While a Mercedes-Benz is known for being luxurious, fast and expensive, the German automaker wants to draw attention to the many safety features it currently offers as well as the ones it is developing. With the launch of the new E-Class, Mercedes introduced numerous new safety programs and now it has created an Experimental Safety Vehicle called the ESF 2009, based on the upcoming S400 Hybird.
Of the dozen new safety features on the ESF 2009, five are particularly worth noting. These include the: Pre-Safe Structure, the Braking Bag, Interactive Vehicle Communication, Pre-Safe Pulse and the Spotlight lighting function.
The Pre-Safe structure is a metal structure that fits inside the doors (or other places) and is unfolded by a blast of pressurized air in the case of an accident. This would not only protect passengers, but it would allow for more compact packaging of the vehicle.
The Braking Bag is easily the most interesting feature on the ESF 2009. This air bag-type balloon is deployed under the car in an emergency braking situation. It is coated in a high-friction surface, which helps to slow the car, while at the same time helping to keep it level. In fact, the bag actually raises the front of the car, compensating for the “dive” typically experienced during such extreme braking, and ensuring that if the car does it another vehicle, the impact will be at the bumper.
Additionally, the Interactive Vehicle Communication system will let the ESF 2009 communicate with other cars on the road, relaying information about poor weather conditions or objects on the road. The Pre-Safe Pulse system works by moving the torso of an individual forward by 50 mm (by moving the seatback) in an accident to reduce the impact-force by one-third. Finally, the ESF 2009′s Spotlight lighting function works with the Mercedes Night View Assist Plus to essentially put a spotlight on an object (such as a deer or pedestrian) that has run onto the road. Using specific LED lights it would bring to a driver’s attention something that would normally be outside the range of the headlights.
“Safety is a central element of the Mercedes-Benz brand. In this respect we have been setting the pace in the market for almost 70 years. For the benefit of our customers and for road users in general. The ESF 2009 shows that we still have plenty of ideas and the absolute will, to lead the automobile industry in this field even in future,” says Mercedes CEO Dr. Dieter Zetsch.
The ESF 2009 made its world-premiere today at the Enhanced Safety of Vehicles (ESV) Conference in Stuttgart, Germany.
See a video of the Braking Bag in action below.
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Official release after the jump:
MERCEDES-BENZ ESF 2009 EXPERIMENTAL SAFETY VEHICLE
Stuttgart – 2009 is a year in which Mercedes-Benz celebrates several anniversaries in the safety field: in August 1939 the safety pioneer Béla Barényi started his work in Sindelfingen. He invented for example the principle of the crumple zone, a trailblazing innovation which entered series production at Mercedes-Benz in 1959. With the help of its in-house accident research function, which was founded in 1969, Mercedes engineers in the following years have developed sev-eral groundbreaking innovations in passenger car safety. Now it is time for a look behind the scenes, and in this anniversary year, Mercedes-Benz is using the ESF 2009 research vehicle to reveal what its safety specialists are currently working on – with a time horizon that often extends well into the future.
The ESF 2009 is the first Experimental Safety Vehicle to be built by Mercedes-Benz since 1974. Like its historic predecessors, it illustrates trailblazing in-novations in the field of safety and makes the progress achieved clearly visible. These amazing but by no means crazy ideas include inflatable metallic sections which give more stability to structural components within fractions of a second, as well as the so-called “Braking Bag”. This airbag housed within the vehicle floor is deployed when a crash is deemed to be unavoidable, and uses a friction coating to support the vehicle against the road surface. The ESF 2009 will be premiered on 15 June 2009, at the Enhanced Safety of Vehicles (ESV) Conference in Stuttgart.
“Safety is a central element of the Mercedes-Benz brand. In this respect we have been setting the pace in the market for almost 70 years. For the benefit of our customers and for road users in general. The ESF 2009 shows that we still have plenty of ideas and the absolute will, to lead the automobile industry in this field even in future”, says Dr. Dieter Zetsche, Chairman of Daimler AG and CEO of Mercedes-Benz Cars.
