Expert System Applications to the Cockpit of the '90s

There is a strong requirement for a new generation of avionics systems with a more integrated hardware and software structure. This integrated avionics system will use significant increases in computer automation with more innovative signal processing, sensor fusion and expert system software to reduce pilot workload, while improving total system performance and reliability. Expert system software packages will be implemented within the core architecture of these next generation integrated avionics systems to assist the pilot. The expert systems will consider the pertinent information available from the ``sensor' subsystems to assess the current situation. The expert systems then consult their knowledge base and rule base software structures to determine alternative reactions to the perceived situation. Then pending upon the critical of the function, situation and reaction, the expert system could either execute the most favorable reaction or display the suggested alternative courses of action to the pilot. This paper addresses the requirement, the enabling technologies and the potential structure of this next generation of avionics. It concludes with two examples of the potential of future avionics expert systems. The two examples are 1) A Navigation and Route Planning Expert and 2) A Threat Assessment and Threat Reaction Expert. Significant things are happening in technology at an accelerating pace that enable the development of this new generation of avionics.     

Viral attack to Internet banking applications

The PC Bank may be the most timesaving banking innovation since the ATM (Automatic Teller Machine). However, it also brings new possibilities for thieves. This is mainly because we have not completely solved the growing problem of computer viruses and Trojans that can act on our computers against our will. Several methods are used against them, although none can be considered 100% effective. Even more, most personal computers have little or no virus protection, so they are very easy to attack. This can become a problem as nearly all PC banking systems rely on authentication with identification passwords. This system is vulnerable and we will show that it does not provide enough protection for the users that want to make transfer operations from their accounts     

Replacement strategy for aging avionics computers

With decreasing defense dollars available to purchase new military aircraft, the inventory of existing aircraft will have to last many more years than originally anticipated. As the avionics computers on these aging aircraft get older, they become more expensive to maintain due to parts obsolescence. In addition, expanding missions and changing requirements lead to growth in the embedded software which, in turn, requires additional processing and memory capacity. Both factors, parts obsolescence and new processing capacity, result in the need to replace the old computer hardware with newer, more capable microprocessor technology. New microprocessors, however, are not compatible with the older computer instruction set architectures. This generally requires the embedded software in these computers to be rewritten. A significant savings-estimated in the billions of dollars-could be achieved in these upgrades if the new computers could execute the old embedded code along with any new code to be added. This paper describes a commercial-off-the-shelf (COTS)-based form, fit, function, and interface (F³I) replacement strategy for legacy avionics computers that can reuse existing avionics code “as is” while providing a flexible framework for incremental upgrades and managed change. It is based on a real-time embedded software technology that executes legacy binary code on the latest generation COTS microprocessors. This technology promises performance improvements of 5-10 times that of the legacy avionics computer that it replaces. It also promises a 4× decrease in cost and schedule over rewriting the code and provides a “known good” starting point for incremental upgrades of the embedded flight software. Code revalidation cost and risk are minimized since the structure of the embedded code is not changed, allowing the replacement computer to be retested at the “blackbox” level using existing qualification tests     

计算机图形系统发展简述

飞机座舱显示控制系统是航空电子系统的核心子系统,其技术基础之一是计算机图形学。本文简要介绍了计算机图形学的发展历史及其标准,重点分析了计算机图形系统从专业图形工作站到PC机到嵌入式设备的发展历程,可作为研究机载嵌入式图形系统的理论背景。     

Managing change through roadmapping [changes in aviation electronics]

Presently the USAF is operating with 90 different Model Design Series (MDS) aircraft. The 90 MDS aircraft make up a total of 5778 airframes, each with a different number of Line Replaceable Units (LRUs) which make up the avionics systems. Some of the MDSs have as few as 53 avionics LRUs while others as many as 495. The total dollar value of the USAF aircraft avionics LRUs is approximately $42.4B and $30.68B in spares. Depot repairable cost to maintain these components each year is approximately $1.2B. Each MDS is assigned specific missions and the avionics systems are developed to support those missions. Due to the evolution of mission types and user needs, change is constant for the avionics manager.     

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.     

