, Zhaoyang Zhou, Shicheng Zhao, Linjie Chen, Mingjun Cheng, Jian School of Mechatronics Engineering Harbin Institute of Technology Harbin China State Key Laboratory of Robotics and System Harbin Institute of Technology 150001 China

ISBN: (数字)9781510687820

ISBN: (纸本)9781510687813

Optics in high-power solid-state laser devices will be damaged and adhere to contaminates on the surface during manufacturing and operation, which reduces the service life. To facilitate the positioning and recognition of the flaw (damage and contaminates) in the process of automatic repair, the dark-field flaw size calibration algorithm was studied. In this paper, a flaw size calibration model based on convolutional neural network was established. The size, exposure time, and loss function of damage and contaminate were optimized respectively. The training parameter of the damage regression model is determined to be size of less than 500μm, 30ms of exposure time and SmoothL1 loss function, and the parameter of contaminate is 0-100μm, 20ms of exposure and SmoothL1 loss function. After data balancing, the calibration precision was improved. To improve the calibration consistency of the full-size segment, a comprehensive size calibration strategy is proposed. The CNN regression algorithm is used for small size, and the pixel-level calibration algorithm is used for large size. Compared with the single regression calibration algorithm, the relative error and absolute error of the calibration results of small damage ( © 2024 SPIE.

关键词： Solid state lasers

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Effect of the grain boundary character distribution on the sulfur corrosion behaviour and mechanisms of copper windings under different high temperatures

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High Voltage 2024年第3期9卷 566-580页

作者： Xu Dai Yuan Yuan Jiang Zhou Guoyong Liu Tao Zhu Huiying Xiang Qi Yu Xue Gao Ruijin Liao State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqingChina College of Materials Science and Engineering Chongqing UniversityChongqingChina Dongfang Electric Machinery Co. LtdDeyangChina

As a typical failure phenomenon in transformers,sulfur corrosion has garnered significant attention in the field of high-voltage *** boundary character distribution(GBCD)copper windings have been introduced to enhance sulfur corrosion resistance by slowing down intergranular *** this study,the sulfur corrosion behaviour and mechanisms of the GBCD copper windings under various temperatures were experi-mentally and theoretically *** show that GBCD can enhance the corrosion resistance of copper in liquid *** the increase in temperatures,the insulating properties of oil and papers in traditional copper windings experience notable degradation,while GBCD copper windings show more stable insulating *** addition,modelling of grain boundary energy indicates that the grain boundary structure of GBCD copper windings has a lower average interface energy of 0.170 eV/Å***-culations of reaction thermodynamics show that GBCD copper windings possess a higher failure temperature(135.2℃)and inhibition degree(activation energy)of the sulfur corrosion(32,557.62 J/mol),revealing the stability and enhanced sulfur corrosion resis-tance at elevated temperatures.

关键词： corrosion grain copper

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Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

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High Voltage 2024年第1期9卷 137-149页

作者： Ruoyu Han Yuchen Cao Yakun Liu Xi Chen Ting Li Chen Li Pengfei Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijingChina Department of Electrical Engineering Shanghai Jiaotong UniversityShanghaiChina Beijing Institute of Astronautical System Engineering BeijingChina Aerospace Research Institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the *** paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed *** visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical *** results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal *** transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate *** inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive *** addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion *** information reveals two different plasma states of main discharge arc channel and adjacent surface electrical *** correspondence of the physical mechanism of electrical explosion and optical radiation is *** images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism *** research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

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Flight control of a large-scale flapping-wing flying robotic bird:system development and flight experiment

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Chinese Journal of Aeronautics 2022年第2期35卷 235-249页

作者： Wenfu XU Erzhen PAN Juntao LIU Yihong LI Han YUAN School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen 518055China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

Large-scale flapping-wing flying robotic birds have huge application potential in outdoor tasks,such as military reconnaissance,environment exploring,disaster rescue and so *** this paper,a multiple modes flight control method and system are proposed for a large-scale robotic bird which has 2.3 m wingspan and 650 g *** from small flapping wing aerial vehicle,the mass of its wings cannot be neglected and the flapping frequency are much ***,the influence of transient aerodynamics instead of only mean value are considered in attitude estimation and controller ***,flight attitude and trajectory are highly coupled,and the robot has only three actuators----one for wings flapping and two for tail adjustment,it is very difficult to simultaneously control the attitude and ***,a fuzzy control strategy is addressed to determine the command of each actuator by considering the priority of attitude stabilization,trajectory tracking and the flight ***,the on-board controller is designed based on *** not only satisfies the strict restrictions on mass,size,power and space but also meets the autonomous,semi-autonomous and manual flight control ***,the developed control system was integrated to the robotic prototype,*** experiments under different environment conditions such as sunny and windy weather were completed to verify the control method and system.

