- Published in Technology.
BMW is developing autonomous driving functions capable of overtaking and lane changes on motorways at up to 130km/h. If the technology makes it to series production the firm hopes it will make high speed driving on motorways safer and less tedious for drivers.
Adaptive cruise control (ACC) is the starting point for the system, but additional, redundant sensors make the vehicle more intelligent and capable of acting, effectively, as an autopilot. The engineers from BMW Group research and technology working on the system have already completed 5,000km of testing using a 5 Series sedan.
Project manager for highly automated driving, Dr Nico Kämpchen, said: “This is an entirely new experience for the driver – it's a strange feeling handing over complete control to an autonomous system. But after a few minutes experiencing the smooth, safe driving style, drivers and passengers begin to relax and trust it. But the driver is still responsible at all times and must constantly keep an eye on traffic and the surroundings.”
For the system to work the vehicle must know where it is, and know what other vehicles and objects are around it. Sensor fusion is the solution. As well as the ACC system's forward-looking long-range radar and the lane departure warning system's video camera, the test car has additional radar sensors plus lidar and ultrasound to detect and classify objects in front, behind and to the sides of the vehicle.
The combination of GPS, digital map data and camera data tells the vehicle its position within its own lane, how many lanes the road has and what the speed limit is. The vehicle is also able to read no overtaking signs.
The system becomes active at the push of a button. When active the system controls acceleration and braking, passing of slower vehicles and merging with other traffic at junctions. To do this the prototype can either allow other vehicles to join the lane or it can change lanes to let them in.
The next stage in development is to make the system good enough to cope with road works. Average speeds are lower but density is much greater and lane markings – especially temporary ones – can be more complex and also harder for cameras to read. This poses great challenges for the lateral guidance algorithms controlling the vehicle's steering.
“Construction sites are a big challenge because they take on all kinds of forms, which makes detection, localisation and determining the right vehicle response quite difficult,” said Kämpchen.