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13th International Symposium on Linear Drives for Industry Applications, LDIA 2021

作者： Liu, Yingquan Lu, Junyong Long, Xinlin National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (纸本)9781728172101

Missile steering gear is the executive mechanism of missile control system, its performance directly affects the precision of missile guidance and control. An air-cored U-type permanent magnet linear motor is designed in this paper to simplify the structure of the missile steering system, reduce the connection cables and improve the reliability. The motor employs double side cambered PMs as excitation, and the air-cored coils directly drives the rudder blade. By canceling the reduction gear, the transmission efficiency of the steering system is enhanced. Moreover, the air-cored actuator can improve the response performance due to its light weight. The analytical thrust is derived in this paper. The design structure is optimized by finite element simulation. The transient calculation shows that the designed direct-driven actuator can achieve the expected thrust theoretically. © 2021 IEEE

关键词： Linear motors

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Dynamic Rod Worth Estimation with Extended Kalman Filter and Background Current Elimination

Dynamic Rod Worth Estimation with Extended Kalman Filter and...

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第40届中国控制会议

作者： Hao Xia Junqi Yang Chao Bao Dalian University of Technology Science and Technology on Reactor System Design Technology Laboratory

The dynamical rod worth method(DRWM) is a fast and accurate method to measure and validate the worth of control rod during the zero power physics test at pressure water nuclear *** control rod worth is obtained from the reactivity change caused by the fast insertion of the control rod into the bottom of the *** reactivity is calculated based the measured ex-core detector signals which normally varies from～10 nA to～10 nA during the rod insertion *** the later stage of the test,as the detector signal becomes～10 nA,the impact of the measurement noise and the gamma-ray background current on the reactivity calculation becomes *** this paper,we developed an extended Kalman filter(EKF) with suitable weighing matrices to filter out the measurement *** most measurement noise filtered out,a background current estimation method is used to eliminate the effect of the background *** combining the background current estimation method with EKF filter,accurate control rod worth is obtained from the real test data.

关键词： Dynamic Rod Worth Method Reactivity Extended Kalman filter Background Current

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Research on Fault Mode Analysis Method of Nuclear I&C Software Based on Time Automata

Research on Fault Mode Analysis Method of Nuclear I&C Softwa...

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Prognostics and system Health Management Conference (PHM-Qingdao)

作者： Genhua Liang Yong Li Yanqun Wu Fei Yang Zhichuan Zeng Xuanlin Zhu HongXin Deng National key Laboratory of Nuclear Reactor Technology Nuclear Power Institute of China Chengdu China School of Electronic and Electrical Engineering Shanghai University of Engineering Science Shanghai China

ISBN: (数字)9798350354010

ISBN: (纸本)9798350354027

This paper presents a novel fault mode analysis method for nuclear instrumentation and control (I&C) software based on timed automata. The proposed approach addresses the limitations of traditional fault analysis techniques in handling complex, real-time systems by accurately capturing the dynamic characteristics and intricate interaction patterns of nuclear I&C software. key contributions include: (1) development of a timed automata-based modeling framework tailored for nuclear I&C software; (2) design of a comprehensive fault mode library compatible with timed automata models; and (3) implementation of an automated fault mode analysis algorithm leveraging model checking techniques. The method's efficacy is demonstrated through a case study on a digital reactor protection system, specifically the reactor Coolant Pump speed protection subsystem. Results show significant improvements in fault mode identification rates, particularly for time-related faults, and enhanced capabilities in quantitative analysis and dynamic behavior capture compared to traditional methods. This approach provides a more rigorous and systematic tool for improving the reliability and safety of digital I&C systems in nuclear power plants, with potential applications in other safety-critical domains.

关键词： Analytical models systematics Statistical analysis Instruments Software algorithms Automata Software Software reliability Protection Inductors

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Research on Characteristics Analysis and Suppression Method of Short Circuit Fault of Coaxial Cable in Electromagnetic Launch 4

Research on Characteristics Analysis and Suppression Method ...

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4th IEEE China International Electrical and Energy Conference, CIEEC 2021

作者： Cui, Junwei Zhang, Xiao Lu, Junyong Dai, Yufeng National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (纸本)9781728171494

In electromagnetic launch systems, coaxial cables are used for energy transmission from the power supply to the launcher. Once the cable has a short-circuit fault, it will cause the cable to over-current or even explode, causing the launch to fail. This paper first established the dynamic launch model of the capacitive energy storage electromagnetic launch system, and analyzed in detail the influence of the coaxial cable short-circuit fault location on the load current, projectile exit speed, and coaxial cable current. The results show that the closer the short-circuit fault location is to the load side, The larger the cable fault current, the smaller the projectile exit *** 1m the cable fault current reached 1.9 times the normal current, resulting in a 76% drop in exit ***,an electromagnetic launch system model with a high-temperature superconducting current limiter was established,and the installation position of the current limiter was optimized. The fault current before and after the installation of the current limiter was simulated and compared. The results showed that: after the current limiter was added, the cable short-circuit current The peak value dropped by 29%, and the projectile exit speed was reduced by 61 % compared to normal conditions, which can effectively reduce the impact of short-circuit current on the cable, increase the projectile exit speed, and provide guidance for the safety design of the electromagnetic launch system. © 2021 IEEE.

