Researchers at the University of British Columbia are utilizing camera-equipped pigeons to see how they use their vision during flight. This approach aims to improve autonomous drone flights.
The researchers discovered that pigeons use their eyes in a very ingenious way during flight and landing. Instead of fixing their eyes on one spot during landing, pigeons make slow, subtle eye movements, allowing them to better take in their surroundings.
Subtle eye movements
The researchers discovered that pigeons move their eyes very subtly during flight. That goes against expectations, according to researcher Anthony Lapsansky. It provides valuable information if you keep your eyes still when you move.
“If you walk through a hallway, you know that you are walking in the middle, because both walls move just as fast,” Lapsansky gives as an example. “But if you get too close to one of the walls, it seems to move much faster.”
The idea was therefore that pigeons keep their eyes still during flight, to prevent their eye movements from disturbing this visual information. But instead, the researchers saw that the pigeons move their eyes very subtly. “Possibly they do this to distinguish finer details or to see features of their environment that help them with navigation,” says Lapsansky.
The Hardware Burden: 27 Grams of Avionics
Anthony Lapsansky, who has experience as a falconer, sewed custom-made helmets and backpacks for the equipment. This consisted of, among other things, a minicomputer, a small camera, and a sensor to measure movement and orientation. In total, the pigeons carried about 27 grams of equipment with them.
The researchers of the University of British Columbia deliberately chose to use the pigeon in their experiment. “They are representative of many birds,” explains Doug Altshuler, one of the researchers. “Their eyes are located on the side of their head, giving them almost panoramic vision. In addition, they are easy to train and they always fly home, so you don’t have to worry about losing them.”
Stereoscopic Depth and the Landing Paradox
Another surprise was that pigeons turn both eyes inward when they land on a branch. That indicates that the birds may have stereoscopic vision—estimating depth by looking with each eye separately. Until now, this ability has only been observed in a few birds of prey.
Bridging the Gap to True Autonomous Flight
According to the researchers, the pigeon’s eye techniques can also improve drone flights. Most drones have a fixed camera, and the motion sensor tells the drone how fast it is flying, in which direction, and whether or not it will collide with an object.
“Birds use their vision to do all these things, but they also move their ‘cameras’ to get even more information from the environment. It is all more complicated than we initially thought,” says Lapsansky.
The researchers see possibilities to apply the pigeon’s strategy in autonomously flying robots or drones. “That would make them more ‘animal-like’,” says Lapsansky. In other words: better at navigating complex environments and closer to performing a truly autonomous flight.
The 30-Second Verdict
The researchers hope to improve autonomous drone flights with their findings.
