Display and Control Concept: Warning

The active system is ready whenever the prerequisites for a lane departure warning have been fulfilled: Lane detected and V > 40 mph.

If the vehicle threatens to drive over the lane marking, the system warns the driver by causing the steering wheel to vibrate.

Based on the detection of one or two lanes, the system first calculates the position of the vehicle in relation to these lanes.

Using the vehicle's steering angle and road speed, the system calculates the time (t) remaining before the vehicle would cross the lane marking.

The warning is output in time before the vehicle crosses the marking.

Fig 1: Lane Departure Warning Vibration Actuator On Steering Wheel

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Identifying F01/F02 Lane Departure Warning

Courtesy of BMW OF NORTH AMERICA, INC.

A warning is output only once on approach to a roadway marking. The warning lasts a maximum of 2.5s. No more warnings are output if the vehicle then continues to drive along the lane marking.

A new warning can only be issued if the vehicle has been steered back into the lane or the vehicle has completed a change of lane.

No warning is given if the control unit has received an input signal indicating the activation of the turn signals because this signal announces that the driver is about to change lane intentionally.

Similarly, no warning is given if the hazard warning lights are switched on.

The warning ends when:

• The driver steers back into the lane
• A lane change is completed
• The vehicle drives along the line for longer than 2.5 seconds
• The turn signal is operated to indicate a change of lane
• The brake pedal is depressed with force (brake-pressure-dependent).