Drones based on birds soar above their limits Tuesday, 12 April 2016

As drone technology continues to develop, new opportunities are opening for the industrial and commercial use of drones. However, battery life and flight times limit their application in some areas. Researchers at RMIT University are using smart engineering to increase the amount of time drones can spend in the air.

The Unmanned Aircraft Systems Research Team, led by Professor of Engineering Simon Watkins, based their work on the natural flight patterns of birds. This bio-mimicry led to the first soaring drone that utilises updrafts around buildings to stay airborne.

A drone that includes features that allow it to exploit updrafts, the researchers claim, can sustain itself in the air for five times longer than conventional commercial designs that are driven solely by a propeller.

Updrafts are currents of warm air that rise into the cooler air above. They are formed as air is pushed upwards by natural or man-made features like hills, mountains or buildings. Professor Watkins says the use of updrafts is an energy-efficient way to generate flight.

“Birds use updrafts to try to gain altitude or to try and extend their flight range and they do this as an energy saving method,” Watkins said.

“Using atmospheric winds allows a drone to sustain longer periods of flight and could also enable on-board batteries to be recharged by harnessing wind energy through the propellers.”

Consistency in wind strength and direction is key, of course, but predicting the location and behaviour of updrafts in an urban environment can be difficult.

The researchers sought to address the challenge by conducting complex simulations to understand the air flow environment, and identify “hotspots” around buildings where updrafts are strongest.

With this environmental intelligence in place, the researchers can then enhance the flight performance of drones by implementing physical bird-like features on them, including “feather-inspired turbulence systems” that can sense and track updrafts. These design features, together with the data from air flow simulations, will open the way to further developments of the technology.

The research team worked with the Defence Science and Technology Organisation on the project. Potential applications include disaster control, border patrol and infrastructure inspection to coastline and wildlife monitoring.

The improved efficiency would allow the drones to be more easily deployed across wide areas, and in remote parts of Australia, allowing them to be used to detect sharks, monitor wildlife on windy coastal sites, survey the land, etc.