GF54.71-P-0002LE Automatic Lane Recognition, Function
GF54.71-P-0002LE Automatic Lane Recognition, Function
- with CODE (476) Automatic lane recognition
- refinement package
- as of model year 2010
Function requirements, general
^ Circuit 15 On
^ Function enabled via the instrument cluster (A1)
^ Radius of curve r >150 m
^ Track width s = 2.2 up to 4.6 m
^ Recognizable lane markings available (no snow, not covered etc., i.e. contrast too low)
^ Vehicle speed less than v = 60 to 250 km/h
The instrument cluster sends the vehicle speed over the chassis CAN (CAN E). The status of circuit 15 is transmitted by the EIS [EZS] control unit (N73) via the chassis CAN.
Automatic lane recognition, general
In the automatic lane recognition system any driving across the lane markings is detected and the driver warned in certain situations by a warning system about leaving the lane.
The warnings are issued to the driver if the road marking is touched or driven over with the respective front wheel. To enable a warning to be issued for a specific circumstance obviously unwanted warnings are suppressed. For this the activity of the driver is evaluated by the primary controls such as steering wheel, brake and accelerator pedal and "corner cutting" is explicitly allowed. In addition the use of controls (e.g. seat/steering column or mirror adjustment ) is monitored and assessed.
If any driver distraction is recognized, the system will issue a warning even if driver activity has been detected. The warning instant of the system is adapted to the respective conditions, so for example.:
- The driver is warned later on narrow lanes
- With corner cutting on the inside of the curve depending on the lateral acceleration driven in the curve, warnings are issued later; on the other hand with corner cutting on the outside of the curve, warnings are issued earlier
- On very wide lanes, in particular on freeways, the warning is issued earlier
The automatic lane recognition function is activated by way of the "Assistance" menu in the instrument cluster.
Component Identification:
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 recognition of driver activity
^ Function sequence for issuing warning
^ Function sequence for suppression of warning output
Function sequence for lane recognition
The multifunction camera, which is mounted below the (A40/11) inside rearview mirror (A67) on the windshield, observes the road space in front of the vehicle and takes photos at a fixed scanning rate and makes them available to the control unit integrated into the multifunction camera for further processing. In doing so, measurements are made of the lane markings. The recorded photo sequences and the measured values on the lane markings are used to calculate the lane. This means that the position of the vehicle within the lane and the course of the lane in front of the vehicle can be determined. This data can be used by the multifunction camera to determine whether the driver has crossed over a lane marking.
No lane information can be issued where there are no lane markings or if they are covered up (e.g. by dirt or snow) or where there is a low contrast between the road surface and lane marking.
For multiple markings on the traffic lane, the inner marking is always taken as the reference point. When in construction site area the system is unable to issue warnings because of multiple markings.
The instrument cluster continuously displays the current status, in particular the warning readiness.
Possible displays:
- System status ON/OFF
- Warning readiness
Function sequence for recognition of control interventions
In the event of a detected operating intervention function at one of the following components the "distracted driver" is determined and actively warned by the automatic lane recognition system when crossing over the lane marking:
- Rotary light switch (S1)
- Left front seat operation switch group (S22) or switch group for power windows, outside mirrors and trunk lid on driver side (S20/1)
- COMAND controller unit (A40/3) (with code (526) COMAND with single DVD drive (without navigation) or code (527) COMAND APS with single DVD drive (with navigation) or code (530) COMAND APS USA (with navigation))
- Combination switch (S4)
- Roof system switch (N70s1) (with code (413) Panoramic glass sunroof with top sliding sunroof or code (414) Glass electric tilting/sliding roof)
- via the steering column adjustment switch (S59) (without code (443) steering wheel heater)
- steering column adjustment/steering wheel heater switch (S59/1) (with code (443) Steering wheel heater)
- Left multifunction steering wheel button group (S110 ) or right multifunction steering wheel button group (S111)
The signals from the combination switch and steering column adjustment switch are read in by the steering column tube module (N80) via the steering LIN (LIN E1) and transmitted on the chassis CAN. The signals from the multifunction steering wheel button groups are read in by the steering wheel electronics (N135) and transmitted to the steering column tube module via the steering LIN. The signals from the power windows, outside mirrors and trunk lid switch group on the driver side and left front seat operation switch group are read in by the left front door control unit via the front door LIN (LIN B1)(N69/1) and transmitted to the central gateway control unit via the interior CAN (CAN B) (N93). The central gateway control unit transmits to the multifunction camera via the chassis CAN.