The ESF 2009 was developed and built completely in the test vehicle workshops in Sindelfingen. This safety research vehicle based on the Mercedes S 400 HYBRID fea-tures more than a dozen safety innovations, most of which are fully functioning in demonstration mode. “With the ESF 2009, we have chosen this particular time to clearly demonstrate the innovative strength of Daimler. Anybody examining the ESF 2009 in detail will recognise that more safety and improved energy efficiency are not necessarily a contradiction in terms. We want to make progress in both fields with new, trailblazing ideas “, says Dr. Thomas Weber, the member of the Daimler Executive Board responsible for corporate research and development at Mercedes-Benz Cars.
The following five innovations on the basis of the S 400 Hybrid are among the high-lights of the ESF 2009:
• PRE-SAFE Structure: The inflatable metal structures save weight or increase the stability of structural components. When at rest, the metal section is in a folded state to save space. If its protective effect is required, a gas generator builds up an internal pressure of 10 to 20 bar within fractions of a second, causing the sec-tion to unfold for significantly more stability.
• Braking Bag: This auxiliary brake accommodated in the vehicle floor is a new type of PRE-SAFE® component. If the sensor system concludes that an impact is unavoidable, the Braking Bag is deployed shortly before the crash and stabilises the car on the road surface by means of a friction coating. The vehicle’s vertical acceleration increases the friction, and helps to decelerate the vehicle before the impact occurs.
• Interactive Vehicle Communication: The ESF 2009 is able to communicate di-rectly with other vehicles, or via relay stations. Using “ad hoc” networks and WLAN radio technology, it is e.g. able to receive and transmit warnings of bad weather or obstacles in the road.
• PRE-SAFE Pulse: This further development of PRE-SAFE® is able to reduce the forces acting on the torsos of the occupants during a lateral collision by around one third. It does this by moving them towards the centre of the vehicle by up to 50 millimetres as a precautionary measure. As an active re-straint system, it uses the air chambers in the side bolsters of the seat backrests.
• Spotlight lighting function: This partial LED main beam specifically illuminates potential hazards. If the infrared camera of Night View Assist PLUS e.g. detects deer at the roadside or pedestrians on the road, these can be briefly il-luminated beyond the normal area covered by the main beams, as if by a spot-light.
Mercedes-Benz is also presenting an innovative PRE-SAFE Demonstrator at the 21st ESV Conference. For the first time this simulator uses a linear motor for this purpose, in order to accelerate the vehicle cabin to up to 16 km/h within a distance of four me-tres before the impact occurs. The linear drive system, which is similar to that used by the Transrapid train, is freely programmable and also works in the opposite direction. This enables various acceleration profiles and also a rear-end collision to be demonstrated. The special feature of this system is that the ‘vehicle occupants’ experience the effect of the PRE-SAFE® functions live, e.g. belt pretensioning, NECK-PRO and the inflatable side bolsters of the seats.
Mercedes-Benz is continuing a longstanding tradition with the ESF 2009: for the ESV Safety Conferences held in 1971 to 1975, the safety experts in Stuttgart built more than 30 experimental vehicles and subjected them to crash tests to satisfy the vision-ary safety requirements of that time. Four of these ESFs (Experimental Safety Vehicles) were presented to the public, and many of the revolutionary ideas such as ABS or the airbag first entered series production at Mercedes-Benz.
Daimler management comments on the ESF 2009: “Safety is one of our core brand values”
“Safety is a central element of the Mercedes-Benz brand. In this respect we have been setting the pace in the market for almost 70 years. For the benefit of our customers and for road users in general. The ESF 2009 shows that we still have plenty of ideas and the absolute will, to lead the automobile industry in this field even in future.” Dr. Dieter Zetsche, Chairman of Daimler AG and CEO of Mercedes-Benz Cars.
“Even in economically difficult times, we refuse to make any cuts where innovation is concerned, as shown by the highly complex ESF 2009 project, where we have chosen this particular time to clearly demonstrate the innovative strength of Daimler and Mercedes-Benz. Anybody examining the ESF 2009 in detail will recognise that more safety and less fuel consumption are not necessarily a contradiction in terms. We want to make progress in both fields with new, trailblazing ideas.” Dr. Thomas Weber, the member of the Daimler Executive Board responsible for corporate research and development at Mercedes-Benz Cars.
