Track Guidance, Basic Function - GF54.71-P-9900A
Model All (CAR)
Overview
This document contains information on:
- General
- Function requirements
- Function
General
The track guidance function evaluates the course of the road in front of the vehicle using the multifunction camera (lane recognition).
Lane recognition
The multifunction camera calculates the lane based on two lane algorithms. If comparison of these lane algorithms results in a match, the multifunction camera generates a safe lane. The multifunction camera uses this data to calculate the relative position of the vehicle in the lane.
If the track guidance function detects that the vehicle has left the lane, it warns the driver with noticeable steering wheel vibrations generated by the steering system. The system also evaluates the driving behavior of the driver and decides the point at which a warning is to be issued. In addition, the track guidance function can guide the vehicle back into the lane by means of targeted intervention by the brake system. The track guidance function can be switched on and off manually.
As of market launch of model 223 (FAP Gen. 5), course-correcting steering intervention takes place instead of targeted brake applications. Under certain circumstances, this may not be sufficient to keep the vehicle in the lane. A warning message is shown in the driver's display after steering intervention.
Sequence up to market launch of model 223 (FAP Gen. 5)
Function requirements
- Engine running or drive train operational.
- Multifunction camera soiling and function test completed successfully.
- Radar sensor system soiling and function test completed successfully (vehicles with Driving Assistance Package).
- Vehicle moving forward.
Function
The driver can choose between various track guidance modes, depending on the model and equipment installed. Here, sensitivity is increased or reduced so that warnings are then issued earlier and more frequently or later. As of market launch of model 223 (FAP Gen. 5), it is possible to switch support on or off in the case of broken lane markings ("enhanced assistance").
The track guidance function operates in a vehicle speed range from 60 to approx. 200 km/h.
The track guidance function evaluates the following function-relevant parameters:
- Information from the lane recognition system
- Information about parallel/oncoming traffic (vehicles with Driving Assistance Package or Blind Spot Assist)
- Driver activity
- Driver distracted
Up to market launch of model 223 (FAP Gen. 5):
If the multifunction camera detects that the vehicle has crossed lane markings, the steering wheel vibrates to warn the driver that the vehicle has left the lane. If the driver does not react to this warning and the vehicle continues to leave the lane, the track guidance function steers the vehicle back into the lane. For this purpose, the track guidance function requests wheel-specific interventions by the brake system. However, brake application is only triggered when 2 stored lane algorithms deliver the same result.
As of market launch of model 223 (FAP Gen. 5):
If the crossing of lane markings is detected by a camera, corrective steering intervention take places to return the vehicle to the lane. If there is no driver response, a haptic warning is also issued in the form of pulsed vibrations at the steering wheel.
Vehicles with Active Lane Keeping Assist:
The track guidance function compares the results of the lane algorithm of the multifunction camera (mono) with a reference algorithm.
Vehicles with Driving Assistance Package:
The multifunction camera (stereo) contains 2 lane algorithms, the results of which are compared with each other.
The track guidance function triggers course-correcting brake application if the vehicle crosses a continuous or broken line.
The following conditions must be fulfilled here:
- Lane width 2.6 to 4.7 m
- Curve radius > 500 m (inside radius), > 150 m (outside radius)
- Tire pressure of all wheels within the tolerance range (run-flat mode not active) (vehicles with tire pressure monitoring system)
- No trailer operation (vehicles with trailer hitch)
- Brake application by brake system enabled (no active control intervention by brake system)
If the system detects driver activity or driver distraction, the brake or steering intervention is canceled.
Vehicles with Driving Assistance Package or as of market launch of model 223 (FAP Gen. 5) also vehicles with Blind Spot Assist:
In the case of lane-correcting brake or steering intervention, the track guidance function takes the oncoming/parallel traffic in the adjacent lane into consideration and guides the vehicle back onto a collision-free course.
Vehicles with Active Steering Assist:
Lateral guidance with small steering torques takes place continuously in the vehicle speed range from 0 to 210 km/h based on the lane markings detected by the multifunction camera (stereo). When driving straight ahead, lateral guidance is also supported if the lane marking is on one side. Even if there are no lane markings for a short time, the vehicle in front is followed up to a speed of 130 km/h in this case.
| Function schematics | |||
| Track guidance, function schematic | Model 118, 167, 177, 243, 247, 293 with code 243 (Active Lane Keeping Assist (camera)) except code 51B (Rating, country group EURO-NCAP) Model 213, 238, 257, 290 as of model year 2021 with code 243 (Active Lane Keeping Assist (camera)) except code 51B (Rating, country group EURO-NCAP) | PE54.71-P-2501-97A | |
| Model 118, 167, 177, 243, 247, 293 with code 243 (Active Lane Keeping Assist (camera)) with code 51B (Rating, country group EURO-NCAP) except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) Model 213, 238, 257, 290 as of model year 2021 with code 243 (Active Lane Keeping Assist (camera)) with code 51B (Rating, country group EURO-NCAP) except code 233 (Adaptive cruise control Plus (DISTRONIC PLUS)) | PE54.71-P-2501-97B | ||
| Model 118, 167, 177, 243, 247, 293 Model 213 238, 257, 290 as of model year 2021 | PE54.71-P-2501-97C | ||
| Model 223, 297 | PE54.71-P-2501-97D | ||
| Model 206, 232, 254, 295, 296 | PE54.71-P-2501-97E | ||
| 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 | ||
| Intelligent driving control unit, basic function | GF30.30-P-9890A | ||
| Electronic Stability Program control unit, basic function | GF42.45-P-9890A | ||
| Electric power steering control unit, basic function | GF46.35-P-9890A | ||
| Front multifunction camera, basic function | GF54.71-P-9890A | ||
| Intelligent driving radar sensor, basic function | GF54.71-P-2005A |