Lane Keeping Assist, Function - GF54.71-P-0005RR
Model 190
With Code 22P (Lane tracking package)
Shown up to 30.11.2018
Shown as of 01.12.2018
Function requirements, general
- Engine running
- Lane Keeping Assist activated
The ME-SFI control unit sends the "engine running" signal via the drive train CAN, the powertrain control unit, chassis CAN 1, the front SAM control unit and chassis CAN 2 to the multifunction camera.
Model 190 up to 11/30/18
with code 22P (Lane tracking package)
Lane Keeping Assist can be switched on or off via the instrument cluster. The instrument cluster sends the status of the Lane Keeping Assist via the user interface CAN, the AMG gateway control unit and chassis CAN 2 to the multifunction camera.
Model 190 as of 12/1/18
with code 22P (Lane tracking package)
Lane Keeping Assist can be switched on or off via the head unit. The head unit sends the status of Lane Keeping Assist to the multifunction camera via the user interface CAN, AMG gateway control unit and suspension CAN 2.
Lane Keeping Assist, general
The Lane Keeping Assist detects when the vehicle crosses lane markings, and issues a haptic warning to the driver in certain situations by means of vibrations at the steering wheel.
Crossing over lane markings is optically recorded and processed by the multifunction camera.
The haptic warning is generated by the steering wheel vibration motor.
The Lane Keeping Assist takes the driver's behavior into consideration and decides the point at which a warning is to be issued. Here, the driver has the opportunity to adjust the sensitivity of Lane Keeping Assist using the system settings.
The following operating modes can be selected:
- Standard, sensitivity increased (warnings issued earlier and more frequently)
- Adaptive, sensitivity reduced (warnings issued later and less often)
The instrument cluster (up to 30.11.2018) or head unit (as of 01.12.2018) transmits the selected operating mode to the multifunction camera via the user interface CAN, AMG gateway control unit and suspension CAN 2.
Illustration of the principle of Lane Keeping Assist
Warnings are issued as soon as the vehicle is in the direct vicinity of a broken or solid line or crosses over it.
Lane Keeping Assist operation is speed-dependent. The vehicle speed is calculated on the basis of the wheel speeds. The Electronic Stability Program control unit sends this to the multifunction camera via chassis CAN 1, front SAM control unit and chassis CAN 2. The Electronic Stability Program control unit additionally sends the wheel speeds via chassis CAN 1, the AMG gateway control unit and the user interface CAN to the instrument cluster. The instrument cluster calculates the vehicle speed to be displayed and sends it via the user interface CAN, the AMG gateway control unit and chassis CAN 2 to the multifunction camera.
The Lane Keeping Assist function encompasses the following subfunctions:
- Lane recognition
- Recognition of driver activities
- Recognition of control interventions
- Warning output
Additional function requirements for lane recognition
- Detectable lane marking present on both sides (no construction site markings (ambiguous markings), no snow, not covered etc., i.e. not enough contrast)
- Two lane dividers present
Lane recognition
The multifunction camera is mounted at the top center of the windshield and it records the road space in front of the vehicle. The multifunction camera records pictures of the lane at a fixed scanning rate and makes these pictures available to the integrated control unit.
Schematic of lane recognition by multifunction camera
The multifunction camera calculates the lane based on two different lane algorithms that are implemented in the multifunction camera. If the comparison between the two lane algorithms results in a match, the multifunction camera uses the data to generate a safe lane.
The multifunction camera uses this data to calculate the relative position of the vehicle in the lane. The Active Lane Keeping Assist measures are all derived from this position. No lane information can be issued in cases where there are no lane markings or if they are not visible (e.g. owing to dirt or snow), where there is a low contrast between the road surface and the lane markings or where there is a high level of glare.
For multiple markings on the traffic lane, the inner marking is always taken as the reference point. If there are several markings present (e.g. in construction site zones), Lane Keeping Assist may not be ready to issue a warning. If tar joints in the road surface are interpreted as lane markings, a warning is suppressed.
Recognition of driver activities
The following situations suggest driver activity and result in suppression of any pending warning:
- Clearly active steering (steering intervention), braking or accelerating
- Turn signals
- Sporty driving (high cornering speeds, cutting tight corners or heavy acceleration)
Steering:
Up to 30.11.2018
Steering movements are recorded by the steering wheel angle sensor. The steering column tube module control unit reads in the signals from the steering wheel angle sensor directly and sends information about the steering wheel angle via chassis CAN 1, the front SAM control unit and chassis CAN 2 to the multifunction camera.
As of 01.12.2018
Steering movements are recorded by the steering wheel angle sensor. The steering column tube module control unit directly reads in the signals of the steering wheel angle sensor and transmits information to the multifunction camera via the AMG FlexRay, AMG gateway control unit and suspension CAN 2.
Brakes:
The Electronic Stability Program control unit sends the status of the brake pedal to the multifunction camera via chassis CAN 1, the front SAM control unit and chassis CAN 2.
Acceleration:
The ME-SFI control unit sends information about the accelerator pedal position via the drive train CAN, the powertrain control unit, chassis CAN 1, the front SAM control unit and chassis CAN 2 to the multifunction camera.
Turn signaling:
Up to 30.11.2018
The steering column tube module control unit directly reads in the switch position of the combination switch and sends this to the multifunction camera via chassis CAN 1, front SAM control unit and chassis CAN 2.
As of 01.12.2018
The steering column tube module control unit directly reads in the switch position of the combination switch and transmits this to the multifunction camera via the AMG FlexRay, AMG gateway control unit and suspension CAN 2.
