A simulation-based methodology for aiding advanced driver assistance systems hazard analysis and risk assessment

The increasing complexity of the Advanced Driver Assistance Systems (ADAS) is making more difficult to perform the Hazard Analysis and Risk Assessment (HARA). These items require high-performance Electronic Control Units (ECU) with extensive software functionalities. To correctly operate they interact with the driver, environment and other vehicle functions through high-speed in-vehicle networks, as well as a wide range of sensors and actuators. As a result, they implement complex behaviors whose outcome in presence of faults is not trivial to identify and classify as requested by the concept phase included in the most recent functional safety standards. In this paper we present a simulation-based methodology to perform the HARA of a vehicle function by mixing the usual industrial approach, based on the designers' knowledge, with one that makes use of a vehicle-level simulator. The simulation-based approach provides an automatic and systematic method to assess the complex interaction of the item under analysis with other vehicle functions in possibly complex operational situations, thus making the prediction of hazards easier. We choose to demonstrate the approach by applying it to a well-known automotive industry case study: an Advanced Emergency Braking System (AEBS). In this way, it is possible to analyze the effects of the function provided by the item, keeping into account the simulations results and comparing them to similar situations analysis available in literature. Thanks to the obtained simulation-based results, safety engineers can formulate a more objective hypothesis, in particular during the hazard classification subphase.