GF54.71-P-0002FL Automatic Lane Recognition, Function

GF54.71-P-0002FL Automatic Lane Recognition, Function
- with CODE (476) Automatic lane recognition

Function requirements, general
^ "Attention Asst." function activated using "Assist." menu in instrument cluster (A1)
^ Vehicle speed less than v = 60 to 250 km/h
^ Radius of curve r >150 m
^ Track width s = 2.2 up to 4.6 m

Automatic lane recognition, general
The automatic lane recognition system detects any unintentional driving across lane markings and issues a haptic warning to the driver in certain circumstances through initiating vibrations on the steering wheel.
Pictures of the traffic area in front of the vehicle are recorded by the MFK (A40/11), in the area of the inside rearview mirror (A67), and processed further.

The haptic warning is generated by the steering wheel vibration motor (M99). The automatic lane recognition system takes the driver's behavior into consideration and decides the point at which a warning is to be issued.

Under the following conditions any driving over lane markings is detected, but a warning is not issued:
- For driver activities through evaluation of steering-wheel movement, brake requests and the accelerator pedal position
- For sporty cornering (cutting corners)
- When turn signaling
- For active control intervention functions by the brake assist system

If the driver however is distracted by operating a comfort function and therefore drives over a lane marking, a warning will be issued. All control interventions made by the driver are notified to the automatic lane recognition system.

The following comfort functions are monitored:
- Seat adjustment (with code (275) Memory package for electrically adjustable front seats)
- Outside mirror adjustment
- Power window
- Steering-wheel adjustment (with code (275) Memory package for electrically adjustable front seats)
- Interior lighting
- Operation of audio system
- Operation of tilting/sliding roof (with code (414) Electric glass tilting/sliding roof)
- Operation of panoramic sliding sunroof (with code (413) Panoramic glass sunroof with top sliding sunroof)

If the automatic lane recognition system considers the driver to have been distracted during a driver activity (steering, braking, accelerating, turning off) and driving over the lane marking is recognized, a warning is still issued.

The time at which this warning is issued is adapted to match the prevailing ambient conditions:
- In narrow lanes the warning is issued later
- When cutting corners on the inside of the corner, the warning is issued later to match the lateral acceleration driven in the corner, by contrast, on the outside of the corner the warning is issued earlier
- On very wide lanes, in particular on freeways, the warning is issued earlier

The instrument cluster multifunction display (A1p13) shows the current status and the automatic lane recognition system's readiness to issue a warning.

The vehicle speed is calculated by the instrument cluster and sent to the multifunction camera over the chassis CAN (CAN E). The radius of bend is calculated using the steering angle sensor (N49) data. The steering column tube module control unit (N80) reads in the data and sends the data over the chassis CAN to the multifunction camera.

The automatic lane recognition system is made up of the following component functions:
^ Function sequence for lane recognition
^ Function sequence for recognition of control interventions
^ Function sequence for observing driving performance
^ Function sequence for issuing warning

Function sequence for lane recognition
The multifunction camera records pictures of the traffic area in front of the vehicle in a fixed scanning rate and evaluates them with the aid of reference data. If lane markings are present, they are measured and the lane then calculated. Following this, the multifunction camera calculates the position of the vehicle within this lane and its position as it continues in this lane. This calculation is used as the basis for deciding whether the driver has crossed over a lane marking or not.

If, for example, leaves, dirt or snow covers up the lane markings or if the contrast between the lane and the lane marking is too low, a lane cannot be recognized.
With multiple markings, the inner marking is always taken as the reference point. When in roadworks the system is unable to issue warnings because of the multiple markings.

Component Identification:

Function sequence for recognition of control interventions
Control interventions by the driver, which could distract the driver, are defined by evaluating the following controls:
- Left front seat adjustment switch group (S22) (with code 275) Memory package with electrically adjustable front seats)
- Driver-side power window and outside mirror adjustment switch group (S20)
- Steering column adjustment switch (S59) (with code (275) Memory package (electrically adjustable front seats without code (443) Steering wheel heater)
- Steering column adjustment switch (S59/1s1) (with code (275) Memory package (electrically adjustable front seats with code (443) Steering wheel heater)
- Radio (A2) (with code (523) Radio MB Audio 20 or code (510) Audio 20 incl. CD changer)
- Radio with autopilot system (A2/56) (with code (525) Radio MB Audio 50 APS or code (511) Audio 50 APS incl. DVD changer)
- COMAND control unit (A40/3) (with code (527) COMAND APS with single DVD drive (with navigation) or code (528) COMAND incl. DVD changer (without navigation) or code (512) COMAND APS with DVD changer)
- Left multifunction steering wheel button group (S110) or right multifunction steering wheel button group (S111)
- Tilting/sliding roof switch (N70s1) (with code (414) Power glass tilting/sliding roof)
- Panoramic sliding roof switch (N70/3s1) (with code (413) Panoramic glass sunroof with top sliding sunroof)
- Overhead control panel control unit (N70) interior illumination operating switch

