Engineers seeking better ways to stabilize drone cameras for better video images say they've taken inspiration from nature — specifically from geese and swans, who can hold their heads completely still while flapping and flying.
Using high-speed video cameras and computer models, researchers at Stanford University have discovered that swans have a complex neck tuned like a car's suspension, which lets them stabilize their heads even during aerial acrobatics.
A built-in method of vision stabilization that compensates for the up-and-down body motions resulting from flapping wings is common to all birds — but before now, scientists have only been able to study the phenomenon in walking birds. Revealing the secrets of how they do it during flight has been impossible.
Stanford mechanical engineering professor David Lentink has compared high-speed video footage of swans in flight with computer models designed to simulate the supple damping effect of the birds' necks.
The muscles and vertebrae of the birds' necks respond with the right combination of flexibility and stiffness to keep their heads steady during flapping flight, in much the same way a car's suspension system allows a smooth ride over bumpy road surfaces, the researchers report in Interface, a journal of the Royal Society.
"This simple mechanism is a remarkable finding considering the daunting complexity of avian neck morphology with about 20 vertebrae and more than 200 muscles on each side," said Lentink, the study's senior author.
A former graduate student of Lentink, Ashley Pete, first came up with the concept and the study methodology while taking Lentink's Biomechanics of Flight class at the university.
"The paper she wrote for this class was so good that we expanded it together and submitted it to Interface, where it got published," Lentink said. "This really shows students can make remarkable discoveries in the classroom, going beyond textbooks, based on their creativity and enthusiasm."
Lentink and students in his lab are pursuing the goal of better design and performance in camera-carrying drones, based on an understanding of some key flight characteristics of birds.
One of Lentink's undergraduate students, Marina Dimitrov, is developing a swan-inspired prototype camera suspension technology that could lead to improved video capture from drones with flapping wings (see video below.)
