Bistable Aerial Transformer: Quadrotor Fixed-Wing Hybrid that Morphs Dynamically via Soft Mechanism

Title: Bistable Aerial Transformer (BAT): A Quadrotor Fixed-Wing Hybrid that Morphs Dynamically via
Passive Soft Mechanism

Authors: Jessica Weakly, Xuan Li, Tejas Agarwal, Minchen Li, Spencer Folk, Chenfanfu Jiang, and Cynthia Sung

Abstract: Aerial vehicle missions require navigating trade-offs during design, such as the range, speed, maneuverabil-
ity, and size. Multi-modal aerial vehicles enable this trade-off to be negotiated during flight. This paper presents
a Bistable Aerial Transformer (BAT) robot, a novel morphing hybrid aerial vehicle (HAV) that switches between
quadrotor and fixed-wing modes via rapid acceleration and without any additional actuation beyond those required
for normal flight. The design features a compliant bistable mechanism made of thermoplastic polyurethane (TPU)
that bears a large mass at the center of the robot’s body. When accelerating, inertial forces transition the vehicle be-
tween its stable modes, and a four-bar linkage connected to the bistable mechanism folds the vehicle’s wings in and
out. The paper includes the full robot design and a comparison of the fabricated system to the elastodynamic simu-
lation. Successful transitions between the two modes in mid-flight, as well as sustained flight in each mode indicate
that the vehicle experiences higher agility in the quadrotor mode and higher flight efficiency in the fixed-wing mode,
at an energy equivalent cost of only 2 s of flight time per pair of transitions. The vehicle demonstrates how compli-
ant and bistable mechanisms can be integrated into future aerial vehicles for controllable self-reconfiguration for
tasks such as surveillance and sampling that require a combination of maneuverability and long-distance flight.


Full paper doi: https://doi.org/10.1115/1.4065159