Air traffic management design considerations

An air traffic management system (ATMS) is a network-centric system being used to manage another network-centric system, namely, an air transportation system. We are developing a design language for network-centric systems and design guidelines for the development system of engineers and domain specialists involved in designing and integrating systems. Note: this development system with today's technology is also a network-centric system. An outline of the design language under construction and the design guidelines being studied is provided. Specifically we discuss ATMS mission objectives (e.g., average yearly throughput of people and freight for a high demand scenario); ATMS sample usage scenarios (e.g., ATMS reroutes air traffic in time and space in reaction to major weather deviation along the northeast coast); and system objectives for an ATMS (e.g., timelines of a specific high volume of messages from aircraft, weather sensors, and airports). We lay out some key design decisions associated with both the development system of engineers and domain specialists and the operational ATMS. Examples of key design decisions for the engineering system are: 1) appropriate partitioning of functional/physical architectures of the engineering system; 2) appropriate degree to telecollaboration and collaboration among design/integration groups; 3) appropriate incremental delivery packages for an incremental delivery schedule of ATMS elements; and 4) appropriate levels and thrusts of the risk management program. Examples of key design decisions for the operational ATMS are: 1) throughput and security trades of the ATMS and 2) throughput and resiliency to weather changes. Finally, we relate network-centric architecture issues to both of the above sets of design decisions.     

An overview of Allied-Signal's avionics development in the CIS

AlliedSignal Commercial Avionics Systems (ASCAS) and its partners have established the following business objectives: short term (forward-fit and retrofit with off-the-shelf products; co-development of integrated systems); mid term (co-production of avionics products in the CIS); long term (become an integrated element of CIS aerospace industry in partnership with local firms and to maintain the necessary focus to achieve these goals). ASCAS has formed a strategic business enterprise which is dedicated to developing the avionics market within the CIS. ASCAS was fortunate to find a joint venture partner who possesses skills that complement its present core competencies. The advantage of this business arrangement is that, while expanding their experience and expertise in the area of systems integration, they can directly benefit from the expertise and capabilities of indigenous airframe and equipment manufacturers (customer knowledge, simulation and integration experience, capable/skilled manpower)     

系统工程方法在民用航空产品研制中的应用思考

随着航空产品研制日益复杂,越来越多的民用航空企业都期望在产品研制中应用并推广系统工程的方法,以提高企业民用航空产品的研制能力,为此需要按系统工程的方法构建民用航空产品研制体系。针对该问题,从要求层、程序层、方法层、作业层四层体系架构进行了阐述,对顶层的系统工程要求如何在具体实践之间的落地进行了探索。     

一种基于 ICT 的工件模型三维重建方法

基于ICT的CAD建模技术,是一种引入了ICT这一高新科技的逆向工程方法,模型三维重建是这一技术的关键。针对具有机加表面的产品工件,提出一种模型三维重建方法,对其实现过程进行了描述,并通过了实验验证。     

全球知识城市视野下城市知识管理的有效路径

随着知识经济时代的来临,知识越来越成为城市提升核心竞争力、赢得竞争优势的关键性要素。如何管理好知识,已经成为城市现实发展和未来选择的全新主题。同时,全球成功知识城市的发展经验也表明,城市能否充分有效地管理好知识,将是决定城市经济社会可持续发展与提升综合竞争力的关键所在。在当前中国城市化走上快车道、国际国内城市竞争越发激烈的关键时期,从战略的高度、以前瞻性的眼光加强对城市知识管理(Knowledge Man-agement,KM)的认识和研究,是中国城市化进程中一个值得十分关注的重要课题。城市知识管理(Urban Knowledge Management),是促使城市转型、产业结构调整和提升城市品质,以赢得未来竞争主动权的重要途径和手段。文章在全球知识城市的视野下,阐述了城市知识管理的深刻内涵与主要内容,分析知识城市与城市知识管理的内在关系,继而提出城市进行知识管理的有效路径。     

JETS - Junior Engineering Technical Society

Junior Engineering Technical Society - JETS - was launched in 1950 after several years of research and preparation, it was designed to provide for the engineering profession what the 4-H clubs provided for agriculture. Initially known as BETS - Better Engineering Talent for Schools - it did not take long to evolve into JETS, the name that has been used to serve the pre-college engineering community for over fifty years. JETS has, however, respected its heritage through its motto: better talent for engineering. JETS is the only academic program at the high school level (Grades 9-12) that focuses completely on developing "real-life" engineering teamwork and necessary engineering problem-solving skills. JETS is working with more than thirty thousand students and their teachers with programs that are in use throughout the United States, Puerto Rico, and the Virgin Islands     

