Blind Spot Monitoring, Basic Function - GF54.71-P-9901A
Model All (CAR)
Overview
This document contains information on:
- General
- Function requirements
- Function
- Criteria for issuing visual warning
- Criteria for issuing visual and acoustic warnings
- Active brake application
- Active Blind Spot Assist with exit warning function
- Rear Cross Traffic Alert
General
Blind Spot Assist uses two radar sensors in the rear of the vehicle to monitor the area behind and beside the vehicle, the so-called blind spot. As of the market launch of model 223 and Driving Assistance Package Gen. 5 two additional radar sensors are installed on each side at the front. Through 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 changes lane 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 his obligation to change lanes safely on his own responsibility.
Blind Spot Assist is operated through 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 (analogously to interventions for objects in the blind spot) (as of market launch of model 223). 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 (vehicles with trailer hitch)
Function
The Blind Spot Assist process is shown in an animation at https://moba.i.mercedes-benz.com/baix/cars/223.0_mbux-premium_2022_a/en_GB/page/highlight.html.
The animation example uses the S-Class.
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 lights up permanently red.
Criteria for issuing 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 series 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.
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) (vehicles with tire pressure monitoring system)
- Active intervention by the brake system 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 grille 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 involved, 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 he presses 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.
Active Blind Spot Assist with exit warning function
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 bike riders or vehicles when exiting the vehicle.
Example illustration of warning messages
If a vehicle enters the collision zone at a speed of approx. 2 m/s, the display in the outside mirror lights up (A).
If a vehicle occupant then opens a door, a warning tone sounds and the display in the outside mirror starts to flash (B). 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.
Rear Cross Traffic Alert
The Rear Cross Traffic Alert function is a subfunction of Active Parking Assist (235) in combination with Blind Spot Assist (code 234) or the Driving Assistance Package (code 23P) or the Driving Assistance Package Plus (code P20).
Depending on the equipment, the system can issue warnings about crossing traffic when you are reversing out of a parking space.
If a critical situation is detected, a corresponding symbol will appear on either the left or right side of the camera image in the multimedia system.
A visual warning will be issued if the vehicle is at a standstill.
If the warning is not followed by a reaction from the driver, the vehicle may be braked automatically.
The function is switched on and off using the maneuvering assistant.
The function is not available on inclines, when driving with a trailer or if the radar sensors are concealed by vehicles or other objects.
| Function schematics | |||
| Monitor blind spot, function schematic | Model 118, 167, 177, 243, 247, 293 with code 234 (Blind Spot Assist) except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) Model 213, 238, 257, 290 as of model year 2021 with code 234 (Blind Spot Assist) except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) |
PE54.71-P-2502-97A | |
| Model 118, 167, 177, 243, 247, 293 with code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) Model 213, 238, 257, 290 as of model year 2021 with code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) |
PE54.71-P-2502-97B | ||
| Model 223, 297 | PE54.71-P-2502-97C | ||
| Model 192, 206, 214, 232, 236, 254, 294, 295, 296 | PE54.71-P-2502-97D | ||
| Additional basic functions | |||
| Brakes, basic function | GF42.00-P-9900A | ||
| Driver activity detection, basic function | GF54.30-P-1000A | ||
| Traffic area monitoring, basic function | GF54.71-P-1000A | ||
| Ambient lighting, basic function | Vehicles with ambient lighting | GF82.20-P-9901A | |
| Intelligent driving control unit, basic function | Model all (CAR) with code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) | GF30.30-P-9890A | |
| Electronic Stability Program control unit, basic function | GF42.45-P-9890A | ||
| Blind spot monitoring radar sensor controller unit, basic function | Model all (CAR) with code 234 (Blind Spot Assist) except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) |
GF54.71-P-9891A |