Mission/flight systems integration study: a long-term electronicsplanning project

The objective of the Mission/Flight System Integration Study (M/FSIS) is to identify the requirements and development objectives for electronics systems technologies and conceptual architectures in future weapon system applications (in and around the year 2005), based on analyses of future missions, threats, scenarios, aerospace system concepts, and technology trends. The products are substantiated requirements for future electronics functions, systems, and architecture; technology development objectives and roadmaps; and conceptual electronics architectures and functional definitions. The study outputs will serve to guide laboratory technology development planning and programs; guide weapon system program office long-range electronics planning; illustrate user needs in terms of electronics requirements; and guide air logistics center weapon-system master planning     

新形势下航天测控系统建设转型思考

针对航天测控系统建设目前所面临的角色定位转换、功能体制转型,以及任务要求不断提高、测控技术快速发展等新形势和新要求,分析了航天测控系统的建设管理和功能体制现状,提出了坚持一体规划、推动系统建设,坚持与时俱进、提升建设标准,坚持信息主导、突出建设重点的系统建设转型思路.并在此建设思路的基础上,提出了装备研制向型谱化、标准化转型,维修保障向全寿命、体制化转型,软件开发向产品化、装备化转型,以及推进一体化网络化、强化综合能力、重视安全性可靠性等建设举措.     

Reconfigurable COTS test systems

Automatic Test Equipment (ATE) systems are used to qualify, accept, and troubleshoot electronic products. ATE systems may be in the form of large general-purpose systems that can test a wide variety of products or the more commonly used custom, turnkey systems that are designed for specific test application(s) and requirements. Turnkey ATE systems are labor-intensive; as a result, even a relatively simple turnkey tester is costly and may take months (or even years) to develop, integrate, and deploy. The main reason for this aspect of turnkey ATE systems is that even though the instrumentation may be off-the-shelf components, most everything else is custom and requires design, development, extensive debug and integration. Time and again, systems integrators have tried to find a solution that would combine the cost effectiveness of COTS systems with the flexibility of custom ATE. This paper suggests a solution to this problem and that it is feasible to combine COTS testers with custom requirements. This solution, called CreATE, provides a flexible architecture using COTS components (including instruments, cabling and interfacing products)     

Lessons learned using software-assisted systems engineering on large satellite development contracts

Over the years, the world's defense industries have become quite proficient at developing large, complex hardware and software systems. In recent years, the ubiquitous deployment of personal computers has changed the way we work. Additionally, took designed to facilitate systems engineering have recently matured enough to start having a major impact on many major systems development efforts. Finally, the government's faster-better-cheaper acquisition philosophy has started driving prime contractors to a concurrent engineering approach toward systems engineering. This confluence of experts is has had unexpected impacts on both the flexibility and rigor of requirements management processes. While the maturing requirements and design took hold great promise in maintaining requirements traceability throughout the design process, the widespread use of desktop computing systems has inadvertently lulled many experienced systems engineers into sloppy processes because it now appears to be a simple matter to make a requirements change in a softcopy of a requirements document. Without strong process and management support, requirements changes inevitably start being derived in a broad spectrum of incompatible took and formats. This author is currently participating in the design phase of a major classified government satellite development effort. As an integral member of an extremely experienced requirements management team (boasting over 150 years of combined experience in the defense industry), this author has had the opportunity to watch the team navigate straight into many of the systems engineering potholes created when talented engineers implement concurrent engineering using a variety of tools without a consistent process framework. This paper, therefore, specifically addresses process and implementation challenges that arose when establishing a software-assisted concurrent-engineering approach on a large satellite development contract.     

Trunking vs. conventional radio systems

Correctional Service Canada (CSC) has recently replaced the aging, out-of-date radio communications systems in all major CSC facilities with new conventional digital radio systems. Based on very specific and restrictive operational requirements coupled with developments in digital radio technology and the Associated Public Communications Officers (APCO) Project 25 digital radio standards, it was determined that digital radio communications would best meet CSC's needs. The CSC national radio replacement program was completed in March 2000. Switching to a digital radio communications system gave CSC an opportunity to consider changing the existing radio system from a number of conventional, single-site systems to a trunking system. Areas to be considered when determining the architecture for a radio communication network, whether radio trunking systems or conventional radio systems should be used, are presented, In addition, the paper will also outline the requirements and measures taken to keep the radio communication network active and operational while the equipment was converted from an analog technology to a digital one     

下一代数据中继卫星系统发展思考

通过系统阐述中继卫星系统的发展过程,给出了主要国家和组织的中继卫星系统技术体制和现状.再结合卫星、载人航天器和深空探索的未来发展趋势,分析了下一代中继卫星系统的发展需求.在此基础上,从体系结构、卫星平台、链路调制体制、网络协议等方面,探讨并给出了下一代中继卫星系统的发展趋势和技术途径.为满足未来近地、深空航天任务,以及临近、低空快速移动用户的不同要求,节约系统成本,下一代中继卫星系统将向专业化和与其他系统融合的方向发展:星间链路将增加激光链路,数据速率可达到10 Gbit/s以上;多址业务成为主用,同时支持用户数能力将极大提高;对于链路调制体制,在采用CR(Cognitive Radio,认知无线电)和SDR(Software Defined Radio,软件定义无线电)技术的基础上,可实现实时自适应调整和根据需求加载配置;数据传输将采用网络化方式,天地间构成一体化DTN(Delay Tolerant Network,容延迟网络).     

