DESC field failure evaluation program-`a cradle to grave approach'

The Defense Electronics Supply Center's (DESC's) field failure evaluation program is described. The primary objective of the program is to take positive corrective action steps to assure that quality electronics parts are used in US Department of Defense (DoD) weapon systems. The process flow of field failures from their inception to final corrective action is discussed. To illustrate this, four case studies are presented in which lab testing and coordination with the supplier has resulted in positive corrective action, improving the quality and reliability of the electronic components in DoD weapon systems     

Advances in DoD's ATS Framework

The Automatic Test System (ATS) Executive Directorate (ED) is charged with developing objectives for the Department of Defense (DoD) ATS modernization. The DoD ATS Framework Working Group (FWG) was established by the ATS ED to create a Framework addressing these objectives. The FWG consists of two sub-groups: Management, that includes members from all of the DoD Services, and Technical. The Framework is made up of key elements and associated specifications and standards that form the open system architecture approach for DoD ATSs. In addition to creating and updating key element definitions, the FWG focuses on identifying commercial ATS related specifications that might satisfy the elements in the Framework. The standards specified in the DoD ATS Framework are documented in the DoD's Information Technology Standards Repository (DISR) and thereby become a mandatory requirement for all DoD ATS acquisitions. The Framework is also being specifically called out in DoD ATS requirements documents so that its standards are incorporated in future DoD ATS acquisitions, such as the Navy's eCASS.     

Proposal to TPS delivery in 4 months?

Decreasing the often lengthy Test Program Set (TPS) development time is a high priority for both DoD and commercial industry. A protracted test development time for a commercial product can make or break its success. It can impact time-to-market goals for a product, which in turn, can result in a loss of market share. Though the DoD world has different objectives, they, too, are concerned with long test development times which can increase costs and jeopardize a weapon system's mission readiness. The case study for this paper is a test system developed by BAE Systems in less than four months to meet a commercial customer's stringent schedule requirements. The factors that contributed to the success of this project are examined, as is their relevance to the DoD world. The desire is to apply relevant lessons learned from the commercial industry to DoD programs, yielding a decrease in TPS development time     

飞行器智能柔性工装无线控制系统

用于飞行器大型薄壁件加工的智能柔性工装系统由数十个甚至上百个定位/支撑单元构成,每一单元又是复杂的机、电、液、气一体化系统,需在运动中与外界实时通信获取上位机指令同时反馈内部状态信息。对于这种由众多运动子系统构成的复杂大系统的网络化控制需求,若采用传统的有线控制方案不仅成本高而且难以实现,而本文提出的无线通信与有线网络相结合的网络化分布式递阶控制系统却为解决这一难题提供了新的途径。重点介绍了该系统的总体结构和无线主控子系统、网络化协调控制子系统、分布式执行控制子系统等核心环节的硬件电路和软件实现技术,并给出了相关问题的解决方案。实验结果表明,该系统具有较高的稳定性、可靠性和鲁棒性,有效解决了大规模运动通信和分布式控制问题,可很好满足项目的总体要求。     

The J-MASS Marketplace: a new way for DoD to do business

It is current DoD policy to use commercial off-the-shelf software whenever it meets DoD requirements. The application of this policy to modeling and simulation has resulted in the concept of “The Joint Modeling and Simulation System (J-MASS) Marketplace.” J-MASS is designed as an Open Systems Architecture with the capability for the Simulation Support Environment (SSE) to be expanded by the addition of site specific software. In the “J-MASS Marketplace” industry will build commercial tools to work with J-MASS and individual organizations will license what they need for their particular site. The J-MASS SSE is a framework or backplane into which everything else plugs. A J-MASS product release would have the core capabilities, but the unique needs of various organizations would be satisfied by industry. This paper addresses how the J-MASS Marketplace could work and how compliance can be defined. It will outline opportunities for industry in both building software for the Marketplace and in defining the Marketplace concept     

A Survey of Software Quality Assurance

This summarizes the authors' research into the state-of-the-practice of software quality assurance (SQA) in software organizations throughout the Department of Defense (DoD). Information was obtained through personal visits to a limited number of software facilities and by utilizing a SQA questionnaire that was mailed to 27 DoD software organizations. Twenty questionnaires were returned from Army, Navy, Marine Corps, and Air Force organizations involved in the Life Cycle Software Support (LCSS) process. The survey developed information regarding such topics as: staffing; personnel qualifications; quality standards used; SQA responsibilities; error data collection; adequacy of existing documentation; staff composition; distribution of SQA effort; and workforce mix. In addition, a list of SQA ``Lessons Learned' was developed from comments made by DoD quality managers. The results of this study indicate a wide variance in the application of SQA within the DoD.     