“Real Life Safety is about more than scoring points in standardised crash tests, or the number of onboard airbags. The ESF 2009 clearly illustrates the comprehensive ap-proach of Mercedes-Benz with its numerous innovations for more passive and active safety. In line with our claim: One star is sufficient.” Ulrich Mellinghoff, Head of Mercedes Safety Development
PRE-SAFE Structure: inflatable metal structures
It sounds like science-fiction: concealed metallic structures that wait patiently in a collapsed, space-saving state until they are required to go
into action. Daimler researchers working together with the gas generator specialists at Autoliv spent two years actively researching such active metal sup-port systems, and tested a variety of applications. For the very first time, inflat-able metal side impact protection can be seen in the ESF 2009.
Imagine an inflatable mattress. When it is not needed, it is rolled up flat and e.g. con-signed to a shelf in the attic. When inflated, however, it has a highly resistant structure that can easily carry a man weighing 100 kilograms. Inflatable metallic structures work in the same way: when not in use, the metal section is folded together to save space. Once its protective effect is needed, a gas generator just like those used to inflate airbags builds up an internal pressure of 10 to 20 bar within frac-tions of a second, the metal section is unfolded and the structure has significantly greater stability.
The advantages are obvious, and mainly involve packaging and weight: more stable structures can be accommodated within the increasingly tight installation spaces of an automobile, or weight can be greatly reduced while maintaining the same stability. Using the example of the side impact protection member in the doors of the S-Class, the researchers have calculated that around 500 grams less weight per door would be feasible.
Daimler safety researchers examined various applications for these innovative, crash-responsive metal structures, among them side impact protection, the side skirts and the seat cross-members. These have the advantage of being several centimetres away from the impact zone. The gas generator therefore only needs to be activated when a crash has definitely taken place.
One of the still unsolved problems of these protective members is that unlike the PRE-SAFE® measures already in series production, their active deformation is not reversi-ble. Moreover, the activation of protective members installed well to the outside of the bodyshell that can be inflated by internal pressure requires their deployment before the crash. The pre-crash sensor system must therefore provide highly reliable signals.
Another hurdle is the currently still uncompetitive cost level of the required gas gen-erators in relation to the cost requirements for weight-saving measures. These crash-responsive metal structures are therefore still a thing of the future – but the same was also once true of standard safety features like the airbag, ABS or ESP®.
Braking Bag: a braking parachute for the car
Airbags in cars have previously only been used as a restraint system for the occupants. In the future they might also be a PRE-CRASH- component, acti-vating an auxiliary brake in the vehicle floor and improving both deceleration and compatibility with the other vehicle involved in the accident.
Energy is not only reducible by braking the road wheels: jet fighters and dragsters use braking parachutes, for example. And as early as 1952, Mercedes-Benz was already experimenting with an air-brake at the Le Mans race: when decelerating, the driver was able to move a metal panel on the roof of his racing SL to a vertical position. Even earlier, coachmen used special wheel chocks. These were placed in front of one of both rear wheels on long downhill gradients, and their iron-clad base helped to brake the vehicle during the descent.
This is an old idea that Mercedes safety researchers have revitalised on a similar prin-ciple with the Braking Bag, an airbag installed between the front axle carrier and the underbody panelling. If the sensor system concludes that an impact is inevitable, the PRE-SAFE® system not only initiates automatic emergency braking. At the same time the Braking Bag is deployed just before the crash, supporting the car against the road surface by means of a friction coating. The vehicle’s vertical acceleration increases the friction and has an additional braking effect before the impact. The Braking Bag uses the PRE-CRASH sensors in Mercedes-Benz cars, which are already able to initiate pre-ventive occupant protection measures in critical driving situations.
There are several advantages to this unusual auxiliary brake:
• The rate of deceleration is briefly increased to over 20 m/sec/sec. This scrubs additional energy beyond the potentials of a wheel brake, thereby reducing ac-cident severity.
