Controllable Steering Torque Generation Via Flapping Motion by a Cross-Coupled Two-Degree-Of-Freedom Drive System
Masaki Hamamoto, Makoto Yamashita, Mika Tanaka, Kei Senda
AI summary
Problem
Conventional flapping-wing systems lack precise attitude control due to limited degrees of freedom, mechanical play, and path-dependent wing kinematics that cause unstable aerodynamic forces.
Approach
The authors designed a parallel direct-drive mechanism with cross-coupled torsion springs to decouple stroke angle and angle of attack, enabling stable, independent 2-DoF wing actuation.
Key results
- Validated motion and stiffness matrices against theoretical models
- Achieved over 10 gf lift force with a single wing
- Generated controllable yaw torque up to 1.5 mNm via phase and offset control
- Eliminated path dependency to ensure stroke-synchronized aerodynamic modulation
Why it matters
Enables precise, agile maneuvering in next-generation flapping-wing micro aerial vehicles by emulating biological flight strategies.
Abstract
We present a novel flapping‐wing mechanism capable of generating steering torque through a two‐degree‐of‐freedom (2‐DoF) coordinated actuation. Whereas most existing flapping‐flight systems produce steering torque by incorporating additional mechanisms that asynchronously alter passive deformation limits, our approach enables transient aerodynamic force modulation synchronized with each flapping stroke. The concept draws inspiration from biological flyers such as dragonflies and hawkmoths, which utilize multiple synchronous muscles per wing and perform stroke‐synchronized, multi‐DoF wing kinematics—strategies thought to contribute to their precise attitude and position control even at low flapping frequencies. To emulate this capability, we developed a mechanism employing parallel direct‐drive actuators within a coupled multi‐DoF architecture. By introducing a cross‐coupling force between the actuators, we eliminate path dependency in the wing‐twist motion, thereby enabling stable and independent control of both stroke angle and angle of attack. Using a single‐wing 2‐DoF testbed, we successfully demonstrate a lift force exceeding 10 gf and a yaw‐steering torque range of 1.5 mNm. This work advances the development of biologically inspired, stroke‐synchronized steering mechanisms for next‐generation flapping‐wing micro aerial vehicles.