White Papers
Designing and Implementing Architectures for Distributed Automotive E/E Systems
The complexity of electrical and electronic systems in cars has grown drastically during the past decade. Model-based function design and simulation are widely used by the Automotive E/E community today in order to manage this complexity. Emerging new standards, such as AUTOSAR, define standardized interfaces to low-level software and, most importantly, introduce a new level of abstraction to function implementers. This improves the reusability of software components, but unfortunately, there is little guidance on how to translate the results of model-based function design into robust and efficient system implementations in a highly distributed environment. There's also little connection to the physical side of the design process. This paper outlines a proposed system-level design methodology, covering architecture design, scheduling of networks and tasks distributed across multiple ECUs, harness design, and metrics generation.
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The Electrifying Side of AUTOSAR: The Case for Using the ECU Resource Template
This paper describes a meta-model that covers specific portions of software-oriented AUTOSAR development methodology using the ECU Resource Template.
Prior to actual software development, the standardized and open AUTOSAR meta-model can be used to develop an architecture. The ECU Resource Template is particularly well suited for such tasks, because it opens up the actual software-oriented AUTOSAR development methodology to the electrical architecture process.
Top-down Design of Distributed Embedded Systems in Light of Timing Considerations
Proper safeguarding of safety-critical systems in an automotive environment cannot be ensured sufficiently without taking timing into consideration. The failure to observe timing constraints can lead to malfunctions and, in a worst-case scenario, can cause vehicle damage and personal injury. AUTOSAR 4.0 now supports timing constraints, but the standard, although very powerful, still is not able to address all aspects and requirements for electric/electronic (E/E) architectural design. However, alternative standards, such as EastADL2 and the Timing Extension (TIMMO) standard, have tackled this issue. This paper discusses a way to combine AUTOSAR with EastADL2 and the TIMMO timing language (TADL), enabling a consistent, top-down design approach at both the functional and timing levels.
AUTOSAR and FlexRay: A Tale of Two Standards
The emerging automotive design software standard known as AUTOSAR (Automotive Open System Architecture) began as the product of an industry-wide effort among European auto makers and their suppliers. Its objectives are similar to those of software standards in other industries: to bring structure, clean interfaces and implicit methodologies to a process—in this case, the design of distributed systems within automobiles. FlexRay™ is a serial bus communication standard that has evolved over roughly the same time span as AUTOSAR. FlexRay came into existence as a solution for the shortcomings of the prevailing automotive bus standards, particularly the CAN protocol.
Like AUTOSAR, FlexRay counts many prominent automotive OEMs and suppliers among its advocates. Boasting much higher performance (in every respect) than other in-vehicle buses, FlexRay alone is suited for “x-by-wire” applications that must deliver absolutely predictable results for steering, braking, and so forth. What do these lofty aspirations mean to the designer who needs to get a complex array of automotive functions working together with high reliability? To the executive responsible for minimizing costs while delivering timely, compelling products to customers? To the end-users of tomorrow’s automobiles?
Developing Automotive Products Using the EAST-ADL2, an AUTOSAR Compliant Architecture Description Language
Current development trends in automotive software feature increasing standardization of the embedded software structure. But, it still remains the critical issue of the overall engineering information management to control the system definition and manage its complexity. System modeling based on an Architecture Description Language (ADL) is a way to keep these assets within one information structure. The original EAST-ADL was developed in the EAST-EEA project and basic concepts were reused in the AUTOSAR standardization initiative. The original EAST-ADL is currently refined in the ATESST project to EAST-ADL2. This paper presents the results of the language extension provided by the EAST-ADL2 domain model and focuses on its possible extension of the AUTOSAR standard to support decomposition of E/E automotive systems.
Experimental Jitter Analysis in a FlexCAN-based Drive-by-Wire Automotive Application
This paper describes several experiments designed to characterize jitter in an actual automotive application designed using FlexCAN, a CAN-based communication architecture. Large and variable jitter has been a liability of the CAN protocol. The paper also explains how FlexCAN reduces jitter by using a simple message scheduling technique that synchronized with control system applications.