Timing modeling and analysis for AUTOSAR-based software development - a case study

Safety-critical automotive systems must fulfill hard real-time constraints for reliability and safety. This paper presents a case study for the application of an AUTOSAR-based language for timing modeling and analysis. We present and apply the Timing Augmented Description Language (TADL) and demonstrate a methodology for the development of a speed-adaptive steer-by-wire system. We examine the impact of TADL and the methodology on the development process and the suitability and interoperability of the applied tools with respect to the AUTOSAR-based tool chain in the context of our case study.

I. Introduction

Concepts and means for timing modeling and analysis are mandatory in the automotive software development process to allow verification and systematic reasoning about the timing behavior of a system under development. Elements influencing the timing behavior due to hardware or software can be scattered all over the system. Their timing properties, which may depend on the implementation and vary between manufacturers, shall be verified against the timing constraints derived from the safety analysis. Those timing properties could be task execution times, bus latencies and sensor sampling rates, for instance. A timing constraint can be a requirement of a controlling algorithm for an ECU that expects updated sensor data every 1ms, for example. When timing properties as well as timing constraints are not modeled explicitly, it is nearly impossible to apply an (automated) verification process.