• Because the car is raised upwards by up to eight centimetres within a short time, the dive effect that occurs with conventional brakes is substantially com-pensated. This improves geometrical compatibility with
the other party in an accident.
• This vertical movement also improves the effects of the restraint systems: the seats move towards the occupants by around three centimetres, which enables the belt tensioners to take up more slack. The high deceleration rate before the impact has a “pretensioning” effect on the occupants, so to speak.
• Downward support for the vehicle during the crash reduces the typical diving motion during a collision.
All in all, the braking airbag has the effect of an additional crumple zone.
Mercedes engineers have calculated that even at a low 50 km/h, the additional decel-eration has the same effect as lengthening the front end by 180 mm. Initial driving tests in a C-Class have already shown the effectiveness of this new auxiliary brake – though it will still be some time before the Braking Bag becomes another component of the PRE-SAFE® system.
Interactive Vehicle Communication: cars report what their sen-sors have detected
Cars sometimes know more about their surroundings than their drivers. With the help of intelligent communication systems, vehicles themselves are able to con-tribute to improved road safety and mobility.
A patch of black ice on the next bend? A bank of fog three kilometres down the road? A new traffic tailback where roadworks are being carried out? What used to come as an unpleasant surprise is far less frightening if the approaching driver receives an up-to-date is warning beforehand. This is a task that will in future be carried out by the other vehicles on the roads at the time – automatically, by radio. This is the basic idea behind Interactive Vehicle Communication.
Cars are nowadays able to collect a great deal of information about the current driving situation, as the numerous sensors, cameras and control units for the dynamic and assistance systems can register e.g. poor weather conditions just as well as sudden braking and avoiding manoeuvres, or broken-down vehicles on the road. There are also other sources of information, for example local police reports. This information can be passed on via additional relay stations (“car-to-x”) such as radio masts at the roadside, stationary nodal points (e.g. traffic centres and overhead gantries) or via the internet. The onboard computer classifies all the reports according to plausibility and relevance. Tailback reports on the radio which are out-of-date or irrelevant to the individual driver will then be a thing of the past.
Mercedes engineers have been working on “Interactive Vehicle Communication” as a technology of the future for more than seven years.
The ESF 2009 safety concept vehi-cle demonstrates the current status of this research: this Mercedes can automatically recognise an approaching police car, for example, and warn its driver by showing a symbol in the display. It is also possible to send and receive warnings of bad weather or obstacles in the road.
The exchange of data between vehicles is via so-called “ad hoc” networks, connections that are spontaneously formed between the vehicles over short
distances. These wireless local area networks (WLANs) are self-organising, and require no external infrastructure. Transmission and reception is at a frequency of 5.9 giga-hertz, over a distance of up to 500 metres. In fact the achievable communication range is much greater, as oncoming vehicles pass the messages on.
Cars that communicate with each other can do more than just pass on information: linked to modern proximity control systems such as DISTRONIC Plus from Mercedes-Benz, they can help to harmonise the traffic flow and avoid tailbacks by automatically selecting the most suitable vehicle speed when joining a motorway. And collisions can be avoided if onboard sensors recognise an impending accident and automatically regulate the distance.
This technology is currently demonstrating its practicality in the “Safe Intelligent Mo-bility – Test area Germany” project (simTD), in which Mercedes-Benz and other German manufacturers and suppliers are taking part. Up to 400 vehicles communicate with each other in these, the world’s largest field trials for Interactive Vehicle Communication. simTD is being conducted in the densely populated Frank-furt/Rhine-Main area from autumn 2008 to 2012. Experts expect usable mobile infor-mation networks with full coverage to become a possibility when around ten percent of all vehicles have this communications capability.
PRE-SAFE Pulse: an automatic nudge in the ribs
With the multiple award-winning PRE-SAFE® system, Mercedes-Benz has once again been underlining its role as a pioneer in the safety field since 2002: once the system recognises certain critical driving situations, PRE-SAFE® activates occupant protection measures as a precaution. As a further development, PRE-SAFE Pulse is able to reduce the loads acting on the torsos of the occupants by around one third during a side impact by preventively moving them towards the centre of the vehicle.
