Design, Control, and Motion Strategy of the Quadrotor Unit with the Ability of In-flight Autonomous Assembly and Disassembly

Abstract

The article presents a new aerial robot unit that can perform both aerial assembly and disassembly. The robot is controlled as an under-actuated quadrotor in the unitary state and as a fully-actuated octocopter in the assembly state. The system includes novel docking mechanism, rotor configuration, and control system that enables the transition between two control models during assembly and disassembly motions. We also presents a motion strategy for aerial assembly and disassembly motion that includes a recovery action for hazardous states. The robot’s capabilities were tested through experiments, which demonstrated a success rate of aeiral assembly/disassembly is approximately 90%. Moreover, in the assembly state, the robot can utilize full-pose tracking and generate more than nine times the torque of a single unit. To the best of our knowledge, this is the first robot system that can perform both assembly and disassembly while seamlessly transitioning between fully-actuated and under-actuated models.