Advanced Driver Assistance Systems in Winter Conditions
Author(s): Charlebois, Dube
Slidedeck Presentation:
Abstract:
Background:
Advanced Driver Assistance Systems (ADAS), including automatic emergency braking, lane support, and pedestrian detections systems, have potential to avoid collisions and reduce severe injuries and fatalities on Canadian roads. However, there is limited data available on the performance of these systems in winter conditions. In order to identify opportunities to improve safety, there is a need to better understand how ADAS equipped vehicles perform in complex winter conditions.
Aims:
The objectives were to develop and implement test procedures for assessing the performance of ADAS in winter conditions, including the effects of snow and ice accumulation on vehicles and roads, and winter clothing worn by pedestrians. Results will inform approaches to evaluating ADAS performance, and enhance the understanding of current ADAS safety features when engaged during winter.
Methods:
Winter testing methods were developed based on standard European New Car Assessment Program (EuroNCAP) and UNR152 (European Automatic Emergency Braking Regulation) methodologies, with modifications to be performed in winter conditions. Modifications included winter clothing on pedestrian targets (heavy winter coat, winter hat, backpack and color contrast against background), snow and ice accumulation on vehicle ADAS sensors and on target vehicles, as well as partially snow covered roads. The testing equipment had to be modified to sustain snow and harsh working conditions. Procedures were also developed for capturing effects of winter clothing on radar cross section. The ADAS performance of six vehicles was tested in a range of winter conditions, as well as under standard conditions at Transport Canada’s test track. Vehicles with different technologies were selected to obtain the best representation of the current Canadian fleet.
Results:
The need for consistent winter environments for repeat tests and comparisons between vehicles and test scenarios created a challenge. Extra documentation was included to capture the environmental conditions. Preliminary results show a degradation in ADAS performance in winter conditions, including delays in vehicle and pedestrian detection. ADAS performance varied between vehicles under baseline summer conditions. Winter ADAS performance was compared to the summer baseline and vehicles were affected differently by the test conditions. Testing is continuing until the end of March 2021.
Discussion:
Some test vehicles showed longer reaction times to winter collision scenarios when compared to the same test conducted in summer conditions. This can affect the potential collision mitigation. This is not considering the extra time required due to braking on snow or ice covered road surfaces. Although manufacturers often warn that ADAS may not be operational under adverse conditions, it is important to understand that Canadians are crossing the street, or driving with other cars on the road all year long. Benefits from ADAS may be reduced during winter.
Conclusions:
Future testing will capture the evolution of commercially available systems in their ability to mitigate collision risk all year long. Robust winter testing methodologies will continue to be developed.