The B-Class provides its drivers with comprehensive support and protection by means of numerous driving assistance systems, from drowsiness detection with ATTENTION ASSIST to proximity control with DISTRONIC PLUS. These assistance systems, which have been the reserve of higher vehicle segments to date, are based on state-of-the-art radar, camera and sensor technology and are designed to address the common causes of accidents, such as inadequate distance, fatigue and darkness.


As a world first in the compact segment, the B-Class features a radar-based collision warning system with adaptive Brake Assist as standard, which can lower the risk of rear-end collisions. The COLLISION PREVENTION ASSIST system is able to output a visual and acoustic warning to alert a distracted driver and prepares Brake Assist for the most precise possible braking response. This is initiated as soon as the driver emphatically operates the brake pedal.

In contrast to systems currently on the market in the compact class, the new COLLISION PREVENTION ASSIST feature is not merely a system intended to minimise minor damage in urban traffic. Rather, this innovative solution is aimed at protecting motorists from typical rear-end collisions in dangerous traffic situations.

Mercedes-Benz expects the new safety system to have a significant positive effect on accident statistics. On the basis of detailed analyses of accident data, Mercedes-Benz safety experts assume that around 20 percent of all rear-end collisions can be avoided with this radar-based technology, while the severity of such accidents can be reduced in a further 25 percent of cases.

Electronic helpers: all the other assistance systems at a glance

The democratisation of safety also encompasses an array of other assistance systems which have been adopted into the B-Class from the larger model series. These include:

- 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. The driver benefits from a longer dipped beam range and does not generally need to switch manually between high and dipped beam.

- Blind Spot Assist: this radar-based system employs two additional radar sensors in the rear of the vehicle to warn the driver before a lane-change if it detects another vehicle in the exterior mirror's blind spot.

- Lane Keeping Assist: a camera behind the windscreen recognises clear carriageway markings and outputs a warning if the car is about to leave its lane unintentionally.

- ATTENTION ASSIST(standard): warns drivers when it detects typical signs that they are over-tired. 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, 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.

- Speed Limit Assist: a camera fitted behind the windscreen detects speed limit signs at the roadside and compares this data to information contained in the GPS system or the digital map. The relevant speed limit is then displayed in the instrument cluster.

- Brake hold function: when stopping, for example at traffic lights, the driver merely has to press the brake pedal slightly more firmly. He can then take his foot off the brake pedal and the brake will remain engaged until he moves off again. The brake is released automatically when the driver steps on the accelerator.

- Hill Start Assist: this function is able to prevent the vehicle from rolling back unintentionally when moving off on an uphill slope.

- Reversing camera: the B-Class is optionally available with a reversing camera incorporating a wide-angle lens which is integrated in the handle strip on the tailgate. When reverse gear is engaged, the image from the camera is transmitted to the screen of the Audio 20 system or the COMAND system. Static and dynamic guide lines assist the driver during manoeuvring.

- DISTRONIC PLUS: the radar-based adaptive cruise control supports the driver at speeds between zero and 200 km/h by maintaining 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.

A number of assistance systems which provided for added comfort and safety in the previous B-Class are also optionally available for the new generation. These include:

- Cruise control with SPEEDTRONIC: the cruise control function of the speed control system maintains the preset speed. The additional SPEEDTRONIC function ensures that the stored speed is not exceeded. Both functions come as standard with the 7G-DCT dual clutch transmission and are optionally available for the models with manual transmission.

- Active Parking Assist: two ultrasonic sensors installed on the right and left of the front bumper measure the length and depth of a potential parking space. If the parking space fits, the driver is shown an arrow next to the "P" symbol in the instrument cluster. The optimum path into the space is calculated on the basis of the vehicle's present position and the system assists the driver during the parking manoeuvre by operating the electromechanical steering. The driver is still required to perform acceleration and braking, however. The speed is limited to 10 km/h for the parking manoeuvres.

Arriving at the destination safely, rapidly and in a relaxed frame of mind: detecting traffic problems before they are seen, being aware of hazards before they become a threat. Intelligent mobility at a new level was another key focus during the development of the F 125!. This is to be achieved by electronic networking of the vehicle and the external infrastructure - so-called Car-to-X communication. It allows information to be exchanged both between vehicles, and between vehicles and traffic control centres. In this way following and oncoming vehicles can be informed about potential hazards, enabling them to take timely and appropriate action in the relevant situation.


In Car-to-X communication, anonymised information about the traffic situation is also relayed to control centres so that further developments can be reliably predicted and the road infrastructure can be optimally configured in response. This information is in turn made available to road users, so that they can vary their routes accordingly and reach their destinations conveniently and safely in the shortest time.

