Open systems architecture solutions for military avionics testing

Raytheon makes extensive use of open systems architecture methods in developing special test equipment (STE) for testing military avionics equipment. Such use has resulted in significant cost and schedule savings in the development of production test equipment for radar and infrared systems. With open systems architectures, a test system can be assembled using COTS products. This brings economies of scale to test equipment, which is normally built in very low quantities. Therefore, the potential cost savings due to COTS usage is proportionately greater in STE than in the higher volume avionics systems that are tested. A second major benefit of using COTS products is that test system development schedule cycle time is greatly reduced. This paper describes the application of Open Systems Architectures (OSA) to avionics testing. The following major architectures are surveyed: VME bus, VXI bus, IEEE GPIB, IEEE 1149.1 JTAG test bus, 1553 Military Bus, Fibre Channel, and COTS Test Applications Software. We describe how the benefits of OSA have been extended at Raytheon into achieving vertical test commonalities. The flexibility of OSA can be exploited to provide an overall optimum test solution, taking all levels of test into account. For example, test systems can be tailored with COTS products to provide integrated methods for avionics tests at the module, unit, and system levels. Test systems can be configured to maximize the reuse of COTS hardware over all test levels. Test software can also be programmed to optimize such reuse over levels of test. Additional test verticality synergies derived from such OSA usage are described, including: test false alarm avoidance; test cones of tolerance optimization; and efficient test of field returns     

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     

Next generation space avionics: layered system implementation

Advances in electronics over the past decade have produced major improvements in the power and flexibility of computer systems. Unfortunately current avionics systems for space applications typically have not leveraged these COTS advantages. A decade ago, the state-of-the-art for avionics systems made a step change to the Integrated Modular Avionics (IMA) used in the Boeing 777. This next generation avionics architecture is not based upon traditional Byzantine redundancy structures, but on a truth-based scheme where each element knows when an internal failure occurs and removes itself from the system. IMA utilizes a lock-step microprocessor design that communicates to a COTS Backplane for input/output, and to a Virtual Backplane/spl trade/ (a reliable high-speed serial bus) for intra-system communication. The system functions are implemented using a time and space partitioned operating system. The entire system provides the simplicity of a simplex system, implements the highest level of reliability providing complete flexibility to reconfigure both software applications and hardware interfaces, allows for rapid prototyping using low-cost COTS hardware, and is easily expandable beyond the initial point implementation. As the only 5/sup th/ generation avionics architecture, the concepts incorporated into Honeywell's IMA are ideally suited to be the backbone of the next generation Space Exploration Program avionics architectures.     

基于COTS的航空电子软件开发

介绍了商用货架产品(COTS)在航空电子软件开发中应用的优点和缺点,和基于COTS的航电软件构架;并给出了一个开发过程和部分开发工具。最后通过一个实例说明基于COTS的航电软件开发是实际可行的。     

Technology roll lessons learned on embedded avionics platforms

Open system architectures based on commercial off-the-shelf (COTS) building block components offer the ability to leverage the latest technology into fielded products while minimizing the impact to the operational flight software, typically the most costly component of an avionics development or upgrade. Our team has developed a layered hardware and software approach based on industry standard hardware and software interfaces to abstract the application (operational) software developers from the underlying technology rolls to the hardware and operating system software that naturally occur as part of the commercial marketplace, A technology roll is defined as the replacement of a current product with a subsequent generation of a product from the same product family. In this article, we describe the components and the layered architecture of our open system architecture approach. We discuss specific system, hardware, and software technology insertions that incorporate the latest available technology and how these changes have been abstracted from the application software. The article concludes by discussing lessons Learned from the use of these common components and corresponding technology rolls across various platforms     

