Frankfurt show: Mercedes-Benz teases self-driving car

MERCEDES-Benz has retraced the route of one of the first trips in a motor vehicle, but this time around it was the car – not the driver – doing all the work.

The German luxury car-maker today revealed a self-driving version of the S-Class limousine that had made the 100-kilometre trip from Mannheim to Pforzheim, retracing the 100km route driven by Bertha Benz, the wife of the inventor of the automobile, Karl Benz, 125 years ago.

However, instead of contending with horses and carts, unsealed roads and buying supplies of kerosene from chemist shops, the modern-day trip had to contend with heavy traffic, red lights, roundabouts, pedestrians, cyclists and trams.

“It should be noted that this trailblazing success was not achieved using extremely expensive special technology, but with the aid of near-production-standard technology, very similar to that already found in the new E and S-Class,” Mercedes-Benz said.

“The project thus marks a milestone along the way that leads from the self-propelled (automobile) to the self-driving (autonomous) vehicle.”

Benz used a version of its S500 limousine equipped with Intelligent Drive, using off-the-shelf equipment to build a view of the world around the car. It also used newly developed software called “Route Pilot” to help the car find its way.

Instead of taking the autobahn, Mercedes-Benz opted to take the more difficult route through suburban streets.

"This S-Class spells out where we're headed with "Intelligent Drive" and what tremendous potential there is in currently available technology," Mercedes-Benz head Dieter Zetsche said.

"Of course, it would have been a lot easier to take the autobahn for the autonomous drive from Mannheim to Pforzheim,” Dr Zetsche said.

“But there was a special motivation for us to carry out this autonomous drive along this very route 125 years after Bertha Benz. After all, we wouldn't be Mercedes-Benz unless we set ourselves challenging goals and then went on to achieve them."Mercedes-Benz said developers taught the technology platform to know where it was, what it was seeing and how to react autonomously.

"For us, autonomous vehicles are an important step on the way to accident-free driving," Dr Zetsche said.

"They will bring greater comfort and safety for all road users. That's because autonomous vehicles also react when the driver is inattentive or fails to spot something.

“On top of that, they relieve the driver of tedious or difficult tasks while at the wheel."Mercedes-Benz Cars development head Thomas Weber said the S-Class was the first car to drive autonomously during traffic jams.

“We also want to be the first to bring other autonomous functions in series production vehicles,” he said. “You can expect that we will reach this goal within this decade.”

He said Mercedes-Benz’s development work on autonomous driving would not come overnight, but would be realised in stages.

“With this drive, we've now taken another important step into the future," Prof Weber said.

The core of the autonomous Mercedes-Benz is the car-maker’s Distronic Plus system that can keep the car a set distance from the vehicle in front, and even automatically jump on the brakes for the driver to avoid a crash. It is tied in with active steering and the car’s stop-and-go system that can automatically bring the car to a complete stop in traffic, and take off again when the driver touches the accelerator pedal.

The car was modified slightly to increase the distance between a pair of cameras mounted behind the rear-vision mirror to give the S-Class a better depth perception so it could judge distances more accurately.

Engineers also added pair of long-range radars at the front of the vehicle to detect oncoming traffic at T-intersections, as well as a rearward-facing one.

Short-range sensors were added at each corner of the vehicle to increase its awareness of what was around it.

Meanwhile, a forward-facing colour camera was used to monitor traffic lights, while a rear-facing camera picked out predefined landmarks to help the car confirm where it was in the world more accurately than the GPS system would allow.

It wasn’t all a dream run for the S-Class, though. Mercedes-Benz said the drive showed it still needs to do more work on recognising traffic lights – an engineer was behind the wheel of the car ready to take control at any time – and roundabouts presented a unique set of problems.

At times, too, it was a bit of a laugh as the car tried to make sense of a situation by taking the most cautious approach.

"This sometimes results in comical situations, such as when, having stopped at a zebra crossing, the vehicle gets waved through by the pedestrian – yet our car stoically continues to wait, because we failed to anticipate such politeness when we programmed the system," Daimler Group Research and Advance Development head of driver assistance and suspension systems, Ralf Herrtwich, said.

Car-makers are stepping up the race to develop an autonomous vehicle. Volvo says it will develop what it calls an uncrashable car by 2020, while Nissan announced earlier this month that it would also have a self-driving car by the end of the decade.

However, it is not without its challenges. Honda recently scored a four-star crash rating for its Accord despite the newly-designed large car rolling out a raft of driver-assist technologies to give it a safety edge over competitors.