New Horizons-the pottery problem, and its relation to computerarchitecture

The evolution of the appearance of the computer is described, and the future appearance of the personal computer is predicted. Changes to the inside of the computer are also forecast. It is suggested that computers will be the pottery of a future generation for archaeologists, allowing them to date an archaeological find     

航空电子系统中应用多核处理器的挑战分析

作为嵌入式计算的一种,航空电子系统中的处理器具有强实时性、高确定性、高安全性的特征。因此,同其他嵌入式系统相比,在航空电子系统中应用多核处理器面临更多的挑战。针对多核处理器基本的软硬件架构,对挑战产生的原因进行了简要的分析,指出了在航空电子系统中应用多核处理器需要解决的问题。     

General aviation aircraft avionics: integration & system tests

The avionics of current-day aircraft is termed as modular integrated full glass cockpit. Unlike lots of dials and gauges, the pilot will interact with Multi-Function Displays (MYD). This means that the systems are coupled with multi-function displays, communication and navigation radios with control units, multi-mode interactive instruments for control and navigation, recording and fault management systems, airframes and health monitoring diagnostic capabilities. Pilot Vehicle Interface (PVI) is an important measure of good avionics and cockpit layout, which implies the optimization of man-machine interface, enhancement of the economy, and safety of flight operations. This presents the avionics architecture of a 14-seat Light Transport Aircraft (LTA) for general aviation, which has multi-role commuter capabilities. LTA is a twin turbo-prop, multi-role aircraft, with air taxi and commuter services as its primary roles. The avionics is built on the digital communication mode for both command and control with current requirements of TCAS, digital Autopilot, and AMLCD multi-purpose glass displays. The LTA Avionics suite is grouped into six major groups based on functionality: Display System, Communication System, Navigation System, Recording System, Radar System, and Engine instruments and other cockpit displays. This paper also covers details about the extensive tests carried out to prove the avionics design in terms of functionality, inter-operability, interference, and compatibility. Various practical integration and flight-test issues, methodologies, and details of the scenarios is presented herein.     

A study of flight-critical computer system recovery from spaceradiation-induced error

It is well known that space radiation, containing energetic particles such as protons and ions, can cause anomalies in digital avionics onboard satellites, spacecraft, and aerial vehicles flying at high altitude. Semiconductor devices embedded in these applications become more sensitive to space radiation as the features shrink in size. One of the adverse effects of space radiation on avionics is a transient error known as single event upset (SEU). Given that it is caused by bit-flips in computer memory, SEU does not result in a damaged device. However, the SEU induced data error propagates through the run-time operational flight program, causing erroneous outputs from a flight-critical computer system. This study was motivated by a need for a cost-effective solution to keep flight-critical computers functioning after SEU occurs. The result of the study presents an approach to recover flight-critical computer systems from SEU induced error by using an identity observer array. The identity observers replicate the state data of the controller in distinct data partitions. The faulty controller can be recovered by replacing data image of the faulty data partition with that of the healthy data partition. The methodology of applying such an approach from the fault tolerant control perspective is presented. The approach is currently being tested via computer simulation     

解析美国机载计算机的“三化”道路

通过介绍美国海军的标准机载计算机的发展历史,讨论美国空军的航空电子系统模块化体系,以及展现美国机载计算机的“三化”历程和美国先进机载计算机的“三化”情况,剖析了美国机载计算机实施“三化”的策略,揭示出了美国机载计算机标准化的内容和发展的轨迹。     

高可靠航电文件系统浏览技术研究

利用远程系统浏览技术,研究并实现了一种基于Reliance的高可靠航电文件系统的远程浏览系统。系统采用客户端／服务器架构,通过在综合化航电系统内核中建立一个嵌入式文件服务器,可使得用户通过集成在E—clipseIDE中的远程文件浏览器客户端,对此文件系统进行访问、浏览和管理。系统能够有效地提高远程文件操作的可视性和透明性,功能丰富,操作简便,可移植性好,易于扩展。     

虚拟现实技术在军事上的应用

虚拟现实技术汇集了计算机图形学、多媒体技术、人工智能、人机接口技术、计算机仿真技术、传感器技术、计算机视觉和人的行为学研究等多项关键技术,是一门基于多种学科发展起来的计算机领域的高新技术。本文主要介绍了虚拟现实技术在军事领域的应用以及真三维立体显示技术,表明基于虚拟现实技术的军事仿真训练系统在飞行训练、海军潜艇训练、立体三维坦克作战指挥系统、立体三维直升机训练系统、立体三维海军作战指挥系统、立体三维实战演示系统等领域具有非常广阔的应用前景。     

