An astonishing experience: the wiper blade glides over the badly soiled windscreen of the new SL, without a sign of a cleaning water jet, the occupants do not notice anything yet the windscreen is still cleaned! The new SL is the first vehicle to be equipped with the adaptive MAGIC VISION CONTROL wiper/washer system developed by Mercedes-Benz. It cleans the windscreen without the splash of water that usually briefly disrupts the driver’s field of view in the case of conventional windscreen washing systems – something that is especially unpleasant at night or when the sun is low in the sky and at high speeds.
In fact, the windscreen cleaning operation in the SL is still performed with washer fluid in the conventional manner. The innovation lies in the way the fluid is conducted to the windscreen in order to clean it. This is done by means of water guides integrated on both sides along the wiper blade – one on the left and one on the right – with minute laser-cut spraying holes. Via these channels, the innovative washer/wiper system always supplies washing fluid to the windscreen discreetly, precisely where it is needed: just in front of the wiper blade lip, according to the direction of movement of the wiper. The holes are distributed along the entire length of the wiper blade, being more closely spaced towards the outside of the blade, where it sweeps a greater area, than closer in, where the area swept is smaller.
Programs for summer, winter and cabriolet operation
Mercedes-Benz controls the MAGIC VISION CONTROL system intelligently via three partly autonomous wash programs – for summer, for winter and for cabriolet driving. It is the first windscreen wipe/wash system anywhere in the world to operate in this way. In summer, small quantities of water are sufficient to remove a light powdering of dust. In winter the dirt mixed with de-icing salt requires a greater amount of water. The MAGIC VISION CONTROL system works in accordance with the outside temperature, and it also automatically adapts the washer fluid quantity to the surrounding conditions.
A particularly interesting feature of the SL Roadster is the Cabriolet function: when the hardtop is down, the electronic control system reduces the amount of water, apart from which it demands the required water mainly on the downward stroke of the wiper arm. This way the windscreen can be conveniently cleaned during the journey and with an open roof, without any of the water spraying into the vehicle interior. Another pleasant side effect is that, since the washer fluid is directed specifically and in a well-metered manner to the area to be cleaned, one doesn’t douse anyone else in the surroundings with water, either, and it also doesn’t distribute any spray onto the vehicles behind. At the end of the day, a better cleaning effect is attained with up to half the amount of washer fluid. It has therefore been possible to reduce the volume of the washer fluid reservoir by 1.7 litres compared with the preceding model. This in turn contributes to a reduction in weight and consequently to greater efficiency.
Winter-proof thanks to the heated system
On request the MAGIC VISION CONTROL wiper blades are completely heated on the new SL, making Mercedes-Benz the first manufacturer in the world to offer a fully heated wiper/washer system. It consists of a washer fluid container heated through coolant waste heat, electric heating for the entire hose system and, as a newly-developed highlight, a fully heated wiper blade. This effectively prevents the formation of snow on the wiper blades, so typical in winter. To do this each of the spring rails of the blade is equipped with a heater foil with an output of 35 watts per blade. It heats the spoiler and the wipe lip. Snow and ice cannot freeze onto the blade; it remains supple in winter, too, and always cleans well.
The heating is also controlled as required according to the duration of operation and the outside temperature. It is only below a temperature of minus 20 degrees Celsius that the system makes use of the entire system’s maximum output, 270 watts. Between 5 degrees above and 20 degrees below zero the heating operates in an energy-saving mode and only requires the output needed to thaw out the wiper/washer system and keep it free of snow and ice.
Credits: Daimler AG
Copyright © 2012, Mercedes-Benz-Blog. All rights reserved.
Superb THERMOTRONIC automatic climate control: Perfect climate aboard M-Class and E-Class
Carefully balanced control of the interior climate is especially important in the winter. This is why Mercedes-Benz offers the THERMOTRONIC luxury automatic climate control system for the E-Class and M-Class. Apart from regulating the climate separately for the driver, front passenger and passengers in the rear, it allows individual pre-settings to be programmed too.
This system furthermore includes a pollutant sensor which automatically switches to air recirculation mode if it detects any sudden increase in the carbon monoxide or nitrogen oxide levels in the outside air – when driving through a tunnel, for instance. Another highlight of the THERMOTRONIC system is the residual heat function: pressing the “Rest” button heats or ventilates the passenger compartment for around 30 minutes when the engine is switched off.
THERMOTRONIC heats up the passenger compartment efficiently, even after a cold start on winter mornings. This is thanks to a heating output of eleven kilowatts, equivalent to the capacity of the central heating system in a modern family home. On the diesel models, a heat exchanger with six integral PTC heating elements (PTC = Positive Temperature Coefficient) is also activated when the outside temperature falls below a certain level in order to boost the effect of the main heat exchanger with an electrical output of around 1200 watts. The assistance from the PTC heater is necessary due to the high thermal efficiency of today’s CDI engines, which is precisely what makes them so economical and means that they dissipate considerably less heat to the coolant under partial load conditions than conventional engines. The E-Class and M-Class are equipped as standard with THERMATIC, a two-zone automatic climate control system.
To make long journeys or lengthy winter outings in the M-Class even more enjoyable, the centre console holds a little surprise in store: the tempered cup holders include a Peltier element that is capable of keeping drinks hot or chilled in a temperature range of 8° to 55° Celsius at the push of a button. So, a “take-away” coffee can be kept hot on the morning drive to the slopes, for example. Alternatively, with the cooling function activated, the thermal cup holders are able to stop chocolate bars from melting if a very high interior temperature has been set.
