Honeybees are inspiring scientists at Australia’s Vision Centre to help build a robot aircraft.
Bees are able to land anywhere with amazing precision and grace, and this skill could soon be included in future aircraft. Scientists found that honeybees are able to control their flight speed in time for a perfect touchdown without needing to know how fast they are flying or how far away the destination is.
Professor Mandyam Srinivasan of The Vision Centre (VC) and The University of Queensland Brain Research Institute said the discovery could lead to cheaper, lighter robot aircraft that only need a video camera to land safely on surfaces of any orientation.
“Orchestrating a safe landing is one of the greatest challenges for flying animals and airborne vehicles,” Professor Srinivasan, an author of a paper published in the Proceedings of the National Academy of Sciences, said in a press release. “To achieve a smooth landing, it’s essential to slow down in time for the speed to be close to zero at the time of touchdown.”
Humans use stereovision to help discern distances between objects. We are able to do this because we have two eyes with enough separation to enable us to capture different views of an object. Insects are unable to use stereovision because they have close-set eyes.
“So in order to land on the ground, they use their eyes to sense the speed of the image of the ground beneath them. By keeping the speed of this image constant, they slow down automatically as they approach the ground, stopping just in time for touchdown,” he said in the release. “However, in the natural world, bees would only occasionally land on flat, horizontal surfaces. So it’s important to know how they land on rough terrain, ridges, vertical surfaces or flowers with the same delicacy and grace.”
Researchers trained honeybees to land on discs that were placed vertically, and filmed them using high speed video cameras. The discs carried spiral patterns that could be rotated at various speeds by a motor, helping the team to see how a honeybee uses its speed to make a perfect landing.
“When we spun the spiral to make it appear to expand, the bees ‘hit the brakes’ because they thought they were approaching the board much faster than they really were,” Srinivasan said. “When we spun the spiral the other way to make it appear to contract, the bees sped up, sometimes crashing into the disc. This shows that landing bees keep track of how rapidly the image ‘zooms in’, and they adjust their flight speed to keep this ‘zooming rate’ constant.”
The team developed a mathematical model for guiding landings based on the bees’ landing strategy. Srinivasan said this visually guided technique does not require knowledge about the distance to the surface or the speed at which the surface is approached.
“The problem with current robot aircraft technology is they need to use radars or sonar or laser beams to work out how far the surface is. Not only is the equipment expensive and cumbersome, using active radiation can also give the aircraft away,” he said. “On the other hand, this vision-based system only requires a simple video camera that can be found in smartphones. The camera, by ‘seeing’ how rapidly the image expands, allows the aircraft to land smoothly and undetected on a wide range of surfaces with the precision of a honeybee.”
Source: Lee Rannals for redOrbit.com – Your Universe Online
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