The control interventions for seat adjustment, outside mirror adjustment and power windows are sent to the multifunction camera over the following path:
- Seat adjustment switch group or
- Power window and outside mirror adjustment switch group
- Left front door LIN (LIN B5)
- Left front door control unit (N69/1)
- Interior CAN (CAN B)
- front SAM control unit with fuse and relay module (N10/1)
- Chassis CAN

The steering wheel adjustment control interventions are sent to the multifunction camera over the following path:
- Steering column adjustment switch
- Direct line
- Steering column module control unit
- Chassis CAN

The control interventions via the multifunction steering wheel button group are sent to the multifunction camera over the following path:
- Multifunction steering wheel button groups
- Direct line
- Steering wheel electronics (N135)
- Steering LIN (LIN E1)
- Steering column module control unit
- Chassis CAN

The interior illumination control interventions are sent to the multifunction camera over the following path:
- Operating switch for interior illumination on overhead control panel control unit
- Interior CAN
- Front SAM control unit
- Chassis CAN

The audio system control interventions are sent to the multifunction camera over the following path:
- Radio or
- Radio with auto pilot system or
- COMAND control unit
- Interior CAN
- Front SAM control unit
- Chassis CAN

The tilting/sliding roof control interventions are sent to the multifunction camera over the following path:
- Tilting/sliding roof switch
- Overhead control panel control unit
- Interior CAN
- Front SAM control unit
- Chassis CAN

The panoramic sliding sunroof control interventions are sent to the multifunction camera over the following path:
- Panoramic sliding roof switch
- Panoramic sliding roof control module (A98)
- Interior CAN
- Front SAM control unit
- Chassis CAN

Function sequence for observing driving performance
Driver activities are defined by evaluating the signals for the following components:
- Combination switch (S4) (turn signaling)
- Accelerator pedal sensor (B37) (accelerating)
- Status of service brake
- Yaw rate sensors for lateral and longitudinal acceleration (B24/15) (vehicle acceleration)

The switch position for the combination switch is sent to the multifunction camera over the following path:
- Combination switch
- Direct line
- Steering column module control unit
- Chassis CAN

The accelerator pedal sensor data are sent to the multifunction camera over the following path:
- Accelerator pedal sensor
- Direct line
- CDI control unit (N3/9) (with diesel engine) or
- ME-SFI [ME] control unit (N3/10) (on gasoline engine)
- Chassis CAN

The service brake status is sent to the multifunction camera over the following path:
- Stop lamp switch (S9/1)
- Direct line
- Electronic Stability Program control unit (N30/4) (without code (233) DISTRONIC PLUS) or
- Electronic Stability Program Premium control unit (N30/7) (with code (233) DISTRONIC PLUS)
- Chassis CAN

The vehicle acceleration data are sent to the multifunction camera over the following path:
- Yaw rate sensors for lateral and longitudinal acceleration
- Vehicle dynamics CAN (CAN H)
- Electronic Stability Program control unit
- Chassis CAN

Additional function requirements for warning output
^ Recognized leaving of lane
^ No currently applied suppression of warning output

Function sequence for issuing warning
The multifunction camera sends the request to issue a haptic warning over the chassis CAN to the steering column tube module control unit. The steering column tube module control unit then actuates the steering-wheel vibration motor over the steering LIN and the steering wheel electronics. The warning is conducted in multi stages. The vibration is performed in intervals if the warning is a high-priority one.

Three pulses with a warning duration of t = 1.5 s are issued and perceived by the driver as a vibration.
If a driver reaction is detected during the warning, e.g. by turning back into the lane or through turn signaling, only two pulses are issued with a warning duration of t = 1.0 s.

The issue of a haptic warning is canceled if driver activity is detected (brakes, accelerating or turn signaling).