Open System Avionics Architectures

Over the last three years, Open System Avionics Architecture concepts have been addressed by the avionics community as a method for increasing affordability. The Naval Air Systems Command (Nav Air) led Advanced Avionics Architecture and Technology Review team of 1992, followed by the multiservice Avionics Engineering SubBoard (AESB) implementation phase team are two examples. The Perry memo and formation of the Open Systems Joint Task Force (OS-JTF) are further evidence of the importance placed on open systems at the DoD level. This paper summarizes these activities and their importance. Examples of the savings that can be expected by application of open systems are presented. Finally, significant on-going work along with critical technologies and concepts that need to be matured to make open systems successful are discussed     

Open systems architecture for integrated RF electronics

The Integrated Sensor System (ISS) program is defining an Open System Architecture (OSA) for Radio Frequency (RF) electronics, which represent the largest portion of an advanced aircraft's avionics flyaway cost. An integrated architecture is used to reduce costs in a number of ways, including time-sharing, centralization of resources, and reduction of the number of unique module types. The OSA approach extends these cost reductions by simplifying technology insertion, using well-understood standards, and increasing use of commercial hardware and software. This paper describes interim results. The work was funded by the Open Systems Joint Task Force (OS-JTF)     

基于控制变量参数化的主动反拦截突防最优控制计算方法

针对由于敌防空系统防御能力不断提高所带来的进攻导弹突防难题,提出主动反拦截突防(IAIP)的概念,以弥补传统机动突防仅考虑进攻导弹的逃逸而忽略其攻击任务的缺陷。根据IAIP制导的内涵,在综合考虑目标的机动性能、拦截导弹末段的拦截特性及进攻导弹的控制系统性能的基础上,建立进攻导弹-目标-拦截导弹的三体运动模型。将突防制导指令的设计等效为最优控制的求解,其中突防指令为实现燃料最省目标的最优解,进攻导弹的过载、拦截导弹的脱靶量、进攻导弹的攻击角、打击精度和突防后的视线角,分别为控制约束、路径约束和末端约束。借鉴控制变量参数化(CVP)方法将最优控制问题转化为非线性数学规划问题,并将路径约束离散化后采用序列二次规划(SQP)算法得到突防时机给定条件下制导指令的数值解。提出基于CVP的混合遗传算法(CVP-GA),用于求解最优突防时机及制导指令。仿真结果显示,采用IAIP最优控制算法的进攻导弹在成功突防后的打击精度仍可满足任务要求,且其燃料消耗相对于传统串联式突防方法降低了23.7%,验证了该方法的有效性及优越性。     

GPS III system operations concepts

Over the past three years, the Lockheed Martin GPS III team has analyzed potential operational concepts for the Air Force. The completed tasks support the government's objective of a "realizable and operationally feasible" US Strategic Command (USSTRATCOM) and Air Force Space Command (AFSPC) concept of operations. This paper provides an overview of the operational improvements for the command and control of satellites, the provision of safe, precise navigation and timing services to end-users. The GPS III system changes existing operational paradigms. Improved operator capabilities are enabled by a new high-speed uplink/downlink and crosslink communication architecture. Continuous connectivity allows operators a "contact one satellite - contact all satellites" concept enabling near-real-time navigation updates and telemetry monitoring. This paper describes potential improvements for the following operations: constellation monitoring, command and control, navigation upload monitoring, global service monitoring, global service prediction, civilian navigation (CNAV) messaging, and anomaly detection and resolution. This paper also describes future operational improvements as GPS applications continue to proliferate and the need for an improved infrastructure to effectively manage all the systems that affect GPS service grows     

Tracking and data acquisition for space exploration

The tracking and data acquisition systems provide the key link between the remote spacecraft and the scientific experimenter on the ground. The operation of the space experiment takes place through the links of command, telemetry and tracking. The evolution from the early very simple spacecraft missions toward more complex and sophisticated missions has been paralleled by a similar evolution in the tracking and data acquisition systems. The early Minitrack interferometer tracking system still carries the major tracking workload for space missions; however greater tracking accuracy requirements for more recent missions, such as the Orbiting Geophysical Observatory and the Apollo mission, have brought about the development of unified tracking and data acquisition systems which utilize hybrid pseudo-random code/sidetone ranging techniques. The data acquisition has evolved from analog telemetry systems to the present day heavy use of PCM digital telemetry. Likewise the command systems have evolved from early simple on/off command systems into PCM digital command data systems. The trend is toward greater real time control of more complex functions on board the spacecraft. Newer spacecraft are incorporating computer-type systems in the spacecraft which require programming and memory load through the ground command link. The most attractive concept for the next generation network for tracking and data acquisition is a network consisting of synchronous-orbit Tracking and Data Relay Satellites for covering launches and low-orbit earth satellites plus a few selected ground stations for supporting spacecraft in high earth orbit and lunar orbit.     

