Engineers have developed a prototype drone that dives like a gannet and launches like a flying fish in order to collect water samples more efficiently and cheaply than current methods.
The AquaMAV robot, developed by researchers at the Imperial College London, uses carbon dioxide, which is stored internally, to propel itself out of the water, and when in the air, retractable wings are deployed to help it glide, much in the same way that fins help flying fish. These ‘impulsive’ leaps from the water solve current drawbacks for small scale flying robots, which generally lack sufficient power to make the transition from water to the air.
The drone’s plunge diving approach, which mimics how the gannet dives into the sea to hunt fish, reduces the need for highly accurate control and lowers manufacturing costs.
The AquaMAV is designed to collect samples in situations such as monitoring water quality in reservoirs and measuring changes in ocean salinity to gauge the effects of climate change.
Currently, researchers generally have to use boats to manually collect water samples. The Imperial engineers said that the AquaMAV is designed to be rapid, efficient, and more cost effective than this method. It can also carry out tests in dangerous situations such as in disaster zones or from locations currently inaccessible to people, such as deep under the ocean.
The drone weighs 200g and can currently achieve speeds of around 30mph from a starting point beneath the water, and can make the aerial leap even if conditions on the surface are rough. The researchers said AquaMAV can currently fly around 5km to and from an analysis, which would enable those analysing the samples to be at a safe distance away from a potentially hazardous situation.
The research, part funded by the Engineering and Physical Sciences Research Council, is published in the journal Interface Focus.
Dr Mirko Kovac, the director of the Aerial Robotics Lab in Imperial's Department of Aeronautics, said: "During an emergency scenario such as a major oil leak, an AquaMav could fly and dive into an isolated patch of water, where it could collect samples or loiter and record environmental data. The vehicle could then perform a short take-off and return to its launch site to submit samples for analysis. This would enable a fast, targeted response that could not be matched by the current methods."
Previous studies have demonstrated the effectiveness of water sampling using drones that have large multi-rotational propellers. Imperial researchers said that this approach is more complex, relying on very accurate sensing and control systems to maintain the drone in the air while sample probes are carefully lowered into the water to collect specimens.
The researchers aim to collaborate with oceanographers and various water authorities to test the robot's limits in waves, wind and weather, and examine the physics of high speed dives into water. An additional propulsion system is also under development to make the AquaMAV fully aquatic and capable of long periods of submarine operation.