Comparison of component frameworks for real-time embedded systems

The use of components significantly helps in development of real-time embedded systems. There have been a number of component frameworks developed for this purpose, and some of them have already became well established in this area. Even though these frameworks share the general idea of component-based development, they significantly differ in the range of supported features and maturity. This makes it relatively difficult to select the right component framework and thus poses a significant obstacle in adoption of the component-based development approach for developing real-time embedded systems. To provide guidance in choosing a component framework, or at least relevant concepts when building a custom framework, we present a survey, which illustrates distinguishing features and provides comparison of selected modern component-based frameworks for real-time embedded systems. Compared to other existing surveys, this survey focuses specifically on criteria connected with real-time and embedded systems. Further, to be practically relevant, we restrict the survey only to the frameworks that support the full development life cycle (i.e. from design till execution support). In this context, the survey illustrates the complexity of development in each framework by giving specification and code samples.     

Flex‐eWare: a flexible model driven solution for designing and implementing embedded distributed systems

The complexity of modern embedded systems increases as they incorporate new concerns such as distribution and mobility. These new features need to be considered as early as possible in the software development life cycle. Model driven engineering promotes an intensive use of models and is now widely seen as a solution to master the development of complex systems such as embedded ones. Component‐based software engineering is another major trend that gains acceptance in the embedded world because of its properties such as reuse, modularity, and flexibility. This article proposes the Flex‐eWare component model (FCM) for designing and implementing modern embedded systems. The FCM unifies model driven engineering and component‐based software engineering and has been evaluated in several application domains with different requirements: wireless sensor networks, distributed client/server applications, and control systems for electrical devices. This approach highlights a new concept: flexibility points that arise at several stages of the development process, that is, in the model (design phase), in the execution platform, and during the execution itself. This flexibility points are captured with model libraries that can extend the FCM. Copyright © 2011 John Wiley & Sons, Ltd.     

Automated prototyping tool-kit (APT)

Automated prototyping tool-kit (APT) is an integrated set of software tools that generate source programs directly from real-time requirements. The APT system uses a fifth-generation prototyping language to model the communication structure, timing constraints, I/O control, and data buffering that comprise the requirements for an embedded software system. The language supports the specification of hard real-time systems with reusable components from domain specific component libraries. APT has been used successfully as a research tool in prototyping large war-fighter control systems (e.g. the command-and-control station, cruise missile flight control system, patriot missile defense systems) and demonstrated its capability to support the development of large complex embedded software.     

Multi-dimensional analysis of embedded systems security

The primary goals of this paper are to analyze the security of embedded systems at different levels of abstraction and to propose a new procedure to assess and improve the security of embedded systems during various product life cycle phases. To achieve these goals, this paper introduces new classification of embedded systems attacks using a novel multi-dimensional representation, explores the possible threats to embedded systems, and proposes a new procedure to evaluate and improve the security of embedded systems during various product development phases.     

A BIST and boundary-scan economics framework

IC level built-in self-test and IEEE 1149.1 boundary-scan architecture offer potential benefits at all phases of a product's life cycle: development, manufacturing, and field deployment. During early model debugging, for example, boundary scan rapidly flushes out structural defects such as solder bridges or opens. During manufacturing test, BIST and boundary scan can improve coverage, reduce test and diagnosis time, and reduce test capital. In the field, embedded boundary-scan and BIST capabilities may facilitate accurate system diagnostics that isolate defects to individual field-replaceable units. Before investing in these design-for-testability features, however, a product development team should carefully consider their costs as well as their benefits. So far, tools for accurately evaluating these economic trade offs have not been available. At Lucent Technologies, therefore, we have developed a framework to guide a cost-benefit analysis of an investment in BIST and/or boundary scan. The framework is in its formative stages and will continue to evolve. BIST and boundary scan affect cost at all levels of product integration and during all phases of the product life cycle. This analysis framework helps developers decide if the benefits are worth the costs     

基于构件的嵌入式实时软件建模与分析

嵌入式实时软件具有严格的时间要求,任何时间错误都可能造成重大的经济损失甚至导致灾难性的后果。因此,在软件开发早期,对其时间需求进行形式化的分析和验证是非常重要的。本文提出一种基于构件的嵌入式实时软件建模与分析方法,该方法不仅可以检测出需求模型中的时间冲突,有助于保证嵌入式实时软件时间约束的正确性,而且也也使得分析结果具有可复用、可扩展的优点。     

