Mercedes Benz Active safety


New assistance for drivers
Encompassed under the term “Real Life Safety”, Mercedes-Benz’s comprehensive safety philosophy is all about avoiding traffic accidents and mitigating their consequences. In the new E 63 AMG, more than a dozen driver assistance systems are optionally available to help to improve motoring safety significantly.

Mercedes Benz Active Safety

In the E 63 AMG, for example, proven technologies like ABS, 3-stage ESP® and Brake Assist work alongside innovative assistance systems to help prevent accidents and reduce their impact. These range from drowsiness detection to automatic full brake application on recognising that there is an acute risk of a collision, and Adaptive Highbeam Assist.

New optional extras for the E 63 AMG now include Active Blind Spot Assist and Active Lane Keeping Assist. Well-known in the CLS and S-Class, both assistance systems are included as part of the Driver Assistance package.

Active Blind Spot Assist warns the driver when changing lanes, by means of a red signal in the glass of the relevant exterior mirror, if a risk of collision is detected due to another vehicle in the neighbouring lane being in the so-called blind spot of the exterior mirror. If the driver ignores the warning and nevertheless initiates the lane-changing manoeuvre, the Active Blind Spot Assist intervenes.

Thanks to course-correcting brake application, via the 3-stage ESP®, to the wheels on the opposite side of the vehicle, a yaw movement is created which counteracts the collision course, thus helping to avoid the accident.

Active Lane Keeping Assist is also linked to the 3-stage ESP®. This system kicks into action if the driver inadvertently drifts over a solid line to the right or left of a lane. In this case, Active Lane Keeping Assist brakes the opposite wheels and thereby prevents 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.

Mercedes Benz Active Safety 2011

ATTENTION ASSIST warns of drowsiness
Studies have shown that around a quarter of all serious motorway accidents are caused by drowsy drivers, making this factor an even bigger cause of accidents than drink-driving. With ATTENTION ASSIST, fitted as standard in the E 63 AMG, Mercedes-Benz is therefore making another important contribution towards helping to avoid accidents: it employs high-resolution sensors to observe driver behaviour and can recognise whether the driver is tired or not paying attention, based primarily on steering wheel movements.

The ATTENTION ASSIST system developed by Mercedes-Benz measures more than 70 parameters which are analysed to detect fatigue.

This continual monitoring is important in order to recognise the gradual transition from alertness to tiredness and give the driver plenty of warning. Based on a variety of data, ATTENTION ASSIST creates an individual driver profile during the first few minutes of each journey and compares this with sensor data and the driving situation as recognised by the vehicle’s electronic control unit.

Alongside values such as the steering behaviour of the driver, the Mercedes-Benz system also measures driving conditions such as speed, longitudinal/lateral acceleration, indicator and pedal usage, as well as external factors such as the unevenness of the roads, for example.

DISTRONIC PLUS: now with enhanced functions
The radar-based DISTRONIC PLUS proximity control supports the driver at speeds between zero and 200 km/h in automatically adjusting the distance to the vehicles in front. In doing so it is able to apply the brakes to bring the vehicle to a complete standstill and also accelerate it again.

As a result, the system is also particularly convenient in stop-and-go traffic. If the system detects that the distance is being reduced too quickly, it warns the driver with both visual and audible signals.

In addition, the functionality of DISTRONIC PLUS has also been enhanced even further. The system now reacts earlier to vehicles which cut in, and the vehicle accelerates quicker when changing lanes itself and where the overtaking lane is clear.

Additional assistance: from the ADAPTIVE BRAKE to the PRE-SAFE® Brake

  • ADAPTIVE BRAKE: this Mercedes-Benz brake system offers assistance functions for greater safety and comfort, such as a HOLD function when waiting at traffic lights, and Hill-Start Assist which can help prevent rolling backwards when moving off on a slope.
  • Adaptive Highbeam Assist: when vehicles are detected ahead of or oncoming to the vehicle, this system automatically dips the beams and adjusts the range of the headlamps appropriate to the distance.
  • Brake Assist PLUS: this system is able to recognise an impending rear-end collision using radar sensors. It calculates the necessary degree of braking assistance and makes it available immediately when the driver presses the brake pedal.
  • Headlamp Assist: a sensor on the windscreen detects the lighting conditions. As a result, the headlamps can be turned on automatically when darkness falls.
  • Night View Assist Plus: the display in the dashboard shows a realistic grey-scale image from an infrared camera that monitors the road ahead of the vehicle. Any pedestrians detected are additionally highlighted in the display with so-called photo corners.
  • PARKTRONIC: ultrasonic sensors assist the driver when parking.
  • PRE-SAFE® Brake: autonomous braking if acute danger of an accident is detected. At first the driver is given both an acoustic and an optical wanring if the system identifies there is a danger of collision. If the driver does not react to this, the system brakes the vehicle autonomously.

This occurs in two stages: around 1.6 seconds before the calculated impact point the system decelerates the car with around 40 percent (approx. 4 m/s²) of the maximum braking power, gives the driver an additional, haptic warning of the impending impact and as a precaution activates the reversible PRE-SAFE® occupant protection system.

If the driver still fails to react, the PRE-SAFE® Brake activates the maximum braking power around 0.6 seconds before the now unavoidable collision – this emergency braking can greatly reduce the severity of the impact.

The system therefore acts like an “electronic crumple zone”, offering the car occupants even greater protection. The PRE-SAFE® Brake is active at speeds of between 30 and 200 km/h when moving vehicles are detected in front of the car. The system also reacts if the car approaches a stationary queue of traffic, providing its speed is below 70 km/h.

Passive safety

Nine airbags as standard

With nine airbags fitted as standard, not to mention four seat-belt tensioners and belt-force limiters as well as NECK-PRO crash-responsive head restraints for the driver and front passenger, the E 63 AMG offers an extensive package of safety equipment. The result is excellent occupant protection.