Source: Daimler AG
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
New chassis developments and innovative dynamic handling control systems: Relishing the winter with the M-Class
Outstanding safety and well-balanced ride comfort combined with impressive driving dynamics on dry, wet as well as wintry roads, plus superlative skills off the beaten track are some of the key strengths of the third-generation M-Class with permanent all-wheel drive. The premium SUV also makes its mark with new chassis developments and innovative dynamic handling control systems designed to increase both driving pleasure and active safety in winter.
The optional ON&OFFROAD package for the new M-Class uses six different driving modes to optimise driving dynamics and handling safety by providing the optimum drive control needed to cope with the wide spectrum of operating conditions encountered both on and off the road. Drivers have the choice of an automatic mode, two specially programmed off-road modes as well as three on-road modes – “Winter”, “Sport” and “Towing”.
The specific driving modes for all-wheel drive resolve a conflict of objectives that has previously hampered further development of 4MATIC and the 4ETS electronic traction system as well as ESP® and acceleration skid control (ASR). To take an example: on off-road tracks or snow-covered roads, it is important that the control systems respond very gently due to the low friction coefficients, but this makes a sporty set-up virtually impossible. Conversely, a sporty basic setup impairs performance abilities in off-road terrain and snow. In the past, excellent compromises were always found which worked brilliantly under all conditions. The new ON&OFFROAD package with its specific driving modes, however, enables driving dynamics and handling safety to be optimised almost as far as is physically possible under all operating conditions by maximising networking between the individual control systems.
In terms of “hardware”, the ON&OFFROAD package comprises an underguard, a two-stage transfer case with low-range ratio, an inter-axle differential lock and enhanced AIRMATIC functionality that allows a maximum ground clearance of 285 millimetres and a fording depth of 600 millimetres.
Winter driving mode: more fun, more safety
The driving mode is chosen using a rotary control on the centre console. To ensure the selected driving mode – in this case “Winter” – is clearly indicated, a special snowflake graphic appears in the instrument cluster, while the COMAND screen shows the M-Class in a wintry, snow-covered landscape.
The ON&OFFROAD package’s winter driving mode optimises handling on roads affected by snow, ice or freezing rain and when using snow chains, and offers drivers added safety with its well-defined, predictable reactions. The extensive fine-tuning work carried out focused on further increasing longitudinal traction, at the same time as improving lateral dynamics and handling safety. The development team was able to implement these specifications to impressive effect using targeted control mechanisms in the drivetrain:
- When pulling away with or without the steering turned, the inter-axle lock in the centre differential is triggered earlier in order to increase traction and reduce understeer when accelerating briskly. In parallel to this, the 7G-TRONIC PLUS switches to the “gentler” ECO mode and automatically engages 2nd gear when pulling away to avoid high wheel slip. Finally, a flatter response curve gives the driver more sensitive control over the accelerator pedal.
- Maintaining a locking torque that has been set in the centre differential for longer improves handling stability and helps the driver by making the self-steering characteristics more definite.
- Higher ASR slip thresholds when driving in a straight line result in high traction levels as well as safe operation with snow chains with outstanding tractive power.
- ASR slip thresholds lowered when cornering in order to ensure stable handling characteristics at all times as far as is physically possible.
ACTIVE CURVE SYSTEM for safe fun in the snow at its very best
When the ON&OFFROAD package is combined with the ACTIVE CURVE SYSTEM (ACS), a specially programmed winter set-up guarantees dynamic driving pleasure while giving the driver excellent control over the vehicle for a high degree of handling safety. ACS uses active anti-roll bars at the front and rear axles to compensate for the roll angle of the body through bends, increasing agility and driving pleasure in the process. At the same time, the system is capable of giving the M-Class greater traction, especially in wintry road conditions with low grip levels.
The ACTIVE CURVE SYSTEM “Snow mode” features two control strategies. Firstly, many of the parameters needed for driving on wintry roads are already incorporated into the basic functions, i.e. when the ON&OFFROAD package’s Automatic driving mode is activated. This means that the system’s reactions to the driver’s steering inputs will be less dynamic on slippery surfaces. External influencing factors, such as fluctuating friction coefficients on roads that are partially covered in ice or snow, are balanced out faster though. Thanks to this control strategy, the M-Class becomes far more docile, even if the vehicle switches between moderate oversteer and understeer.
Secondly, the system control for the winter driving mode includes a special control algorithm. In just the same way as the shaped skis thrill alpine skiers by closely following the desired line even through turns with a tight radius, the M-Class handles in tight bends in this mode. This control strategy produces increased traction on snow-covered road surfaces by dynamic displacement of the wheel loads. If the driver turns into a tighter bend while travelling at a constant speed or accelerating, the wheel load and, as a result, the traction will be increased at the front wheel on the outside of the bend. Doing so minimises the understeer that is otherwise typical in this driving situation. If the driver then reduces the steering angle when exiting from the bend while travelling at a constant speed or accelerating, the load at the rear wheel on the outside of the bend will be raised instead. This has the effect of increasing lateral support at the rear axle, so that the vehicle’s handling is stabilised in the same way as when entering the bend. This time though, it is the tendency to oversteer that is countered.
M-Class sets benchmarks in the world of SUVs
The third generation of the Mercedes-Benz M-Class excels above all with its outstandingly efficient use of energy. On average, the fleet consumes 25 percent less fuel than the predecessor models. The ML 250 BlueTEC 4MATIC is the fuel efficiency champion, consuming just 6.0 l per 100 km on the NEDC driving cycle (158 g CO2/km) and capable of covering up to 1500 kilometres on a single tank of fuel. Other key strengths of the premium SUV with permanent all-wheel drive include outstanding safety and well-balanced ride comfort combined with impressive driving dynamics both on the road and off the beaten track. A distinctive body design and a versatile interior that is highly conducive to its occupants' wellbeing further enhance the M-Class driving experience.
Source: Daimler AG
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
