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Modelling Method and Meshing Characteristics of a Novel Curve-Surface Conjugate Internal Gear Drive

Chinese Journal of mechanical engineering 2024年第5期37卷 216-232页

作者： Xinxin Ye Luhe Zhang Dongyu Wang Jingming Jiang Wenjun Luo Bingkui Chen State Key Laboratory of Mechanical Transmission for Advanced Equipment Chongqing UniversityChongqing 400030China Shanghai Aerospace System Engineering Research Institute Shanghai 201109China

Space exploration has become a major focus in the field of technology,with gear transmissions in aerospace equipment playing a crucial *** the extreme environment of space,gear transmissions face challenges like large temperature differentials,deformation and maintenance difficulties,which will severely impact transmission accuracy and service *** meet the growing demands for high-performance gear transmissions with high transmission efficiency and error adaptability in the aerospace field,this paper proposes a novel curve-surface conjugate internal gear drive consisting of an involute internal gear and a curve-surface *** fundamental theory of curve-surface conjugation is introduced,and the construction method for curve-surface gear based on a selected contact path and meshing tube is *** analysis models including induced curvature,sliding ratio and tooth contact analysis with errors(ETCA)are simulated to evaluate the meshing ***,prototypes are manufactured and experimental setups are established to validate the transmission *** results indicate that as the rotational speed increases,the transmission efficiency of the curve-surface conjugate internal gear drive improves,which is contrary to the trend observed in involute gear *** the transmission efficiency of the curve-surface conjugate internal gear drive surpasses that of the involute gear drive at higher rotational ***,this novel gear drive exhibits excellent error adaptability,maintaining intact contact paths and high transmission efficiency even in the presence of assembly *** study provides new ideas for the design and manufacture of high-performance gear transmissions from the perspective of spatial geometric elements.

关键词： Internal gear drive Tooth surface geometry Error adaptability Transmission efficiency

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Hierarchical structures on platinum-iridium substrates enhancing conducting polymer adhesion

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Bio-Design and Manufacturing 2024年第6期7卷 889-898页

作者： Linze Li Changqing Jiang Luming Li School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China National Engineering Research Center of Neuromodulation School of Aerospace EngineeringTsinghua UniversityBeijing 100084China IDG/McGovern Institute for Brain Research at Tsinghua University Beijing 100084China

Conducting polymers(CPs),including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS),are promising coating materials for neural ***,the weak adhesion of CP coatings to substrates such as platinum-iridium is a significant challenge that limits their practical *** address this issue,we used femtosecond laser-prepared hierarchical structures on platinum-iridium(Pt-Ir)substrates to enhance the adhesion of PEDOT:PSS ***,we used cyclic voltammetry(CV)stress and accelerated aging tests to evaluate the stability of both drop cast and electrodeposited PEDOT:PSS coatings on Pt-Ir substrates,both with and without hierarchical *** results showed that after 2000 CV cycles or five weeks of aging at 60℃,the morphology and electrochemical properties of the coatings on the Pt-Ir substrates with hierarchical structures remained relatively *** contrast,we found that smooth Pt-Ir substrate surfaces caused delamination of the PEDOT:PSS coating and exhibited both decreased charge storage capacity and increased ***,enhancing the stability of PEDOT:PSS coatings used on common platinum-iridium neural electrodes offers great potential for improving their electrochemical performance and developing new functionalities.

关键词： Hierarchical structures Femtosecond laser Conducting polymers Neural electrodes Stability

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Applying the Infrared Self-heating Method to a Comprehensive Fatigue Analysis of NiTi Shape Memory Alloys

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Acta Mechanica Solida Sinica 2024年第6期37卷 873-880页

作者： Yongdan Zhou Zihong Liu Yahui Zhang Xiaojun Gu Jihong Zhu Weihong Zhang State IJR Center of Aerospace Design and Additive Manufacturing School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an710072China Unmanned System Research Institute Northwestern Polytechnical UniversityXi’an710072China