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     

Software architecture requirements for DoD automatic test systems

The DoD has achieved success with recent automatic test equipment (ATE) families, as evidenced by the navy's consolidated automated support system (CASS) and the army's integrated family of test equipment (IFTE) programs. However, as these systems age, the increased requirements for technology insertion due to instrument obsolescence and the demands of advanced electronics are becoming evident. Recent advances in test technology promise to yield reduced total ownership costs (TOC) for ATE which can incorporate the new technology. The DoD automatic test system (ATS) executive agent office (EAO) objective is to significantly reduce total ownership cost. Several objectives have been identified including use of synthetic instruments, support for legacy test product sets (TPSs), and more efficient ways of developing TPSs. The NxTest software architecture will meet the objectives by providing an open systems approach to the system software. This will allow for the incorporation of commercial applications in the TPS development and execution environments and support current advances in test technology     

Synthesis of an Electrical Power System for a Manned Lunar Base

Current program planning in the area of lunar surface explorationenvisions missions of increasing energy requirements and duration.During the mid 1970's it has been estimated that the electrical powerrequirements for a 3-man mission of one year duration might be in theorder of 33 000 kWh. Load profiles to support regeneration of fuelcell reactants for lunar roving vehicles and base nighttime operationsindicate potential power levels of from 30 to 100 kW. An electricalpower system using a state-of-the-art photovoltaic energy conversionsource was postulated on the assumption that nuclear power systemtechnology would not be flight ready by this time period.The process of synthesizing an overall electrical power system isdiscussed. Included are analyses and system design rationale. A rangefrom 50 to 500 volts dc is considered and the effect on weight andefficiency determined. Additional system criteria such as thermalcontrol, reliability, and emergency operation are discussed. A shred-out oftotal system weight as a function of voltage and regulation is presentedfor a 36 kWload. The impact ofload level, conditioning efficiency,transmission length, and temperature on system weight is discussed. Sensitivityivity curves depicting the effect of variations in these parameters areprovided.It is concluded that an efficiency of 80 percent or greater can beattained by matching the load profile with distribution voltage.     

US Air Force EarthRadar for detection and discrimination of buriedunexploded ordnance

The US Air Force EarthRadar system is a multi-purpose sensor designed and constructed using "radar" principles. This technology was originally developed for the US Air Force to detect buried unexploded ordnance (UXO). Bakhtar Associates developed the US Air Force EarthRadar technology under the DoD SBIR program. The system is capable of detecting buried metallic and non-metallic objects, including glass vials. In addition, the manner in which system hardware, signal processing, and the integrated high resolution global positioning system (GPS) are configured makes it ideal for applications such as mapping subsurface geological features, locating cavities and collapse features, and identifying contaminated ground     

STEP: a tool for estimating avionics life cycle costs

An overview is presented of how the US Air Force has had significant success in the estimation of life cycle costs (LCC) for avionics hardware and software using the Standardization Evaluation Program (STEP) model for estimating operating and support (O&S) costs. The capabilities of the existing STEP model as well as ongoing enhancements to provide a total LCC estimating methodology are described. In addition to the standard cost reports, STEP has the capability to assess the impact of reliability on life cycle cost. Another unique feature of the STEP model is the capability to assess the impact of retest OK (RTOK) on life cycle costs. The acquisition enhancement is being accomplished in three parts each of which will produce a distinct, usable product. The three products are an automated database, an analogy estimating capability, and a parametric estimating technique. Each is briefly discussed     

Comparative analysis of energy storage media and techniques

Techniques for storing and converting energy from one form to another are examined. The parameters of interest are storage density (in terms of both energy and power), conversion efficiency, and number of steps in the conversion process. The techniques compared are electrostatic, magnetic, inertial, chemical, thermal, and nuclear. Each technique for storage is discussed in terms of the ease with which the energy can be converted to electricity for powering lightweight compact power systems for a variety of uses. The storage density associated with the various mechanisms spans an enormous range (~0.5 MJ/kg to ~10⁵ MJ/kg). The impact upon time-to-refuel within the context of mobile tactical army applications is discussed     

