Connected Reconfiguration of Polyominoes Amid Obstacles using RRT*

Abstract-- This paper investigates the use of a samplingbased approach, the RRT*, to reconfigure a 2D set of connected tiles in complex environments, where multiple obstacles might be present. Since the target application is automated building of discrete, cellular structures using mobile robots, there are constraints that determine what tiles can be picked up and where they can be dropped off during reconfiguration. We compare our approach to two algorithms as global and local planners, and show that we are able to find more efficient build sequences using a reasonable number of samples, in environments with varying densities of obstacles. Cellular structures are related to reconfigurable robotics work, but rather than using intelligent, powered and actuated reconfigurable modules, small robots that walk along the modules are used to move them. This allows the modules to be passive, which reduces their complexity, weight, and cost.