关键词： Projectiles

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Research on design Method of External Coil of Electromagnetic Rail Launch Equivalent Test Platform 4

Research on Design Method of External Coil of Electromagneti...

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4th IEEE China International Electrical and Energy Conference, CIEEC 2021

作者： Du, Wentong Long, Xinlin Cheng, Long Lu, Junyong Li, Songcheng Liu, Yingquan Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan China

ISBN: (纸本)9781728171494

It is difficult to study the interaction mechanism between electromagnetic energy and metal materials directly in the electromagnetic rail launcher. Based on the existing test conditions, under the condition of tens of kiloamperes of current, the loading mode of long pulse current combined with external magnetic field is adopted, which is equivalent to the extreme environment of electromagnetic thermodynamic synthesis in the process of electromagnetic rail launching. In this paper, through theoretical calculation and ANSYS simulation, the magnetic field distribution of circular, rectangular, elliptic and straight slot coils are compared, and the influence of elliptic parameters on the magnetic field is emphatically analyzed. The ratio of long axis to short axis of ellipse when the magnetic field distribution is relatively uniform is obtained by simulated annealing algorithm. The conclusion shows that when the external coil is elliptic and the ratio of long axis to short axis is about 1.6, the magnetic field, current density and electromagnetic force on the metal sample can be equivalent to the electromagnetic rail launch condition. © 2021 IEEE.

关键词： Simulated annealing

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Multi-Resolution Planar Region Extraction for Uneven Terrains

Multi-Resolution Planar Region Extraction for Uneven Terrain...

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IEEE International Conference on Robotics and Automation (ICRA)

作者： Yinghan Sun Linfang Zheng Hua Chen Wei Zhang Shenzhen Key Laboratory of Control Theory and Intelligent Systems School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen China School of Computer Science University of Birmingham UK

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

This paper studies the problem of extracting planar regions in uneven terrains from unordered point cloud measurements. Such a problem is critical in various robotic applications such as robotic perceptive locomotion. While existing approaches have shown promising results in effectively extracting planar regions from the environment, they often suffer from issues such as low computational efficiency or loss of resolution. To address these issues, we propose a multi-resolution planar region extraction strategy in this paper that balances the accuracy in boundaries and computational efficiency. Our method begins with a pointwise classification preprocessing module, which categorizes all sampled points according to their local geometric properties to facilitate multi-resolution segmentation. Subsequently, we arrange the categorized points using an octree, followed by an in-depth analysis of nodes to finish multi-resolution plane segmentation. The efficiency and robustness of the proposed approach are verified via synthetic and real-world experiments, demonstrating our method’s ability to generalize effectively across various uneven terrains while maintaining real-time performance, achieving frame rates exceeding 35 FPS.

关键词： Point cloud compression Deep learning Accuracy Octrees Noise Robustness Real-time systems

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Investigation on the 36MVA PP-IGBT-Based Power Converter for High-Speed Maglev Applications 13

Investigation on the 36MVA PP-IGBT-Based Power Converter for...

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13th International Symposium on Linear Drives for Industry Applications, LDIA 2021

作者： Zhou, Liang Deng, Chen Li, Weichao Yan, Ming Han, Jinyang Zhong, Ying National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (纸本)9781728172101

Press-pack insulated gate bipolar transistors (PP-IGBTs) are a more attractive choice for high-power converters, due to increased current ratings, and an inherent short-circuit failure mode. This paper shows how a power electronics building block (PEBB) based on PP-IGBTs has been carefully designed and assembled to build a 36MVA power converter for high-speed maglev applications. The minimization of the stay inductance, the equalization of power loss and snubberless operation are within the main technical design requisites. Simulation and experiment results show that the developed PEBB based on PP-IGBTs is proved to be suitable for the 36MVA power converter. © 2021 IEEE

关键词： Power converters

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Compound extreme inundation risk of coastal wetlands caused by climate change and anthropogenic activities in the Yellow River Delta,China

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Advances in Climate Change Research 2024年第1期15卷 134-147页

作者： Xiao-Li WANG Ai-Qing FENG Xi-Yong HOU Qing-Chen CHAO Bai-Yuan SONG Yu-Bin LIU Qi-Guang WANG He XU Yu-Xin ZHANG Dong Li Li-Jie DONG Yu GUO CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China Shandong Key Laboratory of Coastal Environmental Processes Yantai 264003China China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Tongji Urban Planning Design Research Institute Shanghai 200092China School of Geography and Tourism Qilu Normal UniversityJinan 250200China China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 10008China University of Chinese Academy of Sciences Beijing 100049China Marine Science and Technology College Zhejiang Ocean UniversityZhoushan 316022China