COTS based open systems for military avionics

The DoD has many acquisition programs that are aggressively implementing open architecture principles in new avionics systems. Since “open” is an unclear attribute, projects eventually give in to a point solution that has no flexibility to cost effectively keep up with rapid changes in technology. The Open Systems Development Initiative (OSDI) project utilized COTS products to study the feasibility of building an open system that has plug-and-play capabilities. Lessons learned from the AV-8B Open Systems Core Avionics Requirements (OSCAR) and the F/A-18 Advanced Mission Computers and Displays (AMC&D) programs clearly indicated that understanding the underlying interfaces is crucial to keeping the system as open as possible to take advantage of the rapid changes in technology. A matrix of Key Open Standard Interfaces (KOSI), called the KOSI matrix, was developed and an applicable standard was identified for each interface. A list of non-conforming interfaces was also identified and the use of extensions or wrappers was investigated in an attempt to comply with standards. Standardization, rather than optimization of such interfaces, was considered more beneficial. It became evident that, with the exception of ruggedization, there is no difference in the use of COTS products for either commercial or military systems. Performing a KOSI analysis helped identify the key interfaces and standards, thus enabling the OSDI system to be scalable, portable and interoperable. A good KOSI matrix provides a vehicle for clear communication and helps systems integration and technology insertion to be less painful than what it is today. It helps reduce time-to-market and provides guidance to systems engineers and vendors to keep the system open     

Data link communication equipment approved by USAF for civil air traffic control

Operations within civil airspace will transition from traditional ground-based air traffic control (ATC) to air traffic management (ATM), a concept that requires aircrews and ground managers to share responsibility of aircraft separation assurance. Increased levels of information exchange will be necessary for this concept to work safely; therefore, air-ground communications will transition from voice to data link communications. The nature of data link communications procurement requires that avionics suppliers not only verify their products meet contractual performance requirements, but also demonstrate that their products are compatible with civil communication networks and ATC. In addition, the USAF needs to demonstrate that their crew-training program is adequate to maintain the required level of aircrew proficiency and equipment can be maintained for the required level of system performance, integrity, and interoperability with the civil environment. This paper outlines some of the certification issues facing the USAF with respect to the "Approval for Use" of data link equipment to be used for communication with ATC. It will also suggest a methodology for the avionics supplier and USAF to obtain the approvals required to ensure the installation of data link communications equipment on military aircraft will remain interoperable with civil ATC.     

面向未来飞机的机载网络存储系统研究

根据未来飞机航电系统的拓扑结构以及机载各类数据特征，提出了一种高性能、高吞吐量和高可靠性的机载网络存储系统设计方法，从而满足了未来飞机对高性能存储系统的需求，允许机载各个设备客户端对服务器进行透明的文件访问，实现了跨平台的数据共享，为网络存储系统关键技术在航空产品上的进一步应用提供了技术基础。     

基于ARINC429总线的 某型机载设备便携式检测设备

针对特定某种机载设备ARINC429总线通信状态的监测需求,设计了一种便携式检测设备。为了减小体积与重量,达到设计目标要求,该系统以PC/104嵌入式工业控制计算机结合ZHHK429-PC104-Plus429通信板卡为核心实现。文章描述了系统硬件的组成及原理,分析了软件结构及板卡的初始化、总线数据接收及发送的方法。经测试,该系统实时性好,可靠性高,可有效满足特定机载设备的状态监测及维护的需要。     

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)     

IMA aircraft improvements

Integrated modular avionics (IMA) is being suggested as the means by which new capabilities can be deployed on aircraft at an affordable cost. RTCA SC-200 is presently considering the guidance document for IMA. All of the functionality that IMA offers can be achieved through a conventional federated architecture; however, the cost, size, and weight penalties of the federated solution make it economically infeasible. IMA is seen as the way forward. It is assuming greater importance as the aircraft industry transitions to commercial-off-the-shelf (COTS) technology with its attendant obsolescence and reliability concerns. IMA may be one of the most cost-effective ways by which rapid obsolescence can be managed. Ironically, this move to COTS is also the greatest threat to IMA systems. IMA achieves reductions in size, cost, and weight by providing a set of flexible hardware and software resources that can be statically or dynamically mapped to a set of required avionics functional capabilities. This introduces a number of new complexities such as mixed criticalities and reconfiguration. We do not address these issues herein. Rather we discuss the mechanisms by which electronics degrades and how a classical safety assessment of a reconfigurable IMA system can be ified by this degradation. We argue that, with the advent of COTS, it is no longer justifiable to consider that electronics has an effectively constant failure rate. Physical considerations suggest that electronics failure occurs when environmental and operating stress causes the accumulation of damage to the underlying structures to exceed the threshold strength of the constituent materials and interfaces. Finally, we suggest how finite-life electronics effects may be mitigated.     