This paper aims to seek expedited fatigue analysis methods using the infrared self-heating *** fatigue analysis of NiTi shape memory alloys is obtained through a hybrid approach:fatigue tests to failure yield relatively shorter fatigue lives,while determining the fatigue limit,normally involving extremely high cycles approaching 107 cycles,is directly achieved via self-heating *** methodology significantly reduces testing cycles,costing only a fraction of the several-thousand-cycle tests typically *** validity of this approach is successfully demonstrated through fatigue testing of 18Ni steel:the entire S–N curve is examined using the traditional fatigue test until a life of up to 10^(7) cycles,and the indicated fatigue limit agrees well with the one directly determined through the self-heating ***,this developed approach is applied to the fatigue analysis of shape memory alloys under complex loading,enabling the concurrent estimation of the limits of phase transformation-dominated low-cycle fatigue and high-cycle fatigue in the elastic regime on a single *** results obtained align well with other supporting evidence.

关键词： Shape memory alloys Self-heating method Fatigue Fatigue limit S–N curve

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Dynamically updated digital twin for prognostics and health management:Application in permanent magnet synchronous motor

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Chinese Journal of Aeronautics 2024年第6期37卷 244-261页

作者： Haoyu GUO Shaoping WANG Jian SHI Tengfei MA Giorgio GUGLIERI Rujun JIA Fausto LIZZIO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 310023China Department of Mechanical and Aerospace Engineering Polytechnic University of TurinTurin 10129Italy Beihang Ningbo Research Institute Ningbo 315800China

Current research on Digital Twin(DT)based Prognostics and Health Management(PHM)focuses on establishment of DT through integration of real-time data from various sources to facilitate comprehensive product monitoring and health ***,there still exist gaps in the seamless integration of DT and PHM,as well as in the development of DT multi-field coupling modeling and its dynamic update *** the product experiences long-period degradation under load spectrum,it is challenging to describe the dynamic evolution of the health status and degradation progression *** addition,DT update algorithms are difficult to be integrated simultaneously by current *** paper proposes an innovative dual loop DT based PHM framework,in which the first loop establishes the basic dynamic DT with multi-filed coupling,and the second loop implements the PHM and the abnormal detection to provide the interaction between the dual loops through updating *** proposed method pays attention to the internal state changes with degradation and interactive mapping with dynamic parameter ***,the Independence Principle for the abnormal detection is proposed to refine the theory of *** at the first loop focus on accurate modeling of multi-field coupling,while the events at the second loop focus on real-time occurrence of anomalies and the product degradation *** interaction and collaboration between different loop models are also ***,the Permanent Magnet Synchronous Motor(PMSM)is used to verify the proposed *** results show that the modeling method proposed can accurately track the lifecycle performance changes of the entity and carry out remaining life prediction and health management effectively.

关键词： Digital Twin(DT) Dynamic Update Independence Principle Multi-field Coupling Permanent Magnet Synchronous Motor(PMSM) Prognostics and Health Management(PHM)

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Flow characteristics of integrated motor-pump assembly with phosphate ester medium for aerospace electro-hydrostatic actuators

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Chinese Journal of Aeronautics 2023年第9期36卷 392-407页

作者： Jiangao ZHAO Jian FU Yuchen LI Haitao QI Yan WANG Yongling FU The Laboratory of Aerospace Servo Actuation and Transmission Beijing 100191China Research Institute for Frontier Science Beihang UniversityBeijing 100191China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China

Motor-pump assembly is the core component of the aerospace Electro-hydrostatic Actuator(EHA).Thus,the design of the motor pump can be very challenging under conditions of high speed and wide pressure range,especially in particular working *** ultimate goal is to pursue better flow characteristics under a wide range of working *** this paper,we built a sub-model of the main friction interfaces and a model of single-shaft coaxial motor-pump assembly adopting the method of hierarchical *** experimental investigation of the output characteristics was mainly carried out in a phosphate ester medium ***,the flow characteristics were compared and analyzed with the simulation *** indicated that the flow characteristics of the motor-pump assembly could be accurately simulated by the model and quite severe in a low speed and high-pressure environment.