The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic ***,these wetlands are also vulnerable to the dual threats of climate change and human *** substantial attention to the historical shifts in YRD's coastal wetlands,uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic *** on a range of remote sensing data sources,this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and ***,the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change(LUCC)simulation using system Dynamic-Future Land Use Simulation(SD-FLUS)model and the extreme water levels projection integrated future sea-level rise,storm surge,and astronomical high tide in 2030,2050,and 2100 under scenarios of SSP1-2.6,SSP2-4.5,and *** revealed that YRD's coastal wetlands underwent a marked reduction,shrinking by 1688.72 km²from 2000 to *** decline was mostly attributed to the substantial expansion in the areas of artificial wetlands(increasing by 823.78 km2),construction land(increasing by 767.71 km²),and shallow water(increasing by 274.58 km²).Looking ahead to 2030-2100,the fate of coastal wetlands appears to diverge based on different *** the SSP1-2.6 scenario,the area of coastal wetland is projected to experience considerable *** contrast,the SSP5-8.5 scenario anticipates a notable decrease in coastal *** to the inundated area suffered from the current extreme water levels,the study projects a decrease of 6.8%-10.6%in submerged coastal wetlands by 2030 and 9.4%-18.2%by 2050 across all *** 2100,these percentages are projected to decrease by 0.4%(SSP2-4.5)and 27.1%(SSP5-8.5),but increase by 35.7%(SSP1-2.6).Results suggest that coastal wetlands in th

关键词： Climate change Anthropogenic activities Compound extreme risk Coastal wetlands Yellow River Delta

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Creep Behavior of a Novel Ods Ferrite Steel Reinforced with Ultra-Fine Y2(Zr0.6, Ti0.4)2O7 Particles

SSRN

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SSRN 2024年

作者： Zhao, Zhenyu Cao, Yuankui Zhang, Yuyang Fu, Ao Zhang, Ruiqian Zhong, Yuntao Li, Jia Fang, Qihong Liu, Bin State Key Laboratory of Powder Metallurgy Central South University Changsha410083 China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of China Chengdu610041 China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body China

Oxide dispersion strengthened (ODS) ferrite steel is a competitive candidate structural material for the Generation IV fission reactors. In this work, a novel ODS ferrite steel reinforced with ultra-fine Y2(Zr0.6, Ti0.4)2O7 particles was prepared by powder metallurgy method, which exhibit superior mechanical properties at elevated temperatures. Creep tested of the ODS ferrite steel at 800 ℃ was conducted to reveal its high-temperature creep failure mechanism. This ODS steel has an average grain size of 1.31 μm, and the mean size and number density of the ultra-fine oxide particles are 5.48 nm and 4.85×1023 m-3, respectively. When the apply creep stress is 100 MPa, the creep rupture time of the ODS steel is 2448.5 h, and the minimum creep rate is only 1.05×10-7 s-1. Under the similar creep stress at 800 ℃, the creep rate of this ODS steel is at least one order of magnitude lower than that of other typical ODS steels reported in the literatures, showing excellent creep properties. By fitting the data of minimum creep rate, apply stress and effective stress normalized by shear modulus, the creep threshold stress of the ODS steel was determined as 56.2 MPa, and the true stress exponent was calculated as 4.5 ± 1.0, which indicates that the creep mechanism is dominated by dislocation. Orowan bypass mechanism and dislocation climb over the particle mechanism play a major role in this dislocation mediated creep behavior. Due to the strong hindering effect of dislocation motion caused by the ultra-fine and dispersed Y2(Zr0.6, Ti0.4)2O7 particles, the novel ODS ferrite steel thereby achieved excellent creep properties. © 2024, The Authors. All rights reserved.

关键词： Creep

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Recent advancement of flow-induced piezoelectric vibration energy harvesting techniques:principles,structures,and nonlinear designs

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Applied Mathematics and Mechanics(English Edition) 2022年第7期43卷 959-978页

作者： Dongxing CAO Junru WANG Xiangying GUO S.K.LAI Yongjun SHEN Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures Beijing 100124China School of Automation Beijing Information Science and Technology UniversityBeiing 100192China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Hong Kong Branch of National Rail Transit Electrification and Automation Engineering Technology Research Center The Hong Kong Polytechnic UniversityKowloonHong KongChina State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Energy harvesting induced from flowing fluids(e.g.,air and water flows)is a well-known process,which can be regarded as a sustainable and renewable energy *** addition to traditional high-efficiency devices(e.g.,turbines and watermills),the micro-power extracting technologies based on the flow-induced vibration(FIV)effect have sparked great concerns by virtue of their prospective applications as a self-power source for the microelectronic devices in recent *** article aims to conduct a comprehensive review for the FIV working principle and their potential applications for energy ***,various classifications of the FIV effect for energy harvesting are briefly introduced,such as vortex-induced vibration(VIV),galloping,flutter,and wake-induced vibration(WIV).Next,the development of FIV energy harvesting techniques is reviewed to discuss the research works in the past three *** application of hybrid FIV energy harvesting techniques that can enhance the harvesting performance is also ***,the nonlinear designs of FIV-based energy harvesters are reported in this study,e.g.,multi-stability and limit-cycle oscillation(LCO)***,advanced FIV-based energy harvesting studies for fluid engineering applications are briefly ***,conclusions and future outlook are summarized.

关键词： vibration-driven energy harvesting flow-induced vibration(FIV) piezoelectric approach nonlinear design

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