Mathematical model of type approval requirements for headlighting

Tomasz Targosinski (Author)

Motor Transport Institute,

Warszawa, Poland

tomasz.targosinski@its.waw.pl

Abstract – Type approval requirements for headlighting are divided to photometrical requirements in component regulations and to installation requirements describing position on vehicle, initial aiming and leveling tolerances. In addition light sources are standardized and type approved. Design of this system of requirements is based on mathematical model of road illumination. This model was not explicitly expressed even is internally included in requirements. But the way of defining of requirements somehow reflect this model. At a time when requirements were created for the first time technology of light sources and headlamps was very special and different than today – low voltage double filament and paraboloidal reflector with rifles glass lens. Simplifications and imperfections of mathematical model used in creating regulation more than 50 years ago significantly influenced for headlamp design evolution and finally for road illumination and glare.

In the paper is presented reconstruction and analysis of the mathematical model and its influence for headlights performance, measurements and verification. This model is imperfect and allow for significant differences in quality of road illumination. It is also analyzed how it works in connection with contemporary headlamps design and technology and practice.

Keywords: Headlights, type approval,mathematical model