Design, Control, and Motion Strategy of TRADY: Tilted‐Rotor‐Equipped Aerial Robot With Autonomous In‐Flight Assembly and Disassembly Ability

Abstract

State‐of‐the‐art aerial robots often prioritize maneuverability or manipulation capabilities, making it difficult to achieve both. The issue arises because aerial robots with agile mobility lack sufficient rotors for manipulation tasks, while those with manipulation ability are too large for agile mobility. To tackle this problem, a novel aerial robot unit named TRADY, tilted‐rotor‐equipped aerial robot with autonomous in‐flight assembly and disassembly capability, is introduced. The TRADY unit can self‐assemble/disassemble with another unit in mid‐air, adjusting the aircraft's control freedom by switching between under‐actuated and fully‐actuated control models. The system implementation involves a docking mechanism design, optimized rotor configuration, as well as a control system with the ability to switch between under‐actuated and fully‐actuated controllers. A proposed state transition method compensates for discrete changes during the controller switchover process. Also, a motion strategy for assembly/disassembly with hazardous condition recovery behavior is presented. Finally, through experiments, TRADY demonstrated a 90 % success rate in executing assembly/disassembly motions, and in the assembly state, it can utilize full‐pose tracking and generate over nine times the torque of a single unit. This is the first aerial robot developed to perform both assembly and disassembly while seamlessly transitioning between fully‐actuated and under‐actuated models.

Keywords

• aerial assembly and disassembly
• aerial robot
• cellular and modular robots
• distributed robot systems