Sporty driving (defined via the inherent motion of the vehicle (turn rate, lateral acceleration and longitudinal acceleration)):
The turn rate, lateral acceleration and longitudinal acceleration sensor sends the values for vehicle longitudinal and lateral acceleration and yaw rate to the Electronic Stability Program control unit via the vehicle dynamics CAN. The Electronic Stability Program control unit evaluates the data and sends the data to the multifunction camera via chassis CAN 1, front SAM control unit and chassis CAN 2.
A pending warning is also suppressed if the multifunction camera detects active corner cutting, crossing over of a lane marking at an angle of 3° or lateral acceleration of 4 m/s2
.
By means of lane recognition and the current vehicle position, the multifunction camera recognizes a road with bends and concludes "corner cutting". Warnings about corner cutting are not issued until a defined lateral acceleration is reached (delay of warning output).
Recognition of control interventions
Controls located in close proximity of the driver and that affect the attention of the driver when they are operated are monitored. If a control intervention is registered, the Lane Keeping Assist deems the driver to be "distracted". Control interventions are evaluated by the multifunction camera. The warning threshold is adjusted to match the actuating frequency of the control elements, i.e. Lane Keeping Assist warns earlier and possibly more often. An active warning is output as soon as the vehicle is in the direct proximity of or crosses over the lane marking.
The following controls are monitored:
- Audio system controls
- Comfort function controls:
- Cruise control lever (up to 30.11.2018)
- Steering column adjustment switch (with CODE P64 (Memory package))
- Multifunction steering wheel button groups
- Driver-side power window and outside mirror adjustment switch group (only the outside mirror adjustment is monitored)
- Interior illumination controls:
- Interior lamp automatic function switch
Control interventions on audio system:
The audio system is only operated via the Audio/COMAND control panel (except code 446 (touchpad only)) or the touchpad (with code 446 (touchpad only)). Control interventions on the Audio/COMAND control panel (except code 446 (touchpad only)) or touchpad (with code 446 (touchpad only)) are received by the head unit via the telematics CAN. The head unit sends information about control interventions at the audio system to the multifunction camera via the user interface CAN, the AMG gateway control unit and chassis CAN 2.
Control interventions on comfort functions:
Up to 30.11.2018
The steering column tube module control unit sends information about control interventions at the cruise control lever, the steering column adjustment switch (with CODE P64 (Memory package)) and the multifunction steering wheel button groups to the multifunction camera via chassis CAN 1, the front SAM control unit and chassis CAN 2.
The steering wheel electronics reads in the control signals on the multifunction steering wheel button groups directly and transmit them to the steering column tube module control unit over the steering LIN.
As of 01.12.2018
The steering column tube module control unit directly reads in control interventions at the steering column adjustment switch and combination switch and transmits the corresponding information to the multifunction camera via the AMG FlexRay, AMG gateway control unit and suspension CAN 2.
The steering wheel electronics directly read in control interventions at the multifunction steering wheel button group and transmits the corresponding information to the multifunction camera via the steering wheel CAN, steering column tube module control unit, AMG FlexRay, AMG gateway control unit and suspension CAN 2.
The left door control unit reads in the control signals from the driver-side power window and outside mirror adjustment switch group via the left door LIN and sends them via the interior CAN, the front SAM control unit and chassis CAN 2 to the multifunction camera.
Interior illumination control interventions:
The status of the interior lamp automatic function switch is read in directly by the front SAM control unit via the overhead control panel electronics. The front SAM control unit sends the status via chassis CAN 2 to the multifunction camera.
Additional function requirements for warning output
- Lane recognition by the multifunction camera
- Vehicle speed between 60 to 200 km/h
- Curve radius less than 150 m
- Leaving of lane recognized
Warning output
The warning is issued haptically by the steering wheel vibration motor, which is integrated into the multifunction steering wheel.
Up to 30.11.2018
The multifunction camera sends the request to actuate the steering wheel vibration motor over chassis CAN 2, the front SAM control unit and chassis CAN 1 to the steering column tube module control unit. The steering column tube module control unit sends this request over the steering LIN to the steering wheel electronics, which then actuates the steering wheel vibration motor.
As of 01.12.2018
The multifunction camera transmits the request to actuate the steering wheel vibration motor to the steering column tube module control unit via the AMG FlexRay, AMG gateway control unit and suspension CAN 1. The steering column tube module control unit sends this request over the steering wheel CAN to the steering wheel electronics, which then actuate the steering wheel vibration motor.
The steering wheel vibration motor is actuated for a period of 1.5 s. The intensity of the haptic warning is adapted to the vehicle speed in order to allow for the perceivable effects of the suspension at high speeds.
The warning is suppressed when the triggering conditions are no longer given or when driver activity is detected (braking, accelerating, steering or turn signaling).
In "Standard" mode, a haptic warning is suppressed under the following prerequisites:
- Turn signaling recognized (the warnings are suppressed for a certain period of time)
- Intervention of a driving safety system recognized (e.g. by Electronic Stability Program (ESP®))
In "Adaptive" mode, a haptic warning is suppressed under the following prerequisites:
- Turn signaling recognized (the warnings are suppressed for a certain time period)
- Intervention of a driving safety system detected (e.g. by ESP®)
- During heavy acceleration (e.g. kickdown)
- During strong braking
- During rapid steering movements (e.g. during an evasive maneuver or during a rapid lane change)
- Corner cutting recognized
Following suppression (driver activity, triggering condition not given), a new warning can only be issued in "Standard" mode after approx. 3 s, in "Adaptive" mode after only approx. 5 s and following turn signaling after only 10 s.
| Electrical function schematic for Lane Keeping Assist | Model 190 up to 11/30/18 with code 22P (Lane tracking package) | PE54.71-P-2057-97HBA | |
| Model 190 as of 12/1/18 with code 22P (Lane tracking package) | PE54.71-P-2057-97HBB | ||
| Overview of system components for driver assistance systems | GF54.00-P-9998RR |