Self-Driving Convoy

Autonomous vehicle technology doesn't come in just one variety. Just look at Google's fully self-driving approach, which takes humans completely out of the equation, versus automakers' use of advanced driver assistance systems.

Nextcar Bug artMany industry experts and policymakers also predict that onboard self-driving technology alone won't be enough to get the zero-accident, full-autonomy future we've been promised, and that vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication will be needed as an extra layer of safety for robo-cars. And while self-driving cars get a lot of attention, many observers expect that the commercial trucking industry will help push adoption of the technology given the significant safety and economic benefits it can provide for businesses.

All of these points were proven this week when several truck makers and their technology providers demonstrated on public roads in Europe a concept known as "platooning," which lets groups of semis travel in semi-autonomous convoys. The trip involved about a dozen big rigs rolling from their respective home bases and traveling more than 1,200 miles and over four borders to the Netherlands port city of Rotterdam as part of the European Truck Platooning Challenge.

The Challenge was designed to not only show the viability of the technology and its benefits, but also how it can transcend individual borders in the European Union and, more specifically, the varying regulations of each EU country. And it could have implications not only for truck travel, but also cars and traffic.

Self-Driving Convoy

Follow the Leader Trucking
While the trucks use some of the cameras, sensors, and software essential for self-driving, the main technology component is an advanced V2V communications system from NXP Semiconductors developed by NXP and Cohda Wireless called RoadLink. The system employs a dedicated wireless transmission standard for V2V that incorporates Dedicated Short Range Communication (DSRC), similar to the technology the U.S. government eventually intends to mandate for passenger cars.

"Radar and cruise control have a sense of what's ahead by a certain distance," said Maurice Geraets, senior director of business development for NXP. "But to enable platooning, you need more than that; you need to know in real time what the lead truck is doing so that all the trucks in a platoon can react simultaneously within milliseconds."

RoadLink allowed the trucks in the trial to do this by securely exchanging information in real time so that each can automatically brake and accelerate in conjunction with the lead truck. This in turn let the trucks travel together at 50mph in a tight pack, with only 30 feet between each vehicle.

"With just radar, the truck couldn't react in time, so that's complemented with V2V technology," Geraets said, noting that the reponse time of the RoadLink system is 35 times faster than that of a normal driver. The technology doesn't allow for fully autonomous driving, partly on purpose, Geraets added.

While the distance-keeping is fully automatic and all but the lead driver doesn't have to accelerate or brake, the rest do have to steer. "That's assisted by lane-keep warning," Geraets said. "We could have enabled full lane-keeping technology, but for this trial it was decided that we would focus on distance-keeping. If the drivers don't have anything to do, they may get distracted and would still need to be able to take over control of the truck."

Self-Driving Convoy

The trucks also don't just blindly behind the leader. "If you're the second driver, you don't really see a lot except the truck in front in you," Geraets said. So the RoadLink system also provides real-time video so that drivers of the platooning trucks can see what's outside of the lead truck's windshield.

If you're worried about having to pass a dozen slow-moving semis instead of just one on the interstate, platooning probably won't happen too soon. "There is still a lot of continued development required before we can introduce platooning as a new technology on the market," said Ron Borsboom, head of product development for Europe's DAF trucks. "This is definitely not a process that will be complete before 2020."

And as with self-driving cars, "there is still a great deal that has to be sorted out in terms of legislation, liability, and acceptance," Borsboom added.

"There are technical aspects to it as well as legislative aspects," Geraets explained. "For example, each country has their own rules on traffic and following distances between vehicles that currently willl not enable platooning."

"This demonstration should pave the way for truck manufacturers to be allowed to carry out further testing of the technology on public roads in order to acquire even more experience," Borsboom added. "It is now up to politicians to make this possible."