Yasemin Ozkan-Aydin, an assistant professor of electrical engineering at the University of Notre Dame, draws inspiration from biological systems as a robotics engineer.
Researchers have built airborne and underwater robotics based on the collective behaviours of ants, honeybees, and birds to solve issues and overcome obstacles. Developing small-scale swarm robots capable of traversing rugged terrain, on the other hand, presents its own set of challenges.
“Legged robots can negotiate hard conditions including rocky terrain and narrow places,” Ozkan-Aydin stated, “and the employment of limbs provides good body support, permits rapid movement, and facilitates obstacle crossing.” “However, in terrestrial contexts, legged robots encounter distinct movement obstacles, resulting in lower locomotor performance.”
Ozkan-Aydin postulated for the study that a physical connection between individual robots could improve the mobility of a terrestrial legged collective system, according to her. Personal robots performed basic or modest tasks like travelling over a smooth surface or carrying a light load. Still, if the job required more than a single unit’s capabilities, the robots physically joined to form a more extensive multi-legged system and collectively overcame problems.
“If an ant encounters a barrier while collecting or transporting an article, the entire colony works together to overcome it. If there’s a gap in the path, for example, they’ll build a bridge so that other ants can get through—this is the study’s inspiration “she stated, “We can obtain a greater knowledge of the dynamics and collective behaviors of these biological systems by using robotics, and we can examine how we might be able to employ this kind of technology in the future.”
Ozkan-Aydin used a 3D printer to create four-legged robots of 15 to 20 cm (6 to 8 inches) in length. Each robot included a lithium polymer battery, microcontroller, and three sensors: a light sensor in the front and two magnetic touch sensors in the front and back, allowing them to communicate. Four flexible legs minimized the need for extra sensors and parts while also providing mechanical intelligence to the robots, which came in handy when negotiating with rugged or uneven terrain.
“You don’t need any additional sensors to detect impediments since the robot’s legs are flexible enough to move right past them,” Ozkan-Aydin explained. “They, like ants, can test for gaps in a path by constructing a bridge with their bodies; move objects individually; or connect to move objects collectively in many types of habitats.”
In early 2020, when much of the country was shut down due to the COVID-19 epidemic, Ozkan-Aydin began her research for the project. After printing it, she created each robot and conducted her tests with her kid at home, in her yard, or at the playground. Grass, litter, leaves, and acorns were used to test the robots. She did flat-ground experiments on particle board and made stairs out of insulation foam. The robots were also tested on shag carpeting and rugged terrain of rectangular wooden blocks bonded to particleboard.
When a single unit became stuck, a signal was sent to other robots, who joined forces to help the team successfully navigate obstacles while working together.
Ozkan-Aydin claims that her design still has to be tweaked. However, she hopes that the study’s findings will help develop low-cost legged swarms that can adapt to unforeseen scenarios and execute real-world cooperative tasks, including search-and-rescue, collective object movement, space exploration, and environmental monitoring. Her study will increase the system’s control, sensing, and power capabilities critical for real-world activity and problem-solving. She hopes to use it to investigate the collective dynamics of insects like ants and termites.
“Battery technology needs to be developed for functional swarm systems,” she stated. “We require compact batteries that can deliver more power and, ideally, last longer than 10 hours. Using this type of system in the actual world would be unsustainable otherwise.” Additional constraints include the requirement for other sensors and more powerful motors while maintaining a modest robot size.
“You must consider how the robots will operate in the actual world, including how much power is required and the size of the battery you will utilize. Because everything is restricted, you must make decisions with each component of the machine.”