You know you have entered the third dimension, a twist on the Hollywood film Minority Report, when your car warns you of impending collision. EU-funded researchers are bringing this dimension to next-generation vehicles dealing with complex driving environments.
It’s 22 November, an overcast day in Wolfsburg, the German headquarters of Volkswagen. Researchers and experts in advanced driver assistance systems (ADAS) and satellite navigation are on hand to witness the final demonstration of the GENEVA ‘Urban Assist’ project. 'Geneva' stands for ‘Galileo/EGNOS Enhanced Driver Assistance’.
Of course, such systems are not new – we’ve had ABS for decades. Nor are satellite-based driver assistance systems – satnav devices the world over tell us to “prepare to turn left”. But the Geneva consortium of leading European industrial research groups, including heavyweights like Volkswagen, TomTom (Tele Atlas) and Fraunhofer IIS, have taken these two complementary fields to the next level.
Driver assistance applications help the driver by monitoring the traffic situation. Geneva’s goal was to design and implement as cost-effectively as possible an intersection assistance system which warns the driver in critical situations, such as oncoming traffic or crossing pedestrians. But urban areas and especially intersections are notoriously complex scenarios to map out.
The special system developed by Geneva for urban areas stands out because it has highly accurate vehicle positioning and robust measures to monitor the integrity of the data (see box). “It’s also a very scalable solution,” suggests the project coordinator Andreas Kahmann Technical Director of OECON, the telematics specialist.
Left turn, stop!
Of the 1.3 million EU-27 road accidents, 570,000 (46%) occur at intersections. Bearing this in mind, at the start of the two-year Geneva project, the partners decided to focus on two important but complex driving hazards at a typical intersection: the left turn and stop line when the traffic lights signal ‘stop’.
ADAS on the market include recognised technologies like automatic braking systems, lane-and distance-keeping assistance, black-spot monitoring, night vision, frontal-collision warning, and parking assistance. But there are no such intersection-assistance systems currently available.
This is because intersections are very busy with different road users coming from different directions, explains Bernd Rössler who specialises in autonomous vehicles at VW. It’s a very complex and hard problem to resolve technically, but the Geneva team knows that with improvements in satellite signals and receivers, and the prospect of more powerful and low-cost microsystems, their work will pay off.
For instance, Günter Rohmer of Fraunhofer IIS stresses the importance of receivers that achieve sub-metre geo-positioning accuracy from “raw signals” – without correction data from outside services. This is possible with a multi-constellation approach, with more satellites visible than what you have today, and building on new features of Galileo and a modernised GPS as the two civil frequencies that will be transmitted (E1/E5 or L1/L5). “Processing the two GPS-Galileo frequency signals is a big challenge,” he says. Going forward, they are synching their work schedule with the Galileo rollout of 18 satellites (from 2014) and GPS with its 12 to 14 satellites with dual frequency signals. For Geneva, they developed a more cost-efficient receiver compared to the dual frequency receivers on today’s market which can run into the thousands of euros, according to Rohmer. They plan to bring the cost down even further, ultimately to below €10 which would then be accurate and cheap enough for car-makers.
But the complexity of Geneva’s task is not only technical, suggests Thomas Ruchatz of VW who quotes some telling figures on the reasons for fatal road accidents (38% mental, 46% misinterpretation, 11% unexpected behaviour, 5% technology). “We need to work on the human factors,” he concludes.
Bringing it all together
The ADAS developed by Geneva support the driver by monitoring the traffic situation. “Using modern technology like this increases the safety and security of vehicle passengers during an accident, but even more importantly, prevents the accident happening,” notes Kahmann. “That’s why the number of fatalities and serious injuries in road traffic has declined consistently in recent decades.”
The technology that Geneva has now demonstrated determines in which lane the car is travelling and what implications this has at the next intersection. To do this, satellite navigation signals have to be combined with sensors, such as odometers or inertial sensors, and accurate maps. Other information, including the car indicator or data from onboard stereoscopic cameras, helps the Geneva system reliably establish position, speed and trajectory as it approaches an intersection.
“Information about the position of all vehicles at an intersection itself can then be exchanged using car-to-car or car-to-infrastructure communication,” adds Kahmann. Onboard radar and lidar sensors also help the car recognise other road users like cyclists and pedestrians.
With all this data, the car can determine if the driver is in imminent danger and issue appropriate warnings (audio, visual and tactile through the brakes). “The car gives the driver easy-to-understand but not invasive instructions which can save his or her life,” says Kahmann. This is an important element of telematics; the car’s instructions and functions should not distract or over-burden the driver who already has a lot of information to process.
Natural-born applications
Today’s ADAS are already capable of ‘reading’ the traffic situation, both static (i.e. lanes, stop lines) and dynamic (other road users, changing traffic lights). But to support drivers in complex situations like intersections, the vehicle needs highly accurate location information. And this is where satellite navigation comes in which combine GPS, EGNOS and Galileo to provide current and accurate positioning.
EGNOS is the European Geostationary Navigation Overlay Service which provides corrected data that can boost the accuracy of current GPS signals. Civil aviation authorities are currently using it and a number of early adopters can be found in the road haulage sector, according to Fiammetta Diani of the European GNSS Agency (GSA), which oversees EU-funded research and activities promoting the development and take-up of Galileo and EGNOS.
“With two satellites now in place, Galileo is becoming a reality,” she told the Geneva gathering. It’s not necessary for full deployment to start using it because it’s compatible with GPS, she suggests. “It’s seamless.”
Urban Assist was already under development at VW before Geneva started, stresses Diani, but there wasn’t an affordable state-of-the-art receiver with accurate and extremely reliable GNSS-enabled functionality inside. “Now, they have developed a [suitable] GNSS solution which has realistic potential for a mass market application of the system.” That’s good news for GNSS as it expands beyond Europe and into new application areas. The results of the project demonstrate how European satellite navigation initiatives can support the continent’s automotive industry.
But how long before we will see this technology saving lives on our roads?
That’s a question no one in Geneva can answer with any certainly right now. More precise maps and positioning are needed, even in tunnels and built-up areas. Investment in updating road infrastructure is needed. More affordable sensors, microprocessors and receivers are essential. Driver behaviour and attitude also needs to be factored in.
“There are so many gates to pass through before it can be widely deployed,” says VW’s Marc-Michael Meinecke. But once they are resolved, one thing is for sure; our cars will have a talent that most drivers would envy … foresight!
Geneva was partly funded by the European Commission’s Seventh Framework Programme for research through the GSA. Geneva consortia: OECON Products & Services (DE), Volkswagen (DE), Fraunhoffer IIS (DE), TeleConsult Austria (AT), TomTom International (NL), NavCert (DE), The 425 Company (UK), Technical University Braunschweig (DE), Institute de Geomàtica (ES).
Integrity is important
Geneva needs detailed and reliable data to get an accurate interpretation of the real situation at the intersection. One possibility is to download map data to the car from external servers to ensure reliability as it approaches the intersection. Standard maps can be quite chunky, but Geneva’s maps are “generated extended maps” with downloaded overlays of detail on top of the “initial guess” from the extended map. With that, the vehicle has the detail needed to do a risk assessment.
Integrity measures – used to activate and deactivate the urban assistance function if needed – combine different sources of information, including landmark detection, satnav and camera data which are cross-referenced to map data. If a difference is detected, the car will indicate it on the dash and Urban Assist will be disarmed.