Out of harm’s way – every millimetre counts during an accident. When an impending lateral collision is recognised, PRE-SAFE Pulse as an active restraint system moves the driver and front passenger towards the centre of the vehicle, using air chambers in the side bolsters of the seat backrests. If the onboard sensors report that a side impact is inevitable, these are inflated within fractions of a second and give the seat occupants a slight nudge in the ribs. This impulse is enough to move them out of the danger zone by up to 50 millimetres. Even before the accident, it also accelerates the seat occupant in the direction he/she will later take during the accident. This reduces the loads acting on the occupant during the impact. The seat does not need to be replaced or repaired when this preven-tive safety system has been activated, as PRE-SAFE Pulse is reversible.
PRE-SAFE Pulse is being developed on the basis of the dynamic multicontour seat in the new Mercedes E-Class. Depending on the steering angle, lateral acceleration and speed, the inflation pressure and volume of the air chambers in the side bolsters of the seat backrests are already varied to give the driver and front passenger even better lateral support.
Partial main beam: full beam ahead at all times Whether as brake lights and indicators in many Mercedes models, or as daytime driving lights in the new E and S-Class, LED lighting technology is see-ing increasing use at Mercedes-Benz. And things will be brightening up at night as well in future: Mercedes lighting specialists are working on an adaptive LED main beam system that automatically excludes oncoming traffic from the cone of light. A special spotlight function also allows potential hazards to receive additional illumination.
Main beam, low beam, main beam… anybody travelling on country roads in western Europe at night is seldom able to drive with the main beams on for very long. The frequency of oncoming traffic dictates that the driver is soon obliged to switch to low beam, either manually or more conveniently using the Main Beam Assist in the new Mercedes E-Class. This is not enough to satisfy the researchers at Mercedes-Benz, however. Because during the phases when the driver switches to low beam – with its shorter range – to avoid dazzling others, it is possible to overlook other road users or potential hazards.
The lighting specialists at Mercedes-Benz are therefore working on an LED-based adap-tive main beam system. This enables the driver to leave the main beams switched on constantly. As soon as the system detects oncoming traffic with the help of a camera, it automatically adjusts the light distribution accordingly. The Mercedes ESF 2009 ex-perimental safety vehicle shows precisely how this works. A headlamp is made up of 100 LEDs. These semiconductor elements can be individually activated, so that when there is oncoming traffic, the precise beam area in which other road users are located can be darkened down. The system recognises these using an infrared camera. The purely electronic module is also able to respond much faster than present electro-mechanical shutter/roller assemblies.
The light distribution can also be refined in the opposite direction: a special spotlight function in the LED array of the research vehicle also enables potential haz-ards to be highlighted. If the infrared camera detects pedestrians in the road ahead, for example, they can be briefly lit up beyond the normal main beam illumination, as if by an aimed spotlight. The driver is thus alerted to the potential danger.
Side Reflect: not all Mercedes are grey at night
Reflective material on the body and tyres could further improve the lateral visibility of vehicles, and help to avoid accidents at road junctions.
Reflective materials have long been commonplace in children’s clothing, and in the case of bicycles it is even mandatory to have reflectors in the wheel spokes. So the engineers at Mercedes-Benz asked themselves why the perceptual safety of cars could not be improved in the same way. Accordingly the ESF 2009 research car features appropriate reflective elements when viewed from the side. These modifications are not visible during the daytime, but the additional benefit shows up when dusk and darkness fall.
Together with the manufacturer Continental, Mercedes specialists have developed a reflective strip on the tyres which visually enlarges the wheels in daylight and creates an easily visible band of light when illuminated at night. As a further safety feature there are reflective seals between the doors and the roof, a joint development with the adhesive foil specialist 3M. The aim is to make the vehicle’s silhouette more easily visible in the dark. This enables potential accident situations on junctions or in the form of unlit, parked vehicles to be defused.
Reflective foils consist if a reflective base layer with tiny balls of glass. When a ray of light hits the foil, it is refracted by the glass balls, reflected by the base layer and refracted again on exiting. As a result, most of the light is reflected back in its original direction.
