The light sensor

The light sensor works with two independent sensors: one has a wide angle of detection so that it captures all ambient light regardless of the angle of incidence. The second sensor measures the road surface light. It is aligned in such a way that it only detects the light intensity directly in front of the vehicle. The automatic brightness adjustment of a head-up display, for example, is based on this measurement method. The automatic activation of the low beam, on the other hand, is based on data from both sensors.

Light sensors form the basis for other interactive measures as regards the regulation of vehicle lighting. Here oncoming vehicles are just as relevant as those driving up ahead. The day/night mode also plays a part in the vehicle lighting as does the recognition of street lighting including the reflecting of traffic signs, for example, when the vehicle is driven into built-up areas. Intelligent assistance systems such as adaptive dynamic cornering light, adaptive light distribution (selective illumination of danger spots) or glare-free high beam (adaptive cut-off line) are also included depending on the headlamp technology involved. The HELLA Group, for example, supplies the relevant systems such as the Advanced Frontlighting System (AFS). In the case of LED headlamps from HELLA, individual LED modules can be switched on and off based on the information from the light sensor (and other ambient parameters), depending on the ambient conditions and the traffic situation.