共查询到19条相似文献,搜索用时 250 毫秒
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无线传感器网络由能量受限的节点组成,高效节能的路由算法是路由设计的关键问题。在LEACH算法的基础上,提出了一种新的分簇式路由策略,从簇头个数的确定、簇头选举方法对LEACH算法进行了改进,数据传输方式允许采用多跳方式与基站节点通信,仿真结果表明该算法具有降低网络能耗、延长网络生命周期的优点。 相似文献
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性能保证条件下航空电子高速交换机的加速方法 总被引:1,自引:1,他引:0
以保证航空电子互连网络的确定性延迟和高带宽为目的,建立航空电子交换式以太网(AFDX)承载于波分复用(WDM)之上的架构,兼容AFDX的延迟确定性和WDM的带宽可扩性,满足航空电子互连网络对实时性和高带宽的要求。通过对实时通信中周期性数据帧的分析,提出光波聚合加速方法,对输入端到达的数据帧进行重新分配和整型,充分利用每条光波的带宽资源,减少交换使用的波长数。在性能保证条件(100%通过率下保证有界延迟)下,对使用光波聚合方法的交换机制进行了数学推导。最后通过计算机仿真,以网络延迟时间率和加速因子为性能衡量指标推证了该加速方法的优越性和可行性。 相似文献
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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。 相似文献
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针对LEACH协议在能耗方面存在的不足,提出了一种分区簇头选择和簇间多跳的新协议。该协议分区域进行簇头选举、考虑了节点剩余能量、簇间采用多跳的方式传输数据。仿真结果表明,与LEACH协议相比,新协议有效的均衡了节点能耗,提高了能量利用率,延长了网络寿命。 相似文献
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航空电子多路传输数据总线通信系统是嵌入式多处理计算机结构航空电子系统综合的基础。从如何进行通信系统设计的角度出发,分析和描述了航空电子多路传输数据总线通信系统。 相似文献
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无线航空电子机内通信(WAIC)宽带互连可选用多天线无线局域网(WLAN)。在航空电子设备舱,无线电信号在机舱结构和航电设备架之间的反射是造成多径衰落的主要因素,而且在进行多入多出(MIMO)传输时,不同天线接收信号间的相关性一般不可忽略。根据航电设备架和设备布置的几何位置关系及其材质,建立了三维模型,采用接收球反射角误差法模拟信号在航电舱内的传播路径。针对不同航电设备安装密度条件,分别考虑均匀线性和圆形天线的信号接收情况进行仿真,使用聚类对数据预处理,得到多簇多径信道模型,并使用多径衰落和时延分布描述的航电舱WAIC信道特性,统计分析得到MIMO信道传输矩阵,以及接收机天线间相关性对信道性能的影响。仿真分析表明,当航电设备安装密度大于60%时,信道条件可近似采用完全满载时的信道参数。文中的仿真分析方法为航电设备架附近的MIMO无线传输特性分析和设计提供了参考。 相似文献
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针对航空电子系统应用软件规模及数量增加带来的系统综合集成复杂度提升,以及任务需求多样性带来的航空电子软件敏捷开发和部署需求,因此开展航空电子系统软件组件服务化设计要求标准研究,定义航空电子系统软件组件模型及设计流程,提出航空电子系统软件组件服务化设计总体要求、定义要求等,并对服务化软件架构、航空电子服务模型和服务封装接口等进行了详细定义和阐述,为面向服务的航空电子系统软件设计开发及持续集成提供了解决思路和参考规范。 相似文献
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以在军事等领域具有重要应用的扩展网络为研究对象,研究并提出了基于最短路树的网络降维方法。当子网络之间有边互连的节点数远小于原网络节点数时,利用降维网络计算扩展网络的最短路径具有很好的效果。 相似文献
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MBI作为多路传输总线接口模块,能够实现MIL-STD-1553B协议,完成航空电子子系统之间的连接,在通信软件的支持下完成航空电子子系统之间的通信。本文将详细介绍为机载设备DTS的MBI接口模块配置的通信软件的标准化及规范化设计。 相似文献
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Hicks B. Riggs L.H. McDaniel L. Sanner J. 《Aerospace and Electronic Systems Magazine, IEEE》2004,19(5):9-15
Presently the USAF is operating with 90 different Model Design Series (MDS) aircraft. The 90 MDS aircraft make up a total of 5778 airframes, each with a different number of Line Replaceable Units (LRUs) which make up the avionics systems. Some of the MDSs have as few as 53 avionics LRUs while others as many as 495. The total dollar value of the USAF aircraft avionics LRUs is approximately $42.4B and $30.68B in spares. Depot repairable cost to maintain these components each year is approximately $1.2B. Each MDS is assigned specific missions and the avionics systems are developed to support those missions. Due to the evolution of mission types and user needs, change is constant for the avionics manager. 相似文献
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《Air & Space Europe》1999,1(1):48-50