The signal from the rotary light switch is read in by the upper control panel control unit (N72/1) via the instrument panel LIN and transmitted to the central gateway control unit via the interior CAN. The central gateway control unit transmits to the multifunction camera via the chassis CAN.
The signal from the roof system switch is transmitted by the overhead control panel control unit (N70) to the central gateway control unit via the interior CAN and from there on the chassis CAN.
The signal from the COMAND controller unit is transmitted to the central gateway control unit via the interior CAN and from there on the chassis CAN.
The multifunction camera transmits the request to warn the driver via the chassis CAN to the steering column tube module. This passes on the request via the steering LIN to the steering wheel electronics which actuates the steering wheel vibration motor (M99) in the steering wheel.
Function sequence for recognition of driver activity
Signals which suggest recognized driver activity, (such as accelerating) are transmitted by the CDI control unit (N3/9) (with diesel engine) or ME-SFI control unit (N3/10) (with gasoline engine) to the multifunction camera via the chassis CAN. The signal from the yaw rate sensor for lateral and longitudinal acceleration (B24/15) is transmitted to the ESP control unit via the vehicle dynamics CAN (CAN H) (N47-5)(without model 221.095/195) or to the regenerative braking system control unit (N30/6) (model 221.095/195). Furthermore, the ESP control unit or regenerative braking system control unit transmits signals of the wheel speeds and the status of the service brake to the multifunction camera via the chassis CAN. The signal from the steering angle sensor (N49) is transmitted by the steering column tube module to the multifunction camera via the chassis CAN.
The current data from the steering angle sensor are assessed for driver activity by the multifunction camera. The sequence for warning comes into force accordingly.
Additional function requirements for warning output
^ Recognized leaving of lane
^ No currently applied suppression of warning output
Function sequence for issuing warning
The warning output consists of the following component functions:
^ Function sequence for haptic warning
^ Function sequence for warning cancellation
Function sequence for haptic warning
The multifunction camera transmits the request to the steering column tube module via the chassis CAN. This passes on the request via the steering LIN to the steering wheel electronics which actuates the steering wheel vibration motor. The warning is conducted in multi stages. If an urgent warning is issued the vibration is conducted in intervals. 3 pulses are output (warning duration t = 1.5 s) and detected by the driver as vibration.
Function sequence for warning cancellation
The warning is terminated by the discontinuity of the triggering conditions or when driver activity is recognized (braking, accelerating and braking or turn signaling). If a driver reaction is detected during a warning, e.g by countersteering or by turn signaling, only 2 pulses are output (warning duration t = 1.0 s).
Function sequence for suppression of warning output
If the multifunction camera receives at least one of the following pieces of information, a warning is suppressed, as it is assumed that the driver intended to change lane:
- Status changes of steering wheel, brake or accelerator pedal
- Recognized "corner cutting" (by means of lane recognition and the current vehicle position the multifunction camera recognizes a road with bends and concludes "corner cutting"). Warnings when cutting corners are not issued.
- Active flashing function (corresponding turn signaling)
- Active or passive safety systems active
If "corner cutting" is recognized a warning period delay occurs, until a defined threshold (lateral acceleration dependent on ground speed) is reached, whereupon a warning is then issued.
The individual pieces of information for suppression of the warning are received by the multifunction camera over the chassis CAN.
