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The new M-Class: Just one star is enough
In line with the Mercedes-Benz brand philosophy, the new M-Class represents the embodiment of the Mercedes-Benz holistic safety concept of Real Life Safety, which is derived primarily from what happens in a real accident situation. The extremely robust occupant compartment of the M-Class, together with the front and rear deformation zones, forms an effective basis for the occupant protection system. Both active safety and driver-fitness safety in the new M-Class are further improved by Assistance Systems, already primarily familiar from the S and E-Class.
As with all passenger car models from Mercedes-Benz, the philosophy behind the safety concept of the M-Class is broken down into four phases:
- Safe driving: avoiding danger, warning and assisting the driver in good time
- In the event of danger: anticipating and enabling preventive protective measures
- In an accident: providing protection as needed
- After an accident: avoiding even worse consequences and making rapid assistance possible
The high level of safety already achieved in the previous model has been increased even further. The many "invisible" Mercedes-Benz solutions in particular bring measurable benefits in real accident situations. To support new technologies or the evolution of existing systems, the engineers carried out numerous crash tests which went way beyond the tests normally specified, such as the roof-drop test for example, as well as various rollover tests. When it detects the need to do so, a rollover sensor system can activate side and window airbags, as well as belt tensioners. In total, as part of the M-Class development Mercedes-Benz tested 36 totally different loads under real test-conditions. This included comprehensive simulations for the digital prototype. Following this intensive development programme, the M-Class now has the potential to pass all international ratings with the best possible results.
The M-Class is also able to demonstrate the highest possible protection potential when it comes to more vulnerable road users such as pedestrians or cyclists. In addition to yielding areas in the front section, folding exterior mirrors and smooth contours, the risk of injury caused by the vehicle has been reduced by adjusting the bonnet and increasing the distance to the components in the engine compartment. In addition, for the first time in the SUV segment, an active bonnet is fitted as standard equipment. It is able to reduce the acceleration forces of an impacting pedestrian or cyclist by intercepting them earlier.
"Electronic crumple zone"
As ever, the best accident is one which does not happen at all. The safety engineers at the Mercedes Technology Center are working intensively on this rather simple sounding statement, which in practice is actually a lot more difficult to implement. Both active safety and driver-fitness safety in the new M-Class are further improved by the numerous active and passive assistance systems:
- ATTENTION ASSIST, warns the driver of drowsiness
- Speed Limit Assist, displays road signs in the instrument cluster
- Tyre pressure loss warning system
- Intelligent Light System with specific lighting functions to match the relevant road and weather conditions
- Night View Assist Plus with automatic person recognition
- ADAPTIVE BRAKE with the functions Hill-Start Assist, priming, brake drying and hold function
- Brake Assist (BAS) to support the driver in critical braking manoeuvres
- DISTRONIC PLUS with BAS PLUS
- Lane Keeping Assist warns the driver as soon as it detects that the driver has unintentionally left a recognised marked lane. In addition, Active Lane Keeping Assist can react with lane-correcting brake application
- Blind Spot Assist warns the driver when vehicles are detected in the area of poor visibility, the so-called "blind spot". Additionally, Active Blind Spot Assist can counteract a possible collision by specific application of the brakes on one side of the vehicle, if the driver does not react to the warning
- Park Assist with PARKTRONIC, a system which can detect parking spaces and carry out the steering manoeuvres required for the parking process, simply leaving the driver to operate the brake and accelerator
- Reversing camera, e.g. with "back-in" mode with dynamic guide lines for reversing into narrow parking bays or to aid with the coupling of trailers
- Adaptive brake light warns vehicles behind in an emergency braking situation with flashing brake lights
Standard equipment forming part of the safety concept of the new M-Class includes the anticipatory safety system PRE-SAFE®, which combines active and passive safety synergies to reduce the loads exerted on the vehicle occupants in the event of an accident by up to 40 percent. Depending on the potential accident situation detected, the following reversible measures can be initiated for preventive occupant protection:
- Driver and front passenger seat belts are tensioned
- Windows are closed
- Sliding sunroof is closed
- Front passenger seat is adjusted (when fitted with Memory package)
Body: high energy absorption in the event of a front impact