复合材料机身框轴向压缩屈曲分析与研究

通过试验研究了复合材料机身框承受轴向压缩载荷下的失效模式,并与工程理论计算、有限元分析进行对比。试验研究的框构型包含"C"型框和"Z"型框,试验结果显示,复合材料机身框与蒙皮结构在承受沿框方向的轴向压缩载荷时,首先蒙皮发生局部屈曲;随着载荷的增大,框腹板和内缘也发生局部屈曲,最终导致整个框截面的破坏。对蒙皮局部屈曲采用两加载边简支、两侧边固支的层压平板屈曲工程分析方法,分析结果表明,工程理论计算与试验数据吻合良好,并且理论值具有保守性。对于框腹板及框内缘这类薄壁结构,其边界支持作用弱于简支,导致工程理论计算结果不保守。为了获得框腹板与框内缘更准确的局部屈曲结果,必须采用几何非线性有限元建模分析。     

浅谈落实以可靠性为中心的维修

文章从四个方面论述了以可靠性为中心维修的基础、核心、重点和保证,说明了开展这四个方面工作的重要性。并提出要着眼于整个航空工程系统,以系统工程的原理和方法,改革维修系统结构,调动设计、制造和使用、维修各方面的力量,来促进飞机维修水平的不断提高。     

ISE: intelligent synthesis environment for future aerospace systems

The Intelligent Synthesis Environment (ISE) being developed by NASA, UVA, and JPL for significantly enhancing the rapid creation of innovative affordable products and missions is described. ISE uses a synergistic combination of leading-edge technologies, including high-performance computing, high-capacity communications and networking, virtual product development, knowledge-based engineering, computational intelligence, human-computer interaction, and product information management. The environment will link scientists, design teams, manufacturers, suppliers, and consultants who participate in the mission synthesis, as well as in the creation and operation of the aerospace system. It will radically advance the process by which complex science missions are synthesized, and high-tech engineering systems are designed, manufactured, and operated. The evolution of engineering design is described along with the shortcomings of current product development techniques. The need for ISE to create high-science payoff missions and aerospace systems at affordable costs is discussed. The five major components critical to ISE and some of their sub-elements are described: namely, human-ISE interaction; infrastructure for distributed collaboration; rapid synthesis and simulation tools; intelligent life-cycle system integration; and cultural change in the creative process. Related government and industry programs are outlined and future impact of ISE on complex missions and aerospace systems is discussed.     

一种基于多普勒频移比的交叉定位中虚假目标清除方法

清除由测向线交叉产生的虚假目标点是无源交叉定位的关键问题,目前已经有多种解决办法,如最小距离法、最大似然法和频谱相关法,但它们或是有效性低,或是计算量大,或是需要较难获得的先验知识。利用多普勒频移比清除双站测向交叉定位产生的虚假目标是一种新方法,这种方法只利用传感器接收到的目标频率,而无需获得目标的发射频率,也不需其它的先验知识,且计算较为简单。计算机仿真结果表明该方法有效。     

襟翼高升力系统和结构部件飞机维修手册程序验证研究

目前,我国民用飞机维修手册验证工作尚无相关标准和规范,亟需开展相关研究工作,争取早日建立完备的手册验证体系。在国产某型客机试飞阶段,结合试飞改装工作进行大批量维修手册操作验证工作,提出手册验证操作的技术要求、操作流程和实施要点;以襟翼高升力系统和结构部件的飞机维修手册验证程序为例,从实际操作可行性和省时性角度出发,开展手册验证计划编排和验证实施方法设计,总结维修操作难度较大的襟翼拆装程序编写实施要点、注意事项、常见维修性问题及改进方法,为后续验证工作提出建议。     

EXPERIMENT RESEARCH ON DYNAMIC LOAD IDENTIFICATION TECHNOLOGY BASED ON GENERALIZED ORTHOGONAL POLYNOMIAL THEORY (GOPT)

Dynamicloadisoneoftheimportantoriginalparametersinstructuraldynamicanalysis.Ithasobviousinfluencestodynamicsdesign,vibrationcontrols,activecontroltechnologyandsoon.Sincel97O,manyresearchitemsinthisfieldhavebeenaccomplishedintheworld-Sometheoriesandexperimentalmethodsofdynamicloadidentificationhadbeencreatedinfrequencydomain[l'2J-Howeverftherearesomedisadvantagesthattheycouldbeadaptedonlytoidenti-fythesteady-stateloadandnottoidentifythetransientload,suchasshockloadwithshortsampling.Forvarious…     

面向战例知识图谱的本体构建

为构建合理的战例知识图谱,提出了一种面向领域知识图谱的工程化本体构建方法。基于该方法,构建了战例领域本体模型,建立了战例本体与实体的映射机制。检验实证,该方法构建的本体合理有效,能够为战例领域知识图谱构建提供有效的模型支撑。     

