One of the major challenges of designing automated driving systems (ADS) is showing that they are safe. This includes safety analysis of interactions between humans and the ADS, a multi-disciplinary task involving functional safety and human factors expertise. In this paper, we lay the foundation for a safety analysis method for these interactions, which builds upon combining human factors knowledge with known techniques from the functional safety domain.
The aim of the proposed method is finding safety issues in proposed HMI protocols. It combines constructing interaction sequences between human and ADS as a variant of sequence diagrams, and use these sequences as input to a cause-consequence analysis with the purpose of finding potential interaction faults that may lead to dangerous failures. Based on a this analysis, the HMI design can be improved to reduce safety risks, and the analysis results can also be used as part of the ADS safety case.