The extremely robust occupant compartment of the M-Class, together with the front and rear deformation zones, forms an effective basis for the occupant protection system. The focus of the work here has been the tangible reduction of the loads exerted on the occupants. In the case of front impacts, the engineers were able to achieve more uniform deceleration, and therefore a lower peak load on the occupants. This was made possible by means of:
- Design of the front axle carrier as a crash element, which is able to deform in a specific manner and in the case of an offset crash, for example, can divert the energy to the side of the vehicle opposite the side of impact
- A novel aluminium gearbox crossmember mount with offset function: isolated against noise and vibration during normal operation, in the event of a crash this component is activated via hooks so that the centre tunnel can absorb additional energy in this area (diesel versions only)
- Guide ramp on the brake booster, thus preventing unwanted block formation between the brake booster and the damper dome. The brake booster is also rotated to minimise possible brake pedal intrusion
- A crash joint ensures that the mudguard is pushed away at the driver's door, and prevents the door from jamming after the impact. For the most part the doors can be opened without much effort
- Ultra-high-strength steels in the A-pillar enhance the stability of the passenger compartment in both front impacts as well as in different rollover scenarios, primarily enabling doors to be opened easily after an offset crash
- Projected sills create a direct load path to the front wheel. As a result, any possible forcing or intrusion of the wheels into the footwell can be avoided
- Optimum energy conversion in the event of a front crash despite relatively short front-end length, thanks to enabling the load paths from the crashbox to the longitudinal body member, from the wheel to the sill, and due to the deformable subframe, which guides forces into the centre tunnel via the engine/transmission joint
- The energy-absorbing steering column deforms up to 100 millimetres when subjected to external forces, thus freeing up additional deformation space for energy conversion. As a result, the loads on the driver can be reduced in the area of the head, neck and thorax
Side-impact protection thanks to intelligent bodyshell
Similar to the design of the front area of the new M-Class, the vehicle's intelligent bodyshell design also performs impressively in side-impact accident scenarios. The specific distribution of high rigidity and high deformability helps to ensure that the occupants benefit from favourable kinematics in the event of a side impact:
- The lower part of the B-pillar, an important component in side impacts, is highly compressible, whereas its upper part is extremely rigid. As a result, intrusions and the speed of intrusions in the lower area are reduced, while in the upper area high-strength steels on the exterior sides of the pillar prevent it from buckling unfavourably in a side impact. In addition, this design solution increases the stability of the passenger compartment in the event of a rollover
- The stiffening of the floor structure by means of a supporting element made of an ultra-high-strength material running across the entire width of the vehicle, and ultra-high-strength reinforcements in the driver's seat crossmember, help to reduce deformations, primarily in the event of a pole impact. As a result, the occupant survival space benefits from even better protection, and the thorax load on the occupants is reduced
- The geometry and body connections of the pillars and the roof frame made of ultra-high-strength material have been optimised to provide the best possible crash safety
Brilliant finish: the rear assembly
The rear area of the M-Class also protects the sturdy passenger compartment in crash situations thanks to specific deformation work, therefore minimising the loads on the occupants. A special impact test conducted to check tank leakage gives an indication of the exceptional load capabilities of the rear part of the M-Class body. The test involved running a crash carriage into the rear of the M-Class at 80 km/h. The tank system survived this fatal impact without suffering any leaks.
To enhance rigidity, increase the energy absorption capability and improve deformation behaviour, the multi-piece rear longitudinal members feature a continuous closed cross-section with stepped plate thicknesses (tailored blanks). The spare wheel well forms an integrated part of the steel floor, and a steel flexible bumper bracket carries the rear bumper covering and is connected to the rear structure via two steel crashboxes.
Comprehensive restraint systems for occupant protection
The passive occupant protection systems, together with the "electronic crumple zone" and intelligent body design which have already been described, provide optimum protection potential, placing the M-Class at the top of its market segment. As part of this, a number of new deployment strategies are used. For example, the system can detect an impending rollover in the event of crash and if necessary deploy the head, side and window airbags, as well as the seat belt tensioners. Thanks to the new generously-sized side airbags and the window airbags with extended area of coverage, in the event of a crash the occupants can be more uniformly supported from the shoulder area down to the pelvic area, and thereby better protected. In side impacts too, the danger of injury is reduced thanks to extended coverage.