Special WLAN-based radio technology

To ensure safe and reliable communication even in very dense traffic, a specially developed radio technology based on the well-known WLAN standard is used. Information is transmitted directly to other vehicles, or to stations installed along the roadside. In the event that the communication partner is not in direct transmission range, other vehicles can relay the information ("Multihopping") or save it for later transmission ("Store & Forward"). In addition two-way radio technologies such as UMTS are integrated, so that gaps in WLAN coverage can be bridged (e.g. where there is no roadside infrastructure) or added value services can be offered.

Specific applications might include a warning of approaching emergency service vehicles, well before the driver can see or hear them, a reminder that other vehicles have the right of way at obscure road junctions, or rapid and precise relaying of information about obstacles or pedestrians on the road ahead.

Networked crossings, speed recommendations and optimised traffic light cycles also enable drivers to make efficient progress thanks to a series of green lights. The touring saloon of the future will therefore relieve the driver's workload in many standard situations, defuse potential sources of danger and make for even more relaxed travel.

Advanced Driving Assist for semi-autonomous driving

When it comes to comfort the F 125! goes a whole stage further by autonomously performing certain frequent driving manoeuvres if the driver so wishes. On multi-lane, one-way roads, for example, Advanced Driving Assist allows autonomous cruising in the same lane (with or without vehicles immediately ahead) and safe, automatic lane-changing, and in a further development stage even overtaking manoeuvres.

In the process the F 125! controls both the linear and lateral vehicle movements, while its sensors "keep an eye on" other road users at all times. The driver merely needs to give the relevant command, leave his hands loosely on the steering wheel, lean back and relax. Naturally he is able to take back full control of the car at any time.

Source: Daimler AG

Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.

OFFICIAL PRESS RELEASE

Stuttgart/Mannheim, Germany, May 20, 2011

The engines for the new Mercedes-Benz Citaro are based on BlueTec diesel technology. The wide-ranging choice of engines for the Citaro covers the full spectrum of power requirements. The OM 906 hLA turbocharged diesel engine is a particularly compact and lightweight six-cylinder unit with a displacement of 6.37 litres, an output of 210 kW (286 hp) and a maximum torque of 1120 Nm. Alternatively, there is the OM 457 hLA six-cylinder engine with a 12 l displacement in a choice of two power ratings: 220 kW (299 hp) and 260 kW (354 hp) with maximum torques of 1250 Nm and 1600 Nm respectively. All of the engine variants stand out for their high pulling power from low rev speeds. This is of particular importance for enabling the bus to pull away dynamically in city traffic, even when full to capacity.


EEV emissions rating even without particulate filter

All engines are Euro V compliant as standard. The engines can furthermore be specified in a version that meets the most stringent voluntary emissions standard that currently exists – the EEV (Enhanced Environmentally-friendly Vehicle) standard. The new Citaro achieves EEV compliance by means of internal engine measures alone without the need for a particulate filter – further evidence of the enormous potential of the efficient, eco-friendly BlueTec diesel technology and its viability for the future. EEV with no filter means reduced costs for procurement as well as maintenance. Further benefits include the lower kerb weight and reduced space requirements, which in turn increases the number of seats. A particulate filter can, of course, be installed as an option. Power transmission is handled by fully automatic torque-converter transmissions made by Voith and ZF. The most up-to-date versions of both are fitted in the Citaro to maximise efficiency. With a choice of engine, transmission and matching final drive ratio, the new Citaro takes to the road with a customised drivetrain, just as its predecessor did.

Further reduction in fuel consumption

A new, electronically controlled air compressor is employed on the articulated Citaro bus with the vertically mounted OM 457 LA engine. This is an EAPU (Electronic Air Processing Unit) that combines the compressed-air drier, pressure governor, four-circuit safety valve and pressure sensors into a single component. The compact construction simplifies assembly and reduces the number of lines required. Where possible, the electronically controlled air compressor operates when the Citaro G is in overrun mode to save fuel. To ensure this is the case as often as possible, the system pressure for the suspension and door operation has been increased from 10 to 13 bar with the introduction of the new air compressor. This produces greater air reserves in day-to-day operation and saves fuel.

Detailed improvements to comfort suspension

The chassis on the new Mercedes-Benz Citaro again excels with exceptional comfort and handling safety thanks to its independent front suspension. In this respect too though, the new Citaro has now gone one better, especially from the driver’s point of view. The reworked steering has improved steering-wheel return, for instance – a key consideration for urban regular-service buses which have to turn so frequently.

Supreme safety levels thanks to innovative assistance system

A new assistance system is making its debut in the low-floor bus and in the Citaro simultaneously: for the first time, the Electronic Stability Program (ESP) is available for an urban regular-service bus. The Mercedes‑Benz Citaro is taking safety technology for urban regular-service buses into a new era with this innovative feature – thereby emulating its predecessor, which also set new benchmarks on its launch.