Open systems avionics network to replace MIL-STD-1553

This paper is a proposal for a future method of avionics data communication. The need for this proposal results from the shortcomings in the current avionics architecture, video distribution network, and in the MIL-STD-1553 data communication system. The separately wired video and data communication systems can be combined to save weight, which is especially critical for rotorcraft. Aircraft, once fielded, have limited capacity for modification and improvement due to fixed computer throughput and processing performance, network bandwidth, and space available in the avionics equipment bays. The changes proposed by this paper are to be made in conjunction with the replacement of the redundant computer boxes with open system avionics functions on industry standard circuit cards. This open architecture approach was developed over the last ten years and is now being implemented in many aircraft applications including the F-22 and the RAH-66 programs. The V-22 rotorcraft, which although just entering production, is being modified for joint service customers where modern computer performance and expanded data network bandwidth is needed. The changes of this proposal will fill this need, reduce the weight of upcoming production models, and provide growth or spare capability so that additional video and data components can be added with minimal effect on existing components. This paper examines the current V-22 avionics video and data communication hardware and wiring and propose a new implementation of open system architecture standards with integrated digital video and data communication based on ANSI standard copper fibre channel     

航电系统并行检测过程与检测设备解耦方法

航电系统在使用或升级改造过程中进行可靠性检测是必不可少的。特别是在当前批量航电系统大量投入使用的背景下，迫切需要能高效、快速、准确地对系统进行可靠性检测。由于航电系统安全性要求高，内置检测软件受限，需要外置检测设备通过航电系统指定接口进行检测，检测过程也不允许出现任何泄露等行为。检测设备与具体航电系统耦合，检测过程与具体检测设备耦合，难以实现批量航电系统并行检测。为此，通过引入逻辑检测设备，给出了一种航电系统并行检测分层框架，解决检测设备与被测系统耦合的问题，同时也保证了检测的安全性。通过逻辑检测设备、检测跳转机和被测主机上检测行为的描述，给出了一种面向通用航电系统并行检测的检测设备协同机制，解决检测过程与检测设备耦合的问题，从而支持多个航电系统并行检测。最后，实现了一个通用航电系统并行检测系统，并通过实际应用和实验对比验证所提方法的有效性。     

信息战及其对机载计算机发展的影响

机载计算机系统是飞机航空电子系统的核心部件，它在信息战环境下的作战能力，直接决定了飞机在信息战中的生存能力和任务成功率。本文介绍了信息战的概念及特点，信息战对机载计算机系统的主要攻击形式，提出了机载计算机系统在现代信息战环境下必须加以考虑的几项关键技术。     

航空电子微距太赫兹互连DRR访问容量分析

为了减轻机载电子系统线缆和连接器的重量,减小其体积并降低维护成本,在航空电子组件的电路板或芯片之间,可以采用太赫兹通信技术实现厘米量级的微距互连。采用开关键控（OOK）调制和非相干解调实现点到点太赫兹互连,给出了数据速率、数据包长度等参数的设计方法,进而构建包含用户节点和簇头节点的半双工多路访问分簇网络架构。在簇内用户节点到簇头节点的介质访问控制协议中采用赤字轮询（DRR）机制,并采用随机网络演算（SNC）方法得到概率保证意义下多路访问的有效服务容量,分析了阻塞干扰对DRR服务曲线的影响。分析和算例表明,DRR访问在保证实时性能界限的条件下兼顾了多路访问的灵活性,满足航空电子微小型化组件之间太赫兹通信和分簇组网的需求。     

捷联惯导系统的软件开发

本文介绍在PC机上开发捷联惯导系统软件并进行数字仿真的方法,讨论了从分配软件任务,到开发实时软件、管理软件、仿真软件,直至固化运行的全过程。还介绍了ASM-86语尔、PL/M-86语言与C语言混合编程的技巧与优点。该方法与传统的在86/380开发系统上开发捷联系统软件的方法相比,具有良好的经济效益与实用价值。同时,本方法具有通用性,可用在以8086为基体的单板机软件开发上。     

机动目标的三维瞄准火控模型

对新型的航炮攻击数学模型进行了研究,将传统的二维瞄准扩展为三维瞄准;在考虑新一代战斗机机载设备的计算能力大幅度提高的情况下,火控模型引入了加速度因素引起的目标机动项,并给出了目标绝对速度和绝对加速度的计算公式,从而减小了瞄准解算公式的原理误差;通过对复杂的瞄准公式所占用计算时间的估算,证明本文提供的火控模型能够满足实时性要求,具有实用意义。     

人机交互风格及其发展趋势

人机交互的风格经历了命令界面、图形界面、多媒体界面等主要发展阶段，目前正向虚拟现实技术和多通道用户界面的方向发展。本文简要回顾人机交互技术的历史，并进而探讨什么是理想、自然的人机交互模式。