卫星多通道异构遥测数据融合分析与比对方法

遥测数据是航天器研制阶段最重要的产品成果之一，是检测航天器功能及性能指标、验证航天器各系统研制成果，以及分析在轨测试数据的重要基线。航天器各通道的遥测数据的正确性和有效性显得尤为重要，本文提出一种卫星多通道异构遥测数据融合分析与比对方法，实现多通道异构遥测数据的预处理、融合分析、融合比对等，解决了直接人工判读效率低和准确性差的历史问题，有效提升卫星综合测试和在轨监视的数据分析效率。     

Adaptive data fusion framework for modeling of non-uniform aerodynamic data

Multi-fidelity Data Fusion(MDF) frameworks have emerged as a prominent approach to producing economical but accurate surrogate models for aerodynamic data modeling by integrating data with different fidelity levels. However, most existing MDF frameworks assume a uniform data structure between sampling data sources; thus, producing an accurate solution at the required level, for cases of non-uniform data structures is challenging. To address this challenge, an Adaptive Multi-fidelity Data Fusion(...     

Effect of adding Nb foil on joint properties of laser fusion welding for TC4 titanium and 7075 aluminum alloy

It is difficult to gain effective Ti-Al fusion welding joints due to their differences in thermal properties and the appearance of brittle Ti-Al Intermetallic Compounds (IMCs). The experiments of laser fusion welding for TC4 titanium and 7075 aluminum alloy were carried out, temperature field and ductility/brittleness, as well as chemical potential of elements, were calculated, and the effect of adding Nb foil on mechanical properties of the weld was also investigated. The results suggested that Nb atoms tend to diffuse toward Al side, which is conducive to the participation of Nb in the metallurgical reaction and contributes to forming the Ti-Nb-Al IMC layer at the interface. As the thickness of Nb foil increases, the tensile-shear force of joint climbs first but then declines, and reaches the highest value of 1663 N with 0.10 mm-thickness Nb foil, representing 58.38% enhancement compared with the non-added one. Adding Nb foil slows down the heat transfer as a blocker, and thus both the melting amount of Al and the mixing area of Ti and Al decrease. In addition, Nb alloying reduces the brittleness of the Ti-Al compound. Hence, the joint properties of titanium/aluminum are improved with the addition of Nb foil.     

A robust Poisson multi-Bernoulli filter for multi-target tracking based on arithmetic average fusion

The coalescence and missed detection are two key challenges in Multi-Target Tracking (MTT). To balance the tracking accuracy and real-time performance, the existing Random Finite Set (RFS) based filters are generally difficult to handle the above problems simultaneously, such as the Track-Oriented marginal Multi-Bernoulli/Poisson (TOMB/P) and Measurement-Oriented marginal Multi-Bernoulli/Poisson (MOMB/P) filters. Based on the Arithmetic Average (AA) fusion rule, this paper proposes a novel fusion framework for the Poisson Multi-Bernoulli (PMB) filter, which integrates both the advantages of the TOMB/P filter in dealing with missed detection and the advantages of the MOMB/P filter in dealing with coalescence. In order to fuse the different PMB distributions, the Bernoulli components in different Multi-Bernoulli (MB) distributions are associated with each other by Kullback-Leibler Divergence (KLD) minimization. Moreover, an adaptive AA fusion rule is designed on the basis of the exponential fusion weights, which utilizes the TOMB/P and MOMB/P updates to solve these difficulties in MTT. Finally, by comparing with the TOMB/P and MOMB/P filters, the performance of the proposed filter in terms of accuracy and efficiency is demonstrated in three challenging scenarios.     

核聚变空间推进器的初步需求分析

参考一种简化的、解析近似的计算模型，以地球到火星的对接任务和往返任务为例，对核聚变等离子体推进器性能关键参数如推进系统质量、比冲、任务时间、有效载荷份额及比功率等进行分析，得出了任务时间和有效载荷质量份额与聚变堆芯输出功率、推进器结构质量和比冲的依赖关系。在此基础上，结合核聚变地面商业堆的相关进展，对现有的技术做合理适当外推，理论计算表明:飞行任务能够在1~2个月内达到目的星球同时可携带超过10%的有效载荷份额，并提出了未来核聚变空间推进器的初步参数方案和设计构想，总体上能够为未来核聚变空间推进技术的发展提供一定的参考。      

航空发动机主轴轴承状态监测研究现状与发展趋势

航空发动机主轴轴承承受着高温、高速、重载、贫油、断油等极端工况,其疲劳、磨损等失效问题严重影响发动机的可靠性.因此,对航空发动机主轴轴承的使用状态进行有效精确监测极为重要.对航空发动机主轴轴承工况特点、主要失效模式和失效机制进行了梳理;针对主轴轴承的状态监测方法和技术,总结并对比分析了现有主轴轴承振动、滑油状态、声音、...