Belt Bag: a clever combination of a seat belt and airbag
The seat belt is regarded as one of the most important inventions of the 20th Century, and has saved countless lives. It has been further improved with belt tensioners and belt force limiters, but that is not the end of its development: an innovative extension to the width of the belt, known as a Belt Bag, is able to reduce the risk of injury even further in an accident.
When a seat belt limits the movement of its wearer’s torso as intended during a collision, it subjects the body to considerable forces. The Belt Bag, on whose development Mercedes-Benz is working intensively with the seat belt specialist Auto-liv, practically doubles its width within fractions of a second during an accident. This increase in the width of the belt spreads the pressure over a wider area, thereby reducing the risk of injury. This is particularly beneficial for older passengers, whose ribcage is no longer so flexible.
As the name suggests, the Belt Bag is a combination of a seat belt and airbag. When the crash sensors detect a serious impact, the airbag control unit activates the Belt Bag. A generator at the belt armature inflates the double-layered belt, which has Velcro seams. The volume of the Belt Bag is around four litres. The developers consider the Belt Bag to deliver the greatest benefits in the rear of the car, where conventional airbags cannot be installed. It is therefore conceivable that the Belt Bag could be used here by Mercedes-Benz in the foreseeable future.
Child Protect: safety and comfort for very small passengers
Mercedes engineers have thought about how children might travel even more safely in a car. The two major advantages of the Mercedes concept study “Child Protect” over conventional child safety seats are an improved protective effect and greater comfort for the child. This is accompanied by a high level of quality and attractive visual integration of the seat into the interior of Mercedes models. This system jointly designed with the restraint system specialist Takata is suitable for children aged between three and 12 years (weight categories II and III). One special feature is its modu-lar construction, as the height and width can be individually adapted to the child’s physical proportions.
“Child Protect” has a tubular frame construction. This design offers better support and greater rigidity than versions of moulded plastic during a side impact. The prominent side bolsters in the shoulder and head area keep the child in place and minimise body movement during an accident. At the same time they prevent the child from coming into contact with vehicle components penetrating into the interior, or with the passenger in the adjacent seat. This seat study, which is approved according to the ECE R44.04 standard, is also equipped with automatic, sen-sor-controlled airbag deactivation on the front passenger seat.
As an additional benefit, Mercedes engineers are considering the addition of a buggy subframe to the child seat. This would also ensure that children travel in comfort, style and safety outside the car.
PRE-SAFE 360°: full emergency braking before an impact
With the multiple award-winning PRE-SAFE® system, Mercedes-Benz has once again been underlining its role as a pioneer in the safety field since 2002: once the system recognises certain critical driving situations, PRE-SAFE® activates occupant protection measures as a precaution. As a further development, PRE-SAFE 360° monitors not only the areas to the side, but also to the rear of the vehicle.
PRE-SAFE 360° uses short-range or multi-mode sensors to monitor the area behind the vehicle to a range of up to 60 metres. If the accident early-warning system registers that a collision is unavoidable, the brakes are applied around 600 milliseconds before the impact. If the already stationary car is braked during a rear-end collision, this not only prevents secondary accidents where the car is e.g. uncontrollably shunted into a road junction or onto a pedestrian crossing. The severity of possible whiplash injuries to the occupants can also be reduced by application of the brakes, as the vehicle and therefore its occupants have less forward acceleration. The driver always has the final decision with PRE-SAFE 360°, however: if he accelerates because he is able to prevent the rear-end collision by moving forward, for example, the brakes are instantly released.
Contrary to the widely held opinion among drivers, it does not make sense to take one’s foot off the brake pedal before an impending rear-end collision. The correct action would be to apply the brakes as hard as possible, however accident research findings show that the driver of a stationary vehicle impacted from the rear is moved backwards by up to 20 centimetres. This inevitably causes his feet to slip from the pedals.
The protective effect of PRE-SAFE 360° supports that of the NECK-PRO crash-responsive head restraints, which are already standard equipment in many Mercedes model series. 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 millimetres within a matter of milliseconds. This means that the heads of the driver and front passenger are supported at an early stage than with conventional head restraints.