The realism of FAA reliability-safety requirements and alternatives

As avionic systems become more complex, realistic qualification requirements for the flight-critical systems becomes more important, but more difficult to define. Requirements developed to establish acceptable levels of performance must be verifiable if they are to have any meaning. This article shows that both the current FAA requirements of flight-critical systems and the FAA recommended methods for probabilistic assessment are flawed, and result in “required” safety assessments which are misleading. Alternatives are then explored     

空间光学遥感器的发展对先进复合材料的需求

从国内外空间光学遥感器技术发展的需要出发,提出了对该领域内基础材料的需求及其应用特点。在此基础上,又提出了空间光学遥感器中光机结构材料和典型的光学反射镜材料在机械稳定性和热稳定性方面的要求。还提出了应用材料在空间中的热真空适应性和表面防护问题。同时介绍了新型空间光学遥感器中应用的新型复合材料。     

基于飞控系统故障后的飞行品质评定方法适航验证技术研究

使用电子飞行控制系统的运输类飞机必须要满足适航安全性的要求。由于运输类飞机通用的规章(14CFAR25部)中许多稳定性和操纵性的要求已经不能代表和覆盖对这类飞机的最低安全要求,因此需要采用新的适航验证方法进行适航评定。通过对某型飞机的研究,采用HQRM方法评定,给出了分析取证的流程以及思路,最后给出按照不同组合概率选取不同的适航验证方案。     

Trials and tribulations of implementing intranet technology: theCassini Information Access System

The Cassini Information Access System (IAS) was built to provide Cassini Integration and Test engineers with ready access to current technical and logistical project information. World Wide Web (www) technology was used to provide a consistent user interface to pre-existing interactive systems as well as new repositories and interactive services developed specifically for Cassini. A Web “gateway” was developed for each pre-existing data service. Each service had its unique requirements including read-only and read-and-write access to SQL databases. Other requirements called for the development of many background processes to handle the access of data produced by proprietary databases and non-database data repositories. Through the use of the www, anonymous ftp, Novell services, and unique data conversion programs, we were able to put the system into limited operation by August 1995 and full operation by March 1996     

High accuracy navigation and landing system using GPS/IMU systemintegration

In this paper, the accuracy, integrity and continuity of function requirements for automatic landing systems using satellite navigation systems are discussed. Such a landing system is the integrated navigation and landing system (INLS) developed by Deutsche Aerospace (DASA/Ulm, Germany). The system concepts of the INLS are presented. It is shown how an INLS, based on system integration of a satellite navigation system (e.g., GPS) in realtime differential mode with an inertial measurement unit (IMU) in the accuracy class of an attitude and heading reference system (AHRS), can meet the requirements: the results given are mainly devoted to the accuracy issues. Using Kalman filter techniques, an in-flight calibration of the IMU is performed. The advantage of system integration, especially in dynamic flight conditions and during phases of flight with satellite masking, is explained. The accuracy, integrity and continuity of function of the INLS were proven by means of flight tests in a commuter aircraft using a laser tracker as a reference. These flight tests have shown that the short-term accuracy (<60 seconds) of the AHRS used within the INLS has been improved from low cost sensor quality to the accuracy of a high quality laser inertial navigation system (LNIS). With the presented INLS, a landing at any airfield, not equipped with conventional Instrument Landing System (ILS) or Microwave Landing System (MLS), is possible by using a very cost effective system. The INLS is a high accuracy navigation and landing system designed to be used instead of conventional landing systems at small airfields and to fill operational gaps of conventional navigation and landing systems in cruise and approach on large airports     

Performance enhancement using power beaming for electric propulsionEarth orbital transporters

Power requirements for an electric propulsion Earth orbital transport vehicle (EOTV), which can effectively deliver large payloads using much less propellant than chemical transfer methods, are addressed. The power beaming concept is described. Arcjets, magnetoplasmadynamic (MPD) thrusters, and ion engines are covered. Power supply characteristics are discussed for nuclear, solar and power-beaming systems. Operational characteristics are given for each, as are the effects of the power supply alternative on the overall craft performance. Because of its modular nature, the power beaming can meet the power requirements of all three electric propulsion types. Commonality of approach allows different electric propulsion approaches to be powered by means of a single power supply approach. Power beaming exhibits better flexibility and performance than onboard nuclear or solar power systems     

航天测控中心系统自主可控建设的研究与思考

着眼于我国航天测控中心系统信息安全的形势要求,对系统软硬件平台自主可控技术的应用现状进行了分析,指出了当前存在的一些安全隐患问题。立足于航天测控中心系统当前发展实际,结合信息安全方面的特殊要求,从加强自主可控的顶层设计、抓好测试验证、分层推广应用等方面提出了系统自主可控建设的思路。针对自主可控建设的长期性和复杂性,从技术继承与发展、技术引进与对外合作、系统升级与安全平稳过渡等三个方面,探讨了在自主可控建设的进程中应该处理好的几个关系问题。对于当前我国航天测控中心面临的自主可控建设有一定的借鉴意义。     