Open system concepts for modular avionics

Advanced communications, guidance and navigation systems play key roles in determining superiority of one combat aircraft over another. The use of advanced technology is essential to meeting the mission requirements of present as well as future aircraft. Modular avionics are being used in next generation aircraft, such as the Air Force F-22 fighter and the Army Comanche helicopter, as the means of achieving higher levels of performance, including reduced volume and improved adaptability, maintainability, and expandability. New system acquisitions such as Joint Strike Fighter will attempt to achieve these same performance levels but at dramatically reduced life cycle cost. Retrofit applications will also take on increasing roles in meeting this affordability need as the Department of Defense (DoD) struggles to maintain readiness in the face of the shrinking defense budget. The government is encouraging the use of open standards practices as a means of addressing the affordability issue. The Open Systems Joint Task Force (OS-JTF), formed in September 1994, is chartered to “sponsor and accelerate the adoption of open systems in weapons systems and subsystem electronics to reduce life-cycle costs and facilitate effective weapon system intra- and interoperability”. The purpose of this paper is to relate the concept of open systems to modular avionics. It discusses the key attributes of an open systems approach and identifies key technologies necessary for its success     

APPLICATION OF DIRECT BTT GUIDANCE LAW BASED ON NONLINEAR INVERSE SYSTEM THEORY TO INTEGRATED FIRE／FLIGHT SYSTEMS（IFFS）

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THE CLUSTER DATA PROCESSING SYSTEM: A DISTRIBUTED SYSTEM IN SUPPORT OF A CHALLENGING SCIENTIFIC MISSION

The Cluster mission is aimed at the study of small-scale structures that are believed to be fundamental in determining the behaviour of key interactive processes of cosmic plasma. The mission will be controlled from the European Space Operations Centre (ESOC). ESOC is also in charge of the commanding of the scientific payloads on-board the four Cluster spacecraft after negotiation with the Cluster Principal Investigators (PIs) and of collecting and distributing the mission's scientific results to the Cluster community. This paper describes the process of translating the scientific requirements of the Cluster mission into a data-processing system supporting the mission via the definition of an appropriate operational scenario. In particular, the process of negotiation between the PIs and ESOC to command the spacecraft is mediated by the Joint Science Operations Centre (JSOC) and finalised by the Cluster Mission Planning System (CMPS) while the return of the data to the Cluster community is actuated by the Cluster Data Disposition System (CDDS). The Cluster Mission Control System (CMCS) provides the interface between these two systems and the spacecraft. These elements constitute the Cluster Data-Processing System (CDPS).     

利用领域专用软件体系结构集成大型指挥系统的方法

以领域专用软件体系结构（Domain Special System Architecture,DSSA）为基础,建立了＂指挥信息系统组装与集成体系框架模型＂,并阐述了该模型的设计思想、总体结构和关键技术。同时,采用对象转换代理层方法和沟通对象模型的桥接技术,分别解决多体制技术的包容性和不同构件间的数据交换及互操作问题。结果表明,利用该模型集成大型指挥系统是可行的,并对其他类似信息系统具有一定的借鉴意义。     

"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.     

基于AADL的机载设备系统可靠性建模

AADL可以描述机栽设备系统的时序需求、任务状态等关键性能特性,已应用于航空、电子自动化、机器人控制等实时系统。提出基于AADL的机载设备系统可靠性建模方法,为该系统模型结构的设计和验证提供了理论依据。采用EMA子语言对AADL描述的机载设备系统进行可靠性建模,给出可靠性模型中的错误模型、错误传播和状态映射规则等子句属性的用法。最后通过一个基于AADL的机载设备可靠性建模实例,验证了所提建模方法的有效性。     

俯仰姿态保持模式下飞机结冰边界保护方法

在研究飞机结冰机翼和平尾失速机理的基础上,以飞机迎角作为关键参数,飞机俯仰指令作为指令参数,提出一种基于飞机自驾仪的结冰后边界保护方法.通过引入铰链力矩检测模块,提前告警飞机失速,为边界保护提供了裕度.建立飞机纵向动力学方程,针对俯仰姿态保持（PAH）模式下机翼失速进行了仿真计算.结果表明:结冰条件下,通过铰链力矩的检测,飞机能在失速迎角为2°之前,进入边界保护模式,增加飞行安全的裕度.通过控制指令的限制,自动驾驶模式下飞机迎角能保持在失速迎角之内.      

