Automatic headlight beam throw adjustment

As standard, vehicles with LED headlights have automatic headlight beam throw adjustment to compensate different load statuses of the vehicle. The automatic headlight beam throw adjustment for the LED headlight includes the following functions:

• Dynamic headlight beam throw adjustment

  The dynamic headlight beam throw adjustment was developed for compensating pitching movements that occur as a result of braking and acceleration.

• Adaptive headlight beam throw adjustment

  The adaptive headlight beam throw adjustment uses vehicle information to identify driving over rises or dips. The headlights are turned appropriately. The automatic headlight beam throw adjustment thus ensures that oncoming traffic is not dazzled.

The automatic headlight beam throw adjustment is supported by 2 ride height sensors. one ride height sensor each located on the front axle and the rear axle of the vehicle. Data from ride height sensors are evaluated directly by the Integrated Chassis Management (ICM). The front electronic module (FEM) receives the signals from the Integrated Chassis Management (ICM) via the FlexRay.

The following graphic shows the light cone's primary motion patterns during operation of the automatic headlight beam throw adjustment.

Fig 1: Adjusting Vehicle With Adaptive Headlight Beam Throw

Courtesy of BMW OF NORTH AMERICA, INC.

The adaptive headlight beam throw adjustment is employed when driving through dips and over crests. In accordance with a request from the front electronic module (FEM), the headlight driver module controls the swivel module via the stepper motors and by doing so, the headlight beam throw.

When the vehicle passes through a dip, the headlight beam throw is increased. The swivel module is moved up slightly. The roadway is illuminated a greater distance ahead.

Fig 2: Adjusting Vehicle Without Adaptive Headlight Beam Throw

Courtesy of BMW OF NORTH AMERICA, INC.

When the vehicle passes over a crest, the headlight beam throw is reduced somewhat. The swivel module is moved down slightly. This reduces dazzling effect of an oncoming vehicle.

Fig 3: Adjusting Vehicle Without Adaptive Headlight Beam Throw

Courtesy of BMW OF NORTH AMERICA, INC.