Got software? what managers and engineers need to know

As part of a JPL-wide software quality initiative aimed at addressing the challenges of developing, managing, and acquiring software, a team at JPL generated a detailed Software Training Plan for both managers and engineers. The team took the approach of treating the software training program as though it were a system development task and went through all the typical phases of system development including requirements, design, and implementation. During the requirements collection phase, the team conducted dozens of interviews and identified the specific skills needed. The skills fell into categories such as software management, software engineering, systems engineering, and other technical areas. However, an equally important finding was that several "soft" skills were deemed critical for the successful and timely management and implementation of software-intensive systems. This discusses JPL's approach and "lessons learned" from planning and delivering a software training program in an engineering and scientific environment.     

Characteristics of a successful space system engineer

The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite was launched on June 24, 1999, on a three-year mission to explore the universe using the technique of high-resolution spectroscopy in the far-ultraviolet spectral region. The FUSE instrument comprises many subsystems, each of which contributes in an essential way to the success of the mission. The instrument system engineer oversees the engineering of all elements in such a complex technical project. In performing system engineering for the FUSE instrument's command, telemetry, data processing and data storage functions, and in leading the engineering efforts for the development of the FUSE instrument on-board computer, the author has learned valuable lessons about the characteristics that are prerequisite to success for a space system engineer. These characteristics fall under various categories of acquired, practical know-how. These categories are described with illustrations drawn from the development of the FUSE instrument. In addition to these practical skills and the concomitant knowledge, the system engineer needs personal integrity, which is the link that connects knowledge with know-how and makes them work together to motivate a team of subsystem engineers. This, too, will be discussed     

The Development of Systems Engineering

Systems engineering is described as the design of the whole as distinguished from the design of the parts. Systems engineers create the architecture of the system, define the criteria for its evaluation, and perform tradeoff studies for optimization of the subsystem characteristics. In addition to their own brains, the principal tool of systems engineers is the computer. Systems engineering has evolved during a long series of major developments, in particular the intercontinental ballistic missile (ICBM) program. The major growth of systems engineering is expected to be in the improvement of its tools and in the enlargement of the range of problems to which it is applied.     

The aerodynamic design of multi-element high-lift systems for transport airplanes

High-lift systems have a major influence on the sizing, economics, and safety of most transport airplane configurations. The combination of complexity in flow physics, geometry, and system support and actuation has historically led to a lengthy and experiment intensive development process. However, during the recent past engineering design has changed significantly as a result of rapid developments in computational hardware and software. In aerodynamic design, computational methods are slowly superseding empirical methods and design engineers are spending more and more time applying computational tools instead of conducting physical experiments to design and analyze aircraft including their high-lift systems. The purpose of this paper is to review recent developments in aerodynamic design and analysis methods for multi-element high-lift systems on transport airplanes. Attention is also paid to the associated mechanical and cost problems since a multi-element high-lift system must be as simple and economical as possible while meeting the required aerodynamic performance levels.     

通信卫星模拟器通用基础平台设计研究

卫星模拟器主要是对地面测控系统遥测接收和遥控指令发送的工作状态进行检查和验证,验证地面测控系统设备正确性,提高地面测控系统对卫星故障的应急处理能力等。本文从软件系统架构高度对不同卫星各分系统模型共有属性进行抽象提炼和设计研究,提高软件架构及模块的复用性、扩展性和维护性,通信卫星模拟器通用基础平台可同时验证不同卫星对地面测试系统的任务要求,使不同卫星模拟器的建设和地面系统测试支持可以纳入一个规范化、通用化的系统框架中。     

MBSE在航空飞行控制系统的应用研究

现代飞机系统的复杂性不断增长,传统的开发方法在管理和维护方面变得越来越具有挑战性。首先,对航空飞控系统研发过程在当前系统工程实践方面进行了评估,阐述了传统开发方式的不足和基于模型的系统工程（MBSE）的核心原则和优点,以及在实现中常用的工具和方法;然后,展示了MBSE如何在飞行控制系统研发时使用模型来支持复杂系统的规范、设计、分析、验证和确认的过程;最后,结合先进的MBSE工具和方法的发展,MBSE结合敏捷的开发前景,以及提高MBSE实践的互操作性和标准化的需求对未来的研究方向进行了展望。本文研究为利用MBSE方法论和工具来改进飞行控制系统的设计、开发和性能感兴趣的航空工业专业人员、系统工程师提供资源和解决思路。     

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.     

