The granulobot is a robotic platform, with many units, which together act as a single robot that changes shape to execute tasks.
How granulobot works?
Built by the University of Chigaco, in 2023, and inspired on properties of granular materials, which gave origin to the name. This system consist in units that look like gears and have some centimeters in diameter. These units joint together due to magnetic coupling.
They can assume collective states similar to solids and liquids, which can be disturbed by actuator or the environment. Depending on task and environment, can change shape, divide in smaller groups and joint together again. In addition to move in different ways.
An unit’s components
Each unit has two permanent magnets, allowing it to join with more two units. A DC motor, controlled by PWM, turns one of these magnets around a central axis, allowing interaction and movement with other units. In contrast with another magnet, which is connected to a passive rotor, whose rotation is free and can move around wheel’s central axis. Robots communicate with each other through a WiFi microcontroller in a descentralized way.
Open-loop control makes the granulobot behave like a liquid, while on closed-loop control, with feedback, the platform acts as a solid. Each unit has three sensors: magnetometer, which detects magnetic field, accelerometer and gyroscope, whose function is to provide feedback signals to closed-loop control, so that the individual granulobot can keep the angular position in relation to other units.
