Schedule Synthesis for the Messages with Precedence Constraint over Dynamic Segment of the FlexRay Protocol

摘要

FlexRay is the leading in-vehicle communication protocol for safety-critical applications in the automotive industry. Due to the richness of configurable parameters, topologies and support to time-triggered as well as event-triggered communication, FlexRay is widely being employed for the safety-critical applications. In this work, we address the problem of priority assignment for the given set of dependent messages which are to be scheduled for the event-triggered communication. As the problem of scheduling has been reported to be computationally intractable, thus we propose three efficient heuristics of varying yields and complexity. Each heuristic computes a schedule that respects the dependency and protocol-specific constraints as well as minimizes the end-to-end delay. Unlike most of the existing works, rather than considering the network in isolation, the effect of the execution time of tasks has also been taken into consideration. To evaluate the performance of the proposed heuristics extensive simulation has been performed. Additionally, the guidelines to design the network have also been provided, such that the end-to-end delay is minimum.