The need for an environment perception block to address all ASIL levels simultaneously

In order to perform safety assessment of vehicles for highly automated driving, it is critical that the vehicle can be proven to adapt its driving according to the sensed objects that might become a hinder. There is a complicated relation between the confidence of what hinders that might exist coming out of an environment perception block, and the tactical decisions about the driving style done by the autonomous vehicle. A good strategy that enables safety assessment according to ISO26262 implies that the environment perception block should address its safety requirements for all the ASIL attribute values simultaneously. In this paper we argue why every functional safety requirement allocated to an environment perception block should preferable be instantiated four times, each with a different ASIL value.