Effects of exhaust gases on laser scanner data quality at low ambient temperatures

Abstract

Safety systems in automated vehicles use surround sensors to perceive their local environment. In contrast to radar sensors, laser scanners provide precise spatial information, which can be used to identify critical traffic situations and trigger reversible or irreversible safety systems. As a consequence, already small errors in sensor data measurements could lead to severe accidents. The performance of surround sensors depends on the ambient atmosphere and weather condition. It is known that rain and fog have negative influence and leads to signal degradation. In winter time or cold climate, the ambient air temperature requires less moisture to attain high relative humidity or to become saturated. Therefore, the hot exhaust gases of vehicles are condensed instantly and can be seen as a distinct mass of fog. To the best of our knowledge, nobody has investigated effects of exhaust gases at low temperatures on sensor quality so far. Based on static and dynamic tests at different temperatures, we have shown that exhaust gases are visible for laser scanners and lead to degraded performance. The results can be used to assign the priorities of sensors in sensor data fusion processes or to develop novel filter algorithms for low temperature situations.