Swarms of simple, interacting robots have the potential to unlock stealthy abilities for accomplishing complex tasks. Getting these robots to achieve a true hive-like mind of coordination has proved to be a challenge. To solve the problem, self-assembling robotic cubes were developed that can climb over and around one another, leap through the air, and roll across the ground. The robots can “communicate” with each other using a barcode-like system on each face of the block that allows the modules to identify each other. The autonomous fleet of 16 blocks can accomplish simple tasks or behaviors such as forming a line, following arrows, or tracking light.
Inside each modular “M-Block” is a flywheel that moves at 20,000 revolutions per minute, using angular momentum when the flywheel is braked. On each edge and every face are permanent magnets that let any two cubes attach to each other.
Applications include inspection and eventually disaster response. In a burning building, for example, where a staircase has disappeared, M-Blocks can be thrown on the ground and will build out a temporary staircase for climbing up to the roof or down to the basement to rescue victims.
While the mechanism is quite intricate on the inside, the exterior is just the opposite, which enables more robust connections. Beyond inspection and rescue, the researchers also imagine using the blocks for things like gaming, manufacturing, and healthcare. M-Blocks can move in a general way; other robotic systems have much more complicated movement mechanisms that require many steps. Previous modular robot systems typically tackle movement using unit modules with small robotic arms known as external actuators. These systems require a lot of coordination for even the simplest movements, with multiple commands for one jump or hop.
On the communication side, other attempts have involved the use of infrared light or radio waves, which can quickly get clunky — if there are multiple robots in a small area and they’re all trying to send each other signals, it creates conflict and confusion. When a system uses radio signals to communicate, the signals can interfere with each other when there are many radios in a small volume.
The six-faced cubes move about using inertial forces — instead of using moving arms that help connect the structures, the blocks have a mass inside of them that they “throw” against the side of the module, which causes the block to rotate and move. Each module can move in four cardinal directions when placed on any one of the six faces, which results in 24 different movement directions. Without little arms and appendages sticking out of the blocks, it is easier for them to stay free of damage and avoid collisions.