Model-Based Simulation Framework for FlexRay Communication Systems

Abstract

Automotive communication systems are complex distributed systems. The design of the electrical physical layer (EPL) is a challenging task. Many parameters affect the signal integrity on the analog bus and the combination of parameter variations can lead to effects (e.g., signal reflections) which degrade the signal and compromise the system reliability. Model-based simulations have been widely proposed as the solution for the design, testing and verification of FlexRay networks. This paper proposes a model-based framework for the design and evaluation of FlexRay communication systems. The framework includes the development of FlexRay system components, the design of different network topologies and the simulation and analysis of EPL. The proposed framework has been developed and possible applications have been figured out. Furthermore, the validation of the proposed approach has been addressed. The validation focuses on the accuracy of the simulations in representing the analog signal on the bus, as well as the accuracy in representing the network timing characteristics. The validation exhaustively explores the system design space, achieving a rigorous analysis of the approach reliability: simulations of 40 different network topologies and 1,264 frames have been evaluated, by comparing simulation results with hardware measurements. The results demonstrate that the proposed framework accurately represents the hardware behavior, and it can be an useful toll during the design and early verification of FlexRay communication networks. Due to the lack of a formal validation approach for the validation of the electrical physical layer, the validation is valuable for the FlexRay community.