Integrating Data Flow Equations with UML/Realtime

Object-oriented (OO) modeling languages, tools, and methods more and more attract the interest of embedded (real-time) system developers. This is especially true if embedded (real-time) system software has to cooperate with interactive multimedia software, as it is more and more the case in automotive systems. It is still an open question whether and how the standard OO modeling language UML and its accompanying tools have to be adapted to the regarded application domain. This paper evaluates the development of a rapid prototype for an air condition controller with the popular CASE tool Rational Rose/RT^®. We point out some weaknesses of the presented solution and propose an extension to Rose/RT^®, which overcomes the weaknesses by combining Rose/RTs UML dialect with data flow equations.     

MCU平台的嵌入式系统软件设计研究

嵌入式系统的运行需要可靠性和实时性的保证,因此良好的可靠性和实时性是嵌入式系统软件设计的重要标准。同时为了使软件系统的鲁棒性更强,嵌入式系统的设计需要一个非常好的软件架构。这里介绍了一种基于MCU平台的嵌入式系统软件架构方法。在这个方法中,事件驱动机制的引入满足了对软件架构的要求,主程序中不仅采用了优先调度机制,同时也加入了软件抗干扰措施,这些都使系统的实时性和可靠性得到了明显的提高。设计实验比较由该方法得到的软件架构与原始软件架构的实时性,得出由该方法优化后的软件架构确实具有更好的性能。     

车流量检测雷达中基于ARM中断的软件设计

车流量检测雷达是智能交通系统中数据采集获取信息的一种重要工具,因此车流量检测雷达的数据传输量很大,而且要求实时性很强。在该课题组研究的车流量检测雷达中,采用ARM(Advanced RISC Machine)嵌入式芯片实现整个系统的接口工作,通过HPI口实现DSP与ARM的通信。嵌入式实时操作系统多任务实现的基础是系统对中断的处理,论文首先详细介绍了ARM的几种中断,并给出了基于ARM中断的整个系统的软件实现的流程及中断实现的部分代码。     

LX800在车载监控系统中的应用

随着嵌入式Linux操作系统的迅速发展,嵌入式Linux已逐渐成为嵌入式操作系统的一个重要分支。介绍了LX800在车载监控系统中的应用,实现了CAN总线实时数据和视频的显示和控制。主要阐述了x86系统平台的硬件总体设计、PCI9054驱动的实现及应用主程序相关流程。     

无线传感器网络的嵌入式软件测试

介绍了无线传感器网络软件模块的基本组成和其中的数据中转器嵌入式软件部分的功能设计,重点介绍嵌入式软件测试的基本概念、测试方法和关键技术。在此基础上给出了数据中转器的嵌入式软件测试系统的基本框架图和必要的软件测试工具介绍。     

无人直升机实时机载和地面站软件架构设计

研究了无人直升机飞行控制系统实时软件系统设计架构,针对机载嵌入式飞控计算机系统和地面站计算机系统,提出了基于VxWorks实时操作系统的多线程任务机载软件设计方案和基于WindowsXP操作系统的地面站软件设计方案,有助于加快完成无人直升机飞行控制系统的设计和验证。机载系统软件设计为数据采集和测量、伺服舵机驱动、飞行控制与发动机控制实现、通信和数据请求存储等功能。地面站系统软件设计为与机载系统的数据通信、终端用户操控,以及实时飞行状态监视等功能。利用组件对象模型设计技术实现了系统软件设计的模块化、软件结构分层组件化,方便了软件系统的集成与扩展。采用多任务线程机制,有效地满足了飞行控制系统实时性要求。利用实时操作系统的定时器任务机制,确保飞行模式的任务管理和调度。依据所提出的软件设计架构完成了实时机载软件和地面站软件组件模块的设计与开发,而且软件集成快捷方便。研究成果已成功应用于某型无人直升机飞行控制系统。     

