  Autonomous emergency steering (AES) systems have the promising potential to
further reduce traffic fatalities with other (potentially vulnerable) traffic
participants by using relatively small lateral deviations to realize
collision-free behavior. In this work, a complete and tractable software
architecture is presented for such an AES system, comprising of the estimation
of the vehicles capabilities, planning a set of paths which exploit these
capabilities, checking the feasibility and risk of these paths and eventually
triggering the decision to drive along one of these paths, i.e., initiating an
AES manoeuvre. A novel methodology is provided to trigger such an AES system,
which is based on a time-to-evade (TTE) notion. In the presence of time-varying
uncertainties or measurement inaccuracies, the system is able to replan the
path from the previously chosen path to ensure collision-free behavior. The
proposed architecture and control approach is validated using a simulation
study and field tests, showing the effectiveness of the architecture and its
sub-components.
