There’s an entire field of science that believes nature and evolution have already solved some of humanity’s most complicated problems. Called biomimetics, the field focuses on studying these natural solutions and attempting to copy them, rebuild them, and use them in ways that can benefit mankind. This past month, we’ve been profiling US laboratories that specialize in biomimicry and highlighting how the animal kingdom is helping humans innovate.
When you’re trying to perfect robotic flight the obvious biological animal to mimic is, of course, the bird. But what’s less obvious is just how exactly you go about quantifying the physical capabilities of motion and engineering while in flight. At David Lentink’s lab at Stanford he is combining specially trained animals with high-tech motion capture to puzzle out just what it is about bird wings that make them such fantastic flyers.
Lentink has trained hummingbirds and parrotlets to perform special maneuvers -- flying from point A to point B -- so that he can capture images of them in motion. With high-speed cameras he can capture 50 images for each wing beat. In addition, using two high-speed lasers that flash from 1,000 to 10,000 times per second, Lentink is able to create an image of how the air flows behind the birds as they fly.
“Our goal is to understand the flow and the forces they generate when they fly and we developed special instruments to do that. You can’t work with a bird like an airplane. We train our birds based on food rewards. So now we point to perch where they need to fly to and they will fly there,” says Lentink. “We’re trying to discover how birds manipulate air to fly more effectively and move better.”
In addition to studying wing movement and the manipulation of air, Lentink and his team have started to research the bird’s vision and how it combines with their wing movements to determine direction. “What do they see and how do they use what they are seeing to control their flight? The main thing we’re looking at is optical flow, something that robots also use. How images move over the retina, the intensity of images over the retina, and how birds use that to decide to go left, right, or stabilize,” he says.
It may sound like very fundamental research, he says, but it’s essential if there’s any hope of building a future robot that can fly like a bird. Especially when you consider the limitation of current flying robots. Quadcopters, according to Lentink, aren’t good at maneuvering through turbulence, around buildings, or through trees and narrow spaces. Yet at the moment they’re our most popular flying bot. Birds, on the other hand, don’t have any trouble performing any of those difficult tasks.