Autonomous Trucks
From MIT news.

Now MIT engineers have studied a simple vehicle-platooning scenario and determined the best ways to deploy vehicles in order to save fuel and minimize delays. The findings may also apply to conventional long-distance trucking and even ride-sharing services. at MIT. “People who study these systems only look at efficiency metrics like delay and throughput. We look at those same metrics, versus sustainability such as cost, energy, and environmental impact. This line of research might really turn transportation on its head.”

Karaman is a co-author of the paper, along with Aviv Adler, a graduate student in the Department of Electrical Engineering and Computer Science, and David Miculescu, a graduate student in the Department of Aeronautics and Astronautics.

Pushing through drag ... Karaman says that for truck-driving — particularly over long distances — most of a truck’s fuel is spent on trying to overcome aerodynamic drag, that is, to push the truck through the surrounding air. Scientists have previously calculated that if several trucks were to drive just a few meters apart, one behind the other, those in the middle should experience less drag, saving fuel by as much as 20 percent, while the last truck should save 15 percent — slightly less, due to air currents that drag behind.
If more vehicles are added to a platoon, more energy can collectively be saved. But there is a cost in terms of the time it takes to assemble a platoon.



Karaman is currently working with trucking companies in Brazil that are interested in using the group’s model to determine how to deploy truck platoons to save fuel. He hopes to use data from these companies on when trucks enter highways to compute delay and energy tradeoffs with his mathematical model.

Eventually, he says, the model may suggest that trucks follow each other at very close range, within 3 to 4 meters, which is difficult for a driver to maintain. Ultimately, Karaman says, truck platoons may require autonomous driving systems to kick in during long stretches of driving, to keep the platoon close enough together to save the most fuel.

“There are already experimental trials testing autonomous trucks [in Europe],” Karaman says. “I imagine truck platooning is something we might see early in the [autonomous transportation] game.”



The researchers are also applying their simulations to autonomous ride-sharing services. Karaman envisions a system of driverless shuttles that transport passengers between stations, at rates and times that depend on the overall system’s energy capacity and schedule requirements. The team’s simulations could determine, for instance, the optimal number of passengers per shuttle in order to save fuel or prevent gridlock.

“We believe that ultimately this thinking will allow us to build new transportation systems in which the cost of transportation will be reduced substantially,” Karaman says.

This research was funded, in part, by the National Science Foundation.