Benz Real Life Safety

A trio of three safety experts has touched down in Australia for the Mercedes-Benz Real Life Safety Program. Ullrich Mellinghof, Dr Joerg Breuer and Dirk Ockel have arrived in the country along with two advanced driving simulators and a cut-away ESF2009 safety concept car, which was unveiled at the Frankfurt motor show last year.

Addressing the local media, Mellinghof provided an overview of Benz's road safety philosophy and the context in which it fits. Dr Breuer outlined the company's leading-edge active safety developments and Ockel, who heads up Benz's accident research, explained the passive (crash) safety features that are being introduced throughout the model range.

Kicking off the presentation, Mellinghof explained that the worldwide vehicle population is growing at a rate five times faster than the human population. That growth, principally attributable to the rapid expansion of new-car sales in developing countries such as China and India, is expected to have a major impact on the global road toll.

"Experts predict that the worldwide passenger-car population will double by the year 2030 and that there will be around two billion cars by 2050," said Mellinghof.

"It's obvious that this increase in worldwide road traffic presents us with a major challenge, regarding emissions and regarding safety. According to the World Health Organisation, road traffic injuries are ranked ninth in terms of overall cause of death. This is expected to change during the next 20 years; in 2030, road traffic will be [ranked] five."

Mellinghof, citing German road traffic, suggests that accident avoidance measures introduced in recent decades have compensated for the larger vehicle population on the roads of both countries. That's despite the human tendency to compensate for new safety technology by driving faster.

In fact, according to Mellinghof, it's actually excessive speed that contributes mostly to the road fatalities, countering the frequently expressed view in Australia that authorities have got it wrong when they argue that 'speed kills'.

"Traffic accidents occur because people make mistakes," said Mellinghof. "It's only very seldom that other factors play a significant part. In more than 80 per cent of traffic accidents caused by car drivers, the diagnosis is human error...

"Speed is the main risk in road traffic. Excessive speed is often... the cause of loss of control accidents, where drivers lose control of their vehicle without the involvement of third parties -- and skid off the road. These [single vehicle accidents] account for roughly one in five of all serious road accidents, and many of them have fatal results."

Dr Breuer was up next, explaining how the introduction of Brake Assist had reduced pedestrian accidents involving Benz vehicles so equipped by 13 per cent and rear-end collisions by eight per cent. The system applies higher braking pressure if it detects a fast but light stab of the brake pedal. It can compensate for a driver not using the car's full emergency braking capacity -- possibly out of fear that the car will lock its brakes or due to physical inability to throw enough weight on the pedal.

Dr Breuer also mentioned other safety systems Benz has developed in recent times, among them radar/camera-enhanced Pre-Safe, which applies "autonomous partial braking" 1.6 seconds prior to a crash -- and pre-tension the seatbelts simultaneously. At 0.6 seconds ahead of a crash the system will apply full braking on the basis that the crash is unavoidable at that point.

Two systems introduced with the latest CLS are Active Lane Keeping Assist and Active Blind Spot Assist. With both systems the car applies braking pressure on one wheel at the rear to drag the car away from the point of danger. In the case of the Active Lane Keeping Assist system, the driver is warned through a three-pulse vibration through the steering wheel if the car is veering out of the lane across a dotted line.

If however, the vehicle is moving out of the lane over a solid line -- such as delineates an emergency lane or hard shoulder -- the car will apply braking on the right-rear wheel (in Australia) to steer back onto the road. This is in addition to the three-pulse vibration.

Other safety features covered in Dr Breuer's presentation include Adaptive High Beam Assist, Night View Assist Plus and Attention Assist. In the case of Attention Assist, the Benz system monitors the driver's steering inputs (up to 70 parameters) to assess how fatigued the driver might be, based on learned inputs. The system must learn the traits of each driver because patterns vary from one individual to the next, says Dr Breuer.

Ultimately, the essential point of these devices is that they do not take the task of operating the vehicle away from the driver.

"The driver will remain the boss," said Dr Breuer.

Dirk Ockel, Head of Passenger Car Development Accident Research, provided a look at some of the crash-safety features invented and/or refined by Benz over the years. The Active Bonnet on the latest W212 E-Class, for example, can rise within a matter of milliseconds to absorb the impact of a pedestrian's head and reduce the load that would otherwise spread through the skull. The bonnet, subsequently demonstrated to the attending journalists, will not only rise to distance the pedestrian's head from the engine underneath -- courtesy of a spring-loaded system -- but can also be readily returned to its normal position by merely opening the bonnet via the manual release and pushing it back into its locked (sprung) state.

It's one of two crash-safety systems that are 'reversible' (can be redeployed in the event that the collision doesn't occur); the other being the motor-driven seatbelt pretensioners that tighten the belts before a crash and work in unison with non-reversible pyrotechnic pretensioners that operate after the crash.

The reversible pretensioners complement adaptive belt force limiters in the rear seat. These adjust the amount of force limiting according to the physique of the seat occupant. If a larger occupant pulls out the seatbelt further from the inertia reel, the force limiting capacity will be adjusted to correspond.

Ockel touched on Pre-Safe, which is a system that straddles active and passive safety. Given that many crashes occur over a relatively long time (measured in seconds rather than milliseconds), the Pre-Safe system can prepare for a roll-over by setting seat backs upright and closing windows and sunroof five seconds ahead of the vehicle rolling.

The passive safety expert handed back to Mellinghof, who concluded the presentation with a run-down of some of the advanced safety features in the ESF 2009 concept car (pictured).

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