Function Limitations Of The Main-Beam Assistant

The main-beam assistant can be subject to function limitations under the following circumstances:

• Inclement weather conditions (e.g. fog)
• Poorly lighted road users (e.g. cyclists, pedestrians)
• Certain road signs (e.g. the warning sign for a tight bend): Reflections from traffic signs may be incorrectly interpreted by the main-beam assistant as a vehicle driving ahead or as oncoming traffic.

  In the case of a the danger sign for a tight bend. On account of the reflections, the image sensor is unable to interpret this road sign correctly:

  • The image sensor interprets the reflections from the white surfaces as the lights of an oncoming vehicle.
  • The image sensor interprets the reflections from the red surfaces as the lights of a vehicle travelling ahead.
  In both cases the headlights are dipped to low beam.

  The headlights are automatically switched back to main beam when the road sign passes outside the image sensor's cone of detection (after the bend).

• Driving over crests and through dips.

  Crests and dips can impose function limitations on the main-beam assistant as follows:

  1. The headlights are not dipped until the headlights of the oncoming vehicle enter the image sensor's cone of detection.
  2. As the car approaches a crest, therefore, the headlights are not dipped until the headlights of the oncoming vehicle are visible. The beam of light that the oncoming vehicle's headlights throw over the crest is not detected by the image sensor.

• Certain traffic situations (e.g. tight bends, vehicles approaching from the side).
• Image sensor's field of view obstructed (e.g. by snow).