Multi-Variant Time Constrained FlexRay Static Segment Scheduling

TL;DR

This paper introduces a heuristic scheduling algorithm for FlexRay static segments that efficiently creates synchronized schedules for multiple vehicle variants, considering timing constraints and ensuring low computational effort.

Contribution

It presents the first fit heuristic for multi-variant FlexRay scheduling that accounts for timing constraints and synchronizes signals across variants.

Findings

The heuristic effectively schedules multiple variants with low computational time.

Comparison shows the algorithm performs well on benchmark sets.

Scheduling consistency simplifies diagnostics and component reuse.

Abstract

The FlexRay bus is a modern standard used in the automotive industry.It offers deterministic message transmission with zero jitter while using time-triggered scheduling in the static segment. When several vehicle variants (i.e. different models and their versions) share the same signal, the car manufacturers require to schedule such signal at the same time in all vehicle variants. This requirement simplifies the signal traceability and diagnostics in different vehicle variants using the same platform and simplifies reuse of components and tools. In this paper, we propose a first fit based heuristic algorithm which creates the schedules for several vehicle variants at once, while transmitting a given signal at the same time in all the schedules. The scheduling algorithm also takes the time constraints as release dates and deadlines into account. Finally, different algorithm versions are compared on benchmark sets and low computational time demands are validated on large instances.