挠性加表摆片批产高精度保证技术

针对批产加工中高精度薄壁摆片变形大,形位精度难以保证设计要求问题,通过采取减少薄弱部位装夹次数,严格控制装夹方式,对关键技术进行有限元深入分析,优化加工参数,调整配合孔轴位置尺寸等多种技术措施,最大程度减少了整个工艺过程中对基准精度的破坏,避免了配合极限效应的产生,提高了加工合格率,保证了批产高精度和装配互换性要求。     

模拟月壤钻进负载分析与试验研究

月壤与采样机具间的相互作用在月球自主采样器的设计、性能评价、控制和仿真等方面具有重要作用,目前对于月壤与采样机具间相互作用中的钻进负载研究尚不充分。本文基于被动土压力理论,根据不同的土体切削状态,将切削刃前土体分为堆积区和破坏区,重点分析堆积区土体和破坏区土体对总钻头负载的贡献,建立了月壤取心钻头钻进松散土体的钻进负载模型。HIT 2型取心钻头和HIT\|LS1#模拟月壤的钻进试验结果表明,钻进负载理论模型与实际情况具有较高的吻合度。     

高超声速风洞WDPR支撑尖锥模型应用可行性分析

绳牵引并联机构(WDPR)能够有效调整飞行器模型的位姿,为扩展风洞试验能力提供了一种新型支撑手段,具有很大的应用潜力。本文将对其在高超声速风洞中应用所涉及的稳定性与气动干扰问题进行研究。以10°尖锥标椎模型为例,设计了8绳牵引的并联支撑系统,可以通过调整绳长控制模型的位置和姿态。模拟了气动载荷作用下支撑系统的稳定性,优化牵引绳直径。基于构建的三维模型,借助CFD软件进行气动计算,包括马赫数为7.8时,不同迎角下绳牵引并联支撑锥体模型的气动力系数,通过与无绳支撑结果以及文献试验数据进行比较,表明在小迎角情况下,绳系支撑引起的气动干扰相对误差较小,但会随迎角的增大而增加。此外,分别对弯刀支撑和绳牵引并联支撑进行了模态分析,对比了2种支撑的固有频率。结果显示绳系支撑固有频率较高,系统刚度较大。本文的理论研究成果可为绳牵引并联支撑技术在高超声速风洞中的应用提供一定的技术支持。     

基于知识工程的外涵机匣设计系统构建

外涵机匣作为航空发动机的主要单元体之一,其设计质量要求高,研制周期长。为提升外涵机匣的设计质量和效率,在传统设计方法的基础上引入了知识工程技术,构建了一体化外涵机匣设计系统。通过对外涵机匣设计的需求分析,提出基于KBE的外涵机匣设计系统研究思路,开发了设计流程驱动、知识融合、工具软件集成、典型结构快速设计以及数据管理等系统功能模块,提出了该系统在实际工作中的应用情况和后续发展目标。     

鸭式翼弹道修正火箭弹修正能力分析

采用十字型鸭式翼二维弹道修正火箭弹弹体布局,系统地研究了修正火箭弹的修正弹道理论,建立了修正质点弹道的数学模型。在Matlab中编制了四自由度弹道模型,仿真分析可用于分析无控和有控情况下的弹道修正能力问题。大射角下舵机45s起控纵向修正效果最好,起控时间越早,横偏修正越好。舵偏角越大,修正能力越强。     

基于航天应用焦距可调镜组装配应力优化

研究了一种航天用可手动调节焦距瞄准镜的设计和装配过程。针对航天产品可靠性要求高、环境条件恶劣、外界应力条件复杂的特殊情况,从保证高安装精度 （光轴对三处基准面平行度误差均小于10″,Y、Z向安装精度高于±0.05mm）和光学性能的角度出发,对加工应力、装配应力、外界环境应力3种应力对产品性能的综合影响进行了深入探讨。得出3种应力对产品的影响方式和相互之间的关系,并结合有限元模拟进行分析与验证。再以分析结果为依据,从设计角度优化装配过程,得出应力最优的装配方式。并以同样的理论基础,设计了专用的镜组装配工装,以减小镜组装配调整时所带来的装配应力,得到了良好的光学成像效果。     

Manipulation of Colloidal Droplets in Space and the Instability of Thermocapillary Convection in Large Prandtl Number Liquid Bridge in Microgravity

In 2016 and 2017, SJ-10 and TG-2 satellites were launched. In this short paper, we report recent progress on the studies of manipulation of colloidal droplets and instability of thermocapillary convection in large Prandtl number liquid bridge that based on the space experiments boarding SJ-10 and TG-2 satellites, separately. It was shown that the colloidal droplets can be successfully formed and manipulated in microgravity through the patterned substrates. In another aspect, the coffee-ring effect was observed at the first time in space. For the studies of the instability of thermocapillary convection in large Prandtl number liquid bridge in microgravity, our experiments in TG-2 broadened the way of such kind of study and abundant experimental results are emerging.      

Adaptive robust cubature Kalman filtering for satellite attitude estimation

This paper is concerned with the adaptive robust cubature Kalman filtering problem for the case that the dynamics model error and the measurement model error exist simultaneously in the satellite attitude estimation system. By using Hubel-based robust filtering methodology to correct the measurement covariance formulation of cubature Kalman filter, the proposed filtering algorithm could effectively suppress the measurement model error. To further enhance this effect and reduce the impact of the dynamics model error, two different adaptively robust filtering algorithms, one with the optimal adaptive factor based on the estimated covariance matrix of the predicted residuals and the other with multiple fading factors based on strong tracking algorithm, are developed and applied for the satellite attitude estimation. The quaternion is employed to represent the global attitude parameter, and three-dimensional generalized Rodrigues parameters are introduced to define the local attitude error. A multiplicative quaternion error is derived from the local attitude error to maintain quaternion normalization constraint in the filter. Simulation results indicate that the proposed novel algorithm could exhibit higher accuracy and faster convergence compared with the multiplicative extended Kalman filter, the unscented quaternion estimator, and the adaptive robust unscented Kalman filter.     

Design and analysis of a novel hinged boom based on cable drive

Hinged booms are widely used in astrophysics missions; however, the trajectory and deployment velocity are difficult to control because they are usually driven by springs, which limits their application in narrow spaces. Thus, a novel hinged boom is highly required to achieve motion controllability. Through an equivalent substitution between the cable drive loop and the binary link in topology, a type synthesis method for the cable-driven single-degree-of-freedom chain is proposed based on the s...     

当代反舰导弹面临的电子对抗挑战

简要叙述当代海战场中复杂电磁环境的构成.对反舰导弹面临的电子对抗威胁展开论述,重点分析先进传感器和海上电子战体系给反舰导弹带来的挑战.最后探讨了反舰导弹对抗电子战威胁的技术途径.