Blind Spot Monitoring, Basic Function - GF54.71-S-9901A
Model All (Light transporter)
Overview
This document contains information on:
- General
- Vehicles with Driving Assistance Package
- Function requirements
- Function
- Active brake application (vehicles with Driving Assistance Package)
- Exit warning
General
Blind Spot Assist uses 2 radar sensors in the rear of the vehicle to monitor the area behind and beside the vehicle, the so-called blind spot. Via displays in the outside mirrors, the system warns when vehicles are in the blind spot. The system differentiates here between a warning zone and a collision zone.
The warning zone covers a wide area next to and behind the vehicle. The collision zone covers a narrower area. Both zones are modified depending on the speed differential of the approaching vehicle. The higher the speed differential is, the further the two zones extend.
In event of any danger (vehicle within warning zone) the display in the outside mirror and in the instrument cluster lights up. When the driver initiates a lane change by operating a turn signal indicator, the system warns acoustically of any vehicles that enter the collision zone.
Blind Spot Assist acts as an extension of the outside mirrors. It does not release the driver of their obligation to carry out a lane change safely on their own responsibility.
Blind Spot Assist is operated via the multimedia system.
Vehicles with Driving Assistance Package
Blind Spot Monitoring can initiate course-correcting brake applications when a collision is imminent. The braking action guides the vehicle back into the lane. This can help to avoid an accident or lessen the consequences of an accident. Course-correcting brake applications can also take place for objects to the side of the vehicle (in line with interventions for objects in the blind spot). Approaching cyclists can also be detected.
Function requirements
- Engine in operation or drivetrain operational
- Forward movement of vehicle (defined through wheel rotation direction)
- Vehicle speed above 12 km/h (exit warning also possible at vehicle standstill)
- No trailer operation (only vehicles with trailer hitch)
Function
The radar sensors record vehicles behind and next to the vehicle. Blind Spot Assist warns the driver with different levels of intensity depending on the hazard potential involved. If a vehicle enters a warning zone at a speed of more than 12 km/h, the driver is warned by the display in the outside mirror lighting up. The display in the outside mirror continuously lights up red.
Criteria for issuing a visual warning:
- A vehicle approaches from behind and reaches the warning zone within approx. 2.5 s.
- A vehicle approaches from the side and the outer edge of the vehicle moves into the warning zone.
- An overtaking vehicle with a speed differential of less than approx. 15 km/h is in the warning zone.
If a lane change is initiated (turn signaling) and a vehicle is located in the collision zone, the display in the outside mirror lights up in red. Warning tones are also issued. Depending on the model and equipment installed, the warning is also displayed in the assistance graphic of the instrument cluster.
Criteria for issuing visual and acoustic warnings:
- A vehicle approaches from behind and reaches the collision zone within approx. one second.
- A vehicle approaches from the side and the outer edge of the vehicle moves into the collision zone.
- An overtaking vehicle with a speed differential of less than approx. 9 km/h is in the collision zone.
Illustration of the Blind Spot Assist principle
The detection ranges of the radar sensor system are based on the angle at which the radar waves are emitted. They are extrapolated by the right rear Blind Spot Assist radar sensor to produce the actual monitoring ranges.
Illustration of the rear detection ranges
Illustration showing rear monitoring range
Active brake application (vehicles with Driving Assistance Package)
Additional function requirements for active brake application:
- Vehicle speed > 30 and < 200 km/h
- Tire pressure of all wheels within the tolerance range (run-flat mode not active) (only vehicles with tire pressure monitoring system)
- Active brake application released by yaw rate interface
A course-correcting brake application also requires the area in front of the vehicle to be monitored for clearance analysis for any system reactions. This analysis is used for situation-optimized adaptation of required course corrections.
The traffic area in front of the vehicle is monitored with the aid of radar sensors behind the radiator shell and the multifunction camera behind the windshield. If objects or vehicles are detected or expected at the side, close to the driver's own vehicle, course corrections in this direction must be reduced or stopped altogether. The side distance, closing speed to the vehicles or obstacles and the driver's reaction time must be evaluated here.
Depending on the vehicle speed, course-correcting brake applications are perceived by the driver to be vehicle deceleration or yaw motion. If the driver steers against the effect of a course-correcting brake application or if they press hard on the accelerator pedal during an application, then the course-correcting brake application is ended.
If the vehicle is cornering or if the driver wishes to change lane, a course-correcting brake application is adapted to meet the current driving condition. During vehicle longitudinal or lateral acceleration, for example during noticeable braking maneuvers or fast evasive maneuvers, course-correcting brake application does not take place.
If a driving safety system with a higher priority intervenes, for example the Electronic Stability Program (ESP®) or Active Brake Assist, the course-correcting brake application is suppressed. The ESP® control unit coordinates all the brake requests.
The driver is notified in the instrument cluster that the system has detected the risk of a side collision with a vehicle in the blind spot and it is introducing a course correction. The display and warning for vehicles in the blind spot are also available to the driver at vehicle speeds over 200 km/h.
Exit warning
When the vehicle is parked up after a journey, Blind Spot Assist remains active for up to 3 minutes after "ignition OFF". The exit warning warns vehicle occupants about possible collisions with cyclists or vehicles when exiting the vehicle.
If a vehicle enters the collision zone at a speed of approx. 2 m/s, the display in the outside mirror lights up. If a vehicle occupant opens a door, a warning tone sounds and the display in the outside mirror starts to flash. If installed, ambient lighting in the doors also lights up in red (flashing).
The indicators in the outside mirrors flash 3 times immediately before the exit warning is no longer available 3 minutes after "Ignition OFF".
The exit warning is an aid only and not a substitute for the attentiveness of the vehicle occupants. Responsibility always lies with the vehicle occupants when opening doors and when leaving the vehicle.
| Function schematics | |||
| Monitor blind spot, function schematic | Model 420 with code JA7 (Blind Spot Monitoring) with code JP7 (Blind Spot Assist) | PE54.71-S-2502-97VRA | |
| Model 447 with code JA7 (Blind Spot Monitoring) with code XM7 (MOPF II) | PE54.71-S-2502-97A | ||
| Additional basic functions | |||
| Driver activity detection, basic function | GF54.30-S-1000A | ||
| Traffic area monitoring, basic function | GF54.71-S-1000A | ||
| Blind spot monitoring radar sensor controller unit, basic function | Model all (Light transporter) with code JA7 (Blind Spot Monitoring) |
GF54.71-S-9891A |