压电类智能梁元的优化布局

分别对具有无限小长度驱动器的悬臂和简支智能梁的一阶模态和二阶模态进行了具体的分析和计算,确定了驱动器在梁元中的最优布局,总结了有关驱动器在梁元中布局的一些基本性质,并从解析的角度对驱动器的最优布局点给予解释.由于以上有关驱动器最优布局的分析是在忽略驱动器的长度的假设基础上进行的,所以又对有限长度的驱动器的布局问题进行了初步的探讨.     

Study on segmented distribution for reliability evaluation

In practice, the failure rate of most equipment exhibits different tendencies at different stages and even its failure rate curve behaves a multimodal trace during its life cycle. As a result, traditionally evaluating the reliability of equipment with a single model may lead to severer errors. However, if lifetime is divided into several different intervals according to the characteristics of its failure rate, piecewise fitting can more accurately approximate the failure rate of equipment. There-fore, in this paper, failure rate is regarded as a piecewise function, and two kinds of segmented dis-tribution are put forward to evaluate reliability. In order to estimate parameters in the segmented reliability function, Bayesian estimation and maximum likelihood estimation (MLE) of the seg-mented distribution are discussed in this paper. Since traditional information criterion is not suit-able for the segmented distribution, an improved information criterion is proposed to test and evaluate the segmented reliability model in this paper. After a great deal of testing and verification, the segmented reliability model and its estimation methods presented in this paper are proven more efficient and accurate than the traditional non-segmented single model, especially when the change of the failure rate is time-phased or multimodal. The significant performance of the segmented reli-ability model in evaluating reliability of proximity sensors of leading-edge flap in civil aircraft indi-cates that the segmented distribution and its estimation method in this paper could be useful and accurate.     

光纤法布里-珀罗传感器及其高温应用

随着航天技术不断发展，大推力运载火箭等精细化设计需求日益增加，飞行器高温工况结构及流场状态感知已成为当前研究的关键环节。基于法布里-珀罗干涉结构的光纤传感器在高温、高压、狭小空间等特殊环境展现出独特优势，被视为下一代高温原位测量工具。介绍了法布里-珀罗传感器的基本结构及原理，并分别从温度、应变和压力监测方面介绍了法布里-珀罗高温传感技术研究进展以及未来的发展趋势。基于石英光纤的法布里-珀罗传感器能够应用于1000°C以下环境，对于1000°C以上环境，需要以蓝宝石光纤作为敏感元件和传光介质。     

Improved Wavelet-based Spatial Filter of Damage Imaging Method on Composite Structures

Piezoelectric sensor array-based spatial filter technology is a new promising method presented in research area of structural health monitoring (SHM) in the recent years. To apply this method to composite structures and give the actual position of dam-age, this paper proposes a spatial filter-based damage imaging method improved by complex Shannon wavelet transform. The basic principle of spatial filter is analyzed first. Then, this paper proposes a method of using complex Shannon wavelet transform to construct analytic signals of time domain signals of PZT sensors array. The analytic signals are synthesized depending on the principle of the spatial filter to give a damage imaging in the form of angle-time. A method of converting the damage imaging to the form of angle-distance is discussed. Finally, an aircraft composite oil tank is adopted to validate the damage imaging method. The validating results show that this method can recognize angle and distance of damage successfully.     

美国航天器交会技术研究

美国交会对接技术的发展可分为三个阶段：＂双子座＂与＂阿波罗＂飞船,航天飞机,以及后航天飞机时代的项目。自主交会技术的发展,首先基于多种制导和导航敏感器的研发,特别是用于最终逼近段的激光敏感器。制导、导航与控制系统的冗余,以及故障检测与隔离的方法,在轨迹安全性中起重要作用。文章研究美国自主交会方案,包括＂双子座＂,＂阿波...     

飞机油量传感器布局设计的CAD方法的研究

根据飞机燃油油量测量的原理引出了数字式燃油测量系统中油量传感器的布局原则，由此提出了可测区的概念，并对相应的可测区计算方法中的关键技术作了阐述。最后给出了通过可测区计算及可测性验证进行油箱中油量传感器布局设计的有关结论。     

血药浓度在位检测仪的光路设计

介绍了血药浓度在位检测仪的光路设计，重点阐述发如何降低光能的损耗。该仪器利用Ｙ型光纤束把紫外光照射到血液中的药物上，再把药物发出的荧光收集并送到检测器，其信号供计算机实时采集。     

星载遥感器对地面目标的定位

系统和深入地研究了多种星载遥感器对地面目标的定位问题。以目标相对于星下点轨迹的方位角和遥感器的视角作为相对定位的结果参量，与卫星轨道参数相结合，导出了地面目标经纬度的通用化计算公式。并在此基础上，完成了关于地面目标定位误差的完整分析，讨论了各误差分量的计算方法，导出了一套相应的计算公式。     

模态参数识别中的激振点和测量点的布局 Ⅰ理论分析

测量点和激振点在被识别结构上的布局对于目标模态的准确识别具有很大影响。本文针对目标模态分别是孤立模态和重频模态，讨论了激振点和测量点的布局准则，给出了模态可识别的必要条件和充分条件。     

流控压比传感器的研制

对某型收音机发动机压比防喘控制装置中的最关键部件流控压比传感器的工作原理，结构参数的选取及压比突降特性进行了分析，认为：调节发动机压比工作点的大小，只有通过发迹劈距Ｈ值一实现；把喷开形状做成拉瓦尔管形，接受嘴张角α做成９０°－１２０°，就可改善压比突降特性，扩大压比工作点的变化范围。