Harnessing stigmergy for emergent adaptive control, in soft modular systems.

Generally, the field of autonomous control achieves versatility by increasing the complexity of centralized controllers. In contrast, the current study takes a decentralized and modular approach where adaptive control emerges from local interactions with the environment. Inspired by collective intelligence in nature (e.g., bird flocking behavior, termite mound construction), we aim to design robust system-level behavior while reducing the complexity of the individual modules to a minimum. With both experiments and simulations, we present a system comprised of light-seeking immobile units physically linked by soft connectors in lattice configurations. Each unit independently senses, actuates, and computes. In arrangements of multiple linked units, the expansion and contraction of the soft connections between the units facilitate the system's mobility as a whole. We demonstrate that the implicit communication imposed by the physical connection between the units is enough to achieve robust system-wide coordination, irrespective of the system's configuration and without prior knowledge of the system. As a result, we pave the way to more general and adaptive control solutions that thrive in unknown environments.