Flying blind is a notoriously risky situation for a person, and it's not a great option for robots, either. However, for a tiny drone, the gift of human-made sight comes in an impractically large package.
Digital cameras have been the primary way of providing drones with vision, but even the smallest digital camera is still bulky for a drone the size of a large insect. This is a problem that has slowed the progress of the small autonomous flying robots, yet nature, of course, figured out a solution for small-scale sight millennia ago.
Studying insect vision led scientists to develop an "artificial eye" so small that it weighs in at a mere 2 milligrams, according to their report in the journal Interface. A U.S. dime, for reference, weighs more than 1,000 times that much. In size, the new sensor is comparable to a sesame seed.
Insect eyes are able to achieve adequate sight with such tiny equipment because they make a key compromise. The vision they afford is very low-resolution, but these eyes are great at picking up on movement and changes in light in the surrounding environment.
For successful navigation, all that a drone needs are basic eyes like this. The sensor that the scientists created accomplishes this by laying a lens atop three electronic photodetectors. These photodetectors are arranged in a triangle so that the drone can use a preprogrammed algorithm to compare measurements from all three to hone in on the speed and direction of motion that the sensor picks up.
These "artificial eyes" are a great option for drones that weigh 50 grams or less, since they can only lift loads of a few grams at most, according to MIT Technology Review. Such small autonomous flying vehicles would be most useful for tasks such as surveillance or delivering supplies to people in disaster areas.
Photo: Charles Lam | Flickr