In addition to proven safety technologies like ABS, ESP® and Brake Assist, Mercedes passenger vehicles incorporate up to a dozen new or enhanced driver assistance systems which help avoid accidents and mitigate their severity. Active Blind Spot Assist and Active Lane Keeping Assist will soon be premiering on Mercedes' luxury segment models.
Active Blind Spot Assist warns the driver if it detects a risk of collision when changing lanes. Short-range radar sensors housed on both sides of the rear bumper monitor the areas directly alongside and behind the car.
This process enables them to see if there is another vehicle in the next lane – in the so-called blind spot. In such situations, the system informs the driver by illuminating a red warning signal in the glass of the exterior mirror. If the driver fails to see this warning and indicates to change lanes, a warning signal sounds as well.
In an innovation from the latest stage of development, if the driver ignores warnings and the vehicle comes dangerously close to the next lane, Active Blind Spot Assist will intervene. Applying braking force to the wheels on the opposite side of the vehicle via the Electronic Stability Program ESP® creates a yaw movement which counteracts the collision course. The system intuitively deactivates as soon as the driver steers against the effects of the braking intervention or the vehicle accelerates.
If an accident can no longer be avoided in spite of correcting the direction, Active Blind Spot Assist can mitigate the consequences of a collision through course correction. Where the system detects vehicles or obstacles just a short distance away on the opposite side, it will adapt its braking intervention accordingly. To do so, Active Blind Spot Assist also uses data from the front sensors for DISTRONIC PLUS proximity control.
Brake actuation to correct the course occurs between 30 and 200 km/h. The effect is limited to longitudinal and latitudinal deceleration of 2 m/s2. When ESP is in OFF mode, Active Blind Spot Assist is switched off. Visible warning in the exterior mirror is active up to a speed of 250 km/h.
Active Lane Keeping Assist with ESP® support
Active Lane Keeping Assist is now also linked to the ESP® for the first time. This system kicks into action if the Mercedes vehicle inadvertently drifts over a solid line to the right or left of a lane. In this case, Active Lane Keeping Assist uses the ESP® to brake the opposite wheels and thereby prevent the vehicle from crossing the line. A display on the instrument cluster warns the driver at the same time. If broken lane markings are crossed, the system controls an electric pulse generator in the steering wheel which generates vibrations for a short time – a discreet but highly effective cue to countersteer immediately. Before the braking system intervenes, the steering wheel always vibrates to provide a warning.
Active Lane Keeping Assist is based around a camera on the inside of the windscreen. It is able to recognise lane markings by analysing the difference in contrast between the road surface and the boundary lines. The image processing solution informs an electronic control unit which determines and detects the position of the vehicle if it drifts out of this lane to the left or right. For maximum reliability, the new generation of Lane Keeping Assist also evaluates radar signals in addition to image processing. Only when both lane algorithms concur is braking force applied to correct the course. Unlike conventional systems of this type, the Mercedes assistance system also assesses the behaviour of the driver and is therefore able to determine whether the vehicle is leaving the registered lane intentionally or unintentionally.
Braking intervention to correct the course occurs between 60 and 200 km/h. It does not materialise if:
ESP® is deactivated,
the radius of the bend is less than 150 metres,
the vehicle is driving on tyres in emergency run-flat mode,
when braking or accelerating by more than 2 m/s², on bends with lateral acceleration of over 2 m/s² (sporty driving style).
The steering wheel will not vibrate if the driver:
is accelerating before overtaking or joining the motorway,
steers into a bend,
cuts a corner intentionally,
uses the indicators,
is moving back into the original lane after overtaking,
Furthermore, Lane Keeping Assist is deactivated immediately if ABS, ESP®, Brake Assist or another active safety system intervenes.
Assistance systems simulator
An interactive guide to active safety
More than a dozen assistance systems can help avoid critical situations and accidents in the E-Class and S-Class. A new simulator provides a realistic insight into these safety systems based on a S-Class. The virtual test drive becomes an impressive demonstration of active safety due to actuation of the S-Class's ABC system (Active Body Control) which normally controls vehicle body movements to maximise comfort. A powerful electric motor with a hydraulic pump has been installed in the simulator in place of the engine to represent pitch and roll via the ABC system. Intervention by DISTRONIC PLUS and the PRE-SAFE® Brake (including belt tensioners) can also be simulated in a realistic way.
At the touch of a button, the occupants of the simulator are able to quickly and easily explore the latest assistance systems in a range of scenarios, delivering an interactive experience.
A high-resolution image simulation with seven channels displays the driver's view to the front on three monitors ahead of the vehicle and the view to the rear on displays that replace the rear-view and interior mirrors. Another screen shows the situation from a bird's eye perspective. This enables spectators outside the vehicle to understand how the systems work.
Eleven computers are responsible for simulating the assistance systems as well as the noise, visuals and driving dynamics. In addition to scenarios such as driving on a motorway, country road or a proving ground, highly critical situations can also be replicated again and again for testing purposes in a way that is simply not possible on a real test run. The simulator can also switch between daytime and night-time driving at the touch of a button.