Attention assist, function - GF54.30-P-0009LE
MODEL 216.3 as of model year 2011 /YoM 10 model refinement package
MODEL 221.0 /1 as of model year 2010/YoM 09 model refinement package
Function requirements, general
- Circuit 15 ON
- Attention assist activated via menu in instrument cluster (A1)
- Vehicle speed v = 80 to 180 km/h
The EZS control unit (N73) makes the status of circuit 15 available on the chassis CAN (CAN E).
Attention assist, general
The ATTENTION ASSIST function assists the driver on long monotonous journeys, e.g. on freeways and expressways, in a vehicle speed range of v = 80 to 180 km/h.
If attention assist establishes driver fatigue or increasing inattentiveness, it proposes a break.
The attention assist assesses driver fatigue or increasing inattentiveness by the analysis of steering ability by means of steering wheel angle signals as well as driving conditions (time of day/night, driving time).
In the first t = 20 min. of monotonous driving individual parameters and a warning threshold are determined by the driver. When the warning threshold is reached a visual as well as an acoustic warning message is issued by the instrument cluster. Other factors are included in the assessment in order to increase reliability.
Attention assist functions in a restricted manner and a warning does not take place or takes place after a delay in the case of:
- Sporty driving style
- Active driving situations (high cornering speeds, hard acceleration, lane change)
- Very poor road surface condition (surface undulations, pot holes)
- Continuous strong crosswind
- Use of audio equipment, telephone or other systems
The master control unit for the ATTENTION ASSIST function is the ESP control unit (N47-5) (except model 221.095/195) or the regenerative braking system control unit (N30/6) (model 221.095/195).
The attention assist function is comprised of the following partial functions:
- Activate attention assist function sequence
- Recording steering movement function sequence
- Evaluating steering movement function sequence
- Output of warning message function sequence
Activate attention assist function sequence
Attention assist is activated as follows in the instrument cluster:
- Select the "Assistance" menu with the system selection button (S110s3)
- Select the "Attention assist" menu item with the scroll forward and back button (S110s1)
- Confirm selection with the OK button (S110s6)
The status of the left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111) is read in by the steering column tube module (N80) via the steering LIN (LIN E1) and made available to the ESP control unit or regenerative braking system control unit via the chassis CAN.
When the ATTENTION ASSIST function is active, the coffee cup symbol (1) appears in the instrument cluster.
Attention assist can be deactivated by pressing the OK button again.
Recording steering movement function sequence
The steering movements are detected by the ATTENTION ASSIST sensor (B24/8) and read in directly by the ESP control unit or by the regenerative braking system control unit.
Evaluating steering movement function sequence
Depending on the various variables, the ESP control unit or regenerative braking system control unit evaluates the current data from the ATTENTION ASSIST sensor. The algorithm detects steering patterns in the steering angle signal which occur more frequently with increasing fatigue and inattentiveness. The algorithm is active and detects steering patterns in the case of:
- a speed between v = 80 and 180 km/h
- monotonous trip (without high longitudinal or lateral acceleration)
- no considerable external excitations (such as surface undulations or crosswind)
- no operating interventions (e.g. audio equipment, various switches)
The individual driver parameters for detecting steering patterns are adapted continuously when the algorithm is active. An individual warning threshold is also determined after driving for t = 20 min when the algorithm is active. The sensitivity of the algorithm is adjusted depending on the driving time and time of day:
- Determining time of day function sequence
- Checking plausibility of time of day function sequence
- Recording operating interventions function sequence
Determining time of day function sequence
The instrument cluster makes information on the current time of day available on the central CAN (CAN F). The central gateway control unit (N93) reads in this information and passes it on to the ESP control unit or regenerative braking system control unit via the chassis CAN.
Checking plausibility of time of day function sequence
The time of day is checked for plausibility via the rain/light sensor (B38/2). In the event of a dusk transition implausible for the time of day, an entry is made in the diagnosis memory of the ESP control unit or regenerative braking system control unit.
The overhead control panel control unit (N70) makes information from the rain/light sensor available on the interior CAN (CAN B). The central gateway control unit passes this on to the ESP control unit or regenerative braking system control unit via the chassis CAN.
Recording operating interventions function sequence
The recognition of steering patterns is suppressed in the event of a recognized control intervention at one of the following components:
- COMAND controller unit (A40/3)
- Combination switch (S4)
- Cruise control push-button switch (S40/4)
- Steering column adjustment switch (S59) (without code (443) Steering wheel heater) or steering column adjustment/steering wheel heater switch (S59/1) (with code (443) Steering wheel heater)
- Left multifunction steering wheel button group and right multifunction steering wheel button group
The signals from the combination switch, cruise control push button, steering column adjustment switch or steering column adjustment/steering wheel heater switch and multifunction steering wheel button groups are transmitted by the steering column tube module on the chassis CAN. The signals from the COMAND controller unit are transmitted via the central CAN to the central gateway control unit and from there on the chassis CAN. The ESP control unit or regenerative braking system control unit receives all the data via the chassis CAN.
Additional function requirements, output of warning message
- A relevant steering pattern recognized
Output of warning message function sequence
The ESP control unit or regenerative braking system control unit transmits the warning message request to the central gateway control unit via the chassis CAN. The central gateway control unit passes on the request to the instrument cluster via the central CAN. The instrument cluster then displays a prompt telling the driver to take a break, and a double four-tone warning signal sounds.
An active warning can be confirmed and thus ended with the OK button in the left multifunction steering wheel button group. The next warning is only possible again after t > 15 min.
The status of the multifunction steering wheel button group is read in by the steering column tube module via the steering LIN and made available to the ESP control unit or regenerative braking system control unit via the chassis CAN.
| Attention assist, location of components | GF54.30-P-0009-02LE | ||
| Electrical function schematic of ATTENTION ASSIST function | Model 221 | PE54.71-P-2050-97SAA | |
| Model 216 | PE54.71-P-2050-97CAA | ||
| Attention assist, block diagram | GF54.30-P-0009-03LE | ||
| Component description for instrument cluster | A1 Model 216.3, model 221 (except 221.095/195) |
GF54.30-P-6000LE | |
| Model 221.095/195 | GF54.30-P-6000LEH | ||
| Component description for 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 system) |
GF82.85-P-3136LE | |
| With code (529) HIGH Class Japan | GF82.85-P-3136LEJ | ||
| With code (530) COMAND APS USA (with navigation system) | GF82.85-P-3136LEU | ||
| Component description for regenerative braking system control unit | N30/6 On model 221.095/195 |
GF42.22-P-1100LEH | |
| Component description for ESP control unit | N47-5 Model 216.3, 221 (except 221.095/195) |
GF42.45-P-5118LE | |
| Component description for overhead control panel control unit | N70 | GF82.20-P-5216LE | |
| EZS control unit, component description | N73 | GF80.57-P-6003LE | |
| Component description for steering column tube module | N80 | GF54.21-P-6050LE | |
| Component description for central gateway control unit | N93 | GF54.21-P-4170LE |