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Automatic modeling algorithm of stochastic error for inertial sensors

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Control Theory and Technology 2024年第1期22卷 81-91页

作者： Luodi Zhao Long Zhao School of Automation Science and Electrical Engineering Beihang UniversityBeijing100191China Digital Navigation Center Beihang UniversityBeijing100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing100191China

This paper proposes an automatic algorithm to determine the properties of stochastic processes and their parameters for inertial error. The proposed approach is based on a recently developed method called the generalized method of wavelet moments (GMWM), whose estimator was proven to be consistent and asymptotically normally distributed. This algorithm is suitable mainly (but not only) for the combination of several stochastic processes, where the model identification and parameter estimation are quite difficult for the traditional methods, such as the Allan variance and the power spectral density analysis. This algorithm further explores the complete stochastic error models and the candidate model ranking criterion to realize automatic model identification and determination. The best model is selected by making the trade-off between the model accuracy and the model complexity. The validation of this approach is verified by practical examples of model selection for MEMS-IMUs (micro-electro-mechanical system inertial measurement units) in varying dynamic conditions.

关键词： GMWM Stochastic process Inertial sensor Sensor calibration Error model Allan variance

A semi-analytical multi-harmonic balance method on full-3D contact model for dynamic analysis of dry friction systems

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Chinese Journal of Aeronautics 2024年第2期37卷 309-329页

作者： He SUN Dayi ZHANG Yaguang WU Qingyang SHEN Dianyin HU Research Institute of Aero-Engine Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beijing Key Laboratory of Aero-Engine Structure and Strength Beijing 100191China Sino-French Engineering School Beihang UniversityBeijing 100191China AECC Sichuan Gas Turbine Research Establishment Chengdu 610500China

Dry friction damping structures are widely-used in aero-engines to mitigate *** nonlinear nature of friction and the two-dimensional in-plane motion on the contact interface bring challenges to accurately and efficiently predict the forced response of frictionally damped *** state-of-the-art Multi-Harmonic Balance Method(MHBM)on quasi-3D contact model in engineering cannot precisely capture the kinematics on the friction interface although the efficiency is *** full-3D contact model can describe the constitutive relationship of the interface in a more accurate manner;however,the efficiency and convergence are not guaranteed for large-scale *** this paper,a semi-analytical MHBM on full-3D contact model is *** original Trajectory Tracking Method(TTM)for evaluating the contact force is reformulated to make the calculation more concise and the derivation of the Analytical Jacobian Matrix(AJM)*** on the chain rule of derivation,the AJM which is the core to upgrade the performance is *** a shrouded blade finite element model,the accuracy and efficiency of the proposed method are compared with both the MHBM on full-3D contact model with numerical Jacobian matrix and the MHBM on quasi-3D contact model with *** results show that the AJM improves significantly the efficiency of the MHBM on full-3D contact *** time cost of the proposed method is in the same order of magnitude as that of the MHBM on quasi-3D contact *** also confirm that the full-3D contact model is necessary for the dynamic analyses of shrouded *** one uses the quasi-3D model,the estimation relative error of damping can even reach 31.8%in some *** addition,the AJM also brings benefits for stability *** is highly recommended that engineers use the MHBM on full-3D contact model for the dynamic analysis and design of shrouded blades.

关键词： Dry friction damping Multi-harmonic balance method Trajectory tracking method Jacobian matrix Shrouded blade

A comprehensive fluid-solid coupling dynamic simulation for spatiotemporal distribution of regression rate in hybrid rocket motors

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Chinese Journal of Aeronautics 2024年第9期37卷 100-112页

作者： Tianfang WEI Guobiao CAI Hui TIAN Xiangyu MENG Xianzhu JIANG Xiaoming GU School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of Education Beijing 100191China

The spatiotemporal distribution characteristics of the regression rate are crucial aspects of the research on Hybrid Rocket Motor(HRM).This study presents a pioneering effort in achiev-ing a comprehensive numerical simulation of fluid dynamics and heat transfer in both the fluid and solid regions throughout the entire operation of an *** accomplish this,a dynamic grid tech-nique that incorporates fluid-solid coupling is *** validate the precision of the numerical simulations,a firing test is conducted,with embedded thermocouple probes being used to measure the inner temperature of the fuel *** temperature variations in the solid fuel obtained from both experiment and simulations show good *** maximum combustion temperature and average thrust obtained from the simulations are found to deviate from the experimental results by only 3.3%and 2.4%,***,it can be demonstrated that transient numerical simu-lations accurately capture the fluid-solid coupling characteristics and transient regression *** dynamic simulation results of inner flow field and solid region throughout the entire working stage reveal that the presence of vortices enhances the blending of combustion gases and improves the regression rate at both the front and rear ends of the fuel *** addition,oscillations of the regression rate obtained in the simulation can also be well corresponded with the corrugated surface observed in the ***,the zero-dimension regression rate formula and the for-mula describing the axial location dependence of the regression rate are fitted from the simulation results,with the corresponding coefficients of determination(R°)of 0.9765 and 0.9298,*** research serves as a reference for predicting the performance of HRM with gas oxygen and polyethylene,and presents a credible way for investigating the spatiotemporal distribution of the regression rate.