关键词： Autonomous flight control Flapping-wing Free RTOS HIT-Phoenix robotic bird

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Research on Multisensor Fusion state Estimation of Automatic Navigation Vehicle Based on RNN Model 13th

Research on Multisensor Fusion State Estimation of Automatic...

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13th International Conference on Frontier Computing, FC 2023

作者： Zhang, Liyuan Cui, Zhiquan Wang, Honggang Harbin Institute of Technology Shandong Weihai264209 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

ISBN: (纸本)9789819992980

Multi sensor fusion state estimation of autonomous navigation vehicle based on RNN model. Multi sensor fusion is a process of combining information from different sensors to estimate a single value. In this paper, we propose a recursive neural network (RNN) model to estimate the state of multiple sensors. This method uses RNN architecture with two hidden layers and one output layer to combine sensor data. The input data is first divided into a sequence and then input into the RNN model to predict the output. We use three types of sensors: IMU, LIDAR and GPS. First, the RNN model is trained using three sensors for the navigation system. Then, we use this trained model to estimate the current position using only one sensor data. Finally, we combine the data of all three sensors to obtain the final estimated position of the vehicle at any given time step. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.

关键词： Neural network models

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Safety assessment of overcharged batteries and a novel passive warning method based on relaxation expansion force

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Journal of Energy Chemistry 2025年第6期105卷 595-607页

作者： Long Chen Shaohong Zeng Jiahua Li Kuijie Li Ruixin Ma Jizhen Liu Weixiong Wu Energy and Electricity Research Center Jinan University School of Electrical and Electronic Engineering Huazhong University of Science and Technology Institute of Refrigeration and Cryogenics Shanghai Jiao Tong University State Key Laboratory of New Energy Power System North China Electric Power University

Due to batteries inconsistencies and potential faults in battery management systems,slight overcharging remains a common yet insufficiently understood safety risk,lacking effective warning *** illuminate the degradation behavior and failure mechanism of various overcharged states（100% SOC,105%SOC,110% SOC,and 115% SOC）,multiple advanced in-situ characterization techniques（accelerating rate calorimeter,electrochemical impedance spectroscopy,ultrasonic scanning,and expansion instrument）were ***,re-overcharge-induced thermal runaway（TR） tests were conducted,with a specific emphasis on the evolution of the expansion force *** indicated significant degradation at 110% SOC including conductivity loss,loss of lithium inventory,and loss of active material accompanied by internal gas *** failure behaviors slow down the expansion force rate during reovercharging,reducing the efficacy of active warnings that depend on rate thresholds of expansion ***,the warning time for 115% SOC battery is only 144 s,which is 740 s shorter than that for fresh battery,and the time to TR is advanced by 9 ***,the initial self-heating temperature（T1） is reduced by 62.4℃ compared to that of fresh battery,reaching only 70.8℃.To address the low safety of overcharged batteries,a passive overcharge warning method utilizing relaxation expansion force was proposed,based on the continued gas generation after stopping charging,leading to a sustained increase in *** to active methods that rely on thresholds of expansion force rate,the passive method can issue warnings 115 s *** combining the passive and active warning methods,guaranteed effective overcharge warning can be issued 863-884 s before *** study introduces a novel perspective for enhancing the safety of batteries.

关键词： Lithium-ion battery Overcharging warning Relaxation expansion force Safety assessment Slight overcharging Thermal runaway

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Multi-Agent Deep Reinforcement Learning for Photovoltaics and Battery Storage Aggregators Coordinated Operation in Active Distribution Network with Incomplete Information 49

Multi-Agent Deep Reinforcement Learning for Photovoltaics an...

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49th Annual Conference of the IEEE Industrial Electronics Society, IECON 2023

作者： Xia, Qinqin Wang, Yu Hu, Bo Shao, Changzheng Xie, Kaigui Li, Chunyan State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing China

ISBN: (纸本)9798350331820

To address the cost-effective voltage regulation in active distribution network (ADN), this paper proposes a multiagent deep reinforcement learning (MADRL) based photovoltaic (PV) and battery storage (BS) aggregators coordinated operation framework. The proposed framework treats PV and BS under each bus as an aggregator and enables model-free separated operation between multiple PV-BS aggregators and ADN by training the control agent of each PV-BS aggregator using MADRL. The coordinated operation only requires incomplete information from the internal information of each PV-BS aggregator and overall ADN information, thereby reducing communication overhead. A test system evaluates the performance of three model-free MADRL algorithms on the proposed PV-BS aggregators coordinated operation in ADN. It also validates the effectiveness of the MADRL for cost-effective voltage regulation in ADN with multiple PV-BS aggregators. © 2023 IEEE.

关键词： Reinforcement learning

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