Additional protection potential is also provided for rear seat passengers with seat belt tensioners and force limiters on the outer seat positions. The integration of optional thorax bags in the tilt-adjustable folding seat backrests enables optimum airbag positioning for each backrest position. The components of the passive occupant protection systems include:
- Two-stage adaptive airbags for the driver and front passenger
- Kneebag for the driver
- Sidebags for driver and front passenger (combined thorax/pelvis bags)
- Sidebags in the rear row of seats as an option
- Windowbags across both rows of seats from the A- to the C-pillar
- 3-point seat belts on all five seats
- Pyrotechnic reel tensioners and permanent belt force limiters as well as electrically reversible belt tensioners in the front, reel tensioners and single‑stage force limiters for the outer seats in the rear
- ISOFIX child seat anchorage
- Belt height adjustment for the driver and front passenger
- Belt status display for rear-seat passengers in the instrument cluster
- Automatic child seat recognition (optional) with deactivation of the front passenger airbag if a special Mercedes-Benz child seat is used
- In a rear-end collision, a passive head restraint system developed specifically for this purpose can reduce the forces exerted on occupants
Occupant protection even after a crash
As part of the POST-SAFE® functions, the new M-Class can activate a variety of systems which can contribute towards avoiding post-accident risks. After a more serious crash, the hazard warning lights are automatically activated to warn surrounding traffic. At the same time, the doors are automatically unlocked so that the emergency services have the best possible unrestricted access to the passengers. And thanks to partial opening of the side windows, the interior is better ventilated after deployment of the restraint systems.
On detecting a collision, the central control unit switches off the fuel system to reduce the risk of a possible fire. After determining the cylinder positions, the engine management system opens the injection valves of those cylinders which are not under compression and discharges the high-pressure fuel area by direct evacuation of the remaining fuel in the combustion chamber. This reduces the risk of fuel escaping. To avoid fuel losses, all M-Class models are also fitted with cut-resistant fuel lines in all relevant locations. This also helps to reduce the risk of a possible fire breaking out.
Source: Daimler AG
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
smart has always been a pioneer in matters of urban mobility and with the smart fortwo electric drive the company is showing the direction of development in cities around the world. Together with BASF, the largest automotive supplier in the chemical industry, smart is demonstrating its leading role in the use of forward-looking technologies above and beyond the drive system. The joint concept vehicle smart forvision presented at the 2011 International Motor Show in Frankfurt combines a futuristic design with technologies relating to energy efficiency, lightweight design and temperature management.
"With the forvision smart is doing justice to its role as Daimler's think tank for urban mobility. We are presenting numerous world premieres that make uncompromising electric mobility possible. With the clear objective of greatly increasing the zero-emission range we concerned ourselves with all factors that influence this on the vehicle. This resulted in completely new concepts and materials in the areas of insulation, reflection, lightweight design and energy management. In addition to transparent organic solar cells, transparent and energy-saving light-emitting diodes and infrared-reflective films and coatings, high-performance foams are used for insulation against cold and heat. smart is also setting new standards of lightweight design with the use of the first all-plastic wheels", says Dr. Annette Winkler, Head of smart. "In conjunction with smart's revolutionary DNA, we have designed a vehicle that is so unique that we can't wait to take it out of the research laboratory and onto the roads!"
"Cars of the future need materials and technologies which reduce energy consumption whilst also increasing the range and level of comfort. Our innovations make a decisive contribution to this", says Dr. Christian Fischer, Head of BASF Polymer Research. "We are proud to have developed a holistic concept for sustainable urban mobility in cooperation with smart. Together we are presenting a pioneering vehicle which is without parallel.
Thanks to the combination of smart's automotive expertise and BASF's material and system competence a vehicle has been created which showcases technologies for sustainable and holistic electric mobility of the future. The researchers and designers intentionally realised a mixture of visionary materials and technologies in the concept vehicle - some of these are still at a laboratory stage, while others have a realistic chance of entering series production.
Energy efficiency: light and energy from above
The hexagonal transparent areas on the roof of the smart forvision are an eye-catching feature – as the first light-transmitting roof that also generates energy. Transparent solar cells covering the entire roof surface are the technology used here. They are based on organic dyes embedded in a sandwich roof. The transparent dyes of the solar cells are light-activated. Even in diffused light and poor light conditions they generate enough energy to power the multimedia components and the three fans that assist with climate management in the vehicle interior. If the vehicle is standing in the sun the ventilation is permanently operated with the help of these solar cells, keeping the car cool. This new photovoltaic technology opens up further efficiency potential and the energy generated can be used for further applications in the car.
There is an additional new feature under the solar cells: transparent OLEDs (organic light-emitting diodes) illuminate the vehicle interior when the door is opened or a button pressed. When switched off they allow for a clear view outside. This results in a glass roof effect during the daytime, whilst the areas are pleasantly illuminated without any dazzle at night. Thanks to a free choice of colours the new OLEDs do not only offer more design freedom, they also consume less than half as much energy as conventional energy-saving lamps.
