Semi-automatic Architectural Suggestions for the Functional Safety of Cooperative Driving Systems

In cooperative driving, vehicles coordinate their actions as part of a system. Cooperative driving capabilities in vehicles are achieved by means of software, making this software safety critical. The current safety standard for vehicles, ISO 26262, is designed for individual vehicles and their software architecture, but not for cooperative driving settings. Moreover, the guidelines from the standard can only be used for generating safety goals and checking adherence to them. The standard's guidelines do not cover mechanisms to meet the unmet safety goals or provide designers with available architecture choices.This paper presents an extension of the ISO 26262 standard from a single vehicle setting to a cooperative vehicle setting. We also show that the use of safety tactics and design patterns, which enable designers to be aware of possible design choices, can seamlessly be integrated into the ISO 26262 process. The resulting methodology enables designers to make informed choices and cover safety goals. Our case study on the software architecture of a real-life cooperative driving prototype shows that the proposed approach can provide new insights about its safety and mechanisms to improve it.