New robotic drones can travel by land and air

MIT scientists have developed a system of eight robotic drones that can fly through the air as well as drive on ground, efficiently navigating cityscapes with parking spots, no-fly zones and landing pads.
Robots that are good at one mode of transportation are usually bad at another.
Airborne drones are fast and agile, but generally have too limited of a battery life to travel for long distances. Ground vehicles, on the other hand, are more energy efficient, but slower and less mobile.
Researchers from Massachusetts Institute of Technology (MIT) Computer Science and Artificial Intelligence Laboratory (CSAIL) are aiming to develop robots that can both manoeuvre around on land and take to the skies.

"The ability to both fly and drive is useful in environments with a lot of barriers, since you can fly over ground obstacles and drive under overhead obstacles," said Brandon Araki, PhD student at MIT.
"Normal drones can't manoeuvre on the ground at all. A drone with wheels is much more mobile while having only a slight reduction in flying time," said Araki.

The project builds on Araki's previous work developing a "flying monkey" robot that crawls, grasps, and flies.
While the monkey robot could hop over obstacles and crawl about, there was still no way for it to travel autonomously.

To address this, the team developed various "path- planning" algorithms aimed at ensuring that the drones do not collide.
To make them capable of driving, they put two small motors with wheels on the bottom of each drone. In simulations, the robots could fly for 90 metres or drive for 252 metres, before their batteries ran out.
Adding the driving component to the drone slightly reduced its battery life, meaning that the maximum distance it could fly decreased 14 per cent to about 300 feet.
However, since driving is still much more efficient than flying, the gain in efficiency from driving more than offsets the relatively small loss in efficiency in flying due to the extra weight.

The team also tested the system using everyday materials such as pieces of fabric for roads and cardboard boxes for buildings.
They tested eight robots navigating from a starting point to an ending point on a collision-free path, and all were successful.
Researchers suggest a better approach creating safe and effective flying cars is not to simply "put wings on cars," but to build on years of research in adding driving capabilities to drones.
"While there are obviously still big challenges to scaling up to vehicles that could actually transport humans, we are inspired by the potential of a future in which flying cars could offer us fast, traffic-free transportation," said CSAIL Director Daniela Rus.