Lightweight design: different, better, stylish
In the smart forvision a world first leads to a considerable weight reduction and a unique design: the first all-plastic wheel suitable for high-volume production. In its current development status, the wheel developed by BASF from a new high-performance material results in a considerable weight saving of three kilograms per wheel. Unlike conventional polyamide composite materials this new plastic has long reinforcing fibres which improve its mechanical properties. The result: excellent thermal and chemical stability, dynamic strength, toughness and good continuous operating characteristics. First intensive product tests at smart show the performance capability of the all-plastic wheel and confirm the potential for possible use in production vehicles.
In addition to the tridion passenger cell, further components such as the doors are made of carbon-fiber-reinforced epoxy resin – a high-performance composite material. The use of such materials enables a weight saving of more than 50 percent to be achieved compared with steel, or 30 percent compared with aluminium. Thanks to short hardening times the resin systems from BASF are also suitable for producing larger volumes.
Heating: close to the body and efficient
The multifunctional, comfortable and lightweight seats in the smart forvision offer a unique combination of efficient temperature management and an energy-saving lightweight design. Here, several innovative products are combined with one another for the first time. A new, lightweight, self-supporting plastic seat shell forms the basis.
Numerous studies have shown that the body only absorbs heat efficiently through certain contact points. This is why "e-textiles" – thin fabrics with custom-tailored conductive coatings – replace conventional seat heating in the smart forvision. With direct heating close to the body in the middle and lower back area of the seats they provide for a pleasant feeling of warmth. The energy, space and weight-saving e-textile technology is also found in the armrests of the doors and ensures that body contact points sensitive to the cold are also warmed in this area.
The innovations continue with the seat foam, which provides for both comfort and weight savings. The material from BASF is around 10 to 20 percent lighter than other materials and enables different degrees of hardness to be realised in different areas of the upholstery in a single work operation – resulting in clear ergonomic advantages.
Superabsorbent containing fleece fabric integrated in the seat greatly enhances seating comfort through its passive climate control. Compared with conventional climate-controlled seats the lightweight seat in the smart forvision does not have the complexity and energy requirement of mechanical ventilation.
Temperature management: heat stays outside
As a large amount of energy is needed to air condition and heat a vehicle, temperature management was a key focus area for the smart and BASF researchers. A whole package of measures has been implemented in the smart forvision to ensure more efficient air conditioning of the vehicle.
At the same time they make energy-intensive heating of the whole interior superfluous.
A heat shield that has not been previously used for automotive applications consists of a new kind of infrared-reflective film from BASF applied in the windscreen and side windows, protecting the car interior from heating up. Integrated between the panes of the safety glass the metal-free film ensures that the infrared rays are effectively reflected. Thanks to its high transparency in the visible range it can also be applied to tinted windows and guarantees an unprecedented level of reflection of sunlight and heat. Unlike metallized films, which are already used in some vehicles, the new film reflects only the infrared rays of the sun. Radio waves needed to use GPS, Bluetooth, mobile phones or for toll collection pass through the glass unhindered.
The high-performance foams from BASF fitted in the bodypanels also provide for a pleasant climate inside the car. They keep the vehicle pleasantly cool in summer and also insulate it against the cold in winter. Thanks to their high efficiency even in a small width, they can be fitted everywhere in the vehicle. With this innovative insulation system in the smart forvision, the two companies are breaking new ground in the automotive sector.
Cool coatings – cool interior
The infrared-reflective and extremely scratch-resistant coating system covers two important aspects at once. Firstly, it supports the extensive temperature management system and, secondly, the brilliant and high-quality look of the coating underlines the unique design of the smart forvision. The concept vehicle features a white special-effect coating with glass flakes that create a gleaming metallic look. An important side effect: the colour white reflects heat rays from sun and light particularly well. But even surfaces coated with dark colours stay much cooler thanks to special colour pigments from BASF. They ensure that heat radiation is reflected rather than absorbed. This leads to a temperature reduction of up to 20 degrees Celsius on the paint surface and of up to approximately four degrees in the vehicle interior.
Futuristic design trendsetter
Painted in pearl white and accentuated by the tridion safety cell coated with a copper-coloured liquid metal paint, there is a deliberate connection between the basic structure of the smart forvision and the design of the smart fortwo. Trendy yet high quality – the aluminium flakes in the liquid metal paintwork create a reflecting surface on the safety cell, changing between light and dark depending on the viewer's perspective. Both the panels and the cell of the smart forvision are additionally painted with an extremely scratch-resistant clear coat.