T-250转塔式加工中心数控系统的设计

简要论述了开放式数控系统的概念，并在华中Ⅰ型开放式数控系统的开放平台上，对T-250转塔式加工中心数控系统进行了设计。     

All terrain ground collision avoidance and maneuvering terrainfollowing for automated low level night attack

The development of an all-terrain ground collision avoidance system (GCAS) in conjunction with a maneuvering terrain-following (TF) system is discussed. Both systems use a digital terrain database. These systems are presented concurrently because of their complementary mission role. The unprecedented pilot interaction available with the automatic systems provides a means to improve combat survivability significantly. The pilot is able to execute high rate turns, evasive maneuvers, and inverted ridge crossings while following the terrain contour. Safety is maintained in day, night and weather by the GCAS. The combination of these systems with an automated attack system, automatic target handoff system, night vision system, and a route planner to provide a lethal night attack capability is examined. Piloted simulation and preliminary flight test results are presented     

CCSDS空间包在MOIMS领域中的应用

为了适应未来航天任务的发展,构建以服务为导向的、开放的、可重用的航天器任务操作系统,分析了CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)中MOIMS (Mission Operations and Information Management System,任务操作及信息管理系统)领域的任务操作服务框架的原理、层次结构及优点,对任务操作相关的通用服务、功能服务、COM(Common Object Model,通用对象模型)及MAL(Message Abstraction Layer,消息抽象层)对服务的抽象化描述方法进行了研究.MAL向任务操作相关的服务提供了通用的服务模型框架,所有服务均可用MAL消息格式进行规范化的描述,在此基础上建立了MAL消息格式与CCSDS空间包的映射关系,从而以CCSDS空间包为信息栽体实现了航天器与地面系统间的任务操作通信,可以作为以服务为导向的任务操作系统实际工程应用的参考.     

国外通用开放式结构标准的应用情况

SAE AS4893标准定义的通用开放式结构（GOA）是嵌入式系统的层次化体系结构模型。通过对GOA领域目录集的开发与维护标准化过程的分析,结合GOA在航空电子领域的应用案例展示其标准化技术的应用现状;并考虑到先进综合式航空电子系统在任务功能划分和系统工程方法方面的应用要求,探讨并展望GOA标准化技术应用于新一代航空电子系统开发过程中的注意事项。     

THE JOINT SCIENCE OPERATIONS CENTRE

The Joint Science Operations Centre (JSOC) has been established to provide the operational interface between the Instrument Principal Investigators (PIs) and the European Space Operations Centre (ESOC). Its key task will be to merge inputs from the Cluster instrument teams and to generate the coordinated command schedule for operation of the scientific payload. In addition, it will collect and process data needed to plan those operations and will monitor the performance of the mission and individual instruments. This paper outlines the JSOC subsystems that have been built to carry out these tasks and highlights points of scientific or technical interest within these systems.     

Digital Flight Control Research Using Microprocessor Technology

The Flight Research Laboratory at Princeton University is engaged in an experimental program to investigate a variety of approaches to digital control by actual flight test. Experimentation is being conducted with Princeton's 6-DOF variableresponse research aircraft (VRA), which is equipped for direct side-force control, direct-lift control, feedback of all motion variables, and multiple-pilot command modes. VRA avionics have been augmented by a microprocessor digital flight control system (Micro-DFCS), which uses off-the-shelf computer components capable of operating in parallel or in series with the existing variable-response system. The digital control laws operate in conjunction either with the "bare airframe" dynamics of the VRA or with the dynamics of a simulated aircraft, provided by the existing variable-response system. The initial flight control computer program CAS-1 provides three longitudinal control options: direct (unaugmented) command, pitch rate command, and normal acceleration command. The latter two options are "Type 0" systems designed by linear-quadratic control theory. Future Micro-DFCS software will provide a variety of increasingly complex control options, including "Type 1," logic, gain scheduling, coupled 3-axis control, and "CCV" command modes.     

虚拟座舱多功能显示器的设计与实现

在剖析座舱显示系统的发展及现状的基础上,本文详细介绍了虚拟座舱多功能显示器的设计原理及过程。整体系统的设计基于Open GL开发的仿真软件平台,系统的通信接口遵循W indows套接字规范,模块化架构兼顾了软件的移植性和继承性。通过任务计算机传输数据,虚拟多功能显示器可以实时显示飞机的飞行、导航、机载设备运行状态等参数,较好地模拟了战机实战状态下的各种数据显示。