关键词： EHA Friction interfaces More electric aircraft Motor-pump Multidisciplinary modeling

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Novel Multipoint-drive Rotary Actuator for Extraterrestrial Celestial Ultrasonic Driller

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Chinese Journal of mechanical engineering 2024年第6期37卷 270-285页

作者： Naiwen Deng Guangchao Han Shuqi Zhu Xingwang Zhang Yong Pang Wei Bai School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China System Design Institute of Hubei Aerospace Technology Academy Wuhan 430040China Beijing Spacecrafts Beijing 100094China

Ultrasonic drilling has emerged as a prominent technique in extraterrestrial environments due to its advantageous ***,its application in extraterrestrial sampling missions is constrained by challenges such as drilling,chip removal e ciency,and high and low temperature *** these limitations,this study introduces a novel multi-point driven rotary helical longitudinal torsion *** initial phase involved a detailed analysis of the actuator’s structure and operational ***,the actuator’s vibration mode and elliptical motion trajectory were validated through finite element *** study further explores a methodology for adjusting the parameters of the helical groove and the displacement amplitude of the impact *** the theoretical analysis,prototypes of the actuator and drill were *** adaptability to high and low temperatures,as well as their output characteristics,were rigorously *** results demonstrate that with an increase in temperature,the dynamic impedance of the actuator initially rises before decreasing,while the mechanical quality factor exhibits the opposite ***,the concurrent activation of points P1and P2significantly enhances the no-load speed,achieving a maximum of 506 revolutions per minute(r/min).Under conditions of power below 35 W and a drilling pressure of 10 N,the drilling speed achieved in basalt is 6.2 millimeters per minute(mm/min).The proposed multipoint-driven actuator can e ectively improve the drilling and chip removal e ciency of the driller,which is an important application prospect in future extraterrestrial drilling missions.

关键词： Extraterrestrial drilling Ultrasonic drilling Longitudinal-torsional compound vibration Multipoint-drive rotary actuator

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Modeling and Analysis on In-line Four-cylinder Vehicle Engine system 8

Modeling and Analysis on In-line Four-cylinder Vehicle Engin...

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8th International Conference on Electromechanical Control Technology and Transportation, ICECTT 2023

作者： Shi, Chunyang Liu, Guotong Bian, Yushu Fan, Ming School of Mechanical Engineering and Automation Beihang University Beijing100191 China Research Institute of System Engineering Beijing China

ISBN: (纸本)9781510668331

The vehicle engine is affected by the external excitation force in the actual work, which will make the engine work in a bad condition and easily produce vibration and noise. Therefore, it is necessary to model the engine to control the engine vibration first. In this paper, a type of vehicle engine is taken as the research object, and the six-degree-of-freedom dynamic equation of the engine is established according to the Lagrange Method. The natural frequency of the engine vibration system is calculated by numerical and simulation analysis. The engine vibration is analyzed, and the two results are compared to verify the correctness of the model. This research lays a foundation for the vibration control of the engine. © 2023 SPIE.

关键词： Numerical methods

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Knowledge Reasoning Method Based on Deep Transfer Reinforcement Learning: DTRLpath

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Computers, Materials and Continua 2024年第1期80卷 299-317页

作者： Lin, Shiming Ye, Ling Zhuang, Yijie Lu, Lingyun Zheng, Shaoqiu Huang, Chenxi Kwee, Ng Yin School of Informatics Xiamen University Key Lab of Information System Requirement Nanjing Research Institute of Electronics Engineering School of Information Engineering Changji University School of Mechanical & Aerospace Engineering Nanyang Technological University

In recent years, with the continuous development of deep learning and knowledge graph reasoning methods, more and more researchers have shown great interest in improving knowledge graph reasoning methods by inferring missing facts through reasoning. By searching paths on the knowledge graph and making fact and link predictions based on these paths, deep learning-based Reinforcement Learning (RL) agents can demonstrate good performance and interpretability. Therefore, deep reinforcement learning-based knowledge reasoning methods have rapidly emerged in recent years and have become a hot research topic. However, even in a small and fixed knowledge graph reasoning action space, there are still a large number of invalid actions. It often leads to the interruption of RL agents’ wandering due to the selection of invalid actions, resulting in a significant decrease in the success rate of path mining. In order to improve the success rate of RL agents in the early stages of path search, this article proposes a knowledge reasoning method based on Deep Transfer Reinforcement Learning path (DTRLpath). Before supervised pre-training and retraining, a pre-task of searching for effective actions in a single step is added. The RL agent is first trained in the pre-task to improve its ability to search for effective actions. Then, the trained agent is transferred to the target reasoning task for path search training, which improves its success rate in searching for target task paths. Finally, based on the comparative experimental results on the FB15K-237 and NELL-995 datasets, it can be concluded that the proposed method significantly improves the success rate of path search and outperforms similar methods in most reasoning tasks. © 2024 Tech Science Press. All rights reserved.

