基于模型的开发的应用:AUTOSAR-Compliant外部灯模块的案例研究2008-01-0221Model-Based Development of AUTOSAR-Compliant Applications: Exterior Lights Module Case StudyDevendra RaiDelphi Automotive Systems Deutschland GmbHT. K. JestinDelphi Automotive SystemsLev VitkinDelphi Electronics and SafetyCopyright 2008 SAE InternationalABSTRACTThe complexity of automotive software and the needs for shorter development time and software portability require the development of new approaches and standards for software architectures. The AUTOSAR project is one of the most comprehensive and promising solutions for defining a methodology supporting a function-driven development process. Furthermore, it manifests itself as a standard for expressing compatible software interfaces at the Application Layer. This paper discusses the implementation of AUTOSAR requirements for the component structure, as well as interfaces to the Application Layer in a model-based development environment. The paper outlines the major AUTOSAR requirements for software components, provides examples of their implementation in a Simulink/Stateflow model, and describes the model based implementation of an operating system for running AUTOSAR software executables (“runnables”).In addition, it describes the use of xml files for the architectural and interface descriptions of software. The architectural development and simulation of the model, along with auto-generation of AUTOSAR-compliant software, are demonstrated based on the Exterior Light Module of an automotive body controller.INTRODUCTIONModel-based development involves the creation of a graphical executable model representing the requirements and/or design, validation of the model, automatic code generation from the model, and model-based verification of the software. The process makes use of modern modeling tools, like MATLAB/Simulink/Stateflow from The Math works, Inc. and code generation tools like Real-Time Workshop Embedded Coder from The Math works, Inc. or Target Link from dSPACE, Inc. Model-based development is a proven way of increasing the robustness of the design and the quality of software. At the same time, the model based approach leads to a reduction of project development time, which is a major requirement in the highly competitive automotive market 1, 2.Standardization is essential to handle the complexity of software and enhance modularity, flexibility, portability, reusability, maintainability etc. Standardization can be achieved via a set of procedures and guidelines, as well as via well-defined architectural and structural requirements for software. The guidelines for modeling and code generation, for example, developed by the Math Works Automotive Advisory Board for Matlabbased models, is one of the ways to achieve such standardization 7. Architectural requirements specified by AUTOSAR aim to achieve the objectives of modularity, flexibility, transferability, and re-usability of functions 13. In order to comply with AUTOSAR requirements, the model should be constructed in such a way that the component configuration, interface definition and interface abstraction would allow easierimplementation of AUTOSAR-compliant software.Two major autocode generation tools supportingMATLAB/Simulink/Stateflow models, TargetLink from dSPACE, Inc, and Real-Time Workshop Embedded Coder from The MathWorks, Inc, have recently introduced the blocksets that assist in generating theAUTOSAR-compliant interfaces to the abstraction layer for software components 8, 9. Along with technical merit, business merit influences the decision of whether to buy the available tools add-ons vs. making these add-ons. This paper describes the alternative for generation of AUTOSAR-compliant software interfaces without the dSPACE AUTOSAR blockset for TargetLink or the AUTOSAR Demonstration Kit (ADK) for Real-Time Workshop Embedded Coder.OVERVIEW OF AUTOSAR CONCEPTSThe main objective of AUTOSAR is to developencapsulated application software that is abstracted from the hardware and is independent of thecommunication technology, operating system etc 3. Such a software component can be relocated to different ECUs, and is reusable across different vehicle manufacturers and suppliers. The high-level AUTOSARconcept is displayed in Figure 1.Figure 1: The AUTOSAR ConceptAUTOSAR SOFTWARE COMPONENT (SWC) An encapsulated software component leads to separation of application and the infrastructure. Each software component is self contained as to the functional features, with well-defined interfaces to interact with other software components. AUTOSAR specifies a standard description format, i.e. “Software Component Description” to describe the component interface and the requirements on infrastructure and computing resources 3.RUN-TIME ENVIRONMENT (RTE) AUTOSAR specifies the communication between those software components which are residing on a technology independent abstraction