Washington: Researchers have developed an optical sensor for a car’s windshield that can even tell the difference between fog and darkness thereby helping to prevent accidents.
In the EU-sponsored ADOSE project, researchers at the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin, working with Centro Ricerche Fiat and the chip manufacturer STMicroelectronics, have developed a sensor system that can be inexpensively produced for medium-sized and small cars as well.
The multifunctional system consists of an entire camera, two sensors equipped with Fresnel lenses to detect light signals, and an infrared LED. Because fog and darkness can exhibit optically identical spectra, it is difficult to distinguish between these two light phenomena.
That’s why the infrared LED emits light waves that are scattered back in fog but not in conditions of darkness,“ explains IZM group manager Dr. Ing. Henning Schroeder.
Schroeder and his team have developed lightpipes - hollow, mirrored tubes – for these sensors that can deflect a light signal by as much as 90 degrees.
“With the lightpipes, we have succeeded in making the optical signal transmission more efficient, making the entire system smaller and reducing costs as a result,“ Schroeder points out.
The experts at IZM have also developed Fresnel lenses for these sensors. They are also responsible for the design of the sensor module, which was carried out via Rapid Prototyping. A prototype of the sensor module is already in hand.