Selecting a programming language for your project

Since the mandate was dropped that the Ada language had to be used in all DoD projects, software managers have had more freedom to choose which programming language to use on their DoD projects. For most new DoD software projects that need a general purpose high-level language, Ada, C, or C++ are the main contenders, with increasing attention paid to the new language celebrity, Java. Furthermore, multilanguage systems seems to be getting increasingly popular. As a result, companies offer integrated multilanguage programming environments. Although each programming language has its own strengths and weaknesses, the reason for choosing a particular language may ultimately be based on factors having nothing to do with the technical merits of the language itself. Such factors may include the availability of compilers for the host/target, the maturity and efficiency of available compilers, the availability of programmers who already know the language, whether the language can easily interface with existing systems such as graphical user interfaces or data bases, the existence of legacy software written in a specific language, or how well the language fits in with adopted COTS products. A few common misconceptions that may affect the choice of a programming language are listed     

Spiral evolution applied to legacy avionics systems

The US Department of Defense (DoD), through the Office of the Secretary of Defense (OSD), has determined that evolutionary acquisition is their strategy of choice for future software-intensive systems, and that the spiral development model (SDM) is the preferred method/process for software-intensive development life cycles. Electronic Systems Command (ESC) at Hanscom AFB, Massachusetts, has written a draft handbook on the use of Spiral Development for all future Command and Control (C2) systems, including reference to the DoD 5000 series and Air Force Program Directive 63-1, Acquisition System, which deploys this OSD mandate for future C2 systems. Barry Boehm's continued work on SDM which he conceived in the 1980s, is heavily biased toward development of new systems that are software-intensive, as noted in a workshop he gave at the Software Engineering Institute (SEI) in 2000.     

航空发动机结构系统的可靠性模型

为使航空发动机可靠性模型误差更小,对航空发动机传统可靠性模型进行误差分析,指出可靠性指标扩张的原因,建立了考虑航空发动机结构系统及其失效力学特征的基于结构系统失效模式的航空发动机可靠性模型,并给出了各层的可靠度计算方法.所建立的基于失效模式的航空发动机结构系统可靠性模型考虑了失效模式的相对独立性、时效性和失效率的时变性,可以避免重要失效模式的遗漏、可靠性指标的过度扩张等问题,具有较强的工程适用价值.      

Surveillance through walls and other opaque materials

The Department of Defense (DoD) has funded a dazzling array of “high tech” solutions for many of the problems facing our military forces. Many of these “solutions” have been effective for long range mass destruction but have not been applicable for the close-in hand-to-hand combat that is on our streets. Our goal at the Hughes AET Center has been to convert “high tech” DoD capabilities into cost effective tools to help law enforcement agencies do their jobs better. Surveillance systems presently used by law enforcement officers make extensive use of television, infrared and other Line-of-Sight (LOS) surveillance systems. However, these systems cannot tell what is happening on the other side of a wall, behind bushes, around the corner, in the dark or through a dense fog. A new sensor has been developed that uses technology developed by the DoD for missile warhead fuzing. This small, light weight, low power “Radar” is based upon the fact that radio waves can penetrate nonmetallic materials. This new surveillance capability can help provide information about what is in a wall, ceiling or floor or on the other side of a door or concrete wall. Real field scenarios are used in this paper to show how this radar works and how field users can tell if someone is moving inside a building, even from remote locations     

谈系统可靠性和可用性的几个实际问题

本文是以某工程通信系统建设实践为基础,通过试验、试用统计数据分析,对用国产电子设备组成的系统,就其系统可靠性和可用性方面存在的几个问题作了讨论。在系统可靠性方面,论述了采用分组冗余技术进行系统设计的必要性和合理性。对系统可用性,从广义上作了简述,并通过该工程建设,说明各种因素对系统可用性的影响及应注意的问题,可供同类系统工程参考。     

燃气涡轮发动机的状态监控与故障诊断

 为了提高燃气涡轮发动机的可靠性,耐久性并降低直接使用成本,近年来发展了发动机状态监控与故障诊断系统。大量试验和使用经验证明了这个系统的有效性。目前,该系统已在航空燃气轮机,工业燃气轮机和车辆用燃气轮机上广泛应用。 本文介绍了这个系统的功能,技术要求,并着重介绍了用气动热力参数,振动和滑油分析进行状态监控及故障诊断的原理及其应用。最后,文章讨论了今后发展中的问题。     

Large Capacity Magnetic Bubble Memories for Government Applications

Magnetic bubble memories are an all solid-state, nonvolatile technology that offers a viable alternative to rotating electromechanical memory systems. Rotating memory systems such as magnetic disks, tapes, or drums are often not practical in government applications because of maintenance, reliability, and security problems. Bubble memories offer improvements in the required system reliability for these applications and lend themselves to a modular memory design not possible with mechanical systems. A 244 Mbit memory system is described which is general purpose in design, has a block random access architecture, and has demonstrated its high reliability.