空间目标探测与识别雷达工作频段与体制选择探讨

根据空间目标探测与识别雷达的任务要求,通过对雷达搜索、扫描、探测、多目标处理能力、分辨率的技术分析与经济性比较,给出了空间目标探测与识别雷达工作频段与体制选择的参考性结论。     

Robotic technology integration for army ground vehicles

This paper discusses the US Army Tank Automotive Research, Development and Engineering Center's (TARDEC's) four (4) axis strategy for integration of robotics into the legacy, interim, and objective forces. At the cornerstone of this strategy is the R&D effort concentrating on autonomous perception and navigation, intelligent tactical behavior, command and control, and man-robot interface entailed in the Demo III and Robotic Follower programs. Smart Manned Systems focuses on a systems engineering approach for robotic solutions into the interim force (Vetronics Technology Testbed and Crew Integration & Automation Testbed). In the near-term, application of robotics to the legacy force will be achieved through adapting commercial automation technologies, which address military requirements. Finally, Intelligent Mobility will investigate improving intrinsic platform mobility to lessen the burden on robotic sensing performance. The ultimate goal of this strategy is to advance the robotics technology state-of-the-art to achieve off-road full autonomous operations for military systems in support of the objective force     

Sole means navigation in US Navy aircraft

The current edition of the US Federal Radionavigation Plan, issued in 1984, presents a consolidated federal plane on the management of those radionavigation systems which are used by both the civilian and military sectors. It states the US Dept. of Defense (DoD) goal to phase out the use of TACAN, VOR/DME, OMEGA, LORAN C, and TRANSIT in military platforms and for Global Positioning System (GPS) to become the standard radionavigation system for DoD. This would eliminate all the current sole-means air navigation systems (TACAN and VOR/DME) aboard military aircraft. Instrument Flight Rule (IFR) operations within controlled airspace requires an operating sole-means air navigation system to be aboard the aircraft. The authors investigate the requirements for GPS certification as a sole means air navigation system in the US National Airspace System (NAS); discuss the implication for GPS user equipment (UE) hardware and software; describe the actual UE implementation; and discuss approaches for UE integration with flight instruments on US Navy aircraft     

Reliability Predictions and System Support Costs

A case study demonstrates that spares requirements based on operational reliability predictions result in the system being undersupported during its burn-in and useful-life phases by average factors of 42.2 and 4.22, respectively. However, systems spares requirements based on logistics estimates result in the system being oversupported during its burn-in phase by an average factor of 4.26 with this factor probably increasing as the system enters the useful-life phase of its life cycle. Adequate system support within predetermined cost estimates will be achieved only when reliability predictions are accurate and when systems spares requirements are computed separately for the equipment burn-in phase and useful-lfe phase.     

A flat panel display upgrade solution replaces military CRTtechnology

Successful technology insertion programs must satisfy many system constraints in order to incorporate new capabilities into aging avionics systems while meeting program cost requirements. Such constraints frequently include form, fit, and functional replacement specifications, as well as power and electrical performance restrictions. This paper describes a technology insertion program undertaken with the goal of replacing the 30-year-old azimuth indicator display of a radar warning receiver system. This necessitated the use of electroluminescent (EL) display technology to replace the analog cathode ray tube display currently used in the system. Because of the prohibitively high cost of aircraft wiring modifications, the replacement display was required to be completely form, fit, and functionally equivalent to its replacement. The form, fit, and functional equivalency requirement imposed the following system constraints: (1) power consumption of less than 10 Watts; (2) the need to maintain the same stroke-deflection current electrical interface; and (3) the need to meet the maintenance and repair budget of the existing display unit. Additional requirements included night-vision compatibility and full sunlight readability. The display was also required to be MIL-STD-1553 Remote Terminal communication capable. All requirements posed a challenging technology insertion problem to program personnel. The case study described in this paper illustrates the approach to meeting the particular requirements of this technology insertion program     

"Electric Airplane" Environmental Control Systems Energy Requirements

The "electric airplane" environmental control system (ECS) design drivers is discussed for an electric airplane from two aspects. The first aspect considered is the type of aircraft. The three examples selected are the 150-passenger commercial airline transport, the military on-station electronic-surveillance patrol aircraft, and the air-defense interceptor fighter. These vehicle examples illustrate the effect of both mission and mission profile on the design requirements of the ECS and the differences that the requirements make on the resulting advantages and disadvantages of electrification. For the commercial transport, the selection of the air source for ventilation will be featured. For the patrol aircraft, the cooling unit will be evaluated. For the fighter, emphasis will be placed on the need for systems integration. The second and more important consideration is the definition of the environmental control system requirements for both energy supply and heat sink thermal management integration from the power plant (engine) that make an electric ECS viable for each type of vehicle.