Continuous Sculpting: Persistent Swarm Shape Formation Adaptable to Local Environmental Changes

Despite their growing popularity, swarms of robots remain limited by the operating time of each individual. We present algorithms that allow a human to sculpt a swarm of robots into a shape that persists in space perpetually, independent of onboard energy constraints, such as batteries. Robots generate a path through a shape such that robots cycle in and out of the shape. Robots inside the shape react to human initiated changes and adapt the path through the shape accordingly. Robots outside the shape recharge and return to the shape so that the shape can persist indefinitely. The presented algorithms communicate shape changes throughout the swarm using message passing and robot motion. These algorithms enable the swarm to persist through any arbitrary changes to the shape. We describe these algorithms in detail and present their performance in simulation and on a swarm of mobile robots. The result is a swarm behavior more suitable for extended duration, dynamic shape-based tasks in applications, such as entertainment, agriculture, and emergency response.