Laser-Based Obstacle Detection at Railway Level Crossings

Figure 3

The level crossing model. The two horizontal lines represent the railway. The radial lines stemming from the LIDAR position are representative of the laser beams generated when the sensor is not tilted. These lines give an intuition regarding the loss of point density as a function of the distance to the sensor. The frame of reference represented is the one of the LIDAR. The four filled rectangles represent the four half-barriers present in the site. Note that, in most situations, the barriers disposed in a nonsquare quadrilateral shape.