|
Abstract
|
27th International Technical Conference on the Enhanced Safety of Vehicles (ESV): Enhanced and Equitable Vehicle Safety for All: Toward the Next 50 Years
https://www-esv.nhtsa.dot.gov/Proceedings/27/27ESV-000162.pdf
Adapting the performance and design of Advanced Driver Assistance Systems (ADAS) and Automated Driving Systems (ADS) to human capabilities and safety needs is an important requirement for a safe market introduction of new technologies in this field. A specific challenge for SAE Level 2 systems is the engagement of the driver in the driving task. A high level of driver engagement is necessary to ensure that drivers are able to fulfill their role and responsibility to monitor the system performance and to intervene in system limit situations. However, effectiveness of current driver monitoring technologies to ensure driver engagement are limited with broadly diversified performance parameters. Therefore, the aim of the current research was to develop and validate a standardized procedure for performance-based assessments of driver engagement of Level 2 systems with a direct link to safety by focusing on controllability in accident-prone system limit situations. In total, 39 drivers without prior experience in continuously assisting systems participated in the evaluation study on a test track. To assess the validity of the procedure and the standardized test scenario, half of the participants experienced a Level 2 system (Tesla Autopilot) while the other half drove the same vehicle (Tesla Model 3) conventionally (fully manual). The participants task was to constantly follow a lead vehicle, driven by a second experimenter, on a round course for approx. 30 minutes. At the end of the test drive an accident-prone system limit situation without a prior system-initiated warning was triggered: The lead vehicle performed a cut-out maneuver revealing a stationary crash target in front of the participant. Without driver intervention, the Level 2 system was not able to avoid a collision. Therefore, the participant was required to react by braking and/or steering. Results indicate that the test scenario is controllable by conventional drivers. No driver of this group caused a collision or had a Time-To-Collision minimum below 1 second. However, drivers of the Level 2 system specifically used in the study had difficulties in controlling the system limit situation and intervening adequately to avoid a collision with the stationary target. 15% of these drivers collided with the target and approx. 50% had a Time-To-Collision minimum below 1 second. Furthermore, the median Time-To-Collision minimum of the Level 2 drivers was approx. 1.5 seconds lower compared to conventional drivers. Concluding, it can be stated that the test scenario is in general controllable by conventional drivers but, due to a lack of driver engagement of the Level 2 system tested in the study, participants of this group had problems in intervening adequately to the system limit. In summary, the developed procedure is a pragmatic, reliable and valid way to assess driver engagement independently and in a design-neutral way by focusing on safety critical interaction behavior in system limit situations.
Language: en |