Optical interconnection and packaging technologies for advancedavionics systems

An optical backplane developed to demonstrate the advantages of high-performance optical interconnections and supporting technologies and designed to be compatible with standard avionics racks is described. The hardware demonstrates the three basic components of optical interconnects: optical sources, an optical signal distribution network, and optical receivers. Results from characterization and environmental tests, including a demonstration of the reliable transmission of serial data at a 1 Gb/s, are reported     

片间综合化互连时间触发通信调度方法

未来先进的分布式综合化航空电子系统需要实现跨越计算体系结构的信息综合,对微小型智能器件间的综合化互连提出要求。通过构建一种具有开放式接口的芯片间综合化互连结构,提出一种相应的时间触发（TT）通信调度方法。首先建立片间综合化互连模型和时间触发流量传输模型,给出负载均衡的选径方法;随后依据传输路径中各级节点各流量的发送时间偏移量计算流量传输的等待时间可行值,利用遗传算法优化调整各芯片发送端口的调度表相位,更新各流量在发送端口的时间偏移量,缩短最坏情况下的最大等待时间,得到具有全局优化意义的时间触发调度表。与使用Yices等SMT形式化求解器的TT调度表生成方法相比,本方法不会出现长时间不停机而无法判定的问题,且不论对于对称或非对称结构,案例研究表明本方法的可调度规模至少增加30%。此外,以流量传输等待时间占周期的比例作为归一化的传输延迟度量,与既有的基于特征任务的调度方法相比,案例研究表明本方法得到的传输延迟最多仅为后者的2%。     

航空电子MB-OFDM-UWB无线互连信道分析与仿真

多频带正交频分复用超宽带（MB-OFDM-UWB）是航空电子内部无线互连（WAIC）的候选通信体制之一,不同于普通的室内无线信道,超宽带信号在金属和复合材料的机舱内部存在复杂的反射和多径干扰。给出一种适用于WAIC应用的MB-OFDM-UWB无线通信系统物理层方案,并参照IEEE802.15.4a标准提出一种适应航空电子机舱内部特征的多簇多径UWB信道模型;通过基于接收球的反射角误差法仿真得到无线信道的冲激响应,确定了机舱环境下信道模型的簇到达率、径到达率和混合因子;进而采用Simulink进行MB-OFDM-UWB信号系统仿真,表明在110 Mb/s码速率条件下,当误码率低于国际电信联盟（ITU）标准规定的10^-6,机舱环境下的信噪比应比普通室内环境高1 dB。另外,在研究过程中,为了确认电磁仿真中接收球半径的有效性,针对基准环境将仿真结果与文献报道的实测结果进行了对比。     

Background limited infrared and submillimeter instruments

The temperature and emissivity of infrared and submillimeter telescopes are basic parameters that drive the optical and thermal design of astronomical space projects. They determine also, among other parameters, the self-emission of the instrument and the photon noise produced by this radiation on the detectors. By comparing the telescope brightness with that of the sky in the 1m–1 cm wavelength range, general conditions for background limited photometry are derived. For <0.4 mm, temperature is the driving parameter, and for >0.4 mm, temperature and emissivity have equivalent importances. It can be shown on actual projects that these two regimes determine different optical and thermal concepts. Although based on a simplistic approach, this work intends to help designers to handle some basic system parameters of infrared and submillimeter instruments.     

Wireless power transmission: the key to solar power satellites

Maturing of the enabling technologies has provided much of the infrastructure to support the development of a commercial Solar Power Satellite program. Solar Space Industries was formed to accomplish this goal. The basis of their development plan is to build a Ground Test Installation that will duplicate, in small scale on the Earth, all aspects of the power generating and power transmission systems except for the space environment and the range and size of the energy beam. Space operations issues will be separated from the power generation fixation and verified by testing. Doing the developmental testing on the ground instead of in space will result in a low cost program that can be accomplished in a very short time. The concept is to build a Ground Test Installation that couples an existing 100 kW terrestrial solar cell array to a phased-array wireless power transmitter based on a subarray. Power will be transmitted over a 1-¼ mile range to a receiving antenna and then fed into a commercial utility power grid. The objective is to demonstrate the complete function of the Solar Power Satellites, with the primary issue being the validation of practical wireless power transmission. The key features to demonstrate are: beam control, stability, steering, efficiency, reliability, cost, and safety     

数据融合方法及其在提高智能仪表测量精度中的应用

在智能仪器仪表或系统中，由于工业中存在的各种干扰，软件的数字平均值滤波为广泛采用，但其方差不是最小的，本采用基于参数估计理论方法，提出以递推估计的数据融合方法克服智能仪表的测量干扰，并通过仿真表明其优于传统的算术平均的数字滤波方法。     

大振幅实验对常规动导数实验包容性研究

某飞机模型在南京航空航天大学NH-2低速风洞中进行大振幅振动动态试验.模型绕通过重心的机体坐标轴分别作单独俯仰、偏航、滚转的大振幅振动,采用内式应变天平测量模型的非定常空气动力.通过非定常空气动力建模和动导数仿真方法,获得模型的纵横向稳定性导数和交叉导数.仿真结果与常规动导数试验结果比较,两者在量级和规律上一致.分析表明,模型大振幅振动实验结果包含了常规动导数实验的信息,模型的动导数可以从大振幅振动实验结果中获取.     

