Rain-sensing Wipers
Car evolution and the advancement of technology might be successful, one day, to eliminate windscreen wipers. It’s difficult to imagine how, but with hydrophobic coatings for glass gaining in popularity, the windscreen wipers’ days might just be numbered. Not without a fight. For the moment, the humble windscreen wiper is here to stay.
The first sign of extinction might have been in some manufacturers halving the number of wipers per screen from two to one. A significant step towards wiper cleansing. Despite this attempt, the wiper proved to be irreplaceable so the focus shifted to how to make the wiper perform better. If the wiper cannot be eliminated, surely it can be controlled? Ah! But we have intermittent wipers; automated! Everyone likes a but of labor-saving automation, right?
Automatic wipers. The next step – control their speed automatically.
Rain Sensors.
A sensor projects infrared light into the windscreen at a 45-degree angle. If the glass is dry, most of this light is reflected back into the sensor by the front of the windscreen. If water droplets are on the glass, they reflect the light in different directions; the wetter the glass, the less light makes it back into the sensor.
The electronics and software in the sensor turn on the wipers when the amount of light reflected onto the sensor decreases to a preset level. The software sets the speed of the wipers based on how fast the moisture builds up between wipes. It can operate the wipers at any speed. The system adjusts the speed as often as necessary to match with the rate of moisture accumulation.
There are many different types of rain sensor however they are all equal in the way they perform. Some look different and some incorporate a day and night sensor, or in car terminology: Automatic Headlights.