A timing model for real-time control-systems and its application on simulation and monitoring of AUTOSAR systems

Abstract

AUTOSAR is a common initiative of the automotive industry with the goal to standardize substantial aspects of the software development for automotive embedded systems. Many automotive applications which are realized in software are real-time applications where certain timing requirements are imposed on the temporal execution. The AUTOSAR standard does not yet provide concepts in order to express application-specific timing requirements and to evaluate their degree of fulfillment.

In this thesis, timing requirements are mainly considered in the context of a specific yet important class of real-time applications: control applications. The formal description of timing requirements is a specific challenge. Timing requirements such as those on path latencies must be formulated with respect to input and output signals for which there exists a continuous signal path in the embedded computer system. The description of the signal path is, however, the complex challenge.

A solution for the description of signal paths and the determination of timing properties is provided in this thesis. The introduced concepts allow the description of signal paths as chains of cause-and-effect on the basis of events that need to be observed in a system.

From the signal path specifications, an instrumentation can be automatically derived such that instances of events can be captured during simulation- or monitoring experiments. New kinds of path analysis algorithms are introduced that allow the determination of effective instances of chains of cause-and-effect. From these, timing properties can be derived. These can then visualized by means of a new type of diagram introduced in the thesis, the so-called Timing Oscilloscope Diagram.

The results of the work presented not only provide the necessary concepts for a Timing Model for AUTOSAR; they are also important in a more general context such as the aerospace and automation domains where control applications can also be found.