MIAT Efficient analysis of adaptive variable-rate tasks

Abstract

Response time analysis of adaptive variable-rate tasks (AVR tasks) is a challenging problem in automotive real-time systems. While in periodic event-triggered systems, the worst-case response time is easy to determine, the analysis of AVR tasks has to deal with an exponentially growing number of combinations of execution paths. Each execution path has a specific dynamic behavior. In this paper, we present a new approach for reducing the number of potential worst-case combinations by introducing an intuitive view on the relation of start and end speeds given by speed-phase diagram. Here we propose a minimal inter-arrival time algorithm (MIAT) which is built on time constant lines (isochrones) in a speed-phase diagram first introduced in this work. Compared with previous work, the MIAT algorithm is more accurate and shows a significant improvement in runtime.