软件研发模式的路径依赖与路径突破

型号软件作坊式研发模式很难达到GJB5000A过程要求,软件工程真正要上台阶、上水平,会受到多种因素制约。作坊式研发模式构成了软件工程过程改进的"路径依赖",路径选择错误,沿着错误的路径向前走,走得越远,回到正确路径的难度越大。理想的解决方案是整个产品研发团队一起"贯标"。     

Mechanical engineering's role in multi-disciplinary radar design

Successful execution of a program and full satisfaction of the customer's requirements is a challenge for any contractor. Raytheon Company responds to this challenge by following a proven program execution methodology. The methodology includes all program aspects from financial planning to engineering to validation and test. This discusses the engineering team and the role of the mechanical engineer. A radar system is ultimately an assembly of advanced electronics and software. However, the design, fabrication, assembly, integration, and test Of this complex system requires a coherent multi-disciplinary approach. Raytheon, like many contractors, chooses to assemble an integrated product team (IPT) including all engineering disciplines. Mechanical engineering is integral to satisfying performance requirements, performing preliminary and detailed design, transition of the design to manufacturing, and implementation of the hardware in the field. During definition, mechanical engineering assists fundamental architecture development, conceptual design, and requirements development which precludes issues that are sometimes ignored to the detriment of many programs. These design issues include environmental protection, structural stiffness to meet deflection requirements, cooling system capacity to properly remove dissipated heat, manufacturabilit3' to control cost, maintainability to enable repair in the field, and transportability. Recognizing and trading off these issues early greatly increases the Probability Of satisfying customer objectives. This discusses the approach Raytheon is taking to ensure an overall multi-disciplinary solution to our design challenges from the perspective of the mechanical engineer.     

Spacecraft engineering and research at Saint Louis University

Parks College of Engineering and Aviation of Saint Louis University [1i] has a tradition of offering an outstanding aerospace engineering education to prepare students at the undergraduate and graduate level for careers in commercial aviation, defense systems, and space systems fields. Courses are offered across the engineering spectrum (aerospace, electrical and computer engineering, and physics departments) ranging from an introduction to aerospace engineering to spacecraft design, spacecraft communications, and space physics. Students participate in courses that include orbital mechanics, space dynamics, spacecraft engineering, and space systems. Senior capstone project work is also included. A separate Astronautics Engineering track as well as a Minor in Space Systems Engineering for non-aerospace engineering students is currently being developed. A, number of student-driven space systems projects are in process that involve design, development, and test of small satellites similar to those recently highlighted in the March 2009 Systems article entitled The First one Hundred University-Class Spacecraft 1981 - 2008. Reference [4] identifies student spacecraft launched over the past 27 years.     

Advanced Picosatellite Experiment

The design of the CAPE I satellite was underway for approximately three years. This interdisciplinary project incorporates electrical, mechanical, and aerospace engineering, as well as computer science and physics. The project hoped to teach students how to design, develop, and maintain a lower Earth orbiting satellite. This satellite was delivered to San Luis Obispo, California, December 5, 2006, where it passed the final integration test in order to qualify for launch. After qualification, the satellite was loaded into the poly-picosatellite orbital deployer or P-POD, which is the deployment system for the satellite. The P-POD holds three CubeSats. Once all three satellites were integrated, it was delivered to Kazakhstan and loaded into the DNEPR Russian Rocket on March 17, 2007. After a few delays, the rocket was launched on April 17,2007. The team is currently monitoring and decoding the CW beacons transmitted by the satellite. The project was broken into several subsystems including mechanical, communications, control and data handling, and power. Each of the systems proved to have their own unique challenges. Being that the majority of the team was electrical engineering students, the mechanical subsystem presented the most difficulty. There is currently a design in progress for the next satellite project, CAPE II. This new satellite will attempt a new benchmark by incorporating more advanced technologies than CAPE I and include other campus entities such as The Wetlands Research Center. The team hopes to deploy buoys into the Gulf of Mexico that will communicate to the CAPE 11 satellite in space and then send data to the ground station at the University. This data will include subjects such as coastal erosion, water temperatures, and drift currents throughout the Gulf. With this data, we can give other organizations the information obtained for their use as well.     

航空发动机健康管理用户的诊断预测指标体系

航空发动机健康管理的顶层设计必须要满足不同健康管理用户的使用要求。简要介绍了健康管理系统的用户分类和开发流程,重点分析了面向外场使用的后勤、飞行、维修、机群管理等军方健康管理用户的要求。从健康管理诊断和预测的技术实现出发,分别分析了军方不同用户的要求与诊断、预测指标之间的映射关系,建立了相应的诊断和预测指标体系。可为军方制定满足外场使用需求的研制总要求,工业部门制定贴合用户需求的研制规范提供借鉴。     

基于MBSE的副翼及其操纵系统研发技术及应用

飞机的设计研发是一项涉及多学科领域、多目标、多约束的复杂系统工程过程,系统耦合紧密、参与人员众多、设计信息庞杂,以文档为中心的需求管理等传统研发方法突显出一定的困难,亟需探索新的飞机设计研发方法。以副翼及其操纵系统为研究对象,对基于模型的系统工程(Model Based System Engineering,以下简称MBSE)方法进行了探索研究:采用达索MBSE方法论-MMS(Modeling Methodology for Systems,以下简称MMS),从使命、服务、功能和组件不同视角对副翼及其操纵系统研发的各个方面进行解析,进而完整定义系统;利用达索3D Experience平台,通过RFLP系统工程架构,进行了副翼及其操纵系统的需求开发、功能分析及逻辑架构设计,完成了需求、功能、逻辑架构、系统仿真、物理设计等模型的关联追溯,实现了以达索MBSE方法论为核心的研发技术的有效应用。     

