Contrast measurements for detection and recognition with Laser High Beam Systems in real life drivin

Kobbert, J. M.Sc., Englisch, D. M.Sc., Kosmas, K. M.Sc., Szarafanowicz, M.Sc., Schneider, K. M.Sc, Prof. Dr. –Ing. Khanh, T.Q.,

Abstract

At the Technical University in Darmstadt, a study was performed, to investigate the benefit of increasing the maximum illuminance in the high beam hot spot. For this investigation three light distributions, LED passing beam, LED driving beam, and LED driving beam with additional Laser Booster are chosen. The goal is, to compare detection and recognition rates for these different light distributions and estimate the relevant correlating photometric value. While the LED driving beam has a maximum illuminance of 120 lx, activating the additional Laser Booster leads to a maximum illuminance of over 300 lx in the centre hot spot. To compare these light functions, the test subject is asked to perform two different tests. In the first test, detection of a human like figure is tested, while in the second test a specific sign is used and the test subject has to identify the direction of the sign.

The resulting detection and recognition distances are then compared and significant improvements are shown for all light distributions. Additionally, to the different distances, illuminance and luminance are measured for all relevant measurement points. For all data sets the Weber-Contrast is calculated and correlated with detection and recognition distances. This paper will shortly outline the detection and recognition tests with focus on contrast ratios and illuminance values required to detect the different test objects in real life driving situations.