关键词： Hybrid Rocket Motor(HRM) Transient numerical simulation Fluid-solid couplingheat transfer Spatiotemporal distribution of regression rate Dynamic grid

Multi-faceted spatio-temporal network for weather-aware air traffic flow prediction in multi-airport system

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Chinese Journal of Aeronautics 2024年第7期37卷 301-316页

作者： Kaiquan CAI Shuo TANG Shengsheng QIAN Zhiqi SHEN Yang YANG School of Electronic and Information Engineering Beihang UniversityBeijing 100191China State Key Laboratory of CNS/ATM Beijing100191China Institute of Automation Chinese Academy of SciencesBeijing 100190China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

As one of the core modules for air traffic flow management,Air Traffic Flow Prediction(ATFP)in the Multi-Airport System(MAS)is a prerequisite for demand and capacity balance in the complex meteorological *** to the challenge of implicit interaction mechanism among traffic flow,airspace capacity and weather impact,the Weather-aware ATFP(Wa-ATFP)is still a nontrivial *** this paper,a novel Multi-faceted Spatio-Temporal Graph Convolutional Network(MSTGCN)is proposed to address the Wa-ATFP within the complex operations of ***,a spatio-temporal graph is constructed with three different nodes,including airport,route,and fix to describe the topology structure of ***,a weather-aware multi-faceted fusion module is proposed to integrate the feature of air traffic flow and the auxiliary features of capacity and weather,which can effectively address the complex impact of severe weather,e.g.,***,to capture the latent connections of nodes,an adaptive graph connection constructor is *** experimental results with the real-world operational dataset in Guangdong-Hong Kong-Macao Greater Bay Area,China,validate that the proposed approach outperforms the state-of-the-art machine-learning and deep-learning based baseline approaches in performance.

关键词： Air traffic control Graph neural network Multi-faceted information Air traffic flow prediction Multi-airport system

Proteomics Study of Benzene Metabolite Hydroquinone Induced Hematotoxicity in K562 Cells

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Biomedical and Environmental Sciences 2024年第4期37卷 341-353页

作者： JIN Yi Shan YI Zong Chun ZHANG Yu Jing RONG Long YU Chun Hong School of Biological Science and Medical Engineering Beihang UniversityBeijing 100191China School of Engineering Medicine Beihang UniversityBeijing 100191China

Objective Hydroquinone(HQ),one of the phenolic metabolites of benzene,is widely recognized as an important participant in benzene-induced ***,there are few relevant proteomics in HQ-induced hematotoxicity and the mechanism hasn’t been fully understood *** In this study,we treated K562 cells with 40μmol/L HQ for 72 h,examined and validated protein expression changes by Label-free proteomic analysis and Parallel reaction monitoring(PRM),and performed bioinformatics analysis to identify interaction *** One hundred and eighty-seven upregulated differentially expressed proteins(DEPs)and 279 downregulated DEPs were identified in HQ-exposed K562 cells,which were involved in neutrophilmediated immunity,blood microparticle,and other GO terms,as well as the lysosome,metabolic,cell cycle,and cellular senescence-related *** on the 23 DEGs and 5 DEPs in erythroid differentiation-related pathways,we constructed the network of protein interactions and determined 6 DEPs(STAT1,STAT3,CASP3,KIT,STAT5B,and VEGFA)as main hub proteins with the most interactions,among which STATs made a central impact and may be potential biomarkers of HQ-induced *** Our work reinforced the use of proteomics and bioinformatic approaches to advance knowledge on molecular mechanisms of HQ-induced hematotoxicity at the protein level and provide a valuable basis for further clarification.

关键词： Hydroquinone Proteomics Hematotoxicity K562 cells

Continuous preparation of strong and tough PVA nanocomposite fibers by mechanical stretching-assisted salting-out treatment

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Nano Research 2024年第4期17卷 3156-3163页

作者： Hang Chen Guangze Yang Yingzhi Sun Yichao Xu Mingjie Liu Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China Research Institute for Frontier Science Beihang UniversityBeijing 100191China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

Polymer composite fibers with superior properties such as excellent combined strength and toughness and biocompatibility can be used in high-tech applications of braided protective devices and smart wearable,however the research of high-performance polymer composite fiber remains in the infant *** we present a strategy to produce strong and tough anisotropic polymer nanocomposite fibers with orientedly aligned salt rods using mechanical stretching-assisted salting-out *** prepared nanocomposite fibers have a tensile strength of up to 786±2.7 MPa and an elongation at break of 81%,and the anisotropic fibers exhibit good transmission of mechanical vibration in the longitudinal direction with high *** the fabrication process,the salt builds up into oriented rods during the directional salting process,and the polymer is confined to the 150 nm domain between the rods after the solvent is completely evaporated,giving the nanocomposite fibers superior mechanical *** presented strategy can be applied to the continuous mass production of nanocomposite fibers and is also generalizable to other polymer nanocomposites,which could extend the applicability of nanocomposite fibers to conditions involving more demanding mechanical loading and mechanical vibration transmission.

