Researchers successfully build four-legged swarm robot

As a robotics engineer, Yasemin Ozkan-Aydin, an assistant professor of electrical engineering at the University of Notre Dame, draws inspiration from biological systems. The collective behavior of ants, bees and birds to solve problems and overcome obstacles is something that researchers have developed in aerial and underwater robotics. However, developing small-scale swarm robots with the ability to traverse complex terrain comes with a unique set of challenges.

In research published in Science Robotics, Ozkan-Aydin presented how he was able to create multi-legged robots capable of maneuvering in challenging environments and completing difficult tasks en masse while mimicking their natural-world counterparts. Was.

Ozkan-Aydin said, “Legged robots can navigate challenging environments such as rough terrain and tight spaces, and the use of limbs provides effective body support, enables rapid mobility and obstacle crossing.” provides facilities.” “However, legged robots face unique mobility challenges in terrestrial environments, resulting in reduced locomotor performance.”

For the study, Ozkan-Aydin said, she hypothesized that a physical connection between individual robots could enhance the mobility of a terrestrial legged collective system. Individual robots performed simple or small tasks such as walking on a smooth surface or carrying a light object, but if the task was beyond the capability of the single entity, the robots were physically connected to each other and a larger Used to create a multi-legged system and tackle issues collectively.

“When ants collect or transport objects, if there is an obstacle, the group works collectively to overcome that obstacle. For example, if there is a gap in the way, they will build a bridge so that other ants can cross over – and that is the motivation for this study,” she said. “Through robotics we can gain a better understanding of the dynamics and collective behavior of these biological systems and find out what we can do in the future How can we use this kind of technology?

Using a 3D printer, Ozkan-Aydin created four-legged robots that were 15 to 20 centimeters in length, or about 6 to 8 inches. Each was equipped with a lithium polymer battery, microcontroller, and three sensors – a light sensor in front and two magnetic tactile sensors at the front and back, allowing the robots to interact with each other. Four flexible legs reduced the need for additional sensors and parts and gave the robot a level of mechanical intelligence that helped when negotiating rough or uneven terrain.

“You don’t need additional sensors to detect obstacles because the flexibility in the legs helps the robot move right behind them,” Ozkan-Aydin said. “They can test for gaps along the way, forming a bridge with their bodies; move objects personally; Or connect objects to move collectively in a variety of environments, not unlike ants.”

Ozcan-Aydin began its research for the study in early 2020, when much of the country was closed due to the COVID-19 pandemic. After printing each robot, he built each robot and conducted his experiments at home, in his yard, or on the playground with his son. The robots were tested on grass, mulch, leaves and acorns. Flat-ground experiments were conducted on particle board, and he constructed the stairs using insulation foam. The robots were also tested on shag carpeting, and rectangular wooden blocks glued to particle board to serve as rough terrain.

When an individual unit became stuck, a signal was sent to additional robots, which, working collectively, were linked together to provide support to successfully overcome obstacles.

Ozkan-Aydin says there are still improvements to be made in its design. But he hopes the study’s findings will inform the design of low-cost legged herds that can adapt to unforeseen conditions and work in real-world cooperative tasks such as search-and-rescue operations, mass object transportation, space exploration and environmental monitoring. can do. His research will focus on improving the system’s control, sensing and power capabilities, which are essential for real-world locomotion and problem-solving – and he will use the system to explore the collective dynamics of insects such as ants and termites. is planning to do.

“For functional swarm systems, battery technology needs to be improved,” she said. “We need smaller batteries that can deliver more power, ideally lasting more than 10 hours. Otherwise, it’s not sustainable to use this type of system in the real world.” Additional limitations include the need for more sensors and more powerful motors, while keeping the robot’s size smaller.