Rain situation

Problems:

1. Water directly on the windsheeld
- Special coating for the windsheeld that reduce the rawness of the glass. One solution form Degussa.
- The Mecedes C-Class sportscar is using a special bar at the a-column useing the airflow
to lead the rainwater over the hole car. The back window is useing a rubber lib to keep the glass clean.
- Rain sensor to controll the windscreen wiper. A system from Hella could recognize weatherconditions like rain, light, solarlight and fogging.



2. Raindrops in the air, between other road users
- Adaptive dark-bright-border from hella


3. Water on the street reflect light form other road users

- Polarizationfilter inside of the windsheeld
- Road marking that work with waterfilm on it. Glas bead that are embedded in the marking reflect the drivinglight. The road marking must be designed in a way, that just a small waterfilm is over the glas beads.


One solution to avoid a thick waterfilm is the usage of Agglomeraten that create a big difference of level.
4. Longer Reactiontime
The time a driver need to recognize a pedestrian on the road depense on the contrast between the object (pedestrian) and the background. The contrast is reduced by other lightsources like road lightning, reflections on the street and water drops on the wind shield. If the reflection degree is the same between object and background it's harder for the driver to identificate the object. In this context is xenon is a good source, because of it high contrast. On a daytime driving situation the contrast is automaticly high. In a night situation the contrast is very low.

read the PDF here.