Virtual instruments used for LPG pipeline network monitoring

The paper presents a pipeline liquefied petroleum gas network (PLPGN) monitoring system based upon the virtual instrument architecture. Starting from the introduction of development requirements and environment for the monitoring system, the paper discusses its hardware configuration and software functionalities, in detail. Practical application has demonstrated that the virtual instrument-based structure is very effective and the obtained monitoring system is highly flexible.     

VXIbus instruments: past, present and future

After a brief introduction to the VXIbus specification which was designed to avoid obsolescence by being an open-architecture standard, some of the many events which have occurred in the last few years to make the VXIbus standard the main platform for test, measurement, and high-density data acquisition, are discussed     

光纤图像观测系统在燃烧实验中的应用

阐述了光导纤维图像观测系统的工作原理、主要部件及功能。利用该系统观测燃烧室内部不同工作状态下的火焰状况,对所记录下来的火焰图像进行了较为详细的分析,并对实验过程中出现的一些问题提出了改进措施。     

颤振边界预测技术在颤振试飞中的应用研究

对两种颤振边界预测方法的技术原理进行了详细介绍,进而通过两种颤振边界预测技术在两个型号飞机颤振试飞中的应用研究,表明了该技术具有一定的工程实用性。最后对文章介绍的预测技术在后续试飞中的应用给出了有益的建议。     

宽带无线接入技术

介绍了两种宽带无线接入技术：本地多点分配业务(LMDS)和自由空间光通信(FSOC)。它们各具特色。前者将新兴的LMDS技术引入无线接入网,而后者是实现无线宽带接入的另一种途径。     

无线技术的新应用

<正>SITA公司计划于2009年年底前在全球推广一种用于维修人员和维修系统之间的常规无线连接新平台。通过与网络供应商Appear公司合作,SITA公司的平台将可以实时识别维修人员资质、无线连接类型和位置等,使管     

无线机载娱乐系统前景广阔

无线技术具有高效、经济、质轻和维修量少等优点.它最初的应用始于上世纪90年代后期.1996年瓦卢航空公司的一架DC-9因货舱失火而坠机,FAA要求航空公司为其机队安装烟雾探测和灭火系统.用硬接线的方法在飞机上安装这样一个系统需要花700小时和增加几百千克的导线.而由Securaplane公司推出的一种无线装置可使工时和导线重量都减少70%.以美国西南航空公司作为启动用户,Securaplane公司的首个无线装置在1998年获得STC(补充型号证书),被批准用于空运服务.目前,该公司的产品已安装在数百架飞机上,包括"湾流"Ⅳ和波音777-200.其最新型的ST3000烟雾探测和灭火装置采用无线传感器,可与中央控制系统采用扩频RF进行通信.     

电磁兼容性试验中若干问题的解决方法

结合电磁兼容性试验的实践经验,从电磁干扰源、耦合途径、敏感设备这3个发生电磁兼容性问题的主要因素入手,对电磁兼容性试验中易于超标的项目,提出了若干解决问题的思路和方法。利用这些在工程实践中总结出来的有效方法,可以在电磁兼容性试验中少走弯路,达到降低产品的研制成本并加快产品的研制进度的目的。     

PC机和检测仪器串口通讯的实现

详细分析了实现PC机和检测仪器串行通讯的方法和技巧。介绍了PC机和检测仪器之间RS485串行通讯的硬件连接以及Visual Basic6．0的Mscomm通讯控件的使用方法。利用Mscomm控件的唯一事件OnComm事件通过查询方式实现通讯。实际应用表明，本文设计的程序实现方便且实用性强，很好地解决了企业信息化管理的关键问题。     

Near term approach to data relay for satellites under test

The increasing need for a continuous communications link with U.S. Department of Defense (DoD) spacecraft during test missions in low Earth orbit (LEG) has resulted in greater interest in geosynchronous data relay services. This may be a more economical alternative to building additional remote tracking stations for the Air Force Satellite Control Network (AFSCN), and avoids tying up operational assets for a test mission. A low-cost near-term approach for such a space-based data relay system would utilize two existing Defense Satellite Communication System III spacecraft, two existing ground terminals, and a small, standardized terminal using autonomous antenna pointing for the space vehicle under test. Such a system design is presented     

近距离的无线通信系统的构建

首先介绍使用ET13X340/330无线通信芯片构建300MHz近距离无线通信平台的原理和方法,然后简介使用ET13X211/221无线通信芯片构建27MHz无线通信系统的方法,最后对这二种芯片的使用方法和效果作了讨论和比较.