基于UML-RT的复杂嵌入式系统建模方法及其应用

分析了UML在实时系统设计中的优点和需要解决的主要问题,论述了基于UML RT的实时嵌入式系统设计方法,并且对其进行扩展以支持数据流计算模型的建模,最后以汽车巡航系统为例加以说明。     

嵌入式实时软件在计算机软件 设计中的应用探讨

近年来,在我国科学技术不断发展的推动下,计算机在人们生活和工作中的应用已经非常普遍,成为了一种重 要的工具。在实际的计算机软件设计环节中,科学使用嵌入式的实时软件,切实处理计算机软件的故障,使整个计算机软件的 设计更加简单,简化了设计流程,有效对系统的质量进行了强化。嵌入式实时软件在计算机软件设计中的应用表现出很大的 优势。     

Dual ceiling protocol for real-time synchronization under preemption threshold scheduling

The application of object-oriented design methods to real-time embedded systems is seriously hindered by the lack of existing real-time scheduling techniques that can be seamlessly integrated into these methods. Preemption threshold scheduling (PTS) enables a scalable real-time system design and thus has been suggested as a solution to this problem. However, direct adoption of PTS may lead to long priority inversion since object-oriented real-time systems require synchronization considerations in order to maintain consistent object states. In this paper, we propose the dual ceiling protocol (DCP) in order to solve this problem. While DCP exploits both priority ceilings and preemption threshold ceilings, this is not a straightforward integration of existing real-time synchronization protocols for PTS. We present the rationale for the locking conditions of DCP and show that it leads to the least blocking and response times by comparison with other real-time synchronization protocols. We also present its blocking properties and schedulability analyses. We implemented PTS and DCP in a real-time object-oriented CASE tool and present the associated experimental results, which show that the proposed protocol is a viable solution that is superior to other real-time synchronization protocols for PTS.     

基于vxWorks的数据实时回放研究

在电子注入式仿真中,实航数据是数学仿真模型的最主要和最有效的验模手段。本文采用基于vxWorks的嵌入式单板机系统结合高实时性的I/O板卡,分别以软件顺序回放方式、定时中断方式及硬件中断方式做了相关的对比实验,比较了优劣,最终实现了大容量实航数据的实时回放。     

综合导航系统中的实时多任务软件设计

论文分析了基于实时多任务体系的飞机综合导航系统的软件结构,根据导航系统的功能和数据流,将导航软件划分为多个具有不同优先级的任务,并在嵌入式实时多任务操作系统VxWorks上实现了飞机综合导航系统的软件设计。采用这种实时多任务软件结构,能够有效地降低软件设计的复杂度,显著提高导航系统软件的可靠性、实时性和运行效率,满足了现代飞机导航系统发展的需要。     

CPLD在DSP多分辨率图像采集系统中的应用

基于嵌入式系统中对图像实时采集的需要，设计了一种以CPLD和DSP器件为核心的多分辨率图像采集处理系统，提出一种由CPLD控制图像的行、场信号延时，奇偶数据分离存储来得到不同分辨率的图像数据的方法。全文分别就数据采集的逻辑功能设计；总线逻辑切换设计；CPLD逻辑功能仿真验证等进行了详细介绍。     

Fuzzy logic-based embedded system for video de-interlacing

Video de-interlacing algorithms perform a crucial task in video processing. Despite these algorithms are developed using software implementations, their implementations in hardware are required to achieve real-time operation. This paper describes the development of an embedded system for video de-interlacing. The algorithm for video de-interlacing uses three fuzzy logic-based systems to tackle three relevant features in video sequences: motion, edges, and picture repetition. The proposed strategy implements the algorithm as a hardware IP core on a FPGA-based embedded system. The paper details the proposed architecture and the design methodology to develop it. The resulting embedded system is verified on a FPGA development board and it is able to de-interlace in real-time.     