关键词： poly(vinyl alcohol)(PVA)nanofibers oriented structure ultrastrong and stiff mechanical vibration transmission salting out continuous production

A novel Bayesian-based INS/GNSS integrated positioning method with both adaptability and robustness in urban environments

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Chinese Journal of Aeronautics 2024年第6期37卷 205-218页

作者： Zhe YANG Hongbo ZHAO School of Electronics and Information Engineering Beihang UniversityBeijing 100191China

Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent *** Inertial Navigation System and Global Navigation Satellite System(INS/GNSS)integrated navigation systems have been an important means of fulfilling the above quest due to the complementary error characteristics between INS and *** complex urban driving environment requires the system sufficiently adaptive to keep up with the time-varying measurement noise and sufficiently robust to cope with measurement outliers and prior ***,many efforts lack a balance between adaptability and *** this paper,a novel positioning method with both adaptability and robustness is proposed by coupling the Mahalanobis distance method,the Variational Bayesian method and the student’s t-distribution in one process(M-VBt method).This method is robust against non-Gaussian noise and priori uncertainties,plus adaptive against measurement noise uncertainty and time-varying *** field test results show that the M-VBt method(especially the Mahalanobis distance part)has significantly improved the system performance in the complex urban driving environment.

关键词： Urban environments Mahalanobis distance Adaptability Robustness Integrated navigation

Client selection and resource scheduling in reliable federated learning for UA V-assisted vehicular networks

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Chinese Journal of Aeronautics 2024年第9期37卷 328-346页

作者： Hongbo ZHAO Liwei GENG Wenquan FENG ChangmingZHOU School of Electronics and Information Engineering Beihang UniversityBeijing 100191China

Federated Learning(FL),a promising deep learning paradigm extensively deployed in Vehicular Edge Computing Networks(VECN),allows a distributed approach to train datasets of nodes locally,e.g.,for mobile vehicles,and exchanges model parameters to obtain an accurate model without raw data ***,the existence of malicious vehicular nodes as well as the inherent heterogeneity of the vehicles hinders the attainment of accurate ***,the local model training and model parameter transmission during FL exert a notable energy burden on vehicles constrained in *** view of this,we investigate FL client selection and resource management problems in FL-enabled UAV-assisted Vehicular Networks(FLVN).We first devise a novel reputation-based client selection mechanism by integrating both data quality and computation capability metrics to enlist reliable high-performance ***,to fortify the FL reliability,we adopt the consortium blockchain to oversee the reputation informa-tion,which boasts tamper-proof and interference-resistant ***,we formulate the resource scheduling problem by jointly optimizing the computation capability,the transmission power,and the number of local training rounds,aiming to minimize the cost of clients while guaranteeing *** this end,we propose a reinforcement learning algorithm employing an asynchronous parallel network structure to achieve an optimized scheduling *** results show that our proposed client selection mechanism and scheduling algorithm can realize reliable FL with an accuracy of 0.96 and consistently outperform the baselines in terms of delay and energy consumption.

关键词： Federated learning Vehicular edge computing Resource management Reinforcement learning Optimization techniques

Elastic buckling analysis and optimization of thin-walled bamboo-like pipe beam subjected to pure bending

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Chinese Journal of Aeronautics 2024年第3期37卷 133-152页

作者： Yayun YU Dongli MA Liang ZHANG Xiaopeng YANG Hao GUAN School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

In this paper,a stiffening design imitating the bamboo node is proposed for weight reduction of the long composite pipe beam subjected to bending *** distribution of bamboo nodes can efficiently suppress the ovalization of the section,thus significantly improving the bending resistance of the *** on this principle,ring stiffeners are proposed to be fixed to the pipe beam,making the long beam equivalent to the combination of a series of short pipes that suffered less section ovalization.A database of the optimal laminate orientations for different normalized lengths is obtained through optimizations,where the discreteness of the ply count is *** on this database,weight optimizations are conducted,and the optimal designs of beams with and without stiffeners are obtained and *** comparison results show that the proposed bamboo-like stiffened beam not only regains a near-linear load–displacement relationship,but also reduces the weight by up to 16%under the same buckling *** addition,it is found that for the pipe beams with radius-to-thickness ratios of more than 18,increasing the radius leads to a decrease in elastic buckling resistance when the weight remains a constant,which is opposite to the design for strength and *** model and database developed in this paper can provide a reference for weight reduction design and weight estimation for composite pipe beams.

关键词： Composite beam Buckling Thin-walled structure Unmanned aerial vehicles Bamboo