关键词： Intelligent agent knowledge graph reasoning reinforcement transfer learning

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Skin-inspired interface modification strategy toward a structurefunction integrated hybrid smart fabric system with self-powered sensing property for versatile applications

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Nano research 2024年第9期17卷 8200-8208页

作者： Xiang Cheng Teng Chen De Gong Pengcheng Ma Bo Chen Jun Cai Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100190China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beijing U-Precision Tech Co. Ltd.Beijing 100176China University of Chinese Academy of Sciences Beijing 100049China

Fabric-based composites with superior mechanical properties and excellent perceptive function are highly ***,it remains a huge challenge to attain structure-function integration,especially for hybrid fabric ***,a skin-inspired interface modification strategy is proposed toward this target by constructing a hybrid smart fabric system consisting of two types of smart fabrics:carbon nanotube(CNT)/MXene-modified aramid fabrics and zinc oxide nanorod(ZnO NR)-modified carbon *** on that,flexible piezoelectric pressure sensors with skin-like hierarchical perception interfaces are fabricated,which demonstrate superb sensitivity of 2.39 V·kPa^(-1)and are capable of various wearable monitoring ***,the interface-modified hybrid fabric reinforced plastics can also be fabricated,which are proven to possess 13.6%higher tensile strength,10.1%elastic *** impressively,their average energy absorption can be improved by 111.9%,accompanied with inherent damage alert *** offers a paradigm to fabricate structure-function integrated hybrid smart fabric composites for the smart clothing and intelligent aerial vehicles.

关键词： hybrid fabrics interface modification piezoelectric pressure sensors self-diagnostic composites structure-function integration

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Progress in Zero-gravity Unloading Test and system research of Solar Wing

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Recent Patents on engineering 2024年第8期18卷 123-134页

作者： Hou, Zemiao Li, Qiu Wu, Yuemin Yu, Qiang Liang, Hongfei School of Mechanical Engineering Tianjin University of Technology and Education Tianjin300222 China Structural and Institutional Technology Research Office Institute of Spacecraft System Engineering Beijing100094 China Laboratory of Trails and Testing Technology Tianjin Aerospace Electromechanical Equipment Research Institute Tianjin300301 China

Aim: The solar wing undertakes the important task of providing energy for spacecraft. The deployment test of the solar wing in a zero gravity environment using a zero gravity system on the ground is an important link to ensure the safe and stable deployment of the solar wing in space. This article briefly describes the development process and research progress of solar wings, introduces the ground zero gravity test methods and test platforms for solar wings, including some patents for improving the ground zero gravity test platform for solar wings, and points out some urgent problems that need to be solved in the zero gravity unloading test and system at present. Background: The solar wing needs to be deployed in the weightlessness environment of space before working. Objective: The objective of this study is to summarize the zero gravity experimental methods and systems of solar wings, introduce their categories, characteristics, and development. Methods: This article summarizes various scientific research achievements in the zero gravity test of solar wings, and introduces the advantages and disadvantages of the zero gravity test method of solar wings. Results: This article analyzes the zero gravity test methods for solar wings, compares them among various test methods, analyzes the main problems in their development, and looks forward to the development trend of zero gravity test methods for solar wings. Conclusion: Although research on zero-gravity unloading test systems for solar wings is continuously advancing, there are still several technological bottlenecks that need to be overcome in terms of system precision, payload capacity, dynamic simulation, method optimization, diversifying zero-gravity test methods and system universality for different types of solar panel unloading. © 2024 Bentham Science Publishers.

关键词： Unloading

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