Drivers of Mercedes vehicles are safer on the road than drivers of other car brands. This is the result of a study by Mercedes-Benz accident research based on official, anonymous data samples from the Federal Office of Statistics.

Having looked at around 18,700 accidents resulting in personal injury during the period from 2003 to 2007, the study found that the risk of being seriously or fatally injured as the driver of a Mercedes is 9.6 percent lower than for vehicles of other brands. The result represents clear evidence of the contribution made by the passive safety systems of Mercedes-Benz to reducing the consequences of an accident.

The main prerequisites for this include a stable body structure as well as a whole host of sophisticated restraint systems. The airbags, which can deploy in a matter of milliseconds in the event of an accident, include two adaptive airbags for the driver and front passenger, a kneebag for the driver, two sidebags in the front-seat backrests and two large windowbags which extend from the A-pillar to the C-pillar during a side impact. In addition, pelvisbags are included as standard for front seat passengers, which in the event of a side collision can help to reduce loads in the pelvic area. Sidebags are also available for the rear as an optional extra, which means that the E 63 AMG makes a total of eleven airbags available for occupant protection.

Three-point automatic safety belts with belt tensioners and belt force limiters are fitted as standard for the driver, front passenger and rear passengers. Mercedes-Benz is offering adaptive belt force limiters for the rear seats as an option. These adapt to the size of passengers automatically.

The system detects whether the rear seat passenger is large or small as soon as the seat belt is put on, based on the length of the pulled-out seat belt, and can adapt its protective effect accordingly. The maximum belt force is activated immediately if the rear passenger is large in size, while in the case of smaller occupants the force exerted by the belt is initially set to a lower level.

In addition, the standard equipment also includes ISOFIX, the international standard securing system for child seats. The mechanism comprises two retaining brackets on each of the outer rear seat positions, in the gap between the back rest and seat cushion, as well as an additional third anchor point, the so-called top tether.

NECK-PRO is the name Mercedes-Benz has given to a crash-responsive head restraint whose development, like that of PRE-SAFE® and other Mercedes-Benz innovations, is based on analyses of real accidents. NECK-PRO is an effective means of reducing the risk of whiplash injuries during a rear-end collision.

If the sensor system detects a rear-end collision with a defined impact severity, it releases pre-tensioned springs inside the head restraints, causing the head restraints to move forward by about 40 millimetres and upwards by 30 milli-metres within a matter of milliseconds. This means that the heads of the driver and front passenger can be supported at an early stage.

The PRE-SAFE® occupant protection system
In 2002 Mercedes-Benz became the first automotive brand to offer an anticipatory occupant protection system which can initiate measures to protect the occupants of the vehicle if there is an imminent risk of an accident: PRE-SAFE®. Mercedes-Benz’s intelligent approach takes its lead from nature: PRE-SAFE® activates protective measures for the car occupants as a precaution, just as living things react instinctively and search for cover when they are in danger.

The aim is to prepare the occupants and vehicle for an imminent collision so that the seat belts and airbags are able to fulfil their protective function to the full during an impact. What’s more, the PRE-SAFE® protective measures are reversible: if the accident is averted, the advance tensioning of the seat belts is halted automatically and the occupants are able to reset the positions of the seats and the sliding sunroof. The anticipatory occupant protection system is then ready for action again straightaway.

Early accident detection is possible because PRE-SAFE® is an intelligent synergy of active and passive safety. It is linked to Brake Assist and the 3-stage ESP® Electronic Stability Program, whose sensors detect potentially critical driving situations and send the relevant information to the electronic control units within a matter of milliseconds.

The E 63 AMG is able to offer even more more preventive measures ahead of
an imminent accident than ever before:

  • Whereas PRE-SAFE® previously responded to emergency or panic braking – in other words when the driver hit the brake pedal reflexively – the system can now also be activated if the optional DISTRONIC PLUS has detected an impending collision with the aid of short and long-range sensors, and a certain level of delay in braking has been exceeded.The occupants are prepared for the collision by tensioning of the seat belts and repositioning of the front-passenger seat (if the seat memory function is installed) – which is also optionally available with fully electric seat adjustment – enabling the seat belts and airbags to offer the best possible protection.
  • The standard active multicontour seat ensures that the driver and front passenger are seated even more securely, thereby limiting dangerous whiplash movements by the upper body in th event of an accident.If the PRE-SAFE® control unit detects a critical driving situation, it immediately activates the air chambers in the seat cushions and backrests. These then envelope the seat occupants and give them support. Tests at the Mercedes-Benz Technology Center have shown that this PRE-SAFE® function and preventive belt tensioning increases the distance between the shoulder and the inner door lining by up to 40 millimetres at a lateral acceleration of 0.6 g. This enables the sidebag to fulfil its protective function even more effectively.

PRE-SAFE® triggers the following anticipatory measures:
PRE-SAFE® when braking in an emergency PRE-SAFE® if high lateral acceleration is detected driver and front-passenger seat belts are tensioned the side windows can be closed the seat fore-and-aft adjustment, and the cushion and backrest angles on the front passenger seat* are moved to the best possible positions for crash conditions the sliding sunroof* can be closed bolsters in the seat cushions and backrests of the multicontour front seats* can be inflated

* if fitted in the particular vehicle ** in addition to the emergency-braking measures
When installed in combination with DISTRONIC PLUS, PRE-SAFE® also uses the information provided by the short-range radar sensors in the front bumper to tension the front seat belts at the very last moment before an unavoidable collision, thus reducing the forces exerted on the driver and front passenger during the crash. This PRE-SAFE® function is literally the “ultima ratio” of anticipatory occupant protection.