Recognition of foggy conditions by in-vehicle camera and millimeter wave radar

Recently driving support techniques using in-vehicle sensors have attracted much attention and have been applied to practical systems. We focus on supporting drivers in poor visibility conditions. Fog is one of the causes that lead to lack of visibility. In this paper, we propose a method of judging fog density using in-vehicle camera images and millimeter-wave (mm-W) radar data. This method determines fog density by evaluating both the visibility of a preceding vehicle and distance to it. Experiments showed that judgments made by the proposed method achieved a recognition rate of 84% when compared to the ground truth obtained by human judgments.