A Bi-Level Optimization Framework Based Conceptual Design of Flapping Wing UAV

Bhamidipati Srinath Dhatre¹    Mavurapu Akshith Reddy¹    Jonish Abisheck Joseph²    Harikumar Kandath¹   

¹ Robotics Research Centre (RRC), IIIT Hyderabad, Hyderabad, India    ² Mechanical Engineering Department, Birla Institute of Technology and Science Pilani, Goa, India   

The conceptual design of Flapping-Wing Uncrewed Aerial Vehicles (FWUAVs) is currently constrained by the trade-off between computational cost and modeling fidelity. While high-fidelity solvers like Unsteady Vortex Lattice Methods (UVLM) capture the complex physics of flapping flight, they are too computationally expensive for iterative design optimization. To address this gap, this paper introduces a novel automated inverse-design methodology that directly translates high-level mission requirements into optimized physical hardware specifications. We propose a bi-level optimization framework coupled with a Gaussian Process Regression (GPR) aerodynamic surrogate model, enabling instantaneous force predictions across the design space. The architecture's outer level performs a global search over wing geometry, while the inner level solves for trim-feasible flight kinematics to ensure every candidate design is physically viable. To ensure the reliability of the proposed designs, the underlying aerodynamic and power models are validated against experimental data from three ornithopter prototypes, achieving endurance predictions with a low margin of error relative to the observed values across scales.