Author: Tronserve admin
Saturday 31st July 2021 06:55 AM
Swarm Robots Mimic Ant Jaws to Flip and Jump
Small robots are attractive because they’re simple, cheap, and it’s easy to make a lot of them. Unfortunately, being simple and cheap means that each robot personally can’t do a whole lot. To make up for this, you can do what insects do—leverage that ease and low-cost to just make a huge swarm of simple robots, and together, they can work together to carry out relatively complex tasks.
Using insects as an sample does set a bit of an unfair expectation for the poor robots, since insects are (let’s be genuine) usually smarter and much more flexible than a robot on their scale could ever hope to be. Most robots with insect-like capabilities (like DASH and its family) are really too big and complex to be turned into swarms, because to make a vast amount of small robots, things like motors aren’t going to work because they’re too expensive.
The concern, then, is to how to make a swarm of affordable small robots with insect-like mobility that don’t need motors to get around, and Jamie Paik’s Reconfigurable Robotics Lab at EPFL has an answer, empowered by trap-jaw ants.
Let’s talk about trap-jaw ants for just a second, because they’re ridiculous. You can understand this 2006 paper about them if you’re mainly curious in insane ants (and who isn’t!), but if you just want to listen the insane bit, it’s that trap-jaw ants can fire on their own into the air by biting the ground (!). In just 0.06 millisecond, their half-millimeter long mandibles can close at a top speed of 64 meters per second, which works out to an acceleration of about 100,000 g’s. Biting the ground causes the ant’s head to snap back with a force of 300 times the body weight of the ant itself, which launches the ant upwards. The ants can fly 8 centimeters vertically, and up to 15 cm horizontally—this is a lot, for an ant that’s just a few millimeters long.
Trap-jaw ants can fire themselves into the air by biting the ground, causing the ant’s head to snap back with a force of 300 times the body weight of the ant itself
EPFL’s robots, named Tribots, look almost nothing at all like trap-jaw ants, which for me I am fine with. They’re about 5 cm tall, weighing 10 grams each, and can be built on a flat sheet, and then folded into a tripod shape, origami-style. Or maybe it’s kirigami, because there’s some cutting involved. The Tribots are fully autonomous, meaning they have onboard power and control, including proximity sensors that allow them to detect objects and avoid them.
Preventing objects is where the trap-jaw ants come in. Using two unique shape-memory actuators (a spring and a latch, similar to how the ant’s jaw works), the Tribots can move around using a bunch of different techniques that can adapt to the terrain that they’re on, including:
Vertical jumping for height
Horizontal jumping for distance
Somersault jumping to clear obstacles
Walking on textured terrain with short hops (called "flic-flac" walking)
Crawling on flat surfaces
Tribot’s optimal vertical jump is 14 cm (2.5 times its height), and horizontally it can jump about 23 cm (almost 4 times its length). Tribot is actually quite streamlined in these movements, with a cost of transport much lower than similarly-sized robots, on par with insects themselves.
Working together, small groups of Tribots can complete tasks that a single robot couldn’t do alone. One illustration is pushing a heavy object a set distance. It turns out that you need five Tribots for this task—a frontrunner robot, two worker robots, a monitor robot to determine the distance that the object has been pushed, and then a messenger robot to relay communications around the obstacle.
The scientists recognize that the current version of the hardware is limited in pretty much every way (mobility, sensing, and computation), but it does a sensible job of displaying what’s possible with the concept. The plan going forwards is to speed up fabrication in order to "enable on-demand, ’push-button-manufactured’" robots.
This article is originally posted on IEEESPECTRUM.com