The faceted side doors with integrated door openers are a real eye-catcher. Here, plastic is presented in a new, expressive and three-dimensional form; a reinterpretation that is only possible at smart thanks to the consistent use of plastic. The precise facets give the area stability and enable a smaller material thickness to be used. Optimal use is made of the possibilities offered by plastic as a material. In contrast, the front and rear have a softer design with smooth transitions from the doors. Just as the integrated door handle does not need an additional component, the familiar smart air inlet is represented by small hexagons located right on the outer skin.
The jet-like rear lights are reminiscent of small aircraft turbines and give the rear a futuristic and sporty look. Inside the lights, small propellers convey the air from the inside to the outside. In addition to all the light functions needed, transparent stacks in the form of rings around the lights also show the charge status of the battery during charging.
The headlamps are emphasised by a ring comprising the daytime driving lights and indicator functions. The lights add to the likeable expression of the smart forvision.
Doors open to the future
With a mix of polygonal surfaces and organic shapes the interior of the smart forvision builds a bridge to the architectural design handwriting of the exterior. This also applies to the colour concept: a cool white dominates in the interior as well, accentuated by the inner part of the instrument panel in liquid copper. Hexagons in the form of white rubber nubs on a white floor are a reference to the design idiom of the overall vehicle, as is the tone-in-tone design of the seat upholstery.
The faceted surface of the side doors is also found on their inside. The polygonal surfaces with integrated armrests and stowage compartments curve into the interior. They are painted in the body colour and feature coloured LEDs. These guide the driver with a light animation running from the outside to the inside when the door is opened and closed. After closing the door the animation changes to unobtrusive ambient lighting.
The elliptical user interface with a copper coloured frame – matching the lightweight tridion – is semi-transparent when switched off. When the vehicle is switched on all cockpit information is then projected onto the transparent surface. The driver uses a touchscreen to switch between operating menus.
The white steering wheel that is reminiscent of an aircraft yoke additionally gives the cockpit a futuristic look. As well as function buttons the LED display for the battery charge status is found here.
Forward-looking technologies
The smart forvision not only shows that electric mobility can make emission-free driving possible. At the same time, it paves the way for new technologies in the automotive sector. Many of these innovations are based on nano technology, the key to the development of sustainable solutions. Nano materials serve as drivers of innovation in the automotive industry, as they do in the fields of construction, energy, healthcare and electronics.
The total of all technologies integrated in the concept vehicle make a perceptible contribution to increasing the range.
This is always at the centre of discussions relating to battery-electric driven vehicles. With maximum energy efficiency, intelligent temperature management and consistent lightweight construction it is possible to increase the range by up to 20 percent. An additional bonus for electric mobility of the future.
Source: Daimler AG / BASF
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
After the 'forspeed' showcar was unveiled back in March at the Geneva Auto Salon, smart is bringing to Frankfurt a new concept designed to envision the design philosophy to be featured on the next generation of the fortwo model: the new 'forvision' follows on the trail of the previous prototype and proposes a dynamic approach for the urban car of tomorrow.
The smart forvision comes styled in quite the same manner as the 'forspeed', which means a rounded body with intricate lines and profiles to deliver an aerodynamic appearance, a radiator grille with hexagonal holes, oval headlamps and tail lights with LED technology, a candy-like white paint finish for the front fascia, lower section of the doors, tailgate, rear bumper and wheel arches and a glossy, goldish paint finish for the roof, the B-pillar and the door sills.
Engineers have put their best skills at work to create the 'forvision', sporting an all-electric powertrain and several equipments and breakthroughs which are absolute premieres in its class. They colaborated with chemistry experts from BASF and came up with impressively lightweight wheels constructed out of state-of-the-art plastic compounds that ensures an overall mass of just three kilograms each. Other astonishing technical solutions include the intelligent sunroof designed to feed extra energy into the Li-Ion batteries and the use of a carbon fiber epoxy resin to build the ultrafuturistic passenger shuttle and the doors, which also contributes to save important kilos compared to common compound such as stainless steel or aluminium.
Stay tuned to Mercedes-Benz-Blog as more official details follow the upcoming period! In the mean time, enjoy the preliminary photos of the smart forvision concept!
Source: Daimler AG
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
