Designing drones that drive as well as fly adds versatility

Being good at one mode of transportation is no longer a measure of success when it comes to developing next-gen robotics. Researchers are looking at different ways to make robots and drones more versatile by enabling multiple transportation methods.

One of the researchers’ quadcopter drones with wheels. Photo credit: Brandon Araki/MIT CSAIL.

For the most part, airborne drones are able to maneuver the skies quickly and with agility. However, they have limited battery life to travel any significant distance. Ground vehicles are energy efficient but tend to be much slower options with limited mobility.

Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) are developing robots that can effectively traverse on land and take to the skies.

The team presented a system of eight quadcopter drones that can fly and drive through a city-like setting with parking spots, no-fly zones, and landing pads.

“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,” says PhD student Brandon Araki, lead author on the paper. “Normal drones can’t maneuver on the ground at all. A drone with wheels is much more mobile while having only a slight reduction in flying time.”

Araki and CSAIL Director Daniela Rus developed the system, along with MIT undergraduate students John Strang, Sarah Pohorecky, and Celine Qiu, and Tobias Naegeli of ETH Zurich’s Advanced Interactive Technologies Lab.

Araki previously developed a robot called “flying monkey” that can crawl, grasp and fly. When it come to this project, Araki is building on the successes of “flying monkey.” However, one of the current challenges is that 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 don’t collide. To make them capable of driving, the team put two small motors with wheels on the bottom of each drone. In simulations, the robots could fly for 90 meters or drive for 252 meters, before their batteries ran out.

Although enabling the drone to drive reduced battery life, the efficiency from driving more than offset the relatively small loss in efficiency in flying due to the extra weight.

“This work provides an algorithmic solution for large-scale, mixed-mode transportation and shows its applicability to real-world problems,” says Jingjin Yu, a computer science professor at Rutgers University who was not involved in the research.

The team tested eight robots navigating from a starting point to an ending point on a collision-free path, and all were successful.

According to Rus, systems like theirs suggest that another approach to 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.

“As we begin to develop planning and control algorithms for flying cars, we are encouraged by the possibility of creating robots with these capabilities at small scale,” Rus says. “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.”

www.mit.edu