NLOS Obstacle Position Estimation from Reflected Image

In this paper, a method for estimating the position of obstacles existing outside the line of sight of the vehicle is proposed. By using a stereo vision camera, it estimates the position of obstacles reflected on the side of another vehicle near the subject vehicle or the glass surface of the building next to the road. First, to clarify the feasibility of such an application, the frequency of the reflection of the virtual image of the vehicle traveling in front of the preceding vehicle of the ego-vehicle on the side of the vehicle traveling in the adjacent lane is measured. Next, since those reflecting surfaces are oriented in various directions, proposed method takes its orientation into account for estimating the position of obstacles. As a result of experiments on the 1/5 scale, we could estimate the position within 20 cm of the error for obstacles existing at distances of 1.4 m to 4 m from the camera in the longitude distance direction. This result indicates that it is possible to estimate the position of the obstacle existing outside the line of sight that is present at a distance of about 20 m from the 5 m in the actual road situation with a precision of about 1 to 2 m.