A Strategy for Assessing Safe Use of Sensors in Autonomous Road Vehicles

When arguing safety for an autonomous road vehicle it is considered very hard to show that the sensing capability is sufficient for all possible scenarios that might occur. Already for today’s manually driven road vehicles equipped with advanced driver assistance systems (ADAS), it is far from trivial how to argue that the sensor systems are sufficiently capable of enabling a safe behavior. In this paper, we argue that the transition from ADAS to automated driving systems (ADS) enables new solution patterns for the safety argumentation dependent on the sensor systems. A key factor is that the ADS itself can compensate for a lower sensor capability, by for example lowering the speed or increasing the distances. The proposed design strategy allocates safety requirements on the sensors to determine their own capability. This capability is then to be balanced by the tactical decisions of the ADS equipped road vehicle.