Size Adaptive Airbags: tailor-made airbags
The 1980 Mercedes S-Class (W 126) was the first series production car equipped with an airbag. In the meantime airbags have firmly established them-selves across all vehicle segments. Airbags have saved many human lives and reduced the severity of injuries. Mercedes safety specialists are now working on a further improvement to their protective effect by developing airbags with a variable volume.
There are already adaptive airbags at Mercedes-Benz today, for in many model series the airbags are activated in two stages depending on the assessed severity of the impact. Future generations of this restraint system will not only take accident severity into account, but adapt themselves to the individual vehicle occupants: “Size Adaptive Airbags” automatically adjust their volume to the seating position and stature of the front passenger as recognised by the sensors. For whether a small front passenger is hunched up close to the dashboard or a tall front passenger has his seat moved well back is certainly a factor in the protective effect of the airbag. The weight of the front passenger, and therefore the forces acting on the airbag during an accident, are also important.
“Size Adaptive Airbags” enable occupant contact with the airbag to be optimally timed, whatever his weight and seating position. The restraint system can therefore dampen the impact to optimum effect. This Mercedes development varies the volume on the front passenger side between 90 and 150 litres. For purposes of comparison, conven-tional front passenger airbags have a volume of around 120 litres.
The system uses three retaining bands with which the airbag contours are adjusted to limit the volume. The retaining bands are fitted on electrically driven spools. When the airbag is activated, only as much band length is released as the control unit has calculated on the basis of sensor data for the seating position and weight of the occupant.
Child Cam: keeping an eye on the kids
With the help of a small camera, drivers will in future be able to keep children travelling in the rear under control without taking their eyes off the road.
“Mum, Vanessa keeps pulling my hair!” “John’s seat belt isn’t properly fastened.” – Par-ents know that when the kids are on board, there is usually no shortage of action on the rear seats. But if the driver looks back to see what is going on, there is a risk of an accident. Accordingly Mercedes safety experts have developed “Child Cam”, a simple camera system that enables the kids to be observed without taking one’s eyes off the road.
A small camera is mounted on the roof lining behind the front seats. If required its im-ages can be transferred to the dashboard display – not in video form, but as sequences of stills to avoid distraction. The camera position provides a slight bird’s-eye view, which allows children in rear-facing child seats to be observed more easily.
“Child Cam” also shows rear areas that are not easy for the driver to observe, e.g. the seat directly behind. And in the case of an estate car, SUV or van, it is also possible to monitor the luggage compartment. This is very useful if domestic pets are on board, for example.
Interseat Protection: don’t get too close to me
Danger not only comes from outside during an accident. In unfortunate cases even passengers wearing their seat belts can come into contact and injure each other. Interseat Protection in both seat rows helps to prevent this.
Mercedes safety specialists are presenting two proposed solutions in one with Interseat Protection: a protective system for the driver/front passenger and one for the rear-seat passengers. As a common feature of both, the occupants are physically separated from each other if the PRE-SAFE® system registers an accident. Within fractions of a second, a lattice-like airbag support structure extends from between the front seats to keep the driver and front passenger apart. A seat-mounted solution like this has the advantage that the protective barrier adapts itself to the position of the front seats.
The seat position does not need to be taken into account in the rear, therefore a protective pad located above the centre armrest is used when an accident is detected. This pad helps to prevent the two passengers in the rear from impacting each other. When the pad is at rest it can be activated as part of PRE-SAFE®. Within fractions of a second, the seat divider emerges and the two head supports are deployed.
Mercedes accident research has shown that during a side impact, and also during a rollover, the heads of the passengers move along different paths: around 50 milliseconds after the accident, the head of the person facing the impact changes the direction of its evasive movement towards the centre of the vehicle – impelled by the sidebag and head airbag. A second important finding from these analyses is that a collision between the passengers can only be avoided if the torso is supported. The protective pad of the Interseat Protection system is dimensioned accordingly.
In normal cases the protective pad in the rear is more of an innovative comfort feature: the pad is designed to be extended by the passengers at the touch of a button, when it can be used as a head and shoulder support for a comfortable sleeping position. It would also be conceivable to use the space for stowage or a cooler box, or an entertainment console.