Concurrent metamorphosis of hexagonal robot chains into simple connected configurations

The problem addressed is the distributed reconfiguration of a metamorphic robotic system composed of an arbitrary number of two dimensional hexagonal robots (modules) from specific initial to specific goal configurations. The initial configuration considered is a straight chain of robotic modules, while the goal configurations considered satisfy a more general “admissibility” condition. A centralized algorithm is described for determining whether an arbitrary goal configuration is admissible. We prove this algorithm correctly identifies admissible goal configurations and finds a “substrate path” within the goal configuration along which the modules can move to reach their positions in the goal. A second result of the paper is a distributed algorithm for reconfiguring a straight chain into an admissible goal configuration. Different heuristics are proposed to improve the performance of the reconfiguration algorithm and simulation results demonstrate the use of these heuristics. Keywords—Metamorphic robots, distributed reconfiguration