Safety-relevant automotive systems have particularly high requirements for fault-tolerance, especially in the absence of a mechanical backup, such as for X-by-Wire systems. The replication of components, called structural redundancy, is very often a way to ensure that these systems are free from single points of failure and, hence, fault-tolerant. However, the use of redundancies also implies undesirable effects which make the masking out of faults difficult. Agreement protocols are protocol-based, distributed algorithms which are required to eliminate these effects, in order to profit from the potential of redundancies optimally. These protocols aim to establish agreement among different nodes with respect to a particular value (e.g. sensor value) through an organized message exchange.

As part of the EU project EASIS, which aims to provide a standard software platform for integrated safety applications, and the DFG Project “System Reliability”, this diploma thesis (Diplomarbeit) focuses on the conception and implementation of an agreement protocol as a standard software module to be integrated in the EASIS software platform. Therefore, several approaches to implementing agreement protocols from the literature are analyzed and compared. Based on these variants, a concept for an agreement protocol for fault-tolerant safety electronics is finally presented, where not only the specific requirements for safety electronic systems are taken into account, but also the main stream of standardization, particularly in the scope of the EU Project EASIS.

Following the model-based design, a prevalent approach for the design of electronic systems in the automotive industry, a virtual prototype has been developed in Matlab/Simulink, based on the time-triggered paradigm. This prototype represents a system model including redundant components, where the implemented Agreement Protocol service can be validated. The simulation results for several evaluation cases asserted the functionality of the Agreement Protocol service and, thus, validated the suggested concept.