Volvo uses magnets to keep self-driving cars on the road
By Darren Quick
March 11, 2014
Volvo is continuing its work on autonomous vehicle technology with a research project that involves the use of magnets to keep self-driving cars on the road. As well as preventing cars from running off the road, the Swedish automaker says the technology could help improve road maintenance and allow for lanes to be narrowed.
The recently-completed research project took place at Volvo's testing facilities in Hällered, Sweden. This is just outside Gothenburg, the city hosting Volvo's large-scale autonomous driving project which will see 100 self-driving cars using public roads in everyday driving conditions. It's also the city where Gizmag's James Holloway got to take a ride in a car packed with some of Volvo's autonomous driving technology.
In an attempt to overcome the limitations of other positioning technologies, such as GPS and cameras, which can struggle in certain locations and conditions – in tunnels and thick fog, for example – Volvo Cars' research team embedded round ferrite magnets measuring 40 x 15 mm at a depth of 200 mm below the surface of a 100-meter long test track. A test vehicle equipped with several magnetic sensors was driven on the road at a range of speeds.
"Accurate, reliable positioning is a necessary prerequisite for a self-driving car," says Jonas Ekmark, Preventive Safety Leader at Volvo Car Group. "The magnets create an invisible 'railway' that literally paves the way for a positioning inaccuracy of less than one decimeter (10 cm/4 in)."
Ekmark says that it would be entirely possible to put autonomous vehicles on the road without changes to present infrastructure, but that the magnet-based positioning technology offers benefits other than just keeping self-driving cars on the road. Preventing damage to snow-covered objects by winter road maintenance crews and enabling lanes to be narrowed are just two other possibilities provided by the accurate positioning information provided by road-integrated magnets.
"Our experience so far is that ferrite magnets are an efficient, reliable and relatively cheap solution, both when it comes to the infrastructure and on-board sensor technology," says Ekmark. "The next step is to conduct tests in real-life traffic."
The research was carried out with financial support from the Swedish Transport Administration (Trafikverket), which is interested the potential of the technology.
"The test results are very interesting, especially when adding the potential for improved safety as well the advantages for the development of self-driving vehicles," says Claes Tingvall, Traffic Safety Director at the Swedish Transport Administration. "A large-scale implementation of road magnets could very well be part of Sweden’s aim to pioneer technology that contributes to sustainable mobility."