  Self-assembly of modular robotic systems enables the construction of complex
robotic configurations to adapt to different tasks. This paper presents a
framework for SMORES types of modular robots to efficiently self-assemble into
tree topologies. These modular robots form kinematic chains that have been
shown to be capable of a large variety of manipulation and locomotion tasks,
yet they can reconfigure using a mobile reconfiguration. A desired kinematic
topology can be mapped onto a planar pattern with optimal module assignment
based on the modules' locations, then the mobile reconfiguration assembly
process can be executed in parallel. A docking controller is developed to
guarantee the success of docking processes. A hybrid control architecture is
designed to handle a large number of modules and complex behaviors of each
individual, and achieve efficient and robust self-assembly actions. The
framework is demonstrated in hardware on the SMORES-EP platform.
