-
1851.基于北斗卫星载波相位平滑伪距的列车定位方法
[铁路、船舶、航空航天和其他运输设备制造业] [2014-05-15]
随着我国北斗卫星导航系统的建设,北斗卫星已逐步具备应用于列车定位的能力.列车在铁路线上存在轨道占用区分的需求,北斗民用伪距定位对并行股道占用情况难以精确定位识别.采用北斗实时载波相位定位精度高,但需近距离基准站的差分信号和模糊度解算,不利于大范围内的实时应用.因此,本文结合北斗卫星伪距的无模糊度和载波相位的高精度特点,提出一种基于北斗载波相位平滑伪距的列车定位方法.该方法首先利用北斗组合相位伪距法探测与修复载波数据周跳,并采用修复后的载波相位数据平滑伪距.文中推导北斗载波相位平滑伪距的原理,分析不同平滑方法的特性和对应的噪声检验公式.采用实测数据计算两种平滑方式得到的结果表明:本文提出的方法能够有效快速探测与修复周跳,平滑伪距精度优于0.2m,满足北斗导航系统在铁路列车定位中的精度要求.
关键词：列车定位；北斗卫星；相位平滑伪距；周跳探测
-
1852.基于有限元的高速弓网系统动态性能仿真研究
[铁路、船舶、航空航天和其他运输设备制造业] [2014-05-15]
针对简单链形悬挂接触网与DSA380型受电弓的仿真问题,基于MSC- MARC有限元软件,采用京津城际铁路实际参数建立接触网和考虑弹性变形的受电弓模型,对受电弓-接触网动态性能进行仿真分析.在建模过程中采用欧拉-伯努利梁模型来模拟接触线和承力索;考虑弓头和上框架的弹性变形及其侧滚运动、垂向运动等,并通过非线性弹簧进行链接;受电弓和接触网模型之间通过接触实现耦合,将弓网作为一个整体进行研究.仿真结果表明:DSA380型受电弓以350 km/h速度通过简单链形悬挂时,其平均接触力为190.35 N,接触线的动态抬升量在18.1～73.7 mm之间.通过与西门子公司提供的结果及实测结果比较,可以看出本文建立的弓网系统有限元模型是正确和有效的.
关键词：接触网；受电弓；动态接触；有限元
-
1853.基于模态参数的梁桥结构模型边界条件参数修正
[铁路、船舶、航空航天和其他运输设备制造业] [2014-05-15]
针对实际桥梁结构复杂的边界条件,详细分析边界条件的附加约束参数.以梁桥结构的水平平动附加约束与扭转附加约束参数为讨论对象,采用最小二乘约束优化反演理论,建立以模态参数实测值与理论计算值误差平方和最小为目标的桥梁结构边界条件变异参数约束优化反演求解问题.在其基础上引入矩阵摄动理论,将结构动力方程的特征值及特征向量一阶摄动代人所建立约束优化方程,显著提高优化求解效率,并通过迭代求解的方式提高边界条件变异参数的求解精度.编制相应求解程序,通过某磁浮轨道梁方案的损伤识别验证表明,仅用前几阶仿真计算得到的模拟实测频率与振型经过4次迭代即可精确反演桥梁结构边界条件变异参数.
关键词：模型修正；边界条件；模态参数；优化反演
-
1854.全球商用飞机碳刹车盘市场报告（2014-2018年）
[铁路、船舶、航空航天和其他运输设备制造业] [2014-04-26]
Modern, lightweight, and fuel-efficient aircraft are now in demand and aircraft manufacturers are trying hard to meet this demand. The carbon brake, which is a substitute for the traditional brake, is lightweight and has high energy absorption capability. The cost of carbon brakes used to be high; therefore, steel brakes were used in small aircraft and carbon brakes were used in large aircraft. In recent years, there have been a lot of improvements in the carbon brake technology, making carbon brakes cost competitive with steel brakes. The Global Commercial Aircraft Carbon Brake market is expected to witness steady growth due to the presence of some emerging trends that are expected to negate the impact of the challenges to a certain extent. One such trend is the increasing demand for low-maintenance carbon brakes. Another trend is the increasing focus on R&D.
