Forget cameras, GPS, and laser sensors. To ensure that self-driving cars can accurately locate the edges of driving lanes, Volvo is experimenting with a decidedly low-tech solution: magnets. By embedding magnets in the roadway, Volvo hopes to provide a system that allows autonomous cars to more precisely follow roads.
The system consists of small ferrite magnets placed 7.9 inches below the road surface. Special sensors at the bottom of the Volvo test cars detect the magnets and determine the location of the road edges or lane markings. The company is currently testing this system on a special section of pavement at its test track in Sweden. Volvo says this allows its cars to locate themselves with an accuracy of less than four inches — far better than can typically be achieved with GPS.
“The magnets create an invisible ‘railway’ that literally paves the way for a positioning inaccuracy of less than one decimeter [3.9 inches],” Volvo preventive safety leader Jonas Ekmark said in a statement. “It is fully possible to implement autonomous vehicles without changes to the present infrastructure. However, this technology adds interesting possibilities.”
Even before getting to autonomous cars, Volvo expects that the magnets could be used for other driver safety systems. By detecting the magnets lining the edge of a road, for instance, a car could detect if it was about to drive off the edge of the road. Because the magnetic system is so accurate, Volvo posits that lanes could be narrower as cars will be able to keep themselves within the lane. Finally, the system works even if the road is covered by snow, meaning snow plows could use the magnetic markings to accurately plow roadways without missing the edge of a road of veering of it onto the curb.
Volvo is investing heavily into autonomous car research as part of its goal to reduce injuries or deaths in Volvo cars to zero by the year 2020. The Swedish automaker plans to test a fleet of 100 self-driving cars on Swedish roads starting in 2017, and has demonstrated a car that can park itself without a driver on board.