Researchers from Georgia Tech have been conducting experiments designed to show the simplest of robots can still accomplish tasks. The team created a group of robots they call BOBbots, which stands for “behaving, organizing, buzzing bots.” The robots are made using a cylindrical chassis with vibrating brushes underneath and lose magnets on the periphery. The magnets cause them to spend more time at locations with more neighbors.
Precise computer simulations supplemented the experimental platform as a way to study aspects of the system inconvenient to study in the lab. Researchers say that despite the simplicity of the BOBbots, they discovered that as the robots move and bump into each other compact aggregates form capable of collectively clearing debris too heavy for one robot alone to move.
One researcher on the project, Daniel Goldman, said that most researchers build increasingly complex and expensive robots to guarantee coordination. The goal of his team was to see what complex tasks can be accomplished with very simple robots. Researchers on the project were inspired by a theoretical model of particles moving around on a chessboard. The theoretical abstraction is known as a self-organizing particle system and was used to rigorously study a mathematical model of the tiny robots.
Researchers proved that the theoretical model undergoes a phase changes the magnetic interactions increase using ideas from probability theory, statistical physics, and stochastic algorithms. Researchers found BOBbots abruptly changed from dispersing to aggregating in large, compact clusters, similar to phase changes seen in everyday items like water and ice.
Ultimately, the rigorous analysis used by the researchers allowed them to show how to build BOBbots and revealed inherent robustness in their algorithm that allowed some of the robots to be faulty or unpredictable. Some of the funding for the researchers’ work was given by the Department of Defense.