Abstract: The lattice self-reconfigurable modular robot system is presented, which consists of one central cube and six rotary arms. A novel docking system is proposed. It mainly consists of extension pegs and expansible holes. In order to finish the self-morphing and self-repairing action, each extension peg and each expansible hole are designed to perform the connection/disconnection among normal modules and normal module, normal modules and trouble modules. So they can finish the self-reconfiguration and keep the whole configuration of the robot. According to the geometric feature of each module, docking relationship and docking process among modules are described. There are two stages: The stage of module rotating and the stage of module aligning. Finally, a simulation with 6 modules of the lattice self-reconfigurable robot and an experiment with 3 modules are shown to prove that the analyses are effective.

Key words: Docking process, Modular robot, Self-reconfigurable