Four-Legged 3D-Printed Robot Swarms Work Together to Navigate Obstacles, Cross Gaps

Roboticists at the University of Notre Dame and the Georgia Institute of Technology have developed a new family of multi-legged robots designed to operate in swarms — collaborating to deal with varying terrain and obstacles in tehir path.

"Legged robots can navigate challenging environments such as rough terrain and tight spaces, and the use of limbs offers effective body support, enables rapid maneuverability and facilitates obstacle crossing," first author Yasemin Ozkan-Aydin, assistant professor of electrical engineering at the University of Notre Dame, explains. "However, legged robots face unique mobility challenges in terrestrial environments, which results in reduced locomotor performance."

"When ants collect or transport objects, if one comes upon an obstacle, the group works collectively to overcome that obstacle. If there’s a gap in the path, for example, they will form a bridge so the other ants can travel across — and that is the inspiration for this study," Ozkan-Aydin continues. "Through robotics we're able to gain a better understanding of the dynamics and collective behaviors of these biological systems and explore how we might be able to use this kind of technology in the future."

The ant-inspired quadrupedal robot prototypes, measuring 6-8 inches apiece, were built using a 3D printer and equipped with a microcontroller, battery, and a suite of three sensors: A light sensor at the front and magnetic touch sensors at the front and rear, designed to allow the robots to connect in a chain.

"You don’t need additional sensors to detect obstacles," Ozkan-Aydin claims, "because the flexibility in the legs helps the robot to move right past them. They can test for gaps in a path, building a bridge with their bodies; move objects individually; or connect to move objects collectively in different types of environments, not dissimilar to ants."

The prototype robots proved more than capable over a range of terrains, and could even operate in a simple swarm - sending a signal to rescue a trapped robot, with the remainder linking up to provide support - though there is work still to be done. "For functional swarm systems, the battery technology needs to be improved,” Ozkan-Aydin explains. "We need small batteries that can provide more power, ideally lasting more than 10 hours. Otherwise, using this type of system in the real world isn't sustainable."

"You need to think about how the robots would function in the real world, so you need to think about how much power is required, the size of the battery you use. Everything is limited so you need to make decisions with every part of the machine."

The work has been published under closed-access terms in the journal Science Robotics.