大型客机信息化研制支撑体系架构研究

大型客机的研制具有复杂程度高、技术难度大、协作范围广等特点，随着研制要求的不断提高与研制范围的不断扩大，传统研制模式已经发生重大转变，需要将信息化技术融入大型客机研制过程，以提高大型客机的研制质量和效率。本文提出了大型客机信息化研制支撑体系的基本概念以及总体架构，包括业务应用平台、数据管理平台、基础技术平台，并通过产品生命周期、管理业务流程、产业价值链3个方面的应用管理，可实现对大型客机研制过程的有效支撑。经过实际型号工程研制的验证，该体系能够支撑大型客机研制的全过程，大幅度地提高研制质量、缩短研制周期、降低研制成本。     

“Dakota Sun”-the next generation solar powered racingvehicle

Based on the experience gained from Sunrayce '95, the Solar Motion Team has made many changes to the design of the next generation solar car. These changes have resulted in a vehicle that is very different from the “Solar Rolar”, The Dakota Sun is a three wheeled vehicle with separate cab and solar array. This design allows for improved aerodynamics, decreased weight, lower rolling resistance, and ease of manufacture compared to the four wheeled catamaran used in the last race. However, this design sacrifices total enclosed wheel base area, additional room for components, and added power from side solar panels, The major objectives for the team's redesigned Sunrayce '97 entry are: systems integration; decrease the weight of the car; decrease aerodynamic drag; more efficient use of available energy; and increased driver safety. The team has set a standard to use the latest available technology. Although this increases the complexity of the components, by using a systems engineering approach the “Dakota Sun” has evolved into a more integrated vehicle. This philosophy of integrated design has resulted in great improvements in mechanical design and manufacturing techniques, as well as electrical innovations. The major design changes evident from the original Sunraycen '95 vehicle are the result of an evolutionary design process that has produced the highly competitive Sunraycel '97 design outlined in this article     

A Discussion on System Effectiveness Assurance Elements

Growing complexity of some technological systems requires engineering assurance that the systems will perform effectively at some distant point in time, when all contractual requirements shall have been met and the first assembled system faces the performance test program. The many new- and old-related assurance disciplines are outlined briefly, as being indispensable to effective engineering acquisition of present day systems of large magnitude for civilian or defense purposes.     

基于多目标粒子群算法的导航星座优化设计

导航星座的设计涉及诸多优化变量的选取,优化设计的目的是选取合适的优化变量使导航星座最大程度地满足人们需求。提出了将导航性能和卫星生产成本作为目标对导航星座进行多目标优化设计的研究方案,导航星座基本构型为中轨道(MEO)与地球静止轨道(GEO)卫星组成的混合星座,MEO卫星用于全球导航,GEO卫星用于增强星座对中国及周边地区的导航性能。探讨了MEO和GEO的轨道设计思路。阐述了星座导航性能与卫星生产成本的计算方法,并选取定位精度因子(PDOP)作为导航性能指标。介绍了基本粒子群算法和多目标优化的概念,提出了改进的多目标粒子群算法(MOPSO),给出了该算法的计算步骤和测试结果。讨论了导航星座多目标优化设计的数学模型,列举了优化设计变量的定义域,采用MOPSO算法对导航星座进行了多目标优化设计,通过分析优化设计结果,说明了导航星座多目标优化设计方案的可行性。     

Data-driven reliability analysis of Boeing 787 Dreamliner

The Boeing 787 Dreamliner, launched in 2011, was presented as a game changer in air travel. With the aim of producing an efficient, mid-size, wide-body plane, Boeing initiated innovations in product and process design, supply chain operation, and risk management. Nevertheless, there were reliability issues from the start, and the plane was grounded by the U.S. Federal Aviation Administration (FAA) in 2013, due to safety problems associated with Li-ion battery fires. This paper chronicles events associated with the aircraft’s initial reliability challenges. The manufacturing, supply chain, and organizational factors that contributed to these problems are assessed based on FAA data. Recommendations and lessons learned are provided for the benefit of engineers and managers who will be engaged in future complex systems development.     

Development Engineering on System 465L

The development engineering involved in large scale systems is but one of many problems included in acquisition of these systems. The purpose of this paper is to explore some of the engineering problems encountered in the development of the Strategic Air Command and Control System 465L and to indicate how the interaction between the technical problems and the nontechnical problems affects the final engineering decisions. In this paper we will indicate the basic requirements for the system and show how the system was configured to meet these requirements. The deficiencies uncovered in the design and first cut solutions to the problems and the compromises which were necessary to implement the system will also be discussed. Illustrative examples will be used to show how the design evolved into the final system configuration which is now in use.