基于PC／104总线的交流信号采集方法

介绍了一种用DIAMOND-MM-16-AT采集卡构建的基于PC 104总线的高速数据采集系统采集交流信号的方法,详细说明了采集卡的设置及初始化方法、变量定义及利用多线程、双缓冲区技术实现数据的高速采集和存储的方法,最后给出了滤波和计算交流有效值的算法。     

一种提高通用处理模块数据完整性的设计方法

航空电子产品中为了满足高安全等级应用的驻留需求，通用处理模块的数据完整性指标需要达到 Level A（10-9）级。基于当前元器件的可靠性和产品设计的复杂度，产品的数据完整性一般在10-3 到10-5 的水平， 无法满足产品的设计需求。本文提出了一种基于数据锁步的设计方法，该方法可用当前的软硬件资源在工程项 目中设计出满足高完整性要求的产品。     

虚拟仪器在导弹测试发控系统中的应用

设计的基于PC/104嵌入式计算机系统的虚拟仪器,具有测量各种电学信号和时频信号功能;同时具有输出各种模拟信号、不同频率和幅值的脉冲信号及各种波形信号的信号源功能.其测量精度高,输出信号精度高,可用于导弹测试发控系统对其进行各种测试和控制.     

飞机接口组件仿真器设计

飞机接口组件仿真器主要完成对飞机航电系统中的非1553B总线信号设备的仿真。按要求产生相应的离散量信号、模拟量信号、同步机信号等非1553B总线信号传给总线控制/信号转换器(BC/IFU)。是飞机航电系统仿真试验室进行全系统仿真关键设备。     

基于PC104总线的ARINC429航空接口卡设计

采用FPGA实现了基于PC104总线的ARINC429总线接口卡的设计,该接口卡可有效节约硬件资源,具有处理速度快、抗干扰能力强、成本低廉等特点,可广泛应用于以ARINC429总线作为通信方式的航空设备的通信测试维护中。     

Use of service history for certification credit for COTS [avionic software]

Much has been written in the last ten years about how the use of commercial-off-the-shelf (COTS) components would revolutionize the aerospace industry avionics, communication, navigation, surveillance/air traffic management (CNS/ATM) as well as global air traffic management (GATM). Civil aviation authorities around the world have been faced with numerous requests to certify aircraft containing increasing percentages of COTS components, much of it never designed or intended for use in the safety critical environment of an aircraft. Product service history is one method for demonstrating that such software is acceptable for use. In theory, product service history would seem to be a fairly simple concept, both to understand and to apply. However, in practice, such use has proven extremely problematic, as questions of how to measure the historic performance and the relevance of the provided data have surfaced. This paper elaborates a research effort funded by the United States Federal Aviation Administration to collect, analyze, and synthesize what is known and understood about applying product service history. The effort is limited to the topic of software product service history as applied in the certification of airborne systems and equipment.     

The problem with aviation COTS

Commercial Off the Shelf (COTS) has become a byword for acquisition reform, but there are significant risks associated with the use of COTS products in military systems. These risks are especially acute for aviation systems. This paper explains how COTS can negatively affect military acquisitions and gives ideas on how to plan and resolve COTS caused problems     

基于分区代理机制的FC通信虚拟化方案设计

随着航电系统的发展,处理平台的集成度逐步提高,多核处理器集成多个应用将是未来应用的趋势。 但在使用多核处理器的系统中,由于多个处理器核并行运行,需要解决通信资源在多个处理器核之间的共享问 题。本文提出了一种基于分区代理机制的FC 通信虚拟化方案设计,可以实现多核架构下多应用、多分区共享 FC 网络接口设备进行通信。