焊接结构完整性数据库及专家系统

针对焊接结构完整性研究的需要,建立了焊接数据管理数据库系统,并在此基础上结合BS7910评定方法建立了焊接缺陷评定专家系统。该系统采用模块化设计思路,采用面向对象设计方法,对整个系统进行总体设计。该系统实现了焊接工艺数据的信息化管理,可进行多种焊接方法焊接工艺数据的管理和查询,结合专家系统的合于使用评定方法,可对含缺陷结构进行2个级别的安全评定和裂纹容限尺寸计算。     

航空发动机适航知识库构建方法研究

针对航空发动机适航领域知识重用、共享性差的问题,分析该领域知识特点;采用改进重采样和BRF方法进行知识获取;提出产生式规则、框架网络和面向对象的混合知识表示模型。与数据库软件的有效集成,创建智能知识库系统,实现了知识的查询和维护。     

基于有向点集的多面多孔式装配偏差分析与协调

多面多孔式装配是航天航空等大尺度部件装配/装调常见的连接形式之一,其空间装配关系复杂,调配环节多且存在耦合,以试错式的装配作业方式存在难度大、需反复试装与调配、装配质量一致性差、装配效率低等问题。采用"有向点"表征轴/孔配合的空间装配关系,提出了一种基于有向点集的多面多孔式装配协调数学模型,通过奇异值分解（SVD）分解法对基于有向点集的协调模型进行最优匹配运算,给出了装配调整量的计算方法。最后,以实际工程需求为应用背景,在实验室环境下进行了多面多孔式装配协调试验,结果表明基于测量数据的装配偏差分析与装配调整量计算方法可行。     

Advanced Aircraft Electric System

The topics, advanced aircraft electric system and all-electric airplane, inspire a broad range of concepts from the evolutionary to the revolutionary. The revolutionary developments are exciting to the research and development community but find little encouragement or acceptance from airframe developers whose objective is to build an advanced technology airplane using only-off-the-shelf, proven equipment. Their anthem rings "We know how bad the ___________ is, but we have learned to live with it. We have only your vision of how good an advanced system will be and fear to chance it. "However, the cost of living with these known systems combined with the escalating cost of fuel and the military need to address advanced mission capability demands more than a patch called improved reliability and maintainability. The time is at hand to demonstrate an evolutionary approach to achieve a revolutionary improvement. This paper describes an advanced electric system, the life cycle cost improvement anticipated, and the evolutionary means to implementation.     

逆向工程中曲面重构算法研究与实现

给出了基于坐标测量机测得的海量数据重新构造样板物体的数字化表面模型的算法流程。该算法首先利用部分测量数据构造张量积的B样条网格曲面,通过确定适当的检查点,并计算检查点到所构造的B样条网格曲面间的距离,从而控制重构曲面的构造精度。讨论了与文中算法相关的空间点到NURBS曲面间的距离计算等问题。给出了1个工程应用实例,表明该算法稳定可靠、效率较高。     

COTS based open systems for military avionics

The DoD has many acquisition programs that are aggressively implementing open architecture principles in new avionics systems. Since “open” is an unclear attribute, projects eventually give in to a point solution that has no flexibility to cost effectively keep up with rapid changes in technology. The Open Systems Development Initiative (OSDI) project utilized COTS products to study the feasibility of building an open system that has plug-and-play capabilities. Lessons learned from the AV-8B Open Systems Core Avionics Requirements (OSCAR) and the F/A-18 Advanced Mission Computers and Displays (AMC&D) programs clearly indicated that understanding the underlying interfaces is crucial to keeping the system as open as possible to take advantage of the rapid changes in technology. A matrix of Key Open Standard Interfaces (KOSI), called the KOSI matrix, was developed and an applicable standard was identified for each interface. A list of non-conforming interfaces was also identified and the use of extensions or wrappers was investigated in an attempt to comply with standards. Standardization, rather than optimization of such interfaces, was considered more beneficial. It became evident that, with the exception of ruggedization, there is no difference in the use of COTS products for either commercial or military systems. Performing a KOSI analysis helped identify the key interfaces and standards, thus enabling the OSDI system to be scalable, portable and interoperable. A good KOSI matrix provides a vehicle for clear communication and helps systems integration and technology insertion to be less painful than what it is today. It helps reduce time-to-market and provides guidance to systems engineers and vendors to keep the system open     

Formulation of discovery-class mission concepts

A key feature of the NASA discovery programs is the strategy of allowing a single scientist with a "good idea" to form his/her own team of scientists and engineers to generate a concept which is credible and attractive to a complete body of independent peers. The principle investigator (PI) must accept responsibility for all aspects of the mission. A wide variety of mission types have been found to fit the discovery mold, including fly-bys, orbiters, landers and even sample return missions. To enhance this fit, it has been necessary for scientists and engineers to work closely in: evaluating spacecraft risks, setting data throughput requirements and methods of their amelioration, focusing on key objectives, and deriving strict instrument and experiment requirements from overall goals and engineering realities. Discovery is loaded with challenges, but likewise, represents the most promising opportunities for affordable, frequent scientific advances in planetary exploration.