A Sufficient Response Time Analysis Considering Angular Phases Between Rate-Dependent Tasks

In automotive embedded real-time systems, e.g., the engine control unit, tasks are activated whenever the engine arrives at a specific angular position. In consequence the frequency of activation changes with the speed of the engine. Additionally, the execution times and deadlines may also depend on the engine speed. In recently published works analytical methods for tasks with this rate-dependent behavior were introduced. Though those methods do not consider angular phases between tasks. For instance, in a typical engine control unit one event is displaced a certain angular position after an event of another task. This paper introduces a sufficient analysis, which considers such angular phases. A number of experimental results are reported to compare our method with existing analysis. These illustrate the improvement in terms of precision and runtime.