Abstract

There is a trend in Advanced Driver Assistance systems towards increased automation. Current systems and near-future systems will not yet be able to deal with all different situations that can be encountered and therefore need to share control of the vehicle with the driver. To safely and comfortably share control, a method for the transition of control (from manual to automated driving and vice versa) needs to be developed. This involves answering research questions like ‘how should the system take over’, ‘how can the driver take back control’, ‘can the driver be regarded as a backup if the system fails’, etc. This paper concentrates on finding different parameters and settings that may influence the transition of control for a ‘virtual tow bar’ system that is being developed at TNO . This serves as a first step to finding more general guidelines for transition of control and to develop necessary procedures, models and tools to evaluate these guidelines. Results of a first simulator experiment are presented and discussed.

Abstract

n important question in automated driving research is how quickly drivers take over control of the vehicle in response to a critical event or a take-over request. Although a large number of studies have been performed, results vary strongly. In this study, we investigated mean take-over times from 129 studies with SAE level 2 automation or higher. We used three complementary approaches: (1) a within-study analysis, in which differences in mean take-over time were assessed for pairs of experimental conditions, (2) a between-study analysis, in which correlations between experimental conditions and mean take-over times were assessed, and (3) a linear mixed-effects model combining between-study and within-study effects. The three methods showed that a shorter mean take-over time is associated with a higher urgency of the situation, not using a handheld device, not performing a visual non-driving task, having experienced another take-over scenario before in the experiment, and receiving an auditory or vibrotactile take-over request as compared to a visual-only or no take-over request. A consistent effect of age was not observed. We also found the mean and standard deviation of the take-over time were highly correlated, indicating that the mean is predictive of variability. Our findings point to directions for new research, in particular concerning the distinction between drivers’ ability and motivation to take over, and the roles of urgency and prior experience. © 2019 Elsevier Ltd