关键词：碳刹车；市场状况；飞机
-
1855.全球无人机机载遥感市场报告（2014-2018年）
[计算机、通信和其他电子设备制造业,铁路、船舶、航空航天和其他运输设备制造业] [2014-04-20]
The Global UAV Airborne Remote Sensing Technology market is expected to grow at a moderate rate during the period 2013-2018. The majority of the demand for remote sensing products was from the Americas, which accounted for 64-66 percent of the market revenue in 2013. The APAC and the EMEA regions are experiencing promising growth, and this trend is expected to continue during the forecast period. The Global UAV Airborne Remote Sensing Technology market is expected to reach US$2.86 billion by 2018, growing at a CAGR of 5.39 percent during the forecast period.
关键词：遥感；材料对象；信息；设备收集；空间（卫星）；飞机
-
1856.环球飞行管理系统市场报告（2014-2018年）
[信息传输、软件和信息技术服务业,铁路、船舶、航空航天和其他运输设备制造业] [2014-04-19]
The electronic systems used in spacecraft, aircraft, and artificial satellites are known as avionics systems. Avionics systems include the flight management system, navigation systems, and communication systems. A flight management system is a device that performs the work that was originally carried out by navigators and flight engineers. The prime function of flight management systems is in-flight handling of the flight plan. The systems have various sensors that help the devices locate the position of the aircraft and guide the pilot according to the flight plan.
关键词：航天器；飞机；人造卫星；航空电子设备系统；飞行管理系统；导航系统；通信系统
-
1857.全球航空航天复合材料市场报告（2014-2018年）
[铁路、船舶、航空航天和其他运输设备制造业] [2014-04-15]
This report covers the present scenario and the growth prospects of the Global Aerospace Composites market for the period 2014–2018. The report considers 2013 as the base year and provides data for the trailing 12 months. The market size was calculated on the basis of the total global revenue generated from the shipment of composite materials for the Global Aerospace market. The report also presents the vendor landscape and a corresponding detailed analysis of the top four vendors in the Global Aerospace Composites market. In addition, it discusses the major drivers that influence the growth of the Global Aerospace Composites market. It also outlines the challenges faced by the vendors and the market at large, as well as the key trends that are emerging in the market.
关键词：复合材料；飞机制造；高的强度；重量比；抗疲劳耐力；耐腐蚀性；耐磨性；展性
-
1858.美国宇航局空间通信网络集成
[信息传输、软件和信息技术服务业,计算机、通信和其他电子设备制造业,铁路、船舶、航空航天和其他运输设备制造业] [2014-04-03]
Salient features of the Integrated Network include (a) a central system element that performs service management functions and user mission interfaces for service requests; (b) a set of common service execution equipment deployed at the all stations that provides return, forward, and radiometric data processing and delivery capabilities; (c) the network monitor and control operations for the entire integrated network are conducted remotely and centrally at a prime-shift site and rotating among three sites globally (a follow-the-sun approach); (d) the common network monitor and control software deployed at all three network elements that supports the follow-the-sun operations.
关键词：通信；宇宙通信；网络控制；数据处理；成本
-
1859.北极地区通信小卫星（ARC-Sat）
[计算机、通信和其他电子设备制造业,铁路、船舶、航空航天和其他运输设备制造业] [2014-04-03]
Organizations are unable to support near‐ and mid‐term Arctic operations to include: Humanitarian Response, Environmental Response, International Search & Rescue (SAR), and Counter‐Trafficking (to include WMD).
关键词：通信；小卫星技术；通信卫星；北极地区
-
1860.机场移动航空通信系统干扰对机场的辐射模式特性的影响
[铁路、船舶、航空航天和其他运输设备制造业,计算机、通信和其他电子设备制造业] [2014-04-03]
In this study, the cumulative interference power distribution at low earth orbit from AeroMACS transmitters at the 497 major airports in the contiguous United States was simulated with the Visualyse Professional software. The dependence of the interference power on the number of antenna beams per airport, gain patterns, and beam direction orientations was simulated. As a function of these parameters, the simulation results are presented in terms of the limitations on transmitter power required to maintain the cumulative interference power under the established threshold.
关键词：通信；无线辐射模式；移动通信系统；仿真
027-87841330