Attention Assist, Function - GF54.30-S-0009TRA
Model 447.6/7/8
With Code JW8 (Attention Assist)
Except Code XM0 (Facelift)
Model 447.8
Model 447.6/7
Function requirements in general
- Engine running or drive train operational
The CDI control unit sends the "Engine running" or "Drivetrain operational" signal via the chassis CAN to the Electronic Stability Program (ESP) control unit.
Attention Assist, general
The attention assistance system is integrated in the Electronic Stability Program (ESP) control unit. By evaluating steering patterns any onset of driver fatigue (e.g. on long monotonous journeys on freeways and highways) can be detected. The steering patterns are evaluated within a vehicle speed range of v = 60 to 200 km/h.
If any appropriate signs indicating fatigue or increasing lack of attention by the driver are recognized, the driver is prompted to take a break by means of visual and acoustic warnings.
Development of this software is based on experience gathered with test persons, whose different handling characteristics at night and day times were evaluated.
Function sequence for Attention Assist
The attention assistance system can be activated or passivated in the "Assist." menu in the "Attention Asst." menu level of the instrument cluster (IC) control unit.
Model 447.8
The instrument cluster (IC) control unit sends the status of the attention assistance system to the Electronic Stability Program (ESP) control unit via the user interface CAN, gateway for the user interface CAN and the chassis CAN.
Model 447.6/7
The instrument cluster (IC) control unit transmits the status of the attention assistance system via the chassis CAN to the Electronic Stability Program (ESP) control unit.
The driver can select the following operating modes:
- "Standard"
- "Sensitive"
- "Off"
In "Sensitive" operating mode, the Attention Assist reacts more sensitively and issues warning messages sooner than in "Standard" operating mode.
The output of warnings is suppressed in "Off" operating mode.
"Last-turned-on mode":
If "Standard" or "Sensitive" operating mode was selected before an ignition cycle, this mode is activated again after the next ignition cycle. If the attention assistance system is switched off while driving (operating mode "Off"), the operating mode that was selected before switching off is automatically active after the next ignition cycle.
Model 447.8
If "Off" operating mode has been selected, this is indicated by a crossed-out coffee cup symbol in the multifunction display of the instrument cluster (IC) control unit. If the Attention Assist is in "Standard" or "Sensitive" operating mode, the coffee cup symbol is not displayed.
Model 447.6/7 (without CODE JK3 (Instrument cluster with pixel matrix display))
If operating mode "Off" is selected, this is displayed by the attention assistance system indicator lamp (A1/1e63). If the attention assistance system is in operating mode "Standard" or "Sensitive", the attention assistance system indicator lamp is off.
The driver can call up the following additional information via the "Info page" in the "Attention Asst." menu level of the instrument cluster (IC) control unit:
- "Attention level" (bar display, 5-stage) (model 447.8)
- Driving time since last ignition cycle (in hours and minutes)
- Attention assistance system passive (e.g. vehicle speed v < 60 km/h or v > 200 km/h)
Model 447.8
with code JW8 (Attention Assist)
except code XM0 (Facelift)
If the attention assistance system is switched to passive, the "System passive" message is shown in the multifunction display of the instrument cluster (IC) control unit in addition to the driving time since the start of driving and the bar display.
System language German (the display is country-specific), model 447.8
System language German (the display is country-specific), model 447.8
System language German (the display is country-specific), model 447.8
The driver handling characteristics are also analyzed when the attention assistance system is switched to passive. If the attention assistance system is activated when driving, the entire journey from the start is taken into consideration.
At the start of the journey, the Electronic Stability Program (ESP) control unit uses an algorithm to determine the driver's individual warning threshold. This is the driving time and the time of day. On model 447.8, the "Attention level" display shows 5 bars (green, yellow, red). With increasing signs of inattentiveness and fatigue or in the case of a long driving distance, the number of bars goes down and the color of the remaining bars displayed changes from green to yellow and then to red.
If the warning threshold has been exceeded (only one red bar is displayed):
- Model 447.8
- The Electronic Stability Program (ESP) control unit transmits the request to output a warning via the chassis CAN, gateway for user interface CAN and user interface CAN to the instrument cluster (IC) control unit and to the radio (Audio/COMAND), which evaluate this.
- Model 447.6/7
- The Electronic Stability Program (ESP) control unit transmits the request to output a warning via the chassis CAN to the instrument cluster (IC).
Model 447.8
The warning message "Attention Assist: Pause!" is then displayed on the multifunction display and the driving time since the last break is displayed. An acoustic warning is also issued via the instrument cluster speaker. The instrument cluster (IC) control unit directly actuates the instrument cluster speaker.
