Robotic Self-Repair in a Semi-Structured Environment

The ability of natural organisms to selfassemble, self-repair and reproduce in an environment with sufficient nutrients is one of the defining features of life. In this paper, we build on both our own previous work and that of others to demonstrate the feasibility of robotic systems that can assemble functional copies of themselves from either basic sets of parts or from incomplete replicas that are not functional. Robots capable of self-repair (particularly using in situ resources) will have a profound impact on the way lunar and planetary surfaces are transformed for human use during exploration and colonization. We demonstrate concepts in robotic self-repair and self-assembly using parts from LEGO Mindstorm kits together with a patterned planar environment consisting of five stations. Each station has a location code and contains one of five robot subsystems. Four subsystem may be located at any of the four stations and the base unit is located at the center of the main track (and it can be placed in any of four distinct orientations, but is positioned at the center of the track), indicating 4 × 4! possible layouts. The design we demonstrate is robust to these permutations, i.e., the functional robot can assemble (or ``repair’’) a copy of itself by visiting each station and executing a sequence of behaviors that accounts for all possible permutations. This demonstrates a step in the direction of robotic self-repair and self-replication in unstructured environments, and represents a departure from previous efforts at JHU that were concerned with autonomous self-replication in completely structured environments. Index Terms – robotic self-repair, self-assembly, selfreplication