Assessment of the suitability of public mobile data networks for aircraft telemetry and control purposes

This paper provides a review of the state of the art of relevant work on the use of public mobile data networks for aircraft telemetry and control proposes. Moreover, it describes the characterisation for airborne uses of the public mobile data communication systems known broadly as 3G. The motivation for this study was to explore how this mature public communication systems could be used for aviation purposes. An experimental system was fitted to a light aircraft to record communication latency, line speed, RF level, packet loss and cell tower identifier. Communications was established using internet protocols and connection was made to a local server. The aircraft was flown in both remote and populous areas at altitudes up to 8500 ft in a region located in South East Queensland, Australia. Results show that the average airborne RF levels are better than those on the ground by 21% and in the order of −77 dbm. Latencies were in the order of 500 ms (1/2 the latency of Iridium), an average download speed of 0.48 Mb/s, average uplink speed of 0.85 Mb/s, a packet of information loss of 6.5%. The maximum communication range was also observed to be 70 km from a single cell station. The paper also describes possible limitations and utility of using such communications architecture for both manned and unmanned aircraft systems.     

新型高精度变焦距系统设计

简要介绍了传统凸轮结构变焦距系统的原理、组成及存在的问题,并针对传统凸轮结构变焦距系统存在的主要问题,提出了一种新型高精度变焦距系统,用直线步进电动机替代凸轮机构控制变倍组和补偿组在直线导轨上线性或非线性精确移动,用直线光栅尺替代电位计,完成焦距值实时输出,并对步进电机实现闭环控制。该系统比传统凸轮结构变焦距系统光轴晃动减少90%,定位精度提高80%。     

航天任务控制中心容灾模式研究

航天任务是一项高投入、高风险的活动,作为管理所有在轨飞行航天器及资源的航天任务控制中心,要求具备很高的可靠性与较强的容灾能力。国际航天大国对地面系统,特别是任务中心级的备份均非常重视,也开展了相关建设和系统运行。在对我国航天任务控制中心容灾模式进行探讨的基础上,提出容灾中心的技术要素、需求分析以及运行机制。     

信息物理融合系统及其在航空制造业应用展望

信息物理融合系统(Cyber-Physical System,CPS)是当前国内外研究的热点,是实施智能化制造的核心技术。阐述了CPS的定义、原理和特点,并就CPS在航空制造业的应用前景和发展路线进行了分析。     

Study on the system of night hours for decoding Korean astronomical records of 1625–1787

This paper presents a study of the dates and times of astrophysical phenomena seen in the night time hours in Korea between 1625 and 1787. This is a period when two different calendars were used and it is important to know which calendar was used to record events such as lunar eclipses. It is known that the Joseon court adopted Shixianli (a Chinese calendar of Adam Schall) in 1654, the fifth reign of King Hyojong. However, the year when the court introduced the calendar into the system of night hours has not yet been determined. To know the enforcement year is very important for studies on astronomical events that are presented in Korean historical documents. From Seungjeongwon Ilgi (Daily Records of the Royal Secretariat), we compile a total of 90 lunar eclipse records referring to the observation time of the eclipses and calculate the times of occurrence of the eclipses with respect to the calendrical methods: Chiljeongsan Naepyeon (a Korean calendar) and Shixianli. As a result, we find that the system of night hours by the former calendrical method was used in the Joseon dynasty until as late as 1710. We also verify that the times of sunrise and sunset were considered as the moments when the center of the Sun reached the horizon according to Chiljeongsan Naepyeon at least. Therefore, we think that this study will contribute to the studies on astronomical phenomena of the Joseon dynasty, particularly on the estimate of the observation time.     

我国中继卫星系统在交会对接任务中的应用

我国中继卫星系统在交会对接任务中得到了成功应用,显著提升了测控通信覆盖率,充分体现了中继卫星系统在交会对接任务测控通信中发挥的重要作用.结合中继卫星系统特点,分析交会对接任务对中继卫星系统的任务需求;探讨了中继卫星捕获跟踪用户目标、对用户目标测定轨、着陆场直升机缝隙通信等关键技术;最后总结了中继卫星系统抗雨衰影响、多目标支持能力、应急支持能力等方面的经验做法,并提出了后续改进和完善的建议.     

基于A320飞机横航向控制律架构的LQ设计

前缘缝翼、襟翼活动面及其支承结构的疲劳试验是民用飞机取证前要开展的一项重要工作。在试验中采用主动驱动和随动加载方法加载,不仅能缩小试验规模,同时可提高试验精度。国内某型机采用此技术成功进行了前缘缝翼、襟翼及其悬挂结构的疲劳试验。从试验件及其支承设计、系统构成和载荷与运行三方面,介绍了一种适用于大中型固定翼飞机前缘缝翼和襟翼的疲劳试验技术。     

识别民机产业发展特点 提高民用航空产品研发水平

就基本的管理规律和参数而言,所有航空产品的研制基本一致,但因为市场和客户的不同,民用航空产品研制在体系建设和技术覆盖面方面有自己的特点,尤其是适航规章要求和客户使用环境不同,使得民用航空产品的研制必须要更多地把产品全寿命周期的技术成功和运行支持纳入早期的研制活动,这必然带来在研制体系和技术能力建设方面的差异化,而早日识别和把握这些差别是民用航空产品产业健康发展的必须。