基于任务间通信的嵌入式组件模型

通用组件技术如COM、CORBA等技术已较完善,但是它们应用于嵌入式系统却有很多局限,如需要庞大的底层基础支持、没有实时调度能力等。根据嵌入式系统以及应用的特点,分析了现有的通用组件模型和当前嵌入式组件技术的发展现状,提出了一种新的嵌入式组件模型——基于任务间通信的嵌入式组件模型。该模型具有资源消耗小、有实时调度能力、无须大量底层支持的优点,该文介绍了系统框架和实现方法以及组件开发方法。     

System architecture evaluation using modular performance analysis: a case study

Performance analysis plays an increasingly important role in the design of embedded real-time systems. Time-to-market pressure in this domain is high while the available implementation technology is often pushed to its limit to minimize cost. This requires analysis of performance as early as possible in the life cycle. Simulation-based techniques are often not sufficiently productive. We present an alternative, analytical, approach based on Real-Time Calculus. Modular performance analysis is presented through a case study in which several candidate architectures are evaluated for a distributed in-car radio navigation system. The analysis is efficient due to the high abstraction level of the model, which makes the technique suitable for early design exploration. This work has been carried out as part of the boderc project under the responsibility of the Embedded Systems Institute     

在构件化嵌入式操作系统中应用抢占阈值调度

现有基于构件的嵌入式实时软件开发过程着重于从结构的角度分解系统成若干构件,以及重用构件。实践证明,该开发过程还应从运行角度将构件映射成任务,并选择适当的实时调度算法。为此,根据目前的工程实践提出一种实时构件模型,包含将构件映射成任务的方式。描述了当前构件化嵌入式操作系统可以使用的4种调度算法,并比较这些算法的性能特点。提出抢占阈值(preemptionthreshold)调度模型更适合构件化嵌入式实时系统,仿真实验的结果证明了该结论。比较结果和结论对构件化嵌入式实时系统的设计和开发有一定的参考价值。     

A survey on human detection surveillance systems for Raspberry Pi

Building reliable surveillance systems is critical for security and safety. A core component of any surveillance system is the human detection model. With the recent advances in the hardware and embedded devices, it becomes possible to make a real-time human detection system with low cost. This paper surveys different systems and techniques that have been deployed on embedded devices such as Raspberry Pi. The characteristics of datasets, feature extraction techniques, and machine learning models are covered. A unified dataset is utilized to compare different systems with respect to accuracy and performance time. New enhancements are suggested, and future research directions are highlighted.     

基于构件的嵌入式实时软件组合时间分析研究

在嵌入式实时软件的开发早期,将构件技术应用于对其进行时间需求的形式化分析中,不但有助于保证软件的正确性和可靠性,还能缩短需求分析周期、提高软件生产率。给出了一种基于构件技术、UML和时间ER网技术的组合时间分析方法,对嵌入式实时软件的时间需求进行分析和检测,实践表明该方法可以检测出需求模型中的时间冲突,有助于保证嵌入式实时软件时间约束的正确性,而且其分析结果具有可复用、可扩展的优点。     

基于马尔科夫链的构件化嵌入式软件能耗估算模型

在目前全球倡导"低碳经济"的背景下,嵌入式软件能耗已成为嵌入式系统设计的重要考量因素,一种快速有效的软件能耗估算模型对于嵌入式软件早期开发具有重要的意义.本文着眼于构件化嵌入式软件,从基于状态的角度出发,将嵌入式软件系统的运行过程视为一个状态的集合,提出了一种基于马尔科夫链的嵌入式软件能耗估算模型.然后,通过使用状态转移概率矩阵获得嵌入式软件构件的稳定状态分布,再结合构件的能耗测量值,实现嵌入式软件的能耗估算,并通过实验验证了该模型的有效性.     

基于着色时间Petri网的实时系统的形式验证

嵌入式实时系统多数应用在安全性要求较高的场合,因此需要保证系统的正确性.复杂性不断增加的实时系统迫切需要在系统开发早期引入形式化分析技术来验证系统的期望性质.时间Petri网是有严格数学基础的图形表达工具,适合对实时系统建模;时间自动机(Timed Automata,TA)有成熟的验证工具,被广泛用于实时系统的模型检验和验证.本文提出一种基于着色时间Petri网(Colored Time Petri Net,CTPN)的实时系统的验证方法,用CTPN对带有控制流和数据流的实时系统建模,通过转换规则将CTPN模型转换成语义等价的TA模型,利用模型检验工具UPPAAL验证系统的性质.最后,用实例证明此方法有效.     

