"Virtual bubble" for autonomous cars would mean goodbye traffic lights
Autonomous vehicles not only stand to make our lives safer, but could make them a whole lot more convenient as well. One way they could do this is by smoothing traffic flows through cities, and one technology that could play a part in this is a new algorithm developed by researchers in Singapore. The system would see autonomous cars adapt their speed to cross intersections inside a safe "virtual bubble," without ever needing to come to a stop.
The system was developed by a team at Singapore's Agency for Science, Technology and Research (A*Star) and the thinking is that by employing a mix of smart cruise control with inter-vehicle communications, we can one day do away with traffic lights and give everyone a smoother ride through town.
Such a system would work on a principle that the researchers call "adaptive repulsive force," which means that the closer two cars get to one another in their trajectories, the stronger they are pushed away. But this wouldn't involve last-minute swerving or braking, rather the system would take its cues from communication beacons installed in the vehicles that beam data on distance and speed as they approach the intersection.
All of the approaching cars push this data to an algorithm tasked with overseeing traffic for that particular intersection, which then maps a safe route through courtesy of an automated speed adjustment for each car. In its testing, the team tried out the algorithm simulating even relatively complex intersections, and found that even in those more extreme scenarios the speed adjustments didn't need to be overly drastic.
"In most cases, pre-emptive deceleration only slightly lowered the vehicle velocity, resulting in safe passage of each vehicle across the intersection without coming to a full stop at any point," says Bo Yang from the A*STAR Institute of High Performance Computing, who led the research.
While we're not saying goodbye to traffic lights and stop signs just yet, the team does say that the system wouldn't require fully autonomous vehicles to work and could therefore be rolled out gradually. Plenty of today's cars already have adaptive cruise control, and the fact that many don't wouldn't necessarily be a roadblock.
To begin with, traffic lights would remain in place to help older cars through intersections. But as adaptive cruise control capabilities become more commonplace, along with the type of beacons described in this research, the lights could start to switch off for longer and longer periods, only springing into action when an ill-equipped vehicle rolls into the area.
"Our simple algorithm only requires basic vehicle intelligence, but is also fully compatible with more intelligent vehicles that may come in the future," says Yang.
The research was published in the journal Transportation Research Part C: Emerging Technologies.
Source: A*Star Research