As automation becomes more sophisticated and complex, there is increasing concern about the time and cost of training pilots to use it, and the possibility of pilot errors. In this sense, the evolution of avionics systems is emulating the evolution of personal computers in the 1980s. In the early days of personal computing, users had to learn some basic computer science concepts and an obscure command language with only passing resemblance to natural language. Because the command language was highly codified and condensed, the user had to commit apparently arbitrary syntax rules to memory, and if the user made an error, such as reversing the source and destination drives in the “copy” command, the results could be catastrophic (in this case, erasing the file that was intended to be saved and saving the one that was intended to be erased).The personal computer industry responded to the widespread perception that computers were difficult to use by developing graphic user interfaces. Today, most users can perform rudimentary operations on a personal computer with little or no training or reference to the manual. It is possible that the same type of advance could be achieved with avionics systems, so that almost any trained pilot could operate a new piece of avionics with little or no training in its specific operation. 相似文献
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The avionics components of modern military aircraft significantly impact the cost and effectiveness of the total aeronautical system. In the early conceptual phase, aeronautical system designers give scant attention to designing the avionics components. The design team generally provides weight, volume and power considerations for the desired avionics functions and assumes that an avionics suite can be assembled. Less than comprehensive attention is given to the interacting effect avionics have with the other system components. In contrast, the designers expend a very large effort on finding the best balanced combination of airframe and propulsion components which satisfy the design objectives. This paper shows why avionics must be a co-equal member of the aeronautical system along with airframe, propulsion, and armament. To become a co-equal partner, avionics must be an element of the system design iterations and analysis commencing with the early conceptual design phase of a new aeronautical system. 相似文献
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李海伟 《民用飞机设计与研究》2018,(2):80
测试性是航空电子设备基本设计特性,测试性设计的好坏直接决定了航空电子设备感知自身状态(正常、故障和降级)并自动隔离内部故障的能力。从全寿命周期费用探讨了民用飞机航空电子设备开展测试性设计的必要性,给出了民用飞机研制过程中航空电子设备通用测试性设计、机内测试设计和电路及元器件的测试性设计考虑。实践证明航空电子设备开展测试性设计能有效提高民用飞机的功能安全性和维修经济性。 相似文献
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The V-22 avionic hardware is the first to be designed under MIL-STD-2165 testability program requirements. This paper presents an overview of the avionics design-for-testability approach and lessons learned to date relative to the application of MIL-STD-2165. The paper will discuss incorporation of testability requirements up front in the avionics design which will drive the supportability philosophy at both the Organizational and Depot levels of maintenance. The paper will compare previous avionics hardware testability requirements versus those applied to the V-22 avionics and highlight areas of improvement. A discussion of testability design impacts on reduced level of testing (i.e. WRA/SRA/System) will be included. In addition, the paper discusses an innovative approach to meeting the user requirements for a man-portable forward deployed maintenance capability that forms the basis for a two level support scenario (Organizational and Depot). The innovation comes from the fact that the on-board Central Integrated Checkout system will provide data as well as fault isolation and will use this data as a mechanism to reduce the size and complexity of the stimulus and measurement hardware at either the Organizational or Depot level depending on the deployment requirements. 相似文献