Mark Megahan
Now that we’ve pretty well mastered basic drone technology, the major focus has turned to power consumption. More specifically, any way to reduce it and prolong active operation. The obvious solution is flying around in front of everyone. Hawks and other soaring birds use minimal power in flight. The latest idea is to create a sort of hybrid powered glider.
Soaring drone in development
While the concept of a soaring drone is straightforward enough, there remain several bugs to be worked out of the design. Even so, engineers are well on the way to a final solution.
They’ve had a lot of luck with tests in the wind tunnel. The next step is field testing the concept in real world conditions and they aren’t quite ready for that yet.
Some researchers in the Netherlands are convinced that by “mimicking the techniques of nature’s flying creatures, they’ve designed a winged drone that can soar near effortlessly compared to its peers, almost never requiring powered flight to stay airborne.”
According to the lead author on a recent study, Sunyou Hwang, their 1.5 pound craft “only needed to use its propellers 0.25 percent of the time it spent hovering in place in a wind tunnel, compared to the 38 percent it needed for normal flight.” He’s an aerospace engineer at Delft University of Technology in the Netherlands.
The study hasn’t been peer reviewed yet but nobody is expected to have much in it to pick apart. The concept is called “orographic soaring.” That means they engineered a drone to ride updrafts of wind.
They can use air currents to “maintain a steady position, descending at just the right rate.” The first generation of their design didn’t use any propellers at all.
Imitating nature not easy
It turns out that “imitating the complex mechanics of biology is rarely easy.” The average condor can soar for “over five hours without flapping its wings once.” The best consumer drone on the market today has capability for perhaps half an hour of air time.
The thing that birds do instinctively but computer chips haven’t quite figured out is the “intuitive understanding of the wind, able to harness mercurial gusts as a captain does the sails of their schooner.”
They did, however, come up with an algorithm that works pretty close. Their new drone concept “takes in its airborne environment through a suite of sensors, including one for airspeed, a GPS system, and a camera.”
That means “when the wind field changes, it adapts to the environment and changes its position autonomously.”
So far, they were able to keep their drone without propellers aloft in the wind tunnel for half an hour, using power only for control surfaces and the sensors.
The next step, Jonathan Aitken, a professor of automatic control and systems at the University of Sheffield relates, is to “keep up with real world winds.” For that, the “algorithm will need to respond faster.“
