This robotics lesson from elephant trunks packs a punch
Going from elephant trunks to robots seems like a leap of logic until you grasp the idea
Kelly the elephant snacked with her trunk ... and scientists said goodbye to some of their preconceived ideas about how to design robots.
It sounds like a non sequitur, but it’s not. That’s because elephants’ ability to pick up small objects could be the key to making robots more dextrous.
The experiments were done with a particularly social and active 35-year-old female African elephant at Zoo Atlanta in the US.
Kelly’s handlers offered her swede and carrot cubes of different sizes and piles of wheat bran. They were placed on a pressure plate, and the videotaped experiment measured the force the elephant applied to the piles of food and imaged the shape of her trunk when grabbing each object.
Scientists from the Rochester and Georgia technology institutes discovered that Kelly applied more force when trying to pick up a pile of small particles.
Reporting his findings in Interface, the journal of the Royal Society, physics professor Scott Franklin said: “It seems counterintuitive that you put more weight on something that you’re trying to pick up.
“But the reason that makes sense is that when you push down on this food, because it’s particulate, it forces all the food to squeeze together even more. The more tightly the food is squeezed together, the more likely the friction between the particles will be enough to allow you to pick it up.
“It is very difficult to develop a gripper that is flexible enough to pick up a variety of objects, for example, a single pen or a pile of pens, or a cube of Jell-O.
“The elephant trunk is a single thing; it doesn’t change shape at all, but it is able to pick up food of different sizes, weights and masses, so the idea is that this will give us insight and information into how nature has solved this problem of how to pick up multiple things and then we can try to reproduce it.”
Elephants graze nearly nonstop, and their boneless trunks form kinks or joints to compress small pieces of food into bite-sized morsels.
Zoo Atlanta describes Kelly as its “most engaging” elephant. “Some of her favourite activities are being with her keepers and getting lots of attention from them, painting, throwing mud on herself in her wallow, and scraping bark off of the logs in her habitat to snack on,” it says.
“Her favourite foods are watermelons, apples and her specialised elephant grain that she gets as a daily part of her diet.”