Adaptable Take-Over Concepts: Considering Partial and Gradual Take-Overs

Abstract

In this paper, we explore a novel three-stage take-over (TO) concept for conditionally autonomous vehicles (SAE L3). In a user study in a driving simulator, we evaluated the usability of four different TO concepts: a) a basic concept including only a single TO request, b) a partial take-over (PTO) concept, where the longitudinal coordination of the vehicle remains automatic, when a TO is performed by steering only, c) a concept with an improved minimum safety manoeuvre (MSM) with additional warnings and automatic braking manoeuvres, and d) a TO concept including both PTO and MSM. The results showed that when PTO and MSM were both used, the minimal time-to-collision (TTC) was longer on average, and the maximal lateral acceleration was lower on average compared to the basic or PTO concepts. In addition, significantly fewer collisions were observed when using PTO+MSM compared to the basic TO concept.