Model 447.6/7
The warning message "Attention Assist: Break!" then appears on the instrument cluster (IC) control unit, and the driving time since the last break is displayed. An acoustic warning is also issued via the instrument cluster speaker. The instrument cluster (IC) control unit directly actuates the instrument cluster speaker.
The warning message can be acknowledged with the button "O. K." on the left multifunction steering wheel button group (with CODE CL4 (Multifunction steering wheel with trip computer)). The steering column tube module (MRM) control unit reads the status of the button "O. K." via the steering LIN in the steering wheel electronics and transmits it:
- Model 447.8
- Via chassis CAN, gateway for user interface CAN and user interface CAN to the instrument cluster (IC) control unit. The steering column tube module (MRM) control unit also sends the status of the "O. K." button via the chassis CAN to the Electronic Stability Program (ESP) control unit.
- Model 447.6/7
- Via chassis CAN to the instrument cluster (IC) control unit. The steering column tube module (MRM) control unit also sends the status of the "O. K." button via the chassis CAN to the Electronic Stability Program (ESP) control unit.
A renewed warning message is issued at the earliest after expiry of t = 15 minutes.
Model 447.8
If the warning threshold is exceeded, the nearest rest facilities are displayed to the driver in the Audio/COMAND display in addition to the warning message. Only premium parking places with a gas station and hospitality are taken into consideration.
The display of suitable rest facilities can be deactivated using the "Messages" menu in the Audio/COMAND display control unit. The system remains deactivated after the next ignition cycle.
The Electronic Stability Program (ESP) control unit sends the request to issue a warning message via the chassis CAN, gateway for the user interface CAN and the user interface CAN to the radio (Audio/COMAND).
The radio (Audio/COMAND) uses the global positioning system (GPS) signals and the data from the navigation system to locate suitable rest facilities. The radio (Audio/COMAND) actuates the Audio/COMAND display control unit via the telematics CAN and transmits the corresponding video signals via a low voltage differential signal line.
Multifunction display warning message (system language German (the display is country-specific)), model 447.8
Essentially, the following influencing factors are evaluated:
- Time of day
- Driving time
- Steering movements
- Vehicle speed
- Vehicle longitudinal/lateral acceleration and yaw rate
- Control interventions
Time of day:
The time of day is also defined by the current time.
- Model 447.8
- The instrument cluster (IC) control unit transmits the current time via the user interface CAN, gateway for user interface CAN and chassis CAN to the Electronic Stability Program (ESP) control unit. The received time is checked for plausibility by means of evaluating the ambient brightness.
- Model 447.6/7
- The instrument cluster (IC) control unit transmits the current time via the chassis CAN to the Electronic Stability Program (ESP) control unit. The received time is checked for plausibility by means of evaluating the ambient brightness.
The ambient brightness is detected by the humidity sensor/light sensor/rain sensor (with CODE HH9 (TEMPMATIC semi-automatically controlled air conditioning)) or the humidity sensor/light sensor/rain sensor/sun sensor (with CODE HH4 (THERMOTRONIC automatic air conditioning)). The humidity sensor/light sensor/rain sensor (with CODE HH9 (TEMPMATIC semi-automatically controlled air conditioning)) or the humidity sensor/light sensor/rain sensor/sun sensor (with CODE HH4 (THERMOTRONIC automatic air conditioning)) evaluates this and sends information on the ambient brightness (dusk/dawn level) via the roof LIN, signal acquisition and actuation module (SAM) control unit, interior CAN, electronic ignition lock (EZS) control unit and chassis CAN to the Electronic Stability Program (ESP) control unit.
If there is a transition between dusk and dawn at an implausible time, an entry is made in the diagnostic memory of the Electronic Stability Program (ESP) control unit.
Driving time:
The driving time is determined by the Electronic Stability Program (ESP) control unit.
Steering movements:
Steering movements are recorded by the steering angle sensor. The steering column tube module (MRM) control unit reads in the signals from the steering angle sensor directly and transmits information about the steering wheel angle and the steering wheel velocity to the Electronic Stability Program (ESP) control unit via the chassis CAN.
Vehicle speed:
The vehicle speed is calculated by the Electronic Stability Program (ESP) control unit using the wheel speed.
Vehicle longitudinal/lateral acceleration and yaw rate:
Information on vehicle longitudinal and lateral acceleration as well as yaw rate is recorded by the acceleration sensor integrated in the Electronic Stability Program (ESP) control unit.
