Functional Principle: Notes

The adaptive headlight-range adjustment system only becomes active when the light switch is in position "A" and the driving lights have been switched on by the rain/light/solar/condensation sensor.

Raising or lowering of the headlight beam pattern is based to a great extent upon the calculation of two signals. The signals are the driving speed as well as the longitudinal acceleration of the vehicle. These signals are used to calculate the incline and respectively the downhill gradient compared with the horizon. The footwell module continuously imports the signals via the K-CAN2 and uses them to calculate the current values for the adaptive headlight-range adjustment system. The values correspond to the incline angles over the time period. The incline angles may be positive, negative or zero. The difference between the individual incline angles is used by the footwell module to calculate whether it is necessary to adjust the headlights.

The signal from the ride-height sensors is incorporated into the calculation. This allows the pitch angle of the vehicle body, due to a vehicle load for instance, to be included in the calculation.

Data from the longitudinal acceleration sensor and the ride-height sensors are output through the integrated chassis management via the FlexRay. Data for the driving speed are provided by the integrated chassis management also via the FlexRay. The central gateway module transfers the data from the FlexRay to the K-CAN2. The footwell module receives the data via the K-CAN2.

Beam throw adjustment is soft to avoid the eyes becoming tired or irritated.

Fig 1: Identifying Incline Angle Of Adaptive Headlight-Range Adjustment System F01/F02

Courtesy of BMW OF NORTH AMERICA, INC.