Reliability concerns in embedded system designs

Embedded computing systems have become a pervasive part of daily life, used for tasks ranging from providing entertainment to assisting the functioning of key human organs. As technology scales, designing a dependable embedded system atop a less reliable hardware platform poses great challenges for designers. Cost and energy sensitivity, as well as real-time constraints, make some fault-tolerant techniques unviable for embedded system design. Many techniques to improve reliability can incur performance, energy, or cost penalties. Further, some solutions targeted at a specific failure mechanism could negatively affect other mechanisms. For example, lowering operational voltage can help mitigate thermal problems but increases vulnerability to soft errors. Developers must understand the trade offs when designing reliable embedded systems.     

面向方面的实时系统形式化开发方法

实时系统复杂性的不断增加以及对可配置性和可重用性要求的不断提高,需要如面向方面和基于组件的软件工程方法的支持,同时实时系统的可信性要求采用形式化方法来开发实时系统。本文试图建立一种面向方面的实时系统形式化开发方法,这种方法对RT—Z进行了面向方面和面向部件的扩展,并通过实时组件模型在需求和设计阶段提供了对基于部件的系统开发方法(CBSD)和面向方面的系统开发方法(AOSD)的支持。本文给出了面向方面的实时Z(AO—RT—Z)的组件模型的框架结构、语法要求、方面的联结和功能接口和非功能接口的定义,重点讨论并证明了面向方面的实时Z(AO—RT—Z)作为规格描述语言的健全性。     

Training practicing software engineers at Texas instruments

Much has been written about software engineering programs from the viewpoint of the academician, but do these programs really reflect the need of industry? This paper provides some insight into the needs of practicing software engineers at Texas Instruments who are developing software according to military specifications and requirements for embedded real-time systems. The needs of our environment are compared to the entering skills of a typical newhire, with the differences noted. These differences can be satisfied by internal training that covers all aspects of software engineering, from communicating with co-workers to understanding the system life cycle.     

Generating Natural Language specifications from UML class diagrams

Early phases of software development are known to be problematic, difficult to manage and errors occurring during these phases are expensive to correct. Many systems have been developed to aid the transition from informal Natural Language requirements to semi-structured or formal specifications. Furthermore, consistency checking is seen by many software engineers as the solution to reduce the number of errors occurring during the software development life cycle and allow early verification and validation of software systems. However, this is confined to the models developed during analysis and design and fails to include the early Natural Language requirements. This excludes proper user involvement and creates a gap between the original requirements and the updated and modified models and implementations of the system. To improve this process, we propose a system that generates Natural Language specifications from UML class diagrams. We first investigate the variation of the input language used in naming the components of a class diagram based on the study of a large number of examples from the literature and then develop rules for removing ambiguities in the subset of Natural Language used within UML. We use WordNet, a linguistic ontology, to disambiguate the lexical structures of the UML string names and generate semantically sound sentences. Our system is developed in Java and is tested on an independent though academic case study.     

An integrated life-cycle model for software maintenance

An integrated life-cycle model is presented for use in a software maintenance environment. The model represents information about the development and maintenance of software systems, emphasizing relationships between different phases of the software life cycle. It provides the basis for automated tools to assist maintenance personnel in making changes to existing software systems. The model is independent of particular specification, design, and programming languages because it represents only certain `basic' semantic properties of software systems: control flow, data flow, and data structure. The software development processes by which one phase of the software life cycle is derived from another are represented by graph rewriting rules, which indicate how various components of a software system have been implemented. This approach permits analysis of the basic properties of a software system throughout the software life cycle. Examples are given to illustrate the integrated software life-cycle model during evolution     

基于TMS320F2812的微型实时内核的实现

随着微电子技术的飞速发展,现在的微处理的处理数据的能力越来越强。当然随着嵌入式系统设计的不断深入,这就要求开发嵌入式系统的周期要快,系统的可靠性、可调试性要强。要实现这个目的仅仅采用某种高级语言来开发嵌入式系统是远远不能达到目的的,更需要一个良好的、可靠的、实用的软件开发平台来实现自己的嵌入式产品。实时操作系统就是在这种情况下诞生的。通过对实时操作系统的具体分析,以及实现一个微型实时内核来具体介绍实时内核的实现方法.     

The nature of inter-phase relationships in application system development

This study examines the relationships among the component phases of the development life cycle of computer-based application systems. Results indicate that these relationships not only occur but contribute significantly to the consumption of resources during development. The investigation of these interactions presents a general discussion of the nature of the tradeoffs involved, outlines the form of the interaction models to be tested, and finally, marshals empirical evidence to assess the appropriatenes of the proposed models and the integrity of their structure. Implications drawn from this research for the management and control of application system development are presented.