Control interventions:
Control interventions at one of the following components disable the detection of steering patterns:
- Audio system controls (first-time operation is ignored, continuous operation is evaluated as distraction)
- Comfort function controls:
- CRUISE CONTROL lever (with CODE MS1 (Cruise control) and with or without CODE ET4 (DISTRONIC PLUS))
- Combination switch
- Left multifunction steering wheel button group or right multifunction steering wheel button group (with CODE CL4 (Multifunction steering wheel with trip computer))
- Model 447.8
The audio system is operated using the central operating unit (COU) control unit. The control interventions at the central operating unit (COU) control unit are received by the radio (Audio/COMAND) via the telematics CAN. The radio (Audio/COMAND) sends information about the control interventions at the audio system via the user interface CAN, gateway for the user interface CAN and the chassis CAN to the Electronic Stability Program (ESP) control unit.
- Model 447.6/7
- Operating interventions on the radio (Audio) are transmitted via the interior CAN, instrument cluster (IC) control unit and chassis CAN to the Electronic Stability Program (ESP) control unit.
The steering column tube module (MRM) control unit transmits information on operating interventions on the CRUISE CONTROL lever (with CODE MS1 (Cruise control) and with or without CODE ET4 (DISTRONIC PLUS)), on the combination switch and on the left and right multifunction steering wheel button groups (with CODE CL4 (Multifunction steering wheel with trip computer)) via chassis CAN to the Electronic Stability Program (ESP) control unit.
Model 447.6/7/8
with code CL4 (Multifunction steering wheel with trip computer)
with code JW8 (Attention Assist)
except code XM0 (Facelift)
The control interventions at the left and right multifunction steering wheel button groups are read in by the steering wheel electronics and sent via the steering LIN to the steering column tube module (MRM) control unit.
A warning is suppressed under the following conditions as no inferences about the attentiveness of the driver can be drawn from the driving behavior:
- With a driving time of t < 30_min
- Poor road surface condition (e.g. surface undulations, pot holes)
- Strong crosswind
- Sporty driving style (e.g. high cornering speeds, high acceleration)
- Vehicle speed range predominantly below v = 80 km/h or above v = 180 km/h
- Operation of audio system incl. telephony
- Incorrectly set time
- Active driving situation (e.g. lane change, change of speed)
Also valid is the following function information which can lead to possible function complaints:
- No warning issued because driving time too short in active vehicle speed range:
The attention assistance system analyzes development of the handling characteristics. At the start of the journey the individual handling characteristic is classified. If the handling characteristic changes permanently a warning is issued. If the driving time within the active range (v_=_60_to_200_km/h) is too short, a warning is not issued.
- No warning because of restrictions associated with the system limits:
The handling characteristics cannot be evaluated in the active vehicle speed range (v_=_60_to_200 km/h) either if certain factors occur such as frequent lane changing, twisty roads, frequent control interventions, surface undulations, crosswinds or a dynamic driving style.
- Personal driving behavior:
The attention assistance system detects changes in driving behavior. These changes cannot always be explained as fatigue or increasing inattentiveness, rather they can also be caused by peculiarities in steering behavior. Certain types of driver present particular challenges for attention assistance systems, e.g. drivers with extremely smooth or extremely active steering behavior.
- Influence of the time on the sensitivity of the Attention Assist:
The Attention Assist reacts in accordance with the human bio-rhythm depending on the time (e.g. the mid-day low). These results are determined representatively, but they may also differ on an individual basis.
- Influence of driving time on the sensitivity of the Attention Assist:
As the length of driving time without a break increases, the sensitivity of the Attention Assist function also increases. The weighting of the driving time is based on surveys and correspond to the average fatigue characteristics.
- Warning because of distraction or mild fatigue:
Attention Assist can not only warn in the event of fatigue, it can also warn when a change in handling characteristics occurs, e.g. where the driver is greatly distracted. Therefore, a warning issued because of increasing inattentiveness is also to be deemed correct. The subjective fatigue sensitivity and the objective assessment variable determined by the Attention Assist are different.
- Change in steering ability through other factors:
Next to fatigue or increasing inattentiveness other factors can also significantly change the steering ability, and influence the objective assessment variables as determined by the Attention Assist, e.g. increasingly slippery road surface, worsening visibility, narrowing roadway, worsening roadway.
| Attention Assist electrical function schematic | Model 447.8 with code JW8 (Attention Assist) except code XM0 (Facelift) |
PE54.71-S-2054-97TRA | |
| Model 447.6/7 with code JW8 (Attention Assist) except code XM0 (Facelift) |
PE54.71-S-2054-97TRB | ||
| Overview of system components for driver assistance systems | Model 447.6/7/8 with code JW8 (Attention Assist) except code XM0 (Facelift) |
GF54.00-S-9998TRA |