一种基于ARM及FPGA的新型智能化航迹仪的设计

一种新型智能化航迹仪的设计。系统采用基于ARM的嵌入式结构,软件选用VxWorks实时操作系统,接口板部分采用基于FPGA芯片的设计。详细介绍了航迹仪系统的软硬件设计。     

A CASE tool for software architecture design

This paper describes the Software Architect's Assistant, an automated visual tool for the design and construction of Regis distributed programs. Unlike conventional CASE tools and their supported methodologies, the Architect's Assistant supports a compositional approach to program development in which the software architecture plays a central role throughout the software life-cycle—from the early design stage through to system management and evolution.In its implementation, we have addressed some of the limitations of existing CASE tools, particularly in the degree of automated support offered to the human developer. Conscious effort has been made to maximise usability and efficiency, primarily by enhancing the level of automation and flexibility together with careful design of the user interface. Our objective is to provide a tool which automates all mundane clerical tasks, enforces program correctness and consistency and, at the same time, accommodates the individual working styles of its users.Although currently specific to the development of Regis programs, the Architect's Assistant embodies concepts and ideas which are applicable to CASE tools in general.     

基于DSP和ARM 的网络化数据采集与信号分析终端

提出了一种基于Internet／Intranet的现场实时动态信号采集分析系统的软硬件系统实现方案。从控制管理部分设计、数据处理部分设计以及两部分联合工作等方面介绍了一个网络化数据采集终端的设计和实现，该方案通过采用ARM＋DSP主从结构、嵌入式Linux系统及合理任务分配策略保证，系统的实用性坚求，并将网络数据传输率需求控制在可行范围内。讨论了Ethernet应用于工业测试诊断系统的相关关键技术问题。介绍了系统的构成以及主要工作流程。     

基于RTEMS的软件容错系统设计

在空间环境下运行的计算机系统,高空辐射可能引发各种各样的异常或错误而导致故障。为了提高系统的可靠性,同时尽可能减少对系统实时性能的影响,需要对其进行有效的容错。针对节点和应用软件的故障检测和故障恢复进行研究与分析,提出了多种灵活有效的软件容错策略与设计方案,并基于四节点的多机硬件体系结构和RTEMS软件操作系统,设计并实现了一个系统原型。运行结果显示,该方案有效地提高了嵌入式实时系统的可靠性。     

基于ARM-WinCE的某型航空发动机温控盒检测仪设计

提供了一种基于ARM处理器、Windows CE嵌入式操作系统的检测仪设计方案,介绍了软硬件设计。软件设计中,定制了操作系统,编写了硬件驱动程序,利用多线程技术实现了检测数据的实时显示,同时具有数据保存、故障分析等功能,得出了待测方波频率与测量时机的基本关系。试验结果表明,该检测仪稳定性好、精度高、操作简单,设计思想和工程实现方法对低频方波信号的物理量实时检测具有一定的借鉴意义。     

CASE: analysis and design tools

Computer-aided software engineering (CASE) tools are defined, and ten CASE tools are briefly overviewed. Individual presentations on the various tools follow. The focus is on structured analysis, design, and programming. Two of the tools (Cradle and JSP Workbench) are implementations of the Yourdon and Jackson methods for structured analysis, structured design, and programming; three tools (Time Bench, Card Tools, and Prosa) are for real-time systems development; four (Excelerator, Adagen, Smart System, and Software Through Pictures) are general-purpose front-end CASE tools and one (Virtual Software Factory) is a CASE tool for building CASE tools     

一种基于嵌入式软件构件管理方法

构件化软件开发的最终目的是希望软件像传统产品一样能在生产线上生产出来。软件最终由软件框架来实现,一个良好的软件框架应该能够将设计结果尽量保存下来,同时可以灵活更换和重用软件部件。研究构件化的软件框架对构件化的开发技术在嵌入式实时软件开发中迅速普及具有最直接的推动作用。对嵌入式控制系统嵌入软件构件框架进行了深入研究,完成了框架中的数据管理和构件调度机制等内容,验证了该源码构件模型在嵌入式控制软件领域中的可用性。