RRR2: Reconfigurable Revolving-Wing Robot with Modular Multi-Locomotion

Description

With foreseeable applications such as reconnaissance and transportation, research in small, human-friendly micro aerial vehicles has received tremendous attention from scientists and engineers. These small robots have the potential to revolutionize our use of robots for civilian applications. Compared to conventional aircraft, however, at centimeter scales, flying robots suffer from a radical reduction in aerodynamic efficiency. The elevated energetic cost of staying airborne severely limits the flight endurance.Among a few common platforms, rotary-wing vehicles, such as quadrotors, become popular owing to the simple design and the ability to hover. While being extremely maneuverable, these flying machines rely on direct propulsion force to stay aloft without wings. Compared to fixed-wing aircraft with large aerodynamic surfaces, rotary-wing vehicles are inferior in terms of aerodynamic efficiency and flight endurance. The limitation becomes increasingly acute as multicopters are equipped with additional actuators for improved maneuverability in an effort to perform complex manipulation tasks and physically interact with the environment.In this proposed research, we introduce RRR–a novel transformable flying machine that is energetically efficient and extremely maneuverable despite being severely underactuated. This research will address the issues on flight endurance and functionality of small aerial robots in three steps. First, to create a centimeter-scale robot capable of hovering efficiently, the vehicle mimics the flight principles of winged achenes or samaras. With a pair of airfoils and propellers, RRR leverages large aerodynamic surfaces to hover (by rotation). Moreover, the unique design and intelligent use of cycle-averaged dynamics permit the robot to be fully controllable in three translational and two rotational states, rivaling fully-actuated vehicles with six actuators. Second, we employ an origami-inspired method to fabricate a simple foldable airframe. Together with a human-assisted reconfiguration, two RRR modules are combined to construct a quadcopter with a compact form factor–RRR ². The addition of an alternative flight mode through modular morphological adaptation enhances the versatility of the platform. Finally, we propose to realize sustained solar-powered flight. The prospect of perpetual flight with RRR is highly feasible and remarkably attractive owing to the pronounced surface-to-mass ratio of the unconventional revolving-wing design, amplified by the downscaling of the vehicle size. The accomplishment will markedly improve the endurance of small flying machines.It is perceivable that the proposed research will contribute to advances in the field of micro aerial vehicles by radically expanding their endurance and broadening the applications of aerial robots. Scientific merits will come from (i) the development of a small under-actuated aerial robot with high efficiency and controllability; (ii) the implementation of reconfiguration and modular architecture to achieve multi-locomotion on a flying robot; and (iii) the substantial improvement in endurance of centimeter-scale aerial vehicles through solar power by leveraging the favorable surface-to-mass ratios.