A prototyping language for real-time software

PSDL is a language for describing prototypes of real-time software systems. It is most useful for requirements analysis, feasibility studies, and the design of large embedded systems. PSDL has facilities for recording and enforcing timing constraints, and for modeling the control aspects of real-time systems using nonprocedural control constraints, operator abstractions, and data abstractions. The language has been designed for use with an associated prototyping methodology. PSDL prototypes are executable if supported by a software base containing reusable software components in an underlying programming language (e.g. Ada)     

The Software Development System

This paper contains a discussion of the Software Development System (SDS), a methodology addressing the problems involved in the development of software for ballistic missile defense systems. These are large real-time, automated systems with a requirement for high reliability. The SDS is a broad approach attacking problems arising in requirements generation, software design, coding, and testing. The approach is highly requirements oriented and has resulted in the formulation of structuring concepts, a requirements statement language, process design language, and support software to be used throughout the development cycle. This methodology represents a significant advance in software technology for the development of software for a class of systems such as BMD. The support software has been implemented and is undergoing evaluation.     

嵌入式实时控制系统软件可靠性建模与应用

嵌入式实时控制系统(ERCS)广泛应用于各种控制系统中,其软件不同于普通软件,除满足实时性要求外,可靠性也是相当重要的。首先对嵌入式实时控制系统软件进行形式化抽象定义,然后对不可再分的软件模块进行可靠性建模,并应用Copula函数对软件系统进行建模,最后应用建立的模型,对具体的系统进行了软件可靠性计算。通过实例计算可知,用Copula函数建立的嵌入式实时控制系统软件可靠性模型,考虑了软件各个模块的相依性,进而得到嵌入式实时控制系统软件模块相依的可靠度较各模块独立时有所提高。     

Hardware/software codesign and rapid prototyping of embeddedsystems

The complexity and the short time to market of embedded systems require the use of automated techniques during the specification, implementation, and testing phases of such systems. Due to the cost requirements and the timing constraints of such systems, application-specific hardware solutions are often needed, making the codesign of hardware and software a major topic for the design automation of embedded systems. This article describes tools for the analysis, synthesis, and rapid prototyping of distributed embedded real-time systems and presents a complete design flow from specification to implementation     

From testing to anti-product development

The requirements for testing in large software projects drastically changed in recent years. The reasons for this mainly come from evolving development processes, demanding early stabilisations of complete software loads, early handover to subsequent steps, high software release quality, and in particular flexible adaptations to changing roadmaps. This study is an experience report from industrial testing in the field of telecommunications software and based on a speech given by the author at the Testing and Test Control Notation version 3 (TTCN-3) User Conference in Berlin 2006. It advocates to consider modern testing rather as the development of an anti-product that is to be developed in parallel to the product. This anti-product is itself a complex software system. Following this approach has a significant impact on the testing in these large software projects mentioned and leads to a number of consequences for the development of test systems and the structure of test teams. In this study, the role and virtues of TTCN-3 as programming language for anti-products as well as for defining the test system structure are investigated. Dealing with large embedded software systems that have several concurrent parts and additionally obey soft real-time requirements, similar constraints also hold for the test system. The virtues of parallel testing/software development life cycles as it becomes mandatory in following modern development processes are presented, and it is shown how TTCN-3 turned out in our experience to be a language particularly well suited for this purpose because of its advanced structured programming concepts derived from strong typing, template concepts and parametrizations of templates.     

嵌入式实时系统的软件需求检测

以需求描述模型HRFSM(hierarchical finite state machines based on rules)为基础,提出了一个嵌入式实时系统软件的动态执行模型(dynamic execution model,简称DEM)和基于该模型的检测方法.由于DEM能将控制流、数据流和时间有效地集成为一体,故提出的检测方法能检测嵌入式实时系统的软件需求的一致性和完全性.该检测方法由3种侧重点不同的检测形式组成,并能在检测过程中提供一些重要的检测信息.分析员可以利用基于该检测方法的工具灵活地对嵌入式实时系统的软件需求进行检测,以提高分析和检测软件需求的效率.     

Executable specifications for embedded distributed systems

Combining hardware components with an executable specification language facilitates the specification prototyping of embedded distributed systems. The specification language should cover process management, timing, and communication commands that real-time executive and communication task services of every node prototype can interpret. We use a technique that employs attribute grammars and either a macro processor or Prolog to execute the language     

Automatic synthesis and verification of real-time embedded software for mobile and ubiquitous systems

Currently available application frameworks that target the automatic design of real-time embedded software are poor in integrating functional and non-functional requirements for mobile and ubiquitous systems. In this work, we present the internal architecture and design flow of a newly proposed framework called Verifiable Embedded Real-Time Application Framework (VERTAF), which integrates three techniques namely software component-based reuse, formal synthesis, and formal verification. Component reuse is based on a formal unified modeling language (UML) real-time embedded object model. Formal synthesis employs quasi-static and quasi-dynamic scheduling with multi-layer portable efficient code generation, which can output either real-time operating systems (RTOS)-specific application code or automatically generated real-time executive with application code. Formal verification integrates a model checker kernel from state graph manipulators (SGM), by adapting it for embedded software. The proposed architecture for VERTAF is component-based which allows plug-and-play for the scheduler and the verifier. The architecture is also easily extensible because reusable hardware and software design components can be added. Application examples developed using VERTAF demonstrate significantly reduced relative design effort as compared to design without VERTAF, which also shows how high-level reuse of software components combined with automatic synthesis and verification increases design productivity.     

Implementation of Hard Real-Time Embedded Control Systems

Although the domain of hard real-time systems has been thoroughly elaborated in the academic sphere, embedded computer control systems –- being an important component in mechatronic designs –- are seldom dealt with consistently. Often, off-the-shelf computer systems are used, with no guarantee that they will be able to meet the requirements specified. In this paper, a design for embedded control systems is presented. Particularly, the paper deals with the hardware architecture and design details, the operating system, and high-level real-time language support. It is shown how estimates of process run-times necessary for schedulability analysis can be acquired on the basis of deterministic behavior of the hardware platform.     

Coupling Trends in Industrial Prototyping Roles: An Empirical Investigation

Prototyping in the development cycle claims to improve analyst understanding of system requirements leading to systems which match those requirements more closely. The quality of the end systems, from a user perspective, is thus improved. In this paper, the results of an empirical investigation into the use of prototyping in the development of various systems is described. Nine processes across eight different sites were analysed and data relating to each process was collected. The notation of Role Activity Diagrams (RADs) was used to capture each of the nine processes. Five hypotheses were then investigated: these related the prototyping role to features of other roles such as extent of interaction during the prototyping process, the effect site size had on the prototyping role and the dependence of the prototyping role on other roles in the prototyping process. Two coupling metrics were introduced to quantitatively analyse these RAD features. Results indicated a strong similarity between large and medium-sized sites in terms of interactions and behaviour. The prototyping process in small sites, however, was found to be different to large and medium-sized sites in both respects. The study demonstrates how measures of business models can aid analysis of the process as well as the products of systems development and highlights the need for more empirical investigation into this and other facets of the software development process.     

Visionary prototyping

Today, besides introducing intelligence directly into equipment/systems through embedded microcomputers and providing virtual prototyping through enhanced computer-aided design/computer-aided engineering (CAD/CAE) facilities, information now is well regarded as an essential part of the integrated design approach whereby all members of the prototype development and manufacturing automation team can work closely together throughout the design and manufacturing cycle. The article focuses on two subtopics. The first is the development of a theory for prototyping discrete-event and hybrid systems and its applications. In discrete-event dynamic systems (DEDS), state transitions are caused by internal, discrete events in the system. An overview for the development of a simple graphical environment for simulating, analyzing, synthesizing, monitoring, and controlling discrete-event and hybrid systems is also presented. The second focus is on prototyping machine vision for real-time automation applications. We discuss the problems associated with traditional machine vision systems for cost-effective, real-time applications, novel alternative system design to overcome these problems, and the new trends of modern vision sensors. Modern smart sensors provide the features of traditional machine vision systems at less than half of the usual price by eliminating the signal-conversion electronics, fixed-frame rates, and limited gray-scale quantization. The camera, image-acquisition electronics, and computer are integrated into a single unit to allow dynamic access to the charge-coupled devices without image float or flutter. We also present a physically accurate image synthesis method as a flexible, practical tool for examining a large number of hardware/software configuration combinations for a wide range of parts     

Software evolution through rapid prototyping

Rapid prototyping is defined, and its role in software evolution is examined. Software evolution refers to all activities that change a software system. It differs from maintenance in that the latter is done after the initial development, whereas evolution activities are interleaved with the initial development and continue after the delivery of the initial version of the system. In the author's approach to rapid prototyping, software systems are delivered incrementally and requirements analysis continues throughout the process, interleaved with implementation and evolution. The focus is on reducing requirements errors through prototyping before undertaking the incremental implementation effort for each deliverable version of the system. The evolution of a hyperthermia system is considered as an example     

Targeted processing for real-time embedded mechatronic systems

This paper describes the architecture and design framework for a multiprocessor system on chip (SoC) solution that is being developed for adaptive, high-performance, embedded real-time control applications. Most of the design-to-implementation stages are automated by software tools avoiding most of the error-prone programming tasks and hardware-related issues. Therefore, the work presented here minimises the interdisciplinary design efforts typical to mechatronic systems design, allowing control engineers to focus mainly on the control laws development. The performance achieved by the proposed architecture allows for a straightforward addressing of implementation requirements for a variety of embedded applications, including micro-electromechanical systems.     

一种SysML模型到AADL模型的自动转换方法

安全关键系统的实现需要通过需求、设计、集成、验证和测试等多个阶段。近年来,模型驱动开发方法逐渐成为安全关键系统设计与开发的重要手段。由于还没有一个建模语言能够支持整个安全关键系统开发生命周期,因此选择集成使用2种广泛使用的标准语言:系统建模语言(SysML)和嵌入式实时系统体系结构分析与设计语言(AADL)。SysML和AADL提供了同一系统的2个不同视图,SysML模型为系统工程师提供了一个系统视图,AADL为架构设计师建立一个较低层次的设计视图,它结合了实现所有功能的硬件、操作系统和代码。提出一种SysML模型到AADL模型的自动转换方法。首先,定义SysML子集SubSysML,主要包括模块定义图(BDD)、内部模块图(IBD)、活动图(ACT)子集和从IBD和BDD扩展的AADL Profile;其次,定义SubSysML到AADL的转换规则并设计转换算法;然后,对生成的AADL初始模型进行精化;最后,使用EMF框架技术实现SubSysML到AADL的模型转换工具并通过雷达案例验证所提方法的有效性。     

基于μC/OS-Ⅱ的1553B和ARINC429总线实时协议转换系统的设计

设计了1553B和ARINC429总线实时协议转换系统。系统硬件部分采用"MCU+FPGA+外围芯片"进行构建;软件部分是将嵌入式实时内核μC/OS-II移植到DSP控制器上从而构建一个低成本的通用嵌入式实时软件平台,基于此平台以C语言和汇编语言在DSP集成化软件开发环境CCS上加以实现。对协议转换系统进行了测试和联机验证,结果表明该系统完全符合设计要求。