Verification of the FlexRay Transport Protocol for AUTOSAR In-Vehicle Communications

Abstract

The FlexRay Transport Protocol (FrTp) is designed to support reliable and efficient communication between various computers embedded in vehicles. It uses a standardised FlexRay communication bus and introduces a go-back-N style retransmission algorithm. A formal modelling language, Coloured Petri nets (CPN), has been applied to verify the protocol design. Separate CPN models of the FrTp service and protocol are developed and with state space analysis-used to prove for selected configurations that FrTp is deadlock-free and conforms to the service specification when transferring a single-protocol data unit from sender to receiver. In addition, closed-form solutions relating the state space size, retransmission limit, and number of segments are found, giving